The ratio of cytochrome c oxidase subunit 4 isoform 4I1 and 4I2 mRNA is changed in permanent atrial fibrillation.

AIMS: The conditions of hypoxia are suggested to induce permanent atrial fibrillation (AF). The regulation of COX4I2 and COX4I1 depends on oxygen availability in tissues. A role of COX4I2 in the myocardium of AF patients is supposed for pathogenesis of AF and subsequent alterations in the electron transfer chain (ETC) under hypoxia. METHODS AND RESULTS: In vitro, influence of hypoxia on HeLa 53 cells was studied and elevated parts of COX 4I2 were confirmed. Myocardial biopsies were taken ex vivo from the patients' Right Atria with SR (n = 31) and AF (n = 11), respectively. RT- PCR for mRNA expresson, mitochondrial respiration by polarography and the protein content of cytochrome c oxidase (CytOx) subunit 4I1 and CytOx subunit 4I2 by ELISA were studied. Clinical data were correlated to the findings of gene expressions in parallel. Patients with permanent AF had a change in isoform 4I2/4I1 expression along with a decrease of isoform COX 4I1 expression. The 4I2/4I1 ratio of mRNA expression was increased from 0.630 to 1.058 in comparison. However, the protein content of CytOx subunit 4 was much lower in the AF group, whereas the respiration/units enzyme activity in both groups remained the same. CONCLUSIONS: This study describes a possible molecular correlate for the development of AF. Due to the known functional significance of COX 4I2, mitochondrial dysfunction can be assumed as a part of the pathogenesis of AF.

T4 Lung Carcinoma with Infiltration of the Thoracic Aorta: Indication and Surgical Procedure.

Lung carcinomas infiltrate the aorta mostly on the left side and are altogether rare. As an initial step, complete staging is performed and the results are evaluated in an interdisciplinary tumor board. If the patient's general condition including cardiopulmonary reserves is sufficient, and if there is neither distant metastasis nor an N2 situation, surgical resection may be indicated. The option for neoadjuvant chemotherapy should always be taken into consideration. Depending on the anatomic tumor location, partial lung resection and resection of the affected aortic wall are performed employing a cardiopulmonary bypass. The resected aortic wall is replaced by a vascular prosthesis. In recent years, this proven procedure has partly been replaced by an alternative one, avoiding extracorporeal circulation. An endoaortic stent is implanted in the affected area followed by partial lung resection and resection of the diseased aortic wall. This new procedure has significantly reduced perioperative mortality and morbidity. With proper patient selection, long-term survival can be improved even in this complex malignoma.

Surgical Ablation of Permanent Atrial Fibrillation: Age, LV Dilatation, Obesity.

OBJECTIVES: Although concomitant surgical ablation can help to reach freedom from atrial fibrillation (FREEAF) even in patients with permanent atrial fibrillation (AF), some cardiac surgeons hesitate to perform concomitant ablation to avoid perioperative risk escalation. Here, we investigated outcome and predicators of therapeutic success of concomitant surgical ablation in an all-comers study. METHODS: Ablation-naïve patients with formerly accepted permanent AF (FAP, n = 41) or paroxysmal AF (parAF, n = 24) underwent concomitant epicardial bipolar radio frequency ablation and implantable loop recorder (ILR) at two surgical departments. Follow-up examination for 24 months included electrocardiogram, ILR readout, 24h Holter monitoring, echocardiography, and blood sampling. RESULTS: Eighty-six percent of parAF and 70% of FAP patients reached FREEAF (month 24). Mortality was low (parAF/FAP: 5.3 ± 0.2%/4.1 ± 0.3%; p < 0.05; EuroScoreII; 6.1 ± 0.7%/6.4 ± 0.4%, p = ns) and no strokes occurred. FREEAF induced atrial reverse remodeling (left atrial [LA] diameter: -6.7 ± 2.2 mm) and improved cardiac function (left ventricular ejection fraction [LVEF]: +7.3 ± 2.8%), while AF resulted in further atrial dilation (+8.0 ± 1.0 mm, p < 0.05) and LVEF reduction (-7.0 ± 1.3%, p < 0.05). Higher LV (odds ratio [OR]: 1.164) and LA diameter (OR: 1.218), age (OR: 1.180) and body mass index (BMI) (OR: 1.503) increased the risk factors of AF recurrence. Patients remaining in sinus rhythm (SR) demonstrated a decrease in BMI, while AF recurrence was associated with stable overweight. Further aging did not reduce FREEAF. CONCLUSIONS: Long-term SR is achievable by concomitant surgical ablation even in FAP patients. Therefore, it should be offered routinely. Obesity influences therapeutic long-term success but may also offer addressable therapeutic targets to reach higher FREEAF rates.

