Modular minimally invasive extracorporeal circulation systems; can they become the standard practice for performing cardiac surgery?

Minimally invasive extracorporeal circulation (MiECC) has been developed in an attempt to integrate all advances in cardiopulmonary bypass technology in one closed circuit that shows improved biocompatibility and minimizes the systemic detrimental effects of CPB. Despite well-evidenced clinical advantages, penetration of MiECC technology into clinical practice is hampered by concerns raised by perfusionists and surgeons regarding air handling together with blood and volume management during CPB. We designed a modular MiECC circuit, bearing an accessory circuit for immediate transition to an open system that can be used in every adult cardiac surgical procedure, offering enhanced safety features. We challenged this modular circuit in a series of 50 consecutive patients. Our results showed that the modular AHEPA circuit design offers 100% technical success rate in a cohort of random, high-risk patients who underwent complex procedures, including reoperation and valve and aortic surgery, together with emergency cases. This pilot study applies to the real world and prompts for further evaluation of modular MiECC systems through multicentre trials.

Coronary artery bypass grafting with minimal versus conventional extracorporeal circulation; an economic analysis.

BACKGROUND: This study aims to develop a methodological framework for the comparative economic evaluation between Minimal Extracorporeal Circulation (MECC) versus conventional Extracorporeal Circulation (CECC) in patients undergoing coronary artery bypass grafting (CABG) in different healthcare systems. Moreover, we evaluate the cost-effectiveness ratio of alternative comparators in the healthcare setting of Greece, Germany, the Netherlands and Switzerland. METHODS: The effectiveness data utilized were derived from a recent meta-analysis which incorporated 24 randomized clinical trials. Total therapy cost per patient reflects all resources expensed in delivery of therapy and the management of any adverse events, including drugs, diagnostics tests, materials, devices, blood units, the utilization of operating theaters, intensive care units, and wards. Perioperative mortality was used as the primary health outcome to estimate life years gained in treatment arms. Bias-corrected uncertainty intervals were calculated using the percentile method of non-parametric Monte-Carlo simulation. RESULTS: The MECC circuit was more expensive than CECC, with a difference ranging from €180 to €600 depending on the country. However, in terms of total therapy cost per patient the comparison favored MECC in all countries. Specifically it was associated with a reduction of €635 in Greece, €297 in Germany, €1590 in the Netherlands and €375 in Switzerland. In terms of effectiveness, the total life-years gained were slightly higher in favor of MECC. CONCLUSIONS: Surgery with MECC may be dominant (lower cost and higher effectiveness) compared to CECC in coronary revascularization procedures and therefore it represents an attractive new option relative to conventional extracorporeal circulation for CABG.

Minimal extracorporeal circulation reduces the incidence of postoperative major adverse events after elective coronary artery bypass grafting in high-risk patients. A single-institutional prospective randomized study.

Coronary artery bypass grafting (CABG) using minimal extracorporeal circulation (MECC) has been associated with an improved short-term clinical outcome compared to conventional extracorporeal circulation (CECC). The aim of this study was to evaluate the impact of MECC compared to CECC on postoperative major adverse events in high-risk patients undergoing elective coronary revascularization procedures. Two hundred patients undergoing elective CABG were randomized into two groups. In Group A (n=100), MECC was used while Group B (n=100) included patients who were operated on CECC. The incidence of postoperative major adverse events (myocardial infarction, renal failure, stroke, death) was the primary end-point of the study. MECC was associated with a 77% relative risk reduction in the incidence of major adverse events compared to CECC (p=0.004). The rate of major adverse events occurring in the high-risk patient subgroup (preoperative left ventricular ejection fraction ≤40%, age >65 years, EuroSCORE II >5) operated on with MECC was significantly lower in comparison to their CECC counterparts. Based on our results, cardiac centres should be encouraged to use MECC as the standard circuit when performing elective coronary procedures, even in a high-risk population.

Intramyocardial implantation of autologous bone marrow-derived stem cells combined with coronary artery bypass grafting in patients with ischemic cardiomyopathy: a pilot study.

BACKGROUND: Ischemic cardiomyopathy has the distinctiveness of irreversible myocardial damage with scar tissue formation and mainly impaired perfusion of the remaining viable myocardium. We present results of the first series of patients with severe ischemic cardiomyopathy managed in our institution with intramyocardial implantation of autologous bone marrow stem cells at the time of coronary artery bypass grafting. The aim is to evaluate feasibility and safety of the procedure in our institution. PATIENTS AND METHODS: Nine patients with severe ischemic cardiomyopathy scheduled for elective coronary artery bypass grafting were managed with concurrent intramyocardial autologous bone marrow stem cells injection in pre-defined viable peri-infarct areas that showed poor perfusion and could not be grafted. Detailed mapping of infracted and hibernating myocardial segments was performed in all patients with single photon emission computed tomography segmental analysis. RESULTS: There was no perioperative 30-day mortality. Improvement was evident in left ventricular ejection fraction which was increased significantly from 31.3% preoperatively to 42.4%, 46.6% and 52.5% at 3, 6 and 12 months respectively. Postoperative thallium scintigraphy revealed increased perfusion in myocardial segments corresponding to areas of stem cell injection and a net reduction in the estimated infarct size at 6 and 12 months in 5/8 (62.5%) patients. CONCLUSIONS: Preliminary data from this pilot study show that intramyocardial administration of bone marrow stem cells in patients undergoing coronary bypass grafting for ischemic cardiomyopathy is safe and associated with an improvement in left ventricular function and enhanced reperfusion of non-viable myocardial territories.

