Background: The aim was to evaluate the risk for major hemorrhage complications (MHC) prior to percutaneous renal biopsy and apply a specific procedure in high-risk patients to decrease their incidence. Hemorrhage complications that required blood transfusion or other interventions were diagnosed as MHC.
Methods: One retrospective (Group A, n = 1314) and two prospective cohorts (Group B, n = 249 and Group C, n = 422) were involved in the study. Group A was used to establish a risk equation for MHC, Group B to test its performance, and Group C to evaluate the efficacy of the proposed procedure to reduce MHC incidence. Group C was classified, based on the equation, into high-risk (C1) and low-risk (C2) patients, who received different interventions. The intervention in Group C1 consisted of use of 18-gauge needles, a 12-h rest period post-operation, and reptilase injection; in Group C2, 16-gauge needles were used, with a 6-h rest, and no reptilase injection. Group B was also divided into B1 (high-risk) and B2 (low-risk) using the same cut-off, for further comparison.
Results: (1) In Group A, 4.8% of patients experienced MHC and the equation: Logit (PMHC) = 0.022 × mean arterial pressure (mmHg) + 0.216 × bleeding time (min) - 0.011 × eGFR [ml/(min 1.73 m(2))] - 0.894 × kidney length (cm) - 2.100 × renal cortical thickness (cm) + 6.225 (cutoff = -1.664) was established. (2) The area under the receiver operating characteristic curve was 0.848 (95 % CI 0.797-0.890) for Group B. (3) MHC occurred in 4.8 and 2.8% of patients in Group B and C, respectively; Group B1 suffered significantly more frequent gross hematuria, hematoma and MHC than Group C1; however, no significant difference except for large hematoma was found between Groups B2 and C2 for all complications.
Conclusions: The equation is reliable to predict the risk for MHC; the interventions proposed can decrease the incidence of MHC in high-risk patients.
Keywords: Biopsy; Complications; Hemorrhage; Intervention; Risk adjustment.