Multiple spinal extradural meningeal cysts presenting as acute paraplegia. Case report and review of the literature

Multiple spinal extradural meningeal cysts are rare. To the authors' knowledge, there have been only four reported cases in the world literature. The authors report a case of multiple spinal extradural meningeal cysts in a 31-year-old woman presenting with acute paraplegia. Magnetic resonance imaging of the thoracolumbar spine revealed multiple extradural cystic lesions extending from T-7 to T-8 and from T-12 to L-3. Intraoperative findings demonstrated a white, fibrous, and tense cyst filled with cerebrospinal fluid-like colorless fluid. Excision of the posterior wall of the symptomatic cyst was followed by immediate neurological improvement. The examination of the pathological specimen showed a thick duralike layer of collagen and an inner membrane of arachnoid that is often not found in these lesions. The final diagnosis was based on combined imaging, intraoperative, and histopathological findings. The authors review the literature and discuss the etiological, diagnostic, and therapeutic aspects of this lesion.

Diffusion tensor imaging of two unrelated Chinese men with hereditary spastic paraplegia associated with thin corpus callosum

Hereditary spastic paraplegia (HSP) associated with thin corpus callosum is a rare autosomal recessive neurodegenerative disorder characterized by an abnormally thin corpus callosum, normal motor development, slowly progressive spastic paraparesis and cognitive deterioration. To investigate and localize abnormalities in the brains of two Chinese patients with HSP-TCC, with mutations in the spatacsin gene. Diffusion tensor imaging (DTI) was used to determine the mean diffusion (MD) and fractional anisotropy (FA) in the brains of the patients in comparison to 20 healthy subjects. Voxel-based analysis (VBA) of both the diffusion and anisotropy values were performed using statistical parametric mapping (SPM). Significant changes with MD increase and FA reduction were found in the already known lesions including the corpus callosum, cerebellum and thalamus. In addition, changes were also found in regions that appear to be normal in conventional MRI, such as the brain stem, internal capsule, cingulum and subcortical white matter including superior longitudinal fascicle and inferior longitudinal fascicle. Neither increase in FA nor reduction in MD was detected in the brain. Our study provides clear in vivo MR imaging evidence of a more widespread brain involvement of HSP-TCC. MD is more sensitive than FA in detecting lesions in thalamus and subcortical white matter, suggesting that MD may be a better marker of the disease progression.

Preoperative mapping of arterial spinal supply using 3.0-T MR angiography with an intravasal contrast medium and high-spatial-resolution steady-state

Preoperative mapping of the arterial spinal supply prior to thoracoabdominal aortic aneurysm repair is highly relevant because of high risk for postoperative ischemic spinal cord injuries such as paraparesis or paraplegia.

Should intentional endovascular stent-graft coverage of the left subclavian artery be preceded by prophylactic revascularisation?

Thoracic endovascular aortic repair (TEVAR) has emerged as a promising therapeutic alternative to conventional open aortic replacement but it requires suitable proximal and distal landing zones for stent-graft anchoring. Many aortic pathologies affect in the immediate proximity of the left subclavian artery (LSA) limiting the proximal landing zone site without proximal vessel coverage. In patients in whom the distance between the LSA and aortic lesion is too short, extension of the landing zone can be obtained by covering the LSA's origin with the endovascular stent graft (ESG). This manoeuvre has the potential for immediate and delayed neurological and vascular symptoms. Some authors, therefore, propose prophylactic revascularisation of the LSA by transposition or bypass, while others suggest prophylactic revascularisation only under certain conditions, and still others see no requirement for prophylactic revascularisation in anticipation of LSA ostium coverage. In this review about LSA revascularisation in TEVAR patients with coverage of the LSA, we searched the electronic databases MEDLINE and EMBASE historically until the end date of May 2010 with the search terms left subclavian artery, covering, endovascular, revascularisation and thoracic aorta. We have gathered the most complete scientific evidence available used to support the various concepts to deal with this issue. After a review of the current available literature, 23 relevant articles were found, where we have identified and analysed three basic treatment concepts for LSA revascularisation in TEVAR patients (prophylactic, conditional prophylactic and no prophylactic LSA revascularisation). The available evidence supports prophylactic revascularisation of the LSA before ESG LSA coverage when preoperative imaging reveals abnormal supra-aortic vascular anatomy or pathology. We further conclude that elective patients undergoing planned coverage of the LSA during TEVAR should receive prophylactic LSA transposition or LSA-to-left-common-carotid-artery (LCCA) bypass surgery to prevent severe neurological complications, such as paraplegia or brain stem infarction.

