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Meatal Advancement And Glanuloplasty Hypospadias Repair After 1,000 Cases: Avoidance of Meatal Stenosis And Regression
0022-5347 /92/14 73-0665$03.00/0
Vol. 147, 665-669, March 1992 Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1992 by AMERICAN
UROLOGICAL ASSOCIATION, INC.
MEATAL ADVANCEMENT AND GLANULOPLASTY HYPOSPADIAS REPAIR AFTER 1,000 CASES: AVOIDANCE OF IVIEATAL STENOSIS AND REGRESSION JOHN W. DUCKETT
HOW ARD M. SNYDER, III
AND
From the Division of Urology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
ABSTRACT
We first described the meatal advancement and glanuloplasty (MAGPI) procedure in 1981 as a technique to repair distal hypospadias. During the last 10 years our experience has increased to more than 1,000 cases. Case selection is critical to surgical outcome. Excessively thin or rigid ventral parameatal skin, or a meatus that is too proximal or too wide must be avoided. To prevent the ventral meatal wall from falling back and leaving a retrusive meatus, the glans wrap to support the advanced ventral urethral wall requires a solid approximation of glans tissue in 2 layers. Meatal stenosis may be avoided by an adequately deep dorsal Heineke- Mikulicz tissue rearrangement, making the incision from within the urethral meatus distally into the glanular urethral groove. The MAG PI procedure is routinely performed on an outpatient basis without urinary diversion. A review of our experience with 1,111 cases during a 12-year period reveals that a secondary procedure was required in only 1.2%. The overall success rate with the MAGPI procedure suggests that it should continue to be an important operation in the reconstruction of distal hypospadias. KEY WORDS:
hypospadias; urethra; surgery, plastic
In 1981 we described the hypospadias repair of meatal advancement and glanuloplasty (MAGPI). 1 Since its introduction the MAG PI procedure has withstood the test of time and it has gained international acceptance. Overall, it is the most common hypospadias technique used to date. One in 300 male neonates exhibits hypospadias, which is anterior in 65%, middle in 15% and penoscrotal or scrotal (posterior) in 20%. Of the cases of anterior hypospadias the dystropic meatus is located on the inferior glans in 15%, the coronal groove in 50% and subcoronally in 30%, with the megameatus intact prepuce variant observed in 5% of all cases. 2 Approximately 50% of these anterior variants, or a third of all hypospadias cases, are suited for the MAG PI repair. While we continue to be satisfied with this technique, others have reported meatal retraction and meatal stenosis, leading to dissatisfactory results. 3 - 7 We review our results and discuss the modifications of the MAGPI procedure that have evolved during the last 10 years to help others avoid these complications and, thus, ensure a satisfactory outcome.
stenosis noted. The overall incidence of complications requiring a second operation was 1.2%. During the last 5 years our reoperation rate was 1% (4 of 394 cases). Average followup was 2.3 months, with a range of 2 weeks to 2 years. No followup was obtained in 16 of the last 282 cases (6%). While an average followup of longer than 2.3 months might be preferable, we have noted that the appearance of the repair at that point remains constant. This impression has been supported by the return of select patients years later for other reasons. We have not insisted that parents bring children back for long-term followup, since the majority of them undergo repair at age 6 months to 1 year, and the operation is not remembered by the child. It seems unnecessary to remind the child of the correction of an anomaly that has been rendered close to normal. We do encourage parents to observe the child and report to us any difficulty directing the urinary stream or any cosmetic skin irregularity. Late problems rarely occur, since this repair using only normal genital skin typically matures nicely with the child (fig. 1).
PATIENTS AND METHODS
CASE SELECTION
We reviewed the records of 282 boys at our hospital who underwent the MAGPI procedure between July 1987 and May 1990. These cases have been added to those reported earlier .1• 8 • 9 The table summarizes the overall results and complications, which included urethral fistula, ventral meatal retraction, meatal stenosis, persistent ventral chordee or cosmetically unsatisfactory skin irregularity. There were 5 urethrocutaneous fistulas (0.45%), 7 ventral meatal retractions (0.6%) and 1 persistent ventral curvature (0.09% ), with no meatal
The nature of the meatus and the parameatal skin are of paramount importance in case selection for the MAG PI repair. The ventral parameatal skin must be thick and pliable so that it can be lifted easily off of the underlying urethra. These qualities are essential to permit the ventral parameatal skin to be advanced distally to extend the urethra. If the parameatal skin is thin or nonpliable, then the MAGPI procedure is inappropriate. 10 In these cases an island onlay operation may be a more suitable reconstruction. 11 • 12 The size of the meatus, which usually is small, is also an important consideration. The typically flat glans shape must permit it to be wrapped around the advanced ventral urethral wall in order to reconfigure the glans into a more normal conical shape. The solid healing of glans-to-glans maintains the ventral support for the advanced meatus and, thus, prevents the later falling back of the ventral meatal wall, known as a retrusive meatus. If the meatus is too proximal or large, as is usually seen in the megameatus intact prepuce variant of hypospadias, 2 then its size prevents exposure of the glans for placement of the glansplasty sutures. Either a pyramid 2 or Mathieu 13 opera-
Accepted for publication August 23, 1991.
