Modified Byars’ flaps for securing skin closure in proximal and mid-penile hypospadias

Abstract

Objective: The objective of this study was to describe a modification for skin closure combined with tubularized incised plate (TIP) urethroplasty in the repair of proximal and mid-penile hypospadias.

Patients and methods: The study included 47 patients with nondistal hypospadias who underwent a primary TIP procedure from September 2007 to May 2010. Meatal position was mid-shaft (n = 20), penoscrotal (n = 20), and scrotal (n = 7). The patients in the study were divided into two groups according to a modification in the technique of skin closure, which involved incising the prepuce vertically into two halves, then harvesting the dartos flap for covering the repair from one half, leaving the other preputial half to reconstruct the ventral skin without compromising its blood supply.

Results: In the standard procedure (n = 19 patients), complications included glanular dehiscence (10.5%), glanular fistula (5%), urethrocutaneous fistula (10.5%), and skin complications (21%). In the modified procedure (n = 28 patients), complications included glanular dehiscence (7%) and glanular fistula (3.6%), but no skin complications or urethrocutaneous fistulae occurred.

Conclusion: The modified Byars’ flaps is a useful alternative for skin closure during proximal and mid-shaft TIP urethroplasty, with fewer complications and acceptable cosmetic outcome.

Introduction

Hypospadias is a congenital anomaly with deficient ventral structure of the penis. The choice of operative technique for hypospadias repair depends on the severity of hypospadias, and is influenced by the surgeon’s experience and perception of where the priorities should lie [Bracka, 1995]. The paucity of soft tissues which could be readily and easily mobilized from an adjacent area to reconstruct the ventral defect is believed to be the prime factor responsible for the dilemma experienced by all surgeons involved. The prepuce is an important source of tissues that can be used in different ways in the repair of hypospadias: (1) neo-urethral reconstruction, (2) providing a barrier layer to cover the repair, or (3) providing skin cover to the ventral shaft. Unfortunately, each patient has only one dorsal prepuce, usually serving one function in the repair.

Six decades ago, Luis Byars described his (staged) technique of vertical incision of the dorsal preputial skin and translocation of the resultant skin flaps to the ventral surface to provide adequate skin for the subsequent creation of the neo- urethra [Byars, 1951]. More recently, a modified approach of the Thiersch–Duplay procedure, i.e. the tubularized incised plate (TIP) urethroplasty advocated by Snodgrass [Snodgrass, 1994], has gained popularity as the surgical regimen to correct the deformity.

Here, we report our experience in using a modified approach combining TIP urethroplasty with Byars’ flaps to avoid skin complications in proximal and mid-penile hypospadias. In this technique, we aim to achieve two goals from the prepuce by splitting it into two halves, each serving a function. One half will provide a barrier layer to cover the TIP urethroplasty, and the other half will be used to reconstruct the deficient ventral penile skin.

Patients

The study included 47 boys with nondistal hypospadias, who underwent primary TIP repair from September 2007 to May 2010. We excluded from the study those with distal or recurrent hypospadias, in addition to another two patients with severe chordee and short urethra, who were considered for a staged repair. All patients in this study were operated on by the same surgeon (the author) at two tertiary centers for pediatric surgery in Egypt (Ain-Shams University Children’s Hospital and Benha Specialized Children’s Hospital). Patient age ranged from 6 to 48 months (mean age 19 months). Meatal position was mid-shaft (n = 20), penoscrotal (n = 20), and scrotal (n = 7). The first 19 patients (group 1) underwent the standard procedure. A modification regarding the barrier layer and skin closure was made in the other 28 patients (group 2).

Surgical technique

Operations were performed under general anesthesia with caudal analgesia, using loops magnification (2.5×). Urinary antiseptics were given postoperatively for a week until removal of the urinary catheter.

Standard procedure

A circumcising incision is made about 5 mm from the coronal sulcus. Ventrally the urethral plate is outlined by a U-shaped incision that is extended to healthy skin proximal to the meatus. The penile skin is then degloved to the penoscrotal junction along the Buck’s fascia, and the bands around the proximal plate and spongiosum are released. In the case of residual penile chordee, an artificial erection test is performed and the quality of the urethral plate is assessed. The presence of a short urethra would necessitate division of the urethral plate to straighten the penis, and these patients were excluded from the study. When the urethral plate is adequate, the residual chordee is corrected by dorsal tunica plication. The tunica albuginea is incised longitudinally on each side (avoiding the neurovascular bundle) opposite the point of maximum curvature, and then closed transversely with buried knots (4-0 Prolene).

