Changes in pulmonary function after bullectomy

Bronchoscopic device intervention in chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease is a heterogeneous syndrome associated with varying degrees of parenchymal emphysema and airway inflammation resulting in decreased expiratory flow, lung hyperinflation, and symptoms leading to decreased exercise tolerance and quality of life. Impairment in lung function and quality of life persists following guideline-based medical therapy, thus surgical and minimally invasive bronchoscopic approaches were developed to address this unmet need. We offer a narrative review of the available technologies.

RECENT FINDINGS

Although lung volume reduction surgery has been shown to improve survival in appropriately selected patients, it is infrequently performed. Less invasive bronchoscopic procedures have thus been explored including endobronchial valves, coils, lung sealant, thermal vapor, and other airway approaches. Selection criteria including severity of physiologic and radiographic impairment, degree of lung hyperinflation, presence of intact fissures, type of symptoms, and presence of comorbidities are critical in selecting appropriate candidates.

SUMMARY

Recent advances in minimally invasive approaches to lung volume reduction have offered alternatives to surgical approaches. Two endobronchial valve devices are Food and Drug Administration approved for clinical use, and investigations into alternative bronchoscopic therapies to treat both emphysema and chronic bronchitis have been performed or are currently underway. Notably, each of these treatments requires unique selection criteria and thus a personalized approach to treatment.

Elective surgery for giant bullous emphysema: a 5-year clinical and functional follow-up

BACKGROUND

So far, very few studies in the literature have reported data on the long-term follow-up of patients who have undergone surgery for giant bullous emphysema (GBE), and much still needs to be known on the late fate of these patients.

AIMS

To evaluate patients who have undergone elective surgery due to GBE, early and late mortality following surgery, the early and late reappearance of bullae, and the early and late modifications of clinical and functional data.

SUBJECTS AND METHODS

Forty-one consecutive patients (36 men; mean [+/- SD] age, 48.4 +/- 14.8 years) who underwent elective surgery for GBE were enrolled in a prospective study, and were studied both before and after undergoing bullectomy for a 5-year-follow-up period. Analyses were performed on the whole population and on two subgroups of patients who were divided on the basis of the absence of underlying diffuse emphysema (group A; n = 23) or the presence of underlying diffuse emphysema (group B; n = 18).

RESULTS

The early mortality rate was 7.3% (within the first year), and the late mortality rate was 4.9% (overall mortality rate at 5 years, 12.2%; mortality rate in group B, 27.8%). Bullae did not reappear and residual bullae did not become enlarged in any patients at the site of the bullectomy. During the follow-up, the dyspnea score was reduced significantly soon after bullectomy and up to the fourth year of follow-up; intrathoracic gas volume also was reduced significantly (average, 0.7 L). The same was true for the FEV1 percent predicted and the FEV1/vital capacity ratio, which kept increasing until the second year; then, from the third year of follow-up these values were reduced, yet remained above the prebullectomy values until the fifth year of follow-up. When considered separately, the patients in group B appeared to be the most impaired, clinically and functionally (eg, FEV1 showed a similar significant increase up to the second year in both groups after surgery, while a different mean annual decrease was appreciable from the second to the fifth year of follow-up: group A, 25 mL/year; group B, 83 mL/year. Furthermore, patients in group B were the only ones who contributed to the mortality rate, on the whole showing a behavior similar to that of patients who had undergone lung volume reduction surgery.

CONCLUSIONS

In patients with GBE who were enrolled in the study prospectively and were investigated yearly during a 5-year-follow-up period, elective surgery appears to have been fairly safe, and allowed clinical and functional improvement for at least 5 years. Better results may be expected in patients without underlying diffuse emphysema.

Lung volume reduction surgery for emphysema: correlation of CT and V/Q imaging with physiologic mechanisms of improvement in lung function

PURPOSE

To compare the relationship between computer-derived and visually assessed ventilation-perfusion (V/Q) scintigraphy and computed tomographic (CT) scores in evaluating disease severity and distribution in identifying optimal candidates for lung volume reduction surgery (LVRS) and to correlate these radiologic indices with physiologic measures of outcome.

MATERIALS AND METHODS

In 39 patients, preoperative V/Q and CT scans were visually scored by two radiologists for disease severity and distribution. Results were compared with computer-derived scores for the same cohort. These indices were correlated with clinical improvement measured with forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), and ratio of FEV(1) to FVC.

