Estimating the potential cost of a high dose immune tolerance induction (ITI) therapy relative to the cost of a combined therapy of a low dose ITI therapy with bypassing agent prophylaxis.

INTRODUCTION: The International Immune Tolerance Study (I-ITI) demonstrated comparable success rates between low (FVIII 50 IU/kg/TIW) and high dose (FVIII 200 IU/kg/day) regimens. While costlier, the high dose ITI regimen achieved shorter time-to-treatment success with fewer bleeding episodes compared to the low dose ITI regimen. Adding bypassing agent prophylaxis (BAP) to a low dose ITI regimen may reduce bleeding while still being less costly than high dose ITI. AIM AND METHODS: An economic model was developed to compare high dose ITI to low dose ITI with BAP. All model inputs were derived from clinical trials. The I-ITI study indicated a median time to negative inhibitor titre of 4.6 and 9.2 months and average number of bleeds/patient of 4.2 and 9.9 for the high and low dose regimens respectively. Based on the BAP trials, aPCC (85 U/kg/TIW) and rFVIIa (90 µg/kg/day) achieved a 62% and 45% reduction in bleeding frequency respectively. Cost analysis was from a US third party payer perspective and limited to drug costs. One-way, two-way and probabilistic sensitivity analyses were performed. RESULTS: Costs of low dose ITI with aPCC prophylaxis until negative inhibitor titre is achieved was 24.0% less compared to high dose ITI. Low dose ITI with rFVIIa prophylaxis cost 46.5% more compared to high dose ITI. Model results were robust in the majority of the sensitivity analyses. CONCLUSION: A low dose ITI regimen with aPCC prophylaxis may be cost saving compared to a high dose ITI regimen with the potential to reduce morbidity by lowering the risk for breakthrough bleeds.

Cost-consequence analysis of two different active flowable hemostatic matrices in spine surgery patients.

OBJECTIVES: A recently published retrospective analysis comparing two different active flowable hemostatic matrices (FLOSEAL and SURGIFLO Kit with Thrombin) showed significantly increased resource use and complications (surgery time, risk of blood product transfusion, and amount of matrix used) with SURGIFLO use compared to FLOSEAL in major spine surgery, and also significantly increased surgical time with SURGIFLO use in severe spine surgery. This analysis was developed as a follow-up to this prior analysis, to evaluate the cost-consequence of using FLOSEAL vs SURGIFLO in major and severe spine surgery. METHODS: A cost consequence model was constructed from a US hospital provider perspective. Model parameters combined clinical inputs from the published retrospective analysis with supplemental analyses on annual spine surgery volume using the 2012 National Inpatient Sample (NIS) database. Cost of hemostatic matrices, blood product transfusion, and operating room time were identified from published literature. Various one-way and probabilistic sensitivity analyses were performed. RESULTS: The base case for a medium volume hospital showed that, compared to SURGIFLO, patients receiving FLOSEAL required three fewer blood product transfusions and saved 27 h of OR time, resulting in annual savings of $151 per major and $574 per severe spine surgery. Additional scenarios for high and low volume hospitals supported cost savings in the base case. Probabilistic sensitivity analysis revealed FLOSEAL was cost-saving in 76% of simulations in major spine and 97% of iterations in severe spine surgery. CONCLUSIONS: This economic analysis indicates that use of FLOSEAL instead of SURGIFLO hemostatic matrices to induce hemostasis in both major and severe spine surgery could potentially lead to sizable cost savings in US hospitals, regardless of spinal surgery case-mix.

Cost-consequence analysis of different active flowable hemostatic matrices in cardiac surgical procedures.

