[The hybrid operating room. Home of high-end intraoperative imaging]. / Der Hybridoperationssaal. Zentrum intraoperativer Bildgebung.

A hybrid operating room must serve the medical needs of different highly specialized disciplines. It integrates interventional techniques for cardiovascular procedures and allows operations in the field of orthopaedic surgery, neurosurgery and maxillofacial surgery. The integration of all steps such as planning, documentation and the procedure itself saves time and precious resources. The best available imaging devices and user interfaces reduce the need for extensive personnel in the OR and facilitate new minimally invasive procedures. The immediate possibility of postoperative control images in CT-like quality enables the surgeon to react to problems during the same procedure without the need for later revision.

Endothelial nitric oxide synthase mediates protective effects of hypoxic preconditioning in lungs.

To elucidate the protective mechanism of whole-body hypoxic preconditioning (WHPC) on pulmonary ischemia-reperfusion injury focussing on nitric oxide synthases (NOS), mice were placed in a hypoxic chamber (FIO(2)=0.1) for 4h followed by 12h of normoxia. Then, pulmonary ischemia for 1h followed by 5h of reperfusion was performed by clamping the left hilum in vivo (I/R). WHPC protected WT mice from pulmonary leukocyte infiltration as assessed by myeloperoxidase (MPO) activity, associated with a mild further increase in endothelial permeability (Evans Blue extravasation). When all NOS isoforms were inhibited during WHPC by L-NAME, mortality and MPO activity after I/R markedly increased. To determine the responsible NOS isoform, quantitative RT-PCR was performed for eNOS and iNOS mRNA, showing that only eNOS was upregulated in response to WHPC. While eNOS total protein expression remained unchanged, the amount of phosphorylated eNOS also increased. The WHPC/IR experiments were then repeated with eNOS knockout mice. Here, we found that the protective effect of WHPC on pulmonary leukocyte sequestration was abrogated, and endothelial leakage was further exacerbated. We conclude that WHPC limits neutrophil sequestration via an eNOS-dependent mechanism, and that eNOS helps preserve endothelial permeability during hypoxia and I/R.

Anticoagulation management during multivessel coronary artery bypass grafting: a randomized trial comparing individualized heparin management and conventional hemostasis management.

BACKGROUND: Individualized heparin management (IHM) uses heparin dose-response curves to improve hemostasis management during cardiac surgery as compared with activated clotting time-based methods. OBJECTIVES: IHM was compared with conventional hemostasis management (CHM) in a randomized, prospective study (ID DRKS00007580). METHODS: One-hundred and twenty patients undergoing multivessel coronary artery bypass grafting (CABG) were enrolled. Heparin and protamine consumption, blood losses, blood transfusions and administration of hemostatic agents were recorded. Time courses of platelet counts and of coagulation parameters were determined. Coagulation was analyzed at intensive care unit (ICU) arrival by thromboelastometry. RESULTS: IHM patients received significantly lower initial heparin doses (289.3IU kg(-1) [interquartile range (IQR) 221.5-376.2 IU kg(-1) ] versus 350.5 IU kg(-1) [IQR 346.8-353.7 IU kg(-1) ], P < 0.0001) but similar total heparin doses (418.5 IU kg(-1) [IQR 346.9-590.5 IU kg(-1) ] versus 435.8 IU kg(-1) [IQR 411.7-505.1 IU kg(-1) ]). IHM patients received significantly less protamine, resulting in protamine/total heparin ratios of 0.546 [IQR 0.469-0.597] versus 0.854 [IQR 0.760-0.911] in CHM patients (P < 0.0001). Activated partial thromboplastin time (50.5 s [IQR 40.0-60.0 s] versus 37.0 s [IQR 33.0-40.0 s], P < 0.0001), activated clotting time (136 s [IQR 129.0-150.5 s] versus 126.5 s [IQR 120.3-134.0 s], P = 0.0002) and INTEM clotting times (215 s [IQR 192-237] versus 201 s [IQR 191-216 s], P = 0.0397) were significantly longer in IHM patients than in CHM patients at ICU arrival, with no difference in prothrombin time (P = 0.538). IHM patients lost significantly more blood within 12 h postoperatively (420 mL [IQR 337.5-605.0 mL] versus 345 mL [IQR 230.0-482.5 mL], P = 0.0041), and required significantly more hemostatic agents to control bleeding. Red blood cell transfusion requirements and time courses of platelet counts did not differ between groups. CONCLUSIONS: Multivessel CABG patients did not benefit from IHM in comparison with our established protocol based on activated clotting time.

