Interventional procedure overview of percutaneous image-guided cryoablation of peripheral neuroma for chronic pain

Case series

France

2011 to 2015

n=20 (24 neuromas)

Patients with Morton's neuroma

Mean age 50.3 years; 75% (15/20) female

Patients were included if they presented with typical clinical features (forefoot pain exacerbated by walking and relieved by rest and shoe removal); typical ultrasound and MRI findings; failure of conservative treatments (orthotic assessment, physical therapy) and ultrasound-guided corticosteroid injection; chose not to have surgery.

Patients were excluded if they had contraindications to MRI (such as a pacemaker or claustrophobia).

All procedures were done under local anaesthesia on an outpatient basis. Patients were positioned in a large-bore 1.5 T MRI unit. After a small skin incision, a 2-cm active tip cryoprobe (Ice-Seed, Galil Medical Inc., US) was advanced into the centre of the lesion using an inter-metatarsal approach. A single therapeutic freezing cycle lasting 150 seconds was done, and ice-ball growth was monitored throughout the procedure. The cryoprobe was repositioned (with an additional 90-second freezing cycle for each repositioning) if the target lesion was not completely covered by the ice-ball. Finally, a short thawing cycle was applied to enable cryoprobe withdrawal.

Mean 19.7 months

3 authors are proctors for Galil Medical Inc.

Case series

US

2007 to 2011

n=20 (5 Morton's neuroma, 12 stump neuromas secondary to surgery or trauma, 3 peripheral neuritis with no visible lesion)

Patients with painful neuromas or peripheral neuritis

Mean age 49 years (range 18 to 79); 75% (15/20) female

All patients who had sonographically guided cryoneurolysis for painful neuromas or peripheral neuritis were included. The patients were referred for pain that was refractory to multiple conservative measures, including physiotherapy and steroid injections.

All patients had at least moderate pain improvement after anaesthetic injection.

Cryotherapy machine: Frigitronics CE 2000 (Cooper Surgical Inc., US).

At their request, 1 patient had spinal anaesthesia and 1 had intravenous sedation. An ultrasound scan was used to identify the target nerve or neuroma and to plan the trajectory of the cryoprobe. A proximal nerve block was done in most patients at the start of the procedure to provide regional anaesthesia for the duration of the procedure and short-term periprocedural pain relief. A small amount of 1% lidocaine was used as a local anaesthetic. A trochar tip cryoprobe was advanced under sonographic visualisation until just proximal to the nerve or into the neuroma. A sheath was left around the cryoprobe to protect the skin and nontarget tissues. When there was no visible lesion, an electric stimulator was used to confirm correct positioning. Once in position, the cryoprobe was activated and 2 to 4 ice balls were created, until the lesion was surrounded. The probe was repositioned slightly to create contiguous ice balls.

Morton's neuroma: mean follow up=14 weeks (range 6 weeks to 14 months)

Stump neuromas: mean follow up=6.3 months (range 2 weeks to 38 months)

Peripheral neuritis: mean follow up=5.6 months (range 4 to 8 months)

Not reported

1

Severe

Marked

6 weeks

2

Severe

Marked

14 months of pain relief

3

Moderate

Moderate

4 weeks

4

Moderate

Marked

10 weeks

5 (both feet)

Moderate

None

4 weeks

1 (stump neuroma)

Severe

None

2 weeks

2 (plantar nerve scar)

Moderate

Mild

7 weeks

3 (stump neuroma)

Moderate

Marked

17 weeks

4 (sural nerve scar)

Moderate

Marked

6 months of relief, returned for repeat treatment

5 (plantar nerve scar)

Moderate

Moderate

6 weeks

6 (sural nerve scar)

Moderate

Moderate

Moderate relief at 3 weeks, no relief at 4 months

7 (plantar nerve scar)

Moderate

Marked

8 months of relief, returned for repeat treatment

8 (stump neuroma)

Moderate

None

1 month

9 (saphenous neuroma)

Severe

Marked

38 months of relief, returned for repeat treatment

10 (plantar nerve scar)

Severe

None

3 weeks

11 (stump neuroma)

Moderate

Marked

6 months of relief, returned for repeat treatment

12 (plantar nerve scar)

Severe

Marked

11 weeks

1 (left medial nerve)

Moderate

Marked

5 months of relief, returned for repeat treatment

2 (Baxter nerve neuritis)

Severe

None

4 months

3 (Medial plantar nerve neuritis)

Moderate

Marked

8 months of relief, returned for repeat treatment

Case series

Germany

2018 to 2020

n=7 (8 neuromas)

Patients with a symptomatic stump neuroma after limb amputation

Mean age 42 years (range 25 to 55 years); 43% (3/7) female

Inclusion criteria: patient aged 18 years or over, adequate coagulation status, on imaging recognisable painful stump neuroma and decrease of pain after probatory perineural infiltration. Prior to ablation, all patients had typical neuropathic pain in the stump, restricting them in their daily living activities. Additional complaints were local cramps, phantom pain and an inability or limitation in wearing their limb prosthesis.

