Long-term evaluation of EC-IC bypass patency

Abstract

The EC-IC Bypass Study Group could not detect any benefit from surgery compared to medical management in the prevention of stroke in 1985 [15]. During the past years surgical revascularization was re-evaluated and considered as an appropriate treatment for a small subgroup of patients with recurrent focal cerebral ischaemia and impaired haemodynamics. This retrospective study examines the long-term benefit and patency rate of bypass. We present a follow-up of 5.6 years of 47 patients, all of whom underwent bypass surgery after 1985. Forty patients suffered recurring transient ischaemic attacks due to uni- or bilateral internal carotid artery occlusion. Examination included neurologic status, TCD with CO2 or Diamox challenge, angiography, CT and SPECT scans. Neurological improvement was seen in 23% of patients with better results after early surgery, a worsening in 22% suffering further ischaemic events on a postoperative average of 2.8 years. Patency rate for vein graft material was 50%, for the STA-MCA procedure 91%. Occlusion of the vein graft occurred on an average after 1.4 years, other anastomosis after 2.7 years. We conclude that only few patients derived long-term benefit from EC-IC bypasses. Functioning of the bypass worsens over time, suggesting a role for surgery predominantly in the first year of ischaemic events due to insufficient collateral supply. Actual indications for bypass surgery may be patients with failure of maximal medical therapy and progressive ischaemia and haemodynamic compromise.

Extracranial-intracranial bypass for ischemic cerebrovascular disease: what have we learned from the Carotid Occlusion Surgery Study?

“…23 In addition to these studies, other case series have documented EC-IC bypass graft patency rates between 90% and 96%. 8,29,38,40 In 1978, a literature review examining multiple case series of STA-MCA bypass procedures (376 total operations) reported a permanent neurological morbidity rate of 2.4%, an operative mortality rate of 4.3%, and an "other morbidity" rate of 13.6%. 38 Other surgical case series (from the same time period) that included between 100 and 415 patients undergoing STA-MCA bypass operations reported perioperative ischemic stroke rates and mortality rates of 2%-3.6% and 1.2%-3%, respectively.…”

“…8,35,52 In a more recent series of 47 patients undergoing STA-MCA cortical branch anastomosis for symptoms related to hemodynamic cerebral ischemia, perioperative rates of morbidity, permanent neurological impairment, and mortality were reported to be 25.5%, 6.4%, and 2.1%, respectively. 40 In 2004, Mendelowitsch et al 29 published their results on 73 EC-IC bypass operations in patients with symptomatic atherosclerotic ICA occlusion. They observed a 3% perioperative ischemic stroke rate and a 0% perioperative mortality rate.…”

Staged Cerebral Revascularization in a Patient With an Occluded Common Carotid Artery

“…[13][14][15] Unfortunately, such procedures carry a higher complication profile and lower patency rate than an arteryartery anastomosis of similar-sized vessels. 14,16,17 In 1978, Ausman et al were the first to describe the technique of salvaging the superficial temporal artery for bypass by first performing a subclavian-external carotid artery bypass, followed 6 weeks later by STA-MCA bypass in a patient with retinal ischemia. 18 In 1982, Senter and Long reported simultaneous subclavian-external carotid and STA-MCA bypass in 3 patients with hemispheric ischemia.…”

Risk factors for neurological worsening and symptomatic watershed infarction in internal carotid artery aneurysm treated by extracranial-intracranial bypass using radial artery graft

“…17 The choice of bypass procedure depends on the amount of flow replacement required, and the size and availability of donor and recipient vessels. Immediate results and management of the bypass 13,23,27 and clinical follow-up results 13,22,24 have been reported previously. However, factors related to symptomatic watershed infarction (WI) have not been analyzed.…”