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Biomedical subjects

Douglas E Wood

Publications and source records attributed to Douglas E Wood.

At least 19 recordsLinked to original sources
PubMed2006

A multicenter trial of an intrabronchial valve for treatment of severe emphysema.

OBJECTIVES: Minimally invasive endoscopic treatment of emphysema could provide palliation with less risk than lung volume reduction surgery and offer therapy to patients currently not considered for lung volume reduction surgery. The Intrabronchial Valve is used to block bronchial airflow in the most emphysematous areas of lung. METHODS: Patients with severe chronic obstructive pulmonary disease and heterogeneous upper lobe-predominant emphysema were eligible. Patients underwent flexible bronchoscopic placement of valves into segmental or subsegmental airways in both upper lobes. Outcomes assessed over a minimum of 6 months of follow-up included the safety, feasibility, tolerance, and success of valve placement; health-related quality of life; exercise capacity; pulmonary function; and gas exchange. RESULTS: Five centers treated 30 patients. Patient follow-up ranged from 1 to 12 months. A mean of 6.1 valves were placed per patient. Valves were positioned by means of flexible bronchoscopy in 99% of desired airways, and the procedure duration ranged from 15 to 125 minutes (mean, 65 minutes). Hospital discharge occurred within 2 days in 27 of 30 patients. There were no deaths or episodes of valve migration, tissue erosion, or significant bleeding. Eighty-three percent of patients had no adverse events judged probably or definitely related to the device. Patients experienced significant improvement in health-related quality of life, although the physiologic and exercise outcomes did not show statistically significant improvements. CONCLUSIONS: These first multicenter results with the Intrabronchial Valve demonstrate significant improvements in health-related quality of life and acceptable safety, ease of use, and procedural complication rates. The valve might be a safer and less-invasive alternative to surgical therapy for patients with severe emphysema.

Adult↗
PubMed2006

Patient and surgical factors influencing air leak after lung volume reduction surgery: lessons learned from the National Emphysema Treatment Trial.

BACKGROUND: Although staple line buttressing is advocated to reduce air leak after lung volume reduction surgery (LVRS), its effectiveness is unknown. We sought to identify risk factors for air leak and its duration and to estimate its medical consequences for selecting optimal perioperative technique(s), such as buttressing technique, to preempt or treat post-LVRS air leak. METHODS: Detailed air leak data were available for 552 of 580 patients receiving bilateral stapled LVRS in the National Emphysema Treatment Trial. Risk factors for prevalence and duration of air leak were identified by logistic and hazard function analyses. Medical consequences were estimated in propensity-matched pairs with and without air leak. RESULTS: Within 30 days of LVRS, 90% of patients developed air leak (median duration = 7 days). Its occurrence was more common and duration prolonged in patients with lower diffusing capacity (p = 0.06), upper lobe disease (p = 0.04), and important pleural adhesions (p = 0.007). Duration was also protracted in Caucasians (p < 0.0001), patients using inhaled steroids (p = 0.004), and those with lower 1-second forced expiratory volume (p = 0.0003). Surgical approach, buttressing, stapler brand, and intraoperative adjunctive procedures were not associated with fewer or less prolonged air leaks (p >/= 0.2). Postoperative complications occurred more often in matched patients experiencing air leak (57% vs 30%, p = 0.0004), and postoperative stay was longer (11.8 +/- 6.5 days vs 7.6 +/- 4.4 days, p = 0.0005). CONCLUSIONS: Air leak accompanies LVRS in 90% of patients, is often prolonged, and is associated with a more complicated and protracted hospital course. Its occurrence and duration are associated with characteristics of patients and their disease, not with a specific surgical technique.

Administration, Inhalation↗
PubMed2006

Long-term follow-up of patients receiving lung-volume-reduction surgery versus medical therapy for severe emphysema by the National Emphysema Treatment Trial Research Group.

