Complications of Laparoscopic and Hysteroscopic Surgery

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Chapter 45 Complications of Laparoscopic and Hysteroscopic Surgery

Howard T. Sharp, Tommaso Falcone, William W. Hurd

INTRODUCTION

It has been almost a century since Jacobaeus performed laparoscopy by inserting a Nitze cystoscope (consisting of an incandescent platinum wire loop and a system of lenses) into a patient’s abdomen. Since that time, significant advances in technology have enabled gynecologic surgeons to use laparoscopes to perform procedures that in the past were done exclusively using an abdominal and vaginal approach.

Unfortunately, many laparoscopic advances were developed by trial and error accompanied by significant morbidity and mortality.¹ The application of electrosurgery, automated stapling devices, patient positioning, and trocar use produced unique mechanisms for surgical injury, many of which were not predicted. When can new technologies and procedures be considered safe? How many laparoscopic procedures should be performed before a surgeon is deemed proficient? A recent study of the learning curve associated with laparoscopically assisted vaginal hysterectomies (LAVH) suggests that a gynecologist must perform more than 30 cases before morbidity rates are significantly reduced.¹

This chapter discusses the most common risks associated with laparoscopy and hysteroscopy, including nerve injuries, injuries to structures, including blood vessels, bowel, bladder, and ureters, and electrosurgical injuries related to laparoscopy. The goal is to provide anatomic and technical information that will allow gynecologists to better prevent, recognize, and manage complications associated with laparoscopic and hysteroscopic surgery.

LAPAROSCOPY

Nerve Injury

Mechanisms of Injury

Nerve injuries can occur during laparoscopy by one of three basic mechanisms. The most common mechanism of nerve injury in these patients is related to patient positioning. The dorsal lithotomy position puts many nerves of the lower extremity on stretch or under pressure, resulting in temporary paresthesias on awakening. Unfortunately, prolonged stretch or pressure on nerves during surgery can result in neurologic injury that may take months to resolve or may be permanent. Careful patient positioning, especially during prolonged cases, is important to avoid extreme flexion and abduction, as well as pressure points.

The second mechanism of nerve injury during laparoscopy occurs during port placement through the anterior abdominal wall and the subsequent repair of the incisions. These abdominal wall nerve injuries are uncommon. However, because the nerves involved are not easily identified and their anatomic locations vary greatly, the injuries are difficult to completely prevent. For this reason, diagnosis and treatment become paramount.

The final mechanism of injury is direct trauma to pelvic nerves during retroperitoneal dissections, including resection of severe endometriosis and lymphadenectomy for cancer staging. Surgeons performing these procedures need a thorough understanding of the location of the nerves at risk to minimize injury.

Categories of Nerve Injuries

Nerve injuries are categorized by neurologists according to the degree of injury, which is ultimately reflected in the patient’s subsequent prognosis for recovery. A nerve contusion, referred to as a neurapraxia, is a functional injury in which structural continuity of the nerve is preserved. Diagnostically, it is characterized by a conduction block on electromyelogram. A mild injury results in immediate conduction block at the site of injury with normal conduction distally. A more severe injury results in focal demyelination without disruption of axons, resulting in slowing of conduction velocity across the lesion. Myelin regeneration results in functional recovery within 6 weeks.

The next level of nerve injury is termed axonotmesis and involves separation of axons and myelin sheath of a peripheral nerve with preservation of the nerve’s investing sheaths (i.e., endoneurium, perineurium, and epineurium). This more serious nerve injury results in degeneration of the axon distal to the injury site. Wallerian degeneration occurs, characterized by axonal enlargement and breakdown, as well as schwann cell ingestion of myelin fragments. Spontaneous regeneration of the axon usually results in functional recovery within 6 months to 1 year of injury.

The most serious level of nerve injury is complete division of the nerve, referred to as neurotmesis. After disruption of the axons, myelin sheath, and investing sheaths, wallerian degeneration occurs. Without further treatment there is no recovery. With operative repair of the injured nerve, the prognosis is variable and ranges from complete recovery to permanent disability.

Fortunately, most neurologic injuries associated with patient positioning during laparoscopic surgery do not result in nerve separation and resolve spontaneously with time.² Those associated with radical surgical dissection may be more likely to be serious and permanent.

Specific Nerve Injuries

Femoral Nerve

The femoral nerve is the largest nerve of the lumbosacral plexus and is derived from the posterior divisions of the L2, L3, and L4 nerve roots (Fig. 45-1). It pierces the psoas muscle and runs inferolaterally within the muscle to emerge between the iliacus and psoas muscles. It then courses under the inguinal ligament to enter the femoral sheath lateral to the femoral artery.

Figure 45-1 Schematic representation of nerves that can be injured during laparoscopy.

(Reproduced from Drake R, Vogl W, Mitchell AWM: Gray’s Anatomy for Students. Philadelphia, Elsevier, 2005.)

The femoral nerve contains motor and sensory components. The motor component supplies the iliacus, quadriceps femoris, sartorius, and pectineus muscles, which are hip flexors and leg extensors. Its main sensory branches include the intermediate and medial cutaneous nerves of the thigh and the saphenous nerve, which supplies the medial leg.

Femoral neuropathy during laparoscopy usually results from excessive hip flexion or abduction or from long operating times.² Patients undergoing vaginal or laparoscopic surgery should be placed in a lithotomy position such that the thigh is flexed no greater than 90 degrees and abducted no greater than 45 degrees. If positioning is changed intraoperatively, these relationships should be maintained.

Symptoms of femoral neuralgia include groin pain and weakness of knee extension and thigh flexion. The knee jerk reflex is usually absent. Diagnostic studies such as electromyography and nerve conduction studies can confirm prolonged latencies in the femoral nerve and denervation of the quadriceps muscles.

Obturator Nerve

The obturator nerve arises from the anterior nerve roots of L2, L3, and L4 (see Fig. 45-1). It descends through the psoas muscle, emerging medially at the pelvic brim, and passes through the obturator foramen into the thigh. Its main function is to allow thigh adduction; it supplies motor function to the gracilis, obturator, adductor longus, brevis, and magnus muscles.

The most common cause of obturator neuropathy resulting from gynecologic surgery is direct injury during radical pelvic surgery or lymphadenectomy. The obturator neurovascular bundle is also vulnerable during laparoscopic retropubic dissection, particularly during the paravaginal repair of lateral defects of the anterior vaginal wall. Surgeons who operate in these spaces should be well-versed in the anatomy of the obturator nerve.

Obturator neuropathy can also occur as a result of excessive hip flexion.³ The mechanism whereby excessive hip flexion can cause obturator nerve injury is anatomic. As the obturator nerve leaves the obturator foramen, it lies directly against bone and can become acutely angulated and deformed if the hips are excessively flexed, particularly during prolonged surgery. Injury to the obturator nerve usually manifests as weakness in the hip adductors and sensory loss in the upper medial thigh.

Nerves of the Anterior Abdominal Wall and Inguinal Region: Ilioinguinal, Iliohypogastric, and Genitofemoral

The ilioinguinal, iliohypogastric, and genitofemoral nerves have an overlapping sensory distribution in terms of their cutaneous manifestations, often making it difficult to distinguish between them. The course of these nerves is quite variable. The iliohypogastric and ilioinguinal nerves originate from the T12 and L1 nerve roots of the lumbosacral plexus (see Fig. 45-1). They cross over the quadratus lumborum muscles and pierce the transversus abdominis muscle in parallel at about the level of the anterior superior iliac spine.⁴ The genitofemoral nerve originates from the L1 and L2 nerve roots to pass anterior to the psoas muscles (see Fig. 45-1). The iliohypogastric nerve supplies sensation to the suprapubic region, and the ilioinguinal nerve supplies sensation to the inguinal canal. The genitofemoral nerve provides sensory innervation to the labial skin (genital branch) and the superior thigh (femoral branch).

