Hypothesis / aims of study
Urethral stricture is one of the most common disorders encountered by urologists worldwide. Urethral stricture is an atypical narrowing of the urethral lumen. It is a subepithelial tissue scar of the corpus spongiosum that constricts the urethral lumen. The incidence of urethral stricture in India is unknown. However, it is considered to be approximately 10% of urological practice.
The two most common treatment options for urethral strictures are Direct Vision Internal Urethrotomy and urethroplasty. The Direct Vision Internal Urethrotomy is the preferred treatment for short bulbar strictures. Its long-term success rate varies from 9-30% among various series. Urethroplasty has higher success rates than Direct Vision Internal Urethrotomy. But due to its steep learning curve, longer operative times, bleeding, risk for erectile or ejaculatory dysfunction, wound infection, and incontinence, it is typically used for long and complex urethral strictures.
Many techniques have been developed to deliver the cellular graft to the stricture site endourethraly by using “live cultured buccal epithelial cell”, or “Buccal epithelium Expanded and Encapsulated in Scaffold‐Hybrid Approach”. In the liquid buccal mucosal graft endourethral urethroplasty (LBMGU) technique a minced buccal graft was suspended in a liquid aliquot and delivered under vision with an endoscope over a urinary catheter after DVIU in an animal model. Our technique, Minced buccal mucosal graft endourethral urethroplasty (MBGEU), is based on a similar principle, albeit in humans, for the first time. Minced buccal mucosal graft endourethral urethroplasty combines the advantages of buccal mucosal grafting with Direct Vision Internal Urethrotomy. The objective of this pilot study is to measure the success rate of Minced Buccal Mucosal Graft Endourethral Urethroplasty.
Study design, materials and methods
This was a Pilot Prospective Observational Study. This was IEC approved and CRTI registered(CTRI/2021/09/036651). Males with primary <2cm bulbar-urethral-strictures underwent Minced buccal mucosal graft endourethral urethroplasty.
A 1x1cm buccal-mucosal-graft was harvested, minced, centrifuged and suspended in fibrin glue. After a cold knife urethrotomy, 12-Fr foley was placed. An 11-Fr cystourethroscope was passed by the side of the catheter, and the minced graft suspension was instilled via a 5-Fr ureteric catheter over the urethrotomy site.
The primary outcome was the success rate at six months. The changes in American Urological Association (AUA) symptom score, peak flow rate (Qmax), and post-void residue (PVR) post-operatively at three and six months, were secondary outcomes. The Friedman test was used for statistical significance using SPSS software.
Results
Thirty men underwent Minced Buccal Mucosal Graft Endourethral Urethroplasty. The median stricture length was 1cm (IQR 1.0-1.5). The stricture recurred in two patients at postoperative 3 and 6 months respectively. The success rate of Minced Buccal Mucosal Graft Endourethral Urethroplasty was 93.33%. The median pre-operative AUA score was 18.00 (IQR 16.00-23.00) and the post-operative AUA score at three, six and 12 months were 3.00 (2.00-4.00), 2.00 (1.00-3.00) and 2.00 (1.00-2.00) (p<0.05). The median pre-operative Qmax (ml/sec) was 6.00 (IQR 5.00-8.00) and Qmax at post-operative three, six months and 12 months were 24.00 (20.00-27.00), 22.00 (20.00 -25.00) and 23.00 (20.00-28.00) (p<0.05) respectively. The median pre-operative PVR (ml) was 88.00(IQR 66.25-150.50) and PVR at post-operative three, six and 12 months were 16.00(IQR 10.75-39.00), 15.00(IQR 9.70-22.25) and 15.50(IQR 10.700-22.00) (p<0.05) respectively.
Interpretation of results
This Prospective study showed a high success rate of 93.33% at six months. The median stricture length was 1cm, and two patients experienced recurrence at 3 and 6 months postoperatively. There were significant improvements in the American Urological Association (AUA) symptom score, peak flow rate (Qmax), and post-void residue (PVR) at 3, 6, and 12 months postoperatively compared to preoperative values. These improvements indicate the efficacy of MBGEU in relieving symptoms and improving urinary flow and bladder emptying..