Unusual optical coherence tomography findings resembling sea anemone tentacles after orbital atherectomy for nodular calcification lesions in a haemodialysis patient: a case report.

Background: Optical coherence tomography (OCT) can be used to characterize the details of calcified plaques because it allows high-resolution evaluation of coronary plaques, thrombi, and calcium.

Case Summary: A 72-year-old man on haemodialysis who had stenosis with a severe calcified lesion at the left anterior descending artery underwent percutaneous coronary intervention. Pre-intervention OCT imaging identified a nodular calcification (NC) that protruded into the lumen of the left anterior descending artery. To treat this lesion, we performed orbital atherectomy using the Diamondback 360 coronary orbital atherectomy system. After ablation of the nodular lesions at low and high speed, OCT showed newly emerged granular and filamentous structures that resembled sea anemone tentacles (these represented calcified nodule-like OCT findings). These structures appeared to extend from the proximal part of the ablated small NC, and shifted distally after balloon dilatation. Stent implantation was performed to entirely cover these structures, with no resulting complications. However, early in-stent restenosis occurred at 4 months follow-up.

Discussion: A tentacle-like OCT appearance in calcified lesions has not been previously reported. This represents a very rare and interesting imaging finding that reflects the relationship and origins of NCs and calcified nodules. The maturity of the NC lesions and the lateral sanding style of the orbital atherectomy system may have contributed to this striking OCT finding.