Conduit For Coronary Artery Bypass Grafting Research Articles

Outcomes of Radial Artery Versus Saphenous Vein as A Second Conduit After Coronary Artery Bypass Grafting

Despite the advantages of multiarterial grafting, saphenous vein (SV) configurations predominate in coronary artery bypass grafting (CABG). In addition, the benefits of radial artery (RA) utilization in multivessel CABG remain unclear. This study aims to compare the clinical outcomes of patients who received RA grafts during CABG with those of patients who received SV grafts. A retrospective, single-institution cohort study was performed in 8,774 adults who underwent isolated CABG surgery with multiple grafts between 2010 and 2022. To balance graft cohorts, propensity score matching (PSM) was performed using a 1:2 (RA/SV) match ratio. Long-term postoperative survival was compared in RA and SV graft groups. Similarly, major adverse cardiac and cerebrovascular event (MACCE) rates were compared in the cohorts, with MACCE comprising death, myocardial infarction (MI), coronary revascularization, and stroke. Kaplan-Meier estimation was performed for both mortality and MACCE. A total of 7,218 patients (82.3%) who underwent multivessel CABG were included in this analysis. Of these patients, 341 (4.7%) received RA grafts, and 6,877 (95.3%) received SV grafts secondary to left internal mammary artery use. PSM yielded a cohort of 335 patients with RA and 670 patients with SV. After matching, groups were well balanced across all baseline variables. No significant differences were observed in either immediate postoperative morbidities or long-term survival. However, Kaplan-Meier estimates of long-term postoperative freedom from MACCE were significantly greater in matched patients with SV (73.3%) than in those with RA (67.4%) (p = 0.044, cluster log-rank), with patients with SV also possessing significantly greater freedom from coronary revascularization and MI. In conclusion, RA and SV secondary conduits for CABG were associated with comparable immediate postoperative complications and long-term survival after PSM. SV grafting was associated with significantly decreased rates of postoperative MACCE, likely owing to lower rates of coronary revascularization and MI than in RA grafting.

Abstract 17330: Demographic Factors Associated With Disparity in Radial Artery Usage in Coronary Artery Bypass Graft Surgery: Insights From the National Inpatient Sample

Introduction: The choice of graft for revascularization in coronary artery bypass grafting (CABG) impacts surgical outcomes. While both radial artery (RA) and greater saphenous vein (GSV) are options for secondary conduits to the left internal mammary artery (LIMA), RA graft usage is associated with better patency and better long-term survival benefit. However, equity of RA conduit usage in CABG is unknown. This study aimed to examine demographic factors associated with disparity of RA grafting among patients undergoing CABG. Methods: The National Inpatient Sample (NIS) was used to extract patients received who underwent CABG between Q4 2015-2020 based on ICD10-PCS. Patients less than the age of 40 were excluded for congenital heart defects. Preoperative variables include sex, age, race and ethnicity, socioeconomic status (SES), Elixhauser comorbidities, and hospital characteristics. The rate of RA usage with respect to race, sex, and SES was compared, respectively, while all preoperative variables besides the variable of interest were adjusted by multivariable analysis. Results: There were 56,318 CABG cases identified in the NIS with 11,708 RA and 44,610 GSV grafting. African American race (aOR 0.78, p<0.01), Hispanic race (aOR 0.83, p<0.01), female sex (aOR 0.53, p<0.01), and lower income (0-25 percentile, aOR 0.78, p<0.01; 25-50 percentile, aOR 0.95, p=0.04) were independently associated with lower rates of RA grafting usage among patients who underwent CABG. Conclusion: This study reveals disparities in RA graft usage for CABG, including racial minorities, women, and economically disadvantaged groups who were less likely to receive RA. These findings highlight the need for healthcare equity in choosing the optimal graft conduit in CABG.

A clinical case of myocardial infarction after coronary artery bypass grafting using the internal mammary artery

Coronary artery bypass grafting (CABG) is the most preferred method of myocardial revascularization in multivessel coronary artery disease and severe progressive forms of the disease. The material of choice for CABG of the left anterior descending artery (LADA) is the internal mammary artery (IMA). However, even when using IMA as a conduit for CABG, one should be aware of a possibility of graft failure, which indicates a need for constant vigilance in this category of patients. Endovascular interventions on coronary arteries make it possible to efficiently and safely revascularize an occluded bypass graft, minimizing existing risks and improving both the quality of life of patients and their subsequent survival. The article considers a clinical case of the development of recurrent anterior myocardial infarction in the patient due to occlusion of the mammary graft to the LADA.

