Patients Undergoing Lung Volume Reduction Research Articles

EFFICACY OF AN IMPLANTABLE VALVE FOR TREATMENT OF ALVEOLOPLEURAL FISTULAS WITH PROLONGED AIR LEAKS

EFFICACY OF AN IMPLANTABLE VALVE FOR TREATMENT OF ALVEOLOPLEURAL FISTULAS WITH PROLONGED AIR LEAKS

Applicability of color-coded computed tomography images in lung volume reduction surgery planning.

Adequate patient selection is the key to successful lung volume reduction in patients with pulmonary emphysema. Computed tomography (CT) enables a reliable detection of pulmonary emphysema and allows an accurate quantification of the severity. Our goal was to investigate the usefulness and reliability of color-coded (CC) CT images in classification of emphysema and preoperative lung volume reduction planning. Fifty patients undergoing lung volume reduction surgery at our institution between September 2015 and February 2016 were retrospectively investigated. Three readers visually assessed the amount and distribution patterns of pulmonary emphysema on axial, multi-planar and CC CT images using the Goddard scoring system and a surgically oriented grading system (bilateral markedly heterogenous, bilateral intermediately heterogenous, bilateral homogenous and unilateral heterogenous emphysema). Observer dependency was investigated by using Fleiss' kappa (κ) and the intraclass correlation coefficient (ICC). Results were compared to quantitative results from densitometry measurements and lung perfusion scintigraphy by using Spearman correlation. Recommendations for lung volume reduction sites based on emphysema amount and distribution of all readers were compared to removal sites from the surgical reports. Inter-rater agreement for emphysema distribution rating was substantial for CC images (κ=0.70; 95% CI, 0.64-0.80) and significantly better compared to axial and multiplanar images (P≤0.001). The inter-rater agreement for recommended segment removal was moderate for CC images (κ=0.56; 95% CI, 0.49-0.63) and significantly better compared to axial and multiplanar images (P<0.001). Visual emphysema rating correlated significantly with measurements from densitometry and perfusion scintigraphy in the upper and lower lung zones in all image types. CC CT images allow a precise, less observer-dependent evaluation of distribution of pulmonary emphysema and resection recommendation compared to axial and multiplanar CT images and might therefore be useful in lung volume resection surgery planning.

Individualised risk in patients undergoing lung volume reduction surgery: the Glenfield BFG score

Lung volume reduction surgery (LVRS) has been shown to be beneficial in patients with chronic obstructive pulmonary disease, but there is low uptake, partly due to perceived concerns of high operative mortality. We aimed to develop an individualised risk score following LVRS.This was a cohort study of patients undergoing LVRS. Factors independently predicting 90-day mortality and a risk prediction score were identified. Reliability of the score was tested using area under the receiver operating characteristic curve (AUROC).237 LVRS procedures were performed. The multivariate analysis factors associated independently with death were: body mass index (BMI)<18.5 kg·m-2 (OR 2.83, p=0.059), forced expiratory volume in 1 s (FEV1)<0.71 L (OR 5.47, p=0.011) and transfer factor of the lung for carbon monoxide (TLCO) <20% (OR 5.56, p=0.031). A risk score was calculated and total score assigned. AUROC for the risk score was 0.80 and a better predictor than individual components (p<0.01). The score was stratified into three risk groups. Of the total patients, 46% were classified as low risk. Similar improvements in lung function and health status were seen in all groups. The score was introduced and tested in a further 71 patients. AUROC for 90-day mortality in this cohort was 0.84.It is possible to provide an individualised predictive risk score for LVRS, which may aid decision making for both clinicians and patients.

Lung volume reduction surgery since the National Emphysema Treatment Trial: Study of Society of Thoracic Surgeons Database

