Utilization of coronary computed tomography angiography and computed tomography-derived fractional flow reserve in a critical limb-threatening ischemia cohort.

Objective: Patients with peripheral arterial disease (PAD) have a significant risk of myocardial infarction and death secondary to concomitant coronary artery disease (CAD). This is particularly true in patients with critical limb-threatening ischemia (CLTI) who exceed a 20% mortality rate at 6 months despite standard treatment with risk factor modification. Although systematic preoperative coronary testing is not recommended for patients with PAD without cardiac symptoms, the clinical manifestations of CAD are often muted in patients with CLTI due to poor mobility and activity intolerance. Thus, the true incidence and impact of "silent" CAD in a CLTI cohort is unknown. This study aims to determine the prevalence of ischemia-producing coronary artery stenosis in a CLTI cohort using coronary computed tomography angiography (cCTA) and computed tomography (CT)-derived fractional flow reserve (FFRCT), a noninvasive imaging modality that has shown significant correlation to cardiac catheterization in the detection of clinically relevant coronary ischemia. Methods: Patients presenting with newly diagnosed CLTI at our institution from May 2020 to April 2021 were screened for underlying CAD. Included subjects had no known history of CAD, no cardiac symptoms, and no anginal equivalent complaints at presentation. Patients underwent cCTA and FFRCT evaluation and were classified by the anatomic location and severity of CAD. Significant coronary ischemia was defined as FFRCT ≤0.80 distal to a >30% coronary stenosis, and severe coronary ischemia was documented at FFRCT ≤0.75, consistent with established guidelines. Results: A total of 170 patients with CLTI were screened; 65 patients (38.2%) had no coronary symptoms and met all inclusion/exclusion criteria. Twenty-four patients (31.2%) completed cCTA and FFRCT evaluation. Forty-one patients have yet to complete testing secondary to socioeconomic factors (insurance denial, transportation inaccessibility, testing availability, etc). The mean age of included subjects was 65.4 ± 7.0 years, and 15 (62.5%) were male. Patients presented with ischemic rest pain (n = 7; 29.1%), minor tissue loss (n = 14; 58.3%) or major tissue loss (n = 3; 12.5%). Significant (≥50%) coronary artery stenosis was noted on cCTA in 19 of 24 patients (79%). Significant left main coronary artery stenosis was identified in two patients (10%). When analyzed with FFRCT, 17 patients (71%) had hemodynamically significant coronary ischemia (FFRCT ≤0.8), and 54% (n = 13) had lesion-specific severe coronary ischemia (FFRCT ≤0.75). The mean FFRCT in patients with coronary ischemia was 0.70 ± 0.07. Multi-vessel disease pattern was present in 53% (n = 9) of patients with significant coronary stenosis. Conclusions: The use of cCTA-derived fractional flow reserve demonstrates a significant percentage of patients with CLTI have silent (asymptomatic) coronary ischemia. More than one-half of these patients have lesion-specific severe ischemia, which may be associated with increased mortality when treated solely with risk factor modification. cCTA and FFRCT diagnosis of significant coronary ischemia has the potential to improve cardiac care, perioperative morbidity, and long-term survival curves of patients with CLTI. Systemic improvements in access to care will be needed to allow for broad application of these imaging assessments should they prove universally valuable. Additional study is required to determine the benefit of selective coronary revascularization in patients with CLTI.

Endosuture aneurysm repair in patients treated with Endurant II/IIs in conjunction with Heli-FX EndoAnchor implants for short-neck abdominal aortic aneurysm.

