Effect on myocardial perfusion of simultaneous delivery of cardioplegic solution through a single coronary artery and the coronary sinus.

OBJECTIVE: This study was to determine whether simultaneous antegrade-retrograde cardioplegia through a single coronary artery and the coronary sinus provides sufficient and homogeneous perfusion to the heart. METHODS: Simultaneous antegrade-retrograde cardioplegia was conducted in 7 isolated pig hearts through the coronary sinus in conjunction with the left anterior descending artery, the left circumflex artery, and the right coronary artery, respectively. The efficacy of simultaneous antegrade-retrograde cardioplegia for myocardial perfusion was assessed by monitoring the distribution of magnetic resonance contrast agent and measuring the effluent from the venting coronary arteries. RESULTS: Injection of contrast agent into a perfusing artery during simultaneous antegrade-retrograde cardioplegia resulted in increased image signal intensity not only in the territory of the perfusing artery but also in the areas normally served by the other 2 venting arteries (including the right ventricular wall). The myocardium in the territories of the 2 venting arteries was lightened with contrast agent given into the coronary sinus during simultaneous antegrade-retrograde cardioplegia. Myocardium in the perfusing artery territory and right ventricular wall remained dark. Moreover, a significant amount of effluent was collected from the venting arteries during simultaneous antegrade-retrograde cardioplegia: 4.7 to 7.8 mL/min from the right coronary artery; 10.5 to 17.7 mL/min from the left anterior descending artery; and 9.7 to 15.2 mL/min from the left circumflex coronary artery. CONCLUSIONS: Simultaneous antegrade-retrograde cardioplegia through a single coronary artery and the coronary sinus provides homogeneous perfusion to the entire heart. During simultaneous antegrade-retrograde cardioplegia, arterial flow supports its own designated myocardium, as well as adjacent myocardium normally served by the venting arteries; the arterial route also supports the right ventricular free wall when the right coronary artery is vented. Venous perfusion of simultaneous antegrade-retrograde cardioplegia mainly supports myocardium in the territories of the venting arteries and does not perfuse the right ventricular free wall. Blood flow delivered to myocardium normally supported by the venting arteries is believed to be sufficient to prevent ischemic injury.     

Internal mammary artery bypass graft for impaired coronary perfusion after neonatal arterial switch operation.

Myocardial ischaemia caused by perfusion impairment of translocated coronary arteries is the major cause of perioperative mortality after neonatal arterial switch operation for transposition of the great arteries. We report the successful use of the right internal mammary artery as a bypass graft to a dominant right coronary artery to treat insufficient perfusion of this artery in a newborn. Eight months later, coronary angiography showed a full blood supply of the right coronary artery across the internal mammary anastomosis. After a follow-up period of more than 30 months, somatic development, electrocardiogram and echocardiographically determined contractility of both ventricles are practically normal indicating regular function of the bypass graft.     

Unilateral brachial artery antegrade selective cerebral perfusion following carotid endarterectomy for carotid, coronary, and aortic aneurysmal surgery

Abstract   In the presence of multiple concomitant occlusive and aneurysmal diseases, selection of the brain protection method is a primary concern. A case with a disease triad of stenotic lesions in internal carotid arteries, coronary artery atherosclerosis, and an ascending-arcus aorta aneurysm is presented. We simultaneously performed right carotid endarterectomy, coronary artery bypass grafting, and graft replacement of the ascending-arcus aorta. Brain protection was achieved with continuous right brachial artery antegrade selective cerebral perfusion under moderate hypothermia, following carotid endarterectomy. The operative technique is detailed and antegrade selective cerebral perfusion following the carotid endarterectomy for aneurysmal surgery is discussed.     

Surgical implications of anomalous aortic origin of the left coronary artery

We report a patient with exertional chest pain and anomalous aortic origin of the left coronary artery from the right coronary sinus. This patient also had circumflex coronary and right coronary artery stenoses. Following coronary bypass grafting of the circumflex and right coronary arteries in this patient, angina persisted and there was abnormal septal perfusion shown on the exercise thallium imaging despite patent grafts. The angina and perfusion defect were improved by bypass grafting of the unstenosed left anterior descending coronary artery in this patient. Thallium imaging may be useful in the preoperative assessment of patients with this anomaly.     

