Therapeutic effect of colonic spring expansion and interposition into the small intestine on short bowel model in...

Short bowel syndrome (SBS) is a morbid disease with limited effective treatment modalities. Spring-mediated intestinal distraction has been successfully applied to lengthen the small intestine. This study investigates the therapeutic efficacy of spring-induced colonic lengthening followed by interposition into the small intestine in a rat SBS model.

Twenty Sprague-Dawley rats matched for age and body weight were selected and randomly divided into four groups. Two groups underwent the implantation of nitinol spring-loaded capsules into the colon, while the other two groups underwent colonic resection and anastomosis only. After 3 weeks, 75% of the small intestine was resected, and three of the groups underwent colonic segment transplantation, while the other group did not. Four weeks later, tissue samples were collected and evaluated for histology and the expression of proliferation-related genes.

Compressed spring-implanted colonic segments elongated to 300%±50% of their initial length. One week after colonic interposition, the rate of weight loss slowed significantly (P < 0.01). Compared with the original colonic segments (127±45 μm), the circular muscle layers thickness of the elongated colonic segments (145±40 μm) in the compressed spring group increased (P < 0.01), but there was no significant change in crypt depth (P > 0.1). The interposed colonic segments exhibited higher PCNA expression than the native colon segments, with the highest expression levels (166±10 a.u.) observed in the compressed spring group.

Spring-mediated colonic lengthening and interposition can improve intestinal absorption and survival in SBS rats, showing translational potential for SBS treatment.