User:Ppatalano/VascSurgScopeUpdate

Vascular surgery

Occupation
Names	Doctor, Medical Specialist, Surgeon
Occupation type	Specialty
Activity sectors	Medicine
Description
Education required	Doctor of Osteopathic Medicine (D.O.) Doctor of Medicine (M.D.) Bachelor of Medicine, Bachelor of Surgery
Fields of employment	Hospitals, Clinics

Vascular surgery is a surgical subspecialty in which diseases of the vascular system, or arteries, veins and lymphatic circulation, are managed by medical therapy, minimally-invasive catheter procedures and surgical reconstruction. The specialty evolved from general and cardiac surgery and includes treatment of the body's other major and essential veins and arteries. Open surgery techniques, as well as endovascular techniques are used to treat vascular diseases. The vascular surgeon is trained in the diagnosis and management of diseases affecting all parts of the vascular system excluding the coronaries and intracranial vasculature. Vascular surgeons often assist other physicians to address traumatic vascular injury, hemorrhage control, and safe exposure of vascular structures.

History

Early leaders of the field included Russian surgeon Nikolai Korotkov, noted for developing early surgical techniques, American interventional radiologist Charles Theodore Dotter who is credited with inventing minimally invasive angioplasty (1964), and Australian Robert Paton, who helped the field achieve recognition as a specialty. Edwin Wylie of San Francisco was one of the early American pioneers who developed and fostered advanced training in vascular surgery and pushed for its recognition as a specialty in the United States in the 1970s.

Evolution

Medical science has advanced significantly since 1507, when Leonardo da Vinci drew this diagram of the internal organs and vascular systems of a woman.

The specialty continues to be based on operative arterial and venous surgery but since the early 1990s has evolved greatly. There is now considerable emphasis on minimally invasive alternatives to surgery. The field was originally pioneered by interventional radiologists, chiefly Dr. Charles Dotter, who invented angioplasty. Of note, Dr. Thomas Fogarty invented the balloon catheter which enabled angioplasty. Further development of the field has occurred via joint efforts between interventional radiology, vascular surgery, and interventional cardiology. This area of vascular surgery is called Endovascular Surgery or Interventional Vascular Radiology, a term that some in the specialty append to their primary qualification as Vascular Surgeon. Endovascular and endovenous procedures (e.g., EVAR) can now form the bulk of a vascular surgeon's practice.

The treatment of the aorta, the body's largest artery, dates back to Greek surgeon Antyllus, who first performed surgeries for various aneurysms in the second century AD. Modern treatment of aortic diseases stems from development and advancements from Michael DeBakey and Denton Cooley. In 1955, DeBakey and Cooley performed the first replacement of a thoracic aneurysm with a homograft. In 1958, they began using the Dacron graft, resulting in a revolution for surgeons in the repair of aortic aneurysms. He also was first to perform cardiopulmonary bypass to repair the ascending aorta, using antegrade perfusion of the brachiocephalic artery.

Dr. Edward "Ted" Dietrich, one of Dr. DeBakey's associates, went on to pioneer many of the minimally invasive techniques that later became hallmarks of endovascular surgery. Dietrich later founded the Arizona Heart Hospital in 1998 and served as its medical director from 1998 to 2010. In 2000, Diethrich performed the first endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm. Dietrich trained several future leaders in the field of endovascular surgery at the Arizona Heart Hospital including Venkatesh Ramaiah, MD who served as medical director of the institution following Dietrich's death in 2017.

The development of endovascular surgery has been accompanied by a gradual separation of vascular surgery from its origin in general surgery. Most vascular surgeons would now confine their practice to vascular surgery and, similarly, general surgeons would not be trained or practise the larger vascular surgery operations or most endovascular procedures. More recently, professional vascular surgery societies and their training program have formally separated vascular surgery into a separate specialty with its own training program, meetings and accreditation. Notable societies are Society for Vascular Surgery (SVS), USA; Australia and New Zealand Society of Vascular Surgeons (ANZSVS). Local societies also exist (e.g., New South Wales Vascular and Melbourne Vascular Surgical Association (MVSA)). Larger societies of surgery actively separate and encourage specialty surgical societies under their umbrella (e.g., Royal Australasian College of Surgeons (RACS)).

Currently

Arterial and venous disease treatment by angiography, stenting, and non-operative varicose vein treatment sclerotherapy, endovenous laser treatment are rapidly replacing major surgery in many first world countries. These newer procedures provide reasonable outcomes that are comparable to surgery with the advantage of short hospital stay (day or overnight for most cases) with lower morbidity and mortality rates. Historically performed by interventional radiologists, vascular surgeons have become increasingly proficient with endovascular methods. The durability of endovascular arterial procedures is generally good, especially when viewed in the context of their common clinical usage i.e. arterial disease occurring in elderly patients and usually associated with concurrent significant patient comorbidities especially ischemic heart disease. The cost savings from shorter hospital stays and less morbidity are considerable but are somewhat balanced by the high cost of imaging equipment, construction and staffing of dedicated procedural suites, and of the implant devices themselves. The benefits for younger patients and in venous disease are less persuasive but there are strong trends towards nonoperative treatment options driven by patient preference, health insurance company costs, trial demonstrating comparable efficacy at least in the medium term.