Urgent Pneumonectomy as a Result of an Endoleak Type III-A Late Complication after Aortic Stent Implantation.

We report on an octogenarian, who was hospitalized with acute hemoptysis. Computed tomography angiography revealed a monstrously large thrombosed aortic aneurysm in the left thoracic cavity, completely displacing the lung. Eighteen years ago, the patient had suffered traumatic rupture of the descending aorta loco typico. Surgical exploration revealed a large calcified aneurysmal sac, which had perforated into the left lung. Pneumonectomy was performed, and hemoptysis did not reoccur.

Prediction of stroke reconvalescence after coronary bypass surgery indicated by CT scan parameters.

BACKGROUND: Stroke in the postoperative time course after heart surgery remains a serious risk. Cranial computer tomography (CCT) is the first line option to detect severe intracranial damage. However, only few data are available to predict neurological outcome. Using visual rating scales (VRSs), this study addresses reliability and effectivity to indicate neurological status and likelyhood of improvement. METHODS: In a single-center retrospective evaluation, 3719 patients underwent coronary bypass surgery. Because of a delayed recovery phase and neurologic deficits after cardiac surgery 109 patients had a cranial CT scan in the early postoperative period. The incidence of clinically relevant findings within the imaging was rated by an experienced neuroradiologist using two VRS, that is, the age-related white matter changes (ARWMCs) and the Mendes-Ribeiro visual rating scale (MRVRS). Both are computer-assisted measurement schemes to detect stroke-related intracranial damage. Follow-up was investigated with regard to clinical outcome and patient-related risk profiles. RESULTS: Of 109 patients with postoperative cranial CT scans due to prolonged recovery phases or proven neurological damage 44.5% had one cerebral defect in CCT imaging scans only. The others showed multiple defects. During hospital stay, 92.3% experienced neurological improvement exposing reduced ARWMC, while 7.1% had no improvement and correlating high scores. Of both scales, the ARWMC-VRS demonstrated superior accuracy and discrimination. The preoperative ejection fraction (EF), arteriosclerotic degeneration of carotid arteries, and reduced glomerular filtration rate were found to have a high correlation (r = 0.0005) with the latter group. In-hospital mortality of this cohort was 8.18%. CONCLUSION: Both the ARWMC and MRVRS were found to be appropriate. They reliably discriminate the groups of stroke patients after coronary artery bypass grafting (CABG)  in the analysis of CCT images. When applied at the onset of neurological symptoms both scales are able to predict neurological reconvalescence upon hospital dismission. The ARWMC scale appeared superior as it demonstrated better accuracy and discrimination. The use of both VRS in patients with suspected stroke after CABG surgery can give insightful information toward a progression of neurological dysfunction or postoperative improvement.

Detection of the Lateral Thermal Spread during Bipolar Vessel Sealing in an Ex Vivo Model-Preliminary Results.

