Laparoscopic Abdominoperineal Resection

John H. Marks

Joseph L. Frenkel

INTRODUCTION

While discussing laparoscopic abdominoperineal resection (APR), two major issues come to the forefront. One is the role of laparoscopic surgery in the treatment of rectal cancer, and the other is the indications for APR for low rectal cancer.

The issues of paramount importance regarding laparoscopic surgery in the treatment of rectal cancer include proper performance of TME, as well as visualization and retraction during deep pelvic dissection. The last issue, transection of the distal rectum to perform an anastomosis, is a major one in laparoscopically performing sphincter-preserving surgery in the low rectum. However, this point becomes moot in performing an APR because there is no anastomosis after the sphincter mechanism is excised.

Having performed over 350 laparoscopic TMEs with a local recurrence rate of 3% overall, we feel confident that the laparoscopic approach will be validated as a safe option for rectal cancer. This approach clearly affords a much better visualization in the pelvis and exactness of dissection. In this chapter, we highlight the methods we use to laparoscopically accomplish this operation.

INDICATIONS

Clearly, the issue of sphincter preservation surgery versus permanent colostomy has to do with the level of the rectal cancer, bulk of the tumor, and the patient’s baseline continence. Indications for permanent colostomy include patients with incontinence, patient preference for lifestyle reasons, or direct involvement of the puborectalis. The advent of preoperative chemoradiation therapy has allowed us to alter these indications, greatly diminishing the need for APR. In a multimodal rectal cancer treatment program having treated over 800 cases, we have been able to obtain a sphincter preservation rate of 93%. In the large national trials, APR rates in the past decade have still ranged from 25% to 60%.

Our treatment algorithm for sphincter preservation employing neoadjuvant chemoradiation for low rectal cancers is shown in Figure 35-1. In the properly motivated patient with good sphincter function, the decision regarding sphincter preservation is based on tumor characteristics after completion of neoadjuvant therapy. Only patients whose cancers remained fixed in the distal third of the rectum after completion of chemoradiation therapy undergo APR. Keys to expanded sphincter preservation include (a) basing decisions regarding sphincter preservation on the downstaged rectal cancer after completion of neoadjuvant therapy, (b) a higher dose of radiation therapy to improve downstaging of the rectal cancer to our ideal level of 5,580 cGy, (c) allowing 8-12 weeks following radiation before making a decision regarding surgery, and (d) transanal abdominal transanal (TATA) resection technique for tumors in the distal third of the rectum, which includes an intersphincteric dissection beginning at the dentate line, assuming an adequate distal margin.

It is important to emphasize that the indications for laparoscopic APR are exactly the same as they are for an open APR. Clearly, it is poor trade for the patient to gain the benefits of laparoscopy at the expense of a permanent colostomy.

FIGURE 35-1 Selection scheme for sphincter preservation employing neoadjuvant chemoradiation for low rectal cancers. APR, abdominoperineal resection; CA, carcinoma; CATS, combined abdominotranssacral proctosigmoidectomy; CVI, continuous venous infusion; FTLE, full-thickness local excision; FU, fluorouracil; LAR, low anterior resection; TATA, transanal abdominal transanal.

PREOPERATIVE PLANNING

Patients undergo a standard oncologic evaluation including computed tomography scan of the abdomen and the pelvis and basic lab work, including liver function studies, complete blood cell count, metabolic profile coagulation studies, blood chemistries, and carcinoembryonic antigen level. Endorectal ultrasound is also performed. Oftentimes this assessment is coupled with a magnetic resonance imaging of the pelvis. In patients older than 60 years and in those individuals with coronary artery disease, hypertension, and diabetes, or in smokers, a full preoperative cardiac evaluation is undertaken.

Digital rectal examination and flexible sigmoidoscopic evaluation are performed in the office. Patients are then seen at 3-week intervals during their neoadjuvant treatment until the time of surgery. Final decisions regarding sphincter preservation are made on the basis of digital rectal and flexible endoscopic evaluation between 8 and 12 weeks following their neoadjuvant therapy. In general, patients are treated with 4,500 cGy of radiation to the entire pelvis with a boost of 1,000 cGy to the tumor in the presacral hollow. The limits of this chapter preclude us from being more expansive in this regard. All patients undergo a full bowel preparation and are seen by a stoma nurse preoperatively and marked for a permanent colostomy. This is an essential point because the positioning and function of the stoma will have a major impact on the patient’s quality of life.

SURGERY

Positioning

Generally, patients are positioned in lithotomy. The exception to this rule is the patient with a very large bulky tumor that may require coccygectomy to obtain adequate exposure to the pelvis. In this case, the operation is started with the patient in a right Sims’ position. It is essential that patients are secured firmly to the table because both extreme Trendelenburg and airplaning the table to the “right side down” position will be utilized. This achieves proper retraction of the small bowel, so we can see into the pelvis clearly and position the small bowel out of the way. Shown in Figure 35-2 is our method of securing the patient to the operating room table as well as the overall setup of the operating room that facilitates the procedure.

With the patient in supine position, a strong strap of tape is used to secure the chest to the table. We feel strongly that pads on the shoulders should be avoided because this will predispose the patient to brachial plexus injury.

Technique

Perineal Dissection

It is our preference to start the operation perineally and then proceed abdominally (rendering the operation a perineal-abdominal resection rather than an APR). This is the same strategy that we use in open operations. This order dramatically facilitates the laparoscopic operation, because the most challenging portion of the laparoscopic procedure, the distal-most rectal dissection, has already been done from the perineal approach.

FIGURE 35-2 Setup of operating room to facilitate procedure.

After induction of anesthesia, the patient is placed in stirrups and digital examination is carried out to verify the location of the tumor and make the final determination regarding the need for permanent colostomy. The perineum is prepped and an O-Vicryl suture is used to place a purse string suture around the anal canal, so there is no soilage to the field at the time of surgery. The abdomen and perineum are fully prepped and draped. We find that securing the drapes around the perineum with a few interrupted 2-0 nylon sutures keeps the drapes from moving even when the patient is placed in extended lithotomy position.

As the procedure commences, the patient is put in an exaggerated lithotomy position to gain access to the perineum. A lighted suction device (Vital Vue, Covidien, Norwalk, CT) greatly facilitates the dissection. Electrocautery is used to incise the skin with a 1-cm margin around the anal canal; the size and position of this incision can be adjusted on the basis of tumor location. Dissection continues circumferentially into the fat of the perirectal space. The safest area for the initial approach into the pelvis is the posterior midline. The anococcygeal ligament is incised and the dissection is extended through the levators. At this point, a finger can be placed through the pelvic floor and one can excise a portion of the levators with an adequate margin. In doing this dissection, it is imperative to avoid coning in on the rectum at the levators, because it is this area where tumor margins are at greatest risk. Once one has entered into the plane above the levators, the dissection is brought around circumferentially, taking care in the male patient to avoid going into the prostate anteriorly. Special attention needs to be paid to the infraprostatic urethra in this region to avoid injury. In a straightforward case, the anterior portion of the dissection is the most challenging, and in the male patient it is the last part to be addressed. In the event that there is tumor fixity or a large bulky cancer in another quadrant, it is better to leave this to the end of the dissection having dissected around the right or left so that the best decisions can be made in terms of where to transect. When operating for cure, any area of fixity requires that the adjacent tissue be excised en bloc.

It is well worth noting that in women the vagina is always prepped so that a finger can be placed here to help guide the anterior dissection. The posterior wall of the vagina does not need to be routinely excised when performing an APR in women unless there is an anterior fixation.

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