The fate of the radial artery conduit in coronary artery bypass grafting surgery.

Coronary artery bypass grafting (CABG) is the standard surgical procedure for the treatment of advanced coronary artery disease. CABG surgery has been demonstrated to improve symptoms and, in specific subgroups of patients, to prolong life. Despite its success, the long-term outcome of coronary bypass surgery is strongly influenced by the fate of the vascular conduits used. Impressive long-term disease-free patency rate of the left internal thoracic artery-left anterior descending coronary artery (LITA-LAD) graft, coupled with proven long-term survival benefits, has led to its becoming a 'golden standard' of CABG. Previous long-term studies have also shown unsatisfactory patency of saphenous vein grafts used for myocardial revascularization, compared with internal thoracic artery grafts. Thus, the use of arterial conduits has expanded beyond the internal thoracic arteries (ITAs) to include the right gastroepiploic artery, the inferior epigastric artery, and the radial artery. The assumption is that although the performance of one or two arterial ITA graft is superb, more arterial grafts should perform better in the long-term follow-up. Several studies concerning the use of the radial artery bypass grafts have documented excellent clinical results and satisfactory short-term as well as mid-term patency rates at restudy angiography, supporting its continued use as a bypass conduit. However, a note of caution concerning radial artery conduit patency rate have appeared in few recent reports. Thus, in this paper, we summarize the current evidence about the radial artery as a conduit in CABG surgery, with special emphasis on the clinical results.     

Influence of type 2 diabetes on functional and structural properties of coronary artery bypass conduits

Recent studies have reported a high incidence of postoperative unfavorable cardiac-related events in patients with diabetes who underwent coronary artery bypass grafting (CABG). Structural and functional characteristics of CABG conduits, which have been shown to play an important role in patient outcome after myocardial revascularization, have not been fully investigated in diabetic subjects. Therefore, we sought to determine the influence of adult-onset diabetes on vasoreactivity and morphological profile of venous and arterial grafts. Of the 160 consecutive patients enrolled in the study, 90 were diagnosed with type 2 diabetes and 70 did not have diabetes (control group). All patients underwent evaluation of glucose control before surgery. Tissue specimens were collected from left internal thoracic artery (LITA) and saphenous vein (SV) grafts harvested during elective CABG. Functional tests were performed to assess contractile and vasodilative responses of bypass conduits. Histological evaluation was carried out to examine vessel wall structure. Univariate and multivariate analyses were performed to correlate the preoperative factors related to the control of the endocrine disorder with histological findings. Patient medical history and demographics did not differ between the groups. Diabetic patients showed significant microalbuminuria and higher plasma levels of C-peptide and GHb as compared with nondiabetic subjects. Functional tests of the LITA segments revealed no difference between groups with regard to contractile and vasodilative responses. In contrast, significant impairment in the endothelium-related vasodilation of the SV grafts was observed in diabetic subjects. Histological studies showed structural preservation of the arterial conduits in both groups. However, marked intimal abnormalities (also atherosclerotic calcified plaques) were detected in SV grafts harvested from diabetic patients. Logistic regression analysis showed that high levels of proteinuria and GHb were independent predictors of advanced structural degeneration of SV conduits. Treatment modality, duration of diabetes, and other demographic or metabolic factors were found to have no influence on the morphological characteristics of SV conduits. In conclusion, biological properties of LITA conduits for CABG were preserved in diabetic patients. However, these patients frequently showed impairment of the endothelium-dependent vasorelaxation and intimal degeneration of SV grafts. The extent of structural abnormalities of SV grafts was inversely correlated with the efficacy of the metabolic control of the endocrine disorder. Further studies are required to conclusively correlate preoperative SV graft abnormalities with postoperative conduit patency rate and the occurrence of adverse cardiac-related events in diabetic subjects.     

