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The transverse outer preputial (TOP) island flap: an easy method to cover urethroplasties and skin defects in hypospadias repair
Journal of Pediatric Urology (2005) 1, 89e94
The transverse outer preputial (TOP) island flap: an easy method to cover urethroplasties and skin defects in hypospadias repair R.-B. Galifer*, N. Kalfa Department of Visceral and Urological Pediatric Surgery, Lapeyronie Hospital, Montpellier, 371, Doyen Gaston Giraud Avenue, 34295 Montpellier Ce´dex 5, France Received 16 November 2004; accepted 23 November 2004
KEYWORDS Hypospadias; Epispadias; Urethroplasty; Surgical flap
Abstract Objective The transverse outer preputial (TOP) island flap, a simple procedure inspired by the double-faced island flap, is proposed as a substitute for the Byars repair to provide skin coverage for most of the current reconstructive techniques for hypospadias. Patients and methods From 1996 to 2003, 108 consecutive children (aged 1e8 years) had a primary repair of various forms of hypospadias with different degrees of chordee; the TOP island flap was used in 66. The surgical technique is based on the use of a dorsal transverse skin flap mobilized with its own vascular pedicle from the outer foreskin, then ventrally rotated longitudinally after removing the inner part of the prepuce. Results Partial necrosis of the lateral border of the flap was infrequent (!2%) and did not induce urethral complications. There was no total necrosis in the series. The rate of fistula was comparable with children operated using other techniques (8%). The cosmesis was good, with no ventral bulkiness or hypertrophic scarring. Conclusions The TOP island flap is a safe method for covering a new urethra and penile skin defects, with good cosmetic results. ª 2004 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Abbreviations: TOP, transverse outer preputial. * Corresponding author. Tel.: C33 4 67 33 87 84; fax: C33 4 67 33 95 12. E-mail address: [email protected] (R.-B. Galifer). 1477-5131/$30 ª 2004 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jpurol.2004.11.010
90
Introduction In all surgical procedures for hypospadias repair, skin coverage of the urethroplasty is the last, but not the least important, stage. Whatever be the technique the goal is to bring well-vascularized tissue to the ventral surface of the penis, if possible with no overlapping suture lines, to obtain good healing with minimal risk of fistula formation and the best cosmetic result. One of the most widely used techniques is the Byars repair [1], which vertically splits the dorsal surface of the foreskin into two flaps and brings them around the ventrum to resurface the ventral skin defect with a midline or Z-shaped suture. According to the changing concepts of hypospadias curvature [2,3], the urethral plate is no longer recognized as the cause of penile chordee and its preservation has become an important principle in treating the increasing spectrum of hypospadias. Surgeons can perform most urethroplasties using the usually well developed and healthy urethral plate without dissecting beneath it, as doing so may jeopardize its blood supply. If a residual curvature persists after a correct orthoplasty, a Nesbit [4] procedure is done by dorsal tunica albuginea plication rather than excising the elliptical segments. The technical choices have thus changed over the last decade. We abandoned the Duckett island tube [5] for the onlay island patch and its double-faced variant, both of which have the major advantage of avoiding the creation of a circular anastomosis between the native and the new urethra. However, it soon became apparent that tubularization of the urethral plate according to Thiersch-Duplay is a simpler procedure and almost always possible, thanks possibly to the Snodgrass [6] artifice, so that in our experience, the foreskin is most often unused and still the best material for covering the new urethra and the ventral skin defect. It is from this viewpoint that we adapted the modified Asopa repair [7], as described later. We herein report a new procedure we have used for 8 years and which results in a more satisfactory repair.
R.-B. Galifer, N. Kalfa in 40, the double-faced onlay island flap in six, a Mathieu repair in 55, and the meatoplasty and glanuloplasty incorporated in seven (but none after 1998). The transverse outer preputial (TOP) island flap was used in 66 patients, mostly for those with proximal hypospadias (70%). All patients were examined at least 1 month after surgery and 40 were followed for more than a year.