Human Saphenous Vein Endothelial Cell Isolation and Exposure to Controlled Levels of Shear Stress and Stretch.

Coronary artery bypass graft (CABG) surgery is a procedure to revascularize ischemic myocardium. Saphenous vein remains used as a CABG conduit despite the reduced long-term patency compared to arterial conduits. The abrupt increase of hemodynamic stress associated with the graft arterialization results in vascular damage, especially the endothelium, that may influence the low patency of the saphenous vein graft (SVG). Here, we describe the isolation, characterization, and expansion of human saphenous vein endothelial cells (hSVECs). Cells isolated by collagenase digestion display the typical cobblestone morphology and express endothelial cell markers CD31 and VE-cadherin. To assess the mechanical stress influence, protocols were used in this study to investigate the two main physical stimuli, shear stress and stretch, on arterialized SVGs. hSVECs are cultured in a parallel plate flow chamber to produce shear stress, showing alignment in the direction of the flow and increased expression of KLF2, KLF4, and NOS3. hSVECs can also be cultured in a silicon membrane that allows controlled cellular stretch mimicking venous (low) and arterial (high) stretch. Endothelial cells' F-actin pattern and nitric oxide (NO) secretion are modulated accordingly by the arterial stretch. In summary, we present a detailed method to isolate hSVECs to study the influence of hemodynamic mechanical stress on an endothelial phenotype.

Reconstruction Technique Options for Achieving Total Arterial Revascularization and Multiple Arterial Grafting.

Ischemic heart disease is the leading cause of morbidity and mortality worldwide and may require coronary revascularization when more severe or symptomatic. Coronary artery bypass grafting (CABG) is the most common cardiac surgical procedure and can be performed with different bypass conduits and anastomotic techniques. Saphenous vein grafts (SVGs) are the most frequently used conduits for CABG, in addition to the left internal thoracic artery. Outcomes with a single internal thoracic artery and SVGs are favorable, and the long-term patency of SVGs may be improved through novel harvesting techniques, preservation methods, and optimal medical therapy. However, increasing evidence points towards the superiority of arterial grafts, especially in the form of multiple arterial grafting (MAG). Nevertheless, the uptake of MAG remains limited and variable, both as a result of technical complexity and a scarcity of conclusive randomized controlled trial evidence. Here, we present an overview of CABG techniques, harvesting methods, and anastomosis types to achieve total arterial revascularization and adopt MAG. We further narratively summarize the available evidence for MAG versus single arterial grafting to date and highlight remaining gaps and questions that require further study to elucidate the role of MAG in CABG.

Radial artery – perspective or fallacy?

Highlights. Radial artery is the second after internal thoracic artery by frequency of use among all of autogenous arterial conduits. Some modern studies indicate the superiority of this conduit to autogenous venous conduits; however, it remains an ongoing discussion.The article presence an analytical review regarding the use of the radial artery as one of conduits during coronary artery bypass grafting. Historical and contemporary perspectives of its use are given, examples of large-scale studies and results are provided, including the “graft-artery junction” concept.Abstract. Radial artery (RA) is the second after internal thoracic artery (ITA) by frequency of use among all of autogenous arterial conduits in coronary artery bypass grafting (CABG), however it is used in less than 13% of cases. The story of RA as a conduit starts in the 1970s, when the famous French surgeon, founder of modern mitral valve repair Alain Frédéric Carpentier proposed to use it. During the development of cardiovascular surgery, RA was actively introduced as a conduit for CABG, and nowadays there are both supporters and opponents of its application. On the one hand, long-term results of CABG with RA are superior to CABG with autogenous venous conduits, whereas the patency of RA is comparable with ITA. On the other hand, RA demonstrates worse angiographic indicators, which could be explained by a diffuse narrowing resulting in complete occlusion; such phenomenon is entitled “string-sign”. Moreover, as in case with other conduits, the site of proximal anastomosis, and harvesting method (open or endoscopic) play an important role in the long-term RA functioning and its resistance to atherosclerosis in grafted coronary arteries, thus making RA a good target for studing and predetermining new perspectives of its use.

