|Year : 2019 | Volume
| Issue : 1 | Page : 1-8
Tubularized incised plate urethroplasty (Snodgrass procedure) for distal penile hypospadias: A regional center experience
Aditya P Singh, Arvind K Shukla, Pramila Sharma, Dinesh K Barolia
Department of Pediatric Surgery, SMS Medical College, Jaipur, Rajasthan, India
|Date of Web Publication||26-Aug-2019|
Dr. Aditya P Singh
Near the Mali Hostel, Main Bali Road, Falna, Pali, Rajasthan
Source of Support: None, Conflict of Interest: None
Objective: Tubularized incised plate (TIP) urethroplasty has rapidly become the procedure of choice for repair of distal penile hypospadias (DPH) at most of the centers throughout the world. We did some modifications in the original technique to improve the outcome. In this article, the technique of TIP urethroplasty is discussed and literature is reviewed. Materials and Methods: TIP urethroplasty was performed in 250 new cases of DPH from January 2005 to December 2015 in our institute. We included only primary DPH with typical characteristics including stenotic meatus, deep glandular groove, wide urethral plate distally and in middle, and adequate size penis. We did some modification in the original Snodgrass repair to improve our outcome. Neourethra was covered with vascularized pedicled dartos flap from the inner prepuce. Patients were followed up for a mean of 12 months. Results: Age range of the patients varied between 3 and 11 years with majority of them [235 (94%)] below 9 years; 50 (20%) patients had mild-to-moderate chordee, which was corrected by degloving of the penis. We did not require tunica albuginea plication to correct chordee because it was only skin chordee. The mean age of children was 6 years. Mean duration of surgery was 50 min (45–60 min). Postoperative hospital stay was 10 days. Overall complication rate, requiring specific intervention, was 13.2%. Major complications occurred in 30 (13.2%), urethrocutaneous fistula in 15 (6%), meatal stenosis in five (2%), complete dehiscence in three (1.2%), glanular dehiscence in five (2%), and proximal stricture in five (2%) patients. Functional results as judged by the urinary stream were good in 225 (90%) patients. An excellent cosmetic result was seen in 215 (86%) patients. Conclusion: TIP urethroplasty with dartos flap cover is a simple, single-stage procedure for DPH with excellent cosmetic and functional results and is associated with minimal complications. Finally, some of our modifications in the original technique can improve the outcome.
Keywords: Hypospadias, snodgrass, tubularized incised plate urethroplasty
|How to cite this article:|
Singh AP, Shukla AK, Sharma P, Barolia DK. Tubularized incised plate urethroplasty (Snodgrass procedure) for distal penile hypospadias: A regional center experience. Nigerian J Plast Surg 2019;15:1-8
|How to cite this URL:|
Singh AP, Shukla AK, Sharma P, Barolia DK. Tubularized incised plate urethroplasty (Snodgrass procedure) for distal penile hypospadias: A regional center experience. Nigerian J Plast Surg [serial online] 2019 [cited 2020 May 29];15:1-8. Available from: http://www.njps.org/text.asp?2019/15/1/1/265404
| Introduction|| |
Hypospadias is one of the most common congenital anomalies of the male genital system. Hypospadias causes not only functional problems but also psychological problems for patients and their parents. Hypospadias has an incidence of 3.2 per 1000 live birth, 50% of them being of distal penile type. Surgeons use small variation in the technique to limit complications. The purpose of this study was to present our experience with tubularized incised plate (TIP) urethroplasty for distal penile hypospadias (DPH) in terms of function, cosmesis, and complications, and some variation in original Snodgrass technique. The modifications were proper selection of the patient, complete penoscrotal degloving, distal limit of the deep longitudinal incision that stopped just short of the proposed meatal site and the proximal limit of 5 mm proximal to the hypospadic meatus, two-layer closure to form urethral tube with calibration 10 fr tube and last replaced with 6 fr tube, use of vascularized dartos flap with botton hole, limited dissection to maintain blood supply, extensive dissection of the glans to create glans wing and two-layer tension-free closure, and fixation of the neomeatus to the glans at 4 and 8 o’clock positions [Figure 1],[Figure 2],[Figure 3][Figure 4].
