Snodgrass Tubularized Incised Plate Urethroplasty for Distal and Midpenile Hypospadias

Introduction: Despite hundreds of repair techniques for hypospadias, the introduction of tubularized incised plate urethroplasty (TIP) by Warren T. Snodgrass has become popular because of good functional and cosmetic outcome. The objective of this study was to share our experience of Snodgrass tubularized incised plate (TIP) urethroplasty for the repair of distal and mid-penile hypospadias. Materials and Methods: This prospective study was carried out for a period of 24 months. It included 46 male patients with the mean age of 4.1 years (18 months to 10 years). Proximal hypospadias and those distal with moderate to severe chordee were excluded. All cases underwent TIP urethroplasty as described by Snodgrass and the neourethra was covered by single or double layer of dorsal prepucial layer. The results were analyzed on the basis of duration of surgery, types of postoperative complications like urethrocutaneous fistula, meatal stenosis and wound dehiscence. Functional results assessed with ease of voiding, force and direction of urinary stream and cosmetic with external look of penis. Results: The overall complication rate requiring surgical intervention was 8 (17.3%). Mean duration of surgery was 66 minutes (60-80 minutes). Urethrocutaneous fistula occurred in 5 (10.8%), meatal stenosis in 1 (2.1%) and wound dehiscence in 2 (4.3%) patient. The cosmetic appearance was excellent in all patients involved in this study except 2 cases of wound dehiscence. All of them had vertically oriented slit like meatus with straight urinary stream. Conclusion: Tubularized incised plate urethroplasty gives good functional and excellent cosmetic results with low rate of complications in distal and mid-penile hypospadias.


Introduction
H ypospadias is one of the most common congenital anomaly of external genitalia in males occurring in approximately 1 in 200~300 live birth.The abnormal urethral opening can be anywhere along the ventral side of penile sha and down to the perineum.In over 80% of cases, the meatus is located distal to the midsha 1,2 .
There are over 200 procedures described in literature about hypospadias surgery.The ul mate goal of hypospadias repair is to achieve a func onal penis with normal looking cosme cally 3,4 .Tubularized Incised plate (TIP) urethroplasty by Snodgrass in 1994 has gained popularity and revolu onized the management of diff erent types of hypospadias including proximal hypospadias and in re-opera ve cases.TIP procedure is technically easy giving a normal looking ver cal slit like meatus with low complica ons like urethrocutaneous fi stula, meatal stenosis 5,6,7 .The purpose of our study was to share our experience with TIP urethroplasty in the management of distal hypospadias.

Materials and Methods
A total of 46 male children 18 months to 10 years age with penile hypospadias were included in this study from January 2011 to January 2013 in Kan Children's Hospital and BP Smri Hospital.Only distal and mid penile hypospadias with good and wide urethral plate were included.All children underwent tubularized incised plate urethroplasty described by Snodgrass.Hypospadias with moderate to severe chordee were excluded.All the pa ents did all basic inves ga ons like total blood count, urea, crea nine, urine rou ne and culture and examined for any other associated anomalies of genito-urinary system by abdominal ultrasound.The opera on was performed under general anesthesia along with caudal block.A stay suture was placed in glans to aid in the trac on of the phallus.Eight to 10 French Foleys catheter were placed on the basis of pa ent age and size of phallus.Rubber tourniquet applied at the base of penis and released at 40 minutes interval.A U-shaped incision was made, extending along the edges of the urethral plate approximately 8-10 mm up to the glans and to the healthy skin 2 mm proximal to the meatus.The plate was freed on both side.Then an incision was added in midline of urethral plate from na ve meatus up to the glans.The urethral plate was tubularized over the catheter using 6-0 absorbable suture cen sorb (poly glycolide-co-lac de) with running sub epithelial s tches.Neourtehra was then covered with one or two vascularised subcutaneous (dartos) fl ap those harvested from the dorsal prepuce.Glanuloplasty was done by closure of of glandular wings and the p with neourethral plate.The granular wings, mucosal collar and ventral sha skin were closed in the midline.A light compressive dressing was applied.
Intravenous third genera on cephalosporin with 100 mg/kg/day in three divided doses were given for fi ve days and changed to oral.Pain managed with intramuscular pethidine1mg kg/dose ini ally in addi on with oral paracetamol (fl exon).All cases had dressing opened on 3rd or 4 th postopera ve day.Neosporin ointment was applied a er the dressing was opened regularly.Foleys catheter was taken out on 8 th to 10 th postopera ve days seeing the condi ons of healing and pa ents discharged.Pa ents were informed for follow ups a er two weeks of discharge to see the wound status and see the urinary stream and any other complica on.
Each pa ent was assessed on the 8th-10th postopera ve day a er removal of the catheter and during their fi rst follow-up on two weeks a er discharge.Assessment was done on the basis complica ons like urethrocutaneous fi stula, meatal stenosis, cosme c look of penis and glans and urinary stream.

Results
Overall complica ons occurred in eight pa ents with the complica on rate of 17.3%.Five (10.86%) cases had urethrocutaneous fi stula.Out of 5 fi stula cases, four urethrocutaneous fi stula was seen a er the catheter was removed and the remaining one had fi stula a er two weeks of discharge.Meatal stenosis occurred in one case.In one coronal and subcoronal hypospadias complete wound with glandular dehiscence was seen.Surgery me dura on ranged from 60 minutes to 80 minutes with an average 66 minutes.Forty four(95%) cases had a normally situated ver cal slit like meatus and voided with a straight urinary stream except with two cases with wound dehicence.Meatus was almost at the p of the glans penis with excellent cosme c looking.

