Lingual versus buccal mucosal graft for augmentation urethroplasty: a meta-analysis of surgical outcomes and patient-reported donor site morbidity

Ventral onlay graft urethroplasty using bladder mucosa in a cat with a urethral stricture

A 3-year-old, 4.0 kg, intact male domestic shorthair cat presented with postoperative dysuria following urethral resection and anastomosis for urethral rupture. Retrograde urethrography revealed a stricture in the pelvic urethra. Urethroplasty with bladder mucosa was performed following a bilateral pubic-ischial osteotomy. The bladder wall was resected to harvest an appropriately sized bladder mucosa graft. The graft was placed over the urethral defect in patch fashion and stabilized with interrupted sutures. The cat was able to urinate normally with no evidence of lower urinary tract signs 2 year postoperatively. Therefore, urethroplasty with an onlay bladder mucosa graft may be a feasible alternative to prepubic or subpubic urethrostomy for the treatment of pelvic urethral stricture in cats.

Histological Comparison of Buccal and Lingual Mucosa Grafts for Urethroplasty: Do They Share Tissue Structures and Vascular Supply?

Comparable outcomes were published using a buccal mucosa graft (BMG) from the cheek and a lingual mucosa graft (LMG) from the sublingual area, for urethral augmentation or substitution. To date, no histological comparison between both grafts has been conducted. We histologically assessed BMG and LMG harvested during urethral surgeries, aiming to compare graft properties and vascular support. We conducted a prospective single cohort study, including oral mucosa urethroplasty patients. During surgery, graft dimensions and donor sites were collected, and a 0.5 × 0.5 cm sample was obtained from the prepared graft. Formalin-fixed paraffin-embedded samples were sliced at 4 micrometres (µm) and hematoxylin-eosin stained. Using a telepathology tool, all slides were digitalized and measured from 10× to 40× magnification. In each graft, global and individual layers thicknesses were assessed, including vascular density and area. Descriptive and comparative (parametrical and non-parametrical) statistical analysis occurred. We collected 57 grafts during 33 urethroplasties, with 30 BMG and 22 LMG, finally, included. The mean age was 56.6 (SD 15.2) years, and the mean graft length was 5.8 (SD 1.7) cm and the width was 1.7 (SD 0.4) cm. The median graft thickness was 1598.9 (IQR 1200–2100) µm, the mean epithelium layer was 510.2 (SD 223.7) µm, the median submucosa was 654 (IQR 378–943) µm. the median muscular was 477.6 (IQR 286–772) µm, the median vascular area was 5% (IQR 5–10), and the median adipose tissue area was 5% (IQR 0–20). LMG were significantly longer and narrower than BMG. Total graft thickness was similar between LMG and BMG, but the epithelium and submucosa layers were significantly thinner in LMG. The muscular layer was significantly thicker in LMG. Vascular density and vascular areas were not significantly different between both types of grafts. LMG showed significantly less adipose tissue compared with BMG. Our findings show LMG and BMG for urethroplasty surgeries share the same thickness and blood supply, despite having significantly different graft sizes as well as mucosal and submucosal layers thickness.

Dorsal Onlay Oral Mucosa Graft Urethroplasty for Female Urethral Stricture

OBJECTIVE

To describe and assess the outcomes of dorsal onlay oral mucosa graft urethroplasty for female urethral stricture.

METHODS

We retrospectively reviewed the charts of all female patients who underwent dorsal onlay oral (buccal or lingual) mucosa urethroplasty for urethral stricture between 2011 and 2020 at two academic institutions. The primary endpoint was clinical success defined as any subjective improvement in LUTS self-assessed by the patients 1-3 months after catheter removal. Four surgeons performed the urethroplasties using a standardized technique: suprameatal incision, dissection and longitudinal opening of the dorsal aspect of the urethra, harvest of the oral mucosa graft, graft onlay sutured into the urethral opening.

RESULTS

Nineteen patients were included. The clinical success rate was 94.7% at 1-3 months and 90.9% at 1 year. After a median follow-up of 12 months (range 1-49) there was one recurrence (5.3%), clinical success was achieved in 17 patients (89.5%) and both the maximum urinary flow rate and post void residual were significantly improved (15.2 vs 7.4 ml/s preoperatively; P = .008 and 71.5 vs 161.1 ml preoperatively; P = .001 respectively). The de novo stress urinary incontinence rate was 15.7% at 1-3 months and 9.1% at 1 year.

CONCLUSION

Dorsal onlay oral mucosa graft urethroplasty for female urethral stricture appears feasible across multiple surgeons and is associated with a low perioperative morbidity, satisfactory functional outcomes and a low recurrence rate. Other series with larger sample size and longer follow-up are needed to confirm these findings.

Multi-Factorial Analysis of Recurrence and Complications of Lingual Mucosa Graft Urethroplasty for Anterior Urethral Stricture: Experience from a Chinese Referral Center

OBJECTIVE

To evaluate the risk factors that pertain to stricture recurrence and oral complications.

METHODS

Patients with long segmented anterior urethral stricture who visited our hospital from 2009 to 2016 were treated with lingual mucosa graft (LMG) urethroplasty. The incidence of complications in all of 128 patients were evaluated. The data were analyzed using the chi-squared test and Fisher's exact test. A multi-factorial regression analysis was performed to identify the risk factors responsible for the recurrence and complications.

RESULTS

For patients having LMG urethroplasty, there were no significant difference in recurrence of urethral stricture according to the studied variables. Binary logistic regression analysis reveals that previous surgery involving the urethra was a significant predictor of urethral stricture recurrence (odds ratio [OR]=5.07; 95% confidence interval [95% CI], 1.06-24.40; P = .043). The length of the substitute was significantly related to oral morbidity (P = .020), even after controlling for the studied variables. Patients with a harvested oral mucosa longer than 7 cm had a higher risk of oral morbidity than those with a harvested oral mucosa shorter than 7 cm (OR=4.35; 95% CI, 1.35-14.06; P = .014).

CONCLUSION

Our study shows that LMG urethroplasty is effective for patients with long segmented anterior urethral stricture. Previous urethral surgery was identified as a risk factor to cause recurrence and injury to the tip of the tongue for the oral complications.