Right ventricular dysfunction after major pulmonary resection

Epidemiology of perioperative RV dysfunction: risk factors, incidence, and clinical implications

In this edition of the journal, the Perioperative Quality Initiative (POQI) present three manuscripts describing the physiology, assessment, and management of right ventricular dysfunction (RVD) as pertains to the perioperative setting. This narrative review seeks to provide context for these manuscripts, discussing the epidemiology of perioperative RVD focussing on definition, risk factors, and clinical implications. Throughout the perioperative period, there are many potential risk factors/insults predisposing to perioperative RVD including pre-existing RVD, fluid overload, myocardial ischaemia, pulmonary embolism, lung injury, mechanical ventilation, hypoxia and hypercarbia, lung resection, medullary reaming and cement implantation, cardiac surgery, cardiopulmonary bypass, heart and lung transplantation, and left ventricular assist device implantation. There has however been little systematic attempt to quantify the incidence of perioperative RVD. What limited data exists has assessed perioperative RVD using echocardiography, cardiovascular magnetic resonance, and pulmonary artery catheterisation but is beset by challenges resulting from the inconsistencies in RVD definitions. Alongside differences in patient and surgical risk profile, this leads to wide variation in the incidence estimate. Data concerning the clinical implications of perioperative RVD is even more scarce, though there is evidence to suggest RVD is associated with atrial arrhythmias and prolonged length of critical care stay following thoracic surgery, increased need for inotropic support in revision orthopaedic surgery, and increased critical care requirement and mortality following cardiac surgery. Acute manifestations of RVD result from low cardiac output or systemic venous congestion, which are non-specific to the diagnosis of RVD. As such, RVD is easily overlooked, and the relative contribution of RV dysfunction to postoperative morbidity is likely to be underestimated.We applaud the POQI group for highlighting this important condition. There is undoubtedly a need for further study of the RV in the perioperative period in addition to solutions for perioperative risk prediction and management strategies. There is much to understand, study, and trial in this area, but importantly for our patients, we are increasingly recognising the importance of these uncertainties.

Right Ventricle Response to Major Lung Resection (the RIVER Study)

Backgrounds

Major lung resection is associated with high postoperative morbidity and mortality, especially due to cardiorespiratory complications. Right ventricle (RV) ejection, pulmonary artery (PA) pressure, and tone are tightly coupled. Since the RV is exquisitely sensitive to changes in afterload, an acute increase in RV outflow resistance (i.e., acute pulmonary embolism [PE]) will cause acute RV dilatation and, a reduction of left ventricle compliance too, rapidly spiraling to acute cardiogenic shock and death. We investigated the changing in RV performance after major lung resection.

Materials and Methods

We carried out transthoracic echocardiography (TTE) aiming at searching for the incidence of early RV systolic dysfunction (defined as tricuspid annulus plane systolic excursion [TAPSE] <17 cm, S'-tissue Doppler imaging <10 cm/s) and estimate the RV-PA coupling by the TAPSE/pulmonary artery pressures (PAPs) ratio after major lung resection. The TTE has been performed before and immediately after surgery.

Results

After the end of the operation the echocardiographic parameters of the RV function worsened. TAPSE decreased from 24 (21 ÷ 28) to 18 (16 ÷ 22) mm (P = 0.015) and PAPs increased from 26 (25 ÷ 30) to 30 (25 ÷ 39) mmHg (P = 0.013). TAPSE/PAPs ratio decreased from 0.85 (0.80 ÷ 0.90) to 0.64 (0.54 ÷ 0.79) mm/mmHg (P = 0.002).

Conclusions

In line with previous reports, after major lung resection the increase in afterload reduces the RV function, but the impairment remains clinically not relevant. The different clinical picture of an acute cor pulmonale due to PE implies that the pathogenesis of cardiac failure involves more pathways than the mere mechanic occlusion of the blood flow.

The prevalence of pulmonary hypertension after successful tuberculosis treatment in a community sample of adult patients

There are an estimated 155 million survivors of tuberculosis (TB). Clinical experience suggests that post tuberculosis lung disease (PTLD) is an important cause of Group 3 pulmonary hypertension (PH). However, TB is not listed as a cause of PH in most guidelines. A cross-sectional, community-based study was conducted in nonhealthcare seeking adults who had successfully completed TB treatment. Subjects underwent questionnaires, spirometry, a 6-min walk distance test (6MWD) and transthoracic echocardiography (TTE). Screen probable PH was defined on TTE as an estimated pulmonary artery peak systolic pressure (PASP) of ≥40 mmHg. One hundred adults (71 males) were enrolled, with a mean age of 42 years (SD 13.8 years) and a median of one TB episode (interquartile range: 1-2). Co-morbidities included hypertension (21%), diabetes (16%), human immunodeficiency virus (10%) and asthma/COPD (5%). Only 25% had no residual symptoms after TB. Probable PH was found in 9%, while 7% had borderline raised PASP values (PASP 35-40 mmHg). An association was found between PH and the number of previous TB episodes, with each additional episode of TB increasing the odds of PH-postTB 2.13-fold (confidence interval [CI]: 1.17-3.88; p = 0.013). All of those found to have PH were smokers or ex-smokers yielding an unadjusted odds ratio for PH-postTB of 3.67 (95% CI: 0.77-17.46). There was no statistical difference in spirometry or 6MWD, between those with and without PH. Neither symptoms nor co-morbidities demonstrated significant association with PH. PH after TB was a common finding in this community-based population. Further research is needed to confirm and determine the significance of these findings.

Perioperative cardiovascular pathophysiology in patients undergoing lung resection surgery: a narrative review

Although thoracic surgery is understood to confer a high risk of postoperative respiratory complications, the substantial haemodynamic challenges posed are less well appreciated. This review highlights the influence of cardiovascular comorbidity on outcome, reviews the complex pathophysiological changes inherent in one-lung ventilation and lung resection, and examines their influence on cardiovascular complications and postoperative functional limitation. There is now good evidence for the presence of right ventricular dysfunction postoperatively, a finding that persists to at least 3 months. This dysfunction results from increased right ventricular afterload occurring both intraoperatively and persisting postoperatively. Although many patients adapt well, those with reduced right ventricular contractile reserve and reduced pulmonary vascular flow reserve might struggle. Postoperative right ventricular dysfunction has been implicated in the aetiology of postoperative atrial fibrillation and perioperative myocardial injury, both common cardiovascular complications which are increasingly being appreciated to have impact long into the postoperative period. In response to the physiological demands of critical illness or exercise, contractile reserve, flow reserve, or both can be overwhelmed resulting in acute decompensation or impaired long-term functional capacity. Aiding adaptation to the unique perioperative physiology seen in patients undergoing thoracic surgery could provide a novel therapeutic avenue to prevent cardiovascular complications and improve long-term functional capacity after surgery.

Pulmonary artery wave reflection and right ventricular function after lung resection

BACKGROUND

Lung resection has been shown to impair right ventricular function. Although conventional measures of afterload do not change, surgical ligation of a pulmonary artery branch, as occurs during lobectomy, can create a unilateral proximal reflection site, increasing wave reflection (pulsatile component of afterload) and diverting blood flow through the contralateral pulmonary artery. We present a cardiovascular magnetic resonance imaging (MRI) observational cohort study of changes in wave reflection and right ventricular function after lung resection.

