Search Results (68)

Coronary artery bypass grafting (CABG) has evolved into a cornerstone treatment for coronary artery disease, with graft selection playing a critical role in long-term outcomes. Multiple arterial grafting (MAG) represents a significant advancement over single arterial grafting, utilizing conduits such as the internal thoracic artery and radial artery to enhance graft durability and patient survival. This review examines the outcomes, challenges, and controversies associated with MAG, highlighting its superior patency rates and reduced need for repeat revascularization procedures. While the technique provides long-term survival benefits, concerns such as the complexity of surgical techniques, increased operative time, and higher resource utilization underscore the importance of surgeon expertise and institutional infrastructure. Patient selection remains critical, as factors like age, comorbidities, and gender influence outcomes and highlight disparities in access to MAG. Emerging evidence addresses debates regarding optimal graft choice and balancing long-term benefits against short-term risks. Future directions focus on ongoing clinical trials, innovations in minimally invasive and robotic-assisted CABG, and technological advancements aimed at improving graft patency. Professional guidelines and best practices underscore the need for personalized approaches to optimize MAG’s potential. This article underscores the promise of MAG in redefining CABG care, paving the way for enhanced patient outcomes and broadened applicability. This article highlights the promise of MAG in transforming CABG care, leading to improved patient outcomes and expanded applicability. Full article

Background/Objectives: Bovine pericardial valve conduits (PVCs) are commonly used for right ventricular outflow tract reconstruction in both pediatric and adult patients. Calcification, particularly prevalent in children and young adults, is a leading cause of conduit failure and is affected by the chemical composition of the treated biomaterials. In this study, we aimed to compare the structural changes in diepoxy-treated (DE-PVCs) and glutaraldehyde-treated PVCs (GA-PVCs) and to identify factors contributing to tissue mineralization in a large animal model. Methods: Pulmonary artery replacement was performed in minipigs (33–88 kg) using twelve DE-PVCs and four GA-PVCs. After six months, the animals were euthanized, and the explanted PVCs underwent macroscopic and microscopic examination. Results: Large calcium deposits formed along conduit joining suture (CJS) lines in all PVCs, regardless of the cross-linking agent. Mineral clusters surrounded the multifilament braided thread, and its fibers were encrusted with hydroxyapatite crystals. In DE-PVCs, no mineralization occurred outside the suture lines, and they showed successful integration and graft vitalization with a uniform neointima and well-developed endothelial monolayer. GA-PVCs developed a rigid external capsule, foci of collagen fiber calcification within the walls, and neointimal hyperplasia with limited endothelial coverage. Conclusions: In PVCs, calcification predominantly occurs along the CJS lines, where the multifilament suture acts as a nucleation site for hydroxyapatite crystals. DE treatment prevents collagen mineralization, unlike GA, and offers better integration, reduced neointimal hyperplasia, and a well-developed endothelial layer. These findings suggest that DE-PVCs may be a superior option for pediatric cardiac surgery by reducing calcification and improving conduit durability. Overall, the results will help optimize PVC manufacturing strategies to lower the risk of conduit failure. Full article

Background: Palliative surgery for the treatment of functionally univentricular heart malformations consists of a staged approach to separation of the pulmonary and systemic circulation, including the creation of a superior cavopulmonary connection. Literature on the superior cavopulmonary connection in porcine models lacks information on details of the procedure as well as data on its acute hemodynamic effects. In preliminary experiments, we were unable to reproduce an already published porcine model. Therefore, we used a conduit extension and cardiopulmonary bypass in order to achieve hemodynamic stability and still employ the commonly used straight downward pathway for the superior caval vein onto the right pulmonary artery, as in the human clinical setting. This model of a univentricular circulation utilising the superior cavopulmonary anastomosis is intended to be applied in the setting of unilateral diaphragmatic palsy. Hence, we aim to investigate the effect of unilateral diaphragmatic pacing in a reproducible model of univentricular physiology. Methods: Therefore, we constructed an anastomosis between the superior caval vein and the right pulmonary artery (RPA) in 14 pigs on cardiopulmonary bypass using a 12 mm expanded polytetrafluorethylene interposition graft. Six pigs received a bidirectional cavopulmonary connection with unrestricted atrial septal communication (BDCPC), while eight pigs received a unidirectional cavopulmonary connection (UDCPC) to the excluded RPA. Results: The BDCPC resulted in an impaired cardiopulmonary state (cardiac output dropped from 3.15 ± 0.21 to 2.17 ± 0.19 L/min; p < 0.01), mean arterial pressure plummeted (from 80.8 ± 3.7 to 49.3 ± 7.3 mmHg; p = 0.02), arterial lactate concentration rose (from 0.82 ± 0.09 to 4.36 ± 0.96 mmol/L; p = 0.01), arterial oxygen saturation dropped (from 95.8 ± 1.1 to 60.9 ± 10.4%; p < 0.01), and right ventricular function deteriorated (tricuspid annular plane systolic excursion decreased from 12 ± 0.7 to 5 ± 0.7 mm; p < 0.01). In contrast, in the UDCPC group, the cardiopulmonary parameters indicated a stable condition. Conclusions: Consequently, a UDCPC is a more suitable acute model in pigs for a univentricular circulation. The model’s reproducibility may aid in future research on partial cavopulmonary connection. Full article

