2017 Volume 81 Issue 5 Pages 682-688
Background: Understanding that the common iliac arteries (CIA) are shorter in Asian patients, we investigated whether this anatomic difference affects the clinical outcomes of internal iliac artery (IIA) exclusion during endovascular aneurysm repair (EVAR) of aortoiliac aneurysm and thus limits the use of IIA-preserving devices in Japanese patients.
Methods and Results: From 2008 to 2014, 69 Japanese patients underwent EVAR of aortoiliac aneurysms with 53 unilateral and 16 bilateral IIA exclusions. One patient had persistent buttock claudication during follow-up; however, colonic or spinal cord ischemia was not observed. Anatomic suitability was investigated for the iliac branch device (IBD) by Cook Medical and the iliac branch endoprosthesis (IBE) by WL Gore: 87 aortoiliac segments were analyzed, of which 17% met the criteria for the IBD, 25% met the criteria for the IBE and 40% met the criteria for either. Main exclusions for the IBD were IIA diameter >9 mm or <6 mm (47%) and CIA length <50 mm (39%). Main exclusions for the IBE were proximal CIA diameter <17 mm (44%) and aortoiliac length <165 mm (24%).
Conclusions: EVAR with IIA exclusions in Japanese patients showed low incidence of persistent buttock claudication and no major pelvic complications. Aorto-iliac morphology demonstrated smaller proximal CIA diameters and shorter CIA lengths, limiting the use of IIA-preserving devices.
In 2004, Chang and colleagues first reported that Asian patients with abdominal aortic aneurysms (AAA) have shorter common iliac arteries (CIA) compared with the published literature.1 Their findings found an average right and left CIA length of 29.9 mm and 34.2 mm, respectively; and an aortoiliac length 20 mm shorter than previously noted. Their study also found that 51% coverage of the internal iliac artery (IIA) was necessary for endovascular aneurysm repair (EVAR) with the stent technology at that time. As traditional EVAR devices require distal fixation in the CIA, anatomic constraints such as short length and aneurysmal dilation preclude successful distal fixation and effective seal.2 Previous studies have shown that 15–40% of patients undergoing evaluation for AAA repair have unilateral or bilateral CIAs.3–11 Challenging iliac anatomy can be treated with graft extension into the external iliac artery at the expense of excluding the IIA, with the possibility of pelvic ischemia. Exclusion of the IIA can lead to a wide range of complications that are difficult to predict, from early buttock claudication to the more devastating colon and spinal cord ischemia.12
To preserve pelvic circulation, “branched limbs” or “branched devices” designed with an IIA stent have undergone multiple design revisions to minimize complications and suit a greater diversity of anatomy.13 The Cook (Bloomington, IN, USA) Iliac Branch Device (IBD) underwent multiple revisions to its design and was approved as CE-marked in Europe in 2006 and 2008.14,15 The WL Gore (Flagstaff, AZ, USA) Iliac Branch Endoprosthesis (IBE) was approved in Europe in November 2013 and in March 2016 in the USA.16,17 As these devices are not currently approved in Japan we investigated whether they would be suitable in Japanese patients according to the instruction for use (IFU) guidelines. We also report our clinical outcomes of EVAR of aortoiliac aneurysm with IIA exclusion.
We retrospectively reviewed all patients undergoing endovascular repair of aortoiliac aneurysm, defined as dilation of the infrarenal aorta and/or CIA 1.5-fold the normal size, at a single Japanese academic institution from January 2008 to December 2014. This study was approved by the institution’s review board. The study included patients who underwent EVAR with at least 1 aneurysmal CIA. Open procedures and patients undergoing repair for aneurysm rupture, pseudoaneurysm, or mycotic aneurysm were excluded from the study. Perioperative records, including patient demographics and intraoperative details, were noted. Patients were noted to have endovascular repair with either bilateral or unilateral IIA exclusion. Technical success was defined as exclusion of the aneurysm without type 1 or type 3 endoleaks on completion angiogram.
Patients’ records were investigated regarding re-intervention, major adverse events (MAE) and aneurysm-related death. Endoleak occurrence and endoleak type on follow-up imaging were noted. Symptoms related to IIA exclusion (i.e., buttock claudication, colonic ischemia, and spinal cord ischemia) were investigated. Buttock claudication symptoms were noted according to walking distance, and patients were followed to observe if there was a resolution of symptoms. Phone interviews were conducted as necessary to supplement clinic visit information.
