Daniel Duveau

Surgical-Site Infection After Cardiac Surgery: Incidence, Microbiology, and risk Factors

OBJECTIVE To identify risk factors associated with surgical-site infection according to the depth of infection, the cardiac procedure, and the National Nosocomial Infections Surveillance System risk index. DESIGN Prospective survey conducted during a 12-month period. SETTING A 48-bed cardiac surgical department in a teaching hospital. PATIENTS Patients admitted for cardiac surgery between February 2002 and January 2003. RESULTS Surgical-site infections were diagnosed in 3% of the patients (38 of 1,268). Of the 38 surgical-site infections, 20 were superficial incisional infections and 18 were mediastinitis for incidence rates of 1.6% and 1.4%, respectively. Cultures were positive in 28 cases and the most commonly isolated pathogen was Staphylococcus. A National Nosocomial Infections Surveillance System risk index score of 2 or greater was associated with a risk of surgical-site infection (relative risk, 2.4; P < .004). Heart transplantation, mechanical circulatory assistance, coronary artery bypass graft with the use of internal mammary artery, and reoperation for cardiac tamponade or pericard effusion were independent risk factors associated with surgical-site infection. CONCLUSIONS Data surveillance using incidence rates stratified by cardiac procedure and type of infection is relevant to improving infection control efforts. Risk factors in patients who developed superficial infection were different from those in patients who developed mediastinitis. Coronary artery bypass graft using internal mammary artery was associated with a high risk of surgical-site infection, and independent factors such as reoperation for cardiac tamponade or pericard effusion increased the risk of infection.

Closure of the bronchial stump by manual suture and incidence of bronchopleural fistula in a series of 209 pneumonectomies for lung cancer

OBJECTIVE Bronchopleural fistula after pneumonectomy is a very serious complication, occurring in 1-4% of cases, regardless of the bronchial stump closure technique adopted. The objective of this study was to report a bronchial stump closure technique in pneumonectomy by manual suture (polypropylene running suture) and to study the incidence of bronchopleural fistula. METHODS Between January 1988 and December 1997, 209 patients (186 men and 23 women, mean age = 60.5 years) were operated by the same operator. The indication for surgery was lung cancer in all cases. RESULTS The incidence of bronchopleural fistula was 2.4%; four fistulas during the first postoperative month and another occurred at 6 months; four were located on the left side and one was situated on the right. The bronchial stulnp was covered in only two of these five cases; 40% died of this complication. Neoadjuvant treatment (chemotherapy and/or radiotherapy) was found to increase the risk of development of bronchopleural fistula (40% vs. 7.2%) and this difference was statistically significant (P = 0.046). CONCLUSIONS Manual closure of the bronchial stump by running suture, performed on an open bronchus, is a reliable technique with a low incidence of bronchopleural fistula. Those results could be further improved by systematically covering the right and the left bronchial stumps.

Prospective preoperative mediastinal lymph node staging by integrated positron emission tomography—computerised tomography in patients with non-small-cell lung cancer §

OBJECTIVE Mediastinal lymph node staging determines the treatment strategy for non-small-cell lung cancer. This study aims to evaluate prospectively the accuracy of preoperative integrated 18-fluoro-2-deoxy-D-glucose positron emission tomography-computerised tomography ((18)FDG PET-CT) for mediastinal lymph node staging. METHODS Preoperative integrated (18)FDG PET-CT was used to analyse mediastinal lymph nodes in patients with non-small-cell lung cancer. Nodal stations were identified according to the American Thoracic Society mapping system. Lymph nodes with a standardised uptake value (SUVmax) >3 were considered to be positive. The mediastinal lymph nodes were harvested during lung resection and the results of integrated (18)FDG PET-CT were compared to the mediastinal lymph node histology results. RESULTS A total of 51 patients were enrolled in this study. The mean interval between integrated (18)FDG PET-CT and surgery was 31+/-15.8 days (range: 2-78 days). The mean mediastinal lymph node harvested and station number per patient during surgery were 11.8+/-5.6 (range: 2-27) and 3.8+/-1 (range: 2-6), respectively. The incidence of N2 pathological disease was 19.6%. The integrated (18)FDG PET-CT sensitivity and specificity were 40+/-30% and 85+/-11%, respectively. The positive and negative predictive values were 40+/-30% and 85+/-11%, respectively. False-positive results (six patients) were mainly due to inflammatory lymph nodes. False-negative results (six patients) were mainly due to infra-centimetrical, malignant lymph node invasion. CONCLUSION The sensitivity of integrated (18)FDG PET-CT for mediastinal lymph node staging in patients selected for surgery is low. When positive mediastinal lymph nodes are detected, invasive mediastinal staging must be performed. On the other hand, the specificity is high: patients with negative integrated (18)FDG PET-CT can be operated upon without invasive mediastinal staging.