Coronary heart disease, a leading global cause of mortality, has witnessed significant advancement through robotic coronary artery bypass grafting (CABG), with the internal mammary artery (IMA) emerging as the preferred “golden conduit” for its exceptional long-term patency. Despite these advances, robotic-assisted IMA harvesting remains challenging due to the absence of force feedback, complex surgical maneuvers, and proximity to the beating heart. This study introduces a novel virtual simulation platform for robotic IMA harvesting that integrates dynamic anatomical modeling and real-time haptic feedback. By incorporating a dynamic cardiac model into the surgical scene, our system precisely simulates the impact of cardiac pulsation on thoracic cavity operations. The platform features high-fidelity representations of thoracic anatomy and soft tissue deformation, underpinned by a comprehensive biomechanical framework encompassing fascia, adipose tissue, and vascular structures. Our key innovations include a topology-preserving cutting algorithm, a bidirectional tissue coupling mechanism, and dual-channel haptic feedback for electrocautery simulation. Quantitative assessment using our newly proposed Spatial Asymmetry Index (SAI) demonstrated significant behavioral adaptations to cardiac motion, with dynamic scenarios yielding superior SAI values compared to static conditions. These results validate the platform’s potential as an anatomically accurate, interactive, and computationally efficient solution for enhancing surgical skill acquisition in complex cardiac procedures. Full article

It was in 1989 that we first reported on the use of the radial artery (RA) as a secondary arterial graft for coronary artery bypass grafting (CABG). Nevertheless, discrepancies in clinical endpoints between the RA and alternative conduits have been reported in consecutive randomised trials. With over fifty years of accumulated practice in RA bypass grafting, we sought to identify the second-best option for CABG by reviewing the literature. A consistently successful second-best conduit for CABG has been demonstrated using the radial artery. Compared to saphenous vein grafts, the findings indicate improved outcomes and better patency results. Furthermore, it has been demonstrated to be a safe and effective conduit in the territory of the right coronary artery. The lack of available literature and the scarcity of similar case series restrict the application of the gastroepiploic artery. After five decades of utilisation, it can be unequivocally stated that the radial artery is the optimal conduit for coronary bypass surgery following the left internal thoracic artery to the left anterior descending artery. Full article

