Coronary bypass graft fate: angiographic grading of 1400 consecutive grafts early after operation and of 1132 after one year

Coronary angiography was used to assess the effect of diabetes on off-pump coronary artery bypass graft patency

This study aimed to examine the influence of diabetes on the left internal mammary artery (LIMA) and saphenous vein (SV) graft failure for 5-year follow-up. We enrolled 202 patients who underwent isolated off-pump coronary artery bypass grafting (CABG) surgery in 2014, angiographic follow-up occurred at 5 years after surgery. Angiographic outcomes in patients with or without diabetes were analyzed. Multivariate logistic regression analysis was used to identify independent predictors of graft dysfunction. A total of 66 (32.7%) patients had diabetes. Five-year rates of LIMA and SV graft failure were similar in patients with and without diabetes. In addition, in diabetics, the proportion of complete graft failure was significantly lower in the LIMA grafts (12/66, 18.2%) than in the SV grafts (57/133, 42.9%) (P = .001). In nondiabetic, the proportion of complete graft failure was also significantly lower in the LIMA grafts (28/136, 20.6%) than in the SV grafts (105/275, 38.2%) (P < .001). Multivariate logistic regression analysis showed that mean graft flow (MGF) was an independent predictor factor for LIMA (odds ratio = 1.186, 95% CI = 1.114-1.263, P < .001) and SV (odds ratio = 1.056, 95% CI = 1.035-1.077, P < .001) graft failure. Diabetes did not influence the patency of LIMA or SV grafts over a 5-year follow-up. LIMA grafts should be maximized in patients undergoing off-pump CABG surgery. Diabetes does not affect the patency of grafts CABG. Using angiography, our study proved that diabetes does not affect the patency of grafted vessels after CABG for 5 years.

Quantitative flow ratio and graft outcomes of coronary artery bypass grafting surgery: A retrospective study

OBJECTIVE

Quantitative flow ratio (QFR) is a novel noninvasive tool for the functional assessment of coronary stenosis. Whether or not QFR could predict graft outcomes after coronary artery bypass grafting procedure is unknown. This study aimed to investigate the association of QFR value with graft outcomes after coronary artery bypass grafting surgery.

METHODS

The QFR values were retrospectively obtained from patients receiving coronary artery bypass grafting surgery from 2017 to 2019 in the Graft Patency Between No-Touch Vein Harvesting Technique and Conventional Approach in Coronary Artery Bypass Graft Surgery (PATENCY) trial. QFR calculation was conducted in eligible coronary arteries, defined as those with ≥50% stenosis and a diameter ≥1.5 mm. A threshold of QFR ≤0.80 was considered functionally significant stenosis. The primary outcome was graft occlusion at 12 months evaluated by computed tomography angiography.

RESULTS

Two thousand twenty-four patients with 7432 grafts (2307 arterial grafts and 5125 vein grafts) were included. For the arterial grafts, the risk of 12-month occlusion was significantly increased in the QFR >0.80 group than in the QFR ≤0.80 group (7.1% vs 2.6%; P = .001; unadjusted model: odds ratio, 3.08; 95% CI, 1.65-5.75; fully adjusted model: odds ratio, 2.67; 95% CI, 1.44-4.97). No significant association was observed in the vein grafts (4.6% vs 4.3%; P = .67; unadjusted model: odds ratio, 1.10; 95% CI, 0.82-1.47; fully adjusted model: odds ratio, 1.12; 95% CI, 0.83-1.51). Results were stable across sensitivity analyses with a QFR threshold of 0.78 and 0.75.

CONCLUSIONS

Target vessel QFR >0.80 was associated with a significantly higher risk of arterial graft occlusion at 12 months after coronary artery bypass grafting surgery. No significant association was found between target lesion QFR and vein graft occlusion.

Long-term observational angiographic patency and perfect patency of radial artery compared with saphenous vein or internal mammary artery in coronary bypass surgery

OBJECTIVES

It is uncertain if the long-term biological behavior of the radial artery as a conduit for coronary bypass surgery has a similar resistance to the development of atherosclerosis as for the internal mammary artery. We aimed to examine long-term angiographic patency and disease-free patency (perfect patency) for internal mammary artery, radial artery, and saphenous vein grafts.

METHODS

A retrospective, single-center, individual patient cohort study of angiographic observations from patients' latest postoperative angiogram from 1997 to 2020 was performed. Analysis was per anastomosis and assessed for patency and perfect patency. A generalized linear mixed model premised upon logistic regression was used to minimize confounding bias.

RESULTS

A total of 983 patients with 3064 grafts were included, with a median follow-up of 8.6 (interquartile range, 4.4-12.6) years after the operation. Multivariable analysis revealed differences for radial (patency, 86.9%; perfect patency, 86.4%) and internal mammary artery (patency, 93.9%; perfect patency, 93.5%) versus saphenous vein graft (patency, 72.8%; perfect patency, 46.2%). There were no differences between the 2 arterial conduits for patency (odds ratio, 1.40; 95% CI, 0.85-2.33; P = .189) and perfect patency (odds ratio, 1.14; 95% CI, 0.71-1.84; P = .578). If a conduit was patent, then 99.4% of radial artery, 99.6% of internal mammary artery, and 63.5% of saphenous vein graft were reported as perfectly patent.

CONCLUSIONS

Radial artery and internal mammary artery had similar patency and perfect patency while both were superior to saphenous vein graft.

Saphenous vein to the right coronary system from the right thoracic artery or the aorta. Long-term propensity-matched results of 2 groups

OBJECTIVES

Since 2000, we anastomosed the saphenous vein graft to the right coronary artery system using the stump of the right internal thoracic artery as inflow. The long-term results of patients where the right coronary artery was grafted with the right internal thoracic artery or the ascending aorta as saphenous vein inflow has not been reported.

METHODS

From 2000 to 2018, 699 consecutive patients had right internal thoracic artery elongated with saphenous vein (I-graft group, n = 358, 51.2%) or saphenous vein from the aorta (Ao-graft group, n = 341, 48.8%) on right coronary artery system. Inclusion criteria were age ≤75 years, bilateral internal thoracic arteries as a Y graft on the left system (three-vessel disease, n = 603, 86.3%) or as a left internal thoracic artery on left anterior descending and right internal thoracic artery elongated with saphenous vein on the right coronary artery system (two-vessel disease, n = 96, 13.7%), only 1 saphenous vein per patient. Propensity-matching identified 272 patients per group. One-hundred and twenty-two patients underwent coronary computed tomographic angiography to asses grafts patency after a median follow-up of 88 (65-93) months.

RESULTS

In the paired samples, there was no difference in the early outcome. Ten-year survival and freedom from death, non-fatal acute myocardial infarction and repeat revascularization were higher in I-graft group: 90.6 [standard error (SE): 2.0] vs 78.2 (SE: 5.3), P = 0.0266, and 85.2 (SE: 2.4) vs 69.9 (SE: 5.3), P = 0.0179. Saphenous vein graft, at a long-time follow-up, showed a higher patency rate (81.6% (SE: 7.0) vs 50.7% (SE: 7.9), P < 0.0001) and a smaller internal lumen diameter (2.7, standard deviation: 0.4 vs 3.4, standard deviation: 0.6 mm, P < 0.0001) when right internal thoracic artery was the inflow.