METHODS

Twenty-seven patients scheduled for open lobectomy for suspected lung cancer underwent cardiovascular MRI preoperatively, on postoperative Day 2, and at 2 months. Wave reflection was assessed in the left and right pulmonary arteries (operative and non-operative, as appropriate) by wave intensity analysis and calculation of wave reflection index. Pulmonary artery blood flow distribution was calculated as percentage of total blood flow travelling in the non-operative pulmonary artery. Right ventricular function was assessed by ejection fraction and strain analysis.

RESULTS

Operative pulmonary artery wave reflection increased from 4.3 (2.1-8.8) % preoperatively to 9.5 (4.9-14.9) % on postoperative Day 2 and 8.0 (2.3-11.7) % at 2 months (P<0.001) with an associated redistribution of blood flow towards the nonoperative pulmonary artery (r>0.523; P<0.010). On postoperative Day 2, impaired right ventricular ejection fraction was associated with increased operative pulmonary artery wave reflection (r=-0.480; P=0.028) and pulmonary artery blood flow redistribution (r=-0.545; P=0.011). At 2 months, impaired right ventricular ejection fraction and right ventricular strain were associated with pulmonary artery blood flow redistribution (r=-0.634, P=0.002; r=0.540, P=0.017).

CONCLUSIONS

Pulsatile afterload increased after lung resection. The unilateral increase in operative pulmonary artery wave reflection resulted in redistribution of blood flow through the nonoperative pulmonary artery and was associated with right ventricular dysfunction.

CLINICAL TRIAL REGISTRATION

NCT01892800.

Accelerated right heart failure due to lung resection in the setting of chronic respiratory failure

A 68-year-old woman with a past medical history of chronic obstructive pulmonary disease and squamous cell carcinoma of the lung with recent right upper and middle lobectomy was admitted for dyspnea and volume overload. She was diagnosed with right-sided heart failure (RHF) through clinical, laboratory, and echocardiographic means. In the setting of chronic respiratory failure, the recent right lung lobectomy was deemed to be the inciting factor of the RHF. The mechanism by which RHF occurs in this situation is multifactorial, and it is essential to undergo pre-operative risk stratification and post-operative monitoring to avoid emergent events. <Learning objective: New-onset right heart failure can be a detrimental complication of lung resection surgery in patients with chronic respiratory failure. With proper pre-operative risk stratification and its corresponding post-operative monitoring, we can anticipate such occurrences and avoid emergent admissions, enabling better outcomes in a high-risk patient population.>.

Pulmonary hypertension after pneumonectomy: a preclinical model in rats and human pulmonary endothelial cells

OBJECTIVES

Pulmonary hypertension and heart disease contribute to the high morbidity rate following pneumonectomy (PN). The pathophysiology is still poorly understood. The objective was to investigate the consequences of PN on cardiopulmonary function in rats and to explore in vitro the involved mechanisms.

METHODS

Sixty Sprague-Dawley male rats randomly underwent either a right PN (PN group) or sham surgery. Ten rats per group were sacrificed on postoperative days 3, 7 and 28. Cardiopulmonary alterations were investigated by echocardiographic, haemodynamic and histological analyses. In vitro, the shear stress was reproduced using a Flexcell Tension™ cyclic stretch on cultured human pulmonary endothelial cells (P-ECs) to investigate the impact on pulmonary artery smooth muscle cell (PA-SMC) growth. Data are expressed as mean ± SD.

RESULTS

Mean pulmonary arterial pressure gradually increased in the PN group to reach 35 ± 7 mmHg on postoperative day 28 vs 18 ± 4 in sham (P = 0.001), likewise the proportion of muscularized distal pulmonary arteries, 83 ± 1% vs 5 ± 1%, respectively (P < 0.001), related to in situ PA-SMC proliferation. The right ventricle area and lateral wall thickness were doubled in the PN group on postoperative day 28. The left ventricle ejection fraction decreased on postoperative days 7 and 28 while the right ventricle function was maintained. In vitro, the human PA-SMC growth was significantly greater when seeded with stretched vs non-stretched P-EC media, highlighting the role of shear stress on the P-EC paracrine function.

CONCLUSIONS

Right PN led to pulmonary hypertension and proportional right heart remodelling in rats. The shear stress related to high blood flow alters the pulmonary endothelial paracrine control of SMC growth.

Contralateral pulmonary resection using selective bronchial blockade in postpneumonectomy patients

BACKGROUND

Pulmonary resection is occasionally performed in postpneumonectomy patients with contralateral lung lesions, such as metachronous or metastatic lung cancer. Careful intraoperative respiratory management is essential in such patients. This study evaluated the respiratory management of postpneumonectomy patients who underwent contralateral pulmonary resection with selective bronchial blockade of the lobe or segment to be resected.

METHODS

We retrospectively analyzed the surgical findings and safety of surgery in six patients who underwent contralateral pulmonary resection with selective bronchial blockade after pneumonectomy for non-small cell lung cancer (NSCLC).

RESULTS

The percutaneous oxygen saturation did not decrease in any of the patients during bronchial blockade under high oxygen concentration. The median blockade time was 57.5 minutes. The operative field was tolerable secured under conditions of partial lung collapse, and partial pulmonary resection was performed as planned. Postoperatively, one patient developed acute respiratory distress syndrome due to acute exacerbation of interstitial pneumonia; however, no patients died within one month postoperatively. Two patients underwent pulmonary resection in order to obtain adequate tissue specimens to evaluate the biomarkers of multiple lung metastases. On histopathology, one patient tested positive for anaplastic lymphoma kinase (ALK) and was subsequently administered an ALK inhibitor, which prolonged survival.

CONCLUSIONS

In all patients, intraoperative respiratory condition under partial lung collapse remained stable, and all partial pulmonary resections were safely performed. However, surgical indications should be carefully reviewed preoperatively in patients with interstitial pneumonia.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: Contralateral partial pulmonary resection was performed using selective bronchial blockade in postpneumonectomy patients. Percutaneous oxygen saturation did not decrease during the bronchial blockade under high oxygen concentration, and the operative field was tolerable secured under conditions of partial lung collapse.

WHAT THIS STUDY ADDS

Oxygen concentration can be set to the minimum level, sufficient to maintain oxygenation, during contralateral partial pulmonary resection with selective bronchial blockade.

B-type natriuretic peptide predicts deterioration in functional capacity following lung resection

OBJECTIVES

Following lung resection, there is a decrease in the functional capacity and quality of life, which is not fully explained by changes in pulmonary function. Previous work demonstrates that B-type natriuretic peptide (BNP) is associated with short- and long-term complications following lung resection, leading to the suggestion that cardiac dysfunction may contribute to functional deterioration. Our aim was to investigate any relationship between BNP and subjective and objective indices of functional deterioration following lung resection surgery.

METHODS

Twenty-seven patients undergoing lung resection had serum BNP measured preoperatively, on postoperative day (POD)1 and POD2, and at 2 months postoperatively. The functional deterioration was assessed using 6-min walk tests and the Medical Research Council dyspnoea scale. 'Deterioration in functional capacity' was defined as either an increase in the Medical Research Council dyspnoea score or a significant decrease in the 6-min walk test distance.