Background: As an unwanted side effect, lateral thermal expansion in bipolar tissue sealing may lead to collateral tissue damage. Materials and Methods: Our investigations were carried out on an ex vivo model of porcine carotid arteries. Lateral thermal expansion was measured and a calculated index, based on thermographic recording and histologic examination, was designed to describe the risk of tissue damage. Results: For instrument 1, the mean extent of the critical zone > 50 °C was 2315 ± 509.2 µm above and 1700 ± 331.3 µm below the branches. The width of the necrosis zone was 412.5 ± 79.0 µm above and 426.7 ± 100.7µm below the branches. For instrument 2, the mean extent of the zone > 50 °C was 2032 ± 592.4 µm above and 1182 ± 386.9 µm below the branches. The width of the necrosis zone was 642.6 ± 158.2 µm above and 645.3 ± 111.9 µm below the branches. Our risk index indicated a low risk of damage for instrument 1 and a moderate to high risk for instrument 2. Conclusion: Thermography is a suitable method to estimate lateral heat propagation, and a validated risk index may lead to improved surgical handling.

Initial Airtightness of the Lung Parenchyma After Transection of the Interlobar Fissure - Monopolar Cutter, Stapler Versus Nd: YAG Laser.

INTRODUCTION: Every lobectomy requires the transection of the interlobar fissure. Resection surfaces must be airtight in order to avoid leakage and infection. Using an ex vivo model based on porcine lung, we compared three techniques with respect to initial airtightness at different inspiratory pressures. MATERIALS AND METHODS: In the first technique (group 1), we transected the interlobar fissure with a monopolar cutter and overstitched the edges of the resection area with a monofilament thread. In the second technique (group 2), the interlobar fissure was cut with a stapling device. In the third technique (group 3), the interlobar fissure was cut using a laser fibre connected to an Nd: YAG laser. The resection areas were not overstitched; 15 transections were performed in each group. RESULTS: In group 1, three parenchymatous bridges leaked starting at a pressure of 25 mbar. In the other two groups, all preparations were airtight at this pressure. If the ventilation pressure was increased up to 40 mbar, all seams in group 1 were leaky at a pressure of 35 mbar. Four staple seams were airtight at a pressure of 40 mbar. In group 3, 11 preparations (73.3 %) were airtight up to a pressure of 40 mbar. CONCLUSIONS: Based on our results, the use of an Nd: YAG laser is suitable for the transection of the interlobar fissure. In effect, this technique compares well with the other techniques examined.

Role of matrix metalloproteinases in mitral valve regurgitation: Association between the of MMP-1, MMP-9, TIMP-1, and TIMP-2 expression, degree of mitral valve insufficiency, and pathologic etiology.

BACKGROUND: The pathogenesis of mitral valve insufficiency is not yet fully understood. Several studies stressed the role of matrix metalloproteinases (MMPs) in the emergence of valvular pathologies. The primary objective of the present study is to analyze the role of selected MMPs and their inhibitors in mitral valve insufficiency. PATIENTS AND METHODS: Eighty patients (33 female/47 male, mean age 67 years) underwent cardiopulmonary bypass surgery for mitral valve reconstruction between 2007 and 2015. All patients suffered from mitral insufficiency (MI) Stages iii and iv. When tissue resection was acquired specimens were taken immediately frozen and used for histological examination. Expression of MMP-1, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1, and TIMP-2 was examined immunohistochemically and distribution was analyzed in regard to preoperative clinical, echocardiographic, and histopathological findings. RESULTS: A clear correlation between the MMP expression and the MI degree of severity could be shown. The expression of MMPs proved to be high in relation to mild insufficiencies and relatively weak in the case of severe ones. Additionally, the etiology of the MI was considered in the analysis and a significant difference in the expression of MMPs between the mitral valves with endocarditis and the ones featuring a degenerative disease could be shown. Within the group of valves with degenerative diseases, no significant difference could be established between the subgroups (myxoid and sclerosed valves). CONCLUSION: The increased expression of MMPs and their inhibitors in mild insufficiencies could prove that the molecular changes in the valve precede the macroscopical and thus the echocardiographically diagnosable changes. Hence, new options for early diagnosis and therapy of MIs should be examined in further studies, respectively. Herein, the correlation of the MMP blood levels with MMP tissue expression should be addressed for surgical therapeutical decisions.

Determination of initial airtightness after anatomical laser segmentectomy in an ex vivo model.