Preoperative aortoiliac imaging data was reviewed on a 3-D workstation using Zio station 2 software (Ziosoft, Tokyo, Japan). Briefly, centerlines of flow were created from reconstructed CT studies and aortoiliac lengths and diameters were measured. Inclusion and exclusion criteria of the iliac branch systems from Cook Medical and WL Gore were investigated. For the Cook IBD, exclusion criteria included CIA length <50 mm, CIA Diameter <20 mm, external iliac artery (EIA) length <20 mm, EIA diameter <8 mm, IIA occluded or 50% stenosis, IIA aneurysm distal to landing zone, IIA length <10 mm, IIA diameter <6 or >9 mm. For the Gore IBE the exclusion criteria were: aortoiliac length <165 mm, CIA diameter <25 mm, proximal CIA diameter <17 mm, distal CIA diameter <14 mm, EIA length <10 mm, EIA diameter <6.5 or >25 mm, IIA length <10 mm, and IIA diameter <6.5 or >13.5 mm. The aortoiliac length was defined as the distance from the lowest renal artery to the IIA bifurcation. The IIA landing measurements were performed on the IIA segment before a first-order branch without aneurysmal dilation or stenotic lesions suitable for stent graft placement. Previously published data from American institutions18 were used to compare the aortoiliac aneurysm morphology in the current study.
Descriptive statistics were performed using Microsoft Excel (Bellvue, WA, USA). Differences in outcomes regarding patients undergoing bilateral and unilateral IIA exclusion were evaluated using a t-test for continuous variables and Chi-squared test or Fisher exact test for categorical values.
A total of 69 Japanese patients underwent EVAR with involvement of at least 1 CIA aneurysm during the study period. The mean age of the patients was 73.1 years and 93% were male. There were 53 patients who underwent unilateral IIA exclusion and 16 patients with bilateral IIA exclusion. Patient demographics for bilateral or unilateral IIA exclusion are shown in Table 1. The mean height, weight and BMI of the patients were 1.66 m (range 1.41–1.82), 64.1 kg (range 40–93), and 23.3 m/kg2 (range 16–31), respectively. Coronary artery disease (CAD) was higher in the unilateral group compared with the bilateral IIA exclusion group (43% vs. 13%, P=0.036) and was the only comorbidity with statistical significance.
| Total (n=69) |
Unilateral (n=53) |
Bilateral (n=16) |
P value | |
|---|---|---|---|---|
| Age (year)* | 73.1 (8.8) | 73.3 (9.2) | 72.4 (7.7) | 0.724 |
| Male sex (%) | 65 (93) | 49 (91) | 16 (100) | 0.566 |
| Height (m)* | 1.66 (0.07) | 1.65 (0.07) | 1.67 (0.07) | 0.456 |
| Weight (kg)* | 64.1 (9.1) | 63.16 (11.8) | 64.4 (8.3) | 0.962 |
| BMI (kg/m2)* | 23.3 (2.7) | 22.7 (2.7) | 23.5 (2.7) | 0.420 |
| HTN (%) | 55 (80) | 41 (77) | 14 (88) | 0.494 |
| DM (%) | 5 (7) | 5 (9) | 0 (0) | 0.583 |
| CAD (%) | 25 (36) | 23 (43) | 2 (13) | 0.036 |
| CVD (%) | 8 (12) | 8 (15) | 0 (0) | 0.183 |
| CHF (%) | 5 (6) | 4 (8) | 1 (6) | 1.000 |
| COPD (%) | 12 (17) | 11 (21) | 1 (6) | 0.270 |
| Preoperative Cr (mg/dL)* | 1.02 (0.37) | 1.00 (0.41) | 1.08 (0.36) | 0.503 |
| eGFR (mL/min/1.73m2)* | 59.8 (15.1) | 60.6 (15.1) | 57.3 (15.1) | 0.458 |
| Dialysis | 0 | 0 | 0 | NA |
| Smoking (%) | 57 (83) | 46 (87) | 11 (69) | 0.132 |
| ASA score* | 1.49 (0.61) | 1.45 (0.62) | 1.63 (0.61) | 0.337 |
| Antiplatelet (%) | 36 (52) | 31 (58) | 5 (31) | 0.565 |
| Anticoagulation (%) | 11 (16) | 9 (17) | 2 (13) | 1.000 |
*Continuous data are shown as the mean (standard deviation). ASA, American Society of Anesthesia; BMI, body mass index; CAD, coronary artery disease; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; CVD, cerebrovascular disease; DM, diabetes mellitus; eGFR, estimated glomerular filtration rate; HTN, hypertension.
