Urethral strictures are a common problem in urology and can lead to significant morbidity. Various techniques, including urethral dilation, DVIU, and surgical reconstruction, are used in the treatment of urethral strictures, with surgical reconstruction generally providing superior long-term outcomes. Although skin flaps, bladder mucosa, and penile and preputial flaps have been used in urethroplasties, oral mucosal grafts remain the most commonly utilized material (10). Oral mucosal grafts can be harvested more easily than penile flaps and have a lower risk of morbidity. Additionally, they possess a thick epithelium with a thin lamina propria and a dense panlaminar vascular plexus, which facilitates early inosculation. Chapple et al., in their systematic review, reported that the success rates of augmentation urethroplasty varied between 43% and 100%, depending on the surgical technique used(15). The observed success rate of 74.5% in this study is consistent with previously published data and further supports the effectiveness of buccal mucosal graft urethroplasty.
There are various techniques used for BMG urethroplasty. In our cohort, all patients underwent the dorsolateral onlay graft technique due to its low complication rates and high success rate. The dorsolateral onlay technique involves unilateral urethral dissection, preserving the contralateral vascular supply, bulbospongiosus muscle, and its innervation, while a perineal incision minimizes chordee risk and offers a cosmetic advantage(16). Kartal et al., in their study comparing the dorsal onlay graft and dorsolateral onlay graft techniques, reported success rates of 70.3% and 87.1%, respectively. Furthermore, they noted lower complication rates with the dorsolateral onlay graft technique(11).
Although BMG urethroplasty generally yields high success rates, several factors may contribute to recurrence, including stricture location and length, etiology, whether the procedure is primary or a revision, and the patient’s overall health status(17). Among these, stricture length is the most frequently emphasized factor in the literature. Shalkamy et al. identified stricture length greater than 4.5 cm as a predictor of urethroplasty failure(18). Consistently, Kay et al. reported that strictures longer than 5 cm were associated with a significantly increased risk of recurrence (19). Our findings indicated that patients in the failure group had longer strictures than those in the successful group, in line with previous studies. Moreover, both univariate and multivariate analyses confirmed stricture length as an independent risk factor for recurrence following urethroplasty.
In this study, the recurrence rate was significantly higher among smokers compared to non-smokers. Both univariate and multivariate analyses identified smoking as an independent risk factor for BMG urethroplasty failure. This may be attributed to the adverse vascular effects of smoking, as well as the harmful impact of tobacco smoke on oral mucosal integrity and graft viability. Chronic tobacco exposure contributes to vascular and immune dysfunction in the oral mucosa by increasing prostaglandin synthesis and the number of Langerhans cells(20). A review on smoking in urologic reconstructive surgery suggested that smoking and poor oral hygiene may negatively affect surgical outcomes. It emphasized the importance of encouraging patients to quit tobacco use preoperatively(21). Furthermore, the urethroplasty failure prediction model developed by Barbagli et al. highlighted smoking, graft usage, and instrumentation-related strictures as significant predictors of long-term treatment failure(22).
In line with our findings, a recent systematic review and meta-analysis by Ma et al. also reported that smoking may increase the risk of stricture recurrence following urethroplasty(23). However, that study included a wide range of surgical techniques, graft types, and etiologies, with substantial methodological heterogeneity. Moreover, subgroup analysis specific to buccal mucosa graft urethroplasty was not performed, despite the potential impact of smoking on oral mucosal graft viability. In contrast, our study focused exclusively on patients undergoing single-stage dorsolateral onlay BMG urethroplasty performed by a single surgeon, providing a more homogeneous surgical cohort and controlled setting for evaluating risk factors.
On the other hand, Baradaran et al., in a multi-institutional study evaluating recurrence following anterior urethroplasty, reported that smoking was not a significant factor associated with urethroplasty failure(24). However, in this study, buccal mucosa graft urethroplasties accounted for less than 10% of the cohort, which may explain the discrepancy between their results and those observed in our study.
This study has several limitations that should be acknowledged. First, the sample size was relatively small, which may limit the statistical power to detect associations, particularly for variables with subtle effects. In addition, the etiological distribution observed in our cohort likely reflects the referral pattern of our tertiary center and may differ from large population-based series. However, all surgeries were performed by a single experienced surgeon using a standardized dorsolateral onlay technique, providing a homogeneous cohort that reduces inter-operator variability and enhances internal validity.
Second, although the follow-up duration was extended to an average of 15.8 months, longer-term data would be necessary to evaluate late recurrences and assess the durability of surgical success. Nevertheless, the majority of recurrences in urethroplasty tend to occur within the first postoperative year, and the follow-up duration in our study exceeds the minimum threshold used in many previously published series(2).
Third, the retrospective nature of the study may introduce potential selection bias and limit the granularity of some clinical variables such as smoking intensity, duration, and cessation timing. Future prospective studies incorporating detailed tobacco exposure history and objective oral mucosa assessments could provide further insights into the mechanism by which smoking influences graft-related outcomes.
Lastly, although our findings align with previous reports, the exclusive inclusion of patients undergoing BMG urethroplasty may limit the generalizability of the results. Nonetheless, this focused approach enhances the internal consistency of the study.