If a pulmonary pathology can be removed by anatomical segmentectomy, the need for lobectomy is obviated. The procedure is considered oncologically equivalent and saves healthy lung tissue. In every segmentectomy, lung parenchyma must be transected in the intersegmental plane. Using an ex vivo model based on porcine lung, three transection techniques (monopolar cutter + suture, stapler, and Nd:YAG laser) are to be compared with respect to their initial airtightness. At an inspiratory ventilation pressure of 25 mbar, all three preparations were airtight. Upon further increase in ventilation pressure up to 40 mbar, the laser group performed best in terms of airtightness. Since thanks to its use of a laser fibre, this technique is particularly suitable for minimally invasive surgery; it should be further evaluated clinically for this indication in the future.

Suturing of the laser resection area is recommended over a depth of 2 cm in an experimental porcine lung model.

BACKGROUND: Lung metastases can be removed by an Nd:YAG laser to save lung parenchyma. At these sites, a coagulated lung surface remains. Airtightness was investigated in relation to the depth of resection on an ex vivo porcine lung model. METHODS: Freshly slaughtered porcine double lung preparations were connected to a ventilator via a tube. Non-anatomical laser resections were performed with an 800 µm laser fiber and the Nd:YAG laser LIMAX® 120 (power: 40 and 60 watts). The following resection depths (each n=12) from the lung surface were examined: 0.5, 1, 1.5 and 2.0 cm. After resection the lungs were submerged under water and ventilated (frequency 10/min, Pinsp =25 mbar, PEEP =5 mbar). Airtightness of resection surfaces was determined by a leakage score, as well as the measurement of the leakage volume (in mL) per respiration (Group 1). Afterwards, the resection areas were coagulated for 5 seconds with a laser power of 60 watts at a distance of approximately 1 cm from the surface. This was followed by a re-evaluation for airtightness (Group 2). Finally, the resection surface was closed by a suture (PDS USP 4-0) and re-tested for airtightness (Group 3). The individual groups were compared for their significance (P<0.05) using a nonparametric test. RESULTS: Up to a resection depth of 1.5 cm, the ventilated resection surfaces were completely airtight regardless of the laser power. From a depth of resection of 1.5 cm, a mean air volume loss of 28.9±5.3 mL/respiratory cycle at 40 watts and of 26.4±5.8 mL at 60 watts was found. Additional surface coagulation did not significantly reduce the leakage rate. In contrast, suturing significantly reduced (P<0.0001) to 7.2±3.7 mL/ventilation (40 watts) and 6.0±3.4 mL/ventilation. At a resection depth of 2 cm, the leakage volume was 42.9±3.3 mL/respiratory cycle (40 watt) and 46.3±6.4 mL/respiratory cycle (60 watt). Additional surface coagulation failed to significantly reduce leakage volume, but suture closure provided airtightness. CONCLUSIONS: In non-ventilated porcine lungs, Nd:YAG laser resection surfaces up to a resection depth of 1.5 cm are airtight after ventilation onset. From a depth of 1.5 cm, closure of resection surfaces by an additional suture is needed. Airtightness of resection surfaces was not increased by additional coagulation.

An Unusual Case of Noncatamenial Recurrent Pneumothorax.

In a 28-year-old female, seven recurrent pneumothoraces occurred during a period of 2 years despite multiple thoracic interventions, all on the left thoracic side. Despite profound differential diagnostic analysis, the underlying cause remains unclear. An accumulation of conditions in this patient affecting only the left half of the body is remarkable: sinistral glaucoma as an infant, a sinistral pigmentation disorder, and a sinistral Bochdalek hernia.

Initial Load Stability of Different Trachea Suture Techniques: Tests on an Ex Vivo Model.

