Management of RAAs
In response to two articles published in the January 2011 issue of Endovascular Today on renal artery aneurysm (RAA) management by Drs. Kalva, Wu, and Irani (58–62) and Drs. Murphy, Arko, and Mr. Arko (64–68), we believe that there is a clear discrepancy in terms of suggested indications for the treatment of RAAs.

Drs. Kalva and Murphy recommend revascularization of RAAs when the size reaches 2 cm and 1.5 cm, respectively. However, review of the literature, including Rutherford's Vascular Surgery, contradicts both. The textbook-recommended size for revascularization in asymptomatic RAAs is 3 cm,1 excluding pregnant women and those of childbearing age (2.5 cm for this subset). We believe 3 cm is reasonable, because most aneurysms detected are incidental, and natural history studies have shown a very low rate of rupture.

In one study of 62 asymptomatic patients, RAA sizes 1.5 to 4 cm were followed for a median of 8 years with no ruptures, no need for operations, and no symptoms developed. Twelve percent of patients died during followup due to causes that were unrelated to aneurysm.2 In a second series, 34 patients with RAA were followed conservatively with renal angiography and showed no ruptures and no changes in up to 84% of patients over a period of close to 3 years.3

However, we do agree that there is no clear consensus on the exact size for revascularization in asymptomatic RAA.

ARAVINDA NANJUNDAPPA, MD
Charleston, West Virginia

ROBERT S. DIETER, MD, RVT
Maywood, Illinois

  1. Calligaro KD, Dougherty MJ. Renal artery aneurysms and arteriovenous fistulae. In: Rutherford RB, ed. Rutherford's Vascular Surgery. 6th edition. Philadelphia, PA: Saunders Elsevier; 2005:2243-2250.
  2. Hubert JP Jr, Pairolero PC, Kazmier FJ. Solitary renal artery aneurysm. Surgery. 1980;88:557-565.
  3. Henriksson C, Bjorkerud S, Nilson AE, et al. Natural history of renal artery aneurysm elucidated by repeated angiography and pathoanatomical studies. Eur Urol. 1985;11:244-248.

Response
Clear indications for repair of RAAs include rupture and symptomatic disease. Symptoms may include refractory renovascular hypertension, renal ischemia secondary to embolism, flank pain, and hematuria.1 In asymptomatic patients, repair may be indicated for prevention of rupture. The highest risk of rupture has been shown in patients with false aneurysms and in pregnant women. Therefore, repair for asymptomatic disease is indicated in these patients at any size. Further, while it is generally agreed upon that increased aneurysm size is directly associated with increased rupture risk, there is no current consensus regarding the size criteria for repair of RAAs. Experts have recommended repair for aneurysms ranging from 1.5 to 4 cm, with most suggesting repair at 2 cm.2-6

Proponents of conservative management rely on the well-documented low risk of rupture associated with RAAs. The reported 6% incidence of graft failure and unplanned nephrectomy, as well as a mortality risk of up to 4% associated with standard open repair, also convinces some to approach asymptomatic patients more conservatively.7 Nonetheless, the near 80% mortality rate associated with rupture, should it occur, remains a strong argument for advocates of early repair. The availability and success of endovascular interventions additionally lowers initial concerns regarding the risk of intervention.8

Overall, the decision for repair in most asymptomatic patients is best made on a case-by-case basis after a thorough assessment of the patient's anatomy and surgical risk by the physician and a frank discussion with the patient regarding the risks and benefits of repair.

ERIN H. MURPHY, MD
Dallas, Texas

FRANK R. ARKO, MD
Dallas, Texas

  1. Tham G, Ekelund L, Herrlin K, et al. Renal artery aneurysms. Natural history and prognosis. Ann Surg. 1983;197:348-352.
  2. Dzsinich C, Gloviczki P, McKusick MA, et al. Surgical management of renal artery aneurysm. Cardiovasc Surg. 1993;1:243-247.
  3. Martin RS 3rd, Meacham PW, Ditesheim JA, et al. Renal artery aneurysm: selective treatment for hypertension and prevention of rupture. J Vasc Surg. 1989;9:26-34.
  4. Lumsden AB, Salam TA, Walton KG. Renal artery aneurysm: a report of 28 cases. Cardiovasc Surg. 1996;4:185-189.
  5. Hirsh AT, Haskal ZJ, Hertzer NR, et al. ACC/AHA guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic): a collaborative report from the American Associations for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (writing committee to develop guidelines for the management of patients with peripheral arterial disease)—summary of recommendations. J Vasc Interv Radiol. 2006;17:1383-1397.
  6. Calligaro KD, Dougherty MJ. Renovascular disease: aneurysms and arteriovenous fistulae. In: Cronenwett JL, Johnston KW, eds. Rutherford's Vascular Surgery. 7th ed. Philadelphia, PA: Saunders Elsevier; 2010:2243-2250.
  7. Henke PK, Cardneau JD, Welling TH III, et al. Renal artery aneurysms: a 35-year clinical experience with 252 aneurysms in 168 patients. Ann Surg 2001; 234:454-462; discussion 462-463.
  8. Saltzberg SS, Maldonado TS, Lamparello PJ, et al. Is endovascular therapy the preferred treatment for all visceral artery aneurysms. Ann Vasc Surg. 2005;19:507-515.