I recently saw a young hypertensive patient who had suffered a motor vehicle accident complicated by a transected aorta that was successfully repaired several years back. He has had hypertension since then and was referred to us for evaluation and management of resistant hypertension. The workup is ongoing so we don’t yet have the (secondary) diagnosis, if any, however the differential included some interesting entities, such as post-op coarctation and an interesting phenomenon known as Page kidney.
Page kidney, first described by Dr Irvine Page in 1939, is the phenomenon of hyperreninemic hypertension that results from extrinsic compression of the renal parenchyma. Page first described the phenomenon in animal models, showing that wrapping an animal kidney in cellophane led to hypertension (see original JAMA article
). Clinically, the phenomenon is seen after trauma or after a nephrologic intervention such as a kidney biopsy. In either case, a subcapsular hematoma leads to compression of the affected kidney parenchyma and reduces renal blood flow, leading to renin release. A tumor or cyst can cause the same phenomenon. Time course from traumatic incident to hypertension is not universally consistent, and the hypertension can be immediate or subacute in onset. The hypertension often resolves after nephrectomy, though some case reports of successful evacuation of the hematoma or drainage of the compressing cyst have been reported.
So next time you biopsy, be sure to watch for tachycardia and hypotension as a sign for post-biopsy bleeding as usual, but don’t dismiss new hypertension as a reassuring sign that there is no bleed!
See Page Kidney featured in NEJM’s Images in Clinical Medicine here.