A 6-Fr feeding tube was used for diversion of urine and as a stent, and the repair was covered by sterile dressing. The urethral stent was removed 3 days postoperatively and the patient was discharged.
The protocol of the study was accepted by the the IRB/ethical committee of Mansoura Faculty of Medicine (Code Number: R/17.06.75).
Mansoura modification of the unilateral Koyanagi technique was used to treat 30 patients suffering from hypospadias without chordee. The patients’ age at the time of surgery ranged from 6 to 30 months (mean: 20 months). Sixteen (53%) cases had distal penile meatus; 10 (33%) cases had mid-penile meatus; and four (14%) cases had proximal penile meatus. The operative time ranged from 90 to 120 min (mean 100 min). Most of the operative time was consumed in the harvest of the flap, which was found easier in cases of mid-penile and proximal penile hypospadias than in cases of distal hypospadias. The width of the flap in all our cases was 7–8 mm; however, the width of the urethral plate ranged from 3 to 9 mm (mean: 5 mm). The circumference of the urethral tube ranged from 11 to 16 mm (mean: 13 mm). The urethral tube was removed 3 days postoperatively in all cases and were all discharged on the fourth postoperative day.
The follow-up ranged from 3 months to 1 year (mean: 9 months). They visited our outpatient clinic twice per week for 2 weeks, then weekly for a month, then every 2 weeks for 2 months, and then monthly for a year. The postoperative evaluation was mainly clinical, no dilatation was needed in any of the cases; however, gentle probing of the meatus and urethral calibration was done using Nelaton catheters 6–8 Fr 1 month postoperatively and repeated monthly for 6 months to ensure that there was no meatal nor urethral stricture.
Primary success occurred in 28 (93%) cases with adequate parent satisfaction and accepted cosmetic appearance. Complications occurred in two (7%) cases, in the form of urethrocutaneous fistula. There was no incidence of meatal stenosis nor recession, urethral stricture or flap necrosis.
The two cases with urethrocutaneous fistula occurred in the group of distal penile hypospadias and both needed an operation to close the fistula 6 months later.
There are many novel techniques for the repair of hypospadias anomaly with different changes in patient management plans and the application of plastic surgical principles that have improved the results. However, to the day surgeons agree that no single procedure has gained unanimous support 7. We always assume that there is no such thing as a simple case of hypospadias; thus avoiding to use a minor repair in a major situation which will mostly result in complications. Preoperative planning is also essential to achieve the goals of the surgery 8.
All surgeons aim to achieve what is called a normal penis using different surgical techniques, but what is the standard and how do we measure against it? 9 Urethroplasties must necessarily walk a fine line between luminal stenosis and redundancy. The urethral reconstructions in babies and older boys are planned to have a circumference of 13–15 and 18–20 mm, respectively. Calibration with a 12–14-Fr Nelaton catheter is a useful gauge of patency at the completion of every case 10.
John Duckett was interested to know the limitations and exact measurements involved in the TIP urethroplasty from Snodgrass himself during a meeting a week before he died. He was concerned about the width of the urethral plate before and after the TIP incision 9. We do not really know if Duckett would have shared our concerns regarding the TIP procedure. In our experience, we found that its main drawback is the incidence of postoperative meatal and urethral stenosis. This may be due to healing of the urethral plate incision by fibrosis causing these complications.
Snodgrass denies that the TIP urethroplasty procedure may be a cause of stricture urethra or meatal stenosis. He states that his technique gives the best cosmetic results having complication rates as low as 7% in many studies 9. However, not all hypospadialogists share the opinion of Warren Snodgrass. During a meeting in Alexandria in 2016, I personally communicated with Hadidi 3 who shared my opinion of the possibility of stricture urethra and meatal stenosis after TIP urethroplasty. He backed this by a research he published in 2013.
Koyanagi et al.4 devised a one-stage technique for the repair of proximal hypospadias with chordee. They harvested a bilateral parameatal-based foreskin flap, which was handy in length but lacked the adequate blood supply. This resulted in a high rate of complications and many abandoned the technique 4. Koyanagi et al.6 also described the onlay urethroplasty with unilateral parameatal foreskin flap for distal hypospadias.
Emir et al.5 modified the Koyanagi technique in a brilliant manner harvesting the flap with preservation of the pedicle as well as the lateral blood supply which created a well-vascularized flap thus improving the results significantly. We tried the modified Koyanagi technique in cases of proximal hypospadias with chordee and we had a 90% success rate 11.
These results inspired us to harvest a unilateral parameatal-based penopreputial flap with preservation of the pedicle as well as the lateral blood supply (Mansoura modification of the unilateral Koyanagi technique, which is a modification of onlay urethroplasty with parameatal foreskin flap devised by Koyanagi and colleagues) 6.
We believed that this technique would be superior to the classic TIP urethroplasty in avoiding postoperative urethral stricture and meatal stenosis. We also believed it to be superior to the Mathieu procedure as our flap is better vascularized and is applicable to more proximal forms of hypospadias.
We used this flap in all 30 cases of hypospadias without chordee included in our study with satisfactory results. We also paid great attention to meticulous dissection and fine surgical technique using fine instruments and optical magnification using a ×2.5 optical loupe. This stands in agreement with most hypospadialogists 12.
All patients were followed up for 3 months to 1 year. Gentle probing of the meatus and urethral calibration using Nelaton catheters 6–8 Fr proved that there was no meatal nor urethral stricture in our series. We had an overall complication rate of 7% which is acceptable and found comparable to the results of those using TIP urethroplasty and Mathieu procedures in cases of hypospadias without chordee 9.
We had two cases of urethrocutaneous fistulae in our series; these occurred in patients with distal penile hypospadias. We were not surprised because we found the harvest of the flap more difficult in distal cases than proximal and mid-penile ones. This is because of the fact that the flap in distal cases is closer to the coronal sulcus at the angle with the urethral plate causing a hindrance to application of the technique and increasing difficulty. However, this becomes evident only with repetition of the procedure.
We find the Mansoura modification of the unilateral Koyanagi technique is not suitable for cases of hypospadias with chordee of even less than 30°. These cases are better managed by the modified Koyanagi one-stage repair of proximal hypospadias which we prefer to the two-stage procedures. Snodgrass would agree with us on only the first half of this statement as he has abandoned the TIP urethroplasty in favor of the two-stage procedures for similar cases 9.
We feel that application of this technique to many more patients is necessary to give a solid evaluation. Hopefully, we can convince more parents to approve our novel technique which is based on traditional principles of plastic surgery.
The Mansoura modification of the unilateral Koyanagi technique is an innovative technique that fulfills many criteria for successful surgical results in cases of hypospadias without chordee. In our limited experience, it is an alternative to TIP urethroplasty avoiding urethral stricture and meatal stenosis. It still stands as a new procedure that needs a lot of time and further studies to be truly evaluated.
Conflicts of interest
There are no conflicts of interest.
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