W Brian Perry, Fia Yi, Clarence Clark, and Danny Kim
A 64-year-old woman is 7 days s/p an abdominopernneal resec-tion for a T2N1 rectal adenocarcinoma. She had received preop-erative. Her perineal wound has developed increased tenderness, is swollen, and is draining pus.
The patient’s wound is opened and the patient is started on three times a day dressing changes.After 2 days the wound is clean and a vacuum assisted closure (VAC) dressing is placed.
Abdominoperineal resection (APR) completely removes the dis-tal colon, rectum, and anal sphincter complex using both ante-rior abdominal and perineal incisions, resulting in a permanent colostomy. Developed more than 100 years ago, it remains an important tool in the treatment of rectal cancer despite advances in sphincter-sparing procedures. We will examine a brief history of this procedure, current operative techniques and complica-tions,expected results,(both oncologic and with regard to quality of life), and what the future may hold for this procedure.
Several recent reports have noted the increase in the use of sphincter-sparing options for patients diagnosed with rectal can-cer.Abraham and colleagues found a 10% decrease (60.1–49.9%) in the rate of APR from 1989 to 2001 as compared with low ante-rior resection (LAR) using national administrative data.(1) When controlled for several variables, including patient demographics and hospital volume, patients were 28% more likely to have an LAR later in the study period. Schoetz notes that LAR outnum-bers APR three to one in the submitted case logs of recent color-ectal fellows.(2) This ratio is similar to that found in the Swedish rectal cancer registry, where approximately 25% of over 12,000 patients with rectal cancer underwent APR from 1995–2002.(3) In no study or registry, however, has APR been eliminated.
Early in the twentieth century, most patients with rectal cancer underwent perineal procedures to address typically advanced, symptomatic disease. These included the transcoccygeal Kraske approach and the transsphincteric approach developed by Bevan in America, later attributed to A.York Mason. Patients were typi-cally left with profound sphincter dysfunction or fistulae follow-ing a protracted recovery. A two-staged operation, consisting of an initial laparotomy and colostomy followed by perineal excision, was used until the 1930’s with reasonable results.
The operation we now know as APR was first described by Miles in 1908, but initial reports showed a high operative mortal-ity,upto42%.Improvementsinperioperativecarethatcamelater reduced this considerably. Refinements in technique continued through the first half of the twentieth century. Gabriel described
the operation in one stage, with the abdominal portion done supine and the perineal portion done in the left lateral position. Lloyd-Davies’ synchronous approach to the abdomen and peri-neum with the patient in the lithotomy position eliminated the cumbersome and sometimes dangerous need to reposition the patient while under anesthesia.(4) Recent advances have included total mesorectal excision in patients undergoing APR and the addition of methods to enhance perineal wound healing, espe-cially in patients who have received neoadjuvant chemoradiation. Minimally invasive techniques are also being applied to APR,with good initial results.
PAtient PrePArAtion And Positioning
Preparation for abdominoperineal resection starts with marking the ideal placement of the colostomy by the primary surgeon or enterostomal nurse.(5) Patients are instructed to take a mechani-cal bowel preparation the day before surgery consisting of sodium phosphate solution or polyethylene glycol.Placement ofan epidural catheter may be considered to improve postoperative analgesia and to reduce postoperative ileus.(6) Before induction of general anesthesia, intermittent pneumatic compression devices are placed on the lower extremities to reduce the risk of venous thromboem-bolism.(7) Intravenous antibiotics with efficacy against enteric flora are administered 60 minutes before incision to decrease rate of surgical site infection.(8) The abdomen and perineum are prepped and appropriate monitoring is placed.
After induction of anesthesia,a urinary catheter is inserted;ure-teral stents should be considered if the patient has had prior pelvic surgery,tumor extension into the urinary tract,or prior pelvic radi-ation. The patient is placed in the lithotomy position using Allen stirrups with padding to prevent lower limb acute compartment syndrome.(9) Positioning also includes symmetric hip extension, knee flexion,and thigh abduction (Figure 27.1).Ultimately the legs are balanced in the stirrups, such that the weight is resting on the feet and the ankle and knee are in line with the opposite shoulder. Arectalexamisperformedunderanesthesiafollowedbyirrigation with dilute betadine solution to remove any residual stool.
