Detection of coronary arteries and evaluation of anastomoses with a commercially available 15-MHz, broadband, linear array transducer

BACKGROUND

In coronary artery bypass surgery the detection of the target vessels can be difficult due to their intramural location, coverage by adipose tissue, calcification, or fibrous tissue formation. Their identification is especially critical during off-pump coronary artery bypass (OPCAB) and minimally invasive direct coronary artery bypass (MIDCAB) surgeries. Our objectives were to identify whether (1) the epimyocardial use of the broadband linear array transducer CL15-7 allows a clear and rapid identification of the target artery during on-pump coronary bypass (CPB), OPCAB and MIDCAB surgeries; and (2) if this transducer is helpful in investigating the anastomotic morphology with 2D and color flow Doppler.

METHODS

Thirty-two patients without a visually identifiable left anterior descending artery (LAD) were included in the study and epimyocardial ultrasonography was performed. Stabilization of the beating heart was used in 19 patients; in 13 patients, the surgery was carried out with CPB on the arrested heart. Two-dimensional ultrasound alone, or in combination with color Doppler, was used to identify the affected vessel as well as a suitable anastomosis site. Pulsed wave Doppler had to be used occasionally to differentiate between artery and vein. Patency of the anastomoses was established with color Doppler immediately after reinitiating blood flow. An evaluation of the distal graft diameter, its length, and the quality of the anastomosis was made with 2D and color Doppler. Transit-time Doppler flow was used to confirm patency.

RESULTS

The LAD could be identified ultrasonographically in all 32 patients at a depth of 3 to 15 mm. The right coronary artery (RCA) was located at a depth of 3 to 10 mm in the 5 patients where this vessel was to be bypassed. The coronary arteries located on the lateral or posterior aspect of the heart could not be reached due to the shape and rigidity of the transducer handle. The intended anastomosis sites of the LAD and RCA were identified with ultrasound according to their topography and morphology. In all cases the vessel could be dissected and bypassed without undue damage or bleeding. In one OPCAB patient, the LAD was identified in close proximity to the overlying vein along the whole of the anterior wall. This resulted in conversion to CPB, thus facilitating secure exposure of the LAD. The ultrasonographic visibility of the left internal mammary artery to LAD and saphenous vein graft to RCA anastomoses was excellent, and patency correlated well with the transit time flow measurements.

CONCLUSION

The CL15-7 transducer gives excellent near field visibility of the LAD and RCA. This is extremely valuable for the safe dissection of these vessels, especially during off-pump coronary surgery. The anatomical morphology of the anastomoses can be identified but, due to the shape of the transducer handle, only the coronary arteries on the anterior surface of the heart can be evaluated. A flexible, rather than a rigid, hockey stick-shaped handle would eliminate this problem. Training is essential to obtain reliable results.

[Motor vehicle accidents with entrapment. A medical and technical investigation of crash mechanism, injury pattern and severity of entrapment of motor vehicle occupants between 1983 and 2003]

AIM

Crash mechanisms, injury patterns, and severity of injury of entrapped motor vehicle occupants were analysed by the Accident Research Unit's scientific teams between 1983 and 2003.

RESULTS

Of the 1281 vehicle passenger entrapments in our study, 18.3% happened on highways, 25.6% on federal roads, 35.9% on country roads, and 18.3% on city roads. Of those involved, 69.9% were drivers, 19.4% were front passengers, and 8.5% were rear passengers. Coinvolved objects in car collisions were: other cars 30.9%, trucks 50.2%, objects 18.6%, and motorbikes 0.3%. Coinvolved objects in truck collisions were: other trucks 61.8% and objects 38.2%. The mean Delta-V was 42 km/h (cars 46.2, trucks 32.2). Maximum AIS levels were 31% I, 25.2% II, 19.4% III, 7.8% IV, 7.8% V, and 8.6% VI. Of injuries, 68.7% were to the head, 23.5% to the neck, 50.8% to the chest, 43.6% to upper extremities, 15.4% to the abdomen, 16.4% to the pelvis, and 52.9% to lower extremities. The incidence of multiple injuries (ISS>16) was 23.7%, and mortality was 15.9%.

CONCLUSION

Car drivers are more at risk of accidents with entrapment on rural streets, and truck drivers are more at risk on highways. In most cases car occupants crash with trucks or other cars, and truck drivers collide more frequently with other trucks or objects. Besides a high degree of severe single injuries, there is also a high incidence of multiple injury victims and high mortality. Of the fatalities, 74.5% occur during the preclinical course and 24.5% during the clinical course.