BACKGROUND: A recent retrospective comparative effectiveness study found that use of the FLOSEAL Hemostatic Matrix in cardiac surgery was associated with significantly lower risks of complications, blood transfusions, surgical revisions, and shorter length of surgery than use of SURGIFLO Hemostatic Matrix. These outcome improvements in cardiac surgery procedures may translate to economic savings for hospitals and payers. OBJECTIVE: The objective of this study was to estimate the cost-consequence of two flowable hemostatic matrices (FLOSEAL or SURGIFLO) in cardiac surgeries for US hospitals. METHODS: A cost-consequence model was constructed using clinical outcomes from a previously published retrospective comparative effectiveness study of FLOSEAL vs SURGIFLO in adult cardiac surgeries. The model accounted for the reported differences between these products in length of surgery, rates of major and minor complications, surgical revisions, and blood product transfusions. Costs were derived from Healthcare Cost and Utilization Project's National Inpatient Sample (NIS) 2012 database and converted to 2015 US dollars. Savings were modeled for a hospital performing 245 cardiac surgeries annually, as identified as the average for hospitals in the NIS dataset. One-way sensitivity analysis and probabilistic sensitivity analysis were performed to test model robustness. RESULTS: The results suggest that if FLOSEAL is utilized in a hospital that performs 245 mixed cardiac surgery procedures annually, 11 major complications, 31 minor complications, nine surgical revisions, 79 blood product transfusions, and 260.3 h of cumulative operating time could be avoided. These improved outcomes correspond to a net annualized saving of $1,532,896. Cost savings remained consistent between $1.3m and $1.8m and between $911k and $2.4m, even after accounting for the uncertainty around clinical and cost inputs, in a one-way and probabilistic sensitivity analysis, respectively. CONCLUSIONS: Outcome differences associated with FLOSEAL vs SURGIFLO that were previously reported in a comparative effectiveness study may result in substantial cost savings for US hospitals.

Health-related quality of life assessment in haemophilia patients on prophylaxis therapy: a systematic review of results from prospective clinical trials.

INTRODUCTION: Prophylaxis is effective in reducing the number of bleeding episodes in patients with severe or moderately severe haemophilia A and B, including those with inhibitors. However, data, predominantly from observational studies, suggest more equivocal effects on health-related quality of life (HRQoL). AIM: To examine the impact of prophylaxis on HRQoL from prospective clinical trials. METHODS: We performed a systematic literature review of clinical trials evaluating the efficacy of prophylaxis with factor VIII, FIX or bypassing agents. Trials assessing HRQoL via validated instruments were selected and summarized. RESULTS: Thirteen trials (haemophilia A [n = 8]; haemophilia B [n = 2]; inhibitors [n = 3]) met all inclusion criteria. HRQoL instruments included the EQ-5D, SF-36, Haem-QoL-A, Haem-A-QoL, Haemo-QoL and CHO-KLAT. Improvements in HRQoL following prophylaxis were observed with the EQ-VAS, SF-36 and haemophilia-specific instruments in adult patients and were associated with reduced pain, fewer restrictions in physical activities and better general health. Prophylaxis led to statistically significant or clinically meaningful HRQoL improvement in six trials and non-significant improvement in four trials; two trials found no improvement and one reported no data. Despite study differences, consistent trends suggested that patients previously treated solely on-demand and those who experienced marked reductions in the frequency of bleeding with prophylaxis had a greater improvement in HRQoL. CONCLUSION: Contrary to findings of observational studies, the results from the majority of prospective trials using validated instruments showed positive trends for improved HRQoL with prophylaxis in adults.

Improvement in health-related quality of life with recombinant factor IX prophylaxis in severe or moderately severe haemophilia B patients: results from the BAX326 Pivotal Study.

Little is known about the health-related quality of life (HRQoL) burden of haemophilia B. The aim of this study was to assess HRQoL burden of haemophilia B, the benefit of recombinant factor IX (rFIX) prophylaxis and the HRQoL benefit of achieving a zero annual bleed rate. Subjects receiving rFIX (BAX326) prophylaxis or on-demand completed the SF-36 survey. Baseline SF-36 scores were compared to the general US population scores to understand the HRQoL burden. Changes in SF-36 scores between baseline and follow-up were tested using t-tests. Subgroup analysis was conducted to examine SF-36 change among subjects who switched to BAX326 prophylaxis. SF-36 scores were also compared between those with zero bleeds and those who bled during the study. Compared to the US norms, subjects reported lower average scores in all physical and several mental HRQoL domains. At follow-up, prophylaxis subjects reported statistically significant and clinically meaningful improvements in overall physical HRQoL, as measured by the Physical Component Score (PCS) (mean change 2.60, P = 0.019), Bodily Pain (BP) (3.45, P = 0.015) and Role Physical (RP) domains (3.47, P = 0.016). Subjects who switched to prophylaxis from intermittent prophylaxis or on-demand experienced more pronounced improvements not only in the PCS (3.21, P = 0.014), BP (3.71, P = 0.026), RP (4.43, P = 0.008) but also in Vitality (3.71, P = 0.04), Social Functioning (5.06, P = 0.002) and General Health domains (3.40, P = 0.009). Subjects achieving zero bleeds reported lower BP (P = 0.038). Prophylaxis with BAX326 significantly improved HRQoL in patients with moderately severe or severe haemophilia B by reducing bleeds.

