Chad P. Ammar

Volumetric analysis of the initial index computed tomography scan can predict the natural history of acute uncomplicated type B dissections

OBJECTIVE Our objective was to characterize the predictive impact of computed tomography (CT) scan volumetric analysis on the natural history of acute uncomplicated type B aortic dissections (ADs). METHODS We conducted a retrospective review of patients with acute type B ADs from 2009 to 2014. On an iNtuition workstation (TeraRecon, Foster City, Calif), volume measurements were obtained using the true lumen volume (TLV), false lumen volume (FLV), and total aortic volume from the left subclavian artery to the celiac artery. Growth rate was calculated as the change in maximal diameter between first and last available CT scans during the time interval. The primary outcome of the study was delayed aortic intervention. P < .05 was considered statistically significant. RESULTS During a 5-year period, 164 patients had CT scan evidence of acute type B ADs; 11 patients were excluded for lack of subsequent follow-up imaging; 36 patients who underwent urgent repair (<14 days from presentation) were also excluded. We evaluated a total of 117 patients: 85 patients who did not require intervention and 32 who underwent delayed (>14 days) thoracic endovascular aneurysm repair (29) or open repair (3). Mean age was 66 ± 12 years. Mean TLV/FLV ratio on initial CT scan was significantly higher in patients who did not eventually require an operation (1.55 vs 0.82; P = .02). The mean growth rate was higher in those eventually requiring operation (2.47 vs 0.42 mm/mo; P = .003). Patients were divided into three subgroups on the basis of their initial imaging TLV/FLV ratios (<0.8, 0.8-1.6, and >1.6). There was a significant difference in the growth rates between these three groups (4.6 vs 2.4 vs 0.8 mm/mo; P < .025). Area under the receiver operating characteristic curve analysis revealed that a TLV/FLV ratio <0.8 was highly predictive for requiring an intervention (area = 0.8; sensitivity, 69%; specificity, 84%: positive predictive value, 71%; negative predictive value, 81%), with an odds ratio of 12.2 (confidence interval, 5-26; P < .001). Conversely, a TLV/FLV ratio of >1.6 was highly predictive for freedom from delayed operation (sensitivity, 91%; specificity, 42%; positive predictive value, 61%; negative predictive value, 86%). After Kaplan-Meier analysis, 1-year and 2-year survival free of aortic interventions was 60% and 42% with a TLV/FLV ratio <0.8 and 92% and 82% with a ratio >1.6 (P = .001). CONCLUSIONS Initial CT scan volumetric analysis in patients presenting with uncomplicated acute type B ADs is a useful tool to predict growth and need for future intervention.

Abdominal aortic aneurysm anatomic severity grading score predicts implant-related complications, systemic complications, and mortality

OBJECTIVE The aim of our study was to examine the predictive value of the anatomic severity grading (ASG) score for abdominal aortic aneurysms (AAAs) on implant-related complications, systemic complications, and mortality at 30-day and midterm, defined as 2 years, follow-up assessments. METHODS Patients who underwent endovascular aneurysm repair for infrarenal AAAs between 2009 and 2012 were retrospectively reviewed, and ASG scores were calculated from three-dimensonal computed tomography reconstructions. Two independent patient groups were created: those with a low ASG score (score <14) and those with a high ASG score (score ≥14). RESULTS We identified 190 patients (77% male), with a mean age of 73 years, and 84% Caucasian, with 104 patients in the low-score group and 86 in the high-score group. Within 30 days of the index endovascular aneurysm repair, 10 implant-related complications occurred in six patients (3%) and 25 systemic complications in 18 (9%). The incidence of 30-day implant-related complications was not significantly different between the low-score group (2 [2%]) and the high-score group (4 [5%]; P = .41). The incidence of patients with 30-day systemic complications was significantly different between the low-score group (5 [5%]) and the high score group (13 [15%]; P = .023). A composite end point of combined implant-related and systemic complications at 30 days showed there was a statistically significant difference between the low-score (7 [7%]) and high-score group (17 [20%]; P = .007). At a midterm follow up of 26 months (range, 1-64 months), implant-related complications occurred in 21 patients (11%), and systemic complications occurred in 29 (15%). The incidence of implant-related complications was significantly different between the low-score group (7 [7%]) and the high-score group (14 [16%]; P = .037). The incidence of midterm systemic complications was significantly different between the low-score group (11 [11%]) and the high-score group (18 [21%]; P = .048). A composite end point of combined implant-related and systemic complications at midterm follow-up resulted in a statistically significant difference between the low-score group (16 [15%]) and the high-score group (26 [30%]; P = .014). Kaplan-Meier analysis revealed that the low-score group had fewer overall complications (combined implant-related and systemic) at 1 year (14% vs 34%) and 2 years (15% vs 45%) compared with the high-score group (P < .001). The low-scoring group also had significantly higher survival at 1 year (96% vs 86%) and 2 years (88% vs 84%) compared with the high-score group (P = .047). CONCLUSIONS The AAA ASG score can be used to predict patients at risk for midterm implant-related complications, 30-day and midterm systemic complications, and all-cause mortality.