Outcome of Heart Transplants 15 to 20 Years Ago : Graft Survival, Post-transplant Morbidity, and Risk Factors for Mortality

OBJECTIVES The study was conducted to determine the long-term outcome of patients who underwent heart transplantation 15 to 20 years ago, in the cyclosporine era, and identify risk factors for death. METHODS A retrospective analysis was done of 148 patients who had undergone heart transplantation between 1985 and 1991 at a single center. Operative technique and immunosuppressive treatment were comparable in all patients. RESULTS Actuarial survival rates were 75% (n = 111), 58% (n = 86), and 42% (n = 62) at 5, 10, and 15 years, respectively. The mean follow-up period was 12.1 +/- 5.6 years for patients who survived more than 3 months after transplantation (n = 131). The major causes of death were malignancy (35.8%) and cardiac allograft vasculopathy (24.7%). No death related to acute rejection was reported after the first month of transplantation. Graft coronary artery disease was detected on angiography in 66 (50.3%), and 7 (5.3%) had retransplantation. Malignancies developed in 131 patients (48.1%), including skin cancers in 31 (23.6%), solid tumors in 26 (19.8%), and hematologic malignancies in 14 (10.6%). Severe renal function requiring dialysis or renal transplantation developed in 27 patients (20.6%). By multivariable analysis, the only pre-transplant risk factor found to affect long-term survival was a history of cigarette use (p < 0.0004). CONCLUSIONS Long-term survival at 15 years after cardiac transplantation remains excellent in the cyclosporine era. Controlling acute allograft rejection can be achieved but seems to carry a high rate of cancers and renal dysfunction. History of cigarette use affects significantly long-term survival in our study.

Surgical resection of pulmonary metastases from colorectal carcinoma : Five-year survival and main prognostic factors

Between 1986 and 1994, 19 patients underwent pulmonary resection for metastatic colorectal carcinoma. The mean interval between colon resection and appearance of pulmonary metastasis was 41 +/- 21 months. All the patients had no more than two metastases. Wedge resection alone or associated with lobectomy was performed in four patients, lobectomy in ten, and pneumonectomy in five. One patient died within the month after surgery. Mean follow-up was 35 +/- 26 months. The 5-year survival rate was 38.7%. Repeat thoracotomy for recurrent metastases was performed in one patient. The disease-free interval, the size of metastases, the type of pulmonary resection, and the location and the stage of primary cancer had no apparent influence on survival, but the survival rate at 4 years was 25% for patients with high carcinoembryonic antigen (CEA) level versus 80% for those with low CEA level. We conclude that, at least when the number of metastases is less than two, resection of colorectal lung metastasis is safe and effective.

