Vascular surgery
Vascular surgery is a surgical subspecialty in which vascular diseases involving the arteries, veins, or lymphatic vessels, are managed by medical therapy, minimally-invasive catheter procedures and surgical reconstruction. The specialty evolved from general and cardiovascular surgery where it refined the management of just the vessels, no longer treating the heart or other organs. Modern vascular surgery includes open surgery techniques, endovascular techniques and medical management of vascular diseases – unlike the parent specialities. 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 also are called to assist other physicians to carry out surgery near vessels, or to salvage vascular injuries that include hemorrhage control, dissection, occlusion or simply for 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, 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. The most notable historic figure in vascular surgery is the 1912 Nobel Prize winning surgeon, Alexis Carrel for his techniques used to suture vessels.Evolution
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 like Dr. Charles Dotter, who invented angioplasty using serial dilatation of vessels.The surgeon Dr. Thomas J. Fogarty invented a balloon catheter, designed to remove clots from occluded vessels, which was used as the eventual model to do endovascular 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 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. Ted Diethrich, 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 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 succeeded him as medical director of the institution in 2010.
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, USA; Australia and New Zealand Society of Vascular Surgeons. Local societies also exist. Larger societies of surgery actively separate and encourage specialty surgical societies under their umbrella.
Currently
Arterial and venous disease treatment by angiography, stenting, and non-operative varicose vein treatment sclerotherapy, endovenous laser treatment have largely replaced major surgery in many first world countries. These procedures provide reasonable outcomes that are comparable to surgery with the advantage of short hospital stay 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.
Vascular surgery encompasses surgery of the aorta, carotid arteries, and lower extremities, including the iliac, femoral, vascular trauma and tibial arteries. Vascular surgery also involves surgery of veins, for conditions such as May–Thurner syndrome and for varicose veins. In some regions, vascular surgery also includes dialysis access surgery and transplant surgery.
Management of arterial diseases
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. Symptomatic stenosis may also result from a complication of arterial dissection. Other less common causes of stenosis include fibromuscular dysplasia, radiation induced fibrosis or cystic adventitial disease. Dilation of an artery which retains histologic layers is called an aneurysm. An aneurysms can be fusiform, saccular or a combination of the two. Arterial dilation which does not contain three histologic layers is considered a pseudoaneurysm. Additionally, there are a number of congenital vascular anomalies which lead to symptomatic disease that are managed by the vascular surgeon, a few of which include aberrant subclavian artery, popliteal artery entrapment syndrome or persistent sciatic artery. Vascular surgeons treat arterial diseases with a range of therapies including lifestyle modification, medications, endovascular therapy and surgery.Aneurysms
Aortic aneurysms
;AbdominalAn abdominal aortic aneurysm 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 5 cm are at <1% rupture risk per year. When the aneurysm meets size criteria it can be treated with aortic replacement or EVAR.
;Thoracic
Thoracic aortic 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 ascending aorta are generally within the scope of cardiac surgeons, but upcoming endovascular technology may allow for a more minimally invasive approach in some patients.
;Thoracoabdominal
Thoroacoabdominal aneurysms are those which span the chest and abdominal cavities. The Crawford classification was developed and describes five types of thoracoabdominal aneurysms.
Other arterial aneurysms
In addition to treating aneurysms which arise from the aorta, vascular surgeons also treat aneurysms elsewhere in the body.;Visceral arteries
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 3 cm, and those of any size in women of childbearing age; whereas celiac and hepatic artery aneurysms are indicated for repair when their size is greater than 2 cm. This is in contrast to superior mesenteric artery aneurysms which should be repaired regardless of size when they are discovered.
;Popliteal artery
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 2 cm in diameter a vascular surgeon are able to offer vascular bypass or endovascular exclusion depending on several factors.