Graft Occlusion Research Articles

Alternative Approaches to the Abdominal Aorta: Outcomes of the Right Retroperitoneal Approach for Aortic Surgery

The left retroperitoneal (LRP) approach to the aorta is a well-established technique for aortic exposure. The right retroperitoneal (RRP) approach to the aorta has been performed less often, and the outcomes remain unknown. The purpose of our study was to evaluate the outcomes of RRP aortic procedures and to determine whether it is a viable strategy to preserve the LRP space for future procedures. We performed a retrospective review of a prospectively maintained computerized database with a query for all retroperitoneal aortic procedures. The patients' medical records were reviewed and data collected. The demographics, indications, intraoperative details, and outcomes were tabulated. We found 6076 retroperitoneal approaches for aortic procedures that had been performed between 1984 and 2020. Of these, 225 had used the RRP approach. Of the 225 patients, 153 were men (68%), and the median age was 65.2 years (range, 26-88). The comorbidities included hypercholesterolemia (n = 98; 15.6%), hypertension (n = 38; 16.9%), coronary artery disease (n = 25; 11.1%), current tobacco use (n = 98; 43.6%), diabetes (n = 32; 14.2%), and renal failure (n = 5; 2.2%). The indications for intervention included aneurysm (n = 112; 49.8%), occlusive disease (n = 100; 44.4%), and other (n = 13; 5.8%). The intraoperative blood loss was 967.1 mL (range, 50-8000 mL). Perioperative complications occurred in 43 patients (19.1%), with a total of 50 complications. These included cardiac events (n = 5), cerebrovascular events (n = 3), multiorgan failure (n = 8), renal failure (n = 4), pulmonary events (n = 3), bleeding (n = 7), colon ischemia (n = 6), hematoma (n = 1), infection (n = 2), limb loss (n = 3), and graft occlusion or stenosis (n = 5). Four patients died perioperatively (1.8%). Of the 225 patients treated with a RRP approach, 31 required 66 subsequent procedures. These procedures included 29 cases of extra-anatomic bypass, 19 cases of thrombectomy or embolectomy, 10 cases of bypass revision, 5 cases of infected graft excision, and 3 cases of aneurysm revision. Of the 225 patients in the RRP group, 8 had eventually undergone a LRP approach for aortic reconstruction and had also required 26 subsequent procedures. Of the RRP group, 14 had undergone a prior LRP approach and had required 12 subsequent procedures. The RRP approach to the aorta is a useful technique in the setting of prior surgery, anatomic abnormality, or infection that complicates the use of other approaches. The outcomes were similar to those with other more standard approaches. The RRP aortic approach has the added benefit of preserving the left retroperitoneum for future inflow procedures.

Percutaneous coronary intervention of totally occluded coronary venous bypass grafts: An exercise in futility?

BACKGROUNDPercutaneous coronary intervention (PCI) of diseased saphenous vein grafts (SVG) continues to pose a clinical challenge. Current PCI guidelines give a class III recommendation against performing PCI on chronically occluded SVG. However, contemporary outcomes after SVG intervention have incrementally improved with distal protection devices, intracoronary vasodilators, drug-eluting stents, and prolonged dual antiplatelet therapy. AIMTo reassess the procedural and long-term outcomes of PCI for totally occluded SVG with contemporary techniques.METHODSThis was a retrospective observational study conducted at a single university hospital. The study population consisted of 35 consecutive patients undergoing PCI of totally occluded SVG. Post-procedure dual antiplatelet therapy was continued for a minimum of one year and aspirin was continued indefinitely. Clinical outcomes were assessed at a mean follow-up of 1221 ± 1038 d. The primary outcome was freedom from a major adverse cardiac event (MACE) defined as the occurrence of any of the following: death, myocardial infarction, stroke, repeat bypass surgery, repeat PCI, or graft reocclusion. RESULTSThe study group included 29 men and 6 women with a mean age of 69 ± 12 years. Diabetes was present in 14 (40%) patients. All patients had Canadian Heart Classification class III or IV angina. Clinical presentation was an acute coronary syndrome in 34 (97%) patients. Mean SVG age was 12 ± 5 years. Estimated duration of occlusion was acute (< 24 h) in 34% of patients, subacute (> 24 h to 30 d) in 26%, and late (> 30 d) in 40%. PCI was initially successful in 29/35 SVG occlusions (83%). Total stent length was 52 ± 35 mm. Intraprocedural complications of distal embolization or no-reflow occurred in 6 (17%) patients. During longer term follow-up, MACE-free survival was only 30% at 3 years and 17% at 5 years.CONCLUSIONPCI of totally occluded SVG can be performed with a high procedural success rate. However, its clinical utility remains limited by poor follow-up outcomes.

