Radial artery versus saphenous vein conduits for coronary artery bypass surgery: forty years of competition--which conduit offers better patency? A systematic review and meta-analysis

Nonlinear Elasticity of Blood Vessels and Vascular Grafts

The transplantation of vascular grafts has emerged as a prevailing approach to address vascular disorders. However, the development of small-diameter vascular grafts is still in progress, as they serve in a more complicated mechanical environment than their counterparts with larger diameters. The biocompatibility and functional characteristics of small-diameter vascular grafts have been well developed; however, mismatch in mechanical properties between the vascular grafts and native arteries has not been accomplished, which might facilitate the long-term patency of small-diameter vascular grafts. From a point of view in mechanics, mimicking the nonlinear elastic mechanical behavior exhibited by natural blood vessels might be the state-of-the-art in designing vascular grafts. This review centers on elucidating the nonlinear elastic behavior of natural blood vessels and vascular grafts. The biological functionality and limitations associated with as-reported vascular grafts are meticulously reviewed and the future trajectory for fabricating biomimetic small-diameter grafts is discussed. This review might provide a different insight from the traditional design and fabrication of artificial vascular grafts.

Recent Advances in the Fabrication and Performance Optimization of Polyvinyl Alcohol Based Vascular Grafts

Cardiovascular disease is one of the diseases with the highest morbidity and mortality rates worldwide, and coronary artery bypass grafting (CABG) is a fast and effective treatment. More researchers are investigating in artificial blood vessels due to the limitations of autologous blood vessels. Despite the availability of large-diameter vascular grafts (Ø > 6 mm) for clinical use, small-diameter vascular grafts (Ø < 6 mm) have been a challenge for researchers to overcome in recent years. Vascular grafts made of polyvinyl alcohol (PVA) and PVA-based composites have excellent biocompatibility and mechanical characteristics. In order to gain a clearer and more specific understanding of the progress in PVA vascular graft research, particularly regarding the preparation methods, principles, and functionality of PVA vascular graft, this article discusses the mechanical properties, biocompatibility, blood compatibility, and other properties of PVA vascular graft prepared or enhanced with different blends using various techniques that mimic natural blood vessels. The findings reveal the feasibility and promising potential of PVA or PVA-based composite materials as vascular grafts.

Development of tissue-engineered vascular grafts from decellularized parsley stems

Cardiovascular diseases are mostly associated with narrowing or blockage of blood vessels, and it is the most common cause of death worldwide. The use of vascular grafts is a promising approach to bypass or replace the blocked vessels for long-term treatment. Although autologous arteries or veins are the most preferred tissue sources for vascular bypass, the limited presence and poor quality of autologous vessels necessitate seeking alternative biomaterials. Recently, synthetic grafts have gained attention as an alternative to autologous grafts. However, the high failure rate of synthetic grafts has been reported primarily due to thrombosis, atherosclerosis, intimal hyperplasia, or infection. Thrombosis, the main reason for failure upon implantation, is associated with damage or absence of endothelial cell lining in the vascular graft's luminal surface. To overcome this, tissue-engineered vascular grafts (TEVGs) have come into prominence. Alongside the well-established scaffold manufacturing techniques, decellularized plant-based constructs have recently gained significant importance and are an emerging field in tissue engineering and regenerative medicine. Accordingly, in this study, we demonstrated the fabrication of tubular scaffolds from decellularized parsley stems and recellularized them with human endothelial cells to be used as a potential TEVG. Our results suggested that the native plant DNA was successfully removed, and soft tubular biomaterials were successfully manufactured via the chemical decellularization of the parsley stems. The decellularized parsley stems showed suitable mechanical and biological properties to be used as a TEVG material, and they provided a suitable environment for the culture of human endothelial cells to attach and create a pseudo endothelium prior to implantation. This study is the first one to demonstrate the potential of the parsley stems to be used as a potential TEVG biomaterial.

Arterial Bypass in the Treatment of Complex Middle Cerebral Artery Aneurysms: Lessons Learned from Forty Patients

OBJECTIVE

Complex middle cerebral artery (MCA) aneurysms incorporating parent or branching vessels are often not amenable to standard microsurgical clipping or endovascular embolization treatments. We aim to discuss the treatment of such aneurysms via a combination of surgical revascularization and aneurysm exclusion based on our institutional experience.

METHODS

Thirty-four patients with complex MCA aneurysms were treated with bypass and aneurysm occlusion, 5 with surgical clipping or wrapping only, and 1 with aneurysm excision and primary reanastomosis. Bypasses included superficial temporal artery (STA)-MCA, double-barrel STA-MCA, occipital artery-MCA, and external carotid artery-MCA. After bypass, aneurysms were treated by surgical clipping, Hunterian ligation, trapping, or coil embolization.

RESULTS

The average age at diagnosis was 46 years. Of the aneurysms, 67% were large and most involved the MCA bifurcation. Most bypasses performed were STA-MCA bypasses, 12 of which were double-barrel. There were 2 wound-healing complications. All but 2 of the aneurysms treated showed complete occlusion at the last follow-up. There were 3 hemorrhagic complications, 3 graft thromboses, and 4 ischemic insults. The mean follow-up was 73 months. Of patients, 83% reported stable or improved symptoms from presentation and 73% reported a functional status (Glasgow Outcome Scale score 4 or 5) at the latest available follow-up.

CONCLUSIONS

Cerebral revascularization by bypass followed by aneurysm or parent artery occlusion is an effective treatment option for complex MCA aneurysms that cannot be safely treated by standard microsurgical or endovascular techniques. Double-barrel bypass consisting of 2 STA branches to 2 MCA branches yields adequate flow replacement in most cases.

Proximal Internal Carotid Artery Occlusion and Extracranial-Intracranial Bypass for Treatment of Fusiform and Giant Internal Carotid Artery Aneurysms

OBJECTIVE

To discuss the treatment of intracranial fusiform and giant internal carotid artery (ICA) aneurysms via revascularization based on our institutional experience.

METHODS

An institutional review board-approved retrospective analysis was performed of patients with unruptured fusiform and giant intracranial ICA aneurysms treated from November 1991 to May 2020. All patients were evaluated for extracranial-intracranial (EC-IC) bypass and ICA occlusion.

