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Keywords:

  • Hypospadias;
  • urethral plate;
  • tubularization;
  • cosmesis;
  • outcome;
  • complications

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. References

Objective

To evaluate the Snodgrass procedure for patients with hypospadias who have not undergone previous surgery and whose urethral plate is too narrow for tubularization alone.

Patients and methods

Thirty-two boys (mean age 18 months) underwent primary hypospadiac surgery performed by one surgeon (P.S.M.). Twenty-five boys had a distal hypospadias (coronal, subcoronal) and seven had a more proximal defect (penile shaft, penoscrotal). The operation involved incision of the urethral plate, which was then tubularized (Snodgrass procedure). The neourethra was then covered with a de-epithelialized pedicled dartos flap from the inner prepuce before glans and skin closure.

Results

With a mean follow-up of 10 months (range 2–14) there were two complications; one child with a coronal hypospadias developed a fistula whist one with a penile shaft defect had complete breakdown of the neourethra. The cosmetic appearance in the other 30 patients is that of a normal slit-like terminal meatus.

Conclusion

Tubularization of the incised urethral plate is a safe advance in the surgery of hypospadias. We recommend it for both distal and proximal defects, in patients where the urethral plate is insufficient for tubularization alone.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. References

Ransley et al. [1] first introduced the concept of tubularization of the urethral plate in the epispadiac patient. The technique was adapted and popularized in hypospadiac surgery because it causes fewer complications and better cosmesis is achieved. This technique was only suitable when the urethral plate was wide enough to allow tubularization. However, Snodgrass [2] described incising the urethral plate down to Buck’s fascia to attain the greater width necessary for tubularization. We present our experience of this procedure.

Patients and methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. References

Since October 1995, 32 patients (mean age at surgery 18 months, range 8–33) have undergone the Snodgrass procedure at our institution. Twenty-five children had a distal defect and seven a proximal defect (Table 1).

Table 1.  Site of hypospadiac defect and results Thumbnail image of

Under a general anaesthetic, the penis was degloved and an erection test performed to assess for residual chordee. One child, with a proximal defect, had a residual chordee which was corrected by a dorsal tunica albuginea plication [3]. The lateral edges of the urethral plate were incised and glans wings created and retracted. The urethral plate was then incised in its midline, down to Buck’s fascia, as described by Snodgrass (Fig 1a,b) [2]. The urethral plate was tubularized over an 8 F stent with 7/0 polydioxanone sutures. A well vascularized pedicled dartos flap covered the suture line of the neourethra. The pedicled flap is then ‘buttonholed’ and brought ventrally to lie over the neourethra, where it is secured with interrupted sutures (Fig. 1c). The glans was reconstructed in two layers and the skin closed [4]. The result provides a circumcised penis with a slit-like terminal meatus (Fig. 1d). The neourethra is stented for 7 days with a dripping stent and a standard pressure dressing applied.

image

Figure 1. (a) Glans wings are retracted and the urethral plate is about to be incised. (b) After incision of the urethral plate; note the width achieved. (c) The vascularized de-epithelialized dartos flap shown overlying the neourethra. (d) The end result, with a slit-like terminal meatus.

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Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. References

The results are presented in Table 1. The mean follow-up was 10 months (range 2–14). There were only two complications: one child with a coronal hypospadias, who had a thin urethra down to the mid-shaft, developed a fistula at the mid-shaft level. This was corrected with a local procedure; one child with a proximal shaft hypospadial defect had complete breakdown of his neourethra and required a buccal mucosal graft repair. Three children whose meatus appeared narrow underwent examination under anaesthesia, and all were calibrated normally with no need for dilatation.

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. References

Incision of the urethral plate has been described previously, but this was combined with meatal-based flaps or onlay island flaps [5]. The ingenuity of Snodgrass was to combine the urethral plate incision with tubularization, thereby continuing with the advantages of tubularization, especially that of cosmesis, which we question with other types of repair [6,7].

The present low complication rate compares favourably with that reported by Snodgrass et al. [2,8]; one aspect of the repair that contributes significantly to this is the covering of the neourethra with a well-vascularized flap. Although peri-urethral tissue may be used, in the primary hypospadiac child, the de-epithelialized inner preputial dartos flap is the covering of choice. If ‘buttonholed’ to bring it ventrally, as described by Gonzalez et al. [9] then there is no lateral bulk, which is seen when the flap is rotated around the penis [7].

Although Snodgrass [2] described this procedure for distal hypospadias defects, we have extended its application to more proximal defects. As described by Baskin et al. [10], once the penis is degloved the incidence of residual chordee declines dramatically. Although there was one complication, we have only recently begun including the more proximal defects and feel that the cosmetic results make this procedure one that surgeons should be aware of for the more severe hypospadiac defects.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and methods
  5. Results
  6. Discussion
  7. References