Intraoperative Pedal Pressure Changes Offers Another Quantitative Assessment for Revascularization.

BACKGROUND: Lower extremity angiography is one of the most prevalent vascular procedures performed, generally via the contralateral common femoral artery. The use of retrograde pedal artery access to perform angiography has long been reserved as a "bail-out" technique to help cross chronic total occlusions that were not amenable from an antegrade approach. Recently, there have been reports and discussions involving increased utilization of pedal access for primary revascularization. The purpose of this study is to describe the outcomes of pedal access as a primary approach and to propose a novel evaluation of distal perfusion changes associated with interventions using direct pressure measurements. METHODS: A retrospective observational study evaluating all patients who underwent lower extremity angiography via retrograde pedal access between December 1, 2020, and June 30, 2021, within a single health-care system spanning 3 hospitals was performed. Demographics, comorbidities, procedural indications, and details were all recorded. Hemodynamic measurements were obtained and recorded upon initial pedal access and post intervention with a pressure transducer connected directly to the access sheath. Outcomes were analyzed with paired t-test. RESULTS: Twenty-eight angiograms using primary pedal access for endovascular intervention were performed during the study period. Most patients were African American (75%) females (57.1%) with hypertension (89.3%), hyperlipidemia (78.6%), diabetes (85.7%), coronary artery disease (64.3%), and current tobacco users (57.1%). The most prevalent indication for angiography was nonhealing wounds (67.9%). Pedal access was mostly achieved via the anterior tibial artery (79%). Sixty-three vessels were treated during the 28 angiograms (averaging 2.3 vessels per angiogram), most commonly the superficial femoral (27%), anterior tibial (25%), and popliteal (22%) arteries. Balloon angioplasty with or without stenting (98.5%) was predominately performed with an overall technical success rate of 94%. The mean preintervention and postintervention pressures were 36.5 mm Hg (standard deviation [SD] 25.7) and 83.4 mm Hg (SD 19.5), respectively. The mean change in pressure after intervention was 46.9 mm Hg (SD 23.3) (Table 3). There was a statistically significant difference detected between preintervention and postintervention pressure (P < 0.001) (Figure 1). There were no major amputations or adverse cardiovascular events at a mean first follow-up duration of 89 days. Six of the total 28 patients (21.4%) underwent repeat endovascular intervention on the ipsilateral extremity within a median of 45 (interquartile range 22.5-62.3) days. CONCLUSIONS: Primary pedal access is a viable option for performing lower extremity angiographic interventions. A significant increase in pedal artery pressure can be observed after angiographic intervention from retrograde pedal artery access. Further studies are necessary to define the clinical prognostic importance of these findings in relation to wound healing rates.

Optimization of factors for the prevention of spinal cord ischemia in thoracic endovascular aortic repair.

OBJECTIVES: Spinal cord ischemia following thoracic endovascular aortic repair (TEVAR) is a devastating complication. This study seeks to demonstrate how a standardized protocol to prevent spinal cord ischemia affects incidence in patients undergoing TEVAR. METHODS: Using CPT codes 33880 and 33881, all TEVAR procedures performed at a single tertiary care center from January 2017 to December 2018 were examined. Patients who had concomitant ascending aortic repairs or a TEVAR for traumatic indications were excluded from analysis, leaving 130 TEVAR procedures. Comorbid conditions, procedural characteristics, extent of coverage, peri-procedural management strategies, and post-operative outcomes were collected and analyzed retrospectively. RESULTS: One hundred thirty patients undergoing TEVAR were examined for four perioperative variables: postoperative hemoglobin greater than 10 g/dL, subclavian revascularization, preoperative spinal drain placement, and somatosensory evoked potential monitoring (SSEP). All conditions were met in 46.2% (60/130) of procedures; 37.8% (28/74) in emergent/urgent cases and 61.5% (32/52) in elective cases. Of patients who required subclavian coverage, 87.1% (54/62) underwent subclavian revascularization; 70.8% (92/130) of patients received spinal drains preoperatively; 68.5% (89/130) of patients had SSEP monitoring; 73.8% (93/130) of patients obtained a postoperative hemoglobin of >10 g/dL. Out of all patients, two (1.5%) developed spinal cord ischemia. CONCLUSION: Incidence of spinal cord ischemia in our cohort was low at 1.5% (2/130). Individual and bundled interventions for the prevention of spinal cord ischemia were unable to demonstrate a statistically significant effect given the low rate. Nonetheless, we advocate for a proactive approach for the prevention of spinal cord ischemia given our experience in this complex population.

Transcarotid Arterial Revascularization Adoption Should not Be Hindered by a Concern for a Long Learning Curve.

