Persistent sciatic artery. Case report

Reasonable classical concepts in human lower limb anatomy from the viewpoint of the primitive persistent sciatic artery and twisting human lower limb

The main aim of this review is (1) to introduce the two previous studies we published human lower limb anatomy based on the conventional macroscopic anatomical [corrected] criteria with hazardous recognition of this description, (2) to activate the discussion whether the limb homology exists, and (3) to contribute to future study filling the gap between the gross anatomy and embryology. One of the topics we discussed was the human persistent sciatic artery. To date, numerous human cases of persistent sciatic artery have been reported in which the anomalous artery was present in the posterior compartment of the thigh alongside the sciatic nerve. As one of the important criteria for assessing the human primitive sciatic artery, its ventral arterial position with respect to the sciatic nerve is reasonable based on the initial positional relationship between ventral arterial and dorsal nervous systems and comparative anatomical findings. We also discuss ways of considering the topography of muscles of the lower limb and their innervations compared to those of the upper limb. We propose a schema of the complex anatomical characteristics of the lower limb based on the vertebrate body plan. According to this reasonable schema, the twisted anatomy of the lower limb can be understood more easily. These two main ideas discussed in this paper will be useful for further understanding of the anatomy of the lower limb and as a first step for future. We hope that the future study in lower limb will be further developed by both viewpoints of the classical gross anatomy and recent embryology.

Large-caliber persistent sciatic artery with aneurysm

Herein is reported a rare case of right persistent sciatic artery (PSA) in the cadaver of a 96-year-old woman who did not have any clinical manifestations related to this anomaly when alive. The anomalous PSA originated from the internal iliac artery, directed toward the infrapiriform foramen, and descended the dorsal side of the thigh. Approximately 20 mm inferior to the infrapiriform foramen, the PSA formed a relatively large aneurysm elongating for approximately 30 mm in length. It then passed under the long head of the femoral biceps muscles, and reached the popliteal fossa, maintaining a constant caliber (approx. 13 mm) as it went down distally. In contrast, the femoral artery was very narrow, and tapered at the level of the knee joint. In addition, the popliteal vein gave rise to two branches, one ran along with the sciatic artery and the other pierced the adductor muscles, and appeared on the ventral side of the thigh. It then drained into the deep femoral vein, which reached the pelvis via the femoral vein. The present case is an interesting example for clinicians who work in pelvic surgery.

Bilateral persistent sciatic arteries in a Japanese man

During student dissecting practice, a rare developmental anomaly showing persistent sciatic artery (PSA) was found in the bilateral lower limbs of a 74-year-old Japanese male cadaver. The PSA was a continuation of the internal iliac artery on both sides, did not anastomose with the perforating arteries and ended by anastomosing with the popliteal artery on both sides. The course and distribution of the PSA were relatively consistent with previous reports. In the present case, however, the PSA and inferior gluteal arteries existed simultaneously on both sides, despite the general assumption that the inferior gluteal artery is a remnant of sciatic artery regression.