Undergoing Lung Volume Reduction Surgery Research Articles

Practicability and safety of dipyridamole cardiac imaging in patients with severe chronic obstructive pulmonary disease.

We tested the practicability of dipyridamole myocardial nitrogen-13 ammonia positron emission tomography (dipyridamole (13)NH(3 )PET) for the perioperative risk assessment of coronary artery disease (CAD) in a cohort of patients with severe chronic obstructive pulmonary disease (COPD) undergoing lung volume reduction surgery (LVRS). Twenty consecutive LVRS candidates, 13 men and 7 women (mean age 57+/-2 years), without symptoms of CAD were prospectively studied by dipyridamole (13)NH(3 )PET. Side-effects and overall tolerance were assessed by a questionnaire and visual analogue scale. Repeated pulmonary function tests were performed before and 4, 12, 16 and 30 minutes after dipyridamole injection. All dipyridamole (13)NH(3 )PET studies were negative for CAD. Seventeen patients underwent LVRS without cardiac complications; three patients did not undergo LVRS for other reasons. Nine patients suffered intolerable dyspnoea requiring i.v. aminophylline. Mean FEV(1) decreased significantly after dipyridamole infusion: in nine patients the reduction in FEV(1)exceeded 15% from baseline. We found that dipyridamole is not well tolerated and causes significant bronchoconstriction in patients with severe COPD. Although all dipyridamole-induced side effects can be promptly reversed by aminophylline, dipyridamole cannot be recommended as a pharmacological stress in this setting.

Advanced emphysema: preoperative chest radiographic findings as predictors of outcome following lung volume reduction surgery.

To determine whether preoperative chest radiographic findings alone can reliably predict which patients will achieve the best functional outcome of lung volume reduction surgery. The preoperative chest radiographs obtained in 57 patients who had undergone lung volume reduction surgery were retrospectively scored by five blinded readers for severity and distribution of emphysema, evidence of lung compression, disease heterogeneity, and other features. Comparisons were made with the 3-6-month postoperative functional outcome for each patient. High disease heterogeneity (score > 2) and unequivocal lung compression (score 1) both were 100% predictive of a favorable outcome (FEV1 increase, > or = 30%). Low heterogeneity (score < 1) was 94% predictive of an unfavorable outcome (FEV1 increase < 30%), as was a lack of lung compression, which was 92% predictive of an unfavorable outcome. These two features also correlated with an improved 6-minute walk test result, although this correlation was weaker. Chest radiography alone may be sufficient for initial screening. High disease heterogeneity and lung compression on chest radiographs are highly predictive of a favorable functional outcome.

Lung Volume Reduction Surgery

Approximately 20% of patients undergoing lung volume reduction surgery (LVRS) exhibit no functional improvement postoperatively.Therefore, we examined whether variables characterizing ventilatory mechanics before LVRS could serve as predictors for outcome. In 32 patients undergoing LVRS, lung functi

The Role of Persisting Infections in the Pathogenesis of Pulmonary Emphysema: Electron Microscopy Reveals a Probable Bacterial Colonization of the Alveolar Space and the Bronchioles

Lung volume reduction surgery (LVRS) yields resection specimens from patients with advanced pulmonary emphysema. Regarding the development of lung function parameters, recent results obtained by light microscopy revealed an unfavorable prognosis in patients with remarkable inflammation, particularly in the bronchioli. Tissue from ten patients (alpha1-antitrypsin level in the normal range) was furthermore investigated by electron microscopy. Scanning electron microscopy shows 0.4-0.6 micron spherical bodies variably densely arranged in the whole alveolar space and in the bronchioles of all patients. These bodies are mostly seen on the microvilli of type II pneumocytes. An immunological reaction with activation of macrophages and granulocytes occurs simultaneously. Macrophages show cytoplasmic extensions to the spherical bodies, which exhibit a cellular membrane but no cellular wall. This favors the diagnosis of bacterial colonization of the alveolar space and the bronchioles by mycoplasmas or L-forms of other bacteria. As patients undergoing lung volume reduction surgery are under optimal medical treatment and without any infection clinically, these findings appear to be relevant for the pathogenesis and/or progression of pulmonary emphysema.

Lung volume reduction for emphysema and the Canadian Lung Volume Reduction Surgery (CLVR) Project.

