Comparison of effect between dartos fascia and tunica vaginalis fascia in TIP urethroplasty: a meta-analysis of comparative studies

Background

Tubularized incised plate (TIP) urethroplasty is the most commonly performed procedure for hypospadias. Several flap procedures have been recommended to decrease the postoperative complication rate in TIP repair, but no single flap procedure is ideal. This study aimed to compare the outcomes of dartos fascia (DF) and tunica vaginalis fascia (TVF) as intermediate layers in TIP urethroplasty.

Methods

We searched PubMed, EMBASE, the Cochrane Library, Web of Science, clinicaltrials.gov, and other sources for comparative studies up to April 16, 2020. Studies were selected by the predesigned inclusion criteria. The primary outcomes were postoperative complications. The secondary outcomes were functional and cosmetic outcomes.

Results

The pooled RR with 95% CI were calculated. We extracted the relevant information from the included studies. Only 6 comparative studies were included. No secondary outcomes were reported. The RR of the total complications rate for DF was 2.41 (95% CI 1.42–4.07, P = 0.0001) compared with TVF in TIP repair. For each postoperative complication, the RRs were 6.48 (2.20–19.12, P = 0.0007), 5.95 (1.13–31.30, P = 0.04), 0.62 (0.25–1.52, P = 0.29), and 0.75 (0.23–2.46, P = 0.64) for urethrocutaneous fistula, prepuce-related complications, meatal/urethral stenosis, and wound-related complications, respectively.

Conclusions

This meta-analysis reveals that compared to DF, TVF is a better option in TIP repair in terms of decreasing the incidence of the total postoperative complications, urethrocutaneous fistula, and prepuce-related complications. However there is limited evidence for functional and cosmetic outcomes. Overall, larger prospective studies and long-term follow-up data are required to further demonstrate the superiority of TVF over DF.

Trial registration

PROSPERO CRD42019148554.

Abnormal dartos fascia in buried penis and hypospadias: Evidence from histopathology

INTRODUCTION

The importance of the pathology of the dartos fascia in hypospadias and buried penis is still debatable. Understanding the properties of connective tissue of dartos fascia in hypospadias and buried penis may give a clue to the underlying mechanism.

OBJECTIVE

This study aimed to compare connective tissue and vascularization of dartos fascia between normal penis, buried penis, and hypospadias.

STUDY DESIGN

We conducted this prospective study from May 2013 to November 2016. We collected dartos fascia specimens from three groups: buried penis, hypospadias, and normal penis as control. All of the patients underwent primary surgery in all groups. Patients with penile abnormalities, such as phimosis or Balanitis Xerotica Obliterans (BXO) were excluded from the normal penis group. We compared the fibers between these groups using Masson trichrome histochemical staining, Gomori's silver impregnation staining, Weigert resorcin-fuchsin staining, and CD31 immunohistochemistry staining for evaluation of collagen fibers, reticulin fibers, elastin fibers, and endothelial cells of blood vessels, respectively. The collagen fibers, reticular fibers, elastic fibers, and vascular vessels were counted with ImageJ and manually calibrated and counted and were analyzed using the one-way ANOVA test. The assessment conducted by two pathologists was blinded, without knowing the clinical diagnosis of patients.

RESULTS

There was a total of 60 patients with 20 patients in each group. Collagen fibers for most cases of buried penis and hypospadias showed thicker but fewer collagen fibers than the normal penis. There was a reduction of total collagen and elastin of dartos fascia in hypospadias and buried penis cases. On the other hand, the ratio of reticulin fibers, which represents collagen type III to total collagen, was increased compared to normal penis.

DISCUSSION

Although the dartos fascia in buried penis and hypospadias is thick and inelastic when palpated or during traction/counter traction, it is well-vascularized tissue. This inelastic dartos fascia tissue is an abnormal tissue, but its characteristics are not similar to fibrotic tissue. However, further study with a larger sample is warranted and should differentiate the degree of chordee in patients with hypospadias and buried penis.

CONCLUSIONS

There was a difference between connective the tissue of dartos fascia in buried penis and patients with hypospadias compared with normal penis. Inelastic dartos fascia tissue in patients diagnosed with buried penis and hypospadias is an abnormal tissue. Therefore, it is suggested that this tissue is excised during reconstructive surgery. Further research is needed to unveil the pathophysiology of the condition.

Buck's fascia repair with glanuloplasty in hypospadias surgery: A simple approach with excellent outcome

BACKGROUND

Hypospadias is a common problem encountered in surgical practice and its repair is challenging because of various complications. Urethro-cutaneous fistula is the most common postoperative complication (incidence of 0-33%). Different types of intermediate protective layers have been used in attempts to decrease UCF formation; however, no single surgical technique is ideal.

OBJECTIVE

The aim of this study was to compare use of dartos fascia and Buck's fascia as intermediate layers in prevention of the formation of UCF.