RESULTS

BNP increased over time (P < 0.01) and was significantly elevated on POD1 and POD2 (P < 0.02 for both). Seventeen patients demonstrated functional deterioration 2 months postoperatively. At all perioperative time points, BNP was significantly higher in patients showing deterioration (P < 0.05 for all). Preoperative BNP was predictive of functional deterioration at 2 months with an area under the receiver-operating characteristic curve of 0.82 (P = 0.01, 95% confidence interval 0.65-0.99).

CONCLUSIONS

This study has demonstrated, using subjective and objective measures, that preoperative BNP is a predictor of functional deterioration following lung resection. BNP may have a role in preoperative risk stratification in this population, allowing therapy in future to be targeted towards high-risk patients with the aim of preventing postoperative cardiac dysfunction.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01892800.

Effects of Thoracic Epidural Anesthesia on Neuronal Cardiac Regulation and Cardiac Function

Cardiac sympathetic blockade with high-thoracic epidural anesthesia is considered beneficial in patients undergoing major surgery because it offers protection in ischemic heart disease. Major outcome studies have failed to confirm such a benefit, however. In fact, there is growing concern about potential harm associated with the use of thoracic epidural anesthesia in high-risk patients, although underlying mechanisms have not been identified. Since the latest review on this subject, a number of clinical and experimental studies have provided new information on the complex interaction between thoracic epidural anesthesia–induced sympatholysis and cardiovascular control mechanisms. Perhaps these new insights may help identify conditions in which benefits of thoracic epidural anesthesia may not outweigh potential risks. For example, cardiac sympathectomy with high-thoracic epidural anesthesia decreases right ventricular function and attenuates its capacity to cope with increased right ventricular afterload. Although the clinical significance of this pathophysiologic interaction is unknown at present, it identifies a subgroup of patients with established or pending pulmonary hypertension for whom outcome studies are needed. Other new areas of interest include the impact of thoracic epidural anesthesia–induced sympatholysis on cardiovascular control in conditions associated with increased sympathetic tone, surgical stress, and hemodynamic disruption. It was considered appropriate to collect and analyze all recent scientific information on this subject to provide a comprehensive update on the cardiovascular effects of high-thoracic epidural anesthesia and cardiac sympathectomy in healthy and diseased patients.

The right ventricular response to lung resection

OBJECTIVES

Lung cancer is a leading cause of cancer death and in suitable cases the best chance of cure is offered by surgery. Lung resection is associated with significant postoperative cardiorespiratory morbidity, with dyspnea and reduced functional capacity as dominant features. These changes are poorly associated with deterioration in pulmonary function and a potential role of right ventricular (RV) dysfunction has been hypothesized. Cardiovascular magnetic resonance imaging is a reference method for noninvasive assessment of RV function and has not previously been applied to this population.

METHODS

We used cardiovascular magnetic resonance imaging to assess the RV response to lung resection. Cardiovascular magnetic resonance imaging with volume and flow analysis was performed on 27 patients preoperatively, on postoperative day 2 and at 2 months. Left ventricular ejection fraction and RV ejection fraction, the ratio of stroke volume to end systolic volume, pulmonary artery acceleration time, and distensibility of main and branch pulmonary arteries were studied.

RESULTS

Mean ± standard deviation RV ejection fraction deteriorated from 50.5% ± 6.9% preoperatively to 45.6% ± 4.5% on postoperative day 2 and remained depressed at 44.9% ± 7.7% by 2 months (P = .003). The ratio of stroke volume to end systolic volume deteriorated from median 1.0 (quartile 1, quartile 3: 0.9, 1.2) preoperatively to median 0.8 (quartile 1, quartile 3: 0.7, 1.0) on postoperative day 2 (P = .011). On postoperative day 2 there was a decrease in pulmonary artery acceleration time and operative pulmonary artery distensibility (P < .030 for both). There were no changes in left ventricular ejection fraction during the study period (P = .621).

CONCLUSIONS

These findings suggest RV dysfunction occurs following lung resection and persists 2 months after surgery. The deterioration in the ratio of stroke volume to end systolic volume suggests a mismatch between afterload and contractility. There is an increase in indices of pulsatile afterload resulting from the operative pulmonary artery.

The Utility of Eccentricity Index as a Measure of the Right Ventricular Function in a Lung Resection Cohort

Context

Right ventricular (RV) dysfunction occurs after lung resection and is associated with postoperative morbidity. Noninvasive evaluation of the RV is challenging, particularly in the postoperative period. A reliable measure of RV function would have value in this population.

Aims

This study compares eccentricity index (EI) obtained by transthoracic echocardiography (TTE) with cardiovascular magnetic resonance (CMR) determined measures of RV function in a lung resection cohort. CMR is the reference method for noninvasive assessment of RV function.

Design and Setting

Prospective observational cohort study at a single tertiary hospital.

Materials and Methods

Twenty-eight patients scheduled for elective lung resection underwent contemporaneous TTE and CMR imaging preoperatively, on postoperative day (POD) 2 and at 2-month. Systolic and diastolic EI was measured offline from anonymized and randomized TTE and CMR images.

Statistical Analysis

Bland-Altman analysis was performed to determine agreement between EI^TTE and EI^CMR. Changes over time and comparison with CMR determined RV ejection fraction (RVEF^CMR) was assessed.

Results

Bland-Altman analysis showed a negligible mean difference between EI^TTE and EI^CMR, but limits of agreement were wide (SD 0.24 and 0.28). There were no significant changes in EI^TTE and EI^CMR over time (P > 0.35). We found no association between EI^TTE with RVEF^CMR at all-time points (P > 0.22). Systolic and diastolic EI^CMR on POD 2 demonstrated moderate association with RVEF^CMR (r = -0.54 and r = -0.59, P ≤ 0.01). At 2-month, only diastolic EI^CMR correlated with RVEF^CMR (r = -0.43, P = 0.03). There were no meaningful associations between EI^TTE and EI^CMR with TTE-derived RV systolic pressure (P > 0.31).

Conclusions

TTE determined EI is not useful as a noninvasive method of assessing RV function following lung resection.

Unexpected postpneumonectomy exertion-induced acute right heart failure

INTRODUCTION

Thoracic surgery can have serious side effects. Accurate preoperative evaluation to assess which patients with anatomically resectable disease are suitable candidates for surgery is mandatory.

CASE DESCRIPTION

A 58-year-old man, scheduled for left pneumonectomy for lung cancer, passed all the preoperative examinations suggested by guidelines and underwent the surgery. Three days after pneumonectomy, he experienced hemorrhagic shock and subsequent acute respiratory distress syndrome. Fifteen days after left pneumonectomy, he experienced exertional acute right heart failure (ARHF). We administered sildenafil and he improved, clinically and echocardiographically. During the following 2 years of follow-up, he was asymptomatic at rest but under exercise test, he developed pulmonary hypertension with echocardiographic signs of right ventricular impairment.

