Search This Blog

Thursday 27 February 2014

Implantable Intrathecal Pumps for Chronic Pain: Highlights and Updates

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2080496/
a couple Paragraph from the article the Full article in above link xx sharon xxsoft hugs xx




The second category of patients is those with chronic non-malignant pain, for example, failed low back surgery syndrome. The use of intrathecal drug delivery systems in chronic non-malignant pain is more controversial. One has to recognize that chronic non-malignant pain is complicated by physical, psychological, and behavioral factors. To be successful, a treatment must include a multidimensional approach that takes into account each of the elements of the biopsychosocial model. Clearly, treatment for chronic pain should consider conservative approaches before more invasive treatments are considered. These approaches include but are not limited to physical therapy and rehabilitation, psychological and behavioral intervention such as self-relaxation cognitive and behavioral therapies (eg, biofeedback), pharmacotherapy, minimally invasive interventions (such as epidural and transforaminal injections), and alternative therapies such as acupuncture.
Intrathecal drug delivery systems are implanted for chronic pain when conservative therapies have failed, surgery is ruled out, no active or untreated addiction exists, psychological testing indicates appropriateness for implantable therapy, medical contraindications have been eliminated (coagulopathies, infections), and a successful intrathecal drug trial has been completed ().

Intrathecal pumps

Intrathecal pumps deliver small doses of medication directly to the spinal fluid. It consists of a small battery-powered, programmable pump (Figure 1) that is implanted under the subcutaneous tissue of the abdomen and connected to a small catheter tunneled to the site of spinal entry (Figure 2). Sophisticated drug dose regimens can be instituted. Implanted pumps need to be refilled every 1 to 3 months. There is no evidence showing whether it is more clinically effective to use bolus or continuous dosing. injury

Neurologic injury can result from the actual catheter placement, as well as from an inflammatory response that occurs at the catheter tip and is associated with drug delivery.
The implantation of spinal catheters for intrathecal drug delivery is done under fluoroscopy. The catheters are inserted through a spinal needle into the spinal canal. Damage to the nerve roots or the spinal cord itself during catheter insertion could occur, resulting in pain, sensory loss, and/or weakness. The deficits would present in the dermatomal distribution of the damaged nerve root. Damage to the spinal cord would lead to dysesthesias or myelopathies below the level of the damaged spinal cord. Also, intraparenchymal injury can occur (,), as well as cauda equina syndrome with pain, sensory loss, weakness, and bowel and bladder dysfunction. The deficits would present in multiple dermatomes in a saddle distribution. Neurologic injury can also develop later. One patient developed progressive necrotic myelopathy leading to paraplegia, a rare form of transverse myelitis (). It is important for the surgeon to obtain pre-operative CT or MRI to check for canal stenosis, arachnoiditis, or other intraspinal abnormalities that would make insertion of the catheter more difficult.