Graft Occlusion Research Articles

Computational Fluid Flow Model for the Development of an Arterial Bypass Graft

Intimal hyperplasia, an aberrant proliferation of smooth muscle cells that causes stenosis and graft occlusion, is the primary cause of the failure of grafts after a few years. In this way, and using the constructal design method, this study looks at how the stenosis degree, junction angle, and diameter ratio affect the flow through a bypass graft that goes around an idealised coronary artery partially blocked. The results show that the flow effect by several factors: Stenosis ratio (S), Bypass Attachment Point (L2), Bypass Angle (α), and Bypass Diameter (D1). The results indicate that the pressure drop is reduced when S is low, the optimal attachment point L2 = 4 Artery diameter (D), the optimal angle α = 30°, and the optimal D1 = 1.25D.

Limb graft occlusion after endovascular aneurysm repair with the Cook Zenith Alpha abdominal graft

ObjectivePrior reports of the low profile Zenith Alpha abdominal graft (Cook Medical Inc, Bloomington, IN) have shown impaired limb graft patency to be the primary causes of reintervention. Special notices from the manufacturer have indicated certain instructions for use (IFU) violations as the main reasons for these complications. In the present study, we assessed the incidence of limb graft occlusion (LGO) and analyzed the effects of the detailed anatomic risk factors for LGO highlighted in the IFU and previously reported studies. MethodsA retrospective study was performed of 241 patients treated with the low profile Zenith Alpha at a single institution from October 1, 2015 to September 30, 2018. All computed tomography angiograms were analyzed using three-dimensional software. Data were extracted from the electronic medical records until the end of the study period (December 31, 2020). The cumulative incidence of LGO and LGO-related reinterventions were assessed. A regression analysis was performed to evaluate the possible risk factors associated with the development of LGO at specified time points. These included aortic and iliac diameters, graft component oversizing, iliac tortuosity and calcification, overlap of graft components, proximal alignment of ipsilateral and contralateral legs, and sealing zone in the external iliac artery. Reader agreement of iliac calcification and tortuosity was assessed in patients with LGO. ResultsA total of 33 limbs (7%) in 27 patients (11%) had become occluded. The cumulative incidence of LGO was 7% (95% confidence interval [CI], 5%-9%) per limb up to 3 years postoperatively. The previously described risk factors for LGO were studied using regression analysis; however, no positive association with LGO was identified. Heavily calcified common iliac arteries (CIAs) and external iliac arteries were protective against LGO compared with noncalcified vessels up to 3 years postoperatively (decreased risk, 17% [95% CI, −27% to −7%]; P = .001; and 15% [95% CI, −26 to −5]; P = .005, respectively). The reader agreement of iliac calcification and tortuosity showed substantial agreement (CIA intrareader kappa = 0.75; CIA interreader kappa = 0.62) and almost perfect agreement (intrareader kappa = 0.85; interreader kappa = 0.84), respectively. ConclusionsThe cumulative incidence of LGO after endovascular aneurysm repair with the Zenith Alpha graft was 7% per limb up to 3 years postoperatively. None of the analyzed risk factors suggested by the IFUs or current literature were positively associated with LGO.

Outcome of endovascular treatment of internal iliac artery aneurysms: a single center retrospective review

PurposeTo evaluate the technical feasibility and clinical outcomes of endovascular treatment for internal iliac artery (IIA) aneurysms.Material and methodsThis was a retrospective analysis of 25 patients with 32 IIA aneurysms (mean diameter: 39.1 ± 12.6 mm) who underwent endovascular treatment over a 10-year period, and were available for follow-up. Univariate analysis was used to determine the association between variables (including aortoiliac involvement and technique) and outcome.ResultsThe IIA inflow was covered with an iliac stent graft (N = 29) or embolized with a plug (N = 3). The IIA outflow was embolized in all but one case in which there was thrombotic occlusion of outflow branches. Outflow embolization using plugs or coils was performed in the distal IIA or anterior/posterior trunks in 9 cases and distal IIA branches in 22 cases. During a mean follow-up period of 39.9 months, 31.2% of aneurysms demonstrated endoleak and 12.5% demonstrated enlargement. Univariate analysis revealed that endoleak was associated with technical failure (p = 0.01) and that endoleak rate was higher in patients who underwent distal IIA branch embolization (p = 0.03). No variable was associated with sac expansion. Major complication occurred in one patient who died from aneurysm rupture. Minor complications were reported in six patients who developed femoral pseudoaneurysm (N = 2, 8%), buttock claudication (N = 3, 12%), and limb graft occlusion (N = 1, 4%).ConclusionEndovascular treatment of IIA aneurysms effectively prevents sac expansion. Endoleak was more frequently observed in cases of technical failure and those in which distal IIA branches were embolized.Level of EvidenceLevel 3b, retrospective cohort study.