The National Emphysema Treatment Trial demonstrated that lung volume reduction surgery is an effective treatment for emphysema in select patients. With chronic lower respiratory disease being the third leading cause of death in the United States, this study sought to assess practice patterns and outcomes for lung volume reduction surgery on a national level since the National Emphysema Treatment Trial. Aggregate statistics on lung volume reduction surgery reported in the Society of Thoracic Surgeons Database from January 2003 to June 2011 were analyzed to assess procedure volume, preoperative and operative characteristics, and outcomes. Comparisons with published data from the National Emphysema Treatment Trial were made using chi-square and 2-sided t tests. In 8.5 years, 538 patients underwent lung volume reduction surgery, with 20 to 118 cases reported in the Society of Thoracic Surgeons Database per year. When compared with subjects in the National Emphysema Treatment Trial, subjects in the Society of Thoracic Surgeons Database were younger (P < .001), a larger proportion underwent the procedure thoracoscopically (P < .001), and forced expiratory volume in 1 second was 31% versus 28% of predicted (P < .001). When mortality was compared between subjects in the Society of Thoracic Surgeons Database and all subjects in the National Emphysema Treatment Trial randomized to surgery, there were no significant differences. However, mortality was 3% higher in subjects in the Society of Thoracic Surgeons Database when compared with the non-high-risk National Emphysema Treatment Trial subset (P = .005). This study demonstrates the importance of patient selection and the need to develop consensus on appropriate benchmarks for mortality rates after lung volume reduction surgery. It underscores the need for dedicated centers to increasingly address the heavy burden of chronic lower respiratory disease in the United States in a multidisciplinary fashion, particularly for preoperative evaluation and postoperative management of emphysema.

Distinct Responses to Hypoxia in Subpopulations of Distal Pulmonary Artery Cells Contribute to Pulmonary Vascular Remodeling in Emphysema

We have shown previously that hypoxia inhibits the growth of distal human pulmonary artery smooth muscle cells (PASMC) isolated under standard normoxic conditions (PASMCnorm). By contrast, a subpopulation of PASMC, isolated through survival selection under hypoxia was found to proliferate in response to hypoxia (PASMChyp). We sought to investigate the role of hypoxia-inducible factor (HIF) in these differential responses and to assess the relationship between HIF, proliferation, apoptosis, and pulmonary vascular remodeling in emphysema. PASMC were derived from lobar resections for lung cancer. Hypoxia induced apoptosis in PASMCnorm (as assessed by TUNEL) and mRNA expression of Bax and Bcl-2, and induced proliferation in PASMChyp (as assessed by 3H-thymidine incorporation). Both observations were mimicked by dimethyloxallyl glycine, a prolyl-hydroxylase inhibitor used to stabilize HIF under normoxia. Pulmonary vascular remodeling was graded in lung samples taken from patients undergoing lung volume reduction surgery for severe heterogenous emphysema. Carbonic anhydrase IX expression in the medial compartment was used as a surrogate of medial hypoxia and HIF stabilization and increased with increasing vascular remodeling. In addition, a mixture of proliferation, assessed by proliferating-cell nuclear antigen, and apoptosis, assessed by active caspase 3 staining, were both higher in more severely remodeled vessels. Hypoxia drives apoptosis and proliferation via HIF in distinct subpopulations of distal PASMC. These differential responses may be important in the pulmonary vascular remodeling seen in emphysema and further support the key role of HIF in hypoxic pulmonary hypertension.

Lung volume reduction surgery for native lung hyperinflation following single-lung transplantation for emphysema: which patients?

Lung transplantation is an established treatment for patients with advanced emphysema. Double-lung transplantation is favoured to avoid complications following single-lung transplantation, including native lung hyperinflation. Nonetheless, single-lung transplantation continues due to limited donor organ availability. The aim of this study was to evaluate the pre-operative assessment, surgical techniques and outcomes in patients undergoing lung volume reduction surgery for native lung hyperinflation. Eight patients underwent lung volume reduction surgery for native lung hyperinflation between October 2008 and April 2011. Symptoms, pre-operative evaluation, peri-operative morbidity, length of stay, pulmonary function and survival were examined. The mean follow-up was 17 months. Participants underwent high resolution CT and bronchoscopy with transbronchial biopsy and bronchial washings to exclude alternative causes for deterioration in pulmonary function tests. V/Q scan was performed to assess the contribution of each lung to overall function. Measurement of inspiratory airflow resistance in each lung was performed in one case. Seven patients underwent multiple wedge resections and one underwent bilobectomy. All patients survived to hospital discharge, and mean length of stay was 13.9 days. Functional improvement was demonstrated in all cases at follow-up, with a mean percentage increase of 29.3% in forced expiratory volume in one second and 21.6% in forced vital capacity. Symptomatic improvement was also reported by all patients post-operatively. Lung volume reduction surgery for native lung hyperinflation is an effective treatment strategy with an acceptable level of surgical risk. Patient selection, however, remains vital. The non-anatomical multiple wedge excision technique used here was as effective as anatomical lung volume reduction surgery used in other series. With regard to pre-operative assessment, the measurement of single-lung inspiratory airflow resistance is of particular interest. We feel that this may provide an additional method of differentiating between native lung hyperinflation and obliterative bronchiolitis prior to surgery, thus improving patient selection.

