Retroperitoneum: a forgotten and fatal aspect of kidney biopsy.

A kidney biopsy is an important tool for nephrologists in the diagnosis of renal conditions, but not without the risk of bleeding due to its invasive nature. There is abundance of literature on bleeding complications secondary to this procedure in high-risk patient groups such as amyloidosis and chronic hypertension. An undefined and unrecognized risk is a peritoneal penetration. We report here a case where, despite adequately preparing a patient for a kidney biopsy, distortion of the peritoneum and retroperitoneum from previous surgery resulted in a fatal outcome. This was due to loss of peritoneal integrity and the consequent loss of local anatomical hemostatic mechanism.