Intermittent pneumatic compression enhances neurovascular ingrowth and tissue proliferation during connective tissue healing: A study in the rat

Intermittent pneumatic compression (IPC) is a treatment method to decrease venous stasis and stimulate blood flow. Recently, it was hypothesized that IPC may exert positive effects on tissue healing, a process highly dependent upon adequate circulation. In this study, we investigated the effects of daily 1-h IPC treatment during 2 and 4 weeks post-rat Achilles tendon rupture. The tendons were subjectively and semiquantitatively analyzed for collagen organization, fibroblast density, angiogenesis, and the occurrence of sensory neuropeptides, substance P (SP) and calcitonine gene related peptide (CGRP), as well as for a nerve regeneration marker, growth associated protein 43 (GAP-43). After 2 weeks of treatment, fibroblast density increased by 53% (p = 0.0004), vessel density by 64% (p = 0.022), and the occurrence of SP by 110% (p = 0.047) and CGRP by 47% (p = 0.0163) compared to untreated controls. Following 4 weeks of treatment, both the occurrence of sensory neuropeptides and the vessel density remained significantly higher (p < 0.05), whereas fibroblast density returned to normal. However, at 4 weeks the treated tendons displayed a higher degree of organized parallel collagen fibers, a sign of increased maturation. Daily IPC treatment improves neurovascular ingrowth and fibroblast proliferation in the healing tendon and may accelerate the repair process.