The most common injury to these nerves is due to abdominal and pelvic incisions with subsequent suture ligature or fibrotic entrapment. With a Pfannenstiel incision, this injury is most likely to occur when the incision extends beyond the fascial aponeurosis to include the medial edge of the internal oblique muscle.⁵ During laparoscopic trocar insertion, the risk of injuring these nerves increases as the trocars are placed inferior to the anterior superior iliac spine.^4,⁶ Palpation of the anterior superior iliac spine before trocar placement is useful for gaining lateral bearings.

Entrapment of these nerves usually manifests as sharp, burning pain and paresthesia. The putative diagnosis is made when local infiltration with a local anesthetic results in pain relief and paresthesia over the sensory distribution of the nerve. Due to the variability of these nerve pathways, entrapment may occur regardless of the precautions taken. For this reason, prompt recognition and treatment are important to avoid prolonged symptoms.

Sciatic Neuropathy

The sciatic nerve, derived from L4 through S3, is the largest peripheral nerve in the body and has tibial and common peroneal divisions. It is located anterior to the piriformis muscle, passing through the greater sciatic foramen to course down the posterior thigh. It supplies motor function to the hamstring muscles, which provide leg flexion and thigh extension. It divides superior to the popliteal fossa. Its tibial branch descends within the posterior leg to supply motor function to the plantar flexors of the foot and intrinsic foot flexors. It supplies sensory innervation to the toes and plantar surface of the foot. The common peroneal nerve continues anteriorly around the fibular head to supply motor function to the dorsiflexor and evertors of the foot. It also provides sensation to the lateral leg and dorsum of the foot.

The most common mechanism of injury to the sciatic nerve during gynecologic surgery is prolonged hip flexion resulting in nerve tension and stretching. Tension is increased with hip flexion when the knee joint becomes straightened or externally rotated. The sciatic nerve can stretch approximately 1.5 inches when the hip is flexed and the leg extended. Therefore, it is important to be cautious not to use excessive hip flexion when placing patients in stirrups, particularly the hanging type. When free-hanging stirrups are used for gynecologic cases, this injury has been reported in procedures lasting as short as 35 minutes.⁷

Patients at greatest risk for sciatic nerve injury are long-legged, obese, or short in stature. In long-legged or obese patients, there is a tendency for the hip to rotate externally; in short patients, there is a tendency to have less knee flexion. Stirrups that support the entire leg are the most appropriate for all but the shortest cases.

Symptoms of sciatic nerve injury depend on the level of injury, as the nerve divides into two separate divisions. Injury to the nerve trunk results in weakness in the hamstrings, presenting as impaired knee flexion. In cases of peroneal nerve injury, dorsiflexion weakness, or footdrop, occurs.

Treatment for Neuropathies

In the case of an apparent neuropathy, the first step is to obtain consultation from a neurologist or physiatrist to assist in both diagnosis and treatment. Treatment typically consists of supportive care with appropriate functional braces and physical rehabilitation.

In patients with pain, oral analgesics, tricyclic antidepressants, and anticonvulsant medications may be helpful. Unfortunately, neuropathic pain is usually refractory to opioids. An effective alternative is tramadol, a synthetic centrally acting analgesic used in doses of 50 to 100 mg every 6 hours. Amitriptyline and desipramine may be useful in doses starting at 25 mg daily, gradually increasing to 150 mg daily in divided doses if needed. Gabapentin, an anticonvulsant drug that causes less somnolence than most tricyclic antidepressants, can be given in a starting dosage of 100 mg three times daily, with a maximum dosage as high as 1200 mg three times daily.

Effect of Carbon Dioxide Insufflation and Venous Gas Embolism

Effect of Carbon Dioxide Absorption

Carbon dioxide (CO₂) gas is the gas of choice for obtaining a pneumoperitoneum for laparoscopy. CO₂ gas is highly soluble in blood and large amounts will dissolve in blood. It is rapidly eliminated from the vascular space. CO₂ gas is readily absorbed through the peritoneum. The partial pressure of arterial CO₂ (PaCO₂) increases during the first 15 to 30 minutes of a laparoscopic procedure with intra-abdominal pressures of less than 15 mm Hg. Typically the anesthesiologist adjusts minute ventilation to compensate for this increase. During laparoscopy in a pregnant patient, this adjustment should take into consideration the lower PaCO₂ typically found (compensated respiratory alkalosis) to avoid fetal acidosis. After the initial rise and plateau of end-tidal CO₂ (ETCO₂), any subsequent rise cannot be attributed solely to the CO₂ insufflation. PaO₂ usually does not change during laparoscopy unless there is a problem.

Capnography (ETCO₂) and pulse oximetry are reliable markers of arterial gases in healthy patients. This may not apply to American Society of Anesthesiologists (ASA) class II and III. Increases in ETCO₂ are usually due to absorption of CO₂ from the peritoneal cavity. However, this may also be due to a variety of clinical circumstances that cause a ventilation/perfusion mismatch (V/Q) that increases the physiologic dead space. A steep Trendelenburg position and increased intra-abdominal pressures can accentuate this mismatch, especially in obese patients. A pneumoperitoneum will decrease pulmonary compliance. Obesity will decrease compliance further ⁸ and increase the airway pressure required to ventilate the patient. Decreased cardiac output will also increase the V/Q mismatch and lead to increase in ETCO_2.

Other clinical events that can increase ETCO₂ are large amounts of CO₂ in the subcutaneous spaces (emphysema), CO₂ pneumothorax, and CO₂ gas embolism. CO₂ pneumothorax is usually the result of CO₂ gas leaking into the pleural space through diaphragmatic defects. Subcutaneous emphysema does not cause desaturation or increases in airway pressure. Swelling and crepitus are usually seen on the abdomen, sometimes tracking down into the labia. A massive CO₂ embolism may initially cause an increase in ETCO_2. However, a drop in ETCO₂ is typically seen in a gas embolism following this initial increase.

Gas Embolism

A gas embolism is a potentially dangerous complication of laparoscopy and hysteroscopy. Direct intravascular injection of CO₂ gas by the pneumoperitoneum needle or trocar can cause a gas embolism. Gas embolization can also occur whenever a significant tear occurs in a large vein during laparoscopy, because the intra-abdominal pressure is higher than the venous pressure. CO₂ gas embolism is occasionally seen during diagnostic hysteroscopy, although the mechanism is unclear. CO₂ should not be used during operative hysteroscopy.

The physical characteristics of CO₂, high solubility and rapid clearance, allow the rapid reversal of clinical symptoms from the embolization. Although there may be an initial increase in ETCO₂, a decrease in ETCO₂ is the most characteristic manifestation of all gas emboli, including CO_2.

Venous air embolism has been reported in many gynecologic procedures, such as hysterectomy, cesarean section, hysteroscopy, and uterine curettage, as well as in normal spontaneous vaginal delivery. The entry of room air into a venous channel usually requires some pressure gradient. As the height above the heart increases at the gas entry point (an open vein), there is a decrease in local pressure. This pressure gradient facilitates gas entry. In theory, air can be introduced into a vein at the hysteroscopic surgical site that is above the level of the heart. It is therefore prudent to not place the patient in Trendelenburg position during an operative hysteroscopy. Insufflation of CO₂ during a hysteroscopy should not commence without purging the tube of room air. Gas should not be used as the cooling system with a laser used for intrauterine surgery.

