Sequential Saphenous Vein Grafts Research Articles

Individual Versus Sequential Saphenous Vein Grafts for on-Pump Coronary Artery Bypass Grafting - Does Smaller Coronaries in Indians Affect Graft Choice? - A Mid-Term Patency Comparison Study.

PurposeAlthough multiarterial grafting or bilateral mammary artery use is being increasingly emphasized for contemporary coronary artery bypass grafting (CABG) practice, saphenous vein graft (SVG) still accounts for 80% of all CABG conduits (Park et al., 2020) [1]. In India, both the individual and sequential saphenous grafting techniques are used arbitrarily, and there has not been a study that compares the mid-term patency of these two. This is specially relevant in view of smaller coronaries in Indians than the Caucasian counterparts. This study aims to compare the patency for on pump CABG’s.MethodsIn the present study, 323 patients underwent either sequential (group A, N = 151 grafts, each graft having two anastomoses each) or individual (group B, N = 344 grafts) saphenous vein CABG, between February 2014 and June 2017. The SVG anastomoses were created on obtuse marginal (OM1/OM2) and posterior descending artery (PDA). The graft patency of the vein grafts as well as the left internal mammary artery were assessed by serial coronary angiograms.ResultsResults were evaluated at 6 months, 1, 2 and 3 years post operatively. Group A showed a higher graft patency at 3 years at 80.8%, and group B, 67.1% (P = 0.002). Also, anastomoses on sequential conduits had overall better patency rates at three years (77.2% vs 67.2%, P = 0.005). The groups showed similar results at one year post operatively.ConclusionsSequential bypass grafts were associated with superior mid-term patency compared with individual grafts. These findings suggest the more favourable results of sequential bypass grafting to be attributed to the enhanced flow haemodynamics.

External stenting of vein grafts in coronary artery bypass grafting: interim results from a two centers prospective study

Backgroundprevious studies evaluating external stents for saphenous vein grafts (SVG) in CABG were limited to on-pump isolated CABG and single grafting technique with one external stent per patient. The objective of this prospective study was to evaluate the safety and the short-term performance of external stents in a heterogeneous group of patients who underwent on- and off-pump CABG, single and sequential grafting.Methods102 patients undergoing CABG were enrolled in two centers. All patients received internal mammary artery to the left anterior descending artery and additional arterial and/or venous grafts. In each patient, at least one SVG was supported with an external stent. Grafts’ patency and SVG lumen uniformity were assessed using CT angiography at a pre-defined time window of 6–12 months post procedure. All patients were prospectively followed-up via phone call and/or visit every 6 months for Major Adverse Cardiac and Cerebrovascular Events.Results51 patients (50%) underwent off-pump CABG and 23 patients (23%) were grafted with bilateral internal mammary arteries. Each patient received one or more SVG grafted in a sequential technique (44%) or as a single graft (56%). All SVG were externally stented in 84% of patients and in 16% (n = 16) one SVG was stented and one remained unsupported. At 6–12 months, patency rates of LIMA, RIMA, externally stented SVG and none-stented SVG were 100, 100, 98 and 87.5% respectively. 90% of the externally stented SVG had uniform lumen compared to 37% of the non-stented SVG. Clinical follow-up was completed for all patients with a mean duration of 20 months (range 6–54 months). During follow up period, one patient experienced myocardial infarction due to occlusion of the LIMA-LAD graft and one patient experienced a transient ischemic attack.ConclusionsExternal stenting of SVG is feasible and safe in CABG setting which includes off pump CABG and sequential SVG grafting and associated with acceptable early patency rates.Trial registrationStudy was registered at ClinicalTrials.gov. NCT01860274 (initial release 20.05.2013).

The main trunk of RCA may be the best choice of sequential vein graft distal end-to-side anastomosis.