[The influence of transportation mode on mortality in polytraumatized patients. An analysis based on the German Trauma Registry]

BACKGROUND

Thirty years after its introduction in Germany, the benefits of the helicopter emergency medical service (HEMS) compared to ground ambulances (GA) still remain unclear. The aim of this study was to evaluate the influence of helicopter transport on rescue time and mortality based on the data of the German Trauma Registry.

METHODS

Data from patients with multiple injuries were documented prospectively between 1993 and 2003 in different trauma centers in Germany, Switzerland, Austria and The Netherlands. From these data, patients with an injury severity score (ISS)<16 were excluded. Patients who were transported to the hospital without a physician were also excluded. The data from included patients were evaluated for time to hospital and influence of transportation service on mortality.

RESULTS

A total of 7,534 patients with multiple injuries were included. Of these, 3,870 patients were transported by HEMS and 3,664 reached the hospital by GA. There were 74.9% male patients in the HEMS group, and 71.3% male patients in the GA group. The mean ISS was higher in the HEMS group (31.4 vs 30.7; P<0.01); patients transported by GA were older (HEMS: 39.2; NEF:41.3; P<0.01). The GA arrived on the scene after 14.33 min, the HEMS after 18.18 min (P<0.01). Time at the scene was longer in the HEMS group (HEMS: 26:26 min; NEF: 22:29 min; P<0.01). Intubation rate in the HEMS group was about 80%, while patients transported by GA were intubated in 60% of cases. The overall mortality was 30.9%. Evaluation of the TRISS prediction of survival showed a benefit for patients transported with HEMS. In a multivariate analysis, intubated patients with ISS<or=60 had a lower mortality rate if transported with HEMS (NEF: 40.1%; HEMS 34.9%; P<0.01).

CONCLUSIONS

Only minor differences in age and ISS were found between the groups. The time between the accident and arrival of the physician was longer in the HEMS group. The HEMS group also remained on the scene for longer, but had a higher rate of intervention. According to our analysis of the German Trauma Registry, patients with multiple injuries benefit from HEMS transportation.

Short-Term Tissue Response of Lapine Carotid Artery Microanastomoses to BioGlue®

BACKGROUND

Minimally invasive coronary artery surgery needs fast, reliable and easy methods of carrying out anastomoses. The aim of our study was to evaluate the use of BioGlue in sutureless vascular anastomoses in the lapine model.

METHODS

In 24 New Zealand white rabbits, 43 transsected carotid arteries were re-anastomosed using either a combination of balloon catheterisation and BioGlue or a conventional suture. In five carotid arteries, only BioGlue was applied. The animals were euthanised and tissue samples were taken for histological and immunohistological examination.

RESULTS

A higher inflammatory cell infiltrate was present in the glue control and glue anastomosis groups, with the invasion of inflammatory cells located especially at the junction between the wall with and the wall without glue. Early calcification was detected in two arteries.

CONCLUSION

The results of this short-term study show that the rabbit is an adequate as well as a sensitive model for the study of microanastomoses by glueing. Marked inflammatory reactions developed which may lead to vascular sclerosis or stenosis, and long-term studies are necessary to elucidate this problem further.

Imaging of carbon nanotubes with tin–palladium particles using STEM detector in a FE-SEM

Upgraded FE-SEM with STEM detector permits the observation and imaging of thin materials such as carbon nanotubes by transmitted electrons directly in a FE-SEM. It is important to know the resolution of transmitted electrons mode compared to the classical secondary electrons mode. The resolution was measured with SMART macro. This routine permits to quickly determine resolution of a micrograph, based on fast Fourier transform analysis. An optimum working distance value was found around 6mm for an accelerating voltage equal to 10 keV. In addition to this, it was shown that the resolution obtained in bright field and secondary electron images at 15 keV had appreciatively the same resolution. Also, it was shown that images in dark field mode have a poorer resolution compared with bright field transmitted electrons and secondary electrons images.

FTY720 for treatment of ischemia-reperfusion injury following complete renal ischemia; impact on long-term survival and T-lymphocyte tissue infiltration

BACKGROUND

Organ dysfunction due to ischemia-reperfusion (I/R) injury is a common problem in transplant, liver, trauma, and heart surgery. I/R injury is mediated by upregulated expression of endothelial cell surface adhesion molecules and subsequent adhesion and activation of circulating leukocytes. The purpose of this study was to evaluate the effect of an intraoperative administration of FTY720 in an animal model with controlled bilateral warm kidney ischemia compared to steroids or placebo application.

METHODS

Male C57BL6/J mice (n = 72, weight 25 to 30 g) were exposed to 30 minutes of bilateral kidney ischemia and followed by a 48 hour observation period. FTY720 (1 mg/kg body weight [BW]), steroids (5 mg/kg BW), or saline solution were administered. In addition, a sham-operated control group was included. At the termination of the experiments, all surviving animals were humanely killed. The impact of the various drugs on overall animal survival, timing of death, peripheral T-cell count, and T-lymphocyte infiltration in the kidneys was determined.