BACKGROUND: Transcarotid arterial revascularization (TCAR) offers a novel technique for carotid artery stenting (CAS) that provides flow reversal in the carotid artery and avoids aortic arch manipulation, thus, potentially lowering ipsilateral and contralateral periprocedural stroke rates. As a new technology, adoption may be limited by concern for learning a new technique. This study seeks to examine the number of cases needed for a surgeon to reach technical proficiency. METHODS: Retrospective analysis was performed using a prospectively collected database of all TCAR procedures performed in a tertiary health care system between 2016 and 2020. Patient demographics and anatomic characteristics were collected. Intraoperative variables and perioperative outcomes were examined. These variables were collated into groups for the first 4 procedures, procedures 5-8, and after 8. Independent Samples t test, 1-way ANOVA, and logarithmic regression were used to statistically analyze the data. RESULTS: One-hundred and eighty-seven TCARs were performed by 14 surgeons. One hundred and twenty-two (65%) were male, 59 (32%) were older than 75 years, and 83 (44%) were symptomatic. The most common indications were high-lesions in 87 patients (47%) and recurrent stenosis after CEA in 37 patients (20%). Significant differences were found between the first and second groups of 4 cases when comparing mean operative time (71 vs. 58 min; P = 0.001) and flow reversal time (10.8 vs. 7.9 min; P= 0.004). similar significant differences were found between the first and third groups of 4 cases but not between the second and third groups. There was a reduction in contrast usage and fluoroscopy time after the first 4 cases, however, this did not reach statistical significance. There was no ipsilateral perioperative strokes. One patient had a contralateral stroke on postoperative day 2 due to intracranial atherosclerosis, and there was one perioperative mortality that occurred on postoperative day 3 after discharge. CONCLUSIONS: Procedural and flow reversal times significantly shorten after 4 TCAR procedures are performed. Other metrics, such as fluoroscopy time and contrast usage, are also decreased. Complications, in general, are minimal. Proficiency in TCAR, as measured by these metrics, is met after performing only 4 procedures.

Results of Obturator Foramen Bypass in Patients with Groin Infection and Arterial Involvement.

BACKGROUND: Arterial bypass tunneling via the obturator foramen (OFB) can be performed to circumvent groin infections during lower extremity revascularization. The objective of this study is to report safety and efficacy outcomes of OFB in the setting of infected femoral pseudoaneurysms and infected prosthetic femoral bypass grafts. METHODS: A multihospital, single-entity healthcare system retrospective review was conducted for all patients who underwent OFB between January 2014 through June 2020. Any patient >18 years of age who underwent OFB in the setting of groin infection with a minimum of 30 days follow-up was included in the trial. Demographic, operative, and clinical characteristics of patients were gathered during chart review. Statistical analysis was performed using Microsoft Excel and R studio. RESULTS: Seventeen patients underwent OFB during the defined time-period. Demographic data are presented in the first table (Demographic Characteristics). Mean American Society of Anesthesiologists score was 3.25. Mean estimated blood loss was 500 mL. Mean operative time was 307 min. Mean follow-up time was 8.5 months (range 0-35 months). In total, 41.2% patients underwent fluoroscopic-guided tunneling, and, when compared to blind tunneling, showed no difference in intraoperative complications or operative time (P value 0.3). In total, 52.9% of patients required ICU admission resulting in a mean number of 0.8 ICU days. The overall mean length of stay was 16.8 days. Two major amputations were reported during follow-up. Patient mortality within 30 days was 0%. Primary patency within 30 days was 100%. Intravenous drug use was not associated with an increased number of subsequent groin wound procedures (P value 0.3). Intravenous drug use was not associated with concomitant methicillin-resistant Staphylococcus aureus infection (P value 0.3). CONCLUSION: OFB is a safe and effective surgical option in patients who are unable to undergo anatomic tunneling during lower extremity bypass. OFB is associated with favorable rates of primary patency and amputation-free survival at midterm follow-up.

Systematic review and meta-analysis of endovascular interventions for Stanford type A aortic dissection.

OBJECTIVE: The standard surgical approach to Stanford type A aortic dissection is open repair. However, up to one in four patients will be declined surgery because of prohibitive risk. Patients who are treated nonoperatively have an unacceptably high mortality. Endovascular repair of the ascending aorta is emerging as an alternative treatment for a select group of patients. The reported rates of technical success, mortality, stroke, and reintervention have varied. The objective of the study was to systematically report outcomes for acute type A dissections repaired using an endovascular approach. METHODS: The systematic review and meta-analysis was conducted in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. We performed online literature database searches through April 2020. The demographic and procedural characteristics of the individual studies were tabulated. Data on technical success, short-term mortality, stroke, and reintervention were extracted and underwent meta-analysis using a random effects model. RESULTS: Fourteen studies with 80 cases of aortic dissection (55 acute and 25 subacute) were included in the final analysis. A wide variation was found in technique and device design across the studies. The outcomes rates were estimated at 17% (95% confidence interval [CI], 10%-26%) for mortality, 15% (95% CI, 8%-23%) for technical failure, 11% (95% CI, 6%-19%) for stroke and 18% (95% CI, 9%-31%) for reintervention. The mean Downs and Black quality assessment score was 13.9 ± 3.2. CONCLUSIONS: The technique for endovascular repair of type A aortic dissection is feasible and reproducible. The results of our meta-analysis demonstrate an acceptable safety profile for inoperable patients who otherwise would have an extremely poor prognosis. Data from clinical trials are required before the technique can be introduced into routine clinical practice.

