Expanded PTFE bladder neck slings for incontinence in children: the long-term outcome

What makes the bladder neck sling procedure a success in a selected population of children and adolescents? A STROBE-compliant investigation

INTRODUCTION

Achievement of continence in children suffering from neurogenic bladder dysfunction or severe urogenital malformation is of fundamental importance to the wellbeing of affected children and their families. A valid approach to treating incontinence with hypoactive sphincter is the placement of a bladder neck sling thus increasing outlet resistance of the bladder.

OBJECTIVES

In this retrospective study in children and adolescents, we aimed to assess the outcome of bladder neck sling procedures conducted at our institution. In addition, we aimed to identify predictors of the successful correction of incontinence.

PATIENTS AND METHODS

We treated 36 patients (25 girls, 11 boys, aged 5.0-19.7 years). In total, 32 (88.9%) patients suffered from neurogenic incontinence. Overall, 16 patients had previously received unsuccessful injection of bulking agent into the bladder neck. For the bladder neck sling, we used a fascial strip of rectus abdominis muscle (n = 29), detrusor muscle (n = 6), or combined fascial and detrusor strip (n = 1). In 8 (22.2%) patients, the surgical procedure involved wrapping the strip around the bladder neck, while in 6 (16.7%) patients, the bladder neck was suspended with the sling. In 22 (61.1%) patients, the two techniques were combined. Overall, 22 (61.1%) and 9 (25.0%) patients additionally underwent enterocystoplasty or detrusorotomy, respectively. We assessed urinary continence of our patients after 3-6 months (first evaluation) and ≥12 months (final evaluation). We classified the state of continence as 'dry' (dry for >3 h between catheterizations and dry at night), 'significantly improved' (minimal incontinence, no more than one protective pad per day, interval of at least 3 h between catheterizations, dry at night, and no demand for additional treatment), or 'wet'. Bladder neck sling treatment was considered successful if the patient was rated as 'dry' or 'significantly improved'.

RESULTS

At the first evaluation, the bladder neck sling procedure proved successful in 19 (52.8%) patients. Enterocystoplasty significantly increased the success rate compared to detrusorotomy or no bladder augmentation (68.1% vs. 28.6%; p = 0.04). The remaining 17 patients who were still classified as wet after bladder neck sling placement subsequently underwent one or more additional interventions, i.e. implant injection (n = 11), bladder augmentation (n = 10), and/or sling replacement (n = 5). At the final evaluation after a median follow-up of 64.5 months (range, 12-181 months), continence without sling replacement was achieved in 29 (80.6%) of the 36 patients.

CONCLUSION

In our study population, bladder neck sling placement achieved good results in the treatment of severe organic urinary incontinence with hypoactive sphincter. To optimize treatment outcome, bladder neck sling placement should be combined with enterocystoplasty.

Adhesion of fibroblast cells on thin films representing surfaces of polymeric scaffolds of human urethra rationalized by molecular models of integrin binding: cell adhesion on polymeric scaffolds for regenerative medicine

This work combines experimental and computational study of Balb/3T3 clone A31 mouse embryo fibroblasts cell line adhesion and proliferation on fourteen different polymeric surfaces prepared from poly(dioxanone) (PDO), poly(glycolic acid) (PGA), poly(hydroxybutyrate) (PHB), and poly(L-lactic acid) (PLA), and their 1:1 mixtures. The study was done with the aim to explore the attractive interactions between various synthetic biomaterials and simple model of the cell attachment mechanism involving the trans-membrane protein integrin. The considered polymeric biodegradable biomaterials can be used as scaffolds for tissue engineering and regenerative urology. During the growth of new tissue, the polymer scaffold is replaced by the extracellular matrix (ECM) synthetized by the proliferating cells. The adhesion and proliferation experiments were done on thin polymer films produced by solvent casting. The computational approach used 3D molecular models of two layers of ordered parallel polymeric fibres, which formed quasi-planar nanosized models of the scaffold surface. Experimental data showed that PGA based polymer films promote the cell adhesion. Cell proliferation testing, performed by incubating the fibroblast cells with the studied polymer films, disclosed that PLA, PHB/PLA and PHB/PGA systems are able to support proliferation of Balb/3T3 clone A31 cells equal to the plain glass. Relative interaction energies between 3D models of polymeric films and the α₂ I domain of the cell adhesion receptor integrin α₂β₁ computed by molecular mechanics suggest that plain polymers PGA, PDO and mixtures PDO/PGA, PHB/PGA, and especially PGA/PLA display elevated affinity to the cell-attachment protein, which confirms the experimental observations. The combination of experimental and modelling approach can assist rational design of synthetic polymeric biomaterial for scaffolds of artificial human urethra that can be efficiently colonized by cells.