CONCLUSIONS

Grafting the right coronary artery with saphenous vein may entail higher patency rate and better outcome when the inflow is the right internal thoracic artery than when is the ascending aorta. Prospective randomized data are needed to test this hypothesis.

Assessment of the Graft Quality and Patency during and after Coronary Artery Bypass Grafting

Coronary artery bypass grafting (CABG) is the gold standard procedure for multi vessels and left main coronary artery disease. The prognosis and survival outcomes of CABG surgery are highly dependent on the patency of the bypass graft. Early graft failure which can occur during or soon after CABG remains a significant issue, with reported incidences of 3-10%. Graft failure can lead to refractory angina, myocardial ischemia, arrhythmias, low cardiac output, and fatal cardiac failure, emphasizing the importance of ensuring graft patency during and after surgery to prevent such complications. Technical errors during anastomosis are among the leading causes of early graft failure. To address this issue, various modalities and techniques have been developed to evaluate graft patency during and after CABG surgery. These modalities aim to assess the quality and integrity of the graft, thus enabling surgeons to identify and address any issues before they lead to significant complications. In this review article, we aim to discuss the strengths and limitations of all available techniques and modalities, with the goal to identify the best modality for evaluating graft patency during and after CABG surgery.

Small-diameter bacterial cellulose-based vascular grafts for coronary artery bypass grafting in a pig model

Surgical revascularization is the gold standard in most cases of complex coronary artery disease. For coronary artery bypass grafting, autologous grafts are state-of-the-art due to their long-term patency. A non-negligible amount of patients lack suitable bypass material as a result of concomitant diseases or previous interventions. As a promising alternative, tissue-engineered vascular grafts made of biomaterials such as bacterial cellulose (BC) are gaining more and more attention. However, the production of small-diameter grafts (inner diameter < 6 mm) of application-oriented length (> 5 cm) and their in vivo long-term patency remain challenging. In this study, grafts of 20 cm in length with an inner diameter of 3 mm were generated in a custom-made bioreactor. To potentially improve graft compliance and, therefore in vivo patency, BC was combined with an embedded cobalt–chromium mesh. The grafts were designed for in vivo endothelialization and specific surgical properties and implanted as an aortocoronary bypass in a left anterior descending occluded pig model (n = 8). Coronary angiography showed complete patency postoperatively at 4 weeks. Following 4 weeks in vivo, the grafts were explanted revealing a three-layered wall structure. Grafts were colonized by smooth muscle cells and a luminal layer of endothelial cells with early formation of vasa privata indicating functional remodeling. These encouraging findings in a large animal model reveal the great potential of small-diameter BC grafts for coronary and peripheral bypass grafting.

Predictors of vein graft disease progression between one week and one year after surgical coronary revascularization: Impact of secondary prevention medications

OBJECTIVE

This study aimed to detect the predictors of vein graft disease (VGD) progression between 1 week and 1 year after surgery and to evaluate the impact of secondary prevention medications.

METHODS

A total of 218 consecutive patients underwent surgical coronary revascularization were evaluated by coronary computed tomography angiography both at 1-week and 1-year follow-up. Logistic regression analyses were performed to investigate the predictors of VGD progression. A risk score (0-4) was set up to evaluate implementation result of secondary prevention measures according to 1-year follow-up result. Association between VGD progression and the risk score was assessed.

RESULTS

VGD progression occurred in 11.3% of saphenous vein grafts (SVG) and 22.1% of patients. At the patient level, poor vein graft (odds ratio [OR] = 4.25), noncontrolled hyperlipidemia (OR = 3.01), and diabetes mellitus (DM) (OR = 2.96) were predictors, while diameter of SVG (mm, OR = 0.35) was protective factor. At the graft level, DM (OR = 3.52), noncontrolled hyperlipidemia (OR = 2.33), and peripheral artery disease (PAD) (OR = 2.20) were predictors, while number of SVGs (OR = 0.63), diameter of SVG (mm, OR = 0.39), and mean graft flow >25 ml/min (OR = 0.35) were protective factors. VGD progression was significantly associated with the risk score at both the patient (OR = 1.52) and the graft level (OR = 1.38).

CONCLUSIONS

Poor vein graft, noncontrolled hyperlipidemia and DM were predictors of VGD progression between 1 week and 1 year after surgery at the patient level, while larger SVG diameter was a protective factor. DM, PAD and noncontrolled hyperlipidemia were predictors at the graft level, while a number of SVGs, larger SVG diameter, and mean graft flow >25 ml/min were protective factors. Implementation failure of secondary prevention medications was associated with VGD progression from as early as 1 year after surgery.

Revascularization strategies for patients with established chronic coronary syndrome

Coronary artery disease is the most common type of cardiovascular disease, leading to high mortality rates worldwide. Although the vast majority can be treated effectively and safely by medical therapy, revascularization strategies remain essential for numerous patients. Outcomes of both percutaneous coronary intervention and coronary artery bypass grafting improve in a rapid pace, resulting from technical innovation and ongoing research. Progress has been achieved by technical improvements in coronary stents, optimal coronary target and graft selection, and the availability of minimally invasive surgical strategies. Besides technical progress, evidence-based patient-tailored decision-making by the Heart Team is the basic precondition for optimal outcome. The combination of fast innovation and long-term clinical evaluations creates a dynamic field. Research outcomes should be carefully interpreted according to the techniques used and the trial's design. Therefore, more and more trial outcomes suggest that revascularization strategies should be tailored towards the specific patient. Although the European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines on myocardial revascularization date from 2018 and a large variety of trial outcomes on revascularization strategies in chronic coronary syndrome have been published since, we aim to provide an updated overview within this review.

Preclinical Comparison of Distal Off-Pump Anastomotic Remodeling: Hand-Sewn Versus ELANA Heart Bypass

Objective: The ELANA Heart Bypass System is a new sutureless technique for coronary anastomoses. A titanium clip connects the graft with the coronary artery, whereafter the arteriotomy is performed by excimer laser. Since this anastomotic construction evidently differs from the standard hand-sewn anastomosis, we aim to evaluate the process of anastomotic healing and remodeling. Methods: Preclinical evaluation of anastomotic remodeling in 42 pigs who underwent off-pump left internal mammary artery to left anterior descending artery anastomosis by either the ELANA Heart Bypass (n = 24) or the hand-sewn (n = 18) technique. Anastomotic remodeling was evaluated by scanning electron microscopy and histology in short-term follow-up intervals up to 3 months. Anastomotic patency is determined by coronary angiography at latest follow-up before termination. Results: The nonendothelial surface of both the ELANA and the hand-sewn anastomoses were covered with neointima from 14 days onwards. Only half the amount of intima hyperplasia was present in the anastomotic surface of the patent ELANA anastomosis, compared with the hand-sewn anastomosis (98 [48–1358] vs 218 [108–296] µm, P = 0.001). Yet patency of the ELANA was inferior to the hand-sewn anastomoses (79% vs 100%, P = 0.06). Conclusions: This study shows the technical perioperative feasibility of the ELANA Heart Bypass System. Although limited intima hyperplasia was observed, hand-sewn anastomoses had superior patency during follow-up. The results of this trial suggest that an additional study with a new prototype is required before clinical implementation.

