The chance of another failure in the redo hypospadias is highly present. The shallow urethral plate, a small glans penis, and earlier circumcision augment this probability. Several techniques have been reported to redo a failed hypospadias, e.g., the para-meatal flap, Snodgrass urethroplasty, and free grafts. These cases may need a staged repair according to the characters of the urethral plate, glans size, and penile curvature, but it may end with an unfavorable outcome [5, 7]. The number of the earlier operations is added to the risks of failure in hypospadias repair. This may be the result of the short distance to meatal opening, a higher chance of ascending infection, hematoma, and with more difficulties with immobilization of the free grafts . Glans size is important to the success of the repair. Snodgrass et al.  argues that the deep glandular wings help to overcome the small glans size. Testosterone intake could augment the penile glans size. Yet, for the redo hypospadias Snodgrass et al.  showed that the risk for glans dehiscence is increased subsequently. In the same study, although glans dehiscence was present in 4% of distal penile hypospadias, it occurred in 14% in the redo cases and the risk of glans dehiscence is increased by 4.7-fold in the redo cases. Hypospadiologists do not like using skin augmentation of the glans penis for cosmetic reasons. However, this may be allowed in difficult situations of small or scarred glans [9, 10]. Moreover, we augment our efforts to decrease the incidence of recurrence in the redo hypospadias. In this study, we applied a modified Mathieu urethroplasty for failed distal penile hypospadias with a small glans, unhealthy urethral plate, and without penile curvature. The flap would cover the urethral plate; at the same time, the distally folded part of the flap could augment the small glans. Elsayed et al.  described a similar technique using a folded preputial flap in the redo non-circumcised hypospadias with small glans and shallow urethral plate. Of their operated 36 cases, they had two urethrocutaneous fistulae; one of them was closed spontaneously. This high success rate may be attributed to the minimal dissection in the previous surgeries which left the prepuce intact. Our cases were circumcised, so we could not apply this technique. The tubularized incised plate (TIP) is the commonest procedure for the primary repair of distal hypospadias. But it has drawbacks in the small and/or the shallow urethral plate [5, 11]. In the present study, patients had shallow urethral plate where TIP was not an ideal option for them. Most of our cases were referred from other centers, and most of the earlier reconstructions were not documented to us. The reported success rate for Mathieu technique exceeds 90% in the primary repair with special precautions and in the hands of expert surgeon . The folded Mathieu has been described by Nezami et al.  for the primary repair of distal hypospadias with small glans. They operated 33 out of 54 studied patients using this technique, and follow-up was 20 months. In this group, they had one urethral fistula and no urethral break down or necrosis with overall 97% success rate. They showed better results with this technique than Snodgrass technique in the patients with shallow urethral grove and small glans penis reflecting the fruitfulness of using such technique. We think that the application of this technique would be wiser in the redo distal hypospadias with a small glans penis and shallow urethral plate. Our overall success rate was 73%. And if we excluded the cases of mild meatal recession which did not need further operations, our rate of success would be 93.6%, which we think is acceptable for cases of redo distal hypospadias with unfavorable glans penis and urethral plate. Many modifications have been reported to decrease complications of Mathieu repair . We used the modified sub-epithelial dartos preservation technique to preserve the blood supply of the flap. Also, it decreases the magnitude of dissection in the scarred tissues from multiple earlier operations . Urinary diversion after Mathieu urethroplasty has been a matter of debate. Hakim et al.  reported similar results for stented versus non-stented repair. Buson et al.  reported an increased incidence of adverse events following non-stented Mathieu repair. Postoperative diversion has been used in most of the literature for the salvage of Mathieu urethroplasty . But, we still need larger prospective studies to test the salvage of Mathieu urethroplasty without diversion . In the present study, we used urethral stenting in all cases. Operative time for this procedure was no longer than the time reported for TIP because we did not need complete degloving nor dartos flap harvesting. We had meatal retraction, urethrocutaneous fistula, and wound disruption in 8 (17.0%), 1 (2%) and 1 (2%) patients, respectively. Our overall success rate was 73%, which was comparable to the result of redo TIP urethroplasty by Snodgrass et al. [5, 20]. At the same time, if we excluded the cases of meatal recession, which did not need further operations, our rate of success was 93.6%. To our knowledge, this technique was described only by Nezami et al.  in their comparative study to repair the primary hypospadias. Our study used the same technique prospectively in the redo circumcised distal penile hypospadias with small glans penis in the presence of a shallow urethral plate. We also used the modification of sub-epithelial dartos preservation to increase the vitality of the ventral flap aiming at increasing the success rate of this technique. Our study showed that the folded Mathieu technique is feasible for redo distal hypospadias because it has low complications and overall good outcomes.
Limitations of the study
In this study, we had short follow-up periods. For this reason, long-term studies are needed. Also, further prospective studies with larger numbers of patients and an adequate assessment scoring are needed to strengthen our findings.