A patient (through window) undergoing non-invasive ablation for essential tremor. Photo: Courtesy Rambam Medical Center.For the first time in Israel, and with only a handful of precedents in the world, doctors at Haifa’s Rambam Medical Center have “ablated” a dysfunctional part of the brain in a patient with essential tremor (ET) using MRIguided ultrasound rather than performing surgery.
Other experts skeptical of the technique, involving ultrasound ablation and MRI.
For the first time in Israel, and with only a handful of precedents in the world, doctors at Haifa’s Rambam Medical Center have “ablated” a dysfunctional part of the brain in a patient with essential tremor (ET) using MRIguided ultrasound rather than performing surgery.
A 73-year-old man, who was unable to sign his name clearly or even hold a cup of tea without spilling it, greatly improved from the painless procedure and was completely awake throughout, doctor said.
Medical ablation is the removal of tissue by vaporization or other erosive processes.
The technique of ablation by heat of deep-seated brain tissue through an intact skull was made possible with Israeli technology originally developed to remove myomas (benign fibroid growths in the uterus) but was later applied abroad to ET, which manifests due to a malfunction in the brain. The therapy was made possible by the integration of MRI guidance and the heating of the tissue using focused ultrasound.
The first Israeli patient, a Jerusalem hardware store owner named Sami Zangi, for years could not hold a cup of water without spilling it, tie his shoelaces or use the simplest tools. After the short treatment, he came out of the special MRI scanner and, as his family watched, he wrote in a steady handwriting Herzl’s famous quotation: “If you will it, it is no dream.”
The patient reportedly spent three calm, wide-awake hours inside an MRI machine, communicating with and monitored by Rambam senior neurologist Dr. Ilana Schlesinger, head of the movement disorders and Parkinson’s center, while Prof.
Menashe Zaaroor of the neurosurgery department used a computer mouse to direct 1,000 ultrasonic beams to the thalamic focal point that had been targeted for thermal ablation.
The trade name of the noninvasive treatment that he underwent is ExAblate Neuro.
The technology, a product of InSightec Ltd., was developed at the Technion-Israel Institute of Technology and experimented on at Sheba Medical Center at Tel Hashomer.
Today, ultrasound ablation is sometimes still used for uterine surgery along with conventional surgery. “But using it on myomas was the proof of concept,” said Rambam director-general Prof. Rafael Beyar, a leading interventional cardiologist.
ET is a slowly progressive movement disorder of rhythmic shaking whose cause lies deep within the brain.
Although usually not a dangerous condition, essential tremor worsens over time and can be severe in some people.
Sometimes mistakenly confused with Parkinson’s disease, it can occur at any age but is most common in people over the age of 40. ET is at least eight times more common than Parkinson’s, but up to a fifth of ET patients develop Parkinson’s disease and a tenth have a family history of PD.
Beyar told The Jerusalem Post that his hospital had spent millions of dollars on the special MRI and InSightec’s ultrasound ablation technology.
Zangi’s treatment was paid for by the patient’s public health fund, but Beyar would not disclose which insurer it was and could not say whether the treatment would be included in the basket of health services available to all Israelis.
“We are a beta site for InSightec’s device,” Beyar said. “The procedure we did here – this ability to treat problems inside the brain without making holes – is a breakthrough. Surgeons can actually see what they are doing from the outside, without going in. We think there is a potential of also treating Parkinson’s and even [to] perform non-invasive surgery on the brains of children. As ultrasound gets into children’s soft skulls more easily than adults’ skulls, it might eventually be used on pediatric brain surgery.”
After identifying the diseased part of the brain that causes the essential tremor, Beyar said, the ultrasound is used to heat it to 40 degrees Celsius. This part of the ablation is reversible. When it is determined that the warming up is effective, it is heated to 60 degrees to stop the tremor permanently, and this is irreversible.
Thus one has to work very exactly. We expect to try it on Parkinson’s symptoms later.”
But Beyar conceded that Rambam will continue to perform the deep-brain stimulation (DBS) – for surgically inserting electrodes into the brains of ET and Parkinson’s patients to relieve their severe tremors. ExAblate Neuro is not suited for everyone, he concluded.
Asked to comment during a visit to London, Prof. Shlomo Constantini, a senior neurosurgeon who heads the pediatric neurosurgery unit at Dana Hospital of Tel Aviv Sourasky Medical Center, told the Post that his own hospital was offered the InSightec device free, but that due to lack of consensus among the staff, it was decided to hold off until treatment results became more clear.
“The technology has been studied already for 10 years.
It will take a long time, if ever, [before] the US Food and Drug Administration approves it to ablate tumors or for use on children,” Constantini said. “[ExAblate Neuro] is a promising technology, but the future will determine whether conventional surgery or non-invasive ablation will be better. I can’t predict now, but I am rather skeptical that it will be widely used. Perhaps it will find a use in treating epilepsy.”
Dr. Zvi Israel, a leading DBS neurosurgeon at Hadassah University Medical Center in Jerusalem’s Ein Kerem, told the Post that while theoretically the InSightec technology was a breakthough, he was not convinced that it would find broad uses.
“It can be used safely only on one side of the brain, and ET usually affects both sides,” he said. “It has been known for 60 years that making bilateral lesions on both sides of brains is associated with a high risk of speech and swallowing difficulties. We at Hadassah will continue to perform DBS implants; we have performed 350 such implants, and only a small proportion were operated on for ET. We think the impact of ultrasound ablation therapy will be small.”
Dr. Kobi Vortman, InSightec’s CEO and president, who is an electro-optics and electrical engineer and not a physician, maintained on his website that “the way I see the future is the building of the next generation operating room, replacing traditional surgery by non-invasive outpatient procedure.”
The company was established in January 1999.
“We’ll definitely look as the next step at brain tumors, prostate cancer, liver tumors, breast cancer and so on,” Vortman said. “Eventually, we see it as a next generation operating room centralized service in the hospital.”