Performance of the A-line Autoregressive Index (AAI) and of the Bispectral Index (BIS) at assessing depth of short-term sedation following cardiac surgery.

This study evaluated the correlation and agreement between the Bispectral Index (BIS) or A-line Autoregressive Index (AAI) and a clinical scoring system, the Ramsay Sedation Scale (RSS), in 40 patients after elective cardiac surgery and admission to the intensive care unit. All patients received sedation with propofol according to the study protocol. BIS, AAI and RSS were documented at two different levels of sedation: deep sedation RSS 4 - 6; and slight sedation/extubation RSS 2 - 3. Both the BIS and AAI agreed well with the RSS (eta-coefficients of 0.902 and 0.836, respectively, for mean overall RSS stages). The systems agreed well among each other (overall intra-class correlations of 0.670 for consistency and 0.676 for absolute agreement). There was significant discrimination between RSS 2 - 3 and RSS 4 - 6 with BIS and AAI (BIS mean difference of 24.73, 95% confidence intervals [CI] 21.08 - 28.37; AAI mean difference of 20.90, 95% CI 14.64 - 27.16). In conclusion, BIS and AAI correlated well with RSS overall and also at different levels of sedation.

Reduction in surgical site infection in patients treated with microbial sealant prior to coronary artery bypass graft surgery: a case-control study.

Surgical site infection (SSI) is a serious complication after cardiac surgery. This case-control study investigated the effect of a cyanoacrylate-based microbial skin sealant (InteguSeal) applied preoperatively on the SSI rate in patients undergoing coronary artery bypass graft (CABG) surgery. Of 676 patients who underwent CABG surgery with or without concomitant procedure(s) between March and November 2007, 545 received standard preoperative care and 131 also received pretreatment with the microbial sealant. Of these, 90 cases pretreated with microbial sealant and 90 controls were matched using established preoperative and intraoperative risk factors for SSI. Preoperative risk scores for SSI were 9.9+/-4.3 and 9.7+/-4.0 (P=0.747) for the microbial sealant and the control group, respectively, and combined preoperative-intraoperative risk scores were 9.7+/-4.1 and 8.7+/-3.5 (P=0.080), respectively. Carotid artery disease (P=0.019), congestive heart failure (P=0.019), acute myocardial infarction (P=0.001) and emergency surgery (P=0.026) were significantly more common in the microbial sealant group. Follow-up was 100% for both groups. Superficial or deep sternal infection 30 days post surgery developed in seven patients (7.8%) in the control group compared with one patient (1.1%) in the microbial sealant group (odds ratio 7.5). In summary, the inclusion of microbial sealant in preoperative patient preparation seems to reduce the incidence of SSI following CABG surgery; further larger studies are needed before firm conclusions can be drawn.

Recombinant activated factor VII for treatment of refractory hemorrhage after surgery for acute aortic dissection.

Despite appropriate treatment, surgery for aortic dissection is frequently associated with bleeding problems. In these series we report on the employment of recombinant activated factor VII (rFVIIa) for refractory hemorrhage after emergency surgery for acute type A aortic dissection, used to face the problems of postoperative blood loss and transfusion requirements. Despite the good results of the therapy, a patient presented with thrombosis of the left cavernous sinus. Although a risk of thromboembolic complications has to be considered, rFVIIa is a reasonable rescue option in life-threatening hemorrhage and enlarges our hemostatic armamentarium in surgery for acute aortic dissection.

Clinical experience with the 3F stentless aortic bioprosthesis: one-year follow up.

