Meckel's Diverticulectomy
Meckel's diverticulectomy
Definition
Meckel's diverticulectomy is a surgical procedure that isolates and removes an abnormal diverticulum (Meckel's diverticulum) or pouch, as well as surrounding tissue, in the lining of the small intestine. It is performed to remove an obstruction, adhesions, infection, or inflammation.
Purpose
Meckel's diverticulum is an intestinal diverticulum (pouch) that results from the inability of the vitteline (umbilical) duct to close at five weeks of embryonic development. The vitteline duct is lined with layers of intestinal tissue containing cells that can develop into many different forms, called pluripotent cells. Meckel's diverticulum is a benign congenital condition that has no symptoms for some people, and develops complications in others.
Ninety percent of diverticula are close to the ileocecal valve in the upper intestine, and tissue made up predominantly of gastric and pancreatic cells is thought to cause chemical changes in the mucosa, or lining of the intestines.
The most common cells found in the mucosa of diverticula are gastric cells (present in 50% of all Meckel's diverticulum cases). The highly acidic secretions of gastric tissue may cause the early symptoms of Meckel's diverticulum. The alkaline secretions of pancreatic tissue are also thought to be a source of diverticula inflammation in a small number—about 5%—of cases.
Inflammation of the diverticula or infection of the intestines around the diverticula results in a condition known as diverticulitis, which may be treated with antibiotics . However, when it is acute and causes obstructions and bleeding, surgery is the treatment of choice.
Demographics
Meckel's diverticulum is present in approximately 2% of the population. It is the most commonly encountered congenital anomaly of the small intestine. Although the abnormality occurs in both sexes, men have more frequent complications with the condition and are more often diagnosed with it. One 15-year study set the complication risk of the abnormality at 4.2%. A recent 10-year study done retrospectively reported an even age distribution for complications of the diverticulum. Malignancy is found in only 0.5–4.9% of patients with complications of Meckell's diverticulum.
Description
Open surgery of the intestines is indicated in acute cases. In the surgery, the intestinal segment containing the diverticulum, usually the ileum or upper intestines, is removed. After the diverticulum is removed, the healthy portions of the intestine are joined together. Some debate exists about whether surgery for asymptomatic Meckel's diverticulum found incidentally is recommended. Some researchers have shown that preventive removal of the diverticulum is less risky than surgical complications, and point to the fact that 6.4% of patients with Meckel's diverticulum develop complications of the condition over their lifetime.
Depending on the surgeon's decision, the operation may be minimal, isolating and then removing the pouch containing the inflammation, or it may be more extensive. In the latter cases, surrounding tissue is removed due to the presence of pervasive inflammation, obstruction, or incarceration in an inguinal hernia (Littre's hernia). Removing additional tissue is done to prevent recurrences. Recent studies have demonstrated the feasibility of laparoscopic, or minimally invasive diverticulectomy, utilizing small incisions and video imagery via tiny cameras. No long-term studies of this procedure have been conducted.
Surgery is performed under general anesthetic. The small intestine is isolated and the diverticulum is removed, sometimes with a small segment of the intestines. Operative techniques are used to conjoin the end sections of the intestines that have been severed. Some surgeons prefer to perform two surgeries, and do not join together the intestinal sections until some healing of the segments has occurred. In this case, a stoma, or temporary outlet for tubal connection to the intestines, is created in the wall of the abdomen where an external appliance, called an ostomy, can receive waste until the intestinal sections are rejoined.
Diagnosis/Preparation
The vast majority of Meckel's diverticulum diagnoses are incidental, that is, discovered during barium studies, abdominal surgery for other conditions, or autopsy. The most common symptom of the condition is intestinal bleeding, which occurs in 25–50% of patients who have complications. Hemorrhage is the most significant symptom in children two years old and younger. Intestinal obstructions are common, resulting from complications of the tissue surrounding the diverticula. Symptomatic Meckel's diverticulum has symptoms similar to appendicitis. Lower abdominable pain or diverculitits accounts for 10–20% of cases, and requires careful diagnosis to distinguish it from appendicitis. Left untreated, diverticulitis can lead to perforation of the intestine and peritonitis.
