François Tronc

Long-term results of sleeve lobectomy for lung cancer

OBJECTIVE Sleeve lobectomy is a lung saving procedure indicated for central tumors for which the alternative is a pneumonectomy. Current controversies relate to the safety of the procedure and adequacy as a cancer operation. The aim of the study is to analyze long-term survival after sleeve lobectomy, particularly in relation with nodal status and histological type. The incidence and patterns of recurrences were reviewed. METHODS From 1972 to 1998, 184 patients (male 152, female 32) underwent sleeve resection for lung cancer. The mean age was 60+/-10 years (11-78 years), and the indications for operation were a central tumor (79%), peripheral tumor with nodal involvement (13%) and compromised pulmonary function (8%). The histological type was predominantly squamous (n=125, 68%), followed by non-squamous (n=50, 27%) and carcinoid tumors (n=9, 5%). Resection was complete in 161 patients (87%). RESULTS The operative mortality was 1.6% (n=3). Follow-up was complete for the remaining 181 patients (mean, 5.7 years; range, 1 month-26 years). The survival at 5 and 10 years of all patients was 52 and 33%, respectively. Theses rates for patients with N0 status (n=97) were 63 and 48%, and 48 and 27% for those with N1 status (n=68; N0 vs. N1, P<0.05). An 8% survival rate was observed with N2 status (n=19) at 5 years, with no survivors after 7 years of follow-up. The 5 and 10 year survival was 56 and 34% for squamous carcinoma vs. 33 and 22% for non-squamous carcinoma (P<0.05). These rates were 58 and 38% for complete resection vs. 11 and 6% for incomplete resection at 5 and 10 years, respectively (P<0.05). Local recurrences occurred in 22% of cases, and the prevalence was statistically different between patients with N0 disease (14%) and N1 disease (23%; P=0.03), but not between N1 and N2 disease (42%; P=0.2). When local and distant recurrence were pooled together, the differences were highly significant between N0 (22%) and N1 (41%) disease (P=0.007), and between N0 and N2 (63%) disease (P=0.0002), but not between N1 and N2 disease (P=0.09). CONCLUSION Sleeve lobectomy is a safe and effective therapy for patients with resectable lung cancer. The presence of N1 and N2 disease, or of non-squamous carcinoma significantly worsen the prognosis.

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.

Cough-induced intercostal lung herniation requiring surgery: Report of a case.

Lung herniation is a rare event defined by protrusion of the lung through an abnormal weakness in the thoracic wall. We report a case of spontaneous intercostal pulmonary herniation, which occurred as a result of vigorous coughing. We repaired the herniation by approximating the ribs with heavy stitches. The mechanism of intercostal muscle disruption, and the etiology and treatment of lung herniations, are discussed.

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.

Completion Pneumonectomy in Patients with Cancer: Postoperative Survival and Mortality Factors

Objective: To describe postoperative complications and long-term outcomes of completion pneumonectomy and highlight prognostic factors. Method: We retrospectively reviewed the records of 46 patients (38 men, 8 women) who underwent completion pneumonectomy for lung cancer between 1995 and 2009 in one of two thoracic surgery departments. Most were current or former smokers (n = 41; 89%) and did not undergo chemotherapy (n = 38; 83%) or radiotherapy (83%) before surgery. Results: Complications after surgery were respiratory failure (n = 11; 24.4%), bronchopleural fistula (n = 6; 13%, with no side preference), and empyema (n = 6; 13%). Blood transfusion was necessary for 43% of the cases (n = 20). The day 90 death rate was 15.2% (n = 7). Postoperative staging showed mostly limited disease. Ten patients (21.7%) underwent operation for a second primary cancer, 25 for local recurrence (54.3%), five for microscopically incomplete resection, and six for other reasons. Median overall survival after completion surgery was 30 months (median follow-up: 46.5 months). Among the 15 living patients (33%), 11 are free of disease (24%). In a Cox regression model, factors negatively influencing overall survival were: age older than 65 years (odds ratio [OR] = 2.47; p = 0.012), current smoker status (OR = 2.285; p = 0.033), postoperative pulmonary (OR = 5.144; p = 0.004), cardiac (OR = 3.404; p = 0.033), or parietal wound complications (OR = 5.439; p = 0.016). Conclusion: Despite its increased postoperative complications and mortality compared with standard pneumonectomy, completion pneumonectomy offers encouraging long-term results. Five main factors seem predictive of shorter overall survival.

