Anesthetic Considerations for an Adult Patient with Freeman-Sheldon Syndrome Undergoing Open Heart Surgery.

Freeman-Sheldon syndrome (FSS) or "whistling face" syndrome is a rare congenital disorder complicated by characteristic facial deformities and muscular contractures. We report on a 64-year-old male patient presenting for surgical replacement of his aortic valve and review the available literature on anesthetic considerations and perioperative management principles. FSS frequently poses a significant challenge to airway management and gaining vascular access. Moreover, these patients are reportedly at risk for developing malignant hyperthermia (MH) or neuroleptic malignant syndrome.

Use of methylene blue in the treatment of refractory vasodilatory shock after cardiac assist device implantation: report of four consecutive cases.

Vasodilatory shock frequently occurs after cardiac surgery, particularly after cardiac assist device implantation. This complication is often associated with high mortality, especially if refractory to conventional vasoconstrictor treatment. Methylene blue, a guanylate cyclase inhibitor, has been successfully used in the management of vasodilatory shock associated with cardiopulmonary bypass. We present four successive cases after implantation of cardiac assist devices suffering from norepinephrine and vasopressin refractory severe vasodilatory shock. In all patients, administration of a single dose of methylene blue (2 mg/kg body weight) resulted in an immediate and persistent decrease in vasoconstrictor dosages and serum lactate concentrations. Despite of this benefit, all patients deceased during hospital stay, however, this was not related to the methylene blue treatment. Methylene blue seems to be a promising therapeutical option in patients with otherwise resistant vasodilatory shock after cardiac assist device implantation. However, controlled clinical trials are necessary to substantiate safety and efficacy.

Effect of anaesthesia and cardiopulmonary bypass on blood endocannabinoid concentrations during cardiac surgery.

BACKGROUND: The endocannabinoid system (ECS) is an endogenous signalling system which includes the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) and specific G-protein-coupled endocannabinoid receptors (CB1 and CB2). Recent studies have described important roles of the peripheral ECS in human atherosclerosis, cardiometabolic disorders, heart failure, and systemic inflammation. We sought to study changes in plasma endocannabinoid concentrations during cardiac surgery (CS) under general anaesthesia with isoflurane/sufentanil, and during cardiopulmonary bypass (CPB). METHODS: We studied 30 patients undergoing CS with CPB. All patients received midazolam and sufentanil for induction and isoflurane and sufentanil for maintenance of general anaesthesia. Blood samples were drawn before and after induction of general anaesthesia, after the beginning of surgery, during and after weaning from CPB, and after admission to intensive care unit (ICU) after surgery. Endocannabinoid measurements were performed by HPLC-tandem mass spectrometry. RESULTS: Induction of general anaesthesia led to a significant decline in plasma AEA concentrations [from mean (sd) 0.39 (0.03) to 0.27 (0.03) ng ml(-1), P<0.01]. CPB induced a pronounced increase in 2-AG concentrations [from 112.5 (163.5) to 321.0 (120.4) ng ml(-1), P<0.01], whereas AEA concentrations remained persistently low until admission to the ICU. 2-AG concentrations returned to preoperative values after surgery. CONCLUSIONS: General anaesthesia with isoflurane significantly reduces plasma AEA concentrations. This could be a consequence of stress reduction after loss of consciousness. The significant increase in 2-AG after initiation of CPB may be part of an inflammatory response. These findings suggest that anaesthesia and surgery have differential effects on the ECS which could have substantial clinical consequences.

Multidrug-resistant gram-positive infections in patients with ventricular assist devices: the role of daptomycin.