STUDY DESIGN

This was a prospective, comparative study conducted over a period of 2 years from January 2014 to December 2015. Patients with primary hypospadias without or with mild ventral penile curvature were included in the study. Patients were categorised into two groups, A and B, with alternate patients assigned to each group. Patients in group A underwent Snodgrass repair with urethroplasty by two-layer subepithelial closure and dartos tissue as an intermediate layer. Patients in group B underwent a urethral repair followed by Buck's fascia repair as intermediate layer and glanuloplasty after excision of a triangular skin strip on either side of the urethral plate. Patients were followed at regular intervals for a minimum of 6 months and complications were noted.

RESULTS

Over a period of 2 years, 160 patients were included in the study: 80 patients in group A and 80 patients in group B. The age of patients ranged from 1 year to 4.6 years, with a mean age of 1.8 years. Postoperative complications are listed in the summary table.

DISCUSSION

A protective intermediate layer between the neourethra and the skin can be used to reduce fistula formation. We describe a technique of urethroplasty using Buck's fascia as intermediate layer and glanuloplasty, with excellent results. Buck's fascia over the corpora spongiosum which is deficient ventrally in hypospadias is not completely absent, and can be easily used to cover the neourethra, needs minimal dissection and hence vascularity of tissues is preserved (summary Fig.). We used this Buck's fascia as a second protective layer over the neourethra in an attempt to decrease UCF formation, and compared it with use of dartos fascia. In our study, UCF occurred in 2.5% of patients in the Buck's fascia group and 12.5% of patients in the dartos group, a statistically significant difference. We believe that the native Buck's fascia lateral to spongiosum is a more appropriate, natural, and strong layer to cover the neourethra.

CONCLUSION

Use of Buck's fascia as an intermediate layer along with glanuloplasty is simple and very effective in preventing UCF formation and glanular dehiscence. We recommend the use of Buck's fascia as an intermediate layer to cover the neourethra to reduce incidence of postoperative complications and improve results.

Single vs. double dartos layers for preventing fistula in a tubularised incised-plate repair of distal hypospadias

Objective

To compare the outcome of a single vs. a double-layer dartos interposition for preventing a fistula after tubularised incised-plate (TIP) distal hypospadias repair.

Patients and methods

We retrospectively reviewed the records of patients with primary distal hypospadias who had the hypospadias repaired between February 2009 and June 2011, operated by one surgeon (S.A.K.). In all of the children a standard TIP urethroplasty was performed, which was covered by a dartos fascial flap fashioned using one of two techniques, i.e. in Group I (48 patients) double dartos preputial flaps were used, and in Group II (52 patients) a single dorsal dartos flap was used and transposed ventrally via a ‘buttonhole’. The fistula rate and other complications related to each group were recorded.

Results

The mean (range) follow-up was 12 (6–22) months for Group I and 14 (6–24) months for Group II. The result was considered a success in 96% of Group I and 92% of Group II. In Group I there were no fistulae, while in Group II there were four fistulae (8%) detected; this difference was statistically insignificant (P = 0.1). Meatal stenosis was associated with a fistula in one patient in Group II but not in the other three. In Group I a meatal stenosis developed late after complete healing of the urethroplasty, with no associated fistula. The repair broke down in one patient in Group I (2%).

Conclusion

A double-dartos neourethral cover in TIP hypospadias repair seems to be more effective than a single layer for preventing a fistula, despite there being no statistically significant difference between the groups. However, the protective effect of double-dartos flaps must be appropriately evaluated in a prospective, randomised and controlled study in more patients.

Soft tissue covers in hypospadias surgery: Is tunica vaginalis better than dartos flap?

AIM

To compare tunica vaginalis with dartos flap as soft tissue cover in primary hypospadias repair.

MATERIALS AND METHODS

25 cases (age range: 12-132 months; all fresh cases) of primary hypospadias were prospectively repaired by tubularized incised plate (TIP)/TIP + graft urethroplasty using tunica vaginalis flap (TVF) as soft tissue cover to urethroplasty (group A). Their results were compared with another set (group B) of age- and anatomy-matched controls (25 patients operated during the previous 3 years) who had undergone TIP repair using dartos flap as soft tissue cover. Statistical analysis of results was done with Fischer's exact test.

RESULTS

GROUP A

No fistula, skin necrosis, meatal stenosis, urethral stricture. One case had partial wound dehiscence that resolved on conservative treatment with no sequelae. One case required catheter removal on 3(rd) day because of severe bladder spasm. There was no testicular atrophy/ascent. Group B: 3 fistulae - all required surgery. There were three cases of superficial skin necrosis that healed spontaneously without sequel. There was no meatal stenosis/urethral stricture. The difference in fistula rate between both the groups, however, was not statistically significant (P = 0.4).

CONCLUSION

TVF may have an edge over dartos fascia for soft tissue coverage of the neourethra.