Patients undergoing vascular surgery frequently have multiple comorbid conditions that should be optimized prior to surgery.

Cardiac events such as myocardial infarction, arrhythmia, and heart failure are the leading cause of morbidity and mortality in patients undergoing vascular surgery. Myocardial infarction (MI) accounts for about one half of early postoperative deaths. According to the ACC/AHA guidelines for preoperative cardiac evaluation, these patients are considered to be at an elevated (>1%) risk for postoperative major adverse cardiac events (MACE). Preoperative cardiac evaluation is addressed in greater detail in Chapter 2. Below are some specific considerations with regard to vascular surgical patients.

1. Cardiac stress testing. For nonemergent cases, in patients with poor functional capacity (<4 METS), cardiac stress testing should be carried out if the results will impact patient care. Pharmacologic stress testing will be necessary for patients with physical limitations such as claudication or disability from prior stroke. The need for coronary artery catheterization is determined based on the results of the stress test, in consultation with a cardiologist.

2. Echocardiography may be indicated if the patient has a new murmur, dyspnea of unknown etiology, valvular heart disease, or compensated heart failure with new, or worsening, symptomatology.

3. Blood pressures should be measured in both arms to determine whether there is a difference. Due to the systemic nature of atherosclerosis, patients may have subclavian or axillary arterial stenoses. Blood pressure should be monitored in the extremity with the higher reading.

4. Coronary revascularization should be carried out only if medically indicated. According to the CARP trial (Coronary Artery Revascularization Prophylaxis), coronary revascularization in advance of major vascular surgery has not been shown to improve outcome when compared with medical management. This trial excluded patients with left main coronary artery disease, ejection fraction less than 20%, and severe AS.

5. β-blocker therapy should be maintained in patients who are on it chronically. Initiation of β-blocker therapy is reasonable in patients with three or more RCRI (revised cardiac risk index) risk factors or in patients with reversible ischemia on preoperative testing. However, improper timing and dose titration may increase risk of stroke and mortality. β-blocker therapy should be started at least 2 days prior to surgery; 7 days is preferred. Therapy should be started at a low dose and titrated slowly to achieve target heart rate of 60 to 80 bpm. They should be held for hypotension.

6. Antiplatelet therapy. Aspirin therapy should be continued in patients with coronary stents, those with cerebrovascular disease, or those with high-risk CAD. Continuation should be considered in all
vascular surgical procedures in discussion with the surgeon. Aspirin therapy is associated with an increased risk of bleeding. POISE-2, a randomized, controlled trial of 10,000 patients undergoing noncardiac surgery, did not show a benefit of aspirin initiation or continuation with respect to MACE or death. However, it excluded patients who had recently received coronary stents and those undergoing carotid endarterectomy (CEA). Furthermore, only a small proportion of the study population underwent vascular surgery. Continuation of clopidogrel therapy depends on patient factors (e.g., presence and type of coronary stents and when they were placed) as well as surgical factors.

7. Statins should be continued perioperatively. The initiation of statin therapy is reasonable in patients undergoing vascular surgery. The statin should ideally be started 1 week to 30 days prior to the surgical procedure. There is evidence that statins decrease coronary inflammation regardless of low-density lipoprotein level. Withdrawal prior to surgery has been associated with increased cardiac events.

8. Warfarin should be discontinued at least 3 to 5 days before surgery, and, if indicated, heparin therapy started.

9. If regional anesthesia is planned, anticoagulant and antiplatelet agents should be held according to guidelines (see Chapter 18) and in consultation with the surgeon and cardiologist.

Many vascular patients have histories of significant tobacco use and may have compromised pulmonary function (see Chapter 3). Routine pulmonary function testing is not indicated. Aortic cross-clamping and associated ischemia-reperfusion can produce a systemic inflammatory response that may contribute to postoperative lung injury.

