Background: Renal biopsy is essential for the diagnosis of kidney diseases, but complications, particularly bleeding incidents, remain problematic.
Methods: To evaluate the frequency of renal biopsy complications, and to reveal clinical and laboratory factors associated with overt bleeding complications, focusing on those available at hospital ward, we conducted a retrospective observational study for the period between 2001 and 2005 at Mie University Hospital in patients who underwent percutaneous renal biopsy of a native kidney. Of a total of 323 patients, 317 met the inclusion criteria.
Results: Only one patient (0.3%) required blood transfusion or intervention to stop bleeding. The mean decrease in hemoglobin (Hb) after biopsy was 0.43 +/- 0.7 g/dL. Hb decreased > or =1.0 g/dL in 66 patients (20.8%) and > or =10% in 32 patients (10.1%). On ultrasonography, perirenal hematoma was detected immediately after biopsy in 273 patients (86.1%), and 41 patients (12.9%) showed hematoma > or =2 cm in width. Analgesics were required for back pain in 67 patients (21.1%). Vasovagal response developed in 31 patients (9.8%). Macrohematuria occurred in 12 patients (3.8%). Urinary catheter was used in 161 patients (50.8%). For Hb decrease > or =10% after biopsy, multivariate analysis revealed perirenal hematoma (> or =2 cm) as a significant factor. Other significant factors were prolonged international normalized ratio of prothrombin time, elevated blood pressure on hospital admission, older age, increased serum creatinine level, and steroid use.
Conclusion: Perirenal hematoma > or =2 cm on ultrasonography immediately after biopsy might well represent a predictive factor for bleeding complications.