Yet again, the debates at Charing Cross proved very popular and a packed Great Hall was treated to an informative, entertaining and provocative session.
The first debate discussed the motion, “There is no case for carotid intervention in asymptomatic patients.” Speaking for the motion was Ross Naylor, Leicester, UK, and against was Ken Ouriel, Cleveland, US. Taylor began by stating that even if you had an operative risk of 0%, you would still only prevent 83 strokes per 1,000 carotid endarterectomys at five years and if the risk was 6% (as observed in the asymptomatic patients in SAPPHIRE), you would only prevent 22 strokes per 1,000 carotid endarterectomys at five years. Therefore, Naylor argued, with an operative risk of 2.8% you have to perform 40 carotid endarterectomys to prevent one disabling or fatal stroke at five years, an operative risk of 4.0% would required 77 CEAs preventing just 13 strokes by performing 1,000 carotid endarterectomys. Naylor called the rush to perform surgery the “oculostenotic reflex,” adding, “You see a stenosis, you just have to fix it!” The problem according to Naylor is locating the patients. He stated that 1% of the population of Leicester will has stenosis >60%, equating to approximately 10,000 patients. “This means that there would be a vascular theatre list everyday of the week and it would take 38 years to clear the list – with no holidays for the surgeon.”
In response, Ouriel stated that most carotid endarterectomys in the US are performed on asymptomatic patients. He claimed studies such as the Asymptomatic Carotid Surgery Trial (ACST) and SAPPHIRE has demonstrated that some asymptomatic patients with high-grade carotid disease should undergo repair with carotid endarterectomys (lower-risk patients with >60% stenoses (ACST) or with carotid artery stenting for patients with >80% stenoses (SAPPHIRE). However, Ouriel did acknowledge that if a very low complication rate cannot be achieved, forget carotid endarterectomy and carotid artery stenting for asymptomatic or symptomatic patients.
The audience voted in favour of the motion (60% – 40%).
In a more lighted-heart second debate, the motion was “Carotid stenting is the new gold standard for symptomatic carotid stenosis.” Peter Gaines, Sheffield, UK, argued for the motion, Peter Bell, Leicester, UK, argued against. In a hilarious video presentation, Gaines claimed that results from the SAPPHIRE study had proved the case for carotid artery stenting intervention over carotid endarterectomy. Moreover, he cited the Cochrane Collaboration 2005, which concluded that both procedures had similar early risks of death or stroke and follow-up with no significant difference between the groups in preventing stroke or death. In addition, there were no significant difference between the two groups when the risk of death, any stroke or MI considered. Furthermore, stenting significantly reduced the risk of cranial nerve damage and carotid artery stenting has the added advantage of being performed without the need for general anaesthesia.
In response, Bell argued that the evidence for the benefits of carotid artery stenting have yet to be proven. He cited the WALLSTENT Study which demonstrated a stroke and death rate of 12.1% in stent group and 3.6% in carotid endarterectomy group (p=0.22). Moreover, the study was terminated prior to the recruitment target of 700 patients was reached and after 219 patients were recruited the sponsors withdrew support. In addition the CAVATAS trial of a 504 patients randomised 253 to carotid endarterectomy, 251 to carotid artery stenting and showed a stroke and death rate of 9.9% for carotid endarterectomy, 10% for carotid artery stenting. At one year 4% carotid endarterectomy patients v 14% carotid artery stenting patients had severe restenosis (p < .0001). Furthermore, the EVA-3S TRIAL - Stroke 2004 (French trial supported by national research funding) was stopped because of the higher rate of stroke and death in the stented group. Bell concluded by stating "In randomised trials, carotid angioplasty and stenting is almost three times more dangerous than carotid endarterectomy and probably causes dementia in the survivors. The audience sided with Peter Bell and voted against the motion by a large majority. The third and final debate discussed the motion, “Small aneurysms less than 5.5cms should be left alone.” Arguing for the motion was Roger Baird, Bristol, UK, and Roger Greenhalgh, Imperial College, UK, and against was Piergiorgio Cao, Perugia, Italy, and Ken Ouriel, Cleveland, US. Baird began by stating that small aneurysms very seldom rupture and if they do the cause is normally something else. He went on to state that the advent of aortic aneurysm screening has resulted in 5% of males over the age of 65 having an aortic aneurysm of more than 3cms. However, there is no advantage for these patients to undergo surgical treatment straight away, indeed the UK Small Aneurysms Trial (UKSAT) resulted in two thirds of patients having an operation at some stage following surveillance. He concluded by stating that “Small aneurysms are best left alone – you can’t make an asymptomatic patient better.” In response, Cao said “the option should not be whether to treat or not to treat, but when to treat.” He argued that surveillance is not a safe option and that previous studies have provided no conclusive evidence for intervention. Coa hoped his CAESER trial would clarify this issue. In conclusion, Cao said that “You can always wait for AAA growth…but you may lose the opportunity for low risk procedure”. Greenhalgh responded by claiming the UKSAT showed that there was little difference in the outcomes of surveillance vs. surgery. Indeed, he said that only in year eight (after the study had ended) was there one difference. The ADAM trial, with the same protocol, confirmed the findings of UKSAT. To conclude, Greenhalgh said, “Yes, small aneurysms do rupture, but the question is how often and should they have an operation? The question is what is the trade off between the mortality of the operation and the risk of rupture?” To conclude, he cited the results of EVAR which showed a mortality of 1.7% and said, “Even by substituting those results, there is no justification for early surgery.” Ouriel believed that the EVAR and DREAM data was encouraging, however, if a procedure could be performed with a lower perioperative mortality rate, that procedure might be able to “beat” surveillance of small AAA. He quoted the Cleveland Clinic Series: Endo Repair of Small AAA. This series treated 456 repairs in seven years, demonstrated a lower mortality compared with endo treatment of larger (>5.5 cm) AAA, a lower risk of subsequent rupture and a lower need for open surgical conversion. Therefore, Ouriel concluded from his own studies that the risk of rupture was below 1%. He said that surveillance is associated with the need to eventually repair an aneurysm in 70% of patients with AAA 4.0-5.5 cm in diameter. The only reasons not to repair a smaller AAA relate to: the morbidity and mortality of the surgical procedure and the failure to protect the patient from long-term complications. If open surgery is roughly equivalent to surveillance, and if EndoAAA is better than open surgery, than EndoAAA should “beat” surveillance when treating smaller aneurysms.
The audience agreed with Baird and Greenhalgh and voted for the motion by an overwhelming majority.