C-arm-based mobile computed tomography: a comparison with established imaging on the basis of simulated treatments of talus neck fractures in a cadaveric study.

OBJECTIVE: To analyse the image quality and diagnostic effectiveness of a new C-arm-based 3D imaging method (C-arm-CT) for intraoperative evaluation of screw osteosyntheses adjacent to a peripheral joint. MATERIALS AND METHODS: Insertion of screws into four cadaveric specimens simulated the surgical treatment of talus neck fractures. Ten orthopedic surgeons and 10 radiologists evaluated X-ray, C-arm fluoroscopy, C-arm-CT and CT images. RESULTS: The best image quality was obtained with X-rays (p < 0.001), followed by C-arm fluoroscopy (2D) and CT, with the C-arm-CT (3D) being rated lowest (p < 0.001). The most correct diagnoses were obtained with CT and C-arm-CT (with no statistical difference between them), while C-arm-fluoroscopy was inferior (p < 0.001) and X-rays were the worst (p < 0.05). CONCLUSIONS: Even if the image quality of C-arm-CT is definitely inferior to that of CT, screw misplacements can be reliably detected using C-arm-CT. As compared to the current standard procedures (intraoperative fluoroscopy and postoperative radiography), C-arm-CT performed better. C-arm-CT is ideally suited to the intraoperative diagnosis of high-contrast inquiries like bone fragments and OS material, especially at the extremities. Coupling of the new 3D imaging to existing navigation systems is possible. C-arm-CT will support the further development and implementation of open and minimally invasive surgical procedures.     

Intramuscular Injection of Sevoflurane Detects Malignant Hyperthermia Predisposition in Susceptible Pigs

Background: The authors hypothesized that intramuscular sevoflurane injection allows diagnostic differentiation between malignant hyperthermia-susceptible (MHS) and -nonsusceptible (MHN) pigs by measurement of intramuscular lactate and carbon dioxide partial pressure (Pco2), and that dantrolene reduces the sevoflurane-induced Pco2 increase.

Methods: With approval of the local animal care committee, microdialysis probes with attached microtubing for sevoflurane injection were placed in the adductor muscles of nine MHS and six MHN pigs, and Pco2 probes with microtubing were positioned in the triceps muscle of eight MHS and six MHN pigs. After equilibration, sevoflurane boluses at different concentrations and a sevoflurane-dantrolene bolus were injected synchronously. Lactate, pyruvate, and glucose as well as Pco2 were measured spectrophotometrically, and the rate of Pco2 increase was calculated.

Results: Intramuscular sevoflurane injection increased local lactate and Pco2 dose dependently, and significantly higher in MHS than in MHN pigs. Measurement of the rate of Pco2 increase allowed a distinct differentiation between single MHS and MHN pigs. No significant increase in Pco2 was found with sevoflurane and dantrolene.     

Safety of the use of Tissucol Duo S in cardiovascular surgery: retrospective analysis of 2149 patients after coronary artery bypass grafting.

OBJECTIVE: Fibrin sealant is widely used in almost all fields of surgery and has proved to be an effective therapeutic tool in cardiothoracic surgery. Nevertheless, there have been concerns about early bypass graft occlusion associated with the use of fibrin glue. This analysis has been performed to assess the risks and benefits of Tissucol Duo S in coronary artery bypass grafting (CABG) surgery. METHODS: Two thousand one hundred forty-nine patients were included in this retrospective study, 879 (40.9%) were intra-operatively treated with Tissucol Duo S fibrin glue, 1270 (59.1%) did not receive fibrin glue (control group). Patient characteristics were documented according to the EuroScore. Intra- and postoperative data were collected. Primary endpoint of this study was the 30-day all-cause mortality rate in the Tissucol Duo S treated group compared to the control group. RESULTS: Mean age was 66.6+/-9.4 years, 76.3% of the patients were male. There was an increased 30-day-mortality rate in the Tissucol Duo S group compared to the control group (8.5 vs 3.5%, p<0.001). In order to determine if and to what extent the apparent fibrin effect might be due to confounding effects from covariates, an adjustment for potential confounding was done. However, multivariable adjustment did not reduce the risk of fibrin glue below an odds ratio of 2.2. CONCLUSION: Although the apparent increase in mortality risk associated with the use of fibrin glue could not be eliminated statistically, we consider Tissucol Duo S fibrin glue a safe and effective therapeutic tool in CABG surgery when it is applied correctly. Due to the retrospective character of this study some detailed information about the indication for the use of fibrin glue and its application is missing which may be important cofactors for mortality. For further clarification a prospective randomized study may be useful.     