The operative technique used today varies little from Ernest Miles’ description in 1908.(10) Unlike Miles’ method we prefer the two-team approach with the patient in lithotomy position rather than lateralsemi-proneposition.Anonabsorbablepurse-stringsutureis placed around the anus.The abdomen and perineum are prepared with antiseptic solution and draped with openings for the abdomi-nal and perineal dissections.The abdomen and pelvis are accessed through a midline hypogastric incision that extends to the right of or through the umbilicus. The abdomen is explored for meta-static disease and synchronous colon lesions.After confirmation of resectability, a self-retaining retractor is placed.
Figure 27.1 Leg positioning for abdominoperineal resection.
The small bowel is packed into the upper abdomen with a moist towel. The sigmoid and descending colons are then mobilized at the white line of Toldt in the left lateral gutter. After confirming adequate mobilization of the descending colon for an end colos-tomy, the left ureter is identified and preserved. The peritoneum incision is carried anterior followed by incision of the right lateral peritoneum. The right ureter is identified and preserved and the peritoneal incisions are connected anteriorly at the base of the bladder. For convenience, the proximal sigmoid can be divided with a linear stapling device and the cut end used as a handle to aid with the dissection. A finger is passed below the inferior mesenteric vessels with the plan to leave the sigmoid branches. This helps minimize vascular compromise of the stoma. It is unnecessary to ligate the inferior mesenteric artery at its origin as this has not been shown to increase survival.(11)
The superior hemorrhoidal vessels are transected. The presacral space is entered without breaching the endopelvic fascia and with
preservation of the mesorectum consistent with Heald’s descrip-tion of total mesorectal excision.(12) After identifying this avas-cular plane, the dissection is aided by using a lighted St. Mark’s retractor to hold the mesorectum anteriorly. As the dissection continues distally,Waldeyer’s fascia is divided with electrocautery or sharply to avoid injuring the presacral venous plexus.Staying in the avascular plane posteriorly and laterally minimizes bleeding.
The lateral ligaments are cauterized or suture-ligated close to the pelvic side wall to maximize the radial margins.Denonvillier’s fas-cia in males is dissected down to the pelvic floor anteriorly.Unless the tumor is anterior,it is not necessary to expose the seminal vesi-cles in males thus avoiding injury to the nervi erigentes.In females, the presence of an anteriorly based tumor may require perform-ance of a posterior vaginectomy. When the pelvic floor is reached circumferentiallyaroundtherectum,theabdominalportionof the dissection is completed. Once the pelvic dissection is completed, the colostomy is created and the abdomen is closed.
improved outcomes in colon and rectal surgery
When the abdominal operator has determined that the lesion is resectable the perineal dissection begins simultaneously with the abdominal portion of the case. The perineal dissection begins with an elliptical incision from the perineal body in males or the posterior vaginal introitus in females to a point midway between the anus and coccyx. The incision should include the entirety of the external sphincter muscle, but does not need to extend laterally to the ischial tuberosities. Dissection is car-ried down to the levator ani muscles with cautery to minimize bleeding. The inferior hemorrhoidal arteries located posterior-laterally are ligated. Using a finger on the tip of the coccyx as a guide, the posterior dissection is directed anterior to the coccyx and the anococcygeal raphe is divided. When all that remains are the anterior attachments,the specimen is drawn through the opening and used to provide traction to continue the remain-ing dissection. The specimen is then removed and the pelvis is irrigated. If sufficient levator muscle remains, the pelvic floor is reapproximated to reduce the risk for perineal herniation. Drains are placed and secured followed by closure of the skin with interrupted permanent or absorbable monofilament suture in a vertical mattress fashion.
