Hyperuricemia Obstructs the Effect of Spinal Cord Stimulation on Peripheral Arterial Occlusive Diseases: The Retrospective Analysis of Eleven Cases

Abstract

Objective The indication of spinal cord stimulation (SCS), a treatment for intractable pain, has been expanded to include pain due to peripheral arterial occlusive disease (PAOD). However, its effectiveness may be influenced by the presence of some medical backgrounds. Then, the influences were analyzed in the current study, which identifyed an obstacle for effectiveness of SCS on PAOD. Methods Eleven patients with PAOD underwent implantation of a SCS device. The Fontaine’s stages (FSs) of all patients before the implantation (pre-FS) were III (4 cases) or IV (7 cases). The relationship between FS 6 months post implantation (post-FS) and the patients’ background, including age, duration of SCS introduction, chronic renal failure (CRF), diabetes mellitus (DM), hypertension, hyperuricemia (HU), hypercholesterolemia (HC), height, and body weight were retrospectively assessed. Results The effect of SCS on PAOD varied among the 11 patients and was not significant. However, a significant Spearman correlation (r=0.7144, p=0.0182) between post-FS and the serum value of uric acid (UA) was demonstrated. Furthermore, the effectiveness of SCS was significant (p=0.0313) in the 6 patients with normouricemia (NU) when comparing the pre- vs. post-FS, and both post-FSs differed significantly (p=0.0065) when comparing NU vs. HU patients. In contrast, the improvement was null in the other 5 patients with HU. There were neither significant changes nor correlations between post-FS and all of the other background characteristics that were assessed. Conclusion Considering that SCS improved FS, both pain scores and tissue blood flow were improved. SCS is an effective treatment for patients with PAOD; however, the results differed depending on the presence of NU or HU. Thus, UA is suggested to be a marker of PAOD or a predictor of its prognosis.