Sonication in Patients With Spinal Cord Stimulation: A New Approach for Infection Diagnostics.

Introduction: Spinal cord stimulation (SCS) offers improvement in pain and function for several chronic pain conditions. There are concerns regarding bacterial colonization of the temporary lead extensions and subsequent infection risk in a two-session implantation procedure. Although there is no standardized evaluation of SCS lead contamination, this study evaluates the infection rate and microbial colonization of SCS lead extensions with sonication, a method that is established in implant-related infection diagnostics.

Materials And Methods: This prospective observational study comprised 32 patients with a two-stage SCS implantation procedure. Microbial colonization of the lead extensions was assessed with sonication. The presence of organisms in the subcutaneous tissue was evaluated separately. Surgical-site infections were recorded. Patient demographics and risk factors including diabetes, tobacco use, obesity, trial length, and infection parameters in serum were recorded and analyzed.

Results: The mean age of the patients was 55 years. On average, the trial length was 13 days. In seven cases (21.9%), a microbial lead colonization was found with sonication. In contrast, there was one positive culture (3.1%) from the subcutaneous tissue samples. The C-reactive protein and leukocyte count remained at the preoperative level. One early surgical-site infection (3.1%) occurred. No other late infections occurred six months after surgery.

Conclusions: There is a discrepancy between the presence of microbial colonization and the occurrence of clinically relevant infections. Although the rate of microbial colonization of the lead extensions is high (21.9%), the surgical-site infection rate remained low (3.1%). Therefore, we can conclude that the two-session procedure is a safe approach that is not associated with a higher incidence of infection. Although the sonication method cannot be used as the sole tool for detecting infections in patients with SCS, it can provide additional value in microbial diagnostics in combination with clinical and laboratory parameters and conventional microbiological methods.