**3.3 The appendix**

The use of the appendix by Mitrofanoff to constitute a catheterizable channel was due to several advantages: it is not a vital organ; its function is uncertain after childhood and puberty, when it has an assumed imunological role; it is easy to mobilize and has a convenient location and an adequate length; has a predictable and reliable irrigation and a steady inner lumen which permits the passage of a 10F catheter [17,18]. Mitrofanoff also described the use of the ureter as a conduit. This, however, is associated with some morbidity which are hard to overcome and limit its use: need for a transureteroureterostomy; limited mobilization; inconsistent irrigation; painful catheterization and high complication rates including stenosis and incontinence. Other options have been described such as tubularized stomach flap, cecum, colon, Meckel diverticulum, bladder, skin, prepuce, clitoris, uterine tube and vas deferens. These, however, have not reached the same acceptance as the appendix [15,17,19].

## **3.4 Surgical technique**

Surgical approach can be accomplished through an infraumbilical median laparotomy or through a Pfannenstiel incision. The appendix is carefully dissected off of the cecum along with its mesentry. The organ is catheterized with a 12 or 14F catheter to assure adequate patency. Next, the catheterizable channel implant is performed either onto the bladder or the ileal segment when dealing with an augmented bladder. Absorbable sutures are used and care is taken to execute a 3-4 cm long anti-reflux tunnel (maintaining a length: diameter ratio of 5:1). Patency must be retested at the end of the implant [3,12,15,20].

Stomal externalization through the abdominal wall also requires attention to detail: it should be easily accessible to the patient's dominant hand and allow effortless access to the reservoir. Aesthetic appearance should also be pursued as long as it does not compromise functionality. Stoma externalization is usually made at the umbilicus or at the right lower quadrant. A stoma therapist is key for adequate positioning. There are several techniques

Continent Urinary Diversions in Non Oncologic Situations: Alternatives and Complications 285

On the first post operative day, irrigation of the reservoir using the suprapubic catheter is started to reduce mucus plug formation. Within 3 to 6 weeks the conduit Foley catheter is removed, cystostomy is clamped and CIC is commenced. Once the patient is familiarized with the procedure and is fully adapted suprapubic cystostomy is removed definitively [25-27,29].

From: Gerharz EW, Tassadaq T, Pickard RS, Shah PJ, Woodhouse CR, Ransley PG. Transverse

525-528.

**3.7 Outcomes** 

are included [1,14].

urethra or the conduit [20,21,31,12-14,17,27-29,32-34].

retubularized ileum: early clinical experience with a new second line Mitrofanoff tube. J Urol 1998; 159:

The risk for some early complications is common to any abdominal surgical intervention involving the urinary and gastrointestinal tracts: bleeding, infection, ileus, intestinal and urinary fistulas, intestinal obstruction, conduit ischemia, abscess, pyelonephritis and sepsis

Long term follow up series show results for both Mitrofanoff and Monti interventions exceeding 90% continence rates. Sahadevan et al. reported a self-reported continence rate of 89% with a mean follow up time of 126 months [30]. Incontinence may occur through the

described for the anastomosis between the conduit and the skin aiming to avoid stomal stenosis. They include V-flaps, tubular skin flaps and V-quadrilateral-Z flaps. Ideally, the conduit should be as short and straight as possible in order to avoid kinking. On the other hand, there must be no tension to the anastomosis [21-24]. Optimal drainage should be maintained post operatively. This is best accomplished with a combination of suprpubic catheterisation and a cathter through the channel.

Conduit Foley catheter is removed 3 to 6 weeks after surgery. Suprapubic cystostomy is clamped and CIC is initialized. Cystostomy may be unclamped at the end of catheterization. Once the patient is familiar with CIC technique cystostomy is definitively removed [3,12,15].
