Improved long-term survival seen after lung volume reduction surgery compared to continued medical therapy for emphysema.
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Actuarial Analysis↗
Biomedical subjects
S S Lefrak
Publications and source records attributed to S S Lefrak.
Outcome of bilateral lung volume reduction in patients with emphysema potentially eligible for lung transplantation.
OBJECTIVE: Between January 1993 and May 1998, we performed 200 consecutive bilateral lung volume reduction operations. After initial assessment, 99 of these patients were eligible for lung volume reduction and potentially eligible for immediate or eventual lung transplantation on the basis of age and absence of contraindications. All chose to proceed with lung volume reduction surgery. The outcomes of these 99 patients are reviewed to assess the consequences of proceeding with lung volume reduction surgery on patients potentially eligible for lung transplantation. METHODS: A retrospective study was performed with the use of a prospectively assembled computer database. RESULTS: The 61 men and 38 women were 55 +/- 7 years old at evaluation for lung volume reduction. Mean values for first second expired volume, total lung capacity, and residual volume were 24% +/- 8%, 141% +/- 19%, and 294% +/- 54% predicted. There were 4 operative deaths and 17 late deaths. Two-year and 5-year survival after evaluation for lung volume reduction are 92% and 75%. The 32 patients who have been listed for transplantation after lung volume reduction include 15 who have undergone transplantation, 14 who remain on the list, and 3 who have been removed from the list. All 15 transplant recipients survived transplantation and 3 have subsequently died of rejection or late infection. The 12 living recipients have a median post-transplantation follow-up of 1.7 years. The age at transplantation was 58 +/- 5 years with transplantation occurring 3.8 +/- 1.1 years after lung volume reduction. Sixteen of 99 patients underwent lower lobe volume reduction with an increased rate of listing (63%, P =.008) and transplantation (38%, P =.003) compared with patients undergoing upper lobe volume reduction. Patients listed for transplantation were younger, more impaired, and experienced less benefit from lung volume reduction than patients not yet listed for transplantation. CONCLUSIONS: The preliminary use of lung volume reduction in patients potentially suitable for transplantation does not appear to jeopardize the chances for subsequent successful transplantation.
Contraindications↗
Repeatability of quantitative CT indexes of emphysema in patients evaluated for lung volume reduction surgery.
PURPOSE: To evaluate the repeatability of quantitative computed tomographic (CT) indexes of emphysema and the effect of spirometric gating of lung volume during CT in candidates for lung volume reduction surgery (LVRS). MATERIALS AND METHODS: Initial and same-day repeat routine inspiratory spiral chest CT studies were performed in 29 LVRS candidates (group 1, routine study vs repeat study). In a separate cohort of 29 LVRS candidates, spiral chest CT studies were performed both without and with spirometric gating by using a spirometer to trigger scanning at 90% of vital capacity (group 2, spirometric gating study). In each study, Pearson and intraclass correlation coefficients were calculated to determine the agreement between multiple pairs of whole-lung quantitative CT indexes of emphysema, and mean values were compared with two-tailed paired t tests. RESULTS: Pearson and intraclass correlation coefficients were high for all quantitative CT indexes (all > or = 0.92). No significant differences were found between mean values of quantitative CT indexes in group 1. Variation in quantitative CT results was small but more prominent in group 2 than in group 1. The variation in quantitative CT results was primarily related to differences in lung volume (r(2) as great as 0.83). CONCLUSION: Repeatability of quantitative CT test results in LVRS candidates is high and unlikely to improve by using spirometric gating.
Aged↗
Dynamic echo planar MR imaging of lung ventilation with hyperpolarized (3)He in normal subjects and patients with severe emphysema.
We applied the rapid imaging capability of echo planar MR pulse sequences and hyperpolarized (3)He ventilation imaging to observe the dynamic distribution of gas in the lungs during breathing. Findings in five normal volunteers (age 19-53 years) and four patients with severe smoking-related emphysema (age 56-71 years) were compared. All studies were performed on a 1.5 T whole body scanner using a 30 cm Helmholtz surface coil and 0.5 l of 20-40% polarized (3)He mixed with 1-2 l nitrogen. Our echo planar imaging pulse sequence allowed acquisition of each image in 0.04 s, with a pixel size of 7 mm(2) (TR = 40.5 ms, TE = 12.1 ms, flip angle = 22 degrees, echo train length = 32, matrix = 32 x 64, field of view = 225 x 450 mm, slice thickness = 10 mm). Imaging was performed in the transaxial plane repeatedly at 3, 10 or 20 evenly spaced levels, immediately before and during breathing of the gas mixture. In normal subjects during the first breath, (3)He appeared throughout each slice first in the mid lungs, then in the lower lungs, then in the upper lungs, with slightly greater signal in the dependent posterior regions. In patients with emphysema, sequential filling of different lung regions was seen during the first breath, with delayed filling of other regions observed during rebreathing and room air washout. We conclude that subsecond dynamic (3)He MR ventilation imaging can reveal normal and abnormal ventilation phenomena not seen with conventional scintigraphic methods, and offers another approach to the study of ventilation physiology and pathophysiology.