Surgical technique At the beginning of the procedure, a circumferential incision (except in the ventral area of urethroplasty) is made proximal to the corona, with care taken to preserve a generous cuff of mucosal glanular tissue 6e8 mm wide. The whole shaft with the attached prepuce is then de-gloved from the corpora cavernosa in the avascular plane between the Buck’s and dartos fasciae down to the penoscrotal junction, in a cylindrical fashion, respecting the parallel incisions that delineate the urethral plate (Fig. 1). When orthoplasty and urethroplasty have been completed, with the glans reconstructed in two planes and the ventral mucosal cuff sutured according to Firlit [8], the whole mucosa of the inner part of the foreskin is removed, taking care not to compromise the vascularization of the rest of the prepuce
Patients and methods Between 1996 and 2003, 46 consecutive children were treated for middle and proximal hypospadias with various degrees of chordee, and 62 for more distal forms. All were operated on by the same surgeon (R.B.G.). The mean (range) age of the patients at operation was 1.9 (0.10e8) years. The techniques of urethroplasty were: Thiersch-Duplay
Figure 1
Preliminary situation.
The transverse outer preputial island flap
Figure 2 removed.
91
Entire inner part of the prepuce to be
(Fig. 2). A transverse line is then drawn at the junction of the dorsal penile skin and the outer prepuce, parallel to its free border and situated so that enough length remains to cover the dorsal penis with no tension after suturing the free border up to the subcoronal incision. This line is superficially and carefully incised with an ophthalmic knife, and a generous vascular pedicle to the skin of the island flap, based on the axial blood supply of the dorsal dartos fascia, is progressively developed by sharp dissection with fine plastic scissors and optical magnification (Fig. 3). It is important to remain as close as possible to the dorsal skin of the penis so that flap vascularization is optimally preserved. An almost rectangular transverse flap is thus constructed, with its length corresponding to the entire foreskin width and its width usually 1.5e2 cm. This step is generally achieved about two-thirds of the way down the dorsal skin when the vascular pedicle is long enough to permit the rotation of the flap on the ventral surface, usually on one side of the penis, the right in most of the present patients (Fig. 4). Care must be taken to mobilize the base of the vascular pedicle on the opposite side to gain sufficient length and reduce the potential effect of penile rotation, which can result from such an asymmetric route. A tension-free transposition
Figure 3
Figure 4
Development of the TOP island flap.
Ventral rotation of the TOP island flap.
92 with no torsion is vitally important to prevent problems of flap viability. To achieve better symmetry and an unrotated penis, the transposition of the flap by bringing the glans through a buttonhole made in the proximal third of the pedicle is an acceptable choice if there is no risk of the blood supply being disturbed by this manoeuvre. The flap is thus transposed with gentle handling from a horizontal dorsal to a vertical ventral position, the left side becoming the upper one after a 90( rotation. It is then maintained in a moistened compress. While the flap is waiting, the dorsal shaft is approximated to the glanular cuff with interrupted sutures, beginning at the dorsal midline point and continuing symmetrically on both sides until half to two-thirds of the surface of the penis is covered (Fig. 5). The thick vascular bundle is then carefully sutured near the urethroplasty (and not over it) with fine absorbable sutures, to serve as a second layer coverage, without damaging the blood supply to the epithelium of the neourethra. Finally, the edges of the flap are trimmed to the exact dimensions of the ventral defect, keeping all the vascularization intact. The suturing is with interrupted sutures on the ventral glanular cuff and with running sutures laterally (Fig. 6). The same principle may be used if an onlay urethroplasty is preferred, especially when the urethral plate seems too narrow to be tubularized.
R.-B. Galifer, N. Kalfa
Figure 6
Final result after trimming.
In that case, the inner prepuce is not removed but trimmed as a strip to the exact length of the urethral plate, and wide enough to create a good urethral circumference when combined with the width of the urethral plate. The TOP island flap is then developed as previously described with the strip of inner prepuce that remains attached to the skin, and both are simultaneously ventrally rotated. The mucosal strip becomes the ventral half circumference of the new urethra by being sutured to the urethral plate, and the TOP island flap serves to cover the ventral skin defect. In an alternative option, the inner prepuce may be trimmed after transposition [9].
Results
Figure 5 Coverage of most parts of the penile surface by the shaft.
Although the flap formed from the outer surface of the prepuce is supposed to have a better blood supply than the flap from the inner surface only [10], the main complication with this technique may be total or partial necrosis of the transposed flap. In the present series there was no total necrosis; partial necrosis was infrequent (!2%) and when present, it usually occurred at the lateral edges of the flap. However, the sloughing was generally limited and when the eschar was removed, this area epithelialized within a few days, with no scar formation or unfavourable consequences to the functional result of the urethroplasty. The fistula rate was 8% (five cases)
The transverse outer preputial island flap and similar for patients undergoing a TOP procedure and those operated on using other techniques. From our 8-year experience with the TOP island flap we consider its greatest advantage to be the uncontested appealing cosmetic result, with no ventral bulkiness or hypertrophic scarring. Mild to moderate ventral edema probably resulting from impaired venous or lymphatic drainage may persist for weeks or months, but resolved in all cases over the long-term follow-up.