RESULTS

Thirty-eight patients were identified. Initially, patients failing preoperative balloon test occlusion were treated with superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and concurrent proximal ICA ligation. We then treated them with STA-MCA bypass, followed by staged balloon test occlusion, and, if they passed, endovascular ICA coil occlusion. We treat all surgical medically uncomplicated patients with double-barrel STA-MCA bypass and concurrent proximal ICA ligation. The mean length of follow-up was 99 months. Symptom stability or improvement was noted in 85% of patients. Bypass graft patency was 92.1%, and all surviving patients had patent bypasses at their last angiogram. Aneurysm occlusion was complete in 90.9% of patients completing proximal ICA ligation. Three patients experienced ischemic complications and 4 patients experienced hemorrhagic complications.

CONCLUSIONS

Not all fusiform intracranial ICA aneurysms require intervention, except when life-threatening rupture risk is high or symptomatic management is necessary to preserve function and quality of life. EC-IC bypass can augment the safety of proximal ICA occlusion. The rate of complete aneurysm occlusion with this treatment is 90.9%, and long-term bypass graft-related complications are rare. Perioperative stroke is a major risk, and continued evolution of treatment is required.

Saphenous Vein Graft Failure: Current Challenges and a Review of the Contemporary Percutaneous Options for Management

The use of saphenous vein grafts (SVGs) in the surgical management of obstructive coronary artery disease remains high despite a growing understanding of their limitations in longevity. In contemporary practice, approximately 95% of patients receive one SVG in addition to a left internal mammary artery (LIMA) graft. The precise patency rates for SVGs vary widely in the literature, with estimates of up to 61% failure rate at greater than 10 years of follow-up. SVGs are known to progressively degenerate over time and, even if they remain patent, demonstrate marked accelerated atherosclerosis. Multiple studies have demonstrated a marked acceleration of atherosclerosis in bypassed native coronary arteries compared to non-bypassed arteries, which predisposes to a high number of native chronic total occlusions (CTOs) and subsequent procedural challenges when managing graft failure. Patients with failing SVGs frequently require revascularisation to previously grafted territories, with estimates of 13% of CABG patients requiring an additional revascularisation procedure within 10 years. Redo CABG confers a significantly higher risk of in-hospital mortality and, as such, percutaneous coronary intervention (PCI) has become the favoured strategy for revascularisation in SVG failure. Percutaneous treatment of a degenerative SVG provides unique challenges secondary to a tendency for frequent superimposed thrombi on critical graft stenoses, friable lesions with marked potential for distal embolization and subsequent no-reflow phenomena, and high rates of peri-procedural myocardial infarction (MI). Furthermore, the rates of restenosis within SVG stents are disproportionately higher than native vessel PCI despite the advances in drug-eluting stent (DES) technology. The alternative to SVG PCI in failed grafts is PCI to the native vessel, 'replacing' the grafts and restoring patency within the previously grafted coronary artery, with or without occluding the donor graft. This strategy has additional challenges to de novo coronary artery PCI, however, due to the high burden of complex atherosclerotic lesion morphology, extensive coronary calcification, and the high incidence of CTO. Large patient cohort studies have reported worse short- and long-term outcomes with SVG PCI compared to native vessel PCI. The PROCTOR trial is a large and randomised control trial aimed at assessing the superiority of native vessel PCI versus vein graft PCI in patients with prior CABG awaiting results. This review article will explore the complexities of SVG failure and assess the contemporary evidence in guiding optimum percutaneous interventional strategy.

A new method for second toe flap revascularization in plantar dominant artery pattern - dorsal metatarsal artery interpositional graf

BACKGROUND

Toe transfer to hand is a viable option for patients, which can provide functionally useful digits. Harvesting of the second toe is still accepted as a demanding surgical procedure. The major questions before this transfer are the location and the dominance of the arterial anatomy of the second toe. The authors present the incidence of patients with a dominant plantar artery system and a description of a versatile technique that can be used for toe transfers in these patients.

METHODS

The study was designed retrospectively. Toe to hand transfers performed between 2010 and 2018 were reviewed. The patients with a dominant plantar arterial system were included in this study. The dorsalis pedis arterial graft technique described by the authors was used in all cases with a dominant plantar system. All of transfers were done by the senior author. All cases followed up at least one year post-operatively. The survival of the transferred finger was examined in the follow-ups.

RESULTS

Eleven toe to hand transplantation cases in nine traumatic patients were included in this series. The reason for the operation was trauma in all patients. Second toe transfer was performed in all of the cases. Plantar dominant arterial system was seen in 3 of the 9 patients. Dorsal arterial system was dominant in the remaining six patients. Dorsalis pedis arterial graft technique was used in these four cases. All of the toes survived, and reexploration was needed in 2 cases because of venous insufficiency. Mean follow-up time was 16.4 months.

DISCUSSION

This is the first study to recommend the use of dorsalis pedis as an arterial graft instead of vein grafts. This surgical method described will make these rarely performed transfers easier and affect the success rates positively.

Differences in long-term survival outcomes after coronary artery bypass grafting using single vs multiple arterial grafts: a meta-analysis with reconstructed time-to-event data and subgroup analyses

OBJECTIVE

We reviewed the available literature on patients with coronary artery disease undergoing isolated coronary artery bypass grafting (CABG) with either single (SAG) or multiple arterial grafting (MAG).

METHODS

Original research studies that evaluated the long-term survival of MAG versus SAG were identified, from 1995 to 2022. The median overall survival (OS) and event-free OS were the primary endpoints. Comparison of median OS between the right internal mammary artery (RIMA) and radial artery (RA) as a second arterial conduit was the secondary endpoint. Subgroup analyses were performed regarding patients older than 70 years, with diabetes mellitus, and females. A sensitivity analysis was performed with the leave-one-out method.

RESULTS

Forty-four studies were included in the qualitative and thirty-nine in the quantitative synthesis. After pooling data from 180 to 459 patients, the MAG group demonstrated a higher OS (HR, 0.589; 95% CI, 0.58-0.60; p < 0.0001) and event-free OS compared with the SAG group (HR, 0.828; 95% CI, 0.80-0.86; p < 0.0001). In addition, RITA was associated with superior OS compared with RA as a second arterial conduit (HR, 0.936; 95% CI, 0.89-0.98; p = 0.009). MAG was also superior to SAG in patients over 70 years, females, and patients with diabetes mellitus. Sensitivity analysis demonstrated a small-size study effect on the female subgroup analysis.

