|Year : 2016 | Volume
| Issue : 2 | Page : 121-126
One-Stage repair of hypospadias using the modified prepucial island flap technique: Experience with 200 cases
Aditya P Singh, Arvind K Shukla, Pramila Sharma, Ramji Prasad
Department of Pediatric Surgery, SMS Medical College, Jaipur, Rajasthan, India
|Date of Web Publication||30-Nov-2016|
Aditya P Singh
Department of Pediatric Surgery, SMS Medical College, Jaipur, Rajasthan
Source of Support: None, Conflict of Interest: None
Background: Surgical repair of hypospadias has taxed the skills of surgeons the world over. One-stage repair is preferable because it decreases operative trauma, allows use of virgin unscarred tissue, decreases number of hospitalizations, and hence is more economical than two-stage repairs. During the last 7 years, the author has managed 200 cases of hypospadias and their complications in a tertiary care service hospital. This study aimed to evaluate the outcomes of using modified onlay island flap technique in the repair of hypospadias with a narrow urethral plate.
Patients and Methods: In this prospective study conducted between June 2008 and June 2015, we performed modified onlay island flap procedure for the repair of hypospadias with a narrow urethral plate – less than 7 mm. This technique was used for all types of hypospadias with minimal or no chordee except penoscrotal. We did not require any tunica plication in our study.
Results: Two hundred patients with age ranging from 3 years to 10 years (average 5 years) underwent modified onlay island flap repair; all had a narrow urethral plate of less than 7 mm; 30 (15%) had mild chordee. Meatus was located in coronal in 10 (5%) cases, subcoronal in 120 (60%), midpenile in 50 (25%), and proximal penile in 20 (10%) patients. Chordee was corrected with degloving only in 30 (15%) patients. Complications were meatal stenosis in none and urethrocutaneous fistula in 10 (5%) patients. Mean follow-up duration was 12 months.
Conclusion: This technique offers acceptable results regarding meatal stenosis, urethrocutaneous fistula, along with good aesthetic outcome.
Keywords: Hypospadias, modified, onlay island flap, urethroplasty
|How to cite this article:|
Singh AP, Shukla AK, Sharma P, Prasad R. One-Stage repair of hypospadias using the modified prepucial island flap technique: Experience with 200 cases. Arch Int Surg 2016;6:121-6
|How to cite this URL:|
Singh AP, Shukla AK, Sharma P, Prasad R. One-Stage repair of hypospadias using the modified prepucial island flap technique: Experience with 200 cases. Arch Int Surg [serial online] 2016 [cited 2021 Jan 20];6:121-6. Available from: https://www.archintsurg.org/text.asp?2016/6/2/121/194988
| Introduction|| |
One-stage repair is naturally favored because it decreases operative trauma, decreases the number of hospitalization, and thus, is economical. Onlay preputial flap repair was first described by Duckett  in 1987. Complications after hypospadias repair are common. Hence, new modifications of repair techniques are usually attempted with the aim of obtaining better results and fewer complications.
In this study, we objectively assessed the feasibility of this technique. Complications such as fistula, wound dehiscence, recurrent ventral curvature, meatal stenosis, diverticulum, torsion, skin necrosis, flap necrosis, megameatus, extravasation of urine, and urethral stricture were analyzed.
| Patients and Methods|| |
Between June 2008 and June 2015, modified onlay island flap hypospadias repair was performed in 200 cases with a narrow urethral plate (less than 7 mm) in our institute by a single surgeon. Data were collected including patient's age at operation, along with data regarding types of hypospadias, complications, and cosmetic outcomes. Cosmetic outcome was assessed by parents and surgeon. This surgical technique was selected in all types of hypospadias except penoscrotal hypospadias and in those with moderate-to-severe chordee. All patients followed up for a minimum of 1 year. For urethral tube reconstruction, inner prepucial layer was used as a flap based on the leash of vessels running dorsally in its mesentery. Width of this flap was kept after proper measurement. Flap length was determined by measuring the distance from ectopic urethral meatus to the tip of the glans.