The basic pathophysiology of a venous gas embolism is V/Q mismatch that results in increase in physiologic dead space and right-to-left shunting. One of the earliest manifestations of a gas embolism is a decrease in ETCO_2. This decrease is thought to be the result of a V/Q mismatch with increases in physiologic dead space. A pneumothorax can also cause a decrease in ETCO_2. Both gas embolism and pneumothorax will cause hypoxemia.

The typical clinical findings of a gas embolism that occurs under anesthesia are abnormal heart murmurs. Typically, it is a systolic murmur and the classic water millwheel murmur only occurs if there is a large amount of air in the right ventricle. Other manifestations include tachycardia, arrhythmias, hypotension, and increases in central venous pressure and pulmonary artery pressure. If the patient is conscious, she may complain of chest pain and breathlessness and may demonstrate altered level of consciousness. Physical examination will show the same classic signs in addition to tachypnea. The anesthesiologist will notice an abrupt fall in ETCO₂. The initial blood gases of a gas embolism are similar to those seen with a venous embolus (a clot) that shows hypoxemia from the V/Q mismatch. A respiratory alkalosis from the tachypnea is also seen if the patient is awake. Treatment consists of the following measures:

• Stop the insufflation.

• Remove the Veress needle.

• Place in steep Trendelenburg position or left lateral decubitus position to reduce right ventricular outflow obstruction.

• Correct hypoxemia with 100% oxygen.

• Remove air from the right atrium using central venous catheter and cardiac massage.

• Carefully search for evidence of venous injury, using laparotomy if necessary.

• If no venous injury is seen, observe the patient overnight.

Successful resuscitations after massive venous CO₂ embolization have been reported.^9,¹⁰

Vascular Injuries during Laparoscopy

The utilization of extremely small abdominal incisions is the primary advantage of laparoscopy. These incisions are also the source of the most serious complications associated with laparoscopy. Techniques used to place primary and secondary laparoscopic ports into the peritoneal cavity are often accompanied by a small but unavoidable risk of injury to blood vessels located in the anterior abdominal wall and the major blood vessels located in the retroperitoneal space. Theses small incisions, which minimize postoperative discomfort, also limit and delay access to treat any vascular injuries. In addition, the use of CO₂ to distend the peritoneal cavity puts patients at the potentially deadly risk of intravascular insufflation. Because of the serious nature of these injuries, every laparoscopic surgeon should develop a plan to deal with these complications before their occurrence. The following is a discussion of methods to avoid injuries and approaches to recognizing and treating injuries should they occur.

The best angle of insertion appears to change according to the patient’s body mass index (BMI=kg/m²) (see Chapter 44). In patients who are either in the ideal weight or overweight groups (corresponding BMI = 25kg/m² and 25 to 30kg/m², respectively), the Veress needle and primary trocar should be inserted through the umbilicus at 45 degrees from horizontal.¹³ A greater angle of insertion in these patients increases the risk of retroperitoneal vessel injury because the bifurcation is beneath the umbilicus in many cases, and the left common iliac vein is beneath the umbilicus in most patients.¹² This is particularly important in the thinnest patients, in whom the distance from the umbilicus to the retroperitoneal vessels may be as little as 2 to 3 cm.¹³

In obese women whose BMI = 30kg/m² (e.g., weight of 200 pounds in a woman who is 67 inches tall), the angle must be increased to as much as 70 to 80 degrees from horizontal to reach the peritoneal cavity, because the thickness of the anterior abdominal wall increases dramatically with weight. Fortunately, the distance between umbilicus and vessels is increased in these patients, and the umbilicus tends to be more caudal in relation to the aortic bifurcation.

When estimating the proper angle of insertion for either the Veress needle or primary trocar, it is important to know the position of the patient in relation to the floor, because it is natural for the gynecologist to use the floor as a point of reference for horizontal. When a patient is placed in the Trendelenburg position with the head lower than the feet, the angle of insertion relative to the floor must be decreased accordingly to avoid the retroperitoneal vessels. Therefore the patient should not be placed in Trendelenburg position before placement of the primary trocar. Open laparoscopy is an alternative method for obtaining peritoneal access that decreases the risk of retroperitoneal vessel injury to almost zero.

Recognition

Immediate recognition of a major vascular injury is necessary to prevent exsanguination. Prompt action must be taken when blood is noted to flow from the open Veress needle or if the patient’s vital signs suggest hemorrhagic shock shortly after the Veress needle or trocar is inserted. In some cases, the first sign of a problem will be a laparoscopic view completely obscured by bright red blood. In other patients, a major vessel injury will manifest as an enlarging retroperitoneal hematoma, which should be approached in an identical manner as a massive intraperitoneal bleeding.

Treatment

Major vessel injuries are a rare but unavoidable laparoscopic complication associated with the closed technique for Veress needle and primary trocar placement. Every laparoscopic surgeon that uses a closed technique should develop a plan of action for major vessel injury. The surgeon should also become familiar with the availability of laparotomy instruments, blood products, vascular clamps, and surgical consultants. This is especially important when these procedures are performed in a freestanding outpatient surgical facility.

When a major vascular injury is suspected, the following steps should be taken without delay:

• Alert nursing personnel to prepare for emergency laparotomy.

• Simultaneously alert anesthesia personnel, who will generally place additional intravenous lines, and call for blood products and additional assistance.

• Immediately perform a laparotomy via a midline incision.

• Control the bleeding using direct pressure over the site of injury.

• Ideally, a trauma surgeon or vascular surgeon can be called in to clearly identify and repair the injury or injuries.

• In the absence of a surgeon experienced in vascular surgery, the laparoscopic surgeon must be prepared to open the retroperitoneal area and stop the bleeding.

• If appropriate personnel and facilities to repair the vascular injury are not available, the patient must be transported to a fully equipped trauma center.

If either the surgeon or facility are not fully prepared to effectively treat a major vascular injury, thought should be given to using only an open laparoscopic technique or performing laparoscopy with a closed technique elsewhere.

Abdominal Wall Vessel Injury

The risk of abdominal wall vessel injury during laparoscopy was extremely uncommon before the widespread use of ports lateral to the midline to perform complex operative procedures. The vessels of the anterior abdominal wall at risk for injury can be divided into two groups: superficial and deep. The superficial vessels consist of the superficial epigastric and circumflex iliac arteries, which are located in the subcutaneous tissue. The deep vessels consist of the inferior epigastric artery and vein, which are located beneath the rectus abdominis muscles immediately above the peritoneum.

Damage to the deep vessels usually leads to immediate and rapid blood loss, whereas damage to the superficial vessels most often results in a persistent external trickle after the port is removed. Postoperatively, a superficial vessel injury (Fig. 45-2) typically presents with pain at the trocar site and a palpable mass. Postoperative deep vessel injury presents with increasing pain and decreasing hematocrit without a palpable mass because the vessels are located behind the rectus abdominis muscle or the bleeding occurs into the peritoneal cavity. A computed tomography scan will demonstrate the correct location of the hematoma.

Figure 45-2 A, Computed tomography scan of a patient with a palpable mass at the trocar site. The hematoma is localized anterior to the fascia of the rectus and oblique abdominal muscles on the patient’s right side. B, Blood is seen in the labia as a result of blood that tracked down from the anterior abdomen.