Cumulative results of MAGPI procedure % Requiring Urethral Meatal Meatal Ventral Yr./Reference No. Pts. Fistula Retraction Stenosis Chordee Secondary Operation 1978-1981 1 1981-19858 1985-19879 1987-1990
Totals
207 510 128 266 1,111
1 2 1
2 1 0
0 0 0 0
5
7
0
1
4
0 0 0 1
I
2.4 0.8 1.5 0.8 1.2
665
666
DUCKETT AND SNYDER
Fm. 1. MAGPI-typical case. a, preoperative view. Note flattened glans and skin bridge distal to meatus producing ventral deflection of stream. b, postoperative results, ventral view. Note conical glans and ventral glans support for advanced meatus. Mucosa! collar gives normal skin configuration of circumcised penis. c, postoperative result, end view. Meatus demonstrates normal slit configuration on end of glans.
tion with a glansplasty involving formal mobilization of glans wings will result in a better long-term glans reconstruction. In cases of distal hypospadias it is rare to see ventral curvature due to more than ventral skin or a subcutaneous tissue abnormality. The flattened glans typically observed in these cases appears to be an indication that once the shaft skin has been dropped back an artificial erection will reveal straight corporeal bodies. Cases ideal for the MAG PI procedure usually have a meatus positioned at the coronal margin or subcoronally. Commonly, there is a lip of tissue distal to the meatus, which ventrally deflects the urinary stream to some degree and is the largest functional impairment of these anterior hypospadias anomalies. The glanular groove varies in depth and it may require deepening as part of the initial Heineke-Mikulicz maneuver, which advances and flattens the dorsal urethral wall. Properly performed, this step corrects ventral deflection of the urinary stream and ensures a well directed stream in the axis of the shaft of the penis. While there often is an accessory dorsal periurethral duct located within the glanular groove distal to the meatus, this does not interfere with the performance of a MAGPI procedure. TECHNIQUE
The technique for the MAGPI operation has been modified considerably since it was introduced. While textbook and atlas diagrams have been modified through the years, it is difficult to depict adequately the 3-dimensional nature of this meatal enlargement and advancement procedure, and the wrap-around 3-dimensional nature of the glanular reconfiguration required for the production of an excellent cosmetic and functional result (fig. 2). A holding stitch of 5-zero polypropylene is placed in the glans for traction, and a 1:100,000 concentration of epinephrine in 1% lidocaine is injected in the subcoronal area and glanular groove for hemostasis. A dorsal penile nerve block with ¼ % bupivacaine hydrochloride is routinely used to de-
crease the need for intraoperative anesthesia and to provide initial postoperative comfort. A circumferential incision is made subcoronal and proximal to the urethral meatus (fig. 2, a). We believe that the exact placement of the incision is not critical since excessive residual skin will be trimmed after the glanuloplasty has been completed, although others have stressed the importance of the initial ventral incision in the construction of the future glanular reconfiguration. 3 • 14• 15 A mucosal collar may be preserved from dorsal preputial skin. 15 The penile shaft skin is mobilized as a sleeve back to the penoscrotal junction, freeing the tethering fibers present in the subdartos fascia, particularly on the ventrum. These fibers appear to be the most likely cause for the ventral tilt of the glans so commonly seen preoperatively. An artificial erection is used to check for residual chordee. Residual curvature usually is caused by corporeal disproportion rather than chordee involving the urethra. Correction is usually done by Nesbit dorsal plicating sutures, 16 which we place without incising the tunica albuginea. The correction of any initial meatal stenosis and the advancement of the dorsal urethral wall are accomplished by a HeinekeMikulicz vertical incision and horizontal closure (fig. 2, b to d). Meatal stenosis subsequently is avoided by making the incision from within the meatus and ensuring that it is sufficiently deep when the groove is shallow. Sometimes a wedge removal of a segment of glanular tissue distal to the meatus is required. The horizontal closure flattens out the glanular bridge and permits the dorsal urethra to be advanced distally to the end of the glanular groove, where it is sutured with interrupted 7-zero polyglactin. The deflecting glans bridge is effectively flattened, which permits the urinary stream to be directed forward in the axis of the shaft of the penis. A satisfactory glanuloplasty is critical to support the advanced ventral wall of the urethral meatus. This procedure is accomplished by shaping the typically flattened glans into a more normal conical shape (fig. 2, e to h). Reconfiguration is
MEATAL ADVANCEMENT AND GLANULOPLASTY FOR HYPOSPAD!AS
667
FIG. 2. MAGPI. a, circumferential incision is made proximal to corona and proximal to meatus. b, skin is dissected down to penoscrotal junction, freeing up all tethering dartos bands, assuring straight erection by artificial injection. c and d, dorsal meatoplasty. Vertical incision is made in transverse web between meatus and distal glans groove and extended proximally into meatus to correct stenosis. Diamond-like defect is closed transversely (Heineke-Mikulicz), advancing and flattening dorsal urethral wall. e to h, glanuloplasty. Holding stitch is placed to elevate ventral urethral meatal edge (e). Good parameatal skin is required. Glans tissue to be approximated in midline is exposed by excising strips of epithelium on each side (dotted lines) (/). Glans tissue is approximated solidly with polyglactin or polydioxanone to support advanced ventral urethral wall (g). Epithelial closure is done with 7-zero chromic suture or subcuticular 7-zero polydioxanone. h, sleeve skin closure. Note conical glans configuration. Mucosa! collar rotation, which is often used, is not shown.
