Folding and everting distal end of graft flap to reduce orifice stenosis following onlay urethroplasty

Rui JIANG¹, Jiang-Hua CHEN¹, Hong-Wei LI², Tong-Liang CHEN²

Asian J Androl 2003 Jun; 5: 159-161             

Keywords: hypospadias; urethra; complications

Abstract

Aim: Orifice stenosis remained to be a common complication of hypospadias repair. We had modified the preputial island flap urethroplasty by folding and everting the distal end of the pedicle graft flap to prevent the neo-orifice from stenosis. Methods: Sixteen patients had undergone hypospadias repair using a modified onlay island flap technique. A urethral catheter was retained for 8 days to 10 days after operation. Results: Satisfactory results were seen in all the patients with a cosmetically fine appearance. One patient had a urinary tract infection and another, urethrocutaneous fistula and both were amply treated. No glanular adhesion or stenosis occurred. A long-term follow up of 6 months to 4 years (mean: 2 years) in 15 patients did not find any complication. Conclusion: The modified preputial island flap urethroplasty technique is an easy, reliable and effective approach to reduce orifice stenosis in hypospadias repair.

1 Introduction

The onlay urethroplasty with a pedicle preputial island flap for hypospadias has gained wide popularity in the last decade [1-2]. It could be used to treat anterior-, mid- and posterior- penile hypospadias with or without chordee. Duckett [2] obtained excellent cosmetic and functional results with only a 10 % complications rate in his patients. However, several authors have reported significantly high complication rates of 25 %~52 %[3], including fistula, stenosis, infection, etc. We developed a neo-meatus by everting the distal end of the flap to reduce the frequency of stenosis formed after operation. In this department, the technique had been routinely used in selected cases suitable for onlay repair. The present paper was a review of the 16 cases underwent hypospadias repair using the technique.

2 Methods

From June 1995 to April 2001, 16 patients, aged 2 ~ 25 (mean: 15) years underwent an onlay urethroplasty with a pedicle preputial island flap repair for hypospadias. Four of them had an anterior and the other 12, a mid-penile hypospadias. Six patients had a mild chordee (20?to 30?bend). The urethral plate was all normal. The distance from the hypospadiac meatus to the corona was 15 mm~25 mm.

The onlay island-flap technique have been described previously [1-4]. Firstly, a traction suture of 5-0 prolene was made at the tip of the glans just beyond the distal margin of the meatal groove. A circumferential incision was created 5 mm proximal to the corona to retract the penile shaft skin and the dartos fascia. This incision was made and carried through the dartos fascia down to the superficial lamina of the Buck's fascia. The skin and the dartos fascia were dissected from the corpus. Two lateral incisions were made by the side of the borders of the urethral plate, which was preserved for 5 mm to 8 mm wide. The chordee was released by dissecting the urethral plate, completely dividing it into 2 cases and not in the other 14 cases. The chordee could be straightened by this technique without dorsal plication and the urethral plates were adequate in length after retracting the skin and dartos fascia completely. Before urethroplasty, intra-operative artificial erection was induced by placing a tourniquet at the base of the penis and injecting normal saline into the corpus cavernosum with a 25-gauge scalp-vein needle. Then extended the incision on both sides of the urethral plate toward the top of glans and dissected the penile spongiosum wing-shaped on both sides of the urethral fossa. The proximal urethra was cut down to the spongiosum. The transverse pedicle graft flap of foreskin or the vertical pedicle graft flap at dorsum of penis should be 0.8 cm~1.0 cm longer than the urethral defect (Figure 1a), i.e., 2.5 cm~3.5 cm in length and 0.8 cm~1.0 cm in width. The flap was carefully defatted over the back of a finger to remove all the surplus areolar tissue and to leave just a thin translucent membrane [5]. The flap was sutured interruptedly along the edges of the urethral plate with 7-0 absorbable sutures to reconstruct the neo-urethra, completing the repair up to the corona. The pedicle graft flap that exceeded the anterior edge of the neo-orifice was folded and everted (Figure 1b). The everted flap was trimmed to a half-moon shape so that the distance of anastomosis of the two glans wings would be less than 2 mm. The lateral glans wings were brought ventral to the urethra and anastomosed to the margin of the everted flap. Thus the neo-orifice of the urethra was not formed by annular anastomosis as in the traditional way (Figure 1c). Finally, the neo-urethra was covered by two layers of tissues with 7-0 absorbable sutures. The inner layer was closed interruptedly and the vascularized dartos fiscia was sutured to cover the inner suture line. Skin was made up in a usual manner by dividing the dorsal preputial skin and closing at the midline. The urethra was catheterized with an appropriate size catheter.