RESULTS

The disease distribution scores measured with the different methods correlated closely: computer-based and visually assessed CT scores (r = 0.89, P <.001), computer-based and visually assessed V/Q scores (r = 0.83, P <.001), visually assessed CT and V/Q scores (r = -0.50, P <.001), and computer-derived CT and V/Q scores (r = -0.57, P =.015). Similarly, a statistically significant correlation was noted between each of the radiologic methods and clinical outcome measurements (P <.001).

CONCLUSION

CT and V/Q preoperative assessment, with either visual scoring or computer-based algorithms, are nearly equivalent in their utility in predicting improvement in FEV(1) measures.

Lung function 4 years after lung volume reduction surgery for emphysema

STUDY OBJECTIVES

Current data for patients > 2 years after lung volume reduction surgery (LVRS) for emphysema is limited. This prospective study evaluates pre-LVRS baseline data and provides long-term results in 26 patients.

INTERVENTION

Bilateral targeted upper lobe stapled LVRS using video thoracoscopy was performed in 26 symptomatic patients (18 men) aged 67 +/- 6 years (mean +/- SD) with severe and heterogenous distribution of emphysema on lung CT. Lung function studies were measured before and up to 4 years after LVRS unless death intervened.

RESULTS

No patients were lost to follow-up. Baseline FEV(1) was 0.7 +/- 0.2 L, 29 +/- 10% predicted; FVC, 2.1 +/- 0.6 L, 58 +/- 14% predicted (mean +/- SD); maximum oxygen consumption, 5.7 +/- 3.8 mL/min/kg (normal, > 18 mL/min/kg); dyspneic class > or = 3 (able to walk < or = 100 yards) and oxygen dependence part- or full-time in 18 patients. Following LVRS, mortality due to respiratory failure at 1, 2, 3, and 4 years was 4%, 19%, 31%, and 46%, respectively. At 1, 2, 3, and 4 years after LVRS, an increase above baseline for FEV(1) > 200 mL and/or FVC > 400 mL was noted in 73%, 46%, 35%, and 27% of patients, respectively; a decrease in dyspnea grade > or = 1 in 88%, 69%, 46%, and 27% of patients, respectively; and elimination of oxygen dependence in 78%, 50%, 33%, and 22% of patients, respectively. The mechanism for expiratory airflow improvement was accounted for by the increase in both lung elastic recoil and small airway intraluminal caliber and reduction in hyperinflation. Only FVC and vital capacity (VC) of all preoperative lung function studies could identify the 9 patients with significant physiologic improvement at > 3 years after LVRS, respectively, from 10 patients who responded < or = 2 years and died within 4 years (p < 0.01).

CONCLUSIONS

Bilateral LVRS provides clinical and physiologic improvement for > 3 years in 9 of 26 patients with emphysema primarily due to both increased lung elastic recoil and small airway caliber and decreased hyperinflation. The 9 patients had VC and FVC greater at baseline (p < 0.01) when compared to 10 short-term responders who died < 4 years after LVRS.

Serial lung function and elastic recoil 2 years after lung volume reduction surgery for emphysema

STUDY OBJECTIVE

To evaluate serial lung function studies, including elastic recoil, in patients with severe emphysema who undergo lung volume reduction surgery (LVRS). To determine mechanism(s) responsible for changes in airflow limitation.

METHODS

We studied 12 (10 male) patients aged 68+/-9 years (mean+/-SD) 6 to 12 months prior to and at 6-month intervals for 2 years after thoracoscopic bilateral LVRS for emphysema.

