| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Guest Access | Sign In via User Name/Password
|
|
|
|||||||
Guest Access | Sign In via User Name/Password |
|||||||||
* From the Divisions of Pulmonary and Critical Care Medicine (Drs. Yusen and Lefrak) and Cardiothoracic Surgery (Drs. Meyers, Patterson, Cooper, and Ms. Davis), and Mallinckrodt Institute of Radiology (Dr. Gierada), Washington University School of Medicine, and Barnes-Jewish Hospital, St. Louis, MO.
Correspondence to: Roger D. Yusen, MD, MPH, FCCP, Washington University School of Medicine, Box 8052, 660 S. Euclid Ave, St. Louis, MO 63110; e-mail: yusenr{at}msnotes.wustl.edu
 |
Abstract |
|---|
 TOP Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Design: We used a prospective cohort study design to assess the first 200 patients undergoing bilateral LVRS (from 1993 to 1998), with follow-up through the year 2000. Each patient served as his own control, initially receiving optimal medical management including exercise rehabilitation before undergoing surgery. Preoperative postrehabilitation data were used as the baseline for comparisons with postoperative data. The primary end points were the effects of LVRS on dyspnea (modified Medical Research Council dyspnea sale), general health-related quality of life (Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36]), patient satisfaction, and survival. The secondary end points were the effects of LVRS on pulmonary function, exercise capacity, and supplemental oxygen requirements.
Setting: A tertiary care urban university-based referral center.
Patients: Eligibility requirements for LVRS included disabling dyspnea due to marked airflow obstruction, thoracic hyperinflation, and heterogeneously distributed emphysema that provided target areas for resection. Patients were assessed at 6 months, 3 years, and 5 years after surgery.
Interventions: Preoperative pulmonary rehabilitation and bilateral stapling LVRS.
Measurements and results: The 200 patients accrued 735 person-years (mean ± SD, 3.7 ± 1.6 years; median, 4.0 years) of follow-up. Over the three follow-up periods, an average of > 90% of evaluable patients completed testing. Six months, 3 years, and 5 years after surgery, dyspnea scores were improved in 81%, 52%, and 40% of patients, respectively. Dyspnea scores were the same or improved in 96% (6 months), 82% (3 years), and 74% (5 years) of patients. Improvements in SF-36 physical functioning were demonstrated in 93% (6 months), 78% (3 years), and 69% (5 years) of patients. Good-to-excellent satisfaction with the outcomes was reported by 96% (6 months), 89% (3 years), and 77% (5 years) of patients. The FEV1 was improved in 92% (6 months), 72% (3 years), and 58% (5 years) of patients. Changes in dyspnea and general health-related quality-of-life scores, and patient satisfaction scores were all significantly correlated with changes in FEV1. Following surgery, the median length of hospital stay in survivors was 9 days. The 90-day postoperative mortality was 4.5%. Annual Kaplan-Meier survival through 5 years after surgery was 93%, 88%, 83%, 74%, and 63%, respectively. During follow-up, 15 patients underwent subsequent lung transplantation.
Conclusions: In stringently selected patients, LVRS resulted in substantial beneficial effects over and above those achieved with optimized medical therapy. The duration of improvement was at least 5 years in the majority of survivors.
Key Words: airflow obstruction • bullectomy • COPD • dyspnea • emphysema • lung volume reduction • outcomes research • personal satisfaction • pneumonectomy • quality of life • thoracic surgery
|
Introduction |
|---|
|
TOPAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
In the 1950s, Brantigan and Mueller4 proposed that excision of the most hyperinflated and destroyed portions of the emphysematous lung might improve lung elastic recoil, reduce airflow limitation, and improve chest wall mechanics. However, the unilateral partial lung reduction, combined with radical hilar stripping, resulted in high mortality, limited clinical success, and general lack of acceptance. Based on the work of Brantigan and Mueller,4 we developed and initiated a procedure for bilateral lung volume reduction surgery (LVRS) at Barnes-Jewish Hospital in 1993.
