Feature | August 21, 2013

Robot Treats Brain Clots with Steerable Needles

For the last four years, a team at Vanderbilt University has been developing a steerable needle system for “transnasal” surgery

August 21, 2013 — The idea that surgery to relieve the pressure caused by hemorrhaging in the brain is a perfect job for a robotic system is the basic premise of a new image-guided surgical system under development at Vanderbilt University. It employs steerable needles about the size of those used for biopsies to penetrate the brain with minimal damage and suction away the blood clot that has formed.

The system is described in an article accepted for publication in the journal IEEE Transactions on Biomedical Engineering. It is the product of an ongoing collaboration between a team of engineers and physicians headed by Robert J. Webster III, assistant professor, and Kyle Weaver, assistant professor of neurological surgery.

For the last four years, Webster’s team has been developing a steerable needle system for “transnasal” surgery: operations to remove tumors in the pituitary gland and at the skull base that traditionally involve cutting large openings in a patient’s skull and/or face. Studies have shown that using an endoscope to go through the nasal cavity is less traumatic, but the procedure is so difficult that only a handful of surgeons have mastered it.

Webster’s design, which he calls an active cannula, consists of a series of thin, nested tubes. Each tube has a different intrinsic curvature. By precisely rotating, extending and retracting these tubes, an operator can steer the tip in different directions, allowing it to follow a curving path through the body. The single needle system required for removing brain clots was actually much simpler than the multi-needle transnasal system.

The brain-clot system only needs two tubes: a straight outer tube and a curved inner tube. Both are less than 1/20th  of an inch in diameter. When a computed tomography (CT) scan has determined the location of the blood clot, the surgeon determines the best point on the skull and the proper insertion angle for the probe. The angle is dialed into a fixture, called a trajectory stem, which is attached to the skull immediately above a small hole that has been drilled to enable the needle to pass into the patient’s brain.

The surgeon positions the robot so it can insert the straight outer tube through the trajectory stem and into the brain. He also selects the small inner tube with the curvature that best matches the size and shape of the clot, attaches a suction pump to its external end and places it in the outer tube.

Guided by the CT scan, the robot inserts the outer tube into the brain until it reaches the outer surface of the clot. Then it extends the curved, inner tube into the clot’s interior. The pump is turned on and the tube begins acting like a tiny vacuum cleaner, sucking out the material. The robot moves the tip around the interior of the clot, controlling its motion by rotating, extending and retracting the tubes. According to the feasibility studies the researchers have performed, the robot can remove up to 92 percent of simulated blood clots.

“The trickiest part of the operation comes after you have removed a substantial amount of the clot. External pressure can cause the edges of the clot to partially collapse making it difficult to keep track of the clot’s boundaries,” said Webster.

The goal of a future project is to add ultrasound imaging combined with a computer model of how brain tissue deforms to ensure that all of the desired clot material can be removed safely and effectively.

For more information: www.vanderbilt.edu

Related Content

Abiomed, Impella heart pump, 50,000 patients treated, United States, milestone
News | Ventricular Assist Devices (VAD)| February 24, 2017
Abiomed Inc. announced that it has supported more than 50,000 patients in the U.S. with its Impella line of heart pumps...
coordinated heart attack care, Ontario STEMI Bypass Protocol, Canada
News | Cath Lab| February 22, 2017
Two new Ontario-wide heart attack protocols for paramedic services and emergency departments that aim to saves lives...
transradial approach, same-day cardiac procedures, radial access, $300 million annual savings, JACC Cardiovascular Interventions study
News | Radial Access| February 22, 2017
If hospitals can perform more transradial, same-day percutaneous coronary intervention (PCI), hospitals across the U.S...
Technology | Radial Access| February 17, 2017
Medtronic plc announced that its coronary portfolio will now include the DxTerity Diagnostic Angiography Catheter line...
Sponsored Content | Videos | Inventory Management| February 17, 2017
The supplies you use in your cath lab are complex and very valuable.
Mercator MedSystems, DANCE trial data, ISET, LINC, Bullfrog Micro-Infusion Device
News | Peripheral Arterial Disease (PAD)| February 15, 2017
Mercator MedSystems announced that the national co-principal investigators of the company’s DANCE trial each presented...
Cardinal Health survey, hospital staff, supply chain management, quality of care
News | Inventory Management| February 15, 2017
Better hospital supply chain management leads to better quality of care and supports patient safety, according to a new...
University of Alabama at Birmingham, Amplatzer PFO Occluder, first implementation
News | Structural Heart Occluders| February 15, 2017
Doctors at the University of Alabama at Birmingham have implemented the first U.S. Food and Drug Administration (FDA)-...
Biotronik, PRO-Kinetic Energy cobalt chromium coronary stent system, FDA approval
Technology | Stents Bare Metal| February 15, 2017
The PRO-Kinetic Energy Cobalt Chromium (CoCr) Coronary Stent System from Biotronik has gained U.S. Food and Drug...
heart team, hybird OR, structural heart team

The heart team approach was first used on a large scale in the CoreValve and Sapien TAVR trials and helped lead to excellent outcomes in high-risk patients.

Feature | Hybrid OR| February 15, 2017 | Dave Fornell
In the current era of healthcare reform and the push toward evidence-based medicine to both lower costs and improve p
Overlay Init