Prevention

The primary method for avoiding injury to any of these vessels is to visualize the vessels before lateral trocar insertion. Two techniques have been used for this purpose: transillumination and direct laparoscopic visualization. Transillumination of the anterior abdominal wall with the laparoscopic light source is an effective way to visualize the superficial vessels in almost 90% of patients.¹⁴ The inferior epigastric vessels cannot be seen by transillumination because they lie beneath the rectus abdominis muscle and fascia. However, the inferior epigastric vessels can be directly visualized laparoscopically immediately beneath the peritoneum in 60% of patients where they lie between the insertion of the round ligament at the inguinal canal and the medial umbilical fold (see Chapter 7).

When these vessels cannot be visualized, knowledge about their average location can decrease the risk of injury. Because both the deep and superficial vessels are located an average 5.5 cm from the midline, risk of vessel injury can be minimized by placing secondary trocars 8 cm lateral to the midline and 8 cm above the pubic symphysis. This location approximates McBurney’s point, one-third the distance from the anterior iliac spine to the umbilicus on the right, and the corresponding Hurd’s point on the left.

Even when ideal sites are used for port placement, there is still a risk of injuring vessels that cannot be visualized because of anatomic variation. Additional precautions that can be taken to minimize the risk of vessel injury in these patients include use of the smallest trocar possible (5 mm vs. 10 or 12 mm) and the use of conical-tipped rather than pyramidal-tipped trocars for lateral port placement.

Treatment

Regardless of the precautions taken, anterior abdominal wall vessel injuries sometimes occur. For this reason, every laparoscopic surgeon should have a plan of action to quickly and effectively treat these injuries.

When a superficial vessel is found to be bleeding after the port is removed, the most effective approach is to grasp the vessel with a Crile hemostat forceps, followed by cautery or ligation. In cases where the injured vessel cannot be grasped, a pressure dressing is often sufficient.

Injury to an inferior epigatric vessel is almost always accompanied by immediate and brisk bleeding at the port site. Treatment consists of the following steps:

• Alert nursing and anesthesiology personnel, who might need to place additional intravenous lines and request blood products if the patient becomes hemodynamically unstable.

• Precisely position sutures above and below the injury using the same instruments and techniques used to close both layers of the fascia when large lateral trocars have been used (e.g., the Endoclose device). These sutures should be tied deep to the skin above the fascia.

• If a suture cannot be placed quickly, place a Foley catheter through the port site to temporarily slow the bleeding. The catheter is placed directly through the trocar sleeve. After the bulb is inflated with saline solution, the sleeve is removed and the catheter is retracted to hold the bulb tightly against the peritoneal surface. A Kelly forceps can be used to cross-clamp the catheter on the skin side to maintain the traction. This is a temporary measure so that the following steps can be performed.

• Attempt to occlude the injured vessel with a laparoscopic bipolar electrosurgery instrument above and below the injury. After the Foley catheter is loosened, the injured vessel is grasped using a bipolar instrument placed through a contralateral port.

• If bipolar electrosurgery is unsuccessful, precisely positioned sutures can be placed above and below the injury using the same instruments and techniques used to close both layers of the fascia when large lateral trocars have been used. These sutures should be tied deep to the skin above the fascia.

• If hemostasis cannot otherwise be achieved, the incision must be widened and the injured vessels individually ligated. The port site incision should be enlarged transversely to at least 4 to 6 cm, the fascia of the anterior rectus sheath incised, and the lateral edge of the rectus abdominis muscle retracted medially. The bleeding vessels can be grasped with hemostatic forceps and selectively ligated above and below the injury.

Delayed bleeding can occur when the abdominal pressure decreases after removal of the carbon dioxide, especially if the method used to occlude an injured vessel becomes loose as the patient awakes from anesthesia and is moved. Signs of hemodynamic instability in the recovery room necessitate a return to surgery, because uncontrolled bleeding from a lacerated inferior epigastric artery can be life-threatening.

Gastrointestinal Injury

Despite the continued development of both laparoscopic instruments and techniques, gastrointestinal injury continues to be a common, yet potentially avoidable, complication of laparoscopy. In the past three decades, the risk of this complication appears to have increased from approximately 3 per 10,000 procedures to as high as 13 per 10,000 procedures.^11,¹⁵ Most bowel injuries occur during placement of the Veress needle or primary trocar when bowel is adherent to the anterior abdominal wall from previous surgery.¹⁶ Other gastrointestinal injuries result from operative procedures, including adhesiolysis, tissue dissection, devascularization injury, and thermal injury.

It is essential to minimize morbidity related to gastrointestinal injuries both by prevention and early recognition. Despite an increasing awareness of these risks, gastrointestinal injuries continue to be one of the most lethal types of injuries associated with laparoscopy, with a mortality rate reported as high as 3.6%.¹⁵ Severe morbidity and mortality is seen with delayed diagnosis of an unrecognized bowel injury. Gastrointestinal injury should be suspected in any patient who presents postoperatively with increasing nausea, abdominal pain, distension, or fever. Rebound tenderness with a white blood cell (WBC) count that is elevated or depressed with a left shift and X-ray findings demonstrating an ileus or persistent air under the diaphragm are very suggestive of injury. CO₂ gas is rapidly absorbed. Air seen under the diaphragm more than 36 hours after surgery, especially in the context of clinical symptoms, warrants further investigation for a gastrointestinal tract injury.

Preventive Measures

No method has yet to be discovered that completely prevents gastrointestinal injuries during laparoscopic port placement.¹⁷ However, it is well-established that patients with previous abdominal surgery are at increased risk of gastrointestinal injury during laparoscopy because adhesions to the anterior abdominal wall occur in approximately 25% of these patients. For this reason, certain measures have been used in an effort to decrease the risk of gastrointestinal injuries in these patients.

Two commonly used techniques for high-risk patients are open laparoscopy, as first described by Hasson, and a left upper quadrant closed technique utilizing Palmer’s point.¹⁷^–²⁰ Unfortunately, intestinal injury can occur with these approaches as well.^17,^21,²²

Another alternative approach is the use of an optical-access trocar. These devices are designed to increase safety by visualizing each layer of the abdominal wall during port placement. Unfortunately, these devices too have been associated with gastrointestinal injuries, although the actual incidence associated with their use remains uncertain.²³

Veress Needle Injuries

The standard closed technique for laparoscopic port placement begins with the blind insertion of a 14-gauge needle with a spring-loaded tip, commonly referred to as a Veress needle. Although the tip of this instrument might decrease the risk of perforating freely mobile bowel, it does not prevent perforation of adherent bowel or bowel with limited excursion related to physiologic attachments (e.g., transverse colon).²⁴ As a general rule, bowel perforation with the Veress needle does not need to be repaired as long as the puncture is not actively bleeding or leaking bowel contents.

Stomach Injuries

Injury to the stomach during laparoscopy is relatively uncommon and was reported to occur in less than 3 in 10,000 cases in the earlier days of laparoscopy.²⁵ Risk factors include a history of upper abdominal surgery and difficult induction of anesthesia, because a gas-distended stomach can be below the level of the umbilicus. Routine decompression of the stomach with a nasogastric or orogastric tube before Veress needle or trocar placement has virtually eliminated this risk, especially when a left upper quadrant approach is used.

Trocar injury to the stomach requires surgical repair. Although this is routinely performed by laparotomy, a laparoscopic approach has been reported.²⁶ The defect should be repaired in layers with a delayed absorbable suture, preferably by a surgeon experienced in gastric surgery. The abdominal cavity should be irrigated, being careful to remove all food particles as well as gastric juices. Nasogastric suction is maintained postoperatively until normal bowel peristalsis resumes.

