Endovascular Repair Of Aortoiliac Aneurysms Research Articles

Overt colon ischemia after endovascular aneurysm repair: The importance of microembolization as an etiology

Objective: The purpose of this study was to analyze the incidence, severity, and etiologic factors of the development of colon ischemia after endovascular aortoiliac aneurysm repair (EVAR). Methods: During the last 9 years we performed 278 elective EVARs using a variety of grafts. To facilitate these repairs, one hypogastric artery (HA) was coil embolized in 109 patients and both HAs were coil embolized in 13 patients. The preprocedural status of the inferior mesenteric, hypogastric, and iliac arteries as well as anatomical characteristics of the abdominal aortic aneurysm were determined arteriographically and by computerized tomographic scans. Postoperative colon ischemia was documented by colonoscopy or operative findings. Results: Colon ischemia occurred in eight patients (2.9%). Three patients with colon ischemia died and had evidence of widespread (cutaneous, renal, small bowel, and/or lower extremity) microembolization. One of these three had a colectomy and microscopic emboli were present. One other patient who required a colectomy also had pathologic evidence of colonic microembolization but survived. Four other patients with colon ischemia were treated conservatively and survived. In one patient, previous colectomy with interruption of mesenteric collaterals may have been a contributory cause of colon ischemia. Of the eight patients with colon ischemia, only one had unilateral HA occlusion, and none had bilateral HA occlusion. The other 121 patients with unilateral and bilateral HA occlusion had no evidence of colon ischemia. Conclusions: Colon ischemia occurs after EVAR with an incidence approximating that of open repair. Colon ischemia was unrelated to HA interruption. Embolization appears to be a major cause of colon ischemia, although inadequate mesenteric collateral circulation may also play an etiologic role. Mortality with colon ischemia accompanied by widespread embolization was high, whereas colon ischemia without it was often mild and amenable to nonoperative management. (J Vasc Surg 2001;34:986-96.)

Internal iliac artery revascularization as an adjunct to endovascular repair of aortoiliac aneurysms

Purpose: Endovascular repair of aortoiliac aneurysms may be limited by extension of the aneurysm to the iliac bifurcation, necessitating endpoint implantation in the external iliac artery. In such cases the circulation to the internal iliac artery is interrupted. Bilateral internal iliac artery occlusion during endovascular repair may be associated with significant morbidity, including gluteal claudication, erectile dysfunction, and ischemia of the sigmoid colon and perineum. We have employed internal iliac artery revascularization (IIR) to allow endograft implantation in the external iliac artery while preserving flow to the internal iliac artery in patients with aneurysms involving the iliac bifurcation bilaterally. Methods: A total of 11 IIR procedures were performed in 10 patients undergoing endovascular abdominal aortic aneurysm (AAA) repair (9 men, 1 woman; mean age, 74 years). IIR was accomplished via a retroinguinal incision in 9 cases and a retroperitoneal incision in 2 cases. Six-mm polyester grafts were used for external-to-internal iliac artery bypass in 10 cases and internal iliac artery transposition onto the external iliac artery was used in one case. Endovascular AAA repair was performed using a modular bifurcated device (Talent-LPS, Medtronics, Minneapolis, Minn) after IIR. Bypass graft patency was determined immediately after the surgery, at 1 month, and every 3 months thereafter, using duplex ultrasound scanning and computed-tomography angiography. Mean aneurysm diameters were as follows: AAA, 6.4 ± 0.7 cm; ipsilateral common iliac, 3.7 ± 1.0 cm; contralateral common iliac, 3.9 ± 0.8 cm. Results: Successful IIR and endovascular AAA repair were accomplished in all cases. No proximal, distal, or graft junction endoleaks occurred. Two patients demonstrated retrograde aneurysm side-branch endoleaks originating from the lumbar arteries. One thrombosed spontaneously within 3 months. One perioperative myocardial infarction occurred. Reduction in aneurysm size was documented in 5 aortic, 5 ipsilateral iliac, and 3 contralateral iliac aneurysms. Gluteal claudication, erectile dysfunction, colon and perineal ischemia, and mortality did not occur. All IIRs have remained patent during a follow-up period of 4 to 15 months (mean, 10.1 months). Conclusions: IIR may be used with good short-term to intermediate-term patency to prevent pelvic ischemia in patients whose aneurysm anatomy requires extension of the endograft into the external iliac artery. This may allow endovascular AAA repair to be performed in patients who might otherwise be at risk for developing complications associated with bilateral internal iliac artery occlusion. (J Vasc Surg 2001;34:892-9.)

