Hybrid Laparoscopic/Open Low Anterior Resection



Hybrid Laparoscopic/Open Low Anterior Resection


Amy L. Lightner

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 and splenic flexure mobilization) is laparoscopically performed 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 were available regarding the oncologic outcomes of a laparoscopic approach to colon and rectal cancer cases. The originators of the hybrid method, convinced of the benefits of laparoscopy, sought means of utilizing laparoscopic techniques to significantly decrease overall incision length and physiologic impact, while permitting an open total mesorectal excision (TME) until data was published regarding the oncologic outcomes with laparoscopy. When the results from the Clinical Outcomes of Surgery Therapy (COST), Conventional versus Laparoscopic-Assisted Surgery In patients with Colorectal Cancer (CLASSIC), and COlorectal cancer Laparoscopic or Open Resection (COLOR) trials were published stating that laparoscopic surgery was equivalent to open surgery for colon cancer, several surgeons moved away from the hybrid approach toward a complete laparoscopic technique for both colon and rectal cancer cases.

The hybrid approach, as described in the following text, allows for an open TME while minimizing incision length with a laparoscopic splenic flexure mobilization. In the authors’ view, limiting the incision related to flexure mobilization still provides significant benefit to the patient in terms of cosmetic outcome, decreased recovery time, and decreased narcotic use, all of which advocate for the use of this hybrid approach.




PREOPERATIVE PLANNING

Planning before any pelvic operation should include physical examination, tissue diagnosis, local and systemic staging, and review of any prior imaging and operative reports. If imaging is not recent or adequate, it should be repeated during the preoperative evaluation. Patients should have had a computed tomography scan of the chest, abdomen and pelvis for systemic staging, and a magnetic resonance imaging of the rectum for local staging. Pathology slides should be obtained for review and confirmation by a local pathologist if there is any question of an accurate diagnosis. At the time of the outpatient visit, digital rectal examination should be performed on all patients, regardless of dictated location of the cancer on endoscopy or imaging reports. If unable to feel the lesion in its entirety, we perform a flexible sigmoidoscopy in the office to note the location and size of the tumor. If not already performed, completion colonoscopy should be performed to ensure there are no synchronous lesions.


Because the risk of anastomotic leak for low-to-mid rectal cancer approaches 15%, most patients will be diverted, especially in the setting of preoperative radiation. Therefore, patients should have a clear understanding as to the likelihood of a stoma, and meet with an enterostomal therapist for counseling and marking before their operation. In addition, the risk of converting to an open operation requiring a larger midline incision should be discussed.


SURGERY


Order of Operation and Division of Tasks

The laparoscopic portion of the operation is performed first, followed by the open portion 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 these 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 and a bladder catheter is placed. Standard anesthesia monitoring, perioperative antibiotics, and subcutaneous heparin are administered. A four-port arrangement is utilized by the authors so that both the surgeon and the first assistant have 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 at the site of the diverting ileostomy marking. Two additional 5-mm ports are placed; one is in the suprapubic position in the midline and the other in the left lower quadrant (Fig. 19-1).

The splenic flexure is mobilized first because if this portion is not amenable to laparoscopic methods, early conversion can be initiated. 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 the 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 (Fig. 19-2).






FIGURE 19-1 Port site setup for the laparoscopic portion of the operation.






FIGURE 19-2 Mobilization of the splenic flexure.



Medial to Lateral Starting at the Inferior Mesentery Vein

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 (Fig. 19-3). 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 upward 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 (Fig. 19-4).

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 bloodless plane 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, whereas 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 (Fig. 19-5). 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 harm’s 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 medially retracted and the remaining lateral attachments are divided sharply. The proximal left colon is released to complete this portion of the procedure. When possible, the left colic vein should be identified before ligating the IMV. The IMV should be ligated cephalad to where the left colic vein drains into the IMV to get maximal mesenteric lengthening.

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May 5, 2019 | Posted by in GENERAL | Comments Off on Hybrid Laparoscopic/Open Low Anterior Resection
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