Analysis of transit time flow of the right internal thoracic artery anastomosed to the left anterior descending artery compared to the left internal thoracic artery

Introduction

We evaluated with transit time flow the performance of the right and left thoracic arteries when used as a graft for the left anterior descending artery.

Methods

Fifty patients undergoing surgery for myocardial revascularization without cardiopulmonary bypass were divided into two groups. In group A patients received graft of right internal mammary artery to the anterior interventricular branch. In group B patients received graft of left internal mammary artery to the same branch. At the end of the operation the flow was assessed by measuring transit time.

Results

In group A, mean age was 60.6±9.49 years. The average height and weight of the group was 80.4±10.32 kg and 169.2±6.86 cm. The average number of grafts per patient in this group was 3.28±1.49. The mean flow and distal resistance obtained in right internal thoracic artery was 42.1±23.4 ml/min and 2.8±0.9 respectively. In group B, the mean age was 59.8±9.7 years. The average height and weight of this group was 77.7±14.22 kg and 166.0±8.2 cm. The average number of grafts per patient in this group was 3.08 ±0.82. The mean flow and distal resistance observed in this group was 34.2±19.1 ml/min and 2.0±0.7. There were no deaths in this series.

Conclusion

Right internal mammary artery presented a similar behavior to left internal mammary artery when anastomosed to the anterior interventricular branch of the left coronary artery. There was no statistical difference between the measured flow obtained between both arteries.     

Long-term follow-up of total arterial myocardial revascularization using exclusively pedicle bilateral internal thoracic artery and right gastroepiploic artery

Objective: In order to reduce remote cardiac events associated with graft occlusions, arterial conduits are being increasingly utilized in coronary artery bypass grafting (CABG). While the internal thoracic artery (ITA) is the graft of choice for CABG, it is sometimes difficult or impossible to obtain a complete arterial revascularization only with ITAs in three-vessel diseases. We present our experience with total arterial myocardial revascularization with bilateral internal thoracic artery (BITA) and right gastroepiploic artery (rGEA). Methods: From April 1994 to January 2004, 174 patients (165 male, mean age 55.9±7.4) underwent coronary artery bypass procedure with exclusive use of BITA and rGEA. Left ventricular ejection fraction ranged from 20 to 68% (mean 55.9±6.8%). Seven patients (4%) had poor ejection fraction (<0.30), 23 (13, 2%) had acute myocardial infarction, 14 (8%) had left main disease. The mean CPB time was 96.9±15.7 min and the mean cross clamping time was 70±14.2 min. The mean number of distal anastomoses was 3.3±0.5 per patient. Results: Early mortality was 1.7%. The patients were followed for up to 9 years (mean follow-up time 6.3±2.6 years). Actuarial freedom from cardiac death (including hospital death) was 97.6%, at 9 years after the operation. Actuarial freedom from angina and cardiac events at 9 years was 79, 5% and 77, 6%, respectively. No perioperative myocardial infarction occurred. None of the patients needed a redo-CABG after leaving the hospital. Conclusions: This study indicates that the myocardial revascularization in young patients with three-vessel disease using exclusively pedicle BITA and rGEA provides excellent 9-year patient survival and improvement in terms of freedom from return of angina pectoris and freedom from any cardiac-related event. These results encourage the more extensive use of BITA and rGEA in selected patients with three-vessel coronary disease.     

Comparative analysis of the patency of the internal thoracic artery in the CABG of left anterior descending artery: 6-month postoperative coronary CT angiography evaluation

Objective

To assess the patency of the pedicled right internal thoracic artery with an anteroaortic course and compare it to the patency of the left internal thoracic artery , in anastomosis to the left anterior descending artery in coronary artery bypass grafting by using coronary CT angiography at 6 months postoperatively.

Methods

Between December 2008 and December 2011, 100 patients were selected to undergo a prospective coronary artery bypass grafting procedure without cardiopulmonary bypass. The patients were randomly divided by a computer-generated list into Group-1 (G-1) and Group-2 (G-2), comprising 50 patients each, the technique used was known at the beginning of the surgery. In G-1, coronary artery bypass grafting was performed using the left internal thoracic artery for the left anterior descending and the free right internal thoracic artery for the circumflex, and in G-2, coronary artery bypass grafting was performed using the right internal thoracic artery pedicled to the left anterior descending and the left internal thoracic artery pedicled to the circumflex territory.

