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.