Use of Direct Oral Anticoagulant and Associated Bleeding and Thrombotic Complication after Lower Extremity Bypass.

Therapeutic anticoagulation with either a vitamin K antagonist (VKA) or direct anticoagulant (DOAC) is often newly prescribed to patients undergoing lower extremity bypass (LEB) to aid in graft patency when risk factors for thrombosis are present or to treat postoperative venous thromboembolism or atrial fibrillation. There is a gap in knowledge as to how DOAC usage impacts postoperative outcomes compared with the standard-of-care VKAs. To determine temporal trends in DOAC prescription after infrainguinal LEB, impact on length of stay (LOS), and associated bleeding and thrombotic complications, patients undergoing elective LEB were identified from the Vascular Quality Initiative between January 2013 and May 2019. Postoperative bleeding, LOS, and graft occlusion for patients receiving VKA compared with DOAC were evaluated. A total of 24,459 LEBs were performed during the study period. Among 2,656 patients newly prescribed an anticoagulant, 78.0% (n = 2,072) received VKA and 22.0% (n = 584) received a DOAC, with DOAC use increasing throughout the study period. There was no significant difference in postoperative bleeding (VKA 2.3%, DOAC 1.7%, p = 0.413) or graft occlusion (VKA 1.2%, DOAC 1.4%, p = 0.762) between the anticoagulant classes. LOS was shorter in the DOAC group than in the VKA group (5.7 vs 6.8 days; p < 0.001). This analysis demonstrates that DOAC use is increasing with time in Vascular Quality Initiative centers. DOACs are a safe and comparable alternative to VKAs in the postoperative setting with similar rates of bleeding complications and early graft patency and are associated with a reduced postoperative LOS.

Primary Inferior Vena Cava Leiomyosarcoma Presenting with Proximal Occlusion with Deep Venous Thrombosis and Lower Extremity Edema: Reconstruct vs Ligate Post Resection? A Single Retrospective Case Report

Introduction: Primary leiomyosarcomas of the inferior vena cava (IVC) are rare tumors with a poor prognosis. Curative treatment remains surgical resection with clear margins. Reconstruction vs ligation of the IVC is debatable, especially if the proximal IVC is occluded. This report presents the surgical management of a patient presenting with acutely worsening lower extremity edema and biopsy proven IVC leiomyosarcoma. Methods: This is a retrospective chart review, and the patient was followed up at 2 weeks and at 3 months. Patient provided consent for creation of this case report. Results: The patient’s age at presentation was 67 years and she was of female gender. The IVC leiomyosarcoma had a maximum diameter of 4.8cm, involved the infrarenal IVC only, and the proximal segment was occluded due to bilateral iliofemoral deep venous thrombosis (DVT). She underwent an R0 resection, with immediate reconstruction using 14mm ringed PTFE. Postoperatively, she was noted to have worsening lower extremity edema. The plan was to recanalize her DVTs via endovascular thrombectomy and stenting, however the patient’s edema improved with compression alone. At 2 weeks follow up, her edema had completely resolved. At 3 months follow up, postoperative CT scan showed expected occluded infrarenal IVC graft, and no evidence of recurrent disease. Conclusion: Reconstructing the occluded IVC after resection of the primary IVC leiomyosarcoma gives the patient the option for future endovascular recanalization if there is ongoing lower extremity edema. Further follow up and research is warranted to determine if this provides a feasible long-term solution.

