Open Left and Sigmoid Colectomy—Lateral to Medial



Open Left and Sigmoid Colectomy—Lateral to Medial


William C. Chapman Jr

Matthew G. Mutch





INDICATIONS/CONTRAINDICATIONS

Left and sigmoid colectomy are most frequently performed for malignancy or diverticular disease. With either process, the location and extent of disease along with vascular anatomic considerations predicate the extent of required resection. Diverticular disease, for example, often requires only a complete sigmoid resection, with dissection of the left colon performed to facilitate the primary anastomosis of the healthy rectum to soft descending colon. However, in the setting of malignancy, complete resection requires removal of both the tumor and the entire vascular and lymphatic tissue of the colonic portion in question. Because the left colon is proximally supplied by arcades of the middle colic pedicle, namely, the marginal artery of Drummond, and distally by the inferior mesenteric artery (IMA), both arteries and the inferior mesenteric vein (IMV) must be resected. The sigmoid colon, also perfused by the IMA, must therefore be taken out at times to facilitate complete removal of a left colon cancer. Finally, re-anastomosis of the left colon to the rectum sometimes requires mobilization of the splenic flexure and high ligation of the IMV.

Physiologically, resection of the left or sigmoid colon is easily postoperatively tolerated by most patients. Therefore, the only true contraindication to either procedure is the inability of the patient to tolerate general anesthesia.


PREOPERATIVE PLANNING

For a left or sigmoid colon resection, preoperative planning involves three typical considerations: additional screening for concomitant colorectal disease, the use of bowel preparation, and the initiation of pain management and venous thromboembolism prevention techniques. In addition, a neoplastic lesion must be accurately localized with endoscopic tattooing or imaging such as computed tomography or contrast enema.

In the setting of malignancy, preoperative axial imaging to adequately stage the cancer and exclude distant metastasis is a must. Colonoscopy, usually in the elective outpatient setting, should also be performed before any elective resection to tattoo lesions and ensure the remainder of the colon is disease free.

The appropriate role of mechanical and chemical bowel preparation is controversial and likely surgeon dependent. Widely recognized data have demonstrated no reduction in surgical site infections with the use of a mechanical preparation alone. However, more recent data from large population databases, such as the National Surgical Quality Improvement Program (NSQIP) and the Michigan Surgical Quality Collaborative, have demonstrated that combined mechanical and oral antibiotic preparations have reduced deep and superficial wound infections. In our practice, all patients scheduled for elective left and sigmoid resections undergo a combined oral preparation consisting of polyethylene glycol solution, neomycin, and metronidazole administered in the 12 hours before surgery. Once in the operating room, 1 g of ertapenem or intravenous (IV) ciprofloxacin and metronidazole in penicillin-allergic patients is given for perioperative infection prophylaxis.

A multimodal pain management program and venous thrombus prophylaxis is utilized in the preoperative period for all elective colon resections. Each patient receives a gram of oral acetaminophen
and 12 mg of alvimopan, along with placement of an epidural analgesic infusion catheter by the anesthesia team. A dose of subcutaneous heparin is also administered before entering the operating room.



  • It is unusual to require proximal diversion after a left colectomy; but if the plan is to include a stoma, the preoperative marking of the site can improve functional outcomes for the patient.


  • The patient should be informed of the postoperative bowel function expected after segmental resection of the left and/or sigmoid colon. Bowel function is somewhat less than normal, influenced by the patient’s age and rejected by multiple bowel movements that occur rapidly and urgently.


  • Patients in whom dense adhesions or inflammatory processes are expected, cystoscopy and ureteric stent placement may be indicated typically at the start of the operation.


SURGERY

Our standard approach for standard open left or sigmoid colectomies is a lateral-to-medial colonic dissection combined with high ligation of the IMV and IMA.


Positioning

The patient is placed in modified lithotomy position using lithotomy stirrups with sequential compression devices in place. A bladder catheter is sterilely inserted, and the rectum is irrigated with a betadine solution to clear any remaining solid stool. The arms are placed with the left arm extended and the right arm tucked to allow for positioning of a Mayo stand over the patient’s chest. Having the scrub assistant above the head allows a direct visual line into the operating field. If the Mayo stand is not placed above the head, both arms may be left out. The abdomen is clipped and prepped, and the patient is then draped in standard manner with sterile leg covers and body drape allowing for abdominal and perineal access.


Technique


Mobilization of the Colon



  • The abdomen is entered through a vertical midline incision from pubis to as far above the umbilicus as needed to mobilize the splenic flexure, and a circumferential plastic wound retractor is placed. The Bookwalter self-retaining retractor is then secured over the laparotomy and opened widely. The small bowel is packed into the right upper quadrant using a damp laparotomy towel and retractors.


  • An incision is made at the base of the lateral aspect of the left colon mesentery along the white line of Toldt with the left colon retracted medially and anteriorly (Fig. 8.1A). The incision is extended from the pelvis to the left upper quadrant. Under tension, the colon and its mesentery are elevated anteriorly and medially while the retroperitoneal tissue is retracted laterally. The exposed areolar tissue plane anterior to the retroperitoneum is dissected off of the mesentery with electrocautery, exposing the ureter and gonadal vessels (Fig. 8.1B). This plane is extended medially to the base of the aorta and cephalad to the level of the splenic flexure, freeing the left colon from the anterior surface of the kidney (Fig. 8.1C).


  • To complete the release of the splenic flexure from the left upper quadrant, the omental attachments to the anterior surface of the transverse colon are incised through the midline. Beginning laterally, an incision is made on the peritoneal attachments of the splenic flexure, using the finger as a guide, with the intent to enter the lesser sac by separating the omentum from the transverse colon. Proceeding medially, the colon is released from the omentum. The key is to stay superficial, dividing only the peritoneal attachment between them. Once all of the omental attachments to the transverse colon mesentery are divided, the lesser sac is widely opened. The thicker portions of these attachments are clamped and suture ligated. To fully release the splenic flexure to the midline, attachments to the undersurface of the tail of the pancreas and the retroperitoneum must be incised to the midline toward the duodenum at the ligament of Treitz (Fig. 8.2). Accordingly, the splenic flexure is pulled down and the right hand placed into the retroperitoneum to expose the plane between the undersurface of the spleen tip and the lateral aspect of the abdominal cavity.


Excising the Specimen

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May 5, 2019 | Posted by in GENERAL | Comments Off on Open Left and Sigmoid Colectomy—Lateral to Medial

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