Long-term follow-up of a novel implantable programmable infusion pump

The Prometra® Programmable Pump System (Flowonix Medical, Inc., Mt. Olive, NJ, USA) is designed for continuous intrathecal administration of morphine sulfate to treat chronic intractable pain. As a follow-up to a previous report on acute six-month data, this study evaluated the efficacy of treatment at one year and the accuracy of drug delivery throughout the study (average of 2.5 years, range 0-3.6 years).

Accuracy of drug delivery was determined as the ratio of delivered-to-programmed drug volume at scheduled refill visits (monthly for the first six months and every three months thereafter). Efficacy was assessed at 12 months using the visual analog and numeric rating scales and the Oswestry Disability Index. Safety was assessed by documenting adverse events and device complications throughout the study.

The mean accuracy of the Prometra pump was 97.9% and was comparable to the reported accuracy at one to six months (97.1%). After 12 months, 68% of the remaining subjects reported improvement in disability scores from baseline and more than 75% of the remaining subjects reported decreases in pain from baseline. The incidence rates of adverse events and device complications were similar to previous reports for this therapy.

The Prometra pump demonstrated accurate drug delivery throughout the study and provides an effective and safe means for intrathecal administration of morphine sulfate for treatment of chronic intractable pain.