Results

The groups were similar with regard to the preoperative clinical data. A male predominance of 75.6% and 88% was observed in G-1 and G-2, respectively. Five patients migrated from G-1 to G-2 because of atheromatous disease in the ascending aorta. The average number of distal anastomoses was 3.48 (SD=0.72) in G-1 and 3.20 (SD=0.76) in G-2. Coronary CT angiography in 96 re-evaluated patients showed that all ITAs, right or left, used in situ for the left anterior descending were patent. There were no deaths in either group.

Conclusion

Coronary artery bypass grafting surgery involving anastomosis of the anteroaortic right internal thoracic artery to the left anterior descending artery has an outcome similar to that obtained using the left internal thoracic artery for the same coronary site.     

Greater vasopressin-induced vasoconstriction and inferior effects of nitrovasodilators and milrinone in the radial artery than in the internal thoracic artery

BACKGROUND: Vasopressin may be a potential cause of spasm in both the radial artery and the internal thoracic artery. This study compared the vasopressin-induced contraction and the effects of milrinone, nitroglycerin, and nitroprusside in vasopressin-induced contraction between the human radial artery and the internal thoracic artery to find effective antispastic methods for arterial grafts. METHODS: Concentration-contraction (normalized as force gram produced by each millimeter of the circumference tissue of the artery) curves for vasopressin with or without pretreatment of vasodilators and concentration-relaxation curves for the vasodilators listed were established in the human radial artery (n = 107) and internal thoracic artery (n = 122) segments. RESULTS: Vasopressin induced a greater contraction in the radial artery than in the internal thoracic artery (1.9 +/- 0.2 g/mm vs 0.6 +/- 0.1 g/mm, P < .001) with a higher sensitivity (lower EC(50): -9.28 +/- 0.11 vs -8.91 +/- 0.05 log(10)M, P = .006). Milrinone was less potent than nitroglycerin and nitroprusside with higher EC(50) (P < .05) in both the internal thoracic artery and radial artery. Pretreatment with milrinone and nitroprusside significantly inhibited vasopressin contraction in the internal thoracic artery but had little effect in the radial artery. Pretreatment with nitroglycerin did not significantly inhibit the maximum vasopressin contraction in either the internal thoracic artery or radial artery. CONCLUSION: The radial artery is more prone to develop spasm related to vasopressin than is the internal thoracic artery, and the effect of vasodilators in vasopressin-induced contraction is different in the radial artery from that in the internal thoracic artery. A more significant prophylactic antispastic effect of milrinone and nitroprusside is demonstrated in the internal thoracic artery than in the radial artery. Therefore, more intensive antispastic treatment is necessary in the radial artery than in the internal thoracic artery during coronary artery bypass grafting.     

Multiple coronary aneurysms due to Kawasaki disease in young man--successful triple coronary bypass grafting by utilizing the right gastroepiploic artery, internal thoracic artery and saphenous vein

A 28-year-old man developed acute anteroseptal myocardial infarction. Emergency coronary angiography revealed multiple coronary aneurysms, associated with complete obstruction of left anterior descending artery (LAD) and 50 to 99% stenosis of the right and the circumflex coronary artery (CX). Coronary artery bypass graftings were performed seven weeks after successful emergency intracoronary thrombolysis. The saphenous vein graft was anastomosed to CX, the internal thoracic artery to LAD, the right gastroepiploic artery to RCA just above the bifurcation. Post-operative course was uneventful. On sixth post operative week cardiac catheterization was performed. The study showed all three bypass grafts and native coronary artery to be patent. The patient is now followed up under anticoagulant therapy.     

Right internal thoracic artery through the transverse sinus in myocardial revascularization

Background. A major concern in evaluating dynamic cardiomyoplasty has been whether the synchronous stimulation of latissimus dorsi muscle is essential for benefit or not. We studied 10 patients to determine the efficacy of the systolic augmentation generated by the synchronous electrical stimulation of the latissimus dorsi muscle.

Methods. Left ventricular ejection fraction, end-systolic and end-diastolic volume indexes, and stroke volume index obtained during resting, peak exercise, and recovery periods (“on” values) were compared with those obtained 1 week after cessation of electrical stimulus (“off” values). Double product and estimated total body oxygen consumption at peak exercise were also calculated and compared.

