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Aortofemoral graft limbs are a rarely used and understudied option for large-bore access for mechanical support due to a risk of downstream vascular events. Here we present a case of left main coronary artery percutaneous intervention utilizing an aortofemoral bypass graft limb for large-bore access for mechanical support with successful hemostasis utilizing a widely available suture-based closure device. Article highlights Aortofemoral bypass grafts are rarely utilized sites for large-bore access due to the risk of vascular complications. In patients with limited vascular access sites, aortofemoral bypass graft may be an option for large-bore access with safe closure achieved using a suture-based closure device. Close postprocedure follow-up with vascular imaging is necessary to ascertain the healing of the large-bore access site following closure. Additional evidence aside from anecdotal case reports supporting the safe utilization of aortofemoral bypass grafts for large-bore access is necessary. [ABSTRACT FROM AUTHOR]

Purpose: To develop and validate a deep learning (DL)-model for automatic reconstruction for coronary CT angiography (CCTA) in patients with origin anomaly, stent or bypass graft. Material and methods: In this retrospective study, a DL model for automatic CCTA reconstruction was developed with training and validation sets from 6063 and 1962 patients. The algorithm was evaluated on an independent external test set of 812 patients (357 with origin anomaly or revascularization, 455 without). The image quality of DL reconstruction and manual reconstruction (using dedicated cardiac reconstruction software provided by CT vendors) was compared using a 5-point scale. The successful reconstruction rates and post-processing time for two methods were recorded. Results: In the external test set, 812 patients (mean age, 64.0 ± 11.6, 100 with origin anomalies, 152 with stents, 105 with bypass grafts) were evaluated. The successful rates for automatic reconstruction were 100% (455/455), 97% (97/100), 100% (152/152), and 76.2% (80/105) in patients with native vessel, origin anomaly, stent, and bypass graft, respectively. The image quality scores were significantly higher for DL reconstruction than those for manual approach in all subgroups (4 vs. 3 for native vessel, 4 vs. 4 for origin anomaly, 4 vs. 3 for stent and 4 vs. 3 for bypass graft, all p < 0.001). The overall post-processing time was remarkably reduced for DL reconstruction compared to manual method (11 s vs. 465 s, p < 0.001). Conclusions: The developed DL model enabled accurate automatic CCTA reconstruction of bypass graft, stent and origin anomaly. It significantly reduced post-processing time and improved clinical workflow. [ABSTRACT FROM AUTHOR]

Acute limb ischemia due to limb-graft occlusion (LGO) after fenestrated endovascular aneurysm repair (FEVAR) and acute bypass graft occlusion with an ePTFE graft pose critical challenges, necessitating prompt intervention to prevent limb loss. This paper discusses two cases of acute limb ischemia treated with a hybrid approach using the AngioJet™ Ultra Thrombectomy System as an adjunct to Fogarty thrombectomy. Case I involved a 69-year-old male post-FEVAR with contralateral iliac limb graft occlusion of the fenestrated Anaconda™, while Case II featured a 70-year-old male (ASA IV) post-bypass surgery (iliopopliteal arterial bypass with ePTFE Graft) with acute bypass graft occlusion. Both cases underwent successful recanalization using the AngioJet™ Ultra Thrombectomy System (ZelanteDVT™ 8F catheter, Solent™ Proxi 6F catheter) (Boston Scientific, Marlborough, MA, USA), combined with adjunctive techniques including Fogarty thrombectomy, balloon angioplasty, stenting, and local lysis. Immediate postoperative and follow-up assessments after 6 months revealed restored limb perfusion and improved clinical outcomes, with palpable pulses and improved ulcer healing. The aim of this treatment strategy is not only to alleviate limb ischemia but also to preserve future options in the event of graft failure. The use of the AngioJet™ Thrombectomy System in cases of LGO aims not only to clear the thrombus load but also to avoid the need for graft relining. In the case of acute arterial bypass graft occlusion in a patient with ASA IV, the goal of using the thrombectomy device is to preserve the native vessels for future procedures, such as long infragenual bypass, in addition to limb salvage. These cases demonstrate the efficacy of a hybrid surgical approach in managing acute limb ischemia following graft occlusion following FEVAR and bypass surgery. Long-term follow-up will further elucidate the durability of these interventions and their impact on limb salvage and overall patient outcomes. By combining mechanical thrombectomy with adjunctive techniques, such as balloon angioplasty and stenting, this hybrid approach offers a comprehensive solution to acute limb ischemia, addressing both the underlying occlusive pathology and ensuring optimal limb perfusion. Furthermore, the utilization of the AngioJet™ Ultra Thrombectomy System provides a minimally invasive yet effective method for thrombus removal, reducing procedural time and potential complications associated with open surgical techniques. As such, this approach represents a valuable addition to the armamentarium of treatments for acute limb ischemia, particularly in cases of graft occlusion following complex endovascular and bypass procedures. [ABSTRACT FROM AUTHOR]

