Jacques Robin

Changing management of cardiac myxoma based on a series of 40 cases with long-term follow-up

BACKGROUND Cardiac myxoma is generally considered to be a surgical emergency. However, as a result of progress in echocardiography and the increasing age of the patients presenting with this disease, the clinical presentation has changed and the management of cardiac myxoma now needs to be reviewed. METHODS Between 1978 and 2001, 40 patients (16 men and 24 women) between the ages of 6 months and 82 years (mean age, 55.6 years) were operated on for cardiac myxoma. Signs of heart failure with pulmonary congestion (22%) or pulmonary embolism (20%) indicated a high-risk emergency situation in some cases, whereas, in other cases (58%), the patients condition was stable and the clinical presentation was less worrying. However, the tumor was always removed within 24 hours of admission. Most cases of cardiac myxoma observed over the last decade correspond to stable forms, as echocardiography has revealed smaller tumors in generally elderly patients. RESULTS The postoperative mortality was 7.5% (3 patients). No patients were lost to follow-up, and the mean follow-up was 13.6 years. One patient was reoperated for recurrence 3 years postoperatively. Five patients required further cardiac surgery: three mitral valve replacements, one coronary artery bypass graft, and one angioplasty. The 15-year survival rate was 69%. CONCLUSIONS Myxoma tends to be observed in a more elderly and higher risk population, often at an early stage. The classic approach of emergency surgery is not always appropriate in these stable forms, allowing more thorough preoperative assessment of these patients.

Rabbit antithymocyte globulin as induction immunotherapy in pediatric heart transplantation.

Background. There is little published data on the use of antithymocyte globulins in children. This retrospective study describes the use of Thymoglobulin (Imtix, SangStat, Lyon, France) in pediatric cardiac transplantation over a 13-year period in a single center that adjusted the dose of Thymoglobulin according to platelet count monitoring and examines the short-term hematological effects as well as longer-term outcomes. Methods. Data for all children who received a heart transplant at the Hôpital Cardiologique at Lyon from 1984 to 2001 and who were given Thymoglobulin as part of their immunosuppressive protocol were extracted. The dose of Thymoglobulin given depended on baseline platelet count and was 2, 1.5, or 1 mg/kg per day over 5 days for the following platelet count groups: greater than 150,000/mm3 (normal group), 100 to 150,000/mm3 (mild thrombocytopenia group), and 50 to 100,000/mm3 (moderate thrombocytopenia group). Results. Thirty children of median age 14.2 years were given a median cumulative dose of Thymoglobulin of 8 mg/kg per patient; the moderate thrombocytopenia subgroup was given significantly less (6.4 mg/kg) (P =0.032). Immediate tolerability of Thymoglobulin was good, with no cases of first-dose syndrome, anaphylaxis, or serum sickness. The platelet count decreased at the start of therapy, but recovered after discontinuation, and did not give rise to clinical concern. Patients were followed up for a median of 6.3 years (7 days–15.5 years); actuarial survival was 90%, 86%, and 74.5%, respectively, at 1, 5, and 10 years. In the first year, 50% of patients suffered an episode of rejection. The overall incidence of infection in the month following transplantation was 40%. One lymphoma occurred at 5 months. Conclusions. The use of Thymoglobulin in pediatric heart-transplant patients as part of an immunosuppressive protocol, with dose adjustment according to platelet levels, has been shown to be effective in terms of rejection rate and patient survival and safe in terms of the incidence of infections and malignancy.

Flow-induced release of endothelium-derived relaxing factor during pulsatile bypass: Experimental study in the fetal lamb

