Evaluation of Previously Cannulated Radial Arteries as Patent Coronary Artery Bypass Conduits

In coronary artery bypass grafting, good-quality conduits are needed to maximize the potential for long-term patency. Revascularization has traditionally been achieved with use of the saphenous vein and the internal thoracic arteries. In recent years, total arterial revascularization with use of the radial arteries has been promoted. Meanwhile, use of the transradial approach for coronary angiography has also increased. The long-term effects of previous cannulation in radial artery bypass grafts are not known. Therefore, we used multidetector computed tomographic angiography to investigate radial-artery graft patency in a small series of patients who had undergone transradial angiography. We found a high patency rate, and we discuss those findings here.

Subxiphoid versus intercostal chest tubes: comparison of postoperative pain and pulmonary morbidities after coronary artery bypass grafting

Chest tubes are one cause of pain after cardiac surgery. In a prospective, randomized study, we investigated the effects of the position of chest tubes on acute postoperative pain and pulmonary morbidities in patients who underwent coronary artery bypass grafting. From June through December 2010, 40 patients who underwent elective coronary artery bypass grafting were enrolled in the study. We investigated 2 randomized groups of patients: Group 1 (n-20) had a left chest tube inserted through the midline inferior to the xiphoid process (subxiphoid approach), and Group 2 (n-20) had a left chest tube inserted through the 6th intercostal space along the anterior axillary line (intercostal approach). We compared the results with respect to postoperative pain, the need for analgesic agents, chest-tube drainage, pulmonary morbidities, and duration of hospitalization. The intensity of postoperative pain was similar between the groups. The cumulative doses of analgesic agents, incidence of pulmonary morbidities, and duration of hospitalization were also similar. Pleural effusion and atelectasis were each diagnosed in 3 patients in Group 1 (15%) and 1 patient in Group 2 (5%) (both P=0.68). Two of the patients in Group 1 required drainage of the pleural effusion. In our study, we found that the subxiphoid and intercostal approaches for chest-tube placement yielded similar clinical outcomes.

Coronary revascularization in adults with dextrocardia: surgical implications of the anatomic variants

Most reports of coronary artery bypass grafting in adult patients with dextrocardia have focused on the surgeon's position with respect to the operating table. Herein, we describe the cases of 2 patients with dextrocardia who underwent surgery at our own institution, then discuss preoperative evaluation, surgical approaches, and patient outcomes that have been reported in the medical literature. Whereas most patients, including ours, have presented with classic situs inversus totalis and dextrocardia, a few patients have had other associated anomalies or atypical morphologic conditions. Careful imaging, and perhaps cardiac catheterization, is required. Particular attention should be paid to cannulation technique and conduits that can best be used within the altered orientation of the heart. Morbidity rates in these revascularized patients seem comparable with those in coronary artery bypass patients whose coronary anatomy is normal. Anatomic variants in dextrocardia are important from the surgical viewpoint due to the increasing population of patients with repaired congenital heart disease who reach adulthood, and in whom other cardiac defects and abnormalities of cardiac position are common.

Circumflex coronary artery bypass via the posterior interatrial sulcus and under the venae cavae

During coronary artery bypass grafting, the length of the graft to the circumflex coronary artery or its end branches can be underestimated because of the posterior location of the circumflex. Herein, we describe a new bypass route--which we consider the shortest--to the ascending aorta. In 2 patients, during proximal anastomosis of the saphenous vein bypass graft (via a route either anterior to the pulmonary artery or the transverse sinus) from the circumflex to the ascending aorta, the vein graft (approximately 5-6 cm in length) proved too short. We performed bypass in a new direction--from the circumflex coronary artery to the right side of the ascending aorta, under the inferior and superior venae cavae and along the interatrial groove--without the need for graft lengthening. To our knowledge, the bypass route to the circumflex system described herein is new. This new route can be successfully used when the bypass conduit is too short to follow the conventional route. Our 2 patients benefited from this approach and were in Canadian Cardiovascular Society Class l two years after the surgical procedure.

