Abdominal and thoracic aortic aneurysm repair: procedures forecast

Below is an excerpt from, “Global Dynamics of Surgical and Interventional Cardiovascular Procedures, 2015-2022,” (Report #C500 described, available online).

Selection of specific management protocols for patients with aortic aneurysms depends on the disease morphology as well as patient’s age, overall health status, and comorbidities involved. In cases involving smaller and relatively stable abdominal or thoracic aortic aneurysm (AAA or TAA), watchful waiting represents a commonly preferred approach. Radical surgical or endovascular interventions are generally reserved for cases when the diameter of the aneurismal sac is larger than 5cm to 5.5cm, or the annual expansion rate exceeds 1.0 cm, or when the aneurysm becomes symptomatic.

Surgical Repair of Aortic Aneurysms

Prior to the advent of AAA/TAA endovascular repair tools and techniques, a highly invasive and risky surgical repair procedure constituted the only curative option for patients with advanced and rupture prone aortic aneurysm. Conducted under the general anesthesia the procedure takes a few hours and entails a major and highly traumatic operation with a 10-15 inch cut in abdominal wall, clamping and isolation of aneurysmic segment of aorta, incision into the aneurysm, evacuation of the clot contained within, placement of a synthetic graft, and wrapping of the graft with remnants of the aortic wall.

The typical surgical aneurysm repair is associated with a substantial (5% to 8%) mortality rate and serious complications, such as stroke, myocardial infarction, renal failure etc.

Due to the close proximity to the heart, the risk and complication rates of surgical intervention for aneurysm repair on the thoracic aorta increase multifold resulting in an average procedural mortality rate of up to 30 percent.

The high cost of the procedure is largely the result of extended ICU and hospital stays, which can last upwards of a week (but average roughly 10-12 days). Further, postoperative recovery may require up to six additional weeks subsequent to discharge, making temporary disability a major consideration for many patients.

Notwithstanding these drawbacks, open surgical aortic aneurysm repair is still commonly regarded as highly effective treatment modality that virtually eliminates the risk of aneurismal sac rupture and does not require extensive postoperative follow-up exams or revisions.

However, because of high prevalence of elderly and health-impaired persons in diagnosed aortic aneurysm caseloads and traumatic nature of AAA/TAA surgery, only a fraction of the patients who could benefit from surgical aneurysm repair is deemed eligible for such a procedure.

Abdominal Aortic Aneurysm Repair with Endovascular Stent-Grafts

During the past two decades, advances in interventional technologies paved the way for the advent of a considerably less invasive and risky endovascular AAA repair procedure. The procedure involves a transcatheter deployment of the specially designed endovascular prosthesis (typically combining sealing functions of the vascular graft and full or partial stenting support structure) into a defective segment of aorta with the goal of excluding the aneurysmal sac from blood circulation.

The endovascular stent-grafts (SGs) – which come both in self-expanding or balloon-expandable versions – are typically anchored to an undamaged part of the aorta both above and below the aneurysm via a compression fit or/and with a special fixation mechanism like hooks, barbs, etc.

To accommodate a great morphological diversity of aortic aneurysms the vast majority of endovascular SGs is employing a modular design concept providing the aorto iliac, bifurcated and straight tubular device configurations to cover a variety of AAA indications. Several SG systems also feature an open stenting structure at proximal end to enable suprarenal device deployment required in about 30% to 35% of all AAA cases warranting intervention.

In its idea, the endovascular repair of abdominal aortic aneurysm was intended to produce clinical outcomes comparable to these yielded by the open surgery, while reducing the associated trauma, recovery time, morbidity and the overall treatment cost. It was also generally expected that availability of less-invasive endovascular treatment option would allow to extend caseloads coverage to sizable rupture-prone AAA patient subsets who are poor surgical candidates.

Limitations of Endovascular AAA Repair

Findings from numerous clinical studies and real-life experience in the field seem to indicate that endovascular aortic aneurysm repair via stent-graft placement tends to provide immediate procedural outcomes comparable to these obtainable with open surgery. Furthermore, the typical ICU and hospital stay for endovascular AAA repair averages 2 days (though it may last twice longer for patients with significant comorbidities). All of these translates into reduced inpatient costs of AAA repair relative to open surgery, although the high price of stent-grafting devices largely offsets these cost savings. Post-discharge recovery is also shortened from weeks or months to an average 7-10-day period.

Unfortunately, comparative long-term clinical efficacy and cost-effectiveness of the endovascular approach to aortic aneurysm repair appears to be problematic due to unavoidable shortcomings of available aortic stent-graft designs and complications associated with their less than perfect performance in situ.

The major problems associated with the endovascular AAA repair approach include relatively high incidence of endoleaks (up to 15%), endotension, and device failure, which multiply the risk of catastrophic aneurysm rupture and necessitate costly revisions (in up to 35% of the cases) as well as long-term (or life-long) patient surveillance (with mandatory imaging exams). Due to that, the actual overall cost of endovascular repair in many considerably exceeds expenses incurred in traditional open surgery.

