Pilorus

Pilorus is a conjoined twin condition characterized by the joining of twins primarily at the sacral region and lower spine. In pilorus twins, the pelvis, lower limbs, and sometimes the abdominal region are fused. The degree of fusion can vary considerably, ranging from a relatively superficial connection to a more extensive integration of internal organs. The upper bodies and heads are typically separate and well-formed.

The condition is extremely rare, occurring in an estimated 1 in 50,000 to 1 in 100,000 births. As with other forms of conjoined twinning, the exact cause of pilorus is not fully understood, but it is believed to arise from incomplete separation of the monozygotic (identical) twin embryos during early gestation. Specifically, the separation process, which normally occurs around 13 days post-conception, is disrupted, leading to physical fusion.

Diagnosis of pilorus can be made prenatally through ultrasound and magnetic resonance imaging (MRI). These imaging techniques allow for detailed visualization of the fetal anatomy and can identify the extent of the conjoined area and the involvement of internal organs.

The management of pilorus twins presents significant ethical and surgical challenges. Depending on the complexity of the fusion and the health status of each twin, separation surgery may be considered. However, separation is not always possible or advisable, particularly if vital organs are shared or the prognosis for one or both twins is poor. The decision regarding separation requires careful evaluation by a multidisciplinary team of specialists, including surgeons, neonatologists, ethicists, and other relevant healthcare professionals. The team must weigh the potential benefits and risks of surgery, taking into account the long-term quality of life for both twins. If separation is deemed not viable or not in the best interest of the twins, supportive care is provided to maximize their comfort and well-being.