Background: The great saphenous vein (GSV) has long been recognized as the best conduit for vascular bypass procedures. Concomitant varicose veins disease may be a reason for GSV unavailability either due to dilatation and tortuosity of the vein or due to its destruction during invasive venous treatment. Objectives—to assess the rate of varicose vein patients with concomitant lower extremity arterial disease (LEAD) who have previously lost their GSV due to venous ablation. Material and Methods: A total of 285 patients (76 F, 209 M) with LEAD were consecutively enrolled. A total of 111 patients (222 limbs) underwent a detailed duplex ultrasound of the lower extremity veins for assessing suitability of the GSV as a conduit. We registered presence of varicose veins (VVs), type of previous invasive procedure and availability of saphenous veins as possible grafts. Results: The mean age of screened patients was 70.5 ± 9.1.62 (21.75%) patients had varicose veins or were operated on before due to varicose veins. A total of 42 patients with varicose veins had C2 disease, 10 had C3, 9 had C4 and 1 had C6 according to CEAP classification. A total of 222 lower extremities were examined by duplex ultrasound of which 51 limbs had VVs. Despite the presence of varicose tributaries, the GSV was suitable for bypass in 9 of those lower extremities. The GSV was not available as a conduit in 34 (19.9%) ipsilateral lower extremities in the LEAD with no VVs group and in 42 (82.6%) ipsilateral lower extremities in the LEAD with VVs group (p = 0.0001). Varicose vein disease was associated with a higher frequency of the GSV unavailability (odds ratio 18.8, 95% confidence interval 8.35–42.35). On the 11 ipsilateral limbs (5% of LEAD patients and 21.6% of LEAD with VVs patients), the GSV was unavailable due to previous venous interventions. Conclusions: Almost 20% of patients may have both LEAD and VVs. Among those with VVs, most have the ipsilateral GSV unavailable as a potential conduit. Additionally, one fifth of limbs with VVs had GSVs destroyed previously due to saphenous ablative procedures. Full article

Assessment of the right ventricular outflow tract and pulmonary arteries (RVOT) for percutaneous pulmonary valve implantation (PPVI) uses discrete measurements (diameters and lengths) from medical images. This multi-centre study identified the 3D RVOT shape features prevalent in patients late after surgical repair of congenital heart disease (CHD). A 3D RVOT statistical shape model (SSM) was computed from 81 retrospectively selected CHD patients (14.7 ± 6.8 years) who required pulmonary valve replacement late after surgical repair. A principal component analysis identified prevalent shape features (modes) within the population which were compared with standard geometric measurements (diameter, length and surface area) and between sub-groups of diagnosis, RVOT type and dysfunction. Shape mode 1 and 2 represented RVOT size and curvature and tapering and length, respectively. Shape modes 3–5 related to branch pulmonary artery calibre, conical vs. bulbous RVOTs and RVOT curvature, respectively. Tetralogy of Fallot, transannular patch type and regurgitant RVOTs were larger and straighter while conduit and stenotic types were longer and more cylindrical than other subgroups. This SSM analysed the main 3D shape features present in a population of RVOTs, exploiting the wide 3D anatomical information provided by routine imaging. This morphological information may have implications for PPVI patient selection and device design. Full article

Background/Objectives: Chronic limb-threatening ischaemia (CLTI) is a significant life and limb-threatening condition. Two recent seminal trials, BEST-CLI and BASIL-2, have provided seemingly conflicting results concerning the optimal treatment modality for patients with CLTI. We sought to investigate the outcomes of patient undergoing infrainguinal bypass at two centres in Aotearoa New Zealand. Methods: A cross-sectional retrospective review of all patients who underwent infrainguinal bypass grafting for CLTI at Auckland City Hospital and Waikato Hospital between January 2020 and December 2021 was performed. The primary outcome was a composite of death, above-ankle amputation, and major limb reintervention. The secondary outcome was minor limb reintervention. Kaplan–Meier survival analysis was performed to determine time to the primary and secondary endpoints. Demographic factors were examined using the log-rank test to examine the effect on the outcome. Results: One hundred and nineteen patients who underwent infrainguinal bypass for CLTI in the study period were identified. Of these, 93 patients had a bypass with ipsilateral or contralateral GSV. The median follow-up time was 1.85 years. The most common indication for surgery was tissue loss (69%, n = 63), with the most common distal bypass target being the below-knee popliteal artery (45%, n = 41). The primary composite outcome occurred in 42.8% of the cohort (n = 39). Death was the most common component of the primary outcome (26%, n = 24). Male sex (HR 0.48, 95% CI 0.26–0.88, p = 0.018) and statin use (HR 0.49, 95% CI 0.24–0.98, p = 0.044) were independent predictors of protection from the composite outcome on multivariate analysis. Dialysis dependence (HR 3.32, 95% CI 1.23–8.99, p = 0.018) was an independent predictor for patients meeting the composite outcome. Conclusions: This study’s results are consistent with the published outcomes of BEST-CLI. The patient cohorts examined, anatomical disease patterns, and conduit use may explain some of the differences observed between this study, BEST-CLI and BASIL-2. Further work is required to define the specific patient populations who will benefit most from an open surgical or endovascular first approach to the management of CLTI. Full article