Objective Tracheal anastomosis can be performed with different suture techniques. In this experimental work, the resilience of anastomotic techniques to pressure and tensile stress was studied. Study Design Ex vivo pig model. Setting Experimental. Subjects and Methods The trachea with the 2 main bronchi in freshly slaughtered pigs was isolated and intubated (CH 8.0). Both main bronchi were closed distally by a stapler. After resection of the trachea, an anastomosis (n = 15 per group) was created: group 1, single interrupted sutures; group 2, continuous running suture; group 3, mixed technique. A continuous tensile stress of 0, 500, 1000, or 1500 g was applied to the preparations. Mechanical ventilation with a maximum pressure of 70 mbar was initiated. The airtightness of the anastomosis was verified by submerging the entire preparation under water. Results At tensile loads of 0.5 and 1.0 kg, all anastomoses created in the single-stitch technique were airtight; at 1.5 kg, 93.3% were without leaks. In the continuous suture technique, the airtightness of anastomoses decreased with increasing tensile load: from 93.3% at 500 g to 73.3% at 1 kg and 66.6% at 1.5 kg ( P = .02 at 1.5 kg). Anastomoses in the mixed technique were airtight in 80% at 500 g, 66.6% at 1 kg, and 46.6% at 1.5 kg ( P = .01 in comparison with single stitches). Conclusion Anastomoses created with single interrupted sutures showed the highest resilience against combined pressure and tensile stress.

Epicardial left atrial appendage closure-comparison of surgical techniques in an ex vivo model.

BACKGROUND: Formation of clots in the left atrial appendage (LAA) may lead to embolism and consecutive cerebral stroke. This risk is reduced by closure and resection. To address the efficacy of surgical LAA closure, resilience to pneumatic pressure was studied. Different surgical techniques were compared in an experimental model. METHODS: From freshly slaughtered pigs cardiopulmonary preparations were taken. The left atrium was clamped airtight and the LAA was cannulated. Via a manually operated pump pressure was applied and a digital pressure gauge was connected. Four groups (each n=12) with different epicardial closures were studied: (I) purse string; (II) single layered continuous suture; (III) double layered suture; (IV) surgical stapler. A nonparametric test was used for group comparisons of mean burst pressures (mmHg). Statistical significance was defined at P<0.05. RESULTS: Mean burst pressures in group 1 amounted to 97.1±13.0 mmHg, in group 2 to 105.5±13.3 mmHg, in group 3 to 124.6±14.2 mmHg and in group 4 to 136.6±12.5 mmHg. Excepting differences between groups 1 and 2 comparisons between groups were significantly different. CONCLUSIONS: In an ex vivo model surgical staplers and double layered hand crafted sutures proved well suitable for closure of the LAA. They were significantly superior to single layered sutures in terms of resilience to pneumatic pressure. This may be relevant to durability and should be discussed with regard to clinical choice.

Pneumatic Burst Pressures After Inverted Closure of the Left Atrial Appendage: An Ex Vivo Model.

BACKGROUND: The left atrial (LA) appendage (LAA) is the main source of thromboembolism in atrial fibrillation. This study addressed initial pressure resistance of surgical LAA closures. METHODS: In an experimental model, pneumatic pressure resistances of different surgical closure techniques were examined, and variations in technique and access were studied. In preparations of the LA from freshly slaughtered pigs, pneumatic pressure was applied to the LAA. Burst pressures (mbar) of various closure techniques (n = 12 specimens per group) were measured: (1) epicardial double-layer suture, (2) epicardial stapler closure (staple height 2 mm), (3) epicardial stapler closure (staple height 4, 4.5, and 5 mm), (4) endocardial inverse double-layer suture, (5) endocardial inverse stapler seam (staple height 2 mm), and (6) endocardial inverse stapler seam (staple height 4, 4.5, and 5 mm). RESULTS: The mean burst pressure in group 1 was 175.5 ± 19.35 mbar. There was no significant difference compared with group 2 (174.5 ± 28.45 mbar) or group 3 (176 ± 27.69 mbar). Group 4 scored significantly higher than all other groups (198.9 ± 18.35 mbar). Burst pressures in group 5 (136.2 ± 16.68 mbar) were significantly lower than in group 4 and in group 6 (165.1 ± 21.94 mbar), but the differences between groups 5 and 6 were also significant. CONCLUSIONS: In an ex vivo model, double-layer suturing of the inverted LAA from an internal LA access led to higher burst pressures compared with epicardial suturing and with both endocardial and epicardial stapled closures.