Abstract P1017: Tissue Engineered Human Acellular Blood Vessels For Coronary Artery Bypass Grafting

Objective: Conduit for coronary artery bypass grafting (CABG) can be limited due to poor quality or prior removal of saphenous veins. A human acellular vessel (HAV) bioengineered from vascular cells and then decellularized for implantation may provide a readily available, off-the-shelf conduit for CABG. Here we evaluate the use of small diameter HAV for CABG in a non-human primate model. Methods: Adult male baboons (n=7; 26.8 - 37.0 kg) were imaged by left heart catheterization and computed tomography angiography. CABG was performed using a 3.5 mm diameter HAV to the left anterior descending (LAD) or right coronary artery (RCA) via sternotomy with cardiopulmonary bypass. The proximal coronary artery was ligated to prevent competitive flow and graft transit time flowmetry (TTFM) was assessed after implant. Angiography at 2 weeks, 1, 3, and 6 months evaluated graft patency and heart function. HAVs explanted at 6 months were assessed by immunohistochemistry for host cellular response and remodeling. Results and Conclusion: Baboons underwent CABG using a 3.5 mm HAV from the ascending aorta to the LAD (n=2) or RCA (n=5). The diminutive LAD led to early graft loss due to size mismatch and poor runoff. HAV bypass to the dominant RCA (TTFM: 22 ± 7.7 mL/min) resulted in sustained graft patency for up to 6 months post-implantation. HAV explant histology revealed infiltration of multiple host cell populations with formation of a neoadventitial layer and evidence of luminal endothelization. HAV conduits retained structural integrity with no evidence of mechanical failure throughout the study. These results demonstrate that tissue-engineered HAVs may provide an off-the-shelf conduit for CABG.

Never again. Once used for cardiac catherization the radial artery cannot be used for CABG.

The use of the radial artery (RA) as a conduit in coronary artery bypass grafting (CABG) has been steadily increasing since the early 1990s and based on the most recent data may well become the standard of care for patients with multivessel coronary artery disease requiring multiple arterial grafts. The transradial access (TRA) approach for cardiac catherization has also increased steadily in use by interventional cardiologists owing to its reduction in bleeding and vascular complications when compared with the femoral approach and is now considered the preferred arterial access. However, prior use of TRA for cardiac catherization is a contraindication for the use of the RA for CABG because of high rates of structural damage to the vascular wall and potential for graft failure. In this issue of the Journal of Cardiac Surgery Clarke et al. examine the RA of two patients who had TRA for coronary angiography 8 and 12 years prior and note that both patients had chronic injury with dissection and obstruction of the lumen secondary to fibrosis suggesting that TRA causes long-term and irreversible damage rendering them unsuitable as conduits for CABG.

Angiographic Results of Radial Artery Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting Surgery

The earliest experience with use of the radial artery as a conduit for Coronary Artery Bypass Grafting (CABG) was in the early 1970’s [1], with disappointing results of 35% graft failure due to spasm...

Technical Aspects of Radial Artery Grafting for Coronary Surgery

The radial artery (RA) has seen a recent resurgence in coronary artery bypass grafting (CABG) surgery. Recent randomized evidence has shown higher long-term patency rates and better clinical outcomes with the RA when compared to other conduits such as the right internal thoracic artery and saphenous vein grafts. In fact, the RA is now class I indication as the second conduit in CABG. Therefore, it is important that the coronary surgeon is familiar with the RA and its use in CABG. In this report we describe our operative technique for RA harvesting and use in CABG. As with any surgical procedure, patient selection is key. We describe our approach to screening including duplex ultrasonography and plethysmography, endoscopic and open harvesting techniques, preservation and grafting strategies, target vessel selection, and anastomotic techniques. The radial artery (RA) has seen a recent resurgence in coronary artery bypass grafting (CABG) surgery. Recent randomized evidence has shown higher long-term patency rates and better clinical outcomes with the RA when compared to other conduits such as the right internal thoracic artery and saphenous vein grafts. In fact, the RA is now class I indication as the second conduit in CABG. Therefore, it is important that the coronary surgeon is familiar with the RA and its use in CABG. In this report we describe our operative technique for RA harvesting and use in CABG. As with any surgical procedure, patient selection is key. We describe our approach to screening including duplex ultrasonography and plethysmography, endoscopic and open harvesting techniques, preservation and grafting strategies, target vessel selection, and anastomotic techniques. Commentary: Techniques Within Arm's ReachOperative Techniques in Thoracic and Cardiovascular SurgeryVol. 26Issue 4PreviewMultiple arterial revascularization (MAR) in coronary artery bypass grafting (CABG) has seen increased use1 for its mortality and morbidity benefits,2 and currently receives a IIa recommendation by the European Society of Cardiology/European Association for Cardio-Thoracic Surgery (ESC/EACTS). The radial artery (RA) has a ESC/EACTS Class I recommendation based on promising long-term clinical and patency outcomes.3 Dr. Mario Gaudino has contributed significantly to the current understanding of RA grafting and its’ acceptance as an excellent conduit choice. Full-Text PDF