The purpose of this study was to investigate the effect of different anastomotic positions on the early patency of the distal end-to-side anastomosis of sequential saphenous vein grafts (SVG) in off-pump coronary artery bypass grafting (OPCAB). A total of 259 patients who underwent OPCAB between August 2014 and August 2019 and presented for coronary computed tomography angiography (CCTA) to evaluate graft patency at 1 year post-OPCAB were analyzed. There are two kinds of distal end-to-side anastomosis of SVG, to posterior descending artery (PDA) and main trunk of right coronary artery (RCA). In all, 1044 distal coronary anastomoses on 518 grafts which included 180 left internal mammary artery (LIMA) grafts, individual 79 SVG and 259 sequential SVG were assessed using CCTA. The blood flow (BF), pulsatility index (PI), and patency of every anastomosis were recorded. Besides, comprehensive data of SV-PDA and SV-RCA patients was also compared. The mean BF of SV-RCA was significantly higher than that of SV-PDA (31.71 ± 18.60 vs 22.62 ± 14.48, p = 0.001), and the PI value of SV-RCA was significantly lower than that of SV-PDA (2.57 ± 1.17 vs 3.50 ± 1.69, p = 0.001). The patency of RCA system was significantly lower than that of the LAD and the left circumflex system (79.25% vs 90.13%, 90.23% respectively, p = 0.001). In sequential SVG, the patency of SV-PDA was significantly lower than that of SV-RCA (74.01% vs 86.59%, p = 0.001). Although, there was no significant difference in left ventricular ejective fraction, the left ventricular end-diastolic diameter (LVDd) in SV-PDA group was significantly larger than that in SV-RCA (52.67 ± 8.72 mm vs 47.34 ± 7.55, p = 0.001). In addition, the target vessel diameter in SV-PDA group was smaller than that in SV-RCA group (1.52 ± 0.41 mm vs 3.17 ± 0.88 mm, p = 0.001). The early patency of sequential SVG end to RCA after OPCAB is generally superior to that of to PDA, especially for patients with large LVDd.

Stable Hemodynamics within "No-Touch" Saphenous Vein Graft.

Purpose: To investigate the hemodynamics characteristics of the “no-touch” saphenous vein graft (SVG) conduits by nicardipine intraluminal administration in vivo experiment.Methods: A total of 59 consecutive patients were enrolled and underwent a sequential SVG to three non-left anterior descending (LAD) targets with the average runoff ≤2 mm, 30 with “no-touch” harvest technique (group A) and 29 with conventional preparation (group B). The patients were subject to nicardipine intraluminal injection during off-pump coronary artery bypass grafting (CABG) procedure. The intraoperative flow was measured with the ultrasonic transit time flow meter (TTFM), and the graft patency testified by multi-detector computed tomography (MDCT) angiography, respectively.Results: The baseline blood flow was higher in group A than that in group B (p <0.05). However, the increases in blood flow of SVG conduits in group A were lower than those in group B with 19.7 ± 5.9 vs. 35.4 ± 9.2 mL/min, 14.8 ± 5.6 vs. 23.1 ± 6.8 mL/min, 6.6 ± 2.1 vs. 11.2 ± 4.3 mL/min before the first, second, and third anastomose after nicardipine intraluminal administration, respectively (all p <0.01).Conclusions: No-touch SVGs were associated with higher baseline blood flow and less rises after nicardipine intraluminal administration during off-pump CABG procedure compared with conventional preparation. The no-touch SVGs seemed to be less spastic and well-tolerated on flow dilatation.

Sequential Versus Individual Saphenous Vein Grafting During Coronary Arterial Bypass Surgery

Although multiarterial grafting or bilateral mammary artery use is being increasingly emphasized for contemporary coronary artery bypass grafting (CABG) practice, saphenous vein graft (SVG) is still the most frequently used CABG conduit, and it accounts for 80% of all CABG conduits. Research focusing on modifiable surgical factors such as anastomosis technique, however, is scarce. This study aimed to compare clinical outcomes and graft patency according to anastomosis methods of vein grafting. From January 2005 through December 2016, patients who underwent CABG using SVG either by a sequential or an individual grafting technique were enrolled in this study. Graft patency was evaluated with coronary computed tomographic angiography. Propensity-score matching was used to compare the clinical outcomes and graft patency of these 2 grafting techniques to reduce treatment selection bias. Overall 2515 eligible patients, 1,037 in the sequential SVG graft group (41.3%) and 1478 (58.8%) in the individual SVG graft group were enrolled. After propensity-score matching, 901 matched pairs of patients and 891 matched pairs of grafts were included in the final outcome analysis. There were no significant differences in unadjusted (P= .83) and adjusted overall mortality (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.79 to 1.17; P= .67). The composite outcome of death, nonfatal myocardial infarction, and repeat revascularization also did not significantly differ between the sequential SVG and the individual SVG groups for both before (P= .20) and after matching (HR, 0.91; 95% CI, 0.75 to 1.09; P= .30). The sequential grafts showed superior patency as compared with the individual grafts for both before (P= .015) and after adjustment (HR, 0.61; 95% CI, 0.45 to 0.82; P < .001). The sequential grafting technique of SVG showed fairly acceptable safety and efficacy with superior long-term graft patency than individual grafts.Sequential SVG grafts perhaps can be a reasonable option as a second graft in CABG in some clinical situations.

