Intravascular Ultrasound Use in Peripheral Arterial and Deep Venous Interventions: Multidisciplinary Expert Opinion From SCAI/AVF/AVLS/SIR/SVM/SVS.

Percutaneous revascularization is the primary strategy for treating lower extremity venous and arterial disease. Angiography is limited by its ability to accurately size vessels, precisely determine the degree of stenosis and length of lesions, characterize lesion morphology, or correctly diagnose postintervention complications. These limitations are overcome with use of intravascular ultrasound (IVUS). IVUS has demonstrated the ability to improve outcomes following percutaneous coronary intervention, and there is increasing evidence to support its benefits in the setting of peripheral vascular intervention. At this stage in its evolution, there remains a need to standardize the use and approach to peripheral vascular IVUS imaging. This manuscript represents considerations and consensus perspectives that emerged from a roundtable discussion including 15 physicians with expertise in interventional cardiology, interventional radiology, and vascular surgery, representing 6 cardiovascular specialty societies, held on February 3, 2023. The roundtable's aims were to assess the current state of lower extremity revascularization, identify knowledge gaps and need for evidence, and determine how IVUS can improve care and outcomes for patients with peripheral arterial and deep venous pathology.

Variations and inconsistencies in venous ablation coverage policies between single-state and multistate carriers in the United States.

BACKGROUND: Vein ablation is a common and effective treatment for patients with chronic venous insufficiency. The overuse of vein ablation despite the existence of evidence-based guidelines has resulted in insurance companies developing restrictive policies for coverage that create barriers to appropriate care. This study compares the insurance coverage by single-state carriers (SSCs) and multistate carriers (MSCs), highlighting the variations and inconsistencies in the various policies. METHODS: The American Venous Forum Venous Policy Navigator was reviewed for the various policies available in the United States. The policies were divided into SSCs and MSCs. The characteristics of the policies, including the anatomic and hemodynamic criteria for specific veins, duration of conservative treatment, disease severity, symptoms, and types of procedures covered, were compared between the two groups. SAS, version 9.4 (SAS Institute Inc) was used for statistical analysis. RESULTS: A total of 122 policies were analyzed and divided between SSCs (n = 85; 69.7%) and MSCs (n = 37; 30.3%). A significant variation was found in the size requirement for great saphenous vein ablation. Although 48% of the policies did not specify a size criterion, the remaining policies indicated a minimal size, ranging from 3 to 5.5 mm. However, no significant differences were found between SSCs and MSCs. Similar findings were encountered for the small and anterior accessory saphenous veins. MSCs were more likely to define a saphenous reflux time >500 ms compared with SSCs (81.1% vs 58.8%; P = .04). A significant difference was found between the SSCs and MSCs in the criteria for perforator ablation in terms of size and reflux time. MSCs were significantly more likely to provide coverage for mechanochemical ablation than were SSCs (24.3% vs 8.2%; P = .03). SSCs were more likely to require ≥12 weeks of compression stocking therapy than were MSCs (76.5% vs 48.7%; P = .01). No significant differences were found in the clinical indications between the two groups; however, MSCs were more likely to mention major hemorrhage than were SSCs. CONCLUSIONS: The results of this study highlight the variations in policies for venous ablation, in particular, the striking inconsistencies in size criteria. MSCs were more likely to cover mechanochemical ablation and require a shorter duration of conservative therapy before intervention compared with SSCs. Evidence-based guidance is needed to develop more coherent policies for venous ablation coverage.

Venous compression syndromes in females: A descriptive review.

Venous compression syndromes have been described, yet the role of sex is poorly understood. Although iliac vein compression has been discussed more often with the advent of newer technologies, research has fallen short on defining epidemiology, best practices for evaluation and treatment, and differences in responses to treatment between men and females. The authors report on iliac vein compression, nonthrombotic renal vein compression, and other venous compression syndromes in females. Literature searches of PubMed were performed using the following keywords: females/females and May Thurner, venous stenting, venous outcomes, deep venous disease, deep venous compression, venous stenting, renal vein compression, renal vein surgery/stent, popliteal vein entrapment, venous thoracic vein entrapment, and popliteal vein entrapment. The articles prompted the authors to research further as the referenced articles were reviewed. Sex representation has not been addressed adequately in the research of venous compression syndromes, making the discussion of best treatment options and long-term outcomes difficult. More specific understanding of epidemiology and response to interventions will only come from research that addresses these issues directly, understanding that some of these syndromes occur rarely.

Endovascular management of chronic total occlusions of the inferior vena cava and iliac veins.