OBJECTIVES: The rate of infection in patients who require ventricular assist devices (VADs) is estimated at more than 35%. Infections with multidrug-resistant (MDR) organisms in VAD recipients present a high mortality rate. Daptomycin (Cubicin, Novartis, Nuremberg, Germany), a new cyclic lipopeptide antibiotic, is useful for MDR gram-positive organisms. We report the successful use of daptomycin in patients presenting with MDR gram-positive infections after VAD implantation. METHODS: We retrospectively studied nine consecutive patients presenting with resistant gram-positive infections after VAD implantation treated with daptomycin. We analyzed type of VAD, type of infection, responsible microorganism, outcome, and adverse events. RESULTS: We studied nine patients (eight males, one female), of overall mean age of 51 +/- 8 years; 78% required a biventricular assist device or a left VAD (Berlin Heart, Berlin, Germany), 22% received other ventricular support. Sixty-six percent presented with catheter-related infections (CRIs). Therapy with daptomycin was empirically initiated in all cases. The initial dose was 6 mg/kg, continued at 4 mg/kg. The mean duration of therapy was 16 +/- 5 days. The reported pathogens were MRSA, 33%; E. faecium, 25%; methicillin-resistant staphylococcus epidermidis, 12.5%; methicillin-sensitive staphylococcus aureus, 12.5%; others, 17%. Successful outcomes were reported in seven subjects (78%), with two patients succumbing due to multiorgan failure related to their heart condition prior completing antibiotic therapy. No adverse events were reported. CONCLUSIONS: Among our VAD patients, daptomycin proved efficient as a therapy for CRI with bacteremia. However, controlled studies are necessary to evaluate this antibiotic in patients presenting with VAD and MDR bacteremia.

Interventional closure of two fistulas after aortic valve surgery.

INTRODUCTION: Paravalvular fistulas may complicate the clinical course after heart valve surgery. Medical treatment may be ineffective, repeated surgical revisions may be associated with increased morbidity and mortality. CASE REPORT: After valve sparing surgery in bicuspid aortic valve, a significant aorto-left atrial fistula was diagnosed in a 72-year-old patient causing heart failure and catecholamine-dependency. Due to the critical hemodynamic state, percutaneous closure was performed with an AGA Amplatzer duct occluder. Secondary to this closure, a second fistula between the aortic root and the right atrium appeared which was closed during the same procedure implanting a second duct occluder beneath the first device. CONCLUSION: Percutaneous closure of paravalvular fistulas is feasible and a safe method for the treatment of significant shunts after valve surgery. Even in multiple fistulas, the implantation of small devices allows for a focussed interventional closure of such leaks. This procedure should be considered for such defects as it represents a safe method for the causative treatment in paravalvular lesions after valve surgery especially in patients with critical hemodynamic conditions.

Successful ABO-incompatible heart transplantation in a child despite blood-group sensitization after ventricular assist device support.

In the first two yr of life blood-group incompatible (ABO-incompatible) heart transplantation can be performed leading to immune tolerance to donor blood group. Antibody titers should be below 1:4. VAD use is correlated with sensitization toward blood-group antigens. A boy was diagnosed with dilated cardiomyopathy at nine months of age and listed for 0-compatible transplantation. Progressive heart failure required implantation of a left VAD. His listing was extended for ABO-incompatible transplantation despite antibody titers of 1:32 anti-A and 1:8 anti-B. After 26 days on VAD, he was transplanted with a B donor heart. No hyperacute or acute rejection occurred in 12 months post-transplant. Anti-B antibodies rose to a maximum of 1:2. No use of rituximab or plasmapheresis was required. There are no signs of graft vasculopathy. This indicates that inclusion criteria for ABO-incompatible transplantation may be extended to immediate cases. This is the first case with a healthy immune system to show signs of tolerance development after ABO-incompatible heart transplantation with increased prior antibody titers and without specific treatment.

Design and fabrication of three-dimensional scaffolds for tissue engineering of human heart valves.

We developed a new fabrication technique for 3-dimensional scaffolds for tissue engineering of human heart valve tissue. A human aortic homograft was scanned with an X-ray computer tomograph. The data derived from the X-ray computed tomogram were processed by a computer-aided design program to reconstruct a human heart valve 3-dimensionally. Based on this stereolithographic model, a silicone valve model resembling a human aortic valve was generated. By taking advantage of the thermoplastic properties of polyglycolic acid as scaffold material, we molded a 3-dimensional scaffold for tissue engineering of human heart valves. The valve scaffold showed a deviation of only +/-3-4% in height, length and inner diameter compared with the homograft. The newly developed technique allows fabricating custom-made, patient-specific polymeric cardiovascular scaffolds for tissue engineering without requiring any suture materials.