Redo coronary artery bypass grafting using the patent left internal thoracic artery graft as an in flow with composite internal thoracic artery Y grafting; report of a case

In redo coronary artery bypass grafting (CABG), graft selection and revascularization methods are major problems. We experienced a redo-CABG with occluded previous vein grafts. These grafts were to the circumflex artery and right coronary artery. We conducted operation using cardiopulmonary bypass. We at this operation, chose right internal thoracic artery (RITA) as a conduit and anastomosed it to the side of functioning left internal thoracic artery (LITA) graft, and then diogonal branch, posterolateral branch, and atrioventricular branch were revascularized with the RITA. Post operative course was uneventful. Internal thoracic artery (ITA) is superior to vein graft and other arterial graft as to long term patency. We believe composite Y graft with the use of bilateral ITA can be one of the revascularization strategy in redo CABG.     

The Shelhigh No-React bovine internal mammary artery: a questionable alternative conduit in coronary bypass surgery?

BACKGROUND: Increasing age and comorbidities among patients undergoing coronary artery bypass surgery (CABG) stimulates the exhaustive research for alternative grafts. No-React treatment should render the tissue resistant against degeneration and reduce early inflammatory response. The aim of the present study was an invasive assessment of the patency of No-React bovine internal mammary artery (NRIMA grafts) used as bypass conduit in CABG surgery. PATIENTS AND METHODS: Nineteen NRIMA grafts were used in 17 patients (2.9%) out of a total of 572 patients undergoing CABG surgery within a 12-month period. All intraoperative data were assessed and in-hospital outcome was analysed. Follow-up examination was performed 7.0+/-4.0 months after initial surgery, including clinical status and coronary angiography to assess patency of the NRIMA grafts. RESULTS: Average perioperative flow of all NRIMA grafts was 71+/-60 ml/min. One patient died in hospital due to a multi-organ failure. Four patients refused invasive assessment. Follow-up was complete in 12 patients with overall 13 NRIMA grafts. Nine NRIMA grafts (69.2%) were used for the right coronary system, two NRIMA grafts (15.4%) on the LAD and two on the circumflex artery. Graft patency was 23.1% and was independent of the intraoperative flow measurement. CONCLUSIONS: NRIMA grafts show a very low patency and cannot be recommended as coronary bypass graft conduits. Patency was independent of the perioperative flow, assessed by Doppler ultrasound. Because of this unsatisfying observation, this type of graft should be utilised as a last resource conduit and used only to revascularise less important target vessels, such as the end branches of the right coronary artery.     

非体外循环冠状动脉旁路移植术围手术期心肌梗死发生率与移植血管血流量的关系

目的探讨冠状动脉旁路移植术（CABG）中移植血管血流量与围手术期心肌梗死（MI）发生率之间的关系,为临床提供借鉴。方法采集2010年1～6月在北京大学第一医院连续58例因冠心病接受单纯择期非体外循环冠状动脉旁路移植术（（）PcAB）患者的临床资料。术中均采用左乳内动脉（I,IMA）吻合于左前降支（I．AD）,其他靶血管则以大隐静脉（SV）作为旁路移植血管,在关胸前循环状态稳定条件下,应用瞬时流量测定技术测量各移植血管的血流量,并计算移植血管总血流量。根据术后是否发生围手术期MI,将患者分成两组：MI组11例,其中男7例,女4例;年龄67．4±10．3岁;非MI组,47例,其中男38例,女9例;年龄63．3±9．9岁。分析两组患者术前及术中的相关危险因素。结果MI组与非MI组的手术时间差异无统计学意义（205．44±59．6rainVS．183．4±32．4min,t=1．69l,P=0．096）。MI组与非MI组移植血管数量（3．00±1．oo支VS．2．96±0．78支,t=0．154,P=0．878）、LIMA-LAD移植血管血流量（15．40±）1．37mi／minVS．16．50±10．83mJ／min,f=0．301,P=0．764）差异均无统计学意义;MI组与非MI组移植血管总血流量（41．03土19．50ml／minVS．64．09±32．44ml／min,t=2．254,P=0．028）差异有统计学意义。移植血管总血流量〈48．5ml／min为发生MI的危险因素EoR：4．706,95％CI（1．099,20．147）]。结论移植血管总血流量可在一定程度上预测CABG后急性心肌缺血事件的发生,总血流量〈48．5ml／min的患者术后发生围手术期MI的概率将明显增加。     

Similarity between internal thoracic artery and gastroepiploic artery graft: pharmacological point of view