No-Touch Versus Conventional Vein Harvesting Techniques at 12 Months After Coronary Artery Bypass Grafting Surgery: Multicenter Randomized, Controlled Trial.

Vein graft occlusion is deemed a major challenge in coronary artery bypass grafting. Previous studies implied that the no-touch technique for vein graft harvesting could reduce occlusion rate compared with the conventional approach; however, evidence on the clinical benefit and generalizability of the no-touch technique is scare. From April 2017 to June 2019, we randomly assigned 2655 patients undergoing coronary artery bypass grafting at 7 hospitals in a 1:1 ratio to receive no-touch technique or conventional approach for vein harvesting. The primary outcome was vein graft occlusion on computed tomography angiography at 3 months and the secondary outcomes included 12-month vein graft occlusion, recurrence of angina, and major adverse cardiac and cerebrovascular events. The generalized estimate equation model was used to account for the cluster effect of grafts from the same patient. During the follow-up, 2533 (96.0%) participants received computed tomography angiography at 3 months after coronary artery bypass grafting and 2434 (92.2%) received it at 12 months. The no-touch group had significantly lower rates of vein graft occlusion than the conventional group both at 3 months (2.8% versus 4.8%; odds ratio, 0.57 [95% CI, 0.41-0.80]; P<0.001) and 12 months (3.7% versus 6.5%; odds ratio, 0.56 [95% CI, 0.41-0.76]; P<0.001). Recurrence of angina was also less common in the no-touch group at 12 months (2.3% versus 4.1%; odds ratio, 0.55 [95% CI, 0.35-0.85]; P<0.01). Rates of major adverse cardiac and cerebrovascular events were of no significant difference between the 2 groups. The no-touch technique was associated with higher rates of leg wound surgical interventions at 3-month follow-up (10.3% versus 4.3%; odds ratio, 2.55 [95% CI, 1.85-3.52]; P<0.001). Compared with the conventional vein harvesting approach in coronary artery bypass grafting, the no-touch technique significantly reduced the risk of vein graft occlusion and improved patient prognosis. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03126409.

Ascending Aortoiliac Bypass for One-Stage Repair of Adult Aortic Coarctation With Concomitant Cardiac Lesions.

To evaluate the efficacy and safety of ascending aortoiliac bypass surgery for one-stage repair of adult coarctation of the aorta (CoA) and concomitant cardiac disease. From March 2012 to October 2018, 51 consecutive CoA patients were treated with ascending aorta to bilateral iliac artery bypass concomitant with and cardiac surgerical procedures performed for a variety of reasons. A Y-shaped graft was used for the bypass procedure. We evaluated early outcomes, including postoperative death, systolic blood pressure and differences between upper and lower limb blood pressure. The average age was 41years and 64.7% of patients were men. Simultaneous cardiac procedures included aortic valve replacement, ventricular septal defect repair, Bentall procedures and Wheat procedures. No deaths occurred in the early postoperative period. Three patients had delayed healing at the site of the abdominal lower quadrant incisions. The average systolic pressure in the upper limb and the average difference between the upper- and lower-limb blood pressure decreased significantly after surgery (162.7 ± 13.4mmHg vs 128.4 ± 6.7mmHg, P = .000; 69.6 ± 15.6mmHg vs 8.7 ± 7.6mmHg, P = .000, respectively); The systolic blood pressure in the lower limb increased after bypass surgery (93.1 ± 6.2mmHg vs 119.6 ± 7.7mmHg, P = .000). The follow-up rate was 100%, with an average follow-up time of 61months. Six patients (11.8%) had graft stenosis or occlusion. Three patients (5.9%) underwent endovascular embolectomy. In our small series, ascending aortoiliac bypass for one-stage repair of CoA with concomitant cardiac lesions appears safe and efficacious in effectively reduceing differences between upper and lower limb systolic blood pressure. Further study with larger sample size and longer follow-up is needed.

Clinical outcomes according to lesion complexity in high bleeding risk patients treated with 1-month dual antiplatelet therapy following PCI: Analysis from the Onyx ONE clear study.

