A Rat Model of Tibial Cortex Transverse Transport for the Treatment of Lower Limb Ischemia.

Abstract

Tibial cortex transverse transport (TTT) is an emerging surgical technique used to promote revascularization in ischemic lower limbs. This video demonstrates a reproducible rat model of TTT, detailing the surgical creation of a cortical bone fragment, the transport protocol, and postoperative assessments. The procedure enables controlled upward and downward transport of a bone fragment to stimulate angiogenic responses. Representative X-ray images acquired on postoperative days 1, 7, and 12, together with microvascular perfusion imaging performed on Day 19 after euthanasia, show clear bone fragment movement and improved limb perfusion following TTT. This model provides a practical and reproducible platform for investigating the molecular mechanisms underlying TTT-induced angiogenesis and evaluating potential therapeutic strategies for ischemic diseases. To construct this model, we simulated the clinical TTT procedure in Sprague-Dawley rats, involving three main surgical steps: ligation of the superficial femoral artery, creation and mobilization of a cortical bone fragment, and application of a custom external fixator. Over 12 days, the fragment was gradually transported forward and then backward. Perfusion imaging confirmed enhanced vascularization in the ischemic limb after the completion of the transport cycle. Overall, this standardized rat model closely mimics clinical TTT procedures and offers a valuable experimental system for studying mechanotransduction, angiogenesis, and vascular regeneration in ischemic limb conditions.