The plate is then separated from the glans, and the glanular wings are mobilized. A deep midline relaxing incision is made in the urethral plate as recommended by Snodgrass to increase its width. Starting at the mid-glans and proceeding proximally to the meatus, the urethral plate is tubularized over an 8-Fr catheter with a single-layer full-thickness continuous running (6-0) polyglactin suture. Next, a wide dartos flap is dissected from the prepuce and dorsal skin to cover the urethroplasty. Ventral transposition of the flap is achieved by passing the penis through a buttonhole created through the proximal third of the flap. For a long urethroplasty (>3 cm), another anteriorly based subcutaneous scrotal flap is turned up to cover the proximal repair. The glanular wings are then closed by interrupted subcuticular (6-0) polyglactin sutures (2–3 stitches) without fixation to the neo-meatus. Mucosal collar is approximated in the midline. A vertical relaxing incision of the dorsal preputial skin is then followed by ventral midline skin closure simulating the median raphe with continuous running (6-0) polyglactin suture (Figure 1B). The dorsal skin is sutured to the coronal skin edge at the 12 o’clock position, and excess terminal skin is equally excised from both sides for circumcision. After completing skin closure with running sutures, the penis is dressed and sandwiched against the anterior abdominal wall.

Figure 1.

Skin complication following dorsal dartos flap dissection from the whole prepuce (standard procedure): (A) Hypospadias with deficient ventral skin (11-month-old boy); (B) ventral midline skin closure; (C) ischemic ventral skin; (D) healing by secondary epithelialization with mild scaring (2-year follow up).

Modified procedure

The procedure is similar except for the barrier layer and skin closure. Before dissection of the dorsal dartos flap, the prepuce is gently stretched and incised vertically into two halves (originally described by Byars [1951]) (Figure 2C). The dartos flap is dissected from one half of the prepuce and brought ventrally around the side of the penile shaft to cover the urethroplasty, leaving the other preputial half with intact vascularity to reconstruct the ventral shaft skin (Figure 2D). After closing the glanular wings, the dorsal skin is sutured to the coronal skin edge usually at the 12 o’clock position, but this can be adjusted to correct penile rotation. The skin of the preputial flap of doubtful viability, from which the dartos flap was dissected, is excised. The other preputial skin flap, still keeping its subcutaneous tissue, is then brought around the other side of the penile shaft to cover its ventral surface after unfolding of its inner layer and excision of any excess skin (Figure 2E). Closure is then completed by running sutures. The ventral skin suture line is shifted from the midline due to inequality of skin flaps (Figure 2E).

Figure 2.

Operative pictures of the steps of the modified approach combining TIP urethroplasty with Byars’ flaps: (A) hypospadias with deficient ventral skin (1.5-year-old boy); (B) penile degloving; (C) vertical incision of the prepuce; (D) the barrier layer is taken from one half of the prepuce; (E) the other preputial half is used to cover the ventral shaft; (F) follow up at 1 month.

Results

Standard procedure

This group included 19 patients. Their mean age at surgery was 22 months, with a mean follow-up period of 20 months. The meatus was mid-penile in 12 patients, while it was more proximal (penoscrotal) in seven patients. Urethrocutaneous fistula developed in two patients (10.5%), glanular dehiscence in another two, and glanular fistula in one patient (5%). Ventral skin loss developed in four patients (21%) but with no effect on the urethroplasty which was well covered by a barrier layer (Figure 1C). Healing by secondary epithelialization occurred with mild to moderate scarring (Figure 1D). Skin complications were more pronounced among patients with penoscrotal hypospadias (42.8%) (Table 1). Patients were not routinely subjected to urethral calibration or endoscopy as there was no clinical signs of obstruction detected during the follow-up period. In one patient, who was brought to the operating room to close a urethrocutaneous fistula, endoscopy was performed revealing a healthy looking patent urethra.

Table 1.

Complication rate in standard and modified approaches.

Technique	Standard approach (19 patients)		Modified approach (28 patients)
Meatal position	Mid-penile (12 patients)	Penoscrotal (7 patients)	Mid-penile (8 patients)	Penoscrotal and scrotal (20 patients)
Lost to follow up	2	1	0	1
Skin complications	1 (8.3%)	3 (42.6%)	0	0
Glanular dehiscence (partial or complete)	3 (25%)	0	1 (12.5%)	2 (10%)
Urethrocutaneous fistula	1 (8.3%)	1 (14.3%)	0	0
Mean follow up	20 months		12 months

Modified procedure

This group included 28 patients. Their mean age at surgery was 18 months, with a mean follow-up period of 11 months. The meatus was mid-penile in eight patients, penoscrotal in 13 patients, and scrotal in seven patients. Glanular dehiscence occurred in two patients (7%), while a glanular fistula occurred in one (3.6%). Neither skin complications nor urethrocutaneous fistulae were observed in this group during the period of follow up (Table 1). Urethral calibration was needed in two patients who presented with clinical signs of obstruction; one of them had stenosis in the glanular urethra which required repeated dilatations. Again an endoscopy revealed a healthy looking urethra in a patient who was brought to the operating room to repeat dorsal tunica albuginea plication for persistent chordee.