Small Intestine Injuries

Intraoperative injuries to the small intestine often go unrecognized during surgery. Injury should be suspected whenever multiple anterior abdominal wall adhesions are present. When the primary trocar and sleeve penetrate completely through both walls of bowel adherent near the umbilicus, the injury will not be visible. Whenever the routine 360-degree survey of the abdominal cavity reveals bowel adherent near the point of insertion, a 5-mm laparoscope should be placed through a lower quadrant port to view the umbilical port site and search for injury. An injury to nonadherent bowel with the Veress needle or a trocar during initial port placement or during lysis of adhesions may fall out of view into the abdomen. If such an injury is suspected, the bowel should be run with laparoscopic bowel graspers or manually using a laparotomy incision until an injury is satisfactorily excluded.

Unrecognized trocar injuries to the small intestine usually present with symptoms of nausea, vomiting, anorexia, abdominal pain, peritoneal signs, and possibly fever culminating on the second to fourth postoperative day. Although the bacterial load of the small intestine is low, the contents are not sterile, and sepsis is a common result of undiagnosed injuries.

A full-thickness injury to the small intestine of 5 mm or greater should be repaired in two layers, sewing perpendicular to the long axis of the intestine to avoid stricture formation. This can be accomplished with an initial interrupted layer of 3-0 delayed absorbable suture to approximate the mucosa and muscularis. A serosal layer of 3-0 delayed absorbable suture is commonly placed in an interrupted fashion. This is usually performed by laparotomy or by minilaparotomy at the umbilical site, where the injured bowel loop is pulled through to the skin surface and repaired. Laparoscopic repair has also been reported by surgeons with advanced gastrointestinal surgical skills.²⁷ If the laceration to the small bowel exceeds one-half the diameter of the bowel lumen, segmental resection is recommended.

Large Intestine Injuries

Trocar injuries to the large intestines are reported to occur with a frequency of approximately 1 per 1000 cases.²⁸ Due to the high concentration of coliform bacteria in the large intestine, unrecognized injuries can result in serious intra-abdominal infections that can quickly become life-threatening. Intraoperative detection and appropriate treatment of these injuries can greatly reduce subsequent morbidity.

Whenever a large intestine injury is suspected, the area should be carefully inspected using atraumatic bowel graspers. If adhesions or anatomy make laparoscopic inspection difficult, laparotomy should be performed. An occult injury to the rectosigmoid colon may be detected using the “flat tire test,” in which the posterior cul-de-sac is filled with normal saline solution and air is injected into the rectum using a proctosigmoidoscope or a catheter-tipped bulb syringe.²⁹ Visible bubbles indicate a large intestine injury.

The management of large intestine injuries depends on size, site, and time between injury and diagnosis. In general, once the diagnosis of colonic injury is made, broad-spectrum antibiotics should be administered and consultation should be sought with a surgeon experienced with these types of injury. In the case of a small tear with minimal spillage of bowel contents, the defect is closed in two layers with copious irrigation. When a larger injury has occurred or the injury involves the mesentery, a diverting colostomy is sometimes necessary. In the case of delayed (postoperative) diagnosis, tissue inflammation usually makes a diverting colostomy necessary.

Thermal Bowel Injuries

In the early days of laparoscopy, thermal bowel injuries were associated with the use of electrosurgical equipment secondary to engineering and technical limitations. Modern advances in the use of these and alternative laparoscopic power sources has decreased but not totally eliminated thermal bowel injuries.³⁰

Thermal bowel injuries are pathologically different from traumatic injuries and therefore must be treated differently.³¹ Thermal injuries are differentiated histologically from traumatic injuries by the presence of coagulation necrosis and the absence of both capillary proliferation and white cell infiltration. Due to this coagulation necrosis, it may take days for the extent of the injury to become grossly visible. As a result, thermal injuries require wide resection of normal-appearing bowel wall adjacent to the visible injury.

Port Site Hernia

Midline Ports

For the first two decades of laparoscopy, ports were placed almost exclusively in the midline, where the anterior and posterior rectus fascia fuses. These midline ports usually consisted of a 10-mm port at the umbilicus and a 5-mm suprapubic port. Port site hernias at these locations are rare, and those reported are usually limited to omental herniation through the umbilical site.

Several actions have been suggested that might reduce the risk of umbilical site herniation, but none have ever been proven to be effective. These include allowing all the carbon dioxide to escape before removal of the umbilical port, avoiding negative pressure within the port during removal by removing the laparoscope and port together or opening the valve, and preventing reversal of anesthesia (with resultant increases in intra-abdominal pressure) at the time of umbilical port removal.³²

Lateral Ports

The use of lateral ports for more complex operative laparoscopy has resulted in a dramatic increase in the risk of port site herniation. In one retrospective review, port site hernias occurred in 5 of 3500 (0.17%) procedures, with all hernias occurring where ports with diameters of 10 mm or greater were placed lateral to the midline.³³ Bowel herniation can occur between fascial layers in what has been called a Spigelian hernia.

To minimize the risk of lateral port site herniation, both the anterior and posterior fascial sheaths should be closed after removal of all ports 10 mm and larger. This closure is usually performed with the aid of one of a number of commercially available devices or needles that incorporate the peritoneum as well as both fascial layers. Unfortunately, port site herniation is not completely prevented by careful fascial closure.³⁴

Closure of the fascia after removal of 5-mm ports is not usually recommended. Although hernias have been reported at 5-mm port sites, they appear to be extremely rare, and closing the fascia at these sites usually requires enlarging the skin incision.

Trocar site hernias usually present as a palpable mass beneath a lateral trocar site skin incision that manifests during a Valsalva maneuver. A persistent mass associated with pain indicates an incarcerated hernia and represents a surgical emergency (Fig. 45-3). Standard treatment includes careful surgical exploration of the site and its contents. Any herniated bowel must be inspected carefully. Although simple repair of the peritoneal and fascial defects is all that is required in most healthy patients, in some cases synthetic mesh may be needed.

Figure 45-3 Computed tomography scan of patient who presented with acute bowel obstruction. Bowel herniation is seen through the fascia on the right where a trocar had been placed.

Urinary Tract Injuries

Bladder Injury

Trocar Injuries

Injury to the bladder during laparoscopic port placement is relatively uncommon and is usually related to insertion of the primary trocar in the presence of a distended bladder or insertion of a suprapubic midline trocar in a patient whose bladder dome had extended cephalad secondary to previous surgery.³⁵

Draining the bladder with a catheter before primary trocar placement can decrease the risk of trocar injuries to the bladder. In patients with prior lower abdominal surgery, it seems prudent to place the suprapubic trocar above any previous transverse skin incisions. In all patients, an attempt should be made to visualize the superior bladder margin laparoscopically before suprapubic trocar placement.¹⁴ In cases in which the superior margin of the bladder cannot be seen, the bladder can be filled with 300 mL of sterile saline to better define its margin. An alternative approach is to use a lateral port site rather than a midline suprapubic site, although the decreased risk of bladder injury may be offset by an increased risk of vessel injury.

Operative Injuries

The rate of bladder injury associated with operative laparoscopy has increased dramatically to as high as 1 in 300 cases. The most common cause of bladder injury appears to be sharp electrosurgical dissection near the bladder.³⁶ Most of these injuries occur during LAVH or bladder neck suspensions, with a risk of bladder injury reported as 2.8% and 1.9%, respectively.³⁷^–³⁹ Resection of endometriosis that obliterates the anterior cul-de-sac is also a risk factor.