CONCLUSIONS

In patients scheduled for major lung resections, preoperative stress echocardiography may give an adjunctive value to cardiopulmonary exercise test, quantifying the exercise-induced reduction in right ventricle ejection fraction and identifying asymptomatic patients at risk for postoperative ARHF.

Is Systolic Right Ventricular Function Reduced after Thoracic Non-Cardiac Surgery? A Propensity Matched Echocardiographic Analysis

Purpose: To assess whether thoracic non-cardiac surgery has an influence on right ventricular function (RVF) compared to known impaired postoperative RV function after cardiac surgery.

Methods: In all, 50 patients (mean age: 61 years), who underwent thoracic non-cardiac surgery were included and matched using propensity score to 50 patients, receiving coronary artery bypass graft surgery (CABG) (CABG_matched). All patients had transthoracic echocardiography (TTE) including two-dimensional speckle tracking (2D-STE) and tissue Doppler imaging (TDI) pre- and 1 week postoperatively.

Results: No significant changes in RV measurements including tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic velocity (TASV), RV fractional area change (RV-FAC), and 2D-STE of the RV and RV freewall within the thoracic non-cardiac surgery patients comparing pre- and postoperative values. Comparing RV TTE values between CABG_matched patients and thoracic surgery patients, only TAPSE differed between groups preoperatively (p <0.0001), where postoperatively, all RV measurements differed significantly between the two groups: TAPSE (p <0.0001), TASV (p <0.001), RVFAC (p = 0.005), and RV 2D-STE (p <0.0001) indicating impairment of RV function post-CABG surgery compared to thoracic non-cardiac surgery.

Conclusion: Thoracic non-cardiac surgery including an opening of the pleural cavity did not influence RV function early postoperative, whereas CABG surgery with pericardiotomy led to an impaired global RV function.

Cardiovascular Computed Tomography Findings after Pneumonectomy: Comparison to Lobectomy

RATIONALE AND OBJECTIVES

To identify and compare cardiovascular findings on computed tomography (CT) scans after pneumonectomy (PNX) with those after lobectomy (LOBX).

MATERIALS AND METHODS

Pre- and postoperative CT scans from 25 PNX patients were retrospectively analyzed and compared to those from 30 LOBX patients. The diameter of the main pulmonary artery (PA) and its ratio to the ascending aorta (PA/Ao) were determined. Cardiac morphometry values were ascertained by measuring maximum diameters of the right and left ventricle on axial (RV_axial, LV_axial) and four-chamber (RV_4-ch, LV_4-ch) views. RV_axial/LV_axial and RV_4-ch/LV_4-ch ratios were calculated. Vessel stumps were evaluated for thrombosis.

RESULTS

After PNX, PA (31.1 ± 5.8 mm vs 28.7 ± 5.4 mm, P = 0.003), PA/Ao (0.97 ± 0.15 vs 0.86 ± 0.12, P = 0.0001), and cardiac morphometry values significantly increased (RV_axial 43.6 ± 7.4 vs 39.4 ± 7.1, P = 0.029; RV_4-ch 41.1 ± 6.3 vs 37.6 ± 5.7, P = 0.041; RV_axial/LV_axial 1.18 ± 0.27 vs 1.03 ± 0.22, P = 0.04; RV_4-ch/LV_4-ch 1.17 ± 0.21 vs 1.02 ± 0.16, P = 0.03). There were no significant differences between right and left PNX. One case of PA stump thrombosis was identified after right PNX. LOBX resulted in a significant increase in PA (30.6 ± 4.3 vs 28.7 ± 3.5, P = 0.005) and PA/Ao (0.90 ± 0.09 vs 0.85 ± 0.10, P = 0.017), whereas cardiac morphometry values were not significantly changed compared to baseline values. No vessel stump thrombosis was observed after LOBX. In comparison to LOBX, all ascertained values were significantly elevated after PNX.

CONCLUSIONS

Morphologic alterations of the cardiovascular system following PNX can be identified on CT scans. Alterations are more distinct after PNX compared to LOBX.

The Outcome of Extracorporeal Life Support After General Thoracic Surgery: Timing of Application

BACKGROUND

Extracorporeal life support (ECLS) is widely used in refractory cardiac or pulmonary failure. Because complications of general thoracic surgery frequently involve the heart or lungs, ECLS can be a useful option. Therefore, we retrospectively reviewed our experience with ECLS after general thoracic surgery.

METHODS

There were 17,185 adult general thoracic surgery procedures between 2005 and 2013 at our institution, including resection of the lung (n = 10,434; 60.7%), esophagus (n = 1,847; 0.7%), and other procedures (n = 4,904; 28.5%). Twenty-nine patients (0.2%) were supported by ECLS postoperatively.

RESULTS

The median age was 64 years (range, 24 to 81). Primary operations were lobectomy (n = 13; 44.8%), pneumonectomy (n = 11; 37.9%), and bilobectomy (n = 5; 17.2%). The initial mode of ECLS was venovenous in 20 patients (69.0%) and venoarterial in 9 patients (31.0%). There were 10 patients (34.5%) who survived to decannulation and 7 patients (24.1%) who survived to discharge. Over the same period, the survival to decannulation rate and survival to discharge rate were 49.5% and 35.0%, respectively, among all ECLS patients (n = 759) at our institution. The hospital mortality of patients with surgery to ECLS time of longer than 2 days was 90.9%. Multivariate analysis revealed that a longer surgery to ECLS time was a risk factor for hospital mortality (odds ratio 1.720, 95% confidence interval: 1.039 to 2.849, p = 0.035).

CONCLUSIONS

ECLS after general thoracic surgery can be a viable rescue therapy option. Late presentation of complications or ECLS for late complications of general thoracic surgery may be predictors of death.

Thoracic Epidural Anesthesia Reduces Right Ventricular Systolic Function With Maintained Ventricular-Pulmonary Coupling

Background:

Blockade of cardiac sympathetic fibers by thoracic epidural anesthesia may affect right ventricular function and interfere with the coupling between right ventricular function and right ventricular afterload. Our main objectives were to study the effects of thoracic epidural anesthesia on right ventricular function and ventricular-pulmonary coupling.

Methods:

In 10 patients scheduled for lung resection, right ventricular function and its response to increased afterload, induced by temporary, unilateral clamping of the pulmonary artery, was tested before and after induction of thoracic epidural anesthesia using combined pressure-conductance catheters.

Results:

Thoracic epidural anesthesia resulted in a significant decrease in right ventricular contractility (ΔESV 25 : +25.5 mL, P =0.0003; ΔEes: -0.025 mm Hg/mL, P =0.04). Stroke work, dP/dt MAX , and ejection fraction showed a similar decrease in systolic function (all P <0.05). A concomitant decrease in effective arterial elastance (ΔEa: -0.094 mm Hg/mL, P =0.004) yielded unchanged ventricular-pulmonary coupling. Cardiac output, systemic vascular resistance, and mean arterial blood pressure were unchanged. Clamping of the pulmonary artery significantly increased afterload (ΔEa: +0.226 mm Hg/mL, P <0.001). In response, right ventricular contractility increased (ΔESV 25 : -26.6 mL, P =0.0002; ΔEes: +0.034 mm Hg/mL, P =0.008), but ventricular-pulmonary coupling decreased (Δ(Ees/Ea) = -0.153, P <0.0001). None of the measured indices showed significant interactive effects, indicating that the effects of increased afterload were the same before and after thoracic epidural anesthesia.

