New Technology for Surgical Coronary Revascularization

Reviewing hybrid coronary revascularization: challenges, controversies and opportunities

Two main approaches to myocardial revascularization currently exist, coronary artery bypass and percutaneous coronary intervention. In patients with advanced coronary artery disease, coronary artery bypass surgery is associated with improved long term outcomes while percutaneous coronary intervention is associated with lower periprocedural complications. A new approach has emerged in the last decade that attempts to reap the benefits of bypass surgery and stenting while minimizing the shortcomings of each approach. This new approach, hybrid coronary revascularization, has shown encouraging early results. Minimally invasive techniques for bypass surgery have played a large part of bringing this approach into contemporary practice.

A new concentric double prosthesis for sutureless, magnetic-assisted aortic arch inclusion

Acute dissection of the ascending aorta is a life-threatening condition in which the aortic wall develops one or more tears of the intima associated with intramural rupture of the media layer with subsequent formation of a two lumina vessel. The remaining outer layer is just the adventitia, with high risk of complete rupture. Vital organs may be under-perfused. Mortality rate in this acute event is about 50% if an emergent surgical procedure is not performed as soon as possible to replace the tract affected by the primary rupture. Nevertheless, the emergent surgical procedure is affected by high risk of mortality or severe neurologic sequelae, due to the need for deep hypothermia and cardiocirculatory arrest and different methods of cerebral protection. If the patient survives the acute event, a frequent outcome is the establishment of a chronic aortic dissection in the remaining aorta and late chronic dissecting aneurysm, usually starting from the surgical suture itself. Traumatism of surgical stitches and of direct blood flow pressure on weak aortic wall can be important contributing factors of the chronic disease. In conclusions, the majority of these patients undergoes a high risk operation without a complete solution of the disease. We hypothesize that excluding the aortic layers from the blood direct flow and using an anastomotic technique which does not include surgical stitches could help to significantly reduce the recurrence of aortic dissection after the acute event and shorten hypothermic arrest duration. We devised a double tubular prosthesis consisting of two concentric artificial tubes between which the aortic wall is confined and excluded from direct blood flow. We also devised a magnetic assisted sutureless anastomotic technique that seals the aortic tissue between the two prostheses and avoids the perforation of the fragile aortic wall with surgical stitches. We are presenting here this new prototype and draw a few different models. Both acute and chronic diseases of the aorta could benefit from the proposed technique, although acute dissection is the ideal scenario for its use.

Minimally invasive direct coronary artery bypass grafting with an improved rib spreader and a new-shaped cardiac stabilizer: results of 200 consecutive cases in a single institution

Background

Performing minimally invasive direct coronary artery bypass (MIDCAB) grafting via small chest incisions on a beating heart is challenging. We report our experiences of MIDCAB with the utilization of both an improved rib spreader to harvest the left internal mammary artery (LIMA) and a new-shaped cardiac stabilizer to facilitate LIMA-left anterior descending (LAD) coronary anastomosis.

Methods

Between May 2012 and June 2104, a total of 200 patients who were consecutively operated on in this period were enrolled in this study. Data reported included demographic information, preoperative clinical and cardiac status, LIMA harvest time, postoperative in-hospital outcomes, and 30-day mortality.

Results

The average LIMA harvest time was 43 min. The mean age was 62.59 ± 10.19 years, and 45 of the 200 were females. The 30-day mortality was 0.5 % (one patient) due to perioperative myocardial infarction. Duration of mechanical ventilation and length of stay in intensive care unit was 9.27 ± 7.65 and 24.27 ± 17.85 h, respectively. The unit of packed RBC transfusion was 0.79 ± 1.58. Postoperative atrial fibrillation was observed in 14 (7 %) patients. There was no postoperative stroke, renal failure, or incision complication.

Conclusion

Performing MIDCAB with the improved retractor and stabilizer utilized in this study showed favorable outcomes in terms of harvesting the LIMA, postoperative morbidities, and 30-day mortality.