Comparison of blood flow in single and sequential vein grafts during off-pump coronary artery bypass.

The use of sequential anastomoses in coronary artery bypass grafting (CABG) is still controversial. This study aimed to evaluate the mean blood flow (MBF) rate and pulsatility index (PI) of single and sequential saphenous vein grafts to the posterior descending artery (PDA) in the same patient during off-pump CABG (OPCABG). Sequential saphenous vein grafts were used to bypass the diagonal artery (Diagonal) (side-by-side), obtuse marginal artery (OM) (side-by-side) and PDA (end-to-side). The anastomoses of Diagonal and OM were temporarily occluded with bulldog clamps, making the sequential graft a "single" graft to PDA. The MBF and PI of this "single" graft to PDA were measured with transit-time flow measurement (TTFM). Then the bulldog clamps were removed and the MBF and PI of sequential graft to PDA were measured again and compared to those of the "single" graft in the same patient. Anastomoses were evaluated with coronary CT angiogram at 6 months. A total of 128 patients with triple vessel disease were enrolled (96 men; mean age, 66.0±8.0 years; range, 54-80 years). The MBF of the "single" vs. sequential graft to PDA was 20.6±9.1 vs. 21.4±10.1 mL/min (P=0.472). The PI of 'single graft' vs. sequential graft to PDA was 1.7±0.6 vs. 1.7±0.5 (P=0.941). The patency of all grafts was good in all patients after 6 months of follow-up. There were no hydrodynamic differences between single and sequential grafts to PDA in OPCABG.

Correlates of haemodynamic flow characteristics of sequential saphenous vein grafts in coronary artery bypass grafting.

A sequential bypass technique has been widely used in the saphenous vein grafts (SVGs) during coronary artery bypass grafting (CABG) surgery. The aim of the present study was to investigate the correlates of haemodynamic flow characteristics of sequential SVGs using transit-time flow measurement. From January 2013 to December 2016, 235 patients underwent isolated CABG using 1 aortosequential SVG to non-left anterior descending targets and the left internal mammary artery to the left anterior descending coronary artery. Among them, 212 patients have completed computed tomography angiography at 1-year follow-up and were included in the present study. The intraoperative flow rate and pulsatility index (PI) of sequential SVGs were assessed with transit-time flow measurement. The univariable and multivariable stepwise linear regression analyses of the possible correlating variables, including distal-end coronary artery (DECA) characteristics, were performed. For sequential SVGs, the mean proximal flow rate was 45.8 ± 19.2 ml/min, and the mean PI was 3.17 ± 1.00. We assessed the following correlates for proximal flow rate and PI: patient characteristics and DECA characteristics. Independent correlates of proximal flow rate were triple sequential SVG (by 21.0 ± 2.5 ml/min; P < 0.001), the DECA with more severe proximal stenosis (3.6 ± 1.3 ml/min per 10% increase; P = 0.007) and the DECA with larger diameter (≥1.5 mm) (by 4.8 ± 2.3 ml/min; P = 0.038). For PI, independent correlate was triple sequential SVG (by -0.55 ± 0.15; P < 0.001), and the DECA with larger diameter (≥1.5 mm) showed a strong trend (P = 0.069). The flow rate plotted against the logarithmic transformation of PI showed a significant inverse relationship in the linear regression analysis (P < 0.001). At 1-year follow-up, the patency of the proximal segment (between the aorta and the first side-to-side anastomosis) was 99.5% (211 of 212). Triple sequential SVG, the DECA with a larger diameter and more severe proximal stenosis were associated with higher proximal flow rate, whereas triple sequential SVG was associated with lower PI. These findings provide new data on flow characteristics and may guide subsequent studies towards improving sequential SVG patency.

