Chapter 8: Laparoscopic Sigmoid Colectomy

PREOPERATIVE CONSIDERATIONS

Ureteral Stents

In general, ureteral stent placement is not required for routine sigmoidectomy. However, you should consider ureteral stent placement in the following cases:

• Smoldering diverticulitis/phlegmon.

• Presence of active sigmoid inflammation.

• Redo operations.

• Large/recurrent tumor in the sigmoid colon.

• If the computed tomography (CT) scan suggests that the lesion or the pathology is intimately associated with the left ureter.

• Morbidly obese patient.

Imaging

Review the CT scan of the patient very carefully, because it will provide you with a road map to the operation. There are many useful pieces of information that you need to get from the CT scan before you start. These include the following:

• Location of disease.

• Relationship of the diseased segment to the surrounding structures including ureter.

• Nature of splenic flexure including relationship to spleen, pancreas, and surrounding structures.

• Presence or absence of redundancy of sigmoid colon.

• Extent of the disease.

Diverticular Disease

The proximal margin of resection should be a normal colon that should be soft, without muscular hypertrophy and the mesentery should be normal without any thickness. The distal resection margin in these cases will be at the top of the rectum where the tenia converges. In case of diverticulitis, it’s important to identify the level of the diseased segment of the colon on preoperative imaging. Diverticulitis usually involves the sigmoid colon. Occasionally, the inflammation is seen in the left colon instead. It is important in this scenario to include the diseased segment and not to limit the resection to the sigmoid colon. Regardless of the proximal extent of resection, the distal resection margin should be the upper rectum.

Occasionally, the upper rectal wall can be very thickened secondary to the diverticulitis, and thus the distal resection could be lower than usual. This will lead to the creation of the colorectal anastomosis lower than anticipated. Typically, this is obvious on a preoperative CT scan and helps in counseling the patient regarding the possible need for a temporary diverting loop ileostomy. These patients are best served by seeing a stoma nurse and getting preoperative stoma marking for an anticipated loop ileostomy.

Cancer Cases

In all cancer cases, adequate margins are paramount, usually 5 cm of clear margin proximally and distally is sufficient. In addition, the inferior mesenteric artery (IMA) should be divided at its origin to ensure adequate lymph node harvest.

CO₂ Colonoscopy

Intraoperative CO₂ colonoscopy is utilized during sigmoid resections in two stages of the operation.

1. It can be used to identify the distal resection margin when resecting an endoscopically unresectable polyp or a tumor that has not been marked preoperatively with a tattoo and it is not easily identified laparoscopically.

2. It can ...