Search

Background CT scan measures of emphysema and airway disease have been correlated with lung function in cohorts of subjects with a range of COPD severity. The contribution of CT scan-assessed airway disease to objective measures of lung function and respiratory symptoms such as dyspnea in severe emphysema is less clear. Methods Using data from 338 subjects in the National Emphysema Treatment Trial (NETT) Genetics Ancillary Study, densitometric measures of emphysema using a threshold of −950 Hounsfield units (%LAA-950) and airway wall phenotypes of the wall thickness (WT) and the square root of wall area (SRWA) of a 10-mm luminal perimeter airway were calculated for each subject. Linear regression analysis was performed for outcome variables FEV 1 and percent predicted value of FEV 1 with CT scan measures of emphysema and airway disease. Results In univariate analysis, there were significant negative correlations between %LAA-950 and both the WT ( r = −0.28, p = 0.0001) and SRWA ( r = −0.19, p = 0.0008). Airway wall thickness was weakly but significantly correlated with postbronchodilator FEV 1 % predicted (R = −0.12, p = 0.02). Multivariate analysis showed significant associations between either WT or SRWA (β = −5.2, p = 0.009; β = −2.6, p = 0.008, respectively) and %LAA-950 (β = −10.6, p = 0.03) with the postbronchodilator FEV 1 % predicted. Male subjects exhibited significantly thicker airway wall phenotypes (p = 0.007 for WT and p = 0.0006 for SRWA). Conclusions Airway disease and emphysema detected by CT scanning are inversely related in patients with severe COPD. Airway wall phenotypes were influenced by gender and associated with lung function in subjects with severe emphysema.

It has been suggested that bilateral thoracoscopic lung volume reduction (BTLVR) yields significantly better long-term survival than unilateral thoracoscopic lung volume reduction (UTLVR).All perioperative data were collected at the time of the procedure. Follow-up data were obtained during office visits or by telephone.A total of 673 patients underwent thoracoscopic LVR: 343 had either simultaneous or staged BTLVR and 330, UTLVR. As of July 1998, follow-up was available on 667 (99%) of the 673 patients with a mean follow-up of 24.3 months. The patients in the BTLVR group were significantly younger (62.6+/-8.0 years versus 65.4+/-8.1 years; p0.0001), had a higher preoperative arterial oxygen tension (69.7+/-12 mm Hg versus 65.3+/-11 mm Hg; p0.0001), and had a superior preoperative 6-minute walk performance (279.9+/-93.6 m [933+/-312 feet] versus 244.5+/-101.4 m [815+/-338 feet] p0.0001). There was no difference in the operative mortality rate between the two groups (UTLVR, 5.1%, and BTLVR, 7%). Actuarial survival rates for the UTLVR group at 1 year, 2 years, and 3 years were 86%, 75%, and 69%, respectively versus 90%, 81%, and 74%, respectively, for the BTLVR group (p = not significant).Contrary to previous reports, survival after BTLVR was not superior to that after UTLVR even though the former group appeared to have a lower risk preoperatively because of younger age, higher arterial oxygen tension, more advantageous anatomy, and better functional status. Despite thoracoscopic LVR, the actuarial mortality rate approached 30% at 3 years, and this calls into question whether this procedure offers any survival advantage to patients with end-stage emphysema.

Lung reduction has been demonstrated to be a promising treatment for end-stage emphysema when performed on both lungs via sternotomy. The role for a thoracoscopic approach has not yet been determined.Unilateral video-assisted thoracic surgical lung reduction was performed on 50 patients for the treatment of end-stage emphysema. There were 34 men and 16 women with a mean age of 61.5 years (range, 31 to 78 years). Emphysema was secondary to smoking in 45 patients (90%), and alpha 1-antitrypsin deficiency in 5 patients (10%), 4 of whom had smoked in the past. Lung reduction was performed unilaterally using a thoracoscope and a stapled resection without the routine use of bovine pericardium. The side to be operated on and site of resection were determined preoperatively by examination of the perfusion and computed tomographic scans of the lungs. The average amount of lung removed was 59 +/- 15 g (range, 29 to 111 g).Morbidity included prolonged air leak in 15 patients (30%), bleeding in 3 (6%), pneumonia requiring reintubation in 3 (6%), myocardial infarction in 1 (2%), and perforated ulcer in 1 (2%). Seven patients (14%) required a second thoracic procedure for management of these complications. Two patients died, for an operative mortality of 4%. Follow-up obtained between 1 and 3 months in 25 patients revealed significant improvement in forced expiratory volume in 1 second (0.71 to 0.95 L; p0.001), forced vital capacity (2.24 to 2.58 L; p0.01), and oxygen tension (59 to 67 mm Hg; p0.01). The improvement in functional capacity as measured by 6-minute walk approached statistical significance (771 to 923 ft; p = 0.06).Significant subjective improvement in dyspnea has been noted in 41 of 48 hospital survivors (85%). For patients with end-stage emphysema, unilateral video-assisted thoracic surgical lung reduction appears to be a preferable alternative to standard medical management.