Renal Transplantation by Automatic Anastomotic Device in a Porcine Model

Automatic vascular staplers for vascular anastomoses in kidney transplantation may dramatically reduce the operative time and, in particular, warm ischemia time, thus increasing the outcome of transplantation. Ten pigs underwent kidney auto-transplantation by automatic anastomotic device. Kidneys were collected by laparotomy with selective ligations at the renal hilum and perfused with cold storage solution. To overcome the shortage in length of renal hilum, a tract of the internal jugular vein was harvested to increase the length of the vessels. The anastomoses were totally performed by the use of the anastomotic device. On 10 kidney transplants, nine were successful and no complications occurred. Renal resistive indexes showed a slight increase in the immediate postoperative period returning normal at 10 days of follow-up. We demonstrated the possibility to perform renal vascular anastomoses by means of an automatic anastomotic device. This instrument developed for coronary bypass surgery by virtue of the small caliber of the vessels could be adopted on a larger scale for renal transplantation. The reduced warm ischemia time needed for anastomosis may help to achieve a better outcome for the graft and expand the pool of marginal donors in renal transplantation.

Meta-analysis of minimally invasive coronary artery bypass versus drug-eluting stents for isolated left anterior descending coronary artery disease

OBJECTIVE

To compare the outcomes between minimally invasive coronary artery bypass (MINI-CAB) and drug-eluting stent (DES) implantation for isolated left anterior descending artery disease.

METHODS

Randomized and observational comparative publications were identified using MEDLINE and Google Scholar databases (January 2003 to December 2013). Studies without outcomes data, without DES use, or using conventional bypass surgery were excluded. The outcomes of interest were cardiac death, myocardial infarction, target vessel revascularization, and periprocedural stroke. Data were compared using the Mantel-Haenszel methods and are presented as odds ratios (ORs), 95% confidence intervals (CIs), and number needed to treat.

RESULTS

From 230 publications, we identified 4 studies (2 randomized and 2 observational) with 941 patients (478 had undergone MINI-CAB and 463 DES implantation). The incidence of target vessel revascularization at maximum follow-up (range, 6-60 months) was significantly lower in the MINI-CAB group (OR, 0.16; 95% CI, 0.08-0.30; P<.0001; number needed to treat, 13). The incidence of cardiac mortality and MI was similar between the MINI-CAB and DES groups during follow-up (OR, 1.05; 95% CI, 0.44-2.47; and OR, 0.83; 95% CI, 0.43-1.58, respectively). In addition, a similar incidence of periprocedural death (OR, 0.85; 95% CI, 0.21-3.47; P=.82), myocardial infarction (OR, 0.98; 95% CI, 0.38-2.58; P=.97), and stroke (OR, 1.36; 95% CI, 0.28-6.70; P=.70) was observed between the 2 treatment modalities.

CONCLUSIONS

Given the available evidence, MINI-CAB will result in lower target vessel revascularization rates but otherwise similar clinical outcomes compared with DESs in patients with left anterior descending artery disease.

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

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

The primary and secondary prevention of coronary artery disease: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)