Application of the descending branch of the lateral circumflex femoral artery in coronary artery bypass grafting

ObjectiveTo investigate a technical method for harvesting and using the descending branch of the lateral circumflex femoral artery (DLCFA) in coronary artery bypass grafting (CABG). MethodsBetween January 2017 and January 2019, 40 patients (36 in the planed selection group and 4 in the temporary decision group) with mean age of 49.1 ± 7.5 years received DLCFA as an arterial conduit in CABG. In all patients, the DLCFA was successfully harvested via an anterior thigh incision. Depending on the location of the target vessel, the DLCFA was used as a free graft or a composite graft. ResultsOf the 44 patients in the planned selection group, DLCFA harvesting was abandoned in 8 patients because computed tomographic angiography revealed anatomical variation or stenosis of the superficial femoral artery. Of the 5 patients in the temporary decision group, harvesting was abandoned in 1 because of short length and thin caliber. On an average, 3.7 ± 0.9 distal anastomoses were created during CABG, with no adverse effects. The length of the harvested DLCFA was 9.9 ± 1.7 cm, with an average proximal lumen diameter of 3.4 ± 0.7 mm. The DLCFA was used as a free graft in 26 patients and as a “Y”-shape composite graft in 14 patients. Total arterial CABG was performed in 75% of the patients. ConclusionsThe DLCFA is an alternative conduit for CABG. It can be harvested easily and safely. However, preoperative computed tomographic angiography examination is necessary for the smooth application of the DLCFA, and an appropriate strategy for graft establishment should be considered.

VENOUS CONDUITS IN CORONARY SURGERY: OLD PROBLEMS — NEW SOLUTIONS

The introduction of autovenous coronary artery bypass grafting (CABG) marked the era of surgical revascularization in patients with coronary artery disease. It provided effective treatment for angina and significantly improved the long-term prognosis. Venous transplants today remain the most popular conduits in coronary surgery due to their availability, ease of harvesting, and the absence of length restrictions. Despite the advantages of autovenous CABG, the main disadvantage is the high incidence of venous graft failure, which represents an important and unresolved problem in cardiac and cardiovascular surgery. On the other hand, the traditional allocation of a large saphenous vein implies the dissection of soft tissues throughout the length of the isolated conduit. Traumatic dissection causes a long-lasting persistent pain syndrome after surgery, frequent abnormalities in skin sensitivity, and a high incidence of wound complications in the lower extremities. These complications lengthen the period of rehabilitation of patients and worsen the quality of life. There is an approach of isolating the vein in a block with surrounding tissues to optimize the long-term functioning of the venous shunt, however, this technique is even more traumatic than the traditional method, and therefore its use is limited in practice. On the other hand, the introduction of minimally invasive methods of isolation allowed to reduce the incidence of wound complications and to improve the cosmetic result, but there is no convincing data regarding the effect on the consistency of shunts in the long-term postoperative period. The problems associated with the use of venous conduits in CABG are multifaceted, and their solutions are necessary to improve the effectiveness of surgical revascularization.