Newly Developed Graft Failure Detected Using Computed Tomography Within 1 Year After Coronary Artery Bypass Grafting Surgery: One Single-Center Experience

Background

Newly developed graft failure negatively affects the short- and long-term outcomes of patients who experience coronary artery bypass grafting (CABG) surgery. This study explored the value of transit time flow measurement (TTFM) parameters for predicting the risk of newly developed graft failure that occurs within 1 year after CABG, as well as investigated the relationship between newly developed graft failure and adverse cardiovascular events.

Methods

A total of 134 patients who underwent CABG and had CT angiography (CTA) data (1 year post-operatively) were divided into two groups: the patient group, in which patients did not have newly developed graft failure, and the occluded group, in which patients developed newly developed graft failure between 1 and 12 months after CABG. The patency rate of grafts in different targets was analyzed. The correlations between graft failure and TTFM parameters and between graft failure and the occurrence of adverse cardiovascular events were investigated.

Results

The overall rate of newly developed graft failure was 7.2%, the venous graft failure was 10.8%, and the arterial graft failure was 0.7%. The occluded group had a higher pulse index (PI) (2.9 vs. 2.4, P = 0.007), a lower mean graft flow (MGF) (20 vs. 25 ml/min, P = 0.028), and a lower diastolic flow fraction (DF) (63.5 vs. 70%, P = 0.019) than the patent group. The cut-off value for predicting newly developed graft failure was PI > 2.75 (P = 0.007), MGF < 23.5 ml/min (P = 0.03), and DF < 65.5% (P = 0.019). Compared with the patent group, the newly developed graft failure group had higher rates of recurrent angina (13.6 vs. 0.9%, P = 0.0014) and revascularization intervention (9.1 vs. 0% P = 0.026). However, there were no differences in death, cardiac death, myocardial infarction, and cerebral infarction after CABG operation between these two groups (P > 0.05).

Conclusions

A high PI and low MGF and DF are risk factors for newly developed graft failure. The patients with newly developed graft failure had higher rates of recurrent angina and revascularization intervention. TTFM parameters may be used to predict the occurrence of newly developed graft failure in patients after CABG surgery.

Transit time flow measurement predicts graft patency in off-pump coronary artery bypass grafting upon 5-year angiographic follow-up

Objective

This retrospective study sought to evaluate the efficacy of transit time flow measurement (TTFM) as a means of predicting bypass graft patency as assessed by coronary artery angiography upon 5-year follow-up.

Methods

Of 311 patients undergone isolated off-pump coronary artery bypass graft surgery from January 2014 through December 2014, 202 (65%) underwent both intraoperative TTFM and angiography at follow-up. 610 grafts, 202 left internal mammary artery grafts and 408 saphenous vein grafts were checked. Any grafts that exhibited Fitzgibbon type B or O lesions upon angiographic evaluation were considered to be failing. Receiver operating characteristic curves were used to identify the optimal TTFM values for predicting graft patency.

Results

A total of 610 grafts were included in this analysis, including 202 LIMA grafts and 408 SV grafts, of which 107, 129, 129, and 43 anastomosed to DIAG, OM, PDA, and PLA, respectively. LIMA, DIAG, OM, PDA, and PLA bypass grafts had overall patency rates of 95.0%, 74.8%, 73.6%, 71.5%, and 74.4%, respectively, upon 5-year follow up. No significant differences in TTFM values (MGF, PI, and DF) were observed when comparing outcomes associated with individual or sequential SV grafting. MGF was found to be predictive of graft failure regardless of the target vessel (P < 0.05). While PI was found to predict LIMA, OM, and PDA graft failure (P < 0.05), it was not associated with the failure of grafts associated with DIAG and PLA vessels. Similarly, DF was found to predict OM and PDA graft failure (P < 0.05), but was not significantly associated with the failure of grafts associated with LIMA, DIAG, or PLA vessels.

Conclusion

LIMA bypass grafts were associated with better 5-year graft patency relative to SV bypass grafts. Similar graft patency rates were observed for both individual and sequential bypass grafts. MGF was able to predict bypass graft failure in patients that underwent off-pump CABG surgery.

No-Touch Versus Conventional Vein Harvesting Techniques at 12 Months After Coronary Artery Bypass Grafting Surgery: Multicenter Randomized, Controlled Trial

BACKGROUND

Vein graft occlusion is deemed a major challenge in coronary artery bypass grafting. Previous studies implied that the no-touch technique for vein graft harvesting could reduce occlusion rate compared with the conventional approach; however, evidence on the clinical benefit and generalizability of the no-touch technique is scare.

METHODS

From April 2017 to June 2019, we randomly assigned 2655 patients undergoing coronary artery bypass grafting at 7 hospitals in a 1:1 ratio to receive no-touch technique or conventional approach for vein harvesting. The primary outcome was vein graft occlusion on computed tomography angiography at 3 months and the secondary outcomes included 12-month vein graft occlusion, recurrence of angina, and major adverse cardiac and cerebrovascular events. The generalized estimate equation model was used to account for the cluster effect of grafts from the same patient.

RESULTS

During the follow-up, 2533 (96.0%) participants received computed tomography angiography at 3 months after coronary artery bypass grafting and 2434 (92.2%) received it at 12 months. The no-touch group had significantly lower rates of vein graft occlusion than the conventional group both at 3 months (2.8% versus 4.8%; odds ratio, 0.57 [95% CI, 0.41-0.80]; P<0.001) and 12 months (3.7% versus 6.5%; odds ratio, 0.56 [95% CI, 0.41-0.76]; P<0.001). Recurrence of angina was also less common in the no-touch group at 12 months (2.3% versus 4.1%; odds ratio, 0.55 [95% CI, 0.35-0.85]; P<0.01). Rates of major adverse cardiac and cerebrovascular events were of no significant difference between the 2 groups. The no-touch technique was associated with higher rates of leg wound surgical interventions at 3-month follow-up (10.3% versus 4.3%; odds ratio, 2.55 [95% CI, 1.85-3.52]; P<0.001).

CONCLUSIONS

Compared with the conventional vein harvesting approach in coronary artery bypass grafting, the no-touch technique significantly reduced the risk of vein graft occlusion and improved patient prognosis. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03126409.

The impact of the quantitative assessment procedure for coronary artery bypass graft evaluations using high-resolution near-infrared fluorescence angiography

PURPOSE

Near-infrared angiography (NIR) is used for on-site graft assessment during coronary artery bypass grafting. This study evaluated the results of a quantitative NIR assessment using a new high-resolution NIR device (h-NIR) for graft assessment.

METHODS

Forty-three patients were enrolled in our study. Internal thoracic artery (ITA) grafts anastomosed to the left anterior descending artery and examined intraoperatively using h-NIR were included. The ITA grafts were divided into 2 groups for a comparative analysis: patent grafts (P group; n = 37) and failed grafts (F group; n = 6). The graft flow was evaluated by a "quantitative NIR assessment", and the fluorescence luminance intensity (FLI) was measured. Direct observation of the graft and anastomosis with h-NIR was also performed.

RESULTS

The FLI was higher in the P group than in the F group. The receiver operating characteristic analysis revealed the following cut-off values for FLIs depending on imaging duration: 21.1% at 1 s, 35.5% at 2 s, 58.4% at 3 s, and 83.3% at 4 s. The sensitivity and specificity for detecting graft failure were 83.3% and 69.8-80.6%, respectively. Furthermore, h-NIR was also able to visualize arterial dissection in ITA grafts.

