The aim of this form of urinary diversion is to create a low-pressure reservoir that stores urine and releases it in a controlled manner. To achieve this, the urologist removes a segment of the small intestine approximately 50–60 cm long. The key step is detubularisation: the intestine is cut lengthways to interrupt the tubular peristalsis. The intestinal wall is then sutured into an intestinal sheet and shaped into a spherical (spherical) form. Depending on the technique, the reservoir is folded into an S- or W-shape. As the urethral sphincter is preserved, the neobladder is continent.
The bladder substitute formed from the small intestine is connected directly to the urethra to mimic natural bladder function.
There are various techniques for this orthotopic bladder replacement. The two best-known procedures were developed by Professors Studer and Hautmann.
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Studer neoblade (Studer neoblade): Here, a longer section of the ileum is used as a ‘chimney’, into which the ureters are implanted (ureteral implantation). This protects the kidneys from reflux.
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Hautmann’s neoblade: This technique uses a W-shaped folded intestinal flap to form the reservoir. It often provides a particularly large volume.
Both methods aim to create an anastomosis (connection) to the urethra, so that the patient does not have to wear a urine bag on the abdominal wall.
As the replacement bladder does not have its own muscle to contract (like the original bladder), emptying works differently. The patient must use their abdominal muscles to push the urine out. Initially, patients must learn to empty the new bladder regularly (every 3–4 hours) to prevent overstretching. As intestinal tissue produces mucus, mucus build-up can make urination difficult. Drinking plenty of fluids helps here. In rare cases (hypercontinence), the patient must self-catheterize to remove residual urine. Nocturnal urine leakage may occur, as the sphincter relaxes during sleep, but the reservoir may still be minimally active due to bowel movements (despite detubularisation).
Not every patient is suitable for orthotopic replacement. A contraindication exists if:
- The tumor has invaded the urethra (in which case the urethra must be removed).
- There is renal insufficiency.
- The sphincter is damaged (incontinence).
Complications may include urinary tract infections, metabolic disorders (acidosis due to reabsorption of urine via the intestinal mucosa) or problems at the anastomosis. If a neobladder is not possible, urinary diversions such as an ileal conduit or a continent pouch (e.g. Mainz pouch) are suitable options.
The creation of a neobladder (e.g. Hautmann or Studer) is a complex surgical procedure, but offers the best chance of a physically unimpeded life following a cystectomy. It provides the best functional and aesthetic replacement for the bladder.
What is the difference between Studer and Hautmann?
Both are forms of the orthotopic ileal neobladder. The difference lies in the folding of the intestinal loops and the way the ureters are connected. The Studer neobladder uses a long inflow segment, while the Hautmann bladder is constructed in a W-shape from the intestinal flap.
How often does the neobladder need to be emptied?
The neobladder is designed to store urine. Patients should empty it regularly (approximately every 4 hours), including once during the night, to prevent excessive pressure build-up and kidney damage.
Do you need a catheter with a neobladder?
Not usually. Emptying is done by pressing the abdomen. Only if the bladder does not empty completely does the patient need to learn how to perform sterile catheterization (self-catheterization).
