What Are Intrathecal Pump Implants?
by Nicole Berardoni M.D, Tory McJunkin M.D, and Paul Lynch M.D.
Intrathecal PumpIntrathecal pumps (ITPs) are devices used in the treatment of many chronic pain states. The pumps have shown effective in treating cancer pain, severe back pain, neuropathic pain, and muscle spasticity. ITPs are an automated piece of equipment that are programmed to deliver medication into the spinal fluid through a small catheter. This exciting pain relief technique has been shown to be both safe and effective. The purpose of the pump is to interrupt pain signals that travel through the spinal cord. Pain signals which normally travel to the brain are lessened, and pain relief is perceived. Medication is delivered into the intrathecal space surrounding the spinal cord. The ITP delivers pain medication directly to the pain receptors in the spinal cord and smaller doses of medication are required to gain relief. ITP implants are considered when oral pain medications and other methods of pain control have been exhausted or proven ineffective.
Before an ITP is placed, an intrathecal medication trial is performed. Medication is placed in the spinal fluid. If pain relief is adequate, an ITP can be permanently placed to control your pain. Placement of the ITP can be performed in an outpatient setting or in the hospital. The implantation of the device is done with local anesthesia and sedation (general anesthesia is usually not required). After a sterile scrub, local anesthesia is used to numb the needle entry location. Once the area is numb, a larger needle and catheter are placed into the intrathecal space using X-ray guidance. Once the catheter is in the proper location, the pump is then connected and placed under the skin on the lower part of your abdomen. The catheter and pump are tunneled under your skin, and all wounds are surgically closed.
The pump delivers pain medication (opiates, local anesthetics, or muscle relaxants) directly into the intrathecal space around the spinal cord. The medication reservoir in the pump is refilled periodically (every four to six weeks) by your pain physician by injecting the medication through your skin into the pump. The entire procedure typically takes one to two hours and may be performed on an outpatient or inpatient basis.
Intrathecal-Pump-Implant-DiagramITPs can be used to treat a variety of painful conditions. Nociceptive pain, or pain from tissue irritation, can usually be effectively treated with uploads like morphine. Nociceptive pain transmission is interrupted at the spinal cord and pain relief is experienced.
Neuropathic pain, peripheral or central nervous system pain, tends to be receptive to treatments with local anesthetics more than opioids. Examples of neuropathic pain syndromes include CRPS (complex regional pain syndrome or reflex sympathetic dystrophy), cancer pain, phantom limb pain, post herpetic neuralgia (shingles), carpal tunnel syndrome, failed back surgery syndrome, and peripheral neuropathy (from diabetes mellitus or vitamin deficiencies).
Spasmodic pain can also be successfully treated by ITPs. This type of pain is effectively treated with anti-spastic muscle-relaxing medications like Baclofen. Spasticity may be caused by impairment in the brain or spinal cord and is seen in several conditions, such as stroke, brain injury, spinal cord injury, cerebral palsy, and multiple sclerosis (Rawlins 2004). Spasticity is an abnormal increase in muscle tone and tightening of the muscles.
Intrathecal pump implants are effective and safe devices used for pain management. The complications associated with implants are mostly pharmacological and transient (Kamran). Some of the common side effects due to the medications that are dispersed through the pump are:
- Nausea and vomiting
- Facial flushing
- Respiratory depression
More serious complications that can ensue are:
- Infection or meningitis
- Catheter malfunction
ITP implants are considered an appropriate treatment for many patients who suffer from chronic difficult-to-control pain. As with any medication taken, there are always risks and potential side effects that may occur. All patients receiving a pump implant should be evaluated by their physician and risks of ITPs should be discussed.
Intrathecal Pumps Cancer PainA large clinical study involving 24 European centers showed that intrathecal pump implant therapy is clinically effective, well-tolerated, and may offer improvements in pain relief and function. Muscle tone, spasm levels, and pain intensity reductions were observed. Also cognition and motor function showed improvements (Guillaume 2005). Intrathecal Baclofen therapy is considered safe and so effective that it has evolved into the standard treatment for severe spasticity (Rawlins 2004). Most patients and caregivers express satisfaction with the therapy and would recommend it to other patients. Spasm frequency appears to be the single most common variable positively affected by therapy (Vender 2006). Another study showed excellent long-term efficacy in the treatment of lower extremity spasticity (Ethans 2007).
Another study observed the effects of intrathecal morphine when delivered to patients with painful cancer. In this study all patients and their families reported an improved quality of life with an increased level of activity, and it was deemed “efficacious and safe” (Gilmer-Hill 1999). Another benefit with ITPs in terminal cancer is that continuous intrathecal narcotic infusion is a very effective method to control terminal cancer pain and enables treatment in an outpatient setting (Motsch 1988). Pain can be a debilitating condition physically, as well as emotionally. ITPs can dramatically help those with painful conditions that are unrelieved by other therapies.