Impact à long terme des complications chirurgicales sur la survie du transplant rénal

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

Urological complications (UC) following kidney transplantation (KT) are associated with increased morbidity. The aim of this study is to evaluate the risk factors for UC in the era of “extended criteria donors” (ECD) and their impact on patient and graft survivals. A retrospective monocentric study of all patients undergoing KT from 2010 to 2019 with a follow-up ≥30 days was performed. Out of 459 patients (males: 296 (64.5%); age: 57 (19–77) years) enrolled, 228 (49.7%) received ECD organs, moreover, 166 (67.2%) grafts had a cold ischemia time ≥10 h. UCs were reported in 32 (7%) patients. In 21 (65.6%) cases UC occurred within 3 months post-KT and 24 (5.2%) were associated with early urinary tract infection (UTI). The overall 5 year patient and graft survival rates were 96.5% and 90.6%, respectively. UC decreased graft survival (UC-group: 75.0% vs. noUC-group: 91.8%, p < 0.001), especially if associated with early UTI (UC-group: 71.4% vs. noUC-group: 77.8%, p < 0.001). At multivariate analysis, early UTI after KT (OR: 9.975, 95%-IC: 2.934–33.909, p < 0.001) and delayed graft function (DGF) (OR: 3.844, 95%-IC: 1.328–11.131, p: 0.013) were significant risk factors for UC, while ECD graft did not increase the risk of post-transplant UC. ECD grafts are not associated with UC. DGF and early UTI post-KT increase the risks of UC and reduce graft survival in the long-term. Therefore, aggressive management of early post-transplant UTI and strategies to reduce DGF incidence, such as machine preservation, are essential to prevent UC after KT.

Recipient and renal allograft survival following living related-donor transplantation: a single center experience

Background

Despite improvements in surgical techniques of renal transplantation, still surgical complications remain a big challenge that might affect the post-transplant recipient and graft outcome. The aim of the current study was to retrospectively assess the surgical complications following living related kidney transplants in our center from 1990 to 2012 and determine their impact on long term recipient and graft survival.

Methods

We conducted a retrospective study of all live related-donor kidney transplants performed at our tertiary referral center between June 1990 and December 2012. Data regarding recipient demographics, details of surgical techniques, any reported complications and cumulative recipient and graft survival was analyzed.

Results

One hundred and four patients were included in the study whom we had access to their complete hospital records and they didn’t miss follow up. There were 41 surgical complications reported in 37 recipients, prevalence of 35.5%. Vascular and urologic complications were reported in 17(16.3%) and 11 (10.5%) recipients respectively. Lymphocele was post-operatively diagnosed in nine (8.7%) recipients. Recipient survival at 1 year and 5-year were 100% and 97% respectively. Graft survival at 1 year and at 5 years were 96% and 85.5% respectively. Surgical complications mentioned, other than renal artery thrombosis, had no statistically significant impact on the graft and recipient survival.

Conclusion

Although surgical complications post-transplantation are not rare, the resulting morbidity can be minimized by prompt management of complications. In general, the existence of surgical complications did not impact recipient or graft survival.

[Results of surgical revisions for ureteral complications after renal transplantation]

OBJECTIVE

To analyze the results of surgical revision for ureteral complication (ureteric stenosis or urinary leakage) after renal transplantation over a period of 10 years.

MATERIALS AND METHODS

We performed a retrospective study on 1313 consecutive kidney transplantations carried out in a University Hospital Center between 2005 and 2014. The data of the patients who developed a ureteral stenosis or a urinary leakage secondary to a renal transplantation were analyzed. Combined organ transplantations (kidney-liver and kidney-pancreas), as well as pediatric transplantations were excluded.