Transcarotid Endovascular Repair of Extracranial Internal Carotid Artery Aneurysms Using Flow Reversal for Distal Embolic Protection.

Extracranial carotid artery aneurysms (ECAAs) have a low incidence between 0.4% and 4% of all peripheral artery aneurysms and involving 0.1-2% of all carotid artery procedures. Some form of repair is generally warranted as nonoperative management has shown mortality as high as 71%. However, to date a standard method for ECAA repair has not been suggested. Generally, open surgical repair is the preferred technique; however, it has its own limitations and risks. Recently, endovascular approach is increasingly being used not only for the elective repair of unruptured ECAA but also for the management of ruptured ECAA. Herein we present 3 cases of distal extracranial internal carotid artery aneurysms treated with placement of stent grafts.

Comparison of commercially available versus customized branched-fenestrated devices in the treatment of complex aortic aneurysms.

OBJECTIVE: To evaluate and compare the early outcomes of patients treated for complex aortic aneurysms using a commercially available Zenith fenestrated endograft (ZFEN) or an advanced customized fenestrated-branched endovascular repair, which includes custom-made device or off-the-shelf p-branch devices available for use in a physician-sponsored investigational device exemption (PSIDE). METHODS: Between July 2012 and July 2015, patients who underwent to complex aortic aneurysms repair at University of North Carolina-Chapel Hill were retrospectively analyzed using data prospectively collected in electronically maintained aortic database. Patients were separated in two groups: ZFEN and PSIDE (custom-made device and p-branch). Demographics data, cardiac risk factors, comorbidities, computed tomography angiography anatomic measurements (aneurysm diameter, length of aortic coverage above the celiac artery), procedural data (operative time, estimated blood loss, intraoperative complications), and 30-day outcomes (mortality, major adverse cardiac events, stroke/transient ischemic attack, paraplegia, gastrointestinal complications, visceral branch complications, and endoleak) were analyzed. RESULTS: Among the 131 repairs for complex aortic aneurysms (juxtarenal or thoracoabdominal), there were 60 ZFEN and 71 PSIDE devices. Demographics and risk factors had similar distribution between groups, except that PSIDE patients more commonly had a history of previous aortic surgery (33% vs 5% [ZFEN]; P = .0001). PSIDE patients had a greater number of stented vessels (3.4 vs 2.2; P < .001) and length of aortic coverage (72 mm vs -13.4 mm) than ZFEN; however, no differences were seen in operative time, estimated blood loss or fluoroscopic time. Early outcomes were similar between groups, except for duration of hospital stay, which was significantly longer in PSIDE cohort (4.4 days vs 3.3 days; P = .05). CONCLUSIONS: More advanced fenestrated-branched endovascular repair does not seem to increase the complications associated with repair compared with patients receiving a ZFEN device in an experienced treatment center. Although mortality and morbidity were comparable between the groups, further studies evaluating long-term outcomes are needed.

The role of selective stenting for superior mesenteric artery scallops during fenestrated endovascular aneurysm repair.

OBJECTIVE: Stenting of small fenestrations of the Zenith fenestrated endograft (ZFEN; Cook Medical, Bloomington, Ind) is necessary during fenestrated endovascular aneurysm repair (FEVAR) of complex abdominal aortic aneurysms to avoid malalignment. However, stenting of superior mesenteric artery (SMA) scallops of ZFEN devices is optional according to the instructions for use. The objective of this study was to assess the early and midterm outcomes of selective use of stents in SMA scallops of ZFEN during FEVAR procedures. METHODS: This study is a single-institution retrospective review of prospectively enrolled patients treated at the University of North Carolina at Chapel Hill between July 2010 and August 2014. Only patients with SMA scallops were included for analysis. We compared results between patients grouped as stented or unstented SMA scallops. The scallops were stented when one or more of the following criteria were present: misalignment of scallop determined by balloon testing intraoperatively; configuration consisting of an SMA scallop and a single renal fenestration or stent; and pre-existing stenosis in the vessel adjacent to the graft scallop. The study was approved by the local Institutional Review Board. Primary outcomes addressed were mortality, vessel patency, early and late complications, and reintervention rates. Baseline characteristics of the patients and procedure data were also described. RESULTS: During the 48-month study period, 61 patients were treated for complex abdominal aortic aneurysms at the University of North Carolina with a mean age of 73 years, and 74.3% of patients were male. Thirty-nine of 61 patients (63.9%) had a device design with an SMA scallop and were included for analysis. Eleven of 39 patients (28%) had the SMA primarily stented and 28 (72%) were unstented. There was only one death (2.5%) during the 30-day postoperative period, with 100% technical success and branch patency. In the unstented group, there were three SMA complications during follow-up, two requiring reintervention; however, there were no associated deaths. Among the stented group, there was one branch-related complication that occurred during the procedure but no stent stenosis or occlusion during the long-term follow-up. During the mean follow-up period of 21.7 months, no SMA stent thrombosis occurred. There was no statistical difference in outcomes between groups. CONCLUSIONS: Single-wide SMA scallops of ZFEN during FEVAR procedures may be selectively stented using specific criteria and rigorous follow-up, without compromising the safety and efficacy of the SMA.

