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Extracorporeal circulation (ECC) is an integral part of cardiac surgery. Yet, the contact with artificial surfaces, mechanical stress, shear, and suction forces within the ECC pose a pronounced risk for damaging the corpuscular components of the blood. These suction forces may be reduced by a repositioning of the roller pumps employed below the reservoir. Furthermore, the repeated compression of the involved silicone tubing is likely to cause degradation. We present our observations regarding changes in the ECC performance following this degradation process. In vitro experiments were performed in a standard as well as a simplified ECC setup and included measurements of pressure, effective flow, and tubing restoring force over a time frame of 12 hours with two different pump positions utilizing transit time flow measurement. Suction forces within the tubing could be significantly reduced by shifting the pump position below the reservoir. Regardless of the setup, the tubing showed significant loss of restoring force as well as effective flow over time. A shift of the pump position within the ECC setup can be recommended to prevent blood damaging negative pressures. Further research is necessary to evaluate the exact cause of the reduction of restoring force overtime as well as its risks for the patients. Finally, our results underline the importance of transit time flow measurements to collect reliable flow data., (© 2020 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Objectives: Although indications for the MitraClip are becoming increasingly liberal, the number of patients requiring valve surgery after an insufficient outcome of the procedure is growing. Referral to surgery is, however, frequently delayed. During this time, the patients often deteriorate. We retrospectively analysed patients before MitraClip implantation and after mitral valve surgery., Methods: A total of 49 patients who received a mitral valve replacement (average 8 ± 12 months after MitraClip implantation) were assessed. Of these, 53% had 2-4 clips inserted. The mean age was 73 years, and the mean log EuroSCORE was 20.79 ± 14.42%. Echocardiographic data obtained prior to MitraClip implantation and preoperatively, 10 days and 6 and 12 months after cardiac surgery were reviewed. Survival analysis, risk profile and postoperative complications were analysed., Results: The 30-day and 1-year mortality was 26.5% and 59.2%, respectively. Prior to MitraClip implantation, 42.8% of patients had mild tricuspid insufficiency and 6.1% had moderate tricuspid insufficiency. Prior to surgery, 26.5% showed mild, 32.7% moderate and 38.8% severe tricuspid insufficiency (P < 0.001). Furthermore, right heart function assessed by tricuspid annular plane systolic excursion deteriorated significantly after Implantation of the MitraClip (P < 0.001). In patients with a MitraClip, the pulmonary artery pressure was significantly higher at the time of mitral replacement than it was before the MitraClip was implanted (P < 0.001)., Conclusions: A subgroup of patients does not benefit from a MitraClip and shows progressive deterioration in cardiac function, making valve replacement under difficult circumstances inevitable. The earlier these patients are operated on, the better it is. It can be assumed that some patients would be better off with primary surgery, especially if mitral reconstruction is then still feasible. Therefore, the indications for MitraClip implantation should be carefully considered and caution should be exercised during monitoring., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: Polymeric heart valves are constructed from flexible synthetic materials, therefore aiming to combine the advantageous hemodynamic of biological and the longevity of mechanical valve prostheses. One such valve prototype in development is the PIZZA valve constructed of flexible triangular silicone leaflets on a foldable metal base for perspective transcatheter implantation. Here we present further improvements in its performance through structural modifications., Methods: Structurally modified prototypes were constructed from silicone sheets and stainless-steel wires. Their performance was then tested in a hemodynamic testing device of the type HKP 2.0., Results: Shift from a planar to a cone shape as well as overlapping of the leaflets significantly improved the valves performance, reducing regurgitation as well as systolic pressure gradients., Conclusions: The results of the modified prototypes expressed superior performance and represented a step forward on the road to an easily producible, polymeric transcatheter valvular prosthesis., Competing Interests: J. M. Albes is the inventor of the valve. All commercial rights have been transferred to NVT AG Luzernerstrasse 91, 5630 Muri, Switzerland., (Thieme. All rights reserved.)

Background: Endoscopic saphenous vein harvesting (EVH) for coronary artery bypass grafting (CABG) has been developed to reduce leg wound problems. This study was undertaken to evaluate postoperative complications and patient's subjective satisfaction comparing EVH and surgical vein harvesting (SVH)., Methods: From January to December 2017, patients undergoing elective cardiac surgery (CABG, CABG + Valve repair or replacement) underwent saphenous vein graft harvesting either by EVH ( n  = 136) or SVH ( n  = 104). Clinical follow-up was scheduled for day 7 and > 45 days after surgery. Primary end points were divided into two subgroups. The first one included postoperative extent of subjective pain and satisfaction with the cosmetic results described by the patients themselves, while the second subgroup included objective postoperative complications including wound healing disturbances, hematoma, and neuropathy. Secondary end point was length of hospital stay., Results: At 7 days follow-up, EVH patients were more satisfied with the cosmetic results than those of the SVH group ( p  < 0.001) and expressed a significant tendency toward lower subjective pain compared with the SVH patients ( p  < 0.001), exhibited significantly lower cellulitis ( p -0.002), neuropathy ( p -0.005), and superficial wound healing disturbance ( p -0.007). During further follow-up at > 45 days, patients with EVH were still more satisfied with the cosmetic results ( p  < 0.001) and expressed lower subjective pain ( p  < 0.001), while the other objective wound parameters did not show significant differences between both groups. Mean length of hospital stay of EVH patients was 0.7 days less compared with SVH patients., Conclusions: Our findings demonstrate the noninferiority of EVH in the short term and in the early medium term., Competing Interests: Mrs Rudolph discloses that she has a financial relationship with company Maquet GmbH; all other authors declare that there is no conflict of interest., (Thieme. All rights reserved.)

