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Proximal Hypospadias: Effect of Urethral Plate Mobilization on Release of Chordee
Pediatric Urology Proximal Hypospadias: Effect of Urethral Plate Mobilization on Release of Chordee Smail Acimi OBJECTIVE
METHODS
RESULTS
CONCLUSION
To accurately measure the correction obtained by the release of the skin and dartos fascia and that obtained by mobilization of the urethral plate and resection of the underlying fibrous tissue (according to Koyanagi and Mollard), in the release of chordee. From February 1996 to February 2011, 234 patients underwent surgery for proximal hypospadias by 1 surgeon. Lateral photographs were taken during successive saline erection tests for 205 patients. The first test was performed at the beginning of the operation, the second test after the release of the skin and dartos fascia, the third test after possible mobilization of the urethral plate and resection of the underlying fibrous tissue, and the last test at the end of surgery. Preservation of the urethral plate was possible in 191 patients (93%). Analysis of the lateral photographs showed that stripping of the penis resulted in complete correction of all chordee ⬍45°. For curvature ⬎90°, stripping of the penis was insufficient in 88% of the cases. However, mobilization of the urethral plate with resection of the underlying fibrous tissue resulted in very low correction (10°-20°), although the blood supply to this plate was preserved. The results of the present study have shown that correction of the curvature that accompanies proximal hypospadias is obtained mainly by release of the skin and dartos fascia. UROLOGY 80: 894 – 898, 2012. © 2012 Elsevier Inc.
C
urvature of the penis is an anomaly often present in the proximal forms of hypospadias. Its severity depends on the degree of hypoplasia of the tissues forming the ventral side of the penis, and its release without excision of the urethral plate with an onlay island flap was a decisive turn in single-stage repair of proximal hypospadias.1 In this technique, Mollard et al1 brought together 2 principles: the onlay island flap initially described by Elder et al2 in the treatment of distal hypospadias and preservation of the urethral plate with resection of the underlying fibrous tissue proposed by Koyanagi et al.3 The principle of mobilization of the urethral plate with resection of the underlying fibrous tissue, such as was recommended by Mollard et al4,5 and Perovic´ and Vukadinovic´6 (who stated that the existing fibrous tissue under the urethral plate is the essential factor of the bend), has many supporters.1,6,7 It also has many critics,8,9 who consider this move unnecessary and dangerous to the blood supply of the plate. Duckett10 stated “A current controversy relates to the need to dissect underneath the urethral plate and lift it off the shaft. . . . They insist on lifting the skin flap and removing the spongiosal tissue beneath the urethral plate. The Financial Disclosure: The author declares that he has no relevant financial interests. From the Department of Pediatric Surgery (UMC), Children’s Hospital Canastel, Faculty of Medicine, University of Oran, Oran, Algeria Reprint requests: Smail Acimi, Ph.D., Department of Pediatric Surgery (UMC), Children’s Hospital Canastel, Faculty of Medicine, University of Oran, Oran, Algeria. E-mail: [email protected] Submitted: March 27, 2012, accepted (with revisions): June 28, 2012
894
© 2012 Elsevier Inc. All Rights Reserved
author refutes this concept, while Mollard and Perovic´ both feel this step is important. . . . But more importantly, there has been no photographic confirmation that a penile curvature present with the plate intact was relieved by dissection under the plate alone, a challenge that detractors of this method cannot meet.” The aim of the present study was to compare the results obtained by the release of the skin and dartos fascia and the results obtained by mobilization of the urethral plate and resection of the underlying fibrous tissue (according to the method of Koyanagi et al3 and Mollard1) in the release of chordee.
MATERIAL AND METHODS From February 1996 to February 2011, 234 patients underwent repair for proximal hypospadias associated with chordee by a single surgeon. In 205 patients, we used lateral photographs taken during successive saline erection tests to measure with precision the correction obtained after each stage. The first test was performed at the beginning of the operation, the second test after release of the skin and dartos fascia, the third test after possible mobilization of the urethral plate and resection of the underlying fibrous tissue, and the last test at the end of the operation (Fig. 1). The angle between the axis of the proximal part and that of the distal part is measured by a protractor. In 29 patients, it was not possible to perform these tests. Testosterone was given to 37 patients with a small penis before surgery to increase the size of the penis. The age of the patients at surgery ranged from 12 months to 5 years (mean 26 months), and the position of the urethral meatus before correction was distal 0090-4295/12/$36.00 http://dx.doi.org/10.1016/j.urology.2012.06.050
Figure 2. (A) Spontaneous erection showed curvature of penis of 120° that had (B) decreased to 28° after simple release of skin and dartos fascia. (Color version available online.)