achieved by rotating the lateral aspects of the wings of the glans around to the midline proximal to the advanced ventral wall of the urethral meatus. Skin adjacent to the glanular edges often must be excised to expose glans tissue for the reapproximation of the glans wings in the midline ventrally (fig. 2, /). The glanular tissue is brought solidly together with interrupted 6-zero polyglactin or polydioxanone sutures, and the superficial epithelial edges are run with 7-zero chromic or, in older children, a subcuticular 7-zero polydioxanone suture (fig. 2, g). In this manner, mesenchymal glans tissue heals to glans tissue between the epithelial layer of the urethra and the outer epithelium of the glans. This solid tissue support for the ventral wall of the urethral meatus prevents meatal retraction. The rotation of the glans wings reconfigures the glans to a nearly normal conical appearance. A bougie aboule is used to calibrate the meatus and ensure that the glanuloplasty has not compromised the lumen of the distal glanular urethra. Ease of expression of the bladder also helps to confirm an adequate urethral lumen. Generally, a sleeve reapproximation of the penile skin is sufficient to complete cover (fig. 2, h). Occasionally, a rotation of excessive dorsal preputial skin to the ventrum is used to correct ventral skin deficiency. Torsion can usually be corrected as part of the initial drop back of the shaft skin, taking the dissection completely back to the dorsal suspensory ligament and the ventral penoscrotal junction. Recently, we have begun using 7-zero chromic sutures for skin closure to minimize postoperative suture sinuses to prevent the rapid ingrowth of genital epithelium along the sutures. No stents or catheters are used. Children usually experience only 1 to 3 days of dysuria.
Procedures are routinely done on an outpatient basis. A nonadherent gauze dressing, as for a circumcision, is left in place for 24 to 48 hours and then it is soaked off at home by the parent. DISCUSSION
For many years surgical techniques with an acceptably low morbidity were not available to reconstruct reliably the urethra out to the tip of the glans in patients with a distally placed meatus. Since these cases exhibited a minimal functional impairment, surgeons were reluctant to undertake an operation with complications that might leave the patient worse off than if the anomaly were left untreated. 17 Methods available to correct distal hypospadias, including the Mathieu, 13 Mustarde 18 and Devine-Horton flip-flap 19 techniques, require the construction of a neourethra and a formal glansplasty with mobilization of glans wings. The MAG PI procedure avoids a sutured urethroplasty and, thus, reduces the risk of fistula. It provides a reliable, reproducible method to reconfigure the glans and meatus without urinary diversion and with minimal moribidity. In our experience meatal stenosis has never been a problem with this type of reconstruction, although it has been reported by others. When the dorsal urethral incision is made vertically from within the urethral meatus and subsequently closed transversely, the meatus is opened into a wide configuration. While many anterior hypospadias anomalies have a significant initial meatal stenosis, a meatoplasty in this fashion using the principle of a Heineke-Mukulicz rearrangement suffices to correct stenosis and avoid postoperative problems of persistent stenosis. If the glanular groove is poorly developed, the vertical
668
DUCKETT AND SNYDER
incision is deepened to the level of the corporeal bodies before it is closed transversely. Diagraming a 3-dimensional explanation for the glanulopasty has been most challenging. During the last 10 years modifications have been made to bring glanular tissue together in a more solid ventral closure. 8 - 10 • 16 This procedure avoids meatal regression, which increases when the ventral wall of the urethra in this or other hypospadias repairs is not supported by a solid layer of glans tissue. An additional layer approximating deep glans tissue has been added to achieve this effect. This technique replaces the vertical epithelial mattress stitches described in the original diagram. 1 We now stress the apposition of glans mesenchyme usually with 2 to 3 polyglactin or polydioxanone sutures, followed by a separate superficial epithelial closure. This. more secme closure avoids the ventral g-lans separation that leads to meatal regression from loss of glans tissue support of the advanced ventral urethral wall. The ventral meatal edge is fixed to the glanular tissue with interrupted fine chromic sutures to prevent it from retracting beneath the glansplasty. Usually, the reconfigured glans has a normal looking conical configuration with a barely perceptible ventral midline glans scar. Some modifications of this basic technique may be necessary in select cases. For instance, the bridge of tissue in the glanular groove may be so thick that a transverse wedge is removed more easily during the dorsal urethral wall advancement. At other times, the glanular groove may be wide and the dorsal urethral wall advancement may leave a prominent dog-ear at each corner. Excision of these dog-ears is needed to complete the creation of a satisfactory vertical neomeatus. Inappropriate application of the MAGPI procedure to unsuitable cases causes most of the poor results reported by others. 4 • 7 The ventral distal parameatal skin must be thick and pliable to be lifted off of the underlying urethra for distal advancement. The meatus must be sufficiently distal and small to permit the glans tissue to be brought to the ventral midline and to support the advanced ventral wall of the meatus. Thin or rigid parameatal skin, or a meatus that is too proximal or too wide, as is commonly seen in the megameatus intact prepuce variant,2 will not permit proper execution of the MAGPI operation and, thus, an unsatisfactory result can be predicted. Modifications of the MAGPI for distinct indications have been developed by others. Arap et al devised a method for urethral extension in cases with a meatus that is too proximal for a standard MAGPl. 5 The ventral parameatal skin margin is brought forward with 2 holding stitches 7 to 10 mm. apart in an M configuration. The central V of the M is closed vertically, forming a urethral extension that is buried beneath the glanular approximation, resulting in a low fistula rate. A dorsal meatal advancement is not beneficial in this setting. 