Radial artery patency: are aortocoronary conduits superior to composite grafting?

Sequential composite BIMA grafting for 3v-CAD: factors that predict successful outcome of the one-inflow and two-inflow revascularization techniques

OBJECTIVE

The effect of one-inflow and two-inflow coronary surgical revascularization techniques inclosing skeletonized double mammary artery (BIMA) as T-graft on outcome is studied.

METHODS

Early ad mid-term outcome of complete BIMA revascularization (C-T-BIMA) versus left-sided BIMA with right-sided aorto-coronary bypass (L-T-BIMA + R-CABG) is quantified and analyzed by multivariate logistic regression, Cox-regression, and Kaplan-Meier analysis in a series of 204 consecutive patients treated for triple-vessel coronary disease (3v-CAD).

RESULTS

The L-T-BIMA + R-CABG technique (n = 104) enables higher number of total (4.02 ± 0.87 vs. 3.71 ± 0.69, p = 0.015) and right-sided (1.21 ± 0.43 vs. 1.02 ± 0.32, p = 0.001) coronary anastomoses, improves total bypass flow (125.88 ± 92.41 vs. 82.50 ± 49.26 ml, p < 0.0001) and bypass flow/anastomosis (31.83 ± 23.9 vs.22.77 ± 14.23, p = 0.001), and enhances completeness of revascularization (84% vs.69%, p = 0.014) compared to C-T-BIMA strategy (n = 100), respectively. Although the incidence of MACCE was comparable in the two groups (8% vs.1.2%, p = 0.055), the progression of functional mitral regurgitation (FMR) was significantly lower after L-T-BIMA + R-CABG, then after C-T-BIMA (47% vs.64%, p = 0.017). The use of C-T-BIMA-technique (HR = 4.2, p = 0.01) and preoperative RCA occlusion (HR = 3.006, p = 0.023) predicted FMR progression, whereas L-T-Graft + R-CABG technique protected against it (X2 = 14.04, p < 0.0001) independent of the anatomic and clinical complexity (Syntax score I: HR = 16.2, p = 0.156, Syntax score II: HR = 1.901, p = 0.751), of early- (0.96% vs.2%, p = 0.617) and mid-term mortality (5.8% vs.4%, p = 0.748) when compared to C-T-BIMA, respectively.

CONCLUSIONS

The two-inflow coronary revascularization by L-T-BIMA + R-CABG better protects against FMR progression without increasing MACCE and mortality. Older patients with RCA occlusion and reduced LV-EF benefit most from the two-inflow L-T-BIMA + R-CABG technique. Younger 3v-CAD patients with normal LV-EF can preferentially be managed with the one-inflow C-T-BIMA; however, long-term outcome remains to be revealed.

Rationale and design of a single-center randomized trial to compare the graft patency between the radial artery and the no-touch saphenous vein in coronary artery bypass grafting surgery (GRAFT-CAB Study)

BACKGROUND

Previous studies suggested only the radial artery and the No-touch (NT) technique were effective in reducing graft occlusion after coronary artery bypass grafting (CABG) surgery. However, there is no randomized trial comparing these 2 graft conduits. The optimum second conduit for CABG remains undetermined.

MATERIALS AND METHODS

This study is a prospective, single-center randomized clinical trial, aiming to compare the graft patency between the radial artery and the NT vein graft. All patients undergoing isolated CABG with left internal mammary artery (LIMA) plus at least 2 additional grafts will be considered eligible. About 774 cases (516 in the radial artery group and 258 in the NT vein group) will be enrolled in over 1 to 2 years. Participants will be randomized and allocated to two bypass strategies: the LIMA plus 1 radial artery and 1 conventional vein graft, or the LIMA plus 2 NT vein grafts. The primary outcome is graft occlusion at 1 year after CABG evaluated by CT angiography. The secondary outcomes include graft occlusion at 3 and 5 years and major adverse cardiac or cerebrovascular events at 1, 3, and 5 years follow-ups.

DISCUSSION

This study will define whether or not the NT vein has a lower graft occlusion rate than the radial artery in short and mid-term follow-ups, and provide new evidence for the second conduit choice in CABG surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06014047. Registered on October 15th, 2023.

Effect of the Proximal Anastomosis Configuration of the Radial Artery in Patients Undergoing Coronary Artery Bypass Grafting

BACKGROUND

Several factors, such as the degree of target vessel stenosis, are known to be associated with radial artery (RA) graft patency in coronary artery bypass grafting (CABG). There is a lack of data regarding the effect of the RA proximal configuration (aortic anastomosis versus T-anastomosis). This study evaluated the effects of the RA proximal configuration on the patency rate and clinical outcomes after CABG.