Sequential Saphenous Vein Coronary Bypass Grafting.

The enormous majority of previous reports focused on evaluating the safety and efficacy of sequential saphenous vein (SV) coronary bypass grafting; however, no reports to date have revealed concern regarding the impacts of the number of distal anastomoses of sequential SV grafting on graft patency after coronary artery bypass grafting (CABG). This single-center retrospective study aimed to evaluate the impacts of three versus two distal anastomoses per single SV conduit on SV graft patency after off-pump CABG, and to determine the independent risk factors for sequential SV graft failure.From January 2011 to December 2014, 1320 eligible patients were assigned to either a triple group (three distal anastomoses of sequential SV grafting, n = 758) or a double group (two distal anastomoses of sequential SV grafting, n = 562). The primary endpoint was over a 2-year follow-up SV graft failure after off-pump CABG.The triple and double group received a similar total patency rate of sequential SV conduits (86.5% versus 87.1%, P = 0.757). The number of distal anastomoses of sequential SV grafting (three versus two) was not a predictive factor for the follow-up graft failure of sequential SV conduits (HR = 0.91, 95% CI: 0.66-2.29, P = 0.137). Moreover, the two groups received a similar follow-up survival freedom from repeat revascularization (χ2 = 1.881, log-rank P = 0.170).Three versus two distal anastomoses per single SV conduit received a similar SV graft patency. The number of distal anastomoses of sequential SV grafting was not an independent risk factor for graft failure.

Análisis de predictores independientes del flujo del bypass coronario en pacientes intervenidos de revascularización miocárdica aislada

Introduction and objectiveThe transit time flowmeter allows knowing two parameters: the mean bypass flow and pulsatility index. These two parameters, when altered, can suggest a bypass stenosis. Factors other than the permeability of the anastomosis, as the quality of coronary bed, may alter the flow of bypass and complicates its interpretation. The aim of our study is to analyze the independent predictors of the mean flow of aorto-coronary bypasses. MethodsWe collected a retrospective series of 90 consecutive patients who underwent isolated coronary artery bypass grafting by the same surgeon from January 2014 to August 2016. From this series, we have built an electronic database where each record corresponds to one graft and the correspondent single or multiple bypasses. Therefore, we built a database including 185 grafts. Of these, 8 grafts were not analyzed because the flow had not been correctly measured. Therefore, the flow and pulsatility index values of 177 grafts were available for our statistical analysis. ResultsMultiple linear regression analysis detected two independent predictors of bypass flow: sequential saphenous vein graft (partial r value: 0.32; P<.0001) and arterial graft (partial r-value: –0.23; P=.0021). Therefore, our model showed a direct correlation between use of saphenous graft with sequential technique and bypass flow and an inverse correlation between arterial graft use and bypass flow. ConclusionsThe predictors of aorto-coronary bypass flow are the use of an arterial graft (negative coefficient) and the use of a sequential venous graft (positive coefficient). Our statistical model has not identified as a predictor the SYNTAX score nor analyzed as a continuous variable nor as a dichotomous variable.

From Myocardial Infarction to Peripheral Stenting

Degenerated saphenous vein grafts (SVGs) are associated with high risk of myocardial infarction (MI). They are difficult to treat percutaneously because of large variability in their wall diameters. We report a case of a 71-year-old male, who presented with an acute inferior ST elevation MI (STEMI) 16 years following revascularization with triple coronary artery bypass graft (sequential SVG to the posterior interventricular and to the second marginal branch of the left circumflex artery, and left internal mammal artery to the left anterior descending). Coronary angiography revealed a massive thrombotic occlusion of the second part of the sequential graft, which was aneurysmal just after the posterior interventricular artery. Thromboaspiration was performed and revealed an 8 mm diameter aneurysmal degenerated graft. We decided to use a balloon-expandable peripheral stent to treat this lesion. TIMI 3 outflow was restored without any no-reflow phenomenon. Patient was discharged to his origin hospital 3 days later. He had an uneventful evolution at the 3 months follow-up. J Med Cases. 2016;7(4):133-135 doi: http://dx.doi.org/10.14740/jmc2451w

