Urological Complications in Kidney Transplant Recipients: Analysis of the Risk Factors and Impact on Transplant Outcomes in the Era of “Extended Criteria Donors”

Evaluation of the correlation between oral infections and systemic complications in kidney transplant patients: a retrospective pilot study

BACKGROUND

Data regarding the efficacy of the dental clearance required prior to kidney transplantation (KT) for preventing post-transplant complications is controversial. The aim of this retrospective study was to investigate a possible correlation between any untreated oral infectious foci and the onset of systemic complications in KT patients.

METHODS

Patients scheduled for regular check-ups during the post-transplant period were visited at the C.I.R. Dental School in Turin, Italy. Patients were asked to bring orthopantomography (OPT) acquired prior to transplantation to compare the possible presence of untreated infectious foci at the time of transplantation with the time of their post-transplant visit. Patients were then divided, according to the evaluation of the OPT obtained prior to the transplantation, into two groups according to their dental status prior to the transplant. "Group Infected" was comprised of patients with no dental clearance, and "Group Clear" included patients with dental clearance. The medical records were then retrospectively reviewed for the evaluation of any systemic complications that occurred after transplantation. The following medical complications were considered: fever, pneumonia, urinary tract infections, systemic infections, kidney rejection, and death. Complications were divided in two groups: early complications, which occurred within 100 days of transplantation, and late complications, which occurred more than 100 days after transplantation.

RESULTS

A total of 77 patients were enrolled in the study. Group Infected was composed of 19 subjects (25%), while Group Clear was composed of 58 patients (75%). In Group Infected, 13 (68%) patients developed complications within 100 days of transplantation, and 11 (58%) did so after 100 days. In Group Clear, 31 (53%) patients had complications within 100 days of the transplant, and 23 (40%) did after 100 days. Patients in Group Infected had a statistically significant increase in episodes of fever (p = 0.03), compared to Group Clear, with a higher relative risk (RR) of 3.66 in the first 100 days after transplantation.

CONCLUSION

Within the limitations of the present retrospective pilot study, and based on the results, a correlation between the absence of dental clearance prior to KT and a higher RR of developing a fever within the first 100 days post transplantation was highlighted. The present results encourage doctors to continue research on the topic, which remains controversial. Further prospective studies are required to confirm the results of the present study.

Transplant Ureteral Stenosis after Renal Transplantation: Risk Factor Analysis

INTRODUCTION

The results of kidney transplants have improved dramatically in recent years, leading to reduced morbidity and mortality. Despite continuous improvements, urological complications occur at a rate of 2.6%-15%. Ureteral stenosis of graft ureters is the most common complication, with a probability of 0.5%-6.3%. This study aimed to determine the incidence of ureteral stenosis after kidney transplantation and identify risk factors that distinguish transplant patients with and without ureteral stenosis.

METHODS

This study retrospectively analyzed patients who had undergone kidney transplantation at the Department of Urology of the Friedrich-Alexander University Erlangen-Nuremberg between 2001 and 2015. Forty-seven patients developed ureteral stenosis during the operation. Most of the ureteral stenosis cases occurred in the first 4 months after transplantation. Kaplan-Meier analysis and the log-rank test were used to calculate the cumulative risk, and the Mann-Whitney U test was used nonparametrically. The significance level was set at p < 0.05.

RESULTS

Statistical analysis showed that residual diuresis (p = 0.008), cold ischemia time (CIT) (p = 0.040), the body mass index (p = 0.027), and donor serum creatinine value (p = 0.039) showed a significantly different distribution between recipients with or without ureteral stenosis after kidney transplantation. In multivariate Cox's regression modeling, residual diuresis and the donor serum creatinine level were identified as the only independent predictors of patients' stenosis-free survival.

CONCLUSION

Urological complications not diagnosed and treated in time endanger the success of kidney transplantation. After evaluating the kidney transplantation data of the patients at the Transplant Center Erlangen-Nuremberg from 2001 to 2015, residual diuresis, CIT, the body mass index, and donor serum creatinine value were found to influence the development of ureteral stenosis.