PreservAtion of sexuAl And urinAry funCtion
As described by Kyo et al.the neuroanatomy begins with the sym-pathetic nerve fibers that travel through the lumbar splanchnic nerves to the superior hypogastric plexus and then divide into two hypogastric nerves. Parasympathetic fibers emerge from the second, third, and fourth sacral spinal nerves as the pelvic splanchnic nerves and join the hypogastric nerves to form the inferior hypogastric (pelvic) plexus. The pelvic plexus is rectan-gular and its midpoint is located at the tips of the seminal vesicles on either side of the rectum (Figure 27.2). The most caudal por-tion of the pelvic plexus travels at the posterolateral border of the prostate, lateral to the prostatic capsular arteries and veins and reaches the hilum of the penis.(13)
The rate of urinary dysfunction and impotence after rectal sur-gery ranges from 33% to 70% and 20% to 46%, respectively, while 20–60% ofpotent patients are unable to ejaculate.(14) A surprisingly large proportion of patients suffer various urinary tract problems and sexual problems due to extended lymphadenectomy involving the hypogastric nerve plexus. Therefore, preservation of the pelvic autonomic nerves lowers the incidence of sexual and urinary mor-bidity. With preservation of the superior hypogastric nerve plexus, ejaculation is maintained in 90% of the patients.(15)
Utilizingprecisedissectionwithpreservationofautonomicnerves Kim et al. noted an erection rate of 80%, penetration ability rate of 75% with only 5.5% of patients in their study reporting complete inabilityforerectionandintercourse.StudybyShirouzuetal.showed oncologic equivalence between previously described extensive resec-tion pre-1984 and plexus preserving low rectal surgery post-1985 with local recurrence rates 9.1 and 3.9%, respectively and 10-year, disease-free survival rate of 77% and 81.5%,respectively.No signifi-cant difference was noted among the groups.(16)
Methods of Closure
The perineal wound can be packed open, partially closed, or completely closed. The peritoneal defect above the pelvic space
Figure 27.2 Nerve supply to the rectum.
can also be sutured closed or left open. Adjunctive procedures such as drainage of the pelvic space, with or without continuous irrigation, and omental plugging may also be considered.
Rates ofprimary healing after perineal wounds are closed range from 4% to 92%.(10, 17, 19) Open packing relegates all wounds to secondary healing, is inconvenient, and often painful but may result in a lower rate of chronic perineal sinus formation.(19) Closure of the pelvic peritoneum has been advocated to prevent perineal evisceration and postoperative small bowel obstruction. However, it may prevent obliteration of the pelvic cavity, lead-ing to formation of a persistent perineal sinus.(20) Loops of small bowel may also become incarcerated in small defects in the peritoneal closure, resulting in postoperative bowel obstruction.
Two studies compared various methods of peritoneal and peri-neal closure. Irvin and Goligher (19) prospectively randomized 106 patients undergoing proctectomy to one of three methods of perineal closure: open packing of the perineal wound; primary closure of the perineal wound without closure of the pelvic peri-toneum with suction drainage of the pelvis; and primary closure of the peritoneal and perineal wounds. The overall complication rate was high: repeated surgery was necessary in 21% of patients in the open packing group, most often because of hemorrhage, and in 25% and 19% of the two closed groups, most commonly for drainage of abscesses.Primary healing occurred in 45% of the patients with primary closure of both the perineum and perito-neum and in 43% of patients with open peritoneal and closed perineal wounds.
In a prospective study part of a multicentre trial in Germany, Meyer et al.published a standardized technique ofperineal closure that reduced wound complication rates from 17% to 5.4%. The principle oftheir approach was to close the perineal wound tightly in multiple layers (specifically the muscle and ischiorectal as well as subcutaneous fat) which help to avoid the accumulation offluid
within the wound cavity. The residual amount of fluid is then removed by closed suction drainage. Additionally, it is thought that the addition of antibiotic carriers provides local infectious prophylaxis leading to lower rates of perineal wound infection. (21) This has also been demonstrated in two other prospective randomized studies and can be considered an adjunct in decreas-ing the overall morbidity of the perineal wound.(22, 23) Myocutaneous flaps have been increasingly utilized in the initial repair of the perineal defect, especially in patients who have had preoperative radiation therapy. Chessin et al. at Memorial Sloan Kettering reviewed their experience with rectus abdominis myocutaneous (RAM) flap closures of the perineal defect. ComparingtheRAMflapgrouptoahistoricalcontrol,theyfound that the incidence of perineal wound complications was 15.8% in the RAM flap group compared to the 44.1% in the control.(24) Butler et al.also looked at vertical rectus abdominis myocutaneous flaps in previously irradiated patients undergoing APR.There was a significantly lower incidence of perineal abscess (9% vs. 37%), major perineal wound dehiscence (9% vs. 30%) and drainage procedures required for perineal or pelvic fluid collections (3% vs. 25%).(25)
In an effort to fill the pelvic space after rectal resection, Page et al. advocates an omental plug. They describe mobilization of the omentum on the left gastroepiploic arterial pedicle,with sub-sequent placement in the pelvis. Advantages include increased local blood flow and lymphatic drainage, and obliteration of the pelvic space. The omental plug also has the advantage of keeping the small bowel out of the pelvis,thereby decreasing the chance of radiation enteritis in patients who require postoperative radiation therapy. The authors report primary healing in 26 of 34 patients (77%).(26) A recent publication by PJ Nilsson reviewed all avail-able English language publications on the use of omentoplasty in APR wound closure. Primary wound healing was the primary outcome measure. Most authors reported positive results after omentoplasty and one study showed significant improvement in perineal healing rate at 6 months. Significant reduction in sinus formation and wound dehiscence also was reported.(27) Despite these promising results, there needs to be randomized trials with well-described patient categories, end points and follow up to firmly assess whether omentoplasty should be a standard part of the wound closure.
