Evolution of type II endoleaks based on different ultrasound-identified patterns

Area of Science:

• Vascular Surgery
• Medical Imaging
• Hemodynamics

Background:

• Type II endoleaks (T2ELs) are a common complication following endovascular aneurysm repair (EVAR).
• Understanding T2EL waveform characteristics is crucial for predicting sac behavior and guiding management.

Purpose of the Study:

• To characterize the specific waveforms present in T2ELs.
• To determine the association between T2EL waveform types and aneurysm sac size changes.

Main Methods:

• Duplex ultrasound was used to evaluate flow velocity characteristics in T2ELs.
• Four distinct flow patterns were identified: high resistance/low flow, low resistance/low flow, low resistance/high flow, and to-fro flow.
• Aneurysm sac diameter was monitored, with CT scans used for confirmation of changes.

Main Results:

• T2ELs were identified in 14.65% of EVAR patients (56 out of 382).
• Most T2ELs (high-resistance, low-flow and some low-resistance, low-flow) spontaneously occluded without sac enlargement.
• Low-resistance, high-flow and to-fro flow T2ELs were associated with a higher incidence of sac enlargement, rupture, and need for reintervention.

Conclusions:

• While most T2ELs resolve spontaneously, specific waveform patterns indicate a higher risk.
• Low-resistance, high-flow and to-fro flow T2ELs require closer monitoring due to their association with adverse outcomes like sac enlargement and rupture.