Recurrent malignant fibrous histiocytoma of the left atrium in a 27-year-old male.

We report a case of recurrent malignant fibrous histiocytoma (MFH) of the left atrium. The primary lesion was surgically removed after it had been diagnosed to be the cause of fulminant pulmonary edema in a 27-year-old male. The tumor recurred 15 weeks following surgery. It was excised completely, leaving a large left atrial defect that was reconstructed using a Dacron patch. Malignant fibrous histiocytoma constitutes 2% of all cardiac malignancies. The typical location is the left atrium. Surgical excision is the primary aim in treating this tumor. Adjuvant radiotherapy and chemotherapy have been suggested in the literature. The prognosis is poor.

The heart produces but the lungs consume proinflammatory cytokines following cardiopulmonary bypass.

OBJECTIVE: Proinflammatory cytokines, such as interleukin-6 (IL-6), and soluble adhesion molecules, such as E-selectin, may play an important role in patient response to cardiopulmonary bypass (CPB). We sought to define whether the heart and the lungs serve as important sources of these inflammatory mediators under clinical conditions of myocardial revascularization using CPB and cardioplegic arrest. METHODS: Plasma levels of IL-6 and E-selectin were measured in coronary sinus (CS), arterial, pulmonary arterial (PA) and left atrial (LA) blood samples taken from 12 consecutive patients (68.3 +/- 11 years; five females) undergoing coronary artery bypass grafting (CABG). Blood samples were collected preoperatively, after reperfusion, and 1, 6, 12 and 18 h following surgery. CS and LA blood was drawn using transcutaneous catheters. PA artery blood was obtained through a Swan-Ganz catheter. Cytokine levels were determined by standard enzyme linked immunosorbent assay (ELISA) technique. RESULTS: A mean of 3.8 +/- 1 coronary anastomoses were performed. The CPB time and aortic X-clamp time were 91 +/- 15 and 45 +/- 10 min, respectively. IL-6 levels increased significantly after CPB and peaked 6 h postoperatively. There was also a significant increase of E-selectin levels with an onset at 1 h and a peak at 12 h postoperatively. At all time points the IL-6 and E-selectin concentrations were significantly higher in the CS than in arterial blood. In contrast, the levels of both mediators measured in the LA were significantly lower than those in the PA. CONCLUSION: The reperfusion of ischemic myocardium during CABG results in a significant increase in plasma levels of IL-6 and E-selectin. Our data indicate that the myocardium, but not the lungs, is a predominant source of IL-6 and E-selectin release following CPB. The lungs may consume rather than release those mediators during reperfusion. Not the CPB per se, but the myocardial ischemia seems to be crucial in the pathogenesis of the inflammatory response observed following open heart surgery.

Clinical results with single lead VDD pacing.

OBJECTIVE: For patients with atrioventricular block single lead atrial synchronous ventricular pacing (VDD) may have advantages compared to conventional dual chamber pacing (DDD) since it eliminates the need for an atrial lead. The purpose of this study was to investigate the clinical performance of a novel VDD pacemaker and the reliability of atrial sensing via the "floating' atrial electrode. METHODS: 31 patients (10 females; age 64 +/- 13 years) underwent an implantation of a VDD pacemaker system (Intermedics UNITY). The patients were analyzed with regard to implantation parameters, complications and postoperative atrial sensing performance using the diagnostic data of the pacemaker memory. The mean follow-up was 6.3 (1-18) months. RESULTS: The implantation procedure did not differ from that of conventional single chamber pacemakers. Dislocation of a ventricular electrode was the only complication observed. The P wave at implantation was 1.6 +/- 0.9 mV and dropped to 0.9 +/- 0.4 mV at predischarge. During follow-up the atrial sensing threshold remained stable. The atrial sensing performance (percentage of atrial synchronous ventricular complexes) after reprogramming the highest atrial sensitivity was 99.7%. Two patients (6%) developed atrial fibrillation. 29 patients (94%) remained in VDD mode as primarily intended. CONCLUSIONS: From these results it is concluded that VDD pacing represents an excellent alternative in patients with atrioventricular block and intact sinus node function. The atrial sensing was found to be reliable.