Operative details regarding the technique for IIA exclusion are shown in Table 2. Staged procedures were performed in 36 patients (52%) to exclude the IIA with the coil-and-coverage technique.19 All patients underwent exclusion of the IIA using this technique except for 1 case of open ligation of the IIA.
| Total (n=69) |
Unilateral (n=53) |
Bilateral (n=16) |
P value | |
|---|---|---|---|---|
| Staged procedure (%) | 36 (52) | 29 (55) | 7 (44) | 0.570 |
| EVAR device | Ex - 27 | Ex - 15 | Ex - 12 | |
| Z - 19 | Z - 17 | Z - 2 | ||
| En - 17 | En - 15 | En - 2 | ||
| EPL - 6 | EPL - 6 | |||
| Operation time** (min)* | 230±116 | 201±82 | 327±156 | 0.006 |
| Blood loss (mL)* | 112±196 | 87±108 | 197±353 | 0.238 |
| Intraoperative complications | 1 | 1 - Embolization | 0 | 1.000 |
| Perioperative MAE | 2 | 1 - CFA Occlusion | 1 - Type B Dissection | 0.413 |
*Continuous data are shown as the mean±standard deviation. **Does not included time of staged procedures. Ex, Gore Excluder Device; En, Medtronic Endurant; EPL, Endologic Powerlink; Z, Cook Zenith Device.
Technical success of endovascular repair of the aortoiliac aneurysm was 100% in the 69 patients. The operative time for unilateral repair (201±82 min) was shorter than for bilateral repair (327±156, P=0.006). One intraoperative complication of limb thrombosis occurred, which was treated successfully with aspiration and additional stent graft placement. No intraoperative deaths occurred. There were 2 perioperative MAE in the follow-up period: 1 common femoral artery occlusion caused by flap occlusion at the femoral access site and requiring flap fixation on the day of the operation; 1 type B dissection with abdominal pain occurring 1 day after the initial operation and treated conservatively with blood pressure control.
Median follow-up was 39.8 months (interquartile range 24.1–59.7) and procedure-related complications are reported in Table 3. Regarding complications from IIA exclusion, no cases of colonic or spinal cord ischemia were observed. There were 23 occurrences of early buttock claudication, with 30% occurring in the unilateral group and 44% in the bilateral exclusion group (P=0.354). There was only 1 occurrence of persistent buttock claudication in the bilateral IIA exclusion group. The incidence of early buttock claudication was similar when excluding the IIA in a staged procedure (13/36, 36%) compared with EVAR with IIA exclusion during a single procedure (10/33, 30%, P=0.806). Analysis of the bilateral IIA exclusion group showed a higher incidence of early buttock claudication with a staged procedure (6/7, 86%) than with a single procedure (1/9, 11%, P=0.009).
| Total (n=69) |
Unilateral (n=53) |
Bilateral (n=16) |
P value | |
|---|---|---|---|---|
| Colon/spinal cord ischemia | 0 | 0 | 0 | NA |
| Buttock claudication - early (%) | 23 (33) | 16 (30) | 7 (44) | 0.354 |
| Average distance at onset (m)* | 485±507 | 539±539 | 364±437 | 0.426 |
| Buttock claudication - persistent (%) | 1 (1) | 0 | 1 (6) | 0.232 |
| No. of patients with endoleaks (%) | 18 (26) | 16 (30) | 2 (13) | 0.206 |
| Description of endoleaks** | Type 1 - 1 | Type 1 - 1 | Type 2 - 2 | |
| Type 2 - 19 | Type 2 - 17 | |||
| Type 3 - 2 | Type 3 - 2 | |||
| Late aneurysm-related complications (%) | 5 (7) | 5 (9) | 0 | 0.583 |
| No. of secondary procedures (%) | 5 (7) | 5 (9) | 0 | 0.583 |
*Continuous data are shown as the mean±standard deviation. **Two patients had multiple types of endoleaks (types 1 & 2, types 2 & 3).
Table 3 shows the details of 20 postoperative endoleaks in 18 patients; 4 of the 23 patients with early buttock claudication had type 2 endoleaks (17%) compared with 14 patients with endoleaks without buttock claudication (30%, P=0.384). The 5 late aneurysm-related complications occurred in the unilateral IIA exclusion group: 2 expanding aortoiliac aneurysms >5 mm, 1 type 1 endoleak, 1 left limb occlusion, and 1 right limb occlusion. Five secondary interventions were performed at an average of 21.5 months after initial operation (range 2–41 months) and included left stent graft extension, coiling for type 2 endoleak, proximal extension cuff, femoral bypass, and thrombectomy with stent insertion.
