Blunt Hepatic Injury

In MVCs, those most susceptible to hepatic injury are unrestrained front-seat passengers. These passengers are particularly vulnerable to a compression injury from the steering wheel especially during periods of rapid deceleration.³ Although the anterior abdominal wall stops, the posterior abdominal wall continues to move forward, and the intra-abdominal organs are “trapped” and compressed resulting in stretching/tearing of the liver at its vascular and structural attachments. As the liver is only partially protected by the rib cage, liver injury from steering wheel contact is one of the most important contributing factors to driver injury.

In lateral impact (“T-bone”) collisions, the target vehicle is hit on its side and accelerated rapidly at 90 degrees to its previous direction of travel. The unrestrained passenger is subject to both compression and shear injuries that cause stretching/tearing and, at times, result in avulsion of the liver. Furthermore, in lateral impact injuries, because the spine/posterior abdominal wall is not in the line of impact in contradistinction to frontal impact injuries, more relative motion of the intra-abdominal organs ensues resulting in a greater likelihood of injury.

Penetrating Hepatic Injury

Damage caused by a penetrating injury is based on the kinetic energy of the projectile and the density and elasticity of the tissue. Lowenergy weapons such as knives only cut and do not create a temporary cavity. Medium-energy and high-energy firearms damage not only the tissue directly in the path of the missile but also the tissue on each side of the missile’s path. As a missile passes through the relatively inelastic liver parenchyma, a temporary cavity (three to six times the size of the missile’s front surface area, lasting for a fraction of a second) and a permanent cavity (visible to the examiner) are created. The higher-energy firearms create larger temporary and permanent cavities, resulting in far more extensive tissue damage; the vacuum created by this larger cavity pulls clothing, bacteria, and other debris from the surrounding area into the wound as well.

Hemodynamically Unstable Patients

Patients who arrive with hemodynamic instability (systolic blood pressure <90 mm Hg) and who do not immediately respond to appropriate fluid resuscitation are expeditiously taken to the operating room without delay, irrespective of mechanism of injury. Further diagnostic evaluation at this point is contraindicated, as unnecessary delays inevitably follow and are often responsible for the ensuing fatalities.

In the hemodynamically unstable patient with pelvic fractures from blunt trauma, diagnostic peritoneal lavage (DPL) and focused abdominal sonography for trauma (FAST) are currently the diagnostic modalities used to detect the presence of intraperitoneal blood. DPL is 96% accurate in detecting intraperitoneal blood and a grossly positive aspiration (>10 ml) mandates immediate operative intervention. In most trauma centers, FAST has replaced DPL as the preferred diagnostic modality for the determination of hemoperitoneum in the unstable bluntly injured patient. Although FAST has a 97% sensitivity for hemoperitoneum greater than 1 liter, the location of the parenchymal injury often cannot be reliably identified. One’s ability to assess the source of the hemorrhage will continue to increase as experience with FAST increases. The sensitivity of FAST drops precipitously when the quantity of intraperitoneal fluid is less than 400 ml.

Hemodynamically Stable Patients

The hemodynamically stable blunt-trauma patient, on the other hand, may undergo further diagnostic studies. Hemodynamic stability, however, should not lull the trauma surgeon into a false sense of security, as significant intra-abdominal injuries may be present despite normal vital signs and a normal abdominal exam. The ability to accurately assess the presence or absence of significant intra-abdominal injuries by physical examination alone in the blunt trauma patient is notoriously poor, as up to 20%–30% of patients with a “benign” abdomen on physical examination have been shown to subsequently have significant intra-abdominal injuries on imaging or at laparotomy.

CT scanning is the preferred initial diagnostic modality in the hemodynamically stable patient with blunt abdominal or lower thoracic cage injuries. High-speed resolution scanning with a spiral scanner is employed after the administration of intravenous and oral (when feasible) contrast. Five-millimeter cuts are obtained after 120 ml of noniodinated contrast (Omnipaque) is injected at a rate of 2 ml/sec. Scanning commences 50 seconds after injection, a delay that corresponds to the portal venous phase of liver imaging.

Scans should immediately be interpreted and classified according to the American Association for the Surgery of Trauma liver injury scale⁴ (Table 1) by the CT fellow or attending radiologist, always in the presence of the chief trauma resident and trauma attending. The senior trauma attending in presence makes the final decision as to the appropriateness of nonoperative therapy. It should be noted that the grade of injury or degree of hemoperitoneum on CT does not determine the need for operative intervention, as this decision is based primarily on the patient’s hemodynamic stability and the absence of peritoneal signs. Instead, the CT scan merely provides the surgeon with a general anatomic overview of the injury, identifies associated abdominal injuries requiring operative intervention, and can be used as a base for comparing future healing of the hepatic injury and resorption of intraperitoneal blood. CT can also identify injuries involving the bare area of the liver, which commonly present with minimal intra-abdominal bleeding, a paucity of abdominal signs, and often a negative DPL.