Discussion After orthoplasty and urethroplasty, the penis must be resurfaced with skin. Although many techniques have been developed for this, several have now been abandoned. Simply suturing the lateral edges of the ventral skin leads to a median suture, usually under tension that can be relaxed by incising the dorsal skin down to the midline [11]. The dorsal defect that is thereby created epithelializes, with no need for grafting. A ventral skin cover can also be achieved by rotating the entire penile shaft spirally around the ventrum [12]. However, these techniques are now rarely used. Indeed, the abundant dorsal foreskin is a natural source and remains the best material to achieve skin coverage. The preputial tissue may be transposed by opening a small buttonhole in its middle and bringing the glans through it, like a head through a ‘poncho’ [13]. The major drawback of this procedure is the difficulty in fashioning the lateral borders without leaving unsightly bulky edges of skin. In a different approach, the prepuce may be split vertically into two flaps that are transposed on the ventral defect, either symmetrically or one above the other. This technique of Byars [1], which is probably one of those used most often, nevertheless has some functional and cosmetic disadvantages. When the two flaps are sutured symmetrically it results in a midline suture and an overlapping with the urethroplasty that may favour fistula formation. Moreover, to preserve the vertically orientated vessels of the foreskin, which are best visualized by transillumination, it is often necessary to make an eccentric split, leading to unequal flaps, and acceptable symmetry or an unrotated penis will be hard to obtain after transposition. If the two flaps are arranged above and below each other, the Z-suture line crosses the urethroplasty twice and unsightly redundant skin is frequent, resulting in two ‘dog ears’. Trimming them can jeopardize the vascularization of the flap tips. When used in
93 association with an inner preputial island flap, this bi-pedicled outer preputial flap is devascularized to a certain degree, and problems of viability add to the above-mentioned drawbacks. Indeed, the double-faced preputial island flap provides the best symmetrical skin cover with well-vascularized skin. The TOP island flap described here is a variant of this former procedure; importantly, it is simple, consumes little extra time and is suitable for most hypospadias reconstructive repairs using the ventral urethral plate. Problems of flap viability must be avoided by carefully dissecting the vascular pedicle. The key is to stay as close as possible to the derma of the dorsal skin. All the vascular bundles must be for the flap, with the dorsal shaft always remaining well vascularized thanks to superficial vessels coming from inferior pudendal arteries [14]. Fistula formation is a complex problem to which many factors other than skin coverage contribute, but good viability of the flap and not having overlying sutures, as in the present technique, are probably important in preventing this complication. The indications for this technique can be extended. Besides middle and proximal hypospadias with penile curvature, we have used this flap for coronal and distal hypospadias, with or without different degrees of chordee, every time the skin defect cannot be treated by direct sutures, as is occasionally seen after the meatoplasty and glanuloplasty incorporated or Mathieu’s perimeatalbased flap. To date, we have had no opportunity to use the TOP island flap in repeat operations for hypospadias cripples or other disasters, but we suggest that such a flap constructed from juxtacoronal dorsal skin may be helpful in these difficult cases. The flap is also suitable for covering the dorsal skin defect in the repair of isolated epispadias or after previous repair of bladder exstrophy. Even if the foreskin is ventrally situated and far less generous in this malformation, the transverse preputial island flap and its double-faced variant have been applied to epispadias surgery [15]. However, these procedures then followed the same development as for ‘hypospadiology’, i.e. preservation of the urethral plate and its use for urethroplasty, as described by Cantwell [16]. During the same period we used the TOP island flap three times at the end-stage of a CantwellRansley urethroplasty [17] with no problems or difficulty in covering the penile part of the dorsal skin. The cosmetic results were excellent and there was no chordee secondary to midline dorsal scarring.