Creation of ventricular septal defects on the beating heart in a new pig model.

BACKGROUND/AIMS: So far, surgical and interventional therapies for muscular ventricular septal defects (mVSDs) beyond the moderator band have had their limitations. Thus, alternative therapeutic strategies should be developed. We present a new animal model for the evaluation of such strategies. METHODS: In a pig model (n = 9), anterolateral thoracotomy was performed for exposure of the left ventricle. mVSDs were created under two- and three-dimensional echocardiography with a 7.5-mm sharp punch instrument, which was forwarded via a left ventricular puncture without extracorporeal circulation. RESULTS: Creation of mVSDs was successful in all animals (n = 9) confirmed by echocardiography, hemodynamic measurements and autopsy. The defects were located in the midmuscular (n = 4), apical (n = 1), inlet (n = 2) and anterior part (n = 2) of the muscular septum. All animals were hemodynamically stable for further procedures. The diameter and shunt volume of the mVSDs were 4.8-7.3 mm (mean: 5.9 mm) and 12.9-41.3% (mean: 22.1%), respectively. Autopsy confirmed in all animals the creation of a substantial defect. CONCLUSION: The described new technique for creation of an mVSD on the beating heart in a pig model is suitable for the evaluation of new therapeutic strategies for mVSD closure.

Cardiac transplantation in a 14-yr-old patient with mitochondrial encephalomyopathy.

We report a rare case of a successful cardiac transplantation in a patient suffering from cardiomyopathy and complex mitochondrial disease. The patient presented with severe heart failure and malignant ventricular arrhythmias requiring implantation of a defibrillator and advanced medical treatment. The patient was listed for urgent heart transplantation and received a donor heart after 36 days. One yr post-operatively, the patient has completely recovered.

Surgical management in paediatric patients with left abnormal subclavian artery and right aortic arch.

Left abnormal subclavian artery and right aortic arch is described as a rare cause of dyspnoea and dysphagia in paediatric patients. The optimal surgical management of such cases is not clearly established. We propose a single-stage repair by transection of the patent ductus arteriosus or ligamentum arteriosum and an additional transection of the left abnormal subclavian artery with reimplantation into the common carotid artery.

Successful single lung fontan operation in 2 children: case reports.

We report on 2 children, aged 3 and 4 years, with single ventricle physiology who underwent Fontan operation in the presence of a single right lung successfully with good midterm outcome. Therefore, the absence of one lung is not a contraindication for a Fontan palliation in selected patients with optimal hemodynamics.

Late-onset tacrolimus-associated cerebellar atrophia in a heart transplant recipient.

Tacrolimus is a macrolide immunosuppressant frequently used after solid-organ transplantation. Moderate and severe neurologic side effects have been reported in patients receiving tacrolimus. Cerebral neurotoxicity is a rare but fatal calcineurin inhibitor-related complication, especially in kidney and liver transplant recipients. Often a reduction or a change in immunosuppressive regimen is the only means of clinical management. Herein we report a case of a 31-year-old man who developed cerebellar atrophia while under immunosuppressive therapy 9 years after heart transplantation. His neurologic constitution ameliorated after an immunosuppressant switch from tacrolimus to sirolimus.

Tissue engineering of vascular conduits: fabrication of custom-made scaffolds using rapid prototyping techniques.

BACKGROUND: The technique of stereolithography, which automatically fabricates models from X-ray computed tomography or magnetic resonance imaging (MRI) data linked to computer-aided design programs, has been applied to the fabrication of scaffolds for tissue engineering. We previously reported on the application of stereolithography in scaffold fabrication of a trileaflet heart valve. In our current experiment we demonstrate a new technique for the fabrication of custom-made conduits for the potential replacement of a coarcted aortic segment. METHODS AND RESULTS: In this experiment the image data derived from a 12-year-old male patient with aortic coarctation scanned by MRI were processed by a computer-aided design program to reconstruct the aortic arch with isthmus stenosis three dimensionally. By defining the stenotic section and the adjacent normal vessel a custom-made nonstenotic descending aorta was reconstructed to replace the stenosed part. The rapid prototyping technique was used to establish stereolithographic models for fabricating biocompatible and biodegradable vascular scaffolds with the anatomic structure of the recalculated human descending aorta through a thermal processing technique. CONCLUSION: Our results suggest that the re-creation and reproduction of complex vascular structures by computer-aided design techniques may be useful to fabricate custom-made polymeric scaffolds for the tissue engineering of living vascular prostheses.