Background/Objectives: Grafting of LIMA to LAD has long been considered the gold-standard conduit choice for patients undergoing CABG. Despite this, the LSV remains the most used conduit by volume and some patients may not receive even a single arterial conduit. However, the outcomes in this group are not frequently explored. This study, therefore, compares in-hospital outcomes of patients who underwent CABG without any arterial conduits to those who received at least one arterial conduit. Methods: Retrospective propensity-matched database analysis of consecutive patients undergoing CABG in the UK between 1996 and 2019 using data from the National Adult Cardiac Surgery Audit. Results: 335,144 patients underwent CABG, with 6% receiving venous conduits only; matched outcomes are reported for 39,812 patients. In both unmatched and matched groups, we found a significant increase in mortality with the use of veins only (matched mortality 5.3% vs. 3.8%, p < 0.001) with estimated treatment effect for mortality OR 1.43, p < 0.001 (95% CI: 1.31–1.57). We also identified greater rates of post-operative dialysis, IABP insertion, and length of hospital stay in this group. Conclusions: We identified a significant increase in in-hospital mortality with the use of veins only compared to using at least one arterial graft to the LAD. While a single arterial graft should be prioritised wherever possible, venous revascularisation retains a critical role for specific patients. We must, therefore, continue to conduct research addressing the mechanisms underlying and propagating vein graft disease in order better to optimise outcomes for this niche patient group after CABG. Full article

The harvesting of conduits for coronary artery bypass surgery has evolved over the last decade to include endoscopic approaches to access the saphenous vein, radial artery, and internal mammary artery. These minimally invasive techniques reduce the morbidity associated with open procedures by decreasing pain and recovery time and increasing mobility post operatively. This review highlights the differences in morbidity, quality, and patency between the most common conduits that are harvested minimally invasively for coronary artery bypass grafting surgery. Full article

Background: Autologous vein grafts are widely used for bypass procedures in cardiovascular surgery. However, these grafts are susceptible to failure due to vein graft disease. Our study aimed to evaluate the impact of the latest-generation FRAME external support on vein graft remodeling in a preclinical model. Methods: We performed autologous internal jugular vein interposition grafting in porcine carotid arteries for one month. Four grafts were supported with a FRAME mesh, while seven unsupported grafts served as controls. The conduits were examined through flowmetry, angiography, macroscopy, and microscopy. Results: The one-month patency rate of FRAME-supported grafts was 100% (4/4), whereas that of unsupported controls was 43% (3/7, Log-rank p = 0.071). On explant angiography, FRAME grafts exhibited significantly more areas with no or mild stenosis (9/12) compared to control grafts (3/21, p = 0.0009). Blood flow at explantation was higher in the FRAME grafts (145 ± 51 mL/min) than in the controls (46 ± 85 mL/min, p = 0.066). Area and thickness of neo-intimal hyperplasia (NIH) at proximal anastomoses were similar for the FRAME and the control groups: 5.79 ± 1.38 versus 6.94 ± 1.10 mm², respectively (p = 0.558) and 480 ± 95 vs. 587 ± 52 μm²/μm, respectively (p = 0.401). However, in the midgraft portions, the NIH area and thickness were significantly lower in the FRAME group than in the control group: 3.73 ± 0.64 vs. 6.27 ± 0.64 mm², respectively (p = 0.022) and 258 ± 49 vs. 518 ± 36 μm²/μm, respectively (p = 0.0002). Conclusions: In our porcine model, the external mesh FRAME improved the patency of vein-to-carotid artery grafts and protected them from stenosis, particularly in the mid regions. The midgraft neo-intimal hyperplasia was two-fold thinner in the meshed grafts than in the controls. Full article