Coronary artery bypass grafting after pneumonectomy

When open-heart operations are necessary in patients who have undergone pneumonectomy, the unavoidable shift of mediastinal structures should be carefully considered. Surgical access, revascularization procedures, and the institution of cardiopulmonary bypass can all require approaches that differ from the usual. In particular, no general recommendations exist regarding the management of patients who undergo coronary artery bypass grafting after pneumonectomy. We successfully performed coronary artery bypass grafting in a 57-year-old man who had undergone a left pneumonectomy 7 years previously. Because the patient's heart was completely displaced into the left posterior hemithorax, access via a left posterolateral thoracotomy was chosen. Saphenous vein grafts were chosen over the internal mammary artery. The distal anastomoses were performed with use of the off-pump technique; for the proximal anastomosis, 2 venous grafts were implanted into the descending aorta. The patient's postoperative course was uneventful, and postoperative angiography revealed patent grafts. Herein, we discuss the case of this patient, and we present some considerations that can influence surgical approaches in similar circumstances.

Systemic and myocardial inflammation in traditional and off-pump cardiac surgery

In this study, we attempted to determine the role of off-pump coronary artery bypass grafting (CABG) in the myocardial and systemic inflammatory responses. Twenty patients who underwent elective CABG were enrolled in this study. Ten patients underwent on-pump CABG, and 10 patients underwent off-pump CABG. There were no differences between patients in preoperative clinical variables. We took systemic venous blood samples for the measurement of tumor necrosis factor-alpha, the MB isoenzyme of creatine kinase (CK-MB), and cardiac troponin I, and we took myocardial biopsies from the interventricular septum for chemiluminescence assay of reactive oxygen species (hydroxyl, hydrogen peroxide, hypochlorite, and superoxide). There was no significant difference in the myocardial tissue release of hydrogen peroxide, hydroxyl, hypochlorite, and superoxide between the 2 groups (P > 0.05). The systemic tumor necrosis factor-alpha levels in the off-pump group were significantly lower than in the on-pump group (P <0.01). The cardiac troponin I and creatine kinase-MB levels at 6, 12, and 24 postoperative hours were not statistically different between the 2 groups (P >0.05). We conclude that off-pump CABG appears to reduce systemic inflammation, without reducing myocardial oxidative stress and inflammation.

Right coronary revascularization by coronary-coronary bypass with a segment of internal thoracic artery

In certain coronary artery bypass grafting operations, the internal thoracic artery is not by itself adequate for complete arterial revascularization. Which graft should be used for revascularization of the right coronary artery is still a matter of debate. From August 2000 through July 2005, we performed coronary-coronary bypass grafting on 48 patients (77.1% men, 22.9% women), whose mean age was 57.2 years (range, 40-75 yr). After completion of the internal thoracic artery anastomoses, we performed coronary-coronary bypass grafting with a remaining (distal) segment of the left (or, rarely, the full length of the free right) internal thoracic artery. The proximal and distal anastomoses of the internal thoracic artery to the right coronary artery were end-to-side. We preferred to use the right coronary ostium as the proximal anastomosis site where possible; otherwise, we used a disease-free segment of the right coronary artery. A total of 192 anastomoses were performed (mean, 4.15 per patient); all used the bilateral internal thoracic arteries as conduits. There were no in-hospital deaths or perioperative myocardial infarctions. The duration of follow-up ranged from 1 to 46 months (mean, 9.6 mo). Follow-up angiography was performed in 24 patients (50%). The mean time to coronary angiography was 16.5 months (range, 7 days-2 years). The patency rate was 100%. We conclude that coronary-coronary anastomosis by means of a distal segment of the internal thoracic artery can help to achieve complete arterial revascularization in selected patients.

Myocardial injury in coronary artery bypass grafting: On-pump versus off-pump comparison by measuring heart-type fatty-acid-binding protein release