The relative burden of haemophilia A and the impact of target joint development on health-related quality of life: results from the ADVATE Post-Authorization Safety Surveillance (PASS) study.

Studies with haemophilia A (HA) patients have shown burden in health-related quality of life (HRQOL) when compared with general population norms. In the current study, HA patients' SF-36v2 health survey scores were compared with general population norms and to patients with other chronic conditions. The impact of target joints (TJs) on HRQOL was also examined. The sample was a subset of HA patients enrolled in the Post-Authorization Safety Surveillance (PASS) programme: a prospective open-label study in which ADVATE [Antihaemophilic Factor (Recombinant), Plasma/Albumin-Free Method] was prescribed. A total of 205 patients who were ≥ 18 years old and had SF-36v2 baseline scores were selected for this study. To measure the burden of HA on HRQOL, manova analyses compared these SF-36v2 scores to age- and gender-matched general population US and EU norms and to patients from other chronic condition groups. manova and correlational analyses examined the relations among TJ, age and SF-36v2 scores. Comparisons with general population norms confirm that HA negatively impacts physical, but not mental, HRQOL. Comparison with other chronic conditions shows the physical burden of HA is greater than for chronic back pain but similar to diabetes and rheumatoid arthritis, while the mental burden of HA is less than for all three patient groups. The presence of TJs was negatively associated with physical HRQOL, although this association was much larger for older patients (45+ years) than for younger ones. Physical, but not mental, HRQOL is diminished in HA patients. Target joints are associated with lower physical HRQOL, although this effect is moderated by age.

Patient and parent preferences for haemophilia A treatments.

Little is known about the relative importance of factor VIII (FVIII) treatment attributes to haemophilia A patients and their willingness to accept trade-offs among these attributes. To quantify patient and parent preferences for FVIII treatments and compare the relative importance of treatment attributes. Adult patients and parents of children with severe haemophilia A in the US completed a web-enabled, choice-format conjoint survey that presented a series of 12 trade-off questions, each including a pair of hypothetical treatment profiles. Each profile was defined by percent of bleeds stopped with one or two infusions, chance of developing an inhibitor, risk of viral infection, preparation volume, dosage strengths available, and history of supply shortage. Trade-off questions were based on a D-optimal experimental design. Preference weights for attribute levels were estimated using random-parameters logit. One hundred and forty seven subjects completed the survey. Over the ranges of attribute levels included in the study, risk of viral infection was the most important attribute. Remaining attributes were ranked in decreasing order of importance as follows: chance of developing an inhibitor, dosage strengths available, percent of bleeds stopped with one or two infusions, history of supply shortage, and preparation volume. Risk of viral infection was 6.0 times as important as percent of bleeds stopped with one or two infusions and 2.7 times as important as the chance of developing an inhibitor. While risk of viral infection was the most important attribute, this research demonstrates that many FVIII treatment attributes are important in the decision-making process.

Analysis of oral lesion biopsies identified and evaluated by visual examination, chemiluminescence and toluidine blue.

