Endovascular surgery, a form of minimally invasive surgery, is designed to access regions of the body through the major blood vessels. The basic technique involves the introduction of a catheter percutaneously (or through the skin) into a large blood vessel either through the femoral artery or vein found near the groin. The catheter is injected with a radio-opaque dye that can be seen on an X-ray or fluoroscopy imaging device. As the dye travels through the circulation, the real-time images seen by the radiologists assist in the diagnosis of diseases. Developments of intravascular balloons, stents and coils have allowed new therapies to evolve as alternatives to the traditional open surgeries.
The field of endovascular surgical intervention is rapidly growing, as the minimally invasive techniques offer advantages over the more traditional invasive surgeries. Clinical trials are underway, including the most recent carotid revascularization endarterectomy versus stent trial (CREST) and international subarachnoid aneurysm trial (ISAT), to assess the long term effects of the procedures. These assessments include reviewing the benefits of endovascular surgery over open surgery—primarily due to device improvements and enhanced procedural techniques. The future of endovascular repair procedures appears to be very promising.
Continuous device improvements and introductions of new generation devices are expected to keep the growth momentum in the double digits in the next couple of years. The endovascular devices market has witnessed a lot of merger and acquisition activities, with the niche players being acquired by tier 1 companies. Some noteworthy acquisitions include ev3’s Incorporation by Covidien, Johnson & Johnson acquisition of Micrus Endovascular Corporation, and Nellix Endovascular Incorporated procurement by Endologix Incorporated, to name a few. The following provides a detailed description of the pertinent global research and commercialization developments in the endovascular surgical interventions sector with major emphasis on technology innovations by the corporate sector and collaborative efforts undertaken by key academic institutions.
Key Market Trends: Endovascular Device Management
The incidence of thoracic aortic aneurysms (TAAs) repair is estimated to be as high as 10 cases per 100,000 people in a given year, amounting to a potential number of 30,000 cases per year in the U.S. and 48,000 cases in Europe. The actual number of diagnosed cases, however, is estimated at 15,000 per year in the U.S. and 16,000 per year in Europe. This number is increasing rapidly due to improved imaging technology and better screening protocols. Even for the most proficient surgeon, surgical repair in the thoracic region is difficult and has been associated with complications, especially in those who are not fit for thoracotomy.
The global market for endovascular abdominal aortic aneurysm (AAA) repair, which was valued at $1 billion in 2011, is expected to reach $1.6 billion by 2016. Continuous device evolutions and introduction of new generations of devices coupled with the recent development of the important Japanese market have been keeping growth momentum in the double digit brackets in recent years. Innovations, such as fenestrated juxtarenal bifurcated designs and aorto-uni-iliac models are important milestones in the stent-graft technology, which is expected to boost the growth of the market. A lot of participants have entered this market in the last few years, and during the next three to four years, the number of participants in this market is expected to double. There is a minor product differentiation between numerous abdominal stents available in the market. Most balloon fixed devices are made of stainless steel and self-expanding devices from nitinol. Most manufacturers also offer a number of different size ranges given the varied nature of the body’s vasculature. Providers select their devices based on essentially two criteria: familiarity and confidence in a device, and whether a patient’s anatomy is better suited for one device over another. With all of these factors being considered, the specialist is likely to select the device he has been trained on and is comfortable in utilizing. There is no definitive head to head clinical data that supports one device over the other.
Tier 1 competitors include the major drug eluting stent manufacturers. Cordis’s stent system is one of the industry’s most utilized devices for many major peripheral vascular stenting procedures. Boston Scientific and its Wallstent also enjoy similar levels of industry esteem due to name recognition and long-standing market performance. These two manufacturers use both their immense market size and trusted brand name recognition to maintain dominance in the market. The second level manufacturers are evenly split among a number of midsized niche manufacturers, such as ev3 and larger manufacturers, such as Medtronic.
Snapshot of Key Innovations
Recent reviews conducted by the clinician community have described the relative outcomes of endovascular repair of abdominal aortic aneurysm (EVAR) versus open surgical repair (OSR) and that of EVAR for abdominal aortic aneurysm (AAA) treatment—based on evidence from both randomized control trials (RCTs) and nonrandomized control trials (nRCTs). EVAR was first introduced to benefit patients with AAA who were at high risk for OSR procedures and to those who were anatomically suitable for EVAR procedure. EVAR technology is evolving over time due to new device generations and improvements in surgical techniques, an example being crossover grafts. Recent reviews of EVAR studies described a decreasing rate of mortality and increasing preference by patients and clinicians over time. However, EVAR procedures have some unmet clinical aspects such as:
- Migration of the endovascular device post-surgery.
- Endoleak, which can be chronic type I or type III or acute type II.
- Stability and durability of the graft, graft movement, and device wear out with time.
- Difficult and angulated anatomies where implantation of the device is difficult.
Some of the next-generation EVAR devices with enhanced features and better treatment option are listed below:
31 mm Gore Excluder AAA Endoprosthesis and GORE C3
Delivery System—W.L. Gore & Associates Inc.