Frequency of subclavian artery stenosis in patients with mammarian artery coronary bypass and suspected coronary artery disease progression

We retrospectively analyzed patient records of all patients with a history of internal mammarian artery (IMA) coronary bypass undergoing coronary angiography at two cardiovascular centers between January 1st 1999 and December 31st 2019. A total of 11,929 coronary angiographies with or without percutaneous coronary intervention were carried out in 3921 patients. Our analysis revealed 82 (2%) patients with documented subclavian artery stenosis. Of these, 8 (10%) patients were classified as having mild, 18 (22%) moderate, and 56 (68%) severe subclavian artery stenosis. In 7 (9%) patients with subclavian artery stenosis, angiography revealed occlusion of the IMA graft. 26 (32%) patients with severe subclavian artery stenosis underwent endovascular or surgical revasculararization of the subclavian artery. In this retrospective multicenter study, subclavian artery stenosis was a relevant finding in patients with an internal mammarian artery coronary bypass graft undergoing coronary angiography. The development of dedicated algorithms for screening and ischemia evaluation in affected individuals may improve treatment of this potentially underdiagnosed and undertreated condition.

Direct Bypass Surgery for Moyamoya and Steno-occlusive Vasculopathy: Clinical Outcomes, Intraoperative Blood Flow Analysis, Long-term Follow-up, and Long-term Bypass Patency in a Single Surgeon Case Series of 162 Procedures

Cerebral extracranial-intracranial (EC-IC) direct bypass is a commonly used procedure for the treatment of cerebral hypoperfusion secondary to chronic steno-occlusive vasculopathy. We sought to determine clinical outcomes, intraoperative blood flow analysis, long term follow up, and long term patency rates from a single surgeon's series of direct cerebral bypass for moyamoya disease, moyamoya syndrome, and steno-occlusive disease. We reviewed clinical, demographic, operative and neuroimaging records for all patients who underwent a direct EC-IC bypass by the senior author between August 1999 and November 2020. Primary outcomes analyzed were functional long-term outcomes (by modified Rankin score [mRS]), surgical complications, and short-term and long-term bypass patency. A total of 162 revascularization procedures in 124 patients were performed. Mean clinical follow up time was 2 years 11 months. The combined immediate and long term postoperative stroke and/or intracerebral hemorrhage rate was 6.2%. There were 17 bypasses (10%) that were found to be occluded at long-term follow-up, all but one were asymptomatic. Long-term graft occlusion was correlated with presence of complete collateralization on preoperative angiography but not cut flow index (CFI). Overall, patients had a significant clinical improvement with a mean mRS score 1.8 preoperatively and 1.2 postoperatively. In our consecutive series of patients treated with direct EC-IC cerebral bypass, there was significant improvement in functional outcome as measured by the mRS. The long term patency rate was 90%. There was a statistically significant correlation between complete or incomplete angiographic collateralization patterns and long-term bypass occlusion. There was no correlation between bypass type, clinical syndrome, or CFI and long-term occlusions. The role of bypass surgery and the need for surgical expertise remain strong in the treatment of moyamoya variants and a select group of atherosclerotic steno-occlusive patients.

Intimal hyperplasia, saphenous vein graft disease, and clinical outcomes: Insights from the CTSN VEST randomized trial

BackgroundDiffuse intimal hyperplasia and graft irregularity adversely affect the long-term patency of saphenous vein grafts (SVGs) and clinical outcomes of patients undergoing coronary artery bypass grafting (CABG). The VEST trial evaluated the efficacy of external graft support in limiting the development of intimal hyperplasia (IH) at 1 year postsurgery. In the present secondary analysis, we explored the associations between graft disease and IH and clinical events. We also examined risk factors for early graft occlusion. MethodsVEST is a within-patient randomized, multicenter trial that enrolled 224 patients with multivessel coronary disease undergoing CABG surgery, of whom 203 were evaluated by 1 year postsurgery. Intimal hyperplasia, lumen uniformity, graft stenosis, and graft perfusion were measured by intravascular ultrasound and angiography. Major cardiac and cerebrovascular events (MACCE; including death, myocardial infarction, stroke, and revascularization) were recorded over a median follow-up of 3 years. ResultsWorse lumen uniformity, greater stenosis, and worse graft perfusion were associated with higher IH values and an increased incidence of clinical events. Consistent with previous findings, we identified endoscopic vein harvesting, female sex, and transit time flow measurement of pulsatility index and flow as risk factors for SVG occlusion during the first year postsurgery. ConclusionsIn this secondary analysis of the VEST trial, we observed an association between intimal hyperplasia area and clinical measures of SVG disease at 1 year postsurgery. More severe SVG disease and larger areas of IH were associated with a higher incidence of 3-year MACCE. Ongoing follow-up to 5 years will further elucidate the impact of SVG disease on long-term clinical outcomes of CABG.