Published results of LVRS during the 1990s have been encouraging. The short-term efficacy of LVRS in selected patients has been demonstrated, and mechanisms of improvement have been described.5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 However, the value of LVRS has remained controversial due to varied patient selection, inconsistent utilization of preoperative rehabilitation, differences in surgical methods, incomplete follow-up data, varying degrees of benefit, and a lack of long-term results in published reports.23 24 This report describes the long-term results of a prospective evaluation of the first 200 patients in our program undergoing bilateral LVRS.
|
Materials and Methods |
|---|
|
TOPAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Setting
All patients underwent evaluation and LVRS at Barnes-Jewish Hospital, a tertiary care hospital affiliated with Washington University School of Medicine. All research tests and protocols were approved by the human studies committee, and all patients provided informed consent for the studies and the operation.
Patients and Evaluation for LVRS
We followed our previously reported methods of evaluation and selection of patients with COPD for LVRS, and the reader is referred to these sources for detailed information.5
20
25
In general, LVRS was offered to patients with marked impairment and disability despite optimal medical therapy, a suitable clinical and physiologic profile, and a favorable radiologic pattern of emphysema.26
Critical selection criteria included disabling dyspnea due to marked airflow obstruction, thoracic hyperinflation, and heterogeneously distributed emphysema that provided target areas for resection. Patients with acceptable anatomic characteristics only in one hemithorax or contraindications to surgery in one hemithorax were not selected for bilateral LVRS, although they were then considered for unilateral surgery. We excluded patients with a predominance of airways disease, an inadequate amount of lung spared from severe emphysema as demonstrated on CT scan, or the presence of major comorbidity. In patients suspected of having pulmonary hypertension, right-heart catheterization was performed. Patients with a systolic pulmonary artery pressure > 45 mm Hg or a mean pulmonary artery pressure > 35 mm Hg were excluded. Patients accepted for unilateral LVRS or giant bullectomy were excluded from this study.
Interventions
In preparation for surgery, medical therapy was optimized, and patients were enrolled in supervised comprehensive pulmonary rehabilitation programs for a minimum duration of 6 weeks (median, 97 days) as previously described.25
The surgical and anesthetic techniques, pain management, and perioperative care of these patients have been previously described.5
20
27
All lung volume reduction operations were performed through a median sternotomy, except one, which was done through a bilateral muscle-sparing thoracotomy because of a previous sternotomy for coronary bypass surgery. Multiple applications of a stapling device were used to excise the lung "target areas" detected by preoperative imaging studies and by intraoperative visual examination and palpation.
Tests and Variables
Questionnaires:
Dyspnea, general health-related quality of life, and patient satisfaction were assessed with questionnaires that were provided on-site or through the mail. All questionnaires were completed during periods of clinical stability.
Dyspnea:
Dyspnea was quantified by the modified Medical Research Council (MRC) of Great Britain Dyspnea Scale.28
29
The scale has five integer grades, 0 through 4, that describe the level of activity that provokes dyspnea; lower numbers indicate less dyspnea. A 1-point change in the dyspnea scale is considered clinically important. Formal preoperative administration of the MRC questionnaire started with case number 75 (administered in cases 75 to 200, n = 126).
General Health-Related Quality of Life:
General health-related quality of life was evaluated by a self-administered questionnaire, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36).30
31
We report the physical functioning (PF) scale scores and the physical component summary (PCS) scores.32
The scores may range from 0 (worst) to 100 (best). The PCS score is standardized so that the general population has a mean ± SD of 50 ± 10. A 10-point change in the PF score and a 3-point change in the PCS score are considered clinically important. Eight patients were excluded from the SF-36 evaluation. The SF-36 evaluation started after the first four patients in this series had surgery. Another four patients from outside the United States who did not use English as their primary language were excluded. The SF-36 was inadvertently not administered to some patients (n = 33) after rehabilitation but before surgery. SF-36 analyses were therefore based on those patients who completed the postrehabilitation preoperative baseline SF-36 (n = 159). Those who did and those who did not complete the postrehabilitation preoperative SF-36 had similar demographic and physiologic preoperative profiles.
Patient Satisfaction With the Operation:
Postoperative patient overall satisfaction was measured with a question, "Please assess your overall satisfaction with the operation based on how you feel at the present time." Patients were asked to choose one of five possible responses: poor, fair, good, very good, and excellent.
