Lumbar Laminectomy

Anesthesia Implications

Position: Prone, arms at side on armboards
Time: 2-4 hours (long)
Blood Loss: Very High (500+ ml)
Post-op Pain: Moderate (3-6)
Maintenance Paralytic: Ask surgeon

This procedure is sometimes termed a laminotomy and is often done in combination with a discectomy (which has all the same anesthetic implications)

Keep the patient motionless – If muscle relaxants are not contraindicated, use them. Any movement could result in a CSF leak, major blood loss, nerve root injury, post-op instability, and/or injury to retroperitoneal structures.

Keep the patient normothermic – Should have the patient prewarmed and potentially heat the room. Preparation after induction can take quite a bit of time, so the patient can be hypothermic by the time the surgery is started.

The surgeon may request a valsalva-like maneuver (sustained inspiration at 30–40 cm H2O).

High Blood Loss (general considerations): Type and cross, CBC, and CMP should be done prior to the procedure. Consider having an A-line, blood tubing, and extra push-lines. Depending on the fragility of the patient, you may want to have blood in the room and available.

Prone Position (general considerations): Maintain cervical neutrality. Keep IV’s out of the antecubital space. The patients arms are typically flexed, which will kink the IV. Eye protection should be used as the prone position heightens the risk of corneal abrasion and/or traction on the globe (which can result in blindness). Check the patients eyes/ears/nose regularly throughout the case to ensure they are free of pressure. Positioning of the leads is typically high on the posterior and posterolateral back (somewhere free of pressure and out of surgical borders). Keep your connections and tubing where you’ll have fast access.

Long procedure (general considerations): Procedures anticipated to last longer than 2 hours generally require a urinary catheter. Also consider checking lines and positioning regularly as the risks of infiltration and nerve damage are increased with procedure time. Consider an IV fluid warmer and a forced air warmer to keep the patient euthermic.

MEPs (general considerations): Most commonly, anything above the cauda equina (T1/T2) will be MEP and SSEP monitored in spinal cases. Long-term paralytics are normally contraindicated. Short term paralytics (eg succinylcholine) may be used for intubation. Some surgeons will prefer complete TIVA (eg. a common combination is propofol 25-150 mcg/kg/min, remifentanil 0.125-1.0 mcg/kg/min), while others are fine with 1/2 MAC of gas and a propofol drip. Ask the surgeon. Additional equipment needed: bite block, BIS monitor (if using TIVA).

There are many indications for this procedure: Lumbar radiculopathy (nerve/root compression), spondylolisthesis (one vertebrae slips over another), spondylolysis (structural defect in the pars interarticularis), lumbar disc disease (hernia or degeneration of lumbar discs), lumbar canal stenosis, lumbar spondylosis (breakdown of lumbar spine), lateral recess stenosis, metastatic tumor in the spine, lumbar spine tumor, neurogenic claudication

The disc is removed piece-by-piece using curettes and disc-biting rongeurs. Risks include damage to the retroperitoneal structures such as the great vessels or intestines. There is also a risk of epidural bleeding, which can be significant.

In short, the structures of the lumbar spine have broken down or stenosed, requiring intervention. This procedure removes part of the lamina of a vertebral arch in order to relieve the pressure that is being put on the vertebral canal.

In the event that the surgery is considered “minimally invasive”, all of the major risks are reduced, but still present (blood loss, postoperative pain, etc).