Cryoablation was done as an inpatient procedure under analgosedation and ultrasound guidance (Visual Ice System, Galil Medical Inc., US). A single cryoprobe (IceSphere or IceSeed) was advanced to the previously identified neuroma and ablation started (2 cycles of 6 minutes freezing separated by a 4-minute thaw cycle). The ablation zone and surrounding structures were continuously monitored with ultrasound. Care was taken that the resulting ice ball covered the whole neuroma without extending less than 0.5 cm to the skin surface. In addition, skin was protected with warm gel cushions. Patients were discharged the next morning, after follow-up ultrasound.

Mean 27 months (range 6.8 to 40 months)

None

Case series

US

2015 to 2016

n=21 (13 with a neuroma)

Patients with refractory phantom limb pain

Mean 56.9 years (range 34 to 91 years); 57% (12/21) female

All patients reported phantom pains or unwanted sensations related to a previously amputated upper or lower limb that were refractory to conventional treatment for at least 6 months. To have cryoablation, each patient was required to have documented symptomatic relief from an image-guided perineural injection of bupivacaine and betamethasone.

Exclusion criteria: active infection, underlying congenital segmentation or other spinal anomalies that result in differential nerve root pressures, severe spinal stenosis, pregnant or planning to become pregnant, immunosuppression, history or laboratory results indicative of any significant cardiac, endocrine, hematologic, hepatic, immunologic, infectious, metabolic, urologic, pulmonary, gastrointestinal, dermatologic, psychiatric, renal, neoplastic, or other disorder that in the opinion of the principal investigator would preclude safe performance of cryoablation, uncorrectable coagulopathies, concurrent participation in another investigational trial involving systemic administration of agents or within the previous 30 days, previous surgical intervention, after amputation, that may have altered the target nerve.

A 2-step method was used, with a diagnostic nerve block injection followed by cryoablation that occurred on separate occasions. For the nerve block, a 22-gauge spinal needle was advanced under CT or ultrasound guidance to the target nerve or neuroma. Needle position was confirmed with fluoroscopic CT.

All ablation procedures were done under conscious sedation. Using technique and targeting analogous to the diagnostic injections, an Ice-Sphere cryoablation needle (Galil Medical Inc., US) was advanced under imaging guidance to the previously identified nerve or neuroma. When position was confirmed, the probe temperature was decreased to −40°C over 10 minutes using the Galil Visual-ICE system. Images were obtained and reviewed 8 minutes into the freeze. A passive thaw cycle was then done for 5 minutes, followed by a second 10-minute freeze and subsequent final 5-minute passive thaw.

Mean 194 days

None

Case series

US

2011 to 2013

n=22 (3 plantar neuromas, 3 ilioinguinal, 4 posterior tibial, 7 saphenous, 1 gluteal, 1 sural, 1 geniculate, and 2 digital nerves were treated)

Patients with refractory peripheral neuropathic pain

Mean age 49.5 years; 41% female

Patients had peripheral neuropathy that failed to respond to first- and second-line therapy. Before referral for neurolysis, all patients had a complete evaluation by a pain physician that included motor testing. All patients showed a response to nerve blocks.

Exclusion criteria included an inability to participate in the pain assessments at any of the scheduled follow-up intervals.

Device: PerCryo 17R (Endocare/Healthtronics, US) was used with ultrasound imaging. All procedures were done under deep sedation. The site of pain was localised by palpation and then the nerve proximal to the area of pain was localised using ultrasound. The ablation probe was advanced to the location of the nerve. When the nerve was localized, 2 to 3 ml of bupivacaine was injected into the nerve. For superficial nerves less than 1 to 2 cm from the skin surface, hydrodissection was used to elevate the skin from the probe tip to prevent skin injury. The ice ball formed as a sphere as much as 1.5 cm proximal to the tip of the probe, and saline solution was injected around this peripheral aspect of the ice ball to ensure at least 1 cm of separation from the ice ball to the skin surface to prevent thermal injury. The cryoablation was performed at 30% of maximum power with a single freeze cycle of 3 minutes. The probe tip reached a minimum temperature of about -135°C to -160°C. A single active thaw cycle was done until the probe temperature reached 5°C to 10°C.

At the end of the procedure, ketorolac was given intravenously if the patient had no contraindication to it.

12 months

1 author has received grants from EDDA Technologies (US) and Endo Pharmaceuticals (US) outside the present work and has a patent pending for Scannerside (US). None of the other authors identified a conflict of interest.