Early Vascular Complications after Endovascular Repair of Aortoiliac Aneurysms

The purpose of this study was to estimate the frequency of and review the treatment options for intraoperative endograft access-related vascular complications and early postoperative vascular complications of endovascular repair for aortoiliac aneuryms (EVAR). Between February 1998 and April 2000, 53 patients (46 males, 7 females) with aneurysms of the abdominal aorta (AAA) and iliac arteries were treated with endovascular grafts (48 AAA, and 5 iliac aneurysms). All procedures were performed using open exposure of the femoral arteries. One patient with an AAA was converted to open repair (primary technical success, 98.1%). We recorded the need for adjunctive vascular procedures or intervention to the access arteries (iliofemoral) or the endograft because of thrombosis or distal embolization. Events were classified as either intraoperative, early postoperative (< 30 postoperative days), or late postoperative. Their etiology and treatment were recorded. The results were compared to those from other series reported in the literature and to published registry data. From our results we concluded that the need for adjunctive vascular procedures to the iliofemoral arteries at the time of EVAR is significant. These procedures are necessary to either repair damage to the access arteries from the delivery system or provide a conduit for graft delivery in cases where the access arteries are inadequate. Early postoperative vascular complications are due to technical factors resulting in residual graft limb stenoses. Both intraoperative and early postoperative vascular complications after EVAR are more common in female patients. These complications can be effectively treated with a variety of open surgical and transfemoral endovascular techniques.

Sloughing of the scrotal skin and impotence subsequent to bilateral hypogastric artery embolization for endovascular aortoiliac aneurysm repair

Sloughing of the scrotal skin is an extremely rare event due to pelvic ischemia. We report herein one case of scrotal skin sloughing and impotence after bilateral hypogastric artery embolization for endoluminal aortoiliac aneurysm repair. Postoperative penile plethysmography demonstrated a 75% reduction in the penile brachial index, suggesting that pelvic ischemia is the main culprit for this complication. The devastating morbidity in our patient underscores the importance of maintaining pelvic collateral circulation when planning for endovascular aortoiliac aneurysm repair. (J Vasc Surg 2001;34:748-50.)

Internal iliac artery embolization before endovascular repair of abdominal aortic aneurysms: frequency, efficacy, and clinical results.

The aim of our study was to assess the frequency, efficacy, and incidence of adverse effects of internal iliac artery embolization. Of 343 patients examined for stent-graft repair, 147 were suitable for endovascular treatment. Fifty-five patients underwent preprocedural embolization of the internal iliac artery either unilaterally (46 patients) or bilaterally (nine patients). Successful embolization was assessed angiographically and with helical CT follow-up examinations. Colonic ischemia was ruled out clinically or colonoscopically. Buttock claudication, and sexual dysfunction in men, were evaluated through a questionnaire. Embolization of the internal iliac artery increased by 16% the percentage of patients for whom endovascular repair was suitable. After successful embolization in all patients, routine CT follow-up examinations after a mean time of 16.7 months showed no evidence of endoleaks related to retrograde perfusion via embolized internal iliac arteries. Nevertheless, in all patients who had undergone embolization, a primary endoleak was detected in 43.4% at the first postoperative CT examination. None of our patients had evidence of colonic ischemia. Clinical follow-up data of 46 patients were available. Of these patients, mild to severe new onset buttock claudication was found in 13 (36.1%) of 36 patients with unilateral, and in eight (80%) of 10 patients with bilateral, internal iliac artery embolization (p = 0.03). Five (25%) of 20 men had an erectile dysfunction after the procedure. Embolization of the internal iliac artery is a safe and efficient procedure that increases the applicability for endovascular repair of aortoiliac aneurysms. However, buttock claudication and erectile dysfunction are a drawback in a substantial number of patients.

Clinical Implications of Internal Iliac Artery Embolization in Endovascular Repair of Aortoiliac Aneurysms

To overcome constraints imposed by iliac artery anatomy, the anatomic inclusion criteria for endovascular aortic aneurysm repair can be extended by means of intentional coil occlusion of one or both internal iliac arteries and extension of the distal limb of the graft into an external iliac artery. We reviewed our experience with this intervention to determine the safety and efficacy of this approach to aneurysm repair. Over a 30-month period, 84 patients underwent endovascular abdominal aortic aneurysm repair; 23 underwent intentional unilateral (22) or bilateral (1) internal iliac artery occlusion. Morbidity, mortality, and long-term clinical outcomes were evaluated in these 23 patients. Patients were specifically questioned about exercise-induced buttock and extremity symptoms. Our results showed that intentional internal iliac artery embolization to allow endovascular repair of abdominal aortic aneurysms is accompanied by significant morbidity and should be approached with caution.