BACKGROUND: The National Emphysema Treatment Trial defined subgroups of patients with severe emphysema in whom lung-volume-reduction surgery (LVRS) improved survival and function at 2 years. Two additional years of follow-up provide valuable information regarding durability. METHODS: A total of 1218 patients with severe emphysema were randomized to receive LVRS or medical treatment. We present updated analyses (4.3 versus 2.4 years median follow-up), including 40% more patients with functional measures 2 years after randomization. RESULTS: The intention-to-treat analysis of 1218 randomized patients demonstrates an overall survival advantage for LVRS, with a 5-year risk ratio (RR) for death of 0.86 (p = 0.02). Improvement was more likely in the LVRS than in the medical group for maximal exercise through 3 years and for health-related quality of life (St. George's Respiratory Questionnaire [SGRQ]) through 4 years. Updated comparisons of survival and functional improvement were consistent with initial results for four clinical subgroups of non-high-risk patients defined by upper-lobe predominance and exercise capacity. After LVRS, the upper-lobe patients with low exercise capacity demonstrated improved survival (5-year RR, 0.67; p = 0.003), exercise throughout 3 years (p < 0.001), and symptoms (SGRQ) through 5 years (p < 0.001 years 1 to 3, p = 0.01 year 5). Upper-lobe-predominant and high-exercise-capacity LVRS patients obtained no survival advantage but were likely to improve exercise capacity (p < 0.01 years 1 to 3) and SGRQ (p < 0.01 years 1 to 4). CONCLUSIONS: Effects of LVRS are durable, and it can be recommended for upper-lobe-predominant emphysema patients with low exercise capacity and should be considered for palliation in patients with upper-lobe emphysema and high exercise capacity.

Aged↗
PubMed2005

Predictors of operative mortality and cardiopulmonary morbidity in the National Emphysema Treatment Trial.

OBJECTIVE: We sought to identify predictors of operative mortality, pulmonary morbidity, and cardiovascular morbidity after lung volume reduction surgery. METHODS: Univariate and multivariate logistic regression analyses were performed. Candidate predictors included demographic characteristics, physical condition characteristics, pulmonary function measures, measures of the distribution of emphysema as determined by radiologists and by means of computerized analysis of chest computed tomographic scans, and measures of exercise capacity, dyspnea, and quality of life. End points analyzed were operative mortality (death within 90 days of the operation), major pulmonary morbidities (tracheostomy, failure to wean, reintubation, pneumonia, and ventilator for > or =3 days), and cardiovascular morbidities (infarction, pulmonary embolus, or arrhythmia requiring treatment). RESULTS: Five hundred eleven patients in the non-high-risk group of the National Emphysema Treatment Trial underwent lung volume reduction. The incidence of operative mortality was 5.5%, major pulmonary morbidity occurred in 29.8% of patients, and cardiovascular morbidity occurred in 20.0% of patients. Predictors for these end points are as follows: [table: see text]. CONCLUSIONS: Although lung volume reduction can be performed in selected patients with acceptable mortality, the incidence of major cardiopulmonary morbidity remains high. The lone predictor for operative mortality of lung volume reduction was the presence of non-upper-lobe-predominant emphysema, as assessed by the radiologist. Pulmonary morbidity can be expected in elderly patients who have a low diffusing capacity for carbon monoxide and forced expiratory volume in 1 second. When assessing morbidity, the computer-assisted chest computed tomographic analysis proved useful only in predicting cardiovascular complications.

Aged↗
PubMed2005

Surgical management of T3 and T4 lung cancer.

Locally advanced lung cancer (T(3) or T(4)) has a significantly worse prognosis than lower stage disease. However, this diagnosis is usually made radiologically, and experienced thoracic surgeons are familiar with the low radiologic to pathologic correlation in tumors that abut the great vessels, mediastinum, or chest wall. Commonly these tumors do not directly invade adjacent structures and are, in fact, T(1) or T(2) tumors that are resectable through standard techniques. Where there is no clearly evident invasion of unresectable structures, the patient should be given the benefit of the doubt and considered at a lower (resectable) stage until proven otherwise. The curability of T(3) tumors varies according to the involved site. A T(3)N(0) tumor involving the chest wall provides the most favorable prognosis among the resected T(3) lesions, with a 5-year survival of >50% in lymph node-negative patients if resection is complete. Palliative incomplete resections of T(4) disease, in which tumor has invaded mediastinal structures, have not shown any survival benefit and are associated with very high morbidity and mortality. However, patients with limited invasion of the carina, left atrium, superior vena cava, or pulmonary artery may be able to be completely resected despite their T(4) classification. Surgical resection remains an important part of the therapy for patients with locally advanced lung cancer. Modern techniques of chest wall resection and reconstruction and bronchoplastic procedures allow complete resection of locally advanced tumors with favorable 5-year survival rates and low morbidity and mortality.

Humans↗
PubMed2004

Relationship between non-small cell lung cancer fluorodeoxyglucose uptake at positron emission tomography and surgical stage with relevance to patient prognosis.

