Persistent Sciatic Artery Aneurysm with Lower Limb Ischemia

Persistent sciatic artery is a very rare clinical entity. Those of us who have not seen the lesion regard this as a condition which is described in the literature through less than 200 cases. We report, here, a case of a 60-year-old female who presented to the surgical outdoor with complaints of a pulsatile gluteal swelling associated with ischemic changes in the ipsilateral lower limb. On Doppler and CT angiographic analysis, the patient was determined as having persistent sciatic artery aneurysm which was then managed by a combined surgical and endovascular approach. Ours is probably the first such case to be reported from India. The objective of this case report is to highlight the relevant embryology, the pathognomonic presenting features, the diagnostic dilemma, management, and complications associated with a case of persistent sciatic artery (PSA). 1. Introduction PSA is a very uncommon embryological vascular aberration. The first description of such an anomaly was published as early as 1832 in the Lancet [1].The first description of aneurysm of the vessel, rupture of which resulted in the patients’ death, was reported in 1864 [2]. The embryological basis and aberrant anatomy of this artery were elucidated in 1919 by reviewing a number of published case reports highlighting this condition [3, 4]. The largest clinical review of this condition was carried out by Ikezawa et al. in 1994 who reported an occurrence of 168 cases throughout the literature [5]. Throughout the literature the incidence of PSA has been estimated to be as low as 0.025–0.04% [6]. A tendency for aneurysm formation has been noted in 14.3–44% of such cases [7]. Besides this, the PSA is prone to atherosclerosis and distal embolization. The correlation of a painful gluteal swelling with persistent sciatic artery aneurysm requires a very high index of clinical suspicion and, as in our case, clinicians at a peripheral health care centre might end up ordering for fine needle aspiration cytology of the swelling, which could prove to be catastrophic. 2. Case Presentation A 60-year-old female presented with swelling in the left gluteal region for the last 2 years. The patient also complained of pain in the swelling for the past 6 months. Additionally the patient gave history of pain in the left lower limb for the past month with blackening of the toes of left lower limb for the past week (Figure 1). Figure 1: Left foot of the patient. The arrows depict gangrene of the 1st and 2nd toes. Also note the cyanosis of the rest of toes and ischemic changes on the skin of the foot. The patient was