Intentional internal iliac artery occlusion to facilitate endovascular repair of aortoiliac aneurysms

Purpose: The safety of intentional occlusion of patent internal iliac arteries (IIAs) to facilitate the endovascular repair of aortoiliac artery aneurysms (abdominal aortic aneurysms [AAAs] and iliac aneurysms [IAs]) was evaluated. Methods: We analyzed the techniques and clinical sequelae of selective occlusion of one or both IIAs in 103 patients and correlated these findings with the results of preoperative angiograms to identify vascular anatomy that may predict postoperative pelvic ischemia. To quantify the clinical presentation of pelvic ischemia, we developed these criteria: class 0, no symptoms; class I, nonlimiting claudication with exercise; class II, new onset impotence, with or without moderate to severe buttock pain, leading to physical limitation with exercise; class III, buttock rest pain, colonic ischemia, or both. IIA occlusion was achieved in 100% of the patients by means of either catheter-directed embolization or orificial coverage with a stent-graft. No patient in this study had angiographic evidence of significant visceral occlusive disease before the procedure. Sixty-four patients had isolated AAAs, 23 patients had AAAs and IAs, and 16 patients had isolated IAs. Ninety-two patients had one IIA selectively occluded, and 11 patients had both IIAs selectively occluded. Results: After IIA occlusion, 12 patients were categorized in class I, 9 patients were categorized in class II, and 1 patient was categorized in class III, for a total of 22 patients (21%) with pelvic ischemia. Sixteen (17%) of 92 patients had unilateral IIA occlusions, and six (17%) of 11 patients had bilateral IIA occlusions. Five patients in class I improved and had no symptoms within 1 year, and one patient in class II was downgraded to class I because of improved symptoms. Two unique preoperative angiographic findings were identified in the remaining 16 patients (16%) with chronic pelvic claudication: (1) stenosis of the remaining IIA origin (> 70%) with nonopacification of more than three of the six IIA branches (63%); and (2) small caliber, diseased or absent medial and lateral femoral circumflex arteries ipsilateral to the side of the IIA occlusion (25%). One patient with class III ischemia died of cardiovascular collapse associated with colon infarction caused by either acute ischemia or particulate embolization. Conclusion: The incidence of pelvic ischemia after IIA occlusion is 20% immediately after endovascular aortoiliac aneurysm repair. A total of 25% of patients had no symptoms within 1 year. Two preoperative radiologic findings may help identify patients who are at risk for pelvic ischemia: stenosis of the patent IIA and disease deep femoral ascending branches ipsilateral to the occluded IIA. The risk of colon ischemia appears to be small after selective IIA occlusion to facilitate endovascular AAA repair. (J Vasc Surg 2001;34:204-11.)

Balloon-expandable common iliac artery occluder device for endovascular aneurysm repair.

This study was performed to evaluate the efficacy of a balloon-expandable Palmaz stent common iliac artery occluder device for endovascular stent-graft repair of aortoiliac aneurysms. Eighty-four patients (79 men, 5 women; age range 60-95 yr; mean age, 76 yr) with aortoiliac aneurysms underwent endovascular stent-graft repair. The repair consisted of a stent-graft extending from the abdominal aorta to the iliac or common femoral artery, a cross-femoral bypass graft, and an endovascular arterial occluder device within the contralateral common iliac artery. The occluder device consisted of a 5-cm segment of 6-mm diameter polytetrafluoroethylene (PTFE) graft with a purse-string suture occluding the leading end and a Palmaz stent sutured to the trailing end. The occluder device was delivered through a 17F catheter via an arteriotomy. Eighty-three of the 84 patients received aortic endografts. In one case, infrarenal aortic rupture occurred during deployment of the aortic stent requiring conversion to an open surgical repair. Initial technical success for occluder device insertion was achieved in 78 of the remaining 83 patients. Failure to advance the occluder device delivery sheath through a diseased iliac artery occurred in one patient. Common iliac artery rupture occurred during balloon expansion and occluder device deployment in two patients. Two patients required additional coil embolization of the common iliac artery adjacent to the occluder device at the time of stent-graft insertion to correct incomplete iliac occlusion. Delayed occluder device-related complications included one patient with a postoperative iliac endoleak who required percutaneous coil embolization and one patient with a postoperative iliac endoleak in whom a contained aortic aneurysm rupture developed that was treated by surgical ligation of the common iliac artery. Use of the Palmaz stent-based iliac artery occluder device is an effective technique to induce common iliac artery thrombosis to facilitate endoluminal stent-graft aneurysm repair.

