Split dorsal dartos flap transposed ventrally as a bed for preputial skin graft in primary staged hypospadias repair

Complication rates of proximal hypospadias: meta-analyses of four surgical repairs

INTRODUCTION

Proximal hypospadias surgery is impacted by a high complication rate. The goal of this work was to assess the overall composite complication rate, fistula rate and stenosis rate following proximal hypospadias surgery realized according to onlay urethroplasty, Duckett, Koyanagi and Bracka techniques.

METHODS

The databases MEDLINE, EMBASE, SCOPUS, Cochrane Library, the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials (CENTRAL) and Sciencedirect were searched. Studies had to report data about the mean age of population, the average duration of patient follow-up and the number of procedures required for surgical treatment of primary and proximal hypospadias. Two independent including one urologist reviewers screened all the articles and selected the articles to be included.

RESULTS

Overall composite complication rates were 32%, 34%, 49%, and 43%, for Onlay urethroplasty, Duckett's tubularized flaps urethroplasty, Koyanagi repair and Bracka 2 stages repair, respectively. Fistula rates were 13%, 18%, 21% and 23% respectively. The heterogeneity of complication rates reported in the different studies was not moderated by age, country, or patient's continent origin.

DISCUSSION

The classifications of complications used in articles were disparate and make comparisons between techniques difficult. The report of post-surgical complications in the literature is often poorly coded and follow-up times were often too short.

CONCLUSION

This meta-analysis attempts to determine to the extent possible, given the serious weaknesses in the hypospadias literature, plausible estimates of complication rates after skin flap urethroplasty. The patched onlay skin flap, the Duckett's tubularized skin flap technique, the Koyanagi's technique, and the Bracka's two-stage urethroplasty procedure lead to very high complication rates. Reported complication rates are comparable across techniques.

The effect of staged TIP urethroplasty on proximal hypospadias with severe chordee

Background

Proximal hypospadias with severe chordee is still a formidable challenge for most pediatric urologists, and the treatment approach remains controversial. Here, we describe a modified two-stage technique to repair proximal hypospadias with severe chordee.

Methods

We retrospectively identified 53 children referred for proximal hypospadias with severe chordee from July 2016 to July 2019, who underwent a two-stage urethroplasty. In group 1, the children were repaired with staged tubularized incised plate (TIP) urethroplasty, while Byars’ two-stage urethroplasty was attempted in group 2. We corrected chordee by releasing all remaining attachments to the corpora after degloving the penis, transceting the urethral plate, and dorsal plication. The mean age of patients in the first stage of surgery was 26.6 months in group 1 and 24.8 months in group 2. Postoperative complications in the two groups included: fistula, urethral stricture, urethral diverticulum, and glanular dehiscence.

Results

A total of 20 cases were repaired with staged TIP urethroplasty (group 1), and 33 cases were repaired with Byars’ two-stage urethroplasty (group 2). The length of follow-up in group 1 was 39.8 ± 10.1 months, and in group 2, it was 38.1 ± 8.7 months (P > 0.05). After the second stage of surgery, 1 case (5%) in group 1 and 11 cases (33.3%) in group 2 developed a urinary fistula (P < 0.05). One case (5%) in group 1 and three cases (9.1%) in group 2 had urethral stricture (P > 0.05). All strictures were cured by repeated dilation, and no patient required reoperation. No cases in group 1 and one case (3%) in group 2 had urethral diverticulum (P > 0.05). There was no residual chordee in both groups. Two cases (10%) in group 1 and 13 cases (39.3%) in group 2 required reoperation (P < 0.05).

Conclusions

Staged urethroplasty is appropriate to repair proximal hypospadias with severe chordee. Particularly, staged TIP urethroplasty is a good choice for patients with proximal hypospadias and severe chordee, especially those with better penile development, wider urethral plate, larger glans, and deeper navicular fossa of the urethra.

A meta-analysis comparing dorsal plication and ventral lengthening for chordee correction during primary proximal hypospadias repair

PURPOSE

Recurrent chordee (RC) is an important complication of proximal hypospadias repair. In this meta-analysis we compared RC incidence following dorsal plication (DP) versus ventral lengthening (VL).

METHODS

We searched the databases to identify all papers between 2001 and 2021 pertaining to proximal hypospadias and recurrent chordee. Duplicate publications, review articles and incomplete articles were excluded. Meta-analysis of heterogeneity was reported with I² statistics. The pooled outcomes were compared to Chi square/Fishers exact test.