Pulmonary Function, Alveolar Gas Exchange, Exercise Tolerance, and Supplemental Oxygen Requirements:
All tests were performed during periods of clinical stability. A complete battery of pulmonary function tests was performed at our institution at the initial evaluation, after completion of the required preoperative rehabilitation program, and during the postoperative follow-up periods. An abbreviated battery of tests results (FEV1 and residual volume [RV]) from other institutions was also used during the follow-up periods. Experienced technicians tested pulmonary function according to American Thoracic Society standards.33
Spirometry and plethysmographic lung volume testing were performed, and only postbronchodilator values (testing 15 min after inhalation of two puffs albuterol via metered-dose inhaler) are reported.34
35
A single-breath technique was utilized to measure the diffusing capacity of the lung for carbon monoxide (DLCO).36
Specimens of arterial blood, obtained with patients sitting at rest breathing room air, were measured with a blood gas analyzer (Model BG3; Instrumentation Laboratory; Lexington, MA). During the standardized 6-min walk test,37
certified respiratory technicians used continuous pulse oximetry (Model N10; Nellcor; Pleasanton, CA) to assess oxygen saturation of hemoglobin, as previously described.5
20
25
Patients were asked to report their usual supplemental oxygen flow rates used at rest and during exertion.
Postoperative Hospital Length of Stay, Complications, and Survival:
Postoperative length of stay and complications that arose during hospitalization were determined by chart review soon after patient discharge. We report 90-day mortality and mortality through 5 years after surgery.
Statistical Analysis
Descriptive statistics are reported as mean ± SD unless otherwise specified. Normally distributed continuous data were evaluated with paired and unpaired two-tailed t tests, and repeated-measures analysis of variance (ANOVA). Wilcoxon rank-sum or signed rank tests were used for nonnormally distributed data. Categorical data were evaluated with Pearson (or Fisher exact test) or McNemar 
2. Change scores for each variable were calculated as the postoperative value minus the preoperative (postrehabilitation) value. Correlations were assessed with Spearman 
. For each postoperative nonsurvival analysis, the follow-up status of evaluable patients (alive, not transplanted, and eligible for follow-up) was described as present or missing. Patients were not evaluable due to death, lung transplantation, or end of follow-up (ineligible for follow-up due to too short of a time interval since LVRS). Kaplan-Meier analysis was used to characterize survival. Data analyses were conducted using SPSS (version 6.1 for MacIntosh; SPSS; Chicago, IL).
|
Results |
|---|
|
TOPAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Patient Characteristics
All patients selected for LVRS were former cigarette smokers with disabling dyspnea resulting from marked emphysema as demonstrated by CT scan. All patients had physiologic characteristics of marked airflow obstruction, air trapping and thoracic hyperinflation, and impairment of alveolar gas exchange (Table 1
).
|
|
|
All patients were extubated within hours after surgery. Nine patients underwent reoperation: 7 patients (3.5%) for air leak, and 2 patients (1%) for bleeding, with all but one of these occurring in our first 2 years of experience. Other surgical interventions occurred in 7 patients (3.5%): 6 patients (3%) for GI complications and 1 patient (0.5%) for coronary artery bypass grafting. Thirteen additional patients (6.5%) underwent reintubation for respiratory failure. Ten of these patients underwent formal tracheostomy. Two patients (1%) were resuscitated from electromechanical dissociation cardiac arrests, and two additional patients (1%) had myocardial infarctions. These four patients recovered without difficulty. No sternal infections or dehiscences occurred. Two patients (1%) were readmitted to the hospital within 30 days after hospital discharge.
The postoperative length of hospital stay of the survivors was a median of 9 days (mean ± SD, 14 ± 16 days; range, 4 to 168 days). The 90-day postoperative mortality was 4.5%, all related to respiratory failure.
Follow-up, Survival, and Subsequent Lung Transplantation
Of the 200 patients, we obtained the postoperative vital status of 99.5% of patients (1 patient was unavailable for follow-up) through the end of the study period, resulting in 735 person-years, or an average of 3.7 ± 1.6 years (median, 4.0 years) of follow-up. Annual Kaplan-Meier survival through 5 years after surgery was 93%, 88%, 83%, 74%, and 63%, respectively (Fig 1
). Fifteen patients (7.5%; average age, 53.9 years) underwent subsequent lung transplantation at an average of 3.6 ± 1.2 years (range, 2.1 to 6.0 years) after LVRS.
|
|
The PF scale may have the most relevance for patients with emphysema, in whom functioning worsens due to the progression of physical limitations. Preoperatively, patients described very poor PF. PF improvements were demonstrated in 93%, 78%, and 69% of respondents at the respective follow-up periods (Table 3) . Clinically significant change, defined as a PF change of at least 10 points, was demonstrated in 90%, 69%, and 57% of respondents at the respective follow-up periods.