Objectives: To increase the safety of aortic valve replacement, we developed the 'Caput medusae' method, where the prosthesis is prefixed with circumferential tourniquets prior to knot tying. We assumed that an even distribution of forces may help reduce tissue damage. To confirm this theoretically, we compared forces between knots and tourniquets., Methods: The experimental set-up included a device with movable acrylic plates, a mounted valve and a set of sutures. Traction forces were measured with a luggage scale. Two different tourniquets were compared individually and as bundles of 15. Force-path curves were generated. Knotting and tourniquet forces of 18 staff surgeons were then compared. Both modalities were measured 10 times on 2 days, resulting in 40 observations per surgeon, or 360 observations per modality., Results: Polyvinyl chloride tourniquets were stiffer than silicone, expressed by a 1.5- to 1.7-fold higher regression-line slope. Fifteen simultaneous tubes produced force increments 7.9-8.9 times higher than their single counterparts. Overall knotting force was 13.64 ± 5.76 vs tourniquet 1.08 ± 0.48 N. Male surgeons' knotting forces were higher compared to female staff (14.76 ± 6.01 vs 10.73 ± 3.74 N; P < 0.001) while tourniquet forces did not differ (1.09 ± 0.47 vs 1.05 ± 0.49 N; P = 0.459). Dedicated valve surgeons (n = 10) tightened the tourniquets more strongly than inexperienced surgeons (1.20 ± 0.52 vs 0.94 ± 0.37 N; P < 0.001); knotting was similar. Multivariable analysis confirmed only valve experience as a predictor of tourniquet strength (experienced surgeons exerted higher force)., Conclusions: Tourniquets exert less force on the tissue than knots. When distributed over the circumference, they can reduce local tension and avoid potential paravalvular leakage. Complete or partial use of tourniquets may thus be an additional option to enhance surgical safety., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: Conventional stented valves (CV) remain gold standard for aortic valve disease. Bovine prostheses have been improved and rapid deployment valves (RDV) have arrived in the recent decade. We compare clinical and hemodynamic short-term outcome of six bovine valves., Methods: We retrospectively evaluated 829 consecutive patients (all-comers) receiving bovine aortic valve replacement (AVR). Four CV from different manufacturers (Mitroflow, Crown, Perimount, Trifecta) and two RDV (Perceval, Intuity) were compared in terms of pre-, intra-, and postprocedural data. A risk model for mortality was created., Results: All valves reduced gradients. From 23 mm, all CV showed acceptable gradients. Twenty-one millimeter Mitroflow/Perceval and 19 mm Crown showed above-average gradients. As baseline data differed, we performed propensity matching between aggregated isolated CV and RDV groups. Cardiopulmonary bypass (CPB), clamp, and surgery times were shorter with RDV (87.4 ± 34.0 min vs 111.0 ± 34.2, 54.3 ± 21.1 vs 74.9 ± 20.4, 155.2 ± 42.9 vs 178.0 ± 46.8, p  < 0.001). New pacemaker rate (10.1 vs 1.3%, p  = 0.016) and the tendency toward neurologic events (8.9 vs 2.5%, p  = 0.086) were higher using RDV, induced mainly by the Perceval. Early mortality was equal (2.5 vs 1.3%, p  = 0.560). Revision for bleeding, dialysis, blood products, length-of-stay, gradients, and regurgitation was also equal. Risk analysis showed that low valve size, low ejection fraction, endocarditis, administration of red cells, and prolonged CPB time were predictors of elevated mortality., Conclusion: Isolated bovine AVR has low mortality. Valves ≥ 23 mm show comparable gradients while the valve model matters < 23 mm. RDV should be used with care. Procedure-related times are shorter than those of CV but pacemaker implantation and neurologic events are more frequent (Perceval). Early mortality is low and valve performance comparable to CV., Competing Interests: None., (Thieme. All rights reserved.)

Background: Prosthetic replacement of aneurysms of the ascending aorta is the gold standard in terms of long-term stability. Wrapping seems to be a less invasive procedure. It has not yet been shown if it is as safe in terms of long-term outcome., Methods: We present a single-center analysis of our experience over 13 years. We retrospectively analyzed data from patients who received either aortic prosthetic wrapping (AW) or aortic prosthetic replacement (AR) with or without aortic valve replacement and assessed them through phone calls. We used propensity score matching to adjust the baseline of the groups., Results: Before propensity matching, 144 patients received AW and 91 patients underwent AR. Mean age was 64 ± 11.8 years. After propensity score matching and adjusting for significant differences in age, gender, body mass index, logistic EuroSCORE I, and left ventricular function, 69 patients in each group remained for further analysis. Rate of early reoperation due to tamponade, inhospital mortality, and survival rates did not differ. In both groups, the surgically treated aortic segment did not show enlargement, whereas the nontreated aortic arch showed comparable aneurysmatical progression., Conclusions: AW is safe and feasible and can be used in elderly or frail patients in order to avoid an AR. Progression of the remaining native aortic segments occurs, thus requiring strict life-long follow-up to ensure an elective and thus safe approach for appropriate consecutive surgical measures, if required., Competing Interests: None., (Georg Thieme Verlag KG Stuttgart · New York.)

Indications for TF-TAVI (transfemoral transcatheter aortic valve implantation) are rapidly changing according to increasing evidence from randomized controlled trials. Present trials document the non-inferiority or even superiority of TF-TAVI in intermediate-risk patients (STS-Score 4-8%) as well as in low-risk patients (STS-Score < 4%). However, risk scores exhibit limitations and, as a single criterion, are unable to establish an appropriate indication of TF-TAVI vs transapical TAVI vs SAVR (surgical aortic valve replacement). The ESC (European Society of Cardiology)/EACTS (European Association for Cardio-Thoracic Surgery) guidelines 2017 and the German DGK (Deutsche Gesellschaft für Kardiologie)/DGTHG (Deutsche Gesellschaft für Thorax-, Herz- und Gefäßchirurgie) commentary 2018 offer a framework for the selection of the best therapeutic method, but the individual decision is left to the discretion of the heart teams. An interdisciplinary TAVI consensus group of interventional cardiologists of the ALKK (Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte e.V.) and cardiac surgeons has developed a detailed consensus on the indications for TF-TAVI to provide an up-to-date, evidence-based, comprehensive decision matrix for daily practice. The matrix of indication criteria includes age, risk scores, contraindications against SAVR (e.g., porcelain aorta), cardiovascular criteria pro TAVI, additional criteria pro TAVI (e.g., frailty, comorbidities, organ dysfunction), contraindications against TAVI (e.g., endocarditis) and cardiovascular criteria pro SAVR (e.g., bicuspid valve anatomy). This interdisciplinary consensus may provide orientation to heart teams for individual TAVI-indication decisions. Future adaptations according to evolving medical evidence are to be expected. Interdisciplinary consensus on indications for transfemoral transcatheter aortic valve implantation (TF-TAVI).

Background:  Endocarditis remains one of the most threatening diagnoses in cardiac surgery and is still increasing. Particularly, device-related as well as prosthetic endocarditis appears to be on the rise. Early mortality and periprocedural complications are high jeopardizing the success of surgical efforts. We looked at the development of the numbers and the distribution of endocarditis in an all-comer analysis., Methods:  From 2003 to 2017, 752 patients with endocarditis were transferred to our cardiosurgical institution (mean age 65 ± 13 years; mean logistic EuroSCORE 28.01%; males 74.33%). A total of 89.49% of them were surgically treated; 30.01% redo cases thereof; and 9.17% had been operated previously for acute endocarditis., Results:  While the total number of cardiosurgical procedures remained relatively stable throughout the years, 20 patients were admitted in 2003 and 79 in 2017 yielding more than fourfold increase ( p  < 0.001). Early mortality of all patients was 25.1%. Septic emboli occurred in 23.7% and 43.8% cerebral emboli thereof. A significant increase of aortic, mitral, and tricuspid valves involvement was observed ( p  < 0.001). An increase of device-related endocarditis was also noted ( p  < 0.001)., Conclusion:  Endocarditis remains a serious problem with high early mortality and morbidity. The vast increase of electrophysiological device implantations has resulted in an increase of tricuspid valve involvement. Liberalization of endocarditis prophylaxis, that is, more restrictive use of antibiotics in 2007 may have at least partially contributed to an increase of the individual risk to suffer from acute endocarditis. A renaissance of a stricter endocarditis-prophylaxis may thus be considered., Competing Interests: None declared., (Georg Thieme Verlag KG Stuttgart · New York.)

