Lingual mucosal graft urethroplasty 12 years later: Systematic review and meta-analysis

Abstract

Objective: To evaluate the functional results and complications of the lingual mucosal graft (LMG) urethroplasty and to sum up the current state of the art of this surgical technique.

Methods: A systematic search of PubMed and Scopus electronic databases was performed, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies involving male patients treated with LMG urethroplasty for urethral stricture were included. Complete protocol is available at http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42017080121. A meta-analysis comparing functional and long-term oral complication outcomes of LMG and buccal mucosal graft (BMG) was performed, calculating the odds ratio (OR) and 95% confidence interval (CI).

Results: Twenty original articles were included in the qualitative analysis. Strictures of 1.5-16.5 cm have been treated with LMG urethroplasty, due to the improvement of harvesting technique and very low rate of long-term oral complications. Very good functional results have been reported by different authors for LMG urethroplasty, with lower rate of oral complications than BMG. The meta-analysis included six comparative studies involving 187 and 178 patients treated with LMG and BMG urethroplasty, respectively. An OR of 1.65 (95% CI [0.95-2.87], I ² = 0%) and 0.18 (95% CI [0.03-1.26], I ² = 68%) were found for LMG vs. BMG urethroplasty, in terms of success and oral complication rate, respectively.

Conclusion: LMG urethroplasty can be reasonably considered a first choice technique for urethral stricture with very good results. Oral complications are temporary and minimally disabling, basically less than those for BMG, and depend mainly on the graft extent.

Keywords: Lingual mucosal graft; Meta-analysis; Systematic review; Urethral stricture; Urethroplasty.

Figure 1

Flow of information through the different phases of the systematic review.

Figure 2

Fundamental steps of the surgical technique for LMG urethroplasty. (A) Patient is placed in lithotomy position under general anesthesia with naso-tracheal intubation. Urethra is probed with a catheter to detect the stricture. (B) The stenotic urethra is completely mobilized from the corpora cavernosa after a complete degloving of the penis (in case of long penile urethroplasty) or a perineoscrotal incision (in case of bulbar urethroplasty). The strictured tract is fully opened by a ventral midline incision and carefully measured. The urethral plate is longitudinally incised on the dorsal midline down to the corpora and the wings of the urethral plate are laterally mobilized. (C) LMG harvesting can be started during the latter part of the urethral mobilization or at the same time by two teams. A silicone bite block prop—mouth opener—is placed. (D) Direct traction is applied with two Babcock clamps to expose the ventrolateral surface of the tongue. A surgical pen is used to mark the required graft after identification of the opening of the Warton duct. (E) The graft edges are incised with a scalpel and a full-thickness mucosal graft is harvested using sharp scissors. Although a graft of 7–8 cm can be easily harvested from one half of the tongue, it should be at least 2 cm longer than the measured stricture length and 15–25 mm wide. Thus for long strictures the procedure can be repeated on the contralateral side. After the lingual mucosa is harvested, the wound is closed with interrupted polyglactin 4-0 sutures, without excessive tension. (F) Lingual mucosa is then prepared completely removing the underlying fibrovascular tissue. (G) The LMG is sutured and quilted on the bed of the dorsal urethral incision with tension free, interrupted, absorbable and at least 4-0 sutures, and an augmentation of the urethral plate is obtained. (H) The urethra is closed and tubularized over an indwelling 14Ch silicone catheter. A dartos fascial flap is obtained to cover the urethral suture. (I) The glans and penile skin are closed with interrupted 3-0 absorbable sutures. A Foley 14Ch silicone catheter should be left in place for at least 3 weeks. LMG, lingual mucosal graft.

Figure 3

Forest plot of OR (95% CI) for success rate (A) and long-term oral complications (B) of LMG (Experimental) vs. BMG (Control) urethroplasty. The center of each square represents the OR, the area of the square is the number of samples and thus the weight used in the meta-analysis and the horizontal line indicates the 95% CI. LMG, lingual mucosal graft; BMG, buccal mucosal graft; OR, odds ratio; CI, confidence interval.

Figure 4

Funnel plots for publication bias. (A) Six studies analyzing success rate of LMG vs. BMG urethroplasty; (B) Five studies analyzing long-term oral complication rate of LMG vs. BMG urethroplasty. LMG, lingual mucosal graft; BMG, buccal mucosal graft.