The impact of current smoking on outcomes after infrainguinal bypass for claudication.

OBJECTIVE: Although smoking cessation is a benchmark of medical management of intermittent claudication, many patients require further revascularization. Currently, revascularization among smokers is a controversial topic, and practice patterns differ institutionally, regionally, and nationally. Patients who smoke at the time of revascularization are thought to have a poor prognosis, but data on this topic are limited. The purpose of this study was to evaluate the impact of smoking on outcomes after infrainguinal bypass for claudication. METHODS: Data from the national Vascular Quality Initiative from 2004 to 2014 were used to identify infrainguinal bypasses performed for claudication. Patients were categorized as former smokers (quit >1 year before intervention) and current smokers (smoking within 1 year of intervention). Demographic and comorbid differences of categorical variables were assessed. Significant predictors were included in adjusted Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) by smoking status for outcomes of major adverse limb event (MALE), amputation-free survival, limb loss, death, and MALE or death. Cumulative incidence curves were created using competing risks modeling. RESULTS: We identified 2913 patients (25% female, 9% black) undergoing incident infrainguinal bypass grafting for claudication. There were 1437 current smokers and 1476 former smokers in our study. Current smoking status was a significant predictor of MALE (HR, 1.27; 95% CI, 1.00-1.60; P = .048) and MALE or death (HR, 1.22; 95% CI, 1.03-1.44; P = .02). Other factors found to be independently associated with poor outcomes in adjusted models included black race, below-knee bypass grafting, use of prosthetic conduit, and dialysis dependence. CONCLUSIONS: Current smokers undergoing an infrainguinal bypass procedure for claudication experienced more MALEs than former smokers did. Future studies with longer term follow-up should address limitations of this study by identifying a data source with long-term follow-up examining the relationship of smoking exposure (pack history and duration) with outcomes.

Performance of acoustic radiation force impulse ultrasound imaging for carotid plaque characterization with histologic validation.

OBJECTIVE: Stroke is commonly caused by thromboembolic events originating from ruptured carotid plaque with vulnerable composition. This study assessed the performance of acoustic radiation force impulse (ARFI) imaging, a noninvasive ultrasound elasticity imaging method, for delineating the composition of human carotid plaque in vivo with histologic validation. METHODS: Carotid ARFI images were captured before surgery in 25 patients undergoing clinically indicated carotid endarterectomy. The surgical specimens were histologically processed with sectioning matched to the ultrasound imaging plane. Three radiologists, blinded to histology, evaluated parametric images of ARFI-induced peak displacement to identify plaque features such as necrotic core (NC), intraplaque hemorrhage (IPH), collagen (COL), calcium (CAL), and fibrous cap (FC) thickness. Reader performance was measured against the histologic standard using receiver operating characteristic curve analysis, linear regression, Spearman correlation (ρ), and Bland-Altman analysis. RESULTS: ARFI peak displacement was two-to-four-times larger in regions of NC and IPH relative to regions of COL or CAL. Readers detected soft plaque features (NC/IPH) with a median area under the curve of 0.887 (range, 0.867-0.924) and stiff plaque features (COL/CAL) with median area under the curve of 0.859 (range, 0.771-0.929). FC thickness measurements of two of the three readers correlated with histology (reader 1: R2 = 0.64, ρ = 0.81; reader 2: R2 = 0.89, ρ = 0.75). CONCLUSIONS: This study suggests that ARFI is capable of distinguishing soft from stiff atherosclerotic plaque components and delineating FC thickness.

Results from multiple prospective single-center clinical trials of the off-the-shelf p-Branch fenestrated stent graft.