OBJECTIVE: Percutaneous recanalization and stenting is currently the standard of care for symptomatic chronic total occlusions (CTOs) of the iliofemoral veins. CTO lesions involving the inferior vena cava (IVC) present a more complex patient subset. In this series we describe our single-center experience with endovascular recanalization of symptomatic occlusions of the IVC. METHODS: Patients were evaluated with duplex ultrasound imaging, venous function tests, and venography before intervention. Occluded segments were recanalized, balloon dilated, and stented. The basic stent technique modified over time to accommodate the iliocaval junction, presence of IVC filters, and lesions extending to the renal veins and atrium. RESULTS: Between November 2000 and August 2015, 71 patients (41 men [58%]) underwent IVC endovascular recanalization procedures for symptomatic chronic IVC occlusions. Patients were an average age of 51 years (range, 23-77 years). Underlying contributing factors for venous occlusion included IVC filter occlusion in 38 (54%), caval ligation/clipping in 4 (6%), and hypercoagulable disorder in 27 (38%). The technical success rate was 85% (n = 60). The proximal extent of the stents were infrarenal in 40 (67%), suprarenal in 11 (18%), or intrathoracic in 9 (15%). There was minimal perioperative morbidity (2 hematomas, 1 renal failure) and no postoperative mortality. Average follow-up was 48.0 ± 43.3 months (range, 6-172 months). Primary, primary assisted, and secondary patency rates at 60 months were 52%, 85%, and 93%, respectively. Significant improvement in pain and swelling was seen in 91% and 83%, respectively; and complete cumulative relief of pain and swelling was 66% and 41% respectively. Ulcers were present in 18 patients and healed completely without recurrence in 14 (78%) after recanalization. The Venous Clinical Severity Score was 8.4 ± 5.1 (range, 4-27) before the intervention and 3.9 ± 3.2 (range, 0-14) after the intervention (P < .001). CONCLUSIONS: Endovascular recanalization of chronic total IVC occlusions can be performed with minimal morbidity and mortality. When successful, symptoms can be substantially improved, with excellent patency.

Deep venous thrombosis associated with caval extension of iliac stents.

BACKGROUND: It is generally difficult to place an iliac vein stent precisely at the iliocaval junction with venographic control or even with intravascular ultrasound guidance. Furthermore, mechanical properties of the Wallstent (Boston Scientific, Marlborough, Mass) can predispose precisely placed stents to distal displacement or stent collapse. Our center has thus advocated extending Wallstents 3 to 5 cm into the inferior vena cava to prevent complications of missed proximal lesions or stent migration. This technique has gradually been accepted, and concerns of jailing of contralateral flow were not initially recognized. We analyzed deep venous thrombosis (DVT) incidence following iliocaval stenting with two alternative techniques: (1) Wallstents with 3- to 5-cm extension into the inferior vena cava; and (2) a modified Z-stent (Cook Medical, Bloomington, Ind) technique, in which overlapping Wallstents end at the iliac confluence and caval extension is performed with a Z-stent placed at the top of the stack. The function of the Z-stent is to provide improved radial force at the iliocaval confluence and to prevent jailing of contralateral flow with larger stent interstices. METHODS: There were 755 limbs with consecutive Wallstent caval extensions (2006-2010) and 982 limbs with Z-stent extensions (2011-2015) analyzed for DVT incidence postoperatively. RESULTS: Demographics were similar for both groups. Mean age was 56 and 58 years in the Wallstent and Z-stent groups, respectively. There was a female predominance (Wallstent, 69%; Z-stent, 67%) and a higher incidence of left-sided disease (Wallstent, 66%; Z-stent, 56%) in both groups. There was a slightly higher incidence of post-thrombotic disease in the Z-stent subgroup (Wallstent, 53%; Z-stent, 68%). Cumulative freedom from contralateral DVT was 99% and 90% in the Z-stent and Wallstent groups, respectively (P < .001) during the 5 years following stent placement. However, all three patients with DVT contralateral to a Z-stent actually had high placement of the Wallstent across the confluence. Thus, no patients with proper Z-stent technique had a contralateral DVT. Cumulative freedom from ipsilateral DVT was 97% and 82% in the Z-stent and Wallstent groups, respectively (P < .001) during the 5 years following stent placement. The decrease in incidence of ipsilateral DVT appeared to be attributable to decreased missed distal lesions with increased operator experience and not attributable to the Z-stent itself. CONCLUSIONS: Contralateral DVT incidence was significantly lower with the Z-stent modification. In addition, the Z-stent modification provides greater radial strength at the iliac-caval confluence and simplifies simultaneous or sequential bilateral stenting. Use of proper technique and intravascular ultrasound is essential to limit the incidence of ipsilateral DVT.

The fate of untreated concomitant suprarenal aortic aneurysms after endovascular aneurysm repair of infrarenal aortic aneurysms.