Pumpless extracorporeal lung assist - experience with the first 20 cases.

OBJECTIVE: Long-term extracorporeal lung assist is limited by a significant mechanical blood trauma resulting in bleeding and hemolysis. To reduce the drawbacks of extracorporeal lung assist a new technique has been developed, by which the driving force for the extracorporeal circuit derives from the patients arterio-venous pressure gradient (pumpless extracorporeal lung assist). The aim of this clinical study was to test the feasibilty and effectiveness of pumpless extracorporeal lung assist in patients with acute respiratory distress syndrome. METHODS: Twenty patients (41+/-16 years) with acute respiratory distress syndrome of various causes and failing respirator therapy were enrolled. The minimum hemodynamic requirements included a cardiac output (CO) >6 l/min and mean arterial pressure (MAP) >70 mmHg. Pumpless extracorporeal lung assist was established using a short circuit arterio-venous shunt including a special designed low-resistance membrane oxygenator which was placed between the patients legs. RESULTS: At the time of inclusion FiO(2) in all patients was 1.0 (paO(2) 45.9+/-7 mmHg, paCO(2) 58.9+/-17 mmHg). After 24 h of pumpless extracorporeal lung assist FiO(2) was reduced to 0.8+/-0.1. A significant improvement in oxygenation (paO(2) 84.1+/-21 mmHg, P<0.05) and CO(2) removal (paCO(2) 32.7+/-5 mmHg, P<0.05) was notable. The mean extracorporeal flow was 2.6+/-0.6 l/min, which represented approximately 25% of the patients mean CO (10.8+/-2 l/min). The median assist time was 12+/-8 (1-32) days. Fifteen out of twenty patients were weaned off pumpless extracorporeal lung assist. Five out of twenty patients died while on the system (four sepsis, one ventricular fibrillation). Three out of twenty patients died after successful weaning on day 8, 30, and 50, respectively. Twelve out of twenty patients were discharged in a healthy state (overall survival 60%). Technical problems included thrombosis of the venous cannula (n=5), thrombus formation within the membrane oxygenator (n=2), membrane oxygenator plasma leakage (n=2), and membrane oxygenator contamination with Candida albicans. No bleeding complication was observed. CONCLUSION: Pumpless extracorporeal lung assist is feasible and effective in a selected group of patients with acute respiratory distress syndrome but preserved hemodynamic function. By eliminating the pump and reducing the tubing length blood trauma can be minimized. Being very simple the system entails fewer risks of technical complications and also facilitates nursing care.

Multicenter results of TADpole heart wire system used to treat postoperative atrial fibrillation.

OBJECTIVE: Postoperative atrial fibrillation (AF) affects 20-30% of patients undergoing open-heart surgery, delays mobilization and impairs hemodynamics. Implantation of TADpole Heart Wires offers a new method of applying internal low-energy-shocks to terminate AF. The safety and efficacy of the TADpole system to treat postoperative AF was evaluated in this multicenter trial. METHODS: Two atrial wires, configured with a highly flexible 11.5 cm distal shocking and a 0.5 cm proximal pacing electrode were sutured onto the right and left atrium. Upon detection of AF, R-wave synchronized low-energy-shocks were administered via an energy attenuating External Defibrillator Interface Module or ICD programmer. RESULTS: A total of 296 patients (65+/-9.2 years, 74.7% male) have been enrolled to date in six European centers. The wire placement time was 4.2+/-2.2 min, 65 patients had a total of 83 episodes of AF treated by the TADpole Heart Wire system with a conversion rate of 88.5% (approximate energy of 6+/-2 J), early recurrence of AF was observed in ten patients (12.8%). No clinical complications were reported. The shocks were well tolerated with slight sedation. The ease of withdrawal was 2.3+/-1.2 on a graded scale of 0 (easy) to 10 (difficult). CONCLUSIONS: These multicenter results indicate that postoperative atrial cardioversion using TADpole Heart Wires is both safe and efficient. It is expected that hospital length of stay and its associated economic impact can be reduced with this therapy.