Silk Fibroin Scaffolds for Urologic Tissue Engineering

Urologic tissue engineering efforts have been largely focused on bladder and urethral defect repair. The current surgical gold standard for treatment of poorly compliant pathological bladders and severe urethral stricture disease is enterocystoplasty and onlay urethroplasty with autologous tissue, respectively. The complications associated with autologous tissue use and harvesting have led to efforts to develop tissue-engineered alternatives. Natural and synthetic materials have been used with varying degrees of success, but none has proved consistently reliable for urologic tissue defect repair in humans. Silk fibroin (SF) scaffolds have been tested in bladder and urethral repair because of their favorable biomechanical properties including structural strength, elasticity, biodegradability, and biocompatibility. SF scaffolds have been used in multiple animal models and have demonstrated robust regeneration of smooth muscle and urothelium. The pre-clinical data involving SF scaffolds in urologic defect repair are encouraging and suggest that they hold potential for future clinical use.

Sling suspension of the bladder neck for pediatric urinary incontinence

OBJECTIVE

Surgery for urinary incontinence in childhood is in the process of an ongoing search for better results because a procedure that guarantees dryness still does not exist. This study has been conducted to assess the overall results of the fascia sling procedure for incontinence in children.

MATERIAL AND METHODS

Eighty-nine patients with neurogenic lower urinary tract dysfunction and follow-up of more than 2 years have been included in the study (46 boys and 43 girls aged 2-17 years). All patients underwent U-type sling suspension of the bladder neck. In 59 patients detrusorectomy and in 11 patients bladder augmentation was performed. Sphincter incompetence was defined as low-pressure (<30 cm H(2)O) leakage observed during urodynamic studies. The results of surgery were assessed clinically (dryness intervals).

RESULTS

Forty-two (47%) patients were completely dry, and 23 (26%) considerably improved. The success rate was higher in males (35) than in females (30) (76% vs 70%). Detrusorectomy did not improve the success rate of the sling procedure (68% vs 79% sling only), but bladder augmentation did (90%). Higher success rates have been observed in adolescents compared to prepubertal children (83% vs 56%). No serious complications were observed.

CONCLUSIONS

Rectus fascia sling suspension is a safe procedure and could be considered a good option for the treatment of neurogenic sphincter incompetence in children.

Bladder neck pubovaginal slings

Over the past 30 years, the pubovaginal sling has surpassed retropubic and transvaginal suspensions as the most common surgical operation for correcting stress urinary incontinence. This resurgence has been due in part to innovative technological advances that have shortened operative times and expedited postoperative recovery. The introduction of novel allografts, xenografts and synthetic materials has also been accompanied by unique complications, previously not encountered with autologous materials. The aim of this review is to compare the available sling materials in the context of biocompatibility and efficacy.

The continent bladder: indications and techniques for the continent catheterizable segment

PURPOSE OF REVIEW

Continent catheterizable segments are a substantial part of the urologist's armamentarium for providing bladder drainage. It is used for a myriad of indications, and there are multiple techniques currently used for its formation. Despite refinements in these techniques significant complications still occur, and there is continued advancement and ongoing investigation. This review examines the current status of the continent catheterizable segment with regard to indications for its use, techniques in its formation, discussion of complications, and ongoing and future directions in research.

RECENT FINDINGS

The continent catheterizable segment is indicated when it is not feasible to use the urethra for evacuation (e.g. bladder exstrophy, neurogenic bladder, radiation injury, and marked urethral dysfunction) or to facilitate catheterization. Compliance with catheterization and irrigation regimens is essential in patient selection. Multiple methods exist for its formation, either with or without the need for bladder augmentation. Although Mitrofanoff techniques with multiple applications predominate, "hemi" augments with efferent limbs also play a significant role. Stoma placement should be performed to best facilitate catheterization. Complications relating to catheterizable segments mainly pertain to continence, stenosis, and ability to catheterize, with more significant morbidity relating to the bladder augmentation. Ongoing research to develop more physiologic tissue substitutes and less invasive techniques may hopefully be superseded by prevention of the underlying lower urinary tract pathology.

SUMMARY

Catheterizable segments allow the patient to control bladder evacuation, and continue to be refined by ongoing investigations in terms of indication and technique, with attendent decreasing morbidity.