Recognition

Laparoscopic bladder injuries are often difficult to recognize intraoperatively. Visible leakage of urine at the time of injury is unlikely in patients with a Foley catheter in place. A common sign of bladder injury is significant bleeding from a suprapubic port site placed in the relatively avascular midline. Frank hematuria suggests a full-thickness injury. An uncommon, but pathognomonic, sign of bladder injury during laparoscopy is insufflation of the Foley catheter bag with carbon dioxide.⁴⁰

If bladder injury is suspected during laparoscopy, an indigo carmine solution can be instilled retrograde through a urethral catheter to detect small leaks. Cystoscopy, or less commonly intentional cystotomy, may be used to inspect the bladder mucosa in questionable cases or to determine the extent of a known injury and ensure that there is no ureteral involvement.

Postoperative recognition of a bladder injury can likewise be difficult. Whenever a patient returns within days of laparoscopy with significant abdominal findings, the possibility of an occult bladder injury should be considered.³⁵ Bladder injury should be included in the differential diagnosis in the presence of painful urination and microscopic hematuria (Table 45-1). Elevation of blood urea nitrogen and serum creatinine level suggests intra-abdominal spill of urine with transperitoneal reabsorption. Drainage from a suprapubic incision can be evaluated further by instillation of a dilute indigo carmine solution into the bladder.

Table 45-1 Signs of Bladder Injury Presenting in the Postoperative Period

Hematuria

Oliguria

Elevated blood urea nitrogen and creatinine levels

Lower abdominal pain/distension

Peritonitis/sepsis

Fistula

When a bladder injury is diagnosed in the postoperative period, a retrograde cystogram should be performed to determine the extent of the injury. If surgery is indicated because of peritoneal signs of uncertain etiology, cystoscopy before laparotomy may be helpful in determining surgical approach.

Treatment

Small, uncomplicated, and isolated injuries of the superior portion of the bladder can be treated with catheter drainage alone.⁴¹ A retrograde cystogram should be performed after 10 days of continuous drainage and will document spontaneous healing in 85% of patients with small injuries. Surgical repair may be necessary if the Foley catheter is unable to provide adequate bladder drainage due to blood clots and in cases of persistent extravasation.

Primary surgical repair is required for larger injuries and those that involve the dependent portions of the bladder, including the trigone, especially if there is a risk of concomitant injury to the urethra or ureter. Closure should be performed using a watertight, multilayered repair with absorbable suture. Laparoscopic repair may be performed in the case of a small injury with adequate surgical expertise and adequate exposure, as long as the ureters and bladder neck are not compromised.

Ureteral Injury

Ureteral injury occurs in approximately 1% of laparoscopies.⁴² The risk is greatest during LAVH, which has become the most common laparoscopic procedure causing ureteral injury, usually related to electrosurgery.³⁶

Laparoscopic ureteral injuries are usually not diagnosed intraoperatively.⁴³ Diagnosis is most commonly delayed until 2 to 7 days after surgery, but has been reported as late as 33 days after surgery. The most common presenting symptoms and findings are abdominal pain, fever, hematuria, flank pain, peritonitis, and leukocytosis.

Management of ureteral injury should be undertaken in collaboration with a urologic surgeon. In the majority of cases, percutaneous or cystoscopic stenting techniques can be successfully used. In severe cases, laparotomy is required for ureteral end-to-end anastomosis or bladder reimplantation. Laparoscopic ureteral repair has been reported.⁴⁴

Electrosurgical Injuries

The use of electrosurgery during laparoscopy has resulted in a unique assortment of complications, many of which are difficult to recognize intraoperatively. Although our understanding of electrophysics as it applies to laparoscopic electrosurgery has improved, complications associated with electrosurgery continue to occur.⁴⁵ Formal electrosurgical training for laparoscopists is uncommon. Unlike the medical laser setup, few institutions require electrosurgery safety courses or credentialing.⁴⁶ This section provides a basic review of electrophysics as it relates to safety in gynecologic electrosurgery. Table 45-2 defines some of the most commonly used terms.

Table 45-2 Electrosurgical Terms

Ampere (A) – the rate at which current flows

Bipolar system – current that flows from an active electrode, through tissue having a cutting or coagulating effect, and returning through a return electrode within the same instrument directly back to the electrosurgical unit, without the need for a return electrode plate on the patient

Capacitive coupling – transference of electrical energy from an insulated active electrode to nearby conductive material

Cautery — searing through the application of a heated element

Coagulating current (interrupted or damped current) — bursts of rapidly increasing current interrupted at intervals such that peak polarity alternates with zero polarity

Current (I) – electron flow measured in coulombs per second or the steady current produced by one volt applied across the resistance of one ohm.

Current density — the amount of current flow per cross-sectional area normal to the direction of current flow, described in amps per meters squared

Cutting current (continuous or undamped current) — continuous high-frequency, low-voltage flow of current from one peak of polarity to the opposite peak without pausing at the zero polarity

Desiccation – coagulation of targeted vessels through the process of dehydration

Fulguration – coagulation of surface bleeding through spraying long electrical sparks

Hertz (Hz) – a unit of frequency expressed in cycles per second

Ohm (Ω) – tissue resistance to current

Power (p) – work per unit time

Radiofrequency – a term given to the current frequency of electrosurgery because it is found within the AM radiofrequency range (500,000 to 4,00,000 Hz)

Unipolar (monopolar) system – current that flows from an active electrode, through tissue having a cutting or coagulating effect, and traveling through the patient, exiting by way of return electrode plate, usually on the patient’s thigh, to the electrosurgical unit

Vaporization – exploding cells at their boiling point (100°C) as a result of applied energy

Voltage (V) – electric potential expressed in volts

Watt (W) – the amount of work produced or work done at a rate of one joule per second

Formulae

Energy = Wattage × Time

Watts = Voltage × Current

“Electrocautery” versus Electrosurgery

Some gynecologists incorrectly use the term electrocautery to refer to electrosurgery. Electrocautery refers to the use of a heated wire to cauterize tissue and is rarely used in laparoscopy today. Electrosurgery uses alternating current to coagulate, desiccate, or vaporize tissue. This alternating current enters the patient’s body, which is included in one of two types of circuits, depending on whether monopolar or bipolar electrosurgery is used.

Energy Frequency

For electrosurgery, current that alternates at a frequency of 60 Hertz (Hz) is transformed to alternate at more than 200,000 Hz, which is in the radiofrequency range. This is necessary to minimize nerve and muscle stimulation, which occurs at frequencies below 100,000 Hz. At this high frequency, electrosurgical energy passes through the patient with minimal neuromuscular stimulation and no risk of electrocution.

Tissue Effects

Waveforms: Cutting versus Coagulation

Multiple factors are involved in the tissue effects of electrosurgery.

Electrosurgical generators can produce two distinct waveforms that differ in their rate of heat production. The rate of heat production determines whether tissue will be vaporized or coagulated: high heat causes vaporization, whereas low heat results in coagulation. A continuous waveform, referred to as cutting current, produces heat rapidly and thus vaporizes and cuts tissue (Fig. 45-4). The disadvantage of this type of current is that it does not seal vessels very effectively. Cutting current causes cells to vaporize at their boiling point (100°C) without elevating tissue temperatures to high levels, thus minimizing lateral thermal spread.

Figure 45-4 Waveforms used for laparoscopic electrosurgery.

An intermittent waveform, referred to as coagulation current, produces less heat. The on time (duty cycle) is reduced, but the peak voltage is increased. Coagulation current seals vessels by producing a coagulum and is thus used for hemostasis.

A blended current is a modification of the duty cycle such that the on time is increased and the off time is decreased compared to coagulation current. The resultant current has both cutting and coagulation characteristics, depending on the percent of on and off time.