Impacts of Intraoperative Flow on Graft Patency of Sequential and Individual Saphenous Vein Grafts

ObjectiveWe sought to delineate the predictor of saphenous vein graft (SVG) failure and to evaluate the impact of sequential grafting of SVG on graft flow as the significant predictor of patency.MethodsAngiograms and clinical records of 439 patients who underwent coronary artery bypass grafting with aortocoronary SVG were reviewed. Of these, 708 distal anastomoses were created by 480 SVGs. Of 349 patients who underwent isolated coronary artery bypass grafting, operation was performed with an off-pump technique in 347 patients (99%). For 90 patients, a combined procedure on cardiopulmonary bypass was performed. A postoperative angiography was performed in 230 SVGs for clinical reasons. Insufficient flow (IF) was defined as a graft flow of 20 mL/min or less, measured by transit-time Doppler flowmetry during operation.ResultsIn 480 SVGs, 44 (9.2%) presented IF, and 24 SVGs presented partial or total occlusion. Six of the nine failed individual SVG had IF, whereas none of the failed sequential SVG was associated with IF. Univariate and multivariate logistic regression analyses demonstrated that IF (P = 0.002; odds ratio, 6.63) and sequential grafting (P = 0.004; odds ratio, 2.51) were significantly correlated with a failure of the SVG. The patency rate of sequential SVG to the most distal target was 78/93 (83.9%), which was significantly lower than 9/139 (93.5%) of the individual SVG (P = 0.02) and 7/113 (93.8%) of the sequential SVG to proximal targets (P = 0.02).ConclusionsWhen both targets seem to have sufficient demand, avoidance of sequential grafting would be reasonable. Moreover, the important target should be grafted by individual grafting or sequential proximal anastomosis.

Efficacy comparison of mid-term patency rates between sequential and individual saphenous vein grafts after off-pump coronary artery bypass grafting

Objective To compare the mid-term patency rates between individual and sequential saphenous vein grafts after off-pump coronary artery bypass grafting (OPCAB) and evaluate the effect of sequential anastomosis technique on the graft patency after OPCAB. Methods Clinical data of 200 patients receiving OPCAB with individual and sequential saphenous vein grafts from June 2011 to June 2013 were retrospectively analyzed. The multislice spiral CT angiography (MSCTA) was performed at an average of (20.0±21.5) months after OPCAB. The patency rate of individual and sequential grafts and anastomoses were compared, and the effect of different locations on the patency rate of the anastomoses was analyzed. Results There was no significant difference in the patency rate between individual and sequential grafts (χ2=1.886, P=0.170). The anastomosis patency rates in different locations had no significant differences between individual and sequential grafts (χ2=4.567, P=0.102). There was no significant difference in the distal anastomosis patency rate between sequential and individual grafts (P>0.05). The anastomosis patency rate in sequential graft had no significant difference in the side-to-side anastomose versus end-to-side anastomose (P>0.05). The patency rate of side-to-side anastomose in the sequential graft was higher than that of distal anastomose in individual graft (χ2=4.653, P=0.031). There were no significant differences in the patency rate in sequential grafts among different coronary systems (including the anterior descending branch, the right coronary artery and the circumflex branch) and individual grafts among different coronary systems respectively (all P>0.05). The anastomosis patency rates had no difference between sequential and individual grafts in the anterior descending branch. There were significant difference in end-to-side anastomosis patency rates between sequential and individual grafts in different coronary systems (χ2=6.184, P=0.045), but the distal anastomosis patency rate had no difference (χ2=1.807, P=0.431). No significant difference in the patency rates between sequential and individual grafts in side-to-side versus end-to-side (all P>0.05). Conclusions There is no significant difference in the mid-term patency rate between individual and sequential saphenous vein grafts after off-pump coronary artery bypass grafting (OPCAB). The patency rate is related with the anastomotic mode, the location of anastomotic, and the quality of the target vessel, diameter, number of grafts and other factors. The mid-term patency rate can be improved by choosing the target vessel with better conditions as the most distal sequential bridge, when conducting sequential anastomosis technique. Key words: Coronary artery bypass grafting, off-pump; Saphenous vein; Surgical stomas

