29 - Comparative Outcomes of Particle versus Ethanol–Lipiodol Embolization for Renal Angiomyolipomas: A 25-Year Experience

Sunday, April 12, 2026

4:12 PM - 4:21 PM ET

Presenting Author(s)

Xiao Wu, MD (she/her/hers)

Resident Physician
University of California, San Francisco, United States

Author/Co-author(s)

KM

Kalpana Manral, MD

Resident
University of California San Francisco, United States
AA

Adam Alyafaie, BS

Medical Student
University of California San Francisco, United States
Rana Rabei, MD

Resident
University of California, San Francisco, United States
Christopher Brunson, MD

Assistant Professor
University of California, San Francisco, United States
MC

Miles B. Conrad, MD , DR IR Board certified ABR (he/him/his)

Professor
UCSF, United States
NF

Nicholas Fidelman, MD

Professor
University Of California San Francisco, United States
BH

Brittany Harrison, MD

Assistant Professor
University of California San Francisco, United States
K. Pallav Kolli, MD, FSIR

Associate Professor of Clinical Radiology
University of California, San Francisco, United States
Vishal Kumar, MD

Associate Professor
University of California, San Francisco, United States
Alexander Lam, MD

Assistant Professor
UCSF Department of Radiology and Biomedical Imaging, United States
R. Peter Lokken, MD, MPH, FSIR (he/him/his)

Associate Professor of Clinical Radiology
UCSF Department of Radiology and Biomedical Imaging, United States
Rajesh Shah, MD

Professor of Clinical Radiology
University of California San Francisco, United States
JS

Jaehoon Shin, MD, PHD

Assistant Professor In Residence in Interventional Radiology
University of California, San Francisco, United States
AT

Andrew G. Taylor, MD

Associate Professor of Clinical Radiology
University of California, San Francisco, United States
RK

Ryan Kohlbrenner, MD

Assistant Professor
University of California, San Francisco, United States

Purpose: To compare the safety and efficacy of renal angiomyolipoma (AML) embolization using particles and ethanol/lipiodol.

Materials and Methods: Patients undergoing AML embolization between May 1995 and May 2022 at a large academic center were retrospectively reviewed after IRB approval. Patients were grouped based on the type of embolic used. Relevant patient- and tumor-specific variables were extracted via chart and imaging review pre- and post-embolization. Continuous variables were compared using student t tests and categorical variables were compared with Chi squared tests or Fisher’s exact test with simulation for small sample size.

Results: A total of 122 patients had 139 AML embolized. Among them, 96 patients (101 tumors) were treated for the first time. Technical success was achieved in all but one patient. Particle embolics (PE) were used alone in 42 patients for 45 tumors, and liquid ethanol/lipiodol embolic (LE) was used alone in 41 patients with 43 tumors. The median age in the PE group was 48 (IQR: 30.5 – 59.5) with female predominance (78.6%), and was 46.5 (IQR: 34.75 – 56.5) and 85.4%, respectively, in the LE group. They had similar proportions of patients with tuberous sclerosis (PE: 10/42, LE 8/41, p = 0.63). There was no difference in SIR grade III or above adverse events (PE: 1/42, LE: 0/41, p = 0.16) or post-embolization syndrome (PE: 5/42, LE: 8/41, p = 0.34). The PE group had more repeat procedures (PE: 13/45, LE: 6/43, p = 0.089) and higher rates of rebleeding (PE: 4/45, LE 0/43, p = 0.04).

Among patients with 6-month follow-up (FU) imaging, PE (mean FU 184 days) and LE (mean FU 168 days) initially had similar tumor sizes, rates of aneurysms and/or arteriovenous fistulas, and emergent presentations. Significant tumor size reduction was noted for both groups, without difference in the extent of reduction (1.54 cm vs 1.87 cm). Only the LE group showed a significant reduction in enhancement post-treatment.

Conclusion: This retrospective review showed high technical success rate and similar safety profile between AML embolizations with particles and embolizations with ethanol/lipiodol {1-4}. Greater reduction in tumor enhancement was seen in the ethanol/lipiodol group which also appeared to have lower retreatment and rebleeding rates.