BACKGROUND AND AIM OF THE STUDY: The 3F equine aortic bioprosthesis is a new stentless valve which is currently undergoing evaluation in a multicenter clinical trial and is considered to have superior hemodynamic performance. Herein is reported the authors' initial experience with the 3F valve, focusing on the hemodynamic performance of the device. METHODS: Between March 2002 and October 2003, 35 patients (age range 61-86 years) underwent aortic valve replacement with the 3F valve implanted in the subcoronary position. Evaluation of valve hemodynamic performance was assessed at discharge (postoperative day 5 +/- 2), at 3-6 months, and at 11-14 months' follow up by means of transthoracic echocardiography. The mean preoperative transvalvular pressure gradient was 63 +/- 14 mmHg. Before surgery, all patients were in NYHA class III or IV, despite aggressive medical treatment. Five patients underwent concomitant coronary artery bypass grafting. RESULTS: The implanted valve sizes ranged from 21 to 29 mm. There were no operative deaths and no major perioperative complications. After 12 months, mean pressure gradients for the 23-, 25-, 27- and 29-mm valves were 13, 13, 12 and 9 mmHg, respectively. Mean systolic pressure gradients and NYHA class were improved significantly after surgery. Mild signs of hemolysis and minimal central regurgitation were detected in some patients, but were of no clinical importance. Valve dysfunction or mechanical failure did not occur during the follow up period. CONCLUSION: Because of its flexible structure, the 3F aortic bioprosthesis is simple to implant, and no major adverse effects have been associated with such valve implantation at the authors' center. Transprosthetic gradients appeared to regress at 6-12 months' follow up. The durability of the device is yet to be established in ongoing long-term trials.

Is there a possibility for a glutaraldehyde-free porcine heart valve to grow?

OBJECTIVE: A challenging issue is to create a heart valve with growth and remodeling potential, which would be of great interest for congenital heart valve surgery. This study was performed to evaluate the growth and remodeling potentials of a decellularized heart valve. METHODS: In 4 juvenile sheep (age 12 +/- 1 weeks) with a weight of 24.3 +/- 4.4 kg, a 17-mm diameter decellularized porcine valve was implanted as pulmonary valve replacement. Valve growth was evaluated by transthoracic echocardiography. At explantation, valves were evaluated by gross examination, light microscopy (hematoxylin and eosin, von Kossa, Sirius red, Weigert and Gomori staining), electron microscopy and immunohistochemistry. Atomic absorption spectrometry was performed to evaluate calcium content. RESULTS: All animals showed fast recovery. The mean follow-up was 9.0 +/- 1.8 months. All sheep at least doubled their weight (54.3 +/- 9.2 kg). Echocardiography showed no regurgitation and a flow velocity of 0.7 +/- 0.1 m/s at the latest follow-up. The valve diameter increased from 17.6 +/- 0.5 to 27.5 +/- 2.1 mm (p < 0.018). Gross examination showed a similar wall thickness of the implanted valve and native pulmonary wall, with smooth and pliable leaflets. Histology showed a monolayer of endothelial cells, fibroblast ingrowth and production of new collagen. No calcification was seen at von Kossa staining, confirmed by low calcium content levels of the valve wall and leaflets at atomic absorption spectrometry. CONCLUSIONS: This glutaraldehyde-free heart valve showed not only the absence of calcification, but also remodeling and growth potential.

Intensive care unit stay of more than 14 days after cardiac surgery is associated with non-cardiac organ failure.

Some studies have shown an association between a prolonged intensive care unit (ICU) stay and risk factors such as mediastinal re-exploration, advanced age, low ejection fraction, lung disease and organ failure. The aim of this retrospective study was first to evaluate peri-operative risk factors (n = 2683) and secondly to evaluate long-term survival (n = 2563) in cardiac surgery patients with an ICU stay > 14 days. Long-term survival was assessed in an observational 3-year follow-up study. An ICU stay of > 14 days was associated independently with respiratory failure and dialysis-dependent acute renal failure, and with a significantly lower survival rate. Since an ICU stay is associated with a higher hospital and long-term mortality, measures should be taken throughout the entire hospital stay to identify and reduce the risk of organ failure.

Aspirin and clopidogrel taken until 2 days prior to coronary artery bypass graft surgery is associated with increased postoperative drainage loss.