Protective and risk factors in amateur equestrians and description of injury patterns: A retrospective data analysis and a case - control survey

Background In Switzerland there are about 150,000 equestrians. Horse related injuries, including head and spinal injuries, are frequently treated at our level I trauma centre. Objectives To analyse injury patterns, protective factors, and risk factors related to horse riding, and to define groups of safer riders and those at greater risk Methods We present a retrospective and a case-control survey at conducted a tertiary trauma centre in Bern, Switzerland. Injured equestrians from July 2000 - June 2006 were retrospectively classified by injury pattern and neurological symptoms. Injured equestrians from July-December 2008 were prospectively collected using a questionnaire with 17 variables. The same questionnaire was applied in non-injured controls. Multiple logistic regression was performed, and combined risk factors were calculated using inference trees. Results Retrospective survey A total of 528 injuries occured in 365 patients. The injury pattern revealed as follows: extremities (32%: upper 17%, lower 15%), head (24%), spine (14%), thorax (9%), face (9%), pelvis (7%) and abdomen (2%). Two injuries were fatal. One case resulted in quadriplegia, one in paraplegia. Case-control survey 61 patients and 102 controls (patients: 72% female, 28% male; controls: 63% female, 37% male) were included. Falls were most frequent (65%), followed by horse kicks (19%) and horse bites (2%). Variables statistically significant for the controls were: Older age (p = 0.015), male gender (p = 0.04) and holding a diploma in horse riding (p = 0.004). Inference trees revealed typical groups less and more likely to suffer injury. Conclusions Experience with riding and having passed a diploma in horse riding seem to be protective factors. Educational levels and injury risk should be graded within an educational level-injury risk index.

[Guidance of interventions in subintimal recanalization and fenestration of dissection membranes using a novel dual-lumen intravascular ultrasound catheter]

PURPOSE: To evaluate the feasibility and effectiveness of IVUS-guided puncture for gaining controlled target lumen reentry in subintimal recanalization of chronic iliac/femoral artery occlusions and in fenestration of aortic dissections. MATERIALS AND METHODS: Between 5/2004 and 12/2005 12 consecutive patients (7 male, 5 female; mean age 64.6 +/- 12.0 years) with chronic critical limb ischemia and ischemic complications of aortic dissection were treated using the Pioneer catheter. This 6.2-F dual-lumen catheter combines a 20-MHz IVUS transducer with a pre-shaped extendable, hollow 24-gauge nitinol needle. This coaxial needle allows real-time IVUS-guided puncture of the target lumen and after successful reentry a 0.014" guidewire may be advanced through the needle into the target lumen. 7 patients were treated for aortic dissection and 5 patients (with failed previous attempts at subintimal recanalization) for chronic arterial occlusion. Patients with aortic dissection (5 type A dissections, 2 type B dissections) had developed renal ischemia (n = 2), renal and mesenteric ischemia (n = 2), or low extremity ischemia (n = 3). Patients with chronic arterial occlusions (2 common iliac artery occlusions, 3 superficial femoral artery occlusions) experienced ischemic rest pain (n = 4), and a non-healing foot ulcer (n = 1). RESULTS: The technical success rate using the Pioneer catheter was 100%. The recanalization/fenestration time was 37 +/- 12 min. Procedure-related complications did not occur. In 10 cases a significant improvement of clinical symptoms was evident. One patient with aortic dissection and ischemic paraplegia required subsequent surgical intervention. One patient had persistent ischemic rest pain despite successful recanalization of a superficial femoral artery occlusion. CONCLUSION: The Pioneer catheter is a reliable device which may be helpful for achieving target lumen reentry in subintimal recanalization of chronic occlusions and in fenestration of aortic dissections.