Total arch replacement through re-median sternotomy after coronary surgery

We report the case of 78-year-old-man who required graft replacement of an aortic arch aneurysm. He previously had undergone off-pump coronary artery bypass grafting with the right internal thoracic artery bypassed to the left anterior descending artery. For this difficult case, we successfully performed total arch replacement using selective antegrade cerebral perfusion through a re-median sternotomy without injuring the right internal thoracic artery, which was the only blood source for the left and right coronary arteries.     

Single left coronary artery with separate origins of proximal and distal right coronary arteries from left anterior descending and circumflex arteries – a previously undescribed coronary circulation

A single left coronary artery with right coronary artery arising from either left main stem (LMS) or left anterior descending artery (LAD) or circumflex artery (Cx) is an extremely rare coronary anomaly. This is the first report of separate origins of proximal and distal RCA from LAD and circumflex arteries respectively in a patient with a single left coronary artery. This 57 year old patient presented with unstable angina and severe stenotic disease of LAD and Cx arteries and underwent urgent successful quadruple coronary artery bypass grafting. The anomalies of right coronary artery in terms of their origin, number and distribution are reviewed.     

经单根冠状动脉与冠状静脉窦同时灌注心肌保护的实验研究

目的探讨经单根冠状动脉和冠状静脉窦（CS）顺行性／逆行性同时心肌灌注（SARC）的效果。方法将离体猪心分别经左前降支（LAD）、左回旋支（LCX）或右冠状动脉（RCA）中的1支和CS行SARC，再依次向动、静脉灌注通路内注入磁共振造影剂[钆喷替酸葡甲胺（Gd-DTPA）]。应用磁共振成像（MRI）检测心肌内造影剂的分布以及对非灌注冠状动脉回流液进行分析，评估心肌灌注效果。结果SARC期间经单根冠状动脉注入Gd-DTPA不但使其支配区域磁共振信号增强，而且其余2根非灌注冠状动脉的支配区域信号也增强（包括右心室游离壁）；而SARC期间经CS注入Gd-DTPA只引起非灌注冠状动脉支配区变亮，灌注冠状动脉的支配区和右心室游离壁的信号强度无改变。SARC期间非灌注冠状动脉收集的回流液速度分别为：LAD 10．5～17．7ml／min，LCX 9．7～15．2ml／min，RCA 4．7～7．8ml／min。结论经单根冠状动脉和CS同时灌注可以提供全面均匀的心肌灌注，足以防止非灌注冠状动脉支配区发生心肌缺血损伤。     

Lower sternal splitting approach for off-pump coronary artery bypass grafting

There are several ways to revascularize coronary arteries without cardiopulmonary bypass using a minimally invasive method. Currently, one of the most commonly used methods is minimally invasive direct coronary artery bypass (MIDCAB) through a left thoracotomy. Using this technique, however, only the left anterior descending and diagonal branch can be grafted. This article describes coronary revascularization of the left anterior descending artery or right coronary artery, or both, via a lower ministernotomy without a transverse cut, namely, the lower sternal splitting method. Through this approach, the left anterior descending, diagonal, and right coronary arteries can be revascularized using a single, minimally invasive approach without the risk of damaging the tissue around the intercostal space when the sternum is transversely divided.     

合并异常冠状动脉法洛四联症和右心室双出口一期根治术

目的 总结合并异常冠状动脉的法洛四联症和右心室双出口一期根治术的经验，探讨有关外科技术的改进。方法1995年6月至2002年6月完成该类一期根治术12例，其中2例采取了肺动脉移位、3例在游离的左前降支下加宽右室流出道、5例改变右室切口并在冠状动脉下缝合、2例经肺动脉和右房疏通流出道。结果无手术死亡。随访3个月～6年，无晚期死亡和并发症发生。结论合并异常冠状动脉的法洛四联症和右心室双出口的一期根治手术是可行的，且效果良好，但必须采用适当的外科技术以保护异常的冠状动脉。     

Internal mammary artery grafts: the shortest route to the coronary arteries

Inadequate length can limit the use of the internal mammary artery (IMA) for coronary revascularization. By following the shortest route from its origin to the recipient coronary artery, IMA use can be maximized. Seven cadavers were studied to determine that shortest route for the left and right IMAs. The shortest route for the left IMA to the left anterior descending coronary, diagonal, and circumflex coronary arteries was through the pericardium (p less than or equal to 0.01). For the right IMA, the significantly shortest routes were across the anterior heart for the left anterior descending and diagonal arteries, through the right pericardium for the right coronary artery or posterior descending artery, and through the pericardium and transverse sinus for the circumflex artery. Thus, any coronary artery can be reached with an in situ IMA, and the route through the pericardium is markedly shorter to ipsilateral coronary arteries.     