Power Setting

It is intuitive that the power setting influences the tissue effect. Electrosurgery power settings are usually in the range of 10 to 60 watts. It is important to be aware of the standard effective power setting for the electrosurgical task you are performing with the available equipment. A requirement for a much higher power setting to achieve an acceptable clinical effect can be a warning sign of a technical malfunction. High power settings and malfunctioning equipment can result in patient injury.

Electrode Size

A smaller electrode surface results in a higher current concentration. The product of the electrode size and power setting is referred to as current density. Consequently, a smaller electrode can achieve the same tissue effect at a lower power setting. This is also the reason the patient is not burned at the site of a large return electrode pad and why electrode contact with a metal retractor that is in full contact with the patient rarely results in tissue damage.

Time

At any given power setting and electrode size, longer current application will produce more heat until the tissue is completely desiccated. More heat and higher temperatures increase the amount of thermal damage to adjacent tissue, referred to as lateral thermal spread.

Spark versus Contact

Manipulation of the electrode can determine whether vaporization or coagulation occurs. The spark created by holding the electrode away from the tissue surface results in extremely high current density and heat, and is thus ideal for cutting. Holding the electrode in direct contact with tissue decreases the current density and thus is relatively more hemostatic.

Tissue Type

Tissue resistance and density both vary widely. Subcutaneous tissue conducts well and cuts quickly. Fibrous tissue conducts poorly and cuts slowly. Most other tissue types are intermediate to these two extremes. The eschar that forms on both the tissue and the electrode during coagulation has extremely high resistance and must be removed for effective electrosurgery.

Monopolar versus Bipolar Electrosurgery

Monopolar electrosurgery is the most commonly used modality due to both its flexibility and effectiveness. During monopolar electrosurgery, the active electrode is used at the surgical site for cutting or coagulation. A return electrode pad is placed on a convenient location elsewhere on the patient’s body. The current completes the circuit by passing through the patient from the active electrode to the return electrode. This type of electrode can be associated with capacitive coupling and return electrode site burns.

For bipolar electrosurgery, both the active and return electrodes are part of a single instrument used at the surgical site; thus, no distant return electrode is needed. Only the tissue between the two electrodes is included in the electrical circuit, and no current passes through the patient. This type of electrocautery is believed to be safer because the current flow is limited to the area between the electrodes.

Interestingly, when bipolar electrosurgery is used to coagulate a bleeding vessel or pedicle, cutting current (rather than coagulation current) is used to desiccate the vessel while applying pressure with a tissue grasper. This causes fibrous bonding of the dehydrated cells of the endothelium without significant lateral thermal spread.

Incidental Causes of Electrical Injury

Capacitive Coupling

A capacitor is formed when two conductors are separated by an insulator. Capacitive coupling occurs when electrical energy is transferred from an insulator to a conductor in close proximity. Under these conditions, the conductor can cause unwanted transfer of energy to tissue that it inadvertently contacts.

The most likely scenario occurring during laparoscopic surgery known to cause capacitive coupling was with the use of hybrid-type trocar systems no longer on the market. A capacitor was created when a unipolar electrode (conductor) with a plastic shield (insulator) was passed through a metal trocar sleeve (conductor) attached to a plastic collar (insulator). In this case, capacitive coupling occurred within the trocar sleeve as energy was unable to be dispersed through the abdominal wall. This problem was prevented by removal of the plastic trocar sleeve collar. “All metal” systems allow current to dissipate through the low current density of the abdominal wall. The use of an “all plastic” system is likewise safe because the active electrode is insulated with plastic and surrounded by a plastic trocar sleeve, thus eliminating the second conductor. Furthermore, the use of cutting current provides additional safety due to lower voltage requirements.

Insulation Failure

In addition to capacitive coupling, insulation failure can also be a cause of inadvertent electrical injury despite using appropriate trocar sleeve systems. Damaged instruments have been demonstrated to cause stray current that can cause injuries during laparoscopy. Insulation failure can take place anywhere along the shaft of the unipolar instrument or within the electrosurgical cable where a breech of insulation has occurred. All reusable electrosurgical instruments should be regularly inspected for deterioration and tested by a qualified biomedical technician.

Other Energy Forms

Mechanical energy (harmonic scalpel) and laser (light amplification stimulated emission of radiation) energy are not as commonly used as electrical energy in gynecologic laparoscopic surgery. No energy form has been found to be superior to others. Laser energy use requires knowledge of certain safety features. Various media are used to produce the laser, such as CO₂ gas or potassium-titanyl-phosphate (KTP) crystal. CO₂ laser energy is in the infrared spectrum and is not visible. It is absorbed by water and has a very limited depth of penetration (0.1 to 0.2 mm). It has limited ability to achieve hemostasis, although increasing the spot size will allow some coagulation. Safety goggles are required, although they do not need to be tinted. Its limited depth of penetration makes it useful for incision of tissues and ablation of superficial lesions.

The argon and KTP lasers have shorter wavelengths than CO₂ and are preferentially absorbed by hemoglobin. They are delivered through flexible quartz fibers. These lasers have a higher depth of penetration (0.3 to 1 mm) and are very useful for coagulation. The neodymium:yttrium-aluminum-garnet (Nd:Yag) laser has a higher wavelength than the argon or KTP laser and is delivered through a flexible fiber. It has been used for hysteroscopic procedures. The depth of tissue penetration can be as high as 3 to 7 mm (noncontact mode). The air-cooled systems carry a risk for air embolism. They are often used with sapphire tips that allow direct contact with tissue.

HYSTEROSCOPY

As with most complications, accurate data on complications of hysteroscopy are not available, and prevalence rates from the literature have a tendency to underestimate the occurrence. Table 45-3 lists the most frequently reported complications. Probably the most frequently seen complication is inability to complete the procedure because of inexperience or inadequate visibility of the uterine cavity.

Table 45-3 Complications Associated with Hysteroscopy

Short-Term
	Trauma Cervical lacerations False passage Uterine perforation

Air embolus Long-Term

Postoperative hematometra

Cancer after endometrial ablation

Pregnancy after endometrial ablation

Poststerilization tubal syndrome

Recurrence of menstrual disorder

The most common traumatic injuries seen with operative hysteroscopy are those associated with insertion of the hysteroscope into the uterine cavity. Difficulties in inserting the hysteroscope are associated with cervical lacerations or creation of a false passage. Steps that can be used to diminish this complication include use of laminaria tents, if the patient is not allergic to shellfish, or the use of misoprostol (off-label use). Results of the efficacy of misoprostol on cervical dilatation are mixed. This is often due to the differences in dose, frequency, timing, and route of administration as well as menopausal status. Misoprostol 400 μg taken orally 12 and 24 hours before the procedure is efficacious in both premenopausal and postmenopausal patients. Some patients report lower abdominal cramps and bleeding after the use of this drug.