The aim of this research is to determine the key risk factors that influence the need for Bypass Graft surgery (BGS). A cohort of one hundred adult patients underwent coronary angiography operations at the Erbil Cardiac Center from January 2016 to December 2020. Multiple logistic regression (MLR) analysis was used to identify the determinants of BGS. Upon detailed statistical analysis, a significant association with BGS was found for several variables, including Age, BMI, Eosinophil, WBC, DBP, HbA1c, MCH, Blood Sugar, PLT, and T3. It was found that the significant variables contributing the most to predicting the likelihood of Bypass Graft surgery through Bayesian logistic regression analysis were Age, WBC, and MCH. These variables were identified as the pivotal risk factors associated with the probability of undergoing BGS. Age, DBP, and Blood Sugar had minimal influence on the likelihood of Bypass surgery. However, for each unit increase in WBC, the odds of surgery reduced by 38 %, and for MCH, the odds reduced by 19 %. DBP and Blood Sugar had little effect on Bypass surgery (Bayesian odds ratio close to 1). This study revealed that Bayesian logistic models offer superiority over classical logistic models. The Bayesian-based models provide more accurate predictions by incorporating informative prior distributions. To improve the accuracy and generalizability of the findings, future research should consider a larger sample size and incorporate informative prior distributions within the Bayesian framework. Also, machine learning algorithms can offer new insights into BGS outcomes by considering various variables and assessing model sensitivity.

Objectives: According to guidelines, the autogenous saphenous vein (ASV) is the preferred conduit for femoropopliteal bypass surgery in all patients with peripheral artery disease. However, in contrast to patients with critical limb ischemia (CLI), patients with intermittent claudication (IC) only, tend to have milder disease, and thus a prosthetic graft may be as good as a vein conduit. The objective of this study was to compare patency rates of the ASV and a prosthetic graft in femoropopliteal bypass surgery in patients with IC. Methods: A systematic literature search was performed in the PubMed, Embase, and Cochrane databases to identify randomized controlled trials comparing prosthetic graft versus ASV in patients with IC. Articles with a mixed IC and CLI study population were included if more than 50% of the study cohort was treated for IC. Primary analysis was performed on IC patients only. Secondary analysis was performed on the mixed group. The primary endpoint was short- and long-term patency and secondary endpoints were complications, limb salvage, and mortality. Results: In total, six studies with 524 patients were included. Only two studies reported solely on patients with IC. All these patients underwent above-the-knee bypasses and average patency rates at one and 5 years were 88% and 76% vs 81% and 68% in the ASV and the PTFE groups, respectively. One and five-year patency was not statistically different between the groups (OR 5.21; 95% CI 0.60–45.36 and OR 2.10; 95% CI 0.88–5.01). In a mixed population of patients with IC and CLI (84% IC patients), 1 year patency was comparable (OR 1.40; 95% CI 0.87–2.25). However, after a follow-up of over 3 years, this mixed group had significantly higher patency rates in favour of the ASV (OR 2.06; 95 % CI 1.30–3.26). Complication and amputation rates were comparable in both groups. Conclusions: Limited data are available for patients receiving above-the-knee femoropopliteal bypass for intermittent claudication. The ASV remains the conduit of choice for femoropopliteal bypass surgery. However, the prosthetic conduit seems a feasible alternative for patients with intermittent claudication in whom the ASV is not present or unsuitable. [ABSTRACT FROM AUTHOR]

