Principles of surgery and management of intraoperative complications

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CHAPTER 8 Principles of surgery and management of intraoperative complications

Angus McIndoe

Chapter Contents

INTRODUCTION 105
THE ROUTE 105
OPENING AND CLOSING THE ABDOMEN 105
URETERIC DAMAGE 107
BLADDER DAMAGE 109
BOWEL DAMAGE 112
VASCULAR DAMAGE 112
UTERINE PERFORATION AND FALSE PASSAGE 114
LAPAROSCOPY 114
KEY POINTS 115

Introduction

In major surgery, occasional damage to vital structures is unavoidable, but with good training, appropriate experience and careful application, such damage should be rare. Timely recognition of potential problems has a major impact on the long-term outcome for patients. The request for appropriate assistance from a more experienced colleague, either within the specialty or from another specialty, and early repair, preferably during the original operation, can make the difference between complete and rapid recovery and long-term morbidity and further surgery.

To minimize complications, a surgical technique should be developed that involves careful and accurate identification of tissue planes, preferably with sharp dissection, with the aim of causing the minimum of damage to tissues and structures that are to be preserved. A gentle approach should be used and tissues handled in such a way as to maintain optimum viability.

One should operate under direct vision at all times. The temptation to push an instrument deep into a plane of dissection should be avoided, since inadvertent damage may be caused and bleeding down a deep hole is more difficult to control. Sufficient time should be allowed for each operation, and surgery should not be hurried. Particularly when in training, greater speed will develop by a methodical attention to detail of technique rather than by hurrying individual cases, and outcome is always more important than operative time.

Every case undertaken should be seen as an opportunity to improve technique. Straightforward cases are particularly useful for the practice of sharp dissection to the correct tissue planes. When tissue planes are more difficult to identify, this practice will be invaluable.

One should aim to keep the operation under control at all times; it is much better to spend a little time controlling bleeding, so that the operation can proceed unhurriedly and with good visibility, than to rush on hoping to stop the bleeding as the operation progresses.

This chapter will discuss the common intraoperative complications, and the aspects of technique that reduce the likelihood of these complications occurring. The chapter will also highlight the range of methods used to repair damage, although for the most part, detailed descriptions are not appropriate in a textbook of this type.

The Route

The provisional decision whether to use an abdominal or a vaginal approach for hysterectomy should be made before theatre, but the final assessment of suitability for vaginal hysterectomy is performed under anaesthesia. Each surgeon has personal criteria for attempting vaginal hysterectomy that are based upon training and experience. While some advocate the vaginal removal of large fibroid uteri, most gynaecologists adopt a more cautious approach. Some have also described the removal of normal-sized ovaries, with or without the fallopian tubes, by a vaginal approach, but this requires both special training and instruments. In the event of difficulty, the surgeon should not hesitate to change to an abdominal approach.

Opening and Closing the Abdomen

The layers of the anterior abdominal wall include skin, subcutaneous fat, rectus sheath and oblique abdominal muscles, transversalis fascia and peritoneum. Within these structures lie segmental arteries, veins and nerves that supply the dermatomes and myotomes, and also the epigastric vessels (Figure 8.1). Abdominal incisions have been developed that preserve function as well as possible and which heal rapidly with good strength. Commonly used incisions are shown in Figure 8.2.

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Figure 8.1 Dermatomes.

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Figure 8.2 Abdominal incisions.

It should not be forgotten that inappropriate wound closure technique can increase the risk of pulmonary complications and death (Niggebrugge et al 1999). While some surgeons prefer to use electrocautery rather than a cold scalpel to open the wound, there seems to be no difference in the early or late complications in midline incisions (Franchi et al 2001).

Incisions

The vertical midline incision avoids all major nerves, vessels and muscles by dividing the rectus sheath. It gives good access to the whole of the abdomen except the subdiaphragmatic areas, and is a very fast incision to make. Its principal drawback is that it heals slowly and suffers from a high incidence of wound dehiscence and incisional hernia. The development of improved sutures and technique has dramatically reduced these complications. A midline incision should always be closed using the ‘mass closure’ technique. This involves 1-cm-deep bites of the rectus muscle and peritoneum in a continuous closure, with sutures placed 1 cm apart. The suture material used does not affect the rates of dehiscence or infection, but incisional hernia is more common if braided absorbable material is used (Rucinski et al 2001). The same meta-analysis showed that incision pain and suture sinus formation are more common after non-absorbable material is inserted. Absorbable monofilament used in a continuous mass closure gave the best results.

The paramedian incision is only included for historical interest. The layered closure that was used improved strength when catgut sutures were employed, and reduced the incidence of dehiscence. It is inferior to the mass closure technique described above, and does not provide improved access to either side of the abdomen.

The majority of gynaecological surgery is performed through a transverse incision, usually a Pfannenstiel incision. By dividing each layer in a different direction, the function is well preserved. Even the muscle-cutting variants of the transverse incision heal more rapidly than vertical incisions. The cosmetic result is superior and, if correctly placed, access to the pelvis is good, although access to the pelvic brim is limited. This incision is difficult to extend if improved abdominal access is required.

The Maylard incision involves dividing all layers in the line of the skin incision and also divides the inferior epigastric vessels. The rectus sheath is not separated from the muscle and closure is in layers, leaving the muscle to be drawn together by the sheath. This incision provides improved access to the pelvic side wall when compared with the Pfannenstiel incision, and is useful for oncological surgery. Many centres now use this incision or a Pfannenstiel incision for radical hysterectomy (Orr et al 1995, Scribner et al 2001).

The Cherney incision is similar to the Pfannenstiel incision but the rectus muscles are divided 1 cm from their insertion into the symphysis pubis. The incision is closed in layers, but the muscle is repaired using a continuous suture in the membranous distal portion of the muscle. This incision can also be useful in oncological surgery or, if placed lower, is useful for complex urogynaecological procedures.