Objective: Most reports of thoracoscopic lung volume reduction (TLVR) are relatively small and early experiences from a single institution, factors which limit both the statistical validity and the applicability to the population at large. In order to address these shortcomings we undertook an analysis of the TLVR experience at five separate institutions to assess operative morbidity and identify predictors of mortality. Methods: Questionnaires were sent to four groups of surgical investigators at five institutions actively performing TLVR. Data was requested regarding preoperative, operative and postoperative parameters. Twenty-five potential predictors of mortality were analyzed and seven proved to be at least marginally significant (P , 0:10). These parameters were entered into a stepwise logistic regression analysis to identify independent predictors. Results: The 682 patients (415 males, 267 females, mean age 64.0 years) underwent unilateral (410) or bilateral (272) TLVRs. Overall, operative mortality was 6% with half of the deaths resulting from respiratory causes. The remaining patients were discharged to home (88%), a rehabilitation facility (4%) or a ventilator facility (2%). There were 25 perioperative factors chosen representing clinically important indices such as spirometry, oxygenation, functional status, clinical and demographic variables. Univariate analysis identified seven variables as predictors of mortality (P , 0:10) and these were entered into a stepwise logistic regression analysis. Only age, 6-min walk, gender (male 8%, female 3% mortality) and the procedure performed (unilateral 4.6%, bilateral 8%) were independent predictors while preoperative steroid therapy, preoperative oxygen administration, and time since smoking cessation dropped out of the model. The specific institution, learning curve (early vs. late experience), type of lung disease, spirometric indices and predicted maximum VO2 were not significant predictors. Conclusion: This experience suggests that unilateral and bilateral lung volume reduction procedure can be performed with acceptable morbidity and mortality. Although age, gender, exercise capacity and the procedure performed are all independent predictors of mortality, the risk of operative death did not appear excessive in this fragile patient subset. q 2000 Elsevier Science B.V. All rights reserved.

Improved ventilation and exercise capacity follows thoracoscopic lung volume reduction surgery (TLVRS) in patients with severe emphysema. This improvement could be related to changes in inspiratory and expiratory flows following surgery, with consequent improvement in dyspnea indices. Changes in inspiratory/expiratory flows at rest and exercise and their relation to subjective improvement in dyspnea after TLVRS are not well known. We studied 25 patients with severe emphysema who underwent unilateral TLVRS performed in well-defined zones with decreased perfusion in nuclear medicine lung scans. Early follow-up after surgery (4.2 +/- 0.8 mo) showed significant improvements in exercise tolerance: The distance covered over a 6 min walk test increased from 934 +/- 297 to 1,071 +/- 241 ft (p = 0.01). Exercise tolerance using a bicycle ergometer showed increased exercise endurance from 4.43 +/- 1.7 to 5.71 +/- 1.8 min (p < 0.001). The maximum workload tolerated increased from 37 +/- 19 to 52 +/- 21 W (p < 0.01) and VO2 max changed from 9.7 +/- 2 to 11.8 +/- 3 (ml.kg)/min (p < 0.01). This increment was achieved by generating significantly larger minute ventilation (VE), from 24 +/- 11 to 29 +/- 10 L/min, reached through larger tidal volumes (increasing from 951 +/- 330 to 1,145 +/- 367 ml), while maintaining the same maximum respiratory rates. Increased VE was also accompanied by significant increases in both average inspiratory and expiratory flows measured during exercise: from 0.89 +/- 0.41 L/s to 1.06 +/- 0.08 L/s, and from 0.77 +/- 0.37 to 0.90 +/- 0.32 L/s respectively (p < 0.01). The parallel increment in flows resulted in constant T1/Ttot relationship. These functional changes correlated with increased inspiratory flows at rest measured with pulmonary function tests (forced inspiratory volume in one s [FIV1], expiratory flows [FVC, FEV1], and increased maximum voluntary ventilation [MVV]) following the surgically induced reduction in residual volume (RV). These objective changes occurred parallel to improved dyspnea indices. The Baseline Focal Score was 3.36 +/- 1.47 and the Transition Focal Score was 6.12 +/- 0.7. The objectively measured variables at rest that best correlated with subjective improvement in dyspnea were the change in MVV, change in resting arterial PaO2, and change in FEV1 following TLVRS. Exercise variables did not have significant correlation with subjective markers indicating improvement in dyspnea, with the exception of the change in Dyspneic Index [(VE/MVV)100] at maximum exercise.

