Separation of craniopagus twins in the era of modern neuroimaging, interventional neuroradiology, and frameless stereotaxy.
BACKGROUND
Craniopagus twinning is a rare embryological event occurring in 1 in 2.5 million births.


METHODS
We present our recent experience with the separation of total vertical craniopagus twins in the modern era of neuroimaging and interventional neuroradiology. Three-dimensional CT images revealed the twins' heads were axially rotated 30 degrees. MRI showed deficient dura between the brains of the twins, and some sharing of parietal brain tissue. Cerebral angiography showed a dominant arterial circulation of one twin with unilateral middle cerebral artery (MCA) branches feeding the other twin. The twins shared a common superior sagittal sinus in its middle segment where a circular sinus was formed. Prior to surgery, endovascular separation of the twins' arterial and venous circulations was achieved in part using tantalum coils for the MCA feeders in one twin, and balloon occlusion of the anterior superior sagittal sinus of the other. Using the ISG wand intraoperatively, surgery proceeded stepwise and included the circumferential removal of bone and opening of the dura, separation of the twins' brains along leptomeningeal planes, and identification of the major draining veins from the superficial cerebral cortex.


CONCLUSIONS
The separation of craniopagus twins demands a multidisciplinary team approach. Utilizing preoperative neuroendovascular techniques to occlude shared vascular anastomotic channels, complex total vertical craniopagus twins can now be successfully separated in a one-stage procedure.
Division of Neurosurgery, Hospital for Sick Children, University of Toronto, Suite 1504, 555 University Avenue, Toronto, ON, M5G 1X8, Canada. james.rutka@sickkids.ca
James T
JT
Rutka
Mark
M
Souweidane
Karel
K
ter Brugge
Derek
D
Armstrong
Ron
R
Zuker
Howard
H
Clarke
Robert
R
Creighton
Elizabeth
E
McLeod
Anthony
A
Khoury
Harold J
HJ
Hoffman
D002675:Child, Preschool; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D020768:Middle Cerebral Artery / Q000473:pathology / Q000601:surgery; D038361:Neuronavigation / Q000379:methods*; D009485:Neuroradiography / Q000379:methods*; D009493:Neurosurgery; D013518:Surgery, Plastic; D016896:Treatment Outcome; D014428:Twins, Conjoined / Q000601:surgery*