This innovative technology represents a milestone in medical innovation by allowing physicians to position the device to the specific anatomy of each patient. The added deployment control provides physicians with increased confidence in treating challenging anatomies.
Zenith Low Profile (LP) AAA Endovascular Graft—Cook
Cook Medical has remained at the forefront of medical research and worldwide sales of products pertaining to endovascular therapy, critical care medicine, general surgery, diagnostic and interventional procedures. The Zenith Low Profile AAA Endovascular Graft (Zenith AAA LP) by Cook Medical is a low profile system, narrower than any other device available for treatment of AAA, and can be delivered to some patients via a needle insertion into the femoral artery percutaneously. Simplified deployment of the Zenith low profile endovascular graft makes it a breakthrough for surgeons treating patients with difficult or tortuous arterial access who might otherwise have been ineligible for EVAR.
INCRAFT AAA Stent-Graft System—Cordis Corp.
Cordis Corporation, a Johnson & Johnson company, has been a leader in the development and manufacture of endovascular interventional technology. Incraft, its new stent graft system designed to treat abdominal aortic aneurysm (AAA), is currently undergoing clinical studies. The clinical trial will assess the safety of the device to treat abdominal aortic aneurysm (AAA). The current stent grafts devices have large and bulky delivery systems, making the device introduction difficult for small or diseased access vessels. The ultra-low profile delivery system of Incraft will make EVAR possible as a treatment alternative for a wider section of patients.
Sac Anchoring AAA Prosthesis—Nellix Endovascular
Nellix Endovascular Inc. is engaged in the manufacturing and distributing of endograft devices. The product portfolio of the company consists of an aortic endograft device used in the treatment of abdominal aortic aneurysms and thoracic aortic aneurysms. In addition, Nellix technology can be used for the treatment of all aortic aneurysms and provides different advantages over current therapies. To expand the capabilities of EVAR and address the limitations observed with current endografts, Nellix Endovascular has designed a fillable, sac-anchoring, low-profile endovascular device. It encompasses a fully contained, polymer-filled endobag, which conforms perioperatively to the specific shape of the patient's aneurysm while providing anchoring and sealing. The polymer is contained inside an expanded polytetrafluoroethylene (ePTFE) bag that is attached on the inside by a metallic endoframe that forms the endoskeleton for the new lumen inside the aneurysm. The polymer is a proprietary formulation based on polyethylene glycol (PEG) and is biostable. This fillable EVAR system is designed to provide aneurysm exclusion and long-term device stability.
Adoption Trends and Insights
Current technologies used for treating vascular conditions include balloon angioplasty and stent placement, but increasingly special covered stents to seal off defects in blood vessels using materials known as embolics, which block off abnormal openings in blood vessels, are emerging for endovascular repair applications of renal artery aneurysms.
The field of endovascular repair of aortic dissections (tears in the wall of the aorta) is growing rapidly due to the development of new techniques. Of particular interest is a new technique using the Core valve device to anchor the graft to the aortic valve to enable repair of Type A dissections, which are dissections to the ascending aorta. This is an exciting development in meeting the challenges in the treatment of dissections. In recent years, vascular surgeons have treated an increasing percentage of aneurysms in the chest and abdomen with stent grafts. The device, called UniFit, is made by LeMaitre Vascular Inc. and is a notably promising product. Zenith Branch Endovascular Graft device from the Aortic Intervention business unit of Cook Medical, the global leader in endovascular therapy products, is another potential product platform. Cook Medical's Zenith Branch device is the only stent-graft available that allows a surgeon to repair an iliac branch aneurysm whilst still maintaining a good flow of blood to these arteries in the leg. The above indicated corporate developments show how rapid proliferation of endovascular repair procedures being adopted for the past three to five years’ timeframe has enabled endovascular surgeons to perform minimally invasive access procedures using novel materials deploying stent-assistance, catheters and endograft sheaths.
The underpinning issue in the development of endovascular surgical interventions, pertaining to its extent of being minimally invasive, is directly related to the surgeon’s comfort level in using the procedure and real treatment effects noticeable in all patient groups involved. This goes along with the existing relationships held amongst different stakeholders.
Currently, endovascular surgical interventional approaches are in a crucial phase, with developments generated in several aspects. New models for collaborative networks between academia and industry have emerged, while significant investment has been derived to extend the approaches striving for endovascular medicine. Competing with this landscape, the governmental agencies have also started to actively participate through the development of novel regulatory and policy frameworks that facilitate a progressive and organized clinical evidence translation. In this space, academic and research centers are also beginning to develop methodologies along with device manufacturing firms, to clearly innovate the use of technology and clinical trials information for achieving economic effectiveness.
Prasanna Vadhana Kannan is a research analyst with Technical Insights of Frost & Sullivan. She is responsible for screening and profiling technologies that have growth potential within the healthcare space. This includes tracking and roadmapping technology trends in the medical device, diagnostic imaging, pharmaceutical, and biotechnology markets. Kannan can be reached at 678-317-4754 or firstname.lastname@example.org.