Conclusions:

Thoracic epidural anesthesia impairs right ventricular contractility but does not inhibit the native positive inotropic response of the right ventricle to increased afterload. Right ventricular-pulmonary arterial coupling was decreased with increased afterload but not affected by the induction of thoracic epidural anesthesia.

Clinical Trial Registration:

URL: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2844 . Unique identifier: NTR2844.

Trapped lung secondary to cardiomegaly in a 78 year-old male with congestive heart failure

Although the etiologies of both trapped lung and cardiomegaly are well-established, co-presentation of the two conditions, and possible interactions between them, are much rarer. Here we describe the case of 78 year-old male found to have both cardiomegaly and trapped lung, with a cause of death of congestive heart failure and subsequent cardiac arrest. This case prompted consideration of possible interactions between the two conditions. Issues related to decision-making for imaging and clinical interventions are also discussed.

Pulmonary arterial enlargement predicts cardiopulmonary complications after pulmonary resection for lung cancer: a retrospective cohort study

BACKGROUND

The finding of pulmonary arterial enlargement on computed tomography has been reported to be associated with pulmonary hypertension. On the other hand, pulmonary hypertension is a known risk factor for thoracic surgery. We investigated whether pulmonary arterial enlargement predicts cardiopulmonary complications following pulmonary resection for lung cancer.

METHODS

We reviewed 237 consecutive patients who underwent pulmonary resection for lung cancer. Preoperative patient characteristics (sex, age, Brinkman index, cardiopulmonary comorbidities, cardiothoracic ratio, pulmonary function, and pulmonary arterial enlargement) and surgical data (surgical procedure, pathological stage, postoperative complications, mortality, and length of postoperative hospital stay) were analyzed. In order to evaluate preoperative pulmonary arterial enlargement, we measured the diameter of the main pulmonary artery at its bifurcation and that of the ascending aorta at its widest point using chest computed tomography and calculated the ratio of the former diameter to the latter.

RESULTS

In all, 16 patients developed postoperative cardiopulmonary complications and 221 did not. One patient died from postoperative pneumonia. The mean age of patients who developed postoperative cardiopulmonary complications was significantly higher than that of those who did not (78 ± 5 years vs 69 ± 9 years, P=0.0001). The pulmonary artery-to-ascending-aorta ratio was significantly higher in patients who developed postoperative complications than in those who did not (0.94 ± 0.15 vs. 0.81 ± 0.11, P=0.03). Other preoperative patient characteristics and surgical data did not differ significantly between the groups. On multivariate analysis, pulmonary artery-to-ascending-aorta ratio (0.1-point increase; odds ratio 2.3, 95 % confidence interval 1.5-3.5; P=0.0002) and age (1-year increase; odds ratio 1.2, 95 % confidence interval 1.1-1.3; P=0.03) were found to be independent predictors of postoperative cardiopulmonary complications.

CONCLUSIONS

A finding of pulmonary arterial enlargement on computed tomography is a potential predictor of postoperative cardiopulmonary complications after lung cancer surgery.

Perioperative fluid management for pulmonary resection surgery and esophagectomy

Perioperative fluid management is of significant importance during pulmonary resection surgery and esophagectomy. Excessive fluid administration has been consistently shown as a risk factor for lung injury after thoracic procedures. Probable causes of this serious complication include fluid overload, lung lymphatics and pulmonary endothelial damage. Along with new insights regarding the Starling equation and the absence of a third space, current evidence supports a restrictive fluid regimen for patients undergoing pulmonary resection surgery and esophagectomy. Multiple minimally invasive hemodyamic monitoring devices, including pulse pressure/stroke volume variation, esophageal Doppler, and extravascular lung water measurement, were evaluated for optimizing perioperative fluid therapy. Further research regarding the prevention, diagnosis, and treatment of acute lung injury after pulmonary resection and esophagectomy is required.

Anesthetic management of the patient with dilated cardiomyopathy undergoing pulmonary resection surgery: a case-based discussion

Interactions between the cardiovascular and respiratory systems are complex and profound. General anesthesia, muscle relaxation, and positive-pressure ventilation all impose physiological effects on cardiovascular function. In patients presenting for pulmonary resection, additional effects resulting from positioning, 1-lung ventilation, surgical procedures, and contraction of the pulmonary vascular bed may impose an additional physiological burden. For most patients with adequate pulmonary and cardiovascular reserve, these effects are well tolerated. However, the cardiothoracic anesthesiologist may be asked to provide anesthetic care for patients with significantly reduced cardiac function who require potentially curative pulmonary resection for lung cancer. These patients present a major perioperative challenge and a thoughtful approach to intraoperative management is required. The authors review a case of a patient with severely impaired biventricular function who presented for elective pulmonary lobectomy in an attempt to effect a curative resection of lung cancer and present a discussion of physiological and pathophysiological considerations for clinical management.

The effect of hypercapnia and hypertension on cerebral oxygen balance during one-lung ventilation for lung surgery during propofol anesthesia

STUDY OBJECTIVE

To investigate whether jugular bulb venous oxygen saturation (SjO(2)) values increased with induced hypercapnia or induced hypertension during propofol-based anesthesia for one-lung ventilation (OLV).

DESIGN

Prospective clinical study.

SETTING

Operating room at University hospital.

PARTICIPANTS

15 adult patients scheduled for elective thoracic procedures in the lateral position.

INTERVENTIONS

General anesthesia was maintained with propofol combined with epidural anesthesia. During OLV, hypercapnia (PaCO(2) = 50 mmHg) and hypertension (20% increase in mean arterial pressure) were applied.

MEASUREMENTS

SjO2 values were measured.

MAIN RESULTS

With hypercapnia, SjO(2) values increased 30 ± 18% (from 54.3 ± 8.8% to 69.3 ± 6.3%). With hypertension, SjO(2) values were increased by 9 ± 18% (from 54.4 ± 9.0% to 58.5 ± 8.8%). These changes were significantly different. No significant differences regarding SaO(2) were observed during OLV in the experimental period.

CONCLUSION

Hypercapnia, not hypertension, significantly improved cerebral oxygen balance without observed side effects during propofol anesthesia.

Pre- and post-operative cardiac evaluation of dogs undergoing lobectomy and pneumonectomy

This study aimed to assess the influence of lobectomy and pneumonectomy on cardiac rhythm and on the dimensions and function of the right-side of the heart. Twelve dogs undergoing lobectomy and eight dogs undergoing pneumonectomy were evaluated preoperatively and one month postoperatively with electrocardiography and Doppler echocardiography at rest. Pulmonary artery systolic pressure (PASP) was estimated by the tricuspid regurgitation jet (TRJ) via the pulse wave Doppler velocity method. Systemic inflammatory response syndrome criteria (SIRS) were also evaluated based on the clinical and hematological findings in response to lobectomy and pneumonectomy. Following lobectomy and pneumonectomy, we predominantly detected atrial fibrillation and varying degrees of atrioventricular block (AVB). Dogs that died within seven days of the lobectomy (n = 2) or pneumonectomy (n = 1) had complete AVB. Preoperative right atrial, right ventricular, and pulmonary artery dimensions increased gradually during the 30 days (p<0.05) following pneumonectomy, but did not undergo significant changes during that same period after lobectomy. Mean PASP was 56.0 ± 4.5 mmHg in dogs having significant TRJ after pneumonectomy. Pneumonectomy, but not lobectomy, could lead to increases (p<0.01) in the SIRS score within the first day post-surgery. In brief, it is important to conduct pre- and postoperative cardiac evaluation of dogs undergoing lung resections because cardiac problems are a common postoperative complication after such surgeries. In particular, complete AVB should be considered a life-threatening complication after pneumonectomy and lobectomy. In addition, pneumonectomy appears to increase the likelihood of pulmonary hypertension development in dogs.