Figure 1. (A) Initial curvature of 75° that had (B) decreased to 50° after releasing skin and dartos fascia. (C) View at 37°, after mobilization of urethral plate and resection of underlying fibrous tissue. (Color version available online.)
UROLOGY 80 (4), 2012
(with a dysplastic distal urethra without the corpus spongiosum), mid or proximal penile shaft in 133, penoscrotal in 45, and scrotal or perineal in 27. The median follow-up was 76 months (range 5-185). We always started an evaluation of the initial curvature of the penis with an artificial erection test. Sometimes, before deepening the anesthesia, a spontaneous erection would occur and we could avoid using the first test (Fig. 2). A traction suture was placed through the glans, and a circumferential incision was made 2 mm proximal to the hypospadiac meatus and extended distally by 2 parallel incisions in the skin and the glans (Ushaped incision). This incision isolated a urethral plate that was sufficiently wide (8-10 mm).1 After the circumferential subcoronal incision, the skin and dartos fascia were dissected from the shaft. This dissection must be extended proximally to the perineal area. The correction obtained was evaluated with a second artificial saline test. If this test demonstrated persistent penile curvature of ⬎10°-15°, the urethral plate was lifted up 895
Table 1. Patient distribution according to penile curvature severity and number of complete corrections obtained by simple release of skin and dartos fascia
Figure 3. Dorsal plication by resection to diamond shape on dorsal side of albuginea. (Color version available online.)
from the corpora cavernosa by a fine scissors slipped between the urethral plate and corpora cavernosa. All the fibrous tissue would then be resected. Sometimes after this mobilization of the urethral plate, significant chordee (⬎15°-20°) would remain. Two parallel longitudinal incisions of Buck’s fascia were made at the 2- and 10-o’clock positions until the tunica albuginea was seen. To keep in contact with this area, fine scissors were placed behind Buck’s fascia to lift it up with the dorsal neurovascular bundle. The dissection must remain directly on top of the tunica albuginea to prevent neuronal and vascular injury when mobilized. We then performed a dorsal tunica albuginea plication by excision of a diamond shape at the point of the maximum bend dorsally (Fig. 3). The edges of this incision were sutured with nonabsorbable running suture (5-0). This method of dorsal plicature is more physiologic than that described by Baskin et al.8 Also, the correction has seemed more stable with time. This is not always possible in some cases of a buried penis with a significant bend. In such cases, resection of the urethral plate is necessary. The onlay urethroplasty was performed in 191 patients (93%). The dissection of the foreskin with its pedicle was made according to Quartey,11 and the inside of the prepuce was sutured to the urethral plate with interrupted sutures. The Byars flap was realized in 146 patients and a double-faced island flap in 43 patients with 6-0 polyglactin absorbable suture. All patients undergoing urinary diversion had a 6F or 8F feeding tube placed for 2-6 days, and a compressive dressing was used. In patients in whom the urethral plate was resected, the urethroplasty was performed with a tubularized island flap12 in 7 patients (combined Dupaly and tubularized island flap in 5 cases) and in 2 stages in 7 patients.
RESULTS Preservation of the urethral plate was possible in 191 patients (93%). The analysis of the lateral photographs taken at the successive saline tests demonstrated that release of the skin and dartos fascia provides complete correction of all curvature ⬍45° and three fourths of those 45°-90°. However, for angles ⬎90°, this procedure by itself was insufficient in 88% of cases (Table 1). In 64 896
Chordee
Patients (%)
0°-45° 45°-90° ⬎90° Total
46/46 (100) 76/101 (75.25) 5/44 (11.36) 127/191 (66.49)
patients insufficiently corrected by the release of the skin and dartos, mobilization of the urethral plate with resection of the underlying fibrous tissue resulted in a low amount of correction (10°-20°), and dorsal tunica albuginea plication was required to straighten the penis in 29 patients. However, although the correction obtained by mobilization of the urethral plate seems fixed in all patients (10°-20°), it is highly variable with release of the skin and dartos fascia, ranging from 20° to 100°. The urethral plate was resected in 14 cases. The resection was accidental in 2 patients, occurring in 2 of our first patients, and resulted from excessive dissection and an inability to preserve the urethral plate in 12 patients. No significant difference (using Fisher’s exact test) was seen in the overall rate of postoperative complications in our patients with and without dissection of the urethral plate (P ⫽ .631). Thus, mobilization of the urethral plate is safe in terms of preserving its blood supply. The complications were dominated by fistulas (5.51% vs 6.25%). A proximal anastomotic stricture developed in 1 of our first patients but remains poorly explained with this type of urethroplasty in which no circular sutures were used that could cause this complication.