To review the literature on the surgical treatment of emphysema and to present preliminary results from a pilot study of lung volume reduction (LVR) surgery. Case series of consecutive patients referred for LVR surgery. Outcomes were quality of life, pulmonary function and exercise capacity. Two university-affiliated hospitals in Ontario. Patients between the ages of 40 and 75 years with emphysema who had severe airflow limitation, hyperinflation of the lungs and impaired quality of life. Bilateral reductions with multiple wedge resections of the lung using a linear stapling device with bovine pericardial buttressing were completed via a median sternotomy. Of 50 patients referred, 24 underwent LVR surgery. Mean age of the cohort was 63 years. Operative 30-day or in hospital mortality was 8%. Two other patients (8%) died from respiratory failure after LVR within the first year. Postoperative complications included prolonged air leaks (six of 24), tracheobronchitis (five of 24), mechanical ventilation (four of 24) and pneumonia (three of 24). Mean length of stay was 18 days (median 12 days). At one year, there was a sustained decrease in total lung capacity from 133% to 123% predicted. There were improvements in forced expiratory volume in 1 s, from 22% of predicted preoperatively to 32% postoperatively, and in 6 min walk performance, from 345 to 381 m. Improvements were also noted in the quality of life assessments. Preliminary results suggest that LVR surgery is feasible and may improve the patient's quality of life, pulmonary function and exercise capacity. A randomized clinical trial comparing LVR plus the best medical management with the best medical management alone is currently underway to determine the effectiveness of LVR.

Serial Lung Function and Elastic Recoil 2 Years After Lung Volume Reduction Surgery for Emphysema

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. 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. 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. 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.

Incidental lung carcinoma detected at CT in patients selected for lung volume reduction surgery to treat severe pulmonary emphysema.

The authors present their experience with previously unsuspected carcinoma of the lung detected at preoperative computed tomography (CT) in patients with severe pulmonary emphysema who were scheduled to undergo lung volume reduction surgery. Preoperative chest CT was performed in 148 patients (84 men, 64 women; mean age, 65 years +/- 8 [standard deviation]) with advanced pulmonary emphysema before lung volume reduction surgery. At surgery, an attempt was made to excise any pulmonary nodule considered suspicious for carcinoma at CT. Eighteen pulmonary nodules suspicious for lung cancer were found at CT in 17 (11%) of the 148 patients. Sixteen of these 148 nodules were resected at lung volume reduction surgery. Nine non-small cell carcinomas (adenocarcinoma, n = 4, including three with bronchioloalveolar differentiation; poorly differentiated, n = 3; squamous cell carcinoma, n = 2) were found in eight (5%) patients. Eight of the cancers were stage I, and one was unstaged surgically. Maximum diameters of the cancers ranged between 1.0 and 3.8 cm (median, 1.6 cm). The seven (5%) other resected nodules were all benign. A 5% rate of stage I primary lung cancer in patients selected for lung volume reduction surgery suggests that performance of chest CT in candidates for lung volume reduction surgery is appropriate not only to identify patterns of pulmonary parenchymal destruction but also to search for stage I lung cancer.

Coronary Artery Disease in Patients Undergoing Lung Volume Reduction Surgery for Emphysema

Most patients with severe pulmonary emphysema referred for lung volume reduction surgery (LVRS) have a long-standing history of cigarette smoking. Coronary artery disease (CAD) predisposes to perioperative cardiac complications. Since symptoms and signs of myocardial ischemia are often absent in patients with severe ventilatory impairment even during exercise, we investigated the prevalence of CAD in candidates for LVRS by angiography. We prospectively studied the prevalence of CAD by angiography and assessed the CAD risk factor profile in 41 candidates for LVRS (26 men, 15 women; mean age, 66+/-6.8 years; range, 52 to 76 years), who had no current symptoms or a history of myocardial ischemia. In six patients (15%), asymptomatic but significant coronary lesions (> 70% stenosis) were detected. In five patients, these findings altered the clinical management. Patients with CAD had significant higher cholesterol levels, tended to have smoked more, and had more often additional vascular risk factors. We found a high prevalence of angiographically significant but clinically silent CAD in this particular population of heavy smokers with advanced emphysema.

Histopathologic Diagnosis Made in Lung Tissue Resected From Patients With Severe Emphysema Undergoing Lung Volume Reduction Surgery