The effect of demographic factors and lesion severity on iliac stent patency

OBJECTIVE The aim of our study was to perform a large multivariate analysis to identify demographic, anatomic, or procedural factors that affect iliac artery stent primary patency (PP). METHODS Patients receiving iliac stents from 2007 to 2013 were retrospectively reviewed. Univariate analysis assessed cohort characteristics and their effect on PP. Variables considered significant (P < .05) were brought forward in the multivariate analysis. RESULTS A total of 213 patients underwent primary iliac artery stenting, and 307 limbs were analyzed. The average age was 66 years (range, 38-93 years), 54% were male, and 55% were Caucasian. Indications for procedure were claudication in 68%, rest pain in 20%, and tissue loss in 12%. All TransAtlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) II classifications were included: 51% TASC II A, 25% TASC II B, 13% TASC II C, and 11% TASC II D. The treated anatomic locations were 27% isolated external iliac artery (EIA), 56% isolated common iliac artery, and 17% combined common iliac artery and EIA. Multivariate analysis found three factors were correlated with decreased PP: non-Caucasian race (hazard ratio [HR], 1.84; 95% confidence interval [CI], 1.08-3.13; P = .025), younger age (HR, 1.04; 95% CI, 1.01-1.08; P = .006), and presence of EIA occlusion (HR, 2.02; 95% CI, 1.05-3.89; P = .036). Overall, Kaplan-Meier analysis at 1 and 3 years revealed a PP of 86% and 53%, assisted PP of 98% and 89%, and secondary patency of 99% of 98%. Kaplan-Meier analysis showed PP at 1 year for was 91% Caucasian patients vs 77% for non-Caucasian (P = .001). PP was 75% in patients aged <60 years, 86% in patients aged 60-70 years, and 96% in patients aged >70 years, with a significant difference between all groups (P < .001). PP was significantly different for those with and without EIA occlusion (P = .002), with 1-year PP of 71% and 88%, respectively. CONCLUSIONS In our experience with a large number of iliac interventions, younger age, non-Caucasian race, and EIA occlusion were strong predictors for loss of PP.

TEVAR Rescue of an Embolized Edwards SAPIEN XT Valve Following TAVR.

Purpose: To report a successful method of managing an embolized Edwards SAPIEN XT aortic valve prosthesis using a thoracic endovascular aortic repair rescue. Case Report: An 84-year-old man underwent transcatheter aortic valve replacement using a 26-mm Edwards SAPIEN XT valve, which immediately embolized into the ascending aorta. Because of the severe tapering of the patient’s transverse aortic arch, the embolized valve was unable to be maneuvered further down the aorta. Therefore, a Cook 36×80-mm Zenith Dissection Endovascular System (ZDES) bare metal stent was used on a compassionate basis to append the embolized valve between the patient’s coronary artery ostia and the innominate artery takeoff within the ascending aorta, with no neurological or cardiovascular complications at 12-month follow-up. Conclusion: A Cook ZDES bare metal stent may be successfully used to append an embolized Edwards SAPIEN XT valve within the ascending aorta.