Diagnosis and management of blunt great vessel trauma.

Traditionally, thoracic aortic rupture, suspected after blunt thoracic trauma, is characterized by a chest radiograph showing a widened mediastinum. The diagnostic machinery consecutively activated still depends heavily on the pressure as additional traumatic lesions. A patient with additional cranio-cerebral trauma would typically undergo contrast-enhanced computed tomography or magnetic resonance imaging of head, chest, and other regions. In a number of patients these analyses would confirm the presence of blood in the mediastinum without formal proof of an aortic disruption. This is because mediastinal hematomas may be caused not only by an aortic rupture, but also by numerous other blood sources including fractures of the spine and other macro- and microvascular lesions providing similar images. Therefore, aortic angiography became our preferred diagnostic tool to identify or rule out acute traumatic lesions of not only the aorta but with great vessels. However recently, a number of traumatic aortic transsections have been identified by transoesophageal echocardiography (TEE). TEE has the additional advantage of being a bed-side procedure providing additional information about cardiac function. The latter analysis allows for identification and quantification of cardiac contusions, post-traumatic myocardial infarctions, and valvar lesions which are of prime importance to develop an adequate surgical strategy and to assess the risk of the numerous emergency procedures required in patients with polytrauma. The standard approach for repair of isthmic aortic rupture is through a lateral thoracotomy. Distal and proximal control of the aorta can be achieved in a substantial number of cases before complete aortic rupture occurs and a higher proportion of direct suture repair can be achieved under such circumstances. Most proximal descending aortic procedures are performed without cardiopulmonary bypass (clamp and go) but paraplegia may occur before, during, or after the procedure. Ascending aortic lesions and disruption of the aortic arch, the supra-aortic vessels, the main pulmonary arteries, the great veins as well as cardiac lesions are best approached through a sternotomy, which may have to be extended. Cardiopulmonary bypass allowing for deep hypothermia and circulatory arrest is often required and carries its own complications. It is not clear whether the increasing proportion of ascending aortic and cardiac lesions which are observed nowadays are due to a change in trauma mechanics (i.e., speed limits, seat belts, air-bags), an improvement of the diagnostic tools or both.

In situ aortobiiliac reconstruction of infected aneurysm using a single superficial femoral vein.

Objective: To demonstrate successful in situ aortoiliac reconstruction of an infected infrarenal aneurysm using one single superficial femoral vein (SFV). Methods: In situ reconstruction using the right SFV sutured in end-to-end anastomosis with the aorta and distally with the right common iliac artery and in end-to-side anastomosis with the left common iliac artery. Results: The operating time was less than reported for aortic in situ reconstruction with bilateral SFV harvesting. The duplex scan 3 months postoperatively showed permeability of the bypass without any anastomotic stenosis or pseudoaneurysm. The right common femoral, popliteal, and greater saphenous veins were patent without thrombus, and the patient did not complain about peripheral edema. Conclusions: The use of only one instead of both the SFVs for aortobiiliac in situ reconstruction might be a way to reduce operating time and allow autogenous venous reconstruction even in patients with limited availability of venous material.

The region makes the difference: disparities in management of acute myocardial infaction within Switzerland

