Anatomy of Corona Mortis: A High Risk Yet Rare Lesson for Medical Students

Abstract

Introduction Knowledge ofretro-pubic pelvic vascular anatomy and in particular the “Corona Mortis” (CMOR) is important to prevent vascular catastrophes during surgery. It is not very uncommon to find CMOR in routine dissections and during surgeries. However, it being a harbinger of a surgical disaster is not known to many medical students. CMOR also known as “crown of death” is the space posterior to the superior ramus of the pubis where there is anastomosis between the external iliac, inferior epigastric and aberrant obturator vessels. Anomalous obturator vessels in the retro-pubic region are at risk of getting accidentally injured during groin or pelvic surgeries. Injury to these vessels can result in significant hemorrhage which may pose difficulty in achieving hemostasis. Hence, anatomical knowledge of these variations are important for surgeons and interventional radiologists. The aim is to increase the awareness of this important anatomical vascular landmark to medical students and highlight its clinical implications during surgical and radiological procedures. Materials and methods Among 38 hemisected pelvises dissected between years 2018-2020, the origin and course of the obturator artery as traced for anatomic variations. Anatomical illustrations of the retro-pubic area were created and digital subtraction angiography images were obtained to supplement the findings and further implicate the clinical importance of this region. Results We found aberrant obturator arteries in 8 pelvises (21.05 %). In 4 hemi-pelvises (9.5 %), the obturator artery originated from the inferior epigastric artery. The Computed Tomography (CT) and Digital Subtraction Angiography (DSA) images show the aberrant obturator artery arising from the inferior epigastric artery. Such obturator arteries are especially prone to injury during laparoscopic herniorrhaphy during dissection of the Bogros’ space and mesh stapling onto Cooper's ligament. Once cut, the obturator artery retracts into the retro-pubic space and results in hemorrhage that is difficult to control. In certain pelvic fractures with uncontrolled bleeding and hemodynamic instability, angio-embolization is the preferred modality of treatment. Knowledge of the aberrant obturator artery is essential for interventional radiologists in order to accurately identify and embolize the source of the bleeding. Conclusion Given the wide-scope clinical significance that CMOR exhibits across medical specialties, knowledge regarding this vascular anatomic variation of the obturator artery is a crucial teaching topic for medical students as well as clinicians who will likely be exposed to such cases during clinical rotations and residency,