OBJECTIVE: Endovascular repair of abdominal aortic aneurysm (AAA) remains a challenging clinical scenario when there is a short or nonexistent segment of healthy infrarenal aorta. This study sought to determine the safety and effectiveness of endosuture aneurysm repair (ESAR) using the Endurant II/IIs endograft (Medtronic Vascular, Santa Rosa, Calif) in conjunction with Heli-FX EndoAnchors (Medtronic Vascular) in the treatment of short-neck AAA. METHODS: In this subgroup analysis, 70 patients were identified from the Aneurysm Treatment Using the Heli-FX EndoAnchor System Global Registry (ANCHOR) who had an infrarenal neck length <10 mm down to 4 mm based on core laboratory measurements. Primary outcomes included technical success of the index procedure, rate of type IA endoleak at 1 month and 12 months, and rate of secondary procedures at 12 months. RESULTS: In this short-neck cohort (n = 70), the average neck length and diameter were 6.9 ± 1.6 mm and 25.7 ± 4.0 mm, respectively. Investigators reported an overall procedural success rate of 97.1% and a technical success rate of 88.6%. The duration of the implant procedure, EndoAnchor implantation, and total fluoroscopy time was 148.0 ± 80.0 minutes, 17.1 ± 11.5 minutes, and 35.3 ± 22.0 minutes, respectively, and an average of 5.5 ± 2.1 EndoAnchors were implanted per patient. Through the 30-day follow-up, type IA endoleaks were reported in four patients, of which three resolved spontaneously by the 12-month follow-up. There was an additional type IA endoleak through the 12-month follow-up that has not resulted in AAA enlargement or required a secondary procedure. The Kaplan-Meier estimate for freedom from secondary endovascular procedures and all-cause mortality is 95.4% and 92.7% through 365 days, respectively. No patient in the short-neck cohort experienced main body stent migration, increase in maximum aneurysm diameter, or aneurysm rupture or required conversion to open surgical repair through 12 months. CONCLUSIONS: In this analysis of the short-neck cohort from ANCHOR, the Endurant II/IIs endograft in conjunction with Heli-FX EndoAnchor implants (ESAR) appears to be a safe and effective treatment option with a high technical success rate and low incidence of type IA endoleaks and secondary interventions. Despite the complex and hostile anatomies, the ESAR method required short procedure and fluoroscopy times. These short-term outcomes suggest that ESAR could be complementary to therapies currently available for treatment of hostile AAA anatomy and a viable off-the-shelf endovascular treatment option for patients with short-neck AAAs, although long-term follow-up is critically important.

Retrograde type A dissection after thoracic endovascular aortic repair for type B aortic dissection.

BACKGROUND: The purpose of this study was to evaluate clinical, anatomic, and procedural characteristics of patients who developed retrograde type A dissection (RTAD) after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD). METHODS: Between January 2012 and January 2017, there were 186 patients who underwent TEVAR for TBAD at a multidisciplinary aortic center. Patients who developed RTAD after TEVAR (n = 15) were compared with those who did not (no-RTAD group, n = 171). Primary outcomes were survival and need for reintervention. RESULTS: The incidence of RTAD in our sample was 8% (n = 15). Kaplan-Meier estimates found that no-RTAD patients had better survival (P = .04). Survival rates at 30 days, 1 year, and 3 years were 93%, 60%, and 60% for RTAD patients and 94%, 87%, and 80% for no-RTAD patients. One RTAD was diagnosed intraoperatively, 5 were diagnosed within 30 days of the index procedure, 6 were diagnosed within 1 year, and 3 were diagnosed after 1 year. Reintervention for RTAD was undertaken in 10 of 15 patients, with a 50% survival rate after reintervention. Partial or complete false lumen thrombosis was more frequently present in RTAD patients (P = .03). RTAD patients more frequently presented with renal ischemia (P = .04). Most RTAD patients (93%, RTAD patients; 64%, no-RTAD patients; P = .02) had a proximal landing zone in zone 0, 1, or 2. Aortic diameter was more frequently ≥40 mm in the RTAD group (47%, RTAD patients; 21%, no-RTAD patients; P = .05). Patients with RTAD had stent grafts placed in the renovisceral arteries for complicated dissections, and this approached significance (P = .05). Three RTAD patients had a type II arch (20%) compared with 53 no-RTAD patients (31%; P = .6), but a comparison of type II arch with type I or type III found no statistical significance (P = .6). No correlations were found between ratio of descending to ascending diameters, average aortic sizing, graft size, or bare-metal struts at proximal attachment zone and development of RTAD. We found no statistically significant differences in demographics, genetic disease, comorbidities, or previous repairs. CONCLUSIONS: The development of RTAD after TEVAR for TBAD does not appear to be correlated with any easily identifiable demographic feature but appears to be correlated with proximal landing zones in zone 1 and 2 and an ascending diameter >4 cm. Furthermore, the presence of partial or complete false lumen thrombosis as well as more complicated presentation with renal ischemia was significantly more frequent in patients with RTAD. TBAD patients should be observed long term, as type A dissections in our patients occurred even after 1 year.

Advanced Techniques for Treating Juxtarenal and Pararenal Abdominal Aortic Aneurysms: Chimneys, Periscopes, Sandwiches and Other Methods.