The role of FAST as a screening exam in hemodynamically stable patients is evolving and in the near future may eliminate the need for CT scan. Currently, many trauma centers forgo CT scanning in stable patients with negative initial FAST exams and merely repeat the FAST in 6 hours. However, scanning for only free fluid has its diagnostic limitations because not all blunt hepatic injuries result in hemoperitoneum. In a recent study looking specifically at sonographic detection of blunt hepatic trauma, Richards et al.⁵ determined the overall sensitivity of FAST for blunt hepatic injuries (all grades) to be 67%, based on the detection of free fluid alone. On the other hand, it is clear that most solid organ injuries without intraperitoneal fluid on FAST are, in general, of minimal clinical significance.⁶ At present, most trauma surgeons agree that those patients who are hemodynamically stable and who have either intraperitoneal blood on their initial FAST exam or positive findings on physical exam over the lower chest and upper abdomen should have a CT to specifically identify a hepatic or splenic injury that can be managed nonoperatively. Once identified, the hepatic injury may be followed with ultrasound if necessary.

Diagnostic laparoscopy (DL) is a safe procedure that has had a major impact in avoiding unnecessary abdominal explorations in patients with stab wounds or gunshot wounds that may not have penetrated the peritoneal cavity. The role of diagnostic laparoscopy in patients with blunt hepatic injury is less clear. DL should allow for an accurate assessment of most hepatic injuries and, as advances in laparoscopic instrumentation progress, perhaps allow for repair of some liver injuries. However, reports of missed enteric and other intra-abdominal injuries with DL are sufficiently significant to warrant further evaluation of DL in blunt trauma patients.

Nonoperative Management/Blunt Hepatic Trauma

Currently, nonoperative management of adult blunt hepatic injuries is the standard of care. Initial hemodynamic stability or hemodynamic stability achieved and maintained with moderate fluid resuscitation is the single most crucial prerequisite qualifying patients for nonoperative management. Once hemodynamic stability has been ascertained, the following criteria must be met:

Absence of peritoneal signs

Precise CT scan delineation and AAST grading (see Table 1)

Absence of associated intra-abdominal or retroperitoneal injuries on CT scan that require operative intervention

Avoidance of excessive hepatic-related blood transfusions

Previously cited inclusion criteria such as neurological integrity are no longer valid, as neurologically impaired patients can be safely managed nonoperatively in a monitored setting.⁷ Furthermore, mandatory repeat CT scans to document improvement or stabilization of injury are unnecessary and contribute little to patient outcome. Rather, the patient’s clinical course should dictate the need for additional evaluation.

Most (80%–90%) blunt hepatic trauma patients can be successfully managed nonoperatively. Although nonoperative management was initially limited to AAST grades I–III injuries, it is now clear that the hemodynamic status of the patient, rather than AAST grade of injury, is the most significant factor in determining the need for operative intervention. Up to 20% of select patients with grades IV and V injuries can be managed nonoperatively. However, many grade IV and most grade V injuries will usually present with hemodynamic instability or concomitant injuries mandating surgery, thus precluding nonoperative intervention. In a multi-institutional study, grades IV and V injuries were responsible for 67% of all patients who failed nonoperative management and subsequently required operative intervention.⁸ Therefore, although hemodynamic stability determines which patients can be managed nonoperatively, the subgroup of patients with complex hepatic injuries (grades IV and V) are at substantially higher risk for treatment failure and should therefore be closely monitored in a critical care unit.

Conversely, the same basic standards apply to patients with lower AAST-grade injuries (i.e., I–III). In these instances, the initial injury may be deemed as “not significant,” and thus it becomes tempting to avoid surgical intervention despite hemodynamic instability or a decreasing hematocrit, relying instead on further fluid and blood transfusions. This course of action is fraught with pitfalls and should be avoided to minimize the morbidity and mortality of nonoperative management. To summarize, of all the variables monitored, hemodynamic stability appears to be the most crucial and is considered the watershed for nonoperative or operative intervention.