OBJECTIVE This study was initiated to test the hypothesis that fetal hemodynamic changes observed under pulsatile flow bypass might be related to the release of endothelium-derived relaxing factor through oscillating shear stress. METHODS Normothermic bypass was instituted in utero in 21 preterm fetal lambs for a 1-hour period through the right atrium and main pulmonary artery. Ultrasonic flowmeters were positioned around the descending aorta and the umbilical artery. The circuit consisted of an oxygenator and a pump set to either continuous flow (n = 7) or pulsatile flow (n = 7) and adjusted to maintain a fetal main arterial pressure of 50 mm Hg. In seven other animals, endothelium-derived relaxing factor was blocked by a continuous infusion of N omega-nitro-L-arginine after 30 minutes of pulsatile flow. RESULTS During the first 30 minutes of bypass, pump flows were significantly lower in the continuous-flow group than in the pulsatile-flow or blocked-flow groups (respectively, 612 +/- 144, 907 +/- 153 and 987 +/- 228 ml/min), with similar changes in aortic and umbilical flows. Systemic vascular resistances were significantly lower in the pulsatile-flow and blocked-flow groups than in the continuous-flow group (550 +/- 106 vs 821 +/- 212 dynes/sec/cm-5). However, after blockade of endothelium-derived relaxing factor, resistances increased gradually in the blocked-flow group to reach the level of that of the continuous-flow group at the end of bypass (943 +/- 77 vs 556 +/- 143 dynes/sec/cm-5 in the pulsatile-flow group). CONCLUSIONS Blockade of endothelium-derived relaxing factor after 30 minutes of pulsatile flow returns fetal hemodynamics to continuous flow conditions. The specific inhibitor of endothelium-derived relaxing factor used in this experiment suggests that nitric oxide may be released by fetal endothelium during pulsatile bypass.

Mechanical valve in aortic position is a valid option in children and adolescents.

OBJECTIVE The choice of a valve substitute remains a challenge in young patients, with numerous reports of early degeneration and calcification of biological valves in this age group. Therefore an assessment of the long-term results after mechanical aortic valve replacement in children was initiated. METHODS A retrospective study was conducted in 54 consecutive patients aged 1.1 to 17 years (mean 12.8 +/- 4 years) operated on between 1975 and 1993. Aetiology was congenital in 34 patients, rheumatic in 13, infectious in 5, and dystrophic in 2. Concomitant surgery included mitral valve replacement (10), aortic annulus enlargement (9), correction of truncus arteriosus (7), Bentall operation (2), coarctation repair (2), tricuspid valvuloplasty (2), correction of double outlet right ventricle (1), and replacement of a right ventricle to pulmonary artery conduit (1). A Bjork-Shiley valve was implanted in 14 patients, and a St Jude Medical valve in 40. All patients were given Warfarin with a monthly INR control. Follow-up was completed through questionnaires mailed to referring physicians and direct clinical examination. RESULTS Overall early mortality was 13% (7 cases), and 6% (2 cases) in the 32 patients operated on after 1984. Follow-up was complete in 45 survivors (2 lost to follow-up), with a total follow-up of 261 patient-years. There were 6 late deaths, 4 being cardiac and due to persistent LV dysfunction, and 2 valve-related, due respectively to major gastro-intestinal bleeding and massive thromboembolism. Linearized rates of valve thrombosis and anticoagulant-related hemorrhage were both 0.3% per patient-year. Actuarial survival rate was respectively 84.5% at 5 years and 70.2% at 10 years. Reoperation was necessary in 3 patients for recurrent LV outflow tract obstruction. One patient with severe LV dysfunction is awaiting a heart transplant. CONCLUSION We conclude that the longterm outcome after mechanical aortic valve replacement in children and adolescents is satisfactory and comparable to currently available reports on biological substitutes. The mandatory anticoagulant therapy is well tolerated in this age group.

Long-term clinical and hemodynamic evaluation of porcine valved conduits implanted from the right ventricle to the pulmonary artery.

OBJECTIVE This retrospective study was initiated to evaluate the long-term results of valved prosthetic conduits implanted in the right ventricular outflow tract in patients with complex ventricular-pulmonary discontinuity. METHODS A cohort of 103 patients out of 127 (24 early deaths, 19%) operated on between 1973 and 1996 with porcine valved conduits was available for evaluation, with a follow-up ranging from 1 to 21.6 years (mean follow-up 8.4 +/- 6 years). A total of 74 hemodynamic studies were performed after the operation, 50 patients having undergone at least 1 cardiac catheterization during the follow-up period. RESULTS There were 16 late deaths, and the actuarial survivals, including early mortality, were 72.9% +/- 4% at 5 years, 63.1% +/- 5% at 10 years, and 58.2% +/- 5% at 15 years, at which time 20 patients were still available for review and exposed to the risk of dying. The mean peak systolic gradient across the right ventricular outflow tract was plotted as a function of time, showing a gradual increase and a significant step-up after the eighth year, from 43 +/- 36 to 69 +/- 19 mm Hg (P < .005). Reoperation was required for progressive conduit obstruction between 1.1 and 17.7 years after implantation (mean 7.4 +/- 4.8 years) in 25 patients (24%, 70% CL 15%-33%), with generally very few symptoms, or for residual ventricular septal defect in 3 patients. Freedom from reoperation was 79.5% +/- 5% at 10 years and 65.8% +/- 7% at 15 years. CONCLUSIONS Porcine conduits may represent a valuable alternative to biologic substitutes with similar long-term results. Given the few symptoms, progressive conduit stenosis after the eighth postoperative year imposes a yearly noninvasive patient evaluation during the follow-up.