Cardiac interleukin-6 release and myocardial recovery after aortic crossclamping. Crystalloid versus blood cardioplegia.

BACKGROUND: Pro-inflammatory cytokines may play an important role in patient response to cardiopulmonary bypass (CPB). Since the myocardium is proposed to be a major source of cytokines, we studied the influence of the cardiolpegia type on interleukin-6 release and early myocardial recovery. EXPERIMENTAL DESIGN: prospective, randomized study. SETTING: university hospital, operative and intensive care. PATIENTS: 20 consecutive patients (3 females) scheduled for elective coronary artery bypass grafting (CABG), mean age 62.8+/-5 years, history of myocardial infarction 11/20, left ventricular ejection fraction 62.9+/-15%. INTERVENTIONS: patients were operated on using randomly either cold blood cardioplegia (B, n = 10) or cold crystalloid cardioplegia (C, n = 10). MEASURES: plasma levels of interleukin-6 (IL-6) were measured prior to CPB, after aortic declamping, after CPB, 1 hour, 6 hours and 12 hours postoperatively. RESULTS: Groups were comparable with respect to demographic data, left ventricular function, number of grafts, CPB and aortic crossclamp time. Group B patients demonstrated significant lower IL-6 levels after 1 hour (210+/-108 vs. 578+/-443 pg/ml), 6 hours (204+/-91 vs. 1210+/-671 pg/ml) and 12 hours (174+/-97 vs. 971+/-623 pg/ml). Post-CPB cardiac index was superior in group B (3.9+/-0.3 vs. 3.2+/-0.3 l/min/m2, p<0.05) with similar doses of inotropes. Group B patients could earlier be weaned off respirator (10+/-4 vs. 13+/-4 hours, p<0.05) and showed minor blood loss (635+/-211 vs. 918+/-347 ml, p<0.05). CONCLUSIONS: Inflammatory response to CPB is associated with delayed myocardial recovery. The use of blood cardioplegia may attenuate inflammatory reactions.

A new face of endocannabinoids in pharmacotherapy. Part I: protective role of endocannabinoids in hypertension and myocardial infarction.

Cannabinoids are compounds which were first isolated from the Cannabis sativa plant. For thousands of years they have been used for treatment of numerous diseases. Currently, synthetic cannabinoids and endocannabinoids are also known. Cannabinoid receptors, endocannabinoids and the enzymes that catalyze their synthesis and degradation constitute the endocannabinoid system which plays an important role in functioning of the cardiovascular system. The results obtained to date suggest the involvement of endocannabinoids in the pathology of many cardiovascular diseases, including myocardial infarction, hypertension and hypotension associated with hemorrhagic, endotoxic, and cardiogenic shock. Cardioprotective effect and dilation of coronary vessels induced by endocannabinoids deserve special attention. It cannot be excluded now that in the future our better understanding of cannabinoid system will allow to develop new strategies for treatment of cardiovascular diseases.

A new face of endocannabinoids in pharmacotherapy. Part II: role of endocannabinoids in inflammation-derived cardiovaascular diseases.

Endocannabinoids play an important role in cardiovascular diseases caused by inflammatory disorders. Endocannabinoids are endogenous bioactive lipids that activate cannabinoid receptors and together with enzymes responsible for their synthesis and degradation constitute endocannabinoid system. The results obtained to date suggest the involvement of endocannabinoids in the pathology of many cardiovascular diseases associated with inflammation, such as atherosclerosis, restenosis, chemotherapy-induced myocardial injury, diabetic and hepatic cirrhosis cardiomyopathy. Our better understanding of cannabinoid system may result in the development of new strategies for the treatment of such disorders.

