How surgeons helped extremely rare conjoined 'spider twins' born with 3 legs & 4 arms

The twins' initial years were marked by severe limitations. (Image: amjcaserep.com)

A pair of conjoined twins in Indonesia, connected at the pelvis and sharing seven limbs, have defied overwhelming odds to survive. This rare condition, affecting only one in two million births, highlights both the challenges and triumphs of modern surgical interventions.

Born in 2018, the ischiopagus-tripus twins, also called 'spider twins' were connected in a unique configuration that included three legs, four arms, and a shared penis. The condition, in which twins are joined at the lower half of the body, is an exceedingly rare subset of conjoined twin cases. Their case was recently detailed in the American Journal of Case Reports.

Despite their complex anatomy, which included a single functioning bladder, rectum, and intestinal tract, the twins managed to survive both gestation and childbirth. This is a significant feat, as over 60% of conjoined twins do not survive the perinatal period.

However, the twins' initial years were marked by severe limitations; their unique configuration prevented them from sitting up, confining them to a flat position for the first three years of their lives.

Medical intervention has played a crucial role in improving their quality of life. Surgeons performed a critical operation to amputate their third leg and stabilise their hip and pelvis, enabling the boys to sit upright and gain a measure of independence.

A follow-up appointment three months post-surgery confirmed that the twins had not experienced any complications from the procedure, a promising sign for their future development.

The possibility of separating the twins remains uncertain due to the complexity and rarity of their condition. "The rarity of ischiopagus tripus conjoined twins complicates the surgical separation, owing to the lack of cases and high complexity," the study authors explained. Despite these challenges, the medical team remains hopeful.

They believe that the successful stabilisation surgery demonstrates that "there is still room for surgical correction to be performed" even in cases where full separation might be impossible.

This case is reminiscent of another successful separation in 2022, where doctors in China managed to separate conjoined twins who shared a penis and testes but had no anus. These twins had two functioning arms and legs, along with one non-responsive fused leg, and the successful separation highlighted the advancements in surgical techniques and medical care.

According to the Mayo Clinic, conjoined twins result from a congenital defect that occurs when an embryo only partially separates to form two individuals. This anomaly most commonly results in physical connections at the chest, abdomen, or pelvis. Of these, only 6 to 11% of conjoined twins are ischiopagus.