METHODS

We conducted a retrospective study, analyzing 328 patients who had undergone CABG with an RA graft. We divided the patients into 2 groups. The primary endpoint was RA patency and the secondary endpoints were overall mortality and major adverse cardiac and cerebrovascular events (MACCE). We performed a propensity score-matched comparison.

RESULTS

Aorta-RA anastomosis was performed in 275 patients, whereas the rest of the 53 patients received T-RA anastomosis. The mean age was 67.3±8.7 years in the T-RA anastomosis group and 63.8±9.5 years in the aorta-RA anastomosis group (p=0.02). The mean follow-up duration was 5.13±3.07 years. Target vessel stenosis ≥70% (hazard ratio [HR], 0.42; 95% confidence interval [CI], 0.20-0.91; p=0.03) and T-RA anastomosis configuration (HR, 2.34; 95% CI, 1.01-5.19; p=0.04) were significantly associated with RA occlusion in the multivariable analysis. However, T-RA anastomosis was not associated with higher risks of overall mortality and MACCE following CABG (p=0.30 and p=0.07 in the matched group, respectively).

CONCLUSION

Aorta-RA anastomosis showed a superior patency rate compared to T-RA anastomosis. However, the RA proximal anastomosis configuration was not associated with mortality or MACCE.

Total Arterial Coronary Bypass Graft Surgery is Associated with Better Long-Term Survival in Patients with Multivessel Coronary Artery Disease: a Systematic Review with Meta-Analysis

INTRODUCTION

The benefit of total arterial revascularization (TAR) in coronary artery bypass grafting (CABG) remains a controversial issue. This study sought to evaluate whether there is any difference on the long-term results of TAR and non-TAR CABG patients.

METHODS

The Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica dataBASE (EMBASE), Cochrane Central Register of Controlled Trials (CENTRAL/CCTR), Clinical Trials.gov, Scientific Electronic Library Online (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), and Google Scholar databases were searched for studies published by October 2020. Randomized clinical trials and observational studies with propensity score matching comparing TAR versus non-TAR CABG were included. Random-effects meta-analysis was performed. The current barriers to implementation of TAR in clinical practice and measures that can be used to optimize outcomes were reviewed.

RESULTS

Fourteen publications (from 2012 to 2020) involving a total of 22,746 patients (TAR: 8,941 patients; non-TAR: 13,805 patients) were included. The pooled hazard ratio (HR) for long-term mortality (over 10 years) was lower in the TAR group than in the non-TAR group (random effect model: HR 0.676, 95% confidence interval 0.586-0.779, P<0.001). There was evidence of low heterogeneity of treatment effect among the studies for mortality, and none of the studies had a particular impact on the summary result. The result was not influenced by age, sex, or comorbidities. We identified low risk of publication bias related to this outcome.

CONCLUSION

This review found that TAR presents the best long-term results in patients who undergo CABG. Given that many patients are likely to benefit from TAR, its use should be encouraged.

Total Arterial Revascularization with Radial Artery and Internal Thoracic Artery T-Grafts Is Associated with Superior Long-Term Survival in Patients Undergoing Coronary Artery Bypass Grafting

AIMS

Compelling evidence encourages the use of the radial artery (RA) as the second arterial graft in coronary artery bypass grafting (CABG). However, its long-term benefits remain disputed. We sought to evaluate long-term outcome and survival by comparing patients receiving RAs with those receiving venous grafts to a single internal thoracic artery (ITA).

METHODS

We analyzed 345 patients undergoing primary multivessel CABG and conducted a 13-year long follow-up. In all, 187 patients received the RA and the left ITA as T-graft; 158 patients received saphenous veins complementing a single ITA. We performed propensity-score matching on 81 pairs to balance treatment selection and confounders.

RESULTS

Patients receiving RAs were younger and less likely to be female or to have pulmonary hypertension, impaired renal function, or left main coronary disease.At 30 days, they showed significantly lower unadjusted mortality and renal impairment. Unadjusted long-term survival was superior in the RA group, even after propensity-score matching. We found that RA use protected from late mortality.

CONCLUSIONS

Using the RA and the left ITA as T-graft is associated with a significant long-term survival benefit in patients undergoing CABG. It may display a promising alternative to conventional use of a single ITA supplemented by saphenous veins.

