Separation of craniopagus joined at the occiput

Abstract

Siamese or conjoined twins have intrigued both the physician and layperson for centuries. The craniopagus type (joined at the head) is exceedingly rare, with an incidence of one in 2.5 million births. Most clinicians never see a case of craniopagus, and those who do rarely see more than one. The authors present a case of the craniopagus type of conjoined twins born and recently separated in Brisbane, Australia. The prenatal diagnosis, subsequent investigations, separation, and outcome are presented.

Craniopagus: second Brisbane case

“…In October 2000, twins joined at the occiput underwent separation at our institution. 2 In April 2001, Nepalese craniopagi were successfully separated in Singapore. In 2002, twins were successfully separated in the US (unpublished data).…”

Role of biplane digital subtraction angiography, and 3D rotational angiography in craniopagus twins: A case report, detailed pictorial evaluation, and review of literature

“…Females are more commonly affected, with a male / female ratio of 1:4. [7] These twins can be joined at the vertex, at the side, or at the forehead; the vertical type being the most common. O’Connell's classification denotes three anatomical types for vertical craniopagus, based on relative facial orientation (type 1: face same direction; type 2: face opposite direction (140 – 180 degrees) and type 3: intermediate angle of rotation of the long axis of one head on that of the other).…”

Successful Separation of Craniopagus Parasiticus

“…3). The fused sinus ran around the perimeter of the connection between the two heads, referred to as the circumferential sinus (4,7).The circumferential sinus was closer to the parasitic brain and was draining both brains. A complex and primitive deep venous system existed with eventual drainage into the shared circumferential sinus.…”