PURPOSE: Because the tumor stage is the most significant prognostic factor for non-small cell lung cancer (NSCLC) and given that NSCLC [(18)F]fluorodeoxyglucose ((18)F-FDG) uptake appears to have prognostic significance, we examined the relationship between NSCLC (18)F-FDG uptake and surgical stage. EXPERIMENTAL DESIGN: One hundred seventy-eight patients with a proven diagnosis of NSCLC were enrolled, then imaged with (18)F-FDG positron emission tomography and their disease thoroughly staged. Primary tumor size at computed tomography and (18)F-FDG uptake were compared to overall tumor stage and to T, N, and M stage descriptors. Tumor uptake was quantitated by maximum pixel-standardized uptake value (maxSUV) and then partial volume corrected for lesion size using recovery coefficients. RESULTS: A significant difference in tumor size was associated with tumors of different TNM stage, T status, N status, or M status. Similarly, the primary tumor maxSUV was significantly associated with TNM stage, T status, and M status. However, we observed no significant difference in the partial-volume-corrected tumor maxSUV for different stages; different T, N, or M descriptors; tumors without evidence of spread (N(0)M(0)) versus tumors with nodal spread (N(1,2,3)M(0)); or tumors without spread (N(0)M(0)) versus all others. CONCLUSIONS: We found an association between tumor stage and (18)F-FDG maxSUV, but this relationship disappeared after correction of tumor uptake for lesion size. Therefore, if partial-volume-corrected (18)F-FDG uptake is prognostic of NSCLC outcome, it is not on the basis of a relationship with tumor stage but through a different mechanism.

Carcinoma, Non-Small-Cell Lung↗
PubMed2004

Prospective randomized study evaluating a biodegradable polymeric sealant for sealing intraoperative air leaks that occur during pulmonary resection.

BACKGROUND: To evaluate the safety and effectiveness of a new biodegradable polymeric sealant to close intraoperative air leaks after pulmonary resection. METHODS: In a multicenter prospective randomized trial, 161 patients with a median age of 67 years old (range 18-85 years old), were randomized in a 2:1 ratio to receive sealant or control for at least one significant air leak (> or = 2.0 mm in size) after pulmonary resection. In the sealant group, all significant air leaks underwent attempted repair by standard methods (sutures, staples, or cautery) prior to the application of sealant. The control group underwent only standard methods. Blood was analyzed for immunologic response. Patients were followed up 1 month after surgery. RESULTS: Intraoperative air leaks were sealed in 77% of the sealant group compared with 16% in the control group (p < 0.001). The sealant group had significantly fewer patients with postoperative air leaks compared with the control group (65% vs 86%, p = 0.005). Median length of hospitalization was 6 days (range, 3-23 days) for the sealant group compared with 7 days (range 4-38 days) for controls (p = 0.028). There was no difference in mortality, morbidity, duration of chest tubes, or immune responses between the two groups. CONCLUSIONS: This study demonstrates the effectiveness of a biodegradable polymer when used as an adjunct to standard closure methods for sealing significant intraoperative air leaks that develop from pulmonary surgery. Use of the sealant led to a reduction in postoperative air leaks, which may have decreased the length of hospitalization.

Adolescent↗
PubMed2004

Pulmonary resection after pneumonectomy.

Patients who have a lung cancer in the residual lung after pneumonectomy should not be automatically excluded for surgical consideration. These patients should be carefully staged and evaluated physiologically. The most important initial differentiation is to distinguish a true second primary lung cancer from metastatic recurrent lung cancer. Meticulous staging with chest CT, PET, brain MRI, and mediastinoscopy should be able to successfully exclude metastatic disease, multifocal disease, or locally advanced tumors. Only patients who have stage I disease are candidates for this type of extended resection. Ideally, these patients should have small peripheral tumors that can be encompassed with a low-volume wedge resection. More extended resections, such as segmentectomy or right middle lobectomy, may be considered in some patients but seem to bear a higher operative morbidity and mortality. The need for an upper or lower lobectomy after contralateral pneumonectomy is probably an absolute contraindication to surgical resection. To tolerate pulmonary resection after pneumonectomy, and to obtain the desired survival benefit, patients should have a good to excellent performance status, no serious comorbidities, and a ppoFEV1 greater than 1.0 L/second. In these highly selected patients, pulmonary resection after pneumonectomy can be accomplished with an acceptable operative morbidity and mortality and, in true cases of metachronous second primary lung cancers, may achieve a 5-year survival rate of up to 50%.

Carcinoma, Non-Small-Cell Lung↗
PubMed2004

Quality of life after lung volume reduction surgery.

