Individual and associated effects of length of inguinal canal and caliber of the sac on clinical outcome in children

Purpose: The caliber of processus vaginalis is accepted to define the clini cal outcome to be an inguinal hernia or hydrocele not based on any evaluati on. The caliber of sacs and length of inguinal canals of boys and girls wer e evaluated to define the relation of sex, age, and the diagnosis with cali ber of the sac and the length of inguinal canal. Methods: A total of 217 inguinal canals in 24 girls and 112 boys with ingui nal hernia, 30 boys with hydrocele or hydrocele of the cord, and 31 boys wi th undescended testis have been evaluated. Twenty patients had bilateral in volvement. The length of inguinal canal, and the circumference of the sac w ere measured. A formula was developed to predict the length of inguinal can al according to the age and sex. The circumferences of the sacs, length of inguinal canals, and the ratios of the circumference to the length were com pared according to the clinical pictures. Results: The regression model of the relationship between the age and the l ength of the inguinal canal is an equation of third degree (inguinal canal in millimeters) = 0.0000119 x age(3) (months) - 0.00292 X age(2) (months) 0.3168 x age (months) + 19.979 (r(2) = 0.47). Inguinal canal is longer in boys (25.133 and 27.996 mm; P = .018), and length does not differ among dia gnoses but differs according to age showing a linear growth after 24 months . Although the circumference as a sole parameter could classify only 55.3% of boys correctly, the ratio of length of inguinal canal to circumference o f the sac has been the significant parameter in classifying boys into 1 of 3 groups including inguinal hernia, undescended testis, and hydrocele with a 70.2% success rate. Conclusions: Inguinal canal that shows a linear growth after 24 months of a ge is longer in boys. Caliber is not the unique factor that determines the clinical outcome. Although the ratio of length of inguinal canal to the cir cumference of the sac defines the clinical picture best, even this paramete r can not classify the cases correctly. Therefore, some factors in addition to the caliber and length of inguinal canal might have roles in determinin g the clinical outcome. J Pediatr Surg 35:1165-1169. Copyright (C) 2000 by W.B. Saunders Company.