Objective: Routine surveillance with duplex ultrasound (DUS) examination is recommended after femoral-popliteal and femoral-tibial-pedal vein bypass grafts with various intervals postoperatively. The presently used methodology to analyze bypass graft DUS examination does not use all the available data and has been shown to have a significant rate for missing impending bypass graft failure. The objective of this research is to investigate recurrent neural networks (RNNs) to predict future bypass graft occlusion or stenosis. Methods: This study includes DUS examinations of 663 patients who had bypass graft operations done between January 2009 and June 2022. Only examinations without missing values were included. We developed two RNNs (a bidirectional long short-term memory unit and a bidirectional gated recurrent unit) to predict bypass graft occlusion and stenosis based on peak systolic velocities collected in the 2 to 5 previous DUS examinations. We excluded the examinations with missing values and split our data into training and test sets. Then, we applied 10-fold cross-validation on training to optimize the hyperparameters and compared models using the test data. Results: The bidirectional long short-term memory unit model can gain an overall sensitivity of 0.939, specificity of 0.963, and area under the curve of 0.950 on the prediction of bypass graft occlusion, and an overall sensitivity of 0.915, specificity of 0.909, and area under the curve of 0.912 predicting the development of a future critical stenosis. The results on different bypass types show that the system performs differently on different types. The results on subcohorts based on gender, smoking status, and comorbidities show that the performance on current smokers is lower than the never smoker. Conclusions: We found that RNNs can gain good sensitivity, specificity, and accuracy for the detection of impending bypass graft occlusion or the future development of a critical bypass graft stenosis using all the available peak systolic velocity data in the present and previous bypass graft DUS examinations. Integrating clinical data, including demographics, social determinants, medication, and other risk factors, together with the DUS examination may result in further improvements. Clinical Relevance: Detecting bypass graft failure before it occurs is important clinically to prevent amputations, salvage limbs, and save lives. Current methods evaluating screening duplex ultrasound examinations have a significant failure rate for detecting a bypass graft at risk for failure. Artificial intelligence using recurrent neural networks has the potential to improve the detection of at-risk bypass graft before they fail. Additionally, artificial intelligence is in the news and is being applied to many fields. Vascular surgeons need to know its potential to improve vascular outcomes.

Vascular smooth muscle cells (VSMCs) are involved in restenosis of bypass grafts and cause artery graft occlusion. This study aimed to explore the role of Slit2 in phenotypic switching of VSMCs and its effect on restenosis of vascular conduits. An animal model of vascular graft restenosis (VGR) was produced in SD rats and assessed by echocardiography. The expression of Slit2 and Hif-1α was measured in vivo and in vitro. After Slit2 overexpression, the migration and proliferation of VSMCs were detected in vitro, and the restenosis rates and phenotype of VSMCs were tested in vivo. The arteries of the VGR model presented significant stenosis, and Slit2 was decreased in VSMCs of the VGR model. In vitro, Slit2 overexpression inhibited the migration and proliferation of VSMCs, but Slit2 knockdown promoted migration and proliferation. Hypoxia induced Hif-1α but reduced Slit2, and Hif-1α negatively regulated Slit2 expression. Moreover, Slit2 overexpression weakened the rate of VGR and maintained the patency of artery bypass grafts, which suppressed the phenotypic switching of VSMCs. Slit2 inhibited the synthetic phenotype transformation to inhibit the migration and proliferation of VSMCs and delayed the VGR via Hif-1α. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate long-term clinical outcomes after revascularization by bypass graft versus Fogarty balloon catheter in acute blunt popliteal artery injury and identify risk factors contributing to amputation. Methods: A retrospective review was conducted in patients treated for acute blunt PAI between 2011 and 2019. Inclusion criteria were patients who underwent bypass graft and Fogarty balloon catheter. The cumulative limb salvage rate was calculated by the Kaplan–Meier test and compared with Breslow–Wilcoxon test. Cox proportional hazard model was performed to estimate the potential risk factors for amputation. Receiver operating characteristic (ROC) curve was used to determine the optimal cut-off value for the potential risk factors. Results: The overall limb salvage rate was 60.4% (29/48), including 24 patients (66.7%) in bypass graft, and 5 patients (41.7%) in Fogarty balloon catheter with mean follow-up of 5 years (range, 2–10 years). Among amputees, 15 patients (15/19, 78.9%) received primary amputation due to vascular failure or severe soft tissue damage, and 4 received secondary amputation because of chronic bone infection or neurologic deficit. Kaplan–Meier curves showed patients who received Fogarty balloon catheter had significantly higher amputation rate than those received bypass graft, with a hazard ratio of 3.801 (95% CI: 1.162–12.43, p = 0.009). In addition, Cox proportional hazard model revealed that MESS was the only independent risk factor for patients developing amputation, and the optimal cut-off value of MESS was 8. Conclusion: Five-year outcome demonstrated that Fogarty balloon catheter is not a safe procedure and has significantly higher amputation rate in severe blunt PAI. MESS is the only risk factor for amputation. [ABSTRACT FROM AUTHOR]

