Discussion
Ureteral stent use is considered as an independent risk factor for BKV viruria, BKV viremia, and BKVN. In a study conducted on 1147 patients, a ureteral stent was used in 443 (38,6%) of the patients, and BKV was observed in 17,2% of these patients, on the other hand, this ratio was 13,5% in patients without stent (16). Moreno et al. (17) detected BKV in 11 patients (6%) in their study conducted on 184 patients. In this study, they explained the low BKV rates by the different ureteral stent techniques. At the same time in this study, ureteral anastomosis was performed using the modified Taguchi extravesical reimplantation technique and, the stent was externalized from the skin with a 6 F radiopaque infant nasogastric tube, and the stent was removed on the 5th day (17). Gupta et al. (18) evaluated 402 transplant kidney biopsies between 2013 and 2016, BKVN was detected in 6 (1,49) patients. They attributed the lower rate of BKVN than the literature to the low immunosuppression dose and the high match in transplants from live relative donors. In our study, BKV was observed in 13 (6,1%) patients, which is lower than the rates of BKV in the literature. Another remarkable inference in our study is that BKV was observed in 9 (8,1%) of 111 patients in which st-DJS was used and in 4% of the patients used ARD-DJS, although these rates are not statistically significant among themselves, they show that ureteral stenting technique and stent type may also have aclinical meaning. BKVN was observed in 3 patients in our study, one of these patients resulted in graft loss, and also diffuse deep vein thrombosis occurred in the same patient. This patient died due to diffuse pulmonary embolism during follow-up. Considering that acute venous thrombosis was observed in a patient diagnosed with BKVN in a case report published in 2015, it is important to pay attention to the relationship between BKVN and DVT despite case-level studies (19).
In our study, we also reached some results that we could not interpret, when we compared the final blood creatinine levels in both groups we revealed that the creatinine level was lower in the patients with ARD-DJS, additionally, although the patients with ARD-DJS had a much longer follow-up period, the number of graft loss was similar to the patients with st-DJS.
The limitations of this study were its retrospective nature, the absence of a control group without DJS, and the need for much higher patient numbers, although the number of patients increased than our previous study. However, to the best of our knowledge, there are not enough studies in the literature evaluating the relationship between ARD-DJS and BKV.
In our study, BKV was observed less in patients with ARD-DJS that were clinically significant but not statistically significant. Also, it was observed that the majority of patients with early developed BKV (first 3 months) were patients with st-DJS. Although close monitoring and reduction of immunosuppression prevent BKVN to a great extent, all arguments that can reduce the risk of BKV deserve to be investigated in detail. Therefore, prospective randomized studies with high patient numbers are needed to determine the effectiveness of ARD-DJS.
Disclosure of conflict of interest
None.