Analysis and mapping of CACNB4, CHRNA1, KCNJ3, SCN2A and SPG4, physiological candidate genes for porcine congenital progressive ataxia and spastic paresis

The cause of porcine congenital progressive ataxia and spastic paresis (CPA) is unknown. This severe neuropathy manifests shortly after birth and is lethal. The disease is inherited as a single autosomal recessive allele, designated cpa. In a previous study, we demonstrated close linkage of cpa to microsatellite SW902 on porcine chromosome 3 (SSC3), which corresponds syntenically to human chromosome 2. This latter chromosome contains ion channel genes (Ca(2+), K(+) and Na(+)), a cholinergic receptor gene and the spastin (SPG4) gene, which cause human epilepsy and ataxia when mutated. We mapped porcine CACNB4, KCNJ3, SCN2A and CHRNA1 to SSC15 and SPG4 to SSC3 with the INRA-Minnesota porcine radiation hybrid panel (IMpRH) and we sequenced the entire open reading frames of CACNB4 and SPG4 without finding any differences between healthy and affected piglets. An anti-epileptic drug treatment with ethosuximide did not change the severity of the disease, and pigs with CPA did not exhibit the corticospinal tract axonal degeneration found in humans suffering from hereditary spastic paraplegia, which is associated with mutations in SPG4. For all these reasons, the hypothesis that CACNB4, CHRNA1, KCNJ3, SCN2A or SPG4 are identical with the CPA gene was rejected.

Thoracic endovascular aortic repair: impact of urgency on outcome and quality of life

OBJECTIVES: Endovascular repair of the descending thoracic aorta is a very promising technique in elective and, particularly, emergency situations. This study assessed the impact of urgency of the procedure on outcome and mid-term quality of life in surviving patients. METHODS: Post hoc analysis of prospectively collected data of 58 consecutive patients (January 2001-December 2005) with surgical pathologies of the descending thoracic aorta treated by endovascular means. Six patients were excluded due to recent operations on the ascending aorta before thoracic endovascular repair. The remaining patients (n=52) were 69+/-10 years old, and 43 were men (83%). Twenty-seven had been treated electively, and 25 for emergency indications. Reasons for emergency were acute type B aortic dissections with or without malperfusion syndrome in 14, and aortic ruptures in 11 cases. Follow-up was 29+/-16 months. Endpoints were perioperative and late morbidity and mortality rates and long-term quality of life as assessed by the short form health survey (SF-36) and Hospital Anxiety and Depression Scale questionnaires. RESULTS: Cohorts were comparable regarding age, sex, cardiovascular risk factors, and comorbidities. Perioperative mortality was somewhat higher in emergency cases (12% vs 4%, p=0.34). Paraplegia occurred in one patient in each cohort (4%). Overall quality of life after two and a half years was similar in both treatment cohorts: 72 (58-124) after emergency, and 85 (61-105) after elective endovascular aortic repair (p=0.98). Normal scores range from 85 to 115. Anxiety and depression scores were in the normal range and comparable. CONCLUSIONS: Thoracic endovascular aortic repair is an excellent and safe treatment option for the diseased descending aorta, particularly in emergency situations. Early morbidity and mortality rates can be kept very low. Mid-term quality of life was not affected by the urgency of the procedure. Similarly, mid-term anxiety and depression scores were not increased after emergency situations.

Long-term outcome of acute spinal cord ischemia syndrome

BACKGROUND AND PURPOSE: Current knowledge of long-term outcome in patients with acute spinal cord ischemia syndrome (ASCIS) is based on few studies with small sample sizes and <2 years' follow-up. Therefore, we analyzed clinical features and outcome of all types of ASCIS to define predictors of recovery. METHODS: From January 1990 through October 2002, 57 patients with ASCIS were admitted to our center. Follow-up data were available for 54. Neurological syndrome and initial degree of impairment were defined according to American Spinal Injury Association (ASIA)/International Medical Society of Paraplegia criteria. Functional outcome was assessed by walking ability and bladder control. RESULTS: Mean age was 59.4 years; 29 were women; and mean follow-up was 4.5 years. The origin was atherosclerosis in 33.3%, aortic pathology in 15.8%, degenerative spine disease in 15.8%, cardiac embolism in 3.5%, systemic hypotension in 1.8%, epidural anesthesia in 1.8%, and cryptogenic in 28%. The initial motor deficit was severe in 30% (ASIA grades A and B), moderate in 28% (ASIA C), and mild in 42% (ASIA D). At follow-up, 41% had regained full walking ability, 30% were able to walk with aids, 20% were wheelchair bound, and 9% had died. Severe initial impairment (ASIA A and B) and female sex were independent predictors of unfavorable outcome (P=0.012 and P=0.043). CONCLUSIONS: Considering a broad spectrum of clinical presentations and origins, the outcome in our study was more favorable than in previous studies reporting on ASCIS subgroups with more severe initial deficits.

