Modified K-Hole Percutaneous Endoscopic Surgery for Cervical Foraminal Stenosis: Partial Pediculectomy Approach.

Background: Percutaneous endoscopic cervical discectomy has evolved as an efficient, minimally invasive spine surgery for radiculopathy caused by soft and/or osseous foraminal stenosis. Although interlaminar access can be used to resect lateral herniated lesions or osteophytes located in the foramina, with limited operative space, nerve retraction may be unavoidable. This procedure may injure the nerve root and cause postoperative arm pain, numbness, and muscle weakness, especially when the herniation is located in the ventral nerve root or when there is a massive osteophyte in the foramina. However, posterior partial cervical pediculectomy under endoscopy provides a new approach to effectively reduce or even avoid nerve retraction and reduce the potential risk of nerve injury.

Objectives: This report presents a partial pediculectomy approach and compares the clinical outcomes of different surgical methods, including posterior percutaneous endoscopic cervical discectomy (P-PECD) and P-PECD combined with partial pediculectomySTUDY DESIGN: This study used a retrospective comparative study design.

Setting: This study took place at the Second Affiliated Hospital of Chongqing Medical University.

Methods: From February 2015 to March 2017, 84 patients with single-level and unilateral soft and/or osseous cervical foraminal stenosis were recruited. Patients were treated with P-PECD (40 patients) and P-PECD combined with partial pediculectomy (44 patients). Postoperative clinical outcomes were assessed using the modified MacNab grading criteria and the Visual Analog Scale (VAS) at different times after surgery. The surgery duration, dosage of postoperative analgesic medication, duration of hospital stay, and postoperative complications were recorded.

Results: The mean duration of the conventional P-PECD surgery was 74.48 ± 7.08 minutes, which was significantly longer (P = 0.002) than that observed for the P-PECD with partial pediculectomy (66.00 ± 9.62 minutes). The analgesic dosage in the conventional P-PECD group was significantly higher than that in the partial pediculectomy group (9.14 ± 3.07 units vs. 5.71 ± 3.41 units; P = 0.001). The hospital stay in the conventional P-PECD group was significantly longer than that in the partial pediculectomy group (3.86 ± 0.85 days vs. 3.24 ± 0.83 days; P = 0.022). The VAS scores at 1 day, 3 days, and 7 days after surgery in the conventional P-PECD group were significantly higher than those in the partial pediculectomy group (all P < 0.001). The modified MacNab grading criteria showed no significant difference at each follow-up (P = 1). The incidence of complications in the P-PECD with partial pediculectomy group (2/44, 4.55%) was significantly lower than that in the conventional P-PECD group (4/40, 10.0%), including complications of increased pain, increased numbness, and worsening of muscle weakness.

Limitations: This study is limited by being a retrospective study, and by having a small sample size and a short follow-up period.

Conclusions: As an alternative to the P-PECD surgical technique, P-PECD with partial pediculectomy effectively reduced the postoperative complications and may be preferable when considering the surgery duration, postoperative hospital stay, analgesic dosage, and postoperative VAS score.

Key Words: Cervical disc herniation, foraminal stenosis, percutaneous endoscopic cervical discectomy, PECD, P-PECD, partial pediculectomy.