[Coronary artery bypass grafting in patients with highly impaired ventricular function. Long-term outcome]. / Koronarbypassoperation bei hochgradig eingeschränkter Ventrikelfunktion - Langzeitergebnisse.

BACKGROUND AND OBJECTIVE: Left ventricular function is the most important predictor of survival in patients with coronary artery disease. It is also an important indicator for hospital mortality after operation for end-stage coronary artery disease. In our study we investigated, how preoperative ventricular dysfunction influences long term survival after coronary bypass surgery. PATIENTS AND METHODS: Between 4/1986 and 12/2000, 1751 patients (1440 men/311 women) with left ventricular ejection fraction (LVEF) 10-30% underwent coronary bypass grafting (CABG) at the Deutsches Herzzentrum Berlin. The age of the patients was calculated to an average of 59,2 years. The prime criterion for CABG was ischemia ("hibernating myocardium") diagnosed by myocardial scintigraphy, echocardiography and in some cases with magnetic resonance imaging and positron emission tomography. RESULTS: Operative mortality for the group was 7,1%. The actuarial survival rate was 87,6% after 2 years, 76,0% after 5, and 53,3% after 9. 455 had LVEF 10-20%, in these actuarial survival was 79,8% after 2 years, 63,0% after 5 and 45,7% after 9 years. CONCLUSION: We conclude that CABG can be used successfully to improve life expectancy of patients with end-stage coronary artery disease. CABG leads to acceptable prognosis for these high-risk patients when the myocardium is preoperatively identified as being viable.

Decreased plasma concentration of brain natriuretic peptide as a potential indicator of cardiac recovery in patients supported by mechanical circulatory assist systems.

OBJECTIVES: We sought to investigate the relationship between the plasma concentration of brain natriuretic peptide (BNP), echocardiographic findings and the clinical outcome of patients supported with ventricular assist devices (VADs) to determine the role of BNP as a predictor for cardiac recovery. BACKGROUND: Ventricular unloading in patients with end-stage heart failure supported by VADs may lead to myocardial recovery. The BNP is produced in the myocardium in response to chronic volume overload, but the effects on it of ventricular unloading by VADs are largely unknown. METHODS: Twenty-one patients diagnosed with nonischemic cardiomyopathy and supported by VADs were evaluated for echocardiographic data and blood chemistry including BNP. They were divided into patients who died while on mechanical support (group I; n = 9), patients who were transplanted (group II; n = 8) and patients who were successfully weaned off the system and did not require transplantation (group III; n = 4). RESULTS: Brain natriuretic peptide plasma concentrations decreased significantly after initiation of mechanical circulatory support (p = 0.017). Furthermore, the changes in BNP plasma concentrations showed a faster decrease to normal levels within the first week after implantation of the VAD in patients who were weaned off the system (group III) compared to patients in group I and group II. CONCLUSIONS: This study shows that ventricular unloading with VADs decreases BNP plasma concentrations in patients who suffer from end-stage heart failure. Furthermore, we hypothesize that an early decrease of BNP plasma concentration may be indicative of recovery of ventricular function during mechanical circulatory support.

Postoperative course of S-100B protein and neuron-specific enolase in patients after implantation of continuous and pulsatile flow LVADs.