RESULTS

Following bilateral kidney I/R injury, FTY720 was associated with a significant improved animal survival (85.7%) compared with steroids (50%) or controls (42.4%). FACS analysis showed significant T-lymphocyte depletion in peripheral blood in the FTY720 but not in the other groups. T-lymphocyte tissue concentration in liver and kidney tissue did not show statistically significant differences following FTY720, steroid, or saline treatment.

CONCLUSION

FTY720, when administered intraoperatively, improved survival significantly in mice submitted to bilateral kidney ischemia but did not have any significant impact on the parenchymal T-lymphocyte infiltration in the ischemic organ.

FTY720 Application Following Isolated Warm Liver Ischemia Improves Long-Term Survival and Organ Protection in a Mouse Model

BACKGROUND

Ischemia-reperfusion-Injury (I/RI) is a common complication in transplant-, liver-, and heart surgery. The I/RI is mediated and aggravated by different types of leukocytes such as lymphocytes, monocytes, and neutrophil granulocytes, with consecutive enlargement of the expression of adhesion molecules. This study shows an organ-protective effect of an intraoperative FTY720 administration following warm liver ischemia (Pringle's maneuver).

METHODS

Male c57BL6/J mice (n = 46, body weight [BW] 25 to 30 g) were used. Either FTY720 (1 mg/kg BW), steroids (5 mg/kg BW), or physiological saline solution was administered intraperitoneally. Liver-ischemia was applied for 30 minutes with subsequent follow-up for 48 hours. At termination, all surviving animals were sacrificed. The impact of the drugs administered on long-term survival, time of death, and development of blood T-lymphocyte concentration was determined. Follow-up of T-lymphocyte concentration in peripheral blood was examined throughout FACS-analysis.

RESULTS

Following 30 minutes of ischemia, FTY720, but not steroid or vehicle treatment, showed a significant protective effect on long-term survival. FACS-analysis showed significant T-lymphocyte depletion in peripheral blood following FTY720 but not steroids or vehicle treatment.

CONCLUSION

The improved long-term survival following FTY720 application shown in this study might be due to a protective effect of FTY720 in prevention of I/RI. This might be mediated by the T-lymphocyte depletion shown in the FACS-analysis.

[Hannover-Polytrauma-Longterm-Study HPLS]

From the period of September 2000 to March 2006 Hannover Reinsurance and the Department of Traumatology of the Hanover Medical School conducted a retrospective observational study of the long-term outcome of patients after polytrauma. The follow-up period was on average 17 +/- 5 years. The goal of the study was to determine the social, financial, medical and psychological long-term outcome after a severe accident. Of the 1560 enrolled patients 519 patients died in the observed period, 397 patients were followed up but could not be examined, 637 patients (female n = 158, male n = 479) were examined and answered detailed questionnaires concerning their social, financial medical and psychological situation. 6 patients did not fullfil the input criteria and one patient had two polytraumata. The average age at the time of accident was 26.5 years (+/- 12.3).

RESULTS

Financial losses were observed in 41.1% of all males and 44.4% of females. 21.7% of all male (female 18.4%) had no financial protection at all. Due to the accident 30.1% of all men were unemployed and 19.8% permanently disabled (women 27.4% and 27.6% respectively). Psychological treatment almost doubled after discharge from rehabilitation centres. Even 20 years after the accident extra-mortality was substantially increased by 79%.

CONCLUSION

Ten to twenty years after polytrauma significant financial, social and medical impairments are still present.

CT-Koronarangiographie bei Patienten mit Vorhofflimmern

PURPOSE

Reliable visualization of the coronary arteries with multislice spiral CT angiography (MSCTA) in patients with atrial fibrillation (AF) remains a challenge despite retrospective ECG gating. A recently developed new algorithm automatically compensates dynamic changes in the heart rate during the scan, thus reducing misregistration and motion artifacts. The HeartBeat-RT algorithm combines a fixed-percent delay determined from the first R wave and the fixed offset delay based on the second R wave in the ECG cycle. The purpose of this study was to find out the optimal reconstruction window in MSCTA in patients with AF for each of the three major coronary arteries during the cardiac cycle.