Vascular poster presentations

Purpose: This study was conducted to establish criteria to aid in the selection of patients for endovascular repair of aorto-iliac aneurysms.Methods: Characterization of pertinent factors used to determine whether a patient is eligible to undergo stent-graft repair of an aorto-iliac aneurysm.Principal findings and conclusions: The determinant factor that dictates whether or not one is eligible to undergo endovascular repair of aorto-iliac aneurysm is the arterial anatomy of the affected area and its surrounding vessels. Some of the initial limitations imposed in this technology have changed such as an acceptance of much shorter neck than initially conceptualized, by the use of supra-renal stent deployment. However, unsolved issues remain regarding the differentiation of thrombus and atherosclerotic plaque in the infra-renal aortic region, iliac artery disease, and the need to have an enhanced flexibility of the delivery system for proper deployment in tortuous aortic necks. The question of long-term device durability remains the most important issue that has to be taken into consideration before one chooses minimally invasive endovascular approaches.

Outcome after unilateral hypogastric artery occlusion during endovascular aneurysm repair

Purpose: The purpose of this study was to determine the long-term functional outcome after unilateral hypogastric artery occlusion during endovascular stent graft repair of aortoiliac aneurysms. Methods: During a 41-month period, 157 consecutive patients underwent elective endovascular stent graft repair of aortoiliac aneurysms with the Medtronic AneuRx device. Postoperative computed tomography scans were compared with preoperative scans to identify new hypogastric artery occlusions. Twenty-three (15%) patients had unilateral hypogastric occlusion, and there were no cases of bilateral occlusions. Telephone interviews about past and current levels of activity and symptoms were conducted, and pertinent medical records were reviewed. All 23 (100%) patients were available for the telephone interview. A disability score (DS) was quantitatively graded on a discrete scale ranging from 0 to 10 corresponding to “virtually bed-bound” to “greater-than-a-mile” exercise tolerance. Worsening or improvement of symptoms was expressed as a difference in DS between two time points (–, worsening/+, improving). Results: Among the 23 patients, two groups were identified: 10 patients (43%) had planned and 13 patients (57%) had unplanned or inadvertent occlusions. The patients in the two groups did not differ significantly in the mean age (73.4 vs 73.7 years), sex (male:female, 9:1 vs 10:3), and duration of follow-up (15.6 vs 14.4 months). Nine (39%) of the 23 patients, five patients in the planned and four patients in the unplanned group, reported significant symptoms of hip and buttock claudication ipsilateral to their occluded hypogastric arteries. The mean decrement from baseline of these nine patients in their DS postoperatively was –3.3. The symptoms were universally noted on postoperative day 1. Although most patients improved (89%), one (11%) never got better. Among those whose symptoms improved, the mean time to improvement was 15 weeks, but with a plateau thereafter resulting in a net decrement of DS of –2.3 from baseline. Finally, when questioned whether they would undergo the procedure again, all 23 patients unanimously answered, “Yes.” Conclusions: A significant number (39%) of patients who sustain hypogastric artery occlusion after endovascular aneurysm repair have symptoms. Although most patients with symptoms have some improvement, none return to their baseline level of activity. Despite this, all patients in retrospect would again choose endovascular repair over conventional open repair. (J Vasc Surg 2001;33:921-6.)

When Should the Internal Iliac Arteries be Preserved in Patients Undergoing Endovascular or Open Repair of Aortoiliac Aneurysms?

-Internal iliac artery (IIA) occlusion during aortic aneurysm repair has been associated with considerable morbidity. We analyzed the consequences of interrupting one or both IIAs in the standard surgical or endovascular treatment of aortoiliac aneurysms (AIAs). From 1992 to 2000, 158 patients with abdominal aortic aneurysms (n = 66), iliac aneurysms (n = 28), or AIAs (n = 64) required interruption of one (n = 134) or both (n = 24) IIAs as part of their endovascular (n = 110) or open repair (n = 48). Endovascular treatment was performed with a variety of industry- or surgeon-made grafts in combination with coil embolization of the IIAs. The standard surgical techniques included oversewing or excluding the origins of the IIAs, and extending the prosthetic graft to the external iliac or femoral artery. There were no cases of buttock necrosis, ischemic colitis requiring laparotomy, or death when one or both IIAs were interrupted. Persistent buttock claudication occurred after 16 (12%) of the unilateral and 3 (13%) of the bilateral IIA interruptions. Impotence occurred in 7 (9%) of the unilateral and 2 (11%) of the bilateral IIA interruptions. Minor neurological deficits of the lower extremity were observed in 2 (1.5%) of the patients with unilateral IIA interruption. Although IIA flow should be preserved if possible, selective interruption of one or both IIAs can usually be accomplished safely during endovascular and open repair of anatomically challenging AIAs. We believe other comorbid factors, such as shock, distal embolization, or the failure to preserve collateral branches from the external iliac and femoral arteries, may have contributed to the morbidity in other reports of IIA interruption.

