**3. Selecting the urinary diversion**

As mentioned previously, urinary diversion (continent versus incontinent) must be based upon: patient's wishes; patient's manual dexterity to perform self catheterization; availability of a care provider; surgical feasibility; quality of life and life expectancy.

Whenever possible, patient's wishes regarding an incontinent conduit or an abdominal catheterizable stoma should be considered. This may result in better acceptance of the urinary diversion and therefore improve quality of life.

While a catheterizable conduit will demand a caregiver's attention every 4 to 6 hours to keep it down to the maximum storage capacity, an incontinent one may yield several hours

Continent Urinary Diversions in Non Oncologic Situations: Alternatives and Complications 283

closure or tight pubovaginal sling); it may facilitate CIC execution in patients with difficulty to access their own urethra (spastic lower limbs, lack of manual dexterity) or who refuse to catheterize due to pain; and it may also offer an option for bladder emptying in patients

In 1980, Paul Mitrofanoff made the first description on the use of a continent urinary catheterizable channel utilizing the appendix which was later popularized by Duckett et al. [3,12]. The Mitrofanoff principle consists in a urinary continent derivation brought to the skin anastomosed to a low pressure reservoir utilizing an anti reflux technique through which one can perform the CIC [13]. Ideally, the stoma should be easily accessible and

The rationale behind the Mitrofanoff procedure is the maintenance of a low pressure reservoir in which filling pressures do not exceed 20 cmH2O, while conduit pressure stands

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,

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

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

within 45-90 cmH2O and reaches up to 80-150 cmH2O under Valsalva maneuver [16].

however, have not reached the same acceptance as the appendix [15,17,19].

ratio of 5:1). Patency must be retested at the end of the implant [3,12,15,20].

with complex urethral stenosis [12,14].

**3.2 Mitrofanoff** 

aesthetically pleasant [13].

**3.3 The appendix** 

**3.4 Surgical technique** 

until the urine collecting bag is full. Changing a collecting bag is incomparably easier than catheterizing a Mitroffanof channel and may significantly facilitate the caregiver's task.

Surgical feasibility of the desired urinary derivation must be assessed taking into account:

a. Previous surgical interventions:

A patient who has undergone a previous laparotomy is at risk of adhesions which can confer risk of intertinal injury and difficulty intraoperatively. If a Mitroffanof procedure is planned the presence or absence of cecal appendix will dictate whether a small bowel segment will be needed instead. In patients with previous enteric resection the residual bowel segments care must be taken not to leave the patient at high risk of a malbsorption syndrome.

With abdominal scars the resultant stoma must be fashioned without risk of ischaemia to the skin flap. Any associated abdominal wall defects will also require attention with wound closure or even access into the abdomen.

b. Obesity:

Ileal conduit externalization may be challenging in obese patients. It is important to properly anticipate the adequate intestinal loop length to assure its passage through the abdominal wall and subcutaneous tissue and also to invert the mucosal end providing an elevated "volcano-like" border. This will allow urine to flow right into the collecting bag, sparing the skin and decreasing the incidence of ammoniac dermatitis.

When externalizing a catheterizable channel, using the umbilicus may overcome the large abdominal wall width challenge.

Finally, quality of life anticipation will be most closely met when detailed preoperative planning is made in order to understand patients' expectations and the attending team is able to anticipate and clarify the patient how his routine will be with the chosen urinary diversion (frequency needed to catheterize or exchange the collecting device; changes in his physical appearance; possible related complications, etc).

The available surgical technique can be divided into continent catheterizable channels (Mitrofanoff procedure and Yang-Monti technique) and incontinent conduits (Bricker procedure and ileovesicostomy). Cutaneous ureterostomy is no longer used in current practice due to its high incidence of related complications and stomal stenosis [4].

#### **3.1 Catheterizable channels: Mitrofanoff and Monti procedures**

The principle of continent urinary diversion (Mitrofanoff principle) is similar to the one which prevents vesicoureteral reflux: to create a submucosal conduit that colapses whenever the reservoir is full preventing urinary leakage through the diversion. This is attained via a Mitrofanoff channel which is a small calibre tube that provides external access to the bladder. Clean intermittent catheterization allows for proper reservoir emptying [12,13].

This type of diversion can benefit patients with refractory urinary incontinence along with a procedure to increase the bladder outlet resistance without incontinence (bladder neck closure or tight pubovaginal sling); it may facilitate CIC execution in patients with difficulty to access their own urethra (spastic lower limbs, lack of manual dexterity) or who refuse to catheterize due to pain; and it may also offer an option for bladder emptying in patients with complex urethral stenosis [12,14].