Experimental right ventricle to pulmonary artery discontinuity: outcome of polyurethane valved conduits.

OBJECTIVE The ideal substitute for the treatment of ventricle-pulmonary artery discontinuity remains a topic of controversy, because of calcifications and degeneration of biologic substitutes leading to subsequent reoperations. Because polyurethane valves used in ventricular assist devices show a satisfactory biocompatibility, the aim of this study was to evaluate a valved conduit composed of a Dacron graft incorporating a trileaflet 25 mm polyurethane valve. METHODS The conduit was implanted between the right ventricle and the main pulmonary artery in adult sheep, with ligation of the proximal pulmonary artery. The animals received no medications. Serial hemodynamic data were collected at the time of implantation and at postoperative intervals of 6 and 12 months. RESULTS The peak pressure gradient across the valve increased significantly between implantation (0.17 +/- 5.6 mm Hg) and 6 months after operation (7.3 +/- 3 mm Hg, p = 0.0007) and remained stable thereafter (6.7 +/- 3 mm Hg at 12 months), whereas the cardiac output remained unchanged (4.6 +/- 0.6 L/min at implantation, 4 +/- 0.6 L/min at 6 months, and 3.9 +/- 1.1 L/min at 12 months). At the completion of the study, valve samples were processed and vapor coated with carbon for microscopic examination. There was one instance of nonadherent thrombus formation inside a cusp but no structural failures. The other valves were free of calcium deposits and no significant amounts of phosphorus could be detected by scanning electron microscopy and energy dispersive spectrometry. CONCLUSIONS These data demonstrate the good hemodynamic performance, low thrombogenicity, and acceptable durability of the polyurethane valves implanted in the right side of the heart in a chronic sheep model.

Extracorporeal life support for refractory out-of-hospital cardiac arrest: Should we still fight for? A single-centre, 5-year experience

BACKGROUND Cardiopulmonary resuscitation displays low survival rate after out-of-hospital cardiac arrest (OHCA). Extracorporeal life support (ECLS) could be suggested as a rescue therapeutic option in refractory OHCA. The aim of this report is to analyze our experience of ECLS implantation for refractory OHCA. METHODS We performed a retrospective observational analysis of our prospectively collected database. Patients were divided into a shockable rhythm (SH-R) and a non-shockable rhythm (NSH-R) group according to cardiac rhythm at ECLS implantation. The primary endpoint was survival to hospital discharge with good neurological recovery. RESULTS From January 2010 to December 2014 we used ECLS in 68 patients (SH-R, n=19, 27.9% vs. NSH-R, n=49, 72.1%) for refractory OHCA. The clinical profile before ECLS implantation was comparable between the groups. Eight (11.7%) patients were successfully weaned from ECLS (SH-R=31.5% vs. NSH-R=4.0%, p=0.01) after a mean period of support of 2.1 days (SH-R=4.1 days vs. NSH-R=1.4 days, p=0.01). Six (8.8%) patients survived to discharge (SH-R=31.5% vs. NSH-R=0%, p=0.00). In the SH-R group 50% of the survivors were discharged without neurological complications. CONCLUSIONS ECLS for refractory OHCA should be limited in consideration of its poor, especially neurological, outcome. Non-shockable rhythms could be considered as a formal contraindication allowing a concentration of our efforts on the shockable rhythms, where the chances of success are substantial.

Influence of technique of coronary artery implantation on long-term results in composite aortic root replacement

