Aldo Cannata

Biological effects of off-pump vs. on-pump coronary artery surgery: focus on inflammation, hemostasis and oxidative stress

Cardiopulmonary bypass (CPB) has been recognized as a cause of complex systemic inflammatory response, which significantly contributes to several adverse postoperative complications. In the last few years, off-pump coronary artery bypass grafting has gained widespread diffusion as an alternative technique to conventional on-pump coronary artery bypass grafting. Surgeons supporting off-pump surgery state that the avoidance of the CPB and myocardial ischemia-reperfusion significantly reduces the postoperative systemic inflammatory response and other biological derangements and, possibly, may improve the clinical outcomes. We review, here, the available evidence concerning possible differences between off-pump and on-pump procedures in terms of inflammation, hemostasis and oxidative stress. Consistent differences in the involvement of these systems are observed, but they are limited to the final steps of the surgical procedures and the early hours after. These findings suggest that the global surgical trauma may be as important, or even more, as the CPB in terms of systemic inflammatory and coagulation-fibrinolytic pathway activation. Further studies are needed in order to confirm this hypothesis.

Off-pump versus on-pump coronary artery bypass: meta-analysis of currently available randomized trials

BACKGROUND Off-pump coronary artery bypass (OPCAB) challenges the conventional on-pump coronary artery bypass grafting (CABG) as the standard of surgical therapy for coronary disease. The aim of this study is to assess the differences in clinical outcomes between CABG and OPCAB by meta-analysis of data published in randomized trials. METHODS A literature search (Medline, Pubmed, Cochrane Controlled Trials Register, and the Cochrane Medical Editors Trial Amnesty of unpublished clinical trials) was done for the period starting from January 1990 until May 2002 and was supplemented with a manual bibliographic review for all peer-reviewed English language publications. A systematic overview (meta-analysis) of the randomized trials was done to define the risk of the composite end point (death, stroke, or myocardial infarction) in CABG versus OPCAB. RESULTS A literature search yielded nine comparable randomized studies, for a total of 1090 patients, of whom 558 and 532 were randomly assigned to CABG and OPCAB, respectively. Meta-analysis of these studies showed a trend, albeit not statistically significant, toward reduction in the risk of the composite end point for patients who had OPCAB (odds ratio 0.48; 95% confidence interval 0.21 to 1.09; p = 0.08). CONCLUSIONS Cumulative analysis of the few prospective randomized studies currently available found a potential clinical benefit of OPCAB, indicating that the avoidance of extracorporeal circulation might result in improved clinical outcomes. Further evidence, however, from large randomized trials is needed to assess potential advantages of OPCAB in terms of early outcomes.

Is aortic wall degeneration related to bicuspid aortic valve anatomy in patients with valvular disease

OBJECTIVE Patients with bicuspid aortic valve are at increased risk for aortic complications. METHODS A total of 115 consecutive patients with bicuspid aortic valve disease underwent surgery of the ascending aorta. We classified the cusp configuration by 3 types: fusion of left coronary and right coronary cusps (type A), fusion of right coronary and noncoronary cusps (type B), and fusion of left coronary and noncoronary cusps (type C). Histopathologic changes in the ascending aortic wall were graded (aortic wall score). RESULTS We observed type A fusion in 85 patients (73.9%), type B fusion in 28 patients (24.3%), and type C fusion in 2 patients (1.8%). Patients with type A fusion were younger at operation than patients with type B fusion (51.3 +/- 15.5 years vs 58.7 +/- 7.6 years, respectively; P = .034). The mean ascending aorta diameter was 48.9 +/- 5.0 mm and 48.7 +/- 5.7 mm in type A and type B fusion groups, respectively (P = .34). The mean aortic root diameter was significantly larger in type A fusion (4.9 +/- 6.7 mm vs 32.7 +/- 2.8 mm; P < .0001). The aortic wall score was significantly higher in type A fusion than in type B fusion (P = .02). The prevalence of aortic wall histopathologic changes was significantly higher in type A fusion. Moreover, there were no statistically significant differences between type A and type B fusion in terms of prevalence of bicuspid aortic valve stenosis, regurgitation, or mixed disease. CONCLUSION In diseased bicuspid aortic valves, there was a statistically significant association between type A valve anatomy and a more severe degree of wall degeneration in the ascending aorta and dilatation of the aortic root at younger age compared with type B valve anatomy.

The radial artery: which place in coronary operation?

Previous long-term studies have shown unsatisfactory patency of saphenous vein grafts, compared with internal mammary artery grafts. Recently, the use of the radial artery as a coronary artery bypass graft has enjoyed a revival, on the basis of the belief that it will help improving long-term results of coronary operations. The recent report of encouraging 5-year patency rates, supports its continued use as a bypass graft. In this paper, we review the current knowledge about the radial artery as a bypass graft, with special emphasis on the clinical results.

The anterior spinal artery: the main arterial supply of the human spinal cord--a preliminary anatomic study.