The radial artery in coronary surgery, 2018

It is now 25 years since the radial artery (RA) was reintroduced in coronary surgery. It has evolved into being a significant coronary artery bypass conduit and ranks third in usage after the internal thoracic artery (ITA) and saphenous vein grafts (SVG). Its advantages are that it can be readily and efficiently harvested, is of good length and appropriate size for coronary artery bypass graft (CABG) surgery, is robust and easy to handle, and remains free of atheroma, and there is minimal wound morbidity. The RA must be used judiciously with attention to spasm prophylaxis because of its muscular wall, and by avoiding competitive flow. Its patency is equivalent to the ITAs when placed to similar coronary territories and under similar conditions (stenosis, size, quality) and RA patencies are always superior to those of SVG in both observational and randomized studies-88-90% versus 50-60% at 10 years, and 80-87% versus 25-40% at 20 years. Its use and excellent patencies result in survival results equivalent to bilateral internal thoracic artery (BITA) grafting and always superior to left internal thoracic artery (LITA) +SVG. Typical radial artery multiarterial bypass grafting (RA-MABG) 10-year survivals are 80-90% versus 70-80% for LITA-SVG. In general, for every 100 patients undergoing CABG, 10 more patients will be alive at 10 years post-operatively. The RA also is important in achieving total arterial revascularization, and several reports indicate a further survival advantage for patients having three arterial grafts over two. The RAs are especially useful in diabetic, morbidly obese patients, those with conduit shortage, and leg pathology, and in coronary reoperations. Although the RA has equivalent patencies to the right internal thoracic artery (RITA), it is much more versatile. RAs that have been instrumented by angiography or percutaneous coronary intervention should be avoided. The radial artery has proved to be an excellent arterial conduit, is equivalent to but more versatile than the RITA, and is always superior to SVG. Its use should be part of every coronary surgeon's skill set.

Comparison of graft patency following coronary artery bypass grafting in the left versus the right coronary artery systems: a systematic review and meta-analysis

Although coronary artery bypass grafting has been the standard of care for patients with complex coronary artery disease for over 50 years, the evolution of graft patency over time in the left versus the right coronary systems remains poorly documented. This systematic review and meta-analysis aimed to characterize the evolution of graft patency over time comparing the left (excluding left anterior descending artery) and right coronary systems, with an emphasis on the comparison of venous versus arterial grafts and symptomatic versus asymptomatic patients. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE from inception to August 2016. We also searched clinical trials registers and reference lists of relevant studies. We included randomized clinical trials and observational studies comparing graft patency in the left versus the right coronary systems. Our outcome was graft patency defined as a binary variable according to whether grafts were reported as patent or failed at the time of angiogram. Data collection and analysis were performed according to the methodological recommendations of the Cochrane Collaboration. From a total 2275 papers, 52 studies were included in the qualitative analysis and 48 studies (including 36 006 grafts) in the meta-analysis. There was a 3.3% significant difference between the left-sided and right-sided graft patency, and the difference appeared to increase over time. Furthermore, patency of arterial grafts was higher in the left coronary system, while venous grafts performed similarly irrespective of the coronary circulation. Symptom recurrence also seemed related to a higher failure rate in the right coronary circulation. However, the high degree of heterogeneity precluded drawing definite conclusions. This meta-analysis suggested that graft patency might be better for left-sided vessels and that this difference might be driven by the better performance of arterial grafts in the left coronary system. However, evidence currently available is limited, and further research is warranted to understand whether certain grafts achieve better patency in the right versus the left coronary circulations.

Bilayered negative-pressure wound therapy preventing leg incision morbidity in coronary artery bypass graft patients: A randomized controlled trial

BACKGROUNDS

The harvesting of great saphenous veins for coronary artery bypass graft (CABG) patients may result in significant complications, including lymphorrhagia, lymphoedema, incision infection, wound dehiscence, and skin flap necrosis. We investigated the function of a self-designed bilayered negative pressure wound therapy (b-NPWT) for reducing the above-mentioned complications using a clinical randomized controlled trial.

METHODS

A single-center, pilot randomized controlled trial was conducted. From December 2013 to March 2014, a total of 72 coronary heart disease patients (48 men and 24 women) received CABG therapy, with great saphenous veins were selected as grafts. Patients were equally randomized into a treatment and a control group. After the harvesting of the great saphenous veins and direct closure of the wound with sutures, b-NPWT was used for the thigh incision in the treatment group for 5 days (treatment thigh). Traditional surgical pads were applied to both the shank incisions of the treatment group patients (treatment shank) and the entire incisions of the control group (control thigh, control shank). Postoperative complications were recorded and statistically analyzed based on outcomes of thigh treatment, shank treatment, thigh control, and shank control groups.

RESULTS

The incidence rates of early complications, such as lymphorrhagia, lymphoedema, infection, wound dehiscence, and skin flap necrosis, of the vascular donor site in the thigh treatment group was significantly lower than those in the 3 other groups.

CONCLUSIONS

The self-designed b-NPWT can effectively reduce postoperative complications, such as lymphedema, incision infection, wound dehiscence, and skin flap necrosis, in CABG patients who underwent great saphenous veins harvesting.

TRIAL REGISTRATION

ClinicalTrials.gov. The unique registration number is NCT02010996.