OBJECTIVE: Platelet aggregation inhibitors, such as aspirin and clopidogrel, are associated with increased bleeding in patients undergoing cardiac surgery with cardiopulmonary bypass. We investigated the impact of time between the last intake of aspirin and clopidogrel before CABG surgery and drainage loss, transfusion requirements and rate of reoperation. PATIENTS AND METHODS: The records of patients who had coronary artery bypass graft surgery (CABG) were reviewed for intake of aspirin and clopidogrel within 7 days prior to surgery. Drainage loss, transfusion requirements and rate of reoperation for bleeding within 5 days after the operation, were recorded. RESULTS: Out of 261 analysed patients, 225 patients (86.2 %) had no anti-platelet medication and 36 patients (13.8 %) were on aspirin and clopidogrel. Aspirin and clopidogrel, taken all until 2 days prior to operation, were associated with a significantly higher postoperative blood loss (1840 mL [1230 - 3710] vs. 280 mL [185 - 765], p = 0.005 for one day and 850 mL [345 - 1725] vs. 277 mL [165 - 778], p = 0.026, for 2 days prior to surgery). The trend showed that patients in the study group received more platelet concentrates (PC: 5.3 % vs. 13.9 %, p = 0.067). The rate of reoperation for bleeding was not different ( p = 0.25). CONCLUSION: Aspirin and clopidogrel up to 2 days prior to CABG were associated with a significantly higher postoperative drainage loss.

Impact of implantation technique on hemodynamic results of the Pericarbon Freedom stentless valve.

BACKGROUND: The Pericarbon Freedom stentless valve has shown excellent hemodynamic results in the midterm course. However, there is no information as to whether a continuous or interrupted suture technique at the inflow site has an impact on postoperative hemodynamics. METHODS: 139 patients were enrolled in a non-randomized, prospective matched trial. An interrupted suture line technique was used in 68 patients and a continuous suture line technique was used in 71 at the inflow site. Isolated valve replacement was performed in 70.4% of the continuous and 67.6% of the interrupted suture group. Pre- and postoperative hemodynamics and one-year follow-up were obtained by echocardiography and expressed as mean and peak gradients and grade of regurgitation. RESULTS: No significant difference between continuous and interrupted suture techniques were noted with respect to mean (11.8 +/- 6.3 vs. 12.5 +/- 6.2 mm Hg, p = 0.251) and peak gradients (21.0 +/- 9.6 vs. 22.0 +/- 10.9 mm Hg, p = 0.292) as well as to the degree of regurgitation. Bypass and cross-clamping times decreased by 22.4 and 20.6 minutes, respectively, with the use of the continuous suture technique. One year follow-up showed a further, significant decrease of mean and peak gradients. CONCLUSIONS: The Pericarbon Freedom stentless valve appears to offer excellent postoperative performance. The suture line technique at the inflow site does not result in any hemodynamic differences.

[Surgery for congestive heart failure--the role of computed tomography in the pre- and postoperative diagnostic evaluation]. / Chirurgie der Herzinsuffizienz -- Stellenwert der Computertomographie in der prä- und postoperativen Diagnostik.

The treatment of advanced, drug resistant congestive heart failure gains in importance in the field of cardiac surgery. Cardiac imaging for preoperative assessment and follow-up focuses on the determination of ventricular volumes and function as well as on the detection of postoperative complications. Computed tomography (CT) is highly accurate irrespective of the individual patient's anatomic situation, has a low examiner dependence and short examination time, does not require an arterial vascular access and can be performed in patients with metal implants. CT is the modality of choice in the follow-up of heart transplants to detect extracardiac and cardiac complications including coronary calcifications as an early sign of transplant vasculopathy. In addition, CT visualizes the elements of mechanical assist devices and can identify their possible local cardiac and mediastinal complications. CT can detect fibrolipomatous involution of the mobilized muscle flap in dynamic cardiomyoplasty and can depict fibrous reactions along the epicardial mesh implant in passive cardiac containment. Further indications include assessment of typical local postoperative complications, such as intrathoracic infection and mediastinal bleeding, intracardiac thrombus formation or pericardial effusion. CT is routinely used for evaluating bypass patency but is limited in assessing associated valve defects since it does not visualize flow.

Results of a decellularized porcine heart valve implanted into the juvenile sheep model.

