Identification of elastic lamina to guide interventional therapy
Described herein is a system and method for identifying elastic lamina during interventional procedures, such as atherectomy. Such identification can be used to avoid trauma to the external elastic lamina during the procedure.
1. A method of performing atherectomy, comprising:
inserting an atherectomy device into a vessel;
gathering optical coherence tomography (OCT) images using an imaging sensor on the device, wherein the OCT images provide a toroidal view of the vessel;
identifying an external elastic lamina in the OCT images by identifying an outer-most bright line in the toroidal view; and
cutting tissue in the vessel, wherein cutting tissue in the vessel comprises adjusting a depth of cut based upon the identification, and wherein adjusting a depth of cut comprises moving a cutter from an active mode to a passive mode.
2. The method of claim 1 , further comprising highlighting the external elastic lamina in the OCT images after the identifying step.
3. The method of claim 1 , wherein the device further includes a balloon configured to inflate or deflate to expose or cover the cutter, and wherein moving the cutter from an active mode to a passive mode comprises at least partially deflating the balloon.
4. The method of claim 1 , wherein the adjusting step is performed automatically.
5. The method of claim 1 , wherein cutting tissue in the vessel based upon the identification comprises reorienting a distal tip of the device based upon the identification.
6. The method of claim 1 , wherein reorienting the distal tip comprises using a marker in the OCT images to reorient the tip.
7. The method of claim 1 , wherein cutting tissue in the vessel comprises not cutting through the external elastic lamina.
8. The method of claim 1 , wherein the identification is performed automatically.
9. The method of claim 1 , further comprising determining a distance between the cutter and the external elastic lamina.
10. The method of claim 9 , further comprising activating an alarm if the distance is below a threshold value.
11. The method of claim 9 , further comprising stopping the cutting if the distance is below a threshold value.