BackgroundThe repair of large abdominal wall defects that cannot be closed primarily is quite challenging. The component separation technique (CST) is a surgical approach using autologous tissue to close large abdominal wall defects. The CST requires extensive dissection between the abdominal skin and the anterior sheath of the rectus abdominis muscle. Subsequently, incisions are made at both sides of the external oblique aponeurosis, releasing the external oblique muscle from the internal oblique muscle, and then the right and left rectus abdominis muscles are brought together in the midline for defect closure. However, impairment of blood flow in the abdominal wall skin and necrotic changes are recognized as potential complications.Case presentationThe CST was performed in a 4-year-old boy with a large ventral hernia who had undergone skin closure with abdominal wall relaxing incisions for the primary treatment of giant omphalocele in the neonatal period. Given his history of incisions on the abdominal wall, he was speculated to be at high risk for postoperative skin ischemia. Dissection was therefore kept to a minimum to preserve the blood supply from the superior and inferior epigastric arteries and perforating branches of those arteries through the rectus abdominis muscle. In addition, care was taken to adjust the muscle relaxant dosage while monitoring the intravesical pressure, ensuring that it did not exceed 20 mmHg to avoid impaired circulation in the abdominal wall caused by abdominal compartment syndrome. He was discharged 23 days after the surgery without any complications, and neither recurrence of the ventral hernia nor bowel obstruction was observed in 4 years.ConclusionsA giant omphalocele with primary skin closure was treated by applying the CST. The procedure can be performed safely while preserving the blood flow to the abdominal wall, even in patients with a history of relaxing incisions on the abdominal skin. The CST is expected to be effective for repairing the large abdominal wall defects seen in giant omphalocele when primary closure is not possible.