OBJECTIVE: Many patients treated with endovascular aortic repair (EVAR) have a concomitant suprarenal abdominal aortic aneurysm (sAAA). The natural history of these sAAAs and whether they require intervention after EVAR is unknown. METHODS: We identified 470 patients from the M2S database (M2S Inc, West Lebanon, NH) as having an infrarenal AAA (iAAA) with a concomitant sAAA (diameter, 2.9-4.7 cm). The analysis included 217 patients with preoperative computed tomography angiography and follow-up imaging of ≥12 months. Patients who did not undergo EVAR (n = 65) served as a control. Patients with EVAR were subdivided into 90 with suprarenal fixation (SR) and 62 with infrarenal fixation (IR). Standard measurements from the M2S images were extracted, and growth rates were calculated for different abdominal aortic segments. RESULTS: The average follow-up was 33.0 ± 18.8 months. The average sAAA initial size and growth rate were 34.6 ± 3.0 and 0.6 ± 1.1 mm/y for SR, 34.0 ± 3.3 and 0.6 ± 1.3 mm/y for IR, and 36.6 ± 3.4 and 1.2 ± 1.5 mm/y for controls (SR vs IR, P > .05; SR or IR vs control, P < .05). After EVAR, two of 152 (1.3%) sAAAs grew to ≥ 50 mm, which was not statistically different from four of 65 (6.2%) in the control group (P = .07). At 48 months, the Kaplan-Meier freedom from sAAA growth to ≥ 50 mm was 99.3% for patients undergoing EVAR and 95.2% for controls (P = .061). Patients with starting sAAAs sized ≥ 40 mm had a higher growth rate (1.4 ± 2.1 mm/y) and frequency of growth to ≥50 mm (14.3%) than patients with starting sAAAs sized <40 mm (0.7 ± 1.2 mm/y and 1.5%; P < .05). CONCLUSIONS: Isolated treatment of iAAAs via EVAR with a concomitant sAAA is acceptable because endografts with or without SR do not affect sAAA growth rates. Routine EVAR follow-up is sufficient for sAAAs of <40 mm, and more intensive follow-up should be considered for sAAAs of 40 to 50 mm. For sAAAs approaching 50 mm, an endograft with IR should be considered in case sAAA repair is required in the future.

The management of endograft infections following endovascular thoracic and abdominal aneurysm repair.

OBJECTIVE: The management of infected aortic endografts is a challenging endeavor. Treatment of this problem has not been well defined as it is fairly uncommon. However, the incidence is increasing. This study examines the results of treatment at a single center for this morbid process. METHODS: A retrospective review was performed of patients treated for infected abdominal or thoracic endograft infection following previous abdominal or thoracic endovascular aneurysm repair. Data was reviewed for patient demographics, details of initial endograft implantation, presentation and timeline of subsequent infection, management of infected grafts, and outcomes during follow-up. RESULTS: Overall, 18 patients were treated for infected endografts (thoracic: six, abdominal:12). Three patients were treated between 2000 and 2006, corresponding to a 0.6% institutional incidence of endograft infection (3/473). There were no transfers for infected endografts from outside institutions. From 2006 to 2011, 15 patients underwent treatment. Six were institutional cases of infections (6/945, 0.6% infection rate), however, there was an increase in transfers (n = 9). Median time to presentation with infection from endograft implant was 90 days, with over one-half (61%) presenting within the first 3 months. Tissue and/or blood cultures were positive in 12/16 growing Escherichia coli (n = 1), group A streptococcus (n = 3), methicillin-resistant Staphylococcus aureus (n = 3), or polymicrobial infections (n = 7). The other four patients were culture negative with computed tomography evidence of gas surrounding the endograft and clinical sepsis. Ten patients (abdominal: eight, thoracic: two) were treated with endograft explantation. The remaining eight patients were considered too high-risk for explant or refused open surgery and were therefore managed conservatively without explant (abdominal: four, thoracic: four). At a mean follow-up of 24.7 months, aneurysm-related mortality was 38.9% (n = 7) and was higher for patients presenting with aortoenteric or aortobronchial fistulas (n = 6/10, 60%) (P = .04) and for thoracic stent infections (n = 5/6; 83%) (P = .03). The only survivor of a thoracic infection was managed surgically. Overall survival for patients with abdominal endografts (n = 12) was similar between the eight patients managed surgically (n = 6/8; 75%) and the four selected for medical management (n = 4/4; 100%) (P = .39). All survivors remain on long-term suppressive antibiotics. Two additional patients died of unrelated causes during follow-up. CONCLUSIONS: Endograft infection is a rare but increasing complication after abdominal or thoracic endovascular aneurysm repair, which carries significant associated morbidity and mortality. Most endograft infections occurred in proximity to other types of infection, suggesting that bacterial seeding of the endograft was the source. Aortoenteric and aortobronchial fistulas are common presentations, which portend a significantly worse prognosis. Thoracic endograft infections, which have the highest rate of fistulization, have the worst outcomes. Surgical excision continues to be standard of care but conservative management with intravenous antibiotics may be of benefit in certain patients with abdominal endograft infections.

Incidence, predictors, and outcomes of hemodynamic instability following carotid angioplasty and stenting.