Conventional visual examination and palpation remains the gold-standard for the identification of oral mucosal lesions. The purpose of this study was to investigate the adjunctive value of a chemiluminescent light source (ViziLite, Zila Pharmaceuticals, Phoenix, Arizona) and application of pharmaceutical grade toluidine blue (TBlue(630), Zila Pharmaceuticals, Phoenix, Arizona) to further assess lesions identified during the conventional oral soft tissue examination. Lesions deemed clinically suspicious by visual examination under incandescent light were further assessed under chemiluminescence and then application of toluidine blue stain. Differences between the conventional visual examination and chemiluminescent examination were noted on four characteristics which may aid in lesion identification. Tissue retention of toluidine blue stain was documented. Each suspicious lesion was biopsied and diagnosed based upon routine histopathology. Both adjunctive exams were evaluated by comparing the histologic diagnosis. The additive value of toluidine blue stain retention was assessed in lesions diagnosed as "serious pathology" defined as severe dysplasia, carcinoma in situ and squamous cell carcinoma. Ninety-seven clinically suspicious lesions in 84 patients were identified. The chemiluminescent exam improved the brightness and/or sharpness of margin in 61.8% of identified lesions. Biopsied lesions with toluidine blue stain retention reduced the false positive rate by 55.26% while maintaining a 100% negative predictive value (NPV). Chemiluminescence was shown to increase the brightness and margins of mucosal lesions in a majority of cases and therefore may assist in identification of mucosal lesions not considered under traditional visual examination. Toluidine blue stain retention was associated with a large reduction in biopsies showing benign histology (false positive biopsy results), while maintaining a 100% NPV for the presence of severe dysplasia or cancer. Practitioners may consider use of these adjuncts in practice, however the results presented are based upon experienced providers in referral centers for mucosal disease or cancer centers and therefore positive findings may be an indication for referral to experienced providers.

Characteristics of oral and paraoral malignant lymphoma: a population-based review of 361 cases.

BACKGROUND: Lymphoma is the second most common neoplasm of the head and neck; almost 50% of all lymphomas occur in this region. Waldeyer's ring is the most common site of lymphomas involving the oral region. The purpose of this study was to review the characteristics of a large series of malignant lymphoma of the oral region. METHODS: Three hundred sixty-one consecutive cases of malignant lymphoma of the oral region were identified in the Tumor Registry between 1969 and 1998. RESULTS: The 361 cases (200 males and 161 females) of malignant lymphoma of the oral region accounted for 3.5% of all oral malignancies. The mean age was 62.5 years and the most prevalent site of involvement was the tonsil (32.7%), followed by the parotid gland (16.1%). Sixty-five percent of the lesions were diagnosed as large-cell (38%) or small-cell (27%) lymphoma. One quarter of the patients died of the disease in a mean of 2.78 years after diagnosis. Of a total 26 patients who died from other causes, 12 died because of other cancers, including 7 (27%) with leukemia and 5 (19%) with oral carcinoma. The prognosis is based, at least partially, on the histologic grading (low, intermediate, or high) and the anatomic stage of the disease. Localized low-grade lymphomas have a more favorable prognosis compared with those that are disseminated and/or have high-grade cellular changes. CONCLUSION: Lymphoma is the second most common malignant oral disease. Thorough head and neck and oral examination is necessary to identify lesions that may represent lymphoma.

Lung function 5 yr after lung volume reduction surgery for emphysema.

Current datum more than 2 yr after lung volume reduction surgery (LVRS) for emphysema is limited. This prospective study evaluates pre-LVRS baseline and 5-yr results in 26 symptomatic patients (mean age 67 +/- 6 yr) (mean +/- SD) who underwent bilateral, targeted upper lobe stapled LVRS using video-assisted thoracoscopy. Baseline forced expiratory volume in 1 s (FEV(1)) was 0.7 +/- 0.2 L (mean +/- SD), 29 +/- 10% predicted. Following LVRS, with none lost to follow-up, mortality due to respiratory failure at 0.5, 1, 2, 3, 4, and 5 yr was 4%, 4%, 19%, 31%, 46%, and 58%, respectively. Increase above baseline for FEV(1) > 200 ml and/or FVC > 400 ml at 1, 2, 3, 4, and 5 yr post-LVRS was noted in 73%, 46%, 35%, 27%, and 8% of all patients; decrease in dyspnea grade >/= 1 in 88%, 69%, 46%, 27%, and 15%; and elimination of initial oxygen dependence in 18 patients in 78%, 50%, 33%, 22%, and 0%, respectively. Expiratory airflow improved due to the increase in both lung elastic recoil and small airway intraluminal caliber. Five patients decreased FEV(1) 141 +/- 60 ml/yr and FVC 102 +/- 189 ml/yr over 3.8 +/- 1.2 yr post-LVRS, similar to their pre-LVRS rate of decline. In the 11 patients who survived 5 yr, at 0.5-1.0 yr post-LVRS peak increase in FEV(1) was 438 +/- 366 ml, with a decline of 149 +/- 157 ml the following year and 78 +/- 59 ml/yr over 4.0-4.5 yr. Bilateral LVRS provided palliative clinical and physiological improvement in 9 of 26 patients at 3 yr, 7 at 4 yr, and 2 at 5 yr.