Purpose: To assess geographical differences within Switzerland regarding management and revascularization procedures for acute myocardial infarction (AMI). Methods: Swiss hospital discharge database for period 2007-2008. The main inclusion criterion was AMI as a primary discharge diagnosis. AMI revascularization procedures were identified and seven Swiss regions (Leman, Mittelland, Northwest, Zurich, Central, Eastern and Ticino) were analyzed. Results: Data from 25,674 AMI discharges were analyzed. Almost half (53.6%) of them were managed in a single hospital, the values ranging from 63.1% (Leman) to 31.4% (Ticino) see table. Relative to the total number of discharges, the highest Intensive Care Unit admission rate was in Leman (69.7%), the lowest (16.4%) in Ticino (Swiss average: 35.8%). Intracoronary revascularization rates were highest in Leman (51.6%) and lowest (30.8%) in Central Switzerland (Swiss average: 41.4%). Bare (non-drug-eluting) stents use was highest in Leman (33.1%) and lowest (7.0%) in Ticino (Swiss average: 15.8%), while drug eluting stent use was highest (32.8%) in Ticino and lowest (13.9%) in Central Switzerland (Swiss average: 24.0%). Coronary artery bypass graft rates were highest (4.6%) in Ticino and lowest (0.4%) in Eastern Switzerland (Swiss average: 2.6%). Mechanical circulatory assistance rates were highest (4.1%) in Zurich and lowest (0.4%) in Ticino (Swiss average: 1.7%). The differences in revascularization procedures remained after adjusting for age, single or multiple hospital management and gender. Conclusion: In Switzerland, significant geographical differences in management and revascularization procedures for AMI were found.

Déficits dans les apports nutritionnels chez les candidats a la chirurgie bariatrique [Nutritional deficiencies in candidates for bariatric surgery]

98% of patients who have undergone a gastric bypass for treating severe obesity develop multiple micronutrient deficits. However, prior to surgery, it isn't rare to find nutrient deficiencies. Indeed, the dietary intakes of surgery candidates are often unbalanced, lacking in variety especially in high vitamin and mineral nutrients. We present the preliminary results concerning the qualitative and quantitative analysis in a group of patients waiting for a gastric bypass. The recommended daily amounts in vitamin B9, vitamin D and iron are insufficient in the majority of the patients. The correction of nutritional intakes is advisable, even before the surgery, in order to reduce the risks of developing biological deficiencies.

The effect of n-3 enriched nutrition therapy on post-operative cognitive dysfunction after cardiac surgery

Background: Postoperative cognitive dysfunction (POCD) occurs frequently after cardiac surgery. Some data suggest that inflammation plays a key role in the development of POCD. N-3 fatty acids have been shown to have a beneficial effect on inflammation. We hypothesised that perioperative n-3 enriched nutrition therapy would reduce the incidence of POCD in this group of patients. Methods: Randomized, double blind placebo controlled trial in patients aged 65 or older undergoing elective cardiac surgery with cardiopulmonary bypass. 2x 250 mL placebo (Ensure Plus™, Abbott Nutrition) or n-3 enriched nutrition therapy (ProSure™ Abbott Nutrition) were administered for ten days starting 5 days prior to surgery. Cognition was assessed preoperatively and 7 days after surgery with the Consortium to Establish a Registry for Alzheimer's Disease - Neuropsychological Assessment Battery (CERAD-NAB) [1]. Results: 16 patients were included. Mean age was 72 } 5.3 for placebo and 75 } 4.8 for ProSure™ respectively. CRP and IL-6 did not differ significantly between groups preoperatively and on postoperative days 1, 3, and 7. Preoperative CERAD total scores were 86 } 10 and 81 } 9 (p = n.s.) for Placebo and ProSure™, respectively. Postoperative scores were 88 } 12, and 77 } 19 (p = n.s.) The change in score was not different between the two groups (Placebo: +3 } 5; ProSure: -5 } 11). Conclusion: In this very small sample no effect of preoperatively started n-3 enriched nutritional supplements on inflammation or cognitive functions were detected. However, there is a large likelihood of a type II error and more patients need to be included to assess possible beneficial effects of this intervention in elderly patients undergoing elective cardiac surgery. 1 Chandler MJ, et al. Neurology. 2005;65:102-6.

Hyperkalemia. A prognostic factor during acute severe hypothermia.

