STUDY DESIGN: Retrospective. PURPOSE: To analyze whether the cross-sectional area of the intervertebral foramen at the outermost edge of the resection site is associated with postoperative outcomes and whether our fluoroscopic method for determining the resection area is appropriate. OVERVIEW OF LITERATURE: There is no consensus on the criteria for determining an optimal resection area to obtain sufficient decompression while maintaining intervertebral stability in posterior percutaneous endoscopic cervical foraminotomy. Previous reports have recommended a facet resection rate (FRR) of ≤50%. Intervertebral foramen stenosis often extends to the exit zone. The cross-sectional area of the intervertebral foramen is occasionally small at the outermost edge of the resection site. No report has analyzed whether these aspects are associated with postoperative outcomes. METHODS: Lateral margins of the resection area were set at lateral borders of the vertebral body on frontal fluoroscopic view. Because the percutaneous endoscope has a small diameter, surrounding structures can easily be identified using frontal view fluoroscopy to determine the resection area. FRRs were calculated from postoperative computed tomography images. The smallest cross-sectional area of the intervertebral foramen around the lateral edge of the resection area (SALE) was measured and compared wit clinical outcomes. RESULTS: The mean FRR was 41.7% at C5–C6 and 48.9% at C6–C7. SALE was not correlated with clinical outcomes. CONCLUSIONS: Residual stenosis in the lateral portion of the intervertebral foramen is weakly associated with postoperative outcomes. Our process achieved adequate FRRs and favorable postoperative outcomes, suggesting that our criteria for determining the resection area are appropriate.
Commerce ; Consensus ; Constriction, Pathologic ; Decompression ; Endoscopes ; Fluoroscopy ; Foraminotomy* ; Methods ; Retrospective Studies

Methods: Our new internal retractor can be inserted into the working channel of a percutaneous full-endoscope, enabling the insertion of a second tool. After partial foraminotomy, the internal retractor and forceps were manipulated to reliably retract the nerve root. Finally, the herniated disc was resected under an endoscopic view. Results: All six cases had a good postoperative course, and postoperative neuropathy was not observed. Conclusions This internal retractor allows for the secure resection herniated cervical intervertebral discs.