CONCLUSION

The present meta-analysis indicates that MAG is associated with enhanced survival outcomes compared to SAG for patients undergoing isolated CABG.

Advances in the Post-coronary Artery Bypass Graft Management of Occlusive Coronary Artery Disease

Revascularisation of chronic total occlusion (CTO) represents one of the most challenging aspects of percutaneous coronary intervention, but advances in equipment and an understanding of CTO revascularisation techniques have resulted in considerable improvements in success rates. In patients with prior coronary artery bypass grafting (CABG) surgery, additional challenges are encountered. This article specifically explores these challenges, as well as antegrade methods of CTO crossing. Techniques, equipment that can be used and reference texts are highlighted with the aim of providing potential CTO operators adequate information to tackle additional complexities likely to be encountered in this cohort of patients. This review forms part of a wider series where additional aspects of patients with prior CABG should be factored into decisions and methods of revascularisation.

Comparative Analysis Following Implementation of Two Types of Y-Composite Multiarterial Revascularization Strategies at a Single Academic Institution

Background

We compared early outcomes, at a single academic institution, of implementing full coronary revascularization in coronary artery bypass grafting using multiarterial Y‐composite grafts with multiple sequential anastomoses.

Methods and Results

Clinical records of 425 consecutive patients who underwent coronary artery bypass grafting using Y‐grafting with left internal mammary artery and radial artery (Y‐RA group) or right internal mammary artery (Y‐RIMA group) from 2015 to 2019, were reviewed. These were compared with the institutional experience of isolated coronary artery bypass grafting cases (in situ on pump/off pump) for the same period of time. When comparing the 4 groups, the Y‐RIMA/RA groups revealed a higher number of distal anastomosis than the in situ on‐ or off‐pump groups. When the number of distal arterial anastomosis was analyzed, there was a superiority of using the Y‐configuration compared with the in situ approach. Moreover, there were no significant differences among groups for mortality and/or major adverse cardiac and cerebrovascular events in hospital or at 30‐day follow‐up. A subanalysis comparing the Y‐RIMA group with the Y‐RA group showed that complementary grafts to the Y‐construct were required to accomplish full revascularization more frequently in the Y‐RIMA group. Full‐arterial revascularization was achieved in 92.2% of the Y‐RA group and 72.0% of the Y‐RIMA group (P<0.001). In 82.8% of the Y‐RA group and 30.8% of the Y‐RIMA group, revascularization was completed as an anaortic procedure (P<0.001).

Conclusions

The 2 types of arterial Y‐composite grafting were able to be introduced in the routine practice of our institution showing comparable results to the established institutional practice. This procedure allowed for more arterial distal anastomosis to be performed safely without compromising outcomes.

The Use of Radial Artery for CABG: An Update

We used the radial artery as a second target conduit for coronary artery bypass grafting since 1971. However, randomized clinical studies have demonstrated differences in clinical outcomes between the radial artery and other grafts because these trials are underpowered. As we proceed toward 50 years of experience with radial artery grafting, we examined the literature to define the best second-best target vessel for coronary artery bypass grafting. The literature was reviewed with emphasis, and a large number of randomized controlled trials, propensity-matched observational series, and meta-analyses were identified with a large patient population who received arterial conduit and saphenous vein grafts. The radial artery has been shown to be effective and safe when used as a second target conduit for coronary artery bypass grafting. Results and patency rates were superior to those for saphenous vein grafting. It has also been shown that the radial artery is a safe and effective graft as a third conduit into the territory of the artery right coronary artery. However, there is little evidence based on a few comparable series limiting the use of the gastroepiploic artery. In its fifth decade of use, we can finally deduced that the aorto-to-coronary radial bypass graft is the conduit of choice for coronary operations after the left internal thoracic artery to the left anterior descending artery.

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.

Use of Arterial Grafts in Hypothenar Hammer Syndrome: Application of Perforator Flap Anatomy

Background

Hypothenar hammer syndrome (HHS) is traditionally treated with venous bypass grafting, but controversy has arisen as arterial grafts have become more available.

Methods

A retrospective review of all patients undergoing ulnar artery bypass grafting for HHS with an arterial graft from 2008 to 2017 was performed. We also review the literature for patency rates and discuss the scenarios that favor different graft choices.

Results

Six patients were included in our series. Five had primary surgery and 1 had revision surgery for HHS. Five arterial grafts were from the deep inferior epigastric artery and 1 was from the lateral circumflex femoral artery. The proximal anastomotic site was the ulnar artery for all: n = 6. The distal anastomosis site was the palmar arch and common digital artery (CDA) of the ring/small finger and CDA of the middle/ring finger: n = 3; the palmar arch and the CDA of the ring/small finger: n = 3. All patients were symptom-free at follow-up and had a patent ulnar artery on Allen's testing or angiogram.

Conclusion

Patency rates of arterial grafts for HHS appear to be excellent and this small series and may offer an alternative to traditional venous grafts and end-to-end arterial anastomoses. We suggest using arterial perforator grafts from free flap donor sites. These have well-described anatomy, are easily harvested, and carry minimal donor site morbidity. Lateral circumflex femoral artery graft is favored in patients requiring a single distal anastomosis, who have a ventral hernia, or who are obese. Deep inferior epigastric artery graft is preferred when multiple distal targets or versatile configurations are needed, in thin patients, or in female patients.

Intraoperative thermal insulation in off-pump coronary artery bypass grafting surgery: a prospective, double blind, randomized controlled, single-center study

Background

About 50% patients who underwent off-pump coronary artery bypass grafting (OPCAB) experienced perioperative hypothermia. Pre-warming and intraoperative infusion of amino acid injection are the most popular perioperative insulation measures in recent years, but neither of them can completely prevent intraoperative hypothermia. The objective is to investigate the effect of preoperative warming and/or intraoperative infusion of amino acid injection on body temperature in patients undergoing OPCAB.

