Olivier Chavanon

Emergency endovascular stent graft repair for acute blunt thoracic aortic injury: a retrospective case control study

ObjectiveTo compare surgical and endovascular stent graft (ESG) treatment of blunt thoracic aortic injury (BAI) in the emergency setting.Design and settingRetrospective case control study in two surgical intensive care units of axa0university hospital.Patients30 patients who presented with BAI between 1995 and 2005: 17 treated surgically and 13 by ESG. The two groups were comparable for the severity of trauma and mean delay before treatment; the mean age was higher in the ESG group (46u202f±u202f18 vs. 35u202f±u202f15u202fyears).ResultsIn the surgical group time spent in the operating theater was longer (310u202f±u202f130 vs. 140u202f±u202f48u202fmin) and blood losses higher (2000u202f±u202f1300 vs. no significant bleeding); aortic clamping time was 48u202f±u202f20u202fmin. The mortality rate was 15% with ESG (nu202f=u202f2) and 23% with surgery (nu202f=u202f4). Complications of the procedure were more frequent in the surgical group (1 vs. 7). In the ESG group there was one pulmonary embolism. In the surgical group there were three neurological complications, one acute aortic dissection, one perioperative rupture, one periprosthetic leak, and one septic shock. Two complications (postoperative aortic dissection and paraplegia) appeared in the same patient in the surgical group. Intensive care unit length of stay, duration of mechanical ventilation, and catecholamine support were similar in the two groups.ConclusionsStent graft for emergency treatment of BAI is efficient and is associated with fewer complications than surgical treatment.

Prognostic factors for extracorporeal cardiopulmonary resuscitation recipients following out-of-hospital refractory cardiac arrest. A systematic review and meta-analysis

PURPOSEnAssociation estimates between baseline characteristics and outcomes are imprecise and inconsistent among extracorporeal cardiopulmonary resuscitation (ECPR) recipients following refractory out-of-hospital cardiac arrest (OHCA). This systematic review and meta-analysis aimed to investigate the prognostic significance of pre-specified characteristics for OHCA treated with ECPR.nnnMETHODSnThe Medline electronic database was searched via PubMed for articles published from January 2000 to September 2016. The electronic search was supplemented by scanning the reference lists of retrieved articles and contacting field experts. Eligible studies were historical and prospective cohort studies of adult patients undergoing ECPR following OHCA.nnnRESULTSnFifteen primary studies were included, totaling 841 participants. The median prevalence of the primary outcome (i.e., short- or long-term survival for five studies and cerebral performance for ten studies) was 15% (range, 0-50%). The primary outcome was associated with an increased odds ratio of initial shockable cardiac rhythm (2.20; 95% confidence interval [CI], 1.30-3.72; P=0.003), shorter low-flow duration (geometric mean ratio, 0.90; 95% CI, 0.81-0.99; P=0.04), higher arterial pH value (difference, 0.12; 95% CI, 0.03-0.22; P=0.01) and lower serum lactate concentration (difference, -3.52mmol/L; 95% CI, -5.05 to -1.99; P<0.001). No significant association was found between the primary outcome and patient age (the odds of female gender and bystander CPR attempt.nnnCONCLUSIONnObservational evidence from published primary studies indicates that shorter low-flow duration, shockable cardiac rhythm, higher arterial pH value and lower serum lactate concentration on hospital admission are associated with better outcomes for ECPR recipients after OHCA.

Coronary artery bypass grafting with left internal mammary artery and right gastroepiploic artery, with and without bypass

