Mechanical distraction enterogenesis utilizing springs has equal effectiveness in adult and juvenile pigs

Purpose: We aim to apply our spring-mediated intestinal lengthening technique to adults and children with short bowel syndrome. We hypothesized that spring-mediated intestinal lengthening would be achieved in adult and juvenile pigs.

Methods: Adult and juvenile pigs underwent insertion of a compressed spring into the jejunum. Jejunum was plicated proximal and distal to the capsule for fixation and control jejunum was marked. Pigs were fed a liquid diet for one week. Spring and control segment lengths were compared using Brown-Forsythe and Welch ANOVA test.

Results: Three adult pigs weighing 30.4 ± 2.1 kg and three juvenile pigs weighing 8.9 ± 1.2 kg underwent spring insertion without complications. Springs were compressed from 7.5 to 2 cm and had an average spring constant of 9.7 ± 1.2 N/m in adults and 5.4 ± 1.5 N/m in juveniles. Springs of 1.3 cm diameter were implanted in adults and springs of 1.0 cm diameter were implanted in juveniles. Spring segments lengthened on average by 86 ± 33% in adults (p = 0.04) and 123% in juveniles (p < 0.01) when compared to the initial length. There was no statistically significant difference in lengthening between juvenile and adult pigs (p = 0.2).

Conclusion: Intestinal lengthening was feasible in adult pigs but required a higher force for their larger diameter intestine compared to juvenile pigs.