When hypothermic patients appear to be dead, the decision to resuscitate may be difficult due to lack of reliable criteria of death. To discover useful prognostic indicators, we reviewed the hospital charts of nine hypothermic victims of snow avalanches (group A: median value of rectal temperature, 29.6 degrees C; range, less than 12 degrees C to 34 degrees C) and of 15 patients with hypothermia following acute drug intoxication and/or cold exposure (group B: 28.8 degrees C; range, 25.5 degrees C to 32 degrees C. In group A, plasma potassium level on admission was extremely high (14.5 mmol/L; range, 6.8 to 24.5 mmol/L) compared with that obtained in group B (3.5 mmol/L; range, 2.7 to 5.3 mmol/L). All patients in group A were in cardiorespiratory arrest. None could be successfully resuscitated despite effective rewarming by cardiopulmonary bypass or peritoneal lavage. In contrast, all of the patients in group B recovered from hypothermia, including two in cardiorespiratory arrest. Thus, extreme hyperkalemia during acute hypothermia appears to be a reliable marker of death. It might be used to select those patients in whom heroic resuscitation efforts can be useful.

Rivascolarizzazione miocardica con arteria radiale: tecniche chirurgiche a confronto e risultati a breve termine [Myocardial revascularization and radial artery: different surgical strategies and short-term results]

BACKGROUND: The radial artery is routinely used as a graft for surgical arterial myocardial revascularization. The proximal radial artery anastomosis site remains unknown. In this study, we analyzed the short-term results and the operative risk determinants after having used four different common techniques for radial artery implantation. METHODS: From January 2000 to December 2004, 571 patients underwent coronary artery bypass grafting with radial arteries. Data were analyzed for the entire population and for subgroups following the proximal radial artery anastomosis site: 140 T-graft with the mammary artery (group A), 316 free-grafts with the proximal anastomosis to the ascending aorta (group B), 55 mammary arteries in situ elongated with the radial artery (group C) and 60 radial arteries elongated with a piece of mammary artery and anastomosed to the ascending aorta (group D). RESULTS: The mean age was 53.8 +/- 7.7 years; 55.5% of patients had a previous myocardial infarction and 73% presented with a satisfactory left ventricular function. A complete arterial myocardial revascularization was achieved in 532 cases (93.2%) and 90.2% of the procedures were performed under cardiopulmonary bypass and cardioplegic arrest. The operative mortality rate was 0.9%, a postoperative myocardial infarction was diagnosed in 19 patients (3.3%), an intra-aortic balloon pump was used in 10 patients (1.7%) and a mechanical circulatory device was implanted in 2 patients. The radial artery harvesting site remained always free from complications. The proximal radial artery anastomosis site was not a determinant of early hospital mortality. Group C showed a higher risk of postoperative myocardial infarction (p = 0.09), together with female gender (p = 0.003), hypertension (p = 0.059) and a longer cardiopulmonary bypass time. CONCLUSIONS: The radial artery and the mammary artery can guarantee multiple arterial revascularization also for patients with contraindications to double mammary artery use. The four most common techniques for proximal radial artery anastomosis are not related to a higher operative risk and they can be used alternatively to reach the best surgical results

Enteral nutrition and cardiovascular failure: from myths to clinical practice.

Cardiovascular failure and low flow states may arise in very different conditions from both cardiac and noncardiac causes. Systemic hemodynamic failure inevitably alters splanchnic blood flow but in an unpredictable way. Prolonged low splanchnic blood flow causes intestinal ischemia, increased mucosal permeability, endotoxemia, and distant organ failure. Mortality associated with intestinal ischemia is high. Why would enteral nutrition (EN) be desirable in these complex patients when parenteral nutrition could easily cover energy and substrate requirements? Metabolic, immune, and practical reasons justify the use of EN. In addition, continuous enteral feeding minimizes systemic and myocardial oxygen consumption in patients with congestive heart failure. Further, early feeding in critically ill mechanically ventilated patients has been shown to reduce mortality, particularly in the sickest patients. In a series of cardiac surgery patients with compromised hemodynamics, absorption has been maintained, and 1000-1200 kcal/d could be delivered by enteral feeding. Therefore, early EN in stabilized patients should be attempted, and can be carried out safely under close clinical monitoring, looking for signs of incipient intestinal ischemia. Energy delivery and balance should be monitored, and combined feeding considered when enteral feeds cannot be advanced to target within 4-6 days.