BACKGROUND Long-term results after composite graft aortic root replacement may depend on the insertion technique. The aim of this study is to assess the influence of the technique of coronary artery implantation on long-term results in composite aortic root replacement. METHODS One hundred fifty consecutive patients (mean age, 55 years; 119 men) with different disorders of the ascending aorta who underwent aortic root replacement with a composite graft prosthesis between January 1985 and December 1999 were retrospectively studied. Thirteen patients had previously undergone cardiovascular surgery. The open button technique was performed in 65 patients (43.3%, group 1) and the inclusion technique in 85 patients (56.7%, group 2). Mean follow-up was 70.5 months. Surgery was elective in 110 procedures (73%). RESULTS Global actuarial survival was 76.1% +/- 4.3% for group 1 and 73.7% +/- 3.9% for group 2 at 10 years (p = 0.22). Freedom from reoperation excluding early deaths was 81% +/- 3% for group 1 and 86% +/- 2.2% for group 2 at 10 years (p = 0.62). Group 2 demonstrated a statistically significantly higher occurrence of pseudoaneurysm formation versus group 1 (p = 0.04). CONCLUSIONS Composite graft aortic root replacement is a safe and effective therapy for proximal aortic aneurysm and dissection, resulting in good early and long-term results irrespective of the anastomotic technique. However, the open button technique seems to avoid late false aneurysm formation at the anastomotic sites.

Mechanical versus biological isolated aortic valvular replacement after the age of 70: equivalent long-term results

OBJECTIVE In order to evaluate the long-term outcome of valvular substitutes in the elderly, we retrospectively analyzed two comparative groups of patients consecutively operated on by the same team for an isolated valvular aortic replacement using either a mechanical or a pericardial prosthesis. METHODS From 1982 to 1996, 206 patients over 70 years (mean 76.5+/-4.4) underwent an isolated aortic valvular replacement using either a St. Jude Medical (Group I, n = 93) or a Mitroflow (Group II, n= 113) prosthesis depending on the surgeons preference at the time of surgery. Both groups matched for the following pre-operative variables: sex ratio, type of aortic valve disease, NYHA status, cardiac rhythm, mean pulmonary arterial pressure, left ventricular end-diastolic pressure, LV-AO gradient, cardiac index and ejection fraction. RESULTS Given an early mortality rate of 6.4% in Group I and 4.4% in Group II (NS), follow-up (mean 4.4+/-3.7 years in Group I and 5.3+/-3.1 years in Group II) was 100% complete. Actuarial survival was 69.9+/-6 and 70.2+/-4.6% at 5 years for Group I and Group II, respectively, and 49.6+/-7.7 vs. 51.4+/-6.3% at 10 years (NS). Freedom from valve-related death was 86.5+/-4.8% in Group I vs. 82.7+/-4% in Group II at 5 years (NS) and 66.7+/-8.7 vs. 66.3+/-7% at 10 years (NS). There were no anticoagulant-related deaths or severe accidents in Group 1. A secondary valvular replacement was necessary in 4 patients in Group II vs. none in Group I. CONCLUSION The study shows a similar late survival in both groups, with a strikingly low incidence of anticoagulant-related deaths in this population. Given a higher rate of reoperation after biological valve replacement, the use of mechanical valve in this aging population seems to be a valid option.

Mechanical cardiac valve thrombosis in patients in critical hemodynamic compromise

BACKGROUND Valve obstruction is a life threatening complication of mechanical valve prosthesis. METHODS From 1985 to 1993, 29 consecutive patients were hospitalized in our intensive care unit for mechanical prosthetic valve thrombosis (PVT). There were 12 men and 17 women aged 25-75 years (57 +/- 12). Prosthetic valve location was mitral in 14 patients, aortic in 6, aortic and mitral in 9. PVT occurred from 15 days to 174 months (67 +/- 52 months) after surgery. Delay from first symptoms to hospitalization ranged from 1 to 45 days (11 +/- 11). RESULTS First clinical symptoms were progressive left heart failure in 17 patients, stroke in 6, and chest pain in 6. Furthermore, acute myocardial infarction was later documented in 3. Left heart failure NYHA III-IV was present in 26 patients (90%) on admission and 10 of those were in cardiogenic shock. Anticoagulation regimen was inadequate in 13 cases (45%). It has been recently stopped in 8 patients and incorrectly conducted in 5. Total hospital mortality was 41.3% (12). It was independent of type and position of the valve prosthesis. Diagnosis of PVT was only made at autopsy in 3 patients who died of recurrent myocardial infarction (2) or cardiogenic shock (1). Five further patients died before any surgery could be attempted (cardiac arrest: 2, cardiogenic shock: 3). Valve replacement could be done in 21 cases, 7 of whom were in cardiogenic shock and 9 had severe pulmonary edema. Four patients died after surgery, the operative mortality was 19%. CONCLUSION PVT remains a serious complication of mechanical heart valve prostheses. Overall mortality rate is high, related to difficulty to diagnosis, delay to hospitalization and severe clinical condition at admission. In our study, operative risk remained acceptable even when the clinical presentation was severe.