Effects of various flow types on maternal hemodynamics during fetal bypass: Is there nitric oxide release during pulsatile perfusion?

OBJECTIVE This study investigates the role of various flow conditions on maternal hemodynamics during fetal cardiopulmonary bypass. METHODS Normothermic fetal bypass was conducted under pulsatile, or steady flow, for a 60-minute period. Fetal lamb preparations were randomly assigned to 1 of the 3 groups: steady flow (n=7), pulsatile flow (n=7), or pulsatile blocked flow bypass (n=7), where fetuses were perfused with Nomega-nitro-L-arginine after the first 30 minutes of pulsatile flow to assess the potential role of endothelial autacoids. RESULTS Maternal oximetry and pressures remained unchanged throughout the procedure. Under fetal pulsatile flow, maternal cardiac output increased after 20 minutes of bypass and remained significantly higher than under steady flow at minute 30 (8.8+/-0.7 L x min(-1) vs 5.9+/-0.5 L x min(-1), P=.02). Maternal cardiac output in the pulsatile group also remained higher than in both steady and pulsatile blocked flow groups, reaching respectively 8.7+/-0.9 L x min(-1) vs 5.8+/-0.4 L x min(-1) (P=.02) and 5.9+/-0.3 L min(-1) (P=.01) at minute 60. Maternal systemic vascular resistances were significantly lower under pulsatile than under steady flow after 30 minutes and until the end of bypass (respectively, 9.1+/-0.6 IU vs 12.7+/-1.1 IU, P=.02 and 8.9+/-0.5 IU vs 12.9+/-1.2 IU, P=.01). Infusion of Nomega-nitro-L-arginine was followed by an increase in systemic vascular resistances from 9.3+/-0.7 IU, similar to that of the pulsatile group, to 13.5+/-1 IU at 60 minutes, similar to that of the steady flow group. CONCLUSIONS Maternal hemodynamic changes observed under fetal pulsatile flow are counteracted after infusion of Nomega-nitro-L-arginine, suggesting nitric oxide release from the fetoplacental unit under pulsatile fetal flow conditions.

Long-term results of heart transplantation deteriorate more rapidly in patients over 60 years of age

It is generally agreed that the upper age limit for heart transplantation is 60 years. However, an increasing number of elderly candidates are accepted for heart transplantation. We retrospectively analyzed our experience with a total of 204 consecutive transplantations, performed in 195 adult patients (9 retransplantations) between March 1987 and September 1993. There were 48 patients older than 60 years (mean 62.9 +/- 3), group I (gr I) and 156 patients between 20 and 59 years old (mean 47.5 +/- 8), group II (gr II). The two groups were matched for sex-ratio (female 10.4 vs 14.2%), indications (cardiomyopathy, ischemic, others), and hemodynamic parameters (pulmonary artery pressure, capillary wedge pressure, cardiac index). A ventricular assist device was used in 14 patients as bridge to transplantation in gr II vs 0 to gr I. There were seven early deaths in gr I (14.6%) vs 14 in gr II (8.97%, NS). A total of 183 survivors (41 vs 142) have been followed up for 1 month-6.3 years (mean follow-up 20.4 +/- 19.3 months in gr I, 35.4 +/- 23 in gr II). No patient was lost to follow-up. There were 11 late deaths in gr I vs 16 in gr II. The most common cause was malignancy (n = 4) in gr I and sudden death (n = 9) in gr II, with a significant difference. The actuarial survival was 68.8% in gr I vs 88.5% in gr II at 1 year 43.5% in gr I vs 76.4% in gr II at 5 years. In conclusion, transplanted patients over 60 years of age have a significantly poorer late survival than younger patients, despite similar good early results. Moreover, the causes of late deaths were different in the two groups. So, heart transplantation in patients over 60 years of age should be carefully considered.