Surgery to prevent stroke. High hopes and deep disappointment

Excimer laser-assisted non-occlusive cerebral vascular Anastomosis (ELANA): review of the first UK experience

The Excimer Laser Assisted Non-occlusive cerebral vascular Anastomosis (ELANA) has been proposed as a major advance in the field of cerebral revascularisation. Appreciable challenges remain, however. We report our experience with introducing this technique to the UK and review the field of cerebral revascularisation and flow replacement. Retrospective review of prospectively recorded case series. Data were collected prospectively, complication data were recorded and analyzed and functional surgical outcomes were measured using the modified Rankin scale (MRS). Ten patients, during a 2-year period, were considered suitable for high-flow cerebrovascular bypass surgery, with 8 proceeding to surgery. Seven bypasses were completed and 1 abandoned. Of the 5 patients neurologically intact preoperatively, 3 remained so postoperatively, 4 experienced no neurological deficit and one suffered transient hemiparesis due to hyperperfusion which resolved. One patient with preoperative hemiparesis improved. One patient died 8 days postoperatively. Overall long-term patency rate was (42%), however 3 thrombosed bypasses were all competitive (used for prophylactic intraoperative reasons), 2 thrombosing after the surgical procedure was completed. We discuss the role for this modern technique and the lessons learnt from its introduction to the UK, and consider the current and future requirements for cerebral revascularisation.

EC-IC bypass: The failure of a clinical trial? Applicability to PFO closure trials

Extracranial-to-intracranial (EC-IC) bypass surgery was used to prevent stroke in patients with carotid occlusion and inadequate collateral flow. Because of inappropriate proliferation of EC-IC bypass, a randomized clinical trial was carried out. The failure of the trial may have been related to inappropriate patient selection and all eligible patients not being randomized. Subsequent study has identified criteria for patient selection and new trials are underway. The present patent foramen ovale closure trials share many of the same difficulties, including overuse of the procedure and interventionalists reluctant to randomize patients. If these trials are not properly done we will be in the same situation in 20 years that the EC-IC trialists are facing today. Improvements in patient selection criteria, randomization of all eligible patients, and better statistical parameters will increase the likelihood of future trials getting the correct answer the first time. The importance of carefully done observational trials should not be overlooked.