COMMENT The curvature of the penis is a physiologic process before birth; it appears at 12-16 weeks of gestation13 and gradually disappears. At birth, an erect penis is normally straight. However, the proximal form of hypospadias is always associated with curvature of the penis. Since the work of Mettauer14 published in 1842, in which he incriminated the urethral plate in the formation of the chordee, this plate has been systematically resected. However, in the 1970s, King15 and Marshall et al16 showed that one did not need to transect the urethral plate to correct the curvature. In 1983, Koyanagi,3 proposed the release of chordee by mobilization of the urethral plate with resection of the underlying fibrous tissue. This radical change in the concept of the cause of chordee, led Mollard et al1 to propose a revolutionary idea in the treatment of patients with proximal hypospadias the use of an onlay island flap2 on a preserved urethral plate. As reported by Mollard et al,1,5,17 the fibrous tissue present under the urethral mucosa is well delineated laterally by 2 large, vascular and fibrous pillars and is the essential factor in the development of chordee. Thus, the UROLOGY 80 (4), 2012
essential act in the release of the chordee consists of resection of the fibrous tissue after mobilization of the urethral plate (in the manner of Koyanagi et al3). They reported that this will correct most cases of curvature. However, these 2 vascular and fibrous pillars reported by Mollard et al1 are difficult to identify. The view of Mollard et al1 was also defended by Perovic´ and Vukadinovic´6 and Mouriquand et al.7 Many other investigators have also remained convinced that mobilization of the urethral plate provides important release of the curvature.18-21 However, Duckett9,10 and Baskin et al8 did not find any advantage to the dissection. For them, this approach results in compromise of the vascularity of the urethral plate with a residual bend from corporeal disproportion and correction achieved by dorsal tunica albuginea plication. Hence, our interest in performing the present study to confirm the preliminary results published in 200522 and allows us to better understand the causes of curvature. Preservation of the urethral plate was possible in 191 children (93%), similar to the results reported by Perovic´ and Vukadinovic´6 and Mollard.5 The analysis of the lateral photographs taken during the successive erection tests showed that release of the skin and dartos fascia, continued widely to upstream of the meatus, usually led to significant correction of the curvature of the penis but that the dissection of the urethral plate could give only provide correction of 10°-20° (Table 1). Thus, the essential factor responsible for formation of the curvature of the penis is the fibrosis present in the lateral areas and back of the urethral plate, and not the fibrous tissue present under the urethral plate, as suggested by Mollard et al1,5,17 and Perovic´ and Vukadinovic´.6 However, no impairment of the vascularization of the urethral plate was found in 64 patients, and the complication rates were nearly identical to the group without mobilization of the urethral plate. This clearly demonstrates that the blood supply to urethral plate is safe even with dissection. This observation was also recently reported by Snodgrass and Bush.19 However, this should not be taken to minimize the important role played by the onlay island flap in the development of 1-stage repair in the treatment of proximal hypospadias. Duckett23 indicated “In all cases of hypospadias the urethral plate should be preserved initially even in the most severe forms. . . . An onlay island flap will provide better results than the tubularized preputial flap or free graft of bladder mucosa.” The better results obtained with an onlay island flap compared to tubulization of the prepuce are due to the ability to resect the poorly vascularized edges, because there is often an excess of prepuce, without the risk of proximal stricture and the presence of the solid floor made from the vestigial dysgenetic tissue from aplasia of the corpus spongiosium, termed the urethral plate. This plate consists of an epithelium covering connective tissue composed of collagen, smooth muscle cells, nerve fibers, UROLOGY 80 (4), 2012