Suppression of right ventricular hypertrophy after extensive pulmonary resection in rats by granulocyte colony-stimulating factor

BACKGROUND

The objective of the present study was to investigate the effects of granulocyte colony-stimulating factor (G-CSF) on right ventricular hypertrophy following extensive pulmonary resection in rats.

MATERIALS AND METHODS

Adult rats were divided into four groups: (1) Group S (right thoracotomy only); (2) Group L (right three lobectomy); (3) Group LG10 (Group L+G-CSF [10microg/kg/d]); and (4) Group LG100 (Group L+G-CSF [100microg/kg/d]). At postoperative day 21, weight ratio of the right ventricular to the left ventricle plus septum (RV/LV+S, indicator of right ventricular hypertrophy) were measured, and a histopathological study was conducted to determine percentage wall thickness of peripheral pulmonary arteries and proliferating cell nuclear antigen labeling index (indicator of oxidative DNA damage) of right ventricles.

RESULTS

Mean RV/LV+S for Group S was 0.27+/-0.02, significantly smaller than that for the lobectomy groups (Group L, LG10, LG100; 0.47+/-0.05, 0.35+/-0.02, 0.38+/-0.05). G-CSF significantly suppressed right ventricular hypertrophy. Mean medial wall thickness of peripheral pulmonary arteries for Group S was 13.6% +/- 4.9%, significantly smaller than that for Group L (22.9% +/- 9.6%). Compared with Group L, G-CSF reduced medial wall thickness (LG10, 17.6% +/- 9.5%; LG100, 18.0% +/- 11.2%). Incidence of proliferating cell nuclear antigen positive nuclei for Group S was 1.07% +/- 0.49%, significantly smaller than that for Group L (13.77% +/- 5.87%). G-CSF significantly reduced the incidence of proliferating cell nuclear antigen positive nuclei (LG10, 4.04% +/- 2.14%; LG100, 3.18% +/- 1.66%).

CONCLUSIONS

G-CSF administration not only reduce medial wall thickness of peripheral pulmonary arteries but also directly protect cardiomyocytes of the right ventricle, thus suppressing right ventricular hypertrophy. These results suggest that low-dose G-CSF administration can prevent right heart failure following extensive pulmonary resection.

Long-term Doppler echocardiographic evaluation of the right heart after major lung resections

OBJECTIVE

The effects of major lung resections on cardiac function in the medium and long term have not been thoroughly evaluated. We have studied right heart function with serial Doppler echocardiography in patients undergoing lobectomy and pneumonectomy during 4 years of follow-up after surgery.

METHODS

Thirty-six patients undergoing lobectomy and 15 receiving pneumonectomy were evaluated with one- and two-dimensional Doppler standard transthoracic echocardiography before surgery and 1 week, 3 months, 6 months, 1 year, and 4 years postoperatively. We have studied the right midventricular diastolic diameter (RVDD), the right ventricle free wall thickness, the tricuspid valve insufficiency (TVI) and regurgitation jet (TRJ), and the pulmonary artery systolic pressure (PASP).

RESULTS

None of the patients died within the first postoperative year. After lobectomy there were no significant modifications of any variable at any time. RVDD progressively increased after pneumonectomy (26.5+/-2.2mm preoperatively vs 34.3+/-7.6 at 4 years; p<0.001). Four years after surgery all patients undergoing pneumonectomy had moderate TVI while only 55% of patients receiving lobectomy showed it (low grade in 50% and moderate in 5%). In this group of patients PASP increased from 26.1+/-2.6 mmHg preoperatively to 34.3+/-7.6 mmHg at 4 years (p<0.00001).

CONCLUSIONS

Right ventricle modifications are clearly evident after pneumonectomy and even if they do not show a clear clinical impact they should not be neglected.

Cardiac Function and Position More Than 5 Years After Pneumonectomy

BACKGROUND

Pneumonectomy not only reduces the pulmonary vascular bed but also changes the position of the heart and large vessels, which may affect the function of the heart. We investigated long-term effects of pneumonectomy on right ventricular (RV) and left ventricular (LV) function and whether this function is influenced by the side of pneumonectomy or the migration of the heart to its new position.

METHODS

In 15 patients who underwent pneumonectomy and survived for more than 5 years, we evaluated by dynamic magnetic resonance imaging the function of the RV and LV and the position of the heart within the thorax.

RESULTS

Long-term effect of pneumonectomy on the position of the heart is characterized by a lateral shift after right-sided pneumonectomy and rotation of the heart after left-sided pneumonectomy. Postoperatively, heart rate was high (p = 0.006) and stroke volume was low (p = 0.001), compared with the reference values, indicating impaired cardiac function. Patients after right-sided pneumonectomy had an abnormal low RV end-diastolic volume of 99 +/- 29 mL together with a normal LV function. No signs of RV hypertrophy were found. In left-sided pneumonectomy patients, RV volumes were normal whereas LV ejection fraction was abnormally low.

CONCLUSIONS

The long-term effects of pneumonectomy on the position of the heart are characterized by a lateral shift in patients after right-sided pneumonectomy and rotation of the heart in patients after left-sided pneumonectomy. Overall, cardiac function in long-term survivors after pneumonectomy is compromised, and might be explained by the altered position of the heart.

Cardiovascular Complications After Lung Surgery

Cardiovascular complications following thoracic surgery remain a challenge to the physician, the hospital, and the health care system. These events add significantly to morbidity, mortality, and the cost of care of the general thoracic surgery patient. A proactive approach to identify patients at high risk for such complications is needed. In this manner, one may enhance prevention and treatment if problems occur. A thoughtful and complete preoperative risk assessment can identify patients who have potential contributing comorbidities, leading to a reduced incidence of postoperative events. Standardization of preoperative, intraoperative, and postoperative care can reduce postoperative events. Implementation of guidelines and pathways that are evidence based can lead to enhanced patient care, better patient and staff satisfaction, and improved outcomes from the operation. Although postoperative cardiac events cannot be completely eliminated from the thoracic surgery population, the prevention, treatment, and follow-up strategies outlined herein can attenuate these significant morbid and mortal events.

Acute effects of lobectomy on right ventricular ejection fraction and mixed venous oxygen saturation

BACKGROUND

Traditional methods of assessing the operative risk for lung resection provide only a modest ability to predict postoperative morbidity and mortality. The aim of this study was to evaluate the effect of lobectomy on pulmonary hemodynamic and gas exchange variables using the RV thermodilution ejection fraction/oximetric catheter.