The patients were at least 3 years of age to have acceptable size structures. We included this age group because the children become more cooperative at this age. If the penis was relatively small, preoperative aqueous testosterone injection (1–2 mg/kg) was given to enlarge its size. Two to three injections were given at 2 weeks interval, and operation was done after 1 month of last injection. Surgery was performed under general anesthesia with infiltration of 1:100000 xylocaine and adrenalin solution. Racket-shaped incision of the skin was performed with preservation of the urethral plate. Circumcoronal incision was done 5 mm proximal to the coronal margin extending proximally by two vertical incisions 6–8 mm apart along the urethral plate up to the proposed site of the urethral meatus and then going around the ectopic urethral meatus and extending in midline proximally. Phallus was degloved completely. The urethral plate was preserved in the all cases. Chordee correction was obtained by only degloving.
For urethral tube reconstruction inner prepucial layer was used as a rectangular flap [Figure 1]a. We measured the length of the urethral plate and access the prepuce available for flap. Rectangular flap should be equal to or more than the urethral plate. Flap based on the leash of vessels running dorsally in its mesentery. The flap along with its mesentery was sufficiently mobilized to rotate it ventrally to the ectopic meatus and sutured to the edge of the urethral plate using continuous 6-0 Vicryl sutures. We did not separate it completely. Keeping a 8 Fr silastic NG tube as a urethral stent, the width of rectangular flap was again measured and the excess part was cut; then, the other edge of the flap was sutured to the opposite edge of the urethral plate to fashion a neourethra [Figure 1]b and [Figure 1]c. Anteriorly, the remaining part of the flap was folded proximally and incorporated in glanuloplasty [Figure 1]d, [Figure 2]a and [Figure 2]b. The prepucial mesentery was then used to cover the suture line by stitching it across the neourethra. Glanuloplasty was carried out in 2 layers in the all cases and a cover was provided using lateral penile flaps with lateral suture line [Figure 2]c. NG tube was replaced with 6 Fr NG silastic tube. Simple penile dressing was performed in all cases. Urinary diversion was carried out in all the cases and in all age group using 6F-feeding tube. We anchored the feeding tube with the glans using prolene 4-0 sutures. Dressing was changed on the 7th postoperative day and catheter removed on the 10th postoperative day. Simple penile dressing after hypospadias surgery is the protocol in our institute. The urethra was stented for 10 days postoperatively. All patients were operated on by a single surgeon. Patients were seen at the time of catheter removal, at 1 week postoperatively, and then at 2 weeks, 1 month, 3 months, 6 months, and 12 months postoperatively.
|Figure 1: (a) Rectangular flap; (b) neourethra formation; (c) second interrupted layer; (d) glanuloplasty in two layers|
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|Figure 2: (a) Extra anterior part of the flap; (b) extra flap sutured with glans; (c) lateral skin closure and complete view postoperatively; (d) single urine stream|
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| Results|| |
Two hundred patients (all had a narrow urethral plate less than 7 mm) underwent modified onlay island flap repair during a period of 7 years. The age of the patients ranged from 3 to 10 (average 5 years) years. The types of hypospadias were coronal in 10 (5%) cases, subcoronal in 120 (60%), midpenile in 50 (25%), and proximal penile in 20 (10%) patients [Table 1]. Thirty patients (15%) had mild chordee. Chordee was corrected with degloving only. We excluded cases with moderate-to-severe chordee because these require two-stage repairs in our case selection criteria to minimize the complications. We preserved urethral plate in all cases. Complications were meatal stenosis in none, urethrocutaneous fistula in 10 (5%), mild torsion 20 (10%), wound dehiscence 4 (2%), skin necrosis in 2 (1%), flap necrosis in none, residual chordee in none, diverticulum in 10 (5%), stricture in none, extravasation of urine 2 (1%), and megameatus in 2 (1%) cases [Table 2]. All case had acceptable voiding in single good urinary stream, satisfactory cosmetics result and appearance. with our modified technique, meatus was vertical slit like and at the tip of the penis. penis looks like a circumcised penis. Follow-up period was 12 months in our study.
| Discussion|| |
Hypospadias is one of the most common congenital genital anomalies in males. The current trend is surgery in early infancy (between 6 to 9 months old). Surgical repair of hypospadias has remained one of the most taxing problems for reconstructive surgeons, urologists, and pediatric surgeons alike because of the high complication rate. The very fact that there are approximately 250 different operations to manage this tricky problem itself is a testimony that no single operation is favored by all surgeons the world over because no single technique provides uniformly good results. A perfect hypospadias repair should reconstruct the urethral continuity keeping sufficient caliber, correct phallus curvature, and provide an acceptable appearance with low complications.