Surface and intracardiac ECG for discriminating conduction disorders after CoreValve implantation.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has been developed to minimize operative morbidity and mortality in high-risk symptomatic patients unfit for open surgery. With the proximity of the aortic valve annulus to the conduction system there is, however, an unknown risk of conduction disturbances necessitating monitoring and often cardiac pacing. MATERIALS AND METHODS: We enrolled 50 consecutive patients from January 2007 to 2008 in our prospective evaluation of conduction disturbances measured by surface and intracardiac ECG recordings. Baseline parameters, procedural characteristics as well as twelve-lead surface ECG and intracardiac conduction times were revealed pre-interventionally, after TAVI and at 7-day follow-up. RESULTS: TAVI was performed successfully in all patients. During 7 days of follow-up the rate for first-degree AV block raised from 14% at baseline to 44% at day 7 (p < 0.001), while rates for type II second- and third-degree were 0 versus 8% (p < 0.001) and 0 versus 12% (p < 0.001), respectively. Similarly, the prevalence of new left bundle branch block (LBBB) rose from 2 to 54% (p < 0.001). Intracardiac measurements revealed a prolongation of both AH and HV interval from 123.7 ± 41.6 to 136.6 ± 40.5 ms (p < 0.001) and from 54.8 ± 11.7 to 71.4 ± 20.0 ms (p < 0.001), respectively. Pacemaker implantation at a mean follow-up of 4.8 ± 1.2 days was subsequently performed in 23 patients (46%) due to complete AV block (12%) and type II second-degree AV block (8%) while another 13 patients (26%) received a pacemaker for the combination of new LBBB with marked HV prolongation. The high rate of first-degree AV block was primarily driven by an increase in HV interval. CONCLUSION: Cardiac conduction disturbances were common in the early experience with CoreValve implantation necessitating close surveillance for at least 1 week.

[Percutaneous aortic valve replacement in high risk patients]. / Die perkutane Implantation von Aortenklappen bei Hochrisikopatienten.

The degenerative, calcified aortic stenosis is the most common form of adult valvular heart disease. Surgical aortic valve replacement is the method of choice and can be performed at low risk in suitable candidates. However, a fair amount of patients is rejected from surgery due to old age and preexisting comorbidities increasing operative mortality. For this reason frequently operation is not accomplished. Today, with the development of percutaneous aortic valve replacement, the treatment of aortic stenosis has entered a new era providing a new durable treatment option.

Direct minimally invasive intramyocardial injection of bone marrow-derived AC133+ stem cells in patients with refractory ischemia: preliminary results.

BACKGROUND: Bone marrow-derived stem cells (BMSC) may represent a viable option for patients with myocardial ischemia refractory to conventional treatments. MATERIAL AND METHODS: In 5 patients (4 males and 1 female, mean age 64 +/- 8 years) with untreatable angina pectoris (Canadian Cardiovascular Society Class III/IV), myocardial segments with stress-induced ischemia as assessed by gated single-photon emission computed tomography were injected with 4 to 12 million CD133+ BMSC. Cells were injected into the myocardium (2 anterior, 2 lateral, 1 inferior wall) through minimally invasive approaches (left minithoracotomy [n = 4] and subdiaphragmatic approach [n = 1]). At baseline, at 6 months and at 1 year of follow-up, an exercise test, gated single-photon emission computed tomography (SPECT), 2-D echocardiography and coronary angiography were performed to assess exercise capacity, myocardial perfusion, LV function and coronary anatomy. RESULTS: Intramyocardial injection of autologous CD133+ BMSC cells was safe. No early or long-term complications were observed. After an average of 3.8 weeks from cell inoculation, all patients experienced a significant improvement of CCS class (from 3.8 to 1.8 at 6 months) and serial SPECT documented improvements of rest and stress perfusion in the injected territories at 6 months from operation. In 3 cases, coronary angiography showed an increase in the collateral score of the target areas. Clinical improvements still persist unchanged in 4 out of 5 cases at a mean of 36.5 months postoperatively. CONCLUSIONS: After stand-alone BMSC transplantation for refractory myocardial ischemia, we observed long-term clinical and perfusion improvements in the absence of adverse events.

