Adopt a wait-and-see attitude for patent processus vaginalis in neonates

The purpose of this paper is to describe the ultrasonographic findings of the patent processus vaginalis (PPV) in neonates.

The patency of the processus vaginalis was examined by ultrasonography in 117 neonates. The ultrasonographic findings, with increment and decrement of the intraabdominal pressure, were categorized into 6 types as follows: type I, the intraabdominal organ is observed; type II, cystic PPV; type III, the PPV is widened with abdominal pressure increment, the length is > or =20 mm; type IV, the PPV contains moving fluid without PPV widening; type V, the PPV is widened with abdominal pressure increment, the length is less than 20 mm; type VI, others. The authors we regarded types I to IV as PPV with inguinal hernia.

Twenty-two of 40 neonates with a birth weight under 2,500 g had PPV, including 8 with type I. Twenty of 37 premature neonates 22 to 37 gestational weeks had PPV, including 8 with type I. Eighty-one percent (13 of 16) of PPV in low-birth-weight neonates and 91% (10 of 11) in premature neonates closed spontaneously. The median ages at the time of spontaneous regression of PPV were 242 days in low birth weight neonates and 262 days in premature neonates.

Most premature or low-birth-weight neonates with PPV regress spontaneously. The inguinal hernia in neonates (especially in premature or low-birth-weight neonates) should be observed until at least 9 months of age without attempting hernia repair.