Evaluation of Infection Resistance of Biodegradable versus Conventional Annuloplasty Rings in an in vivo Rat Subcutaneous Model.

BACKGROUND: Biodegradable atrioventricular annuloplasty rings are theoretically more infection resistant due to their intra-annular implantation technique and nonporous structures (monofilament of poly-1,4-dioxanone). The aim of this study was to investigate the infection resistance of a biodegradable annuloplasty ring (Kalangos-Bioring®) in a rat subcutaneous implantation model and to compare it with a commonly used conventional annuloplasty ring (Edwards Physio II®). METHODS: This study included 32 Wistar albino rats which were divided into 2 groups according to the implantation of sterile or infected annuloplasty rings as control and study groups. Each animal had 2 implantation pockets (made on the right and left side of the dorsal median line) where 1 cm of the biodegradable annuloplasty ring was implanted into one pocket and 1 cm of the conventional annuloplasty ring was implanted into the other pocket. The infection model was created by topical inoculation of 1 mL Staphylococcus aureus strain (2 × 107 colony-forming units/mL) into the implantation pockets before skin closure. Each group was equally divided into 4 subgroups according to different follow-up schedules. The animals were inspected for local as well as systemic infection signs, and the rings were explanted at weeks 2, 4, 9, and 14 following implantation. Implantation pockets were evaluated macroscopically as well as by histopathological examinations. Microbiological analysis of the explanted implants with surrounding tissue was done by using quantitative sonication method. RESULTS: Conventional ring-implanted pockets showed a more prominent inflammation reaction than the biodegradable ring-implanted pockets, and this characteristic was found to be accentuated with bacterial contamination. The sterile rings did not reveal any positive cultures in either group. The number of positive cultures found in conventional rings contaminated with S. aureus was greater than in the biodegradable ring group (11/16 vs. 2/16 positive cultures, respectively; p = 0.0032). The amounts of growing bacteria in the culture environment were also statistically significantly higher in the conventional ring group (7,175 ± 5,936 vs. 181 ± 130 colony-forming units/mL, respectively; p < 0.0005). CONCLUSIONS: This is the first experimental study confirming the theoretical advantage of the infection resistance of the biodegradable annuloplasty ring (Kalangos-Bioring®) when implanted in an active infectious environment. Large animal models mimicking clinical scenarios and clinical comparative studies are needed to verify our results.

Comparison of early postoperative results in patients with and without diabetes with low ejection fraction and normal serum creatinine values who underwent coronary artery bypass operation.

BACKGROUND: Low left ventricular ejection fraction and renal insufficiency are factors that increase the risk of coronary artery bypass graft surgery in patients with diabetes mellitus. The aim of this study was to group patients with low left ventricular ejection fraction undergoing coronary artery bypass graft surgery according to the presence or absence of diabetes mellitus and to evaluate postoperative changes in serum creatinine levels and postoperative outcomes. METHODS: A total of 93 patients undergoing isolated coronary artery bypass grafting were included in this single-centre, retrospective, cohort study. Patients with a pre-operative low left ventricular ejection fraction of less than 35% were included in the study. Patients were divided into diabetic and non-diabetic groups and intra- and intergroup values were compared. Pre-operative, and postoperative days 2 and 5 serum creatinine levels of the patients were measured and compared. RESULTS: Of the 93 patients included in the study, 60 were in the diabetic group (group 1) and 33 were in the non-diabetic group (group 2). Postoperative 2- and 5-day creatinine levels were significantly higher in group 1 than in group 2 (p = 0.033 and p = 0.005, respectively). Postoperative 2- and 5-day creatinine levels were significantly higher than pre-operative creatinine levels in group 1 (p = 0.008 and p = 0.001, respectively). The intensive care unit stay was significantly longer in the diabetes mellitus group than in the group without diabetes mellitus (p = 0.031). CONCLUSION: Following coronary artery bypass graft surgery in patients with low left ventricular ejection fraction, which is already a risk factor, creatinine levels were found to have increased in the diabetes mellitus group.

A new technique to avoid the intraoperative complications of septal myectomy in patients with obstructive hypertrophic cardiomyopathy.

Although transaortic septal myectomy in obstructive hypertrophic cardiomyopathy (OHC) is accepted as a safe procedure, it may end up with serious peroperative complications. We developed a practical method to avoid this unfavorable outcome by using a 20-cc syringe body. We believe this apparatus will provide safe and effective septal myectomy procedures without additional cost.

