Back
Biopsies are important in the diagnosis and management of dysfunction, and protocol biopsies are proposed as a method of detecting subclinical pathological entities that may affect graft evolution. In both scenarios these procedures are not free of complications. The present study aimed to compare the histological results of the biopsies performed as well as the complications associated with their performance according to their indication.
Retrospective cohort design from January 2018 to December 2019. Patients who underwent ultrasound-guided biopsy by the nephrology service of our center were included. The cases were divided into two groups according to the indication to perform the biopsy: one was integrated with the protocol ones and the other with those performed by dysfunction. The study variables were: histological diagnosis, major complications (nephrectomy, surgical management, interventional management, transfusion requirement), minor complications (arteriovenous fistulas, minor bleeding, macroscopic hematuria), hemoglobin (Hb) and hematocrit (Ht) before and after the procedure.
A total of 169 cases were analyzed, 124 protocol cases and 45 dysfunction cases. The diagnoses in the protocol cases were: 111 (65.68%) normal or with unspecific changes, 26 (15.38%) with acute rejection, 16 (9.46%) with tubulointerstitial nephritis (TIN), 8 (4.73%) with chronic rejection and 8 (4.73%) with other diagnoses. In the dysfunction group, 14 (31.11%) were normal or with non-specific changes, 17 (37.77%) with acute rejection, 5 (11.11%) with TIN, 5 (11.11%) with chronic rejection and 4 (8.88%) with other diagnoses. The overall incidence of complications was 4.73%, all of which were minor complications, since no major complications were reported. In the analysis by groups, the incidence of complications in the protocol group was 4.03%, being lower than in the dysfunction group with 6.66%, but without a significant association (p=0.44). The odds ratio for complications was 0.58 (95% CI; 0.13-2.56) for protocols and 1.7 (95% CI; 0.38-7.42) for those performed by dysfunction. In general, a decrease in Hb (13.74 g/dL vs. 13.33, p=0.003) and Ht (40.52% vs. 39.32, p=0.052) was found; this trend was maintained in the protocols with a decrease in Hb (14.04 g/dL vs. 13.46, p=0.0001) and Ht (41.26% vs. 40.21, p=0.085); no significant changes were found in the dysfunction group.
The protocol biopsies allow the detection of subclinical pathological conditions, it should be noted that these conditions are not limited to rejection events but to other entities, the most reported being TIN. The procedures were performed without major complications and with a low incidence of minor complications, which was lower in the protocol procedures, although there was no statistical association. Although there is a tendency for hemoglobin decrease, this does not seem to represent a clinical implication. In summary, biopsies present a low incidence of complications and can provide relevant pathological information for the evolution of the patients.