Abscess formation, intraperitoneal or of the perineal wound, is the most common major complication after APR.(17) Incidence of abscess formation ranges from 11% to 16% (17, 18, 28). In some small series, the incidence of perineal wound infection is 100%.(19) This can be attributed to the large dead space remain-ing after resection of the rectum and from fecal contamina-tion. In a retrospective review of patients who had neoadjuvant chemoradiation followed by APR, Butler observed that there was a significant decrease of perineal abscess formation (3% vs. 37%) after the placement of a vertical rectus abdominis myocu-taneous (VRAM) flap to the perineum. The well-vascularized flap eliminates the dead space in the pelvis, reducing the risk of
fluid collection. The use of a VRAM flap should be considered in patients who are at high risk for postoperative perineal wound complications.(25) Alternatively,an omental pedicle flap sutured to the perineal wound has been observed to decrease the rate of abscess formation.(29)
Incision and drainage with local wound care is the treatment of choice for local perineal wound abscesses. There is a small increased risk of developing a perineal sinus after opening the skin of a subcutaneous abscess.(30) Thus if the incision is heal-ing well, the abscess may be amenable to percutaneous drainage. In addition, percutaneous drainage is the preferred treatment of presacral and pelvic abscesses.(31)
Hemorrhage during surgery can usually be attributed to an error in technique, but when faced with a pelvis that had previously received radiation therapy, hemorrhage may be unavoidable.
Bleedingmayoccurwhendissectionbeginsatthesigmoid.This is usually easily identified and controlled.In the previously irradi-ated pelvis,planes become distorted making it difficult to identify vital structures.It is easy to stray laterally,which may result in iliac vessel injury. These must be repaired immediately to avoid pro-longed hemorrhage. In a pelvis that has not received radiation, or if there is minimal fibrosis, meticulous dissection in the proper plane down to the lateral stalks usually yields minimal bleeding.
The most troublesome bleeding in the pelvis comes from the posterior dissection along the sacrum. Very rarely, there will be a prominent medial sacral artery that may be injured. More com-monly, the bleeding from the sacrum will come from the venous plexus.If present,the basivertebral vein,which connects the inter-nal vertebral venous system to the presacral system, can bleed profusely and be difficult to control. Ideally, by taking sharp dis-section down the presacral plane,there should be little to no bleed-ing.(32,33)Unfortunatelythisspacemaybenonexistentincertain patients or obliterated in an irradiated field.Bleeding from the sac-rum can be controlled by packing, suture ligation, electrocautery, finger compression, or thumbtack compression.
Thumbtack compression is a quick,safe,and effective method of controlling sacral bleeding.There are several commercial applica-tion devices available;however,using a clamp or forceps with finger applications works equally as well (Figure 27.3).Thumbtacks also prevent damage to the surround venous plexus that may occur when using the other methods of attempting hemostasis, such as direct suture ligation or excessive cauterization.(33, 34)
Bleeding after the completion of the surgery is uncommon (<4%) and is most commonly associated with perineal wounds that are packed open.(35) When the perineal wound is packed open, it is hemostatic until the first dressing change when the tampon-ade is released. As the packing is removed, it may pull away clot from surrounding tissues that can result in more bleeding. Conservative treatment can be attempted with adequate resusci-tation if needed,a reapplication of packing,and placement of the patient on strict bed rest. If the patient remains stable, the pack-ing may be removed in 48–72 hours.(36) Occasionally, reopera-tion is necessary to control postoperative perineal hemorrhage.
improved outcomes in colon and rectal surgery
Figure 27.3 Thumbtack occlusion of bleeding basivertebral vein.
