How to prevent venous cannula orifice obstruction during extracorporeal circulation.

Venous cannula orifice obstruction is an underestimated problem during augmented cardiopulmonary bypass (CPB), which can potentially be reduced with redesigned, virtually wall-less cannula designs versus traditional percutaneous control venous cannulas. A bench model, allowing for simulation of the vena cava with various affluent orifices, venous collapse and a worst case scenario with regard to cannula position, was developed. Flow (Q) was measured sequentially for right atrial+hepatic+renal+iliac drainage scenarios, using a centrifugal pump and an experimental bench set-up (afterload 60 mmHg). At 1500, 2000 and 2500 RPM and atrial position, the Q values were 3.4, 6.03 and 8.01 versus 0.77*, 0.43* and 0.58* l/min: p<0.05* for wall-less and the Biomedicus® cannula, respectively. The corresponding pressure values were -15.18, -31.62 and -74.53 versus -46.0*, -119.94* and -228.13* mmHg. At the hepatic position, the Q values were 3.34, 6.67 and 9.26 versus 2.3*, 0.42* and 0.18* l/min; and the pressure values were -10.32, -20.25 and -42.83 versus -23.35*, -119.09* and -239.38* mmHg. At the renal position, the Q values were 3.43, 6.56 and 8.64 versus 2.48*, 0.41* and 0.22* l/min and the pressure values were -9.64, -20.98 and -63.41 versus -20.87 -127.68* and -239* mmHg, respectively. At the iliac position, the Q values were 3.43, 6.01 and 9.25 versus 1.62*, 0.55* and 0.58* l/min; the pressure values were -9.36, -33.57 and -44.18 versus -30.6*, -120.27* and -228* mmHg, respectivly. Our experimental evaluation demonstrates that the redesigned, virtually wall-less cannulas, allowing for direct venous drainage at practically all intra-venous orifices, outperform the commercially available control cannula, with superior flow at reduced suction levels for all scenarios tested.

[Selection and preoperative follow-up of heart transplantation candidates in the French part of Switzerland]. / Sélection et suivi prétransplantation des patients candidats à la greffe cardiaque en Suisse romande.

Heart transplantation (HTx) started in 1987 at two university hospitals (CHUV, HUG) in the western part of Switzerland, with 223 HTx performed at the CHUV until December 2010. Between 1987 and 2003, 106 HTx were realized at the HUG resulting in a total of 329 HTx in the western part of Switzerland. After the relocation of organ transplantation activity in the western part of Switzerland in 2003, the surgical part and the early postoperative care of HTx remained limited to the CHUV. However, every other HTx activity are pursued at the two university hospitals (CHUV, HUG). This article summarizes the actual protocols for selection and pre-transplant follow-up of HTx candidates in the western part of Switzerland, permitting a uniform structure of pretransplant follow-up in the western part of Switzerland.

Effects of different types of exercise training followed by detraining on endothelium-dependent dilation in patients with recent myocardial infarction.

BACKGROUND: In coronary artery disease, exercise training (ET) is associated with an improvement in endothelial function, but little is known about the relative effect of different types of training. The purpose of this study was to prospectively evaluate the effect of different types of ET on endothelial function in 209 patients after a first recent acute myocardial infarction. METHODS AND RESULTS: Endothelial function was evaluated before and after 4 weeks of different types of ET and after 1 month of detraining by measuring flow-mediated dilation and von Willebrand factor levels at baseline and after ET. Patients were randomized into 4 groups: group 1, aerobic ET (n=52); group 2, resistance training (n=54); group 3, resistance plus aerobic training (n=53); and group 4, no training (n=50). At baseline, flow-mediated dilation was 4.5+/-2.6% in group 1, 4.01+/-1.6% in group 2, 4.4+/-4% in group 3, and 4.3+/-2.3% in group 4 (P=NS). After ET, flow-mediated dilation increased to 9.9+/-2.5% in group 1, 10.1+/-2.6% in group 2, and 10.8+/-3% in group 3 (P<0.01 versus baseline for all groups); it also increased in group 4 but to a much lesser extent (to 5.1+/-2.5%; P<0.01 versus trained groups). The von Willebrand factor level after ET decreased by 16% (P<0.01) similarly in groups 1, 2, and 3 but remained unchanged in group 4. Detraining returned flow-mediated dilation to baseline levels (P<0.01 versus posttraining). CONCLUSIONS: In patients with recent acute myocardial infarction, ET was associated with improved endothelial function independently of the type of training, but this effect disappeared after 1 month of detraining.