Short- and long-term results of radial artery and saphenous vein grafts in the right coronary system: a propensity-matched study

PURPOSE

The selection of optimal grafts for the right coronary artery remains controversial. This study aims to evaluate the short- and long-term results of radial artery (RA) grafts and saphenous vein grafts (SVGs) to the right coronary artery.

METHODS

We reviewed, retrospectively, isolated coronary artery bypass grafts, placed between 1997 and 2007, and compared the long-term results of patients who received RA (n = 110) grafts with those of patients who received SVGs (n = 264) using propensity-score matching for risk. The preoperative predictors of graft occlusion were investigated on a per case basis.

RESULTS

Superior survival was noted in the unmatched RA group, but late outcomes after propensity-score matching yielded 91 patient pairs that were similar in the two groups. Graft failure was not correlated with mortality, but showed strong correlation with cardiac events in all patients. The predictors of graft occlusion in the RA group were mild proximal stenosis and low indexing glomerular filtration rates for body surface area, whereas those in the SVG were female gender and off-pump coronary artery bypass grafting.

CONCLUSIONS

There were no significant differences in long-term outcomes between the RA and SVG groups. Predictors of graft occlusion differed between the groups. Notably, renal dysfunction impaired radial patency, emphasizing the importance of careful graft selection.

Endoscopic versus open radial artery harvest and mammario-radial versus aorto-radial grafting in patients undergoing coronary artery bypass surgery: protocol for the 2 × 2 factorial designed randomised NEO trial

Background

Coronary artery bypass grafting using the radial artery has, since the 1990s, gone through a revival. Observational studies have indicated better long-term patency when using radial arteries. Therefore, radial artery might be preferred especially in younger patients where long time patency is important. During the last 10 years different endoscopic techniques to harvest the radial artery have evolved. Endoscopic radial artery harvest only requires a small incision near the wrist in contrast to open harvest, which requires an incision from the elbow to the wrist. However, it is unknown whether the endoscopic technique results in fewer complications or a graft patency comparable to open harvest. When the radial artery has been harvested, there are two ways to use the radial artery as a graft. One way is sewing it onto the aorta and another is sewing it onto the mammary artery. It is unknown which technique is the superior revascularisation technique.

Methods/Design

The NEO Trial is a randomised clinical trial with a 2 × 2 factorial design. We plan to randomise 300 participants into four intervention groups: (1) mammario-radial endoscopic group; (2) aorto-radial endoscopic group; (3) mammario-radial open surgery group; and (4) aorto-radial open surgery group.

The hand function will be assessed by a questionnaire, a clinical examination, the change in cutaneous sensibility, and the measurement of both sensory and motor nerve conduction velocity at 3 months postoperatively. All the postoperative complications will be registered, and we will evaluate muscular function, scar appearance, vascular supply to the hand, and the graft patency including the patency of the central radial artery anastomosis. A patency evaluation by multi-slice computer tomography will be done at one year postoperatively.

We expect the nerve conduction studies and the standardised neurological examinations to be able to discriminate differences in hand function comparing endoscopic to open harvest of the radial artery. The trial also aims to show if there is any patency difference between mammario-radial compared to aorto-radial revascularisation techniques but this objective is exploratory.

Trial registration

ClinicalTrials.gov identifier: NCT01848886.

Danish Ethics committee number: H-3-2012-116.

Danish Data Protection Agency: 2007-58-0015/jr.n:30–0838.

Radial artery as graft for coronary artery bypass surgery: Advantages and disadvantages for its usage focused on structural and biological characteristics

Radial artery (RA) is the most popular arterial graft after the left internal thoracic artery in both low- and high-risk patients undergoing coronary artery bypass grafting. Various arterial grafts such as the right internal thoracic artery, the right gastroepiploic artery, and the inferior epigastric artery have also gained ground over the past 30 years because of the intimal hyperplasia and atherosclerosis of the saphenous vein leading to late graft occlusion. In this review article we would like to present the utility of the RA as a graft, focused mainly on its structural and biological characteristics.

Radial artery for coronary artery bypass grafting: does proximal anastomosis to the aorta or left internal mammary artery achieve better patency?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'in coronary artery bypass grafting using radial artery grafts, does proximal anastomosis to the aorta or left internal mammary artery achieve better patency'. Altogether >183 papers were found using the reported search, of which 9 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Radial artery grafts typically have a narrower lumen than vein grafts, and as such there is some concern that anastomosing them directly to the aorta during coronary artery bypass grafting (CABG) may impair graft patency. As such, some surgeons prefer to anastomose radial artery grafts to a second-order vessel such as the left internal mammary artery (LIMA). We sought to assess the evidence for this. A handful of papers directly addressing the issue of the effect of the site of proximal anastomosis on graft patency were found, with three showing no significant difference. One such study reported an insignificant difference in angiographic patency at 32 months postoperatively, with 94.1% of off-aorta grafts remaining patent vs 87.2% of off-LIMA grafts (p = 0.123). However, a large-scale well-designed study was able to demonstrate a statistically significant difference at five years postoperatively, with 74.3% of off-aorta grafts patent, compared with 65.2% of off-LIMA (p = 0.004). Nonetheless, a number of papers that report patency for either off-aorta or off-LIMA grafts give comparable figures for each technique. Additionally, different centres and investigators report very different patency results for grafts that have the same site of proximal anastomosis. One centre was able to achieve patency rates for off-LIMA grafts of 88% up to a mean of 7.7 years postoperatively while another centre reported a patency rate of only 78.6% at three years. Given this, and the plethora of other factors influencing graft patency, we conclude that the best evidence suggests that the site of proximal anastomosis has little or no effect on radial artery graft patency following CABG.