Methods

A prospective, double blind, randomized controlled, single-center study. Seventy-two patients were randomly divided into 4 groups: control group, pre-warming group, amino-acid group and multi-mode group. Pre-warming and multi-mode group were pre-heated with warming blankets and forced-air warming system before induction. After that, amino-acid and multi-mode group were infused with 18-amino acid solution. The perioperative temperature and complications were monitored.

Results

The temperature of control and amino-acid group decreased significantly, but amino-acid group recovered to preoperative level faster. The temperature of pre-warming group was stable, and that in multi-mode group increased at 60 min after the start of surgery. There was a significant difference in temperature at each time, and no difference in the incidence of complications between the groups.

Conclusions

Preoperative warming and/or intraoperative infusion of amino acid injection can effectively reduce hypothermia in OPCAB surgery. Pre-warming before anesthesia is more effective, and the combination of the two methods has the best effect.

What is the best graft to supplement the bilateral internal thoracic artery to the left coronary system? A meta-analysis

This meta-analysis was designed to assess the effect of the use of arterial conduits (ACs) versus great saphenous vein (GSV) grafts as a third conduit for revascularization of the right coronary artery system, in addition to the bilateral internal mammary artery on the left coronary artery. PubMed and OVID's version of MEDLINE were searched from January 2000 to September 2017 for relevant publications. The primary end point was the long-term mortality rate. The secondary end point was early mortality, defined as either in-hospital death or death within 30 days after the operation. Meta-regression was used to evaluate the effect of female gender and diabetes on the primary and secondary outcomes. A total of 10 studies (4121 patients) were selected for the systematic review and meta-analysis comparing ACs (1619) versus the GSV (2502), 6 (2548) comparing the GSV (2548) versus the right gastroepiploic artery (1023) and 5 comparing the GSV (2548) versus the radial artery (596). The pooled analysis did not show any difference between ACs and the GSV in terms of long-term mortality rates [hazard ratio (HR) = 0.75, 95% confidence interval (CI) = 0.56-1.01; P = 0.061]. When using the leave-one-out analysis, after the exclusion of 1 study (outlier), ACs were significantly associated with lower long-term mortality rates (HR = 0.67, 95% CI = 0.54-0.83; P < 0.001). When the results were stratified according to the type of study, no differences with regard to long-term results were found between ACs and the GSV, either in the pooled analysis of the 6 propensity score-matched studies (HR = 0.69, 95% CI = 0.43-1.08; P = 0.107) or in the pooled analysis of the 4 non-propensity score-matched studies (HR = 0.88, 95% CI = 0.62-1.23; P = 0.438). Again, when the outlier was excluded, the pooled analysis of the propensity score-matched studies confirmed that ACs were associated with lower long-term mortality rates (HR = 0.58, 95% CI = 0.43-0.80; P < 0.001). Comparisons between the GSV and either the right gastroepiploic artery or the radial artery showed similar results. No publication bias was found. This meta-analysis is the first to compare the GSV to the radial artery and the right gastroepiploic artery for right coronary artery grafting in patients receiving a bilateral internal mammary artery to left coronary artery. The choice of a third AC seems to be preferable in order to achieve better long-term survival.

Slow degrading poly(glycerol sebacate) derivatives improve vascular graft remodeling in a rat carotid artery interposition model

Porous synthetic grafts made of poly (glycerol sebacate) (PGS) can transform into autologous vascular conduits in vivo upon degradation of PGS. A long-held doctrine in tissue engineering is the necessity to match degradation of the scaffolds to tissue regeneration. Here, we tested the impact of degradation of PGS and its derivative in an interposition model of rat common carotid artery (CCA). Previous work indicates a complete degradation of PGS within approximately 2 weeks, likely at the fast end of the spectrum. Thus, the derivation of PGS focuses on delay degradation by conjugating the free hydroxy groups in PGS with a long chain carboxylic acid: palmitic acid, one of the most common lipid components. We evaluated two of the resultant palmitate-PGS (PPGS) in this study: one containing 9% palmitate (9-PPGS) and the other16% palmitate (16-PPGS). 16-PPGS grafts had the highest patency. Ultrasound imaging showed that the lumens of 16-PPGS grafts were similar to CCA and smaller than 9-PPGS and PGS grafts 12 weeks post-operation. Immunohistological and histological examination showed an endothelialized lumens in all three types of grafts within 4 weeks. Inflammatory responses to 16-PPGS grafts were limited to the adventitial space in contrast to a more diffusive infiltration in 9-PPGS and PGS grafts in week 4. Examination of calponin+ and αSMA+ cells revealed that 16-PPGS grafts remodeled into a distinctive bi-layered wall, while the walls of 9-PPGS grafts and PGS grafts only had one thick layer of smooth muscle-like cells. Correspondingly, the expression of collagen III and elastin displayed an identical layered structure in the remodeled 16-PPGS grafts, in contrast to a more spread distribution in 9-PPGS and PGS grafts. All the three types of grafts exhibited the same collagen content and burst pressure after 12 weeks of host remodeling. However, the compliance and elastin content of 16-PPGS grafts in week 12 were closest to those of CCA. Overall, placing the degradation of PGS derived elastomer to a window of 4-12 weeks results in vascular conduits closer to arteries in a rat carotid artery interposition model over a 12-week observation period.

A longitudinal serum NMR-based metabolomics dataset of ischemia-reperfusion injury in adult cardiac surgery

Cardiovascular disease is the leading cause of death worldwide and cardiac surgery is a key treatment. This study explores metabolite changes as a consequence of ischemia-reperfusion due to cardiac surgery with the use of cardiopulmonary bypass (CPB). To describe the ischemia-reperfusion injury, metabolite changes were monitored in fifty patients before and after CPB at multiple time points. We describe a longitudinal metabolite dataset containing nearly 600 serum nuclear magnetic resonance (NMR) spectra obtained from samples collected simultaneously from the pulmonary artery (deoxygenated blood) and left atrium (oxygenated blood) before ischemia (pre-CPB), immediately after reperfusion (end-CPB), and the following 2, 4, 8, and 20 hours postoperatively. In addition, a longitudinal dataset including 57 quantified metabolites is also provided. These datasets will help researchers studying ischemia-reperfusion injury, as well as the time-dependent alterations related to the surgical trauma and the subsequent processes required in regaining metabolite balance. The datasets could also be used for the development of processing algorithms for NMR-based metabolomics studies and methods for the analysis of longitudinal multivariate data.