Discussion

In their review article, Baskin and Ebbers referred to the importance of skin coverage by counting it as one of five sequential steps for the successful repair of hypospadias [Baskin and Ebbers, 2006]. This has also been considered by Duckett, who mentioned that one of four goals in the one-stage repair of hypospadias is to cover the penis with skin that is pliable, elastic and symmetrical and preferably non-hair-bearing [Duckett, 1981]. Several techniques have been described to achieve this goal by providing skin flaps of reliable viability to cover the ventral penile shaft [Snodgrass et al. 1988; Gonzalez et al. 1996].

Many reports have emphasized the importance of the barrier layer covering the repair before skin closure [Telfer et al. 1998]. In proximal hypospadias repair, a TIP urethroplasty has the advantage of sparing the prepuce which can provide the dartos flap to be used as a barrier [Retik et al. 1994]. However, this may jeopardize the blood supply of the dorsal skin flaps. In minor forms of hypospadias, these nonviable skin flaps may be considered excess and can be excised; however, in more severe forms these flaps are needed to reconstruct the deficient ventral penile skin. A very good alternative to the dartos flap is the tunica vaginalis flap described by Snow [Snow, 1986]. However, this technique requires dissection around the testis and its pedicle, and may be avoided in patients who have undergone orchidopexy [Telfer et al. 1998].

Among our patients with proximal hypospadias, we noticed a strikingly high incidence of skin complications on using the conventional dorsal dartos flap for covering the TIP urethroplasty. This high complication rate might have been diminished by isolating a smaller island of the dartos flap; or if the dissection were a bit further away from the skin, and both the dartos pedicle and skin would have survived. However, we believe that there are other contributing factors related to the quality of the prepuce which is usually underdeveloped with the more severe degrees of hypospadias [Radojicic and Perovic, 2004]. We thought of changing our technique for skin closure by modifying the old Byars’ technique, to allow a multilayered closure without compromising the blood supply to the ventrally placed skin flap. We aim to achieve two goals by splitting the prepuce into two halves each serving a function. One half will provide a barrier layer to cover the urethroplasty and the other half will be used to reconstruct the deficient ventral penile skin. Reviewing the literature, we found a similar idea, ‘The split prepuce in situ onlay hypospadias repair’, introduced by Rushton and Belman [Rushton and Belman, 1998]. They presented a modification of the onlay hypospadias repair, which is applied essentially for distal types (short repairs). Their modification optimizes the blood supply to the onlay flap and provides well-vascularized coverage of the neo-urethra, resulting in a decreased complication rate [Rushton and Belman, 1998]. Our technique differs in being combined with TIP urethroplasty, and applied in the repair of proximal hypospadias with deficient ventral shaft skin.

Gonzalez and colleagues described the double onlay preputial flap technique to overcome problems of the classic onlay urethroplasty, mainly the doubtful viability of the Byars’ flaps after dissection of the onlay pedicle [Gonzalez et al. 1996]. They reported good cosmetic and functional results. A potential disadvantage of their technique was a persistent bulky appearance of the penile ventrum, which was most probably due to impaired venous and lymphatic drainage of the island skin flap used to reconstruct ventral skin [Gonzalez et al. 1996]. Our technique has escaped this disadvantage, as the skin flap used to cover the penile ventrum is continuous with the dorsal skin (not an island flap), and therefore has intact venous and lymphatic drainage. We believe excess skin is far better than deficiency, however, careful fashioning and trimming of excess flap tissue intra-operatively is needed to obtain the best cosmetic outcome.

In the absence of contraindications to a TIP urethroplasty (unhealthy plate, severe chordee) [Snodgrass et al. 1998], the approach described in this report can be used for proximal and mid-penile hypospadias that are associated with deficient ventral shaft skin. The cosmetic outcome appears well accepted although being suboptimal in lacking a median raphe. However, this approach helps to avoid skin complications (sloughing and scaring) owing to the reliable vascularity of the skin flap used to cover the shaft ventrum. Penile torsion is prevented by the balance created from rotating a flap on either side of the penis. Also, we have noticed decrease in the urethrocutaneous fistulae (none up to now). This might be explained by the skin closure being shifted laterally away from the urethral suture line, adding extra security to the barrier layer. The study is limited by the small number of patients and the relatively short follow up; however, the preliminary results using this modified approach are encouraging.

Conclusion

The modified Byars’ flaps technique is a useful alternative for skin closure that can be combined with TIP urethroplasty in the repair of proximal and mid-penile hypospadias, with fewer complications and accepted cosmetic outcome. This approach maximizes the utilization of the prepuce in the repair by providing a barrier layer for the urethroplasty from one preputial half, and a well-vascularized skin flap to cover the ventral shaft from the other half.