Corona Mortis

Important for inguinal hernia anatomy and surgery, this term is Latin from [corona] meaning "crown' and [mortis] meaning "death'; the "crown or circle of death". The corona mortis (blue arrow) refers to an anatomical variation1, a vascular anastomosis between the obturator and the external iliac vascular systems that passes over Cooper's pectineal ligament and posterior to the lacunar (Gimbernat's) ligament. 

In some cases, the corona mortis is the actual obturator artery that arises from the inferior epigastric artery instead of the internal iliac artery. It can also arise from the external iliac artery. In both cases, it has been called an "aberrant obturator artery". This could be a misnomer, as this anatomical variation can be present in up to 25% of the cases. When present, the corona mortis  can be injured when a surgeon looks to enlarge the femoral ring by opening the lacunar ligament from the anterior aspect. In this approach the "corona mortis" is not visible, as it is found immediately posterior to the lacunar ligament. This vascular structure could even be endangered in a laparoscopic procedure for inguinal of femoral hernia repair and a staple or tack is driven blindly into the pectineal (Cooper's) ligament.

Corona Mortis (A)Image property of:CAA.Inc.Artist:M. Zuptich

Berberoglu states that "although these tiny anastomoses... have been described in classical anatomy textbooks, these texts neglect to mention that theses anastomoses can be life-threatening".

In some rare cases, the corona mortis (aberrant obturator artery) coexists with the normal obturator artery.  Although called a [corona], this anatomical structure is an incomplete circle. In the image, the [corona mortis] is labeled "A".

Sources:
1. Rusu et al: "Anatomical considerations on the corona mortis" Surg Radiol Anat (2010) 32:17–24
2. Berberoglu et al: "An anatomic study in seven cadavers and an endoscopic study in 28 patients" Surg Endosc (2001) 15:72-75