EPIDEMIOLOGYEPIDEMIOLOGY

Monozygotic (identical) twins 4:1,000 birthsMonozygotic (identical) twins 4:1,000 births Dizygotic (fraternal) twins 10-15:1,000 birthsDizygotic (fraternal) twins 10-15:1,000 births Conjoined twins:Conjoined twins:

1:50,000 births in US1:50,000 births in US 1:14,000 births in Africa1:14,000 births in Africa

60% stillborn (~30 cases/year in US)60% stillborn (~30 cases/year in US)70% female70% femaleMaternal age not a factorMaternal age not a factor6% are two of triplets6% are two of tripletsAlways monozygotic identical twinsAlways monozygotic identical twins

““SIAMESE TWINS”SIAMESE TWINS”

Eng & Chang BunkerEng & Chang Bunker

Born in Siam in 1811 Born in Siam in 1811

United by an epigastric band of United by an epigastric band of

tissuetissue

Exhibited by P.T. Barnum circus Exhibited by P.T. Barnum circus

Retired to farms in North Carolina Retired to farms in North Carolina

Each married Each married 22 children 22 children

Chang died age 63 - bronchitis Chang died age 63 - bronchitis

Eng died 6 hours later Eng died 6 hours later

Tissue band simple structure Tissue band simple structure

Could have been easily separated Could have been easily separated

CONJOINED TWINS-CONJOINED TWINS-EMBRYOLOGYEMBRYOLOGY

Division of zygote within first 7 days Division of zygote within first 7 days monozygotic identical twins monozygotic identical twins

Incomplete fission of inner cell mass at Incomplete fission of inner cell mass at 13-16 13-16 days days conjoined twins conjoined twins

Day 5 - cluster of cells ofDay 5 - cluster of cells of zygote becomes blastocyst zygote becomes blastocyst

Inner cell mass forms atInner cell mass forms at one pole one pole embryo, amnion, yolk embryo, amnion, yolk sacsac

CONJOINED TWINS - CONJOINED TWINS - CLASSIFICATIONCLASSIFICATION

Identified by most prominent site of Identified by most prominent site of connection plus Greek root connection plus Greek root paguspagus - - “that which is fixed”“that which is fixed”

– – thoracopagus (thorax)thoracopagus (thorax)40%40%

– omphalopagus (abdomen)– omphalopagus (abdomen)33%33%

– ischiopagus (pelvis)– ischiopagus (pelvis) 6% 6%– pygopagus (sacrum)– pygopagus (sacrum) 19%19%– craniopagus (skull)– craniopagus (skull) 2% 2%

CONJOINED TWINSCONJOINED TWINS

TypeType IncidenceIncidence Common OrgansCommon Organs

ThoracopagusThoracopagus 40%40% Heart, liver, GI tractHeart, liver, GI tractOmphalopagusOmphalopagus 33%33% Liver, GI tractLiver, GI tractPygopagusPygopagus 19%19% Spine, GU, anorectumSpine, GU, anorectumIschiopagusIschiopagus 6% 6% Pelvis, GU, GI, liverPelvis, GU, GI, liverCraniopagusCraniopagus 2% 2% BrainBrain

May 26, 2000May 26, 2000

MOHAMED SHERIFF, M.D.MOHAMED SHERIFF, M.D.JFK MEDICAL CENTERJFK MEDICAL CENTER

E-MAILE-MAIL

DECONTEE & MARY DECONTEE & MARY COLECOLE

ANATOMYANATOMY

TISSUE EXPANSIONTISSUE EXPANSION

TISSUE EXPANSIONTISSUE EXPANSION

TISSUE EXPANSIONTISSUE EXPANSION

MULTIDISCIPLINARY MULTIDISCIPLINARY TEAM APPROACHTEAM APPROACH

– – Pediatric radiologyPediatric radiology– Pediatric general surgery – Pediatric general surgery – Pediatric anesthesiology– Pediatric anesthesiology– Pediatric plastic surgery – Pediatric plastic surgery – Pediatric neurosurgery– Pediatric neurosurgery– Pediatric orthopedic surgery– Pediatric orthopedic surgery– Pediatric urology– Pediatric urology– Pediatric critical care nursing– Pediatric critical care nursing

SEPARATION SURGERYSEPARATION SURGERY

SEPARATION SURGERYSEPARATION SURGERY

SEPARATION SURGERYSEPARATION SURGERY

SEPARATION SURGERYSEPARATION SURGERY

RECTAL DISSECTIONRECTAL DISSECTION

VERTEBRAL VERTEBRAL SEPARATIONSEPARATION

FINAL SEPARATIONFINAL SEPARATION

PERINEAL PERINEAL RECONSTRUCTIONRECONSTRUCTION

SEPARATION SURGERYSEPARATION SURGERY

POST-OP RECOVERYPOST-OP RECOVERY

POST-OP RECOVERYPOST-OP RECOVERY