Transfemoral endovascular repair of iliac artery aneurysms

Transfemoral Endovascular Repair of Iliac Artery Aneurysms Michael L. Marin, MD, Frank J. Veith, MD, Ross T. Lyon, MD, Jacob Cynamon, MD, Luis A. Sanchez, MD, New York, New York

PURPOSE: This report evaluates the application of transfemoral endovascular repair of iliac artery aneurysms. PATIENTS AND METHODS: Over a 20-month period, 11 patients with serious comorbid illnesses and a total of 14 iliac artery aneurysms were treated with endovascular grafts composed of polytetrafluoroethylene conduits combined with balloon expandable iliac artery stents (Palmaz). Nine right common, 3 left common, and 2 right internal iliac artery aneurysms were treated. The patients were men between 58 and 89 years of age (mean 72). Eight patients had isolated aneurysms and 3 had multiple iliac artery aneurysms. RESULTS: Endovascular iliac grafts were successfully placed in all 11 patients. No procedural deaths occurred. Follow-up ranged from 3 to 21 months (mean 11). No acute or late graft thromboses occurred. CONCLUSIONS: Transluminally placed endovascular stented grafts can be used to successfully exclude iliac artery aneurysms from the circulation while maintaining lower-extremity arterial perfusion. However, longer follow-up in more patients is necessary to confirm the durability of this technique. Am J Surg. 1995;170:179-182.

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solated aneurysms cd the iliac arteries are relatively uncommon, accounting for only 2% to 7% of atherosclerotic aneurysms of the aortoiliac segment.” As with abdominal aortic aneurysms, iliac aneurysms may rupture, emh&e, thromhosc, or produce pressure symptoms. Mortality rates following rupture and emergent surgery for iliac artery aneurysms have heen reported to be high, approximately 33%.< However, because of the infrequent nature of these lesions. clear management guidelines have not heen well de-

From the Division of Vascular Surgery, Department of Surgery (MLM, FJV, RTL, LAS), and the Division of Interventional Radiology, Department of Radiology (JC), Montefiore Medical Center, The University Hospital for the Albert Einstein College of Medicine, New York, New York. Supported by grants from the US Public Health Service (HL 02990-02), the James Hilton Manning and Emma Austin Manning Foundation, The Anna S. Brown Trust, and The New York Institute for Vascular Studies. Requests for reprints should be addressed to Michael L. Marin, MD, Division of Vascular Surgery, Montefiore Medical Center, 111 East 210th Street, New York, New York 10467. Presented at the 23rd Annual Meeting of The Society for Clinical Vascular Surgery, Fort Lauderdale, Florida, March 22-26, 1995.

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fined for the asymptomatic patient.’ Furthermore, the technical complexities of operating on vessels Jeep within the pelvis, especially after previous aortic surgery, have made standard elective surgical management of iliac imeu~sms more difficult than for aortic aneurysms.’ Alternative therapies using simple aneurysm ligation, coil emholization, or the placrment of ped of prosthetic grafts and anchoring stents placed within the lumen of the vessels directly across the arterial lesion. TI‘EGq have heen used successfully to treat infrarenal aornc aneurysms, thoracic aortic aneurysms, popliteal artery aneurysms, occlusive VRSCIIlar disease, and vascular trauma”.” This report describes the use of TPEGs for the treatment of iliac artery ,meurysms. PATIENTS AND METHODS Endovascular Graft Device All TPEGs used in this study were composed of 6-mm thinwalled polytetrafluoroethylene (MFE) grafts (W.L. Gore and Associates, Flagstaff, Arizona). Each graft was sewn to a Palmaz balloon expandahle stent (Johnson & Johnson Interventional Systems, Warren, New Jersey) at the cephalad end of the graft (Figure 1). To localize the caudal end of each graft and facilitate placement of a second anchoring stent, radiopaque markers consisting of gold thrttad were placed at the distal end of each TPEG. The TPEGs were then coaxlally loaded onto appropriately sized h&on angioplasty catheters and inserted into 14-Fr introducer sheath> fashioned with a tapered halloon tip and proximal hernosmtic valve. The length of the TPEGs ranged from 7 to 32 cm (mean 20). Mechanism of Repair Selection of the appropriate repair rechniquc ~‘1s based on the morphology of the aneurysm as displayed on a preoperative computed tomographic scan and angiography. In cases in which hackflow from the internal iliac artery and its branches was a concern, Gianturccj cclils (hook, Inc., Bloomington, Indiana) were placed to thromhose and occlude this vessel (techniques B, D, and E). In those instances in which occlusion of the contralateral cc)mrnon iliac artery was required (technique F), a stcnt covered with a PTFE graft sealed at its cephalad end hy a purse-string suture was used (Figure 1). All procedures were perfi)rmed in the operating room under digital fluoroscopic guidance. JOURNAL

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Figure 1. (Top) Endovascular stented graft constructed from a balloon expandable stent (S) and a 6-mm polytetrafluoroethylene (PTFE) graft (G). (Bottom) Occluding stent composed of a Palmaz iliac stent sutured to a 6-mm PTFE graft. The distal end of the graft protrudes like a wind sock from the end of the stent (solid arrow). A purse-string suture is applied to occlude the end of the graft (open arrow).

