Immediate Efficacy of Stents
Twenty-eight of the 31 patients had immediate improvement of their respiratory symptoms; the three patients whose conditions did not improve despite technically successful relief of a local obstruction and proved perfusion of the lung distal to the stent (contrast enhancement of the pulmonary artery on computed tomographic scan) had additional causes for dyspnea, two with left heart failure, and one with obstruction of the vena cava. Comparison of the pretreatment and posttreatment scores of the variables (dyspnea, Kar-nofsky performance scale, and World Health Organization activity index) showed highly significant improvement (p<0.01) (Fig 5).

Dyspnea decreased from a mean grade 3.5 to 2.3, the Karnofsky scale improved from a mean score of 36 to 51, and the activity index decreased from a mean value of 3 down to 2.1. In practical terms, this means that the average patient in this series was hospitalized needing constant care before treatment and was at home needing light daily care by family members after endobronchial palliation.
Pretreatment and posttreatment lung function measurements were available only in the minority of patients with a dyspnea index of ^3 and could not be analyzed for the whole group.

Figure 5. Efficacy of stent insertion (31 patients): change from pretreatment to posttreatment values of dyspnea grade, Karnofsky performance scale, and World Health Organization activity index shows highly significant improvement.