Vytautas Sirvydis

Influence of Inflow Cannula Length in Axial-flow Pumps on Neurologic Adverse Event Rate: Results From a Multi-center Analysis

BACKGROUND The application of axial-flow pumps in patients with end-stage heart failure reveals a significantly reduced infectious complication rate as compared with rates observed with pulsatile devices. The remaining adverse event rate relates mainly to thromboembolic complications with neurologic consequences. We investigated the dependence of the neurologic adverse event rate on the length of the inflow cannula. METHODS A total of 216 consecutive patients with an axial-flow pump (INCOR; Berlin Heart GmbH, Berlin, Germany) were included in a retrospective multi-center analysis. In 138 patients, a short inflow cannula (24-mm tip length into the left ventricle), and in 78 patients a long inflow cannula (tip length 34 mm) was applied. RESULTS Patients with a long inflow cannula (LC) demonstrated a better survival rate than those with a short inflow cannula (SC) at the end of the observation period (LC, 63.4%; SC, 52.9%; p = 0.05). The thromboembolic adverse event rate was also significantly lower. Only 3 of the 78 patients (3.8%) with an LC had a thromboembolic adverse event (thromboembolic events per patient-year = 0.11) as compared with 32 (23.2%) of SC patients (thromboembolic events per patient-year = 0.50, p < 0.001). CONCLUSIONS Patients with a long inflow cannula had a better survival rate and a lower incidence of cerebrovascular adverse events than patients with a short inflow cannula.

Characterisation and validity of inflammatory biomarkers in the prediction of post-operative atrial fibrillation in coronary artery disease patients

Atrial fibrillation (AF) is a common complication of coronary artery bypass grafting (CABG). We sought to determine the diagnostic validity of plasma biomarkers of i) inflammation (marked by interleukin-6 [IL-6] and high-sensitivity C-reactive protein [hs-CRP]), ii) extracellular matrix remodelling (matrix metalloproteinase [MMP-9], tissue inhibitor of matrix metalloproteinase [TIMP-1]) and iii) the prothrombotic state (tissue factor and von Willebrand factor [vWF]) in the risk prediction of post-operative AF. Samples were obtained preoperatively from peripheral/femoral vein and from intracardiac chambers (right atrium [RA], the right atrial appendage [RAA], the left atrium [LA] and the left atrial appendage [LAA]) amongst 100 consecutive patients free of AF and inflammatory disease undergoing elective CABG. Biomarker concentrations were related to incident AF (30 days). At 30 days post CABG, 30 patients were proven to have had AF. Concentrations of tissue factor (TF) and vWF were unrelated to postoperative AF. Peripheral (p=0.018), and intracardiac levels (RAA (p=0.029) and LA (p=0.026)) of hs-CRP were associated with the presence of AF after CABG. Intracardiac levels of IL-6 in samples from the RAA (p=0.031), LA (p=0.042) and LAA (p=0.006), and MMP-9 in the LAA sample were also associated with AF (p=0.007). Our data suggest that an intra-cardiac inflammatory environment that is manifest peri-operatively may predispose to the development of post-operative AF. This intracardiac inflammatory state was reflected by increased peripheral hs-CRP levels. These differences may indicate local substrate abnormalities contributing to the development of AF post-operatively.

Intracardiac expression of markers of endothelial damage/dysfunction, inflammation, thrombosis, and tissue remodeling, and the development of postoperative atrial fibrillation

Summary.  Background: Atrial fibrillation (AF) is a common complication of coronary artery bypass grafting (CABG), and may have an inflammatory and/or thrombotic etiology. We sought to determine the expression of inflammatory (interleukin [IL]‐6), thrombotic (tissue factor and von Willebrand factor [VWF]) and remodeling (matrix metalloproteinase [MMP]‐9 and tissue inhibitor of metalloproteinase [TIMP]‐1) markers by left atrial appendage (LAA) and right atrial appendage (RAA) tissue in the prediction of postoperative AF. We determined whether the tissue expression of markers of certain different pathophysiologic mechanisms predicted the development of AF after CABG. Methods: LAA and RAA tissue was excised during CABG in 100 patients free of AF and inflammation. Tissue marker expression was quantified by immunohistochemistry and was related to 30‐day postoperative AF. Results: Overall, there were no significant differences in staining intensity of any marker between LAA tissue and RAA tissue. However, more intense expression of VWF by LAA tissue predicted the 30 patients with postoperative AF as compared with those free of AF (P = 0.006). IL‐6, MMP‐9 and TIMP‐1 expression by RAA and LAA epicardial tissue was stronger than expression by endocardium or cardiomyocytes (all P < 0.025) but failed to predict AF. Conclusion: In this study, one of the largest to investigate tissue expression of pathophysiologic markers in relation to postoperative AF, we show that more intense expression of VWF by LAA tissue is a significant predictor of postoperative AF. This points towards a possible role of endothelial damage/dysfunction (as reflected by VWF changes) in the pathogenesis of postoperative AF.

Primary cardiac lymphoma: two cases and a review of literature.

