Secundum ASD closure using a right lateral minithoracotomy: five-year experience in 122 patients

BACKGROUND: Surgical closure of secundum atrial septal defect (ASD) is a standard procedure associated with very low mortality and morbidity. We evaluated outcomes in the era of catheter-based interventional closure and minimally invasive techniques. METHODS: From May 1996, February 2002, 177 patients with a body weight of more than 30 kg underwent surgical ASD closure. A right lateral minithoracotomy (LMT) was used in 122 patients and a conventional approach, in 55. Diagnoses included secundum ASD in 106 patients in the LMT group and 40 in the conventional group, sinus venosus ASD in 13 patients in each group, and status post interventional closure in 3 and 2 patients, respectively. Mean age was 37 +/- 17 years in the LMT group and 43 +/- 20 years, in the conventional group and mean body weight was 66 +/- 17 kg and 70 +/- 16 kg, respectively. In the LMT group, femoral cannulation was performed for cardiopulmonary bypass. RESULTS: Direct ASD closure was carried out in 67.2% of patients in the LMT group and 58.2% of those in the conventional group. The remaining patients had pericardial patch closure. There was one death: A patient in the conventional group who required explantation of an Amplatzer device because of infection died postoperatively. Average stay in the intensive care unit was 1.2 +/- 0.5 days. Two patients required reoperation for residual ASD after direct closure; 1 sustained a temporary neurological deficit that resolved completely. On postoperative echocardiography, a minimal residual shunt was seen in only 3 patients. All patients were in good clinical condition with improved functional status at discharge from the hospital. CONCLUSIONS: Secundum ASD closure by LMT has become as standard and safe an operation as the conventional technique and achieves good perioperative results and satisfactory long-term outcomes. Thus LMT is an attractive option for patients who are not suitable for closure using catheter-based devices.     

Intraoperative left atrial ablation (for atrial fibrillation) using a new argon cryocatheter: early clinical experience

PURPOSE: Recently surgical treatment of atrial fibrillation has gained more popularity and presently is being performed in large numbers of patients. This report describes our early experience in treatment of patients with chronic or paroxysmal atrial fibrillation with a new tool for left atrial cryoablation. DESCRIPTION: From July 2002 through January 2003, 28 patients underwent left atrial cryoablation with the Surgifrost CryoCath. Patients underwent cryotherapy as an isolated procedure (n = 1), in combination with mitral valve surgery (n = 13), or with other surgical procedures (n = 14). In all patients contiguous lesion lines to the orifices of the pulmonary veins connected to the mitral annulus and the atriotomy were created. Surgery was performed through a conventional sternotomy in 8 patients (29%) and a right lateral minithoracotomy using video-assistance in 20 patients (71%). EVALUATION: Postoperatively sinus rhythm was restored in 27 patients (96%). At discharge 82% (23/28) of patients were in sinus rhythm and 18% (5/28) were in atrial fibrillation. Four patients (14%) required pacemaker implantation. There was no in-hospital mortality. At 6-months follow-up (19/28 patients) all were alive and 74% were in stable sinus rhythm, New York Heart Association functional class was 1.2 +/- 0.4. CONCLUSIONS: As indicated by our small and early patient cohort left atrial cryoablation with the Surgifrost argon cryocatheter is effective for the treatment of atrial fibrillation. This new device is technically easy to handle, it can be applied through a median sternotomy or lateral minithoracotomy. Long-term follow-up is necessary to evaluate further rhythm outcome.     

Suboptimal restraint affects the pattern of abdominal injuries in children involved in motor vehicle crashes

Background

Both solid and hollow visceral abdominal injuries have been associated with the use of seat belts in children involved in motor vehicle crashes. The relationship between the types of restraint used and the pattern of abdominal injury is unknown.

Methods

A probability sample of restrained children involved in crashes was enrolled in an ongoing crash surveillance system (1998 through 2002) linking insurance claims data to telephone survey and crash investigation data. Significant abdominal injuries were considered when the Abbreviated Injury Scale (AIS) score was ≥2 and were defined as hollow visceral (HV; intestine, bladder), or solid visceral (liver, spleen, pancreas, kidney). Restraint type was categorized as optimal restraint (OR) or suboptimal restraint (S-OR) based on the child’s age and size.

Results

For the 33 months of review, interviews were obtained for 13,558 restrained children aged 0 to 15 years, of which, 56% were OR (n = 7,591) and 44% were S-OR (n = 5,967). A significant abdominal injury was recorded in 78 children. A hollow visceral injury was recorded in 38 (9 OR and 29 S-OR), and a solid visceral injury in 32 (18 OR and 14 S-OR). Both hollow and solid visceral injuries were present in 8 children (2 OR and 6 S-OR). Suboptimally restrained children had a higher risk for hollow visceral injury when compared with optimally restrained children (Odds Ratio, 4.14 [95% Confidence Interval 1.33 to 13.22, P < .01]).

