Endometriosis Nodule Cryoablation

Background and indications

Endometriosis is a chronic condition affecting approximately 10% of women of reproductive age. It is characterized by the presence of endometrial tissue outside the uterus, forming painful nodules. Abdominal wall endometriosis (AWE) typically develops in a cesarean or pelvic surgery scar and presents as a painful mass, cyclical with menstruation. Deep pelvic endometriosis can also form nodules accessible to percutaneous treatment.

Percutaneous cryoablation is a minimally invasive alternative to surgical excision, particularly indicated for recurrence after surgery, surgical contraindications, or when the patient wishes to avoid further surgery with its risks of abdominal wall hernia and scarring.

Pre-procedure assessment

Assessment includes MRI of the abdominal wall and/or pelvis to confirm the diagnosis, precisely locate the nodule(s) and measure their size, standard blood tests, and gynecological consultation. The cyclical nature of pain (worsening during menstruation) is an important diagnostic element.

Procedure

Under local anesthesia and light sedation, one or more cryoprobes (17G needles) are inserted into the endometriosis nodule under ultrasound or CT guidance. The cryoprobes deliver gas (argon) that freezes tissue to -40°C, creating an ice ball visible on imaging that encompasses the entire nodule with a safety margin. Two freeze-thaw cycles of 10 minutes each are performed. The freezing zone is monitored in real time. The procedure takes approximately 30 to 60 minutes.

Results and scientific evidence

The first published series by Prof. Cornelis et al. demonstrated the efficacy and safety of cryoablation for abdominal wall endometriosis, with complete pain relief in 80-100% of cases and significant nodule size reduction (Cornelis et al., American Journal of Roentgenology, 2017; Journal of Vascular and Interventional Radiology, 2023).

A Mayo Clinic series of 18 patients confirmed a 100% technical success rate and significant pain improvement (VAS scores decreasing from 8/10 to 1/10 on average), with a median follow-up of 12 months (Welch et al., Abdominal Radiology, 2021). A systematic review published in Insights into Imaging (2024) confirmed these results with an 80-100% complete relief rate and a very favorable complication profile.

Risks and complications

Complications are rare and minor: bruising at the puncture site (common but inconsequential), transient local pain (a few days), mild swelling of the treated area. Damage to adjacent structures (bowel loops, vessels) is exceptional thanks to real-time ice ball monitoring. Infection risk is minimal (< 1%).

Recovery

Recovery is rapid: return to normal activities within 1 to 3 days. Pain related to the endometriosis nodule decreases gradually over 2 to 6 weeks. Resorption of the treated nodule is gradual over 3 to 6 months. Follow-up by MRI or ultrasound is scheduled at 3 and 6 months.

Practical information

The procedure is performed as an outpatient or short inpatient stay depending on the case. It is performed by an interventional radiologist, in coordination with the treating gynecologist.