RESULTS

At 2 years post-LVRS, relief of dyspnea remained improved in 10 of 12 patients, and partial or full-time oxygen dependency was eliminated in 2 of 7 patients. There was significant reduction in total lung capacity (TLC) compared with pre-LVRS baseline, 7.8+/-0.6 L (mean+/-SEM) (133+/-5% predicted) vs 8.6+/-0.6 L (144+/-5% predicted) (p=0.003); functional residual capacity, 5.6+/-0.5 L (157+/-9% predicted) vs 6.7+/-0.5 L (185+/-10% predicted) (p=0.001); and residual volume, 4.9+/-0.5 L (210+/-16% predicted) vs 6.0+/-0.5 L (260+/-13% predicted) (p=0.000). Increases were noted in FEV1, 0.88+/-0.08 L (37+/-6% predicted) vs 0.72+/-0.05 L (29+/-3% predicted) (p=0.02); diffusing capacity, 8.5+/-1.0 mL/min/mm Hg (43+/-3% predicted) vs 4.2+/-0.7 mL/min/mm Hg (18+/-3% predicted) (p=0.001); static lung elastic recoil pressure at TLC (Pstat), 13.7+/-0.5 cm H2O vs 11.3+/-0.6 cm H2O (p=0.008); and maximum oxygen consumption, 8.7+/-0.8 mL/min/kg vs 6.9+/-1.5 mL/min/kg (p=0.03). Increase in FEV1 correlated with the increase in TLC Pstat/TLC (r=0.75, p=0.03), but not with any baseline parameter.

CONCLUSION

Two years post-LVRS, there is variable clinical and physiologic improvement that does not correlate with any baseline parameter. Increased lung elastic recoil appears to be the primary mechanism for improved airflow limitation.

New principles for the treatment of diffuse pulmonary emphysema

Emphysema is due to destruction of lung tissue but the main cause of the dyspnoea is a diminished elasticity of the lungs. Medical therapy, such as bronchodilation, corticosteroids, and treatment of intercurrent infections, can give temporary relief. Long-term oxygen treatment can improve and prolong life in patients with severe epmphysema. Lung transplantation is a final option in selected patients. Rehabilitation including exercise training will cause increase in maximal exercise tolerance and decrease of dyspnoea, and thereby an improvement of quality of life. In recent years surgical reduction of the lung volume has been reintroduced and in selected cases given dramatic results. The goal is to reduce the volume in both lungs with about 30%. Depending on the distribution of the emphysema, pieces of the upper or lower lobes will be removed. Sternotomy or bilateral thoracoscopy, using staplers, are the most common methods. Short-term results are good, with an improvement of FEV1 of 22-96%, improved arterial oxygen pressure, and a radical improvement of life quality. The impact on the daily life of the patient can be dramatic. The long-term results are still not well known, and many questions remain before volume reduction surgery can be regarded as an established form of treatment for emphysema, and randomized studies are badly needed.

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.

Early and long-term functional outcomes following lung volume reduction surgery

In the past 3 years, lung volume reduction surgery has become the most controversial topic in the clinical management of patients with emphysema. Although literature has added to the understanding of the procedure, many important issues remain unclear. This article emphasizes functional and basic physiologic changes that occur following lung volume reduction surgery in patients with emphysema.

Functional improvement after volume reduction: sternotomy versus videoendoscopic approach

BACKGROUND

Volume reduction has been proved to increase ventilatory mechanics in diffuse, nonbullous lung emphysema. However, the best approach is still controversial.

METHODS

We retrospectively compared the perioperative data of and functional results in 15 patients having sternotomy (group I) with those of 15 patients having a videoendoscopic approach (group II).

RESULTS

The 30-day mortality was 2 patients in group I and 1 patient in group II. Mean duration of chest tube drainage was 8.7 +/- 1.8 days and 8.0 +/- 1.9 days and mean hospital stay, 12.3 +/- 1.9 and 12.5 +/- 2.1 days in groups I and II, respectively. Work of breathing decreased from 1.89 +/- 0.33 J/L and 1.76 +/- 0.22 J/L preoperatively to 0.75 +/- 0.06 J/L and 0.8 +/- 0.06 J/L (p < 0.01 and p < 0.05, respectively) after 3 months; and intrinsic positive end-expiratory pressure decreased from 7.15 +/- 1.31 cm H2O and 6.24 +/- 1.33 cm H2O to preoperatively 0.79 +/- 0.46 cm H2O and 1.13 +/- 0.44 cm H2O (p < 0.005 and p < 0.01, respectively) after 3 months in groups I and II, respectively. Forced expiratory volume in 1 second increased from preoperative values of 21.6% +/- 2.9% and 25.3% +/- 2.4% of predicted to 34.5% +/- 5.0% and 40.9% +/- 7.5% of predicted after 3 months (p < 0.05 in both groups) in groups I and II, respectively.