Atrial assist device, a new alternative to lifelong anticoagulation?

OBJECTIVE: Atrial fibrillation is a very common heart arrhythmia, associated with a five-fold increase in the risk of embolic strokes. Treatment strategies encompass palliative drugs or surgical procedures all of which can restore sinus rhythm. Unfortunately, atria often fail to recover their mechanical function and patients therefore require lifelong anticoagulation therapy. A motorless volume displacing device (Atripump) based on artificial muscle technology, positioned on the external surface of atrium could avoid the need of oral anticoagulation and its haemorrhagic complications. An animal study was conducted in order to assess the haemodynamic effects that such a pump could provide. METHODS: Atripump is a dome-shape siliconecoated nitinol actuator sewn on the external surface of the atrium. It is driven by a pacemaker-like control unit. Five non-anticoagulated sheep were selected for this experiment. The right atrium was surgically exposed, the device sutured and connected. Haemodynamic parameters and intracardiac ultrasound (ICUS) data were recorded in each animal and under three conditions; baseline; atrial fibrillation (AF); atripump assisted AF (aaAF). RESULTS: In two animals, after 20 min of AF, small thrombi appeared in the right atrial appendix and were washed out once the pump was turned on. Assistance also enhanced atrial ejection fraction. 31% baseline; 5% during AF; 20% under aaAF. Right atrial systolic surfaces (cm2) were; 5.2 +/- 0.3 baseline; 6.2 +/- 0.1 AF; 5.4 +/- 0.3 aaAF. CONCLUSION: This compact and reliable pump seems to restore the atrial "kick" and prevents embolic events. It could avoid long-term anticoagulation therapy and open new hopes in the care of end-stage heart failure.

[Monitoring and adjustment of immunosuppression after heart transplantation]. / Suivi du patient après transplantation cardiaque: monitoring et adaptation de l'immunosuppression.

Heart transplantation remains the best therapeutic option for the treatment of end-stage heart failure. However, good survival rates can be obtained only if patients are closely monitored, particularly for their immunosuppressive regimens. Currently, a triple-drug regimen usually based on calcineurin-inhibitors (cyclosporin A or tacrolimus), anti-proliferative agents and steroids is used in most recipients. New agents such as the mTOR inhibitors, a more recently developed class of immunosuppressive drugs, can also be used in some patients. The aim of this article is to review currently used immunosuppressive regimens after heart transplantation, and to propose some individualized options depending on specific patient characteristics and recent pharmacological developments in the field.

[Indications, limits and future of epidural spinal cord electrical stimulation for coronary and peripheral artery disease]. / Indications, perspectives et limites de la stimulation electrique epidurale en cas d'artériopathie périphérique ou coronarienne.

The electrical stimulation of the dorsal columns of the spinal cord exerts a dual analgesic and vasodilatory effect on ischemic tissues. It is increasingly considered a valuable method to treat severe and otherwise intractable coronary and peripheral artery disease. The quality of the results depends from both a strict selection of the patients by vascular specialists and the frequency and quality of the follow-up controls. However the indications, limits, mode of action and results of spinal cord stimulation are still poorly understood. This article, based on a personal experience of 164 implantations for peripheral and coronary artery disease, aims to draw attention to this technique and to provide information on recent and future developments.

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

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.

[Hybrid treatment of aortic aneurysms]. / Les cures hybrides des lésions anévrismales.

The hybrid treatment of aortic aneurysms is indicated in patients having the ostia of supra aortic or visceral branches taken in to the aneurysm. Indeed, these lesions are not eligible for classic endovascular treatment because the existing endoprostheses cannot provide perfusion of the side branches without inducing major endoleaks. The surgical technique consists of 2 steps: firstly, a by-pass between normal aorta and the major aortic branches involved in the aneurysm is performed to guarantee the perfusion of the organs such as brain, bowel, and after endoprosthesis deployment. Secondly, the endoprosthesis is deployed using the classical technique to isolate the aneurysm. The hybrid approach provides safe and reliable treatment of complex aortic aneurysms with mortality and morbidity rate far below the classical open surgery.

[Stents valves for percutaneous valve replacement]. / Remplacement valvulaire percutané au moyen de stent-valves--une nouvelle approche thérapeutique.