The following chapter devoted to antithrombotic therapy for chronic coronary artery disease (CAD) is part of the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Grade 1 recommendations are strong and indicate that the benefits do or do not outweigh risks, burden, and costs. Grade 2 suggests that individual patient values may lead to different choices (for a full understanding of the grading see the "Grades of Recommendation" chapter by Guyatt et al in this supplement, CHEST 2008; 133[suppl]:123S-131S). Among the key recommendations in this chapter are the following: for patients with non-ST-segment elevation (NSTE)-acute coronary syndrome (ACS) we recommend daily oral aspirin (75-100 mg) [Grade 1A]. For patients with an aspirin allergy, we recommend clopidogrel, 75 mg/d (Grade 1A). For patients who have received clopidogrel and are scheduled for coronary bypass surgery, we suggest discontinuing clopidogrel for 5 days prior to the scheduled surgery (Grade 2A). For patients after myocardial infarction, after ACS, and those with stable CAD and patients after percutaneous coronary intervention (PCI), we recommend daily aspirin (75-100 mg) as indefinite therapy (Grade 1A). We recommend clopidogrel in combination with aspirin for patients experiencing ST-segment elevation (STE) and NSTE-ACS (Grade 1A). For patients with contraindications to aspirin, we recommend clopidogrel as monotherapy (Grade 1A). For long-term treatment after PCI in patients who receive antithrombotic agents such as clopidogrel or warfarin, we recommend aspirin (75 to 100 mg/d) [Grade 1B]. For patients who undergo bare metal stent placement, we recommend the combination of aspirin and clopidogrel for at least 4 weeks (Grade 1A). We recommend that patients receiving drug-eluting stents (DES) receive aspirin (325 mg/d for 3 months followed by 75-100 mg/d) and clopidogrel 75 mg/d for a minimum of 12 months (Grade 2B). For primary prevention in patients with moderate risk for a coronary event, we recommend aspirin, 75-100 mg/d, over either no antithrombotic therapy or vitamin K antagonist (Grade 1A).

Coronary Artery Revascularisation : Past, Present and Future

The high prevalence of coronary artery disease has inspired the development of technologies and techniques for coronary revascularisation, including coronary artery bypass grafting (CABG) and percutaneous coronary interventions (PCI). PCI have witnessed the impact of innovation with newer hardware and drug eluting stents (DES). DES have indisputably reduced restenosis, however there is an emerging concern over the risk of late stent thrombosis associated with their use. We discuss the limitations of the current generation DES and review advances in the stent technology. The technology used in CABG has improved, resulting in off-pump coronary artery bypass (OPCAB), endoscopic, video-assisted, and robot-assisted CABG with automated one-shot distal anastomotic devices being used increasingly. The difference in adverse outcomes between CABG and PCI continues to decline and the future may witness a close collaboration between the two.

Trends in cardiac surgery: exploring the past and looking into the future

Today's successes would not be possible without the foundation of yesterday's practitioners and patients. This article assists in the exploration of cardiac surgery procedures, provides a brief historical review of the significant changes in cardiothoracic surgery, and provides an overview of current and future methods of treatment for coronary revascularization and heart failure. It is difficult for one article to encompass all aspects of cardiothoracic surgery. This article highlights many of the transforming moments that have led us to where we are today and explores the current trends of cardiac surgery and possibilities for tomorrow.

The effects of prophylactic coronary revascularization or medical management on patient outcomes after noncardiac surgery - a meta-analysis

PURPOSE

The benefits of prophylactic coronary revascularization for patients undergoing noncardiac surgery are uncertain. The purpose of this study was to systematically evaluate the effect of coronary revascularization and medical management on short- and long-term outcomes after noncardiac surgery.

METHOD

Ten electronic databases including MEDLINE and EMBASE (1980 to February 2006), and bibliographies of included articles were searched without language restrictions. Studies comparing effects of coronary revascularization and medical management before noncardiac surgery were included. Patient outcome data including perioperative mortality, myocardial infarction, long-term mortality, or late adverse cardiac events were extracted and entered into a meta-analysis.

RESULTS

The quality of published evidence was modest, comprising one randomized controlled trial and six retrospective studies. A total of 3,949 patients undergoing high-risk noncardiac surgery were included in the quantitative analysis. There was no significant difference between coronary revascularization and medical management groups with regards to postoperative mortality and myocardial infarction; the odds ratios (95% confidence intervals) were 0.85 (0.48-1.50) and 0.95 (0.44-2.08), respectively. There were no long-term outcome benefits associated with prophylactic coronary revascularization; the odds ratios (95% confidence intervals) were 0.81 (0.40-1.63) and 1.65 (0.70-3.86) for long-term mortality and late adverse cardiac events, respectively.

CONCLUSION

In patients with stable coronary artery disease, prophylactic coronary revascularization before high-risk noncardiac surgery does not confer any beneficial effects, when compared with optimized medical management, in terms of perioperative mortality, myocardial infarction, long-term mortality, or adverse cardiac events.