DISCUSSION
Urethral strictures are a common problem in urology and can lead to significant morbidity. Various techniques, including urethral dilation, DVIU, and surgical reconstruction, are used in the treatment of urethral strictures, with surgical reconstruction generally providing superior long-term outcomes. Although skin flaps, bladder mucosa, and penile and preputial flaps have been used in urethroplasties, oral mucosal grafts remain the most commonly utilized material (10). Oral mucosal grafts can be harvested more easily than penile flaps and have a lower risk of morbidity. Additionally, they possess a thick epithelium with a thin lamina propria and a dense panlaminar vascular plexus, which facilitates early inosculation. Chapple et al., in their systematic review, reported that the success rates of augmentation urethroplasty varied between 43% and 100%, depending on the surgical technique used(15). The observed success rate of 74.5% in this study is consistent with previously published data and further supports the effectiveness of buccal mucosal graft urethroplasty.
There are various techniques used for BMG urethroplasty. In our cohort, all patients underwent the dorsolateral onlay graft technique due to its low complication rates and high success rate. The dorsolateral onlay technique involves unilateral urethral dissection, preserving the contralateral vascular supply, bulbospongiosus muscle, and its innervation, while a perineal incision minimizes chordee risk and offers a cosmetic advantage(16). Kartal et al., in their study comparing the dorsal onlay graft and dorsolateral onlay graft techniques, reported success rates of 70.3% and 87.1%, respectively. Furthermore, they noted lower complication rates with the dorsolateral onlay graft technique(11).
Although BMG urethroplasty generally yields high success rates, several factors may contribute to recurrence, including stricture location and length, etiology, whether the procedure is primary or a revision, and the patient’s overall health status(17). Among these, stricture length is the most frequently emphasized factor in the literature. Shalkamy et al. identified stricture length greater than 4.5 cm as a predictor of urethroplasty failure(18). Consistently, Kay et al. reported that strictures longer than 5 cm were associated with a significantly increased risk of recurrence (19). Our findings indicated that patients in the failure group had longer strictures than those in the successful group, in line with previous studies. Moreover, both univariate and multivariate analyses confirmed stricture length as an independent risk factor for recurrence following urethroplasty.
In this study, the recurrence rate was significantly higher among smokers compared to non-smokers. Both univariate and multivariate analyses identified smoking as an independent risk factor for BMG urethroplasty failure. This may be attributed to the adverse vascular effects of smoking, as well as the harmful impact of tobacco smoke on oral mucosal integrity and graft viability. Chronic tobacco exposure contributes to vascular and immune dysfunction in the oral mucosa by increasing prostaglandin synthesis and the number of Langerhans cells(20). A review on smoking in urologic reconstructive surgery suggested that smoking and poor oral hygiene may negatively affect surgical outcomes. It emphasized the importance of encouraging patients to quit tobacco use preoperatively(21). Furthermore, the urethroplasty failure prediction model developed by Barbagli et al. highlighted smoking, graft usage, and instrumentation-related strictures as significant predictors of long-term treatment failure(22).
In line with our findings, a recent systematic review and meta-analysis by Ma et al. also reported that smoking may increase the risk of stricture recurrence following urethroplasty(23). However, that study included a wide range of surgical techniques, graft types, and etiologies, with substantial methodological heterogeneity. Moreover, subgroup analysis specific to buccal mucosa graft urethroplasty was not performed, despite the potential impact of smoking on oral mucosal graft viability. In contrast, our study focused exclusively on patients undergoing single-stage dorsolateral onlay BMG urethroplasty performed by a single surgeon, providing a more homogeneous surgical cohort and controlled setting for evaluating risk factors.
On the other hand, Baradaran et al., in a multi-institutional study evaluating recurrence following anterior urethroplasty, reported that smoking was not a significant factor associated with urethroplasty failure(24). However, in this study, buccal mucosa graft urethroplasties accounted for less than 10% of the cohort, which may explain the discrepancy between their results and those observed in our study.
This study has several limitations that should be acknowledged. First, the sample size was relatively small, which may limit the statistical power to detect associations, particularly for variables with subtle effects. In addition, the etiological distribution observed in our cohort likely reflects the referral pattern of our tertiary center and may differ from large population-based series. However, all surgeries were performed by a single experienced surgeon using a standardized dorsolateral onlay technique, providing a homogeneous cohort that reduces inter-operator variability and enhances internal validity.
Second, although the follow-up duration was extended to an average of 15.8 months, longer-term data would be necessary to evaluate late recurrences and assess the durability of surgical success. Nevertheless, the majority of recurrences in urethroplasty tend to occur within the first postoperative year, and the follow-up duration in our study exceeds the minimum threshold used in many previously published series(2).
Third, the retrospective nature of the study may introduce potential selection bias and limit the granularity of some clinical variables such as smoking intensity, duration, and cessation timing. Future prospective studies incorporating detailed tobacco exposure history and objective oral mucosa assessments could provide further insights into the mechanism by which smoking influences graft-related outcomes.
Lastly, although our findings align with previous reports, the exclusive inclusion of patients undergoing BMG urethroplasty may limit the generalizability of the results. Nonetheless, this focused approach enhances the internal consistency of the study.