Free neurovascular transfer of latissimus dorsi muscle to the bladder. I. Experimental studies

Experimental studies were undertaken to investigate the practicability of a microneurovascular transfer of latissimus dorsi muscle to the bladder, and to look for possible techniques enhancing evacuation of a reservoir such as the bladder by striated muscle.Twelve dogs were used for the studies. They were divided into 3 groups. Group I: Evacuation proficiency of a re-configured latissimus dorsi under tension was hydrodynamically tested after 6 months. Group II: Microneurovascular latissimus dorsi transposition anastomosing thoracodorsal vessels and nerve to circumflexa ilium profunda vessels and a lumbar plexus motor nerve, respectively, was performed to cover the bladder devoid of up to 50% of the detrusor muscle. Group III: Microneurovascular latissimus dorsi transposition was used to reconstruct the bladder after supratrigonal cystectomy. Urodynamic and radiographic in vivo studies were done after 6 and 9 months.Stimulation of the thoracodorsal nerve of geometrically reconfigurated non-transposed latissimus dorsi reservoirs after 6 months yielded average intraluminar pressures of 190 cm. H2O at maximum capacity, and 35 cm. H2O at a minimum capacity of 10 to 15 cc. Stimulation of latissimus dorsi transposed to the bladder resulted in a visible and measurable contraction of the transplanted muscle after 9 months. Mean bladder volumes in group II animals pre- and postoperatively were 267.5 and 270 cc, respectively. During cystography the bladder outline was smooth both during filling and voiding. Light and electron microscopic examination confirmed viable, re-innervated muscle.The "tension-torsion" reconfiguration produced intraluminal pressures which should enable stimulated striated muscle to evacuate bladder-like reservoirs successfully. Microneurovascular free transfer of latissimus dorsi muscle resulted in reinnervated, functional muscle in the pelvis. Augmentation cystoplasty using the latissimus dorsi in conjunction with a free omental flap for substitution of an accompanying mucosal defect was unsuccessful. The concept of microneurovascular transfer of latissimus dorsi muscle to the pelvis may be used for complicated fistula of the lower urinary tract, and may be a possible solution for the therapy resistent acontractile bladder.