URINARY DIVERSION AND BLADDER SUBSTITUTION
It is most often performed by incorporating various intestinal segments in to the urinary
tract, infract every part of GIT has been used to create urinary reservoir and conduits.
No single technique is ideal for all patients and clinical situations,
The ideal method most closely approximate the normal bladder, it would have the
following characters:
1- Low pressure.
2- Continent.
3- None refluxing.
4- Non absorptive.
Types:
1- Bladder conduit-a reservoir of urine from stomach, small or large bowel not
attached to urethra empted by a catheter.
2- Neobladder-it substitute of bladder from the bowel but attached to the remaining
parts of urethra empted by clean intermittent catheterization (C.I.C.), or by using
abdominal pressure or crede maneuver.
Indications for diversion : -
1- Patients with lower urinary tract cancers (bladder).
2- Sever functional abnormality of the bladder (neurogenic bladder, small capacity
bladder).
3- Sever anatomical abnormality of the bladder (ectopia vesicae) .
4-Haemorhhagic cystitis unresponsive for treatment.
Pre operative Counseling and preparation
All candidates for urinary diversion should undergo careful pre operative counseling
and preparation, including
1- Detail discussion of the objectives and potential complications of each method
2- Any potential impact on a procedure on sexual function
3-Body image and life style should be discussed.
Careful history should be taken and should note any previous abdominal or pelvic
surgery , irradiation, systemic disease , history of intestinal resection or irradiation ,
renal failure , diverticulitis , regional enteritis , ulcerative colitis .
CBC , serum electrolytes , renal function testes ( blood urea , serum creatinine ) , IVU ,
contrast imaging of the small or large bowel or colonoscopy should be performed .
Patients undergo standard mechanical and oral antibiotic bowel cleansing program
beginning 1 or 2 days before surgery.
The patient should be preoperatively evaluated in the lying , sitting and standing
positions to decide the proper site for the stoma , the stoma should preferably be located
above or below the belt line , the most common site for the stoma placing is along a line
between the anterior superior iliac spine and umbilicus and through the rectus
abdominis muscle . The surface area should be flat and able to support an appliance.
Intestinal conduit
Ileal conduit
It is a common method for urinary diversion and is constructed by using a segment of
ileum 18-20 cm long and located approximately 15-20 cm proximal to the ileocecal
valve.
Jejunal Conduit
Is rarely used and mainly in cases where other segments can not be used due to
significant ileal and colonic disease caused by previous irradiation or inflammatory
bowel disease.
Colon Conduit
There are several advantages to using the large bowel in construction of urinary
diversions: -
(1) Non refluxing uretero intestinal anastamoses are easily performed.
(2) Stomal stenosis is uncommon because of the large diameter of the large
bowel.
(3) Limited absorption of electrolytes.
(4) The blood supply to the transverse and sigmoid colon is abundant.
Either the transverse or the sigmoid colon can be used
Complications
Early complications
are uncommon occurring approximately in 10-20% of patients include : -
excessive bleeding , intestinal obstruction infection and urinary
extravasations .
Late complications
Occur in approximately in 10-20% of the cases include: - metabolic disorders
(hyperchloraemic acidosis with hypokalaemia), stomal problems ( stenosis or
hernia ) , pyelonephritis , calculi and rarely bladder or reservoir rupture .