Renal artery false aneurysm. An unusual complication of prosthetic patch angioplasty

False aneurysm formation in a twenty-nine year old black woman treated for renovascular hypertension secondary to fibromuscular hyperplasia by knitted Dacron prosthetic patch angioplasty is reported. Etiologic mechanisms are discussed. The most likely factors leading to false aneurysm formation in this patient are disproportionate compliance between the arterial wall and the prosthesis and increased rigidity of the prosthesis, associated with increased shearing and vibratory stress. This patient was treated successfully by resection of the prosthetic path and involved artery with end-to-end reanastomosis of the artery.