Effect of Lung Volume Reduction Surgery on Gas Exchange and Pulmonary Hemodynamics at Rest and during Exercise

Abstract

Lung volume reduction surgery (LVRS) has become an extended surgery for emphysema in order to improve the dyspnea of severely affected patients. Because resection of lung areas may reduce the vascular bed, which is an important factor of pulmonary hypertension in emphysematous patients, especially during exercise, the aim of our study was to assess the outcome of pulmonary hemodynamics and gas exchange at rest and during exercise after LVRS. Nine patients had right heart catheterization before and 3 to 12 mo (mean, 4.5 mo) after LVRS. FEV1 increased from 705 to 1,005 ml (p < 0.05) after LVRS. PaO2, PaCO2 and mean pulmonary artery pressure (Ppa) did not change after LVRS, either at rest or during exercise. However, a significant overall decrease of the respiratory swings of the pulmonary artery diastolic pressure (DeltaPd) at rest (median value, from 12 to 8 mm Hg, p < 0.01) and during exercise (from 20 to 15 mm Hg, p < 0.05) was observed. There was a significant correlation between the change in resting Ppa (Ppa before minus Ppa after LVRS) and the change in resting DeltaPd (r = 0.73, p < 0.03), and also between the change in exercising Ppa and the change in resting DeltaPd (r = 0.80, p < 0.02). Significant correlations were also found between the change in exercising Ppa and the change in exercising PaO2 (r = -0.70, p < 0.05), and between the change in exercising Ppa and the change in exercising PaCO2 (r = 0.76, p < 0. 03). We conclude that pulmonary hemodynamics in most cases are not impaired by LVRS either at rest or during exercise. The possible mechanisms influencing hemodynamics after a lung volume reduction procedure are discussed.

Pulmonary hypertension in COPD

“…LVRS may have adverse effects on pulmonary haemodynamics owing to the reduction of the vascular bed after the resection of lung tissue. Early studies have shown conflicting results, with increases in Ppa after LVRS in one study [130] but not in others [127,128]. A recent study as part of the National Emphysema Treatment Trial has shown no significant differences in terms of P pa and PVR, 6 months after medical treatment or LVRS [129].…”

“…There have been few studies on pulmonary haemodynamics before and after LVRS [127][128][129]. LVRS may have adverse effects on pulmonary haemodynamics owing to the reduction of the vascular bed after the resection of lung tissue.…”

Pulmonary hypertension in chronic obstructive pulmonary disease

“…OSWALD-MAMMOSSER et al [128] studied pulmonary haemodynamics in a group of patients with advanced COPD before and after LVRS. In their study resting Ppa remained unaltered after LVRS, whereas exercise Ppa decreased slightly, yet not significantly [128].…”

Effects of Lung Volume Reduction Surgery on Gas Exchange and Breathing Pattern During Maximum Exercise

“…19 -24 However, most of the published reports are uncontrolled, unicenter trials involving small numbers of patients with short-term follow-up. 3,5,[17][18][19]22,23,[25][26][27] The National Emphysema Treatment Trial (NETT) represents the most extensively characterized patient cohort with severe emphysema undergoing repeated exercise testing. Here we report the effects of optimal medical therapy plus LVRS vs optimal medical therapy alone on maximum exercise after outpatient rehabilitation and through 2 years postrandomization to treatment.…”