Patency Of Aortocoronary Bypass Grafts Research Articles

Remote patency of aortocoronary bypass grafts after endoscopic and conventional great saphenous vein harvesting

Aim. To compare patency of aortocoronary bypass grafts in remote period after endoscopic and conventional (open) great saphenous vein harvesting. To analyze the patency of aortocoronary bypass grafts after endoscopic vein harvesting from calf and thigh.Methods. The study involved 170 patients who underwent elective isolated coronary artery bypass grafting. Treatment results were evaluated in two prospectively formed groups: endoscopic (85 patients) and open (85 people) vein harvesting. Endoscopic vein harvesting was performed both from the calf and from the thigh through popliteal access using endoscopic system Vasoview 6.0. Patency of autovenous aortocoronary grafts was studied in 2.6±1.17 years after surgery using 64-slice contrast-enhanced MDCT or traditional angiography. Angiographic follow-up covered 76 patients with endoscopic vein harvesting and 79 patients with open vein harvesting.Results. The studied groups did not differ in the frequency of detection of occluded, stenotic and fully patent autovenous aortocoronary bypass grafts (p=0.841). In endoscopic vein harvesting group frequency of autovenous aortocoronary bypass grafts occlusion was 25.7%, in the group of open vein harvesting - 25.1% (p=0.984). There was no difference in the patency of internal thoracic artery grafts to the left anterior descending artery (p=0.227), and freedom from adverse cardiac events (p=0.342). Occlusion of autovenous grafts after endoscopic harvesting from the calf developed less frequently than after endoscopic harvesting from the thigh (15.1 vs. 34.6%; p=0.013). Grafts after endoscopic harvesting in the knee region occluded most often (41.9%). Patency of aortocoronary bypass grafts after open vein harvesting was not dependent on the area of the vein harvesting (p=0.900).Conclusion. Endoscopic vein harvesting does not compromise the patency of aortocoronary bypass graft and does not increase the risk of its occlusion; endoscopic harvesting of the veins from the calf improves indicators of aortocoronary grafts patency and reduces the risk of graft failure (odds ratio 0.3; 95% confidence interval 0.14-0.8; p = 0.013).

Endoscopic Radial Artery Harvest Produces Equivalent and Excellent Midterm Patency Compared with Open Harvest

A recent multicenter study reported reduced patency of aortocoronary bypass grafts when the saphenous vein was harvested by endoscopic technique compared with patency of vein grafted after harvest by the traditional "open" approach. Our aim was to compare the patency rates of radial artery graft (RAG) harvested endoscopically with those harvested using an open technique. Two cohorts were identified: from January 1995 to January 2000, 724 consecutive patients had one or both radial arteries harvested through an open technique, and from February 2000 to January 2008, 727 consecutive patients had endoscopic radial artery (RA) harvest. All patients who underwent symptom-indicated angiography in our institution at any time after coronary artery bypass grafting (CABG) surgery were identified. Two hundred two patients had angiograms for symptoms: 90 of these patients (119 RAG) had open RA harvest and were studied 78.3 ± 40 months (range, 1-156 months) after CABG. The other 112 patients (148 RAG) had endoscopic RA harvest and underwent angiography 36 ± 24 months (range, 1-96 months) after CABG. The two groups had identical demographics and risk profiles. Overall patency of the "open" RAG was 78.9% versus 83.7% for the endoscopic group (P = 0.3). Patency increased to 90% in both groups when the RAG was anastomosed to a native coronary vessel with stenosis >80%. Endoscopic and open RA harvesting techniques have equivalent and excellent midterm and long-term patency rates in CABG patients studied by angiography for recurrent symptoms of myocardial ischemia. The degree of stenosis of the target vessel strongly influences the patency rate independent of the harvesting technique.

Midterm patency of the radial artery used for myocardial revascularization evaluated by new-generation multi-slice spiral computed tomography

Aims: Recent reports have shown multi-slice spiral computed tomography (MSCT) to be useful in the evaluation of aortocoronary bypass graft patency with a sensitivity and specifity of almost 100%. Since longterm-results of ongoing studies are lacking, the value of the radial artery (RA) in coronary artery bypass grafting (CABG) is discussed controversely. This study evaluates the midterm-patency of the RA by new-generation scanners.