BACKGROUNDnTotal arterial and off-pump revascularization are increasingly used in coronary artery bypass grafting. This study describes our experience with the exclusive use of both left internal thoracic artery and gastroepiploic artery by means of a median sternotomy, with and without cardiopulmonary bypass, in a subgroup of patients with two-vessel disease.nnnMETHODSnFrom January 1995 to July 2000, 171 consecutive patients were reviewed in a prospective database. Ninety-one patients underwent coronary artery bypass grafting without cardiopulmonary bypass (group A), and 80 patients were operated on under cardiopulmonary bypass with aortic cross-clamp and cardioplegia (group B).nnnRESULTSnPatient data were similar in both groups except for the Euroscore (mean; 3.4+/-6.1, group A versus 2.5+/-4.5, group B; Euroscore > 6: 26.4%, group A versus 10%, group B; p < 0.05) and ejection fraction (mean, 54.6%+/-15.8%, group A versus 63.1%+/-12.7%, group B; p < 0.001). Severe aortic calcification was present in 6 group A patients, versus no patient in group B. Operative time was shorter in group A (185 versus 213 minutes, p < 0.0001), with less distal anastomoses (2.26 versus 2.5, p < 0.05). Conversion to cardiopulmonary bypass occurred in 1 patient, who was excluded from the study. Bleeding was higher in group A (852.6+/-288 mL versus 712.4+/-274 mL, p < 0.05), but transfusion was similar in both groups. Atrial fibrillation, postoperative inotropic support, and hospital stay were similar in both groups. Myocardial infarction was less frequent in group A (1 versus 4). Postoperative intraaortic balloon pump was used in 2 patients (group B). One patient died (group A) and 1 had an embolic stroke (group B). After discharge, 2 more patients died (group A, day 91; group B day 141), and 1 patient suffered an embolic stroke (group B). One patient in each group presented with dysfunction of the gastroepiploic artery graft requiring successful percutaneous transluminal angioplasty on the right posterolateral artery.nnnCONCLUSIONSnThese results suggest that off-pump coronary artery bypass grafting using the left internal thoracic artery and gastroepiploic artery is safe even in high-risk patients. This approach allows an absolute no-touch technique of the aorta.

Outcome after severe accidental hypothermia in the French Alps: A 10-year review

OBJECTIVEnTo describe the factors associated with outcome after accidental deep hypothermia.nnnMETHODSnWe conducted a retrospective cohort study on patients with accidental hypothermia (core temperature <28 °C) admitted to a Level I emergency room over a 10-year period.nnnRESULTSnForty-eight patients were included with a median temperature of 26 °C (range, 16.3-28 °C) on admission. The etiology of hypothermia was exposure to a cold environment (n = 27), avalanche (n = 13) or immersion in cold water (n = 8). Mean age was 47 ± 22 years, and 58% were males. Thirty-two patients had a cardiac arrest (CA): 15 patients presented unwitnessed cardiac arrest (UCA) and 17 patients presented rescue collapse (RC). Extracorporeal life support (ECLS) was implemented in 21 patients with refractory cardiac arrest and in two patients with hemodynamic instability. Overall mortality was 50%. For cardiac arrest patients, only three out of 15 patients with UCA survived at day 28, whereas eight out of 17 patients with RC survived. The cerebral performance category score was 4 for all the survivors of UCA and 1 [range, 1-2] for survivors of RC. Patients with poor outcome presented more UCA, a lower pH, a higher serum potassium, creatinine, serum sodium or lactate level as well as more severe coagulation disorders.nnnCONCLUSIONnCardiac arrest related to rescue collapse was associated with favorable outcome. On-scene rescue collapse should prompt prolonged resuscitation and ECLS rewarming in all CA patients with deep hypothermia. Conversely, unwitnessed cardiac arrest was associated with unfavorable outcome and will likely not benefit from ECLS.

Neurologic recovery from profound accidental hypothermia after 5 hours of cardiopulmonary resuscitation.

Objective:To describe the successful neurologic recovery from profound accidental hypothermia with cardiac arrest despite the longest reported duration of cardiopulmonary resuscitation. Design:Case report. Setting:Mountain. Patient:A 57-year-old woman experienced profound accidental hypothermia (16.9°C) in a mountainous region of Grenoble. She was unconscious and had extreme bradycardia (6 beats/min) at presentation. A cardiac arrest occurred at the mobilization that was not responsive to electrical shocks or epinephrine. Intervention:Cardiopulmonary resuscitation was continued for 307 minutes after rescue until venoarterial extracorporeal membrane oxygenation blood flow had been established at the emergency department. Measurements and Main Results:At a 3-month follow-up, the patient showed good physical and mental recovery. Conclusion:With no evidence of trauma or asphyxia, profound accidental hypothermia with cardiac arrest represents a specific condition for which successful neurologic recovery is feasible despite prolonged cardiopulmonary resuscitation.