|Figure 2 (a) Creation of the window in flap. (b) Flap transposed to ventral to cover neourethra. (c) Preputial skin divided in midline.(d) Skin closure and complete postoperative view. (e) Urinary stream.|
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| Materials and methods|| |
This is a prospective study in which TIP urethroplasty was undertaken in 250 patients between 3 and 11 years of age over a period of 10 years from January 2005 to December 2015. Majority of patients [235 (94%)] were below 9 years of age. All the cases included in the study were of distal penile (coronal: 50, subcoronal: 150, distal shaft: 50) and underwent repair for the first time. We also used some modifications to reduce complications rate. We performed TIP urethroplasty in primary DPH having stenotic meatus, wide urethral plate distally and in middle, good glanular groove, and adequate size penis. Surgery was performed under general anesthesia with infiltration of 0.5% lidocaine and 1:200,000 epinephrine solution and tourniquet application. Operative procedure involved degloving of the penis with preservation of urethral plate, adequate mobilization of glans wings, midline incision of urethral plate followed by tension-free tubularization, and subsequent covering of repair with vascularized dartos flap mobilized from inner prepuce. Degloving of the penis was performed up to the penoscrotal junction. Cases in our study had mild-to-moderate chordee, so no plication was needed. The distal limit of the deep longitudinal incision stopped just short of the proposed meatal site and the proximal limit was 5 mm proximal to the hypospadic meatus. Urethral tubularization was performed with 6-0 polyglactin in two layers over 8-Fr silastic Naso-gastric (NG) tube in every case, which was replaced with a 6-Fr NG tube. Inner layer in continuous and outer layer with two to three interrupted sutures (inner layer subcuticular and outer with dartos tissue). Dartos flap was raised after being separated from the dorsal prepucial skin and the buttonhole through which it was transposed to cover the neourethra ventrally. We separated it only as we required, not completely, maintaining its vascularity. The glans wings were created after extensive dissection of the glans and two-layer tension-free closures was performed. Then the neomeatus was sutured to glans at 4 and 8 o’clock positions. A 6-Fr NG tube was used as splint and for urinary diversion. In our opinion, construction of the neourethra should be at least on a 8-Fr tube. The dressing was changed on the 7th postoperative day. The catheter was removed on the 10th postoperative day. All the patients were discharged on the 10th postoperative day after catheter removal and were advised for the follow-up in an outdoor clinic. Assessment of the patient was performed at the time of dressing removal, catheter removal, and in the follow-up clinic. The criteria for the assessment of the urinary stream and cosmetic appearance were penile edema, circumcised look of the penis, scarring, no residual chordee, direction of the urinary stream, location of the neomeatus, shape and size, and specially parent satisfaction with the look of the penis.
| Results|| |
The mean age of the 250 cases was 6 years (range 3–11 years). The positions of the urethral meatus are shown in [Table 1]. Complications occurred in 88 (35.2%). The average operating time in our study was 50 min. Chordee was corrected in all patients with only degloving of the penis. The most common early complication noticed in the series was superficial skin necrosis of some part seen in 25 (10%) patients. Three (1.2%) patients had hematoma for which no intervention was needed. Overall 30 (13.2%) patients had major complications, 15 (6%) patients had urethrocutaneous fistula, five (2%) patients had meatal stenosis, three (1.2%) patients had complete dehiscence, and five (2%) patients had glanular dehiscence. In our series, there were no torsion of shaft, catheter blockage, wound infection, persistent chordee, and angulated urinary stream. All the remaining 225 (90%) patients with successful repair had good urinary flow (both objective and subjective) and void with a single stream in forward direction. All of them had normally situated slit-like meatus and excellent cosmetic appearance [Table 2][Tables 3][Tables 4][Tables 5].