OPCABG using right internal mammary artery and sequential saphenous vein graft in reverse sequence) in a PT with right pneumonectomy with compensatory hyperexpansion of the left lung

Case report 77 years old male with worsening angina and shortness of breath and diagnosed with 3 vessel disease and history of right pneumonectomy was referred for coronary artery bypass grafting.Other co morbidities included hypercholesterolemia, exsmoking, recurrent pneumonia, colorectal resection and chemotherapy for cancer and also had gastric ulcers and could not tolerate aspirin (hence not an ideal candidate for PCI). CT chest was performed which showed heart to be deviated to the right side with tracheal deviation due to compensatory hyperexpansion of left lung. Initial plan was to perform on pump CABG in view of single lung. However after midline sternotomy it was clear that the left lung dominated the chestand the heart lay posteriorly in the right hemi-thorax with slight rotation to theright. This made on-pump surgery difficult as there was no access to the right atrium and majority of the aorta lay behind the Pulmonary artery. Femoral venous cannulation would havebeen risky due to the right atrial shift at the level of the diaphragm. Decision was made to perform the procedure without cardiopulmonary bypass. The Right internal mammary artery was harvested in semi-skeletonised fashion and was anastomosed to the mid LAD. There was enough aorta accessible to place a single vein sequentially on the OM2 and PDA performing the top end to the aorta first and then OM2 anastomoses in side to side fashion followed by PDA anastomosesas end to side anastomosis. There were no periods of instability. The postoperative course was uneventful apart from patient going into atrial fibrillation which was treated with amiodarone. Patient was discharged home on 6 postoperative day.

To stent or not to stent - a challenging decision in a rare condition

Introduction: In this case we discuss the management of a patient with recurrent acute coronary syndrome due to Takayasu arteritis (TA). Case report description: In 2007, a 13-year-old Caucasian male with angina, electrocardiographic and troponin abnormalities consistent with an acute coronary syndrome, and widespread bruits, was found to have multiple arterial stenoses involving the aorta, renal and carotid arteries. The erythrocyte sedimentation rate was 32mm (0-7), C reactive protein 36 mg/L (0-7) with a mild normocytic anaemia. Coronary angiography showed triple vessel disease and he was diagnosed with TA with coronary artery involvement. Coronary artery bypass graft surgery (free left internal mammary graft to the left anterior descending artery and sequential saphenous vein graft to the intermediate and left posterolateral vessels) was performed. The patient received intensive medical therapy and angioplasty for hypertension due to bilateral renal artery stenosis. His condition continued to progress and angina recurred in 2012 with coronary angiography demonstrating occlusion of the vein graft segment to the posterolateral artery. The patient was managed medically but was diagnosed with a non-ST elevation myocardial infarction in 2013 due to occlusion of the vein graft to the intermediate. He suffered ongoing symptoms of cardiac ischaemia and after discussion with the Cardiosurgical team a decision was made to treat the diseased native right coronary artery by percutaneous coronary artery intervention (PCI) with drug eluting stents. Despite this measure the patient has experienced ongoing angina and further PCI to the ungrafted left coronary artery territories is under consideration. Discussion: TA most commonly presents in 20-30 year-old females of East Asian descent and coronary artery involvement in children is very rare. From a cardiac perspective this case highlights the challenge of managing coronary artery disease in the setting of active large vessel vasculitis. Limited data exist to guide clinicians in this setting. Whether redo cardiac surgery at age 18 would be superior to a percutaneous approach is unclear. Implications to clinical practice: 1. Our case highlights the importance of considering vasculitis in the differential diagnosis of a young patient presenting with chest pain. 2. Rare clinical scenarios can pose a management dilemma for the treating physician due to the paucity of supporting research available to direct the decision making process. Treatment strategies should be decided on a case-by-case basis and consensus opinion from the multidisciplinary team is recommended.

