Laparoscopic Abdominoperineal Resection (APR)
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.
Since the publication of the COST Trial, few questions remain regarding the application of laparoscopic surgery in the treatment of colon cancer. However, concerns regarding the ability to perform laparoscopic total mesorectal excision (TME) still exist. To this end, the American of College Surgeons Oncology Group (ACOSOG) Z6051 trial is currently accruing patients at the time of this writing, which should definitively address this issue in a multi-institutional randomized trial. The issues of paramount importance regarding laparoscopic surgery in the treatment of a rectal cancer include proper performance of TME, as well as visualization and retraction during deep pelvic dissection. The last issue, that of 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 becomes a moot point in performing an APR as there is no anastomosis since 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.
IndicationsClearly, 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 last decade have still ranged from 25% to 60%.
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 last 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 32.1. 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 resection (TATA) 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.
 Figure 32.1 Selection scheme for sphincter preservation employing neoadjuvant chemoradiation for low rectal cancers. |
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.
Preoperative PlanningPatients undergo a standard oncologic evaluation including CT 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 (CEA) level. Endorectal ultrasound is also performed. Oftentimes this assessment is coupled with an MRI of the pelvis. In patients older than 60 years and in those individuals with coronary artery disease, hypertension, diabetes, or 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 based on the 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. The patients are seen by a stoma nurse preoperatively and marked for a permanent colostomy. This is an essential point as the positioning and function of the stoma will have a major impact on the patient’s quality of life.
SurgeryPositioning
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 they are secured firmly to the table as 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 32.2 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.
 Figure 32.2 Setup of operating room to facilitate 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 as 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, as the most challenging portion of the laparoscopic procedure, the distal most rectal dissection, has already been done from the perineal approach.
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.
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