Another limitation of endovascular stent-grafting relates to its ability to accommodate complex aortic aneurysm morphology and branch involvement. Based on some end-user and industry reporting, only about 50% of patients that develop intervention-warranting AAAs are considered good candidates for endovascular repair with currently available product configurations.

According to some recent reporting, endovascular aneurysm repair (EVAR) treatment with certain stent grafts also appears to be associated with higher late mortality rates (due to aneurysm rupture) compared to surgical AAA repair. Based on available long-term follow-up data, mortality in AAA patients retrofitted with the market-leading SG averages 1.3% and 1.5% at four and five years compared to 0.7% and 0.9% for AAA surgery.

Endovascular Repair of TAA

Introduced in Europe and the U.S. in 1998 and 2005, accordingly, endovascular techniques for aneurysm (and aortic dissection) repair on thoracic aorta represented a logical extension of the very same basic concept and technology platforms that enabled the development of AAA stent-grafts.

Because of extremely high mortality and morbidity rates associated with TAA surgery, the need for minimally invasive endovascular treatment option was even more compelling than that in AAA case.

Similar to AAA endovascular repair devices, TAA stent-grafts are intended to minimize the risk of catastrophic thoracic aortic aneurysm rupture via effective exclusion (isolation) of the aneurismal sac from blood circulation.

Unlike AAA implants, commercially available TAA stent-grafting devices feature relatively simple tubular unibody architecture with sealing cuffs (or flanges) at proximal and distal end.

Insertion of TAA SGs is done under fluoroscopic guidance via a singular femoral puncture with the use of standard transcatheter techniques. Depending on the aneurysm morphology, one or two overlapping devices might be used to ensure proper aneurismal sac isolation.

The average ICU and hospital stays and post-discharge recovery period for endovascular TAA repair procedure are generally similar to these for AAA stent-grafting intervention.

Although practical clinical experience with endovascular repair of thoracic aortic aneurysm remains somewhat limited, findings from European and U.S. clinical studies with TAA stent-grafting tend to be very encouraging. Based on these findings, stent-grafting of rupture-prone aneurysm on ascending thoracic aorta can be performed with close to perfect technical success rate yielding radical reduction in intraoperative mortality and complications compared to TAA surgery as well as impressive improvement in long-term patient survival.

Similar to AAA endografting, the main problems associated with the use of TAA SG systems include significant incidence of endoleaks and occasional device migration which require reintervention.

Aortic Aneurysm Repair Procedure Volumes

Based on the industry reporting, national and international healthcare authority data, and MedMarket Diligence estimates, in 2015, approximately 915 thousand patients worldwide were diagnosed with rupture-prone abdominal or thoracic aortic aneurysms and aortic dissections warranting radical intervention, of which roughly 359.5 thousand (or about 39.3%) were actually referred for surgical or transcatheter treatment. Covered APAC market geography (with combined population of about 2,63 billion) accounted for the largest 37.6% share of all aortic aneurysm repairs performed, followed by the U.S. with 25.6%, largest Western European states with 21.3% and the rest-of-the-world with the remaining 15.5%.

Endovascular stent-grafting techniques were utilized in approximately 162.5 thousand aortic aneurysm repair procedures in 2015, which included an estimated 133 thousand AAA-related and about 29.5 thousand TAA-related interventions (including these targeting selected thoracic aortic dissections).

The cited figures reflected a disparity both in the relative volumes of treated AAA and TAA patients and, especially, in the share of these managed with the less invasive EVAR techniques. The latter indicator was the highest for the U.S. (~75%), compared to 52% for Western Europe, 39% for APAC and only 36.6% for the ROW market geography.

During the forecast period covered in the report, the total global volume of endovascular aortic aneurysm repairs is projected to grow 5.7% per annum to approximately 243 thousand procedures, combining a 5.5% annual expansion in AAA-related interventions with a 6.6% average annual increase in TAA (aortic dissection)-related interventions.

Projected healthy gains in endovascular aortic aneurysm repair procedures should reflect continuous penetration of non-surgical (no option) AAA and TAA patient caseloads, coupled with significant incursion into surgery-eligible patient subsets both in AAA, TAA, and aortic dissection indications. Increasing reliance on utilization of less traumatic AAA and TAA stent-grafting techniques will be expedited by ongoing qualitative improvements in the endograft and delivery tools design that keep yielding more reliable, durable, versatile, and end-user friendly systems with reduced propensity to mechanical and functional failure (device kinking, fracture, endoleaks, migration, etc.) and associated clinical complications.

The largest relative gains in AAA and TAA EVAR procedures (10.9% and 11.8%, accordingly) can be expected in covered APAC territories (mostly China and India) and grossly underserved ROW zone (6.5% and 7.5%). Largely mature U.S., Western European (and Japanese) markets are likely to register a low single digit advances in utilization of endovascular AAA/TAA repair techniques.

The global procedure volume forecast for aortic aneurysm repair is presented below.