94 The TOP island flap technique of covering urethroplasties has several advantages: (i) it brings well-vascularized tissue on the new urethra, with a thick vascular pedicle that acts as a second-layer neourethral coverage, as well as a de-epithelialized flap [18], a tunica vaginalis graft [19] or a dorsal dartos subcutaneous flap [20]; (ii) it separates the suture line of the urethroplasty, which is median, and distances it from the flap lines, which are lateral (a technical point that may also lower the fistula rate); and (iii) it provides an excellent cosmetic result, with no bulkiness or retractile scarring that can be present in other procedures. We conclude that the TOP island flap is a valuable substitute for the Byars repair.
References [1] Byars LT. A technique for consistently satisfactory repair of hypospadias. Surg Gynecol Obstet 1955;100:184e90. [2] Rushton HG. Hypospadias. J Urol 1994;152:1241e2. [3] Baskin LS, Duckett JW, Ueoka K, Seibold J, Snyder III HM. Changing concept of hypospadias curvature lead to more onlay island flap procedures. J Urol 1994;151:191e6. [4] Nesbit RM. Plastic procedure for correction of hypospadias. J Urol 1941;45:699e702. [5] Duckett JW. The island flap technique for hypospadias repair. Urol Clin North Am 1981;8:513e9. [6] Snodgrass W, Koyle M, Gianantonio M, Hurwitz R, Caldamone A, Ehrlich R. Tubularized incised plate hypospadias repair for proximal hypospadias. J Urol 1998;159: 2129e31.
R.-B. Galifer, N. Kalfa [7] Asopa R, Asopa HS. One-stage correction of penile hypospadias using a foreskin tube. Indian J Urol 1984;1:41e3. [8] Firlit CF. The mucosal collar in hypospadias surgery. J Urol 1987;137:80. [9] Gonzales R, Smith C, Denes E. Double onlay preputial flap for proximal hypospadias repair. J Urol 1996;156:832e5. [10] Hinman Jr F. The blood supply to preputial island flap. J Urol 1991;145:1232e5. [11] Browne D. A comparison of the Duplay and Denis Browne techniques for hypospadias operation. Surgery 1953;34: 787e98. [12] Van der Meulen JC. Correction of hypospadias, types I and II. Br J Plast Surg 1971;24:101e8. [13] Mustarde JC. One-stage correction of distal hypospadias and other people’s fistulae. Br J Plast Surg 1965;18: 413e22. [14] Juskiewenski S, Vaysse P, Moscovici J. A study of the arterial blood supply to the penis. Anat Clin 1982;4:101e7. [15] Monfort G, Morisson-Iacombe G, Guys JM, Coquet M. Transverse island flap and double flap procedure in the treatment of congenital epispadias in 32 patients. J Urol 1987;138:1069e71. [16] Cantwell FV. Operative treatment of epispadias by transplantation of the urethra. Ann Surg 1995;22:689e94. [17] Pippi Salle JL, Jednak R, Capolicchio JP, Franca IM, Labbie A, Gosalbez R. A ventral rotational skin flap to improve cosmesis and avoid chordee recurrence in epispadias repair. BJU Int 2002;90:918e23. [18] Belman AB. De-epithelialized skin flap coverage in hypospadias repair. J Urol 1988;140:1273e6. [19] Snow BW. Use of tunica vaginalis to prevent fistulas in hypospadias repair. J Urol 1986;136:861e3. [20] Retik AB, Mandel J, Bauer SB, Atala A. Meatal based hypospadias repair with the use of a dorsal subcutaneous flap to prevent urethrocutaneous fistula. J Urol 1994;152: 1229e31.