OBJECTIVE: To explore the incidence, predictors, and outcomes of hemodynamic instability (HI) following carotid angioplasty and stenting (CAS). METHODS: We retrospectively evaluated data on 257 CAS procedures performed in 245 patients from 2002 to 2011 at a single institution. The presence of periprocedural HI, as defined by hypertension (systolic blood pressure >160 mm Hg), hypotension (systolic blood pressure <90 mm Hg), and/or bradycardia (heart rate <60 beats per minute), was recorded. Clinically significant HI (CS-HI) was defined as periprocedural HI lasting greater than 1 hour in total duration. Logistic regression was used to analyze the role of multiple demographic, clinical, and procedural variables. RESULTS: Mean age was 70.9 ± 9.9 years (67% male). HI occurred following 84% (n = 216) of procedures. The incidence of hypertension, hypotension, and bradycardia was 54%, 31%, and 60%, respectively. Sixty-three percent of cases involved CS-HI. Recent stroke was an independent risk factor for the development of CS-HI (odds ratio, 5.24; confidence interval, 1.28-21.51; P = .02), whereas baseline chronic obstructive pulmonary disease was protective against CS-HI (odds ratio, 0.34; confidence interval, 0.15-0.80; P = .01). Patients with CS-HI were more likely to experience periprocedural stroke compared to other patients (8% vs 1%; P = .03). There were no significant differences in the incidence of mortality or other major complications between those with and without CS-HI. CONCLUSIONS: HI represents a common occurrence following CAS. While the presence of periprocedural HI alone did not portend a worse clinical outcome, CS-HI was associated with increased risk of stroke. Expeditious intervention to prevent and manage CS-HI is of critical importance in order to minimize adverse clinical events following CAS.

Effect of ethnicity and insurance type on the outcome of open thoracic aortic aneurysm repair.

OBJECTIVES: Mortality and complication rates for open thoracic aortic aneurysm repair have declined but remain high. The purpose of this study is to determine the influence of ethnicity and insurance type on procedure selection and outcome after open thoracic aneurysm repair. METHODS: Using the Nationwide Inpatient Sample database, ethnicity and insurance type were evaluated against the outcome variables of mortality and major complications associated with open thoracic aneurysm repair. The potential cofounders of age, gender, urgency of operation, and Deyo index of comorbidities were controlled. RESULTS: Between 2001 and 2005, a total of 10,557 patients were identified who underwent elective open thoracic aneurysm repair, with a significantly greater proportion of white patients (n = 8524) compared with black patients (n = 819), Hispanic patients (n = 556), and patients categorized as other (n = 658). Most patients (67%) were male. Almost half (45%) of the procedures were performed for urgent/emergent indications. Overall mortality was 10.7% (n = 1126) and the rate of spinal cord ischemia was 0.4% (n = 43). Univariate analysis revealed significant differences among race with regard to surgery type, income, hospital region, hospital bed size, and insurance type (P < 0.0001). Differences between insurance coverage were significant for gender, surgery type, income, hospital region, and race (P < 0.0001). Bivariate analysis by race revealed differences for death (P < 0.0001), pneumonia (P < 0.0001), renal complications (P = 0.011), implant complications (P < 0.0001), temporary tracheostomy (P = 0.004), transfusion (P < 0.0001), and intubation (P < 0.0001). In terms of payer status, bivariate analysis by insurance coverage revealed differences in death (P < 0.0001), central nervous system complications (P = 0.008), pneumonia (P < 0.0001), myocardial infarction (P = 0.001), infection (P < 0.0001), renal complications (P < 0.0001), malnutrition (P < 0.0001), temporary tracheostomy (P < 0.0001), spinal cord ischemia (P = 0.001), transfusion (P < 0.0001), and intubation (P < 0.0001). CONCLUSIONS: A high percentage of open thoracic procedures (45%) are performed urgently or emergently in the United States, which is associated with increased morbidity and mortality. Both ethnicity and payer status were associated with significant differences in surgical outcomes, including mortality and frequency of complications after open thoracic aortic aneurysm repair.

Midterm results of percutaneous endovascular treatment for acute and chronic deep venous thrombosis.

BACKGROUND: Treatment of deep venous thrombosis (DVT) with therapeutic anticoagulation has been increasingly challenged by aggressive percutaneous treatment using ultrasound-accelerated catheter-directed thrombolysis (US-CDT) or percutaneous pharmacomechanical thrombectomy (PMT). These techniques have been promoted to improve thrombus removal, prolong venous patency, prevent venous insufficiency, and reduce postthrombotic syndrome. This study reviews midterm results using these endovascular techniques for both acute and chronic DVT. METHODS: A retrospective chart review was performed on patients treated for acute or chronic DVT with US-CDT and/or PMT. Charts were reviewed for patient demographics, medical history and treatment, operative details, and postoperative outcomes. Intraoperative venography and intravascular ultrasound quantified clot response to therapy. Duplex ultrasound defined the pre- and postoperative extent of venous thrombosis, venous patency, and valvular function. RESULTS: Between October 1, 2002 and September 30, 2010, 80 patients were treated for iliofemoral (n = 48), iliofemoropopliteal (n = 15), or femoropopliteal (n = 17) venous thrombosis. Mean age was 45.8 years (range, 15-78 years), and 24 patients (30%) had a documented history of hypercoagulable state. Intravascular ultrasound confirmed May-Thurner syndrome in 34 patients (42.5%). Fifty-two patients (65%) were treated for acute DVT; the mean time to intervention from symptom onset was 8.7 ± 4.5 days (range, 1-14 days). The remaining 28 patients (35%) had chronic symptoms and were treated at a mean of 8.6 ± 10.9 months (range, 1.5-36 months) after DVT diagnosis was made. Patients were treated with PMT (n = 43, 53.8%), US-CDT (n = 14, 17.5%), or both (n = 32, 28.7%). Clot lysis (>90%) was achieved in 72 of 80 patients (90%). Tenecteplase was used for all cases, and the mean dose was 8.6 ± 4.3 mg. Adjunctive procedures, including angioplasty with or without stent placement, were required in 90% (n = 47) of acute patients and in 96% (n = 27) of chronic patients (P = .33). Three patients (3.8%) had postoperative bleeding events requiring blood transfusion; there were no occurrences of intracranial hemorrhage or clinically significant pulmonary embolism. At a mean follow-up of 3.8 years (range, 1-8.9 years), venous patency was present in 49 of 52 acute patients (94%) and in 23 of 28 chronic patients (82%) (P = .12). Valve function was preserved in 41 of 52 (79%) acute patients vs 11 of 28 (39%) chronic patients (P < .001). CONCLUSIONS: US-CDT and PMT can effectively remove acute and chronic thrombus in the lower extremity deep venous system. Vein patency and valvular function is better preserved at midterm follow-up after treatment for acute DVT, however intervention should be considered in patients with chronic DVT as well.