Preexisting renal dysfunction is common. It is related to atherosclerosis, hypertension, diabetes, and advanced age and may exist even in the absence of an abnormal serum creatinine value. Due to a decreased number of functioning glomeruli, these patients have a reduced capacity to autoregulate renal perfusion in the setting of hypotension and are often intolerant to perioperative insults such as ischemia-reperfusion, atheroembolism, and nephrotoxins like contrast dye. Patients with chronically elevated serum creatinine levels (>2 mg/dL) have substantially greater morbidity and mortality following vascular surgery. Open aortic and renal arterial surgeries carry the highest risk for postoperative renal dysfunction. Patients undergoing endovascular procedures are at risk for contrast-induced nephropathy (CIN). CIN is diagnosed by an increase in serum creatinine beginning 24 to 48 hours following contrast exposure in a patient with no other reason for acute kidney injury. Risk factors for CIN include chronic kidney disease, diabetes, anemia, heart failure, the use of high-osmolar contrast, and the use of high volumes of contrast. In patients at risk, crystalloid administration and the use of low volumes of iso-osmolar or low-osmolar contrast agents are recommended. Pretreatment with sodium bicarbonate may also be considered, although the data regarding its benefit are inconsistent. Sodium bicarbonate (150 mEq/L) can be given as a bolus infusion of 3 mL/kg over 1 hour followed by 1 mL/kg/h. The duration should extend for 6 hours after the last dose of contrast. N-acetylcysteine (NAC) administration may also be considered at a dose of 1,200 mg orally every 12 hours, on the day before and on the day of contrast exposure, for a total of 2 days.

Patients should be examined for carotid bruits and questioned for a history of transient ischemic attacks (TIAs) and cerebrovascular accidents. Symptomatic carotid disease may warrant revascularization prior to other elective procedures.

In addition to accelerated atherosclerosis, long-standing diabetics may have extensive microvascular disease resulting in autonomic dysfunction, silent myocardial ischemia, and nephropathy. In consultation with the patient’s endocrinologist, metformin should be discontinued prior to procedures that involve IV contrast dye, or renal or hepatic ischemia due to the potential for the development of severe lactic acidosis. It should also be held in patients with preexisting renal dysfunction or heart failure.

The vascular surgical patient is at particularly high risk to develop heparin-induced thrombocytopenia (HIT) due to the need for repeated and occasionally prolonged exposure to heparin (see Chapter 24). This syndrome is characterized by thrombocytopenia and/or thrombosis in the setting of heparin exposure and is due to the formation of antibodies to the heparin-platelet factor 4 (PF4) complex. In patients with a recent diagnosis of HIT who require vascular surgery with intraoperative anticoagulation, an anti-PF4 antibody level should be checked. If elevated, a serotonin release assay (SRA) is recommended. If the SRA is negative, heparin can be used intraoperatively irrespective of the result of the anti-PF4 antibody test. If both the anti-PF4 antibody test and the SRA are positive, surgery should be delayed or an alternative anticoagulant should be used. The acute management of the patient with HIT includes discontinuation of all heparins, suspension of warfarin, avoidance of platelet transfusions, and the initiation of alternative, nonheparin, anticoagulant therapy.

Peripheral arterial procedures include the bypass or stenting of stenotic arteries; embolectomy of occluded arteries; and the repair of peripheral arterial aneurysms. Endovascular approaches are employed whenever possible and are typically performed in the operating room, angiography suites, or hybrid operating rooms. Special considerations for the provision of anesthesia outside of the operating room are discussed in Chapter 33.

Limb patency and amputation-free survival rates are similar to open bypass surgery. Patients must have a target lesion amenable to the endovascular approach: typically a focal short-segment occlusion with patent vessels distal to the treated lesion (i.e., “good runoff”). Advantages of percutaneous therapy include faster patient recovery, shorter hospital stay, smaller wounds with lower complication rates, and potential cost savings. Procedures on the upper and lower extremities are typically performed in the operating room angiography suites and are frequently done under local anesthesia with sedation.

1. Surgical approach may be percutaneous or through a cutdown to the artery. Brachial artery access may be required necessitating IV placement and blood pressure monitoring on the contralateral arm.

2. Large amounts of intravenous contrast dye may be administered and may require prophylaxis for CIN (see “Renal System” under section I, above).

3. Anesthetic technique frequently involves monitored anesthesia care with standard monitors. Local anesthesia typically provides sufficient
analgesia. Provisions should be made to allow for conversion to general anesthesia in the case of an unplanned conversion to open repair.

4. IV unfractionated heparin is often used as an adjunct and is given prior to arterial cannulation. A vasodilator may be administered intra-arterially by the surgeon to treat catheter or wire-induced vasospasm. Treatment of systemic effects may be required.