Multislice CT of the heart: clinical applications

Since the introduction of last generation multislice MSCT systems and the development of simultaneous electrocardiographic-tracing image acquisition and retrospective reconstruction techniques into clinical routine, cardiac MSCT has been considered a very useful non-invasive technique for the study of cardiac pathology in the daily clinical practice. One of the main clinical applications of this diagnostic technique is the evaluation of the coronary arteries including detection and quantification of coronary calcium, multislice CT coronary angiography (anatomy, anatomical variants and anomalies of the origin and course), the angiographic evaluation of the patency of aortocoronary by-pass grafts and coronary stents, and plaque characterization. The new reconstruction and postprocessing programs allow to obtain, in addition, parameters of myocardial morphology and contraction and cardiac function. Other clinical applications include the characterization of cardiac masses and the evaluation of the pericardium.

Investigation of aortocoronary artery bypass grafts by multislice spiral computed tomography with electrocardiographic-gated image reconstruction

X-ray coronary angiography, the reference standard for investigation of coronary artery bypass grafts, is an invasive and costly procedure that is not risk free. The development of rapid and reliable noninvasive imaging procedures would therefore be desirable. Evaluation of coronary bypass patients with computed tomography (CT) was first reported in 1980. 1 Brundage B.H. Lipton M.J. Herfkens R.J. Berninger W.H. Redington R.W. Chatterjee K. Carlsson E. Non-invasive assessment of coronary artery bypass grafts by computed tomography. A preliminary report. Circulation. 1980; 61: 826-831 Crossref PubMed Scopus (99) Google Scholar In the following years, a number of studies described the application of conventional CT and electron beam tomography for investigation of bypass grafts. 2 Kahl F.R. Wolfman N.T. Watts L.E. Evaluation of aortocoronary bypass graft status by computed tomography. Am J Cardiol. 1980; 48: 304-310 Abstract Full Text PDF Scopus (15) Google Scholar , 3 McCay C.R. Brundage B.H. Ullyot D.J. Turley K. Lipton M.J. Ebert P.A. Evaluation of early postoperative coronary artery bypass graft patency by contrast-enhanced computed tomography. J Am Coll Cardiol. 1980; 2: 312-317 Abstract Full Text PDF Scopus (34) Google Scholar , 4 Foster C.J. Sekiya T. Brownlee W.C. Isherwood I. Computed tomographic assessment of coronary artery bypass grafts. Br Heart J. 1980; 52: 24-29 Crossref Scopus (11) Google Scholar , 5 Daniel W.G. Döhring W. Stender H.S. Lichtlen P.R. Value and limitations of computed tomography in assessing aortocoronary bypass graft patency. Circulation. 1980; 67: 826-831 Google Scholar , 6 Tello R. Costello P. Ecker C. Hartnell G. Spiral CT evaluation of coronary artery bypass graft patency. J Comput Assist Tomogr. 1980; 17: 253-259 Crossref Scopus (59) Google Scholar , 7 Engelmann M.G. von Smekal A. Knez A. Kürzinger E. Huehns T.Y. Höfling B. Reiser M.F. Accuracy of spiral computed tomography for identifying arterial and venous coronary graft patency. Am J Cardiol. 1980; 80: 569-574 Abstract Full Text Full Text PDF Scopus (55) Google Scholar , 8 Stanford W. Brundage B.H. MacMillan R. Chomka E.V. Bateman T.M. Eldridge W.J. Lipton M.J. White C.W. Wilson R.F. Johnson M.R. Marcus M.L. Sensitivity and specificity of assessing coronary bypass graft patency with ultrafast computed tomography Results of a multicenter study. J Am Coll Cardiol. 1980; 12: 1-7 Abstract Full Text PDF Scopus (82) Google Scholar , 9 Knez A. von Smekal A. Haberl R. Spiegl F. Reichart B. Reiser M.F. Steinbeck G. Significance of ultrafast computed tomography in the assessment of coronary bypass graft patency. Z Kardiol. 1980; 85: 629-634 Google Scholar , 10 Achenbach S. Moshage W. Ropers D. Nossen J. Bachmann K. Noninvasive, three-dimensional visualization of coronary artery bypass grafts by electron beam tomography. Am J Cardiol. 1980; 79: 856-861 Abstract Full Text Full Text PDF Scopus (122) Google Scholar However, due to cardiac and respiration artifacts, conventional CT was restricted to assessment of bypass graft patency and the detection of stenoses in patent bypass grafts was not considered possible. Electron beam tomography is not widely available. Recently, contrast-enhanced multislice spiral CT (MSCT) with retrospective electrocardiographic gating has been shown to permit visualization of the coronary artery lumen. 11 Ohnesorge B. Flohr T. Becker C. Kopp A.F. Schoepf U.J. Baum U. Knez A. Klingenbeck-Regn K. Reisser M.F. Cardiac imaging by means of electrocardiographically gated multisection spiral CT Initial experience. Radiology. 1980; 217: 564-571 Crossref Scopus (454) Google Scholar , 12 Achenbach S. Ulzheimer S. Baum U. Kachelriess M. Ropers D. Giesler T. Bautz W. Daniel W.G. Kalender W.A. Moshage W. Noninvasive coronary angiography by retrospectively ECG-gated multislice spiral CT. Circulation. 1980; 102: 2823-2828 Crossref Scopus (438) Google Scholar We therefore performed a prospective comparison of MSCT to invasive coronary angiography in a group of 65 patients after coronary artery bypass surgery to evaluate the method’s accuracy to detect bypass graft occlusion and stenosis.

