Lung volume reduction surgery using the NETT selection criteria.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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 for pulmonary emphysema: Improvement in body mass index, airflow obstruction, dyspnea, and exercise capacity index after 1 year.

OBJECTIVES: We hypothesized that lung-volume reduction surgery for pulmonary emphysema would improve body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index, a multidimensional predictor of survival in chronic obstructive pulmonary disease. We also aimed to identify preoperative predictors of improvement in the BODE index. METHODS: In a prospective cohort study of patients undergoing lung-volume reduction surgery at our center, with the methodology of the National Emphysema Treatment Trial, we compared clinical characteristics before and 1 year after surgery with the Wilcoxon signed rank test. Changes in the BODE index were correlated with preoperative variables with the Spearman correlation coefficient. RESULTS: Twenty-three patients with predominantly upper-lobe pulmonary emphysema underwent lung-volume reduction surgery (14 by video-assisted thoracoscopic surgery, 9 by median sternotomy). There were no postoperative or follow-up deaths. The BODE index improved from a median of 5 (interquartile range 4-5) before surgery to 3 (interquartile range 2-4) 1 year after surgery (P < .0001). Improvements were seen in the lung function and dyspnea components of the BODE index. Lower preoperative 6-minute walk distance and lower postwalk Borg fatigue scores were each associated with greater improvement in the BODE index after 1 year. CONCLUSION: Lung-volume reduction surgery for pulmonary emphysema improved the BODE index in patients with predominantly upper-lobe disease. Lower preoperative 6-minute walk distance correlated with greater improvement in the BODE index.

Genetic and phenotypic characterization of drug-resistant Mycobacterium tuberculosis isolates in Hong Kong.

OBJECTIVES: To characterize 250 drug-resistant Mycobacterium tuberculosis (MTB) isolates in Hong Kong with respect to their drug susceptibility phenotypes to five common anti-tuberculosis drugs (ofloxacin, rifampicin, ethambutol, isoniazid and pyrazinamide) and the relationship between such phenotypes and the patterns of genetic mutations in the corresponding resistance genes (gyrA, rpoB, embB, katG, inhA, ahpC and pncA). METHODS: The MIC values of the aforementioned anti-tuberculosis drugs were determined for each of the 250 drug-resistant MTB clinical isolates by the absolute concentration method. Genetic mutations in the corresponding resistance genes in these MTB isolates were identified by PCR-single-stranded conformation polymorphism/multiplex PCR amplimer conformation analysis (SSCP/MPAC), followed by DNA sequencing of the purified PCR products. RESULTS: Resistance to four or five drugs was commonly observed in these MTB isolates; such phenotypes accounted for over 34% of the 250 isolates. The most frequently observed phenotypes were those involving both rifampicin and isoniazid, with or without additional resistance to the other drugs. A total of 102 novel mutations, which accounted for 80% of all mutation types detected in the 7 resistance genes, were recovered. Correlation between phenotypic and mutational data showed that genetic changes in the gyrA, rpoB and katG genes were more consistently associated with a significant resistance phenotype. Despite this, however, a considerable proportion of resistant MTB isolates were found to harbour no detectable mutations in the corresponding gene loci. CONCLUSIONS: These findings expand the spectrum of potential resistance-related mutations in MTB clinical isolates and help consolidate the framework for the development of molecular methods for delineating the drug susceptibility profiles of MTB isolates in clinical laboratories.