Bypass graft failures are linked to hemodynamic disturbances resulting from poor design. Several studies have tried to improve graft patency by modifying conventional graft designs. One strategy being employed is to induce spiral flow in bypass grafts using an internal ridge which has been proposed to optimize blood flow. However, there is still no study focusing on how the anastomosis angle can affect the hemodynamics of such a design despite its huge influence on local flow fields. To fill this gap, we aimed to understand and optimize the relationship between anastomosis angle and ridged spiral flow bypass graft hemodynamics to minimize disturbances and prolong graft patency. Steady-state, non-Newtonian computational fluid dynamics (CFD) analysis of a distal, end-to-side anastomosis between a ridged graft and idealized femoral artery was used to determine the anastomosis angle that would yield the least hemodynamic disturbances. Transient, pulsatile, non-Newtonian CFD analysis between a conventional and ridged graft at the optimal angle was performed to determine if such a design has an advantage over conventional designs. The results revealed that smaller anastomosis angles tend to optimize graft performance by the reduction in the pressure drop, recirculation, and areas in the host artery affected by abnormally high shear stresses. It was also confirmed that the modified design outperformed conventional bypass grafts due to the increased shear stress generated which is said to have atheroprotective benefits. The findings of the study may be taken into consideration in the design of bypass grafts to prevent their failure due to hemodynamic disturbances associated with conventional designs and highlight the importance of understanding and optimizing the relationship among different geometric properties in designing long-lasting bypass grafts. [ABSTRACT FROM AUTHOR]

Although rare, iatrogenic aortocoronary arteriovenous fistulae (ACAVF) occur when a coronary graft is mistakenly anastomosed to an epicardial vein rather than its intended arterial target. Patients may be asymptomatic, demonstrate angina, dyspnea, arrhythmias, syncope, or diminished exercise capacity, and may have wide pulse pressures with evidence of coronary steal. A thorough insight into the disordered anatomy is critical to safely manage a patient for redo cardiac surgery, especially when attempting to arrest the heart. We present a case for redo cardiac surgery of an iatrogenic ACAVF confirmed perioperatively with multiple modalities and its intraoperative management.

Although autologous vein grafting is essential, the high vein failure rate and specific clinical interventions are not clear, so a potential treatment is critically needed; thus, complex analyses of the relationship between pathobiological and physiological processes in preclinical are essential. The interposition of the femoral vein was performed in a canine model. Maximized expansion and velocity were measured at 8 weeks post-implantation, and a relative decrease was observed at 12 weeks. However, NI formation and NI/Media ratio significantly increased time dependently, and differences between the mechanical properties were observed. Additionally, RhoA-mediated TNF-α induced by rapid structural changes and high shear stress was confirmed. After adaptation to the arterial environment, vascular remodeling occurred by SMC proliferation and differentiation, apoptosis and autophagy were induced through YAP activity without vasodilation and RhoA activity. Our results show that understanding pathobiological processes in which time-dependent physiological changes contribute to vein failure can lead to a potential strategy. The implanted vein graft within the arterial environment undergoes pathobiological processes through RhoA and YAP activity, leading to pathophysiological changes. [ABSTRACT FROM AUTHOR]

