Cryosurgery Or Sclerosing Injections: Which Is Better For Neuromas?
It appears the long lasting relief is due to the reduction of neural edema and fibrosis of the neuroma. Researchers have also reported similar long-term relief using cryosurgery to treat painful trigeminal nerve pathology.5,6 Pertinent Pointers On The Cryosurgery Technique In regard to the specific technique, I first palpate the area of the greatest neuroma pain on the plantar surface of the foot and mark it with a surgical pen. Then I inject the local anesthetic, injecting 3 cc of 1% plain lidocaine into the intermetatarsal space and injecting an additional 1 cc of lidocaine with epinephrine just below the skin dorsally for homeostasis. One should prep the surgical site with betadine and make a 3-mm incision dorsally with a number 65 beaver blade. Use a trocar or angiocatheter to separate the tissue as you advance to the area of pain that you have marked. You will see the deep transverse metatarsal ligament, which you may section if you prefer. Proceed to insert the 2-mm cryoneedle into the area of the neuroma and administer a three-minute freeze cycle. This is followed by a 30-second defrost and another three-minute freeze cycle. Irrigate the wound with 2 cc of 0.5% plain Marcaine and 0.25 cc of steroid. How Should You Handle Postoperative Care? No sutures are required but you should apply a mildly compressive dressing. Give the patient a NSAID to reduce postoperative discomfort. If the patient has only undergone the percutaneous cryosurgery procedure performed, have him or her reduce activity for the next two to three days and apply ice to the surgical site when resting. These patients can remove the dressing the next morning, shower and use a Band-Aid with a topical antibiotic. The incision usually heals in about three days. The destruction of the axons is immediate with cryosurgery so the patients should only feel mild discomfort, which usually resolves in about one week. The patients are usually able to wear normal shoes and be reasonably active during this period. However, if the deep transverse ligament has been released, the surgical site is more uncomfortable and may take two to three weeks to heal. Reviewing Results, Potential Limitations And Contraindications Of Cryosurgery The majority of patients obtain complete relief or significant improvement following cryosurgery. All of my patients who have had cryogenic neuroablation have maintained full motor function with no greater loss of sensation than they had prior to the procedure. The results from this procedure are not considered permanent but, in my experience, some of my patients have reached the three-year mark with no recurrence of neuroma pain. When no relief occurs, it is usually because of dense scar tissue related to a previous excision of the neuroma.7 Performing a percutaneous adhesiotomy or inserting the cryoneedle through the plantar aspect of the foot can overcome this obstacle. Another limitation of this procedure appears to be the size of the neuroma and excessive fibrosis from previous neurectomy. If the neuroma is 3 cm diameter or greater, the 1 cm ice ball may not be able to penetrate the entire mass. In my experience, patients with very large neuromas and excessive scar tissue have also failed all previous treatment including alcohol injections. There is a very low incidence of complications associated with cryosurgery. Infections are rare as is abscess formation at the incision site. However, since cryosurgery involves very cold temperatures, one should avoid performing this procedure for patients who have peripheral vascular disease and conditions such as Raynaud’s phenomena. Final Notes Cryogenic neuroablation is a very safe, minimally invasive procedure that one can perform in the office and achieve very good relief of Morton’s neuroma pain. The postoperative recovery period with this procedure is short as patients only need to reduce activity for two to three days. Unlike alcohol injections, the procedure is not painful and patient acceptance is excellent. Dr. Fallat is a Clinical Assistant Professor within the Department of Family Medicine at the Wayne State University School of Medicine in Detroit. He is the Director of Podiatric Surgical Residency for the Oakwood Healthcare System in Dearborn, Mich. Dr. Fallat is board-certified by the American Board of Podiatric Surgery and is a Fellow of the American College of Foot and Ankle Surgeons. References 1. Dockery GL, Nilsson RZ.