BackgroundPrimary cardiac lymphoma is one of the rarest tumours of the heart. It belongs to the extra-nodal non-Hodgkin’s lymphomas. The most common type of this tumour is diffuse large B cell lymphoma. Usually, right atrium and right ventricle are involved. This tumour is fatal unless diagnosed and treated in time. In this article two female patients who were diagnosed with primary cardiac lymphoma and treated at our clinic are described. The first patient went to remission after the treatment, while the second patient died. The goals of this article are to show the difficulties of diagnosing and treating this disease, the role of cardiac surgery in its treatment and to raise awareness of this disease.Case reportsIn this article two female patients who were diagnosed with primary cardiac lymphoma and treated at our clinic are described. The first patient went to remission after the treatment, while the second patient died.ConclusionsPrimary cardiac lymphoma is a very rare disease. At the moment the most effective treatment is chemotherapy. Palliative surgery may be necessary to correct hemodynamics when venous blood flow to the lungs is disturbed.

Large Scale Laser Two-Photon Polymerization Structuring for Fabrication of Artificial Polymeric Scaffolds for Regenerative Medicine

We present a femtosecond Laser Two‐Photon Polymerization (LTPP) system of large scale three‐dimensional structuring for applications in tissue engineering. The direct laser writing system enables fabrication of artificial polymeric scaffolds over a large area (up to cm in lateral size) with sub‐micrometer resolution which could find practical applications in biomedicine and surgery. Yb:KGW femtosecond laser oscillator (Pharos, Light Conversion. Co. Ltd.) is used as an irradiation source (75 fs, 515 nm (frequency doubled), 80 MHz). The sample is mounted on wide range linear motor driven stages having 10 nm sample positioning resolution (XY—ALS130‐100, Z—ALS130‐50, Aerotech, Inc.). These stages guarantee an overall travelling range of 100 mm into X and Y directions and 50 mm in Z direction and support the linear scanning speed up to 300 mm/s. By moving the sample three‐dimensionally the position of laser focus in the photopolymer is changed and one is able to write complex 3D (three‐dimensional) structures. An illumination system and CMOS camera enables online process monitoring. Control of all equipment is automated via custom made computer software “3D‐Poli” specially designed for LTPP applications. Structures can be imported from computer aided design STereoLihography (stl) files or programmed directly. It can be used for rapid LTPP structuring in various photopolymers (SZ2080, AKRE19, PEG‐DA‐258) which are known to be suitable for bio‐applications. Microstructured scaffolds can be produced on different substrates like glass, plastic and metal. In this paper, we present microfabricated polymeric scaffolds over a large area and growing of adult rabbit myogenic stem cells on them. Obtained results show the polymeric scaffolds to be applicable for cell growth practice. It exhibit potential to use it for artificial pericardium in the experimental model in the future.We present a femtosecond Laser Two‐Photon Polymerization (LTPP) system of large scale three‐dimensional structuring for applications in tissue engineering. The direct laser writing system enables fabrication of artificial polymeric scaffolds over a large area (up to cm in lateral size) with sub‐micrometer resolution which could find practical applications in biomedicine and surgery. Yb:KGW femtosecond laser oscillator (Pharos, Light Conversion. Co. Ltd.) is used as an irradiation source (75 fs, 515 nm (frequency doubled), 80 MHz). The sample is mounted on wide range linear motor driven stages having 10 nm sample positioning resolution (XY—ALS130‐100, Z—ALS130‐50, Aerotech, Inc.). These stages guarantee an overall travelling range of 100 mm into X and Y directions and 50 mm in Z direction and support the linear scanning speed up to 300 mm/s. By moving the sample three‐dimensionally the position of laser focus in the photopolymer is changed and one is able to write complex 3D (three‐dimensional) structures....

Sensitisation and post-transplant course after the implantation of ventricular assist device

The purpose of this study was to evaluate sensitisation, occurring because of bridging with VAD, and development of rejection episodes after transplantation in selected groups of patients using triple drug immunosuppression, without induction or desensitisation therapy. Sensitisation using standard complement dependent cytotoxicity was tested in 16 patients awaiting cardiac transplantation before VAD placement, one month post-implantation and on a six-monthly basis later on. Long-term (955+/-998 days) post-transplant course of six transplanted post-VAD patients was compared with 19 non-bridged recipients (follow-up time 1425+/-1273 days) of the same age. One-third of VAD recipients had developed anti-HLA antibodies one month post-implantation; 4/16 patients were sensitised six months after implantation. No de novo sensitisation development was revealed in VAD group post-transplantation. All sensitised patients independent of VAD placement underwent graft rejection episodes. Only 1 of 6 VAD recipient was treated because of grade 2R rejection, compared to 6/19 in the non-bridged group, P=0.63. None of the patients had failed because of early graft rejection. In conclusion, VAD devices used in our centre cause low level risk for anti-HLA antibodies development. There were no differences in survival due to immunologic reasons between VAD bridged and non-bridged patients.

