Bladder substitution with ileocaecal (Mainz) pouch. Clinical performance over 2 years

Area of Science:

• Urology
• Oncology
• Surgical Innovation

Background:

• Transitional cell carcinoma of the bladder necessitates radical cystectomy and pelvic lymphadenectomy.
• Urinary diversion is a critical component following cystectomy, with various techniques available.
• The Mainz pouch is an ileocaecal bladder substitution method for urinary reconstruction.

Purpose of the Study:

• To evaluate the short- and intermediate-term functional and oncological outcomes of the Mainz pouch procedure.
• To assess complications and patient quality of life after ileocaecal bladder substitution.
• To analyze upper tract changes and metabolic alterations post-Mainz pouch construction.

Main Methods:

• A cohort of 11 patients with transitional cell carcinoma of the bladder underwent radical cystectomy and pelvic lymphadenectomy.
• Ileocaecal bladder substitution (Mainz pouch) with urethral anastomosis was performed.
• Patients were followed for 12 to 27 months (mean 18 months) with clinical assessment, upper tract studies, and serum electrolyte analysis.

Main Results:

• Six patients achieved successful daytime and nighttime urinary continence with timed voiding.
• Four patients required intermittent catheterization due to inadequate Valsalva maneuver.
• One patient developed an enterourethral anastomosis stricture requiring a suprapubic tube.
• Upper tract dilation occurred in 4 of 22 renal units, with one requiring intervention.
• Metabolic changes included elevated chloride in 6 patients, hypocarbia in 3, and reduced vitamin B12 in all, without megaloblastic anemia.

Conclusions:

• The Mainz pouch demonstrates very satisfactory short- and intermediate-term functional results for bladder cancer patients.
• While generally successful, potential complications include voiding dysfunction and anastomosis strictures.
• Regular monitoring for upper tract changes and metabolic disturbances is recommended.