CONCLUSIONS

A quantitative NIR assessment with an h-NIR device can improve the detectability of anastomotic stenosis, and h-NIR successfully detected arterial dissection of grafts.

Skeletonized vs Pedicled Internal Mammary Artery Graft Harvesting in Coronary Artery Bypass Surgery: A Post Hoc Analysis From the COMPASS Trial

Importance

The relative safety and patency of skeletonized vs pedicled internal mammary artery grafts in patients undergoing coronary artery bypass graft (CABG) surgery are unknown.

Objective

To investigate the association of skeletonized vs pedicled harvesting with internal mammary artery graft patency and clinical outcomes 1 year after CABG surgery.

Design, Setting, and Participants

This study was a post hoc analysis of the multicenter, randomized, double-blind, placebo-controlled Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) clinical trial, which enrolled 27 395 patients from 602 centers in 33 countries from March 2013 through May 2016. Eligibility criteria for the trial included CABG surgery for coronary artery disease with at least 2 grafts implanted and an estimated glomerular filtration rate of at least 30 mL/min. A total of 1002 of 1448 patients were randomized to the CABG arm of the COMPASS trial and underwent skeletonized (282 [28.1%]) or pedicled (720 [71.9%]) internal mammary artery harvesting. The patients had evaluable angiography results 1 year after surgery. Data were analyzed from October 11, 2019, to May 14, 2020.

Interventions

Patients underwent graft harvesting with either the pedicled technique or skeletonized technique.

Main Outcomes and Measures

The primary outcome was graft occlusion 1 year after CABG surgery, as assessed by computed tomography angiography.

Results

A total of 1002 patients underwent skeletonized (282 [28.1%]; mean [SD] age, 65.9 [8.1] years; 229 men [81.2%]; 194 White patients [68.8%]) or pedicled (720 [71.9%]; mean [SD] age, 64.8 [7.6] years; 603 men [83.8%]; 455 White patients [63.2%]) internal mammary artery harvesting. Rates of internal mammary artery graft occlusion 1 year after CABG surgery were higher in the skeletonized group than in the pedicled group (33 of 344 [9.6%] vs 30 of 764 [3.9%]; graft-level adjusted odds ratio, 2.41; 95% CI, 1.39-4.20; P = .002), including the left internal mammary artery to left anterior descending artery (21 of 289 [7.3%] vs 25 of 725 [3.4%]; graft-level adjusted odds ratio, 2.10; 95% CI, 1.14-3.88, P = .02). After a mean follow-up of 23 months, skeletonized graft harvesting was also associated with a higher rate of major adverse cardiovascular events (20 [7.1%] vs 15 [2.1%]; adjusted hazard ratio, 3.19; 95% CI, 1.53-6.67; P = .002) and repeated revascularization (14 [5.0%] vs 10 [1.4%]; adjusted hazard ratio, 2.75; 95% CI, 1.10-6.88; P = .03).

Conclusions and Relevance

This post hoc analysis of the COMPASS randomized clinical trial found that harvesting of the internal mammary artery during CABG surgery using a skeletonized technique was associated with a higher rate of graft occlusion and worse clinical outcomes than the traditional pedicled technique. Future randomized clinical trials are needed to establish the safety and patency of the skeletonized technique.

Trial Registration

ClinicalTrials.gov Identifier: NCT01776424.

The Short-Term Patency Rate of a Saphenous Vein Bridge Using the No-Touch Technique in off-Pump Coronary Artery Bypass Grafting in Vein Harvesting

Objective

This study aimed to examine the short-term effect of the no-touch technique on the patency rate of a great saphenous vein (GSV) bridge used during off-pump coronary artery bypass grafting (OPCABG).

Methods

Between June 2018 and September 2020, 140 patients undergoing OPCABG, with grafts obtained from the GSV using the "no-touch" technique or the left internal mammary artery (LIMA), were enrolled in this study. The early clinical results and short-term patency rate of the OPCABG were evaluated at a three-month follow-up by comparing the patency rate of the LIMA bridge and the GSV bridge obtained by the no-touch technique. This study also analyzed the impacts of the postoperative complications of the lower limbs and the distribution area of diseased vessels on the patency rate of a GSV bridge obtained by the no-touch technique at an early stage.

Results

No perioperative death or adverse cardiovascular or cerebrovascular events occurred in the 140 patients undergoing OPCABG. The difference in the early patency rate between the GSV bridge obtained by the no-touch technique and the LIMA bridge was not statistically significant (95.9% vs 97.1%, p = 0.501). There was no significant difference in the patency rate between an end-to-side anastomosed venous bridge and a LIMA bridge (95.0% [248/261] vs 97.1% [136/140], p = 0.314). The overall patency rate of a no-touch vein bridge in the right coronary artery region was lower than it was in the left coronary artery region (93.8% [165/176] vs 97.9% [183/187], p = 0.049).

Conclusion

The no-touch technique may improve the early patency rate of a GSV bridge, and its effect is similar to that of a LIMA bridge.

Mid-Term Outcomes and Angiographic Patency of Redo Coronary Artery Bypass Grafting: A Comparison between Off-Pump and On-Pump Surgery

Background

We evaluated the mid-term outcomes and angiographic patency of redo coronary artery bypass grafting (CABG).

Methods

Of 2,851 patients who underwent isolated CABG at Seoul National University Hospital from 2000 to 2017, 88 underwent redo CABG. Patients’ mean age at redo CABG was 66.0±8.0 years. The mean interval between the first-time and redo CABG was 113.0±62.4 months. The mean follow-up duration was 86 months. Early and mid-term clinical outcomes were evaluated. Angiographic patency rates were evaluated early (1–2 days), 1 year, and 5 years after surgery. Comparative analyses between on-pump and off-pump CABG were also performed.

Results

The culprits for reoperation were previous grafts (65.6%), native coronary vessels (17.8%), and both (16.7%). Off-pump CABG was performed in 75 cases (85.2%), and the mean number of distal anastomoses was 1.8±0.8. The saphenous vein (39.7%) was used most frequently, followed by the right internal thoracic artery (28.4%), right gastroepiploic artery (21.3%), left internal thoracic artery (7.8%), and radial artery (2.8%). Operative mortality was 1.1%. The overall survival, cumulative incidence of cardiac death, and cumulative incidence of major adverse cardiac events were 71.3%,12.0%, and 23.3% at 5 years after surgery, respectively. The overall angiographic patency rates were 95.7%, 90.1%, and 92.2% on early, 1-year, and 5-year angiograms, respectively. The angiographic patency rates of saphenous vein grafts were 93.1%, 85.6%, and 91.3% on early, 1-year, and 5-year angiograms, respectively. No significant differences in clinical outcomes or angiographic patency rates were observed between the on-pump (n=13) versus off-pump (n=75) groups. Multivariable analysis revealed that age (hazard ratio [HR], 1.07; p=0.005) and chronic kidney disease (HR, 3.85; p=0.001) were risk factors for all-cause mortality.

Conclusion

Redo CABG could mostly be performed using the off-pump technique and did not show increased operative mortality and morbidities.

Coronary Artery Bypass Grafting Transit Time Flow Measurement: Graft Patency and Clinical Outcomes

BACKGROUND

This subanalysis of the Randomized On-Off Bypass (ROOBY) trial examined transit time flow measurement (TTFM) use and its impact on graft patency and long-term clinical outcomes after coronary artery bypass graft surgery.