Alternatives to heart transplantation. Symposium of the "Treatment of End-stage Heart and Lung Failure" working group on October 22, 2005 in Munich.

Heart transplantation is currently the treatment of first choice in patients with end-stage refractory heart failure. But already the demand for donor organs cannot be met, and patients face long waiting times for transplantation. In the future waiting times will become even longer as life expectancy increases and the number of heart-failure patients requiring transplantation grows. Consequently, in view of the poor prognosis of the disease in its advanced stages, alternatives to heart transplantation are increasingly gaining importance. In recent years new innovative treatment methods and techniques have been developed which have already proved clinically successful in patients with end-stage heart failure, especially as bridging measures. Some of these techniques appear suitable for long-term use and could therefore serve as an alternative to heart transplantation in some patients. Interesting new avenues of research may even lead to cardiac cell replacement therapies in the future. These approaches are currently undergoing initial clinical trials. This report presents surgical and cardiologic treatments for end-stage heart failure that have already been clinically investigated as well as techniques that are still in the preclinical stage and discusses their potential as alternatives to heart transplantation.

Effect of closed minimized cardiopulmonary bypass on cerebral tissue oxygenation and microembolization.

OBJECTIVE: Coronary artery bypass grafting with cardiopulmonary bypass carries a risk for neurologic complications because of cerebral hypoperfusion and microembolization. The basic goals of a novel closed minimized extracorporeal circulation are to prevent excessive hemodilution and to avoid blood-air interface. The aim of this prospective randomized study was to determine the effect of using the minimized extracorporeal circulation system compared with open conventional extracorporeal circulation on cerebral tissue oxygenation and microembolization. METHODS: Forty patients undergoing coronary artery bypass grafting (20 in each group) were continuously monitored for changes in cerebral oxygenated hemoglobin and tissue oxygenation index by using near-infrared spectroscopy. Total microembolic count and gaseous embolic count in both median cerebral arteries were monitored with multifrequency transcranial Doppler instrumentation. RESULTS: In the conventional extracorporeal circulation group there was a highly significant reduction in both cerebral oxygenated hemoglobin and tissue oxygenation index from the start to the end of cardiopulmonary bypass (P < .01). The rate of decrease in cerebral oxygenated hemoglobin after aortic cannulation was faster in the conventional extracorporeal circulation group (F test = 9.03, P < .001). No significant changes with respect to cerebral oxygenated hemoglobin or tissue oxygenation index occurred in the minimized extracorporeal circulation group, except at the beginning of rewarming (P < .01). Total embolic count, as well as gaseous embolic count, in the left and right median cerebral arteries was significantly lower in the minimized extracorporeal circulation group (all P < .05). Postoperative bleeding was greater (P < .05) and the transfusion rate was higher (P < .05) in the conventional extracorporeal circulation group. CONCLUSIONS: Use of closed minimized cardiopulmonary bypass compared with conventional open cardiopulmonary bypass preserves cerebral tissue oxygenation and reduces cerebral microembolization.

[Diagnostic value of auto-capture: detection of lead dislocation]. / Diagnostische Nutzung von Autocapture: Detektion einer Sondendislokation.

Autocapture is a newly developed automatic threshold tracking algorithm implemented in implantable pacemakers. Based on the detection of the cardiac evoked response, autocapture continuously controls the effectiveness of stimulation. Increases in threshold are immediately followed by an adaption of the pulse amplitude. Automatic threshold tests periodically lower the amplitude in order to adapt to decreased thresholds. Thus, changes in threshold can be monitored over a long period and utilized as a diagnostic tool. This case report demonstrates the diagnosis and monitoring of a microdislodgement by means of autocapture.