Contrast “Blush” on CT

Specific cause for concern is the presence on the initial CT scan, after the administration of intravenous contrast, of a contrast “blush” or “pooling” of contrast material within the hepatic parenchyma. This finding indicates active bleeding. Even in the context of hemodynamic stability and irrespective of AAST grade of injury, preparation for possible surgical intervention should promptly be made, as patients can suddenly and unpredictably decompensate clinically. If the patient remains hemodynamically stable, angiography with the intent of embolizing the lacerated vessel should be attempted (with an operating room on standby secured). An experienced interventional radiologist will usually have little difficulty in selectively catheterizing and embolizing the injured vessel, most often with stainless steel coils and/or Gelfoam. Successful embolization will then permit further nonoperative management. As the natural history of these lesions is unknown, they are best dealt with immediately so that sudden bleeding, false aneurysm formation, and late hemobilia may be avoided.

Persistent and prolonged attempts at controlling the bleeding vessel through angiographic means should be discouraged. In the rare event in which angioembolization fails to control ongoing bleeding, surgical intervention using the angiogram as an anatomic marker to more rapidly achieve intrahepatic hemostasis should promptly be undertaken.

Nonoperative Management/Penetrating Hepatic Trauma

Most penetrating civilian injuries to the liver result in a lesser degree of parenchymal damage than do those incurred by blunt trauma, at least by AAST criteria. Therefore, it seems logical that nonoperative management of a penetrating isolated hepatic injury would be successful in hemodynamically stable patients without evidence of peritonitis.

Renz et al.⁹ nonoperatively managed 13 patients with penetrating right thoracoabdominal gunshot wounds. The authors stressed the importance of serial abdominal exams and contrast-enhanced CT scanning in their successful nonoperative management. Demetriades et al.¹⁰ substantiated this concept with their successful management of select patients with isolated gunshot injuries to the liver. These authors concluded that hemodynamically stable patients with grades I and II liver injuries and no evidence of peritonitis can be safely managed nonoperatively. However, it should be noted that this approach failed in nearly one-third (5/16) of the patients in the “observed group” who eventually required delayed laparotomy. More recently, Omoshoro-Jones et al.¹¹ described successful nonoperative management in 31 of 33 patients with gunshot wounds to the liver, including grades III–V injuries. Although the higher-grade injuries were associated with more complications (most of which were managed nonoperatively), the overall success of nonoperative management did not depend on the AAST grade of liver injury.

Clearly, the most difficult aspect in the nonoperative management of penetrating hepatic trauma is patient selection, as only up to 30% of those with gunshot wounds to the liver are eligible for nonoperative management to begin with. At the very least, hemodynamic stability, an intact level of consciousness to allow serial abdominal exams, absence of peritoneal signs, and no evidence of active bleeding on CT are required for successful nonoperative management.

Operative Management/General Principles

The four basic principles in the management of liver trauma requiring surgery are hemostasis, adequate exposure, debridement, and drainage. With hepatic injuries, these objectives can be reached by the use of the finger-fracture technique (hepatotomy) to incise hepatic parenchyma, often combined with temporary occlusion of the portal triad for hemostasis (discussion follows). Extensive debridement of injured hepatic tissue can then be done, followed by application of a viable pedicled omental pack and closed-suction drainage.

Before the incision is made, the patient should receive a dose of antibiotics to cover aerobic and anaerobic microbes and is placed on a warming blanket. The surgeon must keep in mind that hypothermia is a frequent complication of resuscitation and operation in patients with major hepatic injuries. Appropriate maneuvers to decrease hypothermia are shown in Table 2.¹² Adherence to these maneuvers will usually prevent the development of intraoperative coagulopathies and fatal arrhythmias.

Table 2 Maneuvers to Prevent/Decrease Hypothermia in Patients with Major Hepatic Injuries

Adapted from Pachter H, Liang H, Hofstetter S: Liver and biliary tract trauma. In Feliciano DV, Moore EE, Mattox KL, editors: Trauma, 4th ed. Stamford, CT, Appleton and Lange, 2000, p. 637.

The skin is prepped from the chin to the knees and a standard midline incision is made. The midline incision not only affords excellent exposure of the entire liver but also provides wide access to all peritoneal and retroperitoneal structures. The combination of a long midline incision and the use of large “upper-hand” retractors have, for the most part, eliminated the need for thoracic extension of the abdominal exposure. It should be kept in mind that extending the midline incision to the sternal notch (i.e., completing a median sternotomy) exposes the patient to two open cavities with the attendant increased risks of hypothermia and coagulopathy.