VENOUS CONDUITS IN CORONARY SURGERY: OLD PROBLEMS — NEW SOLUTIONS

The introduction of autovenous coronary artery bypass grafting (CABG) marked the era of surgical revascularization in patients with coronary artery disease. It provided effective treatment for angina and significantly improved the long-term prognosis. Venous transplants today remain the most popular conduits in coronary surgery due to their availability, ease of harvesting, and the absence of length restrictions. Despite the advantages of autovenous CABG, the main disadvantage is the high incidence of venous graft failure, which represents an important and unresolved problem in cardiac and cardiovascular surgery. On the other hand, the traditional allocation of a large saphenous vein implies the dissection of soft tissues throughout the length of the isolated conduit. Traumatic dissection causes a long-lasting persistent pain syndrome after surgery, frequent abnormalities in skin sensitivity, and a high incidence of wound complications in the lower extremities. These complications lengthen the period of rehabilitation of patients and worsen the quality of life. There is an approach of isolating the vein in a block with surrounding tissues to optimize the long-term functioning of the venous shunt, however, this technique is even more traumatic than the traditional method, and therefore its use is limited in practice. On the other hand, the introduction of minimally invasive methods of isolation allowed to reduce the incidence of wound complications and to improve the cosmetic result, but there is no convincing data regarding the effect on the consistency of shunts in the long-term postoperative period. The problems associated with the use of venous conduits in CABG are multifaceted, and their solutions are necessary to improve the effectiveness of surgical revascularization.

Mid-term multi-center outcomes of bilateral radial artery as conduits in coronary artery bypass grafting

Objective: To evaluate the mid-term outcomes of bilateral radial artery (BRA) grafts in coronary artery bypass grafting (CABG). Methods: All perioperative medical records and follow-up results of CABG with BRA grafts in multi-centers of China were analyzed retrospectively. Results: A total of 211 patients (170 males and 41 females) underwent CABG grafting with BRA conduits between August 2013 and September 2018, with a mean age of (56.5±9.7) years old (rang 41 to 73 years). There were 161 cases of triple-vessel disease and 50 cases of two-vessel disease. Ninety patients had diabetes mellitus (DM), 35 patients with peripheral vascular disease, 4 patients with chronic obstructive pulmonary disease and 11 with heart valve disease. Two patients underwent off-pump CABG and 209 patients accepted on-pump CABG with commitment valve surgery. There were 210 cases of total arterial revascularization and 161 cases using left thoracic artery conduits, with a graft number of 2-4 (2.7±0.9). No operation-related death occurred, atrial fibrillation happened in 12 patients, hemothorax in 7 cases, and forearm hematoma in one case, hypoxemia in 13 cases and pneumonia in one case. The duration of mechanical ventilation was (8.3±4.7) hours and the mean hospital length of stay was (7.1±2.9) days. Follow-up was completed in 191 patients (90.52%) with a duration of 3-59 (35.5±9.3) months. The mean left ventricular ejection fraction at 3 months after operation was significantly improved, compared to that of the pre-operation (61.0%±7.2% vs 47.1%±5.3%, P=0.017). All patients survived, except that one died from brain injury. No major cardiac events occurred, with a cumulative survival rate of 100% at 1 year and 99.53% at 3 year after operation, respectively. It was showed in coronary CT angiography (CTA) examination that all grafts in 132 patients were patent at the mean follow-up duration of (21.5±6.4) months. Conclusions: BRA grafts as arterial conduit in CABG are proved to be safe, easy for total arterial revascularization and have good mid-term clinical results.

Randomized Trial of Endoscopic or Open Vein-Graft Harvesting for Coronary-Artery Bypass

BackgroundThe saphenous-vein graft is the most common conduit for coronary-artery bypass grafting (CABG). The influence of the vein-graft harvesting technique on long-term clinical outcomes has not been well characterized.MethodsWe randomly assigned patients undergoing CABG at 16 Veterans Affairs cardiac surgery centers to either open or endoscopic vein-graft harvesting. The primary outcome was a composite of major adverse cardiac events, including death from any cause, nonfatal myocardial infarction, and repeat revascularization. Leg-wound complications were also evaluated.ResultsA total of 1150 patients underwent randomization. Over a median follow-up of 2.78 years, the primary outcome occurred in 89 patients (15.5%) in the open-harvest group and 80 patients (13.9%) in the endoscopic-harvest group (hazard ratio, 1.12; 95% confidence interval [CI], 0.83 to 1.51; P=0.47). A total of 46 patients (8.0%) in the open-harvest group and 37 patients (6.4%) in the endoscopic-harvest group died (hazard ratio, 1.25; 95% CI, 0.81 to 1.92); myocardial infarctions occurred in 34 patients (5.9%) in the open-harvest group and 27 patients (4.7%) in the endoscopic-harvest group (hazard ratio, 1.27; 95% CI, 0.77 to 2.11), and revascularization occurred in 35 patients (6.1%) in the open-harvest group and 31 patients (5.4%) in the endoscopic-harvest group (hazard ratio, 1.14; 95% CI, 0.70 to 1.85). Leg-wound infections occurred in 18 patients (3.1%) in the open-harvest group and in 8 patients (1.4%) in the endoscopic-harvest group (relative risk, 2.26; 95% CI, 0.99 to 5.15).ConclusionsAmong patients undergoing CABG, we did not find a significant difference between open vein-graft harvesting and endoscopic vein-graft harvesting in the risk of major adverse cardiac events. (Funded by the Cooperative Studies Program, Office of Research and Development, Department of Veterans Affairs; REGROUP ClinicalTrials.gov number, NCT01850082.)