TCT-128 Saphenous Vein Graft Occlusion Following Native Vessel Chronic Total Occlusion Percutaneous Coronary Intervention

TCT-128 Saphenous Vein Graft Occlusion Following Native Vessel Chronic Total Occlusion Percutaneous Coronary Intervention

Quantitative flow ratio to predict long-term coronary artery bypass graft patency in patients with left main coronary artery disease

PurposeFractional flow reserve (FFR) has been demonstrated in some studies to predict long-term coronary artery bypass graft (CABG) patency. Quantitative flow ratio (QFR) is an emerging technology which may predict FFR. In this study, we hypothesised that QFR would predict long-term CABG patency and that QFR would offer superior diagnostic performance to quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS).MethodsA prospective study was performed on patients with left main coronary artery disease who were undergoing CABG. QFR, QCA and IVUS assessment was performed. Follow-up computed tomography coronary angiography and invasive coronary angiography was undertaken to assess graft patency.ResultsA total of 22 patients, comprising of 65 vessels were included in the analysis. At a median follow-up of 3.6 years post CABG (interquartile range, 2.3 to 4.8 years), 12 grafts (18.4%) were occluded. QFR was not statistically significantly higher in occluded grafts (0.81 ± 0.19 vs. 0.69 ± 0.21; P = 0.08). QFR demonstrated a discriminatory power to predict graft occlusion (area under the receiver operating characteristic curve, 0.70; 95% confidence interval [CI], 0.52 to 0.88; P = 0.03). At long-term follow-up, the risk of graft occlusion was higher in vessels with a QFR > 0.80 (58.6% vs. 17.0%; hazard ratio, 3.89; 95% CI, 1.05 to 14.42; P = 0.03 by log-rank test). QCA (minimum lumen diameter, lesion length, diameter stenosis) and IVUS (minimum lumen area, minimum lumen diameter, diameter stenosis) parameters were not predictive of long-term graft patency.ConclusionsQFR may predict long-term graft patency in patients undergoing CABG.

Long-Term Patency of Venous Conduits Targeting the Right Coronary Artery System-Single Is Superior to Sequential bypass Grafting.

Objective: Little is known about the fate of bypass grafts to the right coronary system. To investigate the long-term patency of venous bypass grafts directed to the right coronary artery (RCA) based on postoperative angiograms and to identify predictors of graft occlusion. Methods: In this single-center study, all patients who underwent coronary angiography from 2005 to 2021 after previously undergoing isolated coronary artery bypass grafting (CABG) were included. The primary endpoint was graft occlusion over a median follow-up of 9.1 years. Results: Among a total of 1106 patients (17.0% women, 64 (57–71) years median age), 289 (26.1%) received a sequential vein graft and 798 (72.2%) a single graft. Multivariate regression revealed age (HR 1.019, CI 95% 1.007–1.032), the urgency of CABG (HR 1.355, CI 95% 1.108–1.656), and severely impaired left ventricular function (HR 1.883, CI 95% 1.290–2.748), but not gender and chronic total occlusion (CTO) as predictive factors for graft occlusion. Single conduits were found to be a predictor of graft patency (HR 0.575 CI 95% 0.449–0.737). The angiographic outcome showed an overall 10-year freedom from graft occlusion of 73.4% ± 1.6%. The 5-year (10-year) freedom from graft occlusion was 76.9% ± 2.8% (57.8% ± 4.0%) for sequential grafts and 90.4% ± 1.1% (77.8% ± 1.7%) for single grafts (log-rank p < 0.001). Conclusions: In symptomatic patients with renewed angiography, venous bypass grafting of the RCA showed acceptable long-term patency rates. Single bypass grafting of the RCA was superior to sequential grafting, which needs to be further investigated.

