Scintigraphic Assessment of Pulmonary Flow in Patients After Pneumonectomy

Background: Pulmonary circulation typically shows flow divided between the right and left lungs, with a marked predominance of the right lung. Pneumonectomy reduces pulmonary circulation by ~50%, irreversibly changing the pulmonary perfusion characteristics. Here we assessed pulmonary flow after pneumonectomy and investigated how selected factors influenced pulmonary perfusion in this patient group. Methods: This study included 31 patients who underwent pneumonectomy complicated by postpneumonectomy pleural empyema, which was successfully treated, with long-term survival. Testing was conducted at a median of 1100 days after pneumonectomy, after flow stabilization. The control group comprised 31 subjects without pulmonary pathology. Pulmonary flow was assessed by scintigraphy using Technetium (99m-Tc). Results: The average single lung perfusion after pneumonectomy corresponded to the total perfusion in both lungs in the control group without statistic difference between comparable parameters (upper field, 21.35 vs. 22.129, p = 0.4; middle field, 47.15 vs. 49.62, p = 0.099; lower field 30.71 vs. 28.29, p = 0.14). Compared to those with left-sided pneumonectomy, patients with right-sided pneumonectomy exhibited increased upper field perfusion (22.61 vs. 19.82, p = 0.049) and decreased perfusion in the lower field (30.81 vs. 26.22, p = 0.049) and the combined middle and lower field (79.63 vs. 76.49, p = 0.046). Pulmonary flow was not significantly related to age, side of surgery, or empyema duration. Conclusions: Flow rate in the remaining lung after pneumonectomy corresponded to the total flow in both lungs in healthy controls. The perfusion ratio differed after right-sided versus left-sided pneumonectomy, which may be related to the initial anatomical differences of the right and left lung.