METHODS

We evaluated the acute postoperative effects of lung resection on hemodynamic and gas exchange parameters in 30 patients. Anesthesia was induced with thiopentone sodium and maintained with midazolam, fentanyl and pipecuronium. Intubation was performed with a double-lumen, left-sided endobronchial tube for one lung ventilation. The hemodynamic and gas exchange parameters were recorded before and after induction of anesthesia, and two hours after lung resection. These parameters were also recorded after the classification of the patients according to the underlying lung pathology.

RESULTS

Lobectomy was associated with significant hemodynamic changes and good maintenance of gas exchange variables. SVI, LVSWI and RVEF were significantly decreased in the early postoperative period after lung resection. MPAP, COP, CI, SVRI, PVRI, RVSWI, and RVEDVI showed no significant changes during the perioperative period. SVO2 showed a significant increase after lung resection when compared with preinduction values, while VO2 significantly decreased. SaO2, a-A PO2, QS-QT, DO2, and O2ER showed no significant changes during the perioperative period.

CONCLUSIONS

We conclude that in the acute post-resection period (up to 2 hours postoperatively) there is right and left ventricular dysfunction with good maintenance of gas exchange.

Edema pulmonar pós-pneumonectomia

A pneumonectomia, embora seja tecnicamente simples, está associada a alta incidência de complicações (cerca de 60%). As complicações respiratórias correspondem a aproximadamente 15% deste total. A mortalidade global dessa cirurgia é de 8,6%, mas em presença de complicações respiratórias, a taxa de mortalidade chega a 30%. O edema pulmonar pós-pneumonectomia é uma complicação rara (3% a 5%), mas muito grave, sendo fatal na maioria dos casos. Foi descrito pela primeira vez há pouco mais de vinte anos mas, apesar da gravidade alarmante, pouco sabemos acerca de sua fisiopatologia, embora muitas hipóteses tenham sido levantadas. Uma vez instalado, nenhuma medida é comprovadamente eficaz no seu tratamento. Vários fatores de risco estão associados ao aparecimento do edema pulmonar pós-pneumonectomia, dentre os quais a sobrecarga hídrica, que foi o primeiro fator evitado. Entretanto, muitos trabalhos mostram não haver relação direta entre o volume recebido e o desenvolvimento do edema. A prevenção é a melhor forma de evitá-lo e deve ser realizada de maneira multifatorial, envolvendo toda a equipe médica, desde o momento da anestesia até os cuidados cirúrgicos e na terapia intensiva. No entanto, tão importante quanto a prevenção, é a suspeita clínica precoce, identificando os pacientes em risco para essa grave complicação.

Intraoperative solumedrol helps prevent postpneumonectomy pulmonary edema

BACKGROUND

Postpneumonectomy pulmonary edema and pneumonia are life threatening and seemingly unavoidable complications after pneumonectomy. We theorized that an intraoperative dose of intravenous steroids (as a prophylactic measure to reduce pulmonary injury to the remaining lung) just before pulmonary artery ligation might decrease this problem.

METHODS

Seventy-two patients (52 men) who had pneumonectomy during two time periods were studied prospectively. Thirty-five patients received 250 mg of methylprednisolone sodium succinate (Solumedrol; Upjohn, Kalamazoo, MI) just before pulmonary artery ligation (S group) and 37 did not (non-S group). Groups were matched for known or suspected preoperative, intraoperative, and postoperative risk factors for postpneumonectomy pulmonary edema.

RESULTS

The incidence of postpneumonectomy pulmonary edema or adult respiratory distress syndrome was less in the S group (0 of 35, 0% versus 5 of 37, 13.5%, p = 0.049), the overall major complication rate was less in the S group (7 of 35, 20% versus 16 of 37, 43%, p = 0.04), and the length of hospital stay was shorter in the S group (6.1 days versus 11.9 days, p = 0.02). In addition, there were no bronchopleural fistulas in the S group compared with two (both right-sided) in the non-S group.

CONCLUSIONS

The intraoperative intravenous administration of 250 mg of methylprednisolone sodium succinate just before pulmonary artery ligation during pneumonectomy may reduce the incidence of postpneumonectomy pulmonary edema and adult respiratory distress syndrome as well as decrease other major complications and shorten the hospital stay. It does not seem to increase the incidence of bronchopleural fistula. Further randomized trials are needed.

Cardiac complications after noncardiac thoracic surgery: an evidence-based current review

Despite advances in perioperative management, thoracic surgery remains a high-risk procedure for many patients. A systematic review of cardiac complications after thoracic surgery is presented. Most reviews about noncardiac thoracic surgery discuss postoperative analgesic regimens and pulmonary complications. In the present review, we also discuss atrial fibrillation as the most frequently encountered cardiac side effect. An evidence-based approach to other complications, such as myocardial ischemia, pulmonary edema, embolism, and shunt, is described. Furthermore, we offer recommendations for daily practice.

Preload indexes in thoracic anesthesia

PURPOSE OF THE REVIEW

An adequate cardiac preload is essential in the treatment of critically ill patients. During anesthesia for thoracic surgery, volume and vasoactive therapy to optimize cardiac output, oxygen delivery (tissue perfusion) and to avoid pulmonary edema is a central therapeutic aspect. Cardiac preload has been estimated with different techniques in clinical practice, even though studies performed on thoracic anesthesia are lacking.

RECENT FINDINGS

We analyze the conventional pulmonary artery catheter, transesophageal echocardiography and the transpulmonary indicator dilution technique as preload monitoring devices with their indications and limits in thoracic anesthesia.

SUMMARY

The pulmonary artery catheter is confirmed as a fundamental device particularly in patients with pulmonary hypertension. For transesophageal echocardiography monitoring, the dependency on operator experience, the low repeatability and the high costs limit its interpretation and diffusion in clinical practice. During lung transplantation, Swan Ganz catheter monitoring is recommended. The optimization of fluid balance and vasoactive drug administration based on volumetric monitoring makes the transpulmonary indicator dilution technique a new option as an effective monitoring system during anesthesia for thoracic surgery when intravascular volume management is a primary objective.

Effect of lung volume reduction surgery for severe emphysema on right ventricular function

Lung volume reduction surgery (LVRS) can improve the functional capacity of selected patients with severe emphysema. Hypothesized physiologic effects of LVRS include an improvement in right ventricular function, although this has not been investigated in detail. To help clarify this issue, we used fast-thermistor thermodilution at rest and during submaximal upright exercise in 12 patients, before and 6 mo after bilateral LVRS. Preoperatively, all patients had severe airflow obstruction, with a mean FEV(1) of 0.69 L and an RV-to-TLC ratio of 0.67. Six months after LVRS, significant improvements occurred in respiratory function measures (+0.39 L in FEV(1), p < 0.002; and +/- 0.15 in RV/TLC ratio, p < 0.002) and in right ventricular function indexes measured at rest (+0.21 L in cardiac index [CI], p < 0.01; and +3.0 ml in stroke volume, p < 0.01) and during exercise (+0.9 L in CI, p < 0.002; +10.0 ml in stroke volume index, p < 0.002; and +20% in ejection fraction [EF], p < 0.002). A significant correlation was found between pre- to postoperative changes in the EF response to exercise and changes in the RV/TLC ratio (R = -0.68; p = 0.01). We conclude that a significant improvement in right ventricular performance, particularly during exercise, can occur 6 mo after bilateral LVRS.