Projected Dynamics of Aortic Aneurysm Repair Procedures,
World Total, 2015-2022 (#000)

Indications / Procedures20152016201720182019202020212022CAGR 2016-2022
Total EVAR AAA/TAA Procedures1516.317.618.920.221.522.824.16.70%
Diagnosed AAA & TAA Caseloads1651701751801851901952002.80%
Treated AAA & TAA Patients5658.56163.56668.57173.53.90%
Abdominal Aortic Aneurysm (AAA) Repair
Treated AAA Patient Caseloads45474951535557593.90%
Surgical Repair Procedures33343536373839402.80%
Endovascular Repair Procedures12131415161718196.50%
Thoracic Aortic Aneurysm (TAA) Repair
Treated TAA Patient Caseloads1111.51212.51313.51414.53.90%
Surgical Repair Procedures88.28.48.68.899.29.42.30%
Endovascular Repair Procedures33.33.63.94.24.54.85.17.50%
Total Surgical AAA/TAA Repairs4142.243.444.645.84748.249.42.70%

Notes: AAA = abdominal; aortic aneurysm. EVAR = endovascular aneurysm repair. TAA = thoracic aortic aneurysm.

Source: MedMarket Diligence, LLC; Report #C500. (Full cardiovascular procedures report online.)

Source: MedMarket Diligence, LLC; Report #C500. (Full cardiovascular procedures report online.)

 

Cardiovascular procedure volume growth (interventional and surgical)

Cardiovascular surgical and interventional procedures are performed to treat conditions causing inadequate blood flow and supply of oxygen and nutrients to organs and tissues of the body. These conditions include the obstruction or deformation of arterial and venous pathways, distortion in the electrical conducting and pacing activity of the heart, and impaired pumping function of the heart muscle, or some combination of circulatory, cardiac rhythm, and myocardial disorders. Specifically, these procedures are:

  • Coronary artery bypass graft (CABG) surgery;
  • Coronary angioplasty and stenting;
  • Lower extremity arterial bypass surgery;
  • Percutaneous transluminal angioplasty (PTA) with and without bare metal and drug-eluting stenting;
  • Peripheral drug-coated balloon angioplasty;
  • Peripheral atherectomy;
  • Surgical and endovascular aortic aneurysm repair;
  • Vena cava filter placement
  • Endovenous ablation;
  • Mechanical venous thrombectomy;
  • Venous angioplasty and stenting;
  • Carotid endarterectomy;
  • Carotid artery stenting;
  • Cerebral thrombectomy;
  • Cerebral aneurysm and AVM surgical clipping;
  • Cerebral aneurysm and AVM coiling & flow diversion;
  • Left Atrial Appendage closure;
  • Heart valve repair and replacement surgery;
  • Transcatheter valve repair and replacement;
  • Congenital heart defect repair;
  • Percutaneous and surgical placement of temporary and permanent mechanical cardiac support devices;
  • Pacemaker implantation;
  • Implantable cardioverter defibrillator placement;
  • Cardiac resynchronization therapy device placement;
  • Standard SVT & VT ablation; and
  • Transcatheter AFib ablation

For 2016 to 2022, the total worldwide volume of these cardiovascular procedures is forecast to expand on average by 3.7% per year to over 18.73 million corresponding surgeries and transcatheter interventions in the year 2022. The largest absolute gains can be expected in peripheral arterial interventions (thanks to explosive expansion in utilization of drug-coated balloons in all market geographies), followed by coronary revascularization (supported by continued strong growth in Chinese and Indian PCI utilization) and endovascular venous interventions (driven by grossly underserved patient caseloads within the same Chinese and Indian market geography).

Venous indications are also expected to register the fastest (5.1%) relative procedural growth, followed by peripheral revascularization (with 4.0% average annual advances) and aortic aneurysm repair (projected to show a 3.6% average annual expansion).

Source: MedMarket Diligence, LLC; “Global Dynamics of Surgical and Interventional Cardiovascular Procedures, 2015-2022,” (Report #C500).

Geographically, Asian-Pacific (APAC) market geography accounts for slightly larger share of the global CVD procedure volume than the U.S. (29.5% vs 29,3% of the total), followed by the largest Western European states (with 23.9%) and ROW geographies (with 17.3%). Because of the faster growth in all covered categories of CVD procedures, the share of APAC can be expected to increase to 33.5% of the total by the year 2022, mostly at the expense of the U.S. and Western Europe.

However, in relative per capita terms, covered APAC territories (e.g., China and India) are continuing to lag far behind developed Western states in utilization rates of therapeutic CVD interventions with roughly 1.57 procedures per million of population performed in 2015 for APAC region versus about 13.4 and 12.3 CVD interventions done per million of population in the U.S. and largest Western European countries.

Source: MedMarket Diligence, LLC; “Global Dynamics of Surgical and Interventional Cardiovascular Procedures, 2015-2022,” (Report #C500).


Global Cardiovascular Procedures report #C500 details the current and projected surgical and interventional therapeutic procedures commonly used in the management of acute and chronic conditions affecting myocardium and vascular system.

Interventional and Surgical Cardiovascular Procedure Volumes

Cardiovascular diseases (CVDs) are a variety of acute and chronic medical conditions associated with an inability of the cardiovascular system to sustain an adequate blood flow and supply of oxygen and nutrients to organs and tissues of the body. The CVD conditions may be manifested by the obstruction or deformation of arterial and venous pathways, distortion in the electrical conducting and pacing activity of the heart, and impaired pumping function of the heart muscle, or some combination of circulatory, cardiac rhythm, and myocardial disorders.