|Table 5 Types of supportive tissue covering TIP urethroplasty and rates of fistula formation|
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| Discussion|| |
Principles of repair of hypospadias involve straightening of penis (orthoplasty), creating a slit-like meatus at the tip of the penis (urethroplasty and meatoplasty), making the glans conical looking (glanuloplasty), and proper skin coverage. Many operative procedures have been devised for repair of the DPH by different authors from time to time, all being time consuming and associated with complications.,,, In 1994, Snodgrass described TIP urethroplasty for DPH, which is a simple technical innovation that has revolutionized the surgical management of hypospadias. It was subsequently also applied to proximal hypospadias, with encouraging results., The high success rate of the procedure is probably because of the rich vascularity of the muscular urethral plate., Vascularized dartos flap cover of the neourethra decreases the fistula formation rate significantly.
Surgeons use small variation in the technique to limit the complications. We also used some modifications to reduce complications rate. Despite such modifications, complications of hypospadias repair, such as fistulae, urethral stricture, meatal stenosis, penile torsion, persistent chordee, infections, and wound dehiscence, are still reported.
The distal limit of the deep longitudinal incision may be either the mid-glans or the tip of the glans. The covering flap of the neourethra is usually raised from the preputial skin; however, this may result in penile torsion and devascularization of the preputial skin that is often used in reconstruction of the penile skin. A ventral dartos flap has been used to cover the neourethra to avoid these complications.
Snodgrass TIP urethroplasty basically combines the modification of the previously described techniques of urethral plate incision and tubularization. The main advantages of TIP urethroplasty are as follows: decision-making is greatly simplified, incision of the urethral plate enables tubularization of neourethra irrespective of the glanular configuration, and previous attempts at repair or circumcision does not limit the procedure. Most of the studies,,,, have reported encouraging results in terms of short operative time, overall low complication rate, and good functional and cosmetic results. We found the procedure quick to perform, and average time taken in our study was 50 min. Moreover, being a single-stage procedure, the patient does not require multiple anesthesia exposures. Our major complication rates were also comparable as compared with the other studies.,,, The urethrocutaneous fistula occurred in 15 (6%) patients as compared to 0% to 7% reported by other studies.,,, We performed TIP urethroplasty in only DPH. We recommend it because urethral plate is not adequate in mid and proximal penile hypospadias.
Another important step in the Snodgrass repair is the interposition of a barrier layer (flap) between the neourethra and the overlying skin to decrease the rate of urethrocutaneous fistula formation. We recommend two-layer closure of neourethra. It does provide additional barrier function with flap. The most popular flap used is the preputial flap; however, mobilization and ventral transposition of the flap around one side of the penile shaft may cause penile torsion, especially if the flap is of inadequate length and lay on with tension.
Moreover, dissection of the flap may jeopardize the blood supply to the dorsal skin, which is often used for resurfacing closure, and may thus predispose to skin loss and failure of repair. We did some modification in view to maintain the vascularity of both flap and skin and also to prevent penile torsion. We dissected flap in balance to leave tissue with skin which appeared as whitish membrane and only as we required to cover neourethra. It maintained vascularity of both skin and dartos flap. Consequently, it causes less chance of skin necrosis 25 (10%) and fistula formation 15 (6%) in our study.
To avoid penile torsion, a modification of the way in which the perputial flap is immobilized has been described. A window is created in the flap at the midline, and the penile shaft is pulled through it to transfer the dartos flap ventrally over the neourethra. The size of the flap may, however, be inadequate to cover the repair when the ventral skin is deficient, and another modification in flap creation was described, which is to raise the ventral dartos flap to cover neourethra. This technique was claimed to be associated with low fistula rate and easier harvesting and mobilization of the flap to cover the neourethra.,, In our study, postoperative penile torsion was overcome by a window created in the dartos flap in the midline. We had no penile torsion in our study and did not come across the problem of inadequate flap to cover neourethra.