METHODS

Use of TTFM for ROOBY centers and surgeons was assessed. Comparative patient outcomes based on TTFM use included 1-year graft patency and 1-year and 5-year major adverse cardiac events: all-cause mortality, nonfatal myocardial infarction, and revascularization (percutaneous coronary intervention or repeat coronary artery bypass graft surgery).

RESULTS

Transit time flow measurement was used in 1067 patients (TTFM group) and not used in 501 patients (non-TTFM group); of the TTFM group, median percentage TTFM use was 79% (interquartile range, 41% to 98%) among 18 Veterans Affairs Medical Centers, and 74% (interquartile range, 13% to 98%) among 48 surgeons. Patients were comparable in age (63 ± 8.5 years TTFM vs 62 ± 8 years non-TTFM, P = .30) and estimated 30-day mortality risk (1.8 ± 1.7 TTFM vs 1.9 non-TTFM, P = .53). One-year FitzGibbon A patency was 83% (1600 of 1988 grafts) for TTFM assessed grafts and 78% (629 of 803) for non-TTFM assessed grafts (P < .01). Fewer TTFM patients had an occluded graft (29%, vs 38% non-TTFM; P = .01). Comparing TTFM patients with non-TTFM patients, 5-year major adverse cardiac event rates were 30% vs 25% (P = .06). Individual component rates were 14% vs 11% for death (P = .06), 12% vs 8.8% for myocardial infarction (P = .07), and 13% vs 12% for revascularization (P = .62).

CONCLUSIONS

The association of TTFM use with graft patency and clinical outcome is uncertain. Future randomized studies that account for patient risk factors and practice variation would help address this knowledge gap.

The predictive value of intraoperative transit-time flow measurement parameters for early graft failure in different target territories

BACKGROUND

Early graft failure can affect the short- and long-term outcomes of patients undergoing coronary bypass grafting surgery (CABG). The aim of our study was to explore the predictive value of transit-time flow measurement (TTFM) parameters for early graft failure (before discharge) after CABG in different coronary territories and calculate the TTFM cut-off values.

METHODS

We analyzed a total of 761 grafts (360 patients) that were evaluated by intraoperative TTFM and computed tomography angiography prior to discharge. Logistic model was established to detect the parameters of TTFM to predict early graft failure and receiver operating characteristic curve analysis was used to calculate the cut-off values.

RESULTS

The overall early graft failure was 3.5%. The results demonstrated that compared with off-pump CABG, mean graft flow volume was higher (28.0 vs 21.0 mL/min, p = 0.000), but pulse index (PI) (2.3 vs 2.5, p = 0.049) and diastolic flow fraction (DF) (68.0% vs 71.0%, p = 0.001) were lower in on-pump CABGs. DF (73.0% vs 65.5%, p = 0.000) of arterial grafts was higher than that of venous grafts. DF (72.0% vs 62.0%, p = 0.000) in left was higher than that in the right coronary artery territories. The results of multivariate logistic analysis showed that not only in the overall (OR 1.18, 95% CI 1.07-1.30, p = 0.001), but also the left (OR 1.21, 95% CI 1.03-1.41, p = 0.017) and right (OR 1.15, 95% CI 1.03-1.29, p = 0.017) coronary artery target territories, PI was a risk factor for early graft failure and the cut-off value was 3.4, 3.4, and 3.6, respectively. For grafts in left target territories, the results showed that DF (OR 0.94, 95% CI 0.91-0.97, p = 0.000) just in the univariate analysis was a risk factor that affected graft failure.

CONCLUSIONS

The overall early graft failure was about 3.5%. High PI value is a risk factor for early graft failure in not only overall grafts but in grafts of different target territories. DF might be more useful for the quality evaluation of grafts in left than in right target territories.

Outcomes and Patency of Complex Configurations of Composite Grafts Using Bilateral Internal Thoracic Arteries

Background

It is generally agreed that using a bilateral internal thoracic artery (BITA) composite graft improves long-term survival after coronary artery bypass grafting (CABG). Although the left internal thoracic artery (LITA)-based Y-composite graft is widely adopted, technical or anatomical difficulties necessitate complex configurations. We aimed to investigate whether BITA configuration impacts survival or patency in patients undergoing coronary revascularization.

Methods

Between January 2006 and June 2017, 1,161 patients underwent CABG at Seoul National University Bundang Hospital, where the standard technique is a LITA-based Y-composite graft with the right internal thoracic artery (RITA) sequentially anastomosed to non-left anterior descending (LAD) targets. Total of 160 patients underwent CABG using BITA with modifications. Their medical records and imaging data were reviewed retrospectively to investigate technical details, clinical outcomes, and graft patency.

Results

Modifications of the typical Y-graft (group 1, n=90), LITA-based I-graft (group 2, n=39), and RITA-based composite graft (group 3, n=31) were used due to insufficient RITA length (47%), problems using LITA (28%), and target vessel anatomy (25%). The overall 30-day mortality rate was 1.9%. Among 116 patients who underwent computed tomography or conventional angiography at a mean interval of 29.9±33.1 months postoperatively, the graft patency rates were 98.7%, 95.3%, and 83.6% for the LAD, left circumflex artery, and right coronary artery territories, respectively. Patency rates for the inflow, secondary, and tertiary grafts were 98.2%, 90.5%, and 80.4%, respectively. The RITA-based graft (group 3) had the lowest patency rate of the various configurations (p<0.011).

Conclusion

LITA-based Y composite graft, showed satisfactory clinical outcomes and patency whereas modifications of RITA-based composite graft had the lowest patency and 5-year survival rates. Therefore, when using RITA-based composite graft, other options should be considered before proceeding atypical configurations.

Patency of conduits in patients who received internal mammary artery, radial artery and saphenous vein grafts

Background

Where each patient has all three conduits of internal mammary artery (IMA), saphenous vein graft (SVG) and radial artery (RA), most confounders affecting comparison between conduits can be mitigated. Additionally, since SVG progressively fails over time, restricting patient angiography to the late period only can mitigate against early SVG patency that may have occluded in the late period.

Methods

Research protocol driven conventional angiography was performed for patients with at least one of each conduit of IMA, RA and SVG and a minimum of 7 years postoperative. The primary analysis was perfect patency and secondary analysis was overall patency including angiographic evidence of conduit lumen irregularity from conduit atheroma. Multivariable generalized linear mixed model (GLMM) was used. Patency excluded occluded or “string sign” conduits. Perfect patency was present in patent grafts if there was no lumen irregularity.

Results

Fifty patients underwent coronary angiography at overall duration postoperative 13.1 ± 2.9, and age 74.3 ± 7.0 years. Of 196 anastomoses, IMA 62, RA 77 and SVG 57. Most IMA were to the left anterior descending territory and most RA and SVG were to the circumflex and right coronary territories. Perfect patency RA 92.2% was not different to IMA 96.8%, P = 0.309; and both were significantly better than SVG 17.5%, P < 0.001. Patency RA 93.5% was also not different to IMA 96.8%, P = 0.169, and both arterial conduits were significantly higher than SVG 82.5%, P = 0.029. Grafting according to coronary territory was not significant for perfect patency, P = 0.997 and patency P = 0.289. Coronary stenosis predicted perfect patency for RA only, P = 0.030 and for patency, RA, P = 0.007, and SVG, P = 0.032.

When both arterial conduits were combined, perfect patency, P < 0.001, and patency, P = 0.017, were superior to SVG.