Is surgery in acute aortic dissection type A still contraindicated in the presence of preoperative neurological symptoms?

OBJECTIVES Severe neurological deficit (ND) due to acute aortic dissection type A (AADA) was considered a contraindication for surgery because of poor prognosis. Recently, more aggressive indication for surgery despite neurological symptoms has shown acceptable postoperative clinical results. The aim of this study was to evaluate early and mid-term outcomes of patients with AADA presenting with acute ND. METHODS Data from 53 patients with new-onset ND who received surgical repair for AADA between 2005 and 2012 at our institution were retrospectively reviewed. ND was defined as focal motor or sensory deficit, hemiplegia, paraplegia, convulsions or coma. Neurological symptoms were evaluated preoperatively using the Glasgow Coma Scale (GCS) and modified Rankin Scale (mRS), and at discharge as well as 3-6 months postoperatively using the mRS and National Institutes of Health Stroke Scale. Involvement of carotid arteries was assessed in the pre- and postoperative computed tomography. Logistic regression analysis was performed to detect predictive factors for recovery of ND. RESULTS Of the 53 patients, 29 (54.7%) showed complete recovery from focal ND at follow-up. Neurological symptoms persisted in 24 (45.3%) patients, of which 8 (33%) died without neurological assessment at follow-up. Between the two groups (patients with recovery and those with persisting ND), there was no significant difference regarding the duration of hypothermic circulatory arrest (28 ± 14 vs 36 ± 20 min) or severely reduced consciousness (GCS <8). Multivariate analysis showed significant differences for the preoperative mRS between the two groups (P < 0.007). A high preoperative mRS was associated with persistence of neurological symptoms (P < 0.02). Cardiovascular risk factors, age or involvement of supra-aortic branches were not predictive for persistence of ND. CONCLUSION More than half of our patients recovered completely from ND due to AADA after surgery. Severity of clinical symptoms had a predictive value. Patients suffering from AADA and presenting with ND before surgery should not be excluded from emergency surgery.

Spinal Spot Sign.

INTRODUCTION A marker predictive of hematoma expansion in the central nervous system could aid the selection of patients for hemostatic or surgical treatment. CASE REPORT Here, we present a 83-year-old patient with acute spinal subdural hematoma with paraparesis progressing to paraplegia. A contrast extravasation within the intraspinal hematoma was visualized on spinal MR indicating active bleeding (spinal spot sign). A second acquisition of contrast-enhanced MR images showed progression of contrast extravasation helping to different active bleeding from spinal arteriovenous malformations/fistula. CONCLUSIONS A "spinal spot sign" may be important for treatment decisions, notably in patients with incomplete neurological deficits at the time of imaging.

Contemporary spinal cord protection during thoracic and thoracoabdominal aortic surgery and endovascular aortic repair: a position paper of the vascular domain of the European Association for Cardio-Thoracic Surgery†.

Ischaemic spinal cord injury (SCI) remains the Achilles heel of open and endovascular descending thoracic and thoracoabdominal repair. Neurological outcomes have improved coincidentially with the introduction of neuroprotective measures. However, SCI (paraplegia and paraparesis) remains the most devastating complication. The aim of this position paper is to provide physicians with broad information regarding spinal cord blood supply, to share strategies for shortening intraprocedural spinal cord ischaemia and to increase spinal cord tolerance to transitory ischaemia through detection of ischaemia and augmentation of spinal cord blood perfusion. This study is meant to support physicians caring for patients in need of any kind of thoracic or thoracoabdominal aortic repair in decision-making algorithms in order to understand, prevent or reverse ischaemic SCI. Information has been extracted from focused publications available in the PubMed database, which are cohort studies, experimental research reports, case reports, reviews, short series and meta-analyses. Individual chapters of this position paper were assigned and after delivery harmonized by Christian D. Etz, Ernst Weigang and Martin Czerny. Consequently, further writing assignments were distributed within the group and delivered in August 2014. The final version was submitted to the EJCTS for review in September 2014.

