This study is designed to explore if the valve-gated pump requires less drug to manage subject pain than the prior standard peristaltic pump in the same subject. The newly implanted valve-gated pump will be programmed to deliver a minimum dose reduction of 20% of the same medication that was delivered in the peristaltic pump prior to explant. The drug therapy will be evaluated and pain scores will be evaluated over time (3 refill cycles prospectively for the valve-gated pump and 6 months retrospectively for the peristaltic pump).

This study will employ a single-blind where study participants will not be told about the dose reduction of at least 20% when the valve-gated pump is implanted. A study participant has a significant potential to bias when informed they will get less drug with the new pump than they were receiving in the old pump this could subjectively affect pain scores as well. After valve-gated pump implant and dose reduction, the appropriate pain therapy will be provided to adequately address pain management in the opinion of the study investigator using standard of care processes and VAS scores.

Once subjects have been implanted with the valve-gated pump they will be started on a minimum 20% dose reduction (same medications and concentrations prior to explant). If at any time during the subjects' treatment it is determined by the investigator that the subjects' treatment dose needs to be increased, the dose can be increased in increments not to exceed 5% (no change to concentration) based on VAS scores at current and last visits.

Inclusion Criteria:

Subjects meeting all of the following criteria will be eligible for enrollment in the study:

• 21 years of age or older
• Provide written informed consent for study participation
• Active existing peristaltic intrathecal drug delivery system (IDDS)
• Stable IDDS dosage and concentration for at least 6 weeks prior to valve-gated pump implant
• Minimum of 3 months of information from the following:
• VAS, ODI, Global Pain Scale
• Pump refill printouts (dosage and concentration)
• Other Interventions for pain (injections, nerve blocks, etc.)
• Estimated Replacement Indicator (ERI) printout required showing < 12 months of battery life
• Catheter Access Procedure (CAP) study performed to document patency of catheter, if not replacing
• Diagnosis of nonmalignant, chronic intractable pain as documented in medical history
• Appropriate candidate for surgery
• Able to comply with study requirements including visits and assessments, in the opinion of the investigator

Exclusion Criteria:

Subjects meeting any of the following criteria will be excluded from participating in the study:

• Any contraindications listed in the Prometra labeling
• Significant pain disorder not intended to be treated with the test device or comparator
• Terminally ill, malignant cancer diagnosis and/or has a life expectancy of less than 12 months in the opinion of the investigator
• Pregnant/lactating woman or is of child-bearing potential and not utilizing effective birth control.
• Systemic or local infection (contraindicated for pump implantation)
• History/evidence of an active disruptive psychiatric disorder or other known condition with potential to impact compliance with study visits and assessments, in the investigator's opinion

subject will be blinded to dosing decreases and increases