Dataset Information

Physiological modeling of responses to upper versus lower lobe lung volume reduction in homogeneous emphysema.

ABSTRACT:

Rationale

In clinical trials, homogeneous emphysema patients have responded well to upper lobe volume reduction but not lower lobe volume reduction.

Materials/methods

To understand the physiological basis for this observation, a computer model was developed to simulate the effects of upper and lower lobe lung volume reduction on RV/TLC and lung recoil in homogeneous emphysema.

Results

Patients with homogeneous emphysema received either upper or lower lobe volume reduction therapy based on findings of radionucleotide scintigraphy scanning. CT analysis of lobar volumes showed that patients undergoing upper (n = 18; -265 mL/site) and lower lobe treatment (LLT; n = 11; -217 mL/site) experienced similar reductions in lung volume. However, only upper lobe treatment (ULT) improved FEV(1) (+11.1 ± 14.7 versus -4.4 ± 15.8%) and RV/TLC (-5.4 ± 8.1 versus -2.4 ± 8.6%). Model simulations provided an unexpected explanation for this response. Increases in transpulmonary pressure subsequent to volume reduction increased RV/TLC in upper lobe alveoli, while caudal shifts in airway closure decreased RV/TLC in lower lobe alveoli. ULT, which eliminates apical alveoli with high RV/TLC values, lowers the average RV/TLC of the lung. Conversely, LLT, which eliminates caudal alveoli with low RV/TLC values, has less effect.

Conclusion

LLT in homogeneous emphysema is uniformly less effective than ULT.

SUBMITTER: Valipour A

PROVIDER: S-EPMC3461642 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Physiological modeling of responses to upper versus lower lobe lung volume reduction in homogeneous emphysema.

Valipour Arschang A Kramer Mordechai R MR Stanzel Franz F Kempa Axel A Asadi Sherwin S Fruchter Oren O Eberhardt Ralf R Herth Felix J FJ Ingenito Edward P EP

Frontiers in physiology 20121001

<h4>Rationale</h4>In clinical trials, homogeneous emphysema patients have responded well to upper lobe volume reduction but not lower lobe volume reduction.<h4>Materials/methods</h4>To understand the physiological basis for this observation, a computer model was developed to simulate the effects of upper and lower lobe lung volume reduction on RV/TLC and lung recoil in homogeneous emphysema.<h4>Results</h4>Patients with homogeneous emphysema received either upper or lower lobe volume reduction t ...[more]

PMID: 23060811

Similar Datasets

Project description:Bronchoscopic lung volume reduction (BLVR) offers alternative novel treatments for patients with emphysema. Comprehensive evidence for comparing different BLVR remains unclear. To estimate the effects of different BLVR on patients with emphysema. PubMed, EMBASE, Cochrane Library, and Web of Science databases from January 2001 to August 2017 were searched. Randomized clinical trials evaluated effects of BLVR on patients with emphysema. The relevant information was extracted from the published reports with a predefined data extraction sheet, and the risk of bias was assessed with the Cochrane risk of bias tools. Pair-wise metaanalyses were made using the random-effects model. A random-effects network meta-analysis was applied within a Bayesian framework. The quality of evidence contributing to primary outcomes was assessed using the GRADE framework. 13 trials were deemed eligible, including 1993 participants. The quality of evidence was rated as moderate in most comparisons. Medical care (MC)was associated with the lowest adverse events compared with intrabronchial valve (IBV)(-2.5,[-4.70 to -0.29]), endobronchial valve (EBV) (-1.73, [-2.37 to -1.09]), lung volume reduction coils (LVRC) (-0.76, [-1.24 to -0.28]), emphysematous lung sealant (ELS) (-1.53, [-2.66 to -0.39]), and airway bypass(-1.57, [-3.74 to 0.61]). Adverse events in LVRC were lower compared with ELS (-0.77,[-2.00 to 0.47]). Bronchoscopic thermal vapor ablation (BTVA) showed significant improvement in FEV1 compared with MC (0.99, [0.37 to 1.62]), IBV (1.25, [0.25 to 2.25]), and LVRC (0.72, [0.03 to 1.40] ). Six minute walking distance (6 MWD) in ELS was significantly improved compared with other four BLVR, sham control, and MC (-1.96 to 1.99). Interestingly, MC showed less improvement in FEV1 and 6MWDcompared with EBV (-0.45, [-0.69 to -0.20] and -0.39, [-0.71 to -0.07], respectively). The mortality in MC and EBV was lower compared with LVRC alone (-0.38, [-1.16 to 0.41] and -0.50, [-1.68 to 0.68], respectively). BTVA and EBV led to significant changes in St George's respiratory questionnaire (SGRQ) compared with MC alone (-0.74, [-1.43 to -0.05] and 0.44, [0.11 to 0.78], respectively). BLVR offered a clear advantage for patients with emphysema. EBV had noticeable beneficial effects on the improvement of forced expiratory volume 1, 6MWD and SGRQ, and was associated with lower mortality compared with MC in different strategies of BLVR.

Dataset Information

Physiological modeling of responses to upper versus lower lobe lung volume reduction in homogeneous emphysema.

Rationale

Materials/methods

Results

Conclusion

Publications

Physiological modeling of responses to upper versus lower lobe lung volume reduction in homogeneous emphysema.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets