Introduction
Reoperative pelvic surgery is one of the most difficult challenges a colon and rectal surgeon can face. Anatomic, postsurgical, and disease-specific factors combine to present unique challenges with significant potential for major morbidity and even mortality. This is not the occasion for hubris or poor judgment. However, with a thorough understanding of normal and postsurgical anatomy, experience in operating in the pelvis, appropriate planning, sound judgment, and a methodical team approach, a successful outcome may be achieved.
Anatomic Factors
The pelvis is a bony cavity with limited visibility and access. The limitations are due to multiple factors: its bony walls, its angulation, the narrowness and depth of the male pelvis, and patient obesity. The pelvis contains complex gastrointestinal, urologic, gynecologic, and neurovascular structures that are in danger during pelvic surgery, and especially during reoperative pelvic surgery. Particularly vulnerable are the ureters, the presacral veins, and the pelvic nerves.
The Ureters
The distal ureter is a retroperitoneal structure that enters the pelvis by passing over the bifurcation of the common iliac artery. It then runs along the lateral pelvic sidewall beneath the investing parietal pelvic fascia before turning upward and medially to enter the trigone of the bladder.
Presacral Veins
The presacral veins run beneath the thickened parietal pelvic fascia that covers the sacrum and coccyx, which is often referred to as the presacral fascia. These veins form a plexus over the lower part of the sacrum and connect with the large basivertebral veins. There are no valves in the connecting veins to prevent or minimize back bleeding, and the connecting veins themselves are fused to the sacral foramina. They cannot contract. Presacral venous bleeding is usually low pressure but resists attempts at control by suture or cautery.
Pelvic Nerves
The sympathetic nerves originate from the hypogastric plexus above the bifurcation of the aorta and coalesce around the inferior mesenteric artery to form the discrete hypogastric nerves. These nerves then cross the pelvic brim behind the presacral fascia to pass laterally into the pelvis. Pelvic parasympathetic nerves join them to form the pelvic autonomic nerve plexus. Nerves from this plexus pass anteriorly and medially to the bladder, urinary sphincter, rectum, and genital organs, separated from the anterior rectum by Denonvilliers fascia, which may be seen as a discrete white layer in some cases.
Postoperative Changes in the Pelvis
Pelvic surgery can cause a variety of changes to pelvic anatomy. Small bowel may fall into the pelvis and become adherent, sometimes in a dense manner, and must be mobilized before any pelvic work can begin. A previously mobilized rectum sinks deep into the pelvis and often will become fixed to its surroundings and difficult to mobilize. A short rectal stump may retract down to the pelvic floor and not be apparent at all. Similarly, a mobilized ureter can be in a markedly ectopic location, often migrating medially and being fused to intestine or its mesentery, where it is at risk of injury. The usually well-defined fascial planes are often obliterated and may be very difficult to delineate and follow. This situation is of particular relevance with regard to the autonomic nerves and presacral veins, which normally sit behind the endopelvic or presacral fascia. Disturbance of these fascial planes exposes the nerves and veins to damage. Finally, disease or treatment-specific factors such as sepsis, recurrent cancer, irradiation, and obstruction all can add significant difficulty to a surgical approach.
Approach to Reoperative Pelvic Surgery
Strategy
Planning reoperative pelvic surgery demands a realistic analysis of the benefits to be gained and the risks to be run. This analysis is an important part of any surgery but assumes critical importance for a procedure in which the risks are unusually high. Patients must understand the risks and have realistic expectations. The option of performing no surgery at all must be discussed.
Preoperative Planning
Timing
Appropriate timing of a repeat operation may reduce the difficulty and potential complications attributable to adhesions. Early reoperative pelvic surgery is usually an emergency, and thus all efforts are directed to dealing with the urgent problem. Even for emergency surgery, there is a window of about 10 to 14 days before postoperative adhesions reach their most dense and dangerous. After this period, there is a significant risk of iatrogenic injury to the bowel because the inflammatory nature of the adhesions at this point in their development predisposes to bowel injury. It is preferable to wait at least 3 months before performing a repeat operation. If something must be done to divert stool to manage sepsis, approaches such as percutaneous abscess drainage, proximal fecal diversion, or parenteral nutrition can buy time. Factors that may make adhesions worse include sepsis, ischemia, and irradiation. If these factors are present, a repeat operation should be delayed at least 6 months.
Patient Preparation
The patient’s nutritional state should be optimal, and comorbidities should be treated. Long operations, underlying malignancy, and big incisions increase the risk for postoperative atelectasis and pneumonia, as well as deep venous thrombosis. Aggressive deep venous thrombosis prophylaxis may sometimes require caval filter placement. Mechanical bowel preparation is a matter of preference, and many surgeons now believe it is not routine or mandatory.
