Clinical significance of the diverse interlobar veins hidden in the upper oblique fissure

BACKGROUND: The interlobar veins hidden in the upper oblique fissure (UOF) of the right lung are usually mismanaged cursorily according to the target lobe, which results in accidental injury of the interlobar veins and complications. The detailed classification of interlobar veins based on surgical anatomical analysis is of great clinical significance. METHODS: Three-dimensional computed tomography bronchography and angiography (3D-CTBA) reconstructed images of 398 patients from January 2019 to June 2020 were retrospectively analyzed. The interlobar veins in the UOF were observed and classified according to their morphology and distribution. The classification model was further validated in 153 patients who underwent surgery involving dissection of the UOF, and related surgical results were analyzed. RESULTS: The distribution of interlobar veins was diverse, and the general morphology could be divided into 2 main categories and 30 subtypes in the 3D-CTBA images of the 398 patients. Analysis of the 153 patients’ surgical data showed that 60 patients suffered from interlobar vein injury. Interlobar veins hidden in an incomplete UOF were the most susceptible to accidental damage (χ(2)=12.856, P=0.020). A receiver operating characteristic (ROC) curve analysis showed that an interlobar vein diameter larger than 2.4 mm for the oblique fissure interlobar vein type or less than 2 mm for the mediastinal interlobar vein type was associated with a higher risk of injuries (P<0.001). CONCLUSIONS: The diversity of interlobar veins and the completeness of the UOF were noteworthy risk factors in surgery involving dissection of the UOF.