Percutaneous cryoneurolysis

Quick answer

Percutaneous cryoneurolysis durably interrupts the transmission of a pain signal by precisely cooling a nerve (between -20°C and -100°C), using a needle placed under imaging guidance, without surgery, for refractory chronic pain.

📖 What is cryoneurolysis?

Percutaneous cryoneurolysis durably interrupts the transmission of a pain signal by precisely cooling a nerve (between -20°C and -100°C), using a needle placed under imaging guidance (CT or ultrasound), without surgery.

The cold causes a controlled lesion of the nerve that blocks pain conduction, while preserving the connective tissue scaffold that then allows gradual regeneration of the nerve fibre. It is an alternative to chemical neurolysis (alcohol, phenol) and to radiofrequency ablation, with the advantage of visualising the treated zone (the "ice ball") in real time under CT.

⚡ Cryoneurolysis at a glance: key figures

Sources: Sag AA, Bittman R, Prologo JD et al., "Percutaneous Image-guided Cryoneurolysis: Applications and Techniques", RadioGraphics 2022;42(6); Nygaard NB et al., BMC Musculoskeletal Disorders 2021; Mihalko WM et al., Journal of Arthroplasty 2021 (genicular cryoneurolysis, randomised controlled trials). Data validated by the team of Prof. Anthony Dohan, Department of Interventional Radiology, Cochin Hospital AP-HP, Université Paris Cité.

🎯 Indications for cryoneurolysis

The choice of the targeted nerve depends on the location and origin of the pain. These are the main categories we treat:

🎯 Focus on pudendal neuralgia

The pudendal nerves are the main sensory nerves of the perineum, the pelvic musculature and the external genitalia. Pudendal neuralgia is a chronic pain syndrome most often related to pelvic trauma: difficult childbirth, gynaecological surgery, or repeated trauma from cycling or horse riding.

A diagnosis confirmed by a block test

Before any treatment, the diagnosis is confirmed by a block test: an injection of local anaesthetic (bupivacaine) in contact with the pudendal nerve(s), performed under CT guidance. Pain relieved by this block, in the expected anatomical territory, worsened by sitting and not waking the patient at night, confirms the diagnosis and selects the patients likely to benefit from targeted treatment. Conversely, an absence of response to a block whose correct placement has been verified on CT rules out this diagnosis and directs towards other investigations.

Why CT guidance makes a difference

The pudendal nerve runs in a narrow canal (the pudendal canal, in contact with the obturator internus muscle), surrounded by deep pelvic structures that must absolutely be avoided. Other methods of localisation (anatomical landmarks alone, fluoroscopy, transvaginal approach, nerve stimulator) are markedly less accurate and riskier in this area. CT guidance makes it possible to target the nerve with great precision, keeping a safe distance from the rectum, prostate or vagina, and without placing the needle directly in contact with the nerve: the cold zone gradually extends until it encompasses the nerve, generally from the adjacent ischioanal fat.

An alternative to surgery and neuromodulation

Compared with decompression surgery (higher cost and morbidity, risk of recurrence due to postoperative adhesions) or neuromodulation (permanent implantation of a device), percutaneous cryoablation of the pudendal nerve offers a minimally invasive option, performed as a day case, without an implanted device. Cold may also induce nerve regeneration: when the nerve is already damaged, controlled cryoablation can promote regrowth of functional axons.

Beyond neuralgia: cancer pain and other indications

Cryoablation of the pudendal nerve can also relieve refractory pelvic pain related to a tumour mass, in addition to other nerve targets (hypogastric plexuses, pelvic splanchnic nerves) depending on the context. Preliminary work is also exploring other applications unrelated to pain, such as the dorsal nerve of the penis in premature ejaculation, a very common sexual disorder in men, with encouraging but still preliminary results.

🩺 How is the procedure performed?

• Diagnostic block test: injection of local anaesthetic in contact with the suspected nerve, to confirm that the pain does come from this target
• Imaging guidance: the cryoablation probe is positioned under CT or ultrasound in precise contact with the nerve
• Freeze-thaw cycles: cold energy is delivered for several minutes, with direct visualisation of the treated zone under CT
• Return home the same day in the majority of cases, with gradual resumption of activities

❓ Frequently asked questions