Measurement(s)	human blood serum metabolite
Technology Type(s)	one-dimensional nuclear magnetic resonance spectroscopy
Factor Type(s)	cardiac surgery • time series • pulmonary artery and left atrium
Sample Characteristic - Organism	Homo sapiens

Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12249065

Polylysine Enriched Matrices: A Promising Approach for Vascular Grafts

Cardiovascular diseases represent the leading cause of death in developed countries. Modern surgical methods show poor efficiency in the substitution of small-diameter arteries (<6 mm). Due to the difference in mechanical properties between the native artery and the substitute, the behavior of the vessel wall is a major cause of inefficient substitutions. The use of decellularized scaffolds has shown optimal prospects in different applications for regenerative medicine. The purpose of this work was to obtain polylysine-enriched vascular substitutes, derived from decellularized porcine femoral and carotid arteries. Polylysine acts as a matrix cross-linker, increasing the mechanical resistance of the scaffold with respect to decellularized vessels, without altering the native biocompatibility and hemocompatibility properties. The biological characterization showed an excellent biocompatibility, while mechanical tests displayed that the Young's modulus of the polylysine-enriched matrix was comparable to native vessel. Burst pressure test demonstrated strengthening of the polylysine-enriched matrix, which can resist to higher pressures with respect to native vessel. Mechanical analyses also show that polylysine-enriched vessels presented minimal degradation compared to native. Concerning hemocompatibility, the performed analyses show that polylysine-enriched matrices increase coagulation time, with respect to commercial Dacron vascular substitutes. Based on these findings, polylysine-enriched decellularized vessels resulted in a promising approach for vascular substitution.

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.

Coronary artery bypass vs percutaneous coronary intervention in under 50s

BACKGROUND

Young patients with coronary artery disease are undergoing percutaneous coronary intervention (PCI) primarily, with a view to deferring coronary artery bypass grafting (CABG). We investigated the validity of this approach, by comparing outcomes in patients ≤50 years undergoing CABG or PCI.

METHODS

One hundred consecutive patients undergoing PCI and 100 undergoing CABG in 2004 were retrospectively studied to allow for 5 and 12 years follow-up. The two groups were compared for the primary endpoints of major adverse cardiac or cerebrovascular event (MACCE).

RESULTS

Diabetes, peripheral vascular disease, and left ventricular ejection fraction <50% were higher in the CABG group. At 5 years, rates of myocardial infarction (MI) (9% vs 1%, P = .02), repeat revascularization (31% vs 7%, P < .01), and MACCE (34 vs 12, P < .01) were greater in the PCI vs the CABG group. Similarly, at 12 years, rates of MI (27.4% vs 19.4%, P = .19), repeat revascularization (41.1% vs 20.4%, P < .01), and MACCE (51 vs 40, P = .07) were greater in the PCI group. There were no differences in major outcomes in patients with 1 or 2VD, at 5 or 12 years. Rates of MI, revascularization, and MACCE were higher in patients with 3VD undergoing PCI (n = 21; MI, 47.6%; revascularization, 66.7%; and MACCE, 19 events) vs CABG (n = 78; MI, 19.2%; revascularization, 20.5%; and MACCE, 31 events); P < .01, for all end points.

CONCLUSIONS

MACCE was lower in young patients undergoing CABG vs PCI at both 5 and 12 years follow-up, primarily as a consequence of patients with 3VD undergoing PCI having more MI and repeat revascularization. CABG should remain the preferred method of revascularization in young patients with 3VD.

A comparative review of the outcomes of using arterial versus venous conduits in coronary artery bypass graft (CABG)

Nowadays one of the most frequent reasons of death in the world is coronary artery disease. CABG is a portion of a common revascularization mediation that is done to supervise CAD by applying vessels that are grafted to revascularize vessels distal from the blockage. Different sources of grafts are included veins (specifically saphenous) and arteries (include mammary and radial arteries). Multiple conduits are used to this end, but the most suitable is left internal mammary artery (LIMA) to the left anterior descending artery (LAD) as a golden standard. Saphenous vein grafts were the guiding approach applied by the vast majority of cardiac surgeons in the 1970s, even though all approaches were supported by doctors. Although the radial artery graft was introduced simultaneously, this approach due to its complications was not as prevalent. This article is aimed to define the pros and cons of applying each kind of grafts according to the results furnished by existent studies. It has also examined the benefits provided by total arterial coronary artery bypass graft against CABG including venous graft for patients with CAD from the perspective of surgeons.

Assessing the Long-term Patency and Clinical Outcomes of Venous and Arterial Grafts Used in Coronary Artery Bypass Grafting: A Meta-analysis

Introduction

The long-term patency of the grafts used during the coronary artery bypass grafting (CABG) is one of the most significant predictors of the clinical outcomes. The gold standard graft used during CABG with the best long-term patency rate and the better clinical outcomes is left internal thoracic artery (LITA) grafted to the left coronary artery (LCA). The controversy lies in choosing the second-best conduit for the non-left coronary artery (NLCA) with similar patency rate as LITA. This meta-analysis examines the long-term patency and clinical outcomes of all arterial grafts versus all venous grafts used during the CABG.

Methods

A comprehensive literature search of all published randomized control trials (RCTs) assessing long-term patency and clinical outcomes of grafts used in CABG was conducted using PubMed, Cochrane Central Registry of Controlled Trials, and Google Scholar (1966-2018). Keywords searched included combinations of “CABG”, “venous grafts in CABG”, “arterial grafts in CABG”, “radial artery grafts in CABG”, “gastroepiploic artery grafts in CABG”, “patency and clinical outcomes”. Inclusion criteria included: RCTs comparing the long-term patency, and clinical outcomes of radial artery, right internal thoracic artery, gastroduodenal artery, and saphenous vein grafts used in CABG. Long-term patency of the grafts and clinical outcomes were analyzed.