Use of a computer-based health risk appraisal by older adults

BACKGROUND. A health risk appraisal (HRA) is a tool for health promotion. Conversational microcomputer-based HRAs may be more cost effective than other HRA formats. The acceptability of conversational HRAs, however, has not been demonstrated for older adults. METHODS. We studied the acceptability of a conversational microcomputer-based HRA in a sample of 247 adults at the Minnesota State Fair and the Senior Options Exposition. All users were offered the appraisal via mouse or keyboard interface. Acceptability was measured in terms of user-reported helpfulness, intent to change, time of use, and willingness to view HRA health recommendations. Data on completion time and willingness to view HRA recommendations were collected for Senior Exposition users only. Regression analyses were used to examine the combined impact of interface (mouse or keyboard), location (State Fair or Senior Exposition), age, and sex on user acceptability. Results. Interface and location had no effect on helpfulness or change ratings. Older users rated the appraisal more helpful (P less than .007). Both older and female users reported more intent to change behavior (P = .016, both). Time to use the appraisal was related to interface, age, and sex. Mouse users (P less than .0001), older users (P less than .0001) and female users (P less than .05) took significantly longer to use the appraisal. Significantly more mouse users declined to see recommendations (P less than .02). CONCLUSIONS. Older users can derive as much or more value from conversational health risk appraisals as younger users; however, a mouse interface may be less effective for this age group.     

Minimally Invasive Coronary Artery Bypass Grafting: A New Method Using an Anterior Mediastinotomy

The benefit of internal mammary artery (IMA) grafting as a long-lasting intervention for coronary artery disease is well recognized. However, largely because they are less invasive, catheter based alternatives are frequently chosen, particularly to treat single or double vessel disease. To retain the advantages of the IMA graft, and to offset the invasiveness of conventional coronary artery bypass grafting, we developed a new minimally invasive method using an anterior mediastinotomy for treating left anterior descending (LAD) or right coronary artery disease, or both. Feasibility studies using 16 pigs and a human cadaver led to approval by the Institutional Review Board for use of this procedure to treat six patients (four men, two women; mean age, 63.8 ± 13.6 [SD] yrs) who granted informed consent. Pedicle dissection of the IMA, using video assisted thoracoscopy if necessary, was made through a 2-to 3-inch horizontal anterior mediastinotomy. The underlying LAD artery was grafted during femoral vessel cardiopulmonary bypass, with cooling to 30°C, induced ventricular fibrillation, and left ventricular venting if required. Transesophageal echocardiography performed after bypass showed that two patients maintained normal wall motion and four had improvement from the original impairment. One patient suffered a recurrence of angina 4 weeks after the procedure; recatheterization showed an acutely angled IMA, subsequently corrected by balloon angioplasty. The results of follow-up dobutamine echocardiographic stress tests were negative in all patients. With this minimally invasive approach, the procedure should provide the benefits of IMA grafting with shorter hospital stay, more rapid recovery, and less overall cost.     

Laser placement in noncontact Nd:YAG cyclophotocoagulation

We treated 40 eyes of 40 patients by using noncontact transscleral Nd:YAG cyclophotocoagulation to determine whether treatment 1.5 or 3.0 mm posterior to the corneoscleral lumbus was preferable. Patients were randomly assigned to one of the treatment groups, and all other variables, including power, number, and distribution of laser applications, were kept constant. Six months postoperatively, those treated 1.5 mm posterior to the corneoscleral limbus had a lower intraocular pressure (P = .0047) than those treated 3.0 mm from the corneoscleral limbus. The 1.5-mm group also required fewer retreatment (P = .017) and had a slightly lower occurrence of visual acuity loss after this procedure. We believe it may be advantageous to locate the laser application approximately 1.5 mm posterior to the corneoscleral limbus, rather than further posteriorly, when performing noncontact transscleral Nd:YAG cyclophotocoagulation.     

Distribution and disposition of trospectomycin sulfate in the in vivo rat, perfused rat liver, and cultured rat hepatocytes

Trospectomycin sulfate is an experimental, aminocyclitol antibiotic. It has been shown in preclinical, chronic safety studies in the dog and rat to elicit a reversible, lysosomal phospholipidosis in liver. The present experiments were conducted to characterize the tissue distribution and disposition of 3H]trospectomycin sulfate in the male rat, perfused rat, perfused rat liver, and cultured rat hepatocytes. Following a 5 mg/kg iv dose to four rats, approximately 70% of the dose was recovered within 24 hr primarily in urine as unchanged drug, and the remainder was eliminated with a terminal phase half-life in blood and tissues of 3 days. Fecal excretion was relatively minor (16% of the dose recovered in feces in 7 days) until later timepoints, when it was the principal pathway of terminal phase elimination. The liver sequestered approximately 10% of the dose and had the highest tissue levels of drug at all times measured. Liver perfusion experiments indicated that trospectomycin accumulated in a hepatic depot compartment as parent drug by a first-order process which was nonsaturable up to a 1 mM concentration of drug. Biliary excretion of unchanged trospectomycin by the perfused liver was slow (approximately 3% of the dose in 2 hr) and occurred by both paracellular and transcellular mechanisms. The hepatic depot compartment appeared to be responsible for transcellular biliary excretion, and thus for the sustained fecal excretion observed in vivo. Subcellular distribution experiments indicated that at least 50% of the drug in the hepatic depot was sequestered in organelles having a broad density range. The existence of a trospectomycin depot compartment was also demonstrated in cultured hepatocytes.(ABSTRACT TRUNCATED AT 250 WORDS)