Continent Catheterizable Reservoir Made From Colon
HUBERTUS RIEDMILLER
ELMAR W. GERHARZ
ARKADIUS KOCOT
INDICATIONS
The most common indication for continent cutaneous diversion is bladder replacement after anterior pelvic exenteration for malignant disease, followed by functional or morphologic bladder loss for other reasons. Diagnostic modalities therefore should be directed at the underlying pathology and definitive treatment. Despite the recent trend toward orthotopic substitution, continent catheterizable diversions are still a good form of diversion. Whereas previous or synchronous urethral transitional cell carcinoma (TCC) is an absolute contraindication to urethral preservation, the role of multifocality, associated carcinoma in situ, bladder neck, and prostatic involvement on urethral recurrence are less well defined. In these cases, continent cutaneous diversion still is a safe alternative in the appropriate patient. Advanced age (older than 70 years) with its physiologic deterioration of sphincter competence is another contraindication for orthotopic reconstruction; older patients who are otherwise physically fit may well benefit from a continent cutaneous reservoir. Whenever the native sphincter mechanism is lacking, destroyed, or dysfunctional or urethral catheterization is painful or technically impossible, cutaneous diversion is the only alternative to modified ureterosigmoidostomy and ileal loop. As salvage procedure in failed exstrophy reconstruction, other complicated congenital abnormalities of the urinary tract, neurogenic bladder dysfunction (wheelchairbound myelomeningocele patients), otherwise intractable urinary incontinence, severe pelvic trauma, and complicated fistulas, continent cutaneous reservoirs provide excellent results even in extremely complex cases.
Until recently, renal transplant patients were excluded from the benefits of continent urinary diversion. Recently, several authors reported encouraging experiences with kidney transplantation into continent urinary intestinal reservoirs as a planned two-stage procedure in patients with functional or morphologic bladder loss (see the following text) (1,2). But long-term results in larger series of patients are still missing.
Other factors to consider when deciding on the type of urinary diversion include patient age, prognosis of underlying disease, comorbidity, urinary and anal sphincter competence, manual dexterity, renal function and upper urinary tract configuration, and subjective criteria (motivation, compliance, expectation of social support, emotional capability of dealing with clean intermittent catheterization). Patient priorities are considered whenever medically justifiable and technically feasible.
Contraindications of continent urinary diversion include impaired renal function with serum creatinine greater than 2 mg per L (other authors choose a cutoff level of 1.5 mg per L), inflammatory bowel disease, large bowel malignancy, or previous history of multiple bowel ablative procedures, and history of diarrhea.
ALTERNATIVE THERAPY
Alternatives to catheterizable colonic reservoirs include pouches made from ileum (Kock), ileal or colonic conduits, classic and modified ureterosigmoidostomy (e.g., sigma rectum pouch/Mainz pouch II), and orthotopic neobladder (Hautmann, Studer).
SURGICAL TECHNIQUE
While there is a broad consensus among reconstructive urologists regarding detubularization and spheric reconfiguration of bowel as basic principle in the creation of a low-pressure, high-capacity reservoir, the issues of reflux prevention (afferent limb), and continence (efferent limb) are more controversial. The still growing number of techniques described for achieving continence in urinary reconstruction indicates that a universally applicable procedure with a low complication rate has not yet evolved. The principal methods for construction of a continence mechanism depend either on the formation of a nipple valve, utilization of the ileocecal valve, or construction of a flap valve. Among the different techniques, the versatile Mitrofanoff principle (3) has reached significant popularity, predictably providing continence and allowing easy catheterization in more than 90% of cases. In 1990, Riedmiller et al. introduced the Mitrofanoff theme to the ileocecal reservoir, significantly facilitating the Mainz pouch procedure (4).
When performing a Mitrofanoff, the method of attachment of the appendix to the reservoir (reversed, in situ; imbricated, embedded, unaltered), the location of the stoma (umbilicus, lower abdomen), and appropriate alternatives remain controversial. It is known that the success of the Mitrofanoff principle is not dependent upon the underlying pathologic condition, the type of tube and its possible peristalsis, the type and configuration of the reservoir, or the patient’s age but the maintenance of a pressure gradient between channel lumen and the reservoir. It is therefore the availability of the required material and the simplicity of a technique that determine its popularity. Recent variations of the Mitrofanoff theme have aimed at its simplification and reduction of longterm complications.
Ileocecal Pouch (Mainz Pouch I)
Intussuscepted Ileal Nipple
After mobilization of cecum, ascending colon, and the right colonic flexure, the mesentery is divided between the right colic and the ileocolic artery. A 13-cm segment of cecum and ascending colon is isolated along with two equal-sized limbs of distal ileum. If the vermiform appendix is absent as in cloacal exstrophy, completely obliterated, immobile, insufficient in diameter and length, or had been removed beforehand, we usually isolate an additional portion of ileum measuring 10 to 12 cm (Fig. 82.1A). While the latter is left tubularized, the remaining bowel segment is split antimesenterically. These three opened bowel loops are folded in the form of an incomplete W, and their posterior aspects are sutured to one another to form a broad posterior plate (Fig. 82.1B). Both ureters are implanted into the large bowel segment of the pouch plate, forming submucosal tunnels for reflux prevention (Fig. 82.1C).