CONCLUSIONS

Both surgical approaches resulted in similar substantial improvement in lung function and physical fitness. The incidence of air leakage, the duration of chest tube drainage, and the hospital stay were the same for both procedures.

Lung function 12 months following emphysema resection

OBJECTIVE

To investigate the mechanism of airflow limitation before and 6 and 12 months after targeted emphysematous resection in 10 male patients aged 67 +/- 8 years (mean +/- SD) with very severe COPD undergoing bilateral thoracoscopic stapling techniques.

DESIGN

Lung function, including static lung elastic recoil, was measured 2 weeks before and 6 and 12 months after surgery.

RESULTS

Twelve months after surgery, there was a significant (p < 0.001) reduction in total lung capacity (TLC), 9.5 +/- 0.3 L (mean +/- SEM) to 8.5 +/- 0.3 L, functional residual capacity, and residual volume. Airway conductance and FEV1, 0.71 +/- 0.1 L (mean +/- SEM) to 0.95 +/- 0.1 L, improved significantly (p < 0.01). Lung elastic recoil increased markedly at TLC from 11.7 +/- 0.7 cm H2O (mean +/- SEM) to 15.0 +/- 1.0 cm H2O (p < 0.01) as did maximum expiratory airflow in every patient. However, when compared with data obtained in each patient at 6 months, lung volumes are significantly increased, and expiratory airflow and lung elastic recoil pressures are significantly reduced (p < or = 0.05). Analysis of maximum expiratory flow-static elastic recoil pressure curve indicates conductance of the S airway segment (Gs) increased from 0.20 +/- 0.03 L/s/cm H2O (mean +/- SEM) to 0.28 +/- 0.04 L/s/cm H2O (p < 0.02), and critical transmural pressure in the collapsible segment (Ptm') decreased from 3.2 +/- 0.2 cm H2O (mean +/- SEM) to 2.5 +/- 0.2 cm H2O (p < 0.01).

CONCLUSION

The improvement in maximal expiratory airflow can be attributed primarily to increased lung elastic recoil and its secondary effect on enlarging airway diameter causing increased airway conductance, increased Gs, and decreased Ptm'. The improvement in lung function and elastic recoil peaks at 6 months.

Lung volume reduction surgery in ventilator-dependent COPD patients

BACKGROUND

Lung volume reduction surgery has been advocated recently as adjunctive surgical therapy to improve lung and chest wall mechanics in selected patients with diffuse emphysema. Although clear-cut guidelines to select candidates have not been fully established, patients decompensated with significant pulmonary artery hypertension and hypercapnic respiratory failure are currently not considered suitable subjects. Accordingly, ventilator-dependent COPD patients are not considered candidates for this procedure. However, because ventilator-dependent COPD patients have an exceptionally poor prognosis, we elected to offer them this promising, but unproved surgical intervention. Herein, we describe the outcome of these three patients.

PATIENTS

The 3 patients had recurrent exacerbations of COPD precipitating respiratory failure, and following aggressive medical therapy remained mechanically ventilated for 11 to 16 weeks (1 patient had a brief period of successful weaning before returning to mechanical ventilation). Prior to surgery, the patients had severe hypercapnia and cor pulmonale. Compared with preoperative values, surgery resulted in improvements in PaO2/FIO2, 304 +/- 80 (SD) vs 229 +/- 48 mm Hg, reductions in PaCO2, 44 +/- 3 vs 60 +/- 9 mm Hg, increases in FVC, 1.63 + 0.52 vs 1.09 +/- 0.05 L, and maximum inspiratory pressure, 57 +/- 22 vs 29 +/- 12 cm H2O. Postoperative complications included persistent air leaks and one tension pneumothorax. Patients weaned from mechanical ventilation after 10 to 21 days all were discharged home and they continue to demonstrate improved gas exchange and functional status.

CONCLUSIONS

Lung volume reduction surgery in select, ventilator-dependent COPD patients can result in improved gas exchange and respiratory mechanics that enable successful weaning and overall improved functional status.

Bilateral volume reduction surgery for diffuse pulmonary emphysema by video-assisted thoracoscopy

We prospectively studied the surgical aspects, functional results, and complications of video-assisted bilateral thoracoscopic volume reduction surgery in patients with severe diffuse pulmonary emphysema.