Stents have a long history in traditional valve surgery as both, porcine biological valves as well as pericardial valves are mounted on stents prior to implantation. Recently stent-mounted biological devices have been compressed up to the point, where they can be passed through a catheter. Various routes can be distinguished for implantation: open access, the trans-vascular route in antegrade or retrograde fashion, as well as direct trans-apical or trans-atrial access. Direct access has the potentialforvideo-endoscopic valve replacement. In theory, as well as in the experimental setting, valved stents have been implanted in tricuspid and caval position respectively, as well as in pulmonary, mitral and aortic locations. The largest clinical experience has been achieved in pulmonary position whereas current efforts target the aortic position.

Chronic peritoneal effusion secondary to partial caudal vena cava obstruction following traumatic pneumothorax in a dog.

A three-year old, female Boxer Dog was treated initially with thoracocentesis for a right-sided pneumothorax. The dog was re-evaluated after three weeks because of an enlargement of the abdomen. A positive venogram revealed a ventral displacement of the caudal vena cava between the diaphragm and the heart, with a severe reduction of the diameter of the vein. An exploratory thoracotomy showed a displaced accessory lung lobe with an adhesion to the parietal pleura. Inflation of this lung lobe created a dynamic obstruction of the caudal vena cava, which resulted in ascites. Surgery offered successful treatment.

[Cell therapies in cardiology: results from the first randomized clinical trials]. / Thérapie cellulaire en cardiologie: bilan des premiers essais cliniques randomisés.

Following acute myocardial infarction, necrotic cardiac tissue is replaced by scar leading to ventricular remodeling and pump failure. Transplantation of autologous bone marrow-derived cells into the heart, early post-infarct, aims to prevent ventricular remodeling. This strategy has been evaluated in four controlled, randomized clinical trials, which provided mixed results. A transient improvement in ventricular function was observed in one trial, and a modest improvement (the duration of which remains to be determined) in an additional trial, whereas two trials showed negative results. A modest benefit of bone marrow cell transplantation was also observed in patients with chronic ischemic heart disease. Despite mixed results reported so far, cell therapy of heart disease still is in its infancy and has considerable room for improvement.

[Transposition of the great arteries: long-term follow-up]. / Transposition des gros vaisseaux: suivi a long-terme.

The management of transposition of the great arteries has changed importantly over the last decades. New techniques are employed for the diagnosis and surgical intervention has improved. This has lead to an increasing number of long-term survivors, who require specialised and focussed follow-up, depending on their type of surgical repair Mustard/Senning of arterial Switch. The long-term problems vary for each type of repair and require a specific approach, pharmacotherapy, catheter intervention or surgery. These complex sequellae implicate that transposition patients are never completely cured and probably will have a limited life span.

Five-year outcome in patients with isolated proximal left anterior descending coronary artery stenosis treated by angioplasty or left internal mammary artery grafting. A prospective trial.

BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass surgery (CABG) improve the clinical status of patients with isolated proximal left anterior descending coronary artery stenosis. At 2 years, only additional revascularization was more frequently required after PTCA. METHODS AND RESULTS: We monitored 134 patients randomized to PTCA (n=68) or CABG (n=66) for

Congenital cleft of the anterior tricuspid leaflet with severe tricuspid regurgitation in adults.

OBJECTIVES AND BACKGROUND: Severe primary tricuspid regurgitation in the adult is a rare finding. This study describes the diagnostic findings and the treatment of an isolated congenital cleft of the anterior leaflet of the tricuspid valve as the morphologic substrate for severe tricuspid regurgitation. METHODS: The clinical, echocardiographic findings and the follow-up findings of five patients (all male, 20 to 56 years old) with this disorder are described. Four of the five patients underwent cardiac surgery that confirmed the diagnosis. RESULTS: In three of five patients, exertional fatigue was the limiting symptom (New York Heart Association functional classes II and III). The clinical findings included a holosystolic murmur and supraventricular arrhythmias in all patients. Cardiac catheterization, performed in four patients, yielded the incorrect diagnosis of Ebstein's anomaly in three. In one patient the cleft was associated with an atrial septal defect of the secundum type. In four of five patients successful reconstruction of the tricuspid valve with a DeVega annuloplasty was performed. One patient had a partial excision of the right atrium, and one had a closure of a coexisting atrial septal defect. One patient refused operation. CONCLUSIONS: Tricuspid valve anomalies can be accurately identified by Doppler echocardiography. Surgical repair is the treatment of choice in patients with severe tricuspid regurgitation due to a congenital cleft of the anterior leaflet of the tricuspid valve.

Ex vivo evaluation of a new extracorporeal lung assist device: NovaLung membrane oxygenator.

