(P 329) LAPAROSCOPY-ASSISTED PERCUTANEOUS CRYOABLATION FOR THE TREATMENT OF ABDOMINAL WALL DESMOID TUMORS

Objective: Management of abdominal wall desmoid tumors (DT) has evolved over the last decade, with emphasis on conservative management based on guidelines from the Desmoid Tumor Working Group. However, symptoms associated with these tumors and the significant cost of medical therapy warrant exploring safer, more effective procedural options for DT. There is growing evidence for ablative therapies, including percutaneous cryoablation (PCA); however, complications associated with abdominal adhesions and the proximity of bowel to tumor limit the success of this approach. This study describes our approach to and early experience with laparoscopy-assisted PCA for abdominal wall DT.

Methods: Inclusion criteria: Patients with pathologically-confirmed abdominal wall DT were recruited consecutively at a high-volume referral center.
Procedure: Diagnostic laparoscopy (DL), lysis of adhesions (LOA), and PCA were performed in an interventional radiology suite under general anesthetic by a Surgical Oncologist and Interventional Radiologist. The abdomen was insufflated to 12-15 mmHg. LOA was performed to dissect viscera away from tumor. Saline hydrodissection was performed around the tumor, and PCA with standard freeze-thaw cycles was performed with intermittent CT imaging to confirm expanding ice ball in the rectus sheath. The abdomen was desufflated after a prolonged thaw.
Analysis: Data points, including demographics, tumor characteristics, and operative details, were collected. Primary outcomes were the change in total lesion volume (TLV), complications, and symptom resolution.

Results: Five patients had attempted laparoscopy-assisted PCA for abdominal wall DT; four were successful. One patient could not complete PCA after DL due to extensive adhesions. Demographic and tumor characteristics are summarized in Table 1. Median follow-up was 11.8 months (IQR 8.75 – 20). One patient experienced a severe adverse event within 30 days, requiring return to OR. Mean % change in TLV (Δcm3) was -69.8%, and all patients presenting with symptoms had symptom resolution after PCA.

Conclusion: Laparoscopy-assisted PCA is effective for patients with abdominal wall DT, as indicated by a large decrease in TLV and symptom resolution. We noted one severe AE after PCA for a massive DT; for DT at extremes of size, staged interventions can be considered.

Table 1. Patient and tumor characteristics and outcomes after treatment with laparoscopy-assisted PCA.