OBJECTIVE: This study was performed to evaluate the possibility of creating a glutaraldehyde-free porcine xenograft to improve long-term durability. METHODS: A decellularized porcine pulmonary valve was implanted into the right ventricular outflow tract of 7 juvenile sheep. Valves were explanted after 3 months (n = 4) and 6 months (n = 3). Evaluation was performed by gross examination, radiography, histology (hematoxylin-eosin and Sirius red staining), and immunohistochemistry. Quantitative determination of calcium content was investigated by atomic absorption spectrometry. RESULTS: All animals showed fast recovery without complications. At explantation, all decellularized valves showed smooth and pliable leaflets without evidence of thrombosis. The valve wall was also smooth and pliable without hardness. Light microscopy showed a monolayer of host endothelial cells covering the inner surface of the heart valves and repopulation of host fibroblasts into the deeper layers. Sirius red staining enabled visualization of the production of new collagen. Radiographic results showed an absence of calcification, confirmed by the low calcium levels (1.08 +/- 0.28 microg/g and 0.73 +/- 0.31 microg/g at 3 and 6 months, respectively) revealed by atomic absorption spectrometry. CONCLUSIONS: The results with the juvenile sheep model showed that decellularized heart valves are recellularized in vivo. Host endothelial cells form a monolayer on the inner surface of the valve matrix. Furthermore, host fibroblasts repopulate the valve matrix and produce collagen; thus, a remodeling potential can be expected.

Splanchnic oxygen transport, hepatic function and gastrointestinal barrier after normothermic cardiopulmonary bypass.

BACKGROUND: The effect of non-pulsatile, normothermic cardiopulmonary-bypass (CPB) on the splanchnic blood-flow and oxygen-transport, the hepatic function and the gastrointestinal barrier were observed in a prospective observational study in 31 adults undergoing cardiac valve replacement surgery. METHODS: The splanchnic (i.e. hepatic) blood-flow (HBF) was measured by the constant infusion of indocyanine-green (ICG) using a hepatic-venous catheter. Liver function was examined by calculation of lactate uptake, ICG extraction and the monoethylglycinexylidide (MEGX) test. A day before and after surgery the gastrioduodenal and intestinal permeability was measured by determination of sucrose and lactulose/mannitol excretion. RESULTS: Splanchnic blood flow and oxygen delivery did not decrease during and after surgery while splanchnic oxygen consumption (P < 0.0125) and arterial lactate concentrations increased. The splanchnic lactate uptake paralleled the lactate concentration. After but not during CPB an increase of systemic oxygen consumption was observed. The MEGX test values decreased on the first day after surgery. The ICG extraction was attenuated during the operation. The gastroduodenal and the intestinal permeability increased significantly postoperatively (P < 0.002, respectively, P < 0.001). There was no correlation between these findings and the duration of CPB. There was a significant correlation of the intestinal permeability but not of the gastroduodenal permeability between the prior and after surgery values (P < 0.001). CONCLUSION: Increased oxygen consumption during CPB may indicate an inflammatory reaction due to the pump beginning in the splanchnic area or a redistribution of the splanchinc blood flow during the CPB. Normothermic CPB does not lead to a significant or prolonged reduction of liver function. Normothermic CPB causes an increase of gastrointestinal permeability. The intestinal barrier function prior to surgery was accountable for the degree of loss of intestinal barrier function following surgery.

[Evaluation of passive cardiomyoplasty using left- and right-ventricular volume measurements by EBCT and MRI in patients with chronic congestive heart failure]. / Evaluierung der passiven Kardiomyoplastie mittels links- und rechtsventrikulärer EBCT- und MRT-Volumetrie bei Patienten mit chronischer Herzinsuffizienz.