Bilateral internal mammary arteries: evidence and technical considerations

Bilateral internal mammary artery (BIMA) grafts are used for coronary revascularisation by only a minority of surgeons, despite a growing body of evidence suggesting improved survival when compared to use of only one internal mammary artery with additional saphenous vein grafts. Herein we review the evidence supporting revascularisation with BIMA and suggest reasons why the majority of surgeons use only one internal mammary artery. We discuss technical considerations, various graft combinations and the use of BIMA to facilitate anaortic off-pump coronary artery bypass (OPCAB).

Conduits for Coronary Bypass: Arteries Other Than the Internal Thoracic Artery's

This is the third in a series on coronary artery bypass which reviews three alternative arterial conduits. The radial artery has become the most widely used of the three and accumulating experience demonstrates better patency at 10 years versus saphenous vein. Drawbacks are a long incision on the forearm, the propensity for spasm and persistent sensory disturbance in about 10%. The first is answered by endoscopic harvest which may yield a shorter conduit but reduces sensory nerve injury. Spasm is managed pharmacologically and by less harvest trauma. The gastroepiploic artery is used in situ and free and although the abdominal cavity is entered complications are minimal and patency compares favorably with the radial artery. Use of the inferior epigastric artery remains minimal and its similar length often requires composite use but limited patency data are supportive. Other arteries have had rare use and this is unlikely to change because the three presented here have significant advantages and acceptance.

Safety of the extended radial artery conduit in performing complete arterial revascularization

PURPOSE

We have developed a technique to elongate the radial artery (RA) with the distal segment of the left internal thoracic artery. This study investigated the safety and durability of this extended conduit compared with the composite Y-grafts.

METHODS

From January 1998 through December 2010, 750 patients underwent complete arterial revascularization with the use of the left internal thoracic artery (LITA) and RA. Out of these patients, 362 patients were operated on with the use of either RA-LITA extension conduit (n = 103), or a composite LITA-RA Y-graft (n = 259) and were included in this study. Cox regression analyses and Kaplan-Meyer survival curves were used to identify the predictive value of the RA-LITA extension technique on both survival and incidence of re-intervention.

RESULTS

Cox regression analysis showed that the use of RA-LITA extension conduit was not a significant predictor of re-intervention (p = 0.600) or total survival (p = 0.930).Kaplan-meier curves showed no significant difference between the two groups concerning total survival and re-intervention-free survival (p = 0.600).

CONCLUSIONS

Our alternative technique of extending the RA with the distal segment of the LITA is a safe alternative for patients undergoing total arterial revascularization. The long-term survival and incidence of re-intervention is comparable with the composite LITA-RA Y-grafts.

WITHDRAWN: Endoscopic Radial Artery Harvesting: Long-Term Results and Graft Patency Rate

This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy. This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause.

Angiographic evidence for reduced graft patency due to competitive flow in composite arterial T-grafts

OBJECTIVE

Composite arterial grafting causes splitting of internal thoracic artery flow to various myocardial regions. The amount of flow supplying each region depends on the severity of coronary stenosis. Competitive flow in the native coronary artery can cause occlusion or severe narrowing of the internal thoracic artery supplying this coronary vessel.

METHODS

Two hundred three consecutive postoperative coronary angiographies of 163 patients who underwent bilateral internal thoracic artery grafting using the composite-T-graft technique were analyzed. Angiographies were done in symptomatic patients or in patients with positive thallium scan between 2 and 102 months after surgery and were compared with preoperative angiograms.

RESULTS

In 123 patients, both internal thoracic arteries were patent. The remaining 40 control patients had at least 1 nonfunctioning internal thoracic artery. A lower stenosis rate in the left anterior and circumflex arteries was associated with higher occlusion rate of the left internal thoracic artery (P < .005) and the right internal thoracic artery (P < .005), respectively. In 19 angiograms of 18 patients, graft failure could be related to competitive flow. This included 7 patients with disease of the left main artery and a preoperative stenosis degree ranging between 50% and 80%, 8 patients with moderate stenosis (70% or less) of the circumflex artery, and 3 with moderate stenosis of the left anterior descending artery. Three of the patients with disease of the left main artery, 2 of the patients with competitive flow in the circumflex artery, and all patients in the subgroup with left anterior descending arterial disease underwent percutaneous or surgical reintervention.