OBJECTIVE: The purpose of this study was to report prospective data of an off-the-shelf fenestrated endograft (Zenith p-Branch; Cook Medical, Bloomington, Ind) from four centers for the treatment of patients with pararenal abdominal aortic aneurysms. METHODS: Data were combined from four single-center investigational studies conducted in the United States and Europe. The p-Branch endograft consists of a proximal off-the-shelf component incorporating a scallop for the celiac artery, a superior mesenteric artery fenestration, and two conical pivot fenestrations to preserve flow to the renal vessels. The device is available in two configurations, a left renal fenestration at the same (configuration A) or lower (configuration B) longitudinal position than the right to accommodate varied anatomy of the patients. RESULTS: Between August 2011 and September 2015, 76 patients (82% male; mean age, 72 years; 65 elective and 11 emergent) were enrolled, with 55% implanted with option A and 45% with B. The device was deployed successfully in all patients, and stents were placed in all target vessels except in three cases (one elective, two emergent): a left kidney was sacrificed in one patient, and a right renal artery was left unstented in two patients during the index procedure. There was no 30-day mortality. During follow-up (mean, 25 ± 13 months), 10 late deaths occurred (6 elective, 4 emergent; none related to device or procedure), and there were no ruptures or conversions to open repair. Two patients experienced bowel ischemia; one case resolved with nonoperative treatment and one required superior mesenteric artery and celiac artery angioplasty and stent placement. Renal artery occlusion occurred in eight patients (11%) and was deemed procedure related in 63% (5/8) of these patients. Four of these were successfully intervened on with preservation of renal function. The overall renal insufficiency incidence was 7% (5/76). One patient developed renal failure requiring dialysis. CONCLUSIONS: Early results incorporating learning curves for physicians with a new device and delivery system indicate that the use of the Zenith p-Branch device is feasible and safe. Long-term follow-up is needed to assess the effectiveness and durability of this treatment strategy and to refine the indications for use.

Better survival for African and Hispanic/Latino Americans after infrainguinal revascularization in the Society for Vascular Surgery Vascular Quality Initiative.

OBJECTIVE: Inferior survival outcomes have historically been reported for African Americans with cardiovascular disease, and poorer outcomes have been presumed for peripheral arterial disease (PAD) as well. The current study evaluates the effect of race and ethnicity on survival of patients undergoing open or endovascular interventions for lower extremity PAD. METHODS: Data of patients from the Society for Vascular Surgery Vascular Quality Initiative database were obtained for patients undergoing open infrainguinal (INFRA) or suprainguinal (SUPRA) bypass, peripheral vascular intervention (PVI), and amputation (AMP). Patients were further stratified as suprainguinal (SupraPVI) if any of the first three interventions listed included the aorta or iliac vessels or infrainguinal (InfraPVI) if not. The primary outcome was the patient's death (overall mortality) as recorded in the database or determined by cross-reference with the Social Security Death Index (SSDI). The secondary outcome consisted of perioperative mortality during the index hospitalization. Generalized linear modeling provided multivariate analysis, with entry of variables dependent on results of univariate analysis. RESULTS: From January 2003 through September 2015, a total of 24,241 INFRA bypass, 8028 SUPRA bypass, 48,048 InfraPVI, 21,196 SupraPVI, and 3423 AMP patients met criteria for analysis, with a median follow-up of 18 (interquartile range, 8-33) months. Combining all procedures, overall mortality was lower among African Americans than among white Americans (12.4% vs 14.2%; P < .0001) but not death in the periprocedural period (1.1% vs 1.2%; P = .26). To account for differences in length of follow-up, Cox proportional hazards analysis confirmed that the African American race was independently associated with a significantly lower occurrence of overall mortality after INFRA bypass (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.70-0.88; P < .0009), InfraPVI (HR, 0.72; 95% CI, 0.67-0.78; P < .0001), and SupraPVI (HR, 0.77; 95% CI, 0.66-0.90; P = .0009) interventions but not after SUPRA bypass or AMP. Similarly, by Cox proportional hazards, Hispanic/Latino ethnicity was also independently associated with lower overall mortality after INFRA bypass (HR, 0.75; 95% CI, 0.62-0.91; P = .0030), InfraPVI (HR, 0.69; 95% CI, 0.62-0.78; P < .0001), and SupraPVI (HR, 0.68; 95% CI, 0.52-0.89; P = .0045) but not after SUPRA bypass or AMP. CONCLUSIONS: Contrary to the published data for other forms of cardiovascular disease, African American patients as well as patients identified with Hispanic/Latino ethnicity with PAD included in the Society for Vascular Surgery Vascular Quality Initiative undergoing INFRA revascularization for lower extremity PAD experienced better overall survival compared with white Americans.

Incidence and Clinical Significance of Renal Infarct After Fenestrated Endovascular Aortic Aneurysm Repair.

OBJECTIVE: The purpose of this study is to determine the incidence and clinical significance of renal infarcts after fenestrated endovascular aortic aneurysm repair (FEVAR). MATERIALS AND METHODS: All patients who underwent FEVAR with unenhanced and contrast-enhanced CT angiography during a 4-year period were retrospectively reviewed. Two staff radiologists reviewed pre- and post-FEVAR CT examinations for the presence of renal infarcts. Pre- and postoperative serum creatinine levels were examined to determine statistical significance. The incidence of renal infarct and percentage of renal volume reduction were calculated. RESULTS: Ninety patients were included for analysis. All patients had a mild progressive increase in serum creatinine level after FEVAR. Twenty-three patients (26%) had a renal infarct identified on post-FEVAR CT, nine (39%) of which were secondary to intentional exclusion of an accessory renal artery and 14 (61%) of which were presumed to be embolic. Two patients with presumed embolic infarcts and three with exclusion of an accessory renal artery had an increase in serum creatinine level of greater than 0.3 mg/dL at 1 month after FEVAR. CONCLUSION: Although renal infarcts are common after FEVAR, the clinical relevance of these events appears to be limited, with less than one-quarter of patients with renal infarcts experiencing a decline in renal function.