Define the Anatomy
The preoperative strategy may be aided by imaging and endoscopy if the exact details of the prior operation are unclear or unreliable. Knowing the length of a rectal stump or whether there may be an unexpected “stump blowout” or abscess is very helpful. Computed tomography (CT) scanning and magnetic resonance imaging (MRI) also may provide a road map of pelvic anatomy when a significant interval change has occurred as a result of a treated abscess or anastomotic leak.
In the case of malignant disease, it is essential to exclude unresectable pelvic cancer or distant metastatic disease that would preclude a curative procedure. Whereas clinical features such as nerve root or sciatic pain suggest unresectability, determining resectability of malignant pelvic disease on clinical-pathologic grounds alone can be unreliable. CT and/or MRI can identify features associated with either a significantly lower chance of resectability (pelvic side wall involvement and ureteric obstruction) or features more often amenable to curative resections (anterior pelvic or isolated anastomotic recurrence). Positron emission tomographic–CT scanning is also routinely performed in the case of malignant pelvic recurrence. In the absence of sepsis it is usually sensitive and specific for recurrences greater than 1 cm. Identification of liver or lung metastases that are not amenable to resection also may discourage a highly morbid palliative pelvic operation. Positron emission tomographic-CT scanning is also useful in distinguishing postoperative changes from locally recurrent malignant disease in the pelvis.
Anticipate and Prepare for a Difficult Case
Blood should be cross-matched and the availability of clotting agents, such as platelets, fresh frozen plasma, and cryoprecipitate should be confirmed in case massive transfusion is required. Many institutions now have protocols for massive transfusion in which specific additional blood products and clotting factors are given routinely after a specific amount of transfused blood.
Having the right operation at the right time of day by the right surgical team is well worth the investment. One should start early, have experienced help, and forewarn anesthesiologists and other subspecialists who may be needed, such as urologists or gynecologists. Anesthesiologists must be given time to place appropriate lines for rapid volume administration and monitoring.
Functional Considerations
Although avoidance of a permanent stoma is a laudable goal, the likelihood of good function, continence, and patient satisfaction often can be predicted preoperatively by examining factors such as age, anal tone/squeeze, extent of intestinal resection, prior irradiation, and prior pelvic sepsis. Proper informed consent should take these factors into consideration, and when appropriate, a permanent stoma should be part of the discussion.
Intraoperative Conduct
Patient Positioning
Careful positioning and padding are essential to avoid injury due to pressure or poor positioning during a long operation. A bean bag or a foam pad are good choices and help prevent the patient from slipping down the table if a steep Trendelenburg position is applied. Both arms should be tucked securely at the patient’s side even if the patient is obese so as not to limit the room required to obtain adequate access. The legs are placed in carefully positioned and padded Allen or yellow fin stirrups. The hips are not overflexed, which would interfere with a self-retaining retractor placed in the most distal aspect of the wound. Neither are the hips overextended, in the interest of avoiding stretch injury to nerves in the anterior compartment of the thigh. The patient is prepared from the xiphoid to the perineum and draped so that access to the perineum can be obtained without contaminating the abdominal field.
Optimizing Visibility and Exposure
A long midline incision is the standard approach, with the distal end carried down to the pubis and the proximal incision as far cephalad as needed. Safe entry to the abdomen may need to be above the umbilicus, away from prior dense adhesions or fistulas. Enterocutaneous fistulas are left in place until the bowel around them is fully mobilized to minimize contamination and avoid injury to uninvolved bowel. A self-retaining retractor is used, although a variety of retraction systems are available. A bladder blade can be attached to the self-retaining retractor and is tightened up against the pubic bone. A large chromic suture can be placed in the dome of the uterus and then tied around the bladder blade to pull the uterus up out of the pelvis. Once the small bowel has been brought up out of the pelvis, placing the patient in the Trendelenburg position will help keep the pelvic field clear, or it may be packed away using a “C” arm retractor or a broad malleable retractor bent into a “U” shape.
Excellent overhead lighting is essential and can be supplemented by a lightweight fiber-optic headlight, as well as lighted retractors. A number of specialized pelvic retractors are available that are long and curved to fit the shape of the pelvis and can be attached to a fiber-optic light source. The lighted Deaver retractor ( Fig. 82-1 ) has a relatively shallow curve and is a short, broad instrument that is ideal for the early part of the posterior rectal dissection. Deeper in the pelvis we use the deep pelvic retractor, which comes with distal blade widths from 25 to 50 mm and has two styles of handle, one named after the senior author who helped develop it ( Fig. 82-2 ). It is especially useful in lifting the rectum upward and forward with some degree of force to accentuate the correct plane of dissection behind the rectum. In addition, it can be used to retract the bladder and prostate or vagina forward to assist with anterior visualization and dissection. An alternative is the St. Mark retractor, which also comes in a curved and lighted model ( Fig. 82-3 ).