Discussion
The technique of tubularized incised plate urethroplasty for distal hypospadias described here has several advantages over other procedures.Meatal advancement and glanuloplasty (MAGPY) was developed to correct a meatus which has urinary stream going downward as its demerits.Mathew, onlay and island pedicle fl ap procedure has also been widely used with minimal complica ons but the meatus appearing rounded like fi sh mouth in contrast to slit like of a normal meatus was their disadvantage.Thiersc-duplay procedure leads to glanular meatus and is a two stage surgery as its drawback 3,4 .All drawbacks of these procedures are completely omi ed by TIP urethroplasty.The rate of complica ons like urethrocutaneous fi stula, meatal stenosis, ease of surgery and dura on is also in favor of TIP urethroplasty.
Rich et al introduced the principle of incising the urethral plate in the midline to improve the cosme cs of a hypospadias repair in 1989 8 .The goal of hypospadias surgery is a penis that is func onally and cosme cally normal.This is achieved by construc ng a straight penis with meatus as close as possible to normal site with proper shape to allow a forward directed stream and normal coitus 9,10 .
In 1994 Snodgrass used this concept and extended the incision of the urethral plate from the meatus to the TIP of the glans.It has gained popularity so that most surgeons today prefer doing TIP rather than other procedure for distal hypospadias.TIP has be er outcome, less complica ons and good cosme c looks.The main advantage of TIP is it is technically easy, gives a normal looking ver cal slit like meatus which is not achieved in other procedure 10,11,12,13,14 .Forty three (93.4%)pa ents in our series had good looking glans and meatus with straight urinary stream.The other main advantage of TIP is a single stage surgery which helps to reduce mul ple exposure of anesthesia to the pa ent .TIP surgery in terms of surgery dura on is also shorter with the me range of 60-80 minutes in this series.
Although several modifi ca ons and refi nements have been made urethrocutaneous fi stula s ll remains the main postopera ve complica ons 15,16 .Our fi stula rate was 5 (10.86%).Various study shows frequency of fi stula forma on a er TIP urethroplasty ranges 0.5% to 16%.Zhou et al had 12.5% and Ahmad K noted 11.8% fi stula rate 17,18 .The rate of fi stula forma on is markedly less in TIP urethroplasty than other procedure.Anwar et al did a compara ve study between TIP and Mathieu and found overall results in terms of fi stula and cosmesis, TIP is be er for distal hypospadias.Similar report by Muhammad et al in their compara ve study between TIP and Mathieu recommended TIP as their primary treatment for distal hypospadias 19,20 .This marked decrease in fi stula forma on is due to the coverage of neourethra by the subcutaneous vascularised layer of dartos taken from dorsal prepuce and sha skin.It was men oned in 2003 by Sozbir and Snodgrass.In our cases we also had used single or double layer in between neourethra and skin coverage.Cheng et al have also suggested a two layer closure of the neourethra to minimize the fi stula rate 21,22 .Some western study shows fi stula forma on rate less than 2%.It may be due to the development of subspecialty like paediatric urology, paediatric plas c surgery and dedica ons of surgeons to special fi eld of hypospadias.Our result is also excellent and acceptable in our context where we paediatric surgeon have to deal all sorts of general paediatric and urosurgery cases.
The longitudinal incision on the urethral plate in Snodgrass urethroplasty is an innova on of urethral plate preserva on as the plate is not the cause of chordee.This midline incision in urethral plate helps to make a tension free tabulariza on to form a neourethra of an adequate size.Baskin et all in their histological study of urethral plate found sub mucosal layer of plate is highly vascularized with good nerve supply.This makes the healing of this incision by re-epithelializa on with normal ssue but not by scar forma on.This property leads to less chance of urethral stricture resul ng good urinary stream 2,5,8 .In our series we had only one case of meatal stenosis which was managed by meatotomy.
Tubularized incised plate urethroplasty (TIP) can also be used in redo cases as well as proximal and more severe form of hypospadias.A.M. Kamal et al in their series of p urethroplasty in redo cases showed an excellent cosme c and func onal result 23 .Chen et al performed TIP in 40 cases of proximal hypospadias and overall complica on rate was 17.5% 24 .Warren Snodgrass and Selcuk Yucel perform TIP in 65% of all proximal hypospadias with an overall complica on rate of 37%.Fistula occurred in 7 out of 35 pa ents (20%) 25 .At our ini al stage for proximal and severe form of hypospadias we did stage surgeries with orthoplasty (straightening of penis) as fi rst stage and urethroplasty as second stage.Now we have started doing TIP urethroplasty as single stage surgeries for proximal hyposapdias.

Conclusion
Tubularized incised plate urethroplasty is a simple, single stage surgery for distal hypospadias.It gives good func onal neourethra of normal looking glans and meatus with a low rate of complica ons like urethrocutaneous fi stula, stricture.It is our preferred method of repairing distal and midpenile hypospadias in our ins tu on.