6 A glans approximation procedure has been described recently 20 but it does not appear to be suited for cases that are generally appropriate for a MAGPI operation. Other authors have described their experience with the MAGPI procedure. Livne et al reported excellent results in 66 cases with no meatal stenosis or retraction, 21 of which only 3 demonstrated minor cosmetic deficiency. MacMillan et al reviewed 44 MAG PI procedures using photography of the urinary stream and uroflowmetry. 22 An excellent cosmetic result was noted in all but 1 case, in which a small meatal flap was subsequently considered acceptable and it required no surgery. Photography during voiding demonstrated a satisfactory if not entirely normal pattern, and flow rates were normal. MacMillan et al stated, "Until recently, the price of perfection in the management of anterior hypospadias was significantly high. However, with the advent of the MAGPI repair, which virtually guarantees perfect cosmetic results and fully preserves micturitional function, all boys with distal hypospadias should be offered early surgical correction." 22 However, others have reported unacceptable results. Ozen
and Whitaker experienced a 6% incidence of meatal retraction in 67 cases and only a 91 % excellent result. 14 Issa and Gearhart described 8 cases with subsequent meatal retraction, of which 5 were attributed to technical failure and 3 to poor case selection. 7 Hastie et al noted a significant problem with meatal retraction but in no case was the retraction back to the position of the original meatus, and the direction of the urinary stream did not appear to be adversely affected. 4 After 10 years of use in the hands of many surgeons, the primary criticisms of the MAGPI procedure center on meatal regression and stenosis. Our attention now is focused on teaching the avoidance of these problems. Stenosis can be completely avoided by emphasizing a meatoplasty that extends the dorsal vertical incision into the meatus to open widely its caliber, and an incision sufficiently El.eep to correct a poorly developed glanular groove. A timid meatoplasty that does not incise the dorsal meatal wall will likely lead to persistence of the small meatus postoperatively. To avoid meatal regression, the glans wings must be brought together ventrally and fixed snugly to ensure solid glans-to-glans healing. Ventral glans support for a reconstructed ventral urethral wall is essential not only in the MAGPI but in other hypospadias repairs as well. Our results have confirmed that when cases are properly selected and the operation is well executed the MAGPI technique for hypospadias continues to be successful with minimal morbidity. The cases of Drs. William J. Cromie, R. Bruce Filmer, Michael A. Keating and Bruce Blyth were included in this series. REFERENCES 1. Duckett, J. W.: MAGPI (meatal advancement and glanuloplasty):
2. 3. 4. 5. 6. 7. 8.
9. 10. 11. 12.
13. 14. 15. 16.
a procedure for subcoronal hypospadias. Urol. Clin. N. Amer., 8: 513, 1981. Duckett, J. W. and Keating, M. A.: Technical challenge of the megameatus intact prepuce hypospadias variant: the pyramid procedure. J. Urol., 141: 1407, 1989. Deeter, R. M.: M inverted V glansplasty: a procedure for distal hypospadias. J. Urol., part 2, 146: 641, 1991. Hastie, K. J., Deshpande, S. S. and Moisey, C. U.: Long-term follow-up of the MAGPI operation for distal hypospadias. Brit. J. Urol., 63: 320, 1989. Arap, S., Mitre, A. I. and De Goes, G. M.: Modified meatal advancement and glanuloplasty repair of distal hypospadias. J. Urol., 131: 1140, 1984. Scherz, H. C., Kaplan, G. W. and Packer, M. G.: Modified meatal advancement and glanuloplasty (Arap hypospadias repair): experience in 31 patients. J. Urol., part 2, 142: 620, 1989. Issa, M. M. and Gearhart, J.P.: The failed MAGPI: management and prevention. Brit. J. Urol., 64: 169, 1989. Duckett, J. W.: Hypospadias. In: Campbell's Urology, 5th ed. Edited by P. C. Walsh, R. F. Gittes, A. D. Perlmutter and T. A. Stamey. Philadelphia: W. B. Saunders Co., chapt. 47, pp. 19691999, 1986. Smith-Harrison, L. I., Choi, H., Tarry, W. F., Snyder, H. M. and Duckett, J. W.: Current hypospadias experience. J. Urol., part 2, 133: 114A, abstract 2, 1985. Gibbons, M. D. and Gonzales, E. T., Jr.: The subcoronal meatus. J. Urol., 130: 739, 1983. Elder, J. S., Duckett, J. W. and Snyder, H. M.: Onlay island flap in the repair of mid and distal penile hypospadias without chordee. J. Urol., 138: 376, 1987. Hollowell, J. G., Keating, M. A., Snyder, H. M., III and Duckett, J. W.: Preservation of the urethral plate in hypospadias repair: extended applications and further experience with the onlay island flap urethroplasty. J. Urol., 143: 98, 1990. Mathieu, P.: Traitement en un temps de l'hypospadias balanique et juxtabalanique. J. Chir., 39: 481, 1932. Ozen, H. A. and Whitaker, R. H.: Scope and limitations of the MAGPI hypospadias repair. Brit. J. Urol., 59: 81, 1987. Firlit, C. F.: The mucosa! collar in hypospadias surgery. J. Urol., 137: 80, 1987. Duckett, J. W.: Hypospadias. In: Adult and Pediatric Urology, 2nd ed. Edited by J. Y. Gillenwater, J. T. Grayhack, S. S. Howards
MEATAL ADVANCEMENT AND GLANULOPLASTY FOR HYPOSPADIAS
and J. W. Duckett. St. Louis: Mosby Year Book Inc., chapt. 57, p. 2103, 1991.
17. Mills, C., McGovern, J., Mininberg, D., Coleman, J., Muecke, E. and Vaughan, E. D., Jr.: An analysis of different techniques for distal hypospadias repair: the price of perfection. J. Urol., 125: 701, 1981. 18. Mustarde, J. C.: One-stage correction of distal hypospadias and other people's fistulae. Brit. J. Plast. Surg., 18: 413, 1965. 19. Devine, C. J., Jr. and Horton, C. E.: Hypospadias repair. J. Urol., 118: 188, 1977.
20. Zaontz, M. R.: The GAP (glans approximation procedure) for glanular/coronal hypospadias. J. Urol., 141: 359, 1989. 21. Livne, P. M., Gibbons, M. D. and Gonzales, E. T., Jr.: Meatal advancement and glanuloplasty: an operation for distal hypospadias. J. Urol., 131: 95, 1984. 22. MacMillan, R. D. H., Churchill, B. M. and Gilmour, R. F.: Assessment of urinary stream after repair of anterior hypospadias by meatoplasty and glanuloplasty. J. Urol., 134: 100, 1985.