Background:  Transcatheter heart valve (THV) as valve-in-ring is increasingly used in the mitral position. Semi-rigid rings may serve as a more appropriate scaffold for proper anchoring of a THV as they may change from their oval to a round shape thereby fitting to the implanted THV., Methods:  One rigid and five semi-rigid rings of four manufacturers, Edwards Physio I and II, Sorin 3D Memo, Medtronic Simulus, and St. Jude Medical (SJM) Saddle and SJM Sequin, with sizes 28 to 36 mm and Edwards Sapien III THV 23, 26, and 29 mm were used. Preevaluation comprised insertion/inflation of the THV into the ring and visual inspection for the paravalvular gap ≥ 4 mm 2 . Only valves not showing paravalvular gap were then submitted to hemodynamic evaluation with a pulse duplicator. Cusp movement was assessed with a high-speed-camera. Mean transvalvular gradients (TVGs) were measured., Results:  SJM Saddle ring of all sizes and SJM Sequin ring 34 showed marked gaps combined with all THV sizes, thus not undergoing hemodynamic testing. It was further shown that ring sizes ≥ 36 mm did not allow for a proper fit of even the largest THV into the ring of all the manufacturers and were consequently not hemodynamically evaluated. The 23 mm THV was too small for any ring size. The lowest gradients were achieved with the 26 mm THV in 30 and 32 mm and the 29 mm THV in 32 and 34 mm rings., Conclusion:  Not all currently available annuloplasty rings are ideal scaffolds for THV placement. It appears that a more proper fit can be achieved with semi-rigid rings than with rigid ones. Note that 23 mm THV appeared to be too small for an adequate anchoring in even the smallest available ring. Thus, 26 mm as well as 29 mm THV fit properly in ring sizes between 28 and 34 mm. Surgeons may consider to choose from those ring brands and sizes which allow for good placement of a THV in view of possible valve degeneration in the later course., Competing Interests: Disclosure The authors report no conflicts of interest in this work., (Georg Thieme Verlag KG Stuttgart · New York.)

Objectives: The invention of new surgical procedures requires testing at different stages including animal models. To facilitate this process, we have developed a computer-controlled extracorporeal circulation system for testing of an explanted porcine heart simulating a variety of physiological parameters. Mitral valve function can be assessed before and after induced valve insufficiency and after valve repair. Accordingly, techniques and instruments can be modified at early stages of prototype development., Methods: In the diastole, the left atrium is passively filled through the reservoir. The loading pressure of the atrium and flow rates can be widely adjusted. To simulate the systole, a linear motor-driven piston pump promotes volume into the left ventricle and the aorta. An additional circulatory pump compensates for undesired total emptying of the heart chambers. The processor control of the linear pump allows for various settings of flow rate, velocity and even irregular rhythm. Twenty-one isolated porcine hearts were used. The leaflet movement was filmed using a universal serial bus (USB)-probe camera., Results: With 80 mm stroke and 1 m/s speed, a volume of 150 ml can be pumped at a heart rate of up to 73 bpm. Cardiac outputs of up to 10.9 l/min can be achieved. Constant visualization and continuous measurements of the pressure gradients before and after the induction of mitral insufficiency and after repair allowed quantitative verification of repair quality under beating-heart conditions., Conclusions: This model allows a controllable pulsation, loading and unloading of a porcine heart in a wide range. Thus, the function of the leaflets and repair results can be qualitatively and quantitatively evaluated under quasiphysiological conditions., (© The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: MitraClip (Abbott Inc.) is propagated as a palliative option for high-risk patients with mitral insufficiency considered not qualifying for surgical repair. A proportion of patients requires consecutive surgery because of technical failure or inappropriate clinical improvement. Furthermore, surgical reconstruction is impossible in almost all patients after MitraClip implantation. Consequently, these patients receive replacement although primary repair may have been possible. The outcome of those patients compared with patients receiving primary mitral valve replacement (MVR) or mitral valve repair (MVP) was analyzed., Methods: A total of 23 patients were retrospectively analyzed after MVR following MitraClip. Overall, 46 patients with corresponding demographic data and risk profile receiving primary MVR (23 patients) or MVP (23 patients) were retrieved for matched pair analysis., Results: Mean age was 70 years in all groups, log European system for cardiac operative risk evaluation (EuroSCORE) was 22.47% ± 16.30 in MVR after MitraClip (MC), 22.34% ± 16.23 in MVP, and 22.33% ± 16.14 in MVR group. Preoperative left ventricular ejection fraction (LVEF) was 44%, and postoperative LVEF was 48% in all groups. The 30-day mortality was 21.7% in the MitraClip group whereas it was 4.3% in the MVR and 13.0% in the MVP group. The 1-year survival was 56.5% in the MitraClip group while it was 95.6% in the MVR group and 82.6% in the MVP group (Wilcoxon test: p  = 0.007; chi - square test: p  = 0.001 MitraClip vs. MVR; p  = 0.054 MitraClip vs. MVP)., Conclusions: Patients requiring surgical MVR after the previous MitraClip fared worse than matched cohorts receiving primary MVR or MVP. Indication for MitraClip should, therefore, be made very cautiously given the excellent results gained with primary surgery., Competing Interests: Disclosure The authors report no conflicts of interest in this work., (Georg Thieme Verlag KG Stuttgart · New York.)

Background  Acute endovascular aneurysm repair with stent grafts (thoracic endovascular aortic repair [TEVAR]) is safe and feasible. Case Description  A 64-year-old female presented with a perforated aortic aneurysm of the thoracic descending aorta. Primary TEVAR resulted in good management of the perforation but a type Ib endoleakage remained postoperatively. To place another stent, abdominal debranching with saphenous vein bypass to the celiac trunk was required. In the same session, another endograft was inserted successfully. Conclusion  Abdominal debranching is a safe alternative to open aortic repair in acute thoracic and abdominal aneurysms, instead of waiting for a custom-made device.

Interrupted pledget-armed braided sutures are widely used for valve implantation. In a 74-year-old woman with aortic valve endocarditis and shallow annular abscess, annulus dehiscence resulted after resection. As resistance was too high for sufficient primary approximation, a snug fit of the valve by means of circumferential application of curbed tourniquets resembling Medusa's head after suture placement was achieved. Closest possible approximation of the upper and lower part of the annulus with the prosthesis prior to final fixation was thus possible, so that application of too much tension on a single suture could be avoided., (© The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Objectives: Obesity is an ever-growing problem in contemporary cardiac surgery. Although it accounts for many perioperative comorbidities, it has not been shown to increase mortality. Body mass index (BMI) is therefore not considered in the European System for Cardiac Operative Risk Evaluation (EuroSCORE). We sought to confirm whether this holds true for our own single-centre patient population., Methods: Data from 15 314 consecutive patients receiving major cardiac surgery at our institution were analysed. Gender, age, BMI, EuroSCORE, urgency, redo status and all-cause in-hospital mortality were derived from our database. Mortality was grouped into 4 BMI categories. We created a logistic regression model to identify predictors of mortality., Results: There were 11 034 males and 4280 females. Categorical mortality was 8.79% (underweight), 7.04% (normal weight), 5.16% (overweight), 6.30% (obese), rendering an inverse J-shaped pattern known as obesity paradox. Univariable regression detected significant predictors of mortality: rising age, female gender, urgent procedures, redo surgery ( P  < 0.001). BMI was no predictor ( P  = 0.575) but became significant with the multivariable analysis ( P  = 0.004). Its effect on mortality was exclusively indirect, being mediated through age ( P  < 0.001). Receiver-operating characteristics curve analysis also confirmed that BMI did not qualify as a risk factor. However, the overweight category was a predictor of lower mortality., Conclusions: Our findings from >15 000 patients confirm the obesity paradox showing the least mortality in the overweight group. They support the current EuroSCORE model in that BMI is no independent predictor of early mortality. However, such patients still carry the risk of comorbidities. Likewise, special care is required with underweight patients who show the highest in-hospital mortality., (© The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background  Sternal instability after coronary artery bypass grafting (CABG) is a serious complication. Obese patients are at high risk for sternal instability after CABG. This study was conducted to assess the positive impact of double-wire sternal closure on sternal instability. Methods  A total of 200 obese patients with a body mass index ≥ 30 kg/m 2 undergoing isolated CABG with left internal mammary artery (LIMA) graft were randomly assigned to sternal closure either by eight single wires ( n  = 100) or by a combination of four double wires and four single wires. Results  There was a total of 21 cases with sternal instability: 5 cases (i.e., 5%) in the double-wire group versus 16 cases (16%) in the single-wire group ( p  = 0.019). Logistic regression analysis showed sternal closure via double wires as an independent protection factor (odds ratio [OR]: 0.276; p  = 0.029). Smoking (OR: 5.5; p  = 0.006) and postoperative delirium (OR: 3.5; p  = 0.033) turned out to be independent risk factors for the development of sternal instability. Conclusion  Double-wire sternal closure significantly reduces postoperative sternal instability in obese patients undergoing isolated CABG with LIMA graft., Competing Interests: Conflict of Interest: We have no conflicts of interest to declare., (Georg Thieme Verlag KG Stuttgart · New York.)