Current status of endovascular aneurysm repair: 20 years of learning.

Parodi first introduced endovascular aneurysm repair (EVAR) in 1991 and since that time it has been shown to have a lower 30-day morbididty and mortality compared to open surgery. Anatomic constraints governed by the need for adequate access vessels, and sufficient proximal and distal landing zones, as well as the need for long-term surveillance, have been the main limitations of this technology. Anatomic factors were initially estimated to exclude 40% of patients with abdominal aortic aneurysm (AAA). The rapid extension of EVAR technology has been complimented by improved access to both high-quality imaging modalities and a variety of endografts. These developments have led EVAR to become a more practical alternative for patients with ruptured AAA. Early data in this setting is encouraging with even more profound reductions in morbidity and mortality than seen in the elective repair.

Thoracic endovascular repair (TEVAR) in the management of aortic arch pathology.

BACKGROUND: Conventional repair of aortic arch pathology is associated with significant mortality and stroke rates of 6-20% and 12%, respectively. Because endografting has excellent results for descending thoracic aortic disease, extension of thoracic endovascular repair (TEVAR) to the arch is a consideration. METHODS: Records of patients with aortic arch pathology treated with TEVAR were reviewed. Branch vessels were (1) covered without revascularization, (2) surgically bypassed, (3) stented, or (4) fenestrated. Technical success was defined both by accurate endograft deployment with disease exclusion and by target vessel revascularization. Patient postoperative outcomes, complications, and follow-up are reported. RESULTS: Between March 2006 and January 2010, 58 patients with arch pathology were treated with TEVAR. Indications included aneurysm (n = 19, 32.8%), dissection (type A: n = 3, 5.2%; type B: n = 18, 31.0%), transection (n = 8, 13.8%), pseudoaneurysm (n = 6, 10.3%), or other (n = 4, 6.9%). Pathology was zone 0 (n = 1, 1.7%), zone 1 (n = 10, 17.2%), zone 2 (n = 45, 77.6%), or zone 3 (n = 2, 3.4%). Interventions were emergent in 44.8% and elective in 55.2%. The left subclavian (LSA) was covered in all and revascularized (n = 23, 39.7%) via bypass (n = 13, 22.4%), stenting (n = 4, 6.9%), or fenestration (n = 6, 10.3%). The carotid was revascularized (n = 11, 19.0%) with bypass (n = 7, 12.1%) or stenting (n = 4, 6.9%). One patient (1.7%) underwent innominate revascularization with a homemade branched endograft. Technical success was 100% for endograft deployment and 97.1% for revascularization. Thirty-day mortality was 3.4% (2 of 58). ICU and hospital stays were 5.8 ± 6.8 (range: 0-34; median 4) and 10.9 ± 8.0 (range: 1-40; median: 9) days, respectively. Morbidities included renal failure (n = 3, 5.2%), respiratory (n = 2, 3.4%), myocardial infarction (n = 1, 1.7%), stroke (n = 6, 10.3%), and spinal cord ischemia (SCI) (n = 2, 3.4%). SCI (p < 0.001), but not stroke (p = 0.33), was associated with LSA sacrifice. Stroke was associated with underlying pathology and graft selection (p = 0.01). During follow-up of 10.6 ± 9.1 (range: 0-43) months, 17 patients (29.3%) required 20 reinterventions for endoleak (n = 8, 13.8%), disease extension (n = 5, 8.6%), steal (n = 4, 6.9%), or other reasons (n = 3, 5.2%). Dissection patients had a higher rate of reintervention (p = 0.01). All patients with steal had LSA sacrifice and were left-hand dominant. CONCLUSIONS: TEVAR can effectively treat aortic arch pathology in high-risk patients with low morbidity and mortality. TEVAR and branch vessel revascularization techniques may be extended to the more proximal arch without increased complications compared with patients with subclavian only involvement. Stroke remains the most significant drawback of arch interventions. Indications for intervention, graft selection, and revascularization choices may all affect outcome. LSA sacrifice is associated with increased SCI and may predispose left-handed patients to symptomatic weakness.