Conclusions

Among restrained children with intraabdominal injuries, those who were suboptimally restrained were 4 times more likely to have a hollow visceral than a solid visceral injury when compared with those who were optimally restrained. This suggests that the mechanism of injury for hollow viscus may be directly related to the improper positioning of the restraint.     

Carotid stenting using heparin-coated balloon-expandable stent reduces intimal hyperplasia in a baboon model

PURPOSE: This study evaluates the effect of heparin-coated balloon-expandable stents on intimal hyperplasia following carotid artery stenting in a baboon model. MATERIALS AND METHODS: Balloon-expandable (Palmaz-Schatz) stents were placed in bilateral common carotid arteries in 26 male baboons (mean weight: 11.3 kg). In each animal, a heparin-coated (HC) carotid stent was placed on one side, whereas the contralateral carotid artery received an uncoated stent that served as a control. The carotid stents were harvested at 30 days (n = 13) and 90 days (n = 13). Arteriography was performed to assess the carotid patency, and intravascular ultrasound was used to determine neointimal and luminal areas. Histological, morphometric analysis, and scanning electron microscopy were performed in the stented carotid arteries. RESULTS: One animal was excluded in each of the 1-month and 3-month groups because of premature death. Ten control (83%) and 11 HC stents (92%) remained patent in the 30-day group. In contrast, 10 control (83%) and 10 HC stents (83%) remained patent in the 90-day group. Morphometric analysis of the 30-day group showed the HC-stented carotid arteries had larger luminal areas (13%, P < 0.05), less neointimal areas (38%, P < 0.05), less neointimal/media ratios (53%, P < 0.05), and equivalent medial areas (NS) when compared with the control group. Morphometric analysis of the 90-day data showed the HC-stented carotid arteries had less neointimal areas (38%, P < 0.05) and less neointimal/media ratios (48%, P < 0.05), whereas the luminal areas and medial areas remained equivalent (NS) when compared with the control group. CONCLUSIONS: Carotid stenting using heparin-coated stents reduces early intimal hyperplasia in a baboon model. This approach may represent a useful strategy for improving luminal patency in endovascular carotid intervention.     

Development of antidepressant drugs. Experience and prospects

THE FIRST ROUTES OF RESEARCH: The first antidepressants were developed after the discovery of the existence during depression of a perturbation in the synaptic transmission of the principle monoamines: noradrenalin, serotonin and dopamine. The pharmacological effect of the various molecules developed is mainly on the metabolisation routes of neurotransmitters, but may also concern the different receptors present on synaptic level. THE AWARENESS OF NEW MEDIATORS: The progress in research on antidepressants has widened the scope of the development of such medicinal products to the domain of endocrinology (hypothalamo-pituitary-adrenal axis, progestogen hormones, thyreotropic axis) and studies on neuropeptides (substance P, neuropeptide Y). The complexity of the physiopathological mechanisms of depression hence appears enhanced.     

Toxicovigilance: new biochemical tool used in sulfonylurea herbicides toxicology studies

In vitro toxic effects of sulfonylurea herbicides (thifensulfuron-methyl and metsulfuron-methyl) were evaluated according to a new protocol. Physiological conditions were reproduced in order to boost toxicovigilance. Sulfonylureas and their hydrolysis products were added to biological substrates such as urea, alanine, aspartic acid, alpha-ketoglutarate, oxaloacetate, pyruvate and then incubated with some specific enzymes. Addition of these sulfonylureas and their degradation products did not significantly change the enzymatic activity of the urease, aspartate-aminotransferase, glutamate dehydrogenase, malate dehydrogenase and lactate dehydrogenase. However, the acid hydrolysis products inhibited up to 95% of the activity of the alanine-aminotransferase at low concentrations (0.27 micromol L(-1)). Inhibition did not affect the mitochondrial aspartate-aminotransferase.     

Metformin and its liver targets in the treatment of type 2 diabetes

Although a number of assessments disagree, the preponderance of the evidence indicates that the major therapeutic action of metformin in type 2 diabetes (DM2) is on the liver, and glucose production (EGP) in particular. At the level of this organ, the actions of metformin can be characterized as pleiotropic. The major questions addressed here are therefore: (i) the methodological aspects of the determination of glucose fluxes: when glucose production is not found to be elevated in type 2 diabetes, it is not surprising that little action of metformin on this flux is found. The issues of populations examined, experimental protocols, and quantitative methods of flux determination are important in answering this question. Early morning EGP is increased and constitutes a valid target for metformin. (ii) the multiple targets of metformin: metformin acts at a number of sites and interacts with metabolites and hormones. Some of these actions may be expressed at different doses. Although their net effect is therapeutic, not all are oriented towards lowering hyperglycemia, perhaps explaining the more modest effect of this drug than could be anticipated from individual actions. Sites of metformin action can therefore be considered as a compilation of valid therapeutic targets in DM2. Gluconeogenesis, glycogenolysis and glycogen synthesis can be altered by metformin, although in vivo, this also depends on the methodology. Component processes from substrate supply and liver uptake, through a number of glucogenic enzymes, as well as glycogen synthase and phosphorylase have all been shown to be affected. (iii) unifying concepts: reported actions of metformin on the mitochondrial respiratory chain, free fatty acid metabolism, AMP-activated protein kinase, and on membrane proteins directly may all explain subsets of actions that are seen, providing more integrated targets for consideration in the therapy of DM2.     