3D culture of postnatal retinal stem cells using self assembling polymers

PURPOSE We have previously shown that retinal stem cells (RSCs) can be isolated from the radial glia population of the newborn mouse retina (Angénieux et al., 2006). These RSCs have a great capacity to renew and to generate a large number of neurons including cells differentiated towards the photoreceptor lineage (Mehri-Soussi et al., 2006). However, recent published results from our lab revealed that such cells have a poor integration and survival rate after grafting. The uncontrolled environment of a retina seems to prevent good integration and survival after grafting in vivo. To bypass this problem, we are evaluating the possibility of generating in vitro a hemi-retinal tissue before transplantation. METHODS RSC were expanded and cells passaged <10 were seeded in a solution containing poly-ethylene-glycol (PEG) polymer based hydrogels crosslinked with peptides that are chosen to be substrates for matrix metalloproteinases. Various doses of cross linkers peptides allowing connections between PEG polymers were tested. Different growth factors were studied to stimulate cell proliferation and differentiation. RESULTS Cells survived only in the presence of EGF and FGF-2 and generated colonies with a sphere shape. No cells migrated within the gel. To improve the migration and the repartition of the cells in the gels, the integrin ligand RGDSP was added into the gel. In the presence of FGF-2 and EGF, newly formed cell clusters appeared by cell proliferation within several days, but again no outspreading of cells was observed. No difference was even seen when the stiffness of the hydrogels or the concentration of the integrin ligand RGDSP were changed. However, our preliminary results show that RSCs still form spheres when laminin is entrapped in the gel, but they started to spread out having a neuronal morphology after around 2 weeks. The neuronal population was assessed by the presence of the neuronal marker b-tubulin-III. This differentiation was achieved after successive steps of stimulations including FGF-2 and EGF, and then only FGF-2. Glial cells were also present. Further characterizations are under process. CONCLUSIONS RSC can be grown in 3D. Preliminary results show that neuronal cell phenotype acquisition can be instructed by exogenous stimulations and factors linked to the gel. Further developments are necessary to form a homogenous tissue containing retinal cells.

Interventions hybrides et malformations cardiaques congénitales [Hybrid procedures in congenital heart disease]

La complexité croissante de la prise en charge des malformations cardiaques congénitales impose des interventions chirurgicales et des cathétérismes cardiaques interventionnels fréquents. Chacune de ces techniques a ces limitations propres. Les interventions hybrides associent les avantages de la chirurgie cardiaque et du cathétérisme interventionnel. Dans notre expérience, les thérapies hybrides permettent de diminuer le temps de circulation extracorporelle, de diminuer la morbidité des interventions chirurgicales, de raccourcir le séjour du patient aux soins intensifs. Pour certaines malformations cardiaques congénitales complexes pour lesquelles il n'existe pas de chirurgie ou de thérapie interventionnelle idéale, les interventions hybrides sont en train de s'imposer comme la prise en charge incontournable. Increasing complexity in management of congenital heart disease imposes more frequent surgeries and interventions. Each technique has its own limitations, which could impair the anticipated result. Hybrid procedures join the advantages of cardiac surgery and interventions, creating a synergy in the management of these patients with cardiac anomalies. In our experience, hybrid procedures shorten cardiopulmonary bypass, reduce morbidity of surgery and reduce duration of stay in the intensive care unit. For some complex congenital heart diseases for which there are no ideal surgical or interventional options, hybrid procedures are becoming increasingly important in their management. Finally hybrid procedures allow surgeons and cardiologist to achieve complex procedures that could not be possible in another way

O2 consumption by the fick method. Methodologic factors.