METHODS

Fifteen men and five women with a mean age of 64 years (range 42 to 78 years) whose daily activity was substantially impaired by severe airflow obstruction and hyperinflation underwent thoracoscopic volume reduction surgery. The prospective preoperative assessment and postoperative assessment at 3 months included (1) pulmonary function studies, (2) grading of dyspnea, and (3) exercise performance; pulmonary function tests were also performed immediately before discharge from the hospital.

RESULTS

There was no perioperative mortality. All patients left the hospital after a median stay of 15 days (6 to 27 days). Only seven patients had a prolonged chest tube drainage time (>7 days). At 3 months the mean (+/- standard deviation) forced expiratory volume in 1 second had improved by 42% (+/-3.8%), from 0.80 L (+/-0.23) to 1.09 L (+/-0.28) (p < 0.001); residual volume had decreased from 5.8 L (+/-1.5) to 4.4 L (+/-1.0) (p < 0.001). Shortly before discharge the forced expiratory volume in 1 second was already 1.10 L (+/-0.26). The median 12-minute walking distance increased from 495 m (35 to 790 m) to 688 m (175 to 1035 m) (p < 0.001) and the mean maximal oxygen consumption from 10 ml/kg per minute (+/-2.5) to 13 ml/kg per minute (+/-2.3) (p < 0.0005). The patients reported a substantial relief of dyspnea with a mean decrease in the Medical Research Council score from 3.4 to 1.8.

Contribution of lung and chest wall mechanics following emphysema resection

OBJECTIVE

To determine the contributions of (1) chest wall (Pcw) and (2) lung elastic recoil pressure (PL) to (3) total elastic recoil pressure exerted by the respiratory system (Prs) in 18 patients (12 men) aged 66 +/- 6 years (mean +/- 1 SD) with severe emphysema who underwent video-assisted thoracoscopic bilateral lung volume reduction surgery under paralyzed (vecuronium) general anesthesia (isoflurane).

DESIGN

We measured preoperative and 6-week postoperative lung function studies, and intraoperative inspiratory lung conductance (GL), PL, Pcw, and Prs (cm H2O) at end-expiratory lung volume (EELV), EELV plus 0.60 +/- 0.0 L, and EELV plus 1.15 +/- 0.0 L. All values are mean +/- SEM.

RESULTS

Preoperative vs postoperative FVC was 1.9 +/- 0.1 L vs 2.3 +/- 0.1 L (p = 0.03); FEV1 was 0.6 +/- 0.1 L vs 0.9 +/- 0.1 L (p < 0.02); total lung capacity was 7.4 +/- 0.4 L vs 5.9 +/- 0.3 L (p < 0.001); functional residual capacity was 5.7 +/- 0.4 L vs 4.4 +/- 0.2 L (p = 0.001). At EELV preoperative vs postoperative, PL was 0.0 +/- 0.3 vs 1.1 +/- 0.05 (p = 0.04), Pcw was 5.0 +/- 0.7 vs 2.4 +/- 0.9 (p = 0.02), and Prs was 5.0 +/- 0.8 vs 3.5 +/- 0.7 (p = 0.08). AT EELV plus 0.60 L, PL was 3.2 +/- 0.6 vs 6.1 +/- 0.9 (p < 0.001), Pcw was 8.8 +/- 0.8 vs 7.0 +/- 0.9 (p = 0.12), and Prs was 12.0 +/- 0.8 vs 13.1 +/- 0.7 (p = 0.80). At EELV plus 1.15 L, PL was 6.8 +/- 0.9 vs 10.3 +/- 1.1 (p < 0.001), Pcw was 13.5 +/- 1.0 vs 11.2 +/- 1.2 (p = 0.12), and Prs was 20 +/- 1.2 vs 21.5 +/- 1.0 p = 0.93). AT EELV plus 0.06 L, GL was 0.09 +/- 0.00 L/S/cm H2O vs 0.16 +/- 0.01 (p < 0.01). At EELV plus 1.15 L, GL was 0.12 +/- 0.01 vs 0.21 +/- 0.03 (p < 0.05) with similar preoperative vs postoperative GL/PL slopes.

CONCLUSION

The increase in PL and decrease in Pcw following LVRS for emphysema may be responsible for the increase in spirometry and airway conductance.