The effects of small-dose ketamine on morphine consumption in surgical intensive care unit patients after major abdominal surgery

In a randomized, double-blinded study, we evaluated the analgesic effect of ketamine in the management of pain in a surgical intensive care unit after major abdominal surgery. Patients received morphine patient-controlled analgesia with either placebo (Group M) or ketamine (Group K). Morphine was administered with initial loading doses of 2 mg until the visual analog scale (VAS) score was <30 and thereafter with bolus doses of 1 mg and a lockout time of 7 min. Ketamine was administered with an initial bolus of 0.5 mg/kg followed by a perfusion of 2 micro g x kg(-1) x min(-1) during the first 24 h and 1 micro g x kg(-1) x min(-1) during the following 24 h. The 4-h cumulative morphine doses were measured over 48 h. The VAS scores at rest and at mobilization were measured every 4 h during 48 h. A total of 101 patients were enrolled, and 93 were analyzed (41 in Group K and 52 in Group M). VAS scores at rest and at mobilization were similar. The cumulative consumption of morphine was significantly smaller in Group K (P < 0.05). We concluded that small doses of ketamine were a valuable adjunct to opioids in surgical intensive care unit patients after major abdominal surgery.     

Neuroprotective effects of propofol in a model of ischemic cortical cell cultures: role of glutamate and its transporters

BACKGROUND: During cerebral ischemia, excess of glutamate release and dysfunction of its high affinity transport induce an accumulation of extracellular glutamate, which plays an important role in neuronal death. The authors studied the relationship among propofol neuroprotection, glutamate extracellular concentrations, and glutamate transporter activity in a model of ischemic cortical cell cultures. METHODS: Thirteen-day-old primary cortical neuronal-glial cultures were exposed to a 90-min combined oxygen-glucose deprivation (OGD) in an anaerobic chamber, followed by reoxygenation. Propofol was added only during the OGD period, and its effect was compared to that of the N-methyl-d-aspartate receptor antagonist dizocilpine (MK-801). Twenty-four hours after the injury, cell death was quantified by lactate dehydrogenase release and cell viability by reduction of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT). Extracellular concentrations of glutamate in culture supernatants and glutamate uptake were performed at the end of OGD period by high-performance liquid chromatography and incorporation of l-[3H]glutamate into cells, respectively. RESULTS: At clinically relevant concentrations (0.05-10 microm), propofol offered protection equivalent to that of MK-801. It significantly reduced lactate dehydrogenase release and increased the reduction of MTT. At the end of the ischemic injury, propofol was able to reverse the OGD-induced increase in glutamate extracellular concentrations and decrease of glutamate uptake. The inhibition of the glial GLT1 transporter by 3-methyl-glutamate did not further modify the effect of propofol on glutamate uptake, suggesting that GLT1 was not the major target of propofol. CONCLUSION: Propofol showed a neuroprotective effect in this in vitro model of OGD, which was apparently mediated by a GLT1-independent restoration of the glutamate uptake impaired during the injury.     

Changing management of cardiac myxoma based on a series of 40 cases with long-term follow-up

BACKGROUND: Cardiac myxoma is generally considered to be a surgical emergency. However, as a result of progress in echocardiography and the increasing age of the patients presenting with this disease, the clinical presentation has changed and the management of cardiac myxoma now needs to be reviewed. METHODS: Between 1978 and 2001, 40 patients (16 men and 24 women) between the ages of 6 months and 82 years (mean age, 55.6 years) were operated on for cardiac myxoma. Signs of heart failure with pulmonary congestion (22%) or pulmonary embolism (20%) indicated a high-risk emergency situation in some cases, whereas, in other cases (58%), the patient's condition was stable and the clinical presentation was less worrying. However, the tumor was always removed within 24 hours of admission. Most cases of cardiac myxoma observed over the last decade correspond to stable forms, as echocardiography has revealed smaller tumors in generally elderly patients. RESULTS: The postoperative mortality was 7.5% (3 patients). No patients were lost to follow-up, and the mean follow-up was 13.6 years. One patient was reoperated for recurrence 3 years postoperatively. Five patients required further cardiac surgery: three mitral valve replacements, one coronary artery bypass graft, and one angioplasty. The 15-year survival rate was 69%. CONCLUSIONS: Myxoma tends to be observed in a more elderly and higher risk population, often at an early stage. The classic approach of emergency surgery is not always appropriate in these stable forms, allowing more thorough preoperative assessment of these patients.