Association between ascending aortic diameter and coronary artery dilation: a demographic data analysis.

Objective Coronary artery dilations (CDs), a subgroup of coronary artery anomalies (CAAs), are relatively rare but important cardiac pathologies. They are considered to be linked to coronary atherosclerosis in most cases. Methods The demographic data, multi-slice computed tomographic coronary angiography data, coronary calcium score, and ascending aortic diameter (AAD) of 1538 patients were reviewed. In total, 197 (12.8%) patients (166 men, 31 women; age 15 - 84 years; mean 55.78 ± 12.32 years) with CAAs were identified, and 81 (5.3%) patients (70 men, 11 women; age 27 - 80 years; mean 56.63 ± 12.06 years) had CDs. Multiple regression and correlation analyses were performed in all 1538 patients to predict the association between the AAD and the presence of CD and thus their correlation with atherosclerosis. Results The AAD was significantly larger in patients with than without CAAs and CDs. Male sex was significantly more prevalent in patients with CAAs and CDs. According to the multiple logistic regression model, male sex increased the risk of CD by 2.650 and the risk of CAA by 2.017, while hyperlipidaemia decreased the risk of CAA by 0.681. While a moderately weak correlation between the AAD and age was observed in patients with CDs, no correlation was found between the AAD and coronary calcium score. Conclusion Although the natural history and physiopathology of CDs is not yet fully understood, the present study shows an association between the AAD and the presence of CDs but a lack of association between atherosclerosis and CDs.

Oxidant Status following Cardiac Surgery with Phosphorylcholine-Coated Extracorporeal Circulation Systems.

Introduction. Extracorporeal circulation (ECC) related systemic oxidative stress is a well-known entity but the underlying mechanisms are not clearly described. Our aim was to investigate the relation between the oxidative stress indices, inflammatory markers, and phosphorylcholine-coated (PCC) ECC systems. Patients and Methods. Thirty-two consecutive coronary artery bypass grafting (CABG) cases were randomly assigned to Group I (PCC, n = 18) and Group II (noncoated, n = 14) ECC circuits. Total Antioxidant Status (TAS), Total Oxidant Status (TOS), Tumor Necrosis Factor-α (TNF-α), Interleukin-1ß (IL-ß), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-10 (IL-10), and Procalcitonin (PCT) levels were measured at 5 different time points. The association between the oxidative indices levels and PCC system used was analyzed. Results. In Group I TOS and TAS statuses were increased at T1, T2, T3, and T4, while IL-10 and TNF-α levels accompanied those raises only at T2 (Group I-Group II, 4.73 ± 2.04 versus 2.79 ± 0.63, p = 0.002, and 30.56 ± 8.11 versus 23.97 ± 7.8, p = 0.031, resp.). In contrast, mean TAS and TOS levels were similar to baseline at all time points in Group II but IL-6 and IL-8 levels were increased at T2 (Group I-Group II, 16.84 ± 5.63 versus 44.81 ± 17.0, p = 0.001, and 38.88 ± 9.8 versus 46.14 ± 9.25, p = 0.038, resp.). Conclusion. Even coated ECC systems are still incapable of attenuating the inflammatory response to cardiopulmonary bypass (CPB).

A new proximal anastomosis technique in two patients with severely calcified aorta.

A severely calcified aorta carries a high risk of atheroemboli and bleeding for cardiac surgery with an incidence range of 14% to 29%. Various techniques were described avoiding cannulation and clamping of the aorta. Nowadays, the no-touch beating heart technique seems to be the best alternative in patients with calcific aorta. Herein, we present a closed proximal anastomosis technique in this high-risk patient group.

A novel approach to surgical treatment of diseased intracavitary coronary arteries and ventriculotomy closure.

Inadvertent opening of the right ventricle may occur during dissection of an intracavitary artery. Two patients with stenotic intracavitary left anterior descending arteries were operated on. A right ventriculotomy was performed in the operation. The anastomosis was performed to this intracavitary segment of the artery. The ventriculotomy was closed with a pericardium. There were no ischemic changes or aneurysmal formation in the postoperative follow-ups. This technique may be preferable in the closure of right ventriculotomy without compromise of coronary flow or anastomosis.