Fig. 4. Selective right renal DSA, pre-angioplasty. Note that there is no longer any evidence of arteriovenous fistula.		Fig. 5. Selective right renal DSA, post-angioplasty. No residual stenosis is noted.
Case Reference No. CC-0298-01 Update 2/23/98 Followup: I appreciate the preceding comments. In addition to the references provided by Drs. Brown and Stein, here are a few others: 1. Imray TJ, Cohen AJ, Hahn L. Renal arteriovenous fistula associated with fibromuscular dysplasia. Urology 23:378-380, 1984. Abstract: A case is reported of a woman with long-standing progressive hypertension and an abdominal bruit who on angiography demonstrated fibromuscular dysplasia of the right renal artery and an arteriovenous fistula in the upper pole of the right kidney. The various causes of arteriovenous fistula are reviewed. The relationship of mural aneurysms seen in fibromuscular dysplasia and the formation of arteriovenous fistulas by rupture of these aneurysms is discussed. Review of the English literature indicates a probable causal relationship between fibromuscular dysplasia of the renal arteries and intrarenal arteriovenous fistulas. 2. Bron KM, Redman H. Renal arteriovenous fistula and fibromuscular hyperplasia. A new association. Annals of Internal Medicine 68:1039-43, 1968. 3. Oxman HA, Sheps SG, Bernatz PE, Harrison EG Jr. An unusual case of renal arteriovenous fistula--fibromuscular dysplasia of the renal arteries. Report of a case. Mayo Clinic Proceedings 48:207-10, 1973. 4. de Mendonca WC, Espat PA. Pheochromocytoma associated with arterial fibromuscular dysplasia. Am J Clin Path 75:749-54, 1981. Abstract: An unusual case of pheochromocytoma associated with multifocal medial fibromuscular disease of the left subclavian (ruptured), celiac, and bilateral renal arteries is described. Additionally, the coronary arteries, left renal arcuate vessels, and peripancreatic and intracolonic muscular arteries revealed intimal fibroplasia. Thirty-three cases of pheochromocytoma associated with renal artery stenosis have been reported, including four instances radiologically attributed to fibromuscular dysplasia. Renal artery fibromuscular dysplasia associated with pheochromocytoma has not been histologically documented, and extrarenal fibromuscular dysplasia with simultaneous pheochromocytoma has not been previously described. Current etiologic concepts of fibromuscular dysplasia and possible pathogenetic mechanisms for its occurrence with pheochromocytoma are discussed. 5. Quinibi WJ, Taylor TK, Knight TF, Senekjian HO, Gomez L, Weinman EJ. Pheochromocytoma and fibromuscular hyperplasia. South Med J 72:1481-2, 1979. Abstract: We have described a case which documents two possible surgical correctable causes for hypertension in a 55-year-old white man. Preoperative renal arteriograms and renal vein renin determinations suggested the possibility of renal artery stenosis due to fibromuscular hyperplasia. At operation, a pheochromocytoma was found in the left suprarenal area. The presence of two unusual causes for hypertension in a single patient suggests that more than one remediable cause for hypertension should at least be considered in a given hypertensive patient. To get back to the current patient: We felt that an attempt at performing embolization and angioplasty before the presumed pheochromocytoma was resected could place the patient at risk for an intraprocedural (or intraoperative, should problems occur) hypertensive crisis. Therefore, the tumor was resected, and did indeed turn out to be an extraadrenal pheochromocytoma. Once the patient recovered from this, her hypertension improved considerably; indeed, we were faced with a bit of a dilemma as to whether to attempt treatment of the other two lesions. We were persuaded to do so by a concern that the AVF might progress, as well as the feeling by her internist that the patient's blood pressure was still mildly elevated. On the repeat abdominal aortogram (Fig. 4) we were surprised to find that there was no longer any evidence for an arteriovenous fistula! This made decisions regarding whether to dilate or embolize first considerably easier (I'm still not sure which I would have done first--probably the angioplasty). We dilated the stenosis with a good result (Fig. 5); the patient's blood pressure has normalized. Any ideas about how/whether she should be followed up (besides clinically)? Would anyone do another MRA? What does the disappearance of the av fistula say about its etiology? It is interesting that, in general, the presence of an av fistula associated with FMD has been attributed to rupture of an FMD-associated aneurysm into an adjacent vein, but in this case (a) we do not see obvious FMD in the vicinity of the fistula on the original films, and (b) we might have expected that if the latter explanation held, that the fistula would not have disappeared.