and blood vessels.24 This urethral plate is as well vascularized25 as the sponsiosium urethra and glans.26
CONCLUSIONS Correction of chordee caused by the proximal forms of hypospadias can be corrected mainly by the release of the skin and dartos fascia. Involvement of the fibrous tissue present under the urethral plate in the development of chordee is weak. Also, although the correction obtained by mobilization of the urethral plate seems fixed in all patients (10°-20°), it is highly variable with the release of the skin and dartos fascia, ranging from 20° to 100°. References 1. Mollard P, Mouriquand P, Felfela T. Nouvelle technique de traitement des hypospades avec coudure par utilisation du lambeau en onlay. Prog Urol. 1991;1:305-311. 2. Elder JS, Duckett JW, Snyder HM. Onlay island flap in the repair of mid and distal penile hypospadias without chordee. J Urol. 1987;138:376-379. 3. Koyanagi T, Matsuno T, Nonomura K, et al. Complete repair of severe penoscrotal hypospadias in 1 stage: experience with urethral mobilization—wing flap-flipping urethroplasty and “glanulomeatoplasty”. J Urol. 1983;130:1150-1153. 4. Mollard P, Mouriquand P, Felfela T. Application of the onlay island flap urethroplsty to penile hypospadias with severe chordee. Br J Urol. 1991;68:317-319. 5. Mollard P, Castagnola C. Hypospadias: the release of chordee without dividing the urethral plate and onlay island flap (92 cases). J Urol. 1994;152:1238-1240. 6. Perovic´ S, Vukadinovic´ V. Onlay island flap urethroplasty for severe hypospadias: a variant of the technique. J Urol. 1994;151: 711-714. 7. Mouriquand P, Persad A, Sharma S. Hypospadias repair: current principles and procedures. Br J Urol. 1995;76:9-22. 8. Baskin LS, Duckett JW, Ueoka K, et al. Changing concepts of hypospadias curvature lead to more onlay island flap procedures. J Urol. 1994;151:191-196. 9. Duckett JW. Editorial comment. J Urol. 1994;151:714. 10. Duckett JW. The current hype in hypospadiology. Br J Urol. 1995; 76(suppl 3):1-7. 11. Quartey JKM. One-stage penile/preputial cutaneous island flap urethroplasty for urethral stricture: a preliminary report. J Urol. 1983;129:284-287. 12. Duckett JW. Transverse preputial island flap technique for repair of severe hypospadias. Urol Clin North Am. 1980;7:423-430. 13. Glenister TW. The origin and fate of the urethral plate in man. J Anat. 1954;88:413-425. 14. Mettauer JP. Practical observations in those malformations of the male urethra and penis, termed hypospadias and epispadias, with an anomalous case. Am J Med Sci. 1842;4:43-58. 15. King LR. Hypospadias—a one-stage repair without skin graft based on a new principle chordee is sometimes produced by the skin alone. J Urol. 1970;103:660-662. 16. Marshall M Jr, Beh WP, Johnson SH III, et al. Etiologic considerations in penoscrotal hypospadias repair. J Urol. 1978;120:229-231. 17. Mollard P, Basset T, Mure PY. Traitement moderne de l’hypospadias. J Urol (Paris Masson). 1996;102:9-17. 18. Snodgrass W, Prieto J. Straightening ventral curvature while preserving the urethral plate in proximal hypospadias repair. J Urol. 2009;182:1720-1725. 19. Snodgrass W, Bush N. Tubularized incised plate proximal hypospadias repair: continued evolution and extended applications. J Pediatr Urol. 2011;7:2-9.
897
20. Bhat A. Extended urethral mobilization in incised plate urethroplasty for severe hypospadias: a variation in technique to improve chordee correction. J Urol. 2007;178:1031-1035. 21. Ratan SK, Ratan J, Rattan KN. Is tubularization of the mobilized urethral plate a better alternative to tubularization of an incised urethral plate for hypospadias repair? Pediatr Surg Int. 2009;25:185-190. 22. Acimi S, Boukli-Hacene A. Intérêt de la mobilisation de la plaque urétrale dans la libération de la courbure qui accompagne les formes postérieures d’hypospadias. Prog Urol. 2005;15:59-62.
898
23. Duckett JW. Editorial comment. J Urol. 1994;152:1240. 24. Snodgrass W, Patterson K, Plaire JC, et al. Histology of the urethral plate: implications for hypospadias repair. J Urol. 2000;164:988990. 25. Erol A, Baskin LS, Li YW, et al. Anatomical studies of the urethral plate: why preservation of the urethral plate is important in hypospadias repair. BJU Int. 2000;85:728-734. 26. Baskin LS, Erol A, Li YW, et al. Anatomical studies of hypospadias. J Urol. 1998;160:1108-1115.