These diseases are treated via the following surgical and interventional procedures:

  • Coronary artery bypass graft (CABG) surgery;
  • Coronary angioplasty and stenting;
  • Lower extremity arterial bypass surgery;
  • Percutaneous transluminal angioplasty (PTA) with and without bare metal and drug-eluting stenting;
  • Peripheral drug-coated balloon angioplasty;
  • Peripheral atherectomy;
  • Surgical and endovascular aortic aneurysm repair;
  • Vena cava filter placement
  • Endovenous ablation;
  • Mechanical venous thrombectomy;
  • Venous angioplasty and stenting;
  • Carotid endarterectomy;
  • Carotid artery stenting;
  • Cerebral thrombectomy;
  • Cerebral aneurysm and AVM surgical clipping;
  • Cerebral aneurysm and AVM coiling & flow diversion;
  • Left Atrial Appendage closure;
  • Heart valve repair and replacement surgery;
  • Transcatheter valve repair and replacement;
  • Congenital heart defect repair;
  • Percutaneous and surgical placement of temporary and permanent mechanical cardiac support devices;
  • Pacemaker implantation;
  • Implantable cardioverter defibrillator placement;
  • Cardiac resynchronization therapy device placement;
  • Standard SVT & VT ablation; and
  • Transcatheter AFib ablation

In 2016, the cumulative worldwide volume of these procedures is projected to approach 15.05 million surgical and transcatheter interventions. This will include:

  • roughly 4.73 million coronary revascularization procedures via CABG and PCI (or about 31.4% of the total),
  • close to 4 million percutaneous and surgical peripheral artery revascularization procedures (or 26.5% of the total);
  • about 2.12 million cardiac rhythm management procedures via implantable pulse generator placement and arrhythmia ablation (or 14.1% of the total);
  • over 1.65 million CVI, DVT, and PE targeting venous interventions (representing 11.0% of the total);
  • more than 992 thousand surgical and transcatheter heart defect repairs and valvular interventions (or 6.6% of the total);
  • close to 931 thousand acute stroke prophylaxis and treatment procedures (contributing 6.2% of the total);
  • over 374 thousand abdominal and thoracic aortic aneurysm endovascular and surgical repairs (or 2.5% of the total); and
  • almost 254 thousand placements of temporary and permanent mechanical cardiac support devices in bridge to recovery, bridge to transplant, and destination therapy indications (accounting for about 1.7% of total procedure volume).

Below is illustrated the overall global growth for each of the major categories of procedures through 2022.

Source: MedMarket Diligence, LLC; Report #C500.  (Full report available online.)

There is considerable variation in the growth of cardiovascular procedures globally, but most growth is coming out of Asia/Pacific. For example, within the area of venous interventions, the growth in the use of endovenous ablation for chronic venous insufficiency is markedly higher in Asia/Pacific than in other regions, though the U.S. will remain the largest volume of these procedures.

Source: MedMarket Diligence, LLC; Report #C500.  (Full report available online.)


“Global Dynamics of Surgical and Interventional Cardiovascular Procedures, 2015-2022” (Report #C500), published August 2016. See description, table of contents, list of exhibits at link. Available for purchase and download from link.

Forgotten Opportunities: Early Stage Biotech and Medtech Investment

Due to the uncertainty in the development, clinical testing, and regulatory approval of both biotech and medical technologies, which increasingly have to be viewed with the same competitive lens, investors have over the past few years shied away from seed stage or Series A stage company investment in favor of those nearer to market introduction. However, with the advent of a great number of new technologies and advances in the underlying science, there is enormous opportunity to identify companies and emerging sectors arising from these advances. The problem in identifying realistically promising companies is that it must be done so without falling prey to the bad investment practices in the past that ensued from a poor understanding of the technologies and their remaining commercial hurdles. Without careful consideration of remaining scientific development needed, the product’s target market, its competitors, and the sum total of the company’s capabilities to commercialize these technologies, investment in these areas will fall short of investment objectives or fail them outright.

While any of these considerations have the capacity to preempt a successful market introduction, a failure to understand the science behind the product and its remaining development hurdles to commercialization is likely to be the biggest cause of failure.

“We’ve already had one glaring example of a company, and its investors, learning the hard way that health and science advisors are important: Theranos.” (link)

Venture Capital has backed away from early stage investment

Earlier stage investment, with its higher risk, has higher potential reward, so there is a big need for more effective evaluation of potential early stage investments in order to (1) seize these opportunities that will otherwise potentially be lost with the shift to later stage fundings, (2) sort out those companies/technologies with overwhelming commercialization hurdles from those that will profitably tap an opportunity, and (3) gain the value of these opportunities before the innovation appreciates in value, driving up the price of the investment.

The Biotech Bubble

Biotech in the 1980s was enamored with companies pursuing “magic bullets” — technologies that had the potential to cure cancer or heart disease or other conditions with large, untapped or under-treated populations. With few exceptions, these all-in-one-basket efforts were only able achieve a measure of humility in the VCs who had poured volumes of money into them.

