Impact of Major Pulmonary Resections on Right Ventricular Function: Early Postoperative Changes.

BACKGROUND: Right ventricular (RV) dysfunction after pulmonary resection in the early postoperative period is documented by reduced RV ejection fraction and increased RV end-diastolic volume index. Supraventricular arrhythmia, particularly atrial fibrillation, is common after pulmonary resection. RV assessment can be done by non-invasive methods and/or invasive approaches such as right cardiac catheterization. Incorporation of a rapid response thermistor to pulmonary artery catheter permits continuous measurements of cardiac output, right ventricular ejection fraction, and right ventricular end-diastolic volume. It can also be used for right atrial and right ventricular pacing, and for measuring right-sided pressures, including pulmonary capillary wedge pressure. METHODS: This study included 178 patients who underwent major pulmonary resections, 36 who underwent pneumonectomy assigned as group (I) and 142 who underwent lobectomy assigned as group (II). The study was conducted at the cardiothoracic surgery department of Benha University hospital in Egypt; patients enrolled were operated on from February 2012 to February 2016. A rapid response thermistor pulmonary artery catheter was inserted via the right internal jugular vein. Preoperatively the following was recorded: central venous pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac output, right ventricular ejection fraction and volumes. The same parameters were collected in fixed time intervals after 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours postoperatively. RESULTS: For group (I): There were no statistically significant changes between the preoperative and postoperative records in the central venous pressure and mean arterial pressure; there were no statistically significant changes in the preoperative and 12, 24, and 48 hour postoperative records for cardiac index; 3 and 6 hours postoperative showed significant changes. There were statistically significant changes between the preoperative and postoperative records for heart rate, mean pulmonary artery pressure, pulmonary capillary wedge pressure, pulmonary vascular resistance, right ventricular ejection fraction and right ventricular end diastolic volume index, in all postoperative records. For group (II): There were no statistically significant changes between the preoperative and all postoperative records for the central venous pressure, mean arterial pressure and cardiac index. There were statistically significant changes between the preoperative and postoperative records for heart rate, mean pulmonary artery pressure, pulmonary capillary wedge pressure, pulmonary vascular resistance, right ventricular ejection fraction and right ventricular end diastolic volume index in all postoperative records. There were statistically significant changes between the two groups in all postoperative records for heart rate, mean pulmonary artery pressure, pulmonary capillary wedge pressure, pulmonary vascular resistance, right ventricular ejection fraction and right ventricular end diastolic volume index. CONCLUSION: There is right ventricular dysfunction early after major pulmonary resection caused by increased right ventricular afterload. This dysfunction is more present in pneumonectomy than in lobectomy. Heart rate, mean pulmonary artery pressure, pulmonary capillary wedge pressure, pulmonary vascular resistance, right ventricular ejection fraction, and right ventricular end diastolic volume index are significantly affected by pulmonary resection.

Impact of aortic prosthesis-patient mismatch on left ventricular mass regression.

BACKGROUND: Prostheses used for aortic valve replacement may be small in relation to body size, causing prosthesis-patient mismatch and delaying left ventricular mass regression. This study examined the effect of prosthesis-patient mismatch on regression of left ventricular mass after aortic valve replacement. METHODS: We prospectively studied 96 patients undergoing aortic valve replacement between 2007 and 2012. Mean and peak gradients and indexed effective orifice area were measured by transthoracic echocardiography at 3 and 6 months postoperatively. Patient-prosthesis mismatch was defined as indexed effective orifice area ≤0.85 cm(2)·m(-2). RESULTS: Moderate prosthesis-patient mismatch was present in 25% of patients. There were no significant differences in demographic and operative data between patients with and without prosthesis-patient mismatch. Left ventricular dimensions, posterior wall thickness, transvalvular gradients, and left ventricular mass decreased significantly after aortic valve replacement in both groups. The interventricular septal diameter and left ventricular mass index regression, and left ventricular ejection fraction were better in patients without prosthesis-patient mismatch. There was a significant positive correlation between the postoperative indexed effective orifice area of each valve prosthesis and the rate of left ventricular mass regression. CONCLUSIONS: Prosthesis-patient mismatch leads to higher transprosthetic gradients and impaired left ventricular mass regression. A small-sized valve prosthesis does not necessarily result in prosthesis-patient mismatch, and may be perfectly adequate in patient with small body size.