Paraplegia is the most feared complication of surgery of the thoracic aorta. Controversy continues regarding the continuity of the anterior spinal artery (ASA). We studied the arterial vascularization of human spinal cord to indagate ASA continuity and possible anatomic variations of the arteria radicularis magna (ARM). Methods. From July 1998 to January 1999, 31 spinal cords from adult cadavers of both sexes were studied (mean age 72 ± 12 years). The cause of death was well established in each case and no one had spinal, cerebral, or significant aortic disease. The abdomen, thoracic viscera, and vessels were removed after 24 to 36 hours from death; only the upper trunks of the aorta were left in situ. The anterior vertebral spinal column was exposed and the attached muscles were divided. The vertebral bodies were removed with an electrical oscillating saw. The spinal cord in situ was exposed after a longitudinal paramedian incision of the dura mater. In all cases the course of the ASA was visualized and the distribuFrom the Department of Cardiovascular Surgery, Centro Cardiologico “I Monzino” Foundation IRCCS,a and II Department of Pathology,b University of Milan, Milan, Italy. Received for publication April 6, 1999; accepted for publication Sept 20, 1999. Address for reprints: Maurizio Roberto, MD, Department of Cardiovascular Surgery, “I Monzino” Foundation IRCCS, via Parea 4, 20138 Milan, Italy. J Thorac Cardiovasc Surg 2000;119:376-9 Copyright

Direct Aortic Access for Transcatheter Self- Expanding Aortic Bioprosthetic Valves Implantation

BACKGROUND Transcatheter aortic valve implantation (TAVI) has been designed to treat elderly patients with severe aortic stenosis at high risk for operation; however, these patients are also often affected by severe iliac-femoral arteriopathy that prohibits the transfemoral approach. METHODS From May 2008 to January 2012, 400 patients were evaluated for TAVI at our center; of these, 141 patients (64 men; mean age 81.3±8 years) with severe symptomatic aortic stenosis and no reasonable surgical option due to excessive risk were eligible for CoreValve (137 patients; Medtronic Inc, MN) or Sapien (Edwards Lifesciences, CA) implantation. Twenty-five patients (all affected by severe peripheral vasculopathy, including five re-do procedures), with a mean The Society of Thoracic Surgeons mortality score 11%±6%, underwent CoreValve implantation directly from the ascending aorta through a right anterior minithoracotomy. This case series was reviewed to evaluate the clinical outcomes of these patients. A combined team of cardiologists, cardiac surgeons with expertise in hybrid procedures, and anesthetists performed all the procedures. RESULTS In all patients after valve deployment, the mean aortic gradient immediately dropped to 5 mm Hg or less, and the angiographic grade aortic insufficiency was 1 or less in 22 patients. One patient was converted to the transfemoral approach due to an extremely fragile aortic wall, but the patient died of abdominal aorta aneurysm rupture on postoperative day 1. Procedural success was obtained in the remaining 24 patients. A left ventricle tear in 1 patient was successfully surgically treated. Four patients required a permanent pacemaker implantation. Thirty-day mortality was 8% (2 patients). All discharged patients improved their New York Heart Association functional class and functional capacity, and echocardiograms demonstrated good valve performance up to 2 years (mean valve gradient, 9 mm Hg). During follow-up, 1 patient died of cachexia and another of bone marrow aplasia. CONCLUSIONS TAVI with the direct aortic approach is safe and feasible, offering a new attractive option to treat selected high-risk patients with severe aortic stenosis and peripheral vasculopathy, including those requiring a re-do procedure, and has emerged as a valuable alternative route to transapical access.

Endothelial damage during myocardial preservation and storage

Preservation and storage techniques represent two major issues in routine cardiac surgery and heart transplantation. Historically, these methods were conceived to prevent ischemic injury to myocardium after cardiac arrest during heart operations. Evidence shows that endothelium plays a critical role in the maintenance of normal heart function after cardiac operation, mainly by controlling the coronary circulation. Methods for preservation and storage, developed initially to protect cardiomyocyte function, may be deleterious for vascular endothelium and compromise myocardial protection. In this review article the present knowledge about endothelial injury secondary to preservation and storage techniques is discussed.

Statins in coronary bypass surgery: rationale and clinical use.

Statin therapy prevents the first occurrence and recurrence of coronary events and reduces cardiovascular and general mortality in patients with coronary artery disease. These compounds modulate a variety of processes involved in the pathophysiology of arteriosclerosis and vascular graft disease by lipid-dependent and lipid-independent (pleiotropic) mechanisms. As a result, statins produce angiographic and clinical benefits in patients undergoing coronary bypass surgery. We review the present knowledge about the effects of statins on this pathologic condition and the evidence supporting an early treatment initiation.

Prevention of Limb Ischemia and Edema During Peripheral Venoarterial Extracorporeal Membrane Oxygenation in Adults

Abstract  Venoarterial extracorporeal membrane oxygenation (VA‐ECMO) is a mechanical circulatory support indicated for the advanced treatment of refractory heart failure. The cannulation of the femoral vessels may be complicated by distal limb ischemia by arterial hypoperfusion and severe edema by venous obstruction. We describe a modified cannulation technique in order to prevent ischemia and edema of the inferior limb during VA‐ECMO.

A caval homograft for Budd-Chiari syndrome due to inferior vena cava obstruction

Transjugular intrahepatic portosystemic shunt (TIPS) is the standard treatment of Budd-Chiari syndrome (BCS) non responsive to medical therapy. However, patients with inferior vena cava (IVC) obstruction proximal to the atrium do not benefit from TIPS and a surgical approach is mandatory. We report the case of BCS due to intrapericardial IVC obstruction. We describe a novel surgical approach using a fresh caval homograft. An attempt to balloon dilatation of the IVC obstruction was complicated by right atrial disruption with tamponade and ventricular fibrillation. Lately, the patient successfully underwent a reconstruction of the cavo-atrial continuity by the interposition of a fresh caval homograft, a novel surgical approach never described before for BCS. Further follow-up revealed progressive reduction and resolution of ascites, and overall clinical improvement. IVC obstruction near to the atrium can be surgically approached with a new technique consisting in inferior vena cava resection and replacement with a caval homograft.