Simultaneous cardiac operations with pulmonary resection for lung carcinoma

OBJECTIVES

A procedure remains to be established for managing patients with both cardiac and pulmonary diseases requiring surgical interventions. We review our experience with 6 patients having cardiac disease and lung cancer surgically treated simultaneously to determine whether simultaneous surgery is safe and effective.

METHODS

Subjects were 6 men with a mean age of 64 +/- 10 years undergoing cardiac surgery combined with pulmonary lobectomy from January 1986 through June 2000. Cardiac procedures consisted of coronary artery bypass in 3, coronary artery bypass plus left ventricular aneurysm repair, aortic valve replacement, and minimally invasive direct coronary artery bypass surgery in 1 patient each. All underwent lobectomy.

RESULTS

No early deaths occurred. Bleeding complications occurred in 2 patients and lymph node dissection was incomplete in 3. Two died of carcinoma-related events, 1 at 28 and the other at 84 months after surgery. One died suddenly from a cardiac-related event 42 months after surgery. Only 1 patient is currently alive and disease-free at 104 months after surgery.

CONCLUSION

Simultaneous surgery can be conducted with acceptable mortality. The occurrence of bleeding complications and incomplete lymph node dissection, however, indicates combined procedures only in patients requiring simultaneous surgery due to their disease or unable to tolerate a second operation.

Changes in right ventricular performance in elderly patients who underwent lobectomy using video-assisted thoracic surgery for primary lung cancer

OBJECTIVE

Even though lobectomy using video-assisted thoracic surgery for primary lung cancer has been reported to be beneficial in terms of the perioperative outcome, changes in the right ventricular performance have not yet been reported. The aim of this study was to determine whether lobectomy by video-assisted thoracic surgery is also advantageous with respect to the right ventricular performance in elderly patients who are 70 years old or older.

SUBJECTS AND METHODS

Thirteen patients (mean age: 76 years) who underwent lobectomy using video-assisted thoracic surgery (Video-assisted Thoracic Surgery Group), and 10 patients (mean age: 76 years) who underwent lobectomy using a standard thoracotomy as a historical control group (Standard Thoracotomy Group) were studied. The hemodynamics and right ventricular ejection fraction were evaluated preoperatively, and at 6, 12, 24, and at 48 hours postoperatively.

RESULTS

Postoperative values were expressed as a percentage of the preoperative values. The systemic vascular resistance index decreased to a greater extent in the Video-assisted Thoracic Surgery Group than in the Standard Thoracotomy Group. The pulmonary arteriolar resistance index at 24 hours postoperation tended to be higher in the Standard Thoracotomy Group than in the Video-assisted Thoracic Surgery Group. The stroke index, cardiac index, and right ventricular ejection fraction at 24 hours postoperation were each significantly higher in the Video-assisted Thoracic Surgery Group than in the Standard Thoracotomy Group.

CONCLUSION

Lobectomy using video-assisted thoracic surgery for elderly patients offers not only beneficial effects in the right ventricular afterload but also acceleration in the expected compensatory hyperdynamics during the acute postoperative phase.

Surgical treatment for chronic pleural empyema

Various surgical procedures have been developed in an attempt to alleviate the significant problems caused by chronic pleural empyema. The present study evaluates our 11-year experience of employing a number of therapeutic approaches for chronic empyema. Between 1987 and 1997, 45 consecutive patients underwent treatment for chronic empyema at our hospitals. They comprised 21 patients (47%) presenting with post-tuberculosis, 11 (24%) receiving cancer therapy including pulmonary resection, and 13 (29%) with postpneumonic empyema. Omentopexy, lung resection, and thoracoscopic surgery were performed in 10 (22%), 5 (11%), and 4 (9%) patients, respectively. Poor results of treatment were observed in two of the patients with post-tuberculous empyema, and three of the patients treated for cancer died of recurrence. The other 40 patients remain symptom-free. An improvement in quality of postoperative life was revealed by the exercise test rather than by static spirometry. Optimal therapy for chronic empyema requires selection of the most appropriate first and staged procedures for each patient. Moreover, lung resection should be minimal. In a critical state, open thoracostomy must be performed as the first procedure, while omentopexy or thoracoplasty should be restricted to selected cases. Dead space and minor air leakage may safely be left behind. A video-assisted procedure can be selected for postpneumonia empyema.

Pathophysiology of Postpneumonectomy Pulmonary Edema

Pulmonary edema is a rare, potentially fatal complica tion associated with major resection of the lung, usually pneumonectomy. Although pulmonary edema in this setting can often be attributed to a variety of causes such as cardiac failure, bacterial pneumonia, and fluid overload, the specific syndrome of postpneumonec tomy pulmonary edema (PPE) occurs in the absence of these factors. PPE remains a diagnosis of exclusion, and its pathophysiology is poorly understood. Overzealous perioperative fluid administration has traditionally been implicated in clinical cases of postpneumonectomy pulmonary edema, but there is a body of evidence suggesting several other potential mechanisms. These include increases in cardiac output secondary to cat echolamine release, interruption of mediastinal lym phatic drainage, endothelial injury secondary to release of humoral factors or stretching of intercellular junc tions, hyperinflation, and other unknown factors.

Pathogenesis and management of respiratory insufficiency following pulmonary resection

The underlying principle of the surgical treatment of non-small-cell lung cancer (NSCLC) is complete removal of the local/regional disease within the thorax. Pulmonary resection should be as conservative as possible without compromising the adequacy of tumor removal. A multitude of factors influence the incidence and severity of complications following pulmonary resection including the pre-operative physical and psychological status of the patient, the pathologic process requiring resection, the physiologic impact of the procedure, and the addition of pre-operative or postoperative adjuvant therapy. The insidious onset of interstitial changes on chest X-ray (CXR) 1 to 2 days after pulmonary resection forewarns of respiratory distress; however, the pathophysiology of adult respiratory distress syndrome (ARDS) with progression to respiratory failure requiring mechanical ventilation and advanced critical care often unfolds. Management of patients with severe respiratory failure remains primarily supportive. "Good critical care" is the mainstay of therapy: this includes gentle mechanical ventilation to avoid ventilator-induced barotrauma and over-extension of remaining functional alveoli, diuresis, infection identification and management, and nutritional support. New therapeutic strategies that may impact on outcomes in the adult population include pressure-limited ventilation (permissive hypercapnia), inverse ratio ventilation, high-frequency jet ventilation, high-frequency oscillatory ventilation, intratracheal pulmonary ventilation, and prone position ventilation. In addition, alternative therapies such as partial liquid ventilation, inhaled nitric oxide, and extracorporeal techniques including extracorporeal membrane oxygenation (ECMO), extracorporeal carbon dioxide removal (ECCO(2)R), intravascular oxygenation (IVOX), and arteriovenous carbon dioxide removal (AVCO(2)R), provide additional modalities. A component of some or all of these strategies is finding a role in clinical practice.