The anatomic characteristics of the aortoiliac aneurysm are shown in Table 4. The average infrarenal aortic length (125.1±19.6 mm) and CIA length (56.5±20.2 mm) were similar between the 2 groups. However, the aortoiliac length was longer in the bilateral IIA aneurysm group (189.6±34.3 mm) compared with the unilateral IIA group (177.5±22.2, P=0.05). The IIA length was longer for the bilateral IIA group (56.4±25.7 mm) compared with the unilateral group (46.8±14.0, P=0.028); however, the landing length was shorter in the bilateral group (19.6±16.2 mm) compared with the unilateral group (34.0±16.0, P<0.001). CIA and EIA diameters were similar in the 2 groups; however, the IIA diameters were larger in the bilateral IIA exclusion group.
| Total (n=87) |
Unilateral (n=58) |
Bilateral (n=29) |
P value | |
|---|---|---|---|---|
| Infrarenal aortic length | 125.1±19.6 | 122.8±18.2 | 129.6±21.4 | 0.125 |
| CIA length | 56.5±20.2 | 54.8±16.0 | 60.0±26.3 | 0.261 |
| Aortoiliac length | 181.6±27.5 | 177.5±22.2 | 189.6±34.3 | 0.053 |
| IIA length | 50.0±19.3 | 46.8±14.0 | 56.4±25.7 | 0.028 |
| IIA landing length | 29.2±17.8 | 34.0±16.0 | 19.6±16.2 | <0.001 |
| Ao max. diameter | 37.9±13.6 | 37.9±14.3 | 37.8±11.9 | 0.951 |
| Prox. CIA diameter | 19.4±7.7 | 18.3±5.7 | 21.6±10.2 | 0.057 |
| CIA max. diameter | 33.8±9.5 | 32.6±8.2 | 36.3±11.2 | 0.080 |
| CIA min. diameter | 15.1±3.9 | 14.6±3.1 | 16.0±4.9 | 0.111 |
| Distal CIA diameter | 20.8±5.7 | 19.6±5.4 | 23.2±5.4 | 0.004 |
| IIA max. diameter | 17.2±12.7 | 13.5±8.2 | 24.4±16.4 | <0.001 |
| IIA min. diameter | 8.2±4.9 | 7.1±2.6 | 10.3±7.1 | 0.004 |
| IIA landing diameter | 9.8±4.8 | 8.7±2.6 | 11.9±6.8 | 0.002 |
| EIA max. diameter | 9.6±1.5 | 9.5±1.4 | 9.8±1.7 | 0.279 |
| EIA min. diameter | 8.1±1.5 | 8.0±1.3 | 8.4±1.8 | 0.234 |
Expressed in mean (mm)± standard deviation. CIA, common iliac artery; EIA, external iliac artery; IIA, internal iliac artery.
Suitability of the 87 aneurysmal CIA segments for IIA-preserving devices is shown in Table 5. Of note there were 58 CIA segments that were analyzed in the 53 unilateral IIA exclusion group because 5 bilateral CIA aneurysms were treated with a traditional or bell-bottom limb on the non-excluded IIA side. There were 29 CIA segments analyzed in the 16 bilateral IIA exclusion group because there was 1 case of chronic external iliac occlusion leading to aorto-uni-iliac repair, 1 case of a chronically occluded IIA, and 1 case of IIA aneurysm requiring coiling in a non-aneurysmal CIA segment. Of the 87 CIA segments, 15 (17%) met the criteria for the IBD, 22 (25%) met the criteria for the IBE and 35 (40%) met the criteria for either. The main exclusions for the Cook IBD were IIA diameter being >9 mm or <6 mm (n=41; 47%), length of the CIA being <50 mm (n=34; 39%), and the EIA diameter being <8 mm (n=32; 37%). The main exclusions for the Gore IBE were proximal CIA diameter <17 mm (n=39; 44%) and aortoiliac length <165 mm (n=21; 24%).