MATERIALS AND METHODS

20 patients with permanent AF were imaged on a 16-slice scanner (slice collimation: 16 x 0.75 mm; rotation time 0.42 s; 140 kV; 380 mAs; 120 ml Ultravist 370 (R) i.v.). The patients had not received any previous drugs for heart frequency regulation. Acquisition was started after bolus tracking of a biphasic bolus of 120 ml Ultravist 370 injected intravenously. Each coronary segment was reconstructed at 0 % - 90 % of the cardiac cycle in increments of 10 %. For image analysis we used coronary segments as defined by the American Heart Association. Two blinded independent readers assessed the image quality in terms of visibility and artifacts (five-point rating scale 1 = very poor, 2 = poor, 3 = fair, 4 = good and 5 = excellent) and the degree of stenosis (five-point rating scale 1 = 0 %, 2 = 1 % - 49 %, 3 = 50 % - 74 %, 4 = 75 % - 99 %, 5 = 100 %) on axial slices, multiplanar reconstructions and three-dimensional volume-rendered images.

RESULTS

The heart rate during examination ranged between 42 and 156 beats per minute, the average heart rate was 78 +/- 23. Each of the two readers evaluated 300 segments in 20 patients. Visualization of all coronary artery segments was superior at 40 % (mean score of the image quality 2.79) as compared to the standard diastolic reconstruction window at 80 % (image quality 2.33). The second best image quality (2.57) was acquired at 0 % of the cardiac cycle.

CONCLUSION

The use of a frequency adapted delay algorithm with the choice of an end-systolic reconstruction window provided diagnostically valuable images in patients with AF.

Die Kraftübertragung am Handgelenk nach Skaphoid-, Trapezium- und Trapezoideumfusion

Scaphotrapeziotrapezoid (STT) arthrodesis has been proposed to stabilise the radial column and to redirect the load away from the lunate. Midterm effects on force transmission are still unclear. Six patients who were treated with triscaphe arthrodesis were examined after an average of 5 years using CT osteoabsorptiometry of both wrists. STT arthrodesis had been performed in four cases with Kienböck's disease type IIIb and in two cases of scaphotrapeziotrapezoid arthritis. At all contralateral wrists peak mineralisations were found beyond the lunate fossa and in the scaphoid fossa of the distal radius. At the side with STT arthrodesis there was only one peak. In five cases this density maximum was beyond the scaphoid fossa and in one case half beyond the lunate and half beyond the scaphoid fossa. Triscaphe arthrodesis allows load transmission from the lunate to the radial column.

Quantification of Coronary Artery Stenosis with 16-Slice MSCT in Patients before CABG Surgery: Comparison to Standard Invasive Coronary Angiography

Objective: Invasive, selective coronary angiography is the gold standard for evaluation of coronary artery disease (CAD) and degree of stenosis. The purpose of this study was to compare 3-dimensional (3D) reconstructed 16-slice multislice computed tomographic (MSCT) angiography and selective coronary angiography in patients before elective coronary artery bypass graft (CABG) procedure. Methods: Sixteen-slice MSCT scans (Philips Mx8000 IDT) were performed in 50 patients (42 male/8 female; mean age, 64.44 8.66 years) scheduled for elective CABG procedure. Scans were retrospectively electrocardiogram-gated 3D reconstructed. The images of the coronary arteries were evaluated for stenosis by 2 independent radiologists. The results were compared with the coronary angiography findings using the American Heart Association segmental classification for coronary arteries. Results: Four patients (8%) were excluded for technical reasons. Thirty-eight patients (82.6%) had 3-vessel disease, 4 (8.7 %) had 2-vessel disease, and 4 (8.7%) had an isolated left anterior descending artery stenosis. In the proximal segments all stenoses >50% (56/56) were detected by MSCT; medial segment sensitivity was 97% (73/75), specificity 90.3%; distal segment sensitivity was 90.7% (59/65), specificity 77%. Conclusion: Accurate quantification of coronary stenosis greater than 50% in the proximal and medial segments is possible with high sensitivity and specificity using the new generation of 16-slice MSCTs. There is still a tendency to overestimate stenosis in the distal segments. MSCT seems to be an excellent diagnostic tool for screening patients with possible CAD.

Predictors of long-term mortality and cardiac events in patients with known or suspected coronary artery disease who survive major non-cardiac surgery

The aim of this prospective study was to assess predictors of long-term outcome in patients with documented or suspected coronary artery disease who survive major non-cardiac surgery. The impact of patients' comorbidities, pre-operative heart rate variability and postoperative increase in cardiac troponin I on all-cause mortality and major cardiac events within 2 years was explored using multivariable logistic regression. Six of 173 patients died within the first month after surgery and were excluded from the study. Thirty-four of 167 patients (20%) died 1-24 months after surgery. Independent predictors of all-cause mortality were history of congestive heart failure (odds ratio 6.4 [95%, confidence interval 1.7-24]), pre-operatively depressed heart rate variability (odds ratio 6.4 [95%, confidence interval 1.9-21]), and age > 70 years (odds ratio 4.5 [95%, confidence interval 1.2-16]). In contrast, postoperative elevation of cardiac troponin I did not independently predict all-cause mortality or major cardiac events.