When lung function is compromised,alternative devices need to be deployed in order to maintain blood oxygenation. A new device, NovaLung, has been designed for acute lung failure. We went about evaluating its gas exchange capability. Three calves (79.5 +/- 7.8 kg) were connected to the NovaLung System with a priming volume of 240 mL, gas exchange surface area of 1.3 m2 and exhibiting a biologically coated surface. A standard battery of blood samples were taken before implantation and over a six hour period. Hematocrit remained stable ranging from 27 +/- 4% (baseline) to 29 +/- 5% (6 hrs). Platelets were preserved ranging from 882 +/- 27.4 U/L (baseline) to 734 +/- 147 (6 hrs). LDH remained stable at 719 +/- 85 U/L (baseline) vs 686 +/- 190 U/L (6 hrs) and the pressure drop was maintained below 20 mmHg. Minimal hemolysis was observed. Oxygen transfer peaked at two hours acute extracorporeal lung support (ECLS)with a mean value of 130 +/- 50 ml/min. In conclusion, the device is easy to use,provides adequate O2 and CO2 transfer for partial lung support in an acute setting. Shows minimal signs of hemolysis and platelets levels are maintained throughout the six hour ECLS period.

[Pediatrics. Advantages of prenatal diagnosis in congenital cardiopathies]. / Pédiatrie. Avantages du diagnostic prénatal dans les cardiopathies congénitales.

The diagnosis of a congenital heart disease can be made by fetal ultrasound as soon as the 12th week of pregnancy. The main indications for fetal echocardiography are maternal and fetal. Sequential approach is necessary to precise the anatomy and to elaborate a therapeutic strategy for that patient. For severe heart lesions delivery and postnatal care can be programmed, avoiding thus severe hypoxia and acidosis after birth. The prognosis of these children are thus much improved.

[Surgical options for terminal heart failure]. / Options chirurgicates pour l'insuffisance cardiaque terminale.

Terminal heart failure can be the cause or the result of major dysfunctions of the organisms. Although, the outcome of the natural history is the same in both situations, it is of prime importance to differentiate the two, as only heart failure as the primary cause allows for successful mechanical circulatory support as bridge to transplantation or towards recovery. Various objective parameters allow for the establishment of the diagnosis of terminal heart failure despite optimal medical treatment. A cardiac index <2.0 l/min, and a mixed venous oxygen saturation <60%, in combination with progressive renal failure, should trigger a diagnostic work-up in order to identify cardiac defects that can be corrected or to list the patient for transplantation with/without mechanical circulatory support.

Regional diastolic dysfunction in postischaemic myocardium in calf: effect of nisoldipine.

OBJECTIVE: The aim was to assess the effect of nisoldipine on left ventricular systolic and diastolic function during prolonged myocardial ischaemia. METHODS: The left circumflex coronary artery was ligated for 2 h and reperfused for 4 h in 12 calves. The animals were randomised to a control group (n = 6) or to treatment with 1.25 mg.h-1 intravenous nisoldipine (n = 6) during 2 h of ischaemia. Circulatory support by a ventricular assist device was performed throughout the experiment except for the time of haemodynamic measurements. Regional wall thickening of a normal and an ischaemic left ventricular region was determined using pairs of ultrasonic crystals. Left ventricular pressure was measured by micromanometry. Left ventricular wall thickness and regional wall stiffness at a common preload of 10 mm Hg were calculated using an elastic model with shifting asymptote. RESULTS: Ten animals survived after 6 h. No difference was observed in systolic function between controls and nisoldipine treated animals. Systolic thickening of the ischaemic wall remained depressed 4 h after reperfusion and showed some recovery after dopamine infusion. Ischaemic wall stiffness at a common preload was lower after nisoldipine during ischaemia and reperfusion than in controls. Control wall stiffness remained unchanged during the whole experiment with and without nisoldipine. Diastolic thinning of the ischaemic wall was prevented by nisoldipine during ischaemia and after reperfusion. CONCLUSIONS: Prolonged myocardial ischaemia is associated with increased myocardial stiffness of the ischaemic wall. Mechanical unloading can help to bridge the acute phase but cannot prevent postischaemic diastolic dysfunction of the ischaemic wall. Nisoldipine has a beneficial effect on regional diastolic function during ischaemia and reperfusion by decreasing regional wall stiffness and preventing diastolic thinning of the ischaemic wall.

Cardiopulmonary bypass without systemic heparinization. Performance of heparin-coated oxygenators in comparison with classic membrane and bubble oxygenators.