To compare clinical outcomes in high bleeding risk (HBR) patients with and without complex percutaneous coronary intervention (PCI) treated with Resolute Onyx zotarolimus-eluting stents (ZES) after 1-month dual antiplatelet therapy (DAPT). PCI with 1-month DAPT has been demonstrated to be safe in HBR patients treated with Resolute Onyx ZES. Whether these outcomes are consistent in patients with complex lesions is uncertain. Among HBR patients who were event-free 1month after PCI with ZES and treated thereafter with single antiplatelet therapy (SAPT), the clinical outcomes between 1 month and 1 year were compared after complex PCI (3 vessels treated, ≥ 3 lesions treated, total stent length > 60 mm, bifurcation with ≥ 2 stents implanted, atherectomy, or left main, surgical bypass graft or chronic total occlusion PCI) versus noncomplex PCI. Propensity score adjustment was performed to adjust for baseline differences among complex and noncomplex patients. Complex patients (N=401, 26.6% of total) had a higher prevalence of hyperlipidemia, diabetes mellitus and previous myocardial infarction (MI). Between 1 month and 1 year, rates of MI (7.1% vs. 4.0%, p=0.02) and cardiac death/MI (9.3% vs. 6.1%, p=0.04) were higher among complex versus noncomplex patients, although stent thrombosis rates were similar. After adjustment for baseline characteristics, differences in outcomes were no longer significant between groups. Higher rates of ischemic outcomes in complex PCI patients were largely explained by baseline clinical differences, rather than lesion complexity, among HBR patients treated with 1-month DAPT following PCI with Resolute Onyx ZES.

Thirty-day Results from the ZEPHYR Registry: Outcomes of EVAR Using the Zenith Alpha™ Abdominal Endovascular Graft for the Treatment of AAA in 347 Patients

To report technical and clinical 30-day results following treatment with the Zenith Alpha™ abdominal stent graft from the ZEnith alPHa for aneurYsm Repair Registry (ZEPHYR). Multicenter, nonrandomized, single arm, core laboratory-controlled, prospective registry collecting data on the Zenith Alpha Abdominal Endovascular Graft being used in subjects with abdominal aortic aneurysms (AAA) from sites in Germany, Belgium, and The Netherlands between December 2016 and December 2019. Inclusion criteria were non-ruptured AAAs with a maximum diameter ≥50 mm or enlargement >5 mm over 6 months with an AAA neck length ≥10 mm (site reported). Primary outcome measure was treatment success at 30 days. Treatment success was defined as a combined endpoint consisting of technical and clinical success. Technical success was defined as successful stent graft delivery and deployment as well as successful removal of the delivery system. Clinical success at 30 days was defined as freedom from type I and III endoleak, aneurysm rupture, conversion to open surgery and stent graft occlusion. Three hundred forty-seven subjects were included from 14 sites with a median age of 73.0 years (IQR 68.0-79.0). Thirty-four patients were female (9.8%). The median AAA diameter was 58.3 mm (IQR 55.0-63.5). The median proximal neck diameter was 23.6 mm (IQR 22.0-25.2) with a median proximal neck length of 24.4 mm (IQR 15.0-34.8) and a median infrarenal neck angulation of 24.5° (IQR 15.0-35.0). The right and left common iliac diameter were 16.1 mm (IQR 14.1-19.4) and 16.2 mm (IQR 14.1-19.1), respectively. The treatment success rate at 30 days was 94.8% (N=329). Technical success was achieved in 333 patients (96.0%). The clinical success rate at 30 days was 98.8% (N=343). Three patients had limb occlusions at 30 day follow up (0.9%). One patient had a type Ib endoleak (0.3%). Seventy percent of vascular access approaches were percutaneous. The reintervention rate was 1.7% (N=6) within 30 days. Indications for reinterventions were a false aneurysm at puncture site (N=1), limb complications (N=2), stentgraft-associated renal artery occlusions (N=2), and an external iliac artery thrombosis (N=1). Endovascular aneurysm repair using the Zenith Alpha Abdominal Endovascular Graft is effective in the short term. Long term results will be reported in the future.

Early Graft, Limb and Mortality Outcomes from the Omniflow II Bio-Synthetic Graft

Omniflow II biosynthetic grafts are a commonly used alternative to autologous grafts in vascular bypass procedures. They are chosen for their purported resilience to infection, often in instances of existing graft failure or infection. We examined the short term, 1-3 year outcomes of Omniflow grafts in terms of patency, limb survival and mortality in a sample of 24 individuals. This is a single centred retrospective study of Omniflow II grafts implanted between September 23, 2015 and April 05, 2018 in our department. It includes grafts in all anatomical locations. Primary outcome measures were overall patient survival and time to this, primary graft patency (patency with no intervention) and then limb survival at 1 and 3 years. Kaplan-Meier survival analysis was plotted for the 3 primary outcome measures. A total of 24 grafts from 24 individuals were included with mean age 71.4 ± 11.7. We included 5 female and 19 male patients. The commonest indication was rest pain/claudication (N = 8) followed by graft occlusion (N = 6). Femoro-popliteal bypass (N = 13) and Femoro-distal bypass (N = 5) were the commonest procedures. Kaplan-Meier survival analysis demonstrated that 1 and 3-year primary patency rates were 54.2% and 37.5% respectively with Limb survival probability of 75% at 1 year and 70.8% at 3 years. These rates were all considerably lower than those found in previous comparative studies. Mortality however, compared favourably with 1 and 3-year survival probability 91.7% and 87.5% on average 296 days (range 95-451 days) after graft implantation. We found that rates of primary patency and limb salvage for this graft type were markedly lower than in comparable studies. Further work in the form of a RCT is indicated.