Adult↗
MR imaging of diffusion of (3)He gas in healthy and diseased lungs.
Hyperpolarized (3)He gas MRI was used to form maps of the effective diffusivity of gas in human lungs. Images of diffusion as well as spin density are presented from a study of 11 healthy volunteers and 5 patients with severe emphysema. The effective rate of diffusion, D(e), of the gas is reduced by the alveolar walls; tissue destruction in emphysema is hypothesized to result in larger D(e). Indeed, the mean value of D(e) in the emphysematous lungs is found here to be about 2.5 times that of healthy lungs, although still smaller than the unrestricted diffusivity of (3)He in free air. Histograms of D(e) values across coronal slices are presented. The results are discussed in terms of spatial variations, variations among individuals, healthy and diseased, and variations due to changes in lung volume. Magn Reson Med 44:174-179, 2000.
Adult↗
Patient selection for lung volume reduction surgery: An objective model based on prior clinical decisions and quantitative CT analysis.
OBJECTIVES: We used whole-lung quantitative CT analysis (QCT)-an objective method of evaluating emphysema severity and distribution based on measurement of lung density-to determine whether subjective selection criteria for lung volume reduction surgery are applied consistently and to model the patient selection process, and assessed the relationship of the model to postoperative outcome. DESIGN: Logistic regression analysis using QCT indexes of emphysema and preoperative physiologic test results as the independent variables, and the decision to operate as the dependent variable. SETTING: University hospital. PATIENTS: Seventy patients selected for bilateral lung volume reduction surgery and 32 otherwise operable patients excluded from surgery based on subjective assessment of emphysema morphology on chest radiography, CT, and perfusion scintigraphy. INTERVENTION: Bilateral lung volume reduction surgery in the selected group. MEASUREMENTS AND RESULTS: Emphysema in patients selected for surgery was more severe overall and in the upper lungs by multiple QCT indexes (p < 0.01, unpaired two-tailed t test). Physiologic abnormalities were slightly more severe in selected patients (p < 0.05, unpaired two-tailed t test). The range of many QCT and physiologic values overlapped considerably between the selected and excluded groups. The percent severe emphysema (<- 960 Hounsfield units [HU]), upper/lower lung emphysema ratio (- 900 HU threshold), and residual volume were the key variables in the model predicting selection decisions (model r(2) = 0.48; p < 0.0001). The model correctly predicted selection decisions in 87% of all cases, 91% of the selected group, and 78% of the excluded group. Surgical patients with a higher model-derived probability of selection had greater postoperative improvement in FEV(1) and 6-min walk distance. CONCLUSIONS: Radiologic selection criteria are applied consistently to the majority of patients. QCT features are strongly associated with selection decisions, are related to outcome, and may help improve consistency and confidence in patient selection.
Adult↗
Lung-reduction surgery: 5 years on.
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Clinical Trials as Topic↗
Outcome of Medicare patients with emphysema selected for, but denied, a lung volume reduction operation.
BACKGROUND: Lung volume reduction operation shows promise in relieving symptoms and improving function in highly selected patients with emphysema. Withdrawal of Medicare funding for patients selected for operation by standard criteria created a matched control group with which to compare lung volume reduction recipients. METHODS: A retrospective study was done comparing 22 volume reduction candidates denied operation with 65 contemporaneous and comparable volume reduction recipients. Baseline physiologic characteristics were compared and longitudinal measures of pulmonary function were followed up for 24 months. RESULTS: Patients denied operation were similar to volume reduction recipients in all baseline measurements. Patients denied operation experienced a progressive worsening of their function, whereas volume reduction patients experienced sustained improvements. Absolute survival to date is 82% for the surgical group and 64% for the medical group. CONCLUSIONS: The improvement seen in volume reduction patients cannot be attributed to the effects of patient selection or preoperative and postoperative rehabilitation.
