Unrecognized bladder perforation with mid‐urethral slings

Study Type – Therapy (case series)
Level of Evidence 4

OBJECTIVE

To present a series of women with late presentation of mid‐urethral synthetic slings perforating the bladder and their management, this is rare but can lead to significant morbidity with medico‐legal consequences.

PATIENTS AND METHODS

We retrospectively reviewed the case notes of nine women with urinary symptoms referred to our unit for further investigation after synthetic mid‐urethral sling placement.

RESULTS

The women presented between 8 weeks and 18 months after initial sling placement. Eight patients underwent a tension‐free vaginal tape insertion via the retropubic route and one patient had an ‘outside‐in’ obturator sling with the I‐Stop device (CL Medical, Lyon, France). The frequencies of presenting symptoms were: dysuria in six; recurrent urinary tract infection in four; frequency and urgency in four and pelvic pain in two. Seven of the nine women developed bladder calculi on the exposed sling material, all of which were visible on plain X‐ray. In six women, perforations were present at more than one site; in three urethral perforation had occurred together with an anterolateral bladder injury and in the remaining three there was bilateral bladder perforation. Initial management included cystoscopy and cystolithopaxy followed by transurethral resection (TUR) of the visible prolene mesh into the detrusor muscle. One woman required two TURs to clear all the mesh. Two women required further open surgery to remove all of the remaining mesh, both for ongoing pelvic pain that resolved after revision surgery. All the women had resolution of symptoms but all had recurrent stress urinary incontinence after tape division/excision. We used a novel technique to remove intraurethral mesh using a nasal speculum urethrally and excising the tape under direct vision, where resection proved impossible due to poor endoscopic views, with significant risk of sphincter injury.

CONCLUSIONS

The possibility of unrecognized tape perforation or erosion must be considered in women with persistent urinary symptoms, infection or pain after any form of mid‐urethral sling procedure. Bladder stones almost invariably develop if the exposed mesh has been present for >3 months. Most patients can be managed with endoscopic resection to remove all intravesical tape. Cystoscopy should remain a mandatory procedure together with any form of mid‐urethral sling placement but does not prevent unrecognized perforations in inexperienced hands.     

Autologous bone‐marrow‐derived mesenchymal stem cell transplantation into injured rat urethral sphincter

Objectives: To evaluate the functional and histological recovery by autologous bone‐marrow‐derived mesenchymal stem cell (BMSC) transplantation into injured rat urethral sphincters. Methods: BMSC were harvested from female Sprague–Dawley retired breeder rats for later transplantation. The cells were cultured, and transfected with the green fluorescence protein gene. The urethral sphincters were injured by combined urethrolysis and cardiotoxin injection. One week after injury, the cultured BMSC were injected autologously into the periurethral tissues. Controls included sham‐operated rats and injured rats injected with cell‐free medium (CFM). Abdominal leak point pressures (LPP) were measured before and after surgery during the following 13 weeks. The urethras were then retrieved for histological evaluation. The presence of green‐fluorescence‐protein‐labeled cells and the regeneration of skeletal muscles, smooth muscles, and peripheral nerves were evaluated by immunohistochemical staining. Results: LPP was significantly reduced in the injured rats. It increased gradually after transplantation, but there was no significant difference between the BMSC and CFM groups. In the BMSC group, transplanted cells survived and differentiated into striated muscle cells and peripheral nerve cells. The proportions of skeletal muscle cells and peripheral nerves in the urethra were significantly greater in the BMSC group compared to the CFM group. Conclusions: Despite a clear trend towards recovery of LPP in BMSC‐transplanted urethras, no significant effect was detected. Further study is required for clinical applications for the treatment of stress urinary incontinence.     

Biodegradable urethral stents seeded with autologous urethral epithelial cells in the treatment of post‐traumatic urethral stricture: a feasibility study in a rabbit model

OBJECTIVE

To evaluate the adhesion and growth of rabbit urethral epithelial cells (UECs) on a biodegradable unbraided mesh urethral stent, and to assess the feasibility and effect of the cell‐seeded urethral stent for treating post‐traumatic urethral stricture (PTUS) in a rabbit model.

MATERIALS AND METHODS

Rabbit UECs were collected by biopsy from adult rabbit urethra and seeded onto the outer layer of a mesh biodegradable urethral stent. The growth of UECs in cell‐scaffolds was assessed by scanning electron microscopy, immunohistochemical and fluorescence staining. In all, 32 male New Zealand rabbits were used, with either PTUS or uninjured, as a control group. Cell‐seeded stents were implanted into the rabbits strictured urethra. The histological and immunohistochemical findings were assessed after death at 1, 2, 8, 12 and 24 weeks, respectively. The reconstruction and function were evaluated by urethroscopy and retrograde urethrography.

RESULTS

The cultured UECs adhered to the stent and grew well. Immunohistochemistry showed that the cells were stained positively for cytokeratin. At 4 weeks, vs 2 weeks, the thickness of the papillary projections of the epithelium decreased and inflammatory cell infiltration diminished. At 24 weeks the injured urethra was completely covered by integrated regeneration of three to five layers of urothelium. There was no evidence of voiding difficulty, stricture recurrence or other complications.

CONCLUSIONS

The unbraided mesh biodegradable urethral stent with autologous UECs seemed to be feasible for treating PTUS in the rabbit urethra, and provides a hopeful avenue for clinical application allowing reconstruction of PTUS.     

Management of iatrogenic recto‐urethral fistula by transanal rectal flap advancement

Aim Recto‐urethral fistulas are an uncommon, but devastating complication following rectal or urinary tract surgery. Repair is often difficult, and the optimal approach is unclear. We report our recent experience using an endorectal advancement flap. Method A case note review of all patients undergoing repair of recto‐urethral fistula in our institution was undertaken. Data on aetiology of the fistula, patient demographics, operative procedure and outcome both clinically and radiologically were extracted. Results Between 2002 and 2008, six transanal rectal advancement flaps in five patients were carried out. Four had undergone a laparoscopic radical prostatectomy, without any radiotherapy. Two types of fistula (type 1 associated with severe intra‐abdominal sepsis and type 2 associated with localized sepsis) were found, with faecal diversion being less likely with the latter. Four (80%) patients underwent successful primary repair, with one patient requiring a second procedure. Postoperative cystography confirmed closure of the fistula in all five patients, and no recurrence has been observed at a mean follow‐up time of 11 months. Conclusion Rectal advancement flap is a simple, effective technique for iatrogenic recto‐urethral fistula with minimal morbidity.