Lung reduction surgery in chronic obstructive lung disease

In the 1960s the promise of the Brantigan lung reduction surgery was shattered when it was shown that the improvement in airway conductance drifted back towards the preoperative value over a period of 12 to 18 months. Since then there has been a marked improvement in our understanding of emphysema, its pathology, and techniques for obtaining images of the lung. In addition, reliable automated cardiopulmonary and physiologic testing, advances in critical care medicine, and new pharmacologic agents have improved patient care. Surgical techniques now allow better control of air leaks and access to anatomic regions not previously accessible. The combination of all of the above makes lung reduction surgery worth re-examining as a palliative procedure for severely symptomatic patients. Clearly, it is not a panacea but can in some cases produce dramatic improvements in symptomatology and quality of life. This article presents the available data describing potential mechanisms of improvement and clinical outcomes following lung reduction surgery. It also outlines areas that need further work, such as patient selection and surgical techniques.

Improvement in pulmonary function and elastic recoil after lung-reduction surgery for diffuse emphysema

BACKGROUND

Pulmonary function may improve after surgical resection of the most severely affected lung tissue (lung-reduction surgery) in patients with diffuse emphysema. The basic mechanisms responsible for the improvement, however, are not known.

METHODS

We studied 20 patients with diffuse emphysema before and at least three months after either a unilateral or a bilateral lung-reduction procedure. Clinical benefit was assessed by measurement of the six-minute walking distance and the transitional-dyspnea index, which is a subjective rating of the change from base line in functional impairment and the threshold for effort- and task- dependent dyspnea. Pressure-volume relations in the lungs were measured with static expiratory esophageal-balloon techniques, and right ventricular systolic function was assessed by echocardiography.

RESULTS

The patients had significant improvement in the transitional-dyspnea index after surgery (P<0.001). The mean (+/-SD) coefficient of retraction, an indicator of elastic recoil of the lung, improved (from 1.3+/-0.6 cm of water per liter before surgery to 1.8+/-0.8 after, P<0.001). Sixteen patients with increased elastic recoil had a greater increase in the distance walked in six minutes than the other four patients, in whom recoil did not increase (P=0.02). The improved lung recoil led to disproportionate decreases in residual volume as compared with total lung capacity (16 percent vs. 6 percent), but the decreases in both values were significant (P<0.001). Forced expiratory volume in one second increased (from 0.87+/-0.36 to 1.11+/-0.45 liters, P<0.001). End-expiratory esophageal pressure also decreased (P=0.002). These improvements in lung mechanics led to a decrease in arterial partial pressure of carbon dioxide form 42+/-6 to 38+/-5 mm Hg (P=0.006). Furthermore, the fractional change in right ventricular area, an indicator of systolic function, increased from 0.33+/-0.11 to 0.38+/-0.010 (P=0.02).

CONCLUSIONS

Lung-reduction surgery can produce increases in the elastic recoil of the lung in patients with diffuse emphysema, leading to short-term improvement in dyspnea and exercise tolerance.

Reduction pneumoplasty for giant bullous emphysema. Implications for surgical treatment of nonbullous emphysema

A review of the literature on reduction pneumoplasty for giant bullous emphysema was undertaken to identify current criteria for this surgical treatment and in the hope of obtaining insights into evaluating reduction pneumoplasty for nonbullous emphysema. Twenty-two retrospective case series, published since 1950, were retrieved by a computer search of the literature and a search of the Index Medicus prior to 1966. Reduction pneumoplasty is most effective when bullae are larger than one third of a hemithorax with evidence of compression of adjacent lung tissue and an FEV1 of less than 50% predicted; the presence of emphysema in nonbullous lung and the amount of compression are best judged by CT. The rationale for reduction pneumoplasty for nonbullous emphysema is supported by the similar early functional changes after reduction pneumoplasty for bullous and nonbullous-improvement of blood gas values and lung mechanics. A single study showing that decline of lung function after surgery for bullous emphysema was less in those who stopped smoking than in those who continued to smoke supports the need for preoperative and maintained smoking cessation in patients receiving reduction pneumoplasty. After 4 decades, the duration of improvement in lung function, whether worsening of emphysema occurs in remaining lung, and late morbidity and mortality after reduction pneumoplasty for bullous emphysema are not well defined. A registry with an unoperated-on comparison group could more rapidly accumulate such data after reduction pneumoplasty for nonbullous emphysema.