Background  Endovascular valve in stented biological valve implantation (valve-in-valve transcatheter aortic valve implantation [TAVI ViV]) is increasingly becoming a valid option for bioprosthesis degeneration. TAVI implantation in small stented biological valves below 23 mm is controversially discussed. Reduced opening area and high gradients are typical objections against this procedure in cases of small bioprosthesis. Systematic studies about the hemodynamic performance of endovascular valves in small stented bioprosthesis, however, do not exist. Methods  Stented biological valves of 21 mm size were analyzed in a pulse duplicator (cardiac output 4.9 L/min). Edwards Perimount Magna (EP; Edwards Lifesciences, Irvine, California, United States), Medtronic Mosaic (MM; Medtronic Inc., Minneapolis, Minnesota, United States), and Sorin Mitroflow (SM; Milan, Italy) were investigated (three valves, each type). Mean transvalvular gradients were measured before and after implantation of Edwards Sapien 23 mm (SAP) as ViV. Results  There were no marked differences of mean transvalvular gradients before and after ViV (EP21: 12.3 mm Hg; EP21 + SAP: 11.1 mm Hg; SM21: 13.5 mm Hg; SM21 + SAP: 14.9 mm Hg; MM21: 21.4 mm Hg; MM21 + SAP: 15.1 mm Hg). MM valves fabricated from porcine cusps showed higher initial gradients in contrast to valves constructed with pericardium (EP and SM). After ViV, however, this difference was reduced. Conclusion  This in vitro study shows that hemodynamic performance of endovascular valves as ViV in small bioprosthesis does not differ significantly from the performance of the initial implanted prosthesis. Hemodynamic performance of porcine cusp valves could even be optimized. It can thus be speculated that TAVI ViV also offers a reasonable option for patients with typical stented bioprosthetic degeneration to substantially prolong adequate function with one initial surgical and one consecutive interventional procedure even in small valves., (Georg Thieme Verlag KG Stuttgart · New York.)

Background: Some general hospitals within the German health system provide supportive interventions, psychological as well as spiritual, to their patients. It remains to be proven if these interventions are effective when used in routine clinical practice., Aim: To evaluate the effectiveness of psychological and spiritual interventions on improving recovery following bypass surgery., Methods: The BY.PASS study is a pragmatic, patient preference trial (ISRCTN 07297983). Adult patients scheduled for elective coronary bypass surgery were enrolled. Patients were assigned to study conditions according to their personal preference: preference for psychological interventions, for spiritual interventions or for no intervention. Patients who were open for any kind of intervention were randomly assigned either to psychological or spiritual interventions. During a control period, patients were asked about their preference, but did not receive any interventions. Primary outcomes of the study were in-hospital morbidity and early mortality. Psychological measures served as secondary outcomes., Results: A total of 847 patients were enrolled. Patients of the control (n = 260) and the intervention group (n = 269) who explicitly wanted to have interventions were compared. No significant treatment effects either for morbidity (d = 0.08, 95% CI -0.09 to 0.25), or for mortality (OR = 1.81; 95% CI 0.50-6.57) could be found. A reduction of negative mood resulted from both interventions., Conclusions: Although the effects observed were small, the study can serve as a basis to discuss methodological as well as theoretical aspects of a pragmatic trial, based upon patients' preferences., (Copyright © 2012 S. Karger AG, Basel.)

The purpose of this study was evaluation of an ice-free cryopreservation method for heart valves in an allogeneic juvenile pulmonary sheep implant model and comparison with traditionally frozen cryopreserved valves. Hearts of 15 crossbred Whiteface sheep were procured in Minnesota. The valves were processed in South Carolina and the pulmonary valves implanted orthotopically in 12 black faced Heidschnucke sheep in Germany. The ice-free cryopreserved valves were cryopreserved in 12.6 mol/l cryoprotectant (4.65, 4.65, and 3.31 mol/l of dimethylsulfoxide, formamide and 1,2-propanediol) and stored at -80°C. Frozen valves were cryopreserved by controlled slow rate freezing in 1.4 mol/l dimethylsulfoxide and stored in vapor-phase nitrogen. Aortic valve tissues were used to evaluate the impact of preservation without implantation. Multiphoton microscopy revealed reduced but not significantly damaged extracellular matrix before implantation in frozen valves compared with ice-free tissues. Viability assessment revealed significantly less metabolic activity in the ice-free valve leaflets and artery samples compared with frozen tissues (P < 0.05). After 3 and 6 months in vivo valve function was determined by two-dimensional echo-Doppler and at 7 months the valves were explanted. Severe valvular stenosis with right heart failure was observed in recipients of frozen valves, the echo data revealed increased velocity and pressure gradients compared to ice-free valve recipients (P = 0.0403, P = 0.0591). Histo-pathology showed significantly thickened leaflets in the frozen valves (P < 0.05) and infiltrating CD3+ T-cells (P < 0.05) compared with ice-free valve leaflets. Multiphoton microscopy at explant revealed reduced inducible autofluorescence and extracellular matrix damage in the frozen explants and well preserved structures in the ice-free explant leaflets. In conclusion, ice-free cryopreservation of heart valve transplants at -80°C avoids ice formation, tissue-glass cracking and preserves extracellular matrix integrity resulting in minimal inflammation and improved hemodynamics in allogeneic juvenile sheep.

A 59-year-old patient developed endocarditis with coagulase-negative staphylococci after aortic composite graft replacement and pacemaker implantation. She underwent complete pacemaker removal and tricuspid valve reconstruction. Pus was present in and around the aortic graft. Re-replacement of the aortic root and ascending aorta using only biological material was performed. A 23-mm full root stentless prosthesis (Vascutek Root Elan, Vascutec, Terumo, Leeds, UK) was used for aortic root replacement, and a second 25-mm full root prosthesis with removed cusps implanted in a reversed fashion was used for ascending aorta and proximal aortic arch replacement., (© Georg Thieme Verlag KG Stuttgart · New York.)

