P019: PARAVERTEBRAL INTRATHECAL PUMP FOR PAIN CONTROL IN A PATIENT WITH MYASTHENIA GRAVIS
William Grubb; David Habibian; Rutgers Robert Wood Johnson Medical School
A 58 year old female with myasthenia gravis was referred to our service for evaluation for intrathecal therapy. Although stable with current medication (pyridostigmine 60 mg QID), she suffered from chronic diffuse pain and was transitioned to methadone prior to evaluation. She required additional pain relief and reported that her response to medication was irregular. After review of the system risks and benefits, we obtained informed consent for spinal catheter and IT pump placement under sedation, including placement of the pump lateral to the spine in the lower thorax in prone position. The patient had an IT trial, which was effective and without side effects.
Using sterile procedure sedation anesthesia and local anesthesia at L4-L5 interspace, placement via thouy of silastic 18G IT catheter to T12. Confirmed with free flow csf After local infiltration, a pocket was formed for the IT pump, approximately 12 cm lateral to the mid spine between the 12th rib and the iliac crest (see picture). The catheter was anchored, tunneled and connected to the pump. 20 ml of 0.25 marcaine was added to the pump, the site was irrigated with vancomycin, and the pump was placed in a rifampin antibiotic pouch prior to placement in the pocket. The midline incision and pocket were closed with 2.0 vicryl, 3.0 vicryl and 4.0 monocryl in a 4 layer manner. The pump was programmed to deliver 2mg Bupivacaine per24 hours. Subsequent clinical visits for incision care were without issue.
Benefits of lateral thoraco-lumbar placement:
- Identical to procedure utilized by our service for SCS generator placement
- Prone positon maintains integrity of the surgical field for the catheter placement
- Ease of procedure access for pump refill
- Ease and sterile integrity of the incision
- Less potential for turning within the pocket (flipping)
- Lateral (flank) position is cleaner and heals better
Intrathecal therapy benefits:
- Analgesia when oral medication use exceeds federal daily standards and patient ability to use so many pills is challenged
- Efficacy of the IT infusion is supported by literature
- Direct segmental effect of local anesthesia only possible with an IT pump
- Less change of pump position if a patient gains weight
MG is an autoimmune disease that effects the neuromuscular junction. Autoantibody binding interrupts the synaptic function necessary to contract muscles, leading to weakness and subsequent pain. More than 30% of MG patients suffer from chronic pain, typically in the form of muscle spasms or facial pains. Treatment should be individualized, as numerous drug-drug interactions exist between medications for pain management and medications in the treatment of MG. We reported a safe intrathecal therapy for treatment of chronic pain in a patient with MG who significantly benefitted from this treatment modality.
Simon Haroutiunian, Shimon Lecht, Arik A. Zur, Amnon Hoffman & Elyad
Davidson (2009) The Challenge of Pain Management in Patients With Myasthenia Gravis, Journal
of Pain & Palliative Care Pharmacotherapy, 23:3, 242-260, DOI: 10.1080/15360280903098523