Exsanguinating hemorrhage continues to remain the most immediate cause of death in patients sustaining hepatic trauma. The initial incision into the peritoneal cavity can be accompanied by profuse hemorrhage once the tamponading effect has been lost. At this time, all efforts should be directed toward intraoperative resuscitation. Attempts at definitive surgical hemostasis without proper intraoperative resuscitation usually results in systemic hypothermia and profound coagulation defects with their dire consequences. This fundamental pitfall should be avoided at all costs. Irrespective of the severity of hepatic injury, almost all liver injuries can be initially managed by manually compressing the injury overlap pads (Figure 3), while hemodynamic and metabolic stability are restored by the anesthesia team. Failure to correct hypovolemia and acidosis before attempts at surgical control will likely lead to cardiac arrest and subsequent death. Once intraoperative resuscitation has been achieved, manual compression of the liver is slowly released so that a more accurate assessment of the injury can be made.

Figure 3 Manual compression of a severe liver injury overlap pads.

In order to better visualize injuries on the superior or lateral aspects of an injured hepatic lobe, it is often necessary to mobilize the liver into the midline wound. Division of the falciform ligament allows for placement of an “upper-hand” self-retaining retractor in the incision. Once this is done, careful traction on its hepatic end can aid in exposing the dome of the liver and the suprahepatic inferior vena cava. Additional exposure is obtained by placing laparotomy pads behind the posterior surface of the liver. Mobilization of the right and left lobes proceeds with division of the triangular ligaments (Figure 4). If there is a hematoma within the leaves of the triangular ligament, a hepatic vein or venal caval injury is most likely. Extreme caution must be taken because traction may disrupt a stable hematoma and can create massive bleeding.

Figure 4 Mobilization of right triangular ligament.

Operative Management/Minor Injuries (Grades I and II)

Simple techniques of controlling hemorrhage include: a 5–10-minute period of compression, application of topical agents including fibrin glue, electrocautery/Argon beam electrocoagulation, and suture hepatorrhaphy (Figure 5). In many patients with superficial lacerations of the capsule, a 5–10-minute period of compression will frequently control any hemorrhage. If there is no visible leakage of bile, no further therapy is indicated. Topical agents such as Surgicel, Avitene, and fibrin glue are useful when avulsion of Glisson’s capsule is present. Five minutes of compression with lap pads is performed after the application of a topical agent to the raw surface. After releasing compression, the electrocautery can be used for any remaining bleeders. Drainage is not necessary in the absence of further hemorrhage or obvious bile leakage.

Figure 5 Use of argon beam to control hemorrhage.

Suture hepatorrhaphy has historically been the mainstay of hepatic hemostasis in grade II and some grade III injuries. It is important to first enter the hepatic wound and selectively ligate any open/avulsed bile ducts or blood vessels. Figure-of-eight 2-0 or 3-0 Prolene sutures are usually employed. Small defects in the hepatic parenchyma can be closed with simple interrupted 0-chromic or 2-0 chromic liver sutures with blunt-nosed needles (Figure 6). For deeper lacerations, attempts at primary closure of the hepatic defect should not be undertaken. Instead, a tongue of omentum on a pedicle is placed within the hepatic parenchymal defect and is then held in place with interrupted liver sutures (Figure 7). It is important to loosely approximate the edges because portions of the liver beneath can become necrotic in the postoperative period if the sutures are tied too tightly.

Figure 6 Suture hepatorrhaphy.

Figure 7 Omental packing.

Operative Management/Complex Injuries (Grades III to V)

If significant hemorrhage continues after the release of manual compression of the liver, the portal triad should be occluded with an atraumatic vascular clamp (the “Pringle” maneuver; Figure 8). In over 85% of patients with complex hepatic injuries, occlusion of the portal triad will temporarily stop the bleeding. This maneuver, coupled with the finger fracture technique to expose lacerated blood vessels for direct repair, is responsible for the dramatic decrease in mortality from exsanguination.

Figure 8 “Pringle” maneuver.

Complex hepatic injuries (grades III to V) can best be managed by adhering to five sequential crucial steps:

Much controversy has surrounded the normothermic ischemic time produced by the Pringle maneuver. The data are clear that complex hepatic injuries can be managed with continuous cross clamping of the porta hepatis for up to 75 minutes without adverse sequelae.¹³ We prefer to achieve hepatocyte protection before portal triad occlusion by employing topical hypothermia to the hepatic parenchyma and maintaining a core hepatic temperature of 32° C. This maneuver must be achieved without contributing to systemic hypothermia. The rest of the abdomen must be packed off with multiple lap pads, and topical hypothermia with iced Ringer’s lactate is achieved by intermittently pouring the solution directly onto the liver. Essential to this approach is the use of an intrahepatic digital temperature probe so that core hepatic parenchymal temperature can be seen at all times.

