Anterior retroperitoneal rami: until now unnamed direct branches of the abdominal aorta.

The aim of the study was to gain a thorough knowledge of the topography and distribution of until now officially unnamed minute direct branches from abdominal aorta, stemming from its ventral and lateral aspects, supplying surrounding tissue, and to comprise it to the existing studies. The study was performed in fixed cadaverous material collected from India ink injections of abdominal aorta samples with large surrounding retroperitoneal tissue. The 25 samples were dissected under magnifying binocular glass, followed by graphic reconstruction; statistical analysis, and the study was preceded with detailed review of branches from abdominal aorta. For systematization of the segmental anatomy of the abdominal aorta and infrarenal segment of inferior vena cava, we defined three levels in this area. The retroperitoneal branches were most frequently situated simultaneously within all three predefined levels according to renal and inferior mesenteric arteries origin. There were 18% of retroperitoneal branches within Level 1, 39% within Level 2 and 43% within Level 3. They were branches not only from the abdominal aorta, but also from the testicular/ovarian artery, common iliac artery and in one case from the right accessory renal artery. Paired arrangement was recorded mainly cranially to the origin of inferior mesenteric artery, unpaired branches were more frequently found caudally. In conclusion, due to the terminological disunity of these arteries in the clinical literature and total absence in the anatomical literature, we propose to denominate them as anterior retroperitoneal branches of abdominal aorta (rami retroperitoneales anteriores aortae abdominalis).