Evaluation of factors affecting the success of subureteric injection treatment in patients with vesicoureteral reflux undergoing renal transplantation

Kidney transplantation is the gold standard treatment that enhances survival and quality of life for patients with end-stage renal failure. Vesicoureteral reflux (VUR), one of the most common urological complications following renal transplantation, can be defined as the backflow of urine from the bladder to the ureter or, in advanced cases, to the renal collecting system. Endoscopic subureteric substance injection, which is used for the treatment of reflux in renal transplant patients, stands out as a primary approach in surgical treatment due to its procedural ease and low complication rates. In the literature, the success rates of endoscopic subureteric injection treatment vary widely. This point indicates the importance of accurate patient selection. This study aimed at evaluating the factors affecting the success of the procedure, thereby increasing success rates through proper preoperative patient selection, reducing unnecessary procedures, time and cost, and ensuring the implementation of the most suitable treatment approach for the patient. A total of 116 patients with reflux into the transplanted kidney were included in the study. The impact of factors such as age, sex, time elapsed from transplantation to reflux treatment, bladder wall thickness, reflux grade, ureteral diameter ratio (UDR), suitability of transplant orifice for injection, monitoring of post-injection mound appearance, and the amount of injected agent on the clinical or radiological success of endoscopic injection at the 6-month post-treatment mark was examined. The success of injection treatment at the 6-month mark was determined to be 41.4%. According to the statistical analysis, it was observed that as patient age decreased, the success of the injection decreased (p=0.025). An increase in bladder wall thickness was found to be associated with a decrease in success (p=0.018). While no significant relationship was observed between preoperative reflux grade and success (p=0.109), a significant decrease in success was observed with an increase in UDR (P<0.001). No significant relationship was observed between the injected volume of bulking agent and success (p=0.222). A strong significant relationship was found between the suitability of the transplant orifice for injection and post-injection mound appearance with success (p<0.001). The strong relationship between UDR and the success of injection therapy could potentially make this ratio an alternative to the existing reflux grading system. Intraoperative surgical observation can also predict treatment success. By using these results and conducting future comprehensive prospective studies, it may be possible to offer patients the most suitable treatment option.