Introduction: Inguinal vascular surgical site infections (VSSI) and infected prosthetic grafts remain a critical problem in vascular surgery. Prior clinical reports suggest antibiotic-impregnated beads may be used to attempt salvage of the graft and improve outcomes, especially if explant would result in major amputation or mortality. Described is our institutional experience managing inguinal VSSI using bioabsorbable, antibiotic-impregnated beads compared to inguinal VSSI managed with debridement alone., Methods: Patients with VSSIs after lower-extremity procedures were identified through the institutional database and departmental registries from 2014 to 2023. Cases were excluded if they did not involve an inguinal wound infection or an operation for VSSI management. Outcomes, including amputation-free survival, reinfection, and re-operation for infection were recorded, along with microbial isolates. Basic descriptive statistics, Kaplan-Meier, and Multiple variable Cox proportional hazards analyses were performed., Results: There were 43 patients identified (23 with intravenous antibiotics and debridement alone, and 20 treated with intravenous antibiotics, debridement, and antibiotic beads). The two groups differed significantly in their Szilagyi classification, with thirteen patients (65%) with class III infections in the antibiotic bead group compared with one (7%) in the debridement alone group. There was no significant difference in amputation-free survival for those cases that received debridement and antibiotic beads versus debridement alone (P = 0.20) or amputation-free survival between Szilagyi classifications (P = 0.47) despite a higher representation of Szilagyi III cases in the antibiotic bead group (P = 0.0001). Patients with graft infections treated with beads experienced similar survival outcomes to patients with subcutaneous infections treated with debridement alone (P = 0.21)., Conclusions: The efficacy of bioabsorbable antibiotic beads in VSSIs remains controversial. While this cohort study demonstrated an increased risk of re-infection, this is confounded by the antibiotic bead group having a higher frequency of graft infections. Antibiotic beads appear to be safe for use in patients with vascular graft infections and may help achieve outcomes comparable to patients without graft involvement. Further studies with larger patient populations and similar infection severity between groups are needed., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Several veins have been well-recognized as acceptable conduits for infrainguinal bypass surgery when the ipsilateral greater saphenous vein is unavailable. However, there is a paucity of literature describing the brachial vein as an adequate alternative. In the absence of other viable autogenous conduits, we describe the use of a brachial vein as a successful alternative for lower extremity revascularization. Methods: A 70-year-old man presented with a chief complaint of right calf pain. Duplex ultrasound imaging of his right lower extremity revealed right-sided 2.5 cm acutely thrombosed superficial femoral artery and popliteal artery aneurysms. The patient underwent a suction thrombectomy with tissue plasminogen activator using the Power Pulse feature and Solent catheter from the AngioJet® (Boston-Scientific, Marlborough, MA) system. To repair the thrombosed aneurysms, an open bypass was planned. Due to lack of viable alternative traditionally used venous conduits, a bypass was created using the patient's brachial vein. Results: A bypass was created from the superficial femoral artery to the P2 segment of the popliteal artery using a non-reversed brachial vein with ligation of the side branches of the superficial femoral artery and popliteal artery aneurysm from within the sac lumen. Completion angiogram revealed runoff through the anterior tibial artery only. Follow-up imaging at three months demonstrated a patent brachial bypass. Conclusion: Brachial veins can be safely used as viable venous conduits for lower extremity bypass surgery and should therefore be considered as an alternative when more commonly used veins are unsuitable or unavailable. However, more research is needed to determine the potential opportunities and challenges this alternative may present. [ABSTRACT FROM AUTHOR]

