Anomalous occluded vessels and the "Corona Mortis": A reappraisal of nomenclature origins, anatomical variations, and surgical risks.

Abstract

The "corona mortis" (CMOR) typically refers to arterial or venous anastomotic branches located posterior to the superior ramus of the pubis within the Retzius space, connecting the obturator vascular system to the extrailiac or subabdominal vascular system. This anatomical variation is closely associated with inguinal hernia repair, pelvic and acetabular surgery, pelvic tumor lymph node dissection, and pelvic trauma hemorrhage. However, its nomenclature origin, terminological boundaries, and actual bleeding risk have long been controversial across disciplines. To establish standardized terminology, trace the nomenclature origins of CMOR, review its anatomical variations and incidence, summarize key imaging identification features, and propose actionable surgical risk stratification and management recommendations. We conducted a narrative review by retrieving publicly published anatomical, imaging, and clinical studies and systematic reviews from 1996 to 2025, integrating data from representative autopsies, CTA/enhanced CT, and intraoperative observations. Systematic reviews indicate that CMOR is present in approximately half of hemipelves, with venous variants significantly outnumbering arterial ones. Variations in CMOR definitions and the scope of "abnormal/accessory obturator vessels" included across studies account for the wide prevalence range. Recent large-scale CTA studies show detection rates exceeding 70% for at least one arterial or venous CMOR, indicating high imaging detection potential. Concurrently, clinical studies using certain pelvic approaches demonstrate that CMOR-related major hemorrhage is not an uncontrollable event when standardized exposure and prophylactic management are implemented. CMOR is not an "inevitably fatal" anatomical trap. Its risk depends on vessel caliber, location, whether it forms a true external iliac-obturator system communication, and the surgical scenario (e.g., tension, stapler/suture use, sharp fracture edges). It is recommended to define "CMOR" specifically as an external iliac (or infra-abdominal)-obturator artery system communicating vessel crossing the superior ramus of the pubis. Imaging and intraoperative documentation of arterial and venous attributes, vessel caliber, and distance from the symphysis pubis should be performed to support risk stratification and individualized surgical strategies.