Pocket pain, does location matter: a single-centre retrospective study of patients implanted with a spinal cord stimulator

Objectives Spinal cord stimulation (SCS) is an effective therapy for alleviating pain but reported complication rates vary between healthcare centers. This study explored the prevalence of pain associated with Implantable Pulse Generators (IPGs), the component that powers the SCS system. Methods This was a retrospective, single site study analyzing data from 764 patients who had a fully implanted SCS between September 2013 and March 2020. Demographic data were collected together with IPG site and type, patient reported presence of IPG site pain, revisions, explants and baseline scores for neuropathic pain (using the Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs questionnaire). Data were statistically analyzed by one-way analysis of variance, independent sample t-tests, X 2 tests of independence and logistic regression modeling. Results IPG site pain occurred in 127 (17%) of 764 patients. These patients had higher baseline neuropathic pain scores than those who reported no IPG site pain. This complication was more common in females than males. The lowest rates of IPG site pain occurred after posterior chest wall placement and the highest rates occurred after abdominal implants. 7% of patients had revision surgery for IPG site pain (n=55) and 10 of 95 explanted patients stated that IPG site pain was a secondary influencing factor. Conclusions These findings suggest that IPG site pain is a common complication, contributing to SCS revisions and explantation. This study shows that anatomical factors and baseline characteristics of individual patients may contribute to IPG site pain and indicates that exploration of potential factors leading to IPG revision is required.