The use of the right gastro-epiploic artery in coronary artery bypass grafting

Thirty consecutive patients with angina pectoris undergoing coronary artery bypass grafting using the proximally attached right gastro-epiploic artery are described. Posterior coronary arteries were grafted using the right gastro-epiploic artery, and grafts to the left coronary artery were done using predominantly internal mammary artery grafts. The right gastro-epiploic artery graft is mobilized along the greater curvature of the stomach, and transected distally. With cardiopulmonary bypass and blood cardioplegic arrest for myocardial preservation during cross-clamping of the aorta, the distal end of the artery is anastomosed end-to-side to the posterior descending artery or a postero-lateral branch, or to both, using a sequential technique. Twenty-five of the patients complained of symptoms suggestive of angina early postoperatively but are currently symptom-free with normal exercise tolerance. Thirteen patients had postoperative exercise tests: eight were normal, two were inconclusive, and three were abnormal. Nine grafted coronary arteries were re-angiogrammed, and seven were judged to be patent. It is concluded that, as an alternative resource, the right gastro-epiploic artery can be used to bypass coronary obstructions expeditiously and with results comparable to those obtained with the saphenous vein or internal mammary artery.     

The role of coronary artery abnormalities in the prognosis of truncus arteriosus.

A high incidence of coronary ostial and arterial abnormalities was found in a study of 30 pathologic specimens of classic truncus arteriosus at Children's Hospital of Pittsburgh. The following were of special note: (1) left coronary ostium in a posterior and high position; (2) close relation of the left coronary ostium to the pulmonary artery segment in three-leaflet truncal valves; (3) stenosis of the coronary ostium caused by small size, slitlike shape, or the location of the ostium above or in a commissure; (4) the acute angle takeoff of the coronary artery; (5) the position of the left anterior descending artery as it courses posteriorly and close to the truncal wall, and then to the left of the interventricular septum; (6) the size and course of the conal and diagonal arteries from the right coronary artery across the right ventricular outflow area; (7) other coronary abnormalities, including a single coronary artery or ostium with branches crossing the right ventricle below the truncus, the circumflex arising from the right coronary artery and coursing behind the truncus, and the right coronary artery originating from the left anterior descending artery and vice versa. Eight heart specimens with conduit repair were reviewed, and all had injury to coronary arteries, possibly responsible for or contributing to the deaths of six of the eight patients. Coronary abnormalities, often several occurring in combination, may contribute to high operative mortality rate and may be a cause of late sudden death in truncus arteriosus. Surgical procedures should be planned with a view to protecting coronary arteries in the region of the right ventricular outflow tract below the truncus. Coronary artery obstruction (ostial or luminal) can occur and may need to be addressed as a separate issue during surgical procedures.     

Anatomy of the coronary arteries in transposition of the great arteries and methods for their transfer in anatomical correction

For the success of anatomical correction of transposition of the great arteries (TGA) it is essential to transfer the coronary ostia to the posterior vessel without undue tension, torsion, or kinking of the proximal coronary arteries or their early branches. This requires thorough understanding of the different modes of origin and early branching of the coronary arteries in TGA. Based on observations made during anatomical correction, a classification of the coronary arteries in TGA is suggested. In type A the right and left coronary ostia arise from the middle of the right and left posterior aortic sinuses and curve forwards to reach the right atrioventricular groove or anterior interventricular groove respectively. In type B both coronary arteries arise by a single ostium, while in type C the two coronary ostia are situated posteriorly, very close to each other, in a position similar to that in type B. The origin of the coronary arteries in type D is similar to that of type A. However, the right coronary artery gives origin to the circumflex coronary artery that curves round the posterior (pulmonary) vessel to reach the atrioventricular groove. In type E the right coronary artery arises in common with the left anterior descending artery from the left posterior sinus, while the circumflex artery arises separately from the right posterior sinus. Three techniques for the transfer of the different types of coronary arteries during anatomical correction are described.     

Off-pump awake coronary revascularization using bilateral internal thoracic arteries

Background

A new technique has been developed that permits complete arterial revascularization of the lateral and/or inferior wall of the heart using in situ bilateral internal thoracic artery grafts in awake patients. This technique, without cardiopulmonary bypass and mechanical ventilation, creates the least invasive revascularization method for the lateral and/or posterior wall of the heart yet described.