Vol. 147, 665-669, March 1992 Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1992 by AMERICAN
UROLOGICAL ASSOCIATION, INC.
MEATAL ADVANCEMENT AND GLANULOPLASTY HYPOSPADIAS REPAIR AFTER 1,000 CASES: AVOIDANCE OF IVIEATAL STENOSIS AND REGRESSION JOHN W. DUCKETT
HOW ARD M. SNYDER, III
AND
From the Division of Urology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
ABSTRACT
We first described the meatal advancement and glanuloplasty (MAGPI) procedure in 1981 as a technique to repair distal hypospadias. During the last 10 years our experience has increased to more than 1,000 cases. Case selection is critical to surgical outcome. Excessively thin or rigid ventral parameatal skin, or a meatus that is too proximal or too wide must be avoided. To prevent the ventral meatal wall from falling back and leaving a retrusive meatus, the glans wrap to support the advanced ventral urethral wall requires a solid approximation of glans tissue in 2 layers. Meatal stenosis may be avoided by an adequately deep dorsal Heineke- Mikulicz tissue rearrangement, making the incision from within the urethral meatus distally into the glanular urethral groove. The MAG PI procedure is routinely performed on an outpatient basis without urinary diversion. A review of our experience with 1,111 cases during a 12-year period reveals that a secondary procedure was required in only 1.2%. The overall success rate with the MAGPI procedure suggests that it should continue to be an important operation in the reconstruction of distal hypospadias. KEY WORDS:
hypospadias; urethra; surgery, plastic
In 1981 we described the hypospadias repair of meatal advancement and glanuloplasty (MAGPI). 1 Since its introduction the MAG PI procedure has withstood the test of time and it has gained international acceptance. Overall, it is the most common hypospadias technique used to date. One in 300 male neonates exhibits hypospadias, which is anterior in 65%, middle in 15% and penoscrotal or scrotal (posterior) in 20%. Of the cases of anterior hypospadias the dystropic meatus is located on the inferior glans in 15%, the coronal groove in 50% and subcoronally in 30%, with the megameatus intact prepuce variant observed in 5% of all cases. 2 Approximately 50% of these anterior variants, or a third of all hypospadias cases, are suited for the MAG PI repair. While we continue to be satisfied with this technique, others have reported meatal retraction and meatal stenosis, leading to dissatisfactory results. 3 - 7 We review our results and discuss the modifications of the MAGPI procedure that have evolved during the last 10 years to help others avoid these complications and, thus, ensure a satisfactory outcome.
stenosis noted. The overall incidence of complications requiring a second operation was 1.2%. During the last 5 years our reoperation rate was 1% (4 of 394 cases). Average followup was 2.3 months, with a range of 2 weeks to 2 years. No followup was obtained in 16 of the last 282 cases (6%). While an average followup of longer than 2.3 months might be preferable, we have noted that the appearance of the repair at that point remains constant. This impression has been supported by the return of select patients years later for other reasons. We have not insisted that parents bring children back for long-term followup, since the majority of them undergo repair at age 6 months to 1 year, and the operation is not remembered by the child. It seems unnecessary to remind the child of the correction of an anomaly that has been rendered close to normal. We do encourage parents to observe the child and report to us any difficulty directing the urinary stream or any cosmetic skin irregularity. Late problems rarely occur, since this repair using only normal genital skin typically matures nicely with the child (fig. 1).
PATIENTS AND METHODS
CASE SELECTION
We reviewed the records of 282 boys at our hospital who underwent the MAGPI procedure between July 1987 and May 1990. These cases have been added to those reported earlier .1• 8 • 9 The table summarizes the overall results and complications, which included urethral fistula, ventral meatal retraction, meatal stenosis, persistent ventral chordee or cosmetically unsatisfactory skin irregularity. There were 5 urethrocutaneous fistulas (0.45%), 7 ventral meatal retractions (0.6%) and 1 persistent ventral curvature (0.09% ), with no meatal
The nature of the meatus and the parameatal skin are of paramount importance in case selection for the MAG PI repair. The ventral parameatal skin must be thick and pliable so that it can be lifted easily off of the underlying urethra. These qualities are essential to permit the ventral parameatal skin to be advanced distally to extend the urethra. If the parameatal skin is thin or nonpliable, then the MAGPI procedure is inappropriate. 10 In these cases an island onlay operation may be a more suitable reconstruction. 11 • 12 The size of the meatus, which usually is small, is also an important consideration. The typically flat glans shape must permit it to be wrapped around the advanced ventral urethral wall in order to reconfigure the glans into a more normal conical shape. The solid healing of glans-to-glans maintains the ventral support for the advanced meatus and, thus, prevents the later falling back of the ventral meatal wall, known as a retrusive meatus. If the meatus is too proximal or large, as is usually seen in the megameatus intact prepuce variant of hypospadias, 2 then its size prevents exposure of the glans for placement of the glansplasty sutures. Either a pyramid 2 or Mathieu 13 opera-
Accepted for publication August 23, 1991.