Reopening of the occluded saphenous vein composite grafts after coronary artery bypass grafting.

We have observed reopening of the occluded "no-touch" saphenous vein (NT SV) composite grafts on follow-up angiograms in patients who underwent coronary artery bypass graftings (CABGs). Between 2008 and 2018, 1283 patients received NT SV conduits without or with surrounding pedicle tissue as composite grafts based on the in situ left internal thoracic artery (ITA) for CABG and underwent early postoperative angiographies. Among the 1283 patients, 53 patients showed 55 occluded SV conduit anastomoses, and 46 patients who had 48 occluded SV anastomoses were re-evaluated by 1-year postoperative angiographies. Early postoperative angiographies in 1283 patients demonstrated overall occlusion rates of 1.2% (56/4518); occlusion rates of the ITA and SV were 0.08% (1/1259) and 1.7% (55/3260), respectively. One-year angiograms demonstrated that 14 occluded SV anastomoses (29.2% [14/48 occluded SV]) of 14 patients became patent. Reopening of occluded SV conduits occurred more frequently in NT SV with pedicle tissue than in NT SV without pedicle tissue (45.0% [9/20] vs. 17.9% [5/28]; p = .057). When we examined the preoperative and 1-year postoperative angiograms, reopening of the occluded SV conduits was not related with progression (p = .258) or preoperative reversibility score (p = .115) of native target coronary artery disease. More than a quarter of the occluded SV composite grafts on early postoperative angiograms were patent in the 1-year angiograms. The reopening rates were higher in patients who had received NT SV conduits with pedicle tissue than those who had received NT SV conduits without pedicle tissue.

Routine early postoperative computed tomography angiography after coronary artery bypass surgery: clinical value and management implications.

Computed tomography angiography (CTA) is broadly used for long-term follow-up of graft patency after coronary artery bypass graft surgery (CABG). However, its clinical value in the early postoperative setting has not been established yet. We evaluated the benefit of adding CTA to the routine clinical work-up after CABG on patient management. A total of 305 consecutive patients (269 males, median age 68 years) underwent CABG and postoperative CTA with a median of 6 days after surgery. Graft patency and additional imaging findings were assessed and their influence on diagnosis and clinical management was evaluated. Graft occlusion or high-grade stenosis was found in 15% of the patients. Additional findings were reported in 44% of the patients, including pericardial (2%) and pleural effusion (27%), large pneumothorax (11%), pulmonary infection (4%), cardiac or vascular thrombus (2%), pulmonary embolism (2%), sternal dehiscence (1%) and additional incidental findings requiring follow-up (6%). CT findings initiated new diagnostic and/or therapeutic measures in 15% of the patients, 47% of those with diseased grafts and 19% of patients with non-graft-related findings. No adverse events related to CTA were documented. Early routine postoperative assessment of CABG with CTA reveals both cardiac and non-cardiac findings with a high frequency, affecting clinical management in a substantial proportion of patients.

A Novel Risk Scoring Tool to Predict Saphenous Vein Graft Occlusion After Cardiac Artery Bypass Graft Surgery.

Objectives: Coronary artery bypass grafting (CABG) success is reduced by graft occlusion. Understanding factors associated with graft occlusion may improve patient outcomes. The aim of this study was to develop a predictive risk score for saphenous vein graft (SVG) occlusion after CABG.Methods: This retrospective cohort study enrolled 3,716 CABG patients from January 2012 to March 2013. The development cohort included 2,477 patients and the validation cohort included 1,239 patients. The baseline clinical data at index CABG was analyzed for their independent impact on graft occlusion in our study using Cox proportional hazards regression. The predictive risk scoring tool was weighted by beta coefficients from the final model. Concordance (c)-statistics and comparison of the predicted and observed probabilities of predicted risk were used for discrimination and calibration.Results: A total of 959 (25.8%) out of 3,716 patients developed at least one late SVG occlusion. Significant risk factors for occlusion were female sex [beta coefficients (β) = 0.52], diabetes (β = 0.21), smoking (currently) (β = 0.32), hyperuricemia (β = 0.22), dyslipidemia (β = 0.52), prior percutaneous coronary intervention (PCI) (β = 0.21), a rising number of SVG (β = 0.12) and lesion vessels (β = 0.45). On-pump surgery (β = −0.46) and the use of angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) (β = −0.59) and calcium channel blockers (CCB) (β = −0.23) were protective factors. The risk scoring tool with 11 variables was developed from the derivation cohort, which delineated each patient into risk quartiles. The c-statistic for this model was 0.71 in the validation cohort.Conclusions: An easy-to-use risk scoring tool which included female sex, diabetes, smoking, hyperuricemia, dyslipidemia, prior PCI, a rising number of SVG and lesion vessels, on-pump surgery, the use of ACEI/ ARB and CCB was developed and validated. The scoring tool accurately estimated the risk of late SVG occlusion after CABG (c-statistic = 0.71).