Results. Higher ejection fractions (0.36 ± 0.07 versus 0.33 ± 0.06 at rest, 0.40 ± 0.07 versus 0.33 ± 0.07 peak exercise, and 0.37 ± 0.06 versus 0.31 ± 0.06 at recovery) and lower end-systolic volume indexes with relatively constant end-diastolic volume indexes were observed with the cardiomyostimulator on. Further, exercise response was better with the cardiomyostimulator on. Double product indirectly reflected better myocardial oxygen supply/demand ratio when on at peak exercise (17 ± 2.2 mm Hg × beats/min × 10⁻³ for on versus 19 ± 2.6 mm Hg × beats/min × 10⁻³ for off). Estimated total body oxygen consumption was improved at peak exercise when the cardiomyostimulator was functional (12 ± 2.7 mL · kg⁻¹ · min⁻¹ versus 11 ± 2.6 mL · kg⁻¹ · min⁻¹).

Conclusions. Current data suggest a true systolic assist during synchronous contractions of the latissimus dorsi muscle. It is thought, therefore, that synchronous electrical stimulation is essential for maximum benefit and all the beneficial effect of cardiomyoplasty certainly cannot be attributed to simple wrapping itself.     

The human internal thoracic artery releases more nitric oxide in response to vascular endothelial growth factor than the human saphenous vein

OBJECTIVE: Endothelial nitric oxide inhibits smooth muscle cell proliferation, reducing the chance of vascular intimal thickening. In this study we investigated whether the superior long-term patency of the internal thoracic artery in human coronary bypass grafting compared with that of the saphenous vein could be explained by different levels of nitric oxide production. METHODS: The baseline endogenous nitric oxide production appeared to be 50% higher in the internal thoracic artery than in the saphenous vein. Previously, it was shown that vascular endothelial growth factor and the vascular endothelial growth factor receptors KDR (Flk-1) and Flt-1 are expressed in both internal thoracic arteries and saphenous veins and that vascular endothelial growth factor receptor density was higher in internal thoracic arteries than in saphenous veins. Therefore, we also investigated the influence of vascular endothelial growth factor on nitric oxide release in both the internal thoracic artery and the saphenous vein. RESULTS: Vascular endothelial growth factor augmented nitric oxide production by approximately 50% in the saphenous vein and 100% in the internal thoracic artery. As shown by means of immunohistochemistry, expression of endothelial constitutive nitric oxide synthase was similar in the internal thoracic artery and the saphenous vein, and no inducible nitric oxide synthase was expressed in any of the vascular segments. CONCLUSION: Vascular endothelial growth factor augments endothelial constitutive nitric oxide synthase-dependent nitric oxide release to a greater extent in the internal thoracic artery than in the saphenous vein. These findings may help to explain the long-term superiority of the internal thoracic artery versus the saphenous vein as a conduit for coronary artery bypass.     

后路椎弓根系统内固定加前路植骨融合治疗胸腰椎结核

目的 :探讨应用后路椎弓根系统内固定加前路植骨融合术治疗胸腰椎结核的临床效果。方法 :回顾总结1 995年 3月至 2 0 0 0年 3月行后路椎弓根系统内固定同期前路植骨融合的胸腰椎结核患者 35例 ,包括植骨融合率、截瘫恢复情况和后凸畸形矫正状况。随访时间 1 5～ 5年 ,平均 3 4年。结果 :术后 1～ 1 5年所有患者均显示骨性融合 ;2 8例合并截瘫患者中 ,症状改善 2 6例 ,改善率 92 9% ;术后后凸畸形平均矫正 2 9 7° ,1 5～ 5年后随访 ,后凸角度平均丢失 2 9°。结论 :后路椎弓根系统内固定加前路植骨融合能加强脊柱的稳定性 ,促进骨融合和截瘫恢复 ,矫正后凸畸形     

Direct ostioplasty of the left main coronary artery using the right internal thoracic artery as patch material

Three female patients underwent operations for nonatherosclerotic isolated left main coronary artery stenosis. Transaortic patch angioplasty was performed via an anterior approach using the most proximal segment of the right internal thoracic artery as patch material. Six months after surgery coronary angiography revealed good results in all three cases. The internal thoracic artery can be used to enlarge the left coronary ostium safely, if heavy calcification is not present.     

Lateral origin of the right internal thoracic artery: Report of a case

We report herein the unusual case of a patient in whom postoperative angiography following coronary artery bypass grafting (CABG) revealed a lateral origin of the right internal thoracic artery (ITA) and a normal origin of the left ITA, both of which were demonstrated to be patent and did not follow a tortuous course. The CABG had involved revascularization of the left antrior descending artery (LAD) with the right ITA, and the obtuse marginal artery with the left ITA. The patient had an uneventful postoperative course and developed no respiratory symptoms.