Effect of topical vasodilators on gastroepiploic artery graft.

BACKGROUNDnMobilization of the gastroepiploic artery (GEA) often results in a vasospasm with reduction of early graft flow. In order to prevent or suppress this highly reactive arterys spasm, we have compared the effect of 4 vasodilators, used in external application to prepare the GEA graft, prior to myocardial revascularization.nnnMETHODSnWE performed a double-blind clinical study to compare the effects of external application of vasodilators on gastroepiploic artery grafts. Fifty patients, whose gastroepiploic artery was used for coronary artery bypass grafting, were randomized into 5 groups of 10 patients. Gastroepiploic artery free flow and hemodynamic measurements were evaluated immediately after harvesting, before any pharmacological manipulation, and 10 minutes after the topical application of vasodilators, respectively: papaverine, linsidomine, nicardipine, glyceryl trinitrate, and normal saline solution.nnnRESULTSnA significant increase in free flow occurred in all groups except for the normal saline solution group with measurements from 26.1+/-3.6 mL/min to 26.4+/-6.5 mL/min; p = 0.9. The most important increase in flow before and after local application occurred with glyceryl trinitrate and papaverine: from 25.5+/-2 mL/min to 50+/-6.1 mL/min (p < or = 0.01) and from 36.8+/-3.2 mL/min to 62+/-7.8 mL/min (p < 0.01) respectively. Nicardipine and linsidomine produced a less significant increase in flow: from 33.1+/-3.6 mL/min to 47.7+/-8.9 mL/min (p < 0.05) and from 28+/-3.8 mL/min to 39.8+/-7.5 mL/min (p < 0.05) respectively. When comparing percentage of flow increase, glyceryl trinitrate appeared to be significantly more efficient than nicardipine and linsidomine (p < 0.01 versus both groups). Although papaverine was more efficient than nicardipine and linsidomine, it did not reach statistical significance.nnnCONCLUSIONSnDuring intraoperative preparation of the GEA graft, glyceryl trinitrate and papaverine to a lesser extent, used as topical vasodilators, appear to be more efficient in external application to increase the free flow of the GEA.

Computer-guided pericardiocentesis: experimental results and clinical perspectives.

Percutaneous pericardial puncture is a relatively safe and effective technique in case of large pericardial effusions when practiced under echographic or radiological control. The goal of our project is to improve the performance of this technique, mainly in case of smaller and loculated effusions using an accurate guidance towards a preplanned target, based on a model of the pericardial effusion. This paper presents preclinical results of this new computer-assisted technique used to reach the pericardial cavity.The procedure is divide into 3 steps: 1. acquisition of ultrasound data, using an echocardiographic device connected to a 3-D localizer and to a computer, 2. modeling procecure to define the optimal strategy taking into account the mobility of organs on a digital model, 3. guided puncture with a localized needle to reach the predefined target using a passive guidance system. After validation on a dynamic phantom and a feasibility study on dogs, an accuracy and reliability analysis protocol was realized on pigs with experimental pericardial effusion.Feasibility of the technique is demonstrated on animal study with an accuracy of at least 2.5 mm. Further clinical investigation is in progress using a more ergonomic and less cumbersome system.This study demonstrates the feasibility of computer-assisted pericardiocentesis. Beyond the simple improvement of the current technique, this could be a new way to reach the heart or a new tool for percutaneous access and image-guided puncture of soft tissues.ZusammenfassungDie perkutane Perikardpunktion ist ein relativ sicheres und wirksames Therapieverfahren bei größeren Perikardergüssen, wenn sie unter echokardiographischer oder radiologischer Kontrolle erfolgt. Das Ziel einer computergestützten Perikardpunktion ist es, die Punktionstechnik zu verbessern und insbesondere bei kleinen und gekammerten Perikardergüssen eine gezielte Punktion vornehmen zu können. Die Untersuchungen sind Modellversuche einer Perikardpunktion im Sinne präklinischer Datenerhebung.Eine Perikardpunktion mit Computerunterstützung lässt sich in drei Schritte aufteilen: 1. echokardiographische Datenerhebung im 3-D-Format, die in einen Computer eingespeist werden, 2. Wandlung der Daten in ein digitales Modell und 3. gezielte Punktion mit einer computermäßig lokalisierbaren Nadel, um das ausgewählte Ziel (lokalisierter Perikarderguss) zu erreichen. Nach Untersuchungen an einem dynamischen Phantom sowie einer weiteren Untersuchung an Hunden wurden Genauigkeit und Verlässlichkeit des Systems an Schweinen mit einer experimentell induzierten Perikarditis geprüft.Mit Hilfe des Systems kann die Punktion mit einer Genauigkeit von mindestens 2,5 mm erfolgen. Diesen Untersuchungen folgt gegenwärtig eine klinische Erprobungsphase an Patienten mit einem für die Klinik geeigneteren Prototypen.Die Untersuchung zeigt, dass eine computergesteuerte Perikardpunktion durchführbar ist. Sie stellt darüber hinaus eine Perspektive für einen perkutanen Zugang zum Perikard mit gezielter Punktion dar und lässt sich auch an anderen Punktionsorten anwenden.