A recent trend in the United States is the stand-alone day angiography facility associated with a private vascular surgery clinic, thus allowing treatment of most arterial endovascular cases conveniently and possibly with lesser overall community cost. Similar non-hospital treatment facilities for non-operative vein treatment have existed for some years and are now widespread in many countries.

NHS England conducted a review of all 70 vascular surgery sites across England in 2018 as part of its Getting It Right First Time programme. The review specified that vascular hubs should perform at least 60 abdominal aortic aneurysm procedures and 40 carotid endarterectomies a year. 12 trusts missed both targets and many more missed one of them. A programme of concentrating vascular surgery in fewer centres is proceeding.

Management of Arterial Diseases

Infrarenal aortic occlusion imaged with magnetic resonance angiography (MRA).

The management of arterial pathology excluding coronary and intracranial disease is within the scope of vascular surgeons. Disease states generally arise from narrowing of the arterial system known as stenosis or abnormal dilation referred to as an aneurysm. There are multiple mechanisms by which the arterial lumen can narrow, the most common of which is atherosclerosis. Other less common causes of stenosis include fibromuscular dysplasia, radiation induced fibrosis, cystic advevntitial disease, entrapment syndrome... Dilation of an artery which retains histologic layers is called an aneurysm. An aneurysms can be fusiform (concentric dilation), sacular (outpouching) or a combination of the two. Arterial dilation which does not contain three histologic layers is considered a pseudoaneurysm... Vascular surgeons treat arterial diseases with a range of therapies including lifestyle modification, medications, endovascular therapy and surgery.

Aortic Aneurysms

The aorta is the largest artery in the body and has both a thoracic and abdominal component. Aneurysms which are contained in the chest are referred to as thoracic aortic aneurysms wherease aneurysms contained in the abdomen are referred to abdominal aortic aneurysms. Not pictured here are aneurysms which span both cavities and are referred to as thoracoabdominal aortic aneurysms.

Abdominal Aortic Aneurysm

An abdominal aortic aneurysm (AAA) refers to aneurysmal dilation of the aorta confined to the abdominal cavity. Most commonly, aneurysms are asymptomatic and located in the infrarenal position. Often, they are discovered incidentally or on screening exams in patients with risk factors such as a history of smoking. Patients with aneurysms which have a diameter less than 5cm are at <1% rupture risk per year. When the aneurysm meets size criteria it can be treated with aortic replacement or EVAR.

Thoracic Aortic Aneurysm

Thoracic aneurysms are contained in the chest. Aneurysms of the descending aorta can often be treated with thoracic endovascular aortic repair or TEVAR. Treating aneurysms which involve the the ascending aorta are generally the scope of cardiac surgeons but upcoming endovascular technology may allow for a more minimally invasive approach in selected patients.

Thoracoabdominal Aneurysm

Thoroacoabdominal aneurysms are those which span the chest and abdominal cavities. The Crawford Classification was developed and describes five types of thoracoabdominal aneurysms.

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  Abdominal aortic aneurysms can be classified as infrarenal, juxtarenal, pararenal or suprarenal as depicted in the illustration.
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  The Crawford Classification for thoracoabdominal aortic aneurysms is pictured above.

Other Arterial Aneurysms

In addition to treating aneurysms which arise from the aorta, vascular surgeons also treat aneurysms elsewhere in the body.

Visceral Artery Aneurysm

Visceral artery aneurysms include those isolated to the renal artery, splenic artery, celiac artery, and hepatic artery. Of these, data shows that splenic artery aneurysms are the most common.

Indications for repair differ slightly between arteries. For instance, current guidelines recommend repair of renal and splenic artery aneurysms greater than 3cm and any size in women of childbearing age whereas, celiac and hepatic artery aneurysms are indicated for repair when their size is greater than 2cm. This is in contrast to superior mesenteric artery aneurysms which should be repaired regardless of size when they are discovered.

Popliteal Artery Aneurysm

A popliteal artery aneurysm is an arterial aneurysm localized in the popliteal artery which courses behind the knee. Unlike aneurysms located in the abdomen, popliteal artery aneurysm rarely present with rupture but rather with symptoms of acute limb ischemia due to embolization of thrombus. Thus, when a patient presents with an asymptomatic popliteal aneurysm that is greater than 2cm in diameter a vascular surgeon are able to offer vascular bypass or endovascular exclusion depending on several factors.