Here was evidenced a fundamental problem with biotech at a time when true scientific milestones were being reached, including successes in mapping the human genome: Landmark scientific milestones do not equate with commercial success.

As a result, money fled from biotech as few products could make it to market due to persistent development and FDA hurdles. By the late 1980s, many biotechs saw three quarters of their value disappear.

A Renewed Bubble?

The status of biomedical science and technology, with multiple synergistic developments, will lead to wild speculation and investment, potentially leading to yet another investment bubble. However, there will be advances that can point to real timelines for market introduction that will support investment.

Recent advances, developments and trends supporting emerging therapeutics

  1. Stem cells. A double-edged sword in that these do represent some the biggest therapeutics that will emerge, yet caution is advised since the mechanisms to control stem cells are not always sufficient to prevent their nasty tendency to become carcinogenic.
  2. Drug discovery models, such as using human “organoids” and other cell-based models to test or screen new drugs.
  3. Systems to accelerate the rapid evaluation of hundreds, perhaps, thousands of potential drugs before moving to animal models or preclinicals.
    1. Machine-learning algorithms
    2. Cell/tissue/organ models
    3. Meta-analysis, the practice of analyzing multiple, independently produced clinical data to draw conclusions from the broader dataset.
  4. Cross-discipline science
    1. cell biologists, immunologists, molecular biologists and others have a better understanding of pathology and therapeutics as a result of information sharing; plus BIG DATA (e.g., as part of the “Cancer Moonshot”). Thought leaders have called for collection and harnessing of patient data on a large scale and centralized for use in evaluating treatments for specific patients and cancer types.
    2. Artificial intelligence applied to diagnosis and prescribed therapeutics (e.g., IBM Watson).
    3. Examples of resulting therapies, at a minimum, include multimodal treatment – e.g., radiotherapy and immunotherapy – but more often may be represented in considerably more backend research and testing to identify and develop products with greater specificity, greater efficacy, and lowered risk of complications.
  5. Materials science developments, selected examples:
    1. Scaffolds in tissue engineering
    2. Microgels
    3. Graphene
    4. Polyhedral boranes
    5. Nanometric imprinting on fiber
    6. Knitted muscles to provide power link
    7. 3-D printed skin and more complex organs to come
    8. Orthopedic scaffolds made from electrospun nanofibers
  6. CAR-T (chimeric antigen receptor T cell therapy)
  7. CRISPR/Cas-9. Gene editing
    1. Removal, insertion of individual genes responsible for disease
    2. Potential use for creating chimeras of human and other (e.g., pig) species in order to, for example, use pigs for growing human organs for transplant.
  8. Smart devices: smart biopsy needles, surgical probes to detect cancer margins, artificial pancreas. Devices using information

 

We sum this up with these prerequisites for investment:

Prerequisites for Early Stage Med/Bio Investment

  1. A fully understood and managed gap between scientific advance and commercial reality.
    1. Investment must be tied to specific steps (prototyping, preclinicals, clinicals, physician training, etc.).
  2. A management team qualified in commercializing medtech or biotech products.
    1. CEOs (and/or Chief Medical Officers, Chief Scientific Officers) with medical science backgrounds (MD, PhD) favored over CPAs or even JDs.
  3. Reimbursement strategy pursued as something more than an afterthought
  4. Technology development in sync with end-user acceptance and training to leverage the benefits:
    1. Easier to use
    2. Fewer complications
    3. Attractive physician revenue streams
  5. Broad competitive advantage pursued:
    1. Product benefits must stand up against all competition, irrespective of technology type (devices competing with drugs, biotech).
    2. Benefits of reducing the cost of care for an existing patient population are paramount.
    3. Competitive advantage must consider the trend in technology development to avoid being disrupted by other products soon to reach the market.
  6. Predefined exit strategy; selected examples:
    1. Positioning to add innovation to a mid-cap or large-cap medtech or biotech as acquirers.
    2. Development of platform technologies for licensing or sale.
    3. IPO

 

Future investments are likely to track the historical focus on specific diseases and conditions:

Source: MedMarket Diligence, LLC and Emerging Therapeutic Company Investment and Deal Trends; Biotechnology Innovation Organization.


MedMarket Diligence, mediligence.com, tracks medical and biotechnology development to provide meaningful insights for manufacturers, investors, and other stakeholders.

Coronary revascularization options evolve

The number of options that are in use or development for coronary revascularization is extraordinary. Given the mortality associated with coronary artery disease, it is unsurprising that it has been the focus of so much development.

Below gives the “branches” of approaches treatment of coronary artery disease. This may well be incomplete, give the rapid pace of development.

Coronary Revascularization Treatment Options

Source: MedMarket Diligence, LLC

See also “Global Dynamics of Surgical and Interventional Cardiovascular Procedures, 2015-2022”, report #C500. Order online.

