Either of the following 2 methods can be used to prepare the bladder:
· A U-shaped flap can be lifted with its base anterior on the bladder
· The bladder can be opened via a sagittal incision extending from an anterior position posteriorly to the trigone
If part of the bladder is being removed to prevent symptom recurrence (as, for instance, in patients with interstitial cystitis), the bulk of the bladder may be excised around the trigone. In this case, an orthotopic bladder substitution or continent urinary diversion may be a better option. The anastomosis should be widely patent so as not to create a poorly draining diverticulum.
A standard midline laparotomy incision is most often used, though a lower abdominal transverse incision can be used for some nongastric enteric segments.
Before dividing the intestine, test the mobility of the segment to ensure that it will reach the bladder without tension. Always create a vascular arcade within the mesentery to the isolated bowel segment. After reestablishing the continuity of bowel segments, mesenteric defects should be closed to prevent internal hernia formation. To prevent ischemic necrosis, small bowel should not be divided more than 8 cm from an arcade artery.
The abdomen should be packed and draped carefully to prevent contamination of the surgical field with enteric contents. Enteric segments should be irrigated thoroughly to remove gastrointestinal (GI) contents.
Intestinal segments should be detubularized by incising them with a cautery on the antimesenteric side to create a rectangular surface and to minimize forceful contractions in the augmented bladder (see the image below).
Augmentation cystoplasty. Isolate segment of ileum chosen for augmentation on adequate mesentery, and reestablish intestinal continuity. Close ends of segment with suture, and open antimesenteric surface.
Intestinal segments should be sutured through their full thickness with a continuous absorbable suture, and the mucosal layer should be inverted. Forming the intestinal segment into a semispherical shape gives the augmented bladder maximal capacity and compliance. A wide anastomosis between the segment and the native bladder is important for optimal volume and drainage.
A suprapubic tube should be placed through the opened bladder and brought out through a separate skin incision. A drain is placed near the bladder as an indicator for urinary leakage.
The ileal segment should be based 15-20 cm away from the ileocecal valve to preserve the absorptive function of the terminal ileum. It should be between 15 and 40 cm long (usually about 25 cm), depending on patient age and the desired augmentation of bladder volume. A slightly longer segment is preferable to one that is too short.
Once the rectangular patch is formed, it is folded and sutured into a U-shaped cup; longer segments can be folded into S- or W-shaped cups (see the image below).
Augmentation cystoplasty. Fold ileal segment, and sew it upon itself. This detubularizes segment, reduces enteric contractions, and maximizes volume that segment contributes to urinary storage.
A vesicointestinal anastomosis is then performed in 1-2 layers with a 2-0 absorbable suture (see the image below).
Augmentation cystoplasty. Anastomose augmenting segment to prepared bladder. Perform wide-mouthed anastomosis to ensure that augmentation is spherical. If this is not carried out properly, augmenting segment can exist only as poorly draining diverticulum that is prone to complications.
The sigmoid colon is the part of the large intestine that is most commonly used as an augmentation segment. A sigmoid segment should be 15-20 cm long. Because of the strength of sigmoid contractions, proper detubularization of this segment is of particular importance.
The surgical incision and exposure are similar to those used in ileocystoplasty. The sigmoid segment is inspected and palpated to ensure that no pathology is present. The flap is then folded and sutured into an S- or U-shaped segment and anastomosed to the bladder in 2 layers with an absorbable suture.
An ileocecal segment is often used for patients who require a catheterizable stoma. The terminal ileum is narrowed over a catheter, and the continence mechanism of the ileocecal valve is supported by imbrication and intussusception of the ileocecal junction.
A midline incision is made from the xiphoid process to the pubic symphysis. A 10-20 cm wedge of anterior and posterior stomach is isolated, with the base along the greater curvature of the stomach. The apex should not extend to the lesser curvature, where branches of the vagus nerve can be damaged. The vascular segment used for the flap can be the right or left gastroepiploic artery; however, the right is often favored because it is more frequently the dominant blood supply to the stomach.
The stomach is reapproximated with 2 layers of absorbable sutures. Windows are created in the transverse mesocolon and the mesentery of the small intestine, and the gastric wedge is brought to the prepared bladder. Care should be taken to avoid twisting or angulating the vascular pedicle. The augmenting segment is anastomosed to the bladder with 2 layers of absorbable sutures.
Ureterocystoplasty is possible only when the patient has massive ureteral dilation. The dilated ureter can be mobilized into the pelvis. The bladder is opened in the sagittal plane, and the posterior portion of the incision is directed toward the corresponding ureteral orifice.
The ureter is not separated from the bladder but is folded upon itself as a patching segment. It is then anastomose the ureter to the prepared bladder with an absorbable suture. If ipsilateral nephrectomy is not performed, care must be taken to the preserve proximal ureteral blood supply.
Autoaugmentation (also called detrusor myectomy) involves incising or excising the serosa and muscular components of the bladder dome and allowing the mucosa of the bladder to protrude. The mucosa may then be either left alone or supported by a cover of omentum or demucosalized bowel. Autoaugmentation can increase bladder volume and improve detrusor compliance without using enteric segments, thereby reducing surgical morbidity significantly.
Laparoscopic augmentation cystoplasty is becoming increasingly common at many institutions. The primary goal of this procedure is to adhere to the surgical principles of the open procedure outlined above. Many surgeons create a lower midline or transverse incision to perform some parts of the procedure extracorporeally and to assist with some of the reconstructive elements of the operation.