The transverse outer preputial (TOP) island flap: an easy method to cover urethroplasties and skin defects in hypospadias repair R.-B. Galifer*, N. Kalfa Department of Visceral and Urological Pediatric Surgery, Lapeyronie Hospital, Montpellier, 371, Doyen Gaston Giraud Avenue, 34295 Montpellier Ce´dex 5, France Received 16 November 2004; accepted 23 November 2004
KEYWORDS Hypospadias; Epispadias; Urethroplasty; Surgical flap
Abstract Objective The transverse outer preputial (TOP) island flap, a simple procedure inspired by the double-faced island flap, is proposed as a substitute for the Byars repair to provide skin coverage for most of the current reconstructive techniques for hypospadias. Patients and methods From 1996 to 2003, 108 consecutive children (aged 1e8 years) had a primary repair of various forms of hypospadias with different degrees of chordee; the TOP island flap was used in 66. The surgical technique is based on the use of a dorsal transverse skin flap mobilized with its own vascular pedicle from the outer foreskin, then ventrally rotated longitudinally after removing the inner part of the prepuce. Results Partial necrosis of the lateral border of the flap was infrequent (!2%) and did not induce urethral complications. There was no total necrosis in the series. The rate of fistula was comparable with children operated using other techniques (8%). The cosmesis was good, with no ventral bulkiness or hypertrophic scarring. Conclusions The TOP island flap is a safe method for covering a new urethra and penile skin defects, with good cosmetic results. ª 2004 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Abbreviations: TOP, transverse outer preputial. * Corresponding author. Tel.: C33 4 67 33 87 84; fax: C33 4 67 33 95 12. E-mail address: [email protected] (R.-B. Galifer). 1477-5131/$30 ª 2004 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jpurol.2004.11.010
90
Introduction In all surgical procedures for hypospadias repair, skin coverage of the urethroplasty is the last, but not the least important, stage. Whatever be the technique the goal is to bring well-vascularized tissue to the ventral surface of the penis, if possible with no overlapping suture lines, to obtain good healing with minimal risk of fistula formation and the best cosmetic result. One of the most widely used techniques is the Byars repair [1], which vertically splits the dorsal surface of the foreskin into two flaps and brings them around the ventrum to resurface the ventral skin defect with a midline or Z-shaped suture. According to the changing concepts of hypospadias curvature [2,3], the urethral plate is no longer recognized as the cause of penile chordee and its preservation has become an important principle in treating the increasing spectrum of hypospadias. Surgeons can perform most urethroplasties using the usually well developed and healthy urethral plate without dissecting beneath it, as doing so may jeopardize its blood supply. If a residual curvature persists after a correct orthoplasty, a Nesbit [4] procedure is done by dorsal tunica albuginea plication rather than excising the elliptical segments. The technical choices have thus changed over the last decade. We abandoned the Duckett island tube [5] for the onlay island patch and its double-faced variant, both of which have the major advantage of avoiding the creation of a circular anastomosis between the native and the new urethra. However, it soon became apparent that tubularization of the urethral plate according to Thiersch-Duplay is a simpler procedure and almost always possible, thanks possibly to the Snodgrass [6] artifice, so that in our experience, the foreskin is most often unused and still the best material for covering the new urethra and the ventral skin defect. It is from this viewpoint that we adapted the modified Asopa repair [7], as described later. We herein report a new procedure we have used for 8 years and which results in a more satisfactory repair.
R.-B. Galifer, N. Kalfa in 40, the double-faced onlay island flap in six, a Mathieu repair in 55, and the meatoplasty and glanuloplasty incorporated in seven (but none after 1998). The transverse outer preputial (TOP) island flap was used in 66 patients, mostly for those with proximal hypospadias (70%). All patients were examined at least 1 month after surgery and 40 were followed for more than a year.
Surgical technique At the beginning of the procedure, a circumferential incision (except in the ventral area of urethroplasty) is made proximal to the corona, with care taken to preserve a generous cuff of mucosal glanular tissue 6e8 mm wide. The whole shaft with the attached prepuce is then de-gloved from the corpora cavernosa in the avascular plane between the Buck’s and dartos fasciae down to the penoscrotal junction, in a cylindrical fashion, respecting the parallel incisions that delineate the urethral plate (Fig. 1). When orthoplasty and urethroplasty have been completed, with the glans reconstructed in two planes and the ventral mucosal cuff sutured according to Firlit [8], the whole mucosa of the inner part of the foreskin is removed, taking care not to compromise the vascularization of the rest of the prepuce
Patients and methods Between 1996 and 2003, 46 consecutive children were treated for middle and proximal hypospadias with various degrees of chordee, and 62 for more distal forms. All were operated on by the same surgeon (R.B.G.). The mean (range) age of the patients at operation was 1.9 (0.10e8) years. The techniques of urethroplasty were: Thiersch-Duplay
Figure 1
Preliminary situation.
The transverse outer preputial island flap
Figure 2 removed.
