**5. Surgical techniques**

### **5.1 Ileal reservoirs**

For the creation of most ileal reservoirs a 60–75 cm of terminal ileum is used. The segment is detubularized and folded in various ways to create a sphere shape. Several modifications exist regarding the folding technique and variations in the placement of the ureters (with or without antireflux mechanism).

Of the two most popular configurations around the world are the Hautmann W-neobladder (and its various modifications) and the Studer pouch neobladder. Both are relatively simple constructions and allow direct ureteroileal anastomosis, which has been shown to have the lowest risk of subsequent stricture.

#### **5.2 Studer pouch**

Studer and colleagues initially described an ileal bladder substitute, as a long, afferent, isoperistaltic, tubular ileal segment. It is believed that the long segment functionally prevents vesicoureteral reflux when the patient voids by Valsalva maneuver (Studer, 1996) [1]. It is straightforward to construct and has become one of the most popular form of orthotopic diversion in the Urological community. The advantages of this bladder substitute include the simplicity of construction, the lack of a requirement for surgical staples and the ability to accommodate short ureters. The reservoir portion uses the optimal double-folded U configuration as originally described by Kock (Kock, 1989). Studer's group reported on 480 of these procedures performed from 1985 through 2005 with excellent long-term results in terms of continence, preservation of renal function and a ureteroileal stricture rate of less than 3% (Studer, 2006). The original description used a 20-cm afferent segment with 40 cm used for the reservoir. In more recent years Studer has advocated using a somewhat shorter afferent ileal segment with similar results (Studer, 2006) [1].

For Studer reservoir creation, a 54 cm of the terminal ileum is isolated, approximately 15-20 cm from the ileocecal valve. The distal and proximal segments are divided in an avascular plane, with staplers, ensuring mobility of the pouch and small bowel anastomosis to the urethra. In the process the Studer pouch is formed in a U shape using 40-44 cm of distal ileum with each limb measuring 20 cm and a proximal 15 cm segment is used as the afferent limb. The proximal end is closed with absorbable sutures, whereas the distal ileal segment is opened 2 cm away from the mesentery and the incised ileal mucosa is oversewn in two layers, using a running 3–0 polyglycolic acid suture for the creation of the sphere.

The rate of ureteroileal stricture is influenced by the type of anastomosis. The direct end-to-side Leadbetter or the combined Wallace anastomoses with interrupted fine absorbable sutures have been shown to have the lowest risk of stricture, approximately 3–6% (Pantuck, 2000; Hautmann, 2011) [1].

Common observations from series of patients undergoing orthotopic diversion include a gradual period of improvement in daytime continence over the first 6 to 12 months with a slower improvement in night-time continence even into the second year.

The evaluation and management of urinary incontinence after orthotopic diversion should be delayed until the neobladder has had time to expand. This may take 6 months to a year after surgery.