Conclusions

All but one patent internal mammary artery or radial artery grafts had perfect patency and had superior perfect patency and overall patency compared to saphenous vein grafts.

Rivaroxaban, Aspirin, or Both to Prevent Early Coronary Bypass Graft Occlusion: The COMPASS-CABG Study

BACKGROUND

Patients with recent coronary artery bypass graft (CABG) surgery are at risk for early graft failure, which is associated with a risk of myocardial infarction and death. In the COMPASS (Cardiovascular OutcoMes for People Using Anticoagulation StrategieS) trial, rivaroxaban 2.5 mg twice daily plus aspirin 100 mg once daily compared with aspirin 100 mg once daily reduced the primary major adverse cardiovascular events (MACE) outcome of cardiovascular death, stroke, or myocardial infarction. Rivaroxaban 5 mg twice daily alone did not significantly reduce MACE.

OBJECTIVES

This pre-planned substudy sought to determine whether the COMPASS treatments are more effective than aspirin alone for preventing graft failure and MACE after CABG surgery.

METHODS

The substudy randomized 1,448 COMPASS trial patients 4 to 14 days after CABG surgery to receive the combination of rivaroxaban plus aspirin, rivaroxaban alone, or aspirin alone. The primary outcome was graft failure, diagnosed by computed tomography angiogram 1 year after surgery.

RESULTS

The combination of rivaroxaban and aspirin and the regimen of rivaroxaban alone did not reduce the graft failure rates compared with aspirin alone (combination vs. aspirin: 113 [9.1%] vs. 91 [8.0%] failed grafts; odds ratio [OR]: 1.13; 95% confidence interval [CI]: 0.82 to 1.57; p = 0.45; rivaroxaban alone vs. aspirin: 92 [7.8%] vs. 92 [8.0%] failed grafts; OR: 0.95; 95% CI: 0.67 to 1.33; p = 0.75). Compared with aspirin, the combination was associated with fewer MACE (12 [2.4%] vs. 16 [3.5%]; hazard ratio [HR]: 0.69; 95% CI: 0.33 to 1.47; p = 0.34), whereas rivaroxaban alone was not (16 [3.3%] vs. 16 [3.5%]; HR: 0.99, CI: 0.50 to 1.99; p = 0.98). There was no fatal bleeding or tamponade within 30 days of randomization.

CONCLUSIONS

The combination of rivaroxaban 2.5 mg twice daily plus aspirin or rivaroxaban 5 mg twice daily alone compared with aspirin alone did not reduce graft failure in patients with recent CABG surgery, but the combination of rivaroxaban 2.5 mg twice daily plus aspirin was associated with similar reductions in MACE, as observed in the larger COMPASS trial. (Cardiovascular OutcoMes for People Using Anticoagulation StrategieS [COMPASS]; NCT01776424).

Bilateral Internal Thoracic Artery In Situ Versus Y-Composite Graftings: Long-term Outcomes

BACKGROUND

We compared 10-year graft patency rates and long-term clinical outcomes after off-pump coronary artery bypass grafting using bilateral internal thoracic arteries (ITAs) as in situ grafts with those using bilateral ITAs as Y-composite grafts.

METHODS

Of 509 patients who underwent off-pump coronary artery bypass grafting using bilateral ITAs, bilateral ITAs were used as in situ grafts in 172 patients (group I) and as Y-composite grafts in 337 patients (group Y). A propensity score-matched analysis was used to match group I patients (n = 153) with group Y patients (n = 153). Ten-year angiographic patency rates and long-term clinical outcomes were compared. The follow-up data were complete in 99.2% of patients (505/509) with a median follow-up duration of 175 months.

RESULTS

Ten-year overall patency rates and patency rates for distal anastomoses using bilateral ITAs were 87.5% (356/407) and 89.2% (297/333), respectively, in the propensity score-matched groups. No differences in overall patency rates (groups I vs Y, 84.9% vs 89.5%, P = .277) and bilateral ITA patency rates (groups I vs Y, 86.5% vs 91.1%, P = .282) were found between the propensity score-matched groups. There were no differences in the overall survival and cumulative incidence of cardiac death between the propensity score-matched groups (P = .312 and P = .812, respectively) up to 15 years after surgery. Cumulative incidences of target vessel revascularization (P = .606), reintervention (P = .849), and major adverse cardiac events (P = .672) were also similar between the propensity score-matched groups up to 15 years after surgery.

CONCLUSIONS

Off-pump coronary artery bypass grafting using bilateral ITAs as in situ versus Y-composite grafts demonstrated no differences in terms of 10-year patency rates and long-term clinical outcomes between the groups.

Twenty-Year Experience With Off-Pump Coronary Artery Bypass Grafting and Early Postoperative Angiography

BACKGROUND

We have performed off-pump coronary artery bypass grafting and also performed early postoperative angiography to assess anastomosis accuracy and patency in most of our patients requiring surgical revascularization.

METHODS

Of 3083 patients who underwent isolated coronary artery bypass grafting between 1998 and 2017, 2919 patients (94.7%) underwent off-pump coronary artery bypass grafting. Conduits for distal anastomoses were left internal thoracic artery (n = 2764), right internal thoracic artery (n = 866), right gastroepiploic artery (n = 997), radial artery (n = 16), and saphenous vein (n = 1505). Since the introduction of transit-time flow measurement in 2000, we revised abnormal grafts intraoperatively. Early (≤7 days) angiography was performed in 2820 patients (96.6%) at 1.5 ± 1.2 postoperative days, and surgical intervention was performed based on angiographic findings.

RESULTS

Operative mortality was 1.1% (32 of 2919). Average number of distal anastomoses was 3.2 ± 1.0. Intraoperative flowmetry-guided revision for distal anastomosis failures was performed in 109 of 8585 distal anastomoses (1.3%). Angiography showed an overall patency of 98.2% (8836 of 9001): 99.0% (5484 of 5540) for arterial and 96.9% (3352 of 3461) for venous conduits (P < .001). Patency of venous conduits was 87.2% (231 of 265) for free grafts and 97.7% (3121 of 3196) for composite grafts (P = .001). After the introduction of transit-time flow measurement, patency of arterial conduits became significantly higher (97.2% vs 99.2%; P = .038); however, patency of free venous conduits was not significantly improved (86.0% vs 91.4%; P = .181). Early re-intervention according to angiographic findings was performed in 76 patients (2.7%). Reevaluation of graft patency before discharge in 31 who underwent revision of distal anastomoses showed improved patency (65.1% [56 of 86] vs 95.3% [82 of 86]; P < .001).

CONCLUSIONS

Intraoperative flowmetry and revision of abnormal grafts improved early arterial graft patency, and reoperation based on early angiographic findings may further improve graft patency at the time of discharge.

Implications of coronary artery bypass grafting and percutaneous coronary intervention on disease progression and the resulting changes to the physiology and pathology of the native coronary arteries

Myocardial revascularization can be achieved through 2 different methods: coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). Clinical trials comparing PCI and CABG generally use the composite end points of death, stroke, myocardial infarction and target vessel revascularization to determine superiority. Other effects of these interventions, including the preservation of normal coronary physiology, the response of the coronary tree to stressors and the response of the vessel wall to the revascularization intervention, are not routinely considered, but these may have significant implications for patients in the medium and long term. For PCI, relatively small differences in clinical outcomes have been reported between bare metal and drug-eluting stents, and the latter seems to have inconsistent and somewhat unpredictable effects on the vascular biology of the coronary arteries. In coronary bypass, the use of arterial conduits is associated with superior clinical outcomes, better long-term patency and the preservation of essentially normal coronary function after intervention. This review assembles the clinical, physiological, angiographic and pathological literature currently available and attempts to provide a more complete picture of the effects of CABG and PCI on coronary arteries.

