Is vaginal mucosal graft the excellent substitute material for urethral reconstruction in female-to-male transsexuals?

PURPOSE: Construction of a neourethra is always considered to be a difficult part in phalloplasty, especially for the female-to-male (FTM) transsexual patients. We report our experience with prefabricated pars pendulans urethrae using vaginal mucosal graft for phalloplasty in FTM transsexuals. MATERIALS AND METHODS: We retrospectively reviewed notes on the 22 FTM patients treated with pedicled-flap phalloplasty with prefabricated pars pendulans urethrae using vaginal mucosal graft between January 2008 and December 2012. Surgical outcome, urological function, and complications were recorded. Histological difference between normal mucosa and skin, and pathological changes of vaginal mucosal graft were also observed. RESULTS: All the reconstructive penis survived, and patients could void in a standing position finally at a median follow-up of 25.4 ± 6.0 months. Urethral fistula and urethral stricture rates were 31.8 % (7/22 patients) and 4.5 % (1/22 patients), respectively. The occurrence of the urethral stricture was remarkably low compared with previous reports. Our histological results also showed a pronounced similarity between vaginal and buccal mucosa. Morphologically, they resembled urethral epithelium more closely than the forearm skin. Following the free transfer, the vaginal mucosal graft also showed a good revascularization and the inflammatory reaction and the extent of fibrosis of the mucosa decreased to the normal level after a 6-month prefabrication. CONCLUSION: With prefabrication of vaginal mucosal graft, we reconstruct a competent phallic neourethra in these FTM transsexuals. According to its histological similarities and source character, the vaginal mucosa is the excellent substitute material for promising urethral reconstruction in FTM transsexuals.

Architectural properties of the neuromuscular compartments in selected forearm skeletal muscles.

The purposes f this study were to (i) explore the possibility of splitting the selected forearm muscles into separate compartments in human subjects; (ii) quantify the architectural properties of each neuromuscular compartment; and (iii) discuss the implication of these properties in split tendon transfer procedures. Twenty upper limbs from 10 fresh human cadavers were used in this study. Ten limbs of five cadavers were used for intramuscular nerve study by modified Sihler's staining technique, which confirmed the neuromuscular compartments. The other 10 limbs were included for architectural analysis of neuromuscular compartments. The architectural features of the compartments including muscle weight, muscle length, fiber length, pennation angle, and sarcomere length were determined. Physiological cross-sectional area and fiber length/muscle length ratio were calculated. Five of the selected forearm muscles were ideal candidates for splitting, including flexor carpi ulnaris, flexor carpi radials, extensor carpi radialis brevis, extensor carpi ulnaris and pronator teres. The humeral head of pronator teres contained the longest fiber length (6.23 ± 0.31 cm), and the radial compartment of extensor carpi ulnaris contained the shortest (2.90 ± 0.28 cm). The ulnar compartment of flexor carpi ulnaris had the largest physiological cross-sectional area (5.17 ± 0.59 cm(2)), and the ulnar head of pronator teres had the smallest (0.67 ± 0.06 cm(2)). Fiber length/muscle length ratios of the neuromuscular compartments were relatively low (average 0.27 ± 0.09, range 0.18-0.39) except for the ulnar head of pronator teres, which had the highest one (0.72 ± 0.05). Using modified Sihler's technique, this research demonstrated that each compartment of these selected forearm muscles has its own neurovascular supply after being split along its central tendon. Data of the architectural properties of each neuromuscular compartment provide insight into the 'design' of their functional capability. In addition to improving our understanding of muscle anatomy and function, elucidation of forearm neuromuscular compartments architecture may ultimately provide information useful for selection of muscle subdivisions used in tendon transfer.