The pharmacological responses of internal thoracic artery (ITA), gastroepiploic artery (GEA) and saphenous vein (SV) obtained from patients receiving coronary artery bypass grafting (CABG) were assessed by isometric contraction records. The concentration-response curves for ergonovine and serotonin showed the leftward shift in SV compared with ITA and GEA. The 50% effective dose values of SV for ergonovine and serotonin were significantly less than those of ITA and GEA. The concentration-response curves for phenylephrine were similar among three kinds of grafts. There were no significant differences in the 50% effective dose values for phenylephrine among them. The effect of 0.4% papaverine chloride on the free graft flow was assessed in 15 patients receiving CABG with mean body surface area of 1.62 +/- 0.12 M2. The free flow of ITA graft was 71 +/- 32 ml/min before intraluminal papaverine injection, and that increased to 112 +/- 41 ml/min after injection. The free flow of GEA graft was 82 +/- 39 ml/min before injection, and that also increased to 128 +/- 40 ml/min after injection. The patency rates at the mean 2.2 months after grafting were 98% in ITA, 93% in GEA, and 88% in SV. In conclusion, both GEA graft and ITA graft can be expected as an excellent conduit in myocardial revascularization.     

The analysis for surgical procedures of coronary-artery bypass grafting: selection of graft materials]

We analyzed 222 patients undergoing coronary artery bypass grafting (CABG) in our institute. Our selection of graft materials consists of only one arterial conduit and one or more saphenous vein grafts (SVG). An arterial conduits (left internal thoracic artery (LITA) was mainly used for the left anterior descending coronary artery (LAD), while a SVG was used for coronary arterial branch. Our approach was evaluated by the mid-term prognosis as well as cardiac events. Seventy-one percent of patients with CABG could be followed. The graft patency rate was better for ITA grafts than for SVG (97.8% vs 88%). The incidence of late cardiac events was lower in patients with the LITA, to the LAD. Furthermore, these patients had a better survival rate at 4 years comparing with patients who had vein bypass grafts alone. We suggest that this selection of graft materials may be accepted in CABG for the good quality, avoiding the cardiac events.     

Bilateral radial arterial T graft and the left thoracotomy approach for second redo coronary artery bypass grafting.

We herein report a case of third coronary artery bypass grafting (CABG) using a bilateral radial artery T graft. There were patent grafts on the anterior aspect of the heart other than the occluded left internal thoracic artery to the left anterior descending (LAD) artery. A T shaped bilateral radial artery conduit was anastomosed from the left subclavian artery to the LAD and first diagonal branch through a left thoracotomy approach. Postoperative angiography demonstrated excellent flow of radial artery conduits. Left thoracotomy with the use of a bilateral radial artery T graft is a useful substitute for anterior re-sternotomy entry in redo CABG.     

Redo off-pump coronary artery bypass grafting for high risk hemodialysis patients

BACKGROUND: The number of reoperative (redo) coronary artery bypass grafting (CABG) for patients with long-term hemodialysis has been increasing. Off-pump CABG (OPCAB) may decrease risks associated with redo CABG. METHODS: Two patients on chronic hemodialysis with calcification of the ascending aorta underwent redo double coronary OPCAB for the left anterior descending artery (LAD) and the posterior descending artery (PDA) via median sternotomy. The LAD was bypassed with the left internal thoracic artery (LITA). The PDA was exposed with minimum dissection and bypassed with a composite graft of the right internal thoracic artery (RITA) and the saphenous vein (SV). RESULTS: Both patients made a quick recovery with no complications and one had postoperative angiography that showed the patent grafts. Both patients were free from angina pectoris at follow-up of 6 months and 3 months, respectively. CONCLUSION: Redo OPCAB of the LAD and PDA can be performed with minimal dissection via median sternotomy using the LITA and a composite graft of the RITA and SV.     

