Microcatheters are small 0.70-1.30mm diameter catheters that are used for guidewire support, exchanges, to access distal anatomy, cross lesions, deliver therapeutic embolic, inject contrast media and perform other procedures in complex endovascular procedures.
Steerable microcatheters have been used in cardiac applications such as balloon delivery to improve vessel flow in elderly patients, according to a study published in January 2019 in the Journal of Geriatric Cardiology. They can be used to place and exchange guidewires and other interventional devices for diagnostic and therapeutic applications.
Most microcatheters feature a lubricious coating and an integrated steerable or angled tip for easier penetration and deliverability. The hydrophilic coating can enhance navigation through tortuous vasculatures while a coil pitch increases flexibility and proximal pushability.
Microcatheters are also commonly used in percutaneous coronary intervention (PCI), according to the journal. Older populations have a higher prevalence of calcified and ostial lesions, tortuous coronary anatomy, multivessel disease and left main stem stenosis. However, doctors have been reluctant to refer older patients for PCI procedures due to calcified lesions making target vessel, lesion access and vessel preparation difficult. Microcatheters, in recent years, have successfully intervened in complex coronary anatomy.
In studies, microcatheters have shown good support in treating calcified lesions in otherwise difficult procedures due to significant vessel angulation and calcification. Researchers have said that steerable coronary microcatheters have made coronary vessel and lesion access more feasible to treat most fibrotic and heavily calcified stenoses.
Other microcatheters have been used in neurointerventional procedures, some reaching lumen ranges of 0.015 in. to 0.021 in.
In one study, researchers tested microcatheters to investigate the risk of distal embolization associated with navigation across a clot in treating acute ischemic stroke. Results showed that a clot crossing maneuver had a significant effect on the total number of particles induced during a mechanical thrombectomy, according to a 2018 study in the Journal of NeuroInterventional Surgery.