Is surgery in aCute aortiC disseCtion type A still ContraindiCated in the presenCe of preoperative neurologiCal symptoms?

Gebiet: Kardiologie Abstract: OBJECTIVES: Severe neurologiCal defiCit (ND) due to aCute aortiC disseCtion type A (AADA) was Considered a ContraindiCation for surgery beCause of poor prognosis. ReCently, more aggressive indiCation for surgery despite neurologiCal symptoms has shown aCCeptable – postoperative CliniCal results. The aim of this study was to evaluate early and mid-term outComes of patients with AADA presenting with aCute ND. – – METHODS: Data from 53 patients with new-onset ND who reCeived surgiCal repair for AADA between 2005 and 2012 at our institution were retrospeCtively reviewed. ND was defined as foCal motor or sensory defiCit, hemiplegia, paraplegia, Convulsions or Coma. NeurologiCal symptoms were evaluated preoperatively using the Glasgow Coma SCale (GCS) and modified Rankin SCale (mRS), and at disCharge as well as 3–6 months postoperatively using the mRS and National Institutes of Health Stroke SCale. Involvement of Carotid arteries was assessed in the pre- and postoperative Computed tomography. LogistiC regression analysis was performed to deteCt prediCtive faCtors for reCovery of ND. – – RESULTS: Of the 53 patients, 29 (54.7%) showed Complete reCovery from foCal ND at follow-up. NeurologiCal symptoms persisted in 24 (45.3%) patients, of whiCh 8 (33%) died without neurologiCal assessment at follow-up. Between the two groups (patients with reCovery and – those with persisting ND), there was no signifiCant differenCe regarding the duration of hypothermiC CirCulatory arrest (28 ± 14 vs 36 ± 20 min) or severely reduCed ConsCiousness (GCS <8). Multivariate analysis showed signifiCant differenCes for the preoperative mRS between the two groups (P < 0.007). A high preoperative mRS was assoCiated with persistenCe of neurologiCal symptoms (P < 0.02). CardiovasCular risk faCtors, age or involvement of supra-aortiC branChes were not prediCtive for persistenCe of ND. – – CONCLUSION: More than half of our patients reCovered Completely from ND due to AADA after surgery. Severity of CliniCal symptoms had a prediCtive value. Patients suffering from AADA and presenting with ND before surgery should not be exCluded from emergenCy surgery.

Detection of haemorrhagic shock: Are vital signs obsolete? A commentary by Dr M. Luginbühl

