Surgical risk

The benefit of carotid endarterectomy for prevention of recurrent stroke has been studied previously in major trials.25,26 A recent meta-analysis has been completed that has combined these clinical trials to evaluate 6,092 patients.27 Carotid endarterectomy has been shown to be beneficial for preventing ipsilateral stroke in patients with symptomatic carotid artery stenosis of 70% or greater and is recommended in these patients. In patients with symptomatic stenosis of 50% to 69%, a moderate reduction in risk is seen in clinical trials. In all patients with stenosis of 50% to 69% and a recent stroke, carotid endarterectomy is appropriate. In other patients, surgical risk factors and surgeon skill should be considered prior to surgery. The patient should have, at a minimum, a life expectancy of 5 years, and the surgical risk of stroke and/or death should be less than 6%. Carotid endarterectomy is not beneficial for symptomatic carotid stenosis less than 50% and should not be considered in these patients. 

They are particularly useful in patients who cannot take NSAIDs because of renal failure, or for patients in whom all other treatment options have failed and who are at high surgical risk, precluding joint arthroplasty. 

Only a few serious attempts have been made to sort out which other patient-related factors affect perioperative stroke risk, and then which factors are independent from each other so they can be used in combination to predict surgical risk in individuals (Sundt et al. 1975 McCrory et al. 1993 Goldstein et al. 1994 Riles et al. 1994 Golledge et al. 1996 Kucey et al. 1998 Ferguson et al. 1999). Risk factors almost certainly include hypertension, peripheral... 

What is the balance of immediate surgical risk versus long-term benefit ... 

Low-dose narcotic analgesics may be very useful in patients who experience no relief with acetaminophen, NSAIDs, intra-articular injections, or topical therapy. These agents are particularly useful in patients who cannot take NSAIDs dne to renal failure, or for patients in whom aU other treatment options have failed and who are at high surgical risk, precluding joint arthroplasty. Low-dose narcotics are the initial intervention, nsnaUy given in combination with acetaminophen. 

Radiotherapy alone (without chemotherapy or surgery) is the treatment of choice for stage I and II patients who refuse surgery or who are considered high surgical risks because of concomitant illness or restrictive pulmonary reserve. It is also used when the tumor is unresectable because of fixation to a major blood vessel, the trachea, or the esophagus. Of those patients, the 2- and 5-year survival rates appear to be highest for patients whose tumors would otherwise be considered resectable. 

Kudsk KA, Tolley EA, DeWitt RC, et al. Preoperative albumin and surgical site identify surgical risk for major postoperative complications. JPEN J Parenter Enteral Nutr 2003 27 1-9. 

Schofer J, Schliiter M, Treede H, et al. Retrograde Transarterial implantation of a nonmetallic aortic valve prosthesis in high-surgical-risk patients with severe aortic stenosis a first-in-man feasibility and safety study. Circ Cardiovasc Intervent 2008 1 126-33. 

In current clinical practice, deciding who should be revascularized is often based solely on stenosis severity at the time of patient encounter (>70% for low-surgical risk patients and >80% for high-surgical risk patients). Simplification of clinical decision-making certainly has advantages, but the available data clearly indicate that stenosis severity is only one of many other parameters that determine future stroke risk in these patients. 

The results of these trials suggest rates of adverse outcomes in high-surgical risk patients which approach those from the normal-risk CEA landmark trials, but are underpowered to draw significant conclusions. Subsequent studies that enrolled broader patient population with respect to surgical risk provide some of the additional numbers to aid in further comparisons with the CEA historical controls. 

CAPTURE has reported outcomes on 2,500 high-surgical-risk patients treated using the Guidant filter and stent system at 137 centers across the United States, 90.7% of whom were asymptomatic (49). The 30-day major adverse event rate (death, stroke, myocardial infarction) for asymptomatic patients (n = 2268) was 4.9% and for asymptomatic patients under the age of 80 years (n = 1741) was 4.2%. Moreover, if only the 30-day rate of stroke and death is considered the event rate fell to 3.6% in asymptomatic patients under the age of 80 years. Lastly, CASES-PMS enrolled 974 asymptomatic high-surgical risk patients who were treated with Cordis/Johnson 8c Johnson stent and filter system (50). The 30-day risk of stroke and death in the entire asymptomatic group was 4.2% (the breakout for patients under 80 years of age is unavailable). 

Data regarding the role of CAS in low-surgical-risk patients with asymptomatic CAS are limited. The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) lead-in registry has reported data for investigators during the roll-in phase (51). The 30-day rate of stroke and death in the 960 asymptomatic patients was 4.0%, and if limited to only patients under the age of 80 years is 3.3%. The 30-day rate of death and major stroke in patients under the age of 80 years was 1.4%. 

There are two ongoing prospective clinical randomized trials of CAS versus CEA in low-surgical risk patients in the United States (ACT 1, CREST). The Asymptomatic Carotid Stenosis Stenting versus Endarterectomy Trial (ACT 1, Abbott Vascular) is in the enrollment phase and it will randomize up to 1658... 

FIGURE 9.2 Type 3 aortic arch in a high-surgical-risk patient with asymptomatic severe left internal carotid artery stenosis. 

Gray WA, Hopkins NL, Yadav S, et al. Protected carotid stenting in high-surgical-risk patients The ARCHeR results. J Vase Surg 2006 44 258-69. 

The ideal drug for treating patients at high risk for PVR, or for use as an adjunct to surgery in established PVR would be one that achieves therapeutic levels in the eye for weeks to months, one that addresses a variety of mechanisms of PVR development, that can be delivered with minimal added surgical risk, and that has few to no ocular or systemic side effects. 

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