This prospective study uses heart-type fatty-acid-binding protein (hFABP) and creatine kinase-MB (CK-MB) release to compare myocardial injury in on-pump versus off-pump coronary artery bypass grafting (CABG). Fifty patients were randomly assigned to on-pump or off-pump CABG. The hFABP and CK-MB concentrations were measured in serial venous blood samples drawn before heparinization in both groups and after aortic unclamping at 1, 2, 4, 8, 24, 48, and 72 hours in the on-pump group. In the off-pump group, samples were taken after the last distal anastomosis at the same time intervals as in the on-pump group. The total amount of hFABP and CK-MB released was significantly higher in the on-pump than in the off-pump group (hFABP = 100.43 +/- 77.63 vs 3.94 +/- 0.36 ng/mL, P < 0.0001; CK-MB = 33.33 +/- 3.81 vs 28.65 +/- 3.91 log units, P < 0.001). In all patients, hFABP levels peaked as early as 1 hour after declamping (on-pump group) or 2 hours after the last distal anastomosis (off-pump group), whereas CK-MB peaked only at 4 hours after declamping (on-pump group) or 24 hours after the last distal anastomosis (off-pump group). The lower release of hFABP and CK-MB in the off-pump CABG group indicates that on-pump CABG with cardioplegic arrest causes more myocardial damage than does off-pump CABG. Heart-type fatty-acid-binding protein is a more rapid marker of perioperative myocardial damage, peaks earlier than CK-MB, and may predict the requirement for intensive monitoring for postoperative myocardial infarction.

Pedicled right internal mammary artery for reoperative off-pump revascularization of left anterior descending coronary artery

In situ right internal mammary artery is the graft of choice in reoperative off-pump coronary artery bypass grafting, as well as in primary on-pump coronary artery bypass grafting, unless the vessel has been used previously. However, there are not enough data about postoperative angiographic findings of the in situ right internal mammary artery in reoperative coronary artery bypass grafting with the off-pump technique. From September 1993 through January 2004, we reviewed the postoperative course and the graft patency of 12 selected patients who underwent off-pump coronary artery bypass grafting reoperation only for revascularization of the left anterior descending artery, by means of a pedicled right internal mammary artery graft. All patients were evaluated clinically and by postoperative coronary angiography. There were no early or late deaths during the mean follow-up period of 33.08 +/- 30.05 months (range, 1-77 months). The mean interval from the 1st operation to the 2nd operation was 74.1 +/- 57.01 months (range, 4.5-171 months). Postoperative coronary angiograms of all patients showed a 100% patency rate for both in situ grafts and composite grafts. We suggest that use of the in situ right internal mammary artery in off-pump coronary artery bypass grafting is a safe and reliable option for revascularizing the left anterior descending artery, especially in reoperation.

Flow analysis of left internal thoracic artery in myocardial revascularization surgery using y graft

In order to evaluate the left internal thoracic artery flow pattern, when the vessel is used as a graft to supply the left coronary artery system, we evaluated flow by Doppler measurement, both at rest and under dobutamine stress. There were 2 groups of 20 patients each: group A patients received only a left internal thoracic artery graft to the left anterior descending artery, and group B patients received a pedicled left internal thoracic artery graft associated with a vein graft, which together supplied the left anterior descending artery and another branch of the left coronary artery. Angiography showed patent grafts in all patients from both groups. The following characteristics were evaluated: systolic flow, diastolic flow, total flow, total flow under stress/total flow at rest ratio, systolic peak velocity, diastolic peak velocity, and systolic peak velocity/diastolic peak velocity ratio. In group A, the total flow was 45.5 +/- 21.6 mL/min at rest and 68.3 +/- 32.9 mL/min under stress. In group B, the total flow was 98.2 +/- 50.4 mL/min at rest and 175.7 +/- 79.2 mL/min under stress. Comparison between groups showed a total flow increase in group B of 115.8% (P=0.0002) at rest and 157.2% (P <0.0001) under stress. The other characteristics were also statistically significant, except systolic flow, total flow under stress/total flow at rest ratio, and systolic peak velocity. Our results showed that the left internal thoracic artery sufficiently supplies regional myocardium at rest and during exercise (stress), demonstrating its great adaptability in response to demand.

