Through the analysis of this extensive national database, encompassing data collected over a 10-year period, we can offer a broad picture on BPH surgery-related development of urethral strictures, including their management.
We identified 274,808 patients who underwent various BPH treatment modalities, including recently introduced ones. The observed rates of postoperative incidence of urethral strictures varied from 0.65–4.48% (Table 1). PAE, Rezum®, PUL and Aquablation® showed the lowest rates (0.65–1.59%) of US development. This finding could be explained by the reduced operative time and consequent reduced urethral manipulation usually required during MIST such as PUL, Rezum® and Aquablation®, as well as the absence of a potentially harmful energy source [27]–[29]. Similarly, since PAE may requires only the positioning of a urethral catheter as a reference point for the interventional radiologist [30], if not already present before, is it not surprising that this procedure is the one associated with the lowest rate of US (0.65%). An interesting observation is the lower US incidence rate in patients undergoing Lap/Rob SP (1.76%), compared to the 3.21% for those undergoing the open SP procedure. This disparity may be attributed to the laparoscopic system's advantages, which include superior visualization and precision during bladder neck reconstruction [31]–[33]. Such enhancements not only help in minimizing undue stress and traction from stitches on urethral tissues, but may also contribute to better bleeding control, ultimately leading to a shorter catheterization time [34], [35].
HoLEP/ThuLEP and PVP procedures are increasingly favored by urologists [16], [17], [36], [37]. They offer functional results comparable to traditional approaches and may reduce postoperative morbidity. However, our analysis indicates that these procedures have post-operative rates of urethral strictures that are similar to those following TURP (3.85–3.92% vs 4.48%). These data are consistent with the available literature reporting a rate of urethral strictures following TURP between 2.2 and 9.8% [18], and following HoLEP/ThuLEP and PVP between 1.2–7.3% [16], [17], [38].
The overall rate of post-operative strictures observed in our study (3.97%) aligns with the lower limits of ranges reported in literature [13], [39]. This evidence may be attributable to several factors. Firstly, a retrospective analysis might underestimate the actual incidence, especially if we consider patients with mild symptomatic strictures that did not seek evaluation or treatment, ultimately leading to a potential selective reporting of outcomes. This could be further affected by the variability in complication reporting across different healthcare settings, with some institutions possibly having more comprehensive follow-up and reporting protocols that identify more cases. In fact, it is not surprising that higher incidences come from prospective single center study designs [21]. Moreover, the advancements in established surgical techniques over the years, and the growing awareness of possible complications, might have contributed to their rates reduction.
Finally, it is important to acknowledge the possibility that some clinical entities reported as bladder neck contractures (BNC) may fall under the diagnosis of urethral stricture. These two conditions can cause similar urinary symptoms at presentation, and there is a possibility that the respective ICD codes could sometimes be erroneously used interchangeably [40], [41]. Despite this potential for diagnostic overlap, the likelihood of it affecting all groups we have analyzed is uniform, and the robust sample size at our disposal ensures the reliability of the incidence ranges we have observed.
Insightful observations also arise from our adjusted multivariable analysis (Table 3). This analysis confirms the incidence rates previously discussed, highlighting a statistically significant reduced risk of urethral stricture for some MISTs (being between 5% and 76% lower compared to TURP). The only procedure significantly associated with an increased risk of stricture, by 23%, is open SP.
Moreover, we observed that diabetes (1.07 [1.03–1.11], p < 0.001) and tobacco use (1.08 [1.05–1.12], p < 0.001) were statistically significant risk factors for the development of a urethral stricture. These results are consistent with what is known about the etiology of urethral stricture, which appears connected to impaired angiogenesis, excessive formation of fibrous tissue, and inflammation [42]. Interestingly, age was found to be a protective factor (0.98 [0.98–0.99], p < 0.001). This could be attributed to a tendency for reduced postoperative follow-up and diagnosis as age advances. Additionally, healing process in older individuals may vary compared to younger patients, potentially resulting in less aggressive scar formation.
We also examined the rates and treatment strategies employed among the different BPH procedures (Table 2 and Fig. 1). UD and DVIU were the most employed treatment in our cohort. Current literature shows wide and inconsistent ranges of patency rates after UD and DVIU, varying from 35.5–92.3% and 8–77% respectively [43]. Moreover, these procedures carry a well-known inherent risk of potentially worsening the stricture, thereby significantly increasing treatment failure and recurrence rate [19]. Only a minority of patients in our cohort (4.5%) underwent open urethral reconstruction. These data are of interest considering that urethroplasty has proven to be a durable and definitive treatment with lifetime success rates between 75–100% [44]. A possible explanation for this phenomenon is the concern about iatrogenic urinary incontinence. Because endoscopic BPH treatments disrupt the internal urethral sphincter, continence relies on the external sphincter muscle. Therefore, it is plausible that to preserve sphincter control, some urologists recommend repeated endoluminal treatments in place of open repair [19]. Moreover, such procedure is technically demanding and thus predominantly performed in specialized centers by dedicated surgeons [19], [45]. This expertise requirement is a further point that might explain why, despite its high success rates, urethroplasty was the least frequently performed intervention in our study population.
Nevertheless, it is essential to acknowledge the limitations of this retrospective study, particularly those associated with the PearlDiver™ Mariner database. ICD codes do not allow for differentiation between procedure types like monopolar versus bipolar TURP or HoLEP versus ThuLEP. Moreover, since it was not made for this purpose, the database does not provide specific clinical information that could further characterize the diagnosis of interest. Our reliance on diagnosis codes, without details on the anatomical location and length of the stricture, therefore, limits our capacity to draw definitive conclusions about urethral strictures treatment strategies.
The study provides valuable information on the United States population; however, these findings may not be generalizable to other countries with different medical practices and patient demographics.
Finally, it is crucial to recognize that while statistics of medical needs in public health are shaped by the system's regulatory framework, there may be a difference from the scientific reality [46]. However, if we are aware of the nature and limits of this kind of database, these data still provide a valuable representation of the medical practice's reality.