Perioperative Short-term Pulmonary Rehabilitation for Patients Undergoing Lung Volume Reduction Surgery

Although pulmonary rehabilitation is recommended for patients undergoing lung volume reduction surgery, the optimal method of pulmonary rehabilitation is unclear. The aim of this study was to determine the feasibility and safety of perioperative short-term pulmonary rehabilitation. We enrolled candidates for lung volume reduction surgery from 1999 to 2006 and retrospectively evaluated the feasibility and safety of perioperative short-term pulmonary rehabilitation for these patients. The program included the progressive exercise training on a treadmill for approximately 3 weeks. Two primary endpoints, feasibility and safety, were determined by the adherence rates of the program session and the adverse events. Pulmonary function and exercise capacity were evaluated at baseline and the termination of pre- and postoperative short-term pulmonary rehabilitation. Twenty-two patients were enrolled in this study. All patients completed our program without any serious adverse events. The mean values of adherence rates of the preoperative, postoperative, and overall period were, 89.1%, 95.1%, and 92.1%, respectively. All values of pulmonary function tests, except for forced vital capacity, significantly improved at the termination of postoperative short-term pulmonary rehabilitation in comparison to those at the termination of preoperative short-term pulmonary rehabilitation. The values of the 6-minute walk distance, total exercise time, and maximal workload on incremental exercise test were significantly improved by preoperative short-term pulmonary rehabilitation, and their values were maintained until the termination of postoperative short-term pulmonary rehabilitation. The results indicated that it is both feasible and safe to perform perioperative short-term pulmonary rehabilitation.

Lung Volume Reduction Surgery Using the NETT Selection Criteria

The National Emphysema Treatment Trial (NETT) proved that lung volume reduction surgery (LVRS) was safe and effective in patients with certain clinical characteristics and using defined inclusion-exclusion criteria. Based on the selection criteria developed in that trial, we performed bilateral LVRS on 49 patients during the period of February 2004 until May 2009. Forty-nine patients underwent lung volume reduction by either median sternotomy (10) or video-assisted thoracoscopic surgery (39) selected according to NETT described parameters. Preoperative characteristics were the following: mean (±SD) age 62.5±6.6 years, preoperative FEV1 (forced expiratory volume in the first second of expiration) 691 cc (±159), % of predicted FEV1 25.3 (±6.2), preoperative Dlco (diffusing capacity of lung for carbon monoxide) 7.6 (±2.7), and % of predicted DLCO 27% (±7.3). All patients had upper lobe predominant disease and either low exercise capacity (n=23) or high exercise capacity (n=26) as defined by the NETT. There was no operative or 90-day mortality. Median length of stay was 8 days (interquartile range=6 to 10). Two patients required reintubation and tracheostomy but were decannulated prior to discharge. The BODE index (body mass index, airflow obstruction, dyspnea, and exercise capacity), a multidimensional predictor of survival in chronic obstructive pulmonary disease, improved -2.3 (±1.5, p<0.0001) (missing data: 5 of 42, 11.9%) and the FEV1 improved 286 cc (±221, p<0.0001), both 1 year after surgery. Probability of survival was 0.98 (95% CI [confidence interval]=0.94 to 1) at 1 year, and 0.95 (95% CI=0.88 to 1) at 3 years. Surgical lung volume reduction for emphysema can be performed in patients using selection criteria developed by the NETT with very low surgical risk and excellent midterm results. Surgical LVRS is the standard against which other nonsurgical treatments for advanced emphysema should be judged.

Lung volume reduction surgery: nonpharmacological approach

To revise the current nonpharmacologic methods used in the care of patients undergoing lung volume reduction surgery (LVRS). A recent report of the unquestionable palliative role of LVRS awakened a renewed interest in the procedure as a valid treatment alternative in selected patients with severe emphysema. A detailed description of the foundations of the approach to patients undergoing LVRS is described to provide guidance for daily practice.