Safety and effectiveness of high flow extracranial to intracranial saphenous vein bypass grafting in the treatment of complex intracranial aneurysms: a single-centre long-term retrospective study

BackgroundTo summarize the safety and effectiveness of high flow extracranial to intracranial saphenous vein bypass grafting in the treatment of complex intracranial aneurysms.MethodsThe data of complex intracranial aneurysms patients for high flow extracranial to intracranial saphenous vein bypass grafting from January 2008 to January 2020 were retrospectively collected and analyzed. Eighty-two patients (31 men and 51 women) with 89 aneurysms underwent 82 saphenous vein bypass grafts followed by immediate parent vessel occlusion. The aneurysm was located at the internal carotid artery, middle cerebral artery, and basilar artery in 75, 11, and 3 cases, respectively.ResultsThe patency rate of bypass grafting was 100, 100, 96.3 and 92.4% on intraoperation, on the first postoperative day, at discharge and 6 months follow-up, respectively. At discharge and 6 months follow-up, 3 and 6 patients had graft occlusions. The main postoperative complications were transient hemiparesis and hemianopsia. 3 patients died due to bypass complications and poor physical condition.ConclusionsHigh flow extracranial to intracranial saphenous vein bypass grafting is safe and effective in the treatment of complex intracranial aneurysms and the saphenous vein can meet the requirements of brain blood supply. A high rate of graft patency and adequate cerebral blood flow can be achieved.HighlightsA single-centre long-term retrospective study was conducted to assess the safety and effectiveness of high flow EC-IC saphenous vein bypass grafting in the treatment of complex intracranial aneurysms. The data of 82 patients from January 2008 to January 2020 were retrospectively collected and analysed.We found the patency rate of bypass grafting was 100, 100, 96.3 and 92.4% on intraoperation, on the first postoperative day, at discharge and 6 months follow-up, respectively. At discharge and 6 months follow-up, 3 and 6 patients had graft occlusions.Finally, we conclude that high flow extracranial to intracranial saphenous vein bypass grafting is safe and effective in the treatment of complex intracranial aneurysms and the selected blood supply vessels can meet the requirements of blood supply.As far as we know, this study is one of the maximum number of cases in the treatment of complex intracranial aneurysms with saphenous vein bypass.

Early cardiac contractility outcome of reoperative coronary artery bypass grafting using right gastroepiploic artery.

Reoperative coronary artery bypass grafting (redo CABG) still carries higher mortality and increased morbidity compared with primary CABG. In this study, we retrospectively reviewed our operative outcome of redo CABG to evaluate the impact of the left anterolateral thoracotomy approach using the right gastroepiploic artery (RGEA). Between 1994 and 2020, 11 patients (mean age 60.3 ± 13.1 years; nine men, two women) underwent isolated redo CABG using the RGEA via the left anterolateral thoracotomy. The mean duration from the initial CABG was 128.3 ± 88.4 months. Redo CABG was performed because of graft occlusion in six patients (54.5%), graft stenosis in one patient (9.1%), and progressive disease of previously ungrafted vessels in four patients (36.4%). The total number of bypasses using RGEA (including Y-composite vein grafts) was 16 (four left anterior descending branches, two diagonal branches, five circumflex branches, five right coronary arteries). No residual graft injury, major comorbidity, or in-hospital death was observed. Changes in echocardiographic values before and after redo CABG were 210.9 ± 48.2 ml and 175.0 ± 41.4 ml in left ventricular end-diastolic volume, 130.2 ± 49.2 ml and 94.4 ± 33.0 ml in left ventricular end-systolic volume, and 45.6 ± 11.0% and 52.2 ± 10.7% in left ventricular ejection fraction, respectively. These parameters significantly improved after redo CABG. Redo CABG with RGEA grafting via the left anterolateral thoracotomy approach is a safe and effective surgical procedure especially in improving cardiac contractility in patients who required revascularization.

Patient-Specific Coronary Artery Bypass Graft 3D Printing: Implications for Procedural Planning in Complex Percutaneous Coronary Interventions.