Results

Eight RCTs involving 2,091 patients with 1,164 patients receiving arterial grafts and 927 patients receiving venous grafts were included. There was no difference between the long-term patency rate (relative risk (RR) = 1.050, 95% confidence interval (CI) = 0.949 to 1.162, and p = 0.344), overall mortality rate (RR = 1.095, 95% CI = 0.561 to 2.136, and p = 0.790), rate of myocardial infarction (MI) (RR = 0.860, 95% CI = 0.409 to 1.812, and P = 0.692), and re-intervention rate (RR = 0.0768, 95% CI = 0.419 to 1.406, and P = 0.392) between arterial and venous grafts.

Conclusion

The use of arterial conduits over the venous conduits has no significant superiority regarding the long-term graft patency, the rate of MI, overall mortality, and the rate of revascularization following CABG. Additional adequately powered studies are needed to further evaluate the long-term outcomes of arterial and venous grafts following the CABG.

Right internal thoracic or radial artery as the second arterial conduit for coronary artery bypass surgery

PURPOSE OF REVIEW

To summarize the available evidence on the use of the right internal thoracic artery (RITA) and the radial artery as the second arterial graft in coronary artery bypass surgery.

RECENT FINDINGS

The current data support the equipoise of the two conduits in terms of clinical and angiographic outcomes. Both RITA and radial artery have better patency than saphenous vein grafts. The use of the RITA carries an increased risk of deep sternal wound infection (DSWI) if the artery is harvested as pedicle. Bilateral internal thoracic artery grafting is more technically demanding than radial artery use and there is a volume-outcome relationship in terms of mortality and incidence of DSWI. The radial artery is preferable over RITA in right-sided or distal circumflex artery targets with high-degree stenosis and in patients at higher risk for DSWI, whereas it is not recommended to graft vessels with moderate stenosis and in cases of insufficient collateralization from the ulnar artery or previous transradial procedures.

SUMMARY

The patency rate and clinical outcomes of radial artery and RITA are similar. The use of one or the other should be based on a careful evaluation of the patient's coronary anatomy and comorbidities, the conduit availability and the surgeon's and center's experience.

State-of-the-Art Coronary Artery Bypass Grafting: Patient Selection, Graft Selection, and Optimizing Outcomes

Despite the progressive expansion of clinical indications for percutaneous coronary intervention and the increasingly high risk profile of referred patients, coronary artery bypass grafting (CABG) remains the mainstay in multivessel disease, providing good long-term outcomes with low complication rates. Multiple arterial grafting, especially if associated with anaortic techniques, might provide the best longer-term outcomes. A surgical approach individualized to the patients' clinical and anatomic characteristics, and surgeon and team experience, are key to excellent outcomes. Current evidence regarding patient selection, indications, graft selection, and potential strategies to optimize outcomes in patients treated with CABG is summarized.

Effectiveness of Saphenous Vein Y-Grafts in Patients Undergoing Off-Pump Complete Myocardial Revascularization

Background

To evaluate perioperative and mid-term outcomes of saphenous vein Y-grafts in patients with multi-vessel coronary artery disease.

Material/Methods

Sixty patients who underwent off-pump coronary surgery with Y-graft between 2005 and 2016 were enrolled, including 38 patients with natural Y-graft. Sixty patients with multi-vessel lesions in the same period were randomly selected as a control group.

Results

A total of 484 conduits were employed. The intraoperative variables were insignificantly different between groups, but Y-graft group compared with control group had more grafts (4.2±0.84 vs. 3.87±0.85) and anastomoses (6.30±1.39 vs. 5.62±1.15). No patient died during coronary artery bypass grafting and no episode of perioperative myocardial infarction was found. Follow-up duration lasted from 1 to 137 (40.0±27.7) months. No significant difference between Y-graft group and control group was found in Kaplan-Meier 3-year survival rate (93.4% vs. 88.0%) or 5-year survival rate (81.4% vs. 88.0%).

Conclusions

Saphenous vein Y-graft is a feasible and safe revascularization strategy for multi-vessel coronary artery disease patients and brings about satisfactory outcomes.

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.

Long term outcomes of radial artery grafting in patients undergoing coronary artery bypass surgery

Single arterial left internal thoracic artery (LITA) based coronary artery bypass surgery (LITA-SABG) has been the principal revascularization strategy for over 25 years across all patient demographics. In line with the current emphasis being placed on personalized medicine, which tailors individual, patient-specific therapy to optimize outcomes, coronary artery bypass grafting (CABG) techniques have also evolved to achieve enhanced results among specific groups of patients with coronary artery disease. Most notable has been the development of multi-arterial bypass grafting (MABG) techniques, using either the radial artery (RA) or the right internal thoracic artery (RITA) in conjunction with the LITA, as both techniques have been shown to enhance long term survival of CABG patients. This article reviews the latest data on the long-term outcomes of RA-MABG and considers its impact in various sub-cohorts of CABG that are increasingly being treated by cardiac surgeons. The primary aim of this review is to highlight the advantages of RA-MABG over LITA-SABG and thereby potentiate its adoption into clinical practice. Our secondary aim is to summarize the results of RA-MABG in specific CABG sub-cohorts, to more closely align CABG surgery with the emerging consensus that personalized medicine enhances healthcare value.

An exploratory study on the preparation and evaluation of a "same-day" adipose stem cell-based tissue-engineered vascular graft

OBJECTIVE

Tissue-engineered vascular grafts containing adipose-derived mesenchymal stem cells offer an alternative to small-diameter vascular grafts currently used in cardiac and lower-extremity revascularization procedures. Adipose-derived, mesenchymal stem cell-infused, tissue-engineered vascular grafts have been shown to promote remodeling and vascular homeostasis in vivo and offer a possible treatment solution for those with cardiovascular disease. Unfortunately, the time needed to cultivate adipose-derived mesenchymal stem cells remains a large hurdle for tissue-engineered vascular grafts as a treatment option. The purpose of this study was to determine if stromal vascular fraction (known to contain progenitor cells) seeded tissue-engineered vascular grafts would remain patent in vivo and remodel, allowing for a "same-day" process for tissue-engineered vascular graft fabrication and implantation.

METHODS

Stromal vascular fraction, obtained from adult human adipose tissue, was seeded within 4 hours after acquisition from the patient onto poly(ester urethane)urea bilayered scaffolds using a customized rotational vacuum seeding device. Constructs were then surgically implanted as abdominal aortic interposition grafts in Lewis rats.