The common physiologic and functional variables that quantify limitation in emphysema patients have been the most common outcomes measured after LVRS. Spirometric values and exercise capacity are merely surrogates, however, for their impact on symptoms and QOL in patients with severe emphysema. Because LVRS has been developed as a surgery to palliate disabling symptoms of emphysema, many studies now have included HRQOL outcomes along with the commonly measured physiologic and functional outcomes. Some studies have centered on the QOL as the primary outcome instead of physiologic variables. Many symptom scales and disease-specific and general instruments of HRQOL have been used for evaluating emphysema patients before and after LVRS. Case-control studies and randomized studies have shown a consistent improvement in symptoms related to emphysema and general QOL. These studies validate the use of LVRS as a palliative therapy for selected patients with emphysema. The NETT suggests that this benefit is applicable primarily to patients with an upper lobe-predominant pattern of emphysema or patients with low exercise capacity. Validation or refinement of these criteria depends on the continued contributions of the many investigators performing LVRS.

Humans↗
PubMed2003

A randomized trial comparing lung-volume-reduction surgery with medical therapy for severe emphysema.

BACKGROUND: Lung-volume-reduction surgery has been proposed as a palliative treatment for severe emphysema. Effects on mortality, the magnitude and durability of benefits, and criteria for the selection of patients have not been established. METHODS: A total of 1218 patients with severe emphysema underwent pulmonary rehabilitation and were randomly assigned to undergo lung-volume-reduction surgery or to receive continued medical treatment. RESULTS: Overall mortality was 0.11 death per person-year in both treatment groups (risk ratio for death in the surgery group, 1.01; P=0.90). After 24 months, exercise capacity had improved by more than 10 W in 15 percent of the patients in the surgery group, as compared with 3 percent of patients in the medical-therapy group (P<0.001). With the exclusion of a subgroup of 140 patients at high risk for death from surgery according to an interim analysis, overall mortality in the surgery group was 0.09 death per person-year, as compared with 0.10 death per person-year in the medical-therapy group (risk ratio, 0.89; P=0.31); exercise capacity after 24 months had improved by more than 10 W in 16 percent of patients in the surgery group, as compared with 3 percent of patients in the medical-therapy group (P<0.001). Among patients with predominantly upper-lobe emphysema and low exercise capacity, mortality was lower in the surgery group than in the medical-therapy group (risk ratio for death, 0.47; P=0.005). Among patients with non-upper-lobe emphysema and high exercise capacity, mortality was higher in the surgery group than in the medical-therapy group (risk ratio, 2.06; P=0.02). CONCLUSIONS: Overall, lung-volume-reduction surgery increases the chance of improved exercise capacity but does not confer a survival advantage over medical therapy. It does yield a survival advantage for patients with both predominantly upper-lobe emphysema and low base-line exercise capacity. Patients previously reported to be at high risk and those with non-upper-lobe emphysema and high base-line exercise capacity are poor candidates for lung-volume-reduction surgery, because of increased mortality and negligible functional gain.

Aged↗
PubMed2003

Cost effectiveness of lung-volume-reduction surgery for patients with severe emphysema.

BACKGROUND: The National Emphysema Treatment Trial, a randomized clinical trial comparing lung-volume-reduction surgery with medical therapy for severe emphysema, included a prospective economic analysis. METHODS: After pulmonary rehabilitation, 1218 patients at 17 medical centers were randomly assigned to lung-volume-reduction surgery or continued medical treatment. Costs for the use of medical care, medications, transportation, and time spent receiving treatment were derived from Medicare claims and data from the trial. Cost effectiveness was calculated over the duration of the trial and was estimated for 10 years of follow-up with the use of modeling based on observed trends in survival, cost, and quality of life. RESULTS: Interim analyses identified a group of patients with excess mortality and little chance of improved functional status after surgery. When these patients were excluded, the cost-effectiveness ratio for lung-volume-reduction surgery as compared with medical therapy was 190,000 dollars per quality-adjusted life-year gained at 3 years and 53,000 dollars per quality-adjusted life-year gained at 10 years. Subgroup analyses identified patients with predominantly upper-lobe emphysema and low exercise capacity after pulmonary rehabilitation who had lower mortality and better functional status than patients who received medical therapy. The cost-effectiveness ratio in this subgroup was 98,000 dollars per quality-adjusted life-year gained at 3 years and 21,000 dollars at 10 years. Bootstrap analysis revealed substantial uncertainty for the subgroup and 10-year estimates. CONCLUSIONS: Given its cost and benefits over three years of follow-up, lung-volume-reduction surgery is costly relative to medical therapy. Although the predictions are subject to substantial uncertainty, the procedure may be cost effective if benefits can be maintained over time.

Cost-Benefit Analysis↗