Cumulative results of MAGPI procedure % Requiring Urethral Meatal Meatal Ventral Yr./Reference No. Pts. Fistula Retraction Stenosis Chordee Secondary Operation 1978-1981 1 1981-19858 1985-19879 1987-1990
Totals
207 510 128 266 1,111
1 2 1
2 1 0
0 0 0 0
5
7
0
1
4
0 0 0 1
I
2.4 0.8 1.5 0.8 1.2
665
666
DUCKETT AND SNYDER
Fm. 1. MAGPI-typical case. a, preoperative view. Note flattened glans and skin bridge distal to meatus producing ventral deflection of stream. b, postoperative results, ventral view. Note conical glans and ventral glans support for advanced meatus. Mucosa! collar gives normal skin configuration of circumcised penis. c, postoperative result, end view. Meatus demonstrates normal slit configuration on end of glans.
tion with a glansplasty involving formal mobilization of glans wings will result in a better long-term glans reconstruction. In cases of distal hypospadias it is rare to see ventral curvature due to more than ventral skin or a subcutaneous tissue abnormality. The flattened glans typically observed in these cases appears to be an indication that once the shaft skin has been dropped back an artificial erection will reveal straight corporeal bodies. Cases ideal for the MAG PI procedure usually have a meatus positioned at the coronal margin or subcoronally. Commonly, there is a lip of tissue distal to the meatus, which ventrally deflects the urinary stream to some degree and is the largest functional impairment of these anterior hypospadias anomalies. The glanular groove varies in depth and it may require deepening as part of the initial Heineke-Mikulicz maneuver, which advances and flattens the dorsal urethral wall. Properly performed, this step corrects ventral deflection of the urinary stream and ensures a well directed stream in the axis of the shaft of the penis. While there often is an accessory dorsal periurethral duct located within the glanular groove distal to the meatus, this does not interfere with the performance of a MAGPI procedure. TECHNIQUE
The technique for the MAGPI operation has been modified considerably since it was introduced. While textbook and atlas diagrams have been modified through the years, it is difficult to depict adequately the 3-dimensional nature of this meatal enlargement and advancement procedure, and the wrap-around 3-dimensional nature of the glanular reconfiguration required for the production of an excellent cosmetic and functional result (fig. 2). A holding stitch of 5-zero polypropylene is placed in the glans for traction, and a 1:100,000 concentration of epinephrine in 1% lidocaine is injected in the subcoronal area and glanular groove for hemostasis. A dorsal penile nerve block with ¼ % bupivacaine hydrochloride is routinely used to de-
crease the need for intraoperative anesthesia and to provide initial postoperative comfort. A circumferential incision is made subcoronal and proximal to the urethral meatus (fig. 2, a). We believe that the exact placement of the incision is not critical since excessive residual skin will be trimmed after the glanuloplasty has been completed, although others have stressed the importance of the initial ventral incision in the construction of the future glanular reconfiguration. 3 • 14• 15 A mucosal collar may be preserved from dorsal preputial skin. 15 The penile shaft skin is mobilized as a sleeve back to the penoscrotal junction, freeing the tethering fibers present in the subdartos fascia, particularly on the ventrum. These fibers appear to be the most likely cause for the ventral tilt of the glans so commonly seen preoperatively. An artificial erection is used to check for residual chordee. Residual curvature usually is caused by corporeal disproportion rather than chordee involving the urethra. Correction is usually done by Nesbit dorsal plicating sutures, 16 which we place without incising the tunica albuginea. The correction of any initial meatal stenosis and the advancement of the dorsal urethral wall are accomplished by a HeinekeMikulicz vertical incision and horizontal closure (fig. 2, b to d). Meatal stenosis subsequently is avoided by making the incision from within the meatus and ensuring that it is sufficiently deep when the groove is shallow. Sometimes a wedge removal of a segment of glanular tissue distal to the meatus is required. The horizontal closure flattens out the glanular bridge and permits the dorsal urethra to be advanced distally to the end of the glanular groove, where it is sutured with interrupted 7-zero polyglactin. The deflecting glans bridge is effectively flattened, which permits the urinary stream to be directed forward in the axis of the shaft of the penis. A satisfactory glanuloplasty is critical to support the advanced ventral wall of the urethral meatus. This procedure is accomplished by shaping the typically flattened glans into a more normal conical shape (fig. 2, e to h). Reconfiguration is
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FIG. 2. MAGPI. a, circumferential incision is made proximal to corona and proximal to meatus. b, skin is dissected down to penoscrotal junction, freeing up all tethering dartos bands, assuring straight erection by artificial injection. c and d, dorsal meatoplasty. Vertical incision is made in transverse web between meatus and distal glans groove and extended proximally into meatus to correct stenosis. Diamond-like defect is closed transversely (Heineke-Mikulicz), advancing and flattening dorsal urethral wall. e to h, glanuloplasty. Holding stitch is placed to elevate ventral urethral meatal edge (e). Good parameatal skin is required. Glans tissue to be approximated in midline is exposed by excising strips of epithelium on each side (dotted lines) (/). Glans tissue is approximated solidly with polyglactin or polydioxanone to support advanced ventral urethral wall (g). Epithelial closure is done with 7-zero chromic suture or subcuticular 7-zero polydioxanone. h, sleeve skin closure. Note conical glans configuration. Mucosa! collar rotation, which is often used, is not shown.
