Peripheral vascular disease

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Peripheral vascular disease





Objectives


Upon completion of this chapter, the reader will be able to:


• Describe the three most common types of peripheral vascular disease.


• Describe the current diagnostic strategy for workup of peripheral vascular disease.


• Describe the indications for treatment including minimally invasive and open surgical options.



Peripheral vascular disease



CASE 1   Fred Jones (Part 1)


Fred Jones is a 73-year-old former maintenance worker who comes to your office with complaints of lower leg cramping with activity. He is obese with a long-standing history of type 2 diabetes mellitus treated with oral medications. He is also hypertensive with a reduced glomerular filtration rate.




Peripheral vascular disease (PVD) is primarily a disease of the aged. The average age of patients seeking treatment is approximately 70 years of age. With the expected increase in our elderly population, the diagnosis and treatment of PVD will become a priority. A working knowledge of the most common sites of disease, the initial diagnostic tests, and options for treatment as well as their outcomes are necessary to provide optimal guidance for these patients.


A basic framework for diagnosis of vascular disease relies heavily on the vascular laboratory. The majority of structures involved in vascular disease, including retroperitoneal vascular structures, can be imaged because of the increasing resolution of ultrasonography. Additionally, in the periphery and supraclavicular region, vessel proximity to the skin level and the dynamic image acquisition often allow diagnosis and treatment without need for advanced imaging modalities. In fact, the vascular laboratory should be able to document the presence and extent of carotid, aortic, and lower extremity disease for the vast majority of patients, with advanced imaging (computed tomography [CT] and magnetic resonance imaging [MRI]) reserved for those patients in whom diagnosis is in question or for pretreatment planning. With regard to CT and MRI, these techniques also have increased in accuracy and clarity. Thus noninvasive imaging has essentially replaced diagnostic angiography for the detection of vascular disease, with angiography primarily reserved for confirmation of disease during planned endovascular intervention.



Noninvasive imaging has essentially replaced diagnostic angiography for the detection of vascular disease, with angiography primarily reserved for confirmation of disease during planned endovascular intervention.



Similar to the increasing role of noninvasive imaging, there has been an increasing shift in vascular disease treatment to less invasive interventions. Vascular interventions for all patients can follow four different paths. All patients with vascular disease benefit both at disease location and systemically from treatment with antiplatelet agents and from cholesterol-lowering agents, primarily in the form of statin agents. Increasingly, patients are being treated especially in the lower extremities with solely percutaneous interventions requiring arterial access via catheters and guidewires. Although decreasing in usage, open surgical revascularization still remains the gold standard against which all techniques are judged. Lastly, a combination of open and percutaneous endovascular interventions can be combined to create a hybrid operation chosen to address complex vascular disease where outcomes are best served by a unique approach. The important point to remember is the patient at any time can be served by any of these techniques and therefore clinical judgment and informed consent are paramount in choosing the appropriate intervention.



Coronary artery disease




Carotid stenosis


Proper diagnosis, management, and treatment of carotid stenosis are important for reducing risk of ischemic stroke in elderly patients. Stroke is the third leading cause of death in the United States and results in significant disability. Generally 80% of strokes are ischemic and 20% hemorrhagic. Of the 80% of ischemic strokes, 20% to 30% are attributed to atheroembolic disease resulting from stenosis of one carotid artery more than 50%. Focus has been placed on risk stratification for proper selection of appropriate treatment. Treatment will vary depending on degree of stenosis and presence of symptoms and comorbid conditions that could potentially increase operative risks.



Of the 80% of ischemic strokes, 20% to 30% are attributed to atheroembolic disease resulting from stenosis of one carotid artery more than 50%.




History


A complete history is important to identify those patients at increased risk for carotid disease and stroke. It is important to determine if the patient is symptomatic or asymptomatic because this information in combination with imaging studies will dictate what types of treatment are appropriate for patients with varying degrees of stenosis. Patients with prior or current cardiovascular disease may be at increased risk for concurrent carotid disease; therefore, knowing a patient’s cardiac history is critical. Neurologic symptoms such as unilateral weakness, numbness or parasthesias, aphasia or dysarthria, history of transient ischemic attack (TIA), prior stroke, or amaurosis fugax (transient unilateral loss of vision) are all significant historical findings. Patients with TIA, stroke, or amaurosis fugax in the past 3 months are at greater risk for stroke and this warrants further workup for carotid disease. Symptoms not usually associated with carotid disease are vertigo, ataxia, diplopia, nausea, vomiting, decreased consciousness, or generalized weakness.





Optimal diagnostic study


Multiple radiologic studies can be used to assess the carotid arteries including duplex ultrasonography (DUS), angiography with CT or MRI, and conventional digital angiography (DA). Each has utility in specific situations and these studies should not be used interchangeably. Imaging aids the clinician by providing information about the degree of stenosis and the plaque’s morphology and location.






DA


Conventional peripheral catheter-based DA is considered the gold standard for carotid imaging. It provides excellent images that are easy to interpret. The degree of stenosis and location and morphology of plaque can all be assessed with this modality. It is most useful in patients with conflicting imaging prior to operation. Major limitations are cost, risk associated with a percutaneous intervention under mild sedation, and possibly poor vascular anatomy that could preclude a percutaneous study.


Current recommendations for screening of asymptomatic patients are in constant debate. It is generally agreed that population screening examinations for asymptomatic patients are not cost effective. Highly selected patient populations may benefit from screening. This includes patients older than 60 years with one or more risk factors such as hypertension, coronary artery disease, current smoker, a first-degree relative with history of stroke, or if they may be undergoing a planned coronary artery bypass grafting procedure. Screening is not recommended for patients based solely on presence of an abdominal aortic aneurysm, presence of a carotid bruit, or prior head and neck radiotherapy.

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Jun 8, 2016 | Posted by in GERIATRICS | Comments Off on Peripheral vascular disease

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