Volumetric analysis of type B aortic dissections treated with thoracic endovascular aortic repair.

BACKGROUND: Type B aortic dissections are being successfully treated by thoracic endovascular aortic repair (TEVAR). Postoperative false lumen patency has been associated with aneurysmal dilatation and rupture of the thoracic aorta, necessitating further intervention. This is the first volumetric analysis of type B aortic dissections comparing patients with and without false lumen thrombosis (FLT) after TEVAR. We hypothesized that a greater increase in postoperative true lumen volume will lead to FLT, and without this change, false lumen patency will result. METHODS: Preoperative and postoperative computed tomography angiography (CTA) imaging was analyzed using three-dimensional reconstruction to measure the short- and long-axis diameter and cross-sectional area of the true lumen, false lumen, and total aorta. Measurements were taken at 5-cm intervals from the left subclavian artery to the aortic bifurcation. Pre- and postoperative volumetric data were calculated and compared in patients with and without postoperative FLT. RESULTS: Between 2006 and 2010, 132 patients underwent thoracic aortic stent grafting. Of these, 31 (23%) had thoracic endografting for type B aortic dissection. Pre- and postoperative CTA images were available for analysis in 23 patients with a mean age of 59 ± 14 years treated for acute, complicated (n = 8, 35%), and chronic (n = 15, 65%) indications. Mean follow-up imaging was 9 months (range, 1-39 months). Thirteen patients (56%) had postoperative FLT and 10 (43%) had persistent false lumen patency. The dissections involved the left subclavian artery (n = 12), visceral arteries (n = 14), renal arteries (n = 16), and iliac arteries (n = 15). The left subclavian artery was intentionally covered in 15 patients (65%). There were no significant differences in age, acute vs chronic dissection, branch vessel involvement, coverage of the left subclavian artery, or distal extent of the endograft between patients with and without postoperative FLT. Patients with postoperative FLT had a significantly smaller preoperative maximum thoracic aortic diameter (5.05 ± 1.0 vs 6.30 ± 1.4 cm; P = .02). Volumetric analysis demonstrated significantly smaller preoperative true lumen volume (141.3 ± 68 vs 230.5 ± 92 cm(3); P = .01) in patients with FLT, but no difference in preoperative false lumen volume. Patients with FLT had a significant increase in the volume percentage of the true lumen from 42.7% to 61.7% (P = .02) after stent graft repair, compared with an increase from 46.7% to 47.7% (P = .75) in patients with persistent false lumen patency. CONCLUSIONS: This volumetric study of type B aortic dissection treated with TEVAR suggests that the ability of the endograft to significantly increase the true lumen volume as a percent of the total aorta most accurately predicts postoperative FLT. This is best demonstrated in a nonaneurysmal dissection regardless of timing since dissection.

In vitro analysis of type II endoleaks and aneurysm sac pressurization on longitudinal stent-graft displacement.

PURPOSE: To evaluate the effects of type II endoleaks and sac pressurization on stent-graft displacement following endovascular aneurysm repair (EVAR). METHODS: Experimental silicone infrarenal aneurysm (6-cm) models were "treated" with a Talent stent-graft deployed with 20-mm proximal and distal landing zones. Inflow and outflow vessels were created as part of the silicone model to control flow into the aneurysm sac. All aneurysm models were uniform, with a diameter neck of 31 mm, a neck length of 20 mm, and iliac artery diameters of 16 mm. The aortic model was secured in a water bath to a pulsatile pump under physiological conditions; the output phase ratio (%systole/%diastole) was set at 65/35 with a pump rate of 80 beats per minute. Commercially available bifurcated stent-grafts were then displaced in vitro utilizing a linear motion apparatus attached to a force gauge. The mean arterial pressure (MAP) and pulse pressure (PP) at the aortic inflow were 60.1 ± 3.1 and 38.3 ± 7.8 mmHg, respectively. Peak force to cause initial stent-graft migration with and without a type II endoleak was recorded and compared. RESULTS: In aneurysm sacs with no endoleak, the MAP and sac PP were 32 ± 6.4 and 6 ± 1.3 mmHg, respectively (p<0.01). In aneurysm sacs with a type II endoleak, the MAP and sac PP were 54.1 ± 9.7 and 16.1 ± 4.1 mmHg, respectively (p<0.02). Peak force to initiate migration was 16.0 ± 1.41 N (range 15-18) with no endoleak vs. 23.2 ± 2.2 N (range 20-25) in those with a type IIa endoleak and 23.5 ± 2.5 N (range 20-26) in those with a type IIb endoleak (p<0.001). CONCLUSION: Type II endoleaks are associated with a significantly increased sac pressure. Increased sac pressurization from type II endoleaks results in a significantly greater force to displace a stent-graft longitudinally. Type II endoleaks may therefore inhibit migration and offer a benefit following EVAR; however, clinical correlation of these results is required.

Technique for branched thoracic stent-graft repair of a chronic type a aortic dissection in a patient with multiple prior sternotomies.