achieved by rotating the lateral aspects of the wings of the glans around to the midline proximal to the advanced ventral wall of the urethral meatus. Skin adjacent to the glanular edges often must be excised to expose glans tissue for the reapproximation of the glans wings in the midline ventrally (fig. 2, /). The glanular tissue is brought solidly together with interrupted 6-zero polyglactin or polydioxanone sutures, and the superficial epithelial edges are run with 7-zero chromic or, in older children, a subcuticular 7-zero polydioxanone suture (fig. 2, g). In this manner, mesenchymal glans tissue heals to glans tissue between the epithelial layer of the urethra and the outer epithelium of the glans. This solid tissue support for the ventral wall of the urethral meatus prevents meatal retraction. The rotation of the glans wings reconfigures the glans to a nearly normal conical appearance. A bougie aboule is used to calibrate the meatus and ensure that the glanuloplasty has not compromised the lumen of the distal glanular urethra. Ease of expression of the bladder also helps to confirm an adequate urethral lumen. Generally, a sleeve reapproximation of the penile skin is sufficient to complete cover (fig. 2, h). Occasionally, a rotation of excessive dorsal preputial skin to the ventrum is used to correct ventral skin deficiency. Torsion can usually be corrected as part of the initial drop back of the shaft skin, taking the dissection completely back to the dorsal suspensory ligament and the ventral penoscrotal junction. Recently, we have begun using 7-zero chromic sutures for skin closure to minimize postoperative suture sinuses to prevent the rapid ingrowth of genital epithelium along the sutures. No stents or catheters are used. Children usually experience only 1 to 3 days of dysuria.
Procedures are routinely done on an outpatient basis. A nonadherent gauze dressing, as for a circumcision, is left in place for 24 to 48 hours and then it is soaked off at home by the parent. DISCUSSION
For many years surgical techniques with an acceptably low morbidity were not available to reconstruct reliably the urethra out to the tip of the glans in patients with a distally placed meatus. Since these cases exhibited a minimal functional impairment, surgeons were reluctant to undertake an operation with complications that might leave the patient worse off than if the anomaly were left untreated. 17 Methods available to correct distal hypospadias, including the Mathieu, 13 Mustarde 18 and Devine-Horton flip-flap 19 techniques, require the construction of a neourethra and a formal glansplasty with mobilization of glans wings. The MAG PI procedure avoids a sutured urethroplasty and, thus, reduces the risk of fistula. It provides a reliable, reproducible method to reconfigure the glans and meatus without urinary diversion and with minimal moribidity. In our experience meatal stenosis has never been a problem with this type of reconstruction, although it has been reported by others. When the dorsal urethral incision is made vertically from within the urethral meatus and subsequently closed transversely, the meatus is opened into a wide configuration. While many anterior hypospadias anomalies have a significant initial meatal stenosis, a meatoplasty in this fashion using the principle of a Heineke-Mukulicz rearrangement suffices to correct stenosis and avoid postoperative problems of persistent stenosis. If the glanular groove is poorly developed, the vertical
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incision is deepened to the level of the corporeal bodies before it is closed transversely. Diagraming a 3-dimensional explanation for the glanulopasty has been most challenging. During the last 10 years modifications have been made to bring glanular tissue together in a more solid ventral closure. 8 - 10 • 16 This procedure avoids meatal regression, which increases when the ventral wall of the urethra in this or other hypospadias repairs is not supported by a solid layer of glans tissue. An additional layer approximating deep glans tissue has been added to achieve this effect. This technique replaces the vertical epithelial mattress stitches described in the original diagram. 1 We now stress the apposition of glans mesenchyme usually with 2 to 3 polyglactin or polydioxanone sutures, followed by a separate superficial epithelial closure. This. more secme closure avoids the ventral g-lans separation that leads to meatal regression from loss of glans tissue support of the advanced ventral urethral wall. The ventral meatal edge is fixed to the glanular tissue with interrupted fine chromic sutures to prevent it from retracting beneath the glansplasty. Usually, the reconfigured glans has a normal looking conical configuration with a barely perceptible ventral midline glans scar. Some modifications of this basic technique may be necessary in select cases. For instance, the bridge of tissue in the glanular groove may be so thick that a transverse wedge is removed more easily during the dorsal urethral wall advancement. At other times, the glanular groove may be wide and the dorsal urethral wall advancement may leave a prominent dog-ear at each corner. Excision of these dog-ears is needed to complete the creation of a satisfactory vertical neomeatus. Inappropriate application of the MAGPI procedure to unsuitable cases causes most of the poor results reported by others. 4 • 7 The ventral distal parameatal skin must be thick and pliable to be lifted off of the underlying urethra for distal advancement. The meatus must be sufficiently distal and small to permit the glans tissue to be brought to the ventral midline and to support the advanced ventral wall of the meatus. Thin or rigid parameatal skin, or a meatus that is too proximal or too wide, as is commonly seen in the megameatus intact prepuce variant,2 will not permit proper execution of the MAGPI operation and, thus, an unsatisfactory result can be predicted. Modifications of the MAGPI for distinct indications have been developed by others. Arap et al devised a method for urethral extension in cases with a meatus that is too proximal for a standard MAGPl. 5 The ventral parameatal skin margin is brought forward with 2 holding stitches 7 to 10 mm. apart in an M configuration. The central V of the M is closed vertically, forming a urethral extension that is buried beneath the glanular approximation, resulting in a low fistula rate. A dorsal meatal advancement is not beneficial in this setting. 6 A glans approximation procedure has been described recently 20 but it does not appear to be suited for cases that are generally appropriate for a MAGPI operation. Other authors have described their experience with the MAGPI procedure. Livne et al reported excellent results in 66 cases with no meatal stenosis or retraction, 21 of which only 3 demonstrated minor cosmetic deficiency. MacMillan et al reviewed 44 MAG PI procedures using photography of the urinary stream and uroflowmetry. 22 An excellent cosmetic result was noted in all but 1 case, in which a small meatal flap was subsequently considered acceptable and it required no surgery. Photography during voiding demonstrated a satisfactory if not entirely normal pattern, and flow rates were normal. MacMillan et al stated, "Until recently, the price of perfection in the management of anterior hypospadias was significantly high. However, with the advent of the MAGPI repair, which virtually guarantees perfect cosmetic results and fully preserves micturitional function, all boys with distal hypospadias should be offered early surgical correction." 22 However, others have reported unacceptable results. Ozen
and Whitaker experienced a 6% incidence of meatal retraction in 67 cases and only a 91 % excellent result. 14 Issa and Gearhart described 8 cases with subsequent meatal retraction, of which 5 were attributed to technical failure and 3 to poor case selection. 7 Hastie et al noted a significant problem with meatal retraction but in no case was the retraction back to the position of the original meatus, and the direction of the urinary stream did not appear to be adversely affected. 4 After 10 years of use in the hands of many surgeons, the primary criticisms of the MAGPI procedure center on meatal regression and stenosis. Our attention now is focused on teaching the avoidance of these problems. Stenosis can be completely avoided by emphasizing a meatoplasty that extends the dorsal vertical incision into the meatus to open widely its caliber, and an incision sufficiently El.eep to correct a poorly developed glanular groove. A timid meatoplasty that does not incise the dorsal meatal wall will likely lead to persistence of the small meatus postoperatively. To avoid meatal regression, the glans wings must be brought together ventrally and fixed snugly to ensure solid glans-to-glans healing. Ventral glans support for a reconstructed ventral urethral wall is essential not only in the MAGPI but in other hypospadias repairs as well. Our results have confirmed that when cases are properly selected and the operation is well executed the MAGPI technique for hypospadias continues to be successful with minimal morbidity. The cases of Drs. William J. Cromie, R. Bruce Filmer, Michael A. Keating and Bruce Blyth were included in this series. REFERENCES 1. Duckett, J. W.: MAGPI (meatal advancement and glanuloplasty):
2. 3. 4. 5. 6. 7. 8.