Sharp dissection versus electrocautery for radial artery harvesting

Radial arteries have been increasingly used during the last decade as conduits for coronary artery revascularization. Although various harvesting techniques have been described, there has been little comparative study of arterial damage and patency. A radial artery graft was used in 44 consecutive patients, who were randomly divided into 2 groups. In the 1st group, the radial artery was harvested by sharp dissection and in the 2nd, by electrocautery. These groups were compared with regard to radial artery free flow, harvest time, number of clips used, complications, and endothelial damage. Radial artery free flow before and after intraluminal administration of papaverine was significantly greater in the electrocautery group (84.3 +/- 50.7 mL/min and 109.7 +/- 68.5 mL/min) than in the sharp-dissection group (52.9 +/- 18.3 mL/min and 69.6 +/- 28.2 mL/ min) (P=0.003). Harvesting time by electrocautery was significantly shorter (25.4 +/- 4.3 min vs 34.4 +/- 5.9 min) (P=0.0001). Electrocautery consumed an average of 9.76 clips, versus 22.45 clips consumed by sharp dissection. The 2 groups were not different regarding postoperative complications, except for 3 cases of temporary paresthesia of the thumb in the electrocautery group; histopathologic examination found no endothelial damage. We conclude that radial artery harvesting by electrocautery is faster and more economical than harvesting by sharp dissection and is associated with better intraoperative flow and good preservation of endothelial integrity.

Tandem pedicled internal thoracic artery conduit for sequential grafting of multiple left anterior descending coronary artery lesions

A patient presented with severe triple-vessel coronary artery disease, including multiple lesions on the left anterior descending coronary artery (LAD), which supplied a well-contracting myocardium. In approaching our patient, we judged that a pedicled left internal thoracic artery (LITA) would not provide enough length for sequential grafting of the multisegment-diseased LAD. We also considered that a pedicled right internal thoracic artery (RITA) conduit would not be long enough to provide a free segment that would form a tandem graft with a LITA and then arrive at the marginal branch, unless it was detached at its origin. Consequently, we decided to form a composite graft that would connect a free, short segment (6-7 cm) of pedicled LITA to the in situ pedicled RITA, in an end-to-end fashion. This new composite conduit enabled us to perform sequential grafting (3 sequential anastomoses, 2 with the LITA segment) of the multisegment-diseased LAD, following the route anterior to the aorta. The in situ remnant of the LITA was grafted to the marginal branch. Although many large series have reported resourceful solutions, to the best of our knowledge, tandem arterial sequential grafting (an in situ pedicled RITA plus a free, short segment of a pedicled LITA) has not heretofore been reported in application to the multisegmented-diseased LAD artery. We strongly believe that this technique is an attractive variation on bilateral pedicled ITA left-sided revascularization in cases of multivessel coronary artery disease, including LADs with multiple lesions.

Total arterial coronary bypass: long-term results

Three groups of consecutive patients who had undergone primary elective coronary artery bypass operations were compared at 10 to 20 years of follow-up (mean, 13.6 years), in order to test the supposition that arterial conduits provide better long-term outcome than do the "standard" left internal mammary-to-left anterior descending coronary artery plus saphenous vein bypasses. The arterial group was split into groups A (all arterial) and B (2 or more arterial grafts, plus saphenous vein grafts). Control group C comprised the standard operations. The absence of saphenous vein conduit in group A was associated with fewer angiograms for symptoms, fewer reinterventions, and fewer cardiac deaths than those experienced in groups B and C. We conclude that the survival and cardiac quality-of-life advantage found in group A is attributable to the exclusive use of arterial conduits.

19-year patency of a coronary-coronary venous bypass graft

No data are available on the long-term outcome of coronary-coronary venous bypass grafting. We describe a case in which we successfully stented a discrete, critical stenosis of a coronary-coronary venous graft that had been placed 19 years earlier to minimize manipulation of a severely calcified ascending aorta. Coronary-coronary bypass grafting should be considered in cases involving severe aortic calcification, in situ grafts of inadequate length, and stenosed or occluded subclavian arteries. Such a bypass can be performed with either saphenous vein or arterial conduits, and it provides a flow rate similar to that of aortocoronary bypass. This option could be borne in mind as a 2nd-choice technique for the durable restoration of coronary blood flow in selected cases.