Diabetes Mellitus Induces Hyperreactivity of 5-Hydroxytryptamine (5-HT)-Induced Constriction in Human Internal Thoracic Artery and Is Associated with Increase in the Membrane Protein Level of 5-HT<sub>2A</sub> Receptor

Studies indicate that 5-hydroxytryptamine (5-HT) released from activated platelets in coronary artery bypass grafting (CABG) induces 5-HT2A receptor-mediated graft spasm. We previously reported that 5-HT-induced constriction of human endothelium-denuded saphenous vein (SV) was significantly augmented in patients with diabetes mellitus (DM) than in patients without DM (non-DM), without changes in the levels of the membrane-bound 5-HT2A receptor of their smooth muscle cells. Although the internal thoracic artery (ITA) is the key graft conduit for CABG, the effect of DM on the ITA graft spasm is still unclear. Therefore, in this study, we investigated the effect of DM on 5-HT-induced vasoconstriction and the level of membrane-bound 5-HT2A receptor in ITA grafts. 5-HT-induced constriction of the isolated human endothelial-denuded ITA was significantly higher in patients with DM than in patients without DM. In addition, the level of the 5-HT2A receptor in the membrane fraction of human ITA smooth muscle cells was significantly higher in patients with DM than in those without DM. These results demonstrate that DM is a risk factor for CABG in both venous and arterial conduits, and that it differentially affects the level of the membrane-bound 5-HT2A receptor in the venous and arterial smooth muscle cells.

Application of the descending branch of the lateral circumflex femoral artery in the coronary artery bypass grafting operation

Objective: To investigate the technical method for harvesting and application of the descending branch of the lateral circumflex femoral artery (DBLCFA) in the coronary artery bypass grafting (CABG) operation. Methods: Between December 2016 and April 2017, 19 patients were arranged to use DBLCFA and got CT angiography (CTA) of pelvic and femoral arteries pre-operative at Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Finally, DBLCFA was harvested in 16 patients (including 2 female patients, with a mean age of (47.4±8.5) years) through the anterior thigh incision (13 cases on the left side, 3 cases on the right side). The CABG operations were performed under the cardiopulmonary bypass support (in 10 cases) or under the beating heart condition (in 6 cases), and the DBLCFA conduit was used combining with bilateral internal thoracic artery (in 12 cases), radial artery (in 7 cases) and saphenpous vein (in 3 cases). Results: Due to anatomical variations such as short length and anomalous branch, or due to silent atherosclerosis stenosis of femoral artery, DBLCFA in 3 patients was considered inappropriate for use and was not harvested after CTA examination. In another 16 patients, DBLCFA was safely and quickly harvested and successfully used. On average, 3.4±0.6 anastomosis was built up in CBAG, no adverse effects were exhibited. The length of the harvested DBLCFA was (10.3±1.8) cm, with average lumen diameter of (1.9±0.5) mm. DBLCFA was used as free graft in 15 patients (7 to the first diagonal branch, 6 to the ramus intermedius branch, 1 to the left anterior descending branch and 1 to the second obtuse marginal branch). In 1 patient, the DBLCFA was firstly implanted end-to-side to the internal thoracic artery as a "Y" type composite graft, and then anastomosed to the third obtuse marginal branch. Conclusions: The descending branch of the lateral circumflex femoral artery is an option conduit in CABG. It can be harvested easily and safely. However, pre-operative CTA examination is necessary to exclude the variation and appropriate strategy for graft establishment should be considered during the operation.