Pulsed Doppler intraoperative flow assessment and midterm coronary graft patency

Background. This study was designed to assess the value of hemodynamic measurements taken intraoperatively in predicting midterm patency of coronary bypass grafts. Methods. A pulsed Doppler flowmeter was routinely used during operation to determine the hemodynamic parameters of coronary bypass grafts. During a 7-year period, 85 patients underwent angiographic evaluation. As a result, a thorough hemodynamic assessment of 214 grafts (89 arterial and 125 venous) at initial operation was available for analysis. Results. The overall patency rate was 88.3%. The mean flow measured intraoperatively in 168 intact grafts was 60 ± 3 mL/min (range, 9 to 230 mL/min), and the resistance was 1.8 ± 0.1 peripheral resistance units (range, 0.3 to 9.0 peripheral resistance units). The mean flow was 36 ± 5 mL/min (range, 2 to 107 mL/min), and the resistance was 5.9 ± 2.0 peripheral resistance units (range, 0.6 to 46.0 peripheral resistance units) in 25 grafts found occluded at angiographic evaluation. Multivariate analysis identified three independent variables associated with a reduced patency rate: increased resistance as measured in the graft ( p = 0.012), increasing interval of control angiography ( p = 0.006), and preoperative cardiogenic shock ( p = 0.040). Conclusions. The prognosis for midterm patency of aortocoronary bypass grafts depends on the intraoperative hemodynamic status.

Assessment of aortocoronary bypass graft patency by intra-arterial digital subtraction angiography compared to selective graft angiography.

The value of digital subtraction angiography (DSA), in assessing aortocoronary bypass graft patency, was evaluated by studying 22 consecutive patients with 54 aortocoronary saphenous vein bypass grafts, who had postoperative angina pectoris. Each patient underwent selective graft angiography and non-gated DSA. The DSA consisted of a run of 15 to 20 frames, taken at 2.3 frames per second during injection of diluted contrast in the ascending aorta, performed after a test exposure was made. Thirty-two of the 54 grafts (59%) were patent. Thirty of the 32 grafts were seen to be patent by both selective graft angiography and DSA. In addition, a further two grafts were found to be patent on DSA, but were not able to be selectively catheterised and were not seen on the conventional aortogram. Selective graft angiography revealed four tight proximal graft stenoses, of which one only was seen on DSA; and poor distal run-off in five grafts, two of which showed up as late filling grafts on DSA. In summary, the accuracy of intra-arterial DSA in assessment of bypass graft patency was excellent. All grafts seen to be patent on selective graft angiography were also seen by DSA alone and in addition two grafts which could not be selectively catheterised were found to be patent. However, in patients with postoperative chest pain, selective graft angiography is probably required as non-gated intra-arterial DSA does not provide sufficient information to assess graft stenoses, distal flow and the native coronary vessels.

Drugs or Diet

Early observations that the regular use of aspirin (acetylsalicylic acid, ASA), a nonsteroidal anti-inflammatory agent, seemed to protect against myocardial infarction and reduce platelet aggregation made this substance the most frequently used drug in large clinical trials. The objectives of these studies were to reduce thromboembolic complications in arterial cardiovascular diseases (prevention of myocardial infarction in unstable angina, secondary prevention of acute myocardial infarction, and increased patency of aortocoronary bypass grafts) and to reduce platelet deposition on artificial surfaces (artificial heart valves and hemodialysis shunts). Despite the recent synthesis of more selective inhibitors of arachidonic acid metabolism in blood platelets, and a multitude of questions concerning optimal dose, schedule, and mode of action that still remain open, ASA continues to be the most frequently used drug in arterial vascular disorders. Because of the frequent and potentially serious side effects of aspirin, mainly on the gastrointestinal tract, less toxic ways of inhibiting eicosanoid metabolism in blood platelets are attracting more and more interest. Among these, the alimentary substitution of omega-3 fatty acids for a competitive inhibition of the omega-6-arachidonic acid metabolism seems the most promising. Results with fish-oil diet raise the question of whether substitution of polyunsaturated lipid acids influence only platelet metabolism, or whether the action of "anti-platelet" drugs or diet in cardiovascular disorders is mediated primarily by leukocytes or monocytes. This new dietary principle, which possibly corrects only a poor alimentary habit of civilization, could open simple and adequate ways for even a primary prophylaxis of vascular disease by diet alone or, at least for therapeutic aims, in combination with drugs.