Aortic Dissection

Early classification schemes of aortic dissection. Stanford type A are those which originate in the ascending aorta whereas Stanford type originate distal to the left subclavian artery (descending aorta). The Debakey classification describes where the original tear is and the extent of the dissection.

Arteries are comprised of three concentric layers - the intima, media and adventitia. Generally speaking, an arterial dissection is an injury to the inner most layer of an artery allowing for blood to flow between layers in what is sometimes referred to as a dissection plane. An aortic dissection, is an arterial dissection that occurs in the aorta. Patients who experience aortic dissection may have tearing chest or back pain depending on the origination of the tear as well as the extent.

Whereas cardiac surgeons are usually in charge of managing type A dissections, type B dissections are typically managed by the vascular surgeon. The most common risk factor for type B aortic dissection is hypertension. The first line treatment for type B aortic dissection is aimed at reducing both heart rate and blood pressure and is referred to as anti-impulse therapy.

A thoracic aortic stent graft, seen on chest x-ray which was placed during a TEVAR procedure.

Should initial medical management fail or the patient experience compromise of a major branch of the aorta, the vascular surgeon is an expert in both the surgical management of these type B dissections. Treatment may include thoracic endovascular aortic repair (TEVAR) with or without extra-anatomic bypass - carotid-carotid bypass, carotid-subclavian bypass, subclavian-carotid transposition.

Visceral Artery Dissection

Visceral artery dissections are arterial dissections involving the superior mesenteric artery, celiac artery, renal arteries, hepatic artery and others. When they are an extension of an aortic dissection, this condition is managed simulataneously with aortic treatment. In isolation, visceral artery dissections are discovered incidentally in up to a third of patients and in these cases my be managed medically by a vascular surgeon. In cases where the dissection results in organ damage it is generally accepted by vascular surgeons that surgery is necessary. Surgical management strategies depend on the associated complications, surgical ability and patient prefernce.

Mesenteric Ischemia

Mesenteric ischemia results from the acute or chronic obstruction of the superior mesenteric artery (SMA). The SMA arises from the abdominal aorta and usually supplies blood from the distal duodenum through two-thirds of the transverse colon and the pancreas.

Chronic Mesenteric Ischemia

The symptoms of chronic mesesnteric ischemia can be classified as abdominal angina which is abdominal pain which occurs a fixed perior of time after eating. Due to this, patient's may avoid eating, resulting in unintended weight loss. The first surgical treatment is thought to be performed by R.S. Shaw and described in the New England Journal of Medicine in 1958. The procedure Shaw described is refered to as mesenteric endarterectomy. Since then, many advances in treatment have been made in minimally invasive, endovascular techniques including angioplasty and stenting.

Acute Mesenteric Ischemia

Acute mesenteric ischemia (AMI) results from the sudden occlusion of the superior mesenteric artery.

Renovascular Hypertension

The renal arteries supply oxygenated blood to the kidneys. The kidneys serve to filter the flood and control blood pressure through the renin-angiotensin system. One cause of resistant hypertension is atherosclerotic disease in the renal arteries and is generally referred to as renovascular hypertension. If renovascular hypertension is diagnosed and maximal medical fails to control high blood pressure, the vascular surgeon may offer surgical treatment, either endovascular or open surgical reconstruction.

Cerebrovascular Disease

Carotid ultrasound.

Carotid endarterectomy.

Vascular surgeons are responsible for treating extracranial cerebrovascular disease as well as the ineterpretation of non-invasive vascular imaging relating to extracranial and intracranial circulation such as carotid ultrasonography and transcranial doppler. The most common of cerebrovascular conditions treated by vascular surgeons is carotid artery stenosis which is a narrowing of the carotid arteries and may be either clinically sympomatic or asymptomatic (silent). Carotid artery stenosis is caused by atherosclerosis whereby the buildup of atheromatous plaque inside an the artery causes narrowing.

Symptoms of carotid artery stenosis can include transient ischemic attack or stroke. Both symptomatic and asymptomatic carotid stenosis can be diagnosed with the aid of carotid duplex ultrasound which allows for the estimation of severity of narrowing as well as characterize the plaque. Treatment can include medical thereapy, carotid endarterectomy or carotid stenting.

The Society for Vascular Surgery publishes clinical practice guidelines for the management of extracranial cerebrovascular disease. Less common diseases involving cerebral circulation treated by vascular surgeons include vertebrobasilar insufficiency, subclavian steal syndrome, carotid artery dissection, vertebral artery dissection, carotid body tumor and carotid artery aneurysm among others.