Another factor that may affect penile alignment is the degree of the penile skin degloving during hypospadias repair: complete degloving to the penoscrotal junction or limited to the area around the urethral meatus. Turial et al. recommended limited degloving of the penile skin to limit the need for a large covering layer of the neourethra, whereas Selami and Warren performed complete degloving of the penile skin to provide full erection and prevent postoperative torsion or chordee. We recommended complete degloving up to penoscrotal junction. In our study, there was no postoperative penile torsion and persistent chordee. We included only DPH in our study. They had only mild-to-moderate skin chordee, and it was corrected with only degloving. We did not need any tunica albuginea placation also.
The overall reoperation rate in our study was 13.2% which is well comparable to other series. In our study, meatal stenosis was seen in only five (2%) patients. We recommended extensive mobilization of glans wings and tensionless closure and secured the meatus to the glans at 4 and 8 o’clock positions with stitches. Another variation to decrease the development of the meatus stenosis and risk of retraction of the urethra was to secure the neourethra to the glans. This was not described by Snodgrass et al. In their initial report and in reviews,, they mentioned that the meatus should be stitched to the glans at 5 and 7 o’clock positions to improve the cosmetic result as well as to decrease the occurrence of the meatal stenosis. Licevik et al. proposed that the meatus is secured to the glans at three points (4, 6, and 8 o’clock).
In our study, there were less complication as complete in three (1.2%) and glanular dehiscence in five (2%) patients. We recommended extensive mobilization of glans wings and tensionless two-layer closure. There was no megalourethra or diverticulae in our study; as has been reported by other authors, it can be explained by the use of native urethral plate in TIP urethroplasty instead of skin flaps or tubes.
Unsatisfactory cosmetic appearance is seen in 25 (10%) patients in our study; otherwise, penile appearance was normal with successful repair. It was due to superficial skin necrosis. Urethral calibration should be carried out in all patients for prevention of fistula formation and meatal stenosis. We did not calibrate it routinely in our study; still we had less chance of meatal stenosis and urethrocutaneous fistula.
Another topic of controversy in TIP urethroplasty is the use of a urethral stent. Proponents of stenting argue that it keeps the dorsal midline incision stretched open and limits premature healing, which would obviate the benefit of the dorsal incision. In descriptions of cases with no stenting, however, no cases of urethrocutaneous fistula, urethral stricture, or meatal stenosis have been reported., We used stent in all patients for 10 days, which allowed drainage of the urinary bladder and also helped in hemostasis and postoperative bleeding. We created neourethra over 8-Fr NG tube and replaced it with 6-Fr NG tube. This provides urinary diversion and does not limit premature healing. There was no catheter blockage in our study. We used stent as silastic NG tube.
Proximal urethral strictures were seen in five (2%) patients in our study. We extended the urethral plate incision up to 5 mm proximally from the meatus in hypospadias and calibrate it with 10-Fr NG tube. It created wide urethral tube proximally, which is the common site for stricture. In our study, angulated urinary stream was not so problematic; it got improved in the follow-up.
We dissected tissue in proper plane during TIP urethroplasty; therefore, in our study, so there were less chances of hematoma [three (1.2%)] and postoperative hemorrhage [two (0.8%)]. The TIP urethroplasty has virtually replaced all other procedures for repair of DPH in our institution, and we do not recommend it for mid and proximal penile hypospadias.
| Conclusion|| |
TIP urethroplasty is a simple, quick, single-stage procedure for DPH. It provides excellent functional neourethra, cosmetically normal looking glans, and meatus with few complications. We think combined with dartos flap cover, TIP urethroplasty is the ideal operation for DPH. Finally, some of our modifications in the original technique can improve the outcome.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]