Isolating Moving Anatomy in Ultrasound Without Anatomical Knowledge: Application to Computer-Assisted Pericardial Punctures

This paper presents an approach to semiautomatic segmentation over a time series without the use of a priori geometric anatomical knowledge, and demonstrates its applicability to pericardial effusion segmentation from ultrasound. The described technique solves the problem in two stages, first automatically calculating a set of exclusion zones, then leveraging the surgeon’s anatomical knowledge, simply and interactively, to create a region which corresponds to the stable region within the target effusion. In preliminary testing, the system performs well versus manual segmentation, outperforming it both in terms of perceived quality, as measured in a blinded comparison by an expert, and in terms of time required for generation.

Effect of low-dose positive inotropic drugs on human internal mammary artery flow.

BACKGROUNDnDobutamine (a beta-receptor agonist), enoximone (a type III selective phosphodiesterase inhibitor), and epinephrine (an alpha- and beta-mimetic) frequently are used in the perioperative management of patients undergoing coronary artery bypass grafting.nnnMETHODSnWe performed a double-blind clinical study to compare the effects on internal mammary artery free flow of low doses of these three positive inotropic drugs. Thirty patients in whom the left internal mammary artery was used for coronary artery bypass grafting were randomized into three groups. Internal mammary artery free flow and hemodynamic measurements were evaluated before and 10 minutes after the intravenous infusion of dobutamine (3 microg x kg(-1) x min(-1)), enoximone (200 microg/kg), or epinephrine (0.05 microg x kg(-1) x min(-1)).nnnRESULTSnA significant increase in free flow occurred only in the dobutamine group (33 +/- 7.5 and 42.2 +/- 7.9 mL/min before and after drug infusion, respectively; p = 0.013). Comparison of the increase in flow between the groups, however, showed no difference. These drugs, at doses designed to produce a positive inotropic effect, caused little increase in the free flow of the internal mammary artery.nnnCONCLUSIONSnThe use of dobutamine, enoximone, and epinephrine as low-dose positive inotropic treatments in the perioperative and postoperative periods of coronary artery bypass grafting should depend on their positive inotropic effects rather than their vasodilative effects on the arterial grafts.

Unusual aortic stent complication after endovascular repair of the descending thoracic aorta in type B dissection in a patient with giant-cell arteritis.

The advent of endovascular prostheses to treat descending thoracic aortic lesions offers an alternative approach in patients who are poor candidates for surgery. We present a case of a type B descending thoracic aortic dissection with rapid aneurysmal evolution in a woman with a giant-cell arteritis, treated by endovascular repair: 26 months after, we observed the anterior dislocation of the distal segment of the stent. The dislocation required a second treatment in order to avoid the aortic wall rupture and to restore the axis of the prosthesis. This report emphasizes the difficulty of the endovascular repair in the giant-cell arteritis, because of the vascular fragility confirmed by the rapid aneurysmal evolution after the type B dissection and the appearance of the stenting complication.