Hussein D. Aoun MD, Presenter: Nothing to Disclose

Peter John Littrup MD, Abstract Co-Author: Founder, CryoMedix, LLC Research Grant, Galil Medical Ltd Research Grant, Endo Health Solutions Inc Officer, Delphinus Medical Technologies, Inc

Barbara A. Adam MSN, Abstract Co-Author: Nothing to Disclose

Evan N. Fletcher MS, BA, Abstract Co-Author: Nothing to Disclose

Mark J. Krycia BS, Abstract Co-Author: Nothing to Disclose

To assess local recurrence and complication factors for liver cryoablation.  Tumor and ablation volume, location, vessel proximity, and complications were assessed in primary and metastatic tumors using updated techniques.  Focus upon hematologic complications was done to address prior bleeding fears.

CT and/or CT-US fluoroscopic-guided percutaneous cryoablations were performed in 268 procedures on 357 tumors (59 primary hematomas and 298 metastatic carcinomas) in 176 patients, noting tumor and ablation volumes, abutting vessels >3mm, procedure complications and recurrences.  Complications were graded by the National Institutes of Health, Common Terminology of Complications and Adverse Events (CTCAE).  Stress dose(s) of steroids were used in more recent procedures (n=68), which also limited ablation volume per session.  Patients received CT or MRI at 1, 3, 6, 12, 18, 24 months and yearly thereafter.

All patients required only conscious sedation.  Ablation zones and tumors averaged 5.2 and 2.9 cm, respectively.  A total local recurrence rate of 9.8% (35/357) was noted.  Differences in local recurrence rates showed no significance based on tumor size or vessel proximity for metastatic or HCC tumors.  Grade >3 complications were associated with larger ablation volumes (>100cc margin) in earlier procedures and before steroid prophylaxis.  A total of 25% patients also had low hemoglobin or platelets blood values prior to procedure yet still resulted in only 11/268 (4.1%) grade ≥3 total complications, again early in our series.

CT guided percutaneous hepatic cryotherapy provides a low morbidity alternative, especially for more central and peripheral tumors, where cryoablation produces minimal biliary damage and pain, respectively.  Complications ≥3 did not occur in patients with tumors <150cc and given steroids.  Local recurrence rate of <10% was not affected by tumor size or abutting vessels, and much lower compared to heat-based ablations.  Greater cryoprobe density/power is still needed to overcome heat-sink effects, as well as appropriate case selection and steroid prophylaxis.

Appropriately delivered liver cryoablation, appears less susceptible to tumor size and peri-vascular location, with low recurrence rates, and now complication rates comparable to heat-based ablations.

Aoun, H, Littrup, P, Adam, B, Fletcher, E, Krycia, M, Liver Cryoablation: Maximizing Outcomes with Minimal Morbidity.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13027764.html