Trapped wind: A retrospective review of patients undergoing lung volume reduction surgery

Trapped wind: A retrospective review of patients undergoing lung volume reduction surgery

National Emphysema Treatment Trial redux: Accentuating the positive

Under the Freedom of Information Act, we obtained the follow-up data of the National Emphysema Treatment Trial (NETT) to determine the long-term outcome for "a heterogeneous distribution of emphysema with upper lobe predominance," postulated by the NETT hypothesis to be optimal candidates for lung volume reduction surgery. Using the NETT database, we identified patients with heterogeneous distribution of emphysema with upper lobe predominance and analyzed for the first time follow-up data for those receiving lung volume reduction surgery and those receiving medical management. Furthermore, we compared the results of the NETT reduction surgery group with a previously reported consecutive case series of 250 patients undergoing bilateral lung volume reduction surgery using similar selection criteria. Of the 1218 patients enrolled, 511 (42%) conformed to the NETT hypothesis selection criteria and received the randomly assigned surgical or medical treatment (surgical = 261; medical = 250). Lung volume reduction surgery resulted in a 5-year survival benefit (70% vs 60%; P = .02). Results at 3 years compared with baseline data favored surgical reduction in terms of residual volume reduction (25% vs 2%; P < .001), University of California San Diego dyspnea score (16 vs 0 points; P < .001), and improved St George Respiratory Questionnaire quality of life score (12 points vs 0 points; P < .001). For the 513 patients with a homogeneous pattern of emphysema randomized to surgical or medical treatment, lung volume reduction surgery produced no survival advantage and very limited functional benefit. Patients most likely to benefit from lung volume reduction surgery have heterogeneously distributed emphysema involving the upper lung zones predominantly. Such patients in the NETT trial had results nearly identical to those previously reported in a nonrandomized series of similar patients undergoing lung volume reduction surgery.

Taking a chance: the experience of lung volume reduction procedures for chronic obstructive pulmonary disease

Lung Volume Reduction Surgery and Endo-Bronchial Valve(TM) insertion have expanded the therapeutic choices for chronic obstructive pulmonary disease (COPD). Controversy over efficacy, costs and risks limits access to these therapies. There are no published findings to guide our understanding of the patient's experience of surgery. The aim of this study is to understand the experience of palliative surgery for COPD. Merleau-Ponty's philosophy provided a framework for this Heideggerian phenomenological inquiry. Fifty-eight semi-structured interviews were conducted with 15 patients undergoing lung volume reduction procedures and 14 family members. Patients and families felt they had no option but to 'take a chance' on surgery. Interventions frequently led to regaining lost tasks or easier completion of existing tasks. Where patients did not perceive an increase in things they could 'do', surgery allowed some to reclaim their sense of self. Regardless of the outcome, most did not regret their decision for surgery. Meanings of surgery are not always tied to the visible, objective measurements of outsiders but may relate to regaining of self. Despite the concerns of some clinicians, patients and families are more likely to accept the risk of morbidity and mortality from surgery than has previously been realized.

Hyperpolarized 3He MR imaging: physiologic monitoring observations and safety considerations in 100 consecutive subjects.

To evaluate the safety of hyperpolarized helium 3 ((3)He) magnetic resonance (MR) imaging. Local institutional review board approval and informed consent were obtained. Physiologic monitoring data were obtained before, during, and after hyperpolarized (3)He MR imaging in 100 consecutive subjects (57 men, 43 women; mean age, 52 years +/- 14 [standard deviation]). The subjects inhaled 1-3 L of a gas mixture containing 300-500 mL (3)He and 0-2700 mL N(2) and held their breath for up to 15 seconds during MR imaging. Heart rate and rhythm and oxygen saturation of hemoglobin as measured by pulse oximetry (Spo(2)) were monitored continuously throughout each study. The effects of (3)He MR imaging on vital signs and Spo(2) and the relationship between pulmonary function, number of doses, and clinical classification (healthy volunteers, patients with asthma, heavy smokers, patients undergoing lung volume reduction surgery for severe emphysema, and patients with lung cancer) and the lowest observed Spo(2) were assessed. Any subjective symptoms were noted. Except for a small postimaging decrease in mean heart rate (from 78 beats per minute +/- 13 to 73 beats per minute +/- 11, P < .001), there was no effect on vital signs. A mean transient decrease in Spo(2) of 4% +/- 3 was observed during the first minute after gas inhalation (P < .001) in 77 subjects who inhaled a dose of 1 L for 10 seconds or less, reaching a nadir of less than 90% at least once in 20 subjects and of less than 85% in four subjects. There was no correlation between the lowest Spo(2) and pulmonary function parameters other than baseline Spo(2) (r = 0.36, P = .001). The lowest mean Spo(2) varied by 1% between the first and second and second and third doses (P < .001) and was unrelated to clinical classification (P = .40). Minor subjective symptoms were noted by 10 subjects. No serious adverse events occurred. Hyperpolarized (3)He MR imaging can be safely performed in healthy subjects, heavy smokers, and those with severe obstructive airflow limitation, although unpredictable transient desaturation suggests that potential subjects should be carefully screened for comorbidities.