This study aimed to compare O2 consumption (VO2) determination by the gas-exchange (VO2GE) and Fick (VO2F) methods in cardiac surgical patients. A total of 10 mechanically ventilated postoperative patients were studied prospectively. Thermodilution was performed using three randomly applied techniques: room temperature saline injected at end expiration, room temperature saline randomly injected in the respiratory cycle, and iced saline injected at end expiration. The influence of the number of thermodilution determinations was assessed by comparing results from 2 and 10 injections. The variability of VO2F was greater than that of VO2GE. There was no bias between VO2GE and VO2F values using injectate at room temperature. Accuracy and precision were not improved by increasing the number of cardiac output determinations from 2 to 10. A significant bias was observed using ice-cold injectate, VO2F being 18.0 +/- 15.4 ml/min/m2 lower than VO2GE (p = 0.001). Published results when comparing VO2F and VO2GE are discrepant. However, a significant bias was found in all studies using cold injectate, with lower VO2F values. We conclude that iced injectate should not be used to assess VO2 in critically ill patients.

Success of thrombolysis as a predictor of outcome in acute thrombosis of popliteal aneurysms.

PURPOSE: Acute limb ischemia after thrombosis of a popliteal aneurysm is a distinct and limb-threatening entity. Preoperative intra-arterial thrombolysis may improve the outcome in this challenging situation. This study retrospectively analyzed a consecutive series of patients treated with preoperative thrombolysis and subsequent revascularization. METHODS: Thirteen patients with acute limb ischemia caused by thrombosis of a popliteal aneurysm underwent catheter-directed intra-arterial thrombolysis with urokinase and subsequent vascular reconstruction. The angiographic and clinical outcome was analyzed and compared with that in the literature. RESULTS: Complete aneurysm thrombosis with absence of runoff was documented in 12 cases. Thrombolysis restored perfusion with patency of the popliteal artery and a one- or two-vessel runoff in 77% of cases (10/13). Early cumulative graft patency and limb salvage rates were 68% and 83%, respectively, with an ankle/brachial index of 0.8 +/- 0.2. Lytic failure followed by attempts at bypass grafting was present in three patients (23%) and resulted in above-knee amputation. Severe rhabdomyolysis and fatal pulmonary embolism were responsible for a 15% early mortality rate. CONCLUSION: Preoperative thrombolysis followed by bypass grafting is a valid treatment option for patients who can withstand an additional period of ischemia that does not require immediate revascularization and intraoperative lysis. Lytic failure identifies patients with a highly compromised runoff who are probably best treated by means of subsequent amputation, without any attempts at bypass grafting.

Persistent left superior vena cava in cardiac congenital surgery.

Persistent left superior vena cava (LSVC) is a relatively frequent finding in congenital cardiac malformation. The scope of the study was to analyze the timing of diagnosis of persistent LSVC, the timing of diagnosis of associated anomalies of the coronary sinus, and the global impact on morbidity and mortality of persistent LSVC in children with congenital heart disease after cardiac surgery. Retrospective analysis of a cohort of children after cardiac surgery on bypass for congenital heart disease. Three hundred seventy-one patients were included in the study, and their median age was 2.75 years (IQR 0.65-6.63). Forty-seven children had persistent LSVC (12.7 %), and persistent LSVC was identified on echocardiography before surgery in 39 patients (83 %). In three patients (6.4 %) with persistent LSVC, significant inflow obstruction of the left ventricle developed after surgery leading to low output syndrome or secondary pulmonary hypertension. In eight patients (17 %), persistent LSVC was associated with a partially or completely unroofed coronary sinus and in two cases (4 %) with coronary sinus ostial atresia. Duration of mechanical ventilation was significantly shorter in the control group (1.2 vs. 3.0 days, p = 0.04), whereas length of stay in intensive care did not differ. Mortality was also significantly lower in the control group (2.5 vs. 10.6 %, p = 0.004). The results of study show that persistent LSVC in association with congenital cardiac malformation increases the risk of mortality in children with cardiac surgery on cardiopulmonary bypass. Recognition of a persistent LSVC and its associated anomalies is mandatory to avoid complications during or after cardiac surgery.