UROLOGY 80 (4), 2012
METHODS
RESULTS
CONCLUSION
To accurately measure the correction obtained by the release of the skin and dartos fascia and that obtained by mobilization of the urethral plate and resection of the underlying fibrous tissue (according to Koyanagi and Mollard), in the release of chordee. From February 1996 to February 2011, 234 patients underwent surgery for proximal hypospadias by 1 surgeon. Lateral photographs were taken during successive saline erection tests for 205 patients. The first test was performed at the beginning of the operation, the second test after the release of the skin and dartos fascia, the third test after possible mobilization of the urethral plate and resection of the underlying fibrous tissue, and the last test at the end of surgery. Preservation of the urethral plate was possible in 191 patients (93%). Analysis of the lateral photographs showed that stripping of the penis resulted in complete correction of all chordee ⬍45°. For curvature ⬎90°, stripping of the penis was insufficient in 88% of the cases. However, mobilization of the urethral plate with resection of the underlying fibrous tissue resulted in very low correction (10°-20°), although the blood supply to this plate was preserved. The results of the present study have shown that correction of the curvature that accompanies proximal hypospadias is obtained mainly by release of the skin and dartos fascia. UROLOGY 80: 894 – 898, 2012. © 2012 Elsevier Inc.
C
urvature of the penis is an anomaly often present in the proximal forms of hypospadias. Its severity depends on the degree of hypoplasia of the tissues forming the ventral side of the penis, and its release without excision of the urethral plate with an onlay island flap was a decisive turn in single-stage repair of proximal hypospadias.1 In this technique, Mollard et al1 brought together 2 principles: the onlay island flap initially described by Elder et al2 in the treatment of distal hypospadias and preservation of the urethral plate with resection of the underlying fibrous tissue proposed by Koyanagi et al.3 The principle of mobilization of the urethral plate with resection of the underlying fibrous tissue, such as was recommended by Mollard et al4,5 and Perovic´ and Vukadinovic´6 (who stated that the existing fibrous tissue under the urethral plate is the essential factor of the bend), has many supporters.1,6,7 It also has many critics,8,9 who consider this move unnecessary and dangerous to the blood supply of the plate. Duckett10 stated “A current controversy relates to the need to dissect underneath the urethral plate and lift it off the shaft. . . . They insist on lifting the skin flap and removing the spongiosal tissue beneath the urethral plate. The Financial Disclosure: The author declares that he has no relevant financial interests. From the Department of Pediatric Surgery (UMC), Children’s Hospital Canastel, Faculty of Medicine, University of Oran, Oran, Algeria Reprint requests: Smail Acimi, Ph.D., Department of Pediatric Surgery (UMC), Children’s Hospital Canastel, Faculty of Medicine, University of Oran, Oran, Algeria. E-mail: [email protected] Submitted: March 27, 2012, accepted (with revisions): June 28, 2012
894
© 2012 Elsevier Inc. All Rights Reserved
author refutes this concept, while Mollard and Perovic´ both feel this step is important. . . . But more importantly, there has been no photographic confirmation that a penile curvature present with the plate intact was relieved by dissection under the plate alone, a challenge that detractors of this method cannot meet.” The aim of the present study was to compare the results obtained by the release of the skin and dartos fascia and the results obtained by mobilization of the urethral plate and resection of the underlying fibrous tissue (according to the method of Koyanagi et al3 and Mollard1) in the release of chordee.
MATERIAL AND METHODS From February 1996 to February 2011, 234 patients underwent repair for proximal hypospadias associated with chordee by a single surgeon. In 205 patients, we used lateral photographs taken during successive saline erection tests to measure with precision the correction obtained after each stage. The first test was performed at the beginning of the operation, the second test after release of the skin and dartos fascia, the third test after possible mobilization of the urethral plate and resection of the underlying fibrous tissue, and the last test at the end of the operation (Fig. 1). The angle between the axis of the proximal part and that of the distal part is measured by a protractor. In 29 patients, it was not possible to perform these tests. Testosterone was given to 37 patients with a small penis before surgery to increase the size of the penis. The age of the patients at surgery ranged from 12 months to 5 years (mean 26 months), and the position of the urethral meatus before correction was distal 0090-4295/12/$36.00 http://dx.doi.org/10.1016/j.urology.2012.06.050
Figure 2. (A) Spontaneous erection showed curvature of penis of 120° that had (B) decreased to 28° after simple release of skin and dartos fascia. (Color version available online.)