Coronary-subclavian steal syndrome following CABG: A case report and literature review

Introduction: Coronary-subclavian steal syndrome (CSSS) is not a common complication but it can cause recurrent angina following coronary artery bypass grafting(CABG). CSSS results from proximal subclavian artery stenosis causing reversal of blood flow in apatent in situ internal thoracic artery utilized as a conduit in CABG, leading to myocardial ischemia. Case Presentation: We present a case of CSSS successfully treated with carotid-subclavian bypass (CSB). A review of articles on the subject has also been conducted. Conclusions: Although CSSS is not a common condition, it should be strongly considered as a possibility in CABG patients presenting with recur- rent chest pain not to be confused with perioperative myocardial infarction (PMI). If indicated, carotid-subclavian bypass maybe performed as an effective treatment option with acceptable outcomes.

Reusing the patent internal mammary artery as a conduit in redo coronary artery bypass surgery.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, in patients with previous internal mammary artery/internal thoracic artery (ITA) grafts, can the internal mammary artery/ITA be reused/recycled in redo coronary artery bypass surgery? Fourteen papers were found using the reported search of which 10 represented the best evidence to answer the clinical question. There was variation in patient selection, the number of patients reported, outcome measures recorded, and methods and duration of follow-up. The results were mostly in favour of using a recycled ITA when it could be safely harvested. Most studies were retrospective. One large series of 60 patients who underwent redo coronary artery bypass grafting (CABG) using previously implanted ITAs had a mean time to reoperation of 117 ± 68 months. They reported no operative deaths; no patients required further or subsequent target vessel revascularization; 30-day mortality was 8.3% and myocardial infarction rate was 3%. Another two series of 16 and 12 patients underwent recycling of arterial grafts during coronary artery revascularization with no perioperative deaths in either. Postoperative angiography was performed in 10 patients in one of these studies, which showed excellent flow in all redone left internal thoracic artery (LITA) grafts. One study reported results from a prospective cohort of 9 patients who underwent redo coronary artery bypass grafting. Interval between operations was between 1 and 132 months. There was no perioperative mortality, but 1 patient required reintervention (to an interposition vein graft). A further study of 4 patients who underwent redo CABG using ITAs that were patent but with severe stenosis at the distal anastomosis had no mortality. Postoperative angiography showed patency of all grafts. There have also been 4 case reports on reusing the ITA/ITA in redo CABG with no damage to the reused LITA, no perioperative mortality and satisfactory follow-up at up to 29 months. Evidently, the recycled ITA can be used in redo coronary artery bypass grafting. Papers found were retrospective series or case reports. As such, there is no direct comparison in outcomes between the recycled ITA and first-time ITA harvest or any other conduit for CABG. In conclusion, we find that when it is possible to harvest a previously used ITA, studies have shown it to be a safe and viable conduit in redo CABG with good long-term outcomes.

Right internal mammary artery versus radial artery as second arterial conduit in coronary artery bypass grafting: A case-control study of 1526 patients

Objective: Additional arterial grafts such as the right internal mammary artery (RIMA) or the radial artery (RA) have been proposed to improve long term outcomes in coronary artery bypass grafting (CABG). RA is largely preferred over RIMA as it is less technically demanding and there is a perception that bilateral IMA usage increases the risk of sternal wound complications. However, there is a paucity of direct comparison of the two conduits to guide surgeons to choose the best second arterial conduit for CABG. Methods: A propensity score adjusted analysis of patients undergoing multiple arterial grafting with RIMA (n = 747) and RA (n = 779) during the study period (2001–2013) was conducted to investigate the impact of the two strategies on early and late outcomes. Results: RIMA did not increase the incidence of postoperative complications including deep sternal wound infection (P = 0.8). Compared to the RIMA, the RA was associated with an increased risk for late mortality (Hazard Ratio [HR] 1.9; 95% confidence interval (CI) 1.2–3.1; P = 0.008) and repeat revascularization (HR 1.5; 95% CI 1.0–2.2; P = 0.044). A trend towards an extra risk for late mortality from RA over RIMA was observed among diabetic (HR 3.3; 95% CI 1.1–9.7) and obese patients (HR 2.1; 95% CI 0.8–5.46). Conclusions: RIMA as a second conduit did not increase the operative risk including sternal wound complications and improved long term outcomes including overall survival when compared to RA. This advantage was stronger among diabetic and obese patients. These findings strongly support RIMA as the first choice second arterial conduit in CABG. Further randomized studies with angiographic control and long-term follow-up are needed to address this issue.