CardioWest (Jarvik) Total Artificial Heart: A Single-Center Experience With 42 Patients

BACKGROUND When implanted in patients with biventricular failure, the CardioWest total artificial heart has asserted itself over time as a reliable bridge-to-transplant device that as yet is used by only a few international teams. The aim of this single-center retrospective study is to assess both the comorbidity and survival of patients awaiting heart transplants while receiving circulatory support with a CardioWest total artificial heart. METHODS From 1990 to December 2006, 42 patients received a CardioWest total artificial heart at our center. Mean age at the time of implantation was 45.7 +/- 9.5 years, and 40 patients (95%) were men. Idiopathic or dilated cardiomyopathy was diagnosed in 45.2% (n = 19) of the patients and ischemic cardiomyopathy in 42.8% (n = 18). Average body surface area was 1.9 +/- 0.22 m(2). RESULTS Duration of support was 1 to 292 days (mean, 101 +/- 86 days). Twelve patients died (28.5%) while receiving device support, and 30 patients (71.5%) underwent transplantation. Actuarial survival rates for the transplanted patients were 90% (n = 25), 81% (n = 14), and 76% (n = 10) at 1, 5, and 10 years, respectively. Causes of death during device support included multiorgan failure in 6 (50%), sepsis in 2, acute respiratory distress syndrome in 2, alveolar hemorrhage in 1, and other cause in 1. There were no device malfunctions that led to patient death. Adverse events included stroke in 3 patients (7%) and infections in 35 patients (85%) during support. CONCLUSIONS The CardioWest total artificial heart is an excellent bridge-to-transplant device for patients with biventricular failure. Our study demonstrates excellent safety, reliability, and efficiency. Exceptional outcome after transplantation underlines its capacity to aid in end-organ recovery.

First clinical use of a bioprosthetic total artificial heart: report of two cases

BACKGROUND The development of artificial hearts in patients with end-stage heart disease have been confronted with the major issues of thromboembolism or haemorrhage. Since valvular bioprostheses are associated with a low incidence of these complications, we decided to use bioprosthetic materials in the construction of a novel artificial heart (C-TAH). We report here the device characteristics and its first clinical applications in two patients with end-stage dilated cardiomyopathy. The aim of the study was to evaluate safety and feasibility of the CARMAT TAH for patients at imminent risk of death from biventricular heart failure and not eligible for transplant. METHODS The C-TAH is an implantable electro-hydraulically actuated pulsatile biventricular pump. All components, batteries excepted, are embodied in a single device positioned in the pericardial sac after excision of the native ventricles. We selected patients admitted to hospital who were at imminent risk of death, having irreversible biventricular failure, and not eligible for heart transplantation, from three cardiac surgery centres in France. FINDINGS The C-TAH was implanted in two male patients. Patient 1, aged 76 years, had the C-TAH implantation on Dec 18, 2013; patient 2, aged 68 years, had the implantation on Aug 5, 2014. The cardiopulmonary bypass times for C-TAH implantation were 170 min for patient 1 and 157 min for patient 2. Both patients were extubated within the first 12 postoperative hours and had a rapid recovery of their respiratory and circulatory functions as well as a normal mental status. Patient 1 presented with a tamponade on day 23 requiring re-intervention. Postoperative bleeding disorders prompted anticoagulant discontinuation. The C-TAH functioned well with a cardiac output of 4·8-5·8 L/min. On day 74, the patient died due to a device failure. Autopsy did not detect any relevant thrombus formation within the bioprosthesis nor the different organs, despite a 50-day anticoagulant-free period. Patient 2 experienced a transient period of renal failure and a pericardial effusion requiring drainage, but otherwise uneventful postoperative course. He was discharged from the hospital on day 150 after surgery with a wearable system without technical assistance. After 4 months at home, the patient suffered low cardiac output. A change of C-TAH was attempted but the patient died of multiorgan failure. INTERPRETATION This preliminary experience could represent an important contribution to the development of total artificial hearts using bioprosthetic materials. FUNDING CARMAT SA.

A mock circulatory system to assess the performance of continuous-flow left ventricular assist devices (LVADs): does axial flow unload better than centrifugal LVAD?