Rationale and design of a multicenter randomized trial to compare the graft patency between no-touch vein harvesting technique and conventional approach in coronary artery bypass graft surgery

BACKGROUND

Vein graft failure is a crucial challenge in coronary artery bypass graft (CABG) surgery. Previous studies have suggested a patency benefit of the No-Touch vein harvesting technique, but only with small sample sizes.

MATERIALS AND METHODS

This study is a prospective, multicenter randomized clinical trial with a large sample size, aiming to investigate the efficacy of the No-Touch technique compared with the conventional approach. All patients requiring isolated CABG with left internal mammary artery plus at least one saphenous vein graft will be considered for entry into the study. Two thousand cases (1000 in each arm) will be enrolled over 1 to 2 years in 7 hospitals in China. Participants will be randomized in equal proportions between two surgical strategies: the No-Touch or conventional technique. The primary endpoint is graft vessel occlusion at 3 months after CABG surgery by CT coronary angiography. Secondary outcomes are major adverse cardiac or cerebrovascular events at 3 and 12 months post-operation and graft vessel occlusion at 1 year.

DISCUSSION

This study will define the role of the No-Touch vein harvesting technique in CABG surgery and provide strong evidence to answer whether this technique could reduce vein graft occlusion.

Is There a Role for Diagonal Coronary Artery Stenting in Patients Undergoing Robotic Coronary Artery Bypass Graft Surgery?

Background

The efficacy of diagonal coronary artery stenting in patients undergoing robotic left internal thoracic artery-to-left anterior descending (LITA-to-LAD) anastomosis is not well defined. The objective of this study was to assess graft and stent patency in a single-stage hybrid revascularization with LITA-to-LAD anastomosis and PCI to a diagonal coronary artery.

Methods

From 2004 to 2014, a total of 25 patients consented to robotic-assisted LITA harvesting and a small left anterior thoracotomy for off-pump coronary artery bypass anastomosis onto the LAD along with concomitant PCI to the diagonal coronary artery. PCI to the diagonal coronary artery was performed in the same fluoroscopy-equipped hybrid operating room.

Results

Patients were on average 66 ± 11 years with 32% female. Pre-operative characteristics of these patients included 8% with a grade 3 or 4 left ventricle, 16% with a recent MI, and 92% with CCS III/IV symptoms. There were no death, one patient required an intra-aortic balloon pump, and one patient required re-operation for bleeding. The average ICU stay was 1.1 ± 0.53 days, and the average hospital stay was 4.6 ± 2.4 days. Fitzgibbon Grade A LITA-to-LAD patency at 6-month follow-up was 100%. As well, at 6-month follow-up the DES to the diagonal coronary artery had a patency rate of 96%.

Conclusions

Single-stage hybrid revascularization strategy for bifurcating lesions of the LAD and diagonal coronary arteries with LITA-to-LAD anastomosis and PCI to a diagonal coronary artery appears to have acceptable clinical results with excellent 6-month angiographic patency results.

A Prospective Randomized Study of Endoscopic Versus Conventional Harvesting of the Radial Artery

OBJECTIVE

The aims of the study were to determine whether endoscopic harvesting of the radial artery (RA) reduces morbidity due to pain, infection, and disability with improvement in satisfaction and cosmesis compared to the conventional technique and (2) to compare the 6-month angiographic patency of the RA harvested conventionally and endoscopically.

METHODS

In a prospective randomized study, 119 patients undergoing coronary artery bypass grafting using the RA were randomized to have RA harvested either conventionally (n = 59) or endoscopically (n = 60).

RESULTS

Radial artery harvest time (open wound time) was significantly reduced in the endoscopic group (36.5 ± 9.4 vs 57.7 ± 9.4 minutes, P < 0.001). Only one patient developed wound infection (1.6%) in the endoscopic group compared with six patients (10.2%), P = 0.061, in the conventional group. Although this was not statistically significant, clinically this was relevant in terms of reduction in postoperative morbidity. Postoperative pain in the arm incision was significantly lower in the endoscopic group at postoperative day 2 (P < 0.001) and at discharge (P < 0.001) and similar to the conventional open group at 6 weeks' follow-up (P = 0.103). Overall patient satisfaction and cosmesis were significantly better in the endoscopic group at postoperative day 2 (P < 0.001), at discharge (P < 0.001), and at 6 weeks' follow-up (P < 0.001). There was no difference in the arm disability postoperatively (P = 0.505) between the two groups. Six-month angiographic assessment of 23 patients (12 endoscopic and 11 open) revealed no difference in the patency rate (10/12 in endoscopic and 9/11 in open group).

CONCLUSIONS

Endoscopic RA harvesting reduced the incidence of postoperative wound infection and wound pain and improved patient satisfaction and cosmesis compared with conventional harvesting technique. There was no difference in the 6-month angiographic patency of the RA harvested conventionally and endoscopically.

On-Pump versus Off-Pump Complete Arterial Revascularization Using Bilateral Internal Mammary Arteries and the T-Graft Technique: Clinical and Angiographic Results for 3,445 Patients in 13 Years of Follow-Up

BACKGROUND

This is an investigation of complete arterial coronary artery bypass grafting (CACABG) using bilateral internal mammary arteries (IMA) and the T-graft technique either on- or off-pump as a routine approach to treat coronary artery disease.

METHODS

Between January 2000 and December 2012, 3,445 patients underwent on-pump (n = 2,216) or off-pump (n = 1,229) CACABG. A 30-day follow-up was performed prospectively, a long-term follow-up by a questionnaire, and coronary angiography in selected patients.

RESULTS

End points at 30 days were death, myocardial infarction, stroke, repeat revascularization, renal replacement, reoperation, sternal wound infection and atrial fibrillation. FitzGibbon A patency rates were 89.8 vs. 91.4% (p = 0.464) with consecutive percutaneous coronary intervention in the grafted area of 1.8 vs. 1.1% (p = 0.693) on- vs. off-pump, and no reoperation in the grafted area in both groups.

CONCLUSION

CACABG by use of skeletonized bilateral IMA with the T-graft technique performed either on- or off-pump is a safe and effective approach.

Predictors of early graft failure after coronary artery bypass grafting for chronic total occlusion

OBJECTIVES

Little is known regarding the transit-time flow measurement (TTFM) variables in grafts anastomosed to chronically totally occluded vessels (CTOs). We aimed to establish the TTFM cut-off values for detecting graft failure in bypass grafts anastomosed to chronically totally occluded arteries and clarify the relationship between early graft failure and the grade of collateral circulation/regional wall motion of the CTO territory.