Anesthetic Considerations in Candidates for Lung Volume Reduction Surgery

The administration of anesthesia to patients undergoing lung volume reduction surgery (LVRS) requires a complete understanding of the pathophysiology of severe chronic obstructive pulmonary disease, the planned surgical procedure, and the anticipated postoperative course for this group of patients. Risk factors and associated morbidity and mortality are discussed within the context of patients with obstructive pulmonary disease in the National Emphysema Treatment Trial having surgical procedures. Preoperative evaluation and the anesthetic techniques used for patients undergoing LVRS are reviewed, as are monitoring requirements. Intraoperative events, including induction of anesthesia, lung isolation, management of fluid requirements, and options for ventilatory support are discussed. Possible intraanesthetic complications are also reviewed, as is the optimal management of such problems, should they occur. To minimize the potential for a surgical air leak in the postoperative period, positive-pressure ventilation must cease at the conclusion of the procedure. An awake, comfortable, extubated patient, capable of spontaneous ventilation, is only possible if there is careful attention to pain control. The thoracic epidural is the most common pain control method used with patients undergoing LVRS procedures; however, other alternative methods are reviewed and discussed.

Lung Volume Reduction Reoperations

Optimal management of emphysematous patients who have lost the benefits achieved after lung volume reduction surgery is a clinical dilemma. We have hypothesized that in stringently selected instances, lung volume reduction reoperations might be considered as a salvage surgical treatment. We sought to analyze the results of a series of patients undergoing lung volume reduction reoperations after successful bilateral lung volume reduction surgery. Between January 2000 and April 2006, 17 patients (mean age, 66 +/- 3 years) with radiologic evidence of distinct regional lung hyperinflation underwent lung volume reduction reoperations. Surgical procedures entailed completion lobectomy in 7 patients, nonanatomic resection of lung target areas were performed in 5 patients under general anesthesia with one-lung ventilation, and awake lung plication was performed in 5 patients under sole epidural anesthesia. Follow-up at 6 and 12 months was complete in all survivors. Mean operative time was 100 +/- 12 minutes. Two patients (11.7%) died perioperatively of adult respiratory distress syndrome. Hospital stay was 9 +/- 2 days. Significant improvements occurred for up to 12 months in forced expiratory volume in 1 second (FEV(1); p < 0.001), forced vital capacity (p < 0.002), residual volume (p < 0.001), 6-minute walk test (p < 0.001), and modified Medical Research Council dyspnea index (p < 0.001). At 6-months, improvements in FEV(1) were greater than 200 mL in 11 patients and correlated with the postoperative reduction in residual volume (r = -0.62, p = 0.01); baseline residual volume was inversely correlated with the degree of improvement in the dyspnea index (r = -0.54, p = 0.03). Lung volume reduction reoperations can offer significant clinical improvement to stringently selected patients who have lost the clinical benefit achieved after lung volume reduction surgery.

To breathe or not to breathe: the respiratory muscles and COPD

The respiratory muscles are unique among skeletal muscles in that they are required to work without sustained rest throughout life. It is not surprising, therefore, that the ventilatory pump has been the subject of intense investigation over the past 30 years, with particular interest in the ability

Distance and oxygen desaturation in 6-min walk test predict prognosis in COPD patients

The aim of the present study was to predict the prognosis of Chronic obstructive pulmonary disease (COPD) patients who underwent comprehensive pulmonary rehabilitation (PR). A total of 144 patients who performed PR between 1992 and 1999 was assessed. After PR, 67 patients underwent lung volume reduction surgery (LVRS). Baseline data before PR consisted of body mass index, serum albumin levels, use of supplement oxygen at home, pulmonary function, arterial blood gas analysis, and distance and fall of hemoglobin oxygen saturation (DeltaSpO(2)) in 6-min walk test. In addition to pre-PR factors, treatment with LVRS was taken into the analysis. The prognostic significance of variables influencing survival was determined by univariate analysis with Log rank test or multivariate analysis using Cox's proportional hazard model. By a median follow-up time of 8.4 years, the median survival time was 8.1 years (95% confidence interval: 6.9-9.4 years). Albumin level, PaCO(2), distance and DeltaSpO(2) were significant prognostic factors in univariate analysis. LVRS did not affect the prognosis. The multivariate analysis showed short distance and increase of DeltaSpO(2) as significant independent predictors of the risk of death. 6-min walk test was very useful for predicting the prognosis of the COPD patients.