Transplantation of cryopreserved heart valves (allografts) is limited by immune responses, inflammation, subsequent structural deterioration and an expensive infrastructure. In previous studies we demonstrated that conventional frozen cryopreservation (FC) is accompanied by serious alterations of extracellular matrix (ECM) structures. As the main culprit of the observed damages ice crystal formation was identified. Objective of this study was the application principles of cryoprotection as observed in nature, occurring in animals or plants, for ice-free cryopreservation (IFC) of heart valves. Using IFC, valves were processed and stored above the glass transition temperature of the cryoprotectant formulation (-124 degrees C) at -80 degrees C to avoid any ice formation, tissue-glass cracking and preserving ECM. After implantation in the orthotopic pulmonary position in sheep, we demonstrate that IFC resulted in cell free matrices, while maintaining crucial ECM-components such as elastin and collagen, translating into superior hemodynamics. In contrast, we reveal that FC valves showed ECM damage that was not restored in vivo, and T-cell inflammation of the stroma with significant leaflet thickening. Compared to currently applied FC practice IFC also reduced infrastructural needs for preservation, storage and shipping. These results have important implications for clinical valve transplantation including the promise of better long-term function and lower costs., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Endovascular valves have become a valid option for patients not qualifying for conventional surgery. Biological valves mounted in a stent are currently used. After implantation, however, geometrical distortion of the valve can occur. We tested whether biological valves suitable for transcatheter implantation exhibit hemodynamic deficits after deployment in a distorted position. Two types of valves [bovine pericardium (BP) and porcine cusps], of 21 and 23 mm diameter, respectively were investigated. Mean transvalvular gradient (TVG), effective orifice area (EOA), and regurgitation fraction (REG) were measured prior to and after the 20% distortion of the original diameter. All valves exhibited an increase of TVG and reduction of EOA whereas REG increased only in BP valves after distortion. The 21 mm valves demonstrated a more pronounced alteration than the 23 mm valves. Even moderately distorted implantation of a biological valve results in a marked functional alteration. The susceptibility of pericardial valves is higher than that of porcine valves probably owing to better coaptation properties of native cusps even under deformed conditions when compared to valves constructed with pericardium. Care should therefore be taken during implantation of endovascular valves in order to avoid fixed hemodynamic deficits. Native valves may preferably be used as they demonstrate a more robust behavior regarding suboptimal implantation.

Objective: Fibrin glue products and collagen surgical patches (TachoSil) coated with coagulation factors I and IIa are increasingly being used to prevent oozing from distal or proximal coronary anastomosis. Furthermore, an increasing number of patients are being operated upon anti-platelet therapy. These patients often exhibit diffuse bleeding. Especially in an off-pump scenario surgeons refrain from placing additional stitches in order to avoid an impairment of the graft. In these situations, a biological glue can help resolve this dilemma. It is, however, assumed that these products may exert negative effects on the anastomosis. For obvious reasons a systematic histological assessment in humans is impossible. Therefore, a chronic, large animal model was developed to study the fate of these products on a coronary anastomosis., Methods: In 15 pigs receiving off-pump coronary artery bypass graft of the left mammary artery to the left anterior descending coronary artery, three groups were defined. Group A served as control. In group B the anastomosis was covered with 1 ml fibrin glue; in group C TachoSil coverage was performed. Bypass flow (BF) was measured using a Doppler probe. After 3 months the pigs were sacrificed and the anastomoses were evaluated macroscopically and by means of light microscopy regarding patency and fibrosis., Results: In group A, all five animals survived, three of the five anastomoses were patent and the mean BF was 26 ml min(-1). In group B, three of the five animals survived, all anastomoses were patent. The BF was 21 ml min(-1). In group C, all five animals survived, four of the five anastomoses were patent and BF was 21 ml min(-1). Macroscopic and histological evaluation showed no differences between the groups. Remnants of Tachosil or fibrin glue were not observed., Conclusions: In the chronic course, no evidence of adverse effects of TachoSil or fibrin glue was noted. Both agents can therefore be used safely in clinical practice for haemostyptic or positioning purposes.

Effects of psychological as well as spiritual interventions on outcome in cardiac surgery have mostly been studied with a focus on presurgical interventions. Systematically controlled analyses of the effects of psychological and spiritual interventions depending on the patients' preference have not been performed so far, although these studies would help to assign patients to an adequate support. The By.pass study is a bi-center, controlled trial of patients undergoing coronary bypass surgery and coronary bypass surgery combined with valve replacement surgery in 2 different German hospitals. Patients are assigned to 1 of 5 conditions, mainly according to their personal therapeutic preference: preference for psychological interventions (group 1), preference for spiritual interventions (group 2), or preference for no intervention (group 5). Patients who are open for any kind of intervention are randomly assigned either to psychological (group 3) or spiritual interventions (group 4). Six months before the start and 6 months after the end of the treatment phase, patients were assigned to the control groups. These were asked about their subjective preference (psychological, spiritual, no intervention, or no specific preference) as well but received no interventions. Patients will be enrolled from October 2006 to December 2009. The 6-month follow-up will be completed in July 2010.

Background: The surgeon's individual performance is a key component of total quality management (TQM) in cardiac surgery. Early mortality as well as postoperative complications can be stratified in order to develop a surgeon performance index (SPI)., Material and Methods: In three consecutive annual periods (3703 patients) data of board-certified cardiac surgeons were compared. Risk-adjustment of early mortality and postoperative complications was performed by logistical EuroSCORE (logES). Early mortality (EM), early rethoracotomy for bleeding (ReTh), sternal rewiring for instability (ReWr), and mediastinitis (Med) were assessed. ReTh, ReWr, and Med were weighted according to empiric data: (ReThx2; ReWrx1; Medx3). Surgeon performance index was computed as follows: SPI=(EM/logES+[((ReTh/logES)x2)+((ReWr/logES)x1)+((Med/logES)x3)]/6)/2. Ideal SPI was considered

Background: Bonewax is routinely used to seal sternal edges after median sternotomy. Adverse effects on sternal healing, however, have been proclaimed although clear evidence does not exist. We performed a study on coronary bypass patients with or without bonewax application to verify negative effects and risk factors for early rethoracotomy, wound healing problems, and mediastinitis., Methods: In a prospectively randomized study on 400 patients undergoing isolated coronary bypass surgery, 200 patients with (bonewax) and 200 patients without bonewax (nonwax) application after median sternotomy were compared. Blood product consumption, early rethoracotomy, sternum stabilization, mediastinitis, and early mortality were compared. Risk factors such as age, sex, diabetes mellitus, and bonewax were analyzed by means of logistical regression analysis., Results: Blood product consumption was almost identical in both groups (red blood cells, 3.9 +/- 4.7 units in the bonewax group; 3.8 +/- 3.4 units in the nonwax patients; fresh frozen plasma, 0.5 +/- 1.6 units versus 0.5 +/- 1.3 units; platelet concentrates, 0.07 +/- 0.3 units versus 0.04 +/- 0.2 units). Early rethoracotomy (bonewax 6.5%; nonwax 5%), sternal stabilization (bonewax 3%; nonwax 3%), and mediastinitis (bonewax 1%; nonwax 0.5%) did not differ significantly. Early mortality was 2.5% in the bonewax group and 0.5% in the nonwax cohort. Bonewax did not appear as an independent risk factor for adverse outcome., Conclusions: Negative effects of bonewax on the percentage of postoperative complications and outcome were not shown. However, positive effects such as a reduction of blood product substitution were also not observed. Using bonewax on sternal edges is obviously safe but not particularly beneficial.

