Catheter Obstruction of Intrathecal Drug Administration System -A Case Report-

Intrathecal drug administration system (ITDAS) can reduce the side effects while increasing the effectiveness of opioids compared to systemic opioid administration. Therefore, the use of ITDAS has increased in the management of cancer pain and chronic intractable pain. Catheter obstruction is a serious complication of ITDAS. Here, we present a case of catheter obstruction by a mass formed at the side hole and in the lumen. A 37-year-old man suffering from failed back surgery syndrome received an ITDAS implantation, and the ITDAS was refilled with morphine every 3 months. When the patient visited the hospital 18 months after ITDAS implantation for a refill, the amount of delivered morphine sulfate was much less than expected. Movement of the pump rotor was examined with fluoroscopy; however, it was normal. CSF aspiration through the catheter access port was impossible. When the intrathecal catheter was removed, we observed that the side hole and lumen of the catheter was plugged

Management of Intrathecal Catheter-Tip Inflammatory Masses: A Consensus Statement

In a companion article, we synthesized current clinical and preclinical data to formulate hypotheses about the etiology of drug administration catheter-tip inflammatory masses. In this article, we communicate our recommendations for the detection, treatment, mitigation, and prevention of such masses. Methods. We reviewed published and unpublished case reports and our own experiences to find methods to diagnose and treat catheter-tip inflammatory masses in a manner that minimized adverse neurological sequelae. We also formulated hypotheses about theoretical ways to mitigate, and possibly, prevent the formation of such masses. Results. Human cases have occurred only in patients with chronic pain who received intrathecal opioid drugs, alone or mixed with other drugs, or in patients who received agents that were not labeled for long-term intrathecal use. Most patients had noncancer pain owing to their large representation among the population with implanted pumps. Such patients also had a longer life expectancy and exposure to intrathecal drugs, and they received higher daily doses than patients with cancer pain. Clues to diagnosis included the loss of analgesic drug effects accompanied by new, gradually progressive neurological symptoms and signs. When a mass was diagnosed before it filled the spinal canal or before it caused severe neurological symptoms, open surgery to remove the mass often was not required. Anecdotal reports and the authors' experiences suggest that cessation of drug administration through the affected catheter was followed by shrinkage or disappearance of the mass over a period of 2-5 months. Conclusions. Attentive follow-up and maintenance of an index of suspicion should permit timely diagnosis, minimally invasive treatment, and avoidance of neurological injury from catheter-tip inflammatory masses. Whenever it is feasible, positioning the catheter in the lumbar thecal sac and/or keeping the daily intrathecal opioid dose as low as possible for as long possible may mitigate the seriousness, and perhaps, reduce the incidence of such inflammatory masses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75020/1/j.1526-4637.2002.02055.x.pd

Current Developments in Intraspinal Agents for Cancer and Noncancer Pain

Since the late 1980s, intrathecal (IT) analgesic therapy has improved, and implantable IT drug delivery devices have become increasingly sophisticated. Physicians and patients now have myriad more options for agents and their combination, as well as for refining their delivery. As recently as 2007, The Polyanalgesic Consensus Conference of expert panelists updated its algorithm for drug selection in IT polyanalgesia. We review this algorithm and the emerging therapy included. This article provides an update on newly approved as well as emerging IT agents and the advances in technology for their delivery

Intrathecal reboxetine suppresses evoked and ongoing neuropathic pain behaviours by restoring spinal noradrenergic inhibitory tone.

The descending noradrenergic (NAergic) projection to the spinal cord forms part of an endogenous analgesic system. After nerve injury, a localised failure in this compensatory system has been implicated as a permissive factor in the development of neuropathic sensitisation. We investigated whether restoring descending NAergic tone with intrathecal reboxetine can oppose the development of the neuropathic pain phenotype after tibial nerve transection (TNT). Rats had a lumbar intrathecal catheter implanted at the time of nerve injury for administration of reboxetine (10 μg) in both acute and chronic dosing experiments. In acute dosing experiments, both intrathecal and systemic (30 mg/kg) reboxetine partially reversed mechanical allodynia. This antiallodynic effect of intrathecal reboxetine was blocked by prior administration of yohimbine (α2-adrenoceptor antagonist, 30 μg) but not by prazosin (α1-adrenoceptor antagonist, 30 μg) or propranolol (β-adrenoceptor antagonist, 100 μg). Chronic intrathecal reboxetine (10 μg, intrathecally, twice daily for 2 weeks) suppressed the development of cold and mechanical allodynia. Nerve-injured animals demonstrated a place preference for intrathecal reboxetine, suggesting that it also reduced spontaneous pain. In contrast, an equivalent antiallodynic dose of systemic reboxetine (30 mg/kg) was aversive in both naive and TNT rats. On cessation of chronic intrathecal reboxetine, there was a gradual development of allodynic sensitisation that was indistinguishable from control TNT animals by 7 days after the end of dosing. Our results suggest that pharmacological restoration of spinal NAergic tone with intrathecal reboxetine can suppress both allodynia and spontaneous pain in the TNT model