PCS score improvements were demonstrated in 86%, 74%, and 63% of respondents at the three respective follow-up periods (Table 3) . Clinically significant change, defined as a PCS change of at least 3 points, was demonstrated in 81%, 65%, and 54% of respondents at the three respective follow-up periods.
In the cohort of patients with 5 years of follow-up (n = 67; Fig 3 ), PF was improved in 97%, 87%, and 69% of the respondents at 6 months, 3 years, and 5 years after surgery, respectively. Though the known natural history of emphysema is one of deterioration, 97% of the respondents were better or no worse than their preoperative state at 3 years after surgery, and 85% of the respondents were better or no worse at 5 years after surgery.
|
|
|
|
|
5 Years After Surgery:
Eighty-one patients were evaluable for the 5-year postoperative follow-up, and results were obtained in 79% (64 of 81 patients). Five years after surgery, 58% of patients had sustained improvement in the FEV1 (Table 5
, Fig 5
). The RV (n = 55) was improved compared to the baseline value in 82% of patients, a proportion of patients with improvement significantly greater than the proportion of patients with improvement in the FEV1. The proportion of patients in this cohort reporting use of supplemental oxygen at rest before surgery was 40%, and 5 years after surgery was 46% (n = 82; p = 0.002). The proportion of patients reporting use of supplemental oxygen during exertion before surgery was 87%, and 5 years after surgery was 71% (n = 82; p = 0.072).
Correlations of Patient-Reported Outcomes and Changes in FEV1
At 6 months, 3 years, and 5 years after surgery, the absolute change in FEV1 and the percentage change in FEV1 had similar statistically significant correlations with the change in the modified MRC dyspnea scale score, the change in the SF-36 PF scale score, and the patient satisfaction scores after surgery. Increases in FEV1 were associated with decreases in dyspnea scores, increases in PF scores, and higher patient satisfaction scores. The statistically significant correlations of largest magnitude were seen between the change in FEV1 and the change in the SF-36 PF scores (all p < 0.001). Changes in RV showed poor correlation with the change in the modified MRC dyspnea scale score, the change in the SF-36 PF scale score, and the patient satisfaction scores at all three postoperative follow-up periods.
|
Discussion |
|---|
|
TOPAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
A paucity of data describing long-term outcomes following LVRS exists. A recent study provided insight into the durability of LVRS: Flaherty and colleagues22 at the University of Michigan described a cohort of 89 consecutive patients who underwent bilateral LVRS during the interval of 1994 through 1998. The 30-day postoperative mortality rate was 5.6%, and a total of 16 patients died during the 3-year follow-up period. All survivors who completed testing initially showed improvement in dyspnea (Mahler transitional dyspnea index) following LVRS, compared to their preoperative postrehabilitation baseline, although the average improvement waned over time. The majority of patients demonstrated improvement in FEV1, and the mean FEV1 was significantly improved throughout follow-up, although the FEV1 did trend downward over time. Of the 46 patients eligible for follow-up at 3 years after LVRS, 34 patients (74%) completed testing. Ten of the 34 patients had an FEV1 at least 200 mL greater than the preoperative baseline, and half of these had an FEV1 > 400 mL above baseline. The average 6-min walk distance improved throughout the follow-up period. These significant improvements in dyspnea, lung function, and exercise capacity suggest that select patients have meaningful outcomes through at least 3 years after surgery.
Another recent study by Gelb and colleagues38 described follow-up of a cohort of patients through 4 years after bilateral LVRS in 1995, with the most detailed long-term data described at 3 years after surgery. The subset of 26 nonconsecutive patients included in the study were able to complete rigorous preoperative physiologic testing, while the study excluded 56 other patients who underwent LVRS but did not have detailed testing. The included and excluded patients had similar preoperative pulmonary function results. Actuarial survival was 96% at 1 year after surgery and 69% at 3 years after surgery. The study found that 46% of surviving patients had an improved modified MRC dyspnea score at 3 years after surgery. However, the study did not specify that the baseline dyspnea measurements were made after completion of a preoperative comprehensive pulmonary rehabilitation program. Since medical therapy can improve dyspnea scores, some of the improvements may have been due to medical therapy. Nineteen of the 26 patients were considered to be short-term (1 year after LVRS) physiologic responders (FEV1 improved > 200 mL or FVC improved > 400 mL compared to baseline), and 9 of these patients met the responder criteria through at least 3 years after surgery. Improvements in maximal expiratory airflow were accompanied by improvements in lung elastic recoil and airway conductance. This study provided a physiologic rationale for long-term improvements in airflow obstruction.