Bypass graft failures are linked to hemodynamic disturbances resulting from poor design. Several studies have tried to improve graft patency by modifying conventional graft designs. One strategy being employed is to induce spiral flow in bypass grafts using an internal ridge which has been proposed to optimize blood flow. However, there is still no study focusing on how the anastomosis angle can affect the hemodynamics of such a design despite its huge influence on local flow fields. To fill this gap, we aimed to understand and optimize the relationship between anastomosis angle and ridged spiral flow bypass graft hemodynamics to minimize disturbances and prolong graft patency. Steady-state, non-Newtonian computational fluid dynamics (CFD) analysis of a distal, end-to-side anastomosis between a ridged graft and idealized femoral artery was used to determine the anastomosis angle that would yield the least hemodynamic disturbances. Transient, pulsatile, non-Newtonian CFD analysis between a conventional and ridged graft at the optimal angle was performed to determine if such a design has an advantage over conventional designs. The results revealed that smaller anastomosis angles tend to optimize graft performance by the reduction in the pressure drop, recirculation, and areas in the host artery affected by abnormally high shear stresses. It was also confirmed that the modified design outperformed conventional bypass grafts due to the increased shear stress generated which is said to have atheroprotective benefits. The findings of the study may be taken into consideration in the design of bypass grafts to prevent their failure due to hemodynamic disturbances associated with conventional designs and highlight the importance of understanding and optimizing the relationship among different geometric properties in designing long-lasting bypass grafts.

The incidence of acquired left internal mammary artery-to-pulmonary vein fistulas has been increasing in the last few decades. This has been attributed to the increase in coronary artery bypass surgery (CABG). The most commonly reported symptoms are angina and dyspnea. The timing of the presentation varies widely from a few months to several years after CABG. Medical management is the treatment of choice and usually controls the symptoms in most patients. Percutaneous intervention is, however, indicated when medical therapy fails. In this case report, a 72-year-old man with a history of CABG presented with progressively worsening chest pain and dyspnea. Troponin was negative and the electrocardiogram showed no acute ischemic changes. He was found to have left internal mammary artery-to-pulmonary vein fistula on coronary angiogram. His symptoms improved upon intensifications of his guideline-directed therapy for coronary artery disease. This represents an unusual cause of unstable angina. [ABSTRACT FROM AUTHOR]

It has been well documented that the use of the left internal thoracic artery (LITA) to graft the left anterior descending (LAD) artery has a significant benefit in coronary artery bypass graft (CABG) surgery. However, what graft is the best as a second conduit to complement LITA-LAD anastomosis remains uncertain. We thus conducted a network meta-analysis of RCTs to compare graft patency of the radial artery (RA), the right internal thoracic artery (RITA), the right gastroepiploic artery (RGEA), conventional saphenous vein (C-SVG), and no-touch saphenous vein (NT-SVG) as a second conduit in CABG. MEDLINE and EMBASE were searched through August 31, 2020 to identify randomized controlled trials (RCTs) that investigated graft patency of a second conduit in CABG. From each study, we extracted the incidence rate ratios of the outcome. A total of 13 RCTs were identified, including 3728 patients and 2773 angiographic results. The graft failure rates were significantly lower in NT-SVG and RA compared to C-SVG and RGEA. There was no significant difference among the other comparisons. A sensitivity analysis restricting trials with ≥3 years angiographic follow-up time showed the graft failure rates were significantly lower in NT-SVG and RA compared to C-SVG and RGEA, and a sensitivity analysis restricting trials with ≥5 years angiographic follow-up time showed the graft failure rates were significantly lower in NT-SVG and RA compared to C-SVG. In a network meta-analysis of the updated outcomes from RCTs, NT-SVG and RA have better graft patency compared to C-SVG and RGEA. [ABSTRACT FROM AUTHOR]

This paper aims to investigate, through the 3D numerical analysis of an idealized arterial bypass graft, the dependence of the resistance to flow on the bypass insertion point. The computational model assumes a laminar steady-state Newtonian fluid flow and three different Reynolds numbers: 150, 250, and 400. In this study, the constructal theory has been employed, a self-standing law in physics which covers the statement of minimum flow resistance to optimize morphing architectures, i.e. the coronary artery bypass grafting. According to the Constructal Design method, the constraints are stenosis degree, junction angle, and diameter ratio, while the attachment point is defined as a design parameter. The results demonstrate that the distance between the bypass attachment point and the stenosis influences the pressure drop; more specifically, the pressure drop decreases with the augmentation of the distance. In this regard, a different distribution of the mass flows between the bypass, and the artery is observed and seemed to be the main reason for that behavior. The application of the Constructal Design method in hemodynamics is a tool to describe the biological system to search for better flow performance since it is based on the natural evolution of living systems.