Background: Demographic changes and aggressive medication with platelet aggregation inhibitors have resulted in a marked increase in blood and coagulation product expenditure and costs in cardiac surgery. We analyzed the bedside coagulation test (ROTEM) in order to verify clot forming quality and to find a cost-effective treatment algorithm., Patients and Methods: Annual treatment costs of all cardiosurgical patients were retrospectively analyzed before (729 patients) and after (693 patients) implementation of the bedside ROTEM test. Cumulative numbers and costs of platelet concentrates (PltC), fresh frozen plasma (FFP), red blood cell units (RBC), and the coagulation factors prothrombin complex concentrates (PCC), recombinant factor VIIa (rFVIIa), factor XIII (FXIII), and fibrinogen were assessed. Average monthly numbers and costs were compared. The number of rethoracotomies and early mortality were assessed and compared in both periods., Results: After ROTEM implementation cumulative RBC expenditure showed a 25% decrease and PltC a 50% decrease. FFP expenditure remained unchanged. PCC, FXIII were markedly reduced (-80%) while rFVIIa was entirely omitted. Fibrinogen, however, showed a two-fold increase. Cumulative average monthly costs of all blood products decreased from 66,000 EUR to 45,000 EUR (-32%). Coagulation factor average monthly costs decreased from 60,000 EUR to 30,000 EUR (-50%) yielding combined savings of 44%. In contrast, average monthly costs for ROTEM were 1,580 EUR. The total number of rethoracotomies decreased from 6.6% to 5.5% while early mortality (5.9%; 6.0%) remained stable., Conclusions: Cumulative costs for treatment of perioperative coagulation disorders were reduced by bedside ROTEM analysis to achieve a selective substitution management. Saved costs for blood and coagulation products clearly outweighed the expenses of ROTEM. Adequate differential coagulation management can therefore be cost-effective.

Objective: Demographic changes and aggressive platelet inhibition have resulted in a marked increase in blood- and coagulation product expenditure and costs in cardiac surgery. We analyzed "bedside" coagulation test (ROTEM) in order to verify clot forming quality for the purpose of finding a cost-effective treatment path., Methods: Annual treatment costs of all cardiosurgical patients were analyzed before (729 patients) and after (693 patients) implementation of "bedside" ROTEM. Cumulative numbers and costs of platelet concentrates (PltC), fresh frozen plasma (FFP), red blood cell units (RBC), and coagulation factors: pooled coagulation concentrates (PCC), recombinant factor VIIa (rFVIIa), factor XIII (FXIII), and fibrinogen were assessed. Average monthly numbers and costs were compared. Number of resternotomies and early mortality was assessed and compared in both periods., Results: After ROTEM implementation cumulative RBC expenditure showed 25% decrease while PltC exhibited 50% decrease. FFP expenditure remained unchanged. PCC, FXIII were markedly reduced (-80%) while rFVIIa were entirely omitted. Fibrinogen, however, increased two-fold. Cumulative average monthly costs of all blood products decreased from 66,000 euro to 45,000 euro (-32%). Coagulation factor average monthly costs decreased from 60,000 euro to 30,000 euro (-50%) yielding combined savings of 44%. In contrast, average monthly costs for ROTEM were 1.580 euro. Total number of resternotomies decreased from 6.6% to 5.5% while early mortality (5.9%; 6.0%) remained stable., Conclusion: Cumulative costs for treatment of perioperative coagulation disorders can be reduced by "bedside" ROTEM analysis to achieve a selective substitution management. Saved costs for blood- and coagulation products clearly outweighed the expenses of ROTEM. Adequate differential coagulation management can therefore be cost-effective.

Various techniques of stentless aortic valve implantation with or without wall components exist. We investigated the in-vitro performance of stentless valves without or with aortic wall removal mimicking root versus subcoronary implantation. Glutaraldehyde-preserved stentless aortic valves (gpSVG), cryo-preserved human homografts (cpHG), cryo-preserved xenografts (cpXG), and fresh xenografts (fXG) were used. Valves were mounted as full roots or trimmed in a mock circuit. Mean transvalvular gradient (MTVG, mmHg) was measured. Distensibility was quantified using post-systolic backflow volume (BV, ml) - after valve closure. Function was visualized by means of a high-speed camera. Glutaraldehyde-preserved valves exhibited higher MTVG than cryo-preserved or fresh substitutes. After trimming, cpHG, cpXG, and fXG demonstrated marked reduction of MTVG (cpHG: 7.6-5.2 mmHg; cpXG: 6.7-4.9 mmHg; fXG: 8.4-5.2 mmHg). In contrast, after trimming gpSVG exhibited a significant increase of MTVG (7.1-9.2 mmHg). BV remained constant. Visualization indicated maintained distension of all valves and types of all sizes after trimming. In fresh and cryo-preserved grafts, aortic wall trimming resulted in significantly improved systolic performance while glutaraldehyde-preserved stentless valves demonstrated systolic impairment after wall resection. Subcoronary implantation of fresh or cryo-preserved aortic valves may therefore be preferred. In contrast, glutaraldehyde-preserved valves are dependent on wall suspension and may therefore be implanted as a root.

Surgical treatment of a Jehovah's Witnesses continues to be a great challenge in cardiac surgery. Different strategies are used to minimize the risk for early mortality, prolonged intensive care unit stay and hospitalization, resulting from anemia. Minimized closed circuit extracorporeal circulations have been shown to reduce adverse effects of conventional CPB. Two patients underwent urgent coronary revascularization for triple-vessel disease. The miniECC (Stöckert) is a phosphorylcholine-coated device which integrates the functions of oxygenation, filtration, and pumping in a compact manner with reduced total surface area and priming volume. After a well-tolerated operation the patients showed only minimal red blood cell damage (free hemoglobin 93 mg/l). Hematocrit levels decreasing perioperatively in both patients only moderately (32% and 30%). In these two instances using miniECC we showed a markedly reduced blood cell damage and myocardial trauma. Furthermore, we observed hematocrit levels being higher as compared to standard CABG patients, providing an optimized startpoint for an uneventful postoperative course. MiniECC can be routinely employed and reduces red blood cell damage. Therefore, it can be an effective aid in CABG operations in Jehovah's Witnesses.

The purpose of this study was to examine the feasibility of the combined use of intraluminal biodegradable shunts and surgical adhesives for sutureless distal coronary anastomosis. Eighteen LITA-LAD anastomoses were created in a porcine beating heart model. In group I (n=9) a custom-made silicone Y-shunt provided internal stability, while three different adhesives, N-butyl-2-cyanoacrylate-glue (CYAC); albumin-glutaraldehyde-glue (AG); fibrin-glue (FIB), were applied externally. In group II (n=9) biodegradable polydioxanone (PDS) shunts were used. All anastomoses were examined intraoperatively by flow measurement, blood leakage was quantified and physical strength was tested. In all pigs anastomoses could be created successfully at first attempt, but anastomotic leaks requiring additional sutures occurred in 6 animals. LITA-flow significantly decreased in both groups. A patency rate of 89.9% (8/9) was found in group I while it was 66.6% (5/9) in group II. The lowest amount of blood-loss was measured when CYAC adhesive was used while tensile strength was lowest in the FIB-anastomoses. Preliminarily we could demonstrate the feasibility of performing sutureless distal coronary anastomosis by means of a combination of adhesives and temporary intraluminal shunts. PDS-shunts, however, resulted in a high graft-occlusion rate, so that potentially less thrombotic materials need to be investigated.