Peripheral Stenting Worldwide: Arterial, Venous, BMS, DES, AAA, TAA

First introduced about two decades ago as a bailout technique for suboptimal or failed iliac angioplasty, peripheral vascular stenting gradually emerged as a valuable and versatile tool for a variety of primary and adjuvant applications outside the domain of coronary and cerebral vasculature.  Today, peripheral vascular stenting techniques are commonly employed in the management of the most prevalent occlusive circulatory disorders and other pathologies affecting the abdominal and thoracic aortic tree and lower extremity arterial bed. Stents are also increasingly used in the management of the debilitating conditions like venous outflow obstruction associated with deep venous thrombosis and chronic venous insufficiency.

Notwithstanding a relative maturity of the core technology platforms and somewhat problematic opportunities for conversion to value-adding peripheral drug-eluting systems, peripheral vascular stenting appears to have a significant room for qualitative and quantitative growth both in established and emerging peripheral indications.

A panoply of stenting systems are available for the management of occlusive disorders and other pathologies affecting peripheral arterial and venous vasculature. Systems include lower extremity bare metal and drug-eluting stents for treatment of symptomatic PAD and critical limb ischemia resulting from iliac, femoropopliteal and infrapopliteal occlusive disease; stent-grafting devices used in endovascular repair of abdominal and thoracic aortic aneurysms; as well as a subset of indication-specific and multipurpose peripheral stents used in recanalization of iliofemoral and iliocaval occlusions resulting in CVI.

In 2015, these peripheral stenting systems were employed in approximately 1.565 million revascularization procedures worldwide, of which the lower extremity arterial stenting accounted for almost 1.252 million interventions (or 80.9%), followed by AAA and TAA endovascular repairs with 162.4 thousand interventions (or 10.5%) and peripheral venous stenting used in an estimated 132.6 thousand patients (or 8.6% of the total).

The U.S. clinical practices performed almost 528 thousand covered peripheral arterial and venous procedures (or 34.1% of the worldwide total), followed by the largest Western European states with over 511 thousand interventions (or 33.1%), major Asian-Pacific states with close to 377 thousand interventions (or 24.4%), and the rest-of-the-world with about 131 thousand peripheral stent-based interventions (or 8.4%).

Below is illustrated the global market for peripheral stenting by region in 2016 and by segment from 2014 to 2020.

Source: MedMarket Diligence, LLC; Report #V201. Available online.

 

Source: MedMarket Diligence, LLC; Report #V201. Available online.

Cardiovascular Surgical and Interventional Procedures Worldwide, 2015-2022

In 2016, the cumulative worldwide volume of the the following CVD procedures is projected to approach 15.05 million surgical and transcatheter interventions:

  • roughly 4.73 million coronary revascularization procedures via CABG and PCI (or about 31.4% of the total),
  • close to 4 million percutaneous and surgical peripheral artery revascularization procedures (or 26.5% of the total);
  • about 2.12 million cardiac rhythm management procedures via implantable pulse generator placement and arrhythmia ablation (or 14.1% of the total);
  • over 1.65 million CVI, DVT, and PE targeting venous interventions (representing 11.0% of the total);
  • more than 992 thousand surgical and transcatheter heart defect repairs and valvular interventions (or 6.6% of the total);
  • close to 931 thousand acute stroke prophylaxis and treatment procedures (contributing 6.2% of the total);
  • over 374 thousand abdominal and thoracic aortic aneurysm endovascular and surgical repairs (or 2.5% of the total); and
  • almost 254 thousand placements of temporary and permanent mechanical cardiac support devices in bridge to recovery, bridge to transplant, and destination therapy indications (accounting for about 1.7% of total procedure volume).

screen-shot-2016-11-07-at-7-26-38-am

CABG: Coronary artery bypass graft; PCI: Percutaneous coronary intervention; AAA: Abdominal aortic aneurysm; TAA: Thoracic abdominal aneurysm; CVI: Chronic venous insufficiency; DVT: Deep vein thrombosis; PE: Pulmonary embolectomy.

Source: MedMarket Diligence, LLC; Report #C500, “Global Dynamics of Surgical and Interventional Cardiovascular Procedures, 2015-2022.” (To request report excerpts, click here.)

The Evolution of Coronary Revascularization Markets

Coronary artery bypass grafting (CABG) is the most common type of cardiovascular surgical intervention, which “bypasses” acute or chronic coronary artery obstructions via a newly created vascular conduit and thus reinstate normal or sufficient blood flow to the ischemic but still viable areas of the myocardium.

The majority of CABG surgeries (up to 75%) are still performed on the fully arrested heart which is accessed via a foot-long incision over the sternum and completely separated patient’s rib cage. Following a full sternotomy, the CABG patient is typically placed on extracorporeal cardiopulmonary bypass (CPB) with a heart-lung machine, which allows the surgeon to operate on a still and bloodless field. Simultaneously, the patient’s greater saphenous vein or internal mammary artery, or both are harvested (mobilized) for use as a bypass conduit in the ongoing procedure. Depending on the location, character and number of the coronary artery occlusions, the surgery might involve between one and seven coronary bypasses.

Once the bypasses are completed, the heart is restarted and, if it functions normally, the patient is removed from the heart-lung machine and the chest is closed up, the sternum is stabilized with stainless steel wire, and the chest and leg wounds are closed with sutures or clips. Patient’s recovery from a routine uncomplicated CABG usually involves seven to ten days of hospital stay, including two to three days spent in the cardiac intensive care unit.