Figure 1. Folding and everting pedicle graft flap of foreskin. (a) Transverse pedicle graft flap of foreskin or vertical pedicle graft flap at dorsum of penis should be 0.8 cm~1.0 cm longer than urethral defect. The flap was sutured interruptedly along the edges of the urethral plate with 7-0 absorbable sutures to reconstruct the neo-urethra, completing the repair up to the corona. (b) The pedicle graft flap that exceeded the anterior edge of the neo-orifice was folded and everted. (c) The lateral glans wings were brought ventral to the urethra and anastomosed to the margin of the everting flap. Skin was made up in a usual manner by dividing the dorsal preputial skin and closing at the midline.

3 Results

Stitches were removed 7days~14 days after operation without flap necrosis in all the cases. The urethral catheter was withdrawn 8 days to 10 days after operation. There was an episode of transient erythema on day 1~3 and was resolved by oral antibiotics. The surgery was functionally and cosmetically successful in 15 patients (93.75 %) with a single-stage repair. Two to 6 days after removing the drainage, there were 1 urinary tract infection and 1 fistula. The fistula occurred at the anastomotic site between the hypospadiac meatus and the proximal end of the neo-urethra and was successfully closed by primary surgical procedure. No stenosis was noted in all the cases. The new meatus permitted a straight and strong urinary stream and had a cosmetically fine appearance. Fifteen patients were followed up for a mean of 2 years (range: 6 months to 4 years) without other complications, including diverticulum, residual chordee, ventrally displaced meatus, etc. Fifteen patients have been very pleased with the results and 1 case was lost to follow-up.

The dried blood blot and the secretions were likely to form a hardly cleaned crust at the urethral orifice after the classical onlay island flap urethroplasty. Infection may occur under this crust and was believed to be responsible for orifice stenosis. In this study, a new technique of folding and everting the distal end of the graft flap was developed. The modified urethroplasty technique was effective in preventing stenosis and infection. It was important to limit the length of the folding flap to 8 mm so that no redundant tissue exists. This method was also applicable to adolescent patients with fully developed urethral plate and glans and may have the following advantages.

Firstly, the neo-orifice was partially covered by the inner layer of the prepuce or the skin of dorsum penis other than the suture line of the skin incision as described in previous surgical procedures. So the clot will not stick to the edge of the smooth neo-orifice and is easily cleared away. As a result, the infection rate will be decreased.

Secondly, with this method the neo-orifice was not an anastomotic stoma as in the classical surgery, so that scar formation and contraction may be avoided. Meanwhile, the modified technique could maintain a normal appearing meatus as retraction of the neo-orifice back to the corona is prevented.

Finally, the two glans wings were not directly juxtaposed onto the ventral surface of the neo-urethra. Therefore, stenosis induced by compressing the distal neo-urethra may be avoided.

Although the overall results remained excellent, a little bulky appearance of the neo-orifice was found in 1 out of the 3 pre-adolescent patients (data not shown). It should be pointed out that patients with a small glans and a shallow urethral plate may not be appropriate for this kind of onlay repair surgery.

Acknowledgements

The authors wish to thank Professor Teng-Xiang MA, Tianjin Insitute of Urological Surgery for reviewing the manuscript.

References

[1] Elder JS, Duckett JW, Snyder HM. Onlay island flap in the repair of mid and distal penile hypospadias without chordee. J Urol 1987; 138: 376-9.
[2] Duckett JW. Transverse preputial island flap technique for repair of hypospadias. Urol Clin N Am 1980; 7: 423-30.
[3] Elbakry A. Complications of the preputial island flap-tube urethroplasty. BJU Int 1999; 84: 89-94.
[4] Duckett JW. Successful hypospadias repair. Contemp Urol 1992; 4: 42-6.
[5] Bracka A. Hypospadias repair: the two-stage alternative. Br J Urol 1995; 76(Suppl 3): 31-41.

home

Correspondence to: Dr. Rui JIANG, Kidney Diseases Center, First Affiliated Hospital, Zhejiang University Medical College, Hangzhou 310003, China.
Tel: +86-571-8723 0484
E-mail: jiangru8847@sina.com
Received 2002-09-17   Accepted 2003-03-03