Intrathoracic retention time of pericardial fat pads without pedicle in bronchial stump coverage: insights from a retrospective study

Abstract

Background: Bronchopleural fistula (BPF) is a severe complication after anatomical pulmonary resection. The incidence is low, but the mortality rate is high. Risk factors include the site of resection (right pneumonectomy or right lower lobectomy, neoadjuvant therapy, and poor nutritional status. While bronchial stump coverage by autologous tissue reduces the risk of BPF, the optimal tissue for coverage remains unclear. The aim of this study was to evaluate the residual rate of free pericardial fat pad (FPFP) remaining in the thoracic cavity and to investigate whether covering bronchial stump with FPFP is effective for preventing BPF.

Methods: This retrospective study analyzed the residual rate of FPFP postoperatively and risk factors for BPF. Participants comprised 1,745 patients who underwent radical pulmonary resection. In 45 cases, the residual volume of FPFP was assessed from computed tomography (CT) using the 3D Slicer imaging computing platform.

Results: The volume of FPFP was 84% at 3 months postoperatively, and >50% at 6 months postoperatively. The bronchial closure site remained fully covered in all cases at 3-6 months. Multivariate analysis revealed serum albumin level <4.1 g/dL, lower lobectomy, lymph node dissection, and postoperative pneumonia as significant independent risk factors for BPF.

Conclusions: Despite being a minimally invasive method with non-vascularized autologous tissue, FPFP retained more than half its volume for approximately 6 months postoperatively. These findings suggest the possibility that FPFP coverage of the bronchial stump may prevent BPF.

Keywords: Bronchopleural fistula (BPF); anatomical pulmonary resection; free pericardial fat pad (FPFP).

Figure 1

Volume measurement of the FPFP using the 3D Slicer imaging computing platform. (A) CT of the left lower lobe bronchus stump. Arrow indicates the stapler, and the area surrounded by the arrowhead shows the density of the fat area. (B,C) The area of the FPFP is indicated in yellow, while areas other than FPFP are green. These are automatically identified by the 3D Slicer imaging computing platform by specifying a number of slices at random, rather than all slices. (D) The mass is recognized as FPFP. The volume of this mass is measured. 3D, three-dimensional; Ao, aorta; Br, bronchus; CT, computed tomography; FPFP, free pericardial fat pad.

Figure 2

FPFP volume change and residual ratio. Changes in the FPFP volume (mm³) (A) and residual ratio (B) for each postoperative period. FPFP, free pericardial fat pad.