Incidence of and Risk Factors for Pediatric Metachronous Contralateral Inguinal Hernia: Analysis of a 17-Year Nationwide Database in Taiwan.
BACKGROUND
Previous prospective, retrospective, and meta-analysis studies revealed that the overall incidence of metachronous contralateral inguinal hernia (MCIH) ranges from 5.76% to 7.3%, but long-term follow-up postoperative data are scant. We identified the incidence and risk factors of MCIH in pediatric patients during the follow-up using the Taiwan National Health Insurance Research Database (NHIRD).


METHODS
Between 1996/01/01 and 2008/12/31, all pediatric patients with primary unilateral inguinal hernia repair who were born after 1996/01/01 were collected via ICD-9 diagnostic and procedure codes recorded in NHIRD. Patients with another operation during the same admission, complicated hernia, or laparoscopic procedure were excluded. Several reported risk factors, including age, sex, preterm birth, low body weight, and previous ventriculoperitoneal shunt placement, were used for analysis. The primary endpoint was the repairmen of MCIH following the initial surgery. All patients were followed until 2013/12/31 or withdrawal from national health insurance.


RESULTS
A total of 31,100 pediatric patients underwent unilateral inguinal hernia repair, and 111.76 months of median follow-up data were collected. The overall rate of MCIH was 12.3%. Among the 31,100 patients who had the hernia repair, 63.6% had MCIH within 2 years and 91.5% had MCIH within 5 years. After initial surgery, the incidence of MCIH gradually and significantly decreased with age up to approximately 6 years. Multivariable analysis showed that age <4 y and girls were risk factors for subsequent MCIH.


CONCLUSIONS
After 17 years of follow-up, the overall MCIH rate was 12.3%, and 91.7% of patients needed repair for MCIH within the first 5 years after initial surgery. Age <4 years and girls were risk factors for MCIH. The contralateral exploration for inguinal hernia should be considered among these patients.
Department of General Surgery, Buddhist Dalin Tzu Chi Hospital, Chia-Yi, Taiwan.|School of Medicine, Tzu Chi University, Hualien, Taiwan.
Cheng-Hung
CH
Lee
Department of Surgery, Far Eastern Memorial Hospital, Pan-Ciao, New Taipei, Taiwan.
Yun
Y
Chen
Department of General Surgery, Buddhist Dalin Tzu Chi Hospital, Chia-Yi, Taiwan.|School of Medicine, Tzu Chi University, Hualien, Taiwan.
Chi-Fu
CF
Cheng
Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li, Taoyuan City, 32003, Taiwan.|Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Chung-Li, Taoyuan City, 32003, Taiwan.
Chao-Lin
CL
Yao
Department of General Surgery, Buddhist Dalin Tzu Chi Hospital, Chia-Yi, Taiwan.|School of Medicine, Tzu Chi University, Hualien, Taiwan.
Jin-Chia
JC
Wu
Department of General Surgery, Buddhist Dalin Tzu Chi Hospital, Chia-Yi, Taiwan.|School of Medicine, Tzu Chi University, Hualien, Taiwan.
Wen-Yao
WY
Yin
Department of General Surgery, Buddhist Dalin Tzu Chi Hospital, Chia-Yi, Taiwan.|School of Medicine, Tzu Chi University, Hualien, Taiwan.
Jian-Han
http://orcid.org/0000-0001-7360-2238
JH
Chen
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