Coronary revascularization for patients requiring steroids. A report of three cases

Three patients with systemic disease requiring steroids, in whom coronary artery bypass grafting (CABG) was performed, are reported in this paper, Anesthetic problems and operative managements for such patients are also discussed. Patient 1, 57-year-old male with thrombocytosis underwent emergency double CABG using saphenous vein and the Bioflow graft. He discharged with freedom from angina. Patient 2, 59-year-old male with polymyositis who had been receiving steroid for 10 years underwent quadruple CABG using bilateral internal thoracic arteries with sequential technique and the Bioflow graft, but he died of multiple organ failure on 16 days after operation. Postmortem examination revealed that coronary artery sclerosis progressed more severely than we had expected from angiography. All the graft anastomosed were completely patent. Histological examination showed that the saphenous vein was fragile. The pathological changes might be due to steroid administration. On the other hand, arterial grafts were completely normal. Patient 3, 37-year-old male with idiopathic thrombocytopenic purpura who had been on steroids underwent combined triple CABG using internal thoracic artery, gastroepiploic artery and the Bioflow graft and splenectomy. He discharged with freedom from angina and tendency to bleed. Postoperative angiography showed both arterial grafts were well patent and left ventricular wall motion vastly improved. From our experience, a careful consideration of the bypass conduit is a major problem in such patients requiring steroids.     

Current practice of coronary artery bypass surgery. Results of a national survey.

A survey of techniques used in coronary artery bypass graft (CABG) surgery by 400 experienced cardiac surgeons is presented. These surgeons performed 41,000 CABG operations in 1975. A seventy-question survey form was answered by each surgeon on their techniques for cardiopulmonary bypass and myocardial preservation, choice of bypass conduit, and grafting techniques. We found that extracorporeal circulation is almost always used in CABG surgery. A wide divergence of practice exists in the use of left ventricular vents and in methods of myocardial protection during coronary artery grafting. A spectrum of graft suture techniques is employed, the most common being a running double-ended suture anastomosis with the end of the vein initially fixed only at its heel to the coronary artery. Only 23 surgeons (6 per cent) prefer the internal mammary artery (IMA) rather than saphenous vein, when feasible, as the bypass conduit of choice for CABG surgery.     

Comparison of superficial femoral vein and saphenous vein as conduits for mesenteric arterial bypass

PURPOSE: Gangrenous bowel, intraabdominal sepsis, and previous failed mesenteric bypass are indications for use of an autogenous conduit for mesenteric arterial reconstruction. Saphenous vein (SV) is often used as the autogenous conduit of choice, but it may be prone to graft stenosis or occlusion. Recent experience with superficial femoral vein (SFV) suggests that it is an excellent alternative conduit for major arterial reconstruction. The purpose of this study was to compare the outcomes of SV and SFV for mesenteric arterial bypass. METHODS: During a 7-year period, 26 patients underwent 43 mesenteric arterial bypass procedures with autogenous conduit. SV was used for 23 bypasses (53%), and SFV was used for 20 bypasses (47%). Indications for revascularization included chronic mesenteric ischemia (n = 15; 58%), acute mesenteric ischemia (n = 9; 35%), and mycotic aneurysm of the paravisceral aorta (n = 2; 7%). Three patients (11%) underwent revascularization with SV grafts and two patients (8%) with SFV grafts after previous failed mesenteric bypass. RESULTS: The 30-day mortality rate was 15%. Three deaths occurred after SV bypass for acute mesenteric ischemia, and one death occurred after a SFV bypass for a ruptured paravisceral mycotic aneurysm. Twenty-two surviving patients were followed for a mean of 31 +/- 6 months. Three of 11 patients (27%) who survived after SV bypass had recurrent mesenteric ischemia develop (acute, n = 1; chronic, n = 2) from graft thrombosis at a mean interval of 32 +/- 22 months after surgery. No patient had recurrent symptoms develop after SFV bypass. One of the three patients with SV graft failure died of acute mesenteric ischemia, and the other two patients underwent successful bypass with SFV. Symptomatic graft failure was significantly more likely to occur in patients receiving SV grafts compared with SFV grafts (P <.05). CONCLUSION: SFV yields acceptable clinical outcomes for mesenteric arterial bypass compared with SV. SFV is a viable alternative to SV when autogenous conduit is indicated for mesenteric arterial reconstruction.     

Patency of saphenous vein coronary artery bypass grafts from the vascular prosthesis of the ascending aorta.