Methods

In 7 patients double or triple vessel coronary artery bypass grafting was performed without general anesthesia. A high thoracic epidural anesthesia was started one hour before surgery. Bilateral internal thoracic arteries were harvested and all anastomoses were performed with the off-pump technique by standard median sternotomy. Circumflex, or the right coronary artery, were anastomosed with bilateral internal thoracic arteries using a heart positioner. Six patients received double bypass grafting and one patient received triple bypass grafts (bilateral internal thoracic arteries and one radial artery).

Results

All patients remained awake throughout the whole procedure. There was no perioperative myocardial infarction or mortality. Pneumothorax was observed in three patients, but it was repaired in two. Only one patient completed the procedure with unilateral pneumothorax. There were no hemodynamic and pulmonary problems during lateral or posterior wall revascularization. Two patients required unexpected coronary endarterectomy during circumflex and right coronary artery anastomoses.

Conclusions

Complete arterial revascularization by median sternotomy using in situ bilateral internal thoracic artery grafts without general anesthesia is a feasible and safe procedure for multivessel disease. This approach gives a chance for awake revascularization of the right and/or circumflex coronary artery.     

Operative transluminal balloon angioplasty. Adjunct to coronary bypass for extended myocardial revascularization of more than 3000 lesions in 1000 patients

Operative transluminal coronary artery balloon angioplasty has been used for over 3000 lesions in 1000 patients since 1980. Initially it was only used for distal stenoses not accessible to coronary bypass grafting in 200 patients. Recatheterization of patients who had intraoperative transluminal balloon angioplasty of the proximal left anterior descending, right, and circumflex coronary arteries 3 years previously revealed excellent patency of both the bypass grafts and the dilated native coronary arteries. This observation supports the thesis that with properly constructed bypass anastomoses competitive flow does not significantly mandate graft thrombosis. Subsequently, intraoperative balloon angioplasty has been performed for both proximal and distal stenoses in 800 patients to improve native coronary artery perfusion and maximize revascularization. Follow-up from 1 to 7 years revealed perioperative myocardial infarction in 21 patients (2.1%) and death in 19 patients (1.9%). Recatheterization from 1 to 7 years after the operation in 51 patients (41 with symptoms) revealed that patency was almost as prevalent in arteries subjected to angioplasty (82%; 137/167) as in bypass grafts (84%; 102/122). Intraoperative balloon angioplasty appears to improve coronary artery perfusion without detrimental competitive flow when used with bypass grafts.     

Patient with pseudo-retrograde coronary flow in the normal right coronary artery and left circumflex artery: pitfall of retrograde coronary flow to detect coronary artery occlusion

A 75-year-old lady with hypertension and paroxysmal atrial fibrillation underwent echocardiography to evaluate cardiac function. Transthoracic Doppler echocardiography revealed retrograde coronary flow in the right coronary artery (RCA) and left circumflex artery (LCX). Computed tomographic coronary angiography demonstrated normal but tortuous coronary arteries. This tortuosity of the coronary arteries was thought be a cause of pseudo-retrograde coronary flow in the RCA and LCX. The present case demonstrates a pitfall of retrograde coronary flow for the detection of coronary artery occlusion in daily practice.     

Efficacy of coronary sinus cardioplegia in patients with complete coronary artery occlusions

Myocardial areas distal to complete coronary artery occlusions are poorly protected by antegrade cardioplegia. We assessed the effects of coronary sinus cardioplegia in 30 patients undergoing bypass operations and at high risk of cardioplegic maldistribution because of the following anatomical patterns of coronary artery disease: critical (greater than or equal to 50%) stenosis of the left main trunk with total occlusion of the right coronary artery (16 patients) or critical (greater than or equal to 70%) stenosis of the right coronary artery with total occlusion of the left anterior descending (11 patients) or circumflex artery (3 patients). After induction of arrest through the aorta, coronary sinus cardioplegia was given intermittently during the cross-clamp period at a flow rate of 100 mL/min. Intraoperatively, occluded arteries were consistently found to be filled with the retrogradely infused solution. One patient died early postoperatively of low cardiac output and a second patient died later during his hospital stay, presumably of an arrhythmia. At autopsy, none of them had pathological evidence of inadequate myocardial protection. One patient sustained a myocardial infarction and 3 others required inotropes for more than 24 hours postoperatively. Postoperative values for right and left stroke volume indices were not significantly different from prebypass levels. Overall, these results are consistent with the occurrence of limited intraoperative ischemic damage and, by inference, suggest the efficacy of the coronary sinus route in preserving myocardial areas supplied by completely occluded coronary arteries and, hence, in jeopardy of inadequate cardioplegia delivery.     