Less Invasive CABG

Over the past decade, several less-invasive versions of the CABG were developed with the view of reducing morbidity and potentially serious complications associated with extensive surgical trauma and the use of aortic clamping and CPB. The current arsenal of less-invasive coronary artery bypass techniques includes minimally-invasive direct CABG (MIDCAB), full-sternotomy “off-pump” CABG (OPCAB), port-access CABG (P-CAB) with peripheral cannulation and endoclamping of aorta, and endoscopic computer (robotics)-assisted CABG (C-CAB).

Designed to limit surgical trauma of conventional CABG, the MIDCAB procedure is best suited for patients with occluding lesions either in the left anterior descending (LAD) artery, or the right coronary artery (RCA). In contrast to conventional CABG, it is performed on a beating heart without the use of CPB. In MIDCAB surgery, access to targeted arteries is achieved through a limited left anterior thoracotomy in the case of occluded LAD, and right thoracotomy or limited lateral thoracotomy in cases involving diseased proximal RCA or circumflex artery. Because of the smaller surgical trauma and off-pump performance (without aorta clamping), the MIDCAB procedure typically results in fewer complications, lower morbidity and shorter hospital stays compared to conventional CABG. However, its utility is limited to a subset of patients with one or two coronary vascular targets, which constitute a small fraction (<3%) of the total caseloads referred for CABG.

The OPCAB procedure is performed on a beating heart after reduction of cardiac motion with a variety of pharmacological and mechanical devices. These include slowing the heart rate with ß-blockers and calcium channel blockers and the use of special mechanical devices intended to stabilize the myocardium and mobilize target vessels. The use of various retraction techniques allows to gain access to vessels on the lateral and inferior surfaces of the heart. Because the OPCAB technique also involves surgical access via median sternotomy, its primary benefit is the avoidance of complications resulting from the use of cardiopulmonary bypass, not surgical trauma.

Over the past decade, the OPCAB surgery emerged as the most popular form of less-invasive coronary artery bypass procedures in the U.S, and Western Europe. By the beginning of this decade, an estimated 25% of all CABGs performed in these geographies were done without the use of CPB. However, in recent years, the relative usage of OPCAB techniques remained largely unchanged. In the view of many cardiac surgeons, the latter was predicated by the increasing morphological complexity of cases referred for CABG (rather than PCI) and generally superior immediate and longer-term bypass graft patency and patient outcomes obtainable with technically less-demanding on-pump CABG surgery.

In contrast to that, the relative usage of “neurological complications sparing” OPCAB techniques is significantly higher in major Asia-Pacific states reaching over 60% of all CABG procedures in China, India, and Japan.

The rarely used P-CAB procedure involves the use of cardiopulmonary bypass and cardioplegia of a globally arrested heart. Vascular access for CPB is achieved via the femoral artery and vein. Compared to the MIDCAB technique, the use of multiple ports allow access to different areas of the heart, thus facilitating more complete revascularization, and the motionless heart may allow a more accurate and reliable anastomosis. In distinction from conventional CABG, median sternotomy is avoided, which reduces trauma and complications. However, potential morbidity of the port-access operation includes multiple wounds at port sites, the limited thoracotomy, and the groin dissection for femoral-femoral bypass. The procedure is also technically difficult and time consuming and therefore has not achieved widespread popularity.

The Hybrid CABG-PCI procedure combines the use of surgical bypass (typically MIDCAB) and percutaneous coronary interventional techniques (angioplasty and stenting) for optimal management of multi-vessel coronary occlusions in high risk patients. The main rationale behind the utilization of hybrid procedure is to achieve maximally possible myocardial revascularization with minimally possible trauma and reduced probability of post-procedural complications. The most common variation of the hybrid revascularization involves MIDCAB-based radial anastomosis between the left anterior descending artery and left internal thoracic artery accompanied by the PTCA/stenting-based recanalization of less critical coronary artery occlusions.

CABG Utilization Trends and Procedure Volumes

Since the advent of coronary angioplasty in the late 1970s, the relative role and share of CABG procedures in myocardial revascularization have been steadily declining due to a continuing penetration of treated patient caseloads by a less invasive PTCA. This general trend was further expedited by the advent of coronary stents. At the very end of the past decade, the rate of transition towards percutaneous coronary interventions in myocardial revascularization started tapering off, primarily due to growing maturity of PTCA/stenting technology and nearly full coverage of patient caseloads with one- or uncomplicated two-vessel disease amendable through angioplasty and stenting. At the same time, a growing popularity of the less-invasive CABG regimens resulted in some additional influx into CABG caseloads from a no-option patient cohort. A less-invasive surgical coronary bypass also emerged as a preferred treatment option for some gray-area patients that were previously referred for sub-optimal PTCA and stenting to avoid potential complications of conventional CABG.

In 2006 – for the first time in about two decades – the U.S. and European volumes of CABG procedures experienced a visible increase, which was repeated in 2007 and reproduced on a smaller and diminishing scale in the following two years.