Study objectives This study reports histopathologic findings in a group of emphysema patients who underwent thoracoscopic lung volume reduction surgery (75) or sternotomy (five) with the purpose to induce functional improvement and relief of dyspnea. Immediate outcome and complications were correlated to histologic patterns. Design Histopathologic material obtained in lung volume reduction surgery in 80 consecutive patients was analyzed. Thirty patients who had other histopathologic diagnoses in addition to emphysema were grouped and compared with 50 patients found to have emphysema exclusively. Postoperative outcome and preoperative lung function variables were compared. Measurements and results All patients had severe obstructive lung disease and significant air trapping preoperatively documented by pulmonary function testing. All had severe exertional dyspnea. All had chest radiographs, CT, and nuclear medicine lung scans consistent only with emphysema. All portions of resected lung tissue were weighed, lung volume was estimated, and routine histopathologic studies were made. Thirty patients (37.5%) had unsuspected findings such as interstitial fibrosis, noncaseating granulomatosis, chronic inflammation, and unsuspected neoplasia (three carcinomas, one carcinoid). Retrospective review of imaging studies in these patients failed to show infiltrative processes. The average lung weight resected in this group was significantly heavier (65±18 g) compared with the other group (56±13 g), although both had the same estimated lung volume. Average number of days requiring chest tubes and length of hospitalization was also significantly higher (12.8±19 vs 6.4±5 days with chest tubes and 17.4±22 vs 8.5±6 days of hospitalization, respectively). None of the preoperative pulmonary function tests variables were different between the two groups. Serious postoperative complications were more frequent in these patients compared with those who showed only emphysema. Conclusions A significant portion of patients diagnosed as having severe emphysema will have other unsuspected histologic findings. When subjected to lung volume reduction surgery, this subgroup will have more serious complications and longer periods of air leaks, requiring longer hospitalization time. Retrospective review of imaging studies and preoperative pulmonary function tests used to select patients for lung volume reduction failed to identify this subgroup.

We evaluated the following spirometric values: forced vital capacity (FVC), first second expiratory volume (FEV1), FEV1/FVC, the lung volumes, total lung capacity (TLC), residual volume (RV), and single breath diffusing capacity for CO in 22 patients, before and after heart transplant. We found abnormal pulmonary function in 21 patients before heart transplantation. Despite postoperative increases in lung volumes in 10 patients, abnormal pulmonary function persisted in 20 patients after heart transplant. Mean values for lung volumes and flow rates did not change but diffusion for CO decreased significantly after heart transplantation. Diffusion failed to correlate with ejection fraction, pulmonary arterial pressure, pulmonary capillary wedge pressure (PCWP), and pulmonary vascular resistance; however, in a subset of patients with improved postoperative lung volumes, preoperative diffusion for CO correlated with preoperative PCWP. We conclude that pulmonary function abnormalities are common among heart transplant recipients. Diffusion abnormalities are not linearly related to indices of cardiac function measured before transplantation and diffusion abnormalities appear to be multifactorial in cause. The posttransplant decrease in diffusion appears to result from the combined effects of decreased postoperative lung volumes in some patients and relief of heart failure induced pulmonary vascular engorgement in others. Improvement in lung volumes and flow rates may occur but cannot be expected after heart transplantation, and diffusion decreases after heart transplantation. The fact that pulmonary function and lung volumes do not improve following heart transplantation implies to underlying lung disease or permanent lung alterations result from chronic heart failure.