Hybrid Laparoscopic/Open Low Anterior Resection

Makram Gedeon

Richard L. Whelan

Eric J. Dozois

Introduction

The hybrid low anterior resection (LAR), as originally described, is an operation in which the first part of the procedure (left colon mobilization) is performed laparoscopically and the second part (pelvic dissection) is accomplished using open methods via a Pfannenstiel or lower midline incision. The hybrid approach to sphincter-saving rectal resections was first introduced a decade ago when limited data existed concerning the oncologic efficacy of laparoscopic total mesorectal excision (TME) (1). In addition, concerns about the oncologic outcomes of minimally invasive methods for colon cancer existed due to early reports of port site wound recurrences. Data from the large randomized controlled trials (COST, CLASSIC, and COLOR) were not yet available. Moreover, hand-assist devices (second generation) were expensive, cumbersome, difficult to use, and therefore not very popular.

In this environment, the originators of the hybrid method, convinced of the benefits of laparoscopy, sought means of utilizing closed methods to significantly decrease overall incision length and physiologic impact, while permitting an open rectal mobilization and resection for cancer patients. The hybrid approach, as described in the following text, was the result. The hybrid method will significantly decrease incision length only if the splenic flexure would have been mobilized for an open operation. In the authors’ view, flexure mobilization is indicated in the great majority of patients with rectal cancer undergoing LAR and thus most patients will benefit from this hybrid method.

Surgery

Order of Operation and Division of Tasks

The laparoscopic portion of the operation is performed first, followed by the open method to complete the procedure. The steps of the LAR undertaken through the laparoscopic
approach include: (a) splenic flexure mobilization, (b) proximal vessel ligation, (c) division of the colon and mesentery, and (d) the initial mobilization of the rectum. After completion of the above steps, the abdomen is desufflated and a low midline or a Pfannenstiel incision is made and the case is completed using open methods.

Laparoscopic Portion

The patient is placed in the modified lithotomy position with both arms tucked to the side with a foley catheter. Standard anesthesia monitoring, perioperative antibiotics, and subcutaneous heparin are administered. A 5-port arrangement is utilized by the authors so that both the surgeon and the first assistant have 2 ports available to them. A 5 or 10 mm camera port is placed just caudad to the umbilicus. In the lower part of the right lower quadrant a 12 mm port (to allow for intracorporeal stapling) is placed. A 5 mm port is placed more cephalad, also on the right side, at the site chosen for the diverting ileostomy, at the level of the umbilicus or to the right of the upper midline. Two 5 mm ports are placed on the left side, one low in the left lower quadrant and the second approximately at the level of the umbilicus.

The splenic flexure is mobilized first because if this portion is not amenable to laparoscopic methods, early conversion can be initiated and the subsequent incision can be limited. There are four basic approaches to flexure takedown: (a) lateral to medial, (b) medial to lateral, starting just caudal to the sacral promontory on the right side of sigmoid mesentery, (c) medial to lateral, starting at the level of the inferior mesenteric vein (IMV), and (d) starting with the omental “peel” at the level of the distal transverse colon (seldom used). Regardless of the approach that is utilized, the flexure, the descending and distal transverse colon as well as the mesentery must be fully mobilized.

Medial to Lateral Starting at the IMV

The patient is placed in the reverse Trendelenburg position with the right side down. The surgeon and cameraperson stand on the patient’s right side, the latter at the level of the patient’s thighs, and the former just cephalad. The second assistant stands between the patient’s legs. The area to be exposed is the base of the distal transverse and descending colon mesentery adjacent to the ligament of Treitz. The distal transverse colon is gently grasped by the first assistant via the upper port on the left and retracted upwards and cephalad. The proximal descending colon is grasped, also by the first assistant via the lower left port, and retracted up and to the left. This latter move should reveal the location of the left colic vessels that appear as a bowstring. The surgeon then gently moves the small bowel to the right and caudal aspect of the abdomen that should reveal the ligament of Treitz, the proximal jejunum, and the IMV at the base of the descending mesentery. Obtaining this medial and central exposure is the most difficult part of this approach.

The peritoneum of the mesentery is then scored with a scissors parallel to and a short distance above or below the IMV depending on whether this vein is to be sacrificed or preserved. This opening is enlarged with a bipolar or ultrasonic shears (monopolar devices are avoided when working in this central location) and the plane between the posterior surface of the descending colon mesentery and the anterior aspect of Gerota’s fascia is established. This is a bloodless plane that is usually more superficial than anticipated; if minor bleeding is encountered when doing this dissection it is likely that one is working dorsal to the anterior layer of Gerota’s fascia. The correct plane, once found, is further developed in the lateral, caudad, and cephalad directions thus creating a pocket. The lateral limit of dissection is the white line of Toldt while the cephalad limit is the edge of the inferior border of the pancreas. Once the pocket is established, the first assistant’s graspers are placed inside the pocket and used to better expose the retroperitoneal field of dissection. If the IMV is divided at this point, or earlier, then the exposure is improved.

If the inferior mesenteric artery (IMA) is to be transected early, then its location must be established and the vessel exposed by scoring the peritoneum medially and inferiorly toward the pelvis. The retroperitoneal dissection is continued caudally from the already established IMV pocket. The IMA is divided only after it is certain that the left ureter is out of harms way. If the IMA is to be divided later in the case, a second mesenteric window is made, caudal to the left colic vessels toward the base of the mesentery. The retroperitoneal avascular dissection plane between the Toldt and Gerota’s fascia can then be extended beneath the distal descending colon. The left ureter and gonadal vessels are bluntly dissected away from the underside of the colon mesentery toward the left iliac fossa. After completing the medial to lateral mobilization, the descending colon is retracted medially and the remaining lateral attachments are divided sharply. The proximal left colon is released to complete this portion of the procedure.

Medial to Lateral Starting at the Sacral Promontory

Only gold members can continue reading. Log In or Register to continue