Dear Editor:

We read with interest the article by Pini Prato et al. that investigated the outcomes of open inguinal hernia repair in neonates and ex-preterm babies weighing less than 5 kg. The authors performed 184 herniotomies in 154 patients (male to female ratio 4.5:1) [1]. We would like to congratulate the authors on their work; however, we have found several mistakes.

First, the authors observed 20 complications in overall 184 herniotomies and a rate of complications of 9.8%. However, when we recalculated this rate, we found a rate of 10.9% (20/184). Second, they reported the rate of testicular atrophy, hydrocele and testicular ascent taking into account all hernia repairs, including the girls. We think that the rate of should testicular atrophy, hydrocele and testicular ascent should be calculated taking into account not the number of all the patients, but the number of inguinal repairs in males. Therefore, these rates should be greater than those reported. Finally, their rate of recurrence was 4.5% (8/184), but when we recalculated this rate, we found a rate of 4.3%.

Surprisingly, we observed similar mistakes in other papers [2,3,4,5]. Some authors calculated the rate of postoperative complications such as hydrocele, testicular atrophy or high testes without excluding female patients [2, 3]. On the other hand, several authors calculated the recurrence rate based on the number of patients [2,3,4,5]. We think that recurrence rate should be calculated taking into account not the number of patients, but the number of inguinal repairs.

As a consequence of these discrepancies, many studies are not comparable, making it impossible to perform a metaanalysis. In the era of laparoscopic surgery, it seems interesting to us to improve the accuracy of these comparisons. Therefore, we would like to highlight the need of strict formulas to calculate these rates of postoperative complications. We again thank the authors for their contribution.