Use of BioGlue Surgical Adhesive in Hypospadias Repair

Biologic adjuvant urethral coverings for single-stage primary hypospadias repairs: A systematic review and pooled proportional meta-analysis of postoperative urethrocutaneous fistulas

BACKGROUND

The use of barrier layers between the neourethra and skin is associated with lower rates of post-operative urethrocutaneous fistula (UCF) following hypospadias surgery. Recent studies have evaluated the ability of biologic adjuvant urethral coverings (BAUCs) - namely acellular matrix (AM), tissue adhesives (TAs), and autologous platelet-rich plasma or fibrin (PRP/PRF) - to prevent wound complications following hypospadias surgery. In general, however, these studies are small and conducted at single institutions.

OBJECTIVE

To assess the effect of BAUCs on the rate of UCF following single-stage primary hypospadias repair.

METHODS

We conducted a systematic review of studies reporting the rate of postoperative UCF in pediatric patients undergoing single-stage, primary hypospadias repairs using either AM, TA, or PRP/PRF as a layer interposed between the neourethra and skin. We then performed a pooled proportional meta-analysis of post-operative UCF. Patients within each study who underwent comparable surgery but did not receive a BAUC were used as controls.

RESULTS

10 studies were included in our review. The meta-analysis included 280 patients from 7 studies who underwent hypospadias repairs with BAUCs. The pooled incidence of UCF was 10% (95% CI 6-14%). Mean follow-up ranged 5-23.5 months in the 5/7 studies reporting specific durations, and ≥6 month and 14-30 months, respectively, in the other two studies. Patients in whom a BAUC was used had significantly lower odds of UCF than control patients (OR 0.39, 95% CI 0.24-0.64, p = 0.0002). In subgroup analyses, significant superiority held for AM and TA; proximal or penoscrotal cases; transverse preputial island flap (TPIF) technique; when both cases and controls had local flaps; and when neither cases nor controls had flaps.

DISCUSSION

The use of BAUCs was associated with decreased rates of post-operative UCF in single-stage primary hypospadias repairs and may be most beneficial in more severe cases and when used in addition to local flaps or when using a flap is not possible. In 2/3 studies of PRP/PRF and 2/4 studies of tubularized incised plate (TIP) technique, dartos flaps were used in controls but not BAUC patients, which may explain the lack of benefit demonstrated for these subgroups. This meta-analysis is limited by the quality of evidence in the included studies, which are not uniformly randomized. Furthermore, the follow-up durations and methods for assessing complications are not standardized between included studies.

CONCLUSION

The meta-analysis herein suggests that using BAUCs may reduce UCF rates following hypospadias surgery. Rigorous prospective evaluation is needed to validate this benefit.

BioGlue® is not associated with polypropylene suture breakage after aortic surgery

Objective

We have encountered broken or damaged polypropylene sutures (Prolene^®) at the anastomotic sites during aortic reoperations. Because a surgical sealant, bovine serum albumin-glutaraldehyde (BioGlue^®), was used in previous aortic surgery in some of these cases, we undertook this in vitro study to evaluate whether the use of BioGlue^® was associated with breakage of polypropylene sutures at the aortic anastomosis.

Materials and methods

The broken polypropylene sutures, anastomotic sites and aortic tissue at the location of suture breakage were visually inspected and evaluated intraoperatively. Six human cadaveric aortic samples were incised circumferentially and anastomosed proximally to a valved conduit with running 4–0 polypropylene sutures (Prolene^®). In the test group (n = 3), BioGlue^® was applied directly to the Prolene^® sutures at the anastomotic sites, while in the control group (n = 3) the anastomoses were not sealed with any surgical adhesive. The six samples were immersed in Dulbecco's phosphate buffered saline solution and mounted on a M-6 Six Position Heart Valve Durability Testing System and tested up to 120 million cycles for a 2-year period. During and upon completion of the testing, the integrity of Prolene^® sutures, the anastomosis and aortic tissues was regularly assessed by visual inspection.

Results

Intraoperative findings included a stretched and thin aortic wall (some with thrombus), a small cleft between the aortic tissue and the Dacron vascular graft. An excessive amount of BioGlue^® was often found around the anastomosis, with cracking material, but no signs of mechanical damage were observed in these cases. Upon visual inspection during and after in vitro testing, there was no apparent damage to the polypropylene sutures on the interior or exterior of the aortic anastomoses in any of the samples. No difference was observed in the physical integrity of the polypropylene sutures at anastomotic lines, the anastomoses and aortic tissues between the test and control samples.

Conclusions

The results of this study suggest that the use of BioGlue^® was not associated with breakage of the polypropylene sutures at the anastomotic sites after aortic dissection repair.