Endovascular treatment of aneurysms using fenestrated-branched endografts with distal inverted iliac limbs.

BACKGROUND/OBJECTIVE: Open aortoiliac grafts have typically been constructed with a short aortic bifurcation sewn near or to the visceral vessels to avoid limb kinking. Similarly, the majority of endovascular bifurcated stent grafts have short aortic main body ranging from 3 to 5 cm. In these patients, endovascular salvage with fenestrated stent grafts is technically challenging because of the short distance between the renal arteries and the flow divider of the graft. Custom fenestrated stent grafts can be extended into the prior open surgical graft or stent graft using a short distal bifurcated stent graft with inverted iliac limb for the contralateral gate. The aim of this study was to evaluate outcomes of patients treated with fenestrated stent grafts coupled with inverted iliac limbs for salvage of failed open surgical and endovascular stent grafts. METHODS: The clinical data of three U.S. aortic centers that use fenestrated stent grafts was entered into prospectively maintained databases from 2011 to 2014. All patients received customized distal bifurcated devices constructed with a main body less than 70 mm and an inverted iliac limb to dock the contralateral gate. End points were technical success, 30-day mortality, type I or III endoleak, limb occlusion, and secondary reintervention. The Institutional Review Board of each institution approved the use of the modified graft, and each patient provided informed consent. RESULTS: There were 56 patients (41 male), with mean age of 75 years treated by fenestrated stent grafts using distal bifurcated devices with inverted iliac limbs. Forty-seven patients had a previous aortic repair with a short main body device, and nine had short distances between the native renal artery and aortic bifurcation requiring inverted limbs. A total of 184 visceral arteries were targeted by fenestrations. Technical success was 96.4% with no 30-day deaths. At a mean follow-up of 11 months, seven patients developed endoleaks, with one device migration, no occlusions, or other complications associated with the inverted limb. On the inverted iliac limb side, there were four complications. Two patients developed type Ib endoleaks treated by limb extension and angioplasty, and one patient developed distal limb ischemia secondary to embolization treated by thrombectomy. One additional patient developed a component separation of the inverted limb discovered with follow-up imaging treated with aortouni-iliac repair. CONCLUSIONS: Patients with a short distance between the renal arteries and the aortic bifurcation can be challenging for endovascular treatment using currently available devices. The use of inverted limb custom devices avoids the need for aortouni-iliac repair with femoral-femoral bypass preserving antegrade perfusion. In the short term, rates of complication are similar to what has been reported for universal bifurcated devices with noninverted iliac limbs.

Management of acute type B aortic dissections.

INTRODUCTION: For the last several decades, initial management of Stanford type B aortic dissections (DeBakey IIIa or IIIb) has involved medical therapy aimed at reducing blood pressure and impulse stress (Dp/dT). This concept has been indoctrinated into the medical field but is now being challenged with advancements in endovascular therapies and devices. Although there have been advances in the medical management and intensive care unit care, medical modalities alone may still pose a 25 -50% complication rate to the patients, resulting in some physicians seeking alternative approaches to reduce this risk in certain subsets of these patients. AREAS COVERED: This review will detail the etiology, classification, diagnosis and evolution in treatment of acute type B dissections. We will also review data from recent trials on thoracic endovascular aortic repair and its role in the management of type B aortic dissections to help determine which patients may benefit from placement of a stent graft. Expert commentary: As we see new technologies develop and obtain long-term results with TEVAR, the paradigm of management may shift toward a more aggressive operative approach to improve on the longterm mortality of patients with type B aortic dissections.

Ultralow Iodine Dose Transarterial Catheter-Directed CT Angiography for Fenestrated Endovascular Aortic Repair Planning.

