The journey to separate the Conjoined Twins
August 19, 2021
The video shows a simulation exercise ahead of planned surgery for Conjoined Twins connected at the head. A team of Nurses from Ghana’s biggest hospitals assembled at the Greater Accra Regional Hospital, Ridge.
What are conjoined twins?
Doctors at the Greater Accra Regional Hospital (GARH) have separated 25 sets of conjoined twins and have managed the care of many others whose separation was not surgically possible.
Evaluation and diagnosis
Expectant mothers visiting the Center for Fetal Diagnosis and Treatment at GARH will undergo a full day of advanced imaging to collect a detailed picture of the shared organs and any associated anomalies. Prenatal diagnosis will help identify the optimal treatment and delivery plan, and potential for separation after birth.
- Fetal ultrasound: A safe, noninvasive procedure that uses high frequency sound waves to provide detailed high-resolution images, including 3-D and 4-D views. Our team of board-certified radiologists uses highly specialized equipment to ensure the best images possible are obtained.
- Fetal echocardiogram: A noninvasive ultrasound procedure that assesses the structure and function of the fetal heart. Fetal echocardiogram is the most important test for the evaluation of conjoined twins, as it determines if the twins share a heart and if so, where that connection occurs.
- Ultrafast fetal MRI: An imaging technique pioneered at the Children’s Hospital that can include 3-D MRI reconstruction. It requires no sedation of mother or muscle relaxants for the fetus to obtain images. Used with the ultrasound images, the fetal MRI adds another level of detail.
Indicators of conjoined twins include the lack of a separating membrane between the twins, inability to separate the fetal bodies, and constant position of the fetal heads.
- 75 percent are joined at the chest wall or upper abdomen (thoracopagus and omphalopagus)
- 23 percent are joined at the hips, legs or genitalia (pygopagus and ischiopagus)
- 2 percent are joined at the head (craniopagus)
Thoracopagus: The most common type of conjoined twin, which along with omphalopagus, represents about 75 percent of cases. The two babies lie face to face and share a common sternum, diaphragm and upper abdominal wall. In cases of conjoined hearts at ventricular (pumping chamber) level, there are no known survivors.
Omphalopagus: The least-complicated connection, usually considered a subgroup of thoracopagus. The babies face one another and are joined at the anterior abdominal wall from xiphoid to umbilicus. The peritoneal cavity of one tends to be joined with the other, but upper intestinal tracts are usually separate. In the majority of cases, a bridge of liver connects the infants.
Pygopagus: Represents about 20 percent of cases, joined at the buttocks and perineum, facing away from each other. A significant length of the sacrum may be fused, and as a result, the twins often share the sacral spinal canal. A single lower rectum and anus is common, and often the lower genital tract and external genitalia are fused.
Ischiopagus: Represents less than 5 percent of cases, the connection occurs at a single bony pelvis. Four normal legs may be attached, but often two of the four are fused into one malformed limb. The intestinal tracts often join and empty into a single colon.
Craniopagus: The least common type of conjoined twins, accounting for 2 percent of cases, is represented by fusion of the skull. The twins often share large dural sinuses and vascular structures. Rarely, the brains are separated by bone and each brain has separate leptomeninges. In others, the brains are connected, or separated only by arachnoid, making separation extremely difficult and dependent upon a superior sagittal sinus for each brain.
Planning for delivery
Patients carrying conjoined twins have the option of delivering in a location with direct access to all the advanced, specialized services both mom and baby is particularly important for high-risk conjoined twin pregnancies that require a C-section or a potential ex utero intrapartum therapy (EXIT) delivery. The EXIT procedure is a “partial delivery” in which the fetus is partially removed from the uterus but remains attached to the circulation carried by the umbilical cord and placenta so that surgeons can correct airway blockages before performing a full delivery.