Clinical Significance of Lumbar Artery Embolization in Addition to Inferior Mesenteric Artery Embolization to Reduce Persistent Type 2 Endoleak at Endovascular Aneurysm Repair

Abstract

Persistent type 2 endoleak (T2EL) after endovascular aneurysm repair (EVAR) leads to a higher likelihood of reintervention, sac enlargement, and other adverse outcomes. Although embolization of the inferior mesenteric artery (IMA-E) can decrease T2EL, additional effects of lumbar artery embolization (LA-E) remain undetermined. The aim was to evaluate the effects of pre-emptive LA-E at EVAR on the incidences of persistent T2EL and related complications. Safety and radiation exposure were also analyzed. Consecutive patients who underwent EVAR for abdominal aortic aneurysm between 2013 and 2021 were included. Pre-emptive embolizations were IMA-E before April 2018 and IMA-E plus LA-E thereafter. Patients with occluded IMA/LA, severe renal dysfunction, short life expectancy, or contraindication to contrast agents were not considered for pre-emptive embolization (NO-E). The incidence of T2EL, sac enlargement (>5 mm), reintervention, and other adverse events were compared among three different strategies, as well as radiation time and dose-area products. There were 243, 216, and 158 patients in the NO-E, IMA-E, and LA-E groups, respectively. Statistical differences in the backgrounds were found between age, sex, respiratory impairment, chronic kidney disease, hostile abdomen, aneurysm diameter, proximal neck length, right distal landing length, and device used. T2EL occurred at 20.7%, 24.0%, and 9.7% in the NO-E, IMA-E, and LA-E groups at 1 year, 27.7%, 30.8%, and 12.1% at 2 years, and 29.3%, 30.7%, and 9.8% at 3 years, respectively. After adjustment for confounding factors, LA-E compared with IMA-E was less likely to develop T2EL at 1 year (odds ratio [OR]: 0.31, 95% confidence interval [CI]: 0.14-0.66), 2 years (OR: 0.28, CI: 0.13-0.61), and 3 years (OR: 0.23, CI: 0.08-0.66). Similarly, LA-E compared with NO-E was associated with less T2EL at 1 year (OR: 0.45, CI: 0.21-0.96), 2 years (OR: 0.36, CI: 0.17-0.78), and 3 years (OR: 0.29, CI: 0.10-0.87). Reintervention until 3 years was less frequent after LA-E compared with IMA-E (OR: 0.18, CI: 0.05-0.63) and NO-E (OR: 0.15, CI: 0.04-0.50). Sac shrinkage was larger after LA-E compared with IMA-E (differences, 2.9 ± 1.4 mm) and NO-E (differences, 2.9 ± 1.4 mm). Surgical conversion, sac enlargement, rupture, and aneurysm-related death were not statistically different. No embolization-related complication was reported. Radiation time (minutes) and dose-area products (Gycm2) for NO-E, IMA-E, and LA-E were 61 ± 47, 58 ± 39, and 76 ± 43 (P = .0002) and 432 ± 330, 471 ± 345, and 640 ± 454 (P < .0001), respectively. LA-E in addition to IMA-E can decrease persistent T2EL and reintervention over 3 years. Although excessive radiation exposure limits routine use of LA-E and warrants future innovation on imaging guidance, longer-term effects of LA-E are encouraging.Table IBackground characteristicsNone (n = 243)IMA-E (n = 216)IMA+LA-E (n = 158)P valueAge, mean ± SD77.0 ± 0.674.8 ± 0.675.6 ± 0.7.02Age, median (IQR)78 (72-83)76 (69-81)77 (70-82)Sex, male, No. (%)184 (75.7)187 (86.6)125 (79.1).01HT, No. (%)206 (85.1)181 (83.8)124 (78.5).21DM, No. (%)34 (14.1)33 (15.3)23 (14.6).93Stroke, No. (%)44 (18.2)27 (12.5)30 (19.0).16CAD, No. (%)65 (26.9)50 (23.2)30 (19.0).19Respiratory impairment, No. (%)87 (36.0)76 (35.2)75 (47.5).03Smoking, No. (%)193 (79.4)178 (82.4)118 (74.7).41 Ex/current124/69115/6383/35CKD, No. (%)122 (50.2)85 (39.4)79 (50.0).03 3/4/594/20/873/9/372/5/2Hostile abdomen, No. (%)121 (50.0)95 (44.0)48 (30.4).0005Aneurysm diameter, mean ± SD, mm52.4 ± 9.750.0 ± 7.950.2 ± 7.8.002Proximal neck diameter, mean ± SD, mm22.7 ± 3.522.2 ± 3.722.1 ± 3.3.21Proximal neck length, mean ± SD, mm26.1 ± 12.731.1 ± 15.027.7 ± 12.9.0005Right leg landing CIA/EIA168/67166/4697/58.02 CIA diameter, mean ± SD, mm13.7 ± 2.914.1 ± 2.613.8 ± 2.7.54 EIA diameter, mean ± SD, mm9.1 ± 1.610.0 ± 2.89.8 ± 2.1.08Left leg landing CIA/EIA189/44181/31124/31.38 CIA diameter, mean ± SD, mm13.5 ± 3.513.8 ± 3.114.0 ± 2.8.33 EIA diameter, mean ± SD, mm9.6 ± 2.49.9 ± 2.510.2 ± 2.7.57Device, n (%).008 Endurant133 (54.7)151 (69.9)86 (54.4) Excluder86 (35.4)53 (24.5)56 (35.4) Zenith9 (3.7)4 (1.9)10 (6.3) Others15 (6.2)8 (3.7)6 (3.8)CAD, Coronary artery disease; CIA, common iliac artery; CKD, chronic kidney disease; DM, diabetes mellitus; EIA, external iliac artery; HT, hypertension; IMA-E, embolization of the inferior mesenteric artery; IMA+LA-E, inferior mesenteric artery lumbar artery embolization; IQR, interquartile range; SD, standard deviation.Boldface P values represent significance P < .05. Open table in a new tab Table IIMultivariate analysis adjusted for imbalanced factors in the backgroundsComparisonOR95% CIP valueType 2 endoleak 1 yearIMA vs none1.450.83-2.55.19IMA+LA vs none0.450.21-0.96.04IMA+LA vs IMA0.310.14-0.66.003 2 yearsIMA vs none1.270.74-2.18.39IMA+LA vs none0.360.17-0.78.009IMA+LA vs IMA0.280.13-0.61.001 3 yearsIMA vs none1.300.71-2.38.40IMA+LA vs none0.290.10-0.87.03IMA+LA vs IMA0.230.08-0.66.007Age1.051.01-1.09.009Reintervention Until 3 yearsIMA vs none0.810.44-1.53.52IMA+LA vs none0.150.04-0.50.002IMA+LA vs IMA0.180.05-0.63.008CI, Confidence interval; IMA, inferior mesenteric artery; LA, lumbar artery; OR, odds ratio.Boldface P values represent significance P < .05. Open table in a new tab