CONCLUSION

The composite T-graft technique of bilateral internal thoracic artery grafting should be reserved for patients with severe (70% or more) left anterior descending and circumflex arterial stenosis.

Skeletonized gastroepiploic artery as a composite graft for total arterial revascularization

BACKGROUND

Despite the purported advantages of using a gastroepiploic artery graft during coronary artery bypass, insufficient potential flow capacity and vasospasm remain major concerns. We assessed the efficacy and results of using a skeletonized composite gastroepiploic artery graft in situations in which bilateral internal thoracic and radial arteries could not be used.

METHODS

Between January 2000 and August 2002, 37 patients (25 men, 12 women; mean age, 59.9 years) underwent grafting with composite grafts using a skeletonized left internal thoracic artery plus the gastroepiploic artery. Coronary angiograms were performed in the immediate (median, 14 days, 36 patients) and early (median, 348 days, 32 patients) postoperative periods. Off-pump coronary artery bypass grafting was performed in all but 2 patients.

RESULTS

There were no deaths. The respective postoperative patencies of the left internal thoracic artery and gastroepiploic artery were 36 of 37 (97.2%) and 73 of 75 (97.3%) at the immediate period, and 34 of 34 and 62 of 67 (92.5%) at the early period. During follow-up, only 1 patient required percutaneous intracoronary intervention for gastroepiploic artery occlusion.

CONCLUSIONS

Skeletonized composite gastroepiploic artery grafts showed satisfactory clinical and angiographic results in situations in which bilateral internal thoracic and radial arteries could not be used. Although it needs longer follow-up, these early results demonstrated that the gastroepiploic artery may be a useful option in some situations of total arterial revascularization, used either as an in situ or as a composite graft.

Clampless arterial coronary artery bypass grafting with the use of magnetic coupling devices

BACKGROUND

The aim of our study was to evaluate the feasibility of using the Ventrica MVP device to perform proximal anastomoses as part of the clampless off-pump coronary artery bypass (OPCAB) arterial revascularization procedure.

METHODS

We present our preliminary experience of these first nine coronary artery cases performed in the UK from April 2003 to December 2004.

RESULTS

The device was used in eight patients for the proximal anastomosis of a radial artery (n = 8) or right internal thoracic artery (n = 1) graft as a Y-graft from the left internal thoracic artery to the circumflex territories. One patient died in this series although the autopsy showed that the device was intact and free of clots and the reported cause of death was an acute cardiac event due to myocardial ischemia. Anastomotic patency was confirmed in five patients with the use of multidetector row computed tomography coronary angiogram. The anastomosis time in our series was 6.3 +/- 2.1 minutes and the blood loss 814 +/- 245 mL. The mean length of stay was 5.2 +/- 1.2 days. No other significant major morbidity events were observed postoperatively (neurological complications, renal failure, and reopening for bleeding). The assessment of quality of life at 6 months postoperatively using SF-36 questionnaires revealed improvement.

CONCLUSION

The versatile use of Ventrica MVP distal anastomotic device is feasible in clinical practice allowing surgeons to perform proximal anastomoses and arterial OPCAB surgery with short learning curve and without compromising the clinical outcome and quality of life.

Radial Artery Graft for Coronary Artery Bypass Surgery: Biological Characteristics and Clinical Outcome

The radial artery (RA) is gaining popularity as a bypass conduit for coronary artery bypass grafting, and its impact on clinical practice has been extensively explored. In the present article, we provide a review of postoperative hand circulation, vascular biological characteristics of the RA graft, the efficacy of vasodilator therapies, and mid-term clinical results of use of the RA graft. Fundamental studies revealed excellent vascular biological characteristics of the RA graft as a living arterial conduit, making it almost equivalent to the internal thoracic artery (ITA) graft. Clinical studies have yielded encouraging mid-term results. Most studies reported in favor of the RA graft over the saphenous vein graft with regard to patency rate, freedom from cardiac events, and survival. However, superiority of either the RA or right ITA graft has not been conclusively determined. The long-term results of RA grafts remain unknown, but at present, supplementary use of an RA graft with a left ITA graft appears feasible for CABG.

Conventional surgery with aortic cross-clamping

This article provides a brief description of how to perform proximal and distal anastomosis on the arrested empty heart along with the grafting strategy and utilisation of different conduits in coronary artery revascularisation. Sequential grafting and indications of coronary artery revascularisation has also been described.

