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Robert L Berger

Publications and source records attributed to Robert L Berger.

4 recordsLinked to original sources
PubMed2005

Lung volume reduction surgery vs medical treatment: for patients with advanced emphysema.

OBJECTIVE: To contribute to the knowledge on the therapeutic value of lung volume reduction surgery (LVRS). DESIGN: Two similar, independently conceived and conducted, multicenter, randomized clinical trials. SETTING: The Canadian Lung Volume Reduction (CLVR) study and the Overholt-Blue Cross Emphysema Surgery Trial (OBEST). METHODS: Using a fixed-effects meta-analysis, the 6-month results produced by the addition of LVRS to optimal medical therapy were compared to those obtained from optimal medical therapy alone. Patients were required to have severe emphysema, marked airflow limitation (ie, FEV(1), 15 to 40% predicted), hyperinflation (total lung capacity [TLC], > 120% predicted), CO(2), < 55 mm Hg, and measurable dyspnea (chronic respiratory disease questionnaire [CRDQ] scores </= 4 for the CLVR study, or Medical Research Council dyspnea scale >/= 1 for the OBEST). Optimal medical therapy included pulmonary rehabilitation in both arms of both studies. RESULTS: The CLVR study randomized 58 patients and the OBEST randomized 35 patients for a total of 93 patients. Of these, 54 patients were randomized to undergo surgery, and 39 patients were randomized to receive medical treatment. The 6-month mortality rate (including operative mortality) in the surgical and medical cohorts was similar (5.6% vs 5.1%, respectively). A comparison of the medical and surgical arms of the combined CLVR study/OBEST population showed that LVRS was associated with a higher FEV(1) (167 mL or 24% predicted; 95% confidence interval [CI], 29 to 304; p = 0.017), lower residual volume (-1,342 mL or 24.5% predicted; 95% CI, -1,844 to -840; p < 0.001), lower TLC (-1,044 mL or 13% predicted; 95% CI, -1483 to -605; p < 0.001), and higher 6-min walk distance (148.8 feet; 95% CI, 24.3 to 273.2; p = 0.019). Each domain of the CRDQ showed statistically significant improvement in the surgical arm of the study, but not in the medical arm. The summary physical component scale of the Medical Outcomes Study 36-item short form (SF-36) was also more favorable in the LVRS cohort (6.9; 95% CI, 2.86 to 10.90; p < 0.001). The summary mental component scale of the SF-36 did not show a statistically significant difference between the two groups. CONCLUSION: Six months after randomization, LVRS produced better palliation than optimal medical therapy in patients with advanced emphysema.

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PubMed2005

Lung volume reduction surgery: a meta-analysis of randomized clinical trials.

BACKGROUND: Observational studies have suggested that lung volume reduction surgery (LVRS) is superior to optimal medical therapy for selected subsets of patients with advanced emphysema. Randomized clinical trials (RCTs) with the exception of the National Emphysema Treatment Trial (NETT), failed to enroll a sufficient number of patients to provide clinicians and patients with convincing outcome data on the usefulness of LVRS. It was postulated that a meta-analysis of these RCTs (3-12 months' follow up) may provide more compelling information on the value of LVRS in patients with emphysema. METHODS: A comprehensive search of the MEDLINE database between January 1994 and January 2004 for RCTs on LVRS was performed. RESULTS: From a total of eight RCTs on record, six studies (306 patients) with 3- to 12-month follow up were deemed suitable for meta-analysis. Key baseline features of these RCT populations included heterogeneous emphysema, comparable inclusion/exclusion criteria and, in retrospect, low walking capacity as measured by the 6-minute walk distance (6MWD). This profile closely resembles NETT's 'predominantly upper lobe--low exercise tolerance emphysema' cohort. The LVRS arm of the meta-analysis population showed better results than the medical cohort in terms of pulmonary function (FEV(1) p < 0.0001, FVC p < 0.0001, residual volume p < 0.0001, total lung capacity p = 0.004), gas exchange (arterial partial pressure of oxygen p < 0.0001) and exercise capacity (6MWD p = 0.0002). Although information on quality-of-life measures was not sufficiently uniform to qualify for meta-analysis, a survey of available data revealed better results in the surgical than in the medical arms of each RCT. Mortality 6-12 months after random assignment to treatment was similar in the two study arms, suggesting that the operative mortality from LVRS was offset, within months, by deaths in the medical arm. CONCLUSIONS: This meta-analysis showed that a selected subset of patients with advanced, heterogeneous emphysema and low exercise tolerance (6MWD) experienced better outcomes from LVRS than from medical therapy.

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PubMed2002

Bronchoscopic lung volume reduction using tissue engineering principles.

Bronchoscopic lung volume reduction (BLVR), a minimally invasive procedure based on tissue engineering principles, was performed in six sheep with papain-induced experimental emphysema (EMPH). Physiologic measurements, at baseline, after generation of EMPH, and at 3 and 9 weeks after BLVR, included lung volumes, diffusing capacity (DL(CO)), pressure-volume relationships for the lung and chest wall, pleural pressures generated during active respiratory muscle contraction, lung resistance and dynamic elastance. The animal model displayed hyperinflation (change in total lung capacity +8%; change in residual volume +66%), reduced DL(CO) (-21%), and elevated airway resistance (+76%) that resembled advanced human EMPH. BLVR was well tolerated without complications, and it reduced lung volumes (change in total lung capacity -16%; change in residual volume -55%) in a pattern that resulted in significant improvements in vital capacity (10%). At autopsy, well-organized, peripheral scars associated with tissue contraction were observed at 33 of the 36 (91%) treated sites. There was no evidence of infection, abscess, or granuloma formation, or allergic reaction. Scar tissue, generated by BLVR, replaced hyperinflated lung, reduced overall lung volume, and improved respiratory function safely and consistently. The BLVR technology employed in this study addresses the limitations identified in our prior attempt at BLVR therapy and appears safe and effective enough to justify a trial in humans.

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