5. Distal embolization is a potential serious complication with aggressive endovascular instrumentation.

In the presence of multisegment disease or poor distal runoff, open surgical bypass of the lower extremity is preferred over the endovascular approach. An autologous saphenous vein graft is the most commonly used conduit. If this is not available, or is of unacceptable quality, an upper extremity vein from the patient or cryopreserved cadaveric vein may be used. Preparation of the vein and subsequent anastomoses to the arterial circulation may be time consuming but rarely place significant hemodynamic stress on the patient. The use of synthetic grafts in selected patients may reduce the length of these procedures. Blood loss is usually minimal, but it may be significant with revision of a previous bypass. Routine monitoring is usually sufficient. Patient comorbidities or surgical complexity may warrant placement of invasive monitors. No significant differences in morbidity or mortality have been demonstrated between regional anesthesia and general anesthesia for lower limb revascularization.

1. General anesthesia. Any technique is appropriate provided hemodynamic stability is maintained.

2. Regional anesthesia. Potential advantages may include sympathetic blockade, improved pain control, lack of airway instrumentation, improved ability to detect symptoms of myocardial ischemia in an awake patient, and reduced incidence of pneumonia. However, long procedures under regional anesthesia can pose a challenge for patients who may become uncomfortable and restless.

a. A continuous lumbar epidural catheter is commonly used. It provides excellent analgesia and muscle relaxation as well as the ability to administer postoperative analgesia. Spinal anesthesia may be used if the length of the procedure is appropriate. For femoral-popliteal and distal lower extremity bypass limited to a single limb, combined lumbar plexus and sciatic nerve block may be used as an alternative to neuraxial anesthesia. For iliofemoral bypass, a spinal or epidural will require a higher level (i.e., T8-T10) because of proximal extension of the incision and peritoneal retraction for exposure of the iliac artery. Femoral-femoral bypass grafting is used to treat symptomatic unilateral iliac occlusive disease.

b. An α-adrenergic agent (e.g., phenylephrine) should be available to treat the hypotension associated with sympathetic blockade.

c. Neuraxial anesthesia is contraindicated in anticoagulated patients. Clotting abnormalities must be corrected (with fresh-frozen plasma [FFP], vitamin K, or protamine) before catheter insertion, or the patient must receive a general anesthetic. See Chapter 17 for specific medication guidelines. Of note, there is no evidence that the subcutaneous administration of unfractionated heparin for DVT prophylaxis increases the risk of epidural hematoma. If postoperative warfarin therapy is needed, the epidural should be removed before the onset of the anticoagulant effect (within 24 hours of administration of the first dose).

Femoral pseudoaneurysms are most often iatrogenic, occurring in the setting of femoral artery catheterization (e.g., for coronary angiography or intra-aortic balloon pump placement). As such, these patients often have unstable cardiovascular disease (e.g., recent MI with stent placement). Some are anticoagulated or have recently received thrombolytic agents, thus precluding regional anesthesia. Field blocks with local anesthesia may be most appropriate in the setting of cardiovascular instability. Embolectomy of an obstructed artery may be associated with significant blood loss and hypotension.

Peripheral arterial aneurysms, such as popliteal artery aneurysms, rarely rupture but are associated with a high rate of thrombosis and embolism. Either general or neuraxial anesthesia may be used to manage their repair.

An axillofemoral bypass graft restores arterial blood flow to the lower extremities in patients with occluded aortoiliac vessels who are not candidates for aortic reconstruction for various reasons including high anesthetic risk, significant intra-abdominal adhesions due to prior abdominal surgeries, active abdominal infection, or an infected aortic prosthesis. A prosthetic graft is tunneled under the pectoralis muscle and positioned in the subcutaneous layer of the thorax and abdomen and anastomosed distally to the femoral artery. General anesthesia is most appropriate.

Vascular surgery of the upper extremity usually includes distal embolectomy and repair of traumatic injuries. The surgery is localized, but there may be a need to harvest a vein graft at a site distant from the vascular repair. Possible anesthetic techniques include field block and regional or general anesthesia.