With portal triad occlusion achieved by an atraumatic vascular clamp, the surgeon then opens the liver parenchyma (hepatotomy) in the direction of the injury (Figure 9). Although it initially seems crude, the finger-fracture technique constitutes the benchmark of obtaining rapid, adequate exposure. Specifically, using the electrocautery, Glisson’s capsule is incised in the direction of the injury. Normal hepatic parenchyma is then crushed between the surgeon’s thumb and index finger (or a neuro-tipped suction device), thereby rapidly exposing injured blood vessels and bile ducts, which are repaired or ligated under direct vision. Narrow Deaver retractors can be inserted into the hepatotomy tract for better intrahepatic exposure (Figure 10). Large lacerated intralobar branches of the portal vein or hepatic veins can be repaired in a lateral fashion using 5-0 Prolene sutures (Figure 11).

Figure 9 Finger-fracture technique.

Figure 10 Placing Deaver retractors for better exposure.

Figure 11 Ligating large branches with Prolene sutures or clips.

After intrahepatic hemostasis has been achieved, thorough debridement of devascularized hepatic tissue is essential to avoid postoperative septic complications. The use of omentum is extremely beneficial in the management of complex hepatic injuries, as it provides viable tissue to fill dead space, tamponades minor venous oozing, and provides a rich source of macrophages that may help combat infection.

The preferred method of drainage is with closed-suction Jackson-Pratt drains anterior and posterior to the injury. The data rendering drains unnecessary in elective hepatic resection cannot be applied to complex hepatic trauma, where blood loss, hypotension, and the frequent need to terminate surgery are the usual order of the day. In addition, the “zone” of injury may extend centimeters beyond what appears to be normal hepatic parenchyma, leading to eventual necrosis and abscess formation. While routine drainage after elective hepatic resection may be superfluous, enough variables exist in the trauma setting to merit the routine use of closed suction drains for complex hepatic injuries.

Juxtahepatic Venous Injuries (Grade V)

Juxtahepatic venous injuries, especially from blunt trauma, are often fatal, with mortality rates up to 50%. Failure to control hemorrhage from a deep laceration, missile tract, or stab wound with a Pringle maneuver still in place strongly suggests the presence of a juxtahepatic venous injury. Regardless of the technique used to manage these devastating injuries, early recognition is essential because prompt modification of the surgical approach is necessary.

In the past, in order to try to salvage these patients, trauma surgeons inserted an atriocaval shunt with a resultant prohibitively high mortality (60%–100%). Currently, the use of atriocaval shunting has been virtually abandoned, and these difficult injuries have been, at times, successfully managed using a variety of approaches.

At present, there is a general consensus among trauma surgeons that if a retrohepatic caval injury or a hepatic venous injury (grade V) can be adequately controlled with perihepatic packing, no attempts at further repair should be initiated. When adequate resuscitation has been accomplished, there may be a role for endovascular stenting of the injury before pack removal.¹⁴ Even without endovascular stenting, when planned re-exploration is undertaken, no further bleeding is often noted. If bleeding occurs after pack removal, definitive treatment can then be undertaken with the knowledge that the patient’s hemodynamic status has been optimized and that adequate personnel are available if a vascular shunt is necessary.

Another approach is direct hepatotomy through normal hepatic parenchyma to reach the injured retrohepatic cava or hepatic veins.¹⁵ After manual compression, vigorous resuscitation and prolonged portal triad occlusion, mobilization of the liver is performed with medial rotation, thus providing access to the retrohepatic cava and hepatic veins. Rapid and extensive finger fracture should be directed toward the site of injury until the lacerated retrohepatic cava or hepatic vein is found and repaired under direct vision. The surgeon must be prepared to finger fracture the hepatic parenchyma through normal and frequently nonanatomic planes. Because these patients usually have injured hepatic parenchyma as well, portal triad occlusion serves two purposes: it contributes to controlling hemorrhage from intrahepatic branches of the hepatic artery and portal vein, and it decreases the inflow to the liver, thereby aiding finger fracture while minimizing blood loss.