One-year safety and effectiveness of the Alto abdominal stent graft in the ELEVATE IDE trial

ObjectiveThis study reports the results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the polymer based Endologix Alto Stent Graft System in treating abdominal aortic aneurysms (AAAs), with sealing 7 mm below the top of the fabric in aortic neck diameters from 16 to 30 mm. MethodsSeventy-five patients were treated with Alto devices between March 2017 and February 2018 in 16 centers in the United States for infrarenal AAAs (max diameter ≥5.0 cm in diameter or size increase by 0.5 cm in 6 months or diameter ≥1.5 times the adjacent normal aorta). Patients were followed for 30 days, 6 months, and 1 year by clinical evaluation and computed tomography and abdominal x-ray imaging. Treatment success was defined as technical success and freedom from AAA enlargement, migration, type I or III endoleak, AAA rupture or surgical conversion, stent graft stenosis, occlusion, kink, thromboembolic events, and stent fracture attributable to the device requiring secondary intervention through 12 months. Preoperative characteristics, perioperative variables, follow-up clinical evaluations, and radiographic examination results through the first 1 year were analyzed. ResultsThe mean patient age was 73 years, with 93% of patients being male. The 30-day major adverse event rate was 5.3%. At 1 year, the primary endpoint was met with a treatment success rate of 96.7%. Through 1-year post-treatment, all-cause mortality was 4.0%. No AAA-related mortality occurred. AAA enlargement was 1.6%, type I endoleak rate was 1.4%, with 100% freedom from type III endoleaks, device migration, device fracture, stent occlusion, or AAA rupture. The device-related secondary intervention rate was 2.7%. ConclusionsThis prospective study demonstrates the Endologix Alto is safe and effective in treating AAAs with appropriate anatomy at 1 year. The safety endpoint is met by a 5.3% 30-day major adverse event rate, whereas the effectiveness endpoint is met by a treatment success rate of 96%.

Clinical Outcomes of Limb-sparing Tumor Surgery With Vascular Reconstruction for Bone and Soft-tissue Tumors.

This study aimed to retrospectively investigate clinical outcomes after tumor resection surgery and discuss reconstruction methods and postoperative complications. We analyzed the clinical outcomes, such as graft survival and prognosis, of nine patients with bone and soft-tissue tumors of the extremities with major vascular invasion who underwent limb-sparing surgery with vascular reconstruction between January 2006 and December 2020. The primary tumor was malignant in eight cases and intermediate in one case, with a mean postoperative follow-up duration of 52.1 months. A total of 10 vascular reconstructions (arterial in eight patients and both arterial and venous in one) were performed with autologous vein grafts in four cases and synthetic grafts in five cases. Graft occlusion was observed in two cases reconstructed with the great saphenous vein measuring >200 mm in length, and the 5-year arterial patency rate was 8/9. Only one case showed local recurrence, and at 5 years, local control was achieved in eight out of nine patients. Limb-sparing was achieved in all cases and the 5-year overall and disease-free survival rates were 77.8%. Postoperative complications occurred in six patients and wound-related complications were improved by re-surgery, while the others were controlled by conservative treatment. Limb-sparing tumor resection surgery with vascular reconstruction has favorable clinical and oncological outcomes. Most postoperative complications related to this surgery can be controlled by conservative treatment, except for wound-related complications. In reconstructions with autologous vein grafts of a length exceeding 200 mm, the graft occlusion rate may increase, and synthetic grafts may be recommended.

Reduced Morbidity and Mortality Associated With Minimally Invasive Single-vessel Coronary Artery Bypass Compared With Conventional Sternotomy.