Evaluation of flow characteristics of the left internal thoracic artery graft: perioperative color Doppler ultrasonography versus intraoperative free-bleeding technique

From October 2000 through April 2001, we prospectively evaluated the flow characteristics of the left internal thoracic artery (LITA) graft in a homogenous group of 44 men with isolated severe proximal left anterior descending coronary artery stenosis who underwent elective coronary artery bypass grafting with cardiopulmonary bypass. We performed transthoracic color Doppler ultrasonography preoperatively and repeated this examination in each patient between the 5th and 7th postoperative days, obtaining cross-sectional area, total flow volume, diastolic velocity, systolic velocity, mean velocity, pulsatility index, and resistance index. These results were compared with those of the intraoperative free-bleeding technique. Good-quality Doppler images of the LITA were easily obtained with a combined supraclavicular-parasternal approach. After surgery, systolic flow velocity, pulsatility index, and resistance index decreased significantly, but diastolic flow velocity and mean flow velocity increased significantly. The intraoperative flow volume obtained by the free-bleeding technique (32.42 +/- 12.33 mL/min) was significantly less than both pre- and postoperative ultrasonographic values (42.22 +/- 10.77 mL/min and 45.36 +/- 19.52 mL/min, respectively). No significant difference was found when changes in LITA values were compared between patients with (n=19) and without (n=25) normal anterior wall motion. We conclude that color Doppler ultrasonography is a reliable noninvasive technique for preoperative evaluation of the LITA as a graft and for postoperative long-term follow-up of graft function. However the intraoperative free-bleeding technique is not reliable for flow-volume measurement due to anesthesia-related hemodynamic changes and vasospasm. Color Doppler can prevent useless LITA harvesting and decrease the need for postoperative LITA angiography.

Arterial myocardial revascularization using bilateral radial artery 17 years after right pneumonectomy

We report the case of a 51-year-old man who underwent arterial myocardial revascularization with the use of bilateral radial arteries, 17 years after undergoing a right pneumonectomy. We used a fast-track anesthesia protocol for the procedure. There was no perioperative complication, and postoperative recovery was uneventful. The patient was discharged from the hospital 5 days after the operation.

Use of a handheld epicardial ultrasonic Doppler flow detector to locate an intramyocardial coronary artery encased in inflamed neoplastic pericardium

A 44-year-old man had severe stenosis of the left main coronary artery. The middle portion of the left anterior descending coronary artery was in an intramyocardial location. The pericardium, ascending aorta, epicardium, and coronary arteries were encased by a metastatic, poorly differentiated papillary adenocarcinoma. The left anterior descending artery was located with the aid of a handheld epicardial ultrasonic Doppler flow detector, and grafted with the left internal thoracic artery on a beating heart. Subsequently, the patient underwent 10 cycles of chemotherapy More than 22 months later, he was asymptomatic and in remission from neoplastic disease.

Pedicled or skeletonized? A review of the internal thoracic artery graft

The internal thoracic artery is the gold-standard conduit for coronary artery bypass surgery. Until recently, it was used almost exclusively as a pedicle, with construction of 1 distal anastomosis. Skeletonization of the internal thoracic artery has recently been advocated in order to increase the number of arterial anastomoses and decrease the occurrence of sternal wound infections. When skeletonized, the vessel loses its "milieu" which raises the question of whether this technique sacrifices the superior longevity of the conduit. The current status of research on the effects of skeletonization (depriving the internal thoracic artery of vasa vasorum, innervation, and lymphatic and venous drainage, together with creating an imbalance between vasoconstricting and vasodilating substances) appears to support the superiority of the pedicled graft. Long-term patency studies of the skeletonized ITA, with meticulous follow-up and confirmation by angiography, are not currently available. Theoretically, skeletonization of the ITA might adversely affect its long-term resistance to atherosclerosis. More data are needed before this technique can be universally recommended. If the skeletonized ITA has decreased long-term patency, bypass surgery may be at a disadvantage when compared with the new generation of drug-eluting stents.

Coronary-coronary bypass using vein graft on a beating heart in a patient with porcelain aorta

There is increased risk of systemic embolism during cardiopulmonary bypass in patients with a severely atherosclerotic ascending aorta. We report a coronary-coronary bypass in a 74-year-old man with a porcelain aorta. He underwent a proximal right coronary-distal right coronary artery bypass with a saphenous vein graft, combined with a pedicled arterial graft (left internal mammary artery) to the left anterior descending artery, in the presence of a beating heart without cardiopulmonary bypass. The patient survived without evidence of perioperative myocardial infarction or cerebrovascular accident. One year later, follow-up angiography showed graft patency with good distal run-off. Coronary-coronary bypass on a beating heart without cardiopulmonary bypass can be performed safely in a patient with porcelain aorta.