RESULTS

A total of 17 articles were included covering 582 patients. The I² statistics for prevalence of RC among different publications showed no heterogeneity for DP (I² = 0%) and low heterogeneity for VL (I² = 26%). RC was noticed in 31/122 (25.4%; 95% CI 18%-33%) among patients who had DP alone while it was significantly lower, 24/460 (5.3%; 95% CI 4%-8%) when VL was used (p = 0.0001). When compared to DP, all VL techniques had significantly lower incidence of RC. Among the VL techniques lowest incidence of RC was found for ventral corporotomies (4%) followed by small-intestinal- submucosa (SIS 4.2%) and tunica vaginalis flap (TVF)/free graft-TVFG (5%). Among the VL subtypes: the proportion of RC with use of TVF (4/70, 5.7%) and TVFG (3/69, 4.3%) for corporoplasty was comparable (p = 1); single-layer SIS was associated with significantly less RC (1/90, 1.1%) than 4-layer SIS (5/51, 9.8%; p = 0.02).

CONCLUSION

For correction of severe ventral chordee during primary proximal hypospadias repair, dorsal plication carries a higher risk of recurrence compared to ventral lengthening procedures.

Urethral Tissue Reconstruction Using the Acellular Dermal Matrix Patch Modified with Collagen-Binding VEGF in Beagle Urethral Injury Models

Objectives

Urethral tissue reconstruction for hypospadias is challenging for urologists. In this study, bovine acellular dermal matrix (ADM) patch loading with collagen-binding vascular endothelial growth factor (CBD-VEGF) was used to repair the urethral injury in beagles.

Methods

The safety and effectiveness of the scaffold implantation were carefully evaluated by comparing among the urethral injury control group, ADM implantation group, and ADM modified with CBD-VEGF implantation group during 6 months. Urodynamic examination, urethral angiography, and pathological examination were performed to evaluate the recovery of urethral tissue.

Results

Stricture, urethral diverticulum, and increased urethral closure pressure were observed in the control group. Fistula was observed in one animal in the ADM group. By contrast, no related complications or other adverse situations were observed in animals treated with ADM patch modified with CBD-VEGF. The average urethra diameter was significantly smaller in the control animals than in scaffold implantation groups. Pathological examination revealed more distribution of proliferative blood vessels in the animals treated with ADM modified with CBD-VEGF.

Conclusions

Overall, ADM patches modified with CBD-VEGF demonstrated an optimized tissue repair performance in a way to increase tissue angiogenesis and maintain urethral function without inducing severe inflammation and scar formation.

Meta-analysis comparing the outcomes of single stage (foreskin pedicled tube) versus two stage (foreskin free graft & foreskin pedicled flap) repair for proximal hypospadias in the last decade

BACKGROUND

Despite many technical advances the debate continues on single versus staged procedures for proximal hypospadias. In this systematic review and meta-analysis we have compared the contemporary outcomes of proximal hypospadias repair: single stage foreskin pedicle tube (FPT) versus two stage foreskin free graft (FFG) and two-stage foreskin pedicled flap (FPF) over the last decade.

METHODS

A systematic literature review of publications in English of the following electronic databases was conducted: Cochrane Database, PUBMED, MEDLINE and EMBASE. The following keywords were used: (proximal) AND (hypospadias) AND (repair OR urethroplasty) AND (outcomes OR complications). The publication date range for studies was from January 2010 to December 2020. Outcomes analyzed were complications like urethro-cutaneous fistula (UCF), glans dehiscence (GD), meatal stenosis (MS), urethral stricture (US), urethral diverticulum (UD), recurrent curvature or residual chordee (RC), buried penis (BP) and poor cosmesis (PC) as per objective assessment scores, or poor graft uptake (PGF) during first stage. We also divided the papers based on case load into two groups: < 5 cases or >5 cases operated per year and compared the post-operative outcomes.

RESULTS

The I 2 statistics for prevalence of total complications showed high heterogeneity with I 2 of 88% for one stage repair and 92% & 98% for two stage repairs. The pooled data from 26 articles covered a total of 2664 patients; mean follow-up of 4.5 years (1.8-14 years). One stage repair (FPT) was used in 680 (25%) patients while two stage repair was used in 1984 (75%) patients. Complications were encountered in 285/680 (42%) of those who underwent single stage repair (FPT) and this was significantly higher (Fishers; p = 0.001) than 414/1984 (21%) complication rate seen in two stage repair. Among the two different techniques of two stage operations over-all complication rate was not significantly different (Fisher's; p = 0.1) between FFG (155/674; 23%) and FPF (259/1310; 20%). FFG was superior to FPF in terms of individual complications UCF, MS, GD and UD. For two-stage FPT and FPF repairs the complication rate significantly reduced (p = 0.01) with increasing case load. For single stage repairs the complication rate remained high despite the increasing case load.

CONCLUSIONS

Two-stage repair of proximal hypospadias had significantly less complications compared to single stage repair. Among two-stage repairs specific complications were significantly less for FFG, although total complications were not significantly different from that seen with FPF. The results of two-stage repairs improved with higher case load supporting the concept of dedicated hypospadias centres.