Uterine perforation usually occurs at the time of insertion of the cervical dilators or the operative hysteroscope. Perforation is more common in postmenopausal women, patients with cesarean section scars, and those with adenocarcinoma. The procedures that are most commonly associated with perforation are resection of septa or adhesions and myomectomy. Most uterine perforations are small, fundal, and require no specific treatment. If they occur laterally, laparoscopy is mandatory to assess potential uterine artery laceration. If they occur on the fundus, laparoscopy should be considered. At laparoscopy, a small fundal perforation that is not actively bleeding requires no further treatment other than a discussion with the patient that she has an increased risk of uterine rupture in a subsequent pregnancy. If a perforation occurred with an energy form such as the electrical loop, then laparoscopy or laparotomy to assess potential bowel burn is necessary. Persistent or worsening postoperative pain and nausea or fever are symptoms that suggest a complication such as bowel injury. The signs that uterine perforation has occurred during the operative procedure are the dramatic increase in fluid deficit as the fluid leaks into the peritoneal cavity and difficulties in maintaining proper uterine distension. Uterine rupture in a term pregnancy has been reported after hysteroscopic resction of a uterine septum without perforation.⁴⁷

Uterine Bleeding

Uterine bleeding can occur as a result of resection of any intrauterine lesion. Resection of a septum in the wrong plane can result in bleeding. Resection of submucous myomas can be associated with excessive bleeding. The intrauterine pressure usually tamponades most bleeding vessels. Decreasing the pressure slightly may identify the bleeding vessel so that it can be coagulated. If bleeding continues to the point that visibility is compromised, the procedure should be terminated and measures introduced to tamponade the area. The easiest approach is to introduce an intrauterine balloon such as a pediatric Foley catheter and inflate the balloon with 5 to 10 mL of fluid. The catheter is left in place for 6 to 8 hours. During this time a drop in blood pressure without any blood loss through the catheter suggests a large arterial bleed within the peritoneal cavity and surgery is required.

Distension Media

The choice and proper use of the distension media is critical for a safe operative procedure. CO₂ is often used for diagnostic hysteroscopies but not for operative procedures. The CO₂ is insufflated with a special device that delivers the gas at a maximum flow of 100 mL/minute and a maximum pressure of 100 mm Hg. Embolism of CO₂ gas has been reported as a potential complication of the use of this gas. CO₂ embolism has been especially described with the use of this gas when performing hysteroscopic surgery with the Nd:Yag laser.

Complications related to a fluid distension medium are relatively uncommon but can cause significant morbidity and mortality. These complications occur as a result of absorption of fluid. Excessive absorption of fluid can cause fluid overload and possibly electrolyte disturbances. Absorption of fluid during a hysteroscopic procedure is dependent on several variables:

• the intrauterine pressure from the infused fluid (should be kept at approximately 70 mm Hg)

• extent of surgical trauma to the uterus

• length of the procedure

• inflow and outflow rates.

One of the earliest distension media used is 32% dextran in 10% dextrose. It is a high-viscosity branched polysaccharide. Although visibility is excellent, the fluid crystallizes easily on instruments. The fluid is usually infused under pressure. Fluid overload can occur with this agent even with volumes of 500 mL due to the hydrophilic nature of this agent. The plasma volume is expanded by 860 mL for every 100 mL absorbed. Although at higher doses pulmonary edema is due to fluid overload, noncardiogenic pulmonary edema has also been reported. Coagulopathy and mild electrolyte disturbances can occur. It is recommended that volumes less than 500 mL be used. Hypersensitivity reactions have been reported with low doses.⁴⁸

Fluid distension media that are used with monopolar electrical current have no sodium. Fluids with electrolytes will cause dispersal of the monopolar current. Fluids with electrolytes such as normal saline solution can be used with bipolar current. The potential complication of all liquid distension media is fluid overload. Sodium-free distension media may also cause serum electrolyte disturbances. Sodium-free fluids that have been used for operative hysteroscopy include glycine 1.5%, 5% mannitol, and 3% sorbitol. Dextrose 5% is no longer used because of the profound hyponatremia. Glycine is metabolized in the liver to ammonia and can be a problem in patients with liver disease. Visual disturbances such as transient blindness and neurologic manifestations may occur as a result of ammonium toxicity rather than an electrolyte disturbance, especially in patients with a history of liver disease.

Fluid osmolality is the result of the dissolved solutes. Tonicity or effective osmoles are solutes that cannot freely cross membranes and therefore can cause fluid shifts. Normal serum osmolality is 280mOsm/L. Osmolality is finely controlled by arginine vasopressin (AVP) produced by the posterior pituitary gland in response to osmoregulator cells in the hypothalamus. Fluid shifts from the extracellular space to the intracellular space will occur to maintain equal tonicity between these compartments. Cellular swelling and dehydration will occur acutely to maintain tonicity.

The organic solutes used for hysteroscopic procedures (mannitol, sorbitol, and glycine) are initially restricted to the extracellular fluid compartment. Glycine and sorbitol solutions are hypo-osmolar (178mOsm/L). Mannitol 5% has an osmolality of 275mOsm/L. A large infusion of these hypotonic fluids will cause hyponatremia. Typically release of AVP is suppressed by the osmoreceptors that sense a decrease in serum osmolality. However, postoperatively AVP may be secreted in response to nausea, pain, or pain medications. If the intravenous fluid used for postoperative fluid management is hypotonic, such as halfnormal saline solution, then free water absorption can occur that will exacerbate the hyponatremia. Ringer’s lactate solution or normal saline solution is recommended for postoperative intravenous fluid use. Medical conditions such as Addison’s disease can exacerbate this condition.

The intraoperative signs of hyponatremia are often subtle but include tremulousness, hypothermia, and hypoxemia. Postoperatively the patient can complain of mild symptoms that are similar to those seen in many postoperative patients, such as headache and nausea (Table 45-4). Intracerebral fluid shifts cause cerebral edema, increased intracranial pressure, and possible herniation of the brainstem. The intracerebral water gain will cause a decrease in brain osmolality. The brain will rapidly adapt with loss of sodium, potassium, and chloride and slowly adapt by loss of organic osmolytes that lead to loss of cerebral water.

Table 45-4 Symptoms of Hyponatremia

Headache

Nausea and emesis

Lethargy, confusion, change in mental status

Seizures

Treatment of acute hyponatremia in a symptomatic patient is a medical emergency. Serum sodium levels of 120 to 128mmol/L can cause permanent brain damage. Admission and close observation is mandatory. Water restriction should be implemented (800mL/day) and intravenous normal saline solution should be given and the rate adjusted according to the urine output. Furosemide 20 mg can be given intravenously and will induce a hypotonic fluid loss. Monitor the serum sodium every 2 hours. Treatment with hypertonic saline (3%) solution should be considered in the symptomatic patient that does not respond to conservative management. Slow correction of sodium by 0.5 to 1mmol/L per hour for 3 hours should be the goal. Serum electrolytes can then be repeated. Usually 3 to 7mmol/L increase is sufficient. The effect of infusion of 1 liter of any electrolyte solution on serum sodium levels can be calculated with the following formula:

For example, if the serum sodium level is 124mmol/L and the infusing solution is 0.9% sodium chloride (154mmol/L) and the total body water is 30 L (0.5 × 58 kg), then 1L would increase the serum sodium level by 1mmol/L. The fluid volume required would be too high. A 3% sodium chloride solution (513mmol/L) would require far less volume to raise the concentration by 1mmol/L per hour. Raising the serum sodium level too quickly can cause an osmotic demyelination syndrome. Demyelination of pontine neurons can lead to quadraplegia and other neurologic disorders. Severe symptoms in patients that received glycine may be due to ammonia toxicity, and this should be treated with hemodialysis.⁴⁹

Proper intraoperative vigilance is essential to avoid the fluid and electrolyte complications of hysteroscopic surgery. Fluid irrigation systems that rapidly calculate fluid deficits can aid in detecting these disorders. If electrolyte-free solutions are used, serum sodium levels should be ordered with large fluid deficits. Termination of the procedure should be considered with fluid deficits of approximately 1L. If isotonic fluids such as normal saline solution are used, fluid deficits of up to 1.5 to 2.0L can be tolerated in healthy women. Fluid overload in these patients present with dyspnea and hypoxemia but with normal serum electrolytes.