9. 10. 11. 12.
13. 14. 15. 16.
a procedure for subcoronal hypospadias. Urol. Clin. N. Amer., 8: 513, 1981. Duckett, J. W. and Keating, M. A.: Technical challenge of the megameatus intact prepuce hypospadias variant: the pyramid procedure. J. Urol., 141: 1407, 1989. Deeter, R. M.: M inverted V glansplasty: a procedure for distal hypospadias. J. Urol., part 2, 146: 641, 1991. Hastie, K. J., Deshpande, S. S. and Moisey, C. U.: Long-term follow-up of the MAGPI operation for distal hypospadias. Brit. J. Urol., 63: 320, 1989. Arap, S., Mitre, A. I. and De Goes, G. M.: Modified meatal advancement and glanuloplasty repair of distal hypospadias. J. Urol., 131: 1140, 1984. Scherz, H. C., Kaplan, G. W. and Packer, M. G.: Modified meatal advancement and glanuloplasty (Arap hypospadias repair): experience in 31 patients. J. Urol., part 2, 142: 620, 1989. Issa, M. M. and Gearhart, J.P.: The failed MAGPI: management and prevention. Brit. J. Urol., 64: 169, 1989. Duckett, J. W.: Hypospadias. In: Campbell's Urology, 5th ed. Edited by P. C. Walsh, R. F. Gittes, A. D. Perlmutter and T. A. Stamey. Philadelphia: W. B. Saunders Co., chapt. 47, pp. 19691999, 1986. Smith-Harrison, L. I., Choi, H., Tarry, W. F., Snyder, H. M. and Duckett, J. W.: Current hypospadias experience. J. Urol., part 2, 133: 114A, abstract 2, 1985. Gibbons, M. D. and Gonzales, E. T., Jr.: The subcoronal meatus. J. Urol., 130: 739, 1983. Elder, J. S., Duckett, J. W. and Snyder, H. M.: Onlay island flap in the repair of mid and distal penile hypospadias without chordee. J. Urol., 138: 376, 1987. Hollowell, J. G., Keating, M. A., Snyder, H. M., III and Duckett, J. W.: Preservation of the urethral plate in hypospadias repair: extended applications and further experience with the onlay island flap urethroplasty. J. Urol., 143: 98, 1990. Mathieu, P.: Traitement en un temps de l'hypospadias balanique et juxtabalanique. J. Chir., 39: 481, 1932. Ozen, H. A. and Whitaker, R. H.: Scope and limitations of the MAGPI hypospadias repair. Brit. J. Urol., 59: 81, 1987. Firlit, C. F.: The mucosa! collar in hypospadias surgery. J. Urol., 137: 80, 1987. Duckett, J. W.: Hypospadias. In: Adult and Pediatric Urology, 2nd ed. Edited by J. Y. Gillenwater, J. T. Grayhack, S. S. Howards
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and J. W. Duckett. St. Louis: Mosby Year Book Inc., chapt. 57, p. 2103, 1991.
17. Mills, C., McGovern, J., Mininberg, D., Coleman, J., Muecke, E. and Vaughan, E. D., Jr.: An analysis of different techniques for distal hypospadias repair: the price of perfection. J. Urol., 125: 701, 1981. 18. Mustarde, J. C.: One-stage correction of distal hypospadias and other people's fistulae. Brit. J. Plast. Surg., 18: 413, 1965. 19. Devine, C. J., Jr. and Horton, C. E.: Hypospadias repair. J. Urol., 118: 188, 1977.
20. Zaontz, M. R.: The GAP (glans approximation procedure) for glanular/coronal hypospadias. J. Urol., 141: 359, 1989. 21. Livne, P. M., Gibbons, M. D. and Gonzales, E. T., Jr.: Meatal advancement and glanuloplasty: an operation for distal hypospadias. J. Urol., 131: 95, 1984. 22. MacMillan, R. D. H., Churchill, B. M. and Gilmour, R. F.: Assessment of urinary stream after repair of anterior hypospadias by meatoplasty and glanuloplasty. J. Urol., 134: 100, 1985.