RESULTS

Seventy-six patients (5.8%) had ureteric stenosis or urinary leakage after renal transplantation. Forty-six patients (3.5%) underwent surgical revision: 27 for ureteral stenosis, 19 for urinary leakage. Early success was achieved in 26 patients (56.5%), including 14 ureteric stenosis (51.9%) and 12 urinary leakage (63.2%) (P=0.45). After a complementary endoscopic or surgical treatment, the final success rate was increased to 73.1% (34 patients): 20 ureteric stenosis (74.1%) and 14 urinary leakage (73.7%) (P=0.98). There were 2 graft losses (4.3%) and one death (2.2%). The mean glomerular filtration rate estimated by the MDRD was 44.58mL/min/1.73m² (±14.7) before surgery and 45.37mL/min/1.73m² (±16.5) 6 months after surgery (P=0.92).

CONCLUSION

Although frequently challenging, surgical revisions for ureteral complications after renal transplantation give good results, with a low rate of graft loss and mortality.

LEVEL OF EVIDENCE

4.

Tubular Ectasia in Renal Allograft Biopsy: Associations With Occult Obstructive Urological Complications

BACKGROUND

Urological obstructive complications (UOC) affect up to 15% of kidney transplants (KTX). Most cases are excluded by ultrasonography (US); however, accuracy may be limited in the early transplant phase. Features of acute tubular injury (ATI) in KTX biopsy may be informative but histological features indicating UOC are ill defined. Tubular ectasia (TE) was shown to be associated with UOC in experimental data. We evaluated the association of histomorphological features, particularly TE, with occult (=without relevant hydronephrosis in US) UOC and renal outcomes.

METHODS

We included all recipients with an early indication biopsy (976 of 1537 consecutive KTX). The biopsy finding of TE classified as "suspicious of UOC" was compared with the following endpoints: delayed graft function, estimated glomerular filtration rate, and occult UOC. Additionally, histopathological features of ATI were reevaluated by a single pathologist to increase diagnostic accuracy.

RESULTS

Fifty-eight (5.9%) patients presented with TE, which was not related to delayed graft function or estimated glomerular filtration rate. Forty percent of patients had a UOC (most frequently ureteral stenosis) close to biopsy. Comparing these biopsies to matched controls, TE was significantly associated with UOC (odds ratio 2.69; P = 0.018). After histopathological reevaluation of these biopsies including additional features of ATI, we developed a final multivariate model with a highly significant relationship to UOC (Receiver operating characteristic-area under the curve: 0.77; P = 0.001). The model provides a specificity of 78% and negative predictive value of 73%.

CONCLUSIONS

TE together with additional signs of ATI indicates occult UOC. This histological phenotype should trigger more detailed evaluation for UOC when there is no evidence of relevant hydronephrosis in the ultrasonography.

Risk Balancing of Cold Ischemic Time against Night Shift Surgery Possibly Reduces Rates of Reoperation and Perioperative Graft Loss

Background. This retrospective cohort study evaluates the advantages of risk balancing between prolonged cold ischemic time (CIT) and late night surgery. Methods. 1262 deceased donor kidney transplantations were analyzed. Multivariable regression was used to determine odds ratios (ORs) for reoperation, graft loss, delayed graft function (DGF), and discharge on dialysis. CIT was categorized according to a forward stepwise pattern ≤1h/>1h, ≤2h/>2h, ≤3h/>3h,…, ≤nh/>nh. ORs for DGF were plotted against CIT and a nonlinear regression function with best R² was identified. First and second derivative were then implemented into the curvature formula k(x) = f′′(x)/(1 + f′(x)²)^3/2 to determine the point of highest CIT-mediated risk acceleration. Results. Surgery between 3 AM and 6 AM is an independent risk factor for reoperation and graft loss, whereas prolonged CIT is only relevant for DGF. CIT-mediated risk for DGF follows an exponential pattern f(x) = A · (1 + k · e^{(I · x)}) with a cut-off for the highest risk increment at 23.5 hours. Conclusions. The risk of surgery at 3 AM–6 AM outweighs prolonged CIT when confined within 23.5 hours as determined by a new mathematical approach to calculate turning points of nonlinear time related risks. CIT is only relevant for the endpoint of DGF but had no impact on discharge on dialysis, reoperation, or graft loss.