BACKGROUND: Preoperative planning for fenestrated endovascular aortic repair (fEVAR) requires high-quality cross-sectional imaging, most commonly computed tomography angiography (CTA). However, in the setting of chronic kidney disease (CKD), the iodine load delivered during conventional CTA is associated with risk for acute kidney injury (AKI). In this report, we describe the feasibility of using transarterial catheter directed CT angiography (tcd-CTA) with ultralow-dose iodine as an alternative for fEVAR planning in patients with stage 3-4 CKD to lower the risk of AKI. METHODS: Preserum and postserum creatinine levels were retrospectively evaluated from 8 patients with stage 3-4 CKD who underwent tcd-CTA with 20 mL of Iohexol for fEVAR planning for the treatment of pararenal abdominal aortic aneurysms. The tcd-CTA images were evaluated by two vascular surgeons for adequacy for fEVAR planning and progression to fEVAR completion was recorded. RESULTS: The mean serum creatinine before tcd-CTA was 2.1 ± .32 mg/dL, and the mean estimated glomerular filtration rate was 29.7 ± 6.31 mL/min/1.73 m(2). After tcd-CTA, the mean serum creatinine was 1.9 ± .25 mg/dL and the mean estimated glomerular filtration rate was 32.9 ± 5.12 mL/min/1.73 m(2). All 8 of the studies were determined to be adequate for fEVAR planning independently by two vascular surgeons. Six of the patients underwent successful fEVAR and 2 opted for watchful waiting. CONCLUSIONS: tcd-CTA with ultralow-dose iodine is a feasible option for pre-fEVAR planning in patients with stage 3-4 CKD.

Predicting outcomes for infrapopliteal limb-threatening ischemia using the Society for Vascular Surgery Vascular Quality Initiative.

OBJECTIVE: The outcomes of open surgical or endovascular intervention for limb-threatening ischemia (LTI) involving the infrapopliteal vessels are dependent on complex anatomic, demographic, and disease factors. To assist in decision-making, we used the Vascular Quality Initiative (VQI) to derive a model using only preoperatively available factors to predict important outcomes for open or endovascular revascularization. METHODS: National VQI data for the infrainguinal bypass and peripheral vascular intervention (PVI) modules were reviewed in a blinded fashion for patients who underwent intervention for LTI of the infrapopliteal vessels. Primary outcomes consisted of major adverse limb event (MALE) and amputation-free survival (AFS). Generalized linear modeling was used for the multivariate analyses, with entry of variables dependent on results of univariate analysis. RESULTS: From January 2003 through August 2014 a total of 19,053 infrainguinal open bypass and 48,739 PVI procedures were identified, among which 5264 and 5252, respectively, represented infrapopliteal (tibial-peroneal-pedal) revascularization for LTI. From these, 3036 infrapopliteal open bypass patients and 1319 infrapopliteal PVI patients had sufficient follow-up data for study inclusion. For open surgery, the reduced generalized linear model revealed that American Society of Anesthesiologists class 4 or 5, previous major amputation, living at home, and female sex had the greatest adverse effect on MALE, and dialysis dependence, low body mass index, and lack of great saphenous vein as a conduit had the greatest negative effect on AFS. For PVI, lesion length from 10 to 15 cm, treatment of three or more arteries, and classification other than A on the Trans-Atlantic Inter-Society Consensus demonstrated the largest adverse effects on MALE, and dialysis dependence, low body mass index, and congestive heart failure most negatively affected AFS. CONCLUSIONS: This study on a cross-section of patients selected for intervention in academic and community hospitals offers a "real world" glimpse of factors predictive of outcome. The VQI can be used to derive models that predict the outcomes of open surgical bypass or PVI for LTI involving the infrapopliteal vessels.

Current accepted hemodynamic criteria for critical limb ischemia do not accurately stratify patients at high risk for limb loss.

OBJECTIVE: Critical limb ischemia (CLI) has been defined as rest pain or tissue loss in patients who have an ankle-brachial index (ABI) ≤0.50, ankle pressure (AP) <70 mm Hg, or toe pressure (TP) <50 mm Hg. Data suggesting that these patients are at high risk for limb loss without successful revascularization are limited. This study was designed to identify limb loss and mortality rates in patients who did not respond to revascularization or who were not revascularized to determine whether CLI hemodynamic criteria accurately identify patients at high risk for limb loss. METHODS: Between 2008 and 2010, all patients undergoing lower extremity arterial duplex ultrasound testing at our hospital were identified. Those with ABI <0.50, AP <70 mm Hg, or TP <50 mm Hg were retrospectively reviewed to determine whether they had symptoms of rest pain, ischemic ulceration, or gangrene qualifying them for analysis in the database. Patients who underwent revascularization and subsequently had postrevascularization ABI, AP, or TP greater than the CLI criteria were removed from the cohort. Demographic factors, wound healing, amputation rates, and mortality were obtained and analyzed in relation to the initial APs and TPs. Outcomes were measured by Kaplan-Meier life-table analysis and Cox proportional hazards models. RESULTS: In 381 patients identified in the study, 443 limbs met CLI criteria. After revascularization, 98 limbs with ABI or TP that improved to >0.5 and >50 mm Hg, respectively, were removed from the study cohort. In 45 limbs, patients did not respond to initial revascularization as their ABI, AP, or TP remained within CLI criteria. These limbs remained in the patient cohort, yielding a final group of 296 patients and 345 limbs. Mean follow-up was 2 years. In the entire patient cohort, limb loss occurred in 24% at 1 year and in 31% at 3 years. Mortality was 32% at 1 year and 56% at 3 years. Amputation-free survival was 54% at 1 year and 28% at 3 years. Lower TPs were associated with a statistically higher incidence of amputation. Among those with an initial TP ≤10 mm Hg (n = 85), limb loss occurred in 46% at 1 year and 60% at 3 years. This limb loss was significantly greater than limb loss among those with a TP of 31 to 50 mm Hg (n = 115; 18% at 3 years; P < .001) Amputation-free survival in patients with a TP ≤10 mm Hg was 8% at 3 years. CONCLUSIONS: CLI is associated with a high mortality, but not all patients with currently defined hemodynamic criteria for CLI are at high risk of limb loss. Patients with a TP between 31 and 50 mm Hg (41% of the cohort) and not receiving revascularization or not responding hemodynamically to revascularization experienced a low risk of limb loss. We recommend revising the hemodynamic criteria for CLI to better identify patients at high risk for limb loss who require intervention to improve outcomes.