Peripheral Artery Disease

peripheral artery disease PAD is the abnormal narrowing of the arteries which supply the limbs. Patients with this condition can present with intermittent claudication which is pain mainly in the calves and thighs while walking. If there is progression, a patient may also present with chronic limb threatening ischemia which encompasses pain at rest and non-healing wounds. Vascular surgeons are experts in the diagnosis, medical management, endovascular and open surgical treatment of PAD.

A vascular surgeon may diagnose PAD using a combination of history, physical exam and medical imaging. Medical imaging may include ankle-brachial index, doppler ultrasonography and computed tomography angiography, among others. Treatments are individualized and may include medical therapy, endovascular intervention or open surgical options including angioplasty, stenting, atherectomy, endarterectomy and vascular bypass, among others.

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  Illustration of atherosclerosis causing arterial obstruction which clinically presents at peripheral artery disease.
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  Angioplasty (pictured) and stenting are two endovascular treatments employed by the vascular surgeon.
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  ABI testing is used by vascular surgeons in the diagnosis of PAD. The blood pressure in the arm and leg are compared as a ratio.
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  Illustration of vascular bypass.

Management of Venous Diseases

Chronic Venous Insufficiency

Chronic venous insufficiency is the abnormal pooling of blood in the venous system which often leads to inflammation

Deep Venous Thrombosis

Deep venous thrombosis is the formation of thrombus in a deep vein.

Compressive Venopathies

Compression of large veins by adjacent structures or masses may lead to distinct clinical syndromes including May–Thurner syndrome (MTS), nutcracker syndrome and superior vena cava syndrome to name a few. Treatment modalties include venography, intravascular ultrasound and venous stenting as well as more invasive open venous reconstruction and bypass.

Investigations

Major trials

• Netherland Vascular Study
• MASS Trial – The Multicentre Aneurysm Screening Study (MASS) trial, which found reduced mortality after screening for abdominal aortic aneurysms in the UK.
• UK Small Aneurysm Trial – 1090 patients; AAA 4–5.5 cm; Immediate surgery vs. ultrasound surveillance (and treatment for rapid expansion or AAA >5.5); 30-day mortality after elective AAA repair is 5.8%. No difference in survival.
• ADAM VA Cooperative Group Trial – 73451 VA patients screened with no known history of aneurysm; Age 50–79; AAA 4.0-5.4 cm; similar conclusion to Uk Small Aneurysm Trial.
• Joint Vascular Research Group Trial – 284 patients; Study the relationship between intraoperative intravenous heparinization, blood loss during surgery and thrombotic complications. Conclusion: Intraoperative heparin, given before aortic cross clamping, is an important prophylactic against perioperative MI in aortic aneurysm surgery.
• North American Symptomatic Carotid Endarterectomy Trial (NASCET) 1415 patients; trial that showed carotid endarterectomy was beneficial in symptomatic patients. Two year stroke rate in patients with > 70% carotid stenosis decreased from 26% to 9%. Two year stroke rate in patients with > 50% decreased from 15% to 9%.
• Asymptomatic Carotid Atherosclerosis Study (ACAS) 1662 patients; demonstrated benefit in asymptomatic patients with >60% stenosis. Fiver year stroke rate reduced from 11% to 5.1% with carotid endarterectomy.

Training

Previously considered a field within general surgery, it is now considered a specialty in its own right. As a result, there are two pathways for training in the United States. Traditionally, a five-year general surgery residency is followed by a 1-2 year (typically 2 years) vascular surgery fellowship. An alternative path is to perform a five or six year vascular surgery residency. In many countries, Vascular surgeons can opt into doing additional training in cardiac surgery as well as post-residency.

Programs of training are slightly different depending on the region of the world one is in.

Country	Standards body	Professional representation	Minimum Length of training (post intern)
Australia and New Zealand	Royal Australasian College of Surgeons	Australian & New Zealand Society of Vascular Surgery (ANZSVS)	6 years
Canada	Royal College of Surgeons of Canada	Canadian Society for Vascular Surgery	5 years
United Kingdom	Royal College of Surgeons of England, Royal College of Surgeons of Edinburgh	Vascular Society of Great Britain and Ireland	8 years
United States	American Board of Surgery, American Osteopathic Board of Surgery	Society for Vascular Surgery American College of Surgeons	5 years ( 4 via 5-year integrated Vascular Surgery Residency). 7 if completing as a 2-year fellowship following general surgery
Italy			5 years
Iran	Iran National Board of Vascular Surgery	Iranian College of Vascular Surgeons	7 years ( 4 years of general surgery 3 years of vascular surgery)

See also

• Society for Vascular Surgery, the major American professional society
• Ischemia-repurfusion injuries of the appendicular musculoskeletal system
• Kakish Ryskulova
• Vein
• Phlebologist
• Cardiovascular disease
• Cardiology

External links

• Society for Vascular Surgery (U.S.)
• European Society for Vascular Surgery

Category:Surgical specialties