Sustainable Knowledge Transfer in Pediatric Cardiac Surgery A Team Approach to Shared Learning

The study assesses the impact of a program using a model of knowledge transfer on the long-term development of a pediatric cardiac service in Lithuania. A team from the United Kingdom evaluated Lithuanian pediatric cardiac services and provided support in areas targeted for improvement. The total number of infant operations performed in Lithuania from 1990 to 2008, together with in-hospital mortality rates, was broken down into 3 time periods and analyzed to estimate the efficacy of the program: (1) 1990-1998, before the program; (2) 1999-2002, during the program; (3) 2003-2008, following the end of the program. Lithuanian results in children older than 1 year were comparable with other European centers. However, only 315 infant and neonatal cardiac procedures were performed between 1990 and 1998, and there was an in-hospital mortality of 34.2%. Between 1999 and 2002, the UK team performed 23 highly complex demonstration procedures (in-hospital mortality, 13%). During the same period the Lithuanian team performed 305 additional operations in neonates and infants, and in-hospital mortality decreased to 18.7%. From 2003 to 2008 results continued to improve—559 infant operations were performed, with in-hospital mortality of 11.3% (P < .0001). Knowledge transfer has led to substantial and sustainable long-term improvement in the results of infant cardiac surgery in Lithuania. Demonstrating techniques and care on a limited number of more complex cases is an efficient way of transferring knowledge and skills to the developing pediatric cardiac centers.

A Double-Orifice Tricuspid Valve Associated With a Divided Right Atrium

Right atrioventricular valve duplication is a rare congenital anomaly with only isolated cases of a double-orifice tricuspid valve having been described. This article presents a case of the surgical repair of a double-orifice tricuspid valve associated with a divided right atrium, a ventricular septal defect, and Wolff-Parkinson-White syndrome.

Laser microstructured 3D polymeric biocompatible implants

In this report we present experimental results on biocompatibility based on stem cell growth experiments in vitro as well as reaction of living organism to polymer implants in vivo of femtosecond laser 3D micro/nanostructurable photopolymers. A synergetic study on materials for rapid 3D scaffold fabrication having micrometer features and being centimeter in size, their biocompatibility in vitro and in vivo was done. The systematic study was performed providing consistent information which is important for further progress in cell growth and tissue engineering experiments. The chosen materials where of four different classes: well known biocompatible hybrid ORMOCER (Ormocore b59, Micro Resist) [1], widely used biodegradable di-acrylated poly(ethylene)glycol (PEG-DA-258, Sigma-Aldrich) [2], pure acrylate AKRE (SR368, Sartomer) [3] and novel high quality laser structurable material ORMOSIL (SZ2080, FORTH) [4]. All of the materials were evaluated by their suitability for femtosecond laser structuring, which is well established as a technique enabling rapid and flexible production of 3D micro/nanostructures. All photopolymers could be 3D structured with &#60; 1 µm resolution and up to cm in overall sizes, thus materializing the computer models of the scaffolds with required pore sizes and porosities. The typical dimensions of scaffolds were 5 × 5 × 0.5 mm3 discs with 25 µm pore sizes and 40–60% porosity.

Results of surgical treatment of aortic root infection

AIM OF THE STUDY To investigate preoperative status and results of surgery of patients with confirmed diagnosis of aortic root infection. MATERIALS AND METHODS We have analyzed data of 21 patients who were operated on at the Heart Surgery Center, Vilnius University, since January 1, 1997, till December 31, 2006. All these patients underwent surgery because of aortic root infection. The patients were aged 25-72 years (mean age, 53+/-14 years). There were 17 (80.9%) male patients. Sixteen patients (76%) preoperatively were in NYHA class IV. The abscesses of aortic root were confirmed preoperatively by means of esophageal echocardiography in 18 patients (86%). Blood cultures positive for Staphylococcus aureus were found in four patients (19.9%). All the patients underwent replacement of the aortic valve by mechanic prosthesis; one of these patients was reoperated because of persistent sepsis, and replacement of the aortic root with homograft was performed. The duration of follow-up of the patients was 1 to 10 years. RESULTS Inhospital mortality rate was 14.3%. The causes of death included sustained heart failure and sepsis. All these patients were in NYHA functional class IV preoperatively; one of these patients had culture positive for Staphylococcus aureus. Inhospital survival was 85.7%, one-year postoperative survival - 80.9%, and both five-year and ten-year survivals were 76.0%. The long-term survival was negatively influenced by recurrent infective endocarditis, heart failure, and age. Death occurred in 1 patient (11.1%) of the 9 patients who at the time of surgery were younger than 50 years and 4 patients (33.3%) of the 12 who were older than 50 years at the time of operation. CONCLUSIONS The infection of aortic root is not common pathology; however, it is a complicated disease. Esophageal echocardiography is an informative method while diagnosing aortic root abscesses. The inhospital mortality is increased by the heart failure persisting after the operation and sepsis. The long-term survival is decreased by preoperative infective endocarditis of the prosthesis and heart failure. The mortality rate of patients older than 50 years is 3-fold higher than mortality rate of younger ones.