Patients who have diverticulitis symptoms, such as acute abdominal pain are given various imaging tests, including a CT scan, colonoscopy , or a sigmoidoscopy (view of the lower colon through a tiny video instrument placed in the rectum). For children, a special chemical diagnostic test of sodium Tc-pertechnetate, a radioisotope that reacts to the mucosa in the diverticulum, allows inflammation or infection to be viewed radiographically. In adult patients, barium studies may help with diagnosis. When acute hemorrhaging is present, MR imaging of blood vessels is an effective diagnostic tool.
If surgery is indicated for Meckel's diverticulum, an enema is given (unless contraindicated by complications) to completely clear the bowel and avoid infection during surgery.
Aftercare
Intestinal surgery is a serious procedure, and recovery may take two weeks. The number of postoperative days spent in the hospital depends on the extent of the diverticulum surgery and complications of the condition prior to surgery. Barring complications, patients usually stay in the hospital for about one week. Immediately after surgery, the patient is observed carefully, and given intravenous fluids and antibiotics. Surgical catheters, or stents, are removed over the next two days, with food by mouth offered once bowel sounds are heard.
Risks
Intestinal surgery has the surgical complications associated with any open surgery. These include lung and heart complications, as well as reactions to medications, bleeding, and infection.
Normal results
The usual results of this surgery are an end to obstruction, pain, and infection. Highly successful results include the return of bowel function and daily activities.
Morbidity and mortality rates
Patients with complications of Meckel's diverticulum have a 10–12% incidence of early postoperative complications such as an intestinal leak, a suture line leak or intra-abdominal abscess. Later complications occur in about 7% of patients, and include bowel obstructions and intestinal adhesions. The reported mortality rate for surgery on patients with symptomatic diverticulum is 2–5%. With asymptomatic patients who undergo incidental diverticulectomy, both early and late complications occur in 2% of cases, and the mortality rate is 1%.
Alternatives
Diverticulitis is routinely treated with a change in diet that includes increasing bulk with high-fiber foods and bulk additives like Metamucil. Recurrent attacks, perforation, tissue adhesions, or infections are initially treated with antibiotics, a liquid diet, and bed rest. If medical treatment does not clear the complications, emergency surgery may be required.
Resources
books
Townsend, Courtney M. "Diverticular Disease" In Sabiston Textbook of Surgery 16th ed. W. B. Saunders Company, 2001.
periodicals
"Laparoscopy-assisted Resection of Complicated Meckel's Diverticulum in Adults." Surgical Laparoscopy, Endoscopy and Percutaneous Techniques 12(3) (June 1, 2000): 190-4.
"Meckel's Diverticulum." American Family Physician 61(4) (February 15, 2000).
organizations
International Foundation for Functional Gastrointestinal Disorders (IFFGD).P.O. Box 170864, Milwaukee, WI 53217-8076. (888) 964-2001 or (414) 964-1799. fax: (414) 964-7176. <http://www.iffgd.org>.
National Digestive Diseases Information Clearinghouse. 2 Information Way, Bethesda, Maryland 20892-3570. <http://www.niddk.nih.gov>.
other
"Meckel's diverticulectomy." MedlinePlus <http://www.nlm.nih/medlineplus.gov>.
Nancy McKenzie, Ph.D.
WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?
Surgery takes place in a hospital setting by a physician with advanced training in surgery and gastrointestinal surgery. If the surgery is minimally invasive, requiring only small incisions, it may be performed in an outpatient surgical area of the hospital.
QUESTIONS TO ASK THE DOCTOR
- Is this surgery necessary or can changing the diet and medical treatment be just as effective?
- Because this surgery was on an emergency basis, how extensive was the surgery and how much of the intestine was removed?