EPIDEMIOLOGY ã Monozygotic (identical) twins 4:1,000 births ã Dizygotic (fraternal) twins 10-15:1,000 births ã Conjoined twins: 1:50,000 births in US 1:14,000 births in Africa 60% stillborn (~30 cases/year in US) 70% female Maternal age not a factor 6% are two of triplets Always monozygotic identical twins

“SIAMESE TWINS”  Eng & Chang Bunker  Born in Siam in 1811  United by an epigastric band of tissue  Exhibited by P.T. Barnum circus  Retired to farms in North Carolina  Each married  22 children  Chang died age 63 - bronchitis  Eng died 6 hours later  Tissue band simple structure  Could have been easily separated

CONJOINED TWINS-EMBRYOLOGY  Division of zygote within first 7 days  monozygotic identical twins  Division of zygote within first 7 days  monozygotic identical twins  Incomplete fission of inner cell mass at days  conjoined twins  Day 5 - cluster of cells of zygote becomes blastocyst  Inner cell mass forms at one pole  embryo, amnion, yolk sac

CONJOINED TWINS - CLASSIFICATION ã Identified by most prominent site of connection plus Greek root pagus - “that which is fixed” – thoracopagus (thorax)40% – omphalopagus (abdomen)33% – ischiopagus (pelvis) 6% – pygopagus (sacrum)19% – craniopagus (skull) 2%

CONJOINED TWINS TypeIncidenceCommon Organs Thoracopagus40%Heart, liver, GI tract Omphalopagus33%Liver, GI tract Pygopagus19%Spine, GU, anorectum Ischiopagus 6%Pelvis, GU, GI, liver Craniopagus 2%Brain

May 26, 2000

MOHAMED SHERIFF, M.D. JFK MEDICAL CENTER

DECONTEE & MARY COLE

ANATOMY

TISSUE EXPANSION

MULTIDISCIPLINARY TEAM APPROACH – Pediatric radiology – Pediatric general surgery – Pediatric anesthesiology – Pediatric plastic surgery – Pediatric neurosurgery – Pediatric orthopedic surgery – Pediatric urology – Pediatric critical care nursing

SEPARATION SURGERY

RECTAL DISSECTION

VERTEBRAL SEPARATION

FINAL SEPARATION

PERINEAL RECONSTRUCTION

SEPARATION SURGERY

POST-OP RECOVERY