The complex aortic anatomy of patients who present with juxtarenal and pararenal abdominal aortic aneurysms requires advanced techniques to ensure adequate coverage and complete exclusion of the aneurysm. Parallel stent grafting is one option for endovascular repair of complex aneurysms. Using chimneys, periscopes, or snorkels, it is possible to extend the length of the proximal seal zone and maintain perfusion to branch vessels. Because readily available stent grafts and covered stents are used, this technique is highly adaptable to each patient's unique anatomical challenges. However, the complexity of these procedures requires careful preoperative planning, excellent intraoperative imaging capabilities, a thorough understanding of technique, and anticipation of potential procedural pitfalls and complications. We present our experience with chimney/snorkel and sandwich techniques as a reliable and effective treatment strategy for complex aortic aneurysm repair.

Partial distal deployment for precise placement of the GORE Thoracic Endoprosthesis.

The GORE TAG Thoracic Endoprosthesis (TAG) device (W. L. Gore & Associates, Flagstaff, Ariz) and the GORE Conformable TAG Thoracic Endoprosthesis (CTAG) are commonly implanted and effective stent grafts for use during thoracic endovascular aortic repair. Precise placement of the endograft is paramount during thoracic endovascular aortic repair, but like all thoracic stent grafts, maldeployment with inaccurate landing has been reported. The partial distal deployment technique describes an alteration of the TAG and CTAG deployment mechanism to allow isolated deployment of the distal half of the graft, which provides stability during deployment. The graft can be safely repositioned after partial distal deployment, thus allowing precise positioning in the proximal landing zone. Similarly, this technique can be used for precision in the distal landing zone, making the TAG and CTAG devices the only thoracic endografts currently available in the United States with a distal-first deployment option. A discussion of the usefulness of this technique and potential pitfalls is included.

The sequential catheterization amid progressive endograft deployment technique for fenestrated endovascular aortic aneurysm repair.

Fenestrated endovascular aneurysm repair (FEVAR) is an alternative to open repair of complex aortic aneurysms. Despite promising short-term results, the technical complexities of this procedure remain a considerable challenge. The risk of technical failure with loss of visceral or renal arteries is ubiquitous even in the most experienced hands, and thus many patients with unfavorable anatomy are frequently denied FEVAR. We have adopted a new technique for FEVAR that involves retrograde brachial artery access and stepwise deployment of the endograft during target vessel catheterization, overcoming many anatomic limitations encountered from a transfemoral approach. This technique, termed sequential catheterization amid progressive endograft deployment, has become our preferred approach for FEVAR and is described in this article. Of note, currently available Food and Drug Administration-approved fenestrated endografts may not be amenable to sequential catheterization amid progressive endograft deployment as this technique requires preloaded wires incorporated into the endografts.

Maximizing Lumen Gain With Directional Atherectomy.

PURPOSE: To describe the use of a low-pressure balloon inflation (LPBI) technique to delineate intraluminal plaque and guide directional atherectomy in order to maximize lumen gain and achieve procedure success. TECHNIQUE: The technique is illustrated in a 77-year-old man with claudication who underwent superficial femoral artery revascularization using a HawkOne directional atherectomy catheter. A standard angioplasty balloon was inflated to 1 to 2 atm during live fluoroscopy to create a 3-dimensional "lumenogram" of the target lesion. Directional atherectomy was performed only where plaque impinged on the balloon at a specific fluoroscopic orientation. The results of the LPBI technique were corroborated with multimodality diagnostic imaging, including digital subtraction angiography, intravascular ultrasound, and intra-arterial pressure measurements. CONCLUSION: With the LPBI technique, directional atherectomy can routinely achieve <10% residual stenosis, as illustrated in this case, thereby broadly supporting a no-stent approach to lower extremity endovascular revascularization.

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.

Hybrid endovascular treatment of an anomalous right subclavian artery dissection in a patient with Marfan syndrome.

We report the case of a 26-year-old female patient with Marfan syndrome and an aberrant right subclavian artery (ARSA) with associated Kommerell diverticulum. The patient presented with spontaneous acute dissection of the ARSA that showed fusiform dilation to 4 cm in diameter. Definitive treatment was performed using a two-stage hybrid endovascular technique, including extrathoracic bilateral upper extremity bypass and thoracic endovascular aortic repair with debranching of the right and left subclavian arteries. This was followed by coil and plug embolization to exclude the dissection and prevent subsequent endoleak.

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.

Clinical Evidence: Metastases can Metastasize.

We report the unusual case of a 52-year-old female with known stable metastatic ovarian cancer presenting with a new, rapidly growing gastric metastasis, leading to surgical resection. Histologic assessment of the specimen revealed evidence of submucosal and intramuscular metastatic disease originating from a metastatic lesion and not from the primary tumor. This case represents one of an otherwise rarely documented clinical scenario that a metastatic focus can itself metastasize.

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.