Figure 1. (A) Initial curvature of 75° that had (B) decreased to 50° after releasing skin and dartos fascia. (C) View at 37°, after mobilization of urethral plate and resection of underlying fibrous tissue. (Color version available online.)
UROLOGY 80 (4), 2012
(with a dysplastic distal urethra without the corpus spongiosum), mid or proximal penile shaft in 133, penoscrotal in 45, and scrotal or perineal in 27. The median follow-up was 76 months (range 5-185). We always started an evaluation of the initial curvature of the penis with an artificial erection test. Sometimes, before deepening the anesthesia, a spontaneous erection would occur and we could avoid using the first test (Fig. 2). A traction suture was placed through the glans, and a circumferential incision was made 2 mm proximal to the hypospadiac meatus and extended distally by 2 parallel incisions in the skin and the glans (Ushaped incision). This incision isolated a urethral plate that was sufficiently wide (8-10 mm).1 After the circumferential subcoronal incision, the skin and dartos fascia were dissected from the shaft. This dissection must be extended proximally to the perineal area. The correction obtained was evaluated with a second artificial saline test. If this test demonstrated persistent penile curvature of ⬎10°-15°, the urethral plate was lifted up 895
Table 1. Patient distribution according to penile curvature severity and number of complete corrections obtained by simple release of skin and dartos fascia
Figure 3. Dorsal plication by resection to diamond shape on dorsal side of albuginea. (Color version available online.)
from the corpora cavernosa by a fine scissors slipped between the urethral plate and corpora cavernosa. All the fibrous tissue would then be resected. Sometimes after this mobilization of the urethral plate, significant chordee (⬎15°-20°) would remain. Two parallel longitudinal incisions of Buck’s fascia were made at the 2- and 10-o’clock positions until the tunica albuginea was seen. To keep in contact with this area, fine scissors were placed behind Buck’s fascia to lift it up with the dorsal neurovascular bundle. The dissection must remain directly on top of the tunica albuginea to prevent neuronal and vascular injury when mobilized. We then performed a dorsal tunica albuginea plication by excision of a diamond shape at the point of the maximum bend dorsally (Fig. 3). The edges of this incision were sutured with nonabsorbable running suture (5-0). This method of dorsal plicature is more physiologic than that described by Baskin et al.8 Also, the correction has seemed more stable with time. This is not always possible in some cases of a buried penis with a significant bend. In such cases, resection of the urethral plate is necessary. The onlay urethroplasty was performed in 191 patients (93%). The dissection of the foreskin with its pedicle was made according to Quartey,11 and the inside of the prepuce was sutured to the urethral plate with interrupted sutures. The Byars flap was realized in 146 patients and a double-faced island flap in 43 patients with 6-0 polyglactin absorbable suture. All patients undergoing urinary diversion had a 6F or 8F feeding tube placed for 2-6 days, and a compressive dressing was used. In patients in whom the urethral plate was resected, the urethroplasty was performed with a tubularized island flap12 in 7 patients (combined Dupaly and tubularized island flap in 5 cases) and in 2 stages in 7 patients.
RESULTS Preservation of the urethral plate was possible in 191 patients (93%). The analysis of the lateral photographs taken at the successive saline tests demonstrated that release of the skin and dartos fascia provides complete correction of all curvature ⬍45° and three fourths of those 45°-90°. However, for angles ⬎90°, this procedure by itself was insufficient in 88% of cases (Table 1). In 64 896
Chordee
Patients (%)
0°-45° 45°-90° ⬎90° Total
46/46 (100) 76/101 (75.25) 5/44 (11.36) 127/191 (66.49)
patients insufficiently corrected by the release of the skin and dartos, mobilization of the urethral plate with resection of the underlying fibrous tissue resulted in a low amount of correction (10°-20°), and dorsal tunica albuginea plication was required to straighten the penis in 29 patients. However, although the correction obtained by mobilization of the urethral plate seems fixed in all patients (10°-20°), it is highly variable with release of the skin and dartos fascia, ranging from 20° to 100°. The urethral plate was resected in 14 cases. The resection was accidental in 2 patients, occurring in 2 of our first patients, and resulted from excessive dissection and an inability to preserve the urethral plate in 12 patients. No significant difference (using Fisher’s exact test) was seen in the overall rate of postoperative complications in our patients with and without dissection of the urethral plate (P ⫽ .631). Thus, mobilization of the urethral plate is safe in terms of preserving its blood supply. The complications were dominated by fistulas (5.51% vs 6.25%). A proximal anastomotic stricture developed in 1 of our first patients but remains poorly explained with this type of urethroplasty in which no circular sutures were used that could cause this complication.