Aged↗
Evaluation and preoperative management of lung volume reduction surgery candidates.
The efficacy of lung volume reduction surgery has been demonstrated by improvements in functional status, dyspnea, pulmonary function, alveolar gas exchange, and exercise tolerance. However, surgery has a significant morbidity, mortality, and cost. Surgical outcome is dependent on the clinical, anatomical, and physiological features of the patients and their emphysema. Therefore, the patient evaluation process and the preoperative optimization of medical therapy are crucial for success. Through understanding mechanisms for improvement have added insight to the selection process, patient selection needs further clarification.
Algorithms↗
Recent advances in surgery for emphysema.
Volume reduction surgery is based on the removal of volume-occupying but nonfunctioning emphysematous lung, which is thought to improve pulmonary elastic recoil. The reduction in thoracic volume may also improve thoracic cage and inspiratory muscle function. In addition, dyspnea is lessened, exercise tolerance is increased, and measured pulmonary function is improved. Alveolar gas exchange may also be improved. Selection criteria include marked airway obstruction secondary to emphysema, marked hyperinflation of the chest wall, and regional heterogeneity in the distribution of the emphysema. The best results are obtained with a bilateral procedure utilizing stapling resection. The two surgical approaches are median sternotomy and video-assisted thoracic surgery.
Endoscopy↗
Pulmonary emphysema: comparison of preoperative quantitative CT and physiologic index values with clinical outcome after lung-volume reduction surgery.
PURPOSE: To compare quantitative computed tomographic (CT) and preoperative physiologic values in emphysema with outcome after lung-volume reduction surgery. MATERIALS AND METHODS: In 46 patients, emphysema was quantified by measuring lung attenuation on preoperative CT scans. Quantitative CT and preoperative physiologic values and postoperative outcomes (1-second forced expiratory volume, PaO2, and 6-minute walk distance) were compared. RESULTS: Moderately strong correlations were found between several quantitative CT and preoperative physiologic values (magnitude of r = .29-.58, P < .05) and several quantitative CT and outcome measures (magnitude of r = .31-.47, P < .05). With stratification, postoperative outcome was better with mean lung attenuation greater than -900 HU; 75% or greater of upper lung below -900 HU (emphysema index); greater than 25% of lung below -960 HU (severe emphysema index); ratio of upper- and lower-lung emphysema indexes 1.5 or greater; volume of normally attenuated lung (-850 to -701 HU) greater than 1 L; and full width at half maximum of attenuation-frequency distribution 80 HU or less. Differences in outcome measures between groups stratified with quantitative CT values were often two- to threefold; patients with greater numbers of favorable quantitative CT values had better outcome. Correlations between preoperative physiologic measures and outcome were few. CONCLUSION: In emphysema, quantitative CT values correlate with outcome. Quantitative assessment of emphysema in candidates for lung-volume reduction surgery is potentially useful.
Adult↗
Perfusion scintigraphy in the evaluation for lung volume reduction surgery: correlation with clinical outcome.
PURPOSE: To identify preoperative pulmonary perfusion scintigraphic findings that might be associated with clinical outcomes after lung volume reduction surgery. MATERIALS AND METHODS: Preoperative perfusion scintigrams in 103 patients (56 men, 47 women; age range, 41-76 years; mean age, 61 years +/- 9) were reviewed and graded for emphysematous heterogeneity (from isolated areas to diffuse distribution), extent of maximally perfused lung, and lobar predominance (upper-lobe vs lower-lobe asymmetry). These findings were correlated with clinical outcome on the basis of pulmonary function, arterial blood gas levels, and exercise test results before and 6 months after surgery. RESULTS: Among the 96 patients who survived surgery, there was an average improvement of 47% in the forced expiratory volume in 1 second (FEV1), of 20% in arterial oxygen tension, and of 20% in the 6-minute walking distance. Scintigraphic markers correlated best with FEV1 improvement. The strongest scintigraphic predictor of increase in FEV1 was upper-lobe predominance (r = .38, P < .001), which was followed by heterogeneity (r = .31, P = .002). The seven patients who died had a significantly lower percentage of maximally perfused lung than the survivors (25% vs 34%, P = .004). CONCLUSION: Perfusion scintigraphy can provide modest prognostic information in patients who undergo evaluation for lung volume reduction surgery.
Adult↗
Results of 150 consecutive bilateral lung volume reduction procedures in patients with severe emphysema.