法洛四联症伴冠状动脉畸形的外科治疗

目的：总结法洛四联症伴冠状动脉畸形手术治疗经验,探讨冠状动脉畸形在法洛四联症纠治手术中的意义。方法：自1994年1月至1999年12月,手术治疗法洛四联症伴冠状动脉畸形15例,年龄43d-8岁,其中右冠状动脉起源于左冠状动脉或左前降支6例,单支左冠状动脉和左前降支起源于右冠状动脉各3例。双前降支,单支右冠状动脉和右冠状动脉肺动脉瘘各1例。一期根治手术13例,姑息手术2例。结果：姑息手术无死亡,根治手术早期死亡1例;无冠状动脉手术意外损伤;随访结果满意。结论：根据肺血管条件和畸形冠状动脉走行特点,选择适当的手术方式和右室流出道重建方法可提高手术效果;冠状动脉畸形不再是法洛四联症纠治手术中的风险因素。     

Standard coronary artery bypass grafting and beating heart bypass. Indications and long-term results.

OBJECTIVES AND METHOD: We have performed 225 cases of coronary artery bypass grafting (CABG), between October 15 1995 and September 8 1999. We have evaluated the operative results of 121 cases (53.8%) of conventional CABG and 104 cases (46.2%) of minimally invasive coronary artery bypass grafting performed during this period. The average numbers of bypassed grafts was 3.45 for conventional CABG, and 1.41 for minimally invasive coronary artery bypass grafting. Sixty-seven right internal thoracic arteries, 145 left internal thoracic arteries, 71 gastroepiploic arteries, 38 radial arteries and 12 saphenous veins were used for conventional CABG, and 29 right internal thoracic arteries, 81 left internal thoracic arteries, 18 gastroepiploic arteries, 3 radial arteries, 10 saphenous veins and 2 inferior epigastric arteries were used for minimally invasive coronary artery bypass grafting. The total number of 303 grafts were anastomosed to 417 coronary arteries for conventional CABG, and 143 grafts were anastomosed to 147 coronary arteries for minimally invasive coronary artery bypass grafting. RESULTS: Although two saphenous veins were occluded, the early postoperative patency rate was 100% for conventional CABG using right internal thoracic arteries, left internal thoracic arteries, gastroepiploic arteries and radial arteries. Three site of stenosis in 18 left internal thoracic arteries and 2 in 16 right internal thoracic arteries were recognized in minimally invasive coronary artery bypass grafting without the use of stabilizers. One site of stenosis in 63 left internal thoracic arteries was recognized in minimally invasive coronary artery bypass grafting with the use of stabilizers. CONCLUSION: The use of stabilizers enables adaptation of the minimally invasive coronary artery bypass grafting procedure to a wider range of coronary artery bypass procedures, and a higher graft patency can be expected.     

Isoflurane causes regional myocardial dysfunction in dogs with critical coronary artery stenoses

The effects of isoflurane-induced hypotension to mean aortic pressures of 70 and 55 mmHg on global and regional right and left ventricular performance (ultrasonic dimension technique) and on coronary hemodynamics (electromagnetic flow probes) were studied in 12 open-chest dogs (anesthetized and paralyzed by continuous infusions of fentanyl and pancuronium) with critical coronary artery stenoses (micrometer-controlled snares) of the right and left anterior descending coronary arteries. The stenoses reduced resting coronary blood flow by approximately 10% without affecting global or regional myocardial performance. During subsequent isoflurane administration, coronary blood flow fell markedly. In the areas supplied by the stenosed coronary arteries, segment length shortening decreased by 70% (P less than 0.01), and regional akinesis, paradoxical motion, or postsystolic shortening developed in 9 of 12 animals. In contrast, in the areas supplied by normal coronary arteries, myocardial segment length shortening decreased significantly less and did not show signs of dysfunction. In these non-ischemic areas at both concentrations of isoflurane, end diastolic and systolic dimensions were greater in the right than in the left ventricle, probably related to differences in right (unchanged) and left (reduced) ventricular afterloads. The data indicate that in the presence of coronary artery stenoses, isoflurane-induced hypotension may cause regional myocardial dysfunction suggestive of ischemia.