METHODS

Among 491 patients who underwent isolated coronary artery bypass grafting (CABG) from 2009 to 2015, 196 cases with CTOs underwent postoperative coronary angiography within 1 month after CABG. Two hundred and forty-one CTOs in all patients were examined. Thirty-two CTOs (13%) were not bypassed and 214 conduits were anastomosed to CTOs and underwent intraoperative TTFM. Arterial conduits and saphenous vein grafts (SVGs) were used in 102 and 112 cases, respectively. Among the arterial conduit procedures that were performed, 78 involved the left internal thoracic artery (LITA), 10 involved the right internal thoracic artery (RITA) and 14 involved the right gastroepiploic artery (rGEA). Any graft showing Fitzgibbon type B or O lesions on angiography was considered to be a failing graft.

RESULTS

The insufficiency rates for LITA, RITA, rGEA and SVG procedures were 5.1, 10, 14.3 and 7.1%, respectively. The TTFM variables recorded in failing grafts had a significantly lower mean flow (Qmean) and higher pulsatility index (PI) compared with patent grafts. Furthermore, akinetic or dyskinetic wall motion in the territory of bypassed CTOs was observed at a significantly higher rate in failing grafts. A multivariable regression analysis and receiver operating characteristic analysis revealed good predictors of early graft failure as follows: a Qmean value of < 11.5 ml/min for arterial conduits, a PI value of >5.85 and akinetic/dyskinetic wall motion in the CTO territory for SVGs. The Rentrop collateral grade was not associated with early graft failure.

CONCLUSIONS

The Qmean value and PI value by the TTFM are useful to detect early graft failure in conduits anastomosed to CTOs. The collateral grade is not associated with graft failure; however, bypass grafting to CTOs with akinetic/dyskinetic wall motion should be carefully considered.

Morphological Evaluation of Proximal Anastomosis by PAS-Port(®) System in Patients with Long-Term Patent Grafts

PURPOSE

We examined grafts employing for morphological analysis of early and long-term results on proximal anastomosis with the PAS-Port(®).

METHODS

One hundred and four patients treated by OPCAB with PAS-Port(®) were performed postoperative MDCT. Morphological evaluation of the proximal anastomotic region was classified into three groups (A; graft was anastomosed almost perpendicularly to the aortic wall, B; graft was same type A, but subsequently curved to form an acute angle with the aortic wall, C; graft take off acute angle with the aortic wall) evaluated on planar and sagittal sections.

RESULTS

One hundred twenty-six PAS-Port(®) were used. Patency rate was 99.0% at discharge, 94.7% at 1 year, and no blockages were detected thereafter in patients examined. The morphology rate was A 50.6%, B 15.3% and C 34.1% on planar sections, and A 58.8%, B 10.6% and C 30.6% on sagittal sections.

CONCLUSION

The morphological evaluation of grafts revealed the degree of freedom in graft design to be relatively high and long-term patency posed no particular problem even if the layout of the proximal anastomotic region involved a relatively acute angle. The PAS-Port(®) was considered to be a highly reliable device which performed appropriate proximal anastomosis and improved the patency of vein grafting to the aortic wall.

Five-year clinical outcome and patency rate of device-dependent venous grafts after clampless OPCAB with PAS-port automated proximal anastomosis: the PAPA Study

OBJECTIVE

To evaluate long-term clinical performance and angiographic patency of automated proximal venous anastomoses following clampless coronary artery bypass (C-CAB).

METHODS

Observational study in patients submitted for isolated C-CAB and at least one proximal aortosaphenous anastomosis performed with an automated connector (Cardica PAS-Port) including 152 consecutive patients (165 devices and 199 device-dependent distal anastomoses), with LVEF > 30% and saphenous vein diameter of 4-6 mm. Clinical follow-up was 96% complete (4101/4269 pt-months). Graft patency rate was assessed with 64-slice CT-scan or coronary angiography. Freedom from major adverse cardiac and cerebrovascular events (MACCE) was reported as actuarial probability with 95% confidence limits and venous graft patency as actual rate at every year interval.

RESULTS

Early operative mortality was 1.9%; incidence of neurologic injury was zero. Freedom from MACCE was 92.7 ± 2.1 at one year and 85.2 ± 4.8 at five years. The actual patency rate of device-dependent venous grafts was 90%, 85%, 84%, 84%, and 93% for one-, two-, three-, four-, and five-year-old grafts, respectively.

CONCLUSIONS

The device is a well-performing system for proximal anastomoses. The incidence of neurologic complications seems to be reduced with this clampless approach. The high patency rate is stable over time.

Coronary artery bypass grafting: Part 1--the evolution over the first 50 years

Surgical treatment for angina pectoris was first proposed in 1899. Decades of experimental surgery for coronary artery disease finally led to the introduction of coronary artery bypass grafting (CABG) in 1964. Now that we are approaching 50 years of CABG experience, it is appropriate to summarize the advancement of CABG into a procedure that is safe and efficient. This review provides a historical recapitulation of experimental surgery, the evolution of the surgical techniques and the utilization of CABG. Furthermore, data on contemporary clinical outcomes are discussed.

Coronary artery bypass grafting: Part 2--optimizing outcomes and future prospects

Since first introduced in the mid-1960s, coronary artery bypass grafting (CABG) has become the standard of care for patients with coronary artery disease. Surprisingly, the fundamental surgical technique itself did not change much over time. Nevertheless, outcomes after CABG have dramatically improved over the first 50 years. Randomized trials comparing percutaneous coronary intervention (PCI) to CABG have shown converging outcomes for select patient populations, providing more evidence for wider use of PCI. It is increasingly important to focus on the optimization of the short- and long-term outcomes of CABG and to reduce the level of invasiveness of this procedure. This review provides an overview on how new techniques and widespread consideration of evolving strategies have the potential to optimize outcomes after CABG. Such developments include off-pump CABG, clampless/anaortic CABG, minimally invasive CABG with or without extending to hybrid procedures, arterial revascularization, endoscopic vein harvesting, intraprocedural epiaortic scanning, graft flow assessment, and improved secondary prevention measures. In addition, this review represents a framework for future studies by summarizing the areas that need more rigorous clinical (randomized) evaluation.

Real-time graft flow assessment using epigraftic ultrasonography during coronary artery bypass grafting

OBJECTIVES

Real-time graft flow assessment in the operative field has been performed to ascertain the patency in coronary artery bypass grafting (CABG). This study aims to evaluate the efficacy of graft flow assessment by epigraftic ultrasonography.

METHODS

CABG was performed in 135 patients from January 2010 to December 2012. One hundred and ten patients (81.4%) underwent both real-time graft flow measurement using epigraftic ultrasonography and coronary angiography (CAG) with a total of 249 grafts. Parameters were obtained from flow velocity curves in all grafts. The grafts were divided into two groups: patent grafts (Group A) and failing grafts (Group B). All parameters were compared in these two groups. Logistic regression analysis was performed to detect the predictors of graft failure and receiver operating characteristic (ROC) curve analysis was used to calculate the optimal cut-off value of the predictors of graft failure.

RESULTS

The overall patency as measured by CAG of the grafts was 97.2% (242/249). Logistic regression analysis revealed that the percentage of systolic and diastolic reverse flow (%sRF, %dRF) as well as the pulsatility index (PI) were predictors of early postoperative graft failure. ROC curve analysis revealed that mean velocity <12.5 cm/s, %sRF >9.3%, %dRF >4.1% and PI >4.4 were predictors of early graft failure.

CONCLUSIONS

In this series, epigraftic ultrasonography depicted graft flow clearly. Epigraftic ultrasonography is a useful tool to predict graft failure during CABG. This technique is easily performed using a conventional linear ultrasound transducer.