Types Of Inferior Phrenic Arteries: A New Point Of View Based On A Cadaveric Study

Background: The diaphragm is supplied by the superior and inferior phrenic arteries. This present study focusses on the latter. The inferior phrenic arteries (IPA) usually originate from the abdominal aorta. The two arteries have different origins, and knowledge of these is important when performing related surgical interventions and interventional radiological procedures. The aim of this study was to identify variations in the origin of the IPA and conduct relevant morphometric analyses.Materials and methods: The anatomical variations in the origins of the left inferior phrenic artery (LIPA) and the right inferior phrenic artery (RIPA) were examined in 48 cadavers fixed in 10% formalin solution. A dissection of the abdominal region of the cadavers was performed according to a pre-established protocol using traditional techniques. Morphometric measurements were then taken twice by two of the researchers.Results: In the cadavers, six types of origin were observed. In type 1, the most common type, the RIPA and LIPA originate from the abdominal aorta (AA) (14 = 29.12%). In type 2, the RIPA and the LIPA originate from the coeliac trunk (CT) (12 = 24.96%). In type 3, the RIPA and the LIPA originate from the left gastric artery, with no CT observed (3 = 6.24%). Type 4 has two subtypes: 4A, in which the LIPA originates from the AA and the RIPA originates from the CT (9 = 18.72%) and 4B, in which the RIPA originates from the AA and the LIPA originates from the CT (6 = 12.48%). In type 5, the LIPA originates from the AA and the RIPA originates from the AA (1 = 2.08%). Type 6 is characterised by the RIPA and LIPA forming a common trunk originating from the CT (3 = 6.24%).Conclusions: Our findings suggest the presence of six different types of LIPA and RIPA origin. The most common form is type 1, characterised by an IPA originating from the abdominal aorta, while the second most common is type 2, in which the IPA originates from the AA by a common trunk. The diversity of other types of origin is associated with the occurrence of coeliac trunk variation (type 3). No significant differences in RIPA diameter could be found, whereas LIPA diameter could vary significantly. No significant differences in RIPA and the LIPA diameter could be found according to sex.