Video-Assisted Laser Resection of Lung Metastases-Feasibility of a New Surgical Technique.

Background Our pilot study describes our initial experience to do a laser resection of lung metastases under video-assisted thoracoscopic control via a minithoracotomy. With this approach, if needed, mediastinal lymphadenectomy is also possible. Methods In this study, 15 patients (11 men and 4 women, mean age: 60 years) with resectable lung metastases of different solid primary tumors (colorectal cancer in seven patients, melanoma in three patients, renal cell carcinoma in two patients, and one each with oropharyngeal cancer, breast cancer, and seminoma) were included. An anterior minithoracotomy incision (approximately 5-7 cm length) was created in the fifth intercostal space and a soft tissue retractor (Alexis Protector; Applied Medical) was positioned. Two additional working ports were inserted. The entire lung was palpated via the minithoracotomy. All detected lung metastases were removed under thoracoscopic control. Nonanatomic resections were performed using a diode-pumped neodymium-doped yttrium aluminium garnet laser (LIMAX120; KLS Martin GmbH & Co KG) with a laser power of 80 W in a noncontact modus. Deeper parenchymal lesions were sutured. Results A total of 29 lung metastases up to 30 mm in size were resected and all metastases diagnosed on preoperative imaging were detected. All diagnosed lung metastases were completely resected (R0). The median operation time was 102 (range: 85-120) minutes. Median blood loss was 47.6 mL and no postoperative complications occurred. Neither local recurrences nor new lung metastases were observed within 6 months after the procedures. Conclusion Video-assisted laser resection of lung metastases is safe, effective, and fulfills the requirements of modern lung metastases surgery.

Initial Resistance of Carina Anastomoses with Increasing Tensile Stress: An ex vivo Model Comparing Different Suture Techniques.

BACKGROUND: After resection of the carina with a length of more than 4 cm, anastomoses often need to be performed under tension despite maximum mobilization. If the patient cannot be extubated, the anastomosis remains under continued stress. Anastomoses of the carina can be constructed using various suture techniques, including single interrupted sutures, back wall running but front wall single interrupted sutures, and complete running suture. This experimental study was designed to determine the most tensile stress-resistant anastomotic suture technique. MATERIALS AND METHODS: Isolated preparations of tracheobronchial trees were recovered from freshly slaughtered pigs. Resection of the carina was carried out in preparation of the experiments. After blind randomization, anastomoses (n = 15 per group) between the distal trachea and the proximal left main bronchus were performed with PDS 4-0 employing three different suture techniques: (1) single interrupted sutures, (2) back wall running but front wall single interrupted sutures (= mixed technique), and (3) complete running suture. The anastomotic specimen was fixed onto a specially constructed device. The tracheal end was intubated with a tube (CH 8.0) and connected to a respirator. Different weights were attached to the distal end of the preparation via a clamp and guide rollers. Airtightness was investigated at the following tensile loads: 0, 500, 1,000 and 1,500 g. Intrabronchial pressure was increased in 5-mbar steps. In an underwater trial, we analyzed whether anastomoses were airtight at a maximum intrabronchial ventilation pressure of 70 mbar. RESULTS: At an intrabronchial pressure of 25 mbar without tensile stress, all anastomoses were initially airtight. In tensionless anastomoses at 70 mbar, 100% of single interrupted and continuous sutures were airtight, as compared to 80% of sutures in mixed technique. At 70 mbar and tensile loads of 1,500 g, 80% of single interrupted sutures, 60% of sutures in mixed technique and 53% of the running sutures remained competent. CONCLUSION: If tracheal anastomoses can be performed without tension, the suture technique is not important. With increased tension, anastomoses performed in single interrupted suture technique were clearly superior. Thus, in situations, where high tensile stress is to be expected, single interrupted sutures should be preferred.