Innominate Artery as an Alternative Site for Proximal Anastomoses in Patients With a Severely Calcified Aorta

Atheromatous plaques of the ascending aorta are one of the most important risk factors for postoperative mortality and morbidity in coronary artery bypass grafting (CABG). We have retrospectively analyzed the results of proximal anastomoses constructed on the innominate artery in patients with calcific atheromatous plaques (CAP) in their ascending aorta detected intraoperatively. This study is a retrospective review of 16 consecutive patients who underwent CABG operations and had CAP on their ascending aorta between November 2006 and June 2009. The atheromatous lesions were detected intraoperatively and the operation plan was changed to off-pump surgery. All the proximal anastomoses were made on the innominate artery, left internal thoracic artery (LITA) or the other saphenous vein grafts (SVG). Thirteen patients were male and three were female with a mean age of 63.7 ± 5.3 (ranged, 53-71) years. A total of 56 distal anastomoses (3.5 per patient) and 25 proximal anastomoses on the innominate artery were performed. Of the 16 patients, seven (43.7%) had received a sequential SVG; two (12.5%) patients, sequential LITA graft; and one (6.25%) patient sequential SVG and LITA graft. One of the proximal anastomoses was performed on the SVG in four patients (25%) and on the LITA graft in one patient (6.2%). One patient (6.2%) died due to cerebrovascular morbidity. No other complications were observed. The innominate artery is an alternative site for proximal anastomoses in patients with calcific atheromatous aorta.

Analysis of blood flow in sequential and individual saphenous vein grafts in off-pump coronary artery bypass grafting

To compare the blood flow in sequential and individual saphenous vein grafts (SVGs) and to analyze the influence of the location of the target vessel in off-pump coronary artery bypass grafting (OPCAB). A total of 464 SVGs in 412 patients receiving OPCAB were nested into individual SVG (n=206), double (n=241) or triple sequential SVG (n=15), and analyzed. The blood flow in double and triple SVGs was significantly higher than in individual SVGs [(43.4±22.5), (43.7±19.2) and (28.9±18.7) mL/min, respectively, P<0.001, P=0.047]. There were no differences between flow in double and triple SVGs (P=0.96). Pulsatility index (PI) of the three groups were similar (2.6±1.2, 2.5±1.6, 2.8±0.9, respectively, P=0.49, P=0.49). In individual SVGs to right coronary artery, the blood flow was higher than in the posterior descending branch (PDA) (P=0.047) and posterior branch of left ventricle (PBLV), the flow-time in systole period was longer than diagonals (P=0.003), obtuse marginal (OM) (P=0.013) and PDA (P=0.002), PI was significantly lower than PDA (P=0.033) and PBLV (P=0.032). The blood flow in individual SVGs to diagonals was significantly lower than in other target vessels except for PBLV (P<0.05). Flow in double SVGs to PDA-PBLV was significantly lower than in PDA-OM. The mean blood flow in double and triple sequential SVGs is about 1.5 times higher than in individual SVGs. Individual, double, and triple SVGs have similar pI. Flow in individual SVGs to diagonals was significantly lower than in other target vessels except for PBLV.

A completely fractured zotarolimus-eluting stent in an aortocoronary saphenous vein bypass graft

Drug-eluting stents (DES) have significantly improved the rate of target vessel revascularization in comparison with bare metal stents. DES fracture was not reported in multicenter randomized clinical trials, but several case reports of DES fracture have been published, mostly with sirolimus-eluting stents. DES fracture is associated with stent restenosis and thrombosis. We report a zotarolimus-eluting stent fracture in an aortocoronary saphenous vein graft (SVG) bypass. The patient presented with chest pain and a non-ST-elevation myocardial infarction. He underwent cardiac catheterization that showed a complete fracture of a zotarolimus-eluting stent in the ostium of a sequential SVG to the diagonal and obtuse coronary arteries. His management included coronary angioplasty and retrieval of the proximal fractured segment. We discuss the potential causes for this stent fracture and suggest caution when using a DES in an ostial location of a SVG bypass, especially in a highly mobile vessel.