PURPOSE: To evaluate the efficacy of passive cardiomyoplasty with the determination of biventricular volumes, global systolic function as well as left-ventricular muscle mass. MATERIALS AND METHODS: In 19 patients with congestive heart failure of idiopathic or ischemic origin, a polyester mesh-graft was implanted around both ventricles for stabilization and functional support. Before and three months after surgery, 15 patients underwent EBCT and 4 patients with impaired renal function underwent MRI, for the evaluation of the volume and ejection fraction of both ventricles. RESULTS: EBCT demonstrated a decrease from 385 to 310 ml in LV-EDV, from 312 to 242 ml in LV-ESV, from 209 to 160 ml in RV-EDV and from 149 to 87 ml in RV-ESV, and an increase from 20 to 26% in LV-EF and from 37 to 50% in RV-EF as well as a reduction of LV-MM from 300 to 274 g (p < 0.05 each). Similar results were obtained by MRI. CONCLUSION: Following passive cardiomyoplasty, EBCT and MRI revealed an improvement of the global systolic function as well as a reduction of biventricular volumes and left-ventricular muscle mass.

Quality management system of a university cardiac surgery department according to DIN EN ISO 9001 : 2000.

BACKGROUND: A quality management system (QMS) will improve quality in health care units. This report describes the introduction of a QMS according to ISO 9001:2000 in a university cardiovascular surgery department. METHODS: First, a thorough analysis of all processes of patient treatment and clinical research was obtained. Multiple interfaces were defined to different departments as well as to administration units. We evaluated and optimized all necessary resources, evaluating customer satisfaction using patients' and referring physicians' surveys. We started quality rounds including surgeons, nurses and technicians. Based on this preparation, we redefined and explained all processes including their responsibilities and necessary resources in the quality manual. RESULTS: After a process of 18 months, an independent, accredited organization recommended that our QMS be given certification according to ISO 9001:2000. CONCLUSIONS: Certification of a university cardiovascular surgery department according to ISO 9001:2000 is possible, and may represent the first step towards total quality management (TQM). In complex health care units, certification of separate departments may help generate a consciousness of quality on the way to TQM.

Effect of piracetam on cognitive performance in patients undergoing bypass surgery.

In this study, the protective effect of piracetam on select aspects of cognitive function in patients undergoing bypass surgery was investigated. Male patients (n = 64) with an indication for a surgical revascularization using artificial extracorporal circuits were randomly assigned in a double-blind fashion to receive a single challenge of 12-g piracetam infusion or placebo (sterile saline) prior to the bypass surgery. A brief battery of neuropsychological tests for verbal and non-verbal short-term memory and attention was administered 1 day before and 3 days after the surgical intervention. There was a significant difference in short-term memory and attention, with the piracetam-treated patients producing a better level of performance 3 days after surgery compared to the placebo group. The overall postoperative cognitive function (z-transformation of all 6 test results) was more significantly (p < 0.001) reduced in the placebo group than in the piracetam group (z = -1.19 +/- 0.72 vs. -0.46 +/- 0.58, respectively). A single challenge of 12-g piracetam infusion prior to surgical intervention might offer a short-term neuroprotective effect for patients undergoing cardiac bypass surgery. Whether this effect persists for a longer period of time requires further investigation.

Reoperation in a Jehovah's Witness 22 years after aortic allograft reconstruction of the right ventricular outflow tract.

We report the case of a 29-year-old male Jehovah's Witness who presented with hemolysis and right heart failure as a consequence of extreme calcification of an aortic valve-containing allograft and Dacron prosthesis that had been placed 22 years earlier to repair tetralogy of Fallot. Reoperation had been denied by several other centers, because of the patient's refusal to undergo blood transfusion. For 2 weeks preoperatively, we raised the patient's hemoglobin level by treating him with recombinant erythropoietin, oral iron, and folic acid. At surgery, under normothermic cardiopulmonary bypass, we replaced the aortic allograft in the right ventricular outflow tract with a cryopreserved pulmonary allograft, also containing a valve. The postoperative course was uneventful, and the patient was released from the hospital on the 13th postoperative day in excellent condition.

Effects of different steroid treatment on reperfusion-associated production of reactive oxygen species and arrhythmias during coronary surgery.