Bilateral pneumectomy (volume reduction) for chronic obstructive pulmonary disease

We undertook surgical bilateral lung volume reduction in 20 patients with severe chronic obstructive pulmonary disease to relieve thoracic distention and improve respiratory mechanics. The operation, done through median sternotomy, involves excision of 20% to 30% of the volume of each lung. The most affected portions are excised with the use of a linear stapling device fitted with strips of bovine pericardium attached to both the anvil and the cartridge to buttress the staple lines and eliminate air leakage through the staple holes. Preoperative and postoperative assessment of results has included grading of dyspnea and quality of life, exercise performance, and objective measurements of lung function by spirometry and plethysmography. There has been no early or late mortality and no requirement for immediate postoperative ventilatory assistance. Follow-up ranges from 1 to 15 months (mean 6.4 months). The mean forced expiratory volume in 1 second has improved by 82% and the reduction in total lung capacity, residual volume, and trapped gas has been highly significant. These changes have been associated with marked relief of dyspnea and improvement in exercise tolerance and quality of life. Although the follow-up period is short, these preliminary results suggest that bilateral surgical volume reduction may be of significant value for selected patients with severe chronic obstructive pulmonary disease.

Quantitative assessment of dyspnea during exercise before and after bullectomy for giant bulla

Incremental exercise testing using a cycle ergometer was performed in eight patients with giant bulla before and after bullectomy to assess dyspnea. There was a significant positive linear relationship between dyspnea expressed in the Borg scale (BS) and oxygen consumption (VO2) during exercise in all subjects. From these correlations, we introduced the following three new parameters for quantitative assessment of dyspnea: the Borg scale slope (BSS); the threshold load of dyspnea (TLD); and the breakpoint load of dyspnea (BLD), representing the slope of the regression line, onset of dyspnea on the regression line, and the maximum oxygen consumption before the subjects interrupted exercise, respectively. After surgery, the BSS showed marked decrease, and the TLD and BLD showed significant increase. Therefore, the reduction in the dyspnea with peak exercise after surgery was thought to be, at least in part, based on the delay of dyspnea onset, the decrease in dyspnea sensitivity, and the improvement in exercise capacity. The improvement in dyspnea during exercise in patients with giant bulla after surgery was extensively evaluated by newly introduced parameters based on BS-VO2 regression line.

Prediction of postoperative performance status in patients with giant bulla

To predict the postoperative improvement in performance status after bullectomy, preoperative pulmonary function and dyspneic grade were evaluated in 20 patients with giant bulla. The patients were divided into two groups, based on postoperative performance status: group 1 consisted of 15 patients with improved status after surgery; and group 2 of five patients with worsened status after temporary improvement. To determine correlation with the groups, preoperative functional measurements such as %VC, FEV1%, MMF, PEFR, RV/TLC, delta N2, LCI, and PNCD were then analyzed by the multivariate statistic method; results of delta N2 and FEV1% showed significant correlation with the groups. Prediction of the groups based on the two measurements agreed with the actual results except in one patient. These results show that postoperative improvement in performance status of patients with giant bulla can be predicted on the basis of preoperative pulmonary function.

Functional results of surgery for bullous emphysema

Forty-six patients with bullous emphysema were operated on. Respiratory function was investigated before and immediately after surgery, and during the follow-up to five years. The larger the volume of the bullae, the less disturbances of lung function caused by their removal immediately after operation. Respiratory function improved significantly during the long-term follow-up after removal of the bullae that were more than one third of the hemithorax, but it did not change when the bullae were less than one third of the hemithorax and deteriorated after pulmonary resection for the bullae associated with long-term pneumonia. No new bullae were revealed roentgenographically at five years postoperatively.

Bullous emphysema. Progressive incremental exercise testing to evaluate candidates for bullectomy

Various tests of both function and anatomy have been used in patients being considered for surgical resection of giant pulmonary bullae. A young patient had an excellent response to removal of a large bulla in the right lung. In addition to roentgenographic evaluation, ventilation perfusion scanning, and routine preoperative pulmonary function studies, we performed progressive incremental exercise testing to determine both preoperative and postoperative ventilatory and cardiac measurements. We feel that progressive incremental exercise pulmonary function adds another dimension to the selection and follow-up of patients being considered for operative bullectomy.