Saturday, May 15, 2010

Paging the doctor

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.

4 comments:

Raf999 said...

Very interesting post.
This is a wierd cause of HTN.
In the daily practice, does anyone reading this comment have any experience with this entity?
Does anyone follow any specific postbiopsy protocol looking for this complication?

Nice post! Tx.

Anonymous said...

I usually teach that you don't get a Page kidney s/p percutaneous renal biopsy because in essence by puncturing the capsule, you are draining a potential sub-capsular hematoma and thus relieving the compression of the kidney. A Page kidney is usually caused by blunt trauma, renal hemorrhage without capsular interruption (breakage).

turks said...

I had some patients with hypertension after bx. I assumed that was pain...
Hope they are ok!

Ernest Mandel said...

Apparently there are fewer than 100case reports in the literature of Page kidney. Post biopsy Page kidney has been reported, though a fast search and review reveals that it is reported more after allograft biopsies. Given the small sample size I wouldn't draw too many conclusions from this predominance, though it is possible that better compression post allograft biopsy (given more accessible location) may quickly reverse any capsular damage and predispose to a contained hematoma? Of course, Page kidney post-biopsy isn't very common, but should be kept somewhere in the deep reserves of the mind....