COMMENT The curvature of the penis is a physiologic process before birth; it appears at 12-16 weeks of gestation13 and gradually disappears. At birth, an erect penis is normally straight. However, the proximal form of hypospadias is always associated with curvature of the penis. Since the work of Mettauer14 published in 1842, in which he incriminated the urethral plate in the formation of the chordee, this plate has been systematically resected. However, in the 1970s, King15 and Marshall et al16 showed that one did not need to transect the urethral plate to correct the curvature. In 1983, Koyanagi,3 proposed the release of chordee by mobilization of the urethral plate with resection of the underlying fibrous tissue. This radical change in the concept of the cause of chordee, led Mollard et al1 to propose a revolutionary idea in the treatment of patients with proximal hypospadias the use of an onlay island flap2 on a preserved urethral plate. As reported by Mollard et al,1,5,17 the fibrous tissue present under the urethral mucosa is well delineated laterally by 2 large, vascular and fibrous pillars and is the essential factor in the development of chordee. Thus, the UROLOGY 80 (4), 2012
essential act in the release of the chordee consists of resection of the fibrous tissue after mobilization of the urethral plate (in the manner of Koyanagi et al3). They reported that this will correct most cases of curvature. However, these 2 vascular and fibrous pillars reported by Mollard et al1 are difficult to identify. The view of Mollard et al1 was also defended by Perovic´ and Vukadinovic´6 and Mouriquand et al.7 Many other investigators have also remained convinced that mobilization of the urethral plate provides important release of the curvature.18-21 However, Duckett9,10 and Baskin et al8 did not find any advantage to the dissection. For them, this approach results in compromise of the vascularity of the urethral plate with a residual bend from corporeal disproportion and correction achieved by dorsal tunica albuginea plication. Hence, our interest in performing the present study to confirm the preliminary results published in 200522 and allows us to better understand the causes of curvature. Preservation of the urethral plate was possible in 191 children (93%), similar to the results reported by Perovic´ and Vukadinovic´6 and Mollard.5 The analysis of the lateral photographs taken during the successive erection tests showed that release of the skin and dartos fascia, continued widely to upstream of the meatus, usually led to significant correction of the curvature of the penis but that the dissection of the urethral plate could give only provide correction of 10°-20° (Table 1). Thus, the essential factor responsible for formation of the curvature of the penis is the fibrosis present in the lateral areas and back of the urethral plate, and not the fibrous tissue present under the urethral plate, as suggested by Mollard et al1,5,17 and Perovic´ and Vukadinovic´.6 However, no impairment of the vascularization of the urethral plate was found in 64 patients, and the complication rates were nearly identical to the group without mobilization of the urethral plate. This clearly demonstrates that the blood supply to urethral plate is safe even with dissection. This observation was also recently reported by Snodgrass and Bush.19 However, this should not be taken to minimize the important role played by the onlay island flap in the development of 1-stage repair in the treatment of proximal hypospadias. Duckett23 indicated “In all cases of hypospadias the urethral plate should be preserved initially even in the most severe forms. . . . An onlay island flap will provide better results than the tubularized preputial flap or free graft of bladder mucosa.” The better results obtained with an onlay island flap compared to tubulization of the prepuce are due to the ability to resect the poorly vascularized edges, because there is often an excess of prepuce, without the risk of proximal stricture and the presence of the solid floor made from the vestigial dysgenetic tissue from aplasia of the corpus spongiosium, termed the urethral plate. This plate consists of an epithelium covering connective tissue composed of collagen, smooth muscle cells, nerve fibers, UROLOGY 80 (4), 2012
and blood vessels.24 This urethral plate is as well vascularized25 as the sponsiosium urethra and glans.26