The midportion of the intact ileal segment is freed of its mesentery for a distance of 4 to 5 cm to allow its intussusception (Fig. 82.1D and E). We apply only one row of staples to stabilize the intussusception itself (Fig. 82.1F). Thereafter, the intussuscepted nipple is pulled through the intact ileocecal valve and two additional rows of staples are applied to attach the nipple to the ileocecal valve. After the mucosa has been removed from the rim of the intussuscepted nipple and the colonic aspect of the ileocecal valve, their circumferences are sewn together with a resorbable running suture.
The bowel is then folded on itself in a side-to-side fashion, thus creating a low-pressure and high-capacity reservoir. Ureteral stents (6Fr or 8Fr) and a 10Fr pouchostomy are led through the abdominal wall at separate sites. The entire pouch is rotated so as to bring the efferent limb to the region of the umbilicus. A small button of skin is removed from the depth of the umbilical funnel. The pouch is carefully attached to the posterior fascia with interrupted nonabsorbable sutures to prevent the pouch from rotating and kinking. The efferent limb is then connected to the umbilical funnel with interrupted absorbable sutures. If no umbilicus is present (as in the case of exstrophy), it is created by tubularizing a V-shaped cutaneous flap and connecting it to the appendicular stump.
 FIGURE 82.1 Ileocecal pouch (Mainz pouch I) with IIN valve. A: Isolation of the cecum/ascending colon (13 to 15 cm) and two equal-sized ileal loops (13 cm each) for reservoir formation and an additional ileal segment (10 to 12 cm) for nipple formation. Antimesenteric splitting of the bowel. B: Side-to-side anastomosis of the terminal and next proximal ileal loop with subsequent detubularization of the ascending colon. (continued) |
A vigorous washout regimen is started early in the postoperative course. Ureter stents are removed after 10 to 14 days. Clean intermittent catheterization is usually started at the end of postoperative week 3 after leakage and reflux has been ruled out by pouchogram.
Appendix Stoma
If the appendix is present and can be dilated to accommodate a 16Fr to 18Fr catheter, it is our first choice as ideal efferent segment for construction of a continence mechanism. In this case, a 15-cm segment of cecum and ascending colon is isolated along with two equal-sized limbs of distal ileum (12 to 13 cm each). The lower 5 cm of the cecum (cecal pole) is left tubularized and intact. The seromuscular layer of the intact cecal pole is divided along the tenia down to the mucosa analogous to the Lich-Gregoir procedure for vesicoureteral reflux (Fig. 82.2A). By careful dissection of the seromuscular tissue, a broad submucosal bed (5 cm in length) is created for the appendix.
The appendicular mesentery is freed of its excessive fatty tissue. Windows in the mesoappendix are excised between the branches of the appendicular artery without compromising the blood supply (Fig. 82.2B). Anatomic variations of the appendicular artery have to be respected, and an additional branch of the anterior or posterior cecal artery supplying the base of the appendix should be preserved. After the appendix is correctly positioned, the seromuscular layer is closed over the embedded in situ appendix with interrupted 4-0 polydioxanone sutures.
 FIGURE 82.1 (continued) C: Antirefluxing ureteral implantation into the colonic portion of the pouch plate using submucosal tunnels (3 cm length) with insertion of 6Fr or 8Fr ureteral stents. D: Removal of mesentery (4 to 5 cm) in the midportion of the most proximal intact ileal segment in preparation for intussusception. E: Intussusception of the ileal segment and stabilization by applying one row of staples. F: The IIN pulled through the ileocecal valve. G: Two additional rows of staples are used to attach the nipple to the valve. H: Completed attachment of the nipple to the valve. |
 FIGURE 82.2 Ileocecal pouch (Mainz pouch I) with appendix stoma. A: The seromuscular layer of the intact cecal pole is split along the tenia down to the mucosa; a broad submucosal bed (5 cm in length) for the appendix is created. B: Windows in the mesoappendix are excised between the branches of the appendicular artery without compromising the blood supply. C: After the appendix is correctly positioned, the seromuscular layer is closed over the embedded in situ appendix. |
A short mobile portion of the distal appendix remains for creation of the appendicoumbilical stoma (Fig. 82.2C). Formation of the pouch plate, ureterointestinal anastomosis, and attachment to the umbilicus are identical to the pouch with intussuscepted nipple.
Alternative Techniques for Construction of Continence Mechanism
More recent alternative techniques use a small-caliber conduit fashioned from the cecal wall. One technique uses a fullthickness tube lined by mucosa (Fig. 82.3A and B) and the other, a seromuscular tube lined by serosa (Fig. 82.4A-C) (5). Other authors have described transversely retubularized ileum (Fig. 82.5A-C) to create a tunneled access into the right colon (6).
Alternative Techniques for Ureteral Implantation
In dilated, irradiated, or otherwise compromised ureters, ureterointestinal anastomosis may be performed according to a technique that has been described by Abol-Enein and Ghoneim (serous-lined extramural tunnel) (Fig. 82.6A and B) (7).
Right Colon Pouches with Intussuscepted or Embedded Tapered Terminal Ileum
Several other authors use the ileocecal region in continent cutaneous urinary diversion. In contrast to the Mainz technique, they employ the ileum for construction of the continence mechanism but not for creation of the reservoir itself. Other colon pouches using nipple valve technology for the continence mechanism include modifications from many other centers and differ from one another by only a few features, predominantly related to the technique employed for stabilizing the nipple valve. In the “Tiflis” technique, the continence mechanism is created by tapering and submucosal embedding of terminal ileum (Fig. 82.7A and B) (8).
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