BACKGROUND: During conventional cardiac surgery ischemia and reperfusion may cause excessive production of reactive oxygen species leading to tissue damage including early arrhythmias. We therefore assessed the kinetics of markers of radical stress including oxidized and reduced glutathione (GSSG/GSH), oxidized proteins (PCG) and malondialdehyde (MDA), and tested the hypothesis that different steroid treatments inhibit these markers and early reperfusion-associated supraventricular and ventricular extrasystolic beats. METHODS: In a randomized, controlled, blinded, prospective trial 36 patients received a preoperative infusion of methylprednisolone (MP, 15 mg kg-1, n = 12), tirilazad mesylate (TM, 10 mg kg-1, n = 12) or placebo (PL, NaCl, n = 12). Coronary sinus and arterial blood was drawn at baseline and 2, 5, 15, 30, 60 and 240 min after aortic declamping. Holter-ECG analysis was used to identify arrhythmias. RESULTS: Cardiac GSSG release occurred very early (< 15 min) and was not significantly attenuated by either drug treatment. Cardiac PCG production showed biphasic increases, lasted > 4 h and was significantly reduced only by TM. Cardiac MDA release was short (< 30 min) and significantly reduced by MP and TM. Neither treatment had a significant influence on the early occurrence of ventricular or supraventricular arrhythmias. The number of patients needing cardioversions or defibrillations also were not different. CONCLUSIONS: The results indicate that cardiac production of reactive oxygen species occurs after reperfusion in humans and is not inhibited by steroid treatment. Steroid treatment effectively reduces lipid peroxidation during cardiac surgery but has no influence on arrhythmias.

A critical evaluation of results of partial left ventriculectomy.

BACKGROUND: Because of the variation in the surgical procedures designed to reduce ventricular radius, along with differences in hospital care, it is difficult to disentangle the factors that may contribute to the success or failure of the partial left ventriculectomy. METHODS AND RESULTS: We undertook partial left ventriculectomy in 18 patients, 10 suffering from idiopathic dilated cardiomyopathy and 8 from ischemic heart disease. We assessed the amount of reduction in wall stress, the systolic thickening of the ventricular wall, and the extent of connective tissue in the excised segment of the wall. Of the overall group, six patients died, three from infarction, one of stroke, one with asystole, and one with ventricular fibrillation. The mean decrease in measured mesh tension was 40% (p < 0.001). Most patients exhibited improvements postoperatively in terms of the systolic thickening of the posterior and superior free walls of the left ventricle. In those in whom the events could be monitored, life-threatening arrhythmias posed complications in three of four patients with ischemic heart disease, and in two of six patients suffering from idiopathic dilated cardiomyopathy. In one patient, death was associated with a transmural alignment of fibrous tissue. CONCLUSIONS: Our measured reductions in myocardial mesh tension were in keeping with the anticipated theoretical reduction in wall stress expected from partial ventriculectomy. The basic concept underscoring surgical maneuvers to reduce ventricular radius, therefore, is sound. A potential trap is the resection of the marginal artery. Critical myofibrosis was a rare complication. Arrhythmias, which are common, can successfully be treated by implantation of antitachycardic and defibrillatory devices.

Visualization of the pulmonary valve using cine MR imaging.

PURPOSE: To evaluate the capability of bright-blood cine MR to directly visualize the leaflets of the valve replacement in pulmonary position following Ross operation. MATERIAL AND METHODS: Long and short axis views of the pulmonary valve were obtained in 10 normal subjects and 14 patients after Ross operation. Valve morphology and function were analyzed and signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were calculated. Flow measurements were performed in the pulmonary trunk to assess pulmonary regurgitation. RESULTS: In all subjects, tricuspid morphology of the pulmonary valve was visualized. SNR of the leaflets in normal subjects (9.8 +/- 3.0) and in patients after Ross operation (7.5 +/- 2.2) differed significantly from blood (12.6 +/- 3.2 and 11.3 +/- 2.5, respectively, p < 0.05). Valvular regurgitation was seen in 5 patients as an insufficient closure of the valve which was confirmed by flow measurements. CONCLUSION: Cine MR enables in-plane visualization of the pulmonary valve and allows for functional and morphological evaluation in patients after pulmonary valve surgery.