Venovenous bypass, vascular exclusion, and primary repair¹⁶ comprise a third approach. Total vascular isolation of the liver via venovenous bypass (combined with the Pringle maneuver and clamping of the suprarenal and suprahepatic cava) permits direct suture repair of the venous injury. The advantage here is that vascular isolation with venovenous bypass obviates the need for an intracaval shunt. Cannulation for bypass can be done peripherally via saphenous vein and axillary vein cutdowns. Venovenous bypass has been used in a small number of severe retrohepatic liver injuries with an overall survival rate of 88%.

Next is total hepatic resection and delayed liver transplantation.¹⁷ Total hepatectomy and second-stage hepatic transplantation can be a drastic yet life-saving maneuver for devastating liver injuries that have failed all conventional treatments. Perihepatic packing and total hepatectomy with portacaval shunting can be performed in the primary hospital; the anhepatic patient can then be transferred to a transplant center for eventual liver transplant. Although this radical maneuver can be associated with high morbidity and mortality, the prognosis is better if the decision to proceed with total hepatectomy and portacaval shunting is made before the development of intractable multiorgan failure.

Portal Triad Injuries

As exsanguination is the most common (85%) cause of death in these highly lethal and complex injuries, the first priority in portal triad trauma is hemorrhage control, specifically manual compression followed by the Pringle maneuver. A wide Kocher maneuver and mobilization of the hepatic flexure will allow medial rotation of the ascending colon to better expose the portal structures. Exposure of a retropancreatic portal vein injury may require pancreatic transection with distal pancreatectomy after the vascular repair is complete. Although portal vein ligation can be used to expeditiously manage portal vein injuries, the preferred treatment is lateral venorrhaphy, as most series report a 51%–60% survival with this approach.¹⁸

Hepatic artery injuries should generally be managed with ligation. However, the hepatic parenchyma must be evaluated for ischemia after ligation, especially in the presence of portal vein injury or shock. In addition, the gallbladder should be removed if the hepatic artery is ligated. Partial extrahepatic bile duct injuries (less than 50% circumference) may be primarily repaired, with or without stenting. However, complete or complex bile duct injuries are best managed by Roux-en-Y biliary-enteric anastomosis. For the unstable patient, ligation with external drainage and delayed reconstruction is a reasonable approach.

Damage Control/Perihepatic Packing and Planned Re-Exploration

Perihepatic packing has emerged as an essential life-saving maneuver in patients with complex injuries refractory to conventional methods of treatment and usually complicated by brisk bleeding, hypothermia (less than 34° C), acidosis (pH < 7.2), and coagulation defects from massive transfusion (over 10 units). The effectiveness of perihepatic packing is directly related to the tamponading effect of the packs on the hepatic injury. Specifically, the packs raise intra-abdominal pressure, causing tamponade of low-pressure venous and nonmechanical capillary bleeding. The key to the success of perihepatic packing is to insert the packs early in the course of the operation before the onset of repeated episodes of hypotension.

Primary indications for perihepatic packing follow:

As a general rule, the liver should be mobilized before packing to help establish a tamponading effect. If, however, a significant hematoma is encountered in the triangular ligament (indicative of a vena caval or hepatic vein injury), further mobilization is contraindicated as massive and uncontrollable bleeding may follow. Most often, dry multiple-lap pads are placed on top of the injured liver until the ipsilateral hemidiaphragm is reached (Figure 12). In order to lessen the degree of bleeding when lap pads are peeled off the raw liver surface, we routinely place a Steri-Drape (3M, St. Paul, MN) directly upon the liver surface to serve as an interface between the injured liver and the lap pads.

Figure 12 Perihepatic packing.

Resorting to packing is usually synonymous with a dire situation. Under these circumstances, we prefer rapid closure of the abdomen with towel clips. Several large Steri-Drapes impregnated with Betadine cover the entire incision, encompassing all towel clips. Towel-clip closure takes minutes to perform and facilitates rapid patient transfer to a critical care setting where the patient’s metabolic status can be optimized. Alternatively, prosthetic abdominal wall closure with an IV bag can also be employed.

Because perihepatic packing raises intra-abdominal pressure (IAP), monitoring IAP in the perioperative period is critical to avoid the development of an abdominal compartment syndrome. Pack removal should be dictated by the reversal of the patient’s hypothermia, acidosis, and coagulopathy. These goals can usually be achieved within 36–48 hours. Packing has been historically associated with a 20%–30% incidence of perihepatic sepsis. However, early pack removal, the evacuation of intraperitoneal clots and the thorough debridement of necrotic hepatic tissue have lessened the incidence of this complication.