RESULTS

Findings revealed patency in 5 of 7 implanted scaffolds at 8 weeks, along with neotissue formation and remodeling occurring in patent tissue-engineered vascular grafts. Patency was documented using angiography and gross inspection, and remodeling and vascular components were detected using immunofluorescent chemistry.

CONCLUSIONS

A "same-day" cell-seeded, tissue-engineered vascular graft can remain patent after implantation in vivo, with neotissue formation and remodeling occurring by 8 weeks.

Autologous tissue patches acquire vascular identity depending on the environment

Vascular identity is genetically determined, but can be altered during surgical procedures. We hypothesized that the environment of the procedure critically alters the identity of autologous tissue patches implanted into the arterial or venous environment. Autologous jugular vein or carotid artery was used as a patch to repair a rat aorta or inferior vena cava. In the aortic environment patches contained neointimal cells that were CD34/Ephrin-B2-dual positive but not CD34/Eph-B4-dual positive; patches expressed Ephrin-B2, notch-4 and dll-4 but not Eph-B4 and COUP-TFII. In the venous environment patches contained neointimal cells that were CD34/Eph-B4-dual positive but not CD34/Ephrin-B2-dual positive; patches expressed Eph-B4 and COUP-TFII but not Ephrin-B2, notch-4 and dll-4. These data show that autologous tissue patches heal by acquisition of the vascular identity determined by the environment into which they are implanted, suggesting some plasticity of adult vascular identity.

Optimal management of radial artery grafts in CABG: Patient and target vessel selection and anti-spasm therapy

The current literature on radial artery grafting is reviewed focusing on the optimal deployment of radial artery grafts in coronary artery bypass surgery with specific attention to the selection of patients and target vessels for radial artery grafting.

Tissue-Engineered Vascular Graft of Small Diameter Based on Electrospun Polylactide Microfibers

Tubular vascular grafts 1.1 mm in diameter based on poly(L-lactide) microfibers were obtained by electrospinning. X-ray diffraction and scanning electron microscopy data demonstrated that the samples treated at T = 70°C for 1 h in the fixed state on a cylindrical mandrel possessed dense fibrous structure; their degree of crystallinity was approximately 44%. Strength and deformation stability of these samples were higher than those of the native blood vessels; thus, it was possible to use them in tissue engineering as bioresorbable vascular grafts. The experiments on including implantation into rat abdominal aorta demonstrated that the obtained vascular grafts did not cause pathological reactions in the rats; in four weeks, inner side of the grafts became completely covered with endothelial cells, and fibroblasts grew throughout the wall. After exposure for 12 weeks, resorption of PLLA fibers started, and this process was completed in 64 weeks. Resorbed synthetic fibers were replaced by collagen and fibroblasts. At that time, the blood vessel was formed; its neointima and neoadventitia were close to those of the native vessel in structure and composition.

Efficacy and effectiveness of on- versus off-pump coronary artery bypass grafting: A meta-analysis of mortality and survival

BACKGROUND

Despite many studies comparing on- versus off-pump coronary artery bypass graft (CABG), there is no consensus as to whether one of these techniques offers patients better outcomes.

METHODS

We searched PubMed from inception to June 30, 2015, and identified additional studies from bibliographies of meta-analyses and reviews. We identified 42 randomized controlled trials (RCTs) and 31 rigorously adjusted observational studies (controlling for the Society of Thoracic Surgeons-recognized risk factors for mortality) reporting mortality for off-pump versus on-pump CABG at specified time points. Trial data were extracted independently by 2 researchers using a standardized form. Differences in probability of mortality (DPM) were estimated for the RCTs and observational studies separately and combined, for time points ranging from 30 days to 10 years.

RESULTS

RCT-only data showed no significant differences at any time point, whereas observational-only data and the combined analysis showed short-term mortality favored off-pump CABG (n = 1.2 million patients; 36 RCTs, 26 observational studies; DPM [95% confidence interval (CI)], -44.8% [-45.4%, -43.8%]) but that at 5 years it was associated with significantly greater mortality (n = 60,405 patients; 3 RCTs, 5 observational studies; DPM [95% CI], 10.0% [5.0%, 15.0%]). At 10 years, only observational data were available, and off-pump CABG showed significantly greater mortality (DPM [95% CI], 14.0% [11.0%, 17.0%]).

CONCLUSIONS

Evidence from RCTs showed no differences between the techniques, whereas rigorously adjusted observational studies (with >1.1 million patients) and the combined analysis indicated that off-pump CABG offers lower short-term mortality but poorer long-term survival. These results suggest that, in real-world settings, greater operative safety with off-pump CABG comes at the expense of lasting survival gains.

The Surgical Treatment of Coronary Artery Occlusive Disease: Modern Treatment Strategies for an Age Old Problem

Coronary artery disease remains a formidable challenge to clinicians. Percutaneous interventions and surgical techniques for myocardial revascularization continue to improve. Concurrently, in light of emerging data, multiple practice guidelines have been published guiding clinicians in their therapeutic decisions. The multidisciplinary Heart Team concept needs to be embraced by all cardiovascular providers to optimize patient outcomes.

Comparison of radial and bilateral internal thoracic artery grafting in patients with peripheral vascular disease†

OBJECTIVES

The composite T-graft with radial artery (RA) attached end-to-side to the left internal thoracic artery (ITA) provides arterial myocardial revascularization without the increased risk of deep sternal wound infection associated with harvesting 2 ITAs. However, many surgeons are reluctant to use RA in patients with peripheral vascular disease (PVD) due to concerns regarding the quality of the conduit in this subset of patients. The purpose of this study is to compare early- and long-term outcomes of arterial grafting with bilateral ITAs (BITA) to that of single ITA and RA in patients with PVD.

METHODS

Between 1999 and 2010, 619 consecutive patients with PVD (500 BITAs and 119 single ITA and RA) underwent myocardial revascularization in our institution.

