Fissure Integrity and Volume Reduction in Emphysema: A Retrospective Study

Abstract

Background: One-way endobronchial valves (EBVs) relieve symptoms of emphysema, particularly in patients without collateral ventilation between the target and adjacent lobes. Pretreatment knowledge of fissure integrity could serve as an aid in indicating EBV interventions. Objective: This study aimed to investigate the relationship between software-measured lung fissure integrity and clinically relevant lung volume reduction (≥350 ml) in emphysema patients treated with one-way EBVs using a lobar exclusion strategy. Methods: Of 108 patients treated between March 2008 and July 2014, 38 had both baseline and follow-up computed tomography (CT) scans acquired following a specific protocol for quantitative CT analysis and were included in the study (total of 39 treatments, two lungs treated in 1 patient). Outcome measures were fissure integrity measured on baseline CT scans, difference between pre- and postoperative lung volume (considering the lowest measured postoperative volume), and correlation between fissure integrity and volume change. Results: Fissure integrity ≥75% correlated with volume reduction ≥350 ml (Spearman coefficient: -0.65; p < 0.01). The mean and median volume reductions were 1,223.96 ± 907.5 ml and 663 ml, respectively, for lungs with fissure integrity ≥75% (n = 31). The accuracy of fissure integrity ≥75% in predicting a volume reduction was 87.2%. The positive predictive value of fissure integrity ≥75% to predict a volume reduction ≥350 ml was 83.9%, and it was 70% for fissure integrity 75-90% and 90.5% for fissure integrity >90%. Conclusions: A target lobe volume reduction using EBVs is possible with lung fissure integrity ≥75%. For patients with fissure integrity between 75 and 90%, a further evaluation of interlobar ventilation should be performed. A clinically relevant volume reduction following treatment with EBVs is likely with any level of fissure integrity >90%.

Endoscopic Lung Volume Reduction Using Endobronchial Valves in Patients with Severe Emphysema and Very Low FEV₁

“…This proportionally low rate of pneumothoraces is caused by a low rate of complete fissures, leading to CV and incomplete lobar occlusion [20]. Due to an improved patient selection in consideration of catheter-based CV assessment [21,22,23,24] and CT-based analysis [24,25], the rate of pneumothoraces increases up to 25-30%, as in the current analysis.…”

Predicting Lung Volume Reduction after Endobronchial Valve Therapy Is Maximized Using a Combination of Diagnostic Tools

“…Applying a bimodal distribution of patients above and below a single threshold of 90% fissure completeness, the overall accuracy was 75.8%, with a sensitivity of 83.3% and a specificity of 66.7%, which was similar to the results of QCT alone in our study. The third study was performed by de Oliveira et al [16], who retrospectively analyzed 38 treated patients. They investigated the relationship between fissure completeness and clinically relevant lobar volume reduction (≥350 ml), using a QCT analysis.…”

“…These methods are more efficient and have an improved reliability over visual methods. A recent study concluded that the optimal treatment algorithm might be a combination approach, using radiology for an anatomical classification based on fissure completeness, and a physiologic measure of airflow in patients with partially complete fissures [16]. …”

Status of and prospects for bronchoscopic lung volume reduction for patients with severe emphysema

“…In a recent retrospective study (n = 38), de Oliveira et al proposed new criteria for patient selection (40). The study indicated that TLVR would not exceed 350 mL after EBV implantation in patients with an interlobular fissure that was less than 75% complete (n = 8).…”

“…Therefore, EBV implantation in the lower lobe may have more of a benefit, but this contention needs to be verified. Several studies have indicated that EBV implantation in the left lobe was more likely to achieve a TLVR than implantation in the right lobe (40,42). This may be because the left lobe is less likely to have collateral ventilation than the right lobe (46).…”