We aimed to describe the safety and clinical benefits of minimally invasive, nonsternotomy coronary artery bypass grafting (MICABG) using data from The Society of Thoracic Surgeons (STS) National Database. MICABG has gained popularity, owing to expected lower perioperative morbidity and shorter recovery. Despite this, concerns remain regarding anastomotic quality and the validity of proposed perioperative benefits. We queried the STS National Database for all patients who underwent single-vessel coronary artery bypass grafting (CABG) from January 2014 to December 2016 to compare outcomes of MICABG with conventional CABG. Patients who underwent concomitant or emergent procedures were excluded. Propensity-weighted cohorts were compared by operative approach with adjustment for variability across institutions. Of 12,406 eligible patients, 2688 (21.7%) underwent MICABG, and 9818 (78.3%) underwent conventional CABG. Propensity weighting produced excellent balance in patient characteristics, including completeness of revascularization, body mass index, and STS predictive risk scores. MICABG was associated with significant reduction of in-hospital mortality [odds ratio (OR)=0.32, absolute reduction (AR)=0.91%, P <0.0001]; 30-day mortality (OR=0.51, AR=0.88%, P =0.001), duration of ventilation (8.62 vs 12.6 hours, P <0.0001), prolonged hospitalization (OR=0.77, AR=1.6, P =0.043), deep wound infection (OR=0.33, AR=0.68, P <0.004), postoperative transfusions (OR=0.52, AR=7.7%, P <0.0001), and STS composite morbidity (OR=0.72, AR=1.19%, P =0.008). Subgroup analysis of only off-pump left internal mammary artery-left anterior descending CABG showed similar findings. Major adverse cardiac events and graft occlusion did not differ between groups. MICABG is associated with lower mortality and perioperative morbidity compared with conventional sternotomy CABG. MICABG may have a role in treating single-vessel disease.

Geometrical Changes of the Aorta as Predictors for Thromboembolic Events After EVAR With the Anaconda Stent-Graft

Purpose: Thromboembolic events (TE), including limb graft occlusion (LGO) and distal limb embolization (DLE), are common complications after endovascular aneurysm repair (EVAR). The aim of this study was to find predictors for TE in patients treated with the Anaconda stent-graft for infrarenal aneurysms. Materials and Methods: Geometrical and anatomical variables were retrospectively analyzed in a consecutive Anaconda cohort. Pre- and postoperative CT scans were used to derive geometrical parameters length, curvature, torsion, and tortuosity index (TI) from the center lumen lines (CLLs). Limb characteristics, pre-to-post EVAR and mid-term-follow-up changes in the parameters were evaluated for their predictive value for TE. Results: Eighty-four patients (mean age 74±8.3 years, 74 men) were enrolled. The risk of TE was lowered with pre-to-post implant decreasing TI (steps of 0.05: OR: 1.30, 95% CI: 1.01-1.66, p=0.04), pre-to-post implant decreasing mean curvature (OR: 1.08, 95% CI: 1.01-1.16, p=0.03), and a larger degree of circumferential common iliac artery (CIA) calcification (OR: 0.98, 95% CI: 0.97-1.00, p=0.03). The only LGO predictor was the caudal relocation of maximal curvature after EVAR (OR: 1.01, 95% CI: 1.00-1.01, p=0.04). Preventors of DLE were CIA diameter (OR: 0.87, 95% CI: 0.76-0.99, p=0.04), circumferential CIA calcification (OR: 0.97, 95% CI: 0.95-1.00, p=0.03), mean and maximal curvature of the preoperative aortoiliac trajectory (OR: 0.86, 95% CI: 0.79-0.94, p<0.01 and OR: 0.97, 95% CI: 0.95-1.00, p=0.03, respectively) and pre-to-postoperative decrease in mean curvature (OR: 1.11, 95% CI: 1.02-1.21, p=0.02). Midterm TE predictors were length (OR: 0.95, 95% CI: 0.89-1.01, p=0.08) and torsion maximum location (OR: 1.01, 95% CI: 0.99-1.01, p=0.10). Conclusion: The present study confirms that treatment of infrarenal AAA with an Anaconda stent-graft is related to a relatively high TE rate which decreases with a pre-to-postoperative reduction in curvature and TI, and a larger degree of circumferential CIA calcification. In other words, more aortoiliac straightening and more circumferential CIA calcification may prevent TE development after EVAR with this stent-graft.

Results of endovascular treatment of venous anastomotic stenosis in prosthetic arteriovenous for hemodialysis PTFE grafts. Comparative analysis between patent and occluded grafts

ObjectiveTo analyze the results of endovascular treatment of venous anastomotic stenosis (VAS) in humero-axillary arteriovenous grafts (HAG), comparing outcomes between patent and thrombosed HAG. Material and methodsA retrospective cohort study was made of endovascular treated patients because of a VAS in a HAG between January 2009 and December 2019. Group A: Thrombosed HAG secondary to a VAS. Group B: Patent HAG with a VAS detected during follow-up. Technical success was defined as residual stenosis after treatment <30%, and clinical success as satisfactory immediate dialysis after surgery. After ET a biannual clinical and ultrasound follow-up was performed. Statistical analysis: Survival analysis was performed for time-to-event data to assess patency. ResultsGroup A: 55 patients. Group B: 22. There were no significative differences in demographic and anatomical factors between groups.Technical and clinical success were 100% in group B and 94.5% and 91% respectively in group A.Primary patency at 1, 6 and 12 months was: Group A: 81.8%, 22.4% y 15.7% respectively. Group B: 100%, 85.9%, 76,4% (p < 0.001). Secondary patency at 1, 6 and 12 months was: Group A: 85.2%, 45.8% y 31.3% respectively. Group B 100%, 95.3%, 95.2% (p < 0.001). Use of non-covered stents was associated with an increased risk of occlusion (HR 2.669 IC 95% 1.146–6.216, p = 0.010). ConclusionA higher patency of EV performed on a patent HAG is expected. It is therefore advisable to develop surveillance programs that are capable to detect VAS before its occlusion.

External Support for Saphenous Vein Grafts in Coronary Artery Bypass Surgery

Intimal hyperplasia and subsequent saphenous vein graft failure may have significant adverse clinical effects in patients undergoing coronary artery bypass surgery. External support of saphenous vein grafts has the potential to prevent vein graft dilation and hence slow the rate of intimal hyperplasia and increase long-term vein patency. To determine efficacy, as measured by intimal hyperplasia, and safety of an external saphenous vein graft support device in patients undergoing a coronary bypass graft procedure. This within-patient randomized, open-label, multicenter study was conducted at 17 Cardiothoracic Surgical Trials Network centers in North America. Between January 2018 and February 2019, 224 patients with multivessel coronary artery disease undergoing isolated bypass surgery were enrolled. For each patient, 1 of 2 vein grafts was randomized to receive external support or no support. External vein graft support or no support. The primary efficacy end point was intimal hyperplasia area assessed by intravascular ultrasound at 12 months postrandomization for each study graft. Secondary confirmatory end points were lumen diameter uniformity assessed by angiography and graft failure (≥50% stenosis) by quantitative coronary angiography. Major cardiac and cerebrovascular events were collected through month 12. Among 224 patients (mean [SD] age, 65.8 [8.3] years; 178 [79.5%] male), 203 (90.6%) were eligible for intravascular ultrasound, of which 85 (41.9%) had at least 1 study graft occluded or severely diseased at 12 months (55 supported, 56 unsupported). After imputation of data missing because of graft occlusion or severe disease, the estimated mean (SE) intimal hyperplasia area was 5.11 (0.16) mm2 in supported grafts and 5.79 (0.20) mm2 in unsupported grafts (P = .07). In a sensitivity analysis of 113 patients with both grafts imaged, the mean intimal hyperplasia area was 4.58 (0.18) mm2 and 5.12 (0.23) mm2 in supported and unsupported grafts, respectively (P = .04). By 12 months, 5 patients (2.2%) died and 16 patients (7.1%) experienced a major cardiac or cerebrovascular event. The 12-month difference in intimal hyperplasia area between supported and unsupported grafts did not achieve statistical significance. Cumulative mortality and major cardiac or cerebrovascular events rates were similar to those in other randomized coronary artery bypass trials. Further investigation to assess the effect of external graft support devices on long-term graft patency and clinical outcomes is warranted. ClinicalTrials.gov Identifier: NCT03209609.

Clinical outcomes in patients with infrapopliteal arterial occlusive disease treated by lower extremity bypass surgery: a comparison of atherosclerosis and thromboangiitis obliterans.