Adjuncts to Operative Management

Asensio et al.¹⁹ advocate early hepatic angiography and angioembolization (AE) in all patients with grades IV and V hepatic injuries. These authors reported an improved survival with immediate surgery to control life-threatening hemorrhage, the institution of early hepatic packing when necessary, and subsequent patient transport directly from the operating room to the angiography suite for immediate hepatic angioembolization. Clearly, AE is essential in the management of complex hepatic injuries, whether they arise from blunt or penetrating mechanisms.

Early AE may also be useful in the multiply injured patient whose hepatic injury is being managed nonoperatively but whose serial hematocrits are noted to be dropping. Under these circumstances, the patient should immediately undergo repeat CT scanning, rather than arbitrarily receive incremental blood transfusions. If the repeat CT scan confirms that the liver injury has deteriorated and the patient remains hemodynamically stable, then AE should be attempted. Failure of AE to arrest ongoing hemorrhage or hemodynamic instability at any given time should prompt immediate laparotomy.

Late angiography is therapeutic in the presence of hemobilia, bleeding emanating from abdominal drains in the postoperative period, or vascular abnormalities noted when follow-up CT scan is indicated.

Failure of Nonoperative Management

Nonoperative management of adult blunt hepatic injuries has resulted in an overall success rate of 95%. Fears concerning excessive blood transfusions in patients managed nonoperatively have not materialized, as the mean transfusion rate in most large series is approximately two units. Failure of nonoperative management of blunt hepatic injuries is usually associated with the presence of a “contrast blush” on the initial CT scan, indicating active hemorrhage and mandating intervention irrespective of the patient’s hemodynamic status. If stable, AE has emerged as the adjunctive treatment modality of choice. When hemodynamic instability unresponsive to fluid resuscitation manifests itself initially or after the documentation of a contrast blush, operative intervention should be undertaken without delay. For this clinical picture to emerge, a significant injury has likely occurred and often necessitates damage control laparotomy.

Most failures of nonoperative management (with lack of contrast blush on initial CT) result from associated abdominal injuries rather than the liver per se. In a recent series reported by Velmahos et al.,²⁰ the grade of injury did not correlate with failure of nonoperative management. Most impressive was their reported liver-related failure rate of 0%. Although their series was too small to determine independent predictors of failure, they found that patients who failed had a higher Injury Severity Score, required greater volumes of initial fluid resuscitation and blood transfusion, and had other associated abdominal injuries.

Hemorrhage

Hemorrhage complicating the nonoperative management of hemodynamically stable patients with blunt injuries occurs at a frequency of less than 5%, particularly when a helical contrast-enhanced CT scan fails to show an active blush. For the most part, these cases follow a predictable pattern of gradual hemorrhage and hematoma formation, rather than sudden decompensation. The reported incidence of delayed hemorrhage requiring laparotomy is well under 2%–3%.

Bleeding after operative management of hepatic injuries is usually not subtle as evidenced by brisk bleeding from intraperitoneal drains. However, a more subtle presentation is the hemodynamically stable patient with a partially distended abdomen accompanied by a decreasing hematocrit. In the past, reoperation to control bleeding from within the injured liver was promptly undertaken after correction of acidosis, hypothermia, and coagulation defects. Currently, in the absence of hemodynamic instability, AE is the preferred treatment.

In the hemodynamically unstable postoperative patient, reexploration is warranted. The same techniques apply, namely manual compression of the liver with concomitant intraoperative resuscitation, the Pringle maneuver, and finger fracture, if necessary, through the repaired area. If there is a concern that extensive hepatotomy may sever major vascular structures or hepatic bile ducts, persistent bleeding may be controlled by extralobar hepatic arterial ligation or balloon tamponade with Penrose and red rubber catheters. If a diligent search has failed to reveal a mechanical source of bleeding, a transfusion-related coagulopathy is the most likely culprit. Under these circumstances, packing of the injured liver should rapidly be undertaken, following the guidelines for packing removal as described earlier.

Perihepatic Sepsis/Abscess

The predominant cause of the late morbidity and mortality associated with complex hepatic injuries is perihepatic sepsis (3%–5%). Perihepatic sepsis, especially in the multiply injured patient, can lead to septic shock formation, systemic inflammatory response syndrome, and multiple organ failure. Noninfectious factors can also initiate severe inflammatory responses that may culminate in multiple organ failure and death.

A variety of risk factors for postoperative abscesses after hepatic trauma have been identified, including associated enteric injuries, extent of parenchymal damage, transfusion requirements, and inadequate debridement/drainage at the initial operation. For the most part, the rate of hepatic abscess formation can be significantly reduced with meticulous hemostasis, adequate debridement of nonviable hepatic parenchyma, and avoiding open-suction drainage.