The physiologic benefits associated with LVRS provide a rationale for the improved dyspnea and general health-related quality of life and high satisfaction reported by patients. Patients almost certainly had complex physiologic changes beyond an increase in FEV1. Thus, the measured improvements in quality of life and dyspnea following surgery are probably partially explained by other physiologic changes that were not measured as part of this study.39
Defining what constitutes a successful outcome after LVRS is complex. The complexity arises in part from our limited understanding of dyspnea and quality of life, and the enigmatic interactions between major medical interventions and patient perceptions. The sustained improvement in patient-perceived PF and dyspnea and high patient satisfaction after surgery partially define the success of LVRS in this group of patients. Use of measured lung function as the sole outcome to assess LVRS is inadequate.15 22 40 41 Although physiologic parameters such as FEV1 are relatively easy to follow, they are only surrogate markers of the improvement in dyspnea, functional status, and quality of life sought by patients disabled by severe emphysema. Too often, the success or the failure of an intervention is focused on surrogate outcomes (eg, FEV1). We believe that the outcome measurements applied in this study, when used in conjunction with survival data, are of great importance in the evaluation of LVRS. Nevertheless surrogate outcomes, such as physiologic parameters, should be used to validate the outcomes that are based on patient perceptions. For example, the change and percentage change in FEV1 at all postoperative follow-up time periods correlated with the changes in scores of dyspnea and general health-related quality of life and patient satisfaction, providing physiologic data to corroborate the data that are based on patient perceptions.
This study incorporated comprehensive pulmonary rehabilitation, a mainstay of therapy for most patients with far-advanced emphysema,42 as an important preoperative intervention. Preoperative rehabilitation improved functioning and allowed patients to confirm their desire for surgery based on their new baseline state. Similar to previous studies of patients undergoing LVRS, our study demonstrated that preoperative rehabilitation with graded exercise effected no significant change in lung function.12 13 20 21 However, the 6-min walk distance, dyspnea, and perceived PF improved with rehabilitation, also consistent with other studies. The preoperative postrehabilitation data for all measurements were used as the baseline for comparison to postoperative data. Therefore, each patient served as his or her own control in this prospective cohort study. Compared to preoperative rehabilitation, patients demonstrated significantly greater improvements in all assessed outcomes after surgery, and the benefits persisted for 5 years in the majority of survivors.
Patients with emphysema face substantial morbidity and mortality.43 44 45 Therefore, the postoperative complication rate was neither unexpected nor prohibitive. If the age and the preoperative lung function of the patients are considered, the 90-day mortality rate of 4.5% for a bilateral thoracic procedure is comparable to the operative mortality rate for major resectional surgery for lung cancer patients of this age group who have much better pulmonary function.46 Long-term complications after LVRS were not apparent.
The impact of LVRS on the mortality of patients with severe emphysema cannot be accurately determined without using an external control group. The four published randomized controlled trials of LVRS vs medical therapy demonstrated, as expected, a higher short-term mortality in the surgical arms compared to the mortality in the medical arms, mainly due to postoperative complications.12 13 21 47 However, these studies demonstrated significantly better postoperative pulmonary function, exercise capacity, and subjective health status in the surgical treatment arms compared to the medical treatment arms. The four published studies did not assess long-term outcomes.
The natural history of end-stage emphysema has been well documented and is one of unrelenting, progressive decline in spite of optimum medical therapy.43 44 45 48 This natural history, though previously documented in much less stringently selected patients with emphysema, has been confirmed in the four published randomized clinical trials of LVRS.12 13 21 47 Based on this natural history and our use of baseline values for postoperative comparisons, this study may understate the magnitude and duration of benefit of LVRS compared to the anticipated outcome in a similar cohort of patients not undergoing the procedure. Our previous reports on just such a cohort49 50 support this hypothesis.