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.

Contribution of emphysema and small airways in COPD.

BACKGROUND: The contribution and role of emphysema and small airways disease in causing expiratory airflow limitation in COPD is controversial. METHODS: We obtained high-resolution thin-section 2-mm CT scans of the lung for emphysema grading and lung function in 116 consecutively seen COPD outpatients with fixed expiratory airflow limitation. In this group, inflated whole lung(s) were subsequently obtained in 24 patients (23 autopsy, 1 surgery) for morphologic studies and results compared with lung CT. Airway histologic condition was studied in 17 of the 24 patients. RESULTS: There was fair to weak negative correlation between CT emphysema score and either FEV1/FVC percent (r = -0.51, p = 0.001) or FEV1 percent predicted (r = -0.31, p = 0.001). In only 24 of the 81 patients (30%) with FEV1 less than 50% predicted, the CT emphysema score was 60 or more, indicating severe emphysema. In the 24 patients studied, there was a good correlation (r = 0.86, p = 0.001) between CT and pathologic grade of emphysema. While respiratory bronchioles (RBs) and membranous bronchioles (MBs) demonstrated marked morphologic abnormalities, there was a weak correlation with emphysema grade (for RB, r = 0.36, p = 0.16; for MB, r = 0.41, p = 0.10) or with FEV1 percent predicted (for RB, r = -0.21, p = 0.42; for MB, r = -0.28, p = 0.28). There was no correlation between emphysema and FEV1 percent predicted (r = -0.13, p = 0.54). CONCLUSIONS: High-resolution CT lung scans are an in vivo surrogate to quantitate moderate to severe morphologic emphysema. Emphysema does not appear to be primarily responsible for severe expiratory airflow limitation in most patients with severe COPD. There was no correlation between severity of small airway histologic condition and emphysema or FEV1 percent predicted. The causes of the lesions responsible for small airways obstruction need to be identified.

Limited contribution of emphysema in advanced chronic obstructive pulmonary disease.

Previous studies on autopsy specimens or surgically resected lobes or lungs have reached varying conclusions regarding the importance of small airways disease and emphysema in causing fixed expiratory airflow limitation in patients with chronic obstructive pulmonary disease (COPD). We obtained high resolution CT scans of the lung and lung function in 56 consecutive patients with fixed expiratory airflow limitation. There was poor correlation between CT emphysema score and either FEV1/FVC% (r = -0.36) or FEV1 % predicted (r = -0.20). In only 10 of the 35 patients with FEV1 < 50% predicted, the CT emphysema score was > 40, indicating significant emphysema. A strong negative correlation between diffusing capacity % predicted and diffusing capacity per alveolar volume and CT emphysema score was found only in patients with FEV1 > or = 1 L (r = -0.75, p < 0.0001). Thus, emphysema does not appear to be primarily responsible for expiratory airflow limitation in COPD. A low diffusing capacity may be spuriously misleading in patients with FEV1 < 1 L and no or trivial emphysema.

Physiologic studies of tracheobronchial stents in airway obstruction.