Given that nearly all APR wounds are currently closed primarily, this complication is rare.(37, 38)
Perineal Wound Complications
When comparing abdominoperineal resection with other abdom-inal and pelvic procedures,the most striking difference is the peri-neal dissection and ensuing perineal wound. Treatment of this wound has long been the center of debate and controversy. Miles in his original description in 1908, recommended open packing, andhistechniqueisstillusedbysomesurgeons.Overthefollowing 75 years, many techniques to treat the perineal wound have been developed, including partial closure, primary closure, and closure with continuous irrigation or omental plugging. For purposes of discussion, perineal wound complications of abdominoperineal resection can be divided into four categories:hemorrhage,abscess, perineal sinus, and perineal hernia.
Non Healing Wound and Perineal Sinus Perinealsinusisdefinedasaperinealwoundthatremainsunhealed foraminimumof 6months.Characteristicsincludeafixedfibrotic pelvic cavity,a long,narrow track lined with a thick unyielding peel, and a small external opening.(39)
Silen and Glotzer compared the pelvic space after APR with the fixed pleural space after pneumonectomy. The pelvic space is bound posteriorly and laterally by the rigid bony pelvis, ante-riorly by the relatively unyielding genitourinary structures, infe-riorly by the slightly mobile perineal floor (if surgically closed), and superiorly by the peritoneal contents. Of all these borders, certainly the peritoneal structures are the most mobile. They contend that the pelvic space after APR is filled not with gran-ulation tissue but with a combination of upward migration of the perineal soft tissues and descent of the peritoneal contents and argue that any forces (either iatrogenic, such as closure of the peritoneum or prolonged packing of the pelvis, or second-ary to complications, such as pelvic abscess or hematoma) that
produce a fixed fibrotic cavity are likely to result in a nonheal-ing perineal wound.(30) Artioukh et al. reviewed their series of APR non healing wounds and found several possible contrib-uting factors, including distant metastases, excessive alcohol consumption, cigarette smoking, transfusion requirement and chemoradiation.
Other studies have also observed the increased risk in peri-neal wound infection and nonhealing in those who have been exposed to radiotherapy.The Swedish Rectal Cancer trial showed an increase in wound infection from 10% to 20% and the Dutch Colorectal Cancer Group had a 31% perineal complication rate even in those exposed to short-course radiation.(40, 41)
Silen and Glotzer recommended that the peritoneal contents be allowed to descend into the pelvis, the space be kept irrigated and well drained to prevent fluid accumulation, and any packing used in the perineal wound be removed early to prevent develop-ment of fibrotic wound edges. Despite the excellent description of perineal healing by Silen and Glotzer and the development of multiple techniques for perineal closure, nonhealing perineal wounds remain a common problem. Bacon and Nuguid noted a 40% incidence of persistent perineal sinus in 1042 patients after rectal resection.(42) In almost 500 patients who underwent APR at the Lahey and Mayo Clinics, 14–24% had unhealed perineal wounds at 6 months.
Inflammatory bowel disease versus carcinoma. Rectal resec-tion is most commonly performed to treat low rectal cancer or inflammatory bowel disease. Often the extent of soft tissue resection is much greater in the treatment of rectal cancer with complete removal of the levator musculature or posterior vagi-nectomy advocated by some versus the intersphincteric proctec-tomy (sparing the external anal sphincter and the levator ani) often used in surgical treatment of inflammatory bowel disease. An increase in perineal wound complications might be expected after APR to treat cancer,but Irvin and Goligher found a 9% inci-dence of unhealed perineal wounds in the treatment of cancer, compared with a 33% incidence in proctectomies performed for inflammatory bowel disease.(19) A more contemporary review of the risk factors for perineal wound complications undertaken by Christian et al. determined that higher rates of major wound complications occurred in patients who had APR performed for anal cancer (50%) as compared to rectal cancer (10%) or inflam-matory bowel disease (8%).The reasons are unclear although the extensive tissue dissection involved in a cancer operation with larger soft tissue loss may be a possibility.(43) There is some evi-dence to support this in studies that have shown that tumor size can be a risk factor for poor wound healing.
Radiation Therapy. Radiation therapy is often used in the treatment of rectal and anal neoplasia both preoperatively and postoperatively.Christian et al.found that preoperative radiation therapy for anal cancer patients appeared to be a risk factor for poor wound healing.Artioukh et al.also found that patients who had received preoperative radiotherapy were prone to wound complications (39% vs. 6.7% who did not have radiotherapy).
Fecal Contamination. Fecal contamination during proctectomy significantly decreases primary healing and may increase the risk