This study had several limitations. The results are based on the experience at a single center. However, the inclusion of 200 consecutive patients with a broad range of characteristics strengthens its generalizability. Some patients were missing follow-up data. However, over the three follow-up periods, an average of > 90% of evaluable patients had completed testing. Though one could suggest that placebo effects or cognitive dissonance explain the improvements after surgery, the large magnitude long-term improvements in the majority of patients in all of the multiple variables assessed suggest that the benefits were due to LVRS. This report demonstrates that bilateral LVRS, in carefully selected patients with severe emphysema, produces significant and prolonged improvements in dyspnea and general health-related quality of life.
|
Acknowledgements |
|---|
|
Footnotes |
|---|
Supported, in part, by the National Heart, Lung, and Blood Institute of the National Institutes of Health, grant number 5 K23 HL04236-02 (Dr. Yusen).
Dr. Cooper receives a royalty from Biovascular, Inc., for his development of the Peristrip staple-line reinforcement.
Dr. Yusen is a consultant for Spiration, Inc.
Received for publication October 16, 2001. Accepted for publication August 12, 2002.
|
References |
|---|
|
TOPAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
This article has been cited by other articles:
|
|
 |
|
  N. Shigemura, M. Okumura, S. Mizuno, Y. Imanishi, A. Matsuyama, H. Shiono, T. Nakamura, and Y. Sawa Lung Tissue Engineering Technique with Adipose Stromal Cells Improves Surgical Outcome for Pulmonary Emphysema Am. J. Respir. Crit. Care Med., December 1, 2006; 174(11): 1199 - 1205. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. C. Mineo, E. Pompeo, D. Mineo, V. Ambrogi, D. Ciarapica, and A. Polito Resting energy expenditure and metabolic changes after lung volume reduction surgery for emphysema. Ann. Thorac. Surg., October 1, 2006; 82(4): 1205 - 1211. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Venuta, E. A. Rendina, T. De Giacomo, M. Anile, D. Diso, C. Andreetti, F. Pugliese, and G. F. Coloni Bronchoscopic procedures for emphysema treatment Eur. J. Cardiothorac. Surg., March 1, 2006; 29(3): 281 - 287. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Y. P. Wan, T. P. Toma, D. M. Geddes, G. Snell, T. Williams, F. Venuta, and A. P. C. Yim Bronchoscopic Lung Volume Reduction for End-Stage Emphysema: Report on the First 98 Patients Chest, March 1, 2006; 129(3): 518 - 526. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. B. Gorman, D. K. McKenzie, J. E. Butler, J. F. Tolman, and S. C. Gandevia Diaphragm Length and Neural Drive after Lung Volume Reduction Surgery Am. J. Respir. Crit. Care Med., November 15, 2005; 172(10): 1259 - 1266. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Palla, M. Desideri, G. Rossi, G. Bardi, D. Mazzantini, A. Mussi, and C. Giuntini Elective Surgery for Giant Bullous Emphysema: A 5-Year Clinical and Functional Follow-up Chest, October 1, 2005; 128(4): 2043 - 2050. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. K. Myint, R. N. Luben, P. G. Surtees, N. W. J. Wainwright, A. A. Welch, S. A. Bingham, N. J. Wareham, N. E. Day, and K-T. Khaw Respiratory function and self-reported functional health: EPIC-Norfolk population study Eur. Respir. J., September 1, 2005; 26(3): 494 - 502. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. C. Mineo, V. Ambrogi, D. Mineo, A. Fabbri, E. Fabbrini, and R. Massoud Bone Mineral Density Improvement After Lung Volume Reduction Surgery for Severe Emphysema Chest, June 1, 2005; 127(6): 1960 - 1966. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. D. Yusen and B. Littenberg Integrating Survival and Quality of Life Data in Clinical Trials of Lung Disease: The Case of Lung Volume Reduction Surgery Chest, April 1, 2005; 127(4): 1094 - 1096. [Full Text] [PDF]
|
|
|
|
|
|
N. S. Hopkinson, T. P. Toma, D. M. Hansell, P. Goldstraw, J. Moxham, D. M. Geddes, and M. I. Polkey Effect of Bronchoscopic Lung Volume Reduction on Dynamic Hyperinflation and Exercise in Emphysema Am. J. Respir. Crit. Care Med., March 1, 2005; 171(5): 453 - 460. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. C. Mineo, E. Pompeo, D. Mineo, P. Rogliani, C. Leonardis, and I. Nofroni Results of unilateral lung volume reduction surgery in patients with distinct heterogeneity of emphysema between lungs J. Thorac. Cardiovasc. Surg., January 1, 2005; 129(1): 73 - 79. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