The use of tissue sealant in reducing urethrocutaneous fistula event following hypospadias repair: A systematic review and meta-analysis

Background

One of the most frequent complications following hypospadias repair is urethrocutaneous fistula (UCF) event. Tissue sealant has been introduced as a means to reduce UCF. However, reports regarding its benefits are varied. Thus, we initiated a systematic review and meta-analysis to investigate its role in reducing UCF following hypospadias repair.

Methods

We completed a systematic search through the Embase, MEDLINE, and Scopus databases for studies assessing postoperative complications in hypospadias patients undergoing urethroplasty with and without tissue sealant. Cochrane risk of bias 2 (RoB 2) tool was used to assess the quality of randomized clinical trials (RCTs), while the observational studies were assessed with Newcastle-Ottawa Scale. The primary outcome analyzed in this study was UCF, while secondary outcomes consisted of postoperative complications such as edema, infection, and wound dehiscence that increases the risk of UCF formation, measured using odds ratio (OR) with a 95% confidence interval (CI).

Results

Six eligible studies comprising three RCTs and three non-randomized studies were included. Patients undergoing hypospadias repair with tissue sealant had lower UCF events (OR = 3.27; 95% CI 1.92–5.58; p < 0.0001). Likewise other post-operative complications, tissue sealant group had a lower rate of edema (OR = 2.29; 95% CI 1.38–3.78; p = 0.001) and infection (OR = 3.87; 95% CI 1.55–9.70; p = 0.004). The difference in wound dehiscence was insignificant between the groups (OR = 2.08; 95% CI 0.21–20.55; p = 0.53).

Conclusion

Tissue sealant can reduce UCF events following hypospadias repair as well as edema and infection that increases the risk of UCF formation.

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Tissue sealant can reduce UCF events following hypospadias repair.

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Edema and infection increase the risk of UCF formation.

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Tissue sealant provides a watertight surgical anastomosis right after application.

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Tissue sealant can resist hydrostatic pressure of urine at the surgical suture line.

Looking beyond the dartos fascia and tunica vaginalis: reviewing the stance of common adjuvant covering biomaterials in hypospadiology

Hypospadias, one of the commonest congenital anomalies in boys, can have a spectrum of clinical presentation based on the location of the meatus and the presence of chordee. The surgical repair of hypospadias involves great precision, especially in proximal varieties and redo/complex cases of hypospadias. Hypospadiologists have put in tremendous efforts to improve the outcomes of these children. The utilization of adjuvant biomaterials is one such effort that has gained significant attention over the recent years. Biomaterials are used to cover the urethral suture line in instances where the ideal covering agents (dartos fascia and tunica vaginalis) are unavailable. We reviewed the mechanism of action, current stance, and advantages/disadvantages of three commonly used adjuvant agents, i.e. autologous platelet concentrates, tissue glues, and acellular dermal matrixes. Although individual studies have highlighted the therapeutic benefits of these adjuvants, the available literature has a limited level of evidence. Moreover, it is believed that the application procedure of these covering agents needs to be scrutinized in future studies. In addition, it is suggested that the application of any covering agent right up to the meatus is non-anatomical and redundant. Well-designed randomized controlled trials with a uniform application procedure and comparing different covering agents need to be conducted in the future before any definite conclusion is drawn.

Can sealing promote healing?: A systematic review and meta-analysis highlighting the adjunctive role of tissue sealant application during urethroplasty for hypospadias

BACKGROUND

A significant proportion of children require multiple surgeries for successful repair of hypospadias. This is not only a source of a financial burden to the family but also causes long-term social and psychosexual issues. Tissue sealant application can provide additional coverage to the suture line and subsequently prevents operative failure. However, a consensus statement regarding its usage during urethroplasty is lacking. This systematic review and meta-analysis aims to compare the outcomes of hypospadias surgery, in terms of its complications, in children with and without tissue sealant application.

METHOD

The authors systematically searched the databases PubMed, EMBASE, Web of Science and Scopus through September 2020. The occurrence of overall complications, and specific complications (including urethrocutaneous fistula, wound-related complications, flap-related complications, complications involving the neo-urethral tube and meatal stenosis) were the primary and secondary outcomes, respectively. Statistical analysis was performed using a random-effects model, and pooled risk ratio (RR) and heterogeneity (I²) were calculated. The methodological quality of the studies was assessed utilizing the Downs and Black scale.