Detailed Measurement of Wall Strain with 3D Speckle Tracking in the Aortic Root: A Case of Bionic Support for Clinical Decision Making.

Three-dimensional (3D) wall motion tracking (WMT) based on ultrasound imaging enables estimation of aortic wall motion and deformation. It provides insights into changes in vascular compliance and vessel wall properties essential for understanding the pathogenesis and progression of aortic diseases. In this report, we employed the novel 3D WMT analysis on the ascending aorta aneurysm (AA) to estimate local aortic wall motion and strain in case of a patient scheduled for replacement of the aortic root. Although progression of the diameter indicates surgical therapy, at present we addressed the question for optimal surgical time point. According to the data, AA in our case has enlarged diameter and subsequent reduced circumferential wall strain, but area tracking data reveals almost normal elastic properties. Virtual remodeling of the aortic root opens a play list for different loading conditions to determine optimal surgical intervention in time.

In-vivo deformation measurements of the human heart by 3D Digital Image Correlation.

Fast and accurate measurements of the kinetics and deformation of the heart during cardiac surgery can be useful for assessing the best strategies for the protection of the myocardium. While measurements based on ultrasonic technology such as the transesophageal echocardiography are rapidly developing in this direction, also other analysis methods based on optical imaging have been developed within the recent decade. The improved quality of digital cameras and increased computational power of personal computers have led to the development of deformation analysis method known as Digital Image Correlation (DIC). This paper presents preliminary results on the application of the DIC technique on analysing of the movement and deformation of the myocardial movement during a cardiopulmonary bypass surgery. The results show that the natural pattern of the heart should be sufficient for DIC, but better and more accurate results could be obtained with improved contrast conditions. DIC has a potential to be used as a sensitive tool for the surgeon to monitor the cardiac function.

A method for stereoscopic strain analysis of the right ventricle by digital image correlation during coronary bypass surgery: short communication.

Perioperative cardiosurgical management of volume therapy remains one of the challenging tasks in cases of patients with severe heart disease. Early detection of congestive cardiac failure prevents subsequent low output and worse outcome. An effective method for controlling extracorporeal circulation is created by developing a non-invasive intraoperative method for right ventricular strain analysis through digital image contrast correlation.

Plasma protein binding properties to immobilized heparin and heparin-albumin conjugate.

Selective adhesion of plasma proteins to immobilized heparin is considered to be beneficial regarding hemocompatibility of foreign materials in contact with blood. Prothrombin, thrombin, antithrombin III (AT3), and fibrinogen were selected for analysis in an experimental model. Biomolecular interaction analysis employing surface plasmon resonance was utilized to record and analyze their binding properties in real time. Biotinylated heparin, heparin-albumin conjugate, and albumin, respectively, were immobilized onto streptavidin-coated sensors as ligands. Prothrombin did not bind to any of the ligand surfaces and no specific binding of any of the plasma proteins to albumin was observed. Binding kinetics of thrombin to heparin and to heparin-albumin conjugate were calculated using two different methods. For heparin, identical K(D)(equilibrium dissociation constant) values of 61 x 10(-9) M were obtained with both methods. For the conjugate, only slightly different K(D) values of 111 x 10(-9) and 104 x 10(-9) M, respectively, were calculated. The affinity of thrombin toward the heparin-coated surface proved to be higher than its affinity toward the heparin conjugate. The binding pattern of AT3 to both heparin and heparin-albumin conjugate, although specific, was biphasic, possibly due to a conformational change during the binding process. Steady-state kinetic analysis revealed a K(D) value of 281 +/- 24 x 10(-9) M for the heparin surface. For the conjugate surface, a K(D) of 53 +/- 5 x 10(-9) M was calculated, indicating a higher affinity toward heparin-albumin conjugate. A high-affinity binding of fibrinogen to high-density surfaces of both heparin and the conjugate was observed. However, as binding to low-density surfaces was considerably reduced, specificity remained uncertain.