Non-invasive in vivo characterization of human carotid plaques with acoustic radiation force impulse ultrasound: comparison with histology after endarterectomy.

Ischemic stroke from thromboembolic sources is linked to carotid artery atherosclerotic disease with a trend toward medical management in asymptomatic patients. Extent of disease is currently diagnosed by non-invasive imaging techniques that measure luminal stenosis, but it has been suggested that a better biomarker for determining risk of future thromboembolic events is plaque morphology and composition. Specifically, plaques that are composed of mechanically soft lipid/necrotic regions covered by thin fibrous caps are the most vulnerable to rupture. An ultrasound technique that non-invasively interrogates the mechanical properties of soft tissue, called acoustic radiation force impulse (ARFI) imaging, has been developed as a new modality for atherosclerotic plaque characterization using phantoms and atherosclerotic pigs, but the technique has yet to be validated in vivo in humans. In this preliminary study, in vivo ARFI imaging is presented in a case study format for four patients undergoing clinically indicated carotid endarterectomy and compared with histology. In two type Va plaques, characterized by lipid/necrotic cores covered by fibrous caps, mean ARFI displacements in focal regions were high relative to the surrounding plaque material, suggesting soft features were covered by stiffer layers within the plaques. In two type Vb plaques, characterized by heavy calcification, mean ARFI peak displacements were low relative to the surrounding plaque and arterial wall, suggesting stiff tissue. This pilot study illustrates the feasibility and challenges of transcutaneous ARFI for characterizing the material and structural composition of carotid atherosclerotic plaques via mechanical properties, in humans, in vivo.

Race and gender affect outcomes of lower extremity bypass.

BACKGROUND: Race and gender have individually been associated with affecting outcomes in vascular interventions. We hypothesized that race and gender stratification would identify variations in outcomes of lower extremity bypass (LEB) procedures. METHODS: LEB procedures were identified using Current Procedural Terminology (American Medical Association, Chicago, Ill) codes from the 2011 American College of Surgeons National Surgical Quality Improvement Program database. Individuals of races other than black or white were excluded because of small sample size. Preoperative variables, such as age, demographics, medical comorbidities, and laboratory values, were evaluated across race and gender groups using χ(2), the Student t-test, and least square means testing. Significant predictors were entered into a multivariate logistic regression model. Six primary outcomes were evaluated: major complications, minor complications, 30-day mortality, early graft failure, readmission, and length of stay (LOS). RESULTS: There were 4518 LEB procedures performed on black (n = 839; male [BM], 56.5%; female [BF], 43.5%) or white (n = 3679; male [WM], 66.4%; female [WF], 33.6%) patients. Black patients were more likely to be younger, diabetic, smokers, functionally dependent, dialysis dependent, and have hypertension, critical limb ischemia, higher creatinine, lower hematocrits, and higher platelet counts. Multivariate analysis revealed no statistically significant gender differences within the white cohort with respect to complications, death, graft failure, or readmission rates. WF and BM had longer LOS than WM (reference group; 4.7 ± 1.9 days and 5.4 ± 2.0 days vs 4.3 ± 2.0 days, respectively; P < .006 and P < .0001) after LEB procedures, but outcomes among these groups did not differ significantly. BF had a longer LOS than WM (5.8 ± 2.0 days vs 4.3 ± 2.0 days; P < .0001) and trended toward higher readmission rates (odds ratio, 1.28; 95% confidence interval, 0.97-1.70; P = .08). BF had a higher risk of early graft failure than WM (odds ratio, 2.90; 95% confidence interval, 1.52-5.49; P = .001). CONCLUSIONS: BF had higher early graft failure and LOS compared with WM. WF and BM also had increased LOS compared with WM. Race-gender stratification may predict outcomes in patients undergoing LEB procedures that may not be predicted by gender or race alone. Further studies using this stratification methodology may provide better insight into optimal therapeutic strategies and preventative measures for these patient subgroups. Investigation into causes of increased LOS in black patients and increased graft failure in BF may help improve outcomes.