Preoperative (Pre-amputation) Cryoanalgesia to Improve Post-amputation Phantom Limb Pain

Preoperative (Pre-amputation) Cryoanalgesia to Improve Post-amputation Phantom Limb Pain, General Physical and Emotional Disability, and Opioid Consumption: a Randomized Pilot Trial

Investigators will evaluate preamputation cryoanalgesia on pain, mobility, opioid use and general physical and emotional disability using a pilot randomized trial design, to explore the amount and variability of improvement on those outcomes and to investigate the potentiality of conducting a future larger randomized controlled trial, which the investigators will assess quantitatively the benefits of cryoanalgesia.

Primary Aim: To determine preoperative cryoneurolysis improves phantom limb pain compared with no cryoneurolysis. Estimate the standard deviation of phantom limb pain score at baseline and post-treatment (Day 0), Days 1 and 2; Weeks 1, 2, 3, and Months 1, 2 and 3. The investigators will consider using the upper limit of the 75% confidence interval to plan the sample size of future larger trial.

Hypothesis 1: Preoperative cryoneurolysis reduces phantom limb pain over 3 month after surgical leg amputation compared with no cryoneurolysis.

Secondary Aim 1: To determine if preoperative cryoneurolysis improves mobility after lower limb amputation compared with no cryoneurolysis.

Hypothesis 1: Preoperative cryoneurolysis improves mobilization (as measured with accelerometer) over 3 the month after surgical leg amputation compared with no cryoneurolysis.

Secondary Aim 2: To determine if preoperative cryoneurolysis improves general physical and emotional disability after lower limb amputation compared with no cryoneurolysis.

Hypothesis 2: Preoperative cryoneurolysis reduces general physical and emotional disability (as measured with the World Health Organization Disability Assessment) over the 3 month after surgical leg amputation compared with no cryoneurolysis.

Secondary Aim 3: To determine if preoperative cryoneurolysis decreases opioid use after lower limb amputation compared with no cryoneurolysis.

Hypothesis 3: Preoperative cryoneurolysis reduces opioid consumption over the 3 month after surgical leg amputation compared with no cryoneurolysis.

Exploratory Aims:

Hypothesis 1: Preoperative cryoneurolysis reduces residual limb pain over the 3 months after surgical leg amputation compared with no cryoneurolysis.

Inclusion Criteria:

• Adults at least 18 years of age.
• Scheduled for a unilateral lower limb amputation distal to the femoral head and including at least one metatarsal bone.

Exclusion Criteria:

• Pregnancy
• Incarceration
• Morbid obesity (body mass index greater than 40 kg/m2
• Contraindication specific to cryoneurolysis such as a localized infection at the treatment site, cryoglobulinemia, cold urticaria, or Reynaud's syndrome.
• Investigator opinion that the potential subject is a poor candidate for this trial.