Traumatic intrathoracic tracheobronchial injuries: a study of 78 cases.

BACKGROUND: Tracheobronchial injuries are encountered with increasing frequency because of improvements in pre-hospital care. We reviewed our experience of these injuries to determine how to better recognize them and facilitate their correct management. METHODS: Patients with traumatic non-iatrogenic intrathoracic tracheobronchial injuries managed in 2 tertiary centers in Saudi Arabia between 2000 and 2012, were studied. Clinical presentation, diagnostic evaluation, management, and outcome were reviewed. RESULTS: 78 patients with tracheobronchial injuries were included in this study. They were divided into 2 groups according to the management strategy. Forty-seven patients who were managed conservatively, and 31 underwent surgery. Surgery allowed shorter intensive care unit and hospital stays; otherwise, the results were comparable between the two groups. CONCLUSIONS: Early recognition and expedient appropriate management are essential in these potentially lethal injuries. Operative management can be achieved with acceptable mortality, and conservative treatment should be considered as a valuable alternative to the well-established surgical treatment.

Cytochrome P450-isoenzyme 1A1 in susceptibility to tobacco-related lung cancer.

BACKGROUND: Tobacco smoke contains many carcinogens that may mediate susceptibility to lung cancer. Cytochrome P450 isoenzyme 1A1 activity and expression increases several fold in lung cancer due to smoking. Finding the role of cytochrome P450 1A1 in susceptibility to tobacco-related lung cancer may be important to predict the outcome in early stage cancer, and may result in an improved survival rate. PATIENTS AND METHODS: This study was carried on 2 groups of patients: group A was 20 patients with operable smoking-related lung cancer, who underwent surgery at the time of diagnosis; group B was 20 nonsmokers without lung cancer who underwent chest exploration following road traffic accidents. Specimens were obtained from tumor tissue and surrounding healthy tissue in group A patients, and from healthy lung tissue in group B patients. These specimens were sent for measurement of protein content and cytochrome P450 1A1 activity. RESULTS: There was significantly greater tissue cytochrome P450 1A1 activity in group A compared to group B. Patients with stage II cancer showed significantly higher levels of tissue cytochrome P450 1A1 activity than those with stage I. There was also a significant difference in tissue cytochrome P450 1A1 activity between the tumor tissue and the tissue surrounding the tumor. CONCLUSION: Carcinogens in smoke increase cytochrome P450 1A1 activity, which might be considered to play a role in cigarette smoking-induced lung cancer.

Predictive factors of supraventricular arrhythmias after noncardiac thoracic surgery: a multicenter study.

BACKGROUND: Supraventricular cardiac arrhythmias are the most common rhythm disturbances in patients following thoracic surgery. The purpose of our study was to determine which of the clinical parameters are the most valuable in predicting postoperative atrial fibrillation (AF) after lung surgery. METHODS: Retrospective analysis was carried out on 987 patients after noncardiac thoracic surgery to define the prevalence, associated risk factors, and clinical course of postoperative arrhythmias. There were 822 men and 165 women, age 34 to 78 years (mean age: 61 ± 8 years). The patients were divided into two groups depending on the occurrence or absence of supraventricular arrhythmia. Group I consisted of 876 patients who were free from rhythm disturbances. The remaining 111 patients exhibited episodes of supraventricular arrhythmia (29 supraventricular tachycardia; 82 AF). These 111 patients were placed in Group II. Preoperative, operative, and postoperative data were reviewed. Statistical analysis was performed. RESULTS: A statistically significant difference was found between the two groups in age, previous history of heart disease, and lung resection, especially pneumonectomy. CONCLUSION: Age, history of prior heart disease, lung resection, and the extent of pulmonary resection are the main risk factors for postoperative supraventricular arrhythmia in patients undergoing major thoracic operations.