Between January 1993 and February 1996, we performed 150 bilateral lung volume reduction procedures for patients with severe emphysema. Patients were selected on the basis of severe dyspnea, increased lung capacity, and a pattern of emphysema that included regions of severe destruction, hyperinflation, and poor perfusion. Twenty percent to 30% of the volume of each lung was excised with the use of a linear stapler and bovine pericardial strips attached to buttress the staple line. Patients were between 36 and 77 years old, with an average 1-second forced expiratory volume of 25% of predicted, total lung capacity of 142% of predicted, and residual volume of 283% of predicted. Ninety-three percent of patients required supplemental oxygen, continuously or with exertion. All patients but one were extubated at the end of the procedure. The 90-day mortality was 4%. Hospital stay progressively decreased with experience, and for the last 50 patients the median hospital stay was 7 days. Prolonged air leakage was the major complication. Results at 6 months show a 51% increase in the 1-second forced expiratory volume and a 28% reduction in the residual volume. The Pao2 increased by an average of 8 mm Hg, and 70% of the patients who had previously required continuous supplemental oxygen no longer had this requirement. The improvements in measured pulmonary function were paralleled by a significant reduction in dyspnea and an improvement in the quality of life. Reevaluation at 1 year and 2 years after operation showed the benefit to be well maintained. We conclude that lung volume reduction offers benefits not achievable by any means other than lung transplantation for highly selected patients with severe emphysema.
Adult↗
Is volume reduction surgery appropriate in the treatment of emphysema? Yes.
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Humans↗
Lung volume reduction surgery for emphysema.
There has been dramatic resurgence of interest in surgical treatment of emphysema, particularly "lung volume reduction" procedures. Recent studies have demonstrated improvements in pulmonary function, lung mechanics, exercise tolerance, and quality of life in selected patients following volume reduction procedures. However, considerable uncertainty remains regarding overall benefit, optimal patient selection, operative techniques, and duration of response. This summarizes current approaches to lung volume reduction surgery, available clinical outcome information, selection criteria, and physiologic mechanisms of response, and discusses the potential role for surgical volume reduction in treatment of emphysema. Recent data appear to support the efficacy of bilateral staple lung volume reduction surgery in patients with severe symptomatic heterogeneously distributed emphysema. Further studies will be needed to determine relative value of different operative techniques and benefit in patients with other clinical presentations.
Algorithms↗
Evaluation of patients with emphysema for lung volume reduction surgery. Washington University Emphysema Surgery Group.
Lung volume reduction surgery (LVRS) is performed to alleviate the dyspnea of patients with emphysema and improve performance in the activities of daily living. Removing diseased and functionless lung may improve the function of remaining, less diseased lung by (1) increasing elastic recoil pressure, thereby increasing expiratory airflow rates, (2) decreasing the degree of hyperinflation resulting in improved diaphragm and chest wall mechanics, and (3) decreasing inhomogeneity resulting in decreased work of breathing and improved alveolar gas exchange. The guidelines used for patient assessment were (1) airflow limitation with a forced expiratory volume in 1 second (FEV1) less than 35%, (2) hyperinflation and air trapping with total lung capacity more than 125% and respiratory volume more than 250% predicted, and (3) regional heterogeneity of the emphysematous process providing target areas for resection. We sought to exclude patients with the following: (1) obliteration of the pleural space by previous disease or surgery, (2) severe structural abnormalities of the thoracic cage, (3) PaCo2 greater than 55 mm Hg. (4) mean pulmonary artery pressure greater than 35 mm Hg. (5) predominant airway disease such as asthma, bronchiectasis, or chronic bronchitis with persistent excessive purulent secretions, (6) significant coexisting disease, and (7) maintenance corticosteroid therapy in excess of 10 mg prednisone per day. The assessment process continues to be evaluated by analysis of patient outcome.
Activities of Daily Living↗
Assisted death and physician-assisted suicide.
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Ethics, Medical↗
Alternate modes of mechanical ventilation.
As a result of technological progress and a better understanding of respiratory disease processes, new modes of mechanical ventilation for the critically ill patient have been developed. These new methods may offer specific advantages over traditional techniques by avoiding or reducing complications commonly associated with positive pressure ventilation. A thorough understanding of anticipated benefits and potential problems is carefully considered for each mode of mechanical ventilation. Several alternate approaches to ventilatory assistance are discussed. Clinical applications of nursing care are also discussed.
Adult↗