Direct visualization of aorto-coronary bypass grafts by two-dimensional echocardiography: a new clinical application.

An attempt was made to assess noninvasively the patency of aorto-coronary bypass grafts by two-dimensional echocardiography (2-D echo) in 21 patients who underwent myocardial revascularization. Fifteen patients had one graft while the other six had two grafts. All 21 patients underwent angiography 6-18 months after operation. A day before angiography a 2-D echo was performed with the aim of visualizing the bypass grafts. In 18 patients with 23 grafts (13 with 1 graft and 5 with 2 grafts) it was possible to visualize the tract of the graft by 2-D echo; 16 were judged patent on 2-D echo and confirmed by selective angiography, while 5 grafts were considered occluded both on 2-D echo and angiography. The other 2 grafts were considered to be occluded on 2-D echo but angiographic control displayed their patency. In 3 patients 2-D echo failed to visualize grafts that were patent angiographically. These data must be considered preliminary and need validation in a larger number of patients. However it is reasonable to conclude that 2-D echo has a reliable capacity to predict graft patency. Such an application may be of value in sequential control of patients with aorto-coronary bypass surgery, especially when combined with other clinical and/or technical data.

Evaluation of aortocoronary bypass graft patency by transbrachial intraarterial digital subtraction angiography

Evaluation of aortocoronary bypass graft patency by transbrachial intraarterial digital subtraction angiography

Magnetic resonance imaging to evaluate patency of aortocoronary bypass grafts.

To assess the efficacy of magnetic resonance (MR) imaging in evaluating graft patency after coronary bypass surgery, 20 patients who had prior surgery (average 5.5 years, range 1.5 to 14) and recent cardiac catheterization because of chest pain were studied. No patient had surgical intervention or change in symptoms in the time interval between catheterization and MR imaging. These 20 patients had a total of 47 grafts, defined as proximal anastomoses: 20 to the left anterior descending or diagonal artery (LAD), 13 to the left circumflex artery marginal branches (LCX), and 14 to the right coronary artery or posterior descending artery (RCA). The patients underwent cardiac and respiratory gated MR scans in a 0.5 tesla magnet with an echo time of 22 msec and two repetitions in a 128 X 256 matrix. In-plane resolution was 2.7 mm. Every patient had a scan in the transaxial plane and some underwent scanning in the sagittal and coronal planes as well. A graft was considered patent by MR when a signal-free lumen was visualized in an anatomic position consistent with that of a bypass graft, had a lumen larger than the native vessels, was seen on more than one slice, and was seen at a level higher than that of the native vessels. If a known graft was not seen it was considered occluded. The scans were interpreted by consensus of two physicians aware of the operative but not the cardiac catheterization data.(ABSTRACT TRUNCATED AT 250 WORDS)

Cine computed tomographic evaluation of aortocoronary bypass graft patency

Evaluation of the patency of coronary bypass grafts has previously required hospitalization for invasive angiography. This report of three cases documents the unique capability of cardiac cine computed tomography to easily and accurately define coronary bypass graft patency. In each case, the findings altered therapeutic decisions. This early experience justifies wider application of this technique and suggests that it may eliminate the need for diagnostically motivated graft angiography. Large scale studies to establish the sensitivity and specificity of cardiac cine computed tomography for determining graft patency are indicated.

The Influence of Diabetes Mellitus on the Patency of Aortocoronary Bypass Grafts and the Postoperative Function of the Left Ventricle

The Influence of Diabetes Mellitus on the Patency of Aortocoronary Bypass Grafts and the Postoperative Function of the Left Ventricle

Noninvasive evaluation of aortocoronary bypass graft patency by contrast-enhanced computed tomography: incrementation mode and dynamic mode.