Three-dimensional (3D) printing technology has seen tremendous growth in augmenting didactics, research, and preprocedural planning with structural heart procedures. Limited investigative efforts have been made in other areas of the cardiovascular spectrum. 3D-printed models (PMs) of anatomically complex coronary artery bypass graft (CABG) patients from coronary computed tomography angiography (CCTA) have implications for adaptive learning and preprocedural planning. Five patients with CCTA who underwent subsequent coronary angiography were 3D printed for retrospective comparisons. Standard slicer software was used to create a computer-aided image of the ascending aorta, native coronary arteries, bypass grafts, aortic arch, and great vessels and 3D printed using polylactic acid filament. The models were painted with acrylic paint to highlight anatomical features and comparison was made with coronary angiography and 3D-CTA images. All occluded vein grafts, left and right internal mammary artery (IMA) grafts, patent saphenous vein grafts, along with distal graft anastomotic sites, were accurately 3D printed. In cases with chronic total occlusions (CTOs), ambiguous ostial caps, mid or distal vessel chronic occlusions, and occlusions seen as CTOs on coronary angiography were 3D printed showing either distal vessel reconstitution via collaterals or complete arterial filling seen in a setting of calcification, microchannels, and collateral flow. Lastly, 3D printing of the aortic root and great vessels allowed for better appreciation of vessel tortuosity to aid in the cannulation of IMA grafts and optimizing engagement with diagnostic and guiding catheters. 3D printing of anatomically complex CABG patients has the potential to assist with preprocedural planning and operator understanding of complex coronary anatomy.

Open Surgical Secondary Interventions are More Durable than Endovascular Interventions for Lower Extremity Bypass Stenosis or Occlusion.

Objectives: Lower extremity bypasses often require secondary interventions to maintain patency. Our objectives were to characterize effectiveness of secondary interventions to maintain or restore bypass graft patency, and to compare outcomes of open and endovascular interventions. Methods: We reviewed patients who underwent lower extremity bypass at our institution from 2007 to 2010. We recorded the index bypass and subsequent ipsilateral interventions performed through 2018 or until loss of secondary patency. Patient, procedure, and anatomic data were collected. Endovascular intervention was compared with open/hybrid intervention. For outcome analysis, patency measures were defined relative to the time of the secondary intervention rather than the time of the index bypass. Results: 174 secondary interventions (56 open/hybrid, 118 endovascular; 42 for graft occlusion, and 132 for stenosis) treating 228 lesions in 97 bypasses were available for study. The index bypass was most commonly performed for tissue loss (71.1%), utilized a tibial artery target (57.7%), and used single-segment great saphenous vein (59.8%) rather than alternative vein (32.0%) or prosthetic (8.2%). A higher portion of open/hybrid interventions (51.8%) were done for graft occlusion than endovascular interventions (11.0%, P < .001). Mean follow-up for secondary interventions was 3.5years. A multivariate Cox proportional hazards model identified female gender, prior MI, anticoagulation, occlusion, and endovascular intervention as predictors of loss of primary patency. Intervention for occlusion predicted poorer primary and secondary patency. Endovascular intervention was associated with poorer primary patency as compared to open intervention and a trend toward poorer secondary patency. Conclusions: Both open and endovascular secondary interventions on lower extremity bypasses are low-risk procedures that offer acceptable patency. Although more commonly performed in the setting of graft occlusion, open surgical interventions show improved durability compared to endovascular interventions. Some patients, including those with occluded grafts, may benefit from more liberal use of open surgical intervention to restore bypass patency.

Limb Graft Occlusion Following Endovascular Aneurysm Repair for Infrarenal Abdominal Aortic Aneurysm with the Zenith Alpha, Excluder, and Endurant Devices: a Multicentre Cohort Study

Limb graft occlusion (LGO) is a serious complication after endovascular aneurysm repair (EVAR) and while device development enables treatment of increasingly complex aortic anatomy, little is known about how endograft type affects the risk of occlusion. This observational study aimed to explore the incidence of LGO after EVAR for three major endograft systems. All patients with standard EVAR as the primary intervention for infrarenal abdominal aortic aneurysm (AAA), between January 2012 and December 2018, at five Swedish vascular surgery centres, were included in this multicentre retrospective cohort study. LGO was defined as a total limb occlusion regardless of symptoms, or a treated significant stenosis. A nested case control (NCC) design with incidence density sampling of 1:3 was used for analysis of potential per-operative and morphological risk factors. Conditional logistic regression was used to estimate multivariable odds ratios (OR) with 95% confidence intervals (CI) RESULTS: A total of 924 patients were included. The majority were male (84%), the mean age was 76 years (± 7.5 SD), and median AAA diameter was 59 mm (IQR 55, 67). Patients were treated with Zenith Alpha (n= 315, ZISL limbs), Excluder (n= 152, PLC/PXC limbs), and Endurant (n= 457, ETLW/ ETEW limbs). During median follow up of 37 months (IQR 21, 62), 55 occlusions occurred (5.9%); 39 with Zenith Alpha (12.4%), one with Excluder (0.7%), and 15 with Endurant (3.3%). In the NCC analysis, the Zenith Alpha device (OR 5.31, 95% CI 1.97 - 14.3), external iliac artery (EIA) landing (OR 5.91, 95% CI 1.30 - 26.7), and EIA diameter < 10 mm (OR 4.99, 95% CI 1.46 - 16.9) were associated with an increased risk of LGO. Endograft device type is an independent risk factor for LGO after EVAR. Specifically, the Zenith Alpha demonstrated an increased risk of LGO compared with the Endurant and Excluder devices. In addition, a narrow EIA and landing zone in EIA are also risk factors for LGO.