91
Entire inner part of the prepuce to be
(Fig. 2). A transverse line is then drawn at the junction of the dorsal penile skin and the outer prepuce, parallel to its free border and situated so that enough length remains to cover the dorsal penis with no tension after suturing the free border up to the subcoronal incision. This line is superficially and carefully incised with an ophthalmic knife, and a generous vascular pedicle to the skin of the island flap, based on the axial blood supply of the dorsal dartos fascia, is progressively developed by sharp dissection with fine plastic scissors and optical magnification (Fig. 3). It is important to remain as close as possible to the dorsal skin of the penis so that flap vascularization is optimally preserved. An almost rectangular transverse flap is thus constructed, with its length corresponding to the entire foreskin width and its width usually 1.5e2 cm. This step is generally achieved about two-thirds of the way down the dorsal skin when the vascular pedicle is long enough to permit the rotation of the flap on the ventral surface, usually on one side of the penis, the right in most of the present patients (Fig. 4). Care must be taken to mobilize the base of the vascular pedicle on the opposite side to gain sufficient length and reduce the potential effect of penile rotation, which can result from such an asymmetric route. A tension-free transposition
Figure 3
Figure 4
Development of the TOP island flap.
Ventral rotation of the TOP island flap.
92 with no torsion is vitally important to prevent problems of flap viability. To achieve better symmetry and an unrotated penis, the transposition of the flap by bringing the glans through a buttonhole made in the proximal third of the pedicle is an acceptable choice if there is no risk of the blood supply being disturbed by this manoeuvre. The flap is thus transposed with gentle handling from a horizontal dorsal to a vertical ventral position, the left side becoming the upper one after a 90( rotation. It is then maintained in a moistened compress. While the flap is waiting, the dorsal shaft is approximated to the glanular cuff with interrupted sutures, beginning at the dorsal midline point and continuing symmetrically on both sides until half to two-thirds of the surface of the penis is covered (Fig. 5). The thick vascular bundle is then carefully sutured near the urethroplasty (and not over it) with fine absorbable sutures, to serve as a second layer coverage, without damaging the blood supply to the epithelium of the neourethra. Finally, the edges of the flap are trimmed to the exact dimensions of the ventral defect, keeping all the vascularization intact. The suturing is with interrupted sutures on the ventral glanular cuff and with running sutures laterally (Fig. 6). The same principle may be used if an onlay urethroplasty is preferred, especially when the urethral plate seems too narrow to be tubularized.
R.-B. Galifer, N. Kalfa
Figure 6
Final result after trimming.
In that case, the inner prepuce is not removed but trimmed as a strip to the exact length of the urethral plate, and wide enough to create a good urethral circumference when combined with the width of the urethral plate. The TOP island flap is then developed as previously described with the strip of inner prepuce that remains attached to the skin, and both are simultaneously ventrally rotated. The mucosal strip becomes the ventral half circumference of the new urethra by being sutured to the urethral plate, and the TOP island flap serves to cover the ventral skin defect. In an alternative option, the inner prepuce may be trimmed after transposition [9].
Results
Figure 5 Coverage of most parts of the penile surface by the shaft.
Although the flap formed from the outer surface of the prepuce is supposed to have a better blood supply than the flap from the inner surface only [10], the main complication with this technique may be total or partial necrosis of the transposed flap. In the present series there was no total necrosis; partial necrosis was infrequent (!2%) and when present, it usually occurred at the lateral edges of the flap. However, the sloughing was generally limited and when the eschar was removed, this area epithelialized within a few days, with no scar formation or unfavourable consequences to the functional result of the urethroplasty. The fistula rate was 8% (five cases)
The transverse outer preputial island flap and similar for patients undergoing a TOP procedure and those operated on using other techniques. From our 8-year experience with the TOP island flap we consider its greatest advantage to be the uncontested appealing cosmetic result, with no ventral bulkiness or hypertrophic scarring. Mild to moderate ventral edema probably resulting from impaired venous or lymphatic drainage may persist for weeks or months, but resolved in all cases over the long-term follow-up.
