ILEOANAL RESERVOIR SURGERY
Category: General Surgery
Abstract : Ileoanal reservoir surgery Definition Ileoanal reservoir surgery or
ileoanal anastomosis is a two-stage restorative procedure that removes a part of
the colon and uses the ileum (a section of the small intestine) to form a new
reservoir for waste that can be expelled through the anus. This surgery is one
of several continent surgeries that rely upon a newly created pouch to replace
Ileoanal reservoir surgery
Definition
Ileoanal reservoir surgery or
ileoanal anastomosis is a two-stage restorative procedure that removes a part of
the colon and uses the ileum (a section of the small intestine) to form a new
reservoir for waste that can be expelled through the anus.
This surgery is one
of several continent surgeries that rely upon a newly created pouch to replace
the resected colon and retain the patient’s sphincter for natural defecation.
Ileoanal reservoir surgery is also called a J-pouch, endorectal pullthrough, or
pelvic pouch procedure.
Purpose
A number of diseases require removal
of the entire colon or parts of the colon. Proctolectomies (removal of the
entire colon) are often performed to treat colon cancer. Another surgical option
is the creation of an ileoanal pouch to serve as an internal waste reservoir -
an alternative to the use of an external ostomy pouch. An ileoanal reservoir
procedure is performed primarily on patients with ulcerative colitis,
inflammatory bowel disease (IBD), familial polyposis, or familial adenomatous
polyposis (FAP), which is a relatively rare cancer that covers the colon with
100 or more polyps. FAP is caused by a gene mutation on the long arm of human
chromosome 5. Ileoanal reservoir surgery is recommended only in those patients
who have not previously lost their rectum or anus.
Demographics
The
prevalence of familial adenomatous polyposis (FAP) in the United States is two
to three cases per 100,000 persons. It develops before age 40 and accounts for
about 0.5% of colorectal cancers; this figure is declining, however, as more
at-risk families are undergoing detection and prophylactic colon surgery. The
annual incidence of ulcerative colitis is 10.4–12 cases per 100,000 people. The
prevalence rate is 35–100 cases per 100,000. People of Jewish descent have two
to four times the risk of developing ulcerative colitis than people from other
ethnic backgrounds. About 20% of ulcerative colitis patients require surgery of
the colon.
Description
Conventional ileoanal reservoir surgery is an
open procedure that is done in two stages. In the first stage, the surgeon
removes the diseased colon and creates a pouch. The second stage is performed
three months later, when the temporary drainage conduit is closed and the newly
created reservoir allows the patient to defecate in the normal fashion. Both
surgeries can also be done together, bypassing the creation of a temporary
ileostomy.
Some surgeons use a laparoscopic approach to ileoanal surgery.
This technique involves the insertion of scaled-down surgical instruments and a
scope that allows the surgeon to see inside the abdomen through several
relatively small incisions (3.5 inches [9 cm] or about compared to 6.3 inches
[16 cm] or for an open procedure) in the abdominal wall. Studies indicate that
there are few differences in the rates of mortality or complications between
laparoscopic surgery and conventional open surgery. Because the incisions are
smaller, patients typically require less pain medication with laparoscopic
surgery.
Ileoanal surgery includes the following steps:
• The surgeon
isolates the ileum or small segment of bowel.
• The segment is then attached
to the anus with absorbable sutures.
• A pouch is created out of the small
bowel above the anus.
• If the surgeon is performing the procedure in two
stages, he or she creates a temporary ileostomy. An ileostomy is a tubular bowel
segment attached to a stoma at the abdomen that drains into a bag outside the
abdomen.
• In the second-stage operation, the surgeon uses an open abdominal
procedure to close the temporary pouch.
The surgeon will insert stents to
bypass the surgical site and divert urinary and digestive wastes to the outside
of the body, thus allowing the new connection between the ileum and the anus to
heal properly.
Diagnosis / Preparation
The diagnosis of FAP is usually
made after symptoms caused by polyps in the colon, such as rectal bleeding,
diarrhea, and abdominal pain, have led to a physical examination, the taking of
a family history, and in some cases a genetic test. Ulcerative colitis or
inflammatory bowel disease patients have usually been treated with medical
alternatives before they decide to have surgery. All patients who are candidates
for an ileoanal procedure will have an evaluation of the upper gastrointestinal
tract, an x ray of the small bowel, and a colonoscopy with a pathology review.
Most patients will also be given a sigmoidoscopy and a digital rectal
examination.
The surgeon will need to perform an ileostomy in about 5–10%
of cases because the patient’s rectal muscles are not strong enough for an
anastomosis. This possibility is discussed with the patient, as well as the fact
that complications in surgery may lead to an ostomy procedure. The placement of
a stoma must be decided in the event that an ileostomy is necessary. The
physician evaluates the patient’s abdomen while the patient is sitting and then
standing, in order to avoid placing the stoma inside a fatty fold of the
abdomen. A stomal therapist is often called in to prepare the patient for the
possibility that an appliance will be needed. In addition to the medical and
surgical considerations of the procedure, the patient requires psychological
preparation regarding the changes in function and appearance that accompany this
surgery.
Prior to surgery, the patient must undergo a bowel preparation,
which includes a clear-liquid diet for two days before the procedure. In
addition to drinking nothing but clear fluids, the patient must have a cleansing
enema until the bowel runs clear. The importance of a thorough bowel preparation
must be explained to the patient, because leakage from the bowel during surgery
can be life-threatening.
Aftercare
Open ileaoanal reservoir surgery is
a lengthy procedure (as long as five hours) with a slow recovery rate
(approximately six weeks) and a relatively long stay in the hospital (about 10
days). The catheters and stents that were used are removed several days after
surgery. The patient will be introduced to a special diet in the hospital, and
the diet will be altered if needed in response to changes in the chemistry of
the colon. The patient’s stools are measured, and he or she is monitored for
dehydration. In addition, the patient will have the opportunity to discuss his
or her concerns about care of the new reservoir and frequency of defecation with
staff members before leaving the hospital.
Results
For carefully
selected patients this procedure, developed over 30 years, is the preferred form
of radical colon surgery when the patient’s sphincter and rectum are still
intact. The advantage of the ileoanal reservoir surgery is that the patient has
an internal pouch for the collection of waste material and can pass this waste
normally through the anus. Bowel movements may be more fluid, however, and more
frequent with the new reservoir. In a small percentage of cases, the surgeon may
eventually need to perform an ileostomy due to complications. In one quality of
life study for patients who have undergone ileoanal reservoir surgery,
researchers found only slight differences in their general health and level of
daily activity compared with subjects recruited from the general
population.
Morbidity/mortality
Morbidity rates with this procedure
have decreased over time due to improvements in technique. The most common
complication is inflammation of the pouch, which occurs in as many as 40% of
patients. This complication can be treated with medication. Other complications
include severe scarring around the incision, and some risk of injury to the
nerves that control erection and bladder function. In one major study of 379
patients, researchers at the University of Cincinnati reported that 79 patients
had pouch infections (24.3%) and another 20 patients required further surgery
for obstructions of the small bowel (6.2%).
Alternatives
The major
surgical alternative to an ileoanal reservoir procedure is an ileostomy. In an
ileostomy, the patient’s fecal matter drains into a plastic bag attached to a
stoma on the outside of the patient’s abdomen or into a pouch attached to the
abdominal wall to be withdrawn through a plastic tube.
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