Each patient underwent a repair of his iliac artery aneurysm using one of six techniques (Figure 2). (A) Patients with a localized common iliac artery aneurysm were treated with stents anchoring the endovascular graft proximal and distal to the aneurysm. (B) If the aneurysm of the common iliac artery extends to the hypogastric vessel, an occlusion coil is usually placed at the internal iliac artery orifice before endovascular stent grafting to prevent retrograde flow from the hypogastric artery into the iliac aneurysm. (C) Alternatively, retrograde flow into the aneurysm may be prevented by expansion of the graft across the hypogastric orifice or placement of an additional balloon expandable stent within the lumen of the graft securing the graft material across the hypogastric artery orifice. (D) When non aneurysmal neck (normal iliac artery) is present within the cephalad portion of the aneurysm, the stented graft is anchored to a normal portion of the distal aorta. A coil is placed in the proximal hypogastric artery to prevent retrograde flow from this vessel into the aneurysm. A covered “occluding” stent is then positioned in the contralateral common iliac artery. A femorofemoral bypass is placed to reestablish vascular continuity to the occluded extremity. (E) If a wide-mouth opening to a hypogastric artery aneurysm is present, the anterior and posterior divisions of the hypogastric artery are individually coil embolized and the endovascular graft is secured with a stent above and below the origin of the aneurysmal artery, functionally excluding it from the circulation. (F) When the aorta and iliac arteries are involved in the aneurysmal process, all three aneurysms can be treated by modifications of the type F reconstruction. The branches of the aneurysmal iliac arteries are embolized preoperatively with coils. The proximal portion of the endovascular stented graft is then positioned immediately below the renal arteries. The distal part of the graft is brought down one iliac artery to below the most distal extent of the aneurysms. The contralateral iliac artery is then occluded with an occluding stent and a femorofemoral bypass is done to perfuse the opposite leg. In reconstruction techniques B through E, the second stent is responsible for fixing the distal portion of the graft to the arterial wall. The distal stent in these reconstructions may be 180

Figure 2. Techniques A through F used for the endoluminal repair of iliac artery aneurysms (see Mechanism of Repair section). c = coil; o = occluding stent.

eliminated by extending the endovascular graft to the common femoral artery (site of device insertion) and performing an endoluminal anastomos@ before closure of the arteriotomy. Patients All patients ( 11) in this series were men with an age range of 58 to 89 years (mean 72). Five patients in this series had undergone previous surgery for an aortic aneurysm 6 to 26 years before their TPEG procedure. All 11 patients had coronary artery disease and clinical evidence of prior myocardial infarction; 5 (45%) had chronic obstructive pulmonary disease; 5 (45%) had diabetes; and 3 (27%) had chronic renal failure (serum creatinine rate >3.0), 1 of whom required chronic maintenance hemodialysis. All were thought to have a high perioperative risk of significant morbidity and mortality with open surgical repair of their aneurysms. Eleven patients were treated with TPEGs over a 20-month period to exclude 14 iliac artery aneurysms. There were 9 right common, 3 left common, and 2 right internal iliac artery aneurysms. Eight patients were asymptomatic and 3 had back or abdominal pain associated with their aneurysms. Eight had isolated aneurysms and 3 had coexisting iliac artery aneurysms. The aneurysms ranged in diameter from 2.9 to 9.0 cm (mean 4.7). RESULTS Endovascular iliac grafts were successfully placed in all 11 patients (Table, Figure 3). Nine patients had their grafts inserted under epidural, 1 under local, and 1 under general anesthesia. lntraoperative blood loss ranged from 75 to 2,800 mL

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time (mean 420). Operative ranged from 2 to 6 hours (mean 3). No procedure-related deaths occurred. No acute or late graft thromboses occurred. In 1 patient, a postoperative arteriogram demonstrated a kink in the TPEG, which was treated by the percutaneous insertion of a balloon expandahle stent (Figure 4). One pa. tient was treated for contralateral distal extremity ischemia secundary to emholization from a plaque in a diseased i&arena1 aorta. Rstprocedure colonoscopy Figure 3. Computed tomographic scan with intravenous contrast of a common iliac artety in an asymptomatic patient was aneurysm A. before and 6. after the insertion of an endovascular graft. After successful enconsistent with possible mild dovascular grafting, luminal contrast is restricted to the endovascular graft (arrow). colonic mucosal ischemia after sacrifice of the right internal iliac dissection. This IS particularly important m reoperatlvc procearten; rhr condition resolved without intervention. The dures in which previous scarring or infecnon m;ly make redislength of h~~spitalstay ranged from 2 to 13 days. The mean section difficult or hazardous.” hospital stay for L>atients treated solely for their iliac artery Other potential advantages of iliac art-q aneurysm repair aneurysm, including a postoperative arteriogram, was 5 days. by means ofa transluminal route include limited l~~caltrauma, The