Effects of Intra‐Aortic Balloon Pump on Coronary Artery Bypass Grafts Blood Flow: Differences by Graft Type and Coronary Target

The intra-aortic balloon pump (IABP) is used worldwide as an anti-ischemic strategy. However, little is known about the modifications of the graft blood flow during IABP. A retrospective study aimed at analyzing transit-time flow measurements during 1:1 IABP and during its cessation in 401 consecutive patients receiving IABP before coronary artery bypass grafting (n = 880 graft segments) was reported. All normally functioning grafts were considered. Mean diastolic and mean blood flow improved significantly during 1:1 IABP compared with during IABP cessation (P < 0.001), although mean and end-diastolic arterial pressures were significantly lower (P = 0.001). Arterial and sequential saphenous vein (SV) grafts showed greater improvements in mean diastolic and mean flow compared with single venous grafts. Higher flows were also observed in the grafts directed to the circumflex territory. Surplus graft flow (SGF, defined as mean flow during 1:1 IABP/mean flow with IABP off) was recruited (SGF >1) during 1:1 IABP, with higher values in single arterial or sequential SV grafts versus single venous grafts (both P < 0.001). Y-conduit radial artery (RA) grafts showed higher maximum diastolic flow, mean flow, and SGF compared to aortocoronary RA or SV grafts. In this retrospective analysis, IABP was associated with improved diastolic and mean blood flow in bypass grafts. Arterial, sequential, and Y-conduit grafts were associated with greater improvements in blood flow and SGF than aortocoronary SV grafts.

Intra-aortic balloon pumping recruits graft flow reserve by lowering coronary resistances

Background The intra-aortic balloon pump (IABP) is used worldwide as an anti-ischemic strategy and to reduce myocardial workload. However, whether IABP augments coronary flow after coronary bypass via a passive increase in diastolic pressure or an active response of the coronary bed remains uncertain. Methods We analyzed transit-time flow measurements and the contemporary changes in coronary resistances obtained during 1:1 IABP and during its cessation in 144 consecutive patients receiving prophylactic IABP before isolated coronary artery bypass grafting ( n = 340 graft segments). Results Normally functioning grafts showed lower coronary resistances, greater percentage decrease in resistance, and greater increases in average maximum diastolic and mean flow during 1:1 IABP compared with IABP cessation ( P < .001). Arterial and sequential saphenous vein grafts showed better flowmetry and greater reductions in coronary resistances compared with single venous grafts. Accordingly, graft flow reserve (defined as mean flow during 1:1 IABP/mean flow with IABP off) was recruited (graft flow reserve > 1) during 1:1 IABP in all normally functioning grafts, with higher values in single arterial or sequential saphenous vein grafts than in single venous grafts (both P < .001). Coronary resistances were higher in 7 failed grafts versus normal-functioning grafts at baseline; these did not decrease during 1:1 IABP and showed worse transit-time flow results. Conclusions IABP recruits graft flow reserve by lowering coronary resistance in functioning grafts. Arterial and sequential venous grafts showed greater reduction in coronary resistance compared with single saphenous grafts.

The Patency of Sequential and Individual Saphenous Vein Grafts after Off-pump Coronary Artery Bypass Grafting

The impact of the grafting techniques (individual or sequential grafts) on the graft patency of off-pump coronary artery bypass grafting (OPCAB) has not been reported. The mid-term patency rates for individual and sequential saphenous vein grafts (SVGs) as coronary bypass conduits of OPCAB were compared. A total of 714 distal coronary anastomoses on 448 SVGs were assessed using a 64-multislice computed tomography in 398 patients at an average of 26.4 ± 23.6 months (three months to five years) after an OPCAB procedure. The blood flow of grafts in the proximal segment of individual and sequential SVGs was also compared. The overall patency of sequential SVGs (95.9%) was significantly superior to individual ones (90.6%, p = 0.022). The anastomoses on the sequential conduits had better patency (95.1% vs. 90.1%, p = 0.013). The patency of side-to-side anastomoses (97%) was better than that of end-to-side anastomoses (93.1%) and also better than that of the individual end-to-side anastomoses (90.1%, p = 0.002, p = 0.041). No significant difference was observed between the two approaches in regard to the three major coronary systems; however, anastomoses on sequential grafts had superior patency to those on individual grafts in the right coronary system (p = 0.008). The blood flows of double and triple sequential SVGs were significantly higher than those of individual ones (p < 0.001, p = 0.048, respectively). The mid-term patency of a sequential SVG conduit after OPCAB is excellent and generally superior to that of an individual one.