Results of the first-in-human analysis of acute interactions and healing process after flow diverter implantation using optical coherence tomography (OCT) imaging was presented by Boris Pabón and Juan Mejia as members of Angioteam, Angiodinamia, Clinica Del Norte, Medellín, Colombia, at the 15th Congress of the World Federation of Interventional and Therapeutic Neuroradiology (WFITN; 21–24 October 2019, Naples, Italy).
Having evaluated three patients at the time of presentation, Pabón said: “The ultimate objective was to evaluate the feasibility and success of OCT technology after deploying dual layer flow diverter stents intracranially and extracranially, and to describe the acute [immediate] findings, as well as those at the six-week and six-month follow-up.”
During the acute phase, the investigators assessed both the safety and feasibility of the procedure, as well as anatomic and technical considerations. The latter included evaluating each stenting procedure in terms of flow diverter wall apposition, stent confirmability, strut symmetry, and acute thrombosis phenomena events. Additionally, through early (six weeks) and late (six months) follow-up, Pabón and colleagues evaluated the complete occlusion rate, and the healing process at different levels of the parent vessel, including its interactions with different segments of the device.
Discussing his teams experience with OCT, Pabón told delegates at WFITN, that while “OCT is a challenging procedure requiring a highly experienced neuroendovascular team”, it is feasible. He added that the technology is a reliable method to detect: “Acute intrastent thrombosis, any evidence of thrombogenic material, wall apposition of the flow diverter, conformability, the detection of fibrin bridges and the presence of neoendothelium.” Pabón also reported that the team observed no adverse events.
“In the near future, routine use of OCT may direct dual antiplatelet therapy based on individualised analysis,” he said. Now speaking to NeuroNews, he adds, “The community are really excited about these findings, as you can evaluate both mechanical factors, as well as the biological response after flow diverter stent deployment.
“I consider this new technology a new diagnostic tool, because you can evaluate the immediate results after flow diverter implantation, the presence of certain condition, and the healing process, and [subsequently] make judgements as to whether to continue or stop antiplatelet treatment.”
Pabón explains that while conventional digital subtraction angiography (DSA) and MRI are common modalities used to image cerebral vasculature, they have limitations pertaining to image-resolution, which means their capabilities to evaluate the biological healing process are significantly restricted.
OCT is currently more established in coronary plaque characterisation and coronary stenting, Pabón says, but emerging indications in the diagnosis of different neuro and peripheral vascular conditions (from cervical carotid bifurcation to proximal intracranial vessel visualisation) led to an “international interest” in evaluating the possibility to reach more distal intracranial vasculature.
“Now, we are waiting for neuro-dedicated OCT. People are working on it, it is coming soon,” confirms Pabón.