BACKGROUND: Patients who have Stanford type A aortic dissection with impaired coronary arteries or who have aneurysms from the ascending aorta to the aortic arch with coronary artery disease need coronary artery bypass grafting (CABG) with tube graft replacement of the ascending aorta simultaneously. When vein grafts are used for CABG in these patients, the proximal anastomoses of vein grafts are attached to the prosthetic tube graft of the ascending aorta. However, the validity of proximal anastomoses of vein grafts to the prosthetic tube graft of the ascending aorta has not been confirmed. PATIENTS AND METHODS: We retrospectively analyzed patients who underwent venous coronary bypass grafting with prosthetic graft replacement of the ascending aorta. Between January 1984 and October 2002, 35 patients underwent CABG using saphenous vein grafts at the time of tube graft replacement of the ascending aorta, and the proximal anastomoses of the vein grafts were attached to the tube graft of the ascending aorta. Thirty-three venous bypass grafts were analyzed in 24 survivors. RESULTS: The postoperative catheterization showed only one early vein graft occlusion of 16 vein grafts anastomosed distally to the left anterior descending artery (LAD). All 14 venous grafts anastomosed to the right coronary artery (RCA) and 3 to the left circumflex artery (LCX) were patent. Therefore, the postoperative patency rate at discharge was 97.0% (32/33). Spiral computed tomography performed for long term follow-up revealed occlusion of two vein grafts (3.5 years and 9.7 years) anastomosed to the LAD. CONCLUSIONS: The patency rate of vein grafts anastomosed from prosthetic grafts of the ascending aorta to the native coronary arteries was similar to that of conventional CABG using saphenous vein grafts.     

The radial artery for coronary artery bypass grafting

Coronary artery bypass grafting (CABG) is the standard surgical procedure for the treatment of advanced coronary artery disease. CABG surgery has been demonstrated to improve symptoms and, in specific subgroups of patients, to prolong life. Despite its success, the long-term outcome of coronary bypass surgery is strongly influenced by the fate of the vascular conduits used. Previous long-term studies have shown unsatisfactory patency of saphenous vein grafts used for myocardial revascularisation, compared with internal mammary artery grafts. Recently, the use of radial artery for CABG has enjoyed a revival, on the basis of the belief that it will help improving long-term results of coronary operations. The recent reports of encouraging mid-term and long-term patency rates of the radial artery, supports its continued use as a bypass conduit. In this paper, we review the current knowledge about the radial artery as a bypass graft, with special emphasis on the clinical results.     

A Technique to Harvest the Inferior Epigastric Arteries for Coronary Bypass Procedures

The demonstrated superior long-term patency of the internal mammary artery (IMA) over the saphenous vein (SV) has prompted the use of other arterial grafts, particularly for younger patients and patients without a suitable SV. We have used the single or bilateral inferior epigastric arteries (IEA) as a detached arterial conduit in 27 patients undergoing coronary artery bypass operations (CABG). In this report we describe the surgical anatomy of the IEA, preoperative noninvasive evaluation by duplex scan, our harvesting technique, and early surgical experience.     

Coronary artery bypass grafting by utilizing the artery grafts and bovine internal thoracic artery graft (Bioflow in an elderly patient)]

We performed coronary artery bypass grafting (CABG) in a 80-year-old male with calcified ascending aorta and severe varicose veins utilizing the bilateral internal thoracic arteries and the right gastroepiploic artery under fibrillatory arrest without aortic cross-clamp (aortic no-touch technique). After triple coronary artery bypass grafting was completed, heart failure occurred. Additional Bioflow graft to the circumflex artery restored good cardiac function. The aortic no-touch technique is a useful method for CABG in patients with severe calcified ascending aorta. This experience suggests that the Bioflow graft is a helpful conduit at an urgent situation in CABG.     

Concordant cardiac xenotransplantation

Abstract Background: The number of reoperative (redo) coronary artery bypass grafting (CABG) for patients with long‐term hemodialysis has been increasing. Off‐pump CABG (OP‐CAB) may decrease risks associated with redo CABG. Methods: Two patients on chronic hemodialysis with calcification of the ascending aorta underwent redo double coronary OPCAB for the left anterior descending artery (LAD) and the posterior descending artery (PDA) via median sternotomy. The LAD was bypassed with the left internal thoracic artery (LITA). The PDA was exposed with minimum dissection and bypassed with a composite graft of the right internal thoracic artery (RITA) and the saphenous vein (SV). Results: Both patients made a quick recovery with no complications and one had postoperative angiography that showed the patent grafts. Both patients were free from angina pectoris at follow‐up of 6 months and 3 months, respectively. Conclusion: Redo OPCAB of the LAD and PDA can be performed with minimal dissection via median sternotomy using the LITA and a composite graft of the RITA and SV.     

