Relationship between pulmonary blood flow and volume following lung resection using dynamic perfusion digital radiography.

Background: Surgical intervention for lung resection can cause ventilation-perfusion mismatches and affect gas exchange; however, minimally invasive assessment of blood flow is difficult. This study aimed to evaluate changes in pulmonary blood flow after radical lung cancer surgery using a minimally invasive dynamic digital chest radiography system. Methods: We evaluated 64 patients who underwent radical lobectomies. Postoperative changes in pulmonary blood flow, assessed using dynamic chest radiography-based blood flow ratios (BFRs), were compared with the temporal evolution of both functional lung volumes (FLVs) and estimated lung weight (ELW) derived from computed tomography (CT) volumetry. Results: FLVs on the affected side gradually recovered over time from the lowest value observed 3 months after surgery in all procedures. BFRs on the affected side also showed a gradual recovery from the lowest value 1 month after surgery, except for left upper lobectomies (LULs). In LULs, FLVs and ELWs increased proportionally up to 3 months after surgery, with lung volumes continuing to increase thereafter. The recovery of BFRs differed depending on the resected lobe. Conclusions: A relationship between pulmonary blood flow and FLV was observed in the postoperative period. Despite varying compensatory responses depending on the surgical procedure, FLV recovery coincided with increased pulmonary blood flow.