The microsurgical anatomy of the paracentral lobule artery: a cadaveric series

Purpose The paracentral lobule artery (PLA) is a typically present branch of the distal anterior cerebral artery (ACA), irrigating the homonymous lobule. The PLA origin is either a pericallosal portion of the ACA or a prominent branch of the ACA termed callosomarginal (CMA). In addition to the paracentral lobule, the PLA irrigates the cingulate gyrus in the medial hemispheric surface, and the superior portion of the precentral and postcentral gyri in the lateral hemispheric surface. The present cadaveric case series aimed at establishing previously unreported morphometric estimates of the PLA, including its length according to its site of origin, its supplying branches according to its distribution area, as well as its anastomoses. Methods Seventeen colored latex-injected cadaveric heads were studied with a surgical microscope and microsurgical instruments. Results The PLA was invariably present and most commonly originated from the A4 (n = 15 hemispheres, 50%) segment of the ACA. Other PLA origins were the CMA (n = 10, 30%), the A3 (n = 5, 16.7%) and the A5 (n = 1, 3.3%) segments. When the PLA originated from the A4, its mean (SD) overall length was 7.6 (17.9) mm and its mean (SD) diameter was 0.88 (0.26) mm. The PLA supplied the paracentral lobule, cingulate gyrus and post central gyrus with a mean (SD) of 28.07 (13.4), 8.53 (4.27), 5.92 (4.4) branches respectively and the precentral gyrus with a median [IQR] of 2 [0–6] branches. The most common anastomoses of the PLA in the medial and the lateral hemispheric surface involved the ipsilateral posterior internal frontal artery and the branches of the middle cerebral artery, respectively. There were no significant differences between genders or hemispheric sides for the anatomical features of the artery analyzed. Conclusion The present study established previously unreported morphometric estimates for the PLA by considering all possible PLA variant origins and morphological variants. Given that variable pathologies have been previously detected in the areas supplied by the PLA, a better understanding of its anatomy can aid surgical planning and approaches.