Graft Patency and Determinants of Outcome in Infrainguinal Bypasses - A Retrospective Study

Context: Chronic lower limb ischemia, an important marker of atherosclerosis, is a common clinical problem prevalent in all socioeconomic groups in our country and across the globe. Infrainguinal bypass is mandated in a subset of patients with critical limb ischemia to provide immediate limb salvage as well as excellent long-term results. Aim: The purpose of our retrospective study is to elucidate the effect of various known factors on the long term patency of infrainguinal bypass grafts performed in our patient population at a tertiary referral hospital. Methods: We retrospectively reviewed follow up data of 110 patients who had undergone infrainguinal bypass grafting over a period of ten years in our Institutional vascular registry. Graft patency rates and factors affecting thereof over this period were studied and the data statistically analysed. Overall cumulative patency rates were calculated by the life table survival method and compared with that of the patency rates of above-knee bypass procedures in the world literature. Patency rates in a different subset of patients were calculated and compared using the Wilcoxon (Gehan) test and Fisher's exact test to assess the influence of various factors in the long term outcome of the procedure. Results: Cumulative patency in terms of graft survival probabilities based on the life table analysis was 0.84, 0.80, and 0.64 at 30, 60, and 90 months respectively. Grafts in patients who had continued to smoke post-operatively had failed when compared with those who did not smoke (P = 0.01). Cumulative patency rates of non- diabetics were higher as compared to non-diabetics (0.70 vs 0.44; P = 0.04). Conclusion: Our study shows that continued smoking and diabetes are the determinant factors associated with graft occlusion. Strict avoidance of smoking and optimal control of diabetes is likely to improve graft function and long-term patency in patients undergoing infra-inguinal bypass grafting.

Assessment of Electrospun Pellethane-Based Scaffolds for Vascular Tissue Engineering.

We examined the physicochemical properties and the biocompatibility and hemocompatibility of electrospun 3D matrices produced using polyurethane Pellethane 2363-80A (Pel-80A) blends Pel-80A with gelatin or/and bivalirudin. Two layers of vascular grafts of 1.8 mm in diameter were manufactured and studied for hemocompatibility ex vivo and functioning in the infrarenal position of Wistar rat abdominal aorta in vivo (n = 18). Expanded polytetrafluoroethylene (ePTFE) vascular grafts of similar diameter were implanted as a control (n = 18). Scaffolds produced from Pel-80A with Gel showed high stiffness with a long proportional limit and limited influence of wetting on mechanical characteristics. The electrospun matrices with gelatin have moderate capacity to support cell adhesion and proliferation (~30–47%), whereas vascular grafts with bivalirudin in the inner layer have good hemocompatibility ex vivo. The introduction of bivalirudin into grafts inhibited platelet adhesion and does not lead to a change hemolysis and D-dimers concentration. Study in vivo indicates the advantages of Pel-80A grafts over ePTFE in terms of graft occlusion, calcification level, and blood velocity after 6 months of implantation. The thickness of neointima in Pel-80A–based grafts stabilizes after three months (41.84 ± 20.21 µm) and does not increase until six months, demonstrating potential for long-term functioning without stenosis and as a suitable candidate for subsequent preclinical studies in large animals.

Radial To Peripheral: The Efficacy of Transradial Access for Peripheral Interventions in Patients With Complex Transfemoral Access

Introduction: The safety and feasibility of distal transradial access (TRA) is well-established for coronary interventions and has been increasingly used for peripheral angiography and intervention, especially with the increasing innovation and development of longer sheaths, balloons, and stent delivery systems. In the COVID-19 era, the emphasis on same-day discharge has led our institution to approach complex and challenging transfemoral cases through a transradial approach with favorable results. Methods: This is a retrospective review of cases deemed as complex femoral access due to the presence of complete total occlusion (CTOs), limited by patient body habitus or patients with prior endovascular aortic repairs (EVARs), and, thus, necessitated a TRA approach. Details of the patient characteristics and procedure were collected and evaluated. Results: Fifty-four patients underwent ultrasound-guided radial access. The average age was 67 ± 10 years, with 43 patients presenting with critical limb ischemia (Rutherford class 4). The mean height was 173 ± 9 cm and the mean body mass index was 30 ± 4.9 kg/m2. All patients underwent angiography through a transradial approach: 37% of patients had undergone intervention, with the majority of target vessels being iliac and/or femoral arteries;19% of patients were known EVARs with occluded graft limbs, and 22% had occluded surgical grafts. All patients received balloon angioplasty, 55% received mechanical aspiration thrombectomy or atherectomy, and 15% received stenting. The average procedure time was 88 ± 43 minutes with average contrast used of 179 ± 80 ml. The majority of patients were discharged the same day with an outpatient follow-up at one week. Conclusion: Our experience has emphasized the utility, efficacy, and safety in approaching peripheral interventions through distal radial access in obese patients with difficult, unfavorable transfemoral access, allowing same-day discharge and an economically feasible result.