Effects of cryopreservation on the immunogenicity of porcine arterial allografts in early stages of transplant vasculopathy

BACKGROUND

The number of revascularization procedures including coronary and lower extremity bypass, have increased greatly in the last decade. It suggests a growing need for vascular grafts. Cryopreserved allografts could represent a viable alternative but their immunologic reactivity remains controversial.

METHODS

71 pigs (40 recipients and 31 donors) were used. Two femoral grafts per recipient animal were implanted for 3, 7, and 30 days. Types of grafts: fresh autograft as a control graft (n=19), fresh allograft (n=31) and cryopreserved allograft (n=30). Histological and immunohistochemical studies were performed.

RESULTS

Fresh allografts compared to autografts showed intimal inflammatory infiltration at 3 days (328 vs. 0 macrophages/mm2; P<0.05) and 7 days (962 vs. 139 T lymphocytes/mm2; P<0.05) post-transplantation. At 30 days, there was a loss of endothelial cells, presence of luminal thrombus and aneurismal lesions (total area=15.8 vs. 8.4 mm2; P<0.05). Cryopreservation did not reduce these lesions nor modify endothelial nitric oxide synthase (eNOS) expression nor modify the number of animals that developed anti-SLA antibodies. Moreover, at 7 days, cryopreserved allografts compared to fresh allografts showed a higher expression of P-selectin (5 out of 5 vs. 1 out of 5; P<0.05) and, at 30 days, a greater inflammatory reactivity (2692 vs. 1107 T lymphocytes/mm2 in media; P<0.05) with a trend towards a higher presence of multinucleated giant cells than in the fresh ones.

CONCLUSIONS

The cryopreservation method used maintained immunogenicity of allografts and increased the inflammatory reactivity found in fresh allografts up to 30 days of vascular transplantation.

Off-Pump Coronary Artery Bypass Grafting Using Only Arterial Grafts in Elderly Patients

BACKGROUND

This study aimed to elucidate the safety and feasibility of off-pump coronary artery bypass grafting with only arterial grafts for elderly patients.

METHODS

Of 653 patients who underwent off-pump coronary artery bypass grafting from April 2000 to December 2003, 581 patients did so with only arterial grafts. The average age was 66.9 +/- 9.3 years. The patients were divided into the elder group E (75 years old or more: 111 cases) or the younger group Y (younger than 75 years old: 470 cases). The mean follow-up term was 21 +/- 12 months.

RESULTS

Additive and logistic EuroSCOREs of group E were significantly higher than those of group Y (p < 0.0001). The number of bypass grafts was 3.3 +/- 0.9 in group E and 3.3 +/- 1.1 in group Y (p = 0.43). The proportion of total revascularization was 74% (82 of 111) in group E and 80% (377 of 470) in group Y (p = 0.15). The number of bilateral implementations of internal thoracic artery was 10 (9.0%) in group E and 196 (42%) in group Y (p < 0.0001). The graft patency rate was 98.7% in group E and 97.8% in group Y (p = 0.96). Hospital mortality was 2.7% (3 of 111) in group E and 0.2% (1 of 470) in group Y (p = 0.095). The causes of death were unrelated to cardiac events. Major adverse cardiac events occurred in 5 patients (5.1%) in group E and in 24 patients (5.6%) in group Y (p > 0.99).

CONCLUSIONS

Off-pump coronary artery bypass grafting using only arterial grafts in elderly patients is as safe and feasible as in young patients.

Role of Radial Artery Graft in Coronary Artery Bypass Grafting

The use of the radial artery (RA) as a coronary artery bypass graft has assumed a revival and thus a multitude of issues have arisen surrounding the routine and widespread use of this conduit in myocardial revascularization. There has been no uniformity regarding harvest techniques, assessment of the adequacy of hand collateral circulation, antispasm protocols, selection of target vessels, and the site of proximal anastomosis. It is widely believed and practiced that the RA should be harvested as a pedicle graft and preferably be used to bypass critically stenosed (>70% stenosis) coronary arteries. It is used either as a free graft with proximal anastomosis to the ascending aorta or as a composite arterial graft along with the left or right internal thoracic artery. The patency of RA grafts depends on the severity of the target coronary artery stenosis and target artery location rather than its use as an aortocoronary conduit or composite graft. In this article, we reviewed the current knowledge regarding the use of RA grafts as a coronary bypass conduit in an attempt to suggest a few acceptable strategies concerning the above issues in a given clinical scenario.

Revascularization of the Right Coronary Artery in Bilateral Internal Thoracic Artery Grafting

BACKGROUND

Bilateral internal thoracic artery (BITA) grafting with a composite T-graft enables right coronary artery (RCA) system revascularization with the distal end of the free right internal thoracic artery (RITA). This study compares this grafting technique to left-sided BITA grafting and RCA revascularization with the right gastroepiploic artery (RGEA) and saphenous vein grafts (SVG).