Discussion After orthoplasty and urethroplasty, the penis must be resurfaced with skin. Although many techniques have been developed for this, several have now been abandoned. Simply suturing the lateral edges of the ventral skin leads to a median suture, usually under tension that can be relaxed by incising the dorsal skin down to the midline [11]. The dorsal defect that is thereby created epithelializes, with no need for grafting. A ventral skin cover can also be achieved by rotating the entire penile shaft spirally around the ventrum [12]. However, these techniques are now rarely used. Indeed, the abundant dorsal foreskin is a natural source and remains the best material to achieve skin coverage. The preputial tissue may be transposed by opening a small buttonhole in its middle and bringing the glans through it, like a head through a ‘poncho’ [13]. The major drawback of this procedure is the difficulty in fashioning the lateral borders without leaving unsightly bulky edges of skin. In a different approach, the prepuce may be split vertically into two flaps that are transposed on the ventral defect, either symmetrically or one above the other. This technique of Byars [1], which is probably one of those used most often, nevertheless has some functional and cosmetic disadvantages. When the two flaps are sutured symmetrically it results in a midline suture and an overlapping with the urethroplasty that may favour fistula formation. Moreover, to preserve the vertically orientated vessels of the foreskin, which are best visualized by transillumination, it is often necessary to make an eccentric split, leading to unequal flaps, and acceptable symmetry or an unrotated penis will be hard to obtain after transposition. If the two flaps are arranged above and below each other, the Z-suture line crosses the urethroplasty twice and unsightly redundant skin is frequent, resulting in two ‘dog ears’. Trimming them can jeopardize the vascularization of the flap tips. When used in
93 association with an inner preputial island flap, this bi-pedicled outer preputial flap is devascularized to a certain degree, and problems of viability add to the above-mentioned drawbacks. Indeed, the double-faced preputial island flap provides the best symmetrical skin cover with well-vascularized skin. The TOP island flap described here is a variant of this former procedure; importantly, it is simple, consumes little extra time and is suitable for most hypospadias reconstructive repairs using the ventral urethral plate. Problems of flap viability must be avoided by carefully dissecting the vascular pedicle. The key is to stay as close as possible to the derma of the dorsal skin. All the vascular bundles must be for the flap, with the dorsal shaft always remaining well vascularized thanks to superficial vessels coming from inferior pudendal arteries [14]. Fistula formation is a complex problem to which many factors other than skin coverage contribute, but good viability of the flap and not having overlying sutures, as in the present technique, are probably important in preventing this complication. The indications for this technique can be extended. Besides middle and proximal hypospadias with penile curvature, we have used this flap for coronal and distal hypospadias, with or without different degrees of chordee, every time the skin defect cannot be treated by direct sutures, as is occasionally seen after the meatoplasty and glanuloplasty incorporated or Mathieu’s perimeatalbased flap. To date, we have had no opportunity to use the TOP island flap in repeat operations for hypospadias cripples or other disasters, but we suggest that such a flap constructed from juxtacoronal dorsal skin may be helpful in these difficult cases. The flap is also suitable for covering the dorsal skin defect in the repair of isolated epispadias or after previous repair of bladder exstrophy. Even if the foreskin is ventrally situated and far less generous in this malformation, the transverse preputial island flap and its double-faced variant have been applied to epispadias surgery [15]. However, these procedures then followed the same development as for ‘hypospadiology’, i.e. preservation of the urethral plate and its use for urethroplasty, as described by Cantwell [16]. During the same period we used the TOP island flap three times at the end-stage of a CantwellRansley urethroplasty [17] with no problems or difficulty in covering the penile part of the dorsal skin. The cosmetic results were excellent and there was no chordee secondary to midline dorsal scarring.
94 The TOP island flap technique of covering urethroplasties has several advantages: (i) it brings well-vascularized tissue on the new urethra, with a thick vascular pedicle that acts as a second-layer neourethral coverage, as well as a de-epithelialized flap [18], a tunica vaginalis graft [19] or a dorsal dartos subcutaneous flap [20]; (ii) it separates the suture line of the urethroplasty, which is median, and distances it from the flap lines, which are lateral (a technical point that may also lower the fistula rate); and (iii) it provides an excellent cosmetic result, with no bulkiness or retractile scarring that can be present in other procedures. We conclude that the TOP island flap is a valuable substitute for the Byars repair.
References [1] Byars LT. A technique for consistently satisfactory repair of hypospadias. Surg Gynecol Obstet 1955;100:184e90. [2] Rushton HG. Hypospadias. J Urol 1994;152:1241e2. [3] Baskin LS, Duckett JW, Ueoka K, Seibold J, Snyder III HM. Changing concept of hypospadias curvature lead to more onlay island flap procedures. J Urol 1994;151:191e6. [4] Nesbit RM. Plastic procedure for correction of hypospadias. J Urol 1941;45:699e702. [5] Duckett JW. The island flap technique for hypospadias repair. Urol Clin North Am 1981;8:513e9. [6] Snodgrass W, Koyle M, Gianantonio M, Hurwitz R, Caldamone A, Ehrlich R. Tubularized incised plate hypospadias repair for proximal hypospadias. J Urol 1998;159: 2129e31.
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