MILD Procedure

A good candidate has lumbar spinal stenosis with neurogenic claudication — leg or buttock pain, heaviness or numbness with standing or walking that eases with sitting or leaning forward — caused at least partly by a thickened ligamentum flavum^[3][10]. Usually, physical therapy, medicines or epidural injections have not helped enough^[1]. Your physician confirms the cause on MRI or CT, because MILD does not treat narrowing from discs or bone spurs in the nerve openings.

Most people are awake but relaxed. In the MOTION trial, most patients had monitored anesthesia care — light sedation with local anesthetic — and only a few needed general anesthesia^[3]. The skin and deeper tissues are numbed, so you should feel pressure rather than sharp pain. Mild soreness at the small access site is common for a few days afterward.

The procedure usually takes about an hour, depending on how many levels are treated. In the MOTION trial, most patients were treated at one level and about a third at two levels^[3]. Plan on a few hours at the facility in total for check-in, preparation and recovery. The procedure is performed in our office or at an affiliated ambulatory surgery center, and you go home the same day.

Bring your MRI or CT and a full list of your medicines and supplements to your consultation. Percutaneous decompression is classified as a high bleeding-risk procedure, so most blood thinners must be paused beforehand — but only with your prescribing doctor’s approval^[11]. On the day of the procedure, follow the fasting instructions, wear comfortable clothing and bring an adult who can drive you home.

Recovery is usually quick. Most people resume normal activity within about 24 hours, and walking and home exercise are encouraged^[3]. Expect some soreness at the access site for a few days. Call us for fever, drainage from the site, a severe headache when sitting or standing, or new leg weakness.

Results are usually judged by how much longer you can stand and walk over the first months, and for many patients in trials the gains lasted for years. In the MOTION trial, walking time before severe symptoms improved by 258% at one year with MILD, versus 64% with usual care alone^[3]. Among patients followed for five years, improvements in disability, pain and walking were maintained^[6]. Stenosis can progress with age, so results vary and some people later need other treatment.

Serious complications are uncommon. In MiDAS ENCORE, 1.3% of patients had a device- or procedure-related adverse event and none were serious^[7]; MOTION reported none through five years^[6]. Possible risks include soreness, bleeding, infection, a reaction to contrast dye, a tear of the membrane around the nerves with a spinal fluid leak, and nerve injury. The procedure may also not relieve your symptoms enough.

Yes, with conditions. Medicare covers percutaneous image-guided lumbar decompression — the category that includes MILD — under National Coverage Determination 150.13, using “coverage with evidence development.” Medicare pays when the procedure uses an FDA-cleared device that completed a CMS-approved randomized trial and the patient is enrolled in a CMS-approved study that tracks outcomes^[1]. Commercial plans vary and usually require prior authorization; workers’ compensation and no-fault claims follow their own rules. Our staff verifies benefits first.

An epidural steroid injection calms inflammation around the nerves, while MILD removes part of the thickened ligament that is crowding them. Injections are simpler and often tried first, but relief can wear off. Based on the MiDAS ENCORE trial, which compared the two directly, a consensus group of pain specialists rated image-guided lumbar decompression superior to lumbar epidural steroid injections^[8][7]. See epidural steroid injections.

MILD works through a tiny opening, removes only small amounts of bone and ligament, and leaves no implant^[3]. A laminectomy is open surgery that can remove more tissue, including some disc and bone-spur causes of stenosis, but recovery is longer. An interspinous spacer is an implant placed between the bony bumps at the back of the spine to keep the canal from narrowing when you stand. Having MILD first does not rule out surgery later if it is needed.

Alternatives include physical therapy focused on flexion exercises and walking tolerance, medicines, and epidural steroid injections. For narrowing that MILD cannot reach, surgical decompression — including endoscopic spine surgery — or a spacer may be considered. For people with ongoing leg pain who are not surgical candidates, spinal cord stimulation is another option. Your physician will match the choice to the cause and severity of your stenosis^[8].