| Cook IBD exclusion criteria |
n (%) | Gore IBE exclusion criteria |
n (%) |
|---|---|---|---|
| CIA length <50 mm | 34 (39) | Aortoiliac length <165 mm | 21 (24) |
| CIA diameter <20 mm | 2 (2) | CIA diameter <25 mm | 5 (6) |
| EIA length <20 mm | 8 (9) | Proximal CIA diameter <17 mm | 39 (44) |
| EIA diameter <8 mm | 32 (37) | Distal CIA diameter <14 mm | 4 (5) |
| IIA occluded or 50% stenosis | 1 (1) | EIA Length <10 mm | 6 (7) |
| IIA aneurysm distal to landing zone | 9 (10) | EIA diameter <6.5 or >25 mm | 13 (15) |
| IIA length <10 mm | 0 (0) | IIA length <10 mm | 0 (0) |
| IIA diameter <6 or >9 mm | 41 (47) | IIA diameter <6.5 or >13.5 mm | 13 (15) |
| Any factor | 72 (83) | Any factor | 65 (75) |
IBD, Iliac branch device; IBE, Iliac branch endoprosthesis.
Overall, the CIA were shorter inJapanese patients compared with American patients previously reported,18 but overall aortoiliac lengths were similar: 56.5±20.2 mm vs. 71.4±23.7 (P<0.001), 181.6±27.5 mm vs. 183.6±28.3 (P=0.584), respectively. Regarding the 29 CIA segments in the 16 patients with bilateral IIA exclusion, 5 segments (17%) met IFU criteria for the Cook IBD and 8 (28%) segments met IFU criteria for the Gore IBE.
In 2009, Verzini and colleagues reported their results for IIA exclusion vs. IIA preservation with the Cook IBD.20 Their study showed a lower frequency of iliac endoleaks (4% vs. 19%, P=0.07) and buttock claudication (4% vs. 22%, P=0.1) for the IIA preservation group compared with the IIA exclusion group. They concluded that IIA preservation should be considered in younger, active patients with suitable anatomy. Many other studies have confirmed high technical success using IIA-preserving devices with a low frequency of pelvic ischemia.21 However, these grafts are not available throughout worldwide and studies to determine the anatomic suitability and clinical outcomes according to ethnicity are limited.
Our study showed that the rate of early buttock claudication in Japanese patients undergoing EVAR for aortoiliac aneurysm with IIA exclusion was 33%. All but 1 patient had resolution of their symptoms and there were no major complications of colonic or spinal cord ischemia. Overall, our findings of early buttock claudication were consistent with published literature, occurring at 1.6–56% with IIA exclusion. However, our low rate of persistent buttock claudication (6%) is less than the previously noted occurrence of 10–45%.12 The reasons for this are unknown, but may be explained by a lower clotting profile in Japanese patients and a different response to anticoagulation therapy.22,23 Type 2 endoleaks, which are reported to be as high as 28% in Japanese patients,24 were not found to be protective of buttock claudication in our study.
There was a higher frequency of patients with buttock claudication and bilateral IIA exclusion (44%) vs. unilateral exclusion (30%); however, this was not statistically significant. A previous systemic review by Raya et al showed similar rates of buttock claudication and sexual dysfunction with unilateral and bilateral IIA exclusion, demonstrating the difficulty in predicting which patients are at risk.25 CAD, which was found at significantly lower frequency in the bilateral exclusion IIA group, may have contributed to those similar results because ventricular dysfunction is a preoperative risk factor for pelvic ischemia.26 Complications with bilateral IIA exclusion may be mitigated using a staged procedure or possible proximal iliac artery occlusion, allowing distal collateral arteries to provide pelvic ciculation.27–29 However, our series showed a higher incidence of early buttock claudication in the bilateral IIA exclusion group when a staged procedure was performed, which may be related to embolization of the distal arteries during the initial procedure. Currently, no consensus statement has been made regarding staged procedure or the necessity for IIA preservation.2
Re-intervention for IIA exclusion is reported to be 5–14.5%.20,30 In our series, there were 5 re-interventions (7%) during follow-up. There were no re-interventions in the bilateral IIA exclusion group. In the study by Verzini and colleagues the re-intervention rate was higher in the IBD group (16%) compared with their IIA exclusion group (6%); however, there were more type 2 endoleaks in the IIA exclusion group.20 A 5-year Cook IBD re-intervention rate of 20% with iliac limb occlusion occurring in approximately 10% of patients has been reported.31
This leads to a discussion of the cost of endovascular repair between IIA exclusion and IIA preservation. As branch devices cost approximately US$9000, not including the extension IIA stent, there may not be a strong financial advantage to using these branched devices in Japanese patients, given the low rate of pelvic ischemic complications and lower intervention rate. Micro coils cost approximately US$3500 dollars per occluded artery, but may be replaced with cheaper vascular plugs32 or even 0.035-inch coils. Although the major complication of colonic or spinal cord ischemia was not encountered in the present study, these scenarios can have significant long-term patient morbidity and need to be evaluated further. We did not evaluate sexual dysfunction, which also leads to increased morbidity and associated costs. As sexual dysfunction is not routinely evaluated in patients over 70 years of age at the study institution this is a limitation of the study.