When Should the Internal Iliac Arteries be Preserved in Patients Undergoing Endovascular or Open Repair of Aortoiliac Aneurysms?

Internal iliac artery (IIA) occlusion during aortic aneurysm repair has been associated with considerable morbidity. We analyzed the consequences of interrupting one or both IIAs in the standard surgical or endovascular treatment of aortoiliac aneurysms (AIAs). From 1992 to 2000, 158 patients with abdominal aortic aneurysms (n = 66), iliac aneurysms (n = 28), or AIAs (n = 64) required interruption of one (n = 134) or both (n = 24) IIAs as part of their endovascular (n = 110 ) or open repair (n = 48). Endovascular treatment was performed with a variety of industry- or surgeon-made grafts in combination with coil embolization of the IIAs. The standard surgical techniques included oversewing or excluding the origins of the IIAs, and extending the prosthetic graft to the external iliac or femoral artery. There were no cases of buttock necrosis, ischemic colitis requiring laparotomy, or death when one or both IIAs were interrupted. Persistent buttock claudication occurred after 16 (12%) of the unilateral and 3...

Does the endovascular repair of aortoiliac aneurysms pose a radiation safety hazard to vascular surgeons?

Objectives: Endovascular aortoiliac aneurysm (EAIA) repair uses substantial fluoroscopic guidance that requires considerable radiation exposure. Doses were determined for a team of three vascular surgeons performing 47 consecutive EAIA repairs over a 1-year period to determine whether this exposure constitutes a radiation hazard. Methods: Twenty-nine surgeon-made aortounifemoral devices and 18 bifurcated devices were used. Three surgeons wore dosimeters (1) on the waist, under a lead apron; (2) on the waist, outside a lead apron; (3) on the collar; and (4) on the left ring finger. Dosimeters were also placed around the operating table and room to evaluate the patient, other personnel, and ambient doses. Exposures were compared with standards of the International Commission on Radiological Protection (ICRP). Results: Total fluoroscopy time was 30.9 hours (1852 minutes; mean, 39.4 minutes per case). Yearly total effective body doses for all surgeons (under lead) were below the 20 mSv/y occupational exposure limit of the ICRP. Outside lead doses for two surgeons approximated recommended limits. Lead aprons attenuated 85% to 91% of the dose. Ring doses and calculated eye doses were within the ICRP exposure limits. Patient skin doses averaged 360 mSv per case (range, 120-860 mSv). The ambient (> 3 m from the source) operating room dose was 1.06 mSv/y. Conclusions: Although the total effective body doses under lead fell within established ICRP occupational exposure limits, they are not negligible. Because radiation exposure is cumulative and endovascular procedures are becoming more common, individuals performing these procedures must carefully monitor their exposure. Our results indicate that a team of surgeons can perform 386 hours of fluoroscopy per year or 587 EAIA repairs per year and remain within occupational exposure limits. Individuals who perform these procedures should actively monitor their effective doses and educate personnel in methods for reducing exposure. (J Vasc Surg 2000;32:704-10.)

Patient Selection for Endovascular Repair of Aortoiliac Aneurysms

Purpose: This study was conducted to establish criteria to aid in the selection of patients for endovascular repair of aorto-iliac aneurysms. Methods: Characterization of pertinent factors used to determine whether a patient is eligible to undergo stent-graft repair of an aorto-iliac aneurysm. Principal findings and conclusions: The determinant factor that dictates whether or not one is eligible to undergo endovascular repair of aorto-iliac aneurysm is the arterial anatomy of the affected area and its surrounding vessels. Some of the initial limitations imposed in this technology have changed such as an acceptance of much shorter neck than initially conceptualized, by the use of supra-renal stent deployment. However, unsolved issues remain regarding the differentiation of thrombus and atherosclerotic plaque in the infra-renal aortic region, iliac artery disease, and the need to have an enhanced flexibility of the delivery system for proper deployment in tortuous aortic necks. The question of long-term device durability remains the most important issue that has to be taken into consideration before one chooses minimally invasive endovascular approaches.