Augmentation of the insufficient tissue bed for surgical repair of hypospadias using acellular matrix grafts: A proof of concept study

Acellular matrices produced by tissue decellularisation are reported to have tissue integrative properties. We examined the potential for incorporating acellular matrix grafts during procedures where there is an inadequate natural tissue bed to support an enduring surgical repair. Hypospadias is a common congenital defect requiring surgery, but associated with long-term complications due to deficiencies in the quality and quantity of the host tissue bed at the repair site. Biomaterials were implanted as single on-lay grafts in a peri-urethral position in male pigs. Two acellular tissue matrices were compared: full-thickness porcine acellular bladder matrix (PABM) and commercially-sourced cross-linked acellular matrix from porcine dermis (Permacol™). Anatomical and immunohistological outcomes were assessed 3 months post-surgery. There were no complications and surgical sites underwent full cosmetic repair. PABM grafts were fully incorporated, whilst Permacol™ grafts remained palpable. Immunohistochemical analysis indicated a non-inflammatory, remodelling-type response to both biomaterials. PABM implants showed extensive stromal cell infiltration and neovascularisation, with a significantly higher density of cells (p < 0.001) than Permacol™, which showed poor cellularisation and partial encapsulation. This study supports the anti-inflammatory and tissue-integrative nature of non-crosslinked acellular matrices and provides proof-of-principle for incorporating acellular matrices during surgical procedures, such as in primary complex hypospadias repair.

Midline Incision of a Graft in Staged Hypospadias Repair-Feasible and Durable?

Purpose: In severe hypospadias staged repair is commonly used and it is regarded as feasible, safe, and durable. In this article we want to describe the results of a modification of the staged repair: a midline incision of the graft during the second stage. Materials and Methods: This is a consecutive single team (2 surgeons) retrospective series. Between 2014 and 2017, 250 patients underwent hypospadias repair, among them 35 patients that had primary staged hypospadias surgery with completed first and second stage repair. 24 (68.6%) cases received a preputial skin graft and 11 (31.4%) buccal mucosa graft. Median age at first stage was 1.5 (0.5-22.1) years, mean time between first and second stage operation was 0.72 (0.4-1.76) years. Follow up rate was 100%, mean follow up period was 1.50 (0.4-3.8) years. Results: The total complication rate was 22.9%. In buccal mucosa repair the complication rate was 36.4% and in preputial graft repair the complication rate was 16.7%, respectively. In 23 patients (65.7%) during second stage urethroplasty a midline incision was performed (8 glandular graft, 15 penile graft, 6 at level of urethral opening). Complication rate in non-incised urethroplasty was 8.3%, in incision at glandular level 37.5%, in incision at penile level 13.3% and in incision at urethral opening 16.7%, respectively. Conclusions: Two stage repair is the method of choice in the correction of severe hypospadias. In selected cases a midline incision of the graft is feasible and can be applied if needed. Randomized studies will be needed to evaluate the true benefit of incising the graft.

Can a graft be placed over a flap in complex hypospadias surgery? An experimental study in rabbits

Purpose:

To develop a rabbit experimental study to test the hypothesis that surgical repair of hypospadias with severe ventral curvatures might be completed in one stage, if a graft, such as buccal mucosa, could be placed over the tunica vaginalis flap used in corporoplasty for ventral lengthening, with the addition of an onlay preputial island flap to complete the urethroplasty.

Materials and methods:

The experimental procedure with rabbits included a tunica vaginalis flap for reconstruction of the corpora after corporotomy, simulating a ventral lengthening operation. A buccal mucosa graft was placed directly on top of the flap, and the urethroplasty was completed with an onlay preputial island flap. Eight rabbits were divided into 4 groups, sacrificed at 2, 4, 8 and 12 weeks postoperatively, and submitted to histological evaluation.

Results:

We observed a large number of complications, such as fistula (75%), urinary retention (50%) and stenosis (50%). There were two deaths related to the procedure. Histological evaluation demonstrated a severe and persistent inflammatory reaction. No viable tunica vaginalis or buccal mucosa was identified.

Conclusions:

In this animal model, the association of a buccal mucosa graft over the tunica vaginalis flap was not successful, and resulted in complete loss of both tissues.

Unexpected outcome of a modification of Bracka repair for proximal hypospadias: High incidence of diverticula with flaps

INTRODUCTION

Various graft and flap techniques have been proposed for urethral reconstruction in proximal hypospadias repair. The Bracka repair involving the transfer of inner prepuce like a Wolfe graft mostly results in satisfactory results besides a high fistula rate.

AIM

The aim was to decrease the high fistula rate with Bracka repair; we wanted to use the advantages of vascularized skin in the Bracka method. The aim of this study was to evaluate our results with this modification.