The purpose of primary hypospadias repair is to achieve both good cosmetic and functional outcomes. It requires reconstruction of a straight penis, with an acceptable calibre of neourethra, and a vertical slit-like meatus. There are recent reports suggesting an increase in the incidence of hypospadias possibly related to environmental estrogen-like compounds. A study carried out in Finland revealed an increase of prevalence by approximately three times. Technique of repair is based on a number of factors such as degree of curvature, site of the meatus, width of urethral plate, and surgeon's choice. In onlay flap repair, careful protection of the vasculature of the flap and prevention of overlapping suture lines generate a waterproof closure with a minimum risk of postoperative fistula. In our study, we mobilized the mesentery of the rectangular flap not completely but sufficiently to reach the native urethral plate. One-stage repair for hypospadias was introduced in 1955 using full thickness skin grafts from prepuce. The advantage of correcting the chordee and reconstruction of neourethra in a single operative sitting and the associated low morbidity are responsible for the popularity of one-stage repair. However, certain surgeons remain unhappy with the limitations and drawbacks of one-stage repair and continue to practice two-stage repairs.
In the present study, external urethral meatus was located at coronal in 10 (5%) cases, subcoronal in 120 (60%), midpenile in 50 (25%), and proximal penile in 20 (10%) patients. These results are not similar with the results reported Welch in1979. Snodgrass et al. carried out subepithelial biopsies of urethral plate in 17 patients and found no histological evidence of fibrous bands, concluding that there is no requirement of violating the integrity of urethral plate. In our study, we preserved urethral plate in all cases. In all cases, inner prepucial layer was used as an onlay flap over the preserved urethral plate to reconstruct the neourethra. We compare our results with the tubularized incised plate (TIP) because the principle of surgery same for both as native urethral plate saving procedure. Although the TIP might be the most common procedure to repair distal hypospadias because it is reportedly simple and gives better cosmetic outcomes than flap repairs; in the TIP procedure, some features of the urethral plate, especially a flat and narrow plate, potentially increases the risk of complications, i.e., meatal stenosis and urethrocutaneous fistula. In the present study, patients had a narrow urethral plate (<7 mm), and hence the TIP procedure was not an ideal treatment option. An advantage of the onlay island flap technique is the use of preputial skin, which is often available, is hairless, and large enough to construct the defective urethral floor, and is often otherwise discarded.
TIP is a common operation in hypospadias reconstruction, however, our experience shows that risk of stricture and fistula is relatively high and requires an acceptable wide urethral plate for urethroplasty. However, in the study by Sozubir et al., complications after TIP repair were equivalent to other current techniques where caution in technical details could decrease these complications. The authors believed that this procedure regularly generated a vertical meatus and a good aesthetic result. Snodgrass et al. used the TIP procedure for distal and proximal hypospadias, and the main complication in their patients was fistula. Despite the use of a dartos flap in all cases, fistula occurred in 5% of distal and 19% of proximal repairs. Snodgrass et al. used TIP urethroplasty for hypospadias reoperation, however, when it was employed in proximal hypospadias, they encountered a complication rate of 33% with 21% incidence of fistula and persistent chordee in some patients. In our study, we had only 10 (5%) fistula. Results of hypospadias repair vary in different centres. Cheng et al. reported a large multicenter series of patients with both distal and proximal hypospadias who experienced TIP repair with less than 1% occurrence of fistulas. They approximated the corpus spongiosum over the neourethra during proximal repair and protected neouretra with dartos layer and glans wings. In this study, the only parameter for selection of patients was urethral plate diameter less than 7 mm and type of hypospadias was not an effective factor. The advantage of this technique is the preservation of the native urethral plate in neourethra.