Intermediate Clinical Results of Combined Gastroepiploic and Internal Thoracic Artery Bypass

Background. To improve the postoperative results of coronary artery bypass grafting (CABG), the internal thoracic artery (ITA) has become the conduit of choice, with a low operative risk. The gastroepiploic artery as a third arterial conduit for grafting was first reported in 1987, and the early results were reported to be as good as those for the ITA graft. In this report, we present the intermediate-term results of combining ITA and gastroepiploic artery grafts up to 7 years after the operation.

Methods. Between April 1988 and April 1992, 214 patients received CABG with at least one ITA graft and were followed up for more than 3 years. They were divided into two groups: Group I consisted of 155 patients who had CABG using one ITA with or without saphenous vein grafts, and group II consisted of 59 patients who had CABG using an ITA and a gastroepiploic artery with or without saphenous vein grafts. The duration of follow-up for hospital survivors ranged from 36 to 89 months.

Results. There were six late cardiac deaths in group I and one in group II. Fifteen patients complained of recurrent symptoms of angina: 13 in group I and 2 in group II. The actuarial survival rate excluding noncardiac deaths was 95.9% in group I and 96.8% in group II at 7 years (p = not significant). The cardiac event-free rate was 75.4% in group I and 92.2% in group II, which was a significant difference (p < 0.05).

Conclusions. When using both the ITA and gastroepiploic artery, CABG can be performed with minimal operative risk and seems to offer an improved quality of life at least 7 years postoperatively.     

Conduit selection and early graft failure in coronary artery bypass surgery: A post hoc analysis of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) coronary artery bypass grafting study

ObjectivesRelative rates of early graft failure and conduit selection in coronary artery bypass grafting (CABG) surgery remain controversial. Therefore, we sought to determine the incidence and determinants of graft failure of the left internal mammary artery (LIMA), radial artery, saphenous vein, and right internal mammary artery (RIMA) 1 year after CABG surgery.MethodsA post hoc analysis of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) CABG study, involving patients from 83 centers in 22 countries. We completed an analysis of 3480 grafts from 1068 patients who underwent CABG surgery with complete computed tomography angiography data. The primary outcome was graft failure as diagnosed by computed tomography angiography 1 year after surgery.ResultsGraft failure occurred in 6.4% (68/1068) for LIMA, 9.9% (9/91) for radial artery, 10.4% (232/2239) for saphenous vein, and 26.8% (22/82) for RIMA grafts. The RIMA had a greater rate of graft failure (26.8%) than radial artery (9.9%) and veins (10.4%) (adjusted odds ratio, 2.69; 95% confidence interval, 1.30-5.57; P = .008 and adjusted odds ratio, 2.07; 95% confidence interval, 1.33-3.21; P = .001, respectively).ConclusionsIn this international trial dataset, LIMA and radial artery performed as expected, whereas vein grafts performed better. However, high rates of RIMA failure are worrisome and highlight the need for a thorough evaluation of the patency and safety of the RIMA in CABG surgery.     

Internal mammary harvesting: Techniques and evidence from the literature

Coronary artery bypass graft (CABG) is one of the most commonly performed cardiac surgeries in the world. CABG using the internal mammary artery (IMA) remains the gold standard intervention for myocardial intervention in multivessel coronary artery disease. IMA harvesting can be performed with various techniques and approaches: pedicled vs skeletonized harvesting technique as well as approaches such as conventional sternotomy, robotic and endoscopic approaches. While each technique and approach have their respective advantages and disadvantages, evidence remains varied between cohorts. Traditionally, IMA has been used as an in situ conduit; however, IMA free grafts also provide satisfactory outcomes in certain situations. This literature review aims to explore the efficacy of different techniques and approaches of IMA harvesting and grafting. With evidence compiled, this will provide an overview of the complexity of CABG and locate gaps in current literature to direct future research.