Hemodynamic performances comparisons between different types of left ventricular assist devices (LVADs) remain difficult in a clinical context. The aim of this study was to create an experimental model to assess and compare two types of LVAD under hemodynamic conditions that simulated physical effort and pulmonary hypertension. An experimental mock circulatory system was created to simulate the systemic and pulmonary circulations and consisted of pulsatile left and right cardiac simulators (cardiowest pump), air/water tanks to model compliances, and tubes to model the venous and arterial resistances. Two types of continuous-flow ventricular assist devices were connected to this pulsated model: an axial flow pump, Heartmate II (HTM II), and a centrifugal pump, VentrAssist (VTA). The hemodynamic conditions at rest and during exercise were replicated. Mean aortic pressures were not significantly different at rest and during effort but mean flow under maximum pump speed was higher with HTM II (13 L vs. 10 L, p = 0.02). Left atrial pressure was lower at rest and during effort for the HTM II (11 mm Hg vs. 3 mm Hg, p = 0.02 and 9 mm Hg vs. 2 mm Hg, p = 0.008) than with the VTA, but with greater risk of left-ventricle suck-down for the axial flow. Power consumption for a similar flow was lower with the VTA during rest (4.7 W vs. 6.9 W, p = 0.002) and during effort (4.3 W vs. 6.6 W, p = 0.008). In case of high pulmonary vascular resistance with preserved right ventricular function, lower right ventricular pressure was obtained with HTM II (21 mm Hg vs. 28 mm Hg, p = 0.03). Observed results are in favor of a better discharge of the left and right cavities with the HTM II compared to the VTA yet with a higher risk of left cavity collapse occurrence.

Animal studies with the Carmat bioprosthetic total artificial heart

OBJECTIVES The Carmat bioprosthetic total artificial heart (TAH) contains bioprosthetic blood-contacting surfaces, and is designed for orthotopic cardiac replacement. In preparation for clinical studies, we evaluated the TAH performance and its effects on end-organ function in an animal model. METHODS Twelve female Charolais calves, 2-3 months of age and weighing 102-122 kg, were implanted with the TAH through a mid-sternotomy to ensure an adequate anatomic fit. The intended support duration was 4-10 days. Haematological values, creatinine, bilirubin and lactate levels were measured and mean arterial and central venous pressure, central venous oxygen saturation and TAH parameters were monitored. RESULTS The calves were placed in a cage immediately postoperatively, and extubated on postoperative day 1 in most cases. Average support duration was 3 days, with 4 of 12 calves supported for 4, 4, 8 and 10 days. The initial procedures were used to refine surgical techniques and postoperative care. Pump output ranged from 7.3 to 10 l/min. Haemodynamic parameters and blood analysis were within acceptable ranges. No device failures occurred. No anticoagulation was used in the postoperative phase. The calves were euthanized in case of discomfort compromising the animal well-being, such as respiratory dysfunction, severe blood loss and cerebral dysfunction. Device explant analysis showed no thrombus formation inside the blood cavities. Histological examination of kidneys showed isolated micro-infarction in 2/12 animals; brain histology revealed no thromboembolic depositions. CONCLUSION The Carmat bioprosthetic TAH implanted in calves up to 10 days provided adequate blood flow to organs and tissues. Low levels of haemolysis and no visible evidence of thromboembolic depositions in major organs and device cavities, without the use of anticoagulation, may indicate early-phase haemocompatibility of the TAH.

Retrograde Dissections of the Aortic Arch After Exclusion-Bypass of the Descending Thoracic Aorta: A Report of Three Cases

We report three cases of fatal retrograde dissection of the aortic arch after exclusion-bypass with metal clamps according to Carpentiers thromboexclusion method. All three patients were male, aged 59, 66, and 73 years. Initial operative indications were chronic dissections in two cases and atheromatous aneurysm of the descending thoracic aorta in the other. Two of these patients were operated on in an emergency setting for a ruptured aneurysm. In all three cases, an extraanatomic bypass between the ascending aorta and abdominal aorta was performed as the first step: The proximal clamp was then placed distal to the origin of the left subclavian artery. Death occurred two hours, 12 hours, and eight days after operation, respectively. Autopsy revealed retrograde dissection initiating in the aortic arch and reaching the aortic ring as the cause of death. Pathological examination of aortic specimens confirmed that the dissections began just proximal to the site of clamping. To explain this complication, two etiologic factors, occurring either alone or together, have been postulated: postoperative hypertension and trauma to the aortic wall from the clamp.