RESULT

Four comparative studies were included in the meta-analysis. The different types of tissue sealants such as fibrin glue, cyanoacrylate glue, BioGlue and cryocalcium glue were used in these studies. As compared to without sealant application, hypospadias repair performed with sealant application showed no significant difference in the incidence of overall postoperative complications (RR 0.63; 95% CI 0.34-1.14, p = 0.13). However, a significant reduction in some specific complications including urethrocutaneous fistula (RR 0.37; 95% CI 0.19-0.72, p = 0.003), wound-related complications (RR 0.57; 95% CI 0.38-0.86, p = 0.008) and complications involving the neo-urethra (RR 0.15; 95% CI 0.04-0.54, p = 0.004) was observed with sealant usage. The average Downs and Black scale scores ranged from 16 to 18, with all studies having a moderate risk of bias. Kappa statistics showed a value of 0.962 (p < 0.001), highlighting an almost perfect agreement among the two observers.

CONCLUSION

The present meta-analysis revealed no additional benefit of the repair of hypospadias performed with tissue sealants as compared to without sealants in terms of reducing the overall postoperative complications. However, a significant reduction in the occurrence of some specific complications, including UCF, wound-related complications and complications involving the neourethra was observed with sealant application. The level of evidence of the published comparative studies is limited. Therefore, further studies need to be conducted for optimal comparison between the sealant and no sealant (or placebo), and different types of sealants.

Efficacy of fibrin sealant as waterproof cover in improving outcome in hypospadias surgery

BACKGROUND

This prospective comparative study aims to assess the efficacy of fibrin sealant to improve outcomes in paediatric patients operated for hypospadias.

MATERIALS AND METHODS

Forty consecutive patients with hypospadias were randomised into two groups of twenty patients each. The first group underwent hypospadias repair, technique depending on the type of hypospadias, whereas in the second group, fibrin sealant was used to reinforce the urethroplasty. Assessment was done with respect to the type of hypospadias, type of repair done, operative time, immediate post-operative complications (early ooze and skin flap-related complications), intermediate complications (urethra-cutaneous fistula) and delayed post-operative complications (penile torsion and poor cosmetic outcome) at follow-up. We also compared the overall improvement in outcome among the two groups.

RESULTS

First Group: The mean operative time was 1 h and 45 min. Complications were seen in nine patients: Early ooze (n = 2); skin flap-related complications (n = 3); fistula (n = 7); poor cosmetic outcome (n = 7) and penile torsion (n = 4). Second Group (Fibrin Sealant): The mean operative time was 1 h and 30 min. Post-operative complications were observed in five patients: Coronal fistula (n = 3) and poor cosmetic outcome (n = 3). On comparing, the differences in outcomes of ooze, skin flap-related complications and torsion were found to be statistically significant with P < 0.05. The differences in the urethra-cutaneous fistula and cosmetic appearance were not found to be statistically significant. The difference in overall improvement in complications was found to be statistically significant.

CONCLUSION

Fibrin sealant, when applied over the urethroplasty suture line as a waterproof cover, may help to improve the outcome in patients with hypospadias.

The histopathological effect of tissue adhesive on urethra wound healing process: An experimental animal study

INTRODUCTION AND OBJECTIVE

The present study aimed to determine the histopathological effect of Tisseel tissue adhesive on the urethral wound healing process after urethroplasty in a rat model.

STUDY DESIGN

A total of 24 animals were randomly allocated into three groups: Group 1; control group (n = 6); Group 2; suture-closure group (n = 9); and Group 3; suture + adhesive group (n = 9). In group 2, an incision 4 mm long was made on the ventral skin of the penis along the midline from the glans penis, to open the dartos muscle, corpus spongiosum, and urethra. Next, initially, the urethra alone, and then the layers up to the skin were covered in layers with 8/0 vicryl interrupted sutures. Group 3 underwent the same procedures as group 2, but after the urethra was repaired 0.1 cc of Tisseel tissue adhesive was applied over the urethra. Penile tissue samples were obtained 21 days later, and tissue samples were sent for histopathological analysis.

RESULTS

Urethral epithelial thickness and connective tissue thickness in group 3 were higher than in group 1 and group 2. Fibrosis in group 3 was higher than in group 2. The difference in inflammation between group 3 and group 2 was not significant. There was no significant difference in microvessel density between group 2 and group 3.

DISCUSSION

Both increased fibrosis and connective tissue thickness were noted in group 3 compared to group 2 and group 1. These increases may have been caused by the hemostatic effect of the Tisseel adhesive and its triggering of fibroblast growth factors. The epithelial thickness increased significantly in group 3 and group 2 compared to group 1. This increase in tissue thickness without an increased number of epithelial cells can be explained by the development of oedema.

CONCLUSION

The present study suggests that while Tisseel tissue adhesive increases connective tissue thickness and fibrosis, it does not demonstrate a prolonged inflammation or increased neovascularization in the urethral wound at 3 weeks after surgery. The data obtained in our study does not support the use of Tisseel in urethroplasty surgery. The results obtained in this study demonstrate a significantly higher formation of fibrosis (scar tissue), which underlines the importance of new studies to identify new treatments for urethral wound healing after urethra trauma or surgery.