Closed circuit extracorporeal circulation comprising a centrifugal pump has been developed to reduce deleterious effects of standard cardiopulmonary bypass. This study compares such a system with standard extracorporeal circulation (ECC). Twenty patients underwent isolated routine coronary artery revascularization. Ten patients underwent ECC. Ten patients were operated upon using a closed circuit/centrifugal pump system with coated surfaces (ISS) (SYNERGY, Stöckert). Both groups did not differ regarding age, body mass, left ventricular function, number of bypasses, and concomitant diseases. Free hemoglobin (fHb), plasmin-antiplasmin complex (PAPc), platelet function (ROTEG), and interleukin 6 (IL-6) were measured preoperatively, intraoperatively (after sternotomy, during X-Clamp, during reperfusion, post ECC or ISS), and postoperatively. Technical problems were not observed. The ISS group demonstrated significantly less fHb during bypass, a lower intraoperative myocardial damage as well as less increase in IL-6 after bypass and postoperatively compared to ECC. In ISS fluid balance was significantly lower than in ECC whereas drainage loss and hospitalization did not differ statistically. Extracorporeal circulation with a closed circuit/centrifugal pump system can be routinely employed and appears to be safe. Intraoperative and early postoperative reduction of red blood cell trauma and inflammation are of potential value.

To effectively perform an anastomosis on a coronary artery under beating heart conditions, the anastomotic site must be cleared of blood to allow visualization for accurate suturing. We describe a simple, cost effective, on-site assembled blower-mister system.

Objective: Adhesives are useful supplements to seal distal coronary anastomoses, particularly in patients who receive less-invasive coupling techniques. Information regarding long-term structural effects after application, however, is limited. The purpose of this large animal study was to examine the effects of 3 different commercially available surgical adhesives., Methods: Twelve end-to-side anastomoses were created between the left internal thoracic artery and the left anterior descending coronary artery in a porcine beating heart model. Three different adhesives were applied externally and circumferentially to the anastomosis site. In group I (n = 4) gelatin-resorcinol-formaldehyde glue (Cardial, Technopole, Sainte-Etienne, France), in group II (n = 4) n-butyl-2-cyanoacrylate glue, and in group III (n = 4) albumin-glutaraldehyde glue were used. All anastomoses were examined intraoperatively by flow measurement. After 3 months the anastomoses were reassessed for patency and the vessels were evaluated histologically., Results: By means of 4 stay sutures and subsequent glue application, anastomoses could be created successfully on the first attempt in all animals. Perioperative flow through the left internal thoracic artery was similar in all groups. In 4 animals an additional suture was placed to control bleeding. After 3 months, the patency rate was 83.3% (10/12). In group I all anastomoses were patent whereas in both groups II and III one anastomosis was occluded. None of the adhesives caused impaired vessel wall healing but they did demonstrate moderate-to-dense adhesions to the surrounding tissue. On histologic examination, gelantin-resorcinol-formaldehyde glue exhibited minimal tissue reaction (foreign-body granuloma) whereas n-butyl-2-cyanoacrylate glue showed moderate reaction. In contrast, albumin-glutaraldehyde glue caused severe inflammatory reaction with extensive fibroblastic proliferation., Conclusion: Construction of an end-to-side internal thoracic artery-coronary artery sleeve anastomosis using adhesives was feasible in the pig. Among the tissue adhesives used in this study, gelantin-resorcinol-formaldehyde glue appeared to be superior to cyanoacrylate and albumin-glutaraldehyde glue. The latter one, however, caused severe adverse histologic effects and thus cannot be recommended for bonding coronary anastomoses.

The first case of a fracture of a semi-rigid annuloplasty device is reported. A 56-year-old man presented with recurrence of severe mitral and tricuspid regurgitation 10 months after proper implantation of a Colvin-Galloway Future band (Medtronic Inc, Minneapolis, MN). During redo surgery we made the unexpected finding that its metal skeleton was fractured near the posterior segment. A tear in the anterior mitral leaflet was also found. It is speculated that the device fracture may have put additional strain on the native annulus.

Background: In an increasingly senescent population stented biological valves have regained renewed popularity because of the absence of anticoagulation, while the stented design allows for safe and easier implantation. Constructed bovine pericardial valves as well as valves with porcine cusps are used, both of which exhibit good clinical results although degeneration still appears. While clinical hemodynamic studies did not show particular differences between both valves types, the opening and closure behavior of native cusps and artificially constructed pericardial leaflets is different. It is unclear whether these phenomena account for differences in load and stress which may influence onset and course of degeneration., Material and Methods: Edwards Perimount (EP) and Medtronic Mosaic (MM) heart valves with diameters of 21 mm, 23 mm, and 25 mm were investigated in a pulse duplicator. Movements of the valves were visualized with a high-speed camera (1000 frames/sec). Mean transvalvular gradient (mm Hg), dissipated power (mW), and power transfer by stretching (mW), mean orifice area (mm2), opening time (ms), and closure time (ms) were analyzed in a range of cardiac outputs from 1.4 l/min to 6.3 l/min and 70 beats per minute., Results: Closure times were generally longer than opening times for both valve types. Opening time of EP valves was longer than opening time of the MM valves of the same size (EP23: 31.2 +/- 2.5 ms; MM23: 12.7 +/- 0.1 ms). With respect to closure times, however, there were no marked differences between all valves (EP23: 69.3 +/- 2.0 ms; MM23: 63.2 +/- 6.3 ms). Smaller sized Perimount valves exhibited lower mean transvalvular gradients than Mosaic valves of the same size (EP23: 7.21 +/- 0.07 mm Hg; MM23: 10.5 +/- 0.15 mm Hg). In larger sizes these differences diminished. Power transfer to the valve's structures was significantly enhanced in EP valves (EP23: 134 +/- 1.3 mW; MM23: 64 +/- 0.9 mW)., Conclusions: While valves with constructed pericardium showed lower mean transvalvular gradients, particularly in the smaller sizes, this valve type exhibited alterations of movement performance in contrast to porcine valves. It can be speculated that constant power transfer to the valve's structures may result in an earlier degeneration because of the impact of the increased load and stress on the suspension apparatus of the constructed pericardial leaflets.

Background: Aortic annulus calcification can promote tilted implantation of mechanical valves. This study evaluates the hemodynamics of tilting disc valves under this condition., Methods: 23 mm and 25 mm Ultracor (UC) and Medtronic-Hall-Easy-Fit (MH) valves were investigated in a pulse-duplicator under physiological conditions. Mean pressure gradient (dP(mean)), systolic energy loss (dW(sys)), effective orifice area (EOA), closure (V(Cl)), leakage (V(L)), and total regurgitation volume (V(R)) were assessed. Valves were independently positioned at five axial rotations (0 - 180 degrees , zero defined as major orifice facing the top of the "tilt-ramp") and three tilt angles (0 degrees, 10 degrees, 20 degrees) by lifting the prosthesis in the noncoronary sinus., Results: Diameter-enhanced MH valves exhibited a better systolic performance but a higher regurgitation than corresponding UC valves. Moderate tilting showed a rotation-independent increase in dP(mean) and dW(sys) and a decrease in V (R) and EOA with no fundamental differences between valve types. Further tilting caused small additional changes at 90 - 180 degrees rotation. At 0 degrees rotation, however, dramatic regurgitation occurred throughout., Conclusion: Tilting worsened systolic performance regardless of valve type. It should therefore be avoided. Due to extensive regurgitation at 0 degrees rotation, this position should be corrected whenever tilting is inevitable.