Vein grafts are the most used conduits in coronary artery bypass grafting (CABG), even though many studies have suggested their lower patency compared to arterial alternatives. We have reviewed the techniques and technologies that have been investigated over the years with the aim of improving the quality of these conduits. We found that preoperative and postoperative optimal medical therapy and no-touch harvesting techniques have the strongest evidence for optimizing vein graft patency. On the other hand, the use of venous external support, endoscopic harvesting, vein preservation solution and anastomosis, and graft configuration need further investigation. We have also analyzed strategies to treat vein graft failure: when feasible, re-doing the CABG and native vessel primary coronary intervention (PCI) are the best options, followed by percutaneous procedures targeting the failed grafts. Full article

Background: Phrenic nerve injury is a devastating complication that results in significant morbidity and mortality. We developed a novel technique to localize the phrenic nerve and evaluate its success. Methods: Two groups of children underwent repeat sternotomy for a variety of indications. Group I (69 patients, nerve stimulator) and Group II (78 patients, no nerve stimulator). Results: There was no significant difference in the mean age and weight between the two groups: (6.4 ± 6.5 years vs. 5.6 ± 6.4 years; p = 0.65) and (25.2 ± 24.1 vs. 22.6 ± 22.1; p = 0.69), respectively. The two groups were comparable in the following procedures: pulmonary conduit replacement, bidirectional cavopulmonary anastomosis, aortic arch repair, and Fontan, while Group I had more pulmonary arterial branch reconstruction (p = 0.009) and Group II had more heart transplant patients (p = 0.001). There was no phrenic nerve injury in Group I, while there were 13 patients who suffered phrenic nerve injury in Group II (p < 0.001). No early mortality in Group I, while five patients died prior to discharge in Group II. Eleven patients underwent diaphragm plication in Group II (p = 0.001). The mean number of hours on the ventilator was significantly higher in Group II (137.3 ± 324.9) compared to Group I (17 ± 66.9), p < 0.001. Group II had a significantly longer length of ICU and hospital stays compared to Group I (p = 0.007 and p = 0.006 respectively). Conclusion: Phrenic nerve injury in children continues to be associated with significant morbidities and increased length of stay. The use of intraoperative phrenic nerve stimulator can be an effective way to localize the phrenic nerve and avoid its injury. Full article

Valved conduits are often required to replace pulmonary arteries (PA). A widely used Contegra device is made of bovine jugular vein (BJV), preserved with glutaraldehyde (GA) and iso-propanol. However, it has several drawbacks that may be attributed to its chemical treatment. We hypothesized that the use of an alternative preservation compound may significantly improve BJV conduit performance. This study aimed to compare the macroscopic and microscopic properties of the BJV treated with diepoxide (DE) and GA in a porcine model. Twelve DE-BJVs and four Contegra conduits were used for PA replacement in minipigs. To assess the isolated influence of GA, we included an additional control group—BJV treated with 0.625% GA (n = 4). The animals were withdrawn after 6 months of follow-up and the conduits were examined. Explanted DE-BJV had a soft elastic wall with no signs of thrombosis or calcification and good conduit integration, including myofibroblast germination, an ingrowth of soft connective tissue formations and remarkable neoangiogenesis. The inner surface of DE-BJVs was covered by a thin neointimal layer with a solid endothelium. Contegra grafts had a stiffer wall with thrombosis on the leaflets. Calcified foci, chondroid metaplasia, and hyalinosis were observed within the wall. The distal anastomotic sites had hyperplastic neointima, partially covered with the endothelium. The wall of GA-BJV was stiff and rigid with degenerative changes, a substantial amount of calcium deposits and dense fibrotic formations in adventitia. An irregular neointimal layer was presented in the anastomotic sites without endothelial cover in the GA BJV wall. These results demonstrate that DE treatment improves conduit integration and the endothelialization of the inner surface while preventing the mineralization of the BJV, which may reduce the risk of early conduit dysfunction. Full article

Redo cardiac surgery after Coronary Artery Bypass Grafting (CABG) is burdened by high morbidity and mortality, either intraoperatively and postoperatively, with the repeated sternotomy playing a crucial role as risk factor. The right minithoracotomy approach guarantees a safer control on conduits integrity and the right ventricular wall and a low impact on the respiratory mechanics. Herein, we report a patient who previously underwent two CABG (coronary artery bypass grafting) procedures and who was admitted to the hospital with a picture of heart failure caused by a severe mitral regurgitation. He was successfully submitted to a mitral valve repair on a beating heart via the right minithoracotomy approach. Full article