Sigmoidectomy is the surgical removal of the last part of the colon, the sigmoid colon. It is considered in some cases of sigmoid diverticulitis, a common condition in the elderly, or cancerous tumor located on the sigmoid colon.

Sigmoidectomy, or sigmoid resection, is the surgical removal of the sigmoid colon. This is a type of colectomy (removal of a segment of the colon). 

As a reminder, the colon forms with the rectum the large intestine, the last part of the digestive tract. Located between the small intestine and the rectum, it measures approximately 1,5 m and is made up of different segments:

• the right colon, or ascending colon, located on the right side of the abdomen;
• the transverse colon, which crosses the upper part of the abdomen and connects the right colon to the left colon;
• the left colon, or descending colon, runs along the left side of the abdomen;
• the sigmoid colon is the last portion of the colon. It connects the left colon to the rectum.

The operation takes place under general anesthesia, by laparoscopy (laparoscopy) or laparotomy depending on the technique.

We must distinguish two types of situation: emergency intervention and elective intervention (non-urgent), as a preventive measure. In elective sigmoidectomy, usually performed for diverticulitis, the operation takes place away from the acute episode to allow the inflammation to subside. Preparation is therefore possible. It includes a colonoscopy to confirm the presence and determine the extent of diverticular disease, and rule out tumor pathology. A low-fiber diet is recommended for two months after an attack of diverticulitis.

Two operating techniques exist:

• anastomosis resection: the segment of the diseased sigmoid colon is removed and a suture is made (colorectal anastomosis) to put the two remaining parts in communication and thus ensure digestive continuity;
• Hartmann’s resection (or terminal colostomy or ileostomy with rectal stump): the diseased sigmoid colon segment is removed, but digestive continuity is not restored. The rectum is sutured and stays in place. A colostomy (“artificial anus”) is placed temporarily to ensure the evacuation of stool (“artificial anus”). This technique is generally reserved for emergency sigmoidectomies, in the event of generalized peritonitis.

The main indication for sigmoidectomy is sigmoid diverticulitis. As a reminder, diverticula are small hernias in the wall of the colon. We speak of diverticulosis when several diverticula are present. They are usually asymptomatic, but over time can fill with stools that will stagnate, dry out, and lead to “plugs” and eventually inflammation. We then speak of sigmoid diverticulitis when this inflammation sits in the sigmoid colon. It is common in the elderly. The CT scan (abdominal CT-scan) is the exam of choice for diagnosing diverticulitis.

Sigmoidectomy is not, however, indicated in all diverculitis. An antibiotic treatment by the venous route is generally sufficient. Surgery is only considered in the event of a complicated diverticulum with perforation, the risk of which is infection, and in certain cases of recurrence, as a prophylactic. As a reminder, the Hinchey classification, developed in 1978, distinguishes 4 stages in order of increasing severity of the infection:

• stage I: phlegmon or periodic abscess;
• stage II: pelvic, abdominal or retroperitoneal abscess (localized peritonitis);
• stage III: generalized purulent peritonitis;
• stage IV: fecal peritonitis (perforated diverticulitis).

Elective sigmoidectomy, that is to say elective, is considered in certain cases of recurrence of simple diverticulitis or of a single episode of complicated diverticulitis. It is then prophylactic.

Emergency sigmoidectomy, performed in cases of purulent or stercoral peritonitis (stage III and IV).

The other indication for sigmoidectomy is the presence of a cancerous tumor located in the sigmoid colon. It is then associated with a lymph node dissection to remove all the ganglion chains of the pelvic colon.

After the sigmoidectomy, the rest of the colon will naturally take over the function of the sigmoid colon. The transit can be modified for a while, but the return to normal will be done gradually.

In the event of Hartmann’s intervention, an artificial anus is placed. A second operation can, if the patient presents no risk, be considered to restore digestive continuity.

The morbidity of the preventive sigmoidectomy is quite high, with approximately 25% of complication rate and includes a reoperation rate leading to the realization of an artificial anus sometimes definitive of the order of 6% at one year of the prophylactic colostomy, recalls the Haute Autorité de Santé in its 2017 recommendations. This is why prophylactic intervention is now practiced with great caution.