Sarhan et al. in a single-centre study with 500 cases reported the TIP procedure to be a reliable technique for the management of both distal and proximal hypospadias in both primary and reoperative cases with a small rate of complications, however, urethral plate diameter was not mentioned. Postoperative meatal/neourethral stenosis after TIP is common, and hence Shimotakahara  collected a dorsal inlay graft from the inner prepuce and sutured it to the midline incision of the urethral plate. We included only cases with mild chordee 30 (15%), so they were corrected by degloving only and did not require any transection of the urethral plate or dorsal tunica plication to correct the chordee. Although TIP urethroplasty is a choice procedure in distal penile hypospadias for some surgeons, now some authors prefer to use the onlay flap technique, particularly in cases of a small phallus with narrow plate or conical glans, which makes tubularization difficult.
In 1987, Elder reported the first one-stage hypospadias repair using an onlay island flap, although the preputial island flap had been done previously. It permits for repair of distal and midshaft hypospadias. Ehab et al. evaluated the consequences of using a distally folded onlay flap in the repair of distal penile hypospadias in 36 patients, however, they had only two urethrocutaneous fistula and they used onlay flap for distal type; in our study, it was used for all types except penoscrotal. Mamdouh et al. conducted a study among 45 patients with similar mid-penile hypospadias deformities; they designed a comparative study between the TIP and onlay preputial island flap and reported no differences between the two techniques. Braga et al. retrospectively analyzed patients with penoscrotal hypospadias; 35 children underwent TIP and 40 underwent onlay urethroplasty. They reported complication rates of 60% for TIP and 45% for the onlay flap. Leslie et al. used tunica vaginalis graft plus onlay preputial island flap in urethral reconstructive surgery in rabbits in one-stage for complex hypospadias with divided urethral plate. Silva et al. compared three different urethroplasty techniques (onlay, buccal mucosa, Koyanagi type I) in severe hypospadias. The fistula was shown in 15% in onlay group, 32% in the buccal mucosa group, and 19.2% in the Koyanagi cases. Patel et al. explained a technique called the split onlay skin flap, which had fistula in 6 patients. Subramanian et al. described several surgical techniques in hypospadiasis along with their complications.
There was no case of meatal stenosis in our study because we created neourethra over 8 to 10 Fr size of NG tube and folded the extra anterior part of the rectangular flap on itself proximally and sutured with glanuloplasty to cover the raw area. It was wide enough and hence we did not require meatal dilatation routinely in follow-up visit; we do not recommend it. The key of success in our study is the minimal mobilization of flap and case selection for the technique. Owing to minimal mobilization of the flap, we had only 4 (2%) wound infections, 2 (1%) skin necrosis, and no flap necrosis in our study. Still we had 20 (10%) cases of mild torsion and diverticulum in 10 (5%) cases in our study. Diverticulum is caused by a technical error in the measurement of the flap (large). This is a low rate of diverticulum because we measured the rectangular flap during the neourethra formation. We had no complications related to stricture formation in our study because we cut the ectopic urethral meatus back till normal urethra. There were two cases of the megameatus due to over measurement of the meatus as a technical error in our study.
In our series, we found a very low complication rate in cases where prepucial flap was used as onlay flap. Urethrocutaneous fistula occurred in 10 (5%) cases where prepucial onlay flap was sutured to the preserved urethral plate. Barroso et al. have reported excellent results with one-stage double onlay prepucial flap for severe hypospadias. They reported complication rate of 25% in his series of 47 cases; we encountered a complication rate of 25% in our cases managed by modified onlay prepucial flap technique which is comparable. An urethrocutaneous fistula developed postoperatively in 5% of cases. Baskin and Duckett reported this complication in 6% of their cases postoperatively.,, We encountered penile edema in 40 (20%) cases. It resolved in follow-up visits. Hence, we did not mention it as a complication in our study. There were 2 (1%) cases of extravasation of urine as a complication in our study. It was due to lateral skin closure.
We follow case selection criteria for modified onlay preputial flap technique at our institute. We prefer it for distal penile, mid penile, and proximal hypospadias with minimal or no chordee and with good prepuce. Modified onlay island flap technique is versatile technique for single stage hypospadias repair.
| Conclusion|| |
We concluded that the key of success in our study of modified onlay island flap technique were proper case selection criteria, minimal mobilization of the mesentery of the flap, meticulous measurement of the rectangular flap length and width, and folding of the distal flap over itself proximally. These resulted in minimal complications, with pleasing cosmetic and functional result in our study. The overall complication rate as well as the rate of postoperative urethrocutaneous fistula was minimal and is comparable with those reported by others.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2]