Ablation technologies are used to destroy ("ablate") diseased or traumatized tissue for therapeutic benefit. This includes destruction of cancerous tumors, ablation of endometrial tissue associated with endometriosis or abnormal uterine bleeding, creation of myocardial lesions to block the errant electrical signals in arrhythmia, and numerous others.
The largest share of the market for energy-based ablation devices is used in cancer therapy, primarily using the radiation therapy modality. Following that is general surgery with its use of electrocautery and electrosurgical devices, RF ablation, cryotherapy, etc. Cardiovascular applications are growing, particularly for cryoablation and radiofrequency ablation for arrhythmia, and now represent hold the third largest clinical area of ablation. The remaining applications are relatively small and fall in line behind the three leading sectors.
In the aggregate (i.e., for each modality worldwide), the largest segment is radiation-based ablation technologies, based to a large degree on the cost of the systems and their well-established use in clinical practice.
Below is a chart of the 2011 markets for ablation technologies by modality, with their projected compound annual growth rates (CAGRs) from 2011 to 2019.
The worldwide high energy therapies market represents a $25 billion opportunity in 2008. The category consists of therapeutic devices and equipment that deliver the controlled application of one or more modalities of energy to tissue.
The market will grow at an aggressive rate through 2017 for all modalities, but with some modalities exceeding compound annual growth rate of 20%. As a result of this, the adoption and growth of energy therapies will exceed the growth of the overall medical device market and the mix of energy therapies will increase.
Below is illustrated the aggregate growth of the ablation therapies market worldwide, by segment, and the relative growth of each of the segments in the market.
The global market for medical devices is currently a $185 billion opportunity and at least 13% of this market involves products that provide the controlled application of energy to tissue. The segment is dominated by high technology products ranging from devices that can heat and cool tissue over a 600° C temperature range of -200° C to +400° C to those that can vibrate at fifty five thousand cycles per second to denature tissue. While a significant share of the energy-based therapies market is for elective procedures such as refractive eye surgery and cosmetic hair removal, treatments for chronic diseases make up the vast majority of the applications of these technologies.
Underlying the growth of this market will be changes in demographics. The baby boomer generation–those born between 1946 and 1964–represents about one-third of the population in economically-developed countries. Many of these ageing citizens have both the economic means and the demand for therapies that can extend their active lives and delay the visible signs of aging.
Pushing the growth of energy therapies beyond basic changes in demographics are the unique benefits that they offer. They are typically less invasive than traditional surgery and are generally employed without the need for an implant. The therapies can be precisely metered and can be repeated. Emerging energy modalities have the potential to grow at significant, double-digit rates over the next decade as delivery systems evolve.
Ultrasonic energy offers superior control of energy output. 3D control and directionality of the energy delivered provides the ability to treat a prescribed target volume and shape which is critical for tumor ablation as increased energy penetration into the target tissue enables the treatment of larger tumor volumes and reduces treatment times. Peripheral and coronary vascular occlusive conditions that afflict tens of millions of people worldwide are now being treated with technologies that enable the delivery of ultrasonic energy over the active length of a small diameter guidewire-like device in an occluded blood vessel. The popularity of ultrasonic surgical systems is being driven by their inherent advantages. These systems control bleeding by coaptive coagulation at low temperatures ranging from 50ºC to 100ºC. Coagulation occurs by means of protein denaturation as opposed to thermal welding and the absence of smoke improves the visual field.
Cryogenic energy or the extreme absence of heat is very attractive as it is highly containable and thus localized. Cryoablation can be safely employed adjacent to delicate tissue and structures such as certain vasculature. Cryoablation may eliminate many of the problems seen in treating complex arrhythmias such as pulmonary vein stenosis. Cooling freezes tissue and does not seem to cause extracellular matrix changes or damage to the endocardium, which may lower clot-related complications. Thanks largely to advances in ultrasound, which allows physicians to target diseased tissue with pinpoint accuracy, and temperature control, which allows physicians to destroy the diseased tissue without harming the surrounding healthy tissue, cryoablation has become the fastest growing minimally invasive option for prostate cancer patients.
Microwave energy offers the inherent advantage of accommodating parallel delivery points. An increased treatment area can be treated with microwave energy very efficiently. Microwave probes are ideally suited for a full spectrum of cardiac ablation procedure from simple pulmonary vein isolation in paroxysmal AF to a full Maze for permanent AF. Energy delivery times are short, on the order of 25 to 60 seconds, and the unidirectionality of the microwave ensures the protection of surrounding tissues during epicardial application–a significant requirement for beating-heart application. Microwave energy is also being used as a transurethral therapy to treat BPH.
Light energy is being harnessed and focused for a variety of therapeutic applications. CO2 lasers are being used to revascularize injured myocardial tissue while excimer lasers are being adapted to atherectomy catheters that can clear thrombosis and reperfuse vessels. Over 2 million individuals seek the therapeutic benefits of laser vision correction each year; low level “cold” lasers are being employed to treat chronic pain relief for debilitating conditions like carpal tunnel syndrome–a leading cause of lost workdays. Intense pulsed light (IPL) that affects subtle changes in collagen is being used to treat vascular and pigmentation irregularities.
Hydromechanical energy systems that jet streams of saline only five one-thousandths of an inch in diameter — about the thickness of a human hair–can precisely dissect tissue, sparing vessels and nerves, and are being employed for hepatic resection and nerve-sparing retropubic radical prostatectomy. This modality does not cause thermal damage to tissue and can sculpt, ablate and cauterize bleeders.
Radiation energy using focused arrays of intersecting beams of gamma radiation is being used to treat lesions within the brain. Radiosurgery devices that can ablate otherwise untreatable tumors and malformations when directed by computers are finding otherwise untreatable lesions.
Thermal energy is employed successfully to treat menorrhagia due to benign causes in premenopausal women. When tissue is heated above 46°C, cellular protein denatures and the cell dies. Thermal uterine balloon therapy offers a less-invasive option that allows women to preserve their uterus. Thermal therapy is also being employed for breast and prostate cancer. Implants made of ferromagnetic material that can be “turned-on” when placed within an electromagnetic field and heated in situ offer a high degree of specificity with respect to the treated tissue area.
Electrical energy delivered by small implants can deliver a life saving jolt of electricity to shock a patient’s heart back to normal when rhythmic disturbances of the lower heart chambers that can cause sudden cardiac death are detected. Similar devices deliver electrical energy to speed up a heart beating too slowly. Image-guided radiofrequency ablation which uses heat to destroy diseased tissue can preserve kidney function and avoid kidney dialysis for patients with solid renal tumors who are not surgical candidates.
Radiofrequency energy is gaining widespread use in the field of sports medicine surgery for the thermal modification of soft tissue structures within the joint. The use of radiofrequency energy for thermal chondroplasty has gained tremendous popularity because of the quality of the therapy. Radiofrequency surgical systems have the inherent ability to seal large vessels as a result of the tremendous temperatures the energy can generate.
Given the varying clinical utilities of the different energy modalities and the correspondingly different current and potential caseload, the growth in the market for ablation technologies varies by modality, as shown below.