A Simple Neobladder Using a Porcine Model: The Double Limb U-Pouch

Area of Science:

• Urology
• Surgical Innovation
• Biomedical Engineering

Background:

• Orthotopic neobladder construction is a key component of urinary diversion following cystectomy.
• Existing neobladder techniques, such as Studer and Camey I, have established capacities and compliances.
• The development of novel neobladder designs aims to improve functional outcomes and surgical applicability.

Purpose of the Study:

• To create a novel, simple neobladder design: the double-limb U-Pouch (D-LUP).
• To evaluate the capacity and compliance of the D-LUP neobladder in comparison to established models (Studer, Camey I).
• To assess the feasibility of the D-LUP for orthotopic urinary diversion, particularly in robotic surgery.

Main Methods:

• Neobladders (Camey I, spherical, and D-LUP) were constructed from 40-cm segments of porcine small intestine.
• Comparative analysis focused on cystometric capacity, compliance, and pouch-to-urethra anastomotic distance.
• Animal tissue (pig kidneys, ureters, bladders, small intestine) was utilized post-autopsy under approved protocols.

Main Results:

• The D-LUP neobladder demonstrated the largest cystometric capacity (430 mL) at 30 cm H2O, exceeding Camey I (250 mL) and Studer (350 mL).
• Compliance was comparable across the studied neobladders: D-LUP (16 mL/cm H2O), spherical (15 mL/cm H2O), and Camey I (10 mL/cm H2O).
• The D-LUP achieved a pouch-to-urethra anastomotic distance of 0 cm, similar to the Camey I, and shorter than the spherical reservoir (10 cm).

Conclusions:

• The D-LUP neobladder is a simple-to-construct orthotopic diversion with a more dependent ileo-urethrostomy.
• It exhibits a larger capacity and comparable compliance to spherical neobladders.
• The D-LUP design shows potential for application in robotic surgery, supported by laboratory data.