When airway obstruction is due to extraluminal compression and/or dynamic collapse, metal and silicone rubber prosthetic stents may stabilize the affected airway. Through a rigid bronchoscope, we inserted three metal stents in two patients and 18 silicone stents in 15 adult patients with symptomatic tracheobronchial compression and dynamic airway collapse. The underlying cause was malignancy in three patients; benign tracheobronchial malacia in three patients, two of whom refused surgical resection; and tracheobronchial stenosis that developed at the anastomotic site following lung transplantation in 11 patients. Clinical status and lung function studies were analyzed before and after stent insertion. Following stent insertion, airway diameter at least doubled and near normal patency of the affected tracheobronchial tree was achieved in every patient using stents of axial length 4 to 5 cm. The stents were well tolerated clinically, and all patients noted immediate relief of dyspnea. Following stent insertion, the forced vital capacity (FVC) increased from 64 +/- 21% predicted (mean +/- 1 SD) to 73 +/- 19% predicted, p less than 0.1; the forced expiratory volume in 1 s (FEV1) from 49 +/- 25% predicted to 72 +/- 26% predicted, p less than 0.02; the ratio of the FEV1/FVC from 59 +/- 16% to 78 +/- 15%, p less than 0.01; and the maximum flow at 50% expired FVC from 38 +/- 26% predicted to 72 +/- 31% predicted, p less than 0.01.

Computed tomography and bronchoscopy in chest radiographically occult main-stem neoplasm diagnosis and Nd-YAG laser treatment in 8 patients.

We studied 8 adult patients with variable symptoms of cough, dyspnea, stridor, wheezing, or hemoptysis. Fiberoptic bronchoscopy in all showed complete or nearly complete endobronchial obstruction of a main-stem bronchus by neoplasm with a mean bronchial diameter of 1.9 mm +/- 1.6 mm (mean +/- standard deviation). In 4 patients, a lobar bronchus was also completely obstructed. No mass was visible on chest radiographs of any patient; however, computed tomography in each showed main-stem endobronchial obstruction, lobar obstruction (4 instances in 3 patients), and in 6 patients hypoperfusion of the involved lung. Computed tomographic scan showed additional abnormalities that were unsuspected on viewing chest radiographs or at bronchoscopy, including mediastinal adenopathy in 3 patients and an extraluminal tumor component in 4. After therapy with Nd-YAG laser, main-stem airway diameter increased to a mean of 9.6 mm +/- 1.0 mm (P less than .05) and pulmonary functions improved. Results suggest the complementary role of computed tomography and fiberoptic bronchoscopy in the detection and laser-treatment planning of chest radiographically occult severe neoplastic obstruction of the main-stem bronchus.

Herpes zoster infection with trigeminal and facial nerve involvement.

In most cases, herpes zoster (shingles) infections are benign and self-limited, requiring no treatment. However, if patients are elderly or immuno-compromised, they are at increased risk of complications such as visceral dissemination, cranial and nerve palsies, ophthalmic zoster, and postherpetic neuralgia. We present a case of herpes zoster infection complicated by both motor and sensory involvement in an elderly man.

Physiologic characteristics of malignant unilateral main-stem bronchial obstruction. Diagnosis and Nd-YAG laser treatment.

To evaluate the effects of severe, unilateral main-stem malignant bronchial obstruction on airway dynamics, we obtained maximal expiratory flow-volume (MEFV) curves in 11 patients 59 +/- 18 yr of age (mean +/- 1 SD), three with and eight without underlying emphysema, before and after laser therapy (10 patients) or lung resection (one patient). Mean main-stem bronchial diameters before and after treatment were 1.1 +/- 1.3 and 9.0 +/- 0.8 mm, respectively (p less than 0.05). In the three patients with underlying emphysema, MEFV curves showed a diffuse intrathoracic obstructive pattern before and after treatment; in the other eight patients, MEFV curves demonstrated an apparently restrictive pattern, with associated airflow obstruction in four, reversible after laser treatment in three of these four. After treatment, all patients exhibited an increase in FVC with a roughly parallel shift of the MEFV curve and little change in the slope of the descending limb of the MEFV curve: FVC improved from 54 +/- 16 to 86 +/- 13% predicted in patients without emphysema and from 54 +/- 16 to 77 +/- 8% predicted in patients with emphysema, whereas the slope of the descending limb of the MEFV curve between 45 and 55% of FVC changed minimally from 2.0 +/- 0.6 to 1.8 +/- 0.5 s-1 in patients without emphysema and from 0.8 +/- 0.3 to 0.8 +/- 0.1 s-1 in patients with emphysema.(ABSTRACT TRUNCATED AT 250 WORDS)