Utilization of Tubular Retractors for Paramedian Approach in Dorsal Column Spinal Stimulator Paddle Lead Placement: A Technical Report and Literature Review

Spinal cord stimulation (SCS) is an established therapy for refractory back and leg pain, traditionally utilizing laminectomy-placed paddle leads or percutaneous cylindrical leads. Although percutaneous systems reduce soft tissue injury, they suffer higher migration rates and less precise dorsal column targeting. Minimally invasive surgical (MIS) techniques using tubular retractors combine the stability of paddle electrodes with reduced surgical trauma. Here, we describe a paramedian METRx tubular technique designed to minimize disruption of the posterior tension band while preserving paddle lead advantages. From January 2024 to April 2025, the senior author implanted paddle leads in 130 patients undergoing an SCS trial. Six patients (five men and one woman; mean age 67.7±6.4 years; mean BMI 34.9±4.7 kg/m²) underwent definitive paddle lead placement via a 3 cm paramedian incision and sequential dilation to a 22 mm METRx working channel. Neurosensory monitoring (somatosensory evoked potential (SSEP)/motor evoked potential (MEP)) was maintained throughout. Docking was performed at T7-T11 (four at T8-T9, one at T7-T8, and one at T10-T11). Under direct microscopic/endoscopic visualization, hemilaminectomy and flavectomy expose the dorsal epidural space. Boston Scientific paddle leads (Marlborough, Massachusetts, United States) were fluoroscopically confirmed, anchored to the interspinous ligament, tunneled subfascially to the gluteal pocket, and connected to an implantable pulse generator. All six paddle leads were successfully positioned without intraoperative complications. The mean estimated blood loss was 25 mL, and the mean operative time was 56.0±10.6 minutes. At the first postoperative follow-up (mean 2.9±3.1 months), no lead migrations, revisions, or infections were observed. The average Visual Analog Scale (VAS) pain score improved to 4.5±1.3. Importantly, with the paramedian approach, the midline supraspinous and interspinous ligaments were preserved, thereby reducing the osteoligamentous insult compared to midline or open microdissection techniques. The paramedian METRx tubular technique for paddle lead SCS placement is safe, efficient, and reproducible, with minimal blood loss and operative time. By sparing key posterior tension band structures, it may enhance postoperative recovery and preserve spinal stability. Prospective, controlled studies comparing paramedian versus midline MIS approaches are warranted to further elucidate clinical benefits and long-term outcomes.