RESULTS

Occurrence of following risk factors as female sex, age 70+, diabetes, unstable angina, emergency operation, cerebrovascular disease and chronic obstructive pulmonary disease was higher in the RA-ITA group. The RA-ITA group also had a higher logistic EuroSCORE (22.1 vs 13.3). Operative mortality and occurrence of deep sternal wound infection of the two groups was similar (4.2% vs 5.0% and 2.5% vs 4.0% for the radial and bilateral ITA, respectively). Median follow-up was 9.75 years. Unadjusted Kaplan-Meier 10-year survival of the two groups was similar (44.1% vs 49.6%, P  = 0.7). After propensity score matching (100 pairs), assignment to BITA was not associated with better adjusted survival (hazard ratio 0.593, 95% confidence interval 0.265-1.327, P  = 0.20, Cox model).

CONCLUSIONS

In patients with PVD, complete arterial revascularization with left ITA and RA can be justified with regards to survival.

Single-Centre Experience of Off-Pump Multi-Vessel Coronary Artery Bypass Grafting Using Proximal Suture Device

BACKGROUND

To investigate the results of off-pump coronary artery grafting (OPCAB) with the proximal suture device (PSD) regarding postoperative stroke and graft patency.

METHODS

The PSD was used in 376 patients (32.0%), aorta-no-touch OPCAB was performed in 523 patients (45.2%), on-pump beating coronary artery bypass surgery (CABG) (on-beat group) in 125 patients (10.6%) including 51 conversions (conversion rate: 5.4%), and CABG with aortic clamp use (clamp group) in 152 patients. In the PSD group, Enclose II was used in 267 patients (71.0%).

RESULTS

The hospital mortality rate was 1.95%. There was no early stroke in the OPCAB group, whereas the early-stroke rate was 0.8% in the on-beat group and 2.6% in the clamp group. The incidences of stroke at one month were: PSD group, 1.6%; no-touch group, 1.1%; on-beat group, 1.6%; and clamp group, 4.6% (p=0.014). The rates of complete revascularisation were higher in the PSD and clamp groups (94.7 and 94.0%, respectively) compared with the no-touch and on-beat groups (81.5 and 84.9%, respectively; p<0.001). The vein graft patency rates were comparable between the PSD and clamp groups. In multiple logistic regression analysis, OPCAB using the PSD did not increase the risk of stroke compared with the no-touch group (adjusted odds ratio [AOR]: 1.40; p=0.594) or on-beat group (AOR: 0.99; p=0.206), but reduced the risk of stroke compared with the clamp group (AOR: 0.19; p=0.005).

CONCLUSIONS

Off-pump coronary artery grafting using the PSD was a safe and effective procedure. It led to lower incidences of postoperative stroke and excellent rates of graft patency and complete revascularisation compared with conventional CABG.

Metabotyping Patients' Journeys Reveals Early Predisposition to Lung Injury after Cardiac Surgery

Cardiovascular disease is the leading cause of death worldwide and patients with severe symptoms undergo cardiac surgery. Even after uncomplicated surgeries, some patients experience postoperative complications such as lung injury. We hypothesized that the procedure elicits metabolic activity that can be related to the disease progression, which is commonly observed two-three days postoperatively. More than 700 blood samples were collected from 50 patients at nine time points pre-, intra-, and postoperatively. Dramatic metabolite shifts were observed during and immediately after the intervention. Prolonged surgical stress was linked to an augmented anaerobic environment. Time series analysis showed shifts in purine-, nicotinic acid-, tyrosine-, hyaluronic acid-, ketone-, fatty acid, and lipid metabolism. A characteristic 'metabolic biosignature' was identified correlating with the risk of developing postoperative complications two days before the first clinical signs of lung injury. Hence, this study demonstrates the link between intra- and postoperative time-dependent metabolite changes and later postoperative outcome. In addition, the results indicate that metabotyping patients' journeys early, during or just after the end of surgery, may have potential impact in hospitals for the early diagnosis of postoperative lung injury, and for the monitoring of therapeutics targeting disease progression.

Does the surgeon's experience have an impact on outcome after total arterial revascularization with composite T-grafts? A risk factor analysis

OBJECTIVES

When composite T-grafting is performed, total arterial revascularization (TAR) can be accomplished with only two grafts. There is the belief that composite grafting poses a risk of graft failure due to its single inflow via the left internal thoracic artery (LITA). High surgical quality is essential for left internal thoracic artery preparation, T-grafting and length estimation. We investigated whether the surgeon's experience influences postoperative outcome.

METHODS

We analysed the data of 1080 consecutive patients (88% male, age: 62 ± 9 years) who underwent composite T-grafting between 1996 and 2011 in our institution. Patients were operated on either by experienced surgeons (Group A) or by surgeons early on in their career (Group B). Primary end-points were mortality, myocardial ischaemia, graft dysfunction and low cardiac output syndrome. Secondary end-points were persistent neurologic deficits (PNDs), blood transfusions and re-thoracotomy. Logistic regression analysis was performed to reveal independent risk factors for adverse outcome.

RESULTS

Patients in Group B had a lower logistic EuroSCORE (2.8 vs 2.3%; P < 0.05), longer operative times (cross-clamp time: 41 ± 11 vs 47 ± 14 min; P < 0.001) and received less anastomoses (3.2 ± 0.7 vs 3.1 ± 0.7, P = 0.005). Mortality was low in both groups (Group A 0.6% vs Group B 0.4%; P = 1.0). Myocardial ischaemia occurred in 2.3% (Group A) and 2.5% (Group B; P = 0.82). Graft dysfunction was seen in 0.6% (Group A) and 1.4% (Group B; P = 0.25). Incidence of postoperative low cardiac output syndrome was comparable (Group A 1.4% vs Group B 0.7%; P = 0.53). Both groups showed similar incidence of secondary end-points (persistent neurologic deficit: Group A 2.9 vs 3.2% in Group B; P = 0.84; re-thoracotomy: 1.6% in Group A vs 1.8% in Group B, P = 1.0). Blood transfusions were more common in Group B (P = 0.005). Less surgical experience could only be identified as an independent risk factor for blood transfusion (P = 0.001).

CONCLUSIONS

Total arterial revascularization with composite T-grafts can be performed safely by surgeons with different surgical experience. Despite differences in surgical performance parameters (e.g. operation times, blood transfusions), complication rates were extremely low, irrespective of the surgeon's operative experience. Surgeons can be introduced to these procedures in an early phase of training.