The cited unexpected reversal of a long established downward procedural trend reflected an acute (and, probably, somewhat overblown) end-users’ concern about long-term safety (AMI-prone late thrombosis) of drug-eluting stents (DES), which prompted a steep decline in utilization of DES in 2006, 2007, followed by a smaller and tapering decreases in 2008 and 2009 with corresponding migration of advanced CHD patients referred for radical intervention to bare metal stenting and CABG surgery.

In 2010 – 2015 the volume of CABG surgeries remained relatively unchanged, notwithstanding a visible decline in percutaneous coronary interventions and overall myocardial revascularization procedures.

In the forthcoming years, the cumulative global volume of CABG procedures is unlikely to experience any significant changes, while their relative share in coronary revascularization can be expected to decline from about 15.4% in 2015 to roughly 12.3% by the end of the forecast period (2022). The cited assertion is based on the expectation of eventual stabilization and renewal of nominal growth in utilization of PCI in the U.S. and Europe coupled with continuation of robust expansion in the usage of percutaneous revascularization techniques in Asia-Pacific (especially India and China, where PCI volumes were growing by 20% and 10% annually over the past half decade, according to local healthcare authorities).

In 2016, the worldwide volume of CABG surgeries leveled at approximately 702.5 thousand procedures, of which roughly 35.2% involved the use of less-invasive OPCAB techniques. During the forecast period, the global number of CABG procedures is projected to experience a nominal 0.1% average annual increase to about 705.9 corresponding surgical interventions in the year 2022. Within the same time frame, the relative share of less-invasive bypass surgeries is expected to register modest gains expanding to approximately 36.7% of the total in 2022.

Coronary Revascularization Procedures, 2015-2022 
(Figures in thousands)

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CABG and Primary PCI in Coronary Revascularization to 2022.

In, “Global Dynamics of Surgical and Interventional Cardiovascular Procedures, 2015-2022”, Report #C500, we forecast cardiovascular procedure utilization, caseload, technology trends, and device market impacts, for the U.S., Western Europe, Asia/Pacific, and Rest of World.

Cardiac Rhythm Disorders and Implantable, Device-based Treatments

Cardiac rhythm disorders, also called arrhythmias or dysrhythmias, encompass a variety of relatively common acute and chronic conditions characterized by recurrent distortions in the electrical and contractile activity of the heart, which may cause clinically significant and progressive hemodynamic deficits and cardiopulmonary impairment.

According to the available statistics from the American Heart Association (AHA) and Heart Rhythm Society, symptomatic cardiac arrhythmias effect over 10 million Americans and account for approximately 20% of all chronic conditions treated by cardiologists in the United States.

The rate and rhythm of the heart are determined by the intrinsic rhythmicity of special tissues and structures within the heart wall muscle generated by the heart’s natural electrophysiological mechanism. Normal cardiac rate and rhythm ensure continued uninterrupted blood flow an associated supply of oxygen and nutrients to the brain and other vital organs. Irregularities in the rate, rhythm, or origin of a stimulus leading to myocardial contraction can potentially interrupt normal blood circulation, causing inadequate function of important body systems, stroke or sudden cardiac arrest and death. Heart pacing disorders usually degenerate and worsen over time.

Although cardiac arrhythmias may be triggered by congenital heart defects, in which the electrical system of the heart does not develop properly, non-congenital heart disorders are believed to be the most common causes of chronic arrhythmias. The latter is particularly true for ischemic heart disease, which results in reduced blood flow and oxygen delivery to heart tissue, and heart tissue scarring typically caused by myocardial infarction. Other causes of arrhythmia include abnormal blood and tissue concentrations of certain minerals; abnormalities of the autonomic nervous system, which is involved in cardiovascular regulation; stress; and use of alcohol, caffeine, illicit drugs, and tobacco, as well as diet pills and some other medications.

Cardiac arrhythmias are generally categorized according to their impact on heart rates. Bradycardia is an abnormally slow resting heart rate, whereas tachycardia is an abnormally high resting heart rate. Bradycardias are most commonly associated with SA node disease and/or various forms of heart block.

Tachycardias are usually classified by their origination site and may be subdivided into two broad categories, specifically, supraventricular tachycardias (SVTs) and ventricular tachycardias (VTs).

Below are shown the projected implantable pump generator placements by region from 2015 to 2022. These include pacemaker placements, implantable cardioverter defibrillator placements, and cardiac resynchronization therapy placements.

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Source: MedMarket Diligence LLC (Report #C500).

Coronary and venous interventions show inevitable Asia/Pacific dominance

Coronary revascularization, whether by bypass graft or percutaneous coronary intervention, drives an enormous amount of medtech business. Angioplasty catheters, guidewires, and the plethora of devices in cardiothoracic surgery represent many millions in sales annually. Manufacturers pursuing growth in these areas will see big, but slowing growth rates in the U.S., while markets in Asia/Pacific reflect the growing demand for cardio technologies. Already, these markets are surpassing western markets:

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Source: Report #C500.

While coronary applications have a long history, venous interventions have less, and procedure data shows that patient populations have not been fully tapped in any geographic region. Already, Asia/Pacific markets would appear to be on course to eclipse western markets, but not until after 2022, and will eclipse Western Europe markets before challenging the U.S.

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Source: Report #C500.