Most abscesses can be drained percutaneously. Failure of the septic patient to improve within 24–36 hours after percutaneous drainage is a compelling reason to repeat the CT scan to determine if the catheter needs to be readjusted or whether operative intervention is needed. If surgery is required, the abscess cavity should be unroofed, devitalized tissue debrided, and closed-suction drainage established. Rarely, resectional debridement or frank lobectomy may be required to eradicate either an infected biloma or abscess cavity.

Bile Collections/Fistula

The second most common late complication encountered with the nonoperative management of blunt hepatic injuries is either the development of a collection of bile (biloma) or the formation of a biliary fistula. Although leakage of bile from lacerated biliary radicals after hepatic injuries occurs commonly, the reported incidence of clinically significant bile leaks is low (2%–3%). Extravasation of bile demonstrated on nuclear imaging (HIDA scan) rarely requires operative intervention, as percutaneous drainage is usually successful. The key to the management of bile leaks is adequate closed suction drainage. Even a biliary fistula (>50 ml/day over 14 days) that is adequately drained usually closes spontaneously. When biliary fistulas fail to resolve, ERCP with stent and/or sphincterotomy should be performed.

Thoracobiliary fistula is a rare complication of penetrating thoracoabdominal trauma. The responsible mechanism is usually a missed or deliberate non-repair of small diaphragmatic lesion. Percutaneous drainage of the chest collection combined with endoscopic sphincterotomy is almost always curative. It should be stressed, however, that early diagnosis is critical to avoid the corrosive effect of bile on the lungs and pleural space.

Hemobilia

Hemobilia is an uncommon complication of hepatic trauma, occurring at most in 1%. Hemobilia may result from blunt or penetrating trauma or iatrogenically induced by deep suture hepatorrhaphy. Signs and symptoms of gastrointestinal hemorrhage, right upper quadrant pain, and jaundice (Sandbloom’s triad) may occur 4 days to 1 month postinjury. Repeat endoscopy is usually unrevealing. In this setting, a history of trauma mandates celiac angiography. If hemobilia is the cause of the bleeding, angiography will demonstrate a hepatic artery pseudoaneurysm that can be embolized with steel coils, Gelfoam, or acrylate glue. Surgical intervention is rarely necessary unless hemobilia is either associated with a large intrahepatic cavity or angiography is not available. If surgery is required, the optimal treatment is hepatic resection encompassing the large cavity and the pseudoaneurysm. Vascular control (by intraoperative Pringle maneuver or direct ligation of the hepatic artery) is essential before attempting to debride or resect large intrahepatic cavities associated with hepatic artery pseudoaneurysms.

Injury to the Intrahepatic Bile Ducts and Late Stricture

Injuries to the intrahepatic bile ducts are rare. The long-term sequelae of spontaneous healing of the injured hepatic parenchyma surrounding both normal and disrupted intrahepatic bile ducts are presently unknown. While disruption of secondary and tertiary biliary radicals within the liver occurs often, late intrahepatic bile duct stricture formation is an exceedingly rare occurrence.

Postobservational CT Scanning

The physiology of hepatic repair after blunt injury progresses in a predictable fashion that results in virtually complete restoration of hepatic integrity at the end of 3 months. There is general agreement that postobservational scanning in patients with grades I and II injuries contributes little to the clinical management of asymptomatic patients. In patients with grades III to V injuries, repeat CT scan or ultrasound, showing resolution of the injury, can serve as an invaluable guide in identifying patients for whom critical care monitoring may no longer be necessary. The optimal time frame for follow-up CT scan in these patients, if necessary, is 7–10 days after the original injury.

Resumption of Normal Activities

Dulchavsky et al.²¹ demonstrated in experimental models that hepatic wound bursting strength at 3 weeks after injury was comparable and often exceeded wound bursting strength of normal hepatic parenchyma. Moreover, healing by secondary intention resulted in wound bursting strength equal or greater than hepatorrhaphy or hepatorrhaphy and omental packing at 3 and 6 weeks. The healing mechanism responsible for the increased wound bursting strengths appears to be the proliferative fibrosis throughout the injured hepatic parenchyma and the overlying Glisson’s capsule. Hepatic parenchymal healing appears to be virtually complete at 6 to 8 weeks postinjury. A reasonable and safe approach to pursue would be to allow patients with grade III or greater injury to resume normal activities after CT scan documentation, at 3 months, of major injury resolution.