BACKGROUND: In the early post-operative period after implantation of a continuous flow left ventricular assist device (LVAD) a non-pulsatile flow occurs. We compared the post-operative time-courses of protein S-100B (S100B) and neuron-specific enolase (NSE) as biochemical markers of brain injury in patients after implantation of a continuous flow LVAD and patients receiving a pulsatile flow LVAD. METHODS: Since 1998 the continuous flow DeBakey VAD has been implanted in 8 patients at our institution. For comparison purposes, a group of 7 consecutive patients in whom a pulsatile Novacor N100 LVAD was implanted were investigated. In both groups cardiopulmonary bypass (CPB) with cardiotomy suction was used. S100B and NSE were measured in serum pre-operatively, 4 hours after CPB, and on days 1, 3, 7, and 14 after implantation of the LVAD. A neurologic examination was performed pre-operatively and post-operatively on days 3 and 14. RESULTS: No differences were found between groups in pre-operative characteristics. The analysis of variance with repeated measurements for S-100B and NSE showed significant time effects (p = 0.004, p = 0.009, respectively) but no group effects (p = 0.06, p = 0.26, respectively) and no interaction between groups and time (p = 0.12, p = 0.48, respectively). The pre-operative serum level of S100B was significantly higher (p = 0.03) in the DeBakey VAD group. The pre-operative serum level of NSE was similar in the 2 groups (p = 0.7). In both groups there was a significant increase of S100B and NSE immediately after surgery (S100B: p = 0.006, p = 0.019; NSE: p = 0.01, p = 0.001). The values returned to pre-operative levels in the DeBakey VAD group on day 1 after implantation and in the Novacor group for S100B on day 3 and NSE on day 1. Post-operatively the mean values of S100B and NSE in the DeBakey VAD group compared with the Novacor group were significantly elevated only on day 3 (p = 0.005, p = 0.023).No neurologic complications were noted in patients with a continuous flow LVAD, whereas in the pulsatile LVAD group 2 patients presented neurologic abnormalities during the study period. CONCLUSIONS: The similar course of biochemical markers of brain damage in both groups may indicate that the non-pulsatile flow in the early post-operative period does not lead to increased brain injury or permeability of the brain blood barrier.Elevated levels of S100B and NSE in the post-operative period can be used as diagnostic markers of brain injury in patients after implantation of both types of LVAD.

Predictors of survival 1 hour after implantation of an intra-aortic balloon pump in cardiac surgery.

From July 1996 to March 2000, 391 patients with intraoperative cardiac low-output syndrome who underwent surgery with heart-lung bypass and had an intra-aortic balloon pump (IABP) implanted were analyzed in a prospective study. Of these 391 patients, 153 (39%) were operated on in an emergency situation, and 238 (61%) patients had elective surgeries. The perioperative mortality was 34% (133 patients). Clinical parameters were analyzed 1 hour after IABP support began. Statistical multivariate analysis showed that patients with an adrenaline requirement higher than 0.5 microg/kg/min, a left atrial pressure higher than 15 mmHg, output of less than 100 mL/hour, and mixed venous saturation (SvQ2) of less than 60% had poor outcomes. Using this data, we developed an IABP score to predict survival early after IABP implantation in cardiac surgery. We conclude that the success or failure of perioperative IABP support can be predicted early after implantation of the balloon pump. In patients with low-output syndrome despite IABP support, implantation of a ventricular assist system should be considered.

Optimal cell source for cardiovascular tissue engineering: venous vs. aortic human myofibroblasts.

Arterial vascular cells have been successfully utilized for tissue engineering in human cardiovascular structures, such as heart valves. The present study evaluates saphenous vein-derived myofibroblasts as an alternative, easy-to-access cell source for human cardiovascular tissue engineering. Biodegradable polyurethane scaffolds were seeded with human vascular myofibroblasts. Group A consisted of scaffolds seeded with cells from ascending aortic tissue; in group B, saphenous vein-derived cells were used. Analysis included histology, electron microscopy, mechanical testing, and biochemical assays for cell proliferation (DNA) and extracellular matrix (collagen). DNA content was comparable in both groups. Collagen and stress at maximum load was significantly higher in group B. Morphology showed viable, layered cellular tissue in all samples, with collagen fibrils most pronounced in group B. In conclusion, saphenous vein myofibroblasts cultured on biodegradable scaffolds showed excellent in vitro tissue generation. Collagen formation and mechanical properties were superior to aortic tissue derived constructs. Therefore, the easy-to-access vein cells represent a promising alternative cell source for cardiovascular tissue engineering.