METHODS

From April 1996 to July 1999, 1000 consecutive patients underwent left-sided revascularization with BITA. In 231 patients RCA grafting was performed with free RITA, in 246 with RGEA, in 142 with SVG, and 381 did not receive any graft to the RCA (no-graft group).

RESULTS

Female gender, old age (> 70), emergency, and congestive heart failure were less prevalent in the RGEA group, and prior percutaneous transluminal coronary angioplasty was more prevalent in the no-graft group. Thirty-day mortality (3.6%, 4.9%, 2%, and 3.4% in the RITA, SVG, RGEA, and no-graft groups, respectively) and occurrence of perioperative complications (sternal infection, myocardial infarction, cerebrovascular accident, and bleeding) were similar. Overall, however, the trend was toward a higher complication rate in the RITA group (10.3%, 4.9%, 5.6%, and 7.3% respectively, p = 0.06). Midterm follow-up (40 to 78 months) showed similar 6-year survival (Kaplan-Meier) (88%, 87%, 89.5%, and 85.5%, respectively) and similar return of angina (10.8%, 6.3%, 10.6%, and 9.5%, respectively) in the four groups.

CONCLUSIONS

Early and midterm results in patients undergoing left-sided BITA grafting are not affected by the conduit used for RCA grafting.

The radial artery for coronary artery bypass grafting

Coronary artery bypass grafting (CABG) is the standard surgical procedure for the treatment of advanced coronary artery disease. CABG surgery has been demonstrated to improve symptoms and, in specific subgroups of patients, to prolong life. Despite its success, the long-term outcome of coronary bypass surgery is strongly influenced by the fate of the vascular conduits used. Previous long-term studies have shown unsatisfactory patency of saphenous vein grafts used for myocardial revascularisation, compared with internal mammary artery grafts. Recently, the use of radial artery for CABG has enjoyed a revival, on the basis of the belief that it will help improving long-term results of coronary operations. The recent reports of encouraging mid-term and long-term patency rates of the radial artery, supports its continued use as a bypass conduit. In this paper, we review the current knowledge about the radial artery as a bypass graft, with special emphasis on the clinical results.

Evaluation of Myocardial Flow Reserve Using Pharmacological Stress Thallium-201 Single-Photon Emission Computed Tomography: Is There a Difference between Total Arterial Off-Pump Coronary Artery Bypass Grafting and Conventional Coronary Artery Bypass

BACKGROUND

The advantage of total arterial off-pump coronary bypass grafting (OPCAB) over conventional onpump coronary artery bypass grafting with 1 internal thoracic artery and veins (CCAB) in terms of myocardial flow reserve has not been studied. We studied these procedures using thallium- 201 perfusion single-photon emission computed tomography (Tl-201 perfusion SPECT).

METHODS

Between 1997 and 2001, 152 patients were recruited from our database (OPCAB, n = 100; CCAB, n = 52). All patients underwent pharmacological stress Tl-201 perfusion SPECT 3 to 12 months after bypass surgery. Myocardial perfusion was analyzed semiquantitatively with a 5-point scoring system in a 20-segment model (0, normal, to 4, absence of uptake). Summed stress (SSS), rest (SRS), and difference score (SDS) of the entire myocardium as well as average scores (ASS, ARS, ADS) of individual walls (anterior, septal, lateral, and inferior) were compared by Student t test as well as by repeated-measures analysis of variance with Bonferroni correction.

RESULTS

The SSS, SRS, and SDS of OPCAB versus those of CCAB were 6.86 +/- 0.72 versus 7.17 +/- 0.92, 3.95 +/- 0.57 versus 3.75 +/- 0.73, and 2.91 +/- 0.47 versus 3.42 +/- 0.74 (P > .05). However, the lateral wall showed lower scores in OPCAB (ASS, 0.18 versus 0.41, P = .015; ARS, 0.12 versus 0.20, P = .168; ADS, 0.06 versus 0.21, P = .031). The septal wall had higher scores in OPCAB (ASS, 0.33 versus 0.12, P = .003; ARS, 0.18 versus 0.07, P = .037; ADS, 0.14 versus 0.04, P = .030). The anterior and inferior walls were not different between the 2 groups.

CONCLUSIONS

OPCAB led to results similar to those of CCAB. The better results in the lateral wall have been the effect of grafting radial artery rather than vein. The similarity in myocardial reserve in the inferior wall between the 2 groups needs further study. There was no deleterious effect of off-pump as opposed to on-pump CAB.

Radial artery as a conduit for coronary artery bypass graft

Since its resurgence in the 1990s, some 30 years after its abandonment as an alternative conduit, the radial artery has rapidly gained popularity. This article describes the application of this conduit in coronary grafting and details the controversies surrounding its use. A historical account as well as technical aspects such as operative technique are also discussed.