Management of pediatric iatrogenic arterial occlusions can be challenging clinically, leading to chronic complications such as claudication and limb length discrepancy. We report the case of a 6-month-old female patient who had experienced iatrogenic right external iliac and common femoral arterial occlusion. At the age of 8 years, she had developed claudication and a limb length discrepancy of 3.2 cm. She underwent common iliac artery to superficial femoral artery and profunda artery bypass via a branched autologous reverse great saphenous vein using microsurgical techniques for the distal anastomoses. In the present report, we have focused on the musculoskeletal improvements, benefits of microsurgery in pediatric vessels, and maximization of epiphyseal perfusion.

Intimal hyperplasia is the leading cause of graft failure in aortocoronary bypass grafts performed using human saphenous vein (SV). The long-term consequences of the altered pulsatile stress on the cells that populate the vein wall remains elusive, particularly the effects on saphenous vein progenitors (SVPs), cells resident in the vein adventitia with a relatively wide differentiation capacity. In the present study, we performed global transcriptomic profiling of SVPs undergoing uniaxial cyclic strain in vitro. This type of mechanical stimulation is indeed involved in the pathology of the SV. Results showed a consistent stretch-dependent gene regulation in cyclically strained SVPs vs. controls, especially at 72 h. We also observed a robust mechanically related overexpression of Adhesion Molecule with Ig Like Domain 2 (AMIGO2), a cell surface type I transmembrane protein involved in cell adhesion. The overexpression of AMIGO2 in stretched SVPs was associated with the activation of the transforming growth factor β pathway and modulation of intercellular signaling, cell-cell, and cell-matrix interactions. Moreover, the increased number of cells expressing AMIGO2 detected in porcine SV adventitia using an in vivo arterialization model confirms the upregulation of AMIGO2 protein by the arterial-like environment. These results show that mechanical stress promotes SVPs' molecular phenotypic switching and increases their responsiveness to extracellular environment alterations, thus prompting the targeting of new molecular effectors to improve the outcome of bypass graft procedure.

Although rare, iatrogenic aortocoronary arteriovenous fistulae (ACAVF) occur when a coronary graft is mistakenly anastomosed to an epicardial vein rather than its intended arterial target. Patients may be asymptomatic, demonstrate angina, dyspnea, arrhythmias, syncope, or diminished exercise capacity, and may have wide pulse pressures with evidence of coronary steal. A thorough insight into the disordered anatomy is critical to safely manage a patient for redo cardiac surgery, especially when attempting to arrest the heart. We present a case for redo cardiac surgery of an iatrogenic ACAVF confirmed perioperatively with multiple modalities and its intraoperative management. [ABSTRACT FROM AUTHOR]

Occipital artery (OA)–posterior inferior cerebellar artery (PICA) bypass is a challenging procedure and is not frequently performed owing to the difficulty of OA harvest. To facilitate harvest, the intersection between the sternocleidomastoid and splenius capitis (the OA triangle) is used as the anatomical landmark to identify the OA segment that carries the highest risk of damage. This clinical study aimed to demonstrate efficacy and safety of OA harvest using this landmark. The study included 18 patients who underwent OA harvest using the OA triangle as a landmark for treatment of vertebral artery and PICA aneurysms. Patients were retrospectively evaluated for safety and patency of OA after harvest and OA-PICA bypass. Of 18 patients with ruptured and unruptured vertebral artery and PICA aneurysms, 13 (72.2%) underwent OA-PICA bypass and 5 (27.8%) did not undergo bypass. The OA was completely harvested without damage in all patients. After harvest, the OA was patent in 17 patients (94.4%) and was occluded in 1 patient owing to vasospasm; this patient then underwent recanalization resulting in good patency of the OA-PICA bypass. The patency rate of the OA-PICA bypass was 100%. The OA triangle, which is the anatomical landmark of the proximal end of the transitional segment of the OA, facilitated OA harvest using the distal-to-proximal harvest technique with safety and good patency. To the best of our knowledge, this is the first study of OA harvest in clinical cases. [ABSTRACT FROM AUTHOR]