Percutaneous Discectomy



Percutaneous Discectomy


Lubdha M. Shah, MD










PD reaches the disc via a posterolateral approach, passing just anterior to the superior articular facet, behind the nerve, in a trajectory toward the center of the disc. A contained foraminal protrusion is noted image.






Axial NECT shows automated probe passing anterolaterally to the herniation and coming to rest in the center of the disc. Most of the disc removal occurs 1 cm anterior to the herniation.


TERMINOLOGY


Abbreviations



  • Percutaneous discectomy (PD)


Synonyms



  • Automated PD


Definitions



  • Percutaneous disc removal reduces intradiscal pressure



    • Protruded disc retracts back, which helps reduce irritation on annulus nociceptive nerve receptors


    • Also decompresses nerve root from disc


    • Another proposed mechanism is that removing disc material may prevent release of chemical mediators that directly injure nerve root


PRE-PROCEDURE


Indications



  • Radicular pain usually greater than back pain/neck pain



    • Symptoms include sensory loss, tingling, numbness, & muscle weakness


  • Positive CT or MR scan for disc herniation



    • Contained herniated disc of < 6 mm



      • Contained herniated discs have intact outer annulus with displaced disc material held within outer annulus of contained herniated disc


      • Noncontained herniated disc has localized displacement of disc material beyond intervertebral disc space & breach in outer annulus


  • No improvement of symptoms after 6-8 weeks of conservative therapy


  • Positive electromyogram study is helpful


Contraindications



  • Evidence of acute or progressive degenerative spinal cord diseases


  • Evidence of neurologic or vascular pathologies mimicking herniated disc


  • Evidence of advanced spondylosis (significant bony spurs) with disc space narrowing, diffuse annular bulging, or spondylolisthesis


  • Evidence of significant bony spurs blocking entry to disc space


  • Evidence of cervical spinal canal or lateral recess narrowing



    • > 50% compromise of spinal canal by herniated disc


  • Evidence of large extruded disc or sequestered disc fragment


  • Existence of other pathologies or conditions, such as fractures, tumors, pregnancy, or active infections


  • Previous surgery at site of herniated disc


Getting Started



  • Things to check



    • Coagulation parameters


    • Complete blood count, platelet


    • Allergies


  • Medications



    • Lidocaine


    • Minimal sedation with midazolam and fentanyl to reduce anxiety and help control blood pressurerelated changes


  • Equipment list



    • 18-gauge hubless sheath with central trocar is guided toward affected disc


    • Trocar is removed, and smaller 2.5 mm cannula with inner blunt end sleeve is placed over hubless sheath


    • Once correct placement is confirmed, hubless sheath is removed, leaving 2.5 mm cannula


    • 2 mm saw is threaded through cannula, and hole is cut into annulus for aspiration probe to be inserted


    • Aspiration probe is sharpened cannula fitted through outer needle


    • Using suction to pull in disc material, the inner, sharpened cannula uses slide-like cutting motion to slice tissue

Sep 22, 2016 | Posted by in EMERGENCY RADIOLOGY | Comments Off on Percutaneous Discectomy
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