Performance characteristics of heparin-coated hollow-fiber membrane oxygenators (COATED HFMO, n = 5) were evaluated in an open-chest dog model without systemic heparinization. Four other oxygenators were evaluated with standard systemic heparinization (300 IU/kg, activated clotting time more than 400 seconds): a standard hollow-fiber membrane oxygenator (HFMO, n = 5), an inversed hollow-fiber membrane oxygenator (IHFMO, n = 5), a plate membrane oxygenator (PLATE MO, n = 5) and a bubble oxygenator (BUBBLE O, n = 5). The 25 dogs (36 +/- 12 kg) were perfused after cavo-aortic cannulation for 6 hours with a mean flow of 100 ml/kg body weight. At the end of perfusion without systemic heparin, heparin-coated equipment was replaced in three animals with standard uncoated equipment for control studies. Besides continuous hemodynamic evaluation with Mikro-Tip pressure transducers (Millar Instruments, Inc., Houston, Texas), a standard battery of analyses was performed before, after mixing, and every 30 minutes during bypass. All animals could be perfused in accordance with the protocol. Blood-gas values (pH, arterial oxygen tension, and arterial carbon dioxide tension) were maintained within physiologic ranges for all groups. After 6 hours of perfusion, plasma hemoglobin levels were as follows: 0.57 +/- 0.51 gm/L for COATED HFMO without systemic heparinization versus 2.65 +/- 1.02 gm/L for HFMO (p less than 0.05), 1.77 +/- 0.48 gm/L for IHFMO (p less than 0.05), 1.96 +/- 0.41 gm/L for PLATE O (p less than 0.05), and 1.5 +/- 0.40 gm/L for BUBBLE O (p less than 0.05) with systemic heparinization. Platelet levels were highest for COATED HFMO with 47% +/- 36% without systemic heparinization versus 33% +/- 9% for HFMO, 12% +/- 2% for IHFMO, 36% +/- 17% for PLATE O, and 19% +/- 12% for BUBBLE O with systemic heparinization. Activated clotting time for COATED HFMO without systemic heparinization was 135 +/- 75 seconds before bypass, 207 +/- 21 seconds after mixing, and 131 +/- 20 seconds after 4 hours of perfusion. There was no statistically significant increase of plasma heparin levels in the group perfused without systemic heparin. Determination of fibrin split products during perfusion without systemic heparinization did not show a significant increase. At the end of perfusion all devices were disconnected and gently rinsed with saline: There were no macroscopic clots in the COATED HFMO group perfused without systemic heparin. However, uncoated equipment introduced for control in animals perfused without systemic heparin showed major clotting.(ABSTRACT TRUNCATED AT 400 WORDS)

Repeat sternotomy after reconstruction of the pericardial sac with glutaraldehyde-preserved equine pericardium.

The risk of repeat sternotomy is higher than that of the initial sternotomy, especially if the pericardial sac was left open at the first intervention. In 200 consecutive patients with a pericardial defect after open heart operations, the pericardium was closed with a glutaraldehyde-preserved equine pericardial patch. Precardiac adhesions at reoperation were assessed in four groups of patients on a scale of 6, ranging from 0 (no adhesions) to 5 (calcified or ossified adhesions). Group I comprised 13 patients in whom the pericardium was left open at the first operation and an equine pericardial patch was implanted at reoperation. Group Ia included the first five Group I patients who underwent reoperation less than 1 year (early reoperation) after the initial procedure. Group Ib included the other eight patients of Group I, who underwent reoperation more than 1 year (late reoperation) after the first procedure. Group II comprised nine patients who were reoperated on after reconstruction of the pericardial sac with a glutaraldehyde-preserved equine pericardial patch. After a mean follow-up of 20.2 months, the incidence of patch-related complications was 1%. Statistical analysis shows less severe adhesions on reoperation in Group II patients (pericardial defect patched) than in Group I patients (pericardial defect left open): mean grade of adhesions 1.6 +/- 0.9 (Group II) versus 3.2 +/- 0.6 (Group I), p less than 0.001. Precardial adhesions with the pericardium left open were similar in patients having early and late reoperations: mean grade of adhesions 3.0 +/- 0.7 (Group Ia) versus 3.4 +/- 0.5 (Group Ib), no significant difference. Therefore, the glutaraldehyde-preserved equine pericardial patch can be considered a suitable material for primary closure of the pericardial sac in patients with inadequate autologous pericardium.