STUDY DESIGN

Our modification involves using a flap instead of a graft. In the first stage, chordee was corrected by transection of the urethral plate and dorsal midline plication when necessary. Instead of a graft as suggested by Bracka, inner preputial skin with ample blood supply was transferred and stitched to the denuded ventral penile surface. In the second stage after 6 months, this flap was tubularized in the Thiersch-Duplay fashion. Hospital records of patients who had undergone two stage modified Bracka repair between June 2007 and July 2012 were reviewed, including complaints, complications, and need for interventions.

RESULTS

Thirty-eight patients had undergone this operation. Four patients were lost to follow-up. The main complaint was obstructed urinary flow. Voiding symptoms were first attributed to urethral stenosis, but were, however, found to be due to diverticulum and vortex of the urine in the dilated urethra. Twenty-one patients (61%) had voiding problems and 10 patients (29%) had urinary tract infections. Fistula was observed in 23 and diverticula were observed in 24 patients. Of these, 16 patients had both fistula and diverticula. Only two patients (5%) were free of complications and totally satisfied with the operation, and 23 of the 34 patients had complications requiring intervention (Figure).

DISCUSSION

Inner preputial flaps used in proximal hypospadias repairs are prone to diverticula formation. They become redundant in time requiring reoperation, thus decreasing the success rate. Careful fixation of the flap to the corpora and allowing time for additional attachment of the urethral plate substitution through fibrotic activity could not overcome this complication.

CONCLUSION

Our modification of the Bracka technique using a flap for the plate resulted in a high rate of complications (in particular diverticulum formation) and was therefore abandoned. We recommend careful use of flaps in hypospadias surgery and long-term follow-up studies to evaluate actual functional and cosmetic results.

The Effect of Staged Transverse Preputial Island Flap Urethroplasty for Proximal Hypospadias with Severe Chordee

PURPOSE

We compare the effects of staged tranverse preputial island flap urethroplasty and the Byars 2-stage procedure in patients with proximal hypospadias and severe chordee.

MATERIALS AND METHODS

We studied 87 consecutive children referred for proximal hypospadias with severe chordee between March 2011 and March 2014. Of the cases 42 were repaired with staged tranverse preputial island flap (group 1) and 45 were managed by 2-stage Byars urethroplasty (group 2). Mean ± SD age at first stage surgery was 26.6 ± 13.3 months in group 1 and 24.8 ± 14.7 months in group 2. Postoperative complications in both groups were assessed regarding fistulas, urethral strictures, diverticula, meatal stenosis and glanular dehiscence.

RESULTS

After the second stage 2 patients (4.8%) in group 1 and 10 (23.2%) in group 2 had urethrocutaneous fistulas (p <0.05). One patient (2.4%) in group 1 and 2 patients (4.4%) in group 2 had urethral strictures (p >0.05). All patients with stricture were cured by repeated dilation and no patient required reoperation. One patient (2.4%) in group 1 and no patient in group 2 had diverticulum (p >0.05). No patient in either group had signs or symptoms of meatal stenosis or residual chordee. Three patients (7.1%) in group 1 and 12 (26.7%) in group 2 needed reoperation (p <0.05).

CONCLUSIONS

Two-stage urethroplasty, particularly tranverse preputial island flap partial urethroplasty, is appropriate for treating patients with proximal hypospadias and severe chordee. Use of the tranverse preputial island flap can decrease complications associated with the second stage and significantly improve the success rate.

Two-stage urethroplasty is a better choice for proximal hypospadias with severe chordee after urethral plate transection: a single-center experience

It is still debatable whether single- or two-stage urethroplasty is a more suitable technique for treating hypospadias with severe chordee after urethral plate transection. This retrospective study evaluated these two techniques. A total of 66 patients of proximal hypospadias with severe chordee were divided into two groups according to the techniques they underwent: 32 and 34 patients underwent single-stage (Duckett) or two-stage urethroplasty, respectively. Median ages at presentation were 7.5 years and 11.0 years in single-stage and two-stage repair groups, respectively. Median follow-ups were 28.5 months (20-60 months) and 35 months (18-60 months) in the single-stage and two-stage groups, respectively. The meatus of the neourethra was located at the top of the glans in all patients. No recurrence of chordee was found during follow-up, and all patients or parents were satisfied with the penile length and appearance. Complications were encountered in eight patients in both groups, with no statistically significant differences between the two techniques. The late complication rate of stricture was higher after the single-stage procedure (18.75% vs 0%). The complication rate after single-stage repairs was significantly lower in the prepubescent subgroup (10.52%) than in the postpubescent cohort (46.15%). These results indicate that the urethral plate transection effectively corrects severe chordee associated with proximal hypospadias during the intermediate follow-up period. Considering the higher rate of stricture after single-stage urethroplasty, two-stage urethroplasty is recommended for proximal hypospadias with severe chordee after urethral plate transection.