Volumetric evaluation of the lung expansion following resection: a stereological study

Following lung resection, the thoracic cavity may be filled partially or completely by the remaining pulmonary tissue. To our knowledge, no study has yet evaluated this volumetric change in thoracic content using high resolution computed tomography (HRCT) scans. We aimed to evaluate the volume changes of the lungs using HRCT scans during the preoperative and postoperative periods.

In this study, we took HRCT scans of 25 patients preoperatively and 3 months after the resection. All patients were male and their mean age was 59.6 (40-75) years. The volume and volume fraction of individual pulmonary lobes were estimated by superimposing point-counting grids on the preoperative and postoperative HRCT scans.

The means of total lung volume in all patients were 6.40+/-1.40l and 4.92+/-1.21l in the preoperative and postoperative periods, respectively. While 30.79+/-10.64% of pulmonary tissue was resected in expanded patients, the pulmonary tissue was diminished volumetrically by 18.51+/-15.96% postoperatively. Volumetric analyses showed that the remaining structures increased its volume by 12.28%. Thereby, almost 50% of the resected pulmonary tissue was recovered volumetrically by the remaining tissues.

Present results showed that the volume and volume fraction of the total lung and individual lobes could be estimated practically on HRCT scan using the method proposed in this study. The obtained data not only provided information about actual postoperative progress but also information for predicting the possible postoperative course in patients prior to the resection.