PURPOSE: To present a technique for endovascular treatment of a type A aortic dissection in a patient with multiple prior sternotomies and multiple medical comorbidities. TECHNIQUE: The method is illustrated in a 76-year-old man with a history of hypertension, hyperlipidemia, coronary artery disease, and open repair of a type A aortic dissection via a median sternotomy. The latter procedure was complicated by a pericardial effusion requiring drainage and sternal re-wiring. The diameter of the residual type A dissection beginning just distal to the aortic root had increased by 1.5 cm over 1 year, indicating the need for further intervention. To avoid redo sternotomy, a hybrid endovascular approach was planned, but it would require landing the stent in the ascending aortic arch, thus mandating branch vessel revascularization. Prior to stent-graft deployment, right-to-left carotid-carotid and left carotid-subclavian artery bypasses were performed with 8-mm polytetrafluoroethylene grafts. Three Talent grafts were deployed from the celiac artery to the left subclavian artery. A pre-wired homemade branched Talent stent-graft (34×34×115 mm) was used to revascularize the innominate artery and secure the arch. Transvenous ventricular pacing was used to improve deployment accuracy. A 10×38-mm iCast stent was placed through the branch and extended into the innominate artery. The subclavian artery was occluded with 2 Amplatzer plugs. Postoperative computed tomography demonstrated excellent proximal fixation, a widely patent branched graft to the innominate artery, and thrombosis of the aneurysmal false lumen. CONCLUSION: Treatment of type A dissections remains a difficult surgical challenge. The approach taken should be tailored for each patient. We successfully employed a combination of available minimally invasive techniques to treat a patient who was not ideally suited to any of the individual strategies.

The effects of operative indication and urgency of intervention on patient outcomes after thoracic aortic endografting.

BACKGROUND: Endovascular repair for complex thoracic aortic pathology has emerged over the past decade as an alternative to open surgical repair. Reports suggest lower morbidity and mortality rates associated with endovascular interventions. The purpose of this report was to analyze a large single institution experience in endovascular thoracic aortic repair based on clinical presentation as well as within and outside specific instructions for use. METHODS: Records of all patients undergoing thoracic aortic endografting at our institution were retrospectively reviewed for demographics, interventional indications and acuity, operative details, and clinical outcomes. Study outcomes were analyzed by clinical presentation (urgent/emergent vs elective) and aneurysm morphology that was within and outside specific instructions for use as recommended by the manufacturer. RESULTS: Between March 2006 and October 2009, 96 patients underwent thoracic endografting for aneurysm (n = 43), transection (n = 7), penetrating ulcer (n = 11), dissection (n = 19; acute = 9, chronic = 10), pseudoaneurysm (n = 11), or miscellaneous indications (n = 5). Endografting was performed with various endografts (Gore TAG: 59; Medtrontic Talent: 26; Zenith-TX2: 7; Combination: 4.Involvement of the arch (n = 42, 43.75%) was treated with subclavian artery coverage without revascularization in 13 (13.5%), debranching in 20 (20.8%), and fenestration/stenting in 9 (9.38%). Involvement of the visceral vessels (n = 24, 25%) was treated with debranching in 15 (15.6%) or fenestration/stenting in 9 (9.4%). Patients had a mean follow-up of 11.5 ± 10.96 (range: 0-38) months. Overall mortality was 6.25% (n = 6). Mean intensive care unit stay was 6.26 ± 8.55 (range: 1-63, median: 4) days, and hospital stay was 9.97 ± 10.31 (range: 1-65, median: 65) days. Major complications were infrequent and included: spinal cord ischemia (n = 6, 6.25%), stroke (n = 6, 6.25%), myocardial infarction (n = 3, 3.15%), renal failure (n = 6, 6.25%), and wound complications (n = 9, 9.38%). Reoperation was required in 13 (13.54%), with early intervention in 2 (2.1%). The vast majority of patients were discharged directly to home (n = 66, 68.8%). There were no significant differences between death (1/49 [2%] vs 5/47 [10.6%], P = .07), stroke (3/49 [6%] vs 3/47 [6%], P = 1.0), or spinal cord ischemia (3/49 [6%] vs 3/47 [6%], P = 1.0) when comparing urgent/emergent presentation to elective cases, respectively. However, there were significant differences in death (6/58 [10.5%] vs 0/38 [0%], P = .04) and spinal cord ischemia (6/58 [10.5%] vs 0/38 [0%], P = .04) but not stroke (5/58 [8.8%] vs 1/38 [2.5%], P = .24] when procedures were performed outside the specific instructions for use. CONCLUSIONS: Results of this single-institution report suggest that endovascular thoracic aortic repair is a safe and effective treatment option for a variety of thoracic pathology including both elective and emergent cases. However, off-label usage of the devices is associated with a significantly higher risk of mortality and spinal cord ischemia, but the risk still appears acceptable given the majority of cases were emergent.

Device and imaging-specific volumetric analysis of clot lysis after percutaneous mechanical thrombectomy for iliofemoral DVT.