Restitution strategies of the insufficient aortic valve belong to the clinical armamentarium. To date, the accumulated body of evidence comprises 126 articles dealing with restitution strategies on the insufficient aortic valve with concomitant aortic surgery. In a cumulative analysis an almost identical number of reimplantation (506) and remodeling (489) procedures were found in the literature, whereas 357 patients underwent aortic valve resuspension. The cumulative results tend to favor the reimplantation technique in terms of longevity of the reconstruction, particularly in congenital degenerative disorders of the aortic wall, whereas remodeling appears to exhibit a more physiologic behavior of the reconstructed valve and re-suspension serves as a simplified approach particularly in acute type A dissection. Although restitution of the native aortic valve has its place in current treatment options, the accumulated worldwide numbers indicate that it is not yet routinely implemented in the vast majority of cardiac institutions.

Background and Aim of the Study: Positioning of a mechanical prosthesis outside the native annulus facilitates mitral valve replacement, especially when the annulus is small and calcified, and preservation of the posterior leaflet (PML) is desired. Herein is described the authors' initial experience with a new mechanical bileaflet prosthesis comprising a sheltered leaflet housing and a novel, modified asymmetrical sewing ring for an 'atrialized' implantation technique., Methods: Forty-seven patients (24 males, 23 females; mean age 65.8 +/- 10.9 years) were operated on for isolated mitral regurgitation or combined stenosis and insufficiency. Ten of the patients underwent valve replacement due to active endocarditis. Preoperative cardiac insufficiency was reflected by a mean NYHA class of 2.6 +/- 0.7. The On-X Conform-X bileaflet mitral valve prosthesis (25/33 mm) was implanted in either an epiannular (43 patients) or intra-annular (four patients) fashion, and the PML and its chordae tendineae were preservable in 33 patients (70.2%). All patients were monitored intraoperatively by transesophageal echocardiography (TEE) and post-operatively by transthoracic echocardiography (TTE)., Results: TEE and TTE exhibited excellent function with low mean transvalvular gradients early after surgery (4.9 +/- 2.7 mmHg) and after three months (4.8 +/- 1.4 mmHg). Paravalvular leakage was not detected. Initial postoperative left ventricular (LV) function was almost identical to preoperative findings (ejection fraction: preop. 55.1 +/- 13.7%, early postop. 53.7 +/- 13.6%) and improved slightly after three months (60.1 +/- 6.4%). Clinically significant hemolysis was not apparent (LDH at postoperative day 7: 5.3 +/- 0.8 micromol/l x s). Two patients died from multiorgan failure (4.2%) and four are currently in a reduced condition requiring long-term hospitalization (morbidity 8.5%). After three months all other patients were in an excellent clinical state (mean NYHA class 1.5 +/- 0.6) and being followed up as outpatients., Conclusion: Current designs of mechanical bileaflet valves require redundant space in the LV cavity for undisturbed leaflet movement. A small annulus, marked fibrosis and calcification of the valvular apparatus can lead to an impedance of prosthetic leaflet motion. Consequently, the native leaflets are often removed. The cylindrical housing of the On-X valve shelters almost the entire motion of the leaflets, allowing an undisturbed function and improved transvalvular flow pattern. The newly developed asymmetrical sewing ring facilitates anchoring of the ring in an 'atrialized' fashion, while the flexibility of the cuff adapts to all native ring diameters larger than 25 mm.

Background: The optimal closure technique of median sternotomy remains controversial. The objective of this study was to analyze the structural response of the separated sternum using computer-based numerical discretization techniques, such as finite element methods., Methods: Thoracic computer tomographic scans (2.5-mm slices) were segmented, analyzed by image processing techniques, and transferred into a three-dimensional finite element model. In a first approach a linear elastic material model was used; neglecting nonlinear and damage effects of the bones. The influence of muscles and tendons was disregarded. Nonlinear contact conditions were applied between the two sternal parts and between fixation wires and sternum. The structural response of this model was investigated under normal breathing and asymmetric leaning on one side of the chest. Displacement and stress response of the segmented sternum were compared regarding two different closure techniques (single loop, figure-of-eight)., Results: The obtained results revealed that for the normal breathing load case the single loop technique is capable of clamping the sternum sufficiently, assuming that the wires are prestressed. For asymmetric loading conditions, such as leaning on one side of the chest, the figure-of-eight loop can substantially reduce the relative longitudinal displacement between the two parts compared with the single loop., Conclusions: The application of numerical simulation techniques using complex computer models enabled the determination of structural behavior of the chest regarding the influence of different closure techniques. They allowed easy and fast modifications and therefore, in contrast to a real physical model, in-depth parameter studies.

Objective: Closed circuit extracorporeal circulation (CCECC) has been developed to reduce deleterious effects of standard cardiopulmonary bypass (CPB). This study compares the effects of CCECC (CORx system), CPB, and off-pump coronary artery bypass grafting (OPCAB) on red blood cell damage, coagulation activation, fibrinolysis and cytokine expression., Methods: Thirty patients underwent coronary artery bypass grafting (CABG). Twenty of them were randomized into two groups: CCECC (n = 10), CPB (n = 10). While not randomized, OPCAB (n = 10) served as a separate reference group. CCECC and CPB patients received cardioplegic arrest. Interleukin 6 (IL-6), free hemoglobin (fHb), von Willebrand factor activity (vWf), thrombin-antithrombin-III-complex (TATc), prothrombin fragment 1.2 (F 1+2) and plasmin-antiplasmin complex (PAPc) were assessed preoperatively, perioperatively and 24 h postoperatively., Results: CCECC showed significantly lower red blood cell damage than CPB (fHb: CCECC, 7.1+/- 5.7 micromol/l; CPB, 16.8+/-11.4 micromol/l; P = 0.025; OPCAB, 3.4+/-1.1 micromol/l). Perioperatively, CCECC exhibited significantly lower activation of coagulation and fibrinolysis than CPB, but did not differ from OPCAB (vWf: CCECC, 133+/-52%; CPB, 241+/-128%; P = 0.052; OPCAB, 153+/-58%; TATc: CCECC, 4.7+/-0.9 ng/ml; CPB, 31.1+/-15.8 ng/ml; P < 0.001; OPCAB, 2.4+/-0.6 ng/ml; PAPc: CCECC, 214+/-30 ng/ml; CPB, 897+/-367 ng/ml; P < 0.001; OPCAB, 253+/-98 ng/ml). In contrast, fibrinolysis markers and IL-6 were markedly increased in CCECC postoperatively (PAPc: CCECC, 458+/-98 ng/ml; CPB, 159+/-128 ng/ml; P < 0.001; OPCAB, 262+/-174 ng/ml; IL-6: CCECC, 123.4+/-49.8 pg/dl; CPB, 18.8+/-13.1 pg/dl; P < 0.001; OPCAB, 31.6+/-26.2 pg/dl)., Conclusions: CCECC for CABG is associated with a significant reduction of red blood cell damage and activation of coagulation cascades similar to OPCAB when compared with conventional CPB while a delayed fibrinolytic and inflammatory activity was observed. These findings require further investigation to verify the promising concept of CCECC.