Surface anatomy and lumbar lordosis angle.

Awareness of the anatomical variations in abdominal surface anatomy with emphasis on relation to the abdominal planes may facilitate anatomical education and physical examination and inconvenience surgical intervention by giving surgeons more insight in surgical planning and training. This study was designed to verify whether the anatomical planes promote to the comprehension of surface anatomy and how the lumbar lordosis angle affects the vertebral level of the bifurcation of great vessels. This retrospective study was performed using computed tomography angiography images of 155 patients ranging from 18 up to 82 years. The vertebral levels of the celiac truncus, superior mesenteric artery, portal vein confluence, right and left renal arteries were within the transpyloric plane in 60%, 70%, 56.1% and 48.3-36.2% of patients, respectively. The inferior mesenteric artery was below the subcostal plane in 58% of patients. The aortic bifurcation (AB) was mostly corresponded to the level of L4 and was located within the umbilical plane in 73.1% of patients. The level of the inferior vena cava (IVC) confluence was within the supracristal plane in 54% of patients. We measured the mean value of the AB, IVC and lumbar lordosis angles as 39.54°, 58.05° and 54.26°, respectively. The AB and IVC levels showed a downward shift with decreasing lumbar lordosis angle. Precise knowledge of these relationships is crucial in clinical practice and surgical approaches to the anterior lumbosacral spine for safer and effective surgery.