Ultrasonography as a predictor of overt bleeding after renal biopsy

Renal biopsy is essential for the diagnosis of kidney diseases, but complications, particularly bleeding incidents, remain problematic.

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.

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.

Perirenal hematoma > or =2 cm on ultrasonography immediately after biopsy might well represent a predictive factor for bleeding complications.