The Rutherford–Morrison incision involves dividing all layers in the line of the incision and is particularly useful for approaching ovarian masses in the second half of pregnancy. The incision is closed in layers and heals well.

Drains

Drains are used either therapeutically, to remove pus, infected material and products from an abscess, or to prevent accumulation of blood, pus, urine, lymph, bile or intestinal secretions. There is little evidence to support the use of prophylactic drains. In abdominal incisions, drains have been used in an attempt to reduce the incidence of haematoma and wound infection. Unfortunately, they tend to introduce organisms into an otherwise clean area and increase the incidence of wound infection (Cruise and Foord 1973). In addition, pelvic drains do not reduce infection following radical pelvic surgery (Orr et al 1987). Careful attention to haemostasis is preferable and drains should be avoided in most closures.

Closure of peritoneum

This practice has been questioned recently. Research in animal models has suggested that closure of the peritoneum increases rather than decreases peritoneal adhesions. Human studies support this finding, showing that closure of the pelvic peritoneum does not reduce the incidence of postoperative adhesions or obstruction (Table 8.1; Tulandi et al 1988). The peritoneum spreads rapidly across any raw areas left after surgery, although devascularized tissue, such as pedicles, are a focus for adhesion formation. Practice still varies with regard to peritoneal closure, although it probably results in increased adhesion formation (Royal College of Obstetricians and Gynaecologists 1998). However, if a suction drain is used in the wound, the peritoneum must be closed to avoid drawing the bowel into the wound.

Table 8.1 The effect of peritoneal closure on wound infection and adhesion formation.

  Closed (%) Not Closed (%)
Wound infection 3.6 2.4
Adhesions 22.2 15.8
Obstruction 1.6 0

Source: From Tulandi T, Hum HS, Gelfand MM 1988 Closure of laparotomy incisions with or without peritoneal suturing and second look laparoscopy. American Journal of Obstetrics and Gynecology 158:536, with permission of Elsevier.

Ureteric Damage

Ureters are the organs most respected by gynaecologists. They lie close to the genital tract and repair of a damaged ureter is technically demanding, with results that are not always satisfactory. By recognizing when and where the ureters are at greatest risk and by adopting a safe technique, the risk of damage to the ureter should be minimized.

Anatomical relations

The urinary and genital tracts are closely related in embryological development, and their anatomy and physiology, not surprisingly, are intertwined. The ureter develops from a bud on the posterolateral border of the mesonephric duct near the cloaca, which elongates and eventually fuses with the developing kidney. The ventral portion of the cloaca develops into the urethra, bladder and lower portion of the vagina.

The ureters enter the pelvis by crossing the common iliac arteries in the region of their bifurcation. They descend on the pelvic side wall, medial to the branches of the internal iliac arteries and lateral to the ovarian fossae. From there, they run on the anterior surface of the levator ani muscles lateral to the uterosacral ligaments to pass beneath the uterine arteries, 1–1.5 cm lateral to the cervix and vagina. The ureters then swing medially around the vagina, to enter the bladder 2–3 cm below the anterior vaginal fornix.

The ureter is accompanied by a plexus of freely anastomosing fine vessels running in the loose tissue surrrounding it. The blood supply in the upper portion is derived from the renal and ovarian vessels; in the middle third from branches of the aorta, common iliac and internal iliac arteries; and in the lower part from branches of the uterine, vaginal, middle haemorrhoidal and vesical arteries. The ureter may be mobilized extensively provided this plexus of vessels is preserved.

The ureter is at risk during gynaecological surgery in four regions: at the pelvic brim where it can be confused with the infundibulopelvic ligament; lateral to the ovarian fossa where it can be adherent to an ovarian mass; in the ureteric tunnel beneath the uterine artery; and anterior to the vagina where it runs into the bladder.

The ureter at the pelvic brim and ovarian fossa

At the pelvic brim, the infundibulopelvic ligament with the ovarian vessels also crosses the iliac vascular bundle, usually 1–2 cm distal to the bifurcation of the common iliac artery and the ureter (Figure 8.3). At this point, the ureter and the ovarian vessels are running in parallel in a similar plane and may be confused if care is not taken. Occasionally, the ureter may be duplex. Where the ureter runs lateral to the ovary, it will almost inevitably be associated with any inflammatory or malignant mass. Happily, it will lie on the lateral aspect of the mass where it can be identified and dissected free, usually without difficulty, although in patients with endometriosis, the ureter may be fixed in dense fibrosis.

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Figure 8.3 Relationship of ureter to ovarian vessels in the infundibulopelvic ligament. Note how close the ureter lies to the ovarian vessels at the pelvic brim.

The key to the safe identification of the ureter on the pelvic side wall is to open the peritoneum and dissect in the retroperitoneal space. This is most easily done by dividing the round ligament between two clips, dividing the peritoneum in a cranial direction 1.5 cm lateral to the ovarian vessels and in a caudal direction down towards the uterovesical fold. The loose areolar tissue then encountered should be separated by blunt dissection with careful diathermy of any small vessels. The ureter will lie on the lateral aspect of the leaf of peritoneum reflected by this manoeuvre. At this stage, the infundibulopelvic ligament can be safely divided with the ureter under direct vision. If the anatomy of the pelvic side wall has been distorted, this technique will almost always allow the ureter to be identified and followed within the pelvis. If an ovarian mass is present, the ureter may be dissected free from the mass in this retroperitoneal plane.

The lower ureter

The third position where the ureter is at risk is in the ureteric tunnel, where the ureter crosses beneath the uterine artery but superior to the cardinal ligament and approximately 1–1.5 cm lateral to the angle of the vagina (Figure 8.4

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