Fluoroscopy guided lumbar puncture

Dr Owen Kang et al.

Fluoroscopy-guided lumbar punctures (LPs) are a minimally invasive, image-guided diagnostic and therapeutic procedure that involves the removal of a small volume of cerebrospinal fluid (CSF), or an injection of medication or other substance (e.g. radiotracer, chemotherapy agents) into the lumbar (or lower) region of the spinal column. In addition to improving success rates, fluoroscopic guidance may reduce the incidence of traumatic LP ref required.

Fluoroscopic guidance for LP may be required for the following reasons:

  • failed attempts without imaging
  • for patients who have difficult anatomy due to obesity, prior spine surgery or other reasons

Indications for LP in general include 1:

  • CSF sampling
  • opening pressure measurements
  • administration of intrathecal chemotherapy
  • administration of contrast (e.g. CT myelography, nuclear medicine CSF leak studies)

There are no absolute contraindications to performing the procedure. However, caution should be used in patients with:

  • suspected spinal epidural abscess
  • possible raised intracranial pressure
  • thrombocytopaenia or other bleeding diathesis (including ongoing anticoagulant therapy)
Preprocedural evaluation
  • reason for referral and history of presenting complaint
  • relevant medical and surgical history
  • review relevant laboratory results and assess for coagulopathies
  • review prior imaging, especially lumbar spine images
  • discuss procedure and its potential risks and complications to obtain informed consent
  • perform time-out to confirm correct patient, procedure, and site
Positioning/room set up

Correct patient positioning is an important determinant of success in obtaining CSF. LPs can be performed with the patient in the lateral recumbent or prone positions. The prone position is generally preferred for LPs performed under fluoroscopic guidance with the patient being instructed to lie face down. Pillows placed under the abdomen and pelvis may improve patient comfort as well as aid in flexion of the lower lumbar spine. 

The lumbar spinous processes of L3, L4, and L5, and the interspaces between can usually be directly identified by fluoroscopy. The spinal needle can be safely inserted under fluoroscopic guidance at L3-L4 or L4-L5 via a right oblique sublaminar approach since this is well below the termination of the spinal cord.

Equipment

Besides a standard fluoroscopic table, fluoroscopy-guided LP requires the following items:

  • sterile dressing
  • sterile gloves
  • sterile drapes
  • antiseptic solution with skin swabs
  • lignocaine 1% without epinephrine
  • syringe, 3 mL
  • needles, 20 and 25 gauge
  • spinal needles, 20 and 22 gauge
  • three-way stopcock
  • manometer
  • three plastic test tubes, numbered 1-3, with caps
  • syringe, 10 mL
Technique

Following informed consent, the patient should be placed in the prone or prone oblique position on a standard fluoroscopic table. Lignocaine 1% is then administered for local anaesthesia.

Once numb, a spinal needle is inserted under strict aseptic conditions using intermittent-pulse fluoroscopy to identify the appropriate site for the LP (often L2-L3 or L3-L4 intervertebral space). The course of the advancing needle is monitored during the procedure until the subarachnoid space is entered via left or right oblique sublaminar approach, which is confirmed by the reflux of clear CSF. Needle position can be assessed with a lateral projection if there is uncertainty about depth. 

The patient should then be rotated to their side for measurement of opening pressure. Finally, the required amount of CSF is collected in test tubes and sent to a laboratory for investigations.

Postprocedural care
  • patient to rest supine on bed (varies by institution but typically up to 4 hours)
  • pain score assessed immediately and 15-20 minutes post procedure
  • observe for 20-30 minutes for any immediate complications

Complications associated with LP occur rarely. However, minor and major complications can occur even when good technique and standard infection control measures are used. These complications include:

  • post-LP headache (in up to 33% 1)
  • infection
  • bleeding (e.g. from vertebral artery puncture)
  • minor neurologic symptoms, e.g. transient pain/numbness/paralysis
  • back pain
  • cerebral herniation (rare)
  • late onset of epidermoid cysts of the thecal sac

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Article Information

rID: 44901
Synonyms or Alternate Spellings:
  • Fluoroscopy-guided lumbar punctures
  • Fluoroscopy-guided LP

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