Clinical Efficacy of Selective Focal Ablation by Navigable Percutaneous Disc Decompression Device in Patients With Cervical Herniated Nucleus Pulposus

OBJECTIVE: To evaluate the clinical efficacy and safety following percutaneous disc decompression, using navigable disc decompression device for cervical herniated nucleus pulposus (HNP). METHODS: Twenty subjects diagnosed with cervical HNP and refractory to conservative management were enrolled for the study. The herniated discs were decompressed under fluoroscopic guidance, using radiofrequency ablation device with navigable wand. The sagittal and axial plain magnetic resonance images of the clinically significant herniated disc, decided the space between the herniated base and outline as the target area for ablation. Clinical outcome was determined by Numeric Rating Scale (NRS), Neck Disability Index (NDI), and Bodily Pain scale of Short Form-36 (SF-36 BP), assessed after 48 weeks. After the procedure, we structurally matched the magnetic resonance imaging (MRI) and C-arm images through bony markers. The wand position was defined as being ‘correct’ if the tip was placed within the target area of both AP and lateral views; if not, the position was stated as ‘incorrect’. RESULTS: The average NRS fell from 7 to 1 at 48 weeks post procedure (p<0.05). In addition, statistically significant improvement was noted in the NDI and SF-36BP (p<0.05). The location of the wand tip resulted in 16 correct and 4 incorrect placements. Post-48 weeks, 3 of the incorrect tip cases and 1 correct tip case showed unsuccessful outcomes. CONCLUSION: The study demonstrated the promising results and safety of the procedure. Thus, focal plasma ablation of cervical HNP with navigable wand can be another effective treatment option.

Reappraisal of Supraorbital Sensory Nerve Conduction Recordings: Orthodromic and Antidromic Techniques

OBJECTIVE: To establish a supraorbital nerve sensory conduction recording method and assess its usefulness. METHODS: Thirty-one healthy subjects without a history of trauma or neurological disease were recruited. For the orthodromic procedure, the recording electrode was attached immediately superior to the supraorbital notch. The stimulation electrode was placed on points along the hairline which evoked the largest sensory nerve action potentials (SNAPs). The antidromic sensory response was recorded after switching the recording and stimulating electrodes. The measured parameters were onset latency, peak latency, and baseline to peak amplitude of the SNAPs. The electrophysiological parameters of the bilateral supraorbital nerves were compared. We also recruited two patients who had sensory deficits on one side of their foreheads because of laceration injuries. RESULTS: The parameters of orthodromically recorded SNAPs were as follows: onset latency 1.21±0.22 ms (range, 0.9-1.6 ms), peak latency 1.54±0.23 ms (range, 1.2-2.2 ms), and baseline to peak amplitude 4.16±1.92 µV (range, 1.4-10 µV). Those of antidromically recorded SNAPs were onset latency 1.31±0.27 ms (range, 0.8-1.7 ms), peak latency 1.62±0.29 ms (range, 1.3-2.2 ms), and baseline to peak amplitude 4.00±1.89 µV (range, 1.5-9.0 µV). There was no statistical difference in onset latency, peak latency, or baseline to peak amplitude between the responses obtained using the orthodromic and antidromic methods, and the parameters also revealed no statistical difference between the supraorbital nerves on both sides. CONCLUSION: We have successfully recorded supraorbital SNAPs. This conduction technique could be quite useful in evaluating patients with supraorbital nerve lesions.

The Factors Associated With the Successful Outcomes of Percutaneous Disc Decompression in Patients With Lumbar Herniated Nucleus Pulposus

OBJECTIVE: To determine clinical and radiological factors that predict the successful outcome of percutaneous disc decompression (PDD) in patients with lumbar herniated nucleus pulposus (HNP). METHODS: We retrospectively reviewed the clinical and radiological features of patients who underwent lumbar PDD from April 2009 to March 2013. Sixty-nine patients with lumbar HNP were studied. Clinical outcome was assessed by the visual analogue scale (VAS) and the Oswestry Disability Index (ODI). Multivariate logistic regression analysis was performed to assess relationship among clinical and radiological factors and the successful outcome of the PDD. RESULTS: The VAS and the ODI decreased significantly at 1 year follow-up (p<0.01). One year after PDD, the reduction of the VAS (DeltaVAS) was significantly greater in the patients with pain for <6 months (p=0.03) and subarticular HNP (p=0.015). The reduction of the ODI (DeltaODI) was significantly greater in the patients with high intensity zone (p=0.04). Multivariate logistic regression analysis revealed the following 5 factors that were associated with the successful outcome after PDD: pain duration for <6 months (odds ratio [OR]=14.036; p=0.006), positive straight leg raising test (OR=8.425, p=0.014), the extruded HNP (OR=0.106, p=0.04), the sequestrated HNP (OR=0.037, p=0.026), and the subarticular HNP (OR=10.876, p=0.012). CONCLUSION: PDD provided significant improvement of pain and disability of patients. The results of the analysis indicated that the duration of pain <6 months, positive straight leg raising test, the subarticular HNP, and the protruded HNP were predicting factors associated with the successful response of PDD in patients with lumbar HNP.