Carotid revascularization is performed in patients with stenotic lesions of the internal carotid artery. These lesions often present as carotid bruits and may produce TIAs or strokes. The indication for surgical revascularization takes into account patient life expectancy, surgical complication rates, the presence of symptoms, and the degree of stenosis. CEA is indicated for patients with nondisabling stroke or TIA who have greater than 70% stenosis by noninvasive imaging, as long as their life expectancy is greater than or equal to 5 years and the surgeon’s perioperative stroke and death risk is less than 6%. The data are less clear for patients with asymptomatic disease. CEA may be indicated in asymptomatic males with greater than 70% stenosis and a life expectancy in excess of 5 years if the surgeon’s perioperative stroke and death risk is less than 3%. It is not clear that CEA is more effective than medical therapy in women with asymptomatic carotid artery stenosis. If the patient does not meet criteria for surgical revascularization, risk factor modification with medical therapy and lifestyle changes is instituted. This consists of statin and antiplatelet therapy, smoking cessation, blood pressure control, and management of diabetes. CEA is the preferred modality for operative therapy of carotid artery stenosis. The role of carotid artery stenting (CAS) is still being defined. Evidence suggests that CAS and CEA have similar longterm results, but CAS is associated with a higher rate of periprocedural morbidity and mortality. In symptomatic patients, CAS is recommended
for patients with difficult surgical access (i.e., prior neck dissections) or radiation-induced carotid stenosis as long as the surgeon’s postoperative stroke and death risk is less than 6%. CAS is not recommended for patients with asymptomatic carotid artery stenosis.

Along with the standard history and physical, the preoperative anesthetic assessment should focus on the documentation of existing neurologic deficits as well as the range of motion of the patient’s neck.

1. Indications CAS may be preferred over CEA in patients with neck anatomy that is unfavorable for open surgery, such as with prior neck surgery or radiation, or in patients with higher operative risk due to severe cardiac or pulmonary disease. Due to the potential for CIN, CAS is generally avoided in patients with renal dysfunction.

2. Monitoring. An arterial catheter is indicated for continuous hemodynamic monitoring and facilitates frequent blood draws for monitoring of activated clotting time (ACT). Close observation of the patient’s mental status is necessary to detect new-onset stroke resulting from plaque embolization.

3. Anesthetic management usually consists of monitored anesthesia care combined with local anesthesia at the vascular access site. Care should be taken to maintain the patient’s level of alertness to facilitate intraoperative neurologic monitoring. The femoral artery is typically accessed percutaneously. The awake patient may feel pain during balloon angioplasty and arterial dilation that resolves immediately with balloon deflation.

4. IV contrast dye and fluoroscopy are used intermittently throughout the procedure.

5. Heparin is administered prior to arteriotomy.

6. Vagally mediated bradycardia can occur following stent deployment. Pretreatment with glycopyrrolate is helpful.

7. Complications include stroke, vascular access site injuries, device malfunction, restenosis, and CIN. Microembolic injuries are more frequent after CAS compared with CEA; embolic protection devices (EPDs) can reduce neurologic injuries if the operator is experienced with the apparatus.

1. Monitoring.

a. Intra-arterial blood pressure monitoring is necessary.

b. CNS monitoring is necessary, especially during carotid cross-clamp application, to evaluate the adequacy of cerebral perfusion and to identify patients who may require shunting. The awake patient is the gold standard for intraoperative CNS monitoring. If the procedure is being conducted under general anesthesia, the CNS can be monitored using electroencephalography (EEG), transcranial Doppler ultrasound, or arterial stump pressure measurement. CEA can also be conducted with routine shunting without continuous CNS monitoring. There are no data to support the use of routine versus selective shunting. No particular method of CNS monitoring in selective shunting has been shown to produce better outcomes.

2. Anesthetic technique. The choice of anesthetic technique has no significant impact on patient outcome. The decision to proceed with general anesthesia or regional anesthesia is usually based on the preferences of the surgeon and the patient.

1. Regional anesthesia may be performed with a combined superficial and deep cervical plexus block or with a superficial plexus block that is supplemented in the field by the surgeon (see Chapter 18). Both have potential complications.

2. CEA under regional anesthesia requires an alert, cooperative patient who is able to tolerate lying still, with the head rotated to the side, under the drapes.

3. Access to the airway may be necessary at any time, and the patient should be properly positioned and draped with this in mind. An appropriately sized laryngeal mask airway should be readily available.

4. Continuous neurologic assessment is possible in the awake patient.

1. Ventilation and oxygenation is controlled leading to reduced cerebral metabolic demand.

2. Prior to induction, neuromonitoring baselines are established.

3. Blood pressure should be maintained at the patient’s high-normal range that may require a vasopressor such as phenylephrine.

4. A hemodynamically stable induction is desired to preserve cerebral perfusion. Minute ventilation should be adjusted to avoid hypocapnic cerebral vasoconstriction. Hypercarbia, however, has no clinical benefit.