Our anatomic analysis of aortoiliac aneurysm showed an average CIA length of 56.5 mm, which is longer than the previously reported length by Chang et al in AAA patients (29.2–34.2 mm), but shorter than in the published literature of aneurysms of the CIA (64.6–85 mm).18,33–35 Although Asian patients have a shorter non-aneurysmal CIA compared with the literature, when it becomes aneurysmal it also lengthens. When comparing the aortoiliac length we found that Japanese patients had similar lengths (181.6±27.5 mm) to patients treated in America (183.6±28.3 mm), which is somewhat surprising given Japanese patients are noted to have a shorter average height.36,37 Previous morphologic analysis of AAA without iliac aneurysms in Japanese patients found the average aortoiliac length to be 147.6 mm.38 This difference is likely explained by the iliac artery elongating and becoming more tortuous with aneurysmal degeneration. Masuda and colleagues previously described higher iliac tortuosity in Asian patients treated with EVAR in the United States.39 That study also highlighted the smaller EIA diameter in Asian patients (8.2±1.1 mm) undergoing EVAR for AAA, which was associated with endovascular access complications. Our study also found small EIA diameters (8.1±1.5 mm), consistent with the reported literature,38 which limited patients’ suitability for IIA-preserving devices.
Our study also demonstrated larger IIA diameters as well as distal CIA diameters in the bilateral IIA exclusion group compared with the unilateral group. This finding shows that the affected area becomes more diffuse and extends to the IIA when bilateral CIA aneurysms are present. Although there was greater aneurysmal dilation of the IIA in the bilateral group, this alone did not exclude the limbs from the use of IIA-preserving devices compared with the unilateral group.
The number of patients treated with IIA-preserving branch devices based on anatomic criteria was 15 (17%) for the Cook device and 22 (25%) for the Gore device, with 35 (40%) meeting the criteria for either. The main exclusion for the Cook IBD is an IIA diameter <6 mm of >9 mm, which excluded 41/87 (47%) segments in our study. Updated guidelines for the Cook IBD trial in mid-2014 increased the IIA diameter to 10 mm, which would have excluded 27/87 (31%) segments in our study, increasing the overall inclusion percentage from 17% to 22%. Other reasons for exclusion are based on inherent device designs. The Cook IBD incorporates a branch limb off an iliac limb, requiring a longer CIA segment and larger EIA diameter, whereas the IBE uses a short, narrow EVAR device to deploy above the iliac bifurcation, thereby requiring a proximal CIA diameter >17 mm and an aortoiliac length >165 mm. Our series showed similar percentages for inclusion for the Cook IBD (18–33%) and Gore IBE (23%).18,35,40 However, institutions and operators have successfully deployed these devices outside of the IFU according to institutional protocols.35 As overall inclusion percentages were similar in this Japanese study compared with global studies, this supports multinational clinical trials to evaluate new stent designs, such as was done for drug-eluting technology in peripheral arterial disease patients.41
A small series of IIA-preserving devices have been successfully deployed in Japanese patients with bilateral CIAs.42 The reported technical success rate was high and there were minimal short-term complications. Whether it will be cost-effective to implant future IIA-preserving devices in Japanese patients deserves further investigation. Individual patient presentation such as age, cardiac status, previous colonic resection, and possible thoracoabdominal aneurysms, as well as operator experience, need to be considered in the treatment choice for preserving IIA flow.
No major pelvic complications were observed in our series of patients with IIA exclusion during endovascular repair of aortoiliac aneurysms. Early buttock claudication was seen at rates similar to previous studies, while long-term buttock claudication was less than in the published literature. Analysis of aortoiliac morphology showed a smaller diameter of the proximal CIA and shorter CIA length. However, aortoiliac lengths were similar between Japanese patients and patients treated in the United States, which may be related to aortic elongation and increased tortuosity of the aneurysmal artery in Japanese patients. Although similar percentages of aortoiliac segment in Japanese patients were suitable for IIA-preserving devices within the IFU, ethnic differences in aortoiliac anatomy may warrant future stent design consideration.
None.
