ABSTRACT
Purpose : To discuss the role and mechanism of action of soft tissue reinforcement interposition flaps (strifs) in hypospadias repairs (reinforced hypospadiac urethroplasties). Materials and methods : between 2000-2005, 120 consecutive hypospadiacs (distal 85, mid 20, proximal 15), who underwent primary reinforced urethroplasties employing different types of strifs, were retrospectively analyzed. the strifs were highly vascular soft tissue pedicled flaps (devoid of epithelium) interposed between neo-urethras and the covering skin to reinforce the neo-urethras against fistula formation. the strifs were harvested, without much donor site deformity, from: preputial skin, penile skin and scrotal skin by de-epithelialization. those from buck′s fascia, corpus spongiosum and tunica vaginalis are strifs without epithelium anyway, therefore do not need de-epithelialization. redo urethroplasties and micropenises were not included. seven patients were excluded because they had incomplete follow-up. the remaining 113 (distal 84, mid 17, proximal 12) were followed up for nine to 40 months for number, size, location, spontaneous closure and persistence of urethro-cutaneous fistula (ucf), and other complications with regard to the severity of hypospadias, method of neourethral re-construction, types of strifs employed and skin cover used. a total of 158 strifs and 124 skin covers were used in 113 hypospadiac urethroplasties. Results : the first surgery was curative in 74 (65%) of 113 patients. in the remaining 39 (35%), various complications included 12 urethro-cutaneous fistulas (ucfs), 10 urethral strictures, six cases each of penile torsion and meatal stenosis and five cases each of superficial necrosis and poor cosmesis. of these 39 patients, 25 (64%) recovered with conservative treatment and 14 (36%) required re-operation, i.e. ucfs and strictures in four cases each and penile torsion, meatal stenosis and dog-ears in two cases each. all the 12 ucfs were single, pinpointed and were located at the corona in five and at the shaft in seven. eight (67%) of the 12 ucfs healed spontaneously during the follow-up period of 12 weeks.Conclusions : harvesting strifs is technically easy, however, great care is required in their handling, accurate placement and suturing over and around the re-constructed neo-urethras for their secured reinforcement against fistula formation. use of strifs in hypospadias repairs decreases fistula-associated morbidity but does not absolutely prevent fistula formation. the strifs reduce the size and prevent multiplicity of ucfs and locate the ucfs eccentrically well away from the neo-urethra to facilitate their spontaneous (conservative) as well as subsequent (surgical) closure. the mechanism of action of strifs is multi-factorial, like acting as a mechanical barrier; preventing suture line superimposition; inducing neo-angio-genesis; working as biological drain; providing mechanical support; and, filling the dead spaces.
KEY WORDS Hypospadias - soft tissue reinforcement interposition flaps - urethra - urethro-cutaneous fistulas