Surgical bypasses are commonly utilized for the treatment of infrapopliteal arterial occlusive disease resulting from atherosclerosis (ASO) and thromboangiitis obliterans (TAO), especially when endovascular procedures fail. The aim of this study is to compare the in-hospital and follow-up outcomes of ASO and TAO patients treated with infrapopliteal bypass surgery. A total of 32 infrapopliteal bypasses were analyzed in 18 TAO patients and 14 ASO patients. Preoperative and postoperative arterial Doppler ultrasonography was performed in all patients. The ankle-brachial index (ABI) was calculated preoperatively and postoperatively in all cases. All patients were followed-up for at least one year and clinical outcomes were recorded. Within 1-7 days postoperatively, 4 grafts in TAO patients occluded; nevertheless, 1 graft occlusion occurred in ASO patients. Patency rates at in-hospital were 77.8% and 92.9% in TAO and ASO patients, respectively. In 27 patients with successful infrapopliteal bypass, ABIs and crural peak arterial flow velocities significantly increased at 1-7 days postoperatively. During the period of follow-up, 6 graft occlusions occurred in TAO patients, and one ASO patient died of myocardial infarction. Patency rates at follow-up were 44.5% and 85.7% in TAO and ASO patients. For TAO patients with graft failure, ABIs at follow-up did not statistically differ from those postoperatively; however, they were significantly higher than those preoperatively. Infrapopliteal bypass surgery is a feasible and effective procedure for ASO and TAO patients. Patency rates are lower in TAO than those in ASO during the in-hospital and follow-up period. However, TAO patients had the ischemic symptom relief and the improvement in ABI despite graft occlusion one year postoperatively.

Abstract No. 362 Texture analysis of arterial graft thrombus on CT angiography: correlation with age of thrombus and implication on catheter directed thrombolysis

Catheter-directed thrombolysis (CDT) is the widely utilized treatment for patients with acute occlusion of lower extremity arteries and bypass grafts. The success and dose of tissue plasminogen activator (tPA) required is influenced by age of thrombus, which is primarily assessed by clinical parameters. The aim of this study is to investigate the potential role of utilizing quantitative texture analyses in determining the age of thrombus in relation to patients’ clinical profiles, further predicting the dose of required thrombolytic agent.

Outcomes of patients with acute type A aortic dissection and concomitant lower extremity malperfusion

ObjectiveThe occurrence of acute lower limb ischemia (ALLI) is a serious risk within the context of aortic dissection repair. The aim of the present study was to examine the outcomes of patients with acute type A aortic dissection (ATAD) and concomitant lower extremity malperfusion. MethodsWe performed a retrospective medical record review at our tertiary referral center of patients who underwent ATAD repair from January 2002 to June 2018. We used univariate and multivariate analyses to compare the outcomes of patients with and without lower extremity malperfusion. The primary outcomes were 30-day and 1-year mortality. ResultsA total of 378 patients underwent ATAD repair during the study period. Their mean age was 57 years, 68% were men, and 51% were White. A total of 62 patients (16%) presented with concomitant ALLI, including 35 (9%) who presented with isolated ALLI and 27 (7%) who presented with ALLI and concomitant malperfusion of at least one other organ. Of the 62 patients with ALLI, 46 underwent only proximal aortic repair. Of the 378 patients, 6 died within the first 24 hours, and their limb perfusion was not assessed. Among the 40 patients who underwent isolated proximal repair and survived >24 hours, 34 (85%) had resolution of their ALLI. Of the 16 patients who underwent concomitant lower extremity peripheral vascular procedures, 10 had bypass procedures and 1 died within 24 hours due to refractory coagulopathy and hypotension. All six patients with adequate follow-up imaging studies had asymptomatic occlusion of the bypass graft with recanalization of the occluded native arteries. Patients who presented with any organ malperfusion had increased 30-day (odds ratio, 1.8; P = .04) and 1-year (odds ratio, 1.8; P = .04) mortality and decreased overall survival (P < .01). For the patients with isolated ALLI, no significant differences were found in 30-day or 1-year mortality or overall survival (P = .57). ConclusionsProximal repair of ATAD resolves most cases of associated ALLI, and isolated ALLI does not affect short- or long-term survival. All patients with follow-up in our study who underwent extra-anatomic bypass developed asymptomatic graft occlusion, which could be attributed to competitive flow from the remodeled native arterial system. We believe that rapid and aggressive restoration of flow to the lower extremity is the best method to treat ALLI malperfusion syndrome. Close monitoring for the development of compartment syndrome is recommended.