PURPOSE: To determine the most accurate method of assessing clot lysis after percutaneous mechanical thrombectomy for iliofemoral deep vein thrombosis (DVT) and to evaluate the effectiveness of two different pharmacomechanical thrombectomy devices. METHODS: Between 2004 and 2009, 33 patients (18 women; mean age 47 years) with iliofemoral DVT underwent pharmacomechanical thrombectomy using the AngioJet (n = 18) or Trellis (n = 15) devices with 10 mg of tenecteplase. Intravascular ultrasound (IVUS) and venography were performed over the iliofemoral segments before and after treatment. Cross-sectional vessel and lumen diameters were measured from the IVUS scans and the post-procedure anteroposterior and lateral venograms at 3 points (proximal, mid-section, and distal) along each iliofemoral vein by 2 independent observers blinded to the treatment method. Volumes of the recanalized segments were calculated and compared to volumes of the original venous segments to assess clot lysis with each PMT device. IVUS scans and venograms were also compared for their ability to identify residual lesions or clot in need of treatment. Repeatability between and among observers was analyzed using the Bland and Altman method. RESULTS: All procedures were successfully completed; there were only 2 minor bleeding complications. The mean volume of the recanalized segment was 2255+/-66 mm(3) by IVUS, representing 80% lysis of the clot compared to what was perceived as >90% lysis with venography (p<0.05). IVUS was able to delineate significant residual thrombus, stenosis, or May-Thurner anatomy requiring ancillary interventions in 100% of patients versus 48% (16/33) on the venograms (p<0.01). Quantitative assessments of the diameters of the involved venous segments from the venograms and IVUS were consistent between and among observers. Comparing the similar patient subgroups, AngioJet resulted in greater clot lysis (88%) versus the Trellis device (72%; p<0.01), corresponding to recanalized venous segment volumes of 2486+/-74 and 2025+/-57 mm(3) and total venous segment volumes of 2826+/-84 and 2813+/-79 mm(3), respectively. CONCLUSION: IVUS is superior to venography for detection of residual thrombus and underlying venous pathology after pharmacomechanical thrombectomy. While greater clot lysis was seen with the AngioJet system, both the AngioJet and Trellis devices resulted in excellent clinical clot lysis.

Effects of ethnicity and insurance status on outcomes after thoracic endoluminal aortic aneurysm repair (TEVAR).

BACKGROUND: Thoracic endoluminal aortic aneurysm repair (TEVAR) is associated with improved outcomes compared with open thoracic aortic aneurysm repair. This study was designed to better characterize TEVAR outcomes in a large population, and to determine if outcomes are independently influenced by patient ethnicity and insurance status. METHODS: Using the Nationwide Inpatient Sample (NIS) database, we selected patients who underwent TEVAR between 2001 and 2005. Ethnicity and insurance type were independently evaluated against the outcome variables of mortality and postoperative complications. Age, gender, hospital region, hospital location, hospital size, and comorbidities were controlled as cofounders. RESULTS: Between 2001 and 2005, 875 patients underwent TEVAR. There was a significantly greater proportion of Caucasians (n = 650) compared with African Americans (n = 104) or Hispanics (n = 49). Patients had a male preponderance, and most procedures were elective. The overall mortality was 13.3% (n = 117), and spinal cord ischemia was 0.8% (n = 7), with no differences between patients of varied ethnicity or payer status. Significant differences were noted among the races including gender (P = .003), income (P < .0001), hospital region (P < .001), hospital bed size (P = .013), and insurance type (P < .001). Significant variations in demographics characteristics were also present between patients with different insurance classifications including gender (P < .001), surgery type (P = .009), income (P = .003), race (P < .0001), and comorbidity index (P < .0001). After adjustment for cofounders and multiple comparisons, there were no differences in rates of complications among patients with varying race or insurance status. CONCLUSIONS: Mortality after TEVAR remains high in the US, although this may be associated with its early introduction during the study period. Nonetheless, the incidence of spinal cord ischemia is very low. Ethnicity and insurance type do not appear to influence TEVAR outcomes.

Early in vivo analysis of an endovascular stapler during endovascular aneurysm repair.

The objective of this article is to describe the use and technique of a novel endostapling device used in an in vivo animal model. Six ovine underwent implantation of a Dacron endograft into the thoracic aorta followed by placement of endoclips proximally and distally. The animals were survived 35 days to evaluate the performance and safety of the endoclip in an animal model prior to clinical trials. The mean time for securing both the proximal and the distal anastomosis was 22 minutes (range 17-31 minutes). All staples were deployed, without the need for repositioning, on the first attempt. There were no complications related to the implant procedure or indwelling clips. Additionally, no endograft migration occurred. At the time of explant, staples were evaluated for depth of penetration and accuracy of placement. The staples had fully penetrated the endograft and vessel wall through the adventitia in 89% (64 of 72) of clips deployed. The staples were placed accurately, within 10 mm of the endograft proximal and distal attachments in 94% (68 of 72) of the clips deployed. Furthermore, endothelialization of the staples was present without surrounding thrombus. Implant sites were scored as normal without surrounding tissue damage by an independent pathologist. The endoclip performed well in creating proximal and distal fixation of the endograft. There were no adverse outcomes related to the endostaple. Future clinical trials should be undertaken to assess its clinical utility during endovascular aneurysm repair.