Effect of Lung Volume Reduction Surgery on Diaphragmatic Neuromechanical Coupling At 2 Years

We previously reported that patients with emphysema show an increase in diaphragmatic neuromechanical coupling at 3 months after lung volume reduction surgery. Diaphragmatic neuromechanical coupling was quantified as the quotient of tidal volume (normalized to total lung capacity) to tidal change in transdiaphragmatic pressure (normalized to maximal transdiaphragmatic pressure). As such, neuromechanical coupling estimates the fraction of diaphragmatic capacity used to generate tidal breathing. The present investigation was conducted to determine whether benefit is maintained at 2 years. Fifteen patients with severe COPD, 8 of whom completed the 2-year study. Lung volumes, exercise capacity (6-min walking distance), diaphragmatic function (maximal transdiaphragmatic pressure and twitch transdiaphragmatic pressure elicited by phrenic nerve stimulation), and diaphragmatic neuromechanical coupling were recorded before surgery, and at 3 months and 2 years after surgery. Two years after surgery, lung volumes deteriorated to preoperative values, but patients showed persistent improvements in 6-min walking distance (p < 0.05). Three months after surgery, maximal transdiaphragmatic pressure (p < 0.05), twitch transdiaphragmatic pressure (p < 0.01), and diaphragmatic neuromechanical coupling (p < 0.01) had increased over preoperative values. The improvements in neuromechanical coupling resulted from improvements in diaphragmatic strength and, to a lesser extent, from a decrease in transdiaphragmatic pressure required to maintain tidal breathing. The change in respiratory muscle function at 2 years varied among patients: diaphragmatic contractility was > 10% of preoperative value in half of the patients who concluded our study, and neuromechanical coupling was > 10% of preoperative value in three fourths of the patients who concluded our study. Patients who maintained their gains in neuromechanical coupling also maintained their gains in 6-min walking distance. Patients undergoing lung volume reduction surgery can maintain early gains in neuromechanical coupling and exercise capacity 2 years later.

REAL TIME IMAGING AND QUANTITATIVE EVALUATION OF THE EMPHYSEMATOUS LUNG USING INFRARED THORACOSCOPY IN EXPERIMENTAL DOGS

OBJECTIVES: It is necessary to determine the emphysematous region in patients undergoing lung volume reduction surgery or bullectomy. In order to remove the emphysematous region accurately, we attempted to visualize its margin using infrared thoracoscopy (IRT) with indocyanine green (ICG) intravenous injection. METHODS: Emphysema was created in the canine lung by injecting elastase via the bronchi and evaluated periodically by computed tomography and lung biopsy. IRT was performed just after injection of ICC, which becomes distributed in normal lung tissue via its abundant blood flow, and absorbs infrared at 805 nm upon irradiation by IRT. Digitalized static IRT images were prepared at specific time points and their color distribution was analyzed. After IRT, the experimental lung was examined microscopically. RESULTS: The emphysematous lung region was visualized as white and normal lung as blue in real time. The images indicated the zones of transformation between the blue-stained areas of rich blood flow and the white areas where blood flow was absent. Microscopic examination revealed that the blue-stained areas had a normal lung structure whereas the white areas were emphysematous; the zones of transformation represented marginal emphysema. CONCLUSIONS: IRT with ICG administration allowed visualization of the emphysematous lung in real time during thoracoscopic surgery in this animal model, and the images obtained revealed the margin of the emphysematous region.

Anaesthesia for lung volume reduction surgery.

Lung volume reduction surgery is a surgical treatment for severe emphysema that is increasing in popularity. The aim is to reverse the hyperexpansion of the lungs that leads to expiratory airflow limitation, compromises the diaphragm and chest wall mechanics, and tamponades the right ventricle. Optimal patient selection has not yet been established, but it has become clear that those patients with the most severe disease have an unacceptably high surgical mortality. The anaesthetic management of patients undergoing lung volume reduction surgery requires a good understanding of both the pathophysiology of the disease and the surgical procedure. It is important for the anaesthetist and the surgeon to work closely, supported by a large multidisciplinary team. Excellent analgesia is essential to a successful outcome; whether this is best provided by thoracic epidural is as yet unclear.