Virtual ABI: A computationally derived ABI index for noninvasive assessment of femoro-popliteal bypass surgery outcome

Background and objectivePeripheral arterial disease of the lower limbs, which affects 12-14% of the population, is often treated by bypassing a blocked portion of the vessel. Due to the limited ability of clinicians to predict the outcome of a selected bypass strategy, the five-year graft occlusion ranges from 50% to 90%, with a 20% risk of amputation in the first 5 years after the surgery. The aim of this study was to develop a computational procedure that could enable surgeons to reduce negative effects by assessing patient-specific response to the available surgical strategies. MethodsThe Virtual ABI assumes patient-specific finite element modeling of patients’ hemodynamics from routinely acquired medical scans of lower limbs. The key contribution of this study is a novel approach for prescribing boundary conditions, which combines noninvasive preoperative measurements and results of numerical simulations. ResultsThe validation performed on six follow-up cases indicated high reliability of the Virtual ABI, since the correlation with the experimentally measured values of ankle-brachial index was R² = 0.9485. ConclusionThe initial validation showed that the proposed Virtual ABI is a noninvasive procedure that could assist clinicians to find an optimal strategy for treating a particular patient by varying bypass length, choosing adequate diameter, position and shape.

Skeletonized vs Pedicled Internal Mammary Artery Graft Harvesting in Coronary Artery Bypass Surgery

The relative safety and patency of skeletonized vs pedicled internal mammary artery grafts in patients undergoing coronary artery bypass graft (CABG) surgery are unknown. To investigate the association of skeletonized vs pedicled harvesting with internal mammary artery graft patency and clinical outcomes 1 year after CABG surgery. This study was a post hoc analysis of the multicenter, randomized, double-blind, placebo-controlled Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) clinical trial, which enrolled 27 395 patients from 602 centers in 33 countries from March 2013 through May 2016. Eligibility criteria for the trial included CABG surgery for coronary artery disease with at least 2 grafts implanted and an estimated glomerular filtration rate of at least 30 mL/min. A total of 1002 of 1448 patients were randomized to the CABG arm of the COMPASS trial and underwent skeletonized (282 [28.1%]) or pedicled (720 [71.9%]) internal mammary artery harvesting. The patients had evaluable angiography results 1 year after surgery. Data were analyzed from October 11, 2019, to May 14, 2020. Patients underwent graft harvesting with either the pedicled technique or skeletonized technique. The primary outcome was graft occlusion 1 year after CABG surgery, as assessed by computed tomography angiography. A total of 1002 patients underwent skeletonized (282 [28.1%]; mean [SD] age, 65.9 [8.1] years; 229 men [81.2%]; 194 White patients [68.8%]) or pedicled (720 [71.9%]; mean [SD] age, 64.8 [7.6] years; 603 men [83.8%]; 455 White patients [63.2%]) internal mammary artery harvesting. Rates of internal mammary artery graft occlusion 1 year after CABG surgery were higher in the skeletonized group than in the pedicled group (33 of 344 [9.6%] vs 30 of 764 [3.9%]; graft-level adjusted odds ratio, 2.41; 95% CI, 1.39-4.20; P = .002), including the left internal mammary artery to left anterior descending artery (21 of 289 [7.3%] vs 25 of 725 [3.4%]; graft-level adjusted odds ratio, 2.10; 95% CI, 1.14-3.88, P = .02). After a mean follow-up of 23 months, skeletonized graft harvesting was also associated with a higher rate of major adverse cardiovascular events (20 [7.1%] vs 15 [2.1%]; adjusted hazard ratio, 3.19; 95% CI, 1.53-6.67; P = .002) and repeated revascularization (14 [5.0%] vs 10 [1.4%]; adjusted hazard ratio, 2.75; 95% CI, 1.10-6.88; P = .03). This post hoc analysis of the COMPASS randomized clinical trial found that harvesting of the internal mammary artery during CABG surgery using a skeletonized technique was associated with a higher rate of graft occlusion and worse clinical outcomes than the traditional pedicled technique. Future randomized clinical trials are needed to establish the safety and patency of the skeletonized technique. ClinicalTrials.gov Identifier: NCT01776424.