CONCLUSIONS Correction of chordee caused by the proximal forms of hypospadias can be corrected mainly by the release of the skin and dartos fascia. Involvement of the fibrous tissue present under the urethral plate in the development of chordee is weak. Also, although the correction obtained by mobilization of the urethral plate seems fixed in all patients (10°-20°), it is highly variable with the release of the skin and dartos fascia, ranging from 20° to 100°. References 1. Mollard P, Mouriquand P, Felfela T. Nouvelle technique de traitement des hypospades avec coudure par utilisation du lambeau en onlay. Prog Urol. 1991;1:305-311. 2. Elder JS, Duckett JW, Snyder HM. Onlay island flap in the repair of mid and distal penile hypospadias without chordee. J Urol. 1987;138:376-379. 3. Koyanagi T, Matsuno T, Nonomura K, et al. Complete repair of severe penoscrotal hypospadias in 1 stage: experience with urethral mobilization—wing flap-flipping urethroplasty and “glanulomeatoplasty”. J Urol. 1983;130:1150-1153. 4. Mollard P, Mouriquand P, Felfela T. Application of the onlay island flap urethroplsty to penile hypospadias with severe chordee. Br J Urol. 1991;68:317-319. 5. Mollard P, Castagnola C. Hypospadias: the release of chordee without dividing the urethral plate and onlay island flap (92 cases). J Urol. 1994;152:1238-1240. 6. Perovic´ S, Vukadinovic´ V. Onlay island flap urethroplasty for severe hypospadias: a variant of the technique. J Urol. 1994;151: 711-714. 7. Mouriquand P, Persad A, Sharma S. Hypospadias repair: current principles and procedures. Br J Urol. 1995;76:9-22. 8. Baskin LS, Duckett JW, Ueoka K, et al. Changing concepts of hypospadias curvature lead to more onlay island flap procedures. J Urol. 1994;151:191-196. 9. Duckett JW. Editorial comment. J Urol. 1994;151:714. 10. Duckett JW. The current hype in hypospadiology. Br J Urol. 1995; 76(suppl 3):1-7. 11. Quartey JKM. One-stage penile/preputial cutaneous island flap urethroplasty for urethral stricture: a preliminary report. J Urol. 1983;129:284-287. 12. Duckett JW. Transverse preputial island flap technique for repair of severe hypospadias. Urol Clin North Am. 1980;7:423-430. 13. Glenister TW. The origin and fate of the urethral plate in man. J Anat. 1954;88:413-425. 14. Mettauer JP. Practical observations in those malformations of the male urethra and penis, termed hypospadias and epispadias, with an anomalous case. Am J Med Sci. 1842;4:43-58. 15. King LR. Hypospadias—a one-stage repair without skin graft based on a new principle chordee is sometimes produced by the skin alone. J Urol. 1970;103:660-662. 16. Marshall M Jr, Beh WP, Johnson SH III, et al. Etiologic considerations in penoscrotal hypospadias repair. J Urol. 1978;120:229-231. 17. Mollard P, Basset T, Mure PY. Traitement moderne de l’hypospadias. J Urol (Paris Masson). 1996;102:9-17. 18. Snodgrass W, Prieto J. Straightening ventral curvature while preserving the urethral plate in proximal hypospadias repair. J Urol. 2009;182:1720-1725. 19. Snodgrass W, Bush N. Tubularized incised plate proximal hypospadias repair: continued evolution and extended applications. J Pediatr Urol. 2011;7:2-9.
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20. Bhat A. Extended urethral mobilization in incised plate urethroplasty for severe hypospadias: a variation in technique to improve chordee correction. J Urol. 2007;178:1031-1035. 21. Ratan SK, Ratan J, Rattan KN. Is tubularization of the mobilized urethral plate a better alternative to tubularization of an incised urethral plate for hypospadias repair? Pediatr Surg Int. 2009;25:185-190. 22. Acimi S, Boukli-Hacene A. Intérêt de la mobilisation de la plaque urétrale dans la libération de la courbure qui accompagne les formes postérieures d’hypospadias. Prog Urol. 2005;15:59-62.
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23. Duckett JW. Editorial comment. J Urol. 1994;152:1240. 24. Snodgrass W, Patterson K, Plaire JC, et al. Histology of the urethral plate: implications for hypospadias repair. J Urol. 2000;164:988990. 25. Erol A, Baskin LS, Li YW, et al. Anatomical studies of the urethral plate: why preservation of the urethral plate is important in hypospadias repair. BJU Int. 2000;85:728-734. 26. Baskin LS, Erol A, Li YW, et al. Anatomical studies of hypospadias. J Urol. 1998;160:1108-1115.
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