451 - A novel minimally invasive percutaneous disc hydration filament for tr...

General Session: Innovative Technologies

Presented by: J. Shi - View Audio/Video Presentation (Members Only)

Author(s):

J. Shi(1), Y. Yang(1), F. Zhou(1), H. Zhang(1), H. Yang(1), J. Yeung(2), H. Yuan(3)

(1) The First Affiliated Hospital of Soochow University, Suzhou, China
(2) Aleeva Medical Inc, San Francisco, CA, United States
(3) State University of New York, Upstate Medical University, New York, NY, United States

Abstract

Objective: To study the mechanism of a minimally invasive lumbar disc hydration filament (a braided nylon suture, DHF) for treating discogenic low back pain, and analyze its short term clinical outcome.

Methods: (1) In-vitro study, 2, 4 and 6 mM lactic acid solutions were titrated with fresh pork blood to plot the titration curves. Braided nylon sutures were used as the DHF to show capillary action and blood absorbing capabilities. (2) In-vivo study, braided nylon sutures were implanted into lumbar discs of 36 sheep, euthanization at 1-, 3-, 6-, 12- and 30-months. H&E histology stain was used to evaluate biocompatibility of the nylon suture in and around intervertebral discs; and Safranin-O stain was used to evaluate accumulation of proteoglycans around the nylon filaments of braided sutures as DHF. (3) Fifteen patients were diagnosed with discogenic low back pain by discography. The DHF were implanted under local anesthesia through discography needles. Patients had DHF implanted into the following levels of lumbar discs: one L3-4 patient, six L4-5 patients, seven L5-S1 patients, and one L3-4 and L4-5 patient. Clinical outcome evaluation was compared between follow up and baseline VAS, ODI and MRI. Follow-up time points were one-week, three-months, one-year and two-years after implantation. MRI were taken at 3-, 12- and 24-months follow-up.

Results: In-vitro studies, titration of lactic acid solutions with fresh pork blood showed a steep curve beginning at pH 6.65, requiring a large amount of blood to raise pH of the lactic acid solutions to pH 7.14. Incidentally, average pH of painful discs from discectomies was also pH 6.65, lacking sufficient blood to neutralize lactic acid. Average pH of non-painful discs was pH 7.14. In-vivo studies, DHF discs of sheep were harvested. H&E histology stain showed no cellular reaction to the nylon filaments within sheep discs during all euthanized time points, indicated biocompatible of nylon suture in intervertebral discs. Safranin-O staining showed gradual increase of proteoglycans around nylon filaments in sheep discs. For the pilot clinical, improvement of VAS and ODI was highly statistically significant (p< 0.01) during 1-week, 3-, 12- and 24-month follow-up. VAS improvement at 2 years follow up was 79.16%±12.33%. ODI improvement at 2 years follow up was 77.42%±12.20%. Radiological examinations after implant showed no obvious decrease of disc height in part of disc after DHF, and no continual disc degeneration according to Pfirrmann grading scheme.

Conclusion: Percutaneous DHF is an efficacious therapy for discogenic low back pain with multiple advantages such as minimally invasive, low risks, concurrent treatment after discography, rapid pain relief and disability reduction.