This study reports histopathologic findings in a group of emphysema patients who underwent thoracoscopic lung volume reduction surgery (75) or sternotomy (five) with the purpose to induce functional improvement and relief of dyspnea. Immediate outcome and complications were correlated to histologic patterns. Histopathologic material obtained in lung volume reduction surgery in 80 consecutive patients was analyzed. Thirty patients who had other histopathologic diagnoses in addition to emphysema were grouped and compared with 50 patients found to have emphysema exclusively. Postoperative outcome and preoperative lung function variables were compared. All patients had severe obstructive lung disease and significant air trapping preoperatively documented by pulmonary function testing. All had severe exertional dyspnea. All had chest radiographs, CT, and nuclear medicine lung scans consistent only with emphysema. All portions of resected lung tissue were weighed, lung volume was estimated, and routine histopathologic studies were made. Thirty patients (37.5%) had unsuspected findings such as interstitial fibrosis, noncaseating granulomatosis, chronic inflammation, and unsuspected neoplasia (three carcinomas, one carcinoid). Retrospective review of imaging studies in these patients failed to show infiltrative processes. The average lung weight resected in this group was significantly heavier (65+/-18 g) compared with the other group (56+/-13 g), although both had the same estimated lung volume. Average number of days requiring chest tubes and length of hospitalization was also significantly higher (12.8+/-19 vs 6.4+/-5 days with chest tubes and 17.4+/-22 vs 8.5+/-6 days of hospitalization, respectively). None of the preoperative pulmonary function tests variables were different between the two groups. Serious postoperative complications were more frequent in these patients compared with those who showed only emphysema. A significant portion of patients diagnosed as having severe emphysema will have other unsuspected histologic findings. When subjected to lung volume reduction surgery, this subgroup will have more serious complications and longer periods of air leaks, requiring longer hospitalization time. Retrospective review of imaging studies and preoperative pulmonary function tests used to select patients for lung volume reduction failed to identify this subgroup.

Economic Aspects of Lung Volume Reduction Surgery

To investigate the economics of lung volume reduction surgery. Medical center and physician charges obtained from billing records. Academic health center. Twenty-three consecutive patients undergoing lung volume reduction surgery at a single institution who were discharged from the hospital prior to November 1, 1995. Length of hospital stay, mortality, medical center charges and professional fees, and sponsor reimbursement. Median hospital stay was 8.0 days and there were no deaths. The median charge was $26,669 (range, $20,032 to $75,561) of which 73% was for medical center services and 27% was for physician services. Fees for medical center rooms and operating suite time accounted for 71% of medical center charges. Charges by surgeons and anesthesiologists accounted for 77% of professional fees. Total charges were directly related to length of stay (r2 = 0.95). Median reimbursement for medical center services was $22,264 (114%; range, $13,333 to $123,362) and for physician services was $2,783 (34%; range, $2,597 to $11,265), resulting in a median total reimbursement that represented 94% of total charges. The median reimbursement-to-cost ratio was 1.22, compared with 1.05 for all medical services in fiscal year 1995. These data must now be assessed relative to outcomes such as quality of life, patient function, and long-term survival to determine cost-effectiveness of lung volume reduction surgery.

Combined Operations for Lung Volume Reduction Surgery and Lung Cancer

Fifty-three lung masses were found in 51 (16%) of 325 patients who underwent lung volume reduction surgery. This included 11 non-small cell lung cancers and 42 benign lung masses. Eleven patients (mean age, 69.4 years) underwent a combined lung volume reduction surgery and resection of clinical stage I lung cancers (lymph node dissection with either lobectomy [3] or wedge resection [8]). There were no deaths or major complications. The average length of stay was 8.7 days. The mean FEV1 was 654 mL (21.7% predicted) preoperatively and 1,079 mL (49% predicted) postoperatively. Patients who are screened for lung volume reduction surgery should be carefully evaluated for possible lung masses. Lung volume reduction surgery allows lung cancer surgery in patients who otherwise would be considered to have physiologically inoperable disease.

Lung Volume Reduction Surgery

A clinical study was undertaken to define optimal preoperative strategies and intraoperative techniques that would result in the least morbidity and maximum physiologic improvements in patients with end-stage emphysema selected for lung volume reduction surgery. Lung volume reduction surgery recently has been advocated as an alternative or a bridge to lung transplantation for patients with end-stage chronic obstructive pulmonary disease. The risks, benefits, and long-term results have not been clarified. Twenty-six patients underwent lung volume reduction surgery with a 3-month follow-up on 17 patients. Preoperative and postoperative changes in pulmonary function parameters, quality of life, and oxygen requirement were analyzed. The value of preoperative localization of diseased lung segments and how this affects intraoperative resection is addressed. Forty-nine percent improvement in FEV1 (forced expiratory volume in 1 second) and 23% improvement in FVC (forced vital capacity) were seen after lung volume reduction surgery. Supplemental oxygen requirement was decreased and 79% of patients reported a much better quality of life. Mortality was 3.8% and air leak morbidity was 18%. Lung volume reduction surgery can predictably improve objective and subjective pulmonary function in selected patients with end-stage emphysema with low morbidity and mortality. Careful patient selection, accurate preoperative localization of diseased target areas, skilled anesthetic technique, meticulous operative approach, and intense postoperative support are essential to achieve favorable results.