The ATLS program by the American college of surgeons is probably the most important globally active training organization dedicated to improve trauma management. Detection of acute haemorrhagic shock belongs to the key issues in clinical practice and thus also in medical teaching. (In this issue of the journal William Schulz and Ian McConachrie critically review the ATLS shock classification Table 1), which has been criticized after several attempts of validation have failed [1]. The main problem is that distinct ranges of heart rate are related to ranges of uncompensated blood loss and that the heart rate decrease observed in severe haemorrhagic shock is ignored [2]. Table 1. Estimated blood loos based on patient's initial presentation (ATLS Students Course Manual, 9th Edition, American College of Surgeons 2012). Class I Class II Class III Class IV Blood loss ml Up to 750 750–1500 1500–2000 >2000 Blood loss (% blood volume) Up to 15% 15–30% 30–40% >40% Pulse rate (BPM) <100 100–120 120–140 >140 Systolic blood pressure Normal Normal Decreased Decreased Pulse pressure Normal or ↑ Decreased Decreased Decreased Respiratory rate 14–20 20–30 30–40 >35 Urine output (ml/h) >30 20–30 5–15 negligible CNS/mental status Slightly anxious Mildly anxious Anxious, confused Confused, lethargic Initial fluid replacement Crystalloid Crystalloid Crystalloid and blood Crystalloid and blood Table options In a retrospective evaluation of the Trauma Audit and Research Network (TARN) database blood loss was estimated according to the injuries in nearly 165,000 adult trauma patients and each patient was allocated to one of the four ATLS shock classes [3]. Although heart rate increased and systolic blood pressure decreased from class I to class IV, respiratory rate and GCS were similar. The median heart rate in class IV patients was substantially lower than the value of 140 min−1 postulated by ATLS. Moreover deterioration of the different parameters does not necessarily go parallel as suggested in the ATLS shock classification [4] and [5]. In all these studies injury severity score (ISS) and mortality increased with in increasing shock class [3] and with increasing heart rate and decreasing blood pressure [4] and [5]. This supports the general concept that the higher heart rate and the lower blood pressure, the sicker is the patient. A prospective study attempted to validate a shock classification derived from the ATLS shock classes [6]. The authors used a combination of heart rate, blood pressure, clinically estimated blood loss and response to fluid resuscitation to classify trauma patients (Table 2) [6]. In their initial assessment of 715 predominantly blunt trauma patients 78% were classified as normal (Class 0), 14% as Class I, 6% as Class II and only 1% as Class III and Class IV respectively. This corresponds to the results from the previous retrospective studies [4] and [5]. The main endpoint used in the prospective study was therefore presence or absence of significant haemorrhage, defined as chest tube drainage >500 ml, evidence of >500 ml of blood loss in peritoneum, retroperitoneum or pelvic cavity on CT scan or requirement of any blood transfusion >2000 ml of crystalloid. Because of the low prevalence of class II or higher grades statistical evaluation was limited to a comparison between Class 0 and Class I–IV combined. As in the retrospective studies, Lawton did not find a statistical difference of heart rate and blood pressure among the five groups either, although there was a tendency to a higher heart rate in Class II patients. Apparently classification during primary survey did not rely on vital signs but considered the rather soft criterion of “clinical estimation of blood loss” and requirement of fluid substitution. This suggests that allocation of an individual patient to a shock classification was probably more an intuitive decision than an objective calculation the shock classification. Nevertheless it was a significant predictor of ISS [6]. Table 2. Shock grade categories in prospective validation study (Lawton, 2014) [6]. Normal No haemorrhage Class I Mild Class II Moderate Class III Severe Class IV Moribund Vitals Normal Normal HR > 100 with SBP >90 mmHg SBP < 90 mmHg SBP < 90 mmHg or imminent arrest Response to fluid bolus (1000 ml) NA Yes, no further fluid required Yes, no further fluid required Requires repeated fluid boluses Declining SBP despite fluid boluses Estimated blood loss (ml) None Up to 750 750–1500 1500–2000 >2000 Table options What does this mean for clinical practice and medical teaching? All these studies illustrate the difficulty to validate a useful and accepted physiologic general concept of the response of the organism to fluid loss: Decrease of cardiac output, increase of heart rate, decrease of pulse pressure occurring first and hypotension and bradycardia occurring only later. Increasing heart rate, increasing diastolic blood pressure or decreasing systolic blood pressure should make any clinician consider hypovolaemia first, because it is treatable and deterioration of the patient is preventable. This is true for the patient on the ward, the sedated patient in the intensive care unit or the anesthetized patients in the OR. We will therefore continue to teach this typical pattern but will continue to mention the exceptions and pitfalls on a second stage. The shock classification of ATLS is primarily used to illustrate the typical pattern of acute haemorrhagic shock (tachycardia and hypotension) as opposed to the Cushing reflex (bradycardia and hypertension) in severe head injury and intracranial hypertension or to the neurogenic shock in acute tetraplegia or high paraplegia (relative bradycardia and hypotension). Schulz and McConachrie nicely summarize the various confounders and exceptions from the general pattern and explain why in clinical reality patients often do not present with the “typical” pictures of our textbooks [1]. ATLS refers to the pitfalls in the signs of acute haemorrhage as well: Advanced age, athletes, pregnancy, medications and pace makers and explicitly state that individual subjects may not follow the general pattern. Obviously the ATLS shock classification which is the basis for a number of questions in the written test of the ATLS students course and which has been used for decades probably needs modification and cannot be literally applied in clinical practice. The European Trauma Course, another important Trauma training program uses the same parameters to estimate blood loss together with clinical exam and laboratory findings (e.g. base deficit and lactate) but does not use a shock classification related to absolute values. In conclusion the typical physiologic response to haemorrhage as illustrated by the ATLS shock classes remains an important issue in clinical practice and in teaching. The estimation of the severity haemorrhage in the initial assessment trauma patients is (and was never) solely based on vital signs only but includes the pattern of injuries, the requirement of fluid substitution and potential confounders. Vital signs are not obsolete especially in the course of treatment but must be interpreted in view of the clinical context. Conflict of interest None declared. Member of Swiss national ATLS core faculty.