Chronic pain after inguinal hernia repair in children

The prevalence of moderate-to-severe pain after inguinal hernia repair (IHR) in adults is ≈ 10%. Two studies with very long follow-up periods (16.8 and 49 yr, respectively) have, however, suggested that the risk of developing chronic pain is much lower in children. The purpose of the present study was to examine the prevalence of chronic pain 6-48 months after IHR in children.

Postal questionnaires were sent to 156 children who had undergone IHR between the age of 6 months and 12 yr. The children were asked to recall the duration of postoperative pain, if necessary with help from their parents, and to describe the intensity and character of their pain, if the pain was still present. Children with chronic pain were offered quantitative sensory testing (QST), and a surgical examination, including ultrasound, in order to exclude hernia recurrence.

Ninety-eight children, mean (sd) age 7.8 (2.6) yr, answered the questionnaire. Their age at the time of surgery was mean (sd) 4.6 (2.4) yr, and the follow-up period was mean (sd) 3.2 (1.3) yr. Five children (5.1%, 95% confidence interval: 0.75-9.5) had pain located in the inguinal region, and three of these children underwent further examination. There was no hernia recurrence, but QST revealed pinprick hyperalgesia and decreased pressure pain thresholds on the operated side in all three children.

The prevalence of chronic pain after IHR in children is 5.1%, which is lower than the prevalence reported after adult hernia repair.