Repair of aortic regurgitation caused by spontaneous avulsion of aortic valve commissure in a patient with idiopathic thrombocytopenic purpura.

We describe a case of severe acute aortic regurgitation in a 60-year-old woman due to spontaneous avulsion of an aortic valve commissure. She presented with spontaneous bleeding and a platelet count of 4 000/microl caused by idiopathic thrombocytopenic purpura and developed acute heart failure and respiratory insufficiency. Preoperative transesophageal echocardiography was not diagnostic for the exact mechanism of aortic regurgitation. She received a 2-day course of intravenous immunoglobulin (0.5 mg/kg/d) to increase platelet count. At operation detachment (avulsion) of the commissure between the left and the right coronary cusp was evident. Aortic valve repair was performed with resuspension of the commissure. The postoperative course was uneventful. During a 24-month follow-up period, the patient has remained in NYHA class I.

Cardiomyogenic potential of human adult bone marrow mesenchymal stem cells in vitro.

BACKGROUND: The aim of this study was to investigate the ability of adult human bone marrow mesenchymal stem cells to differentiate towards a cardiomyogenic phenotype IN VITRO. METHODS: Bone marrow samples were aspirated from 30 patients undergoing open heart surgery from the anterior iliac crest. Second passaged cells were treated with 10 microM 5-azacytidine. As control groups we used cells not expanded in culture and cells untreated with 5-azacytidine. Morphologic characteristics were analysed by confocal and electron microscopy. The expression of the cytoskeletal protein vimentin and muscle-specific myocin heavy chain was analysed by immunohistochemistry. The expression of the cardiomyocyte specific genes alpha-cardiac actin, beta-myocin heavy chain and cardiac troponin-T was detected by reverse transcriptase polymerase chain reaction. RESULTS: Mesenchymal stem cells were spindle-shaped with irregular processes. Cells treated with 5-azacytidine assumed a stick-like morphology. They connected with adjoining cells to form myotube-like structures. Numerous myofilaments were detected in induced cells which were immunohistochemically positive for myosin heavy chain and vimentin. The mRNAs of all specific cardiac genes were expressed in both induced and uninduced cells. CONCLUSION: These results indicate that adult human bone marrow mesenchymal stem cells treated with 5-aza can differentiate towards a cardiomyogenic lineage IN VITRO.

Secondary endovascular repair of a reconstructed superior vena cava in a patient with a malignant thymic epithelial neoplasm.

Thymic epithelial tumors can cause venous obstruction from compression or direct invasion of the superior vena cava (SVC) or the innominate veins. We report a case of a 40-year-old patient with a Masaoka stage III thymoma that resulted in obstruction of the left innominate vein and extrinsic compression of the SVC. All macroscopic tumors were resected together with ligation of the left innominate vein and reconstruction of the SVC with an ePTFE graft. Early graft thrombosis occurred in the first postoperative month with clinical signs of SVC syndrome. Endovascular repair was performed with the deployment of self-expanding nitinol stents, resulting in immediate relief of symptoms. The stented graft has remained patent for a follow-up period of 7 months.

Midterm results of endovascular abdominal aortic aneurysm repair with Talent stent graft in a single center.

AIM: The aim of this study is to investigate the safety and efficacy of abdominal aortic aneurysm (AAA) repair with modular bifurcated Talent stent-graft. METHODS: Between September 2001 and September 2005, 85 patients with infrarenal AAA underwent treatment with Talent stent-graft. There were 83 men and 2 women with a median age of 69.3 years. Anatomy of the abdominal aorta and the iliac arteries was investigated with high resolution contrast CT together with digital subtraction angiography. The majority of patients had comorbid illnesses like arterial hypertension (60%), CAD (38%) and previous CABG (26%). Duration of follow-up period ranged from 1 to 48 months (median 18 months). RESULTS: Repair was performed with transrenal fixation of the bifurcated Talent stent-graft under regional anesthesia in 80% of all cases. Technical success rate was 97.6%. Aneurysm related mortality was 2.4% due to aneurysm rupture in the postoperative period. Overall mortality rate was 9.4%. Morbidity rate was 16.5%. Immediate conversion to open repair was necessary in 1 patient (1.2%). Endoleak rate was 4.8% at 1 month follow-up period. Secondary intervention was required in 1.2% of patients. Iliac limb occlusion was detected in 1 patient (1.2%). CONCLUSIONS: Talent stent-graft exhibits a high degree of technical success in AAA repair in patients with comorbid conditions with a low perioperative morbidity and mortality rate.