Fourty-three coronary bypass graft patients were examined with contrast-enhanced computed tomography (CT) to evaluate bypass graft patency. Six 4.8-second sequential scans with 1.4-second interscan intervals were obtained during the injection of a bolus of a contrast medium into a peripheral vein. The sequential dynamic mode and the rapid incrementation mode were used for scanning with contrast enhancement. CT diagnosis correlated with angiographic assessment of graft patency in 36 out of 36 grafts to the left anterior descending artery, in 4 out of 4 grafts to the diagonal branch, in 19 out of 20 grafts to the left circumflex artery, and 6 out of 7 grafts to the right coronary artery. Overall, CT correctly identified 62 out of the 64 patent graft (sensitivity 96.9%), and 3 out of the 3 occluded grafts (specificity 100%). The sensitivity of the incrementation mode alone to detect the bypass graft was 93.0% and that of the dynamic mode was 88.6%. The sensitivity of CT with both modes was 100%. Although CT does not have sufficient resolution to define graft stenosis, it is a noninvasive and clinically useful technique to evaluate bypass graft patency with high accuracy.

Evaluation of Aortocoronary Bypass Graft Patency by Contrast-enhanced Computed Tomography

Evaluation of Aortocoronary Bypass Graft Patency by Contrast-enhanced Computed Tomography

Influence of diabetes on aortocoronary bypass graft patency

Influence of diabetes on aortocoronary bypass graft patency

Evaluation of aortocoronary bypass graft status by computed tomography

The efficacy of contrast-enhanced computed tomography to define graft patency status was studied in 42 patients with 100 aortocoronary vein grafts. The status of each graft had been determined earlier by anglography. A rotary fan beam whole body scanner with a 2 second scan duration was used. Initial scans determined the optimal level for study of the graft; patency was assessed by computed tomographic enhancement of the graft after intravenous bolus injection of 30 ml meglumine and sodium diatriazoate. The computed tomographic studies were evaluated without knowledge of the anglographic findings; graft status by computed tomography was interpreted as patent, occluded or equivocal. Overall, computed tomography correctly defined graft patency status in 79 of the 100 grafts and incorrectly identified it in 9; in 12 grafts, the computed tomographic diagnosis was equivocal. Computed tomography correctly identified 61 of 74 patent grafts and 18 of 26 occluded grafts. Patency status was correctly defined by computed tomography in 35 of 37 grafts to the left anterior descending artery, 23 of 30 grafts to circumflex branches and 19 of 31 grafts to the right coronary artery. These data indicate that computed tomography is a promising noninvasive method of determining patency of aortocoronary bypass grafts, especially of grafts to the left anterior descending artery.

Evaluation of aortocoronary bypass graft patency status by computed tomography

Evaluation of aortocoronary bypass graft patency status by computed tomography

Coronary Artery Bypass Grafts: Increased Flow in the Early Postoperative Period

The long-term outcome of coronary artery bypass operations is contingent upon the patency of aortocoronary bypass grafts. Flow measurements taken at operation may not truly reflect the capacity of the graft to carry flow because the heart may not have fully recovered from the consequences of ischemic arrest, despite the protective effects of hypothermic cardioplegia. During a three-year period, we observed increases of up to 200% in the flow rate of 8 of 11 saphenous vein grafts in 7 patients who underwent reoperation for bleeding or cardiac tamponade in the early postoperative period. At initial operation, flow rates ranged from 25 ml/min to 130 ml/min (mean value, 66.8 ± 10.3 ml/min [standard error of the mean]). At reexploration, flow measurements ranged from 0 ml/min (graft clotted) to 260 ml/min (mean value, 110 ± 22.8 ml/min). This difference was statistically significant ( p < 0.02). This study documents that flow rate measurements in saphenous vein aorotocoronary bypass grafts can increase in the early postoperative period although the exact mechanism by which this occurs is not known.

Noninvasive assessment of aortocoronary bypass graft patency using pulsed Doppler echocardiography

To evaluate noninvasively aortocoronary bypass graft patency, pulsed Doppler echocardiography was performed at the time of postoperative coronary angiography in 120 consecutive patients. Ultrasonic examination of 163 vein grafts was possible. One hundred twenty-seven patent and 14 occluded grafts were correctly identified. Eleven patent grafts could not be recorded, and 11 occluded grafts were falsely diagnosed as patent. The method had an overall sensitivity of 92 percent and a specificity of 56 percent. This high sensitivity level may be increased to almost 100 percent by enhanced technical skill and experience. The low specificity level, although the method must be tested in a larger number of bypass grafts, stresses the importance of correctly identifying other sources of diastolic blood flow. Diastolic flows from the superior vena cava, internal mammary veins, tricuspid valve, mitral valve and right ventricle may be eliminated by careful adjustment of the depth, site and size of the pulsed Doppler electronic sampling gate. Standard echocardiographic landmarks for avoiding confusion with the coronary arteries are also described.