What it is treating

Medication taken by mouth travels through the gut, the liver and the bloodstream before a fraction of it ever reaches a spinal receptor. An intrathecal pump skips that entire route. A catheter placed in the intrathecal space delivers medication directly where the receptors live, which means the effective dose can be a hundredth or less of the oral equivalent. That is the whole argument for the device: not more drug, dramatically less, aimed with more precision.

Two populations make up almost everyone who ends up with one. The first is refractory cancer pain, where disease progression or treatment side effects have made oral regimens intolerable or insufficient. The second is selected refractory non-cancer pain — failed back surgery syndrome, severe spasticity, or complex regional pain syndrome that has not responded to less invasive interventional steps — where the goal is durable control at a fraction of the systemic burden.

The trial comes before the implant

Nobody gets a permanent pump on a first visit. A trial dose is delivered first, either through a temporary catheter or a single injection, and we measure what it actually does to pain and function over the following hours to days. A trial that fails is not a failed patient — it is the system doing its job, keeping a permanent implant out of someone it was not going to help.

What goes in the pump

Who is not a candidate

An uncontrolled bleeding disorder, active systemic infection, or anatomy that will not accommodate the catheter rules the device out outright. So does a failed trial. Beyond the mechanical exclusions, a patient whose pain generator has not been identified is not a candidate either — a pump is not a diagnostic tool, and implanting one into an unclear picture usually just adds hardware to a problem that was never mapped.

Refills, and what maintenance actually looks like

The reservoir is refilled percutaneously in the office, on an interval set by the pump’s volume and your dose, typically every one to three months. This is a scheduled visit, not a symptom-driven one — running the reservoir dry is a real risk with real withdrawal or breakthrough-pain consequences depending on the drug, so refill timing is tracked by the practice, not left to memory. Battery life and mechanical function are checked at the same visit; most pumps are rated for several years before the device itself needs replacement.

The terrain around a pump

Two biological facts make the terrain matter here as much as anywhere else in this practice. Chronic systemic opioid exposure itself drives inflammatory and endocrine changes — suppressed testosterone, disrupted sleep architecture, worsened insulin sensitivity — that a pump’s lower total dose can partially reverse but does not automatically fix on its own. And spasticity or refractory pain of this severity is disabling in a way that isolates people from work and from each other, which is its own driver of the pain experience, not a side note to it. This practice pairs a pump with the same behavioral and metabolic work — see sleep, movement and behavior — used everywhere else here, because the device changes the dose, not the whole disease.

The evidence, honestly

The trial that established this therapy’s place in refractory cancer pain is now more than two decades old: a randomized comparison of implantable drug delivery against comprehensive medical management found better pain control, less drug-related toxicity, and a survival advantage in the pump group at six months — a striking result that has not needed to be repeated because the mechanism and the finding both held up. For spasticity, systematic reviews of intrathecal baclofen in spinal cord injury and multiple sclerosis populations consistently show meaningful reduction in spasticity scores, though the same reviews note that functional gains — walking, transfers, independence — are more variable and depend heavily on the rehabilitation built around the device, not the device alone.

What the literature is thinner on is long-term, non-cancer pain outcomes beyond a few years, and that thinness is why polyanalgesic consensus guidelines exist — to standardize drug selection, dosing and screening across a therapy where the evidence base is built more on accumulated multi-center experience than on large placebo-controlled trials, which are hard to run ethically once a therapy is this invasive. We tell patients that directly: this is a well-established mechanism with a genuinely strong cancer-pain trial behind it, and a non-cancer application supported by consensus and long clinical experience rather than an equivalent trial of its own.

What happens on the day

Risks, in plain language

This is a surgical implant, and it carries surgical risks — infection, bleeding, a spinal fluid leak causing a positional headache. Catheter problems (kinking, migration, blockage) can cause a sudden return of symptoms or, more seriously, a withdrawal reaction if the drug stops reaching the space abruptly; that is treated as urgent. Device malfunction is uncommon but is why refills and checks happen on a fixed schedule rather than an as-needed one. This practice implants pumps directly, and we would rather you hear the real list from us than discover it later.

Common questions

Related reading

• Spinal cord stimulation
• Failed back surgery syndrome
• Opioid stewardship
• Complex regional pain syndrome
• When injections stop working