Length of carotid stenosis predicts peri-procedural stroke or death and restenosis in patients randomized to endovascular treatment or endarterectomy.

BACKGROUND: The anatomy of carotid stenosis may influence the outcome of endovascular treatment or carotid endarterectomy. Whether anatomy favors one treatment over the other in terms of safety or efficacy has not been investigated in randomized trials. METHODS: In 414 patients with mostly symptomatic carotid stenosis randomized to endovascular treatment (angioplasty or stenting; n = 213) or carotid endarterectomy (n = 211) in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS), the degree and length of stenosis and plaque surface irregularity were assessed on baseline intraarterial angiography. Outcome measures were stroke or death occurring between randomization and 30 days after treatment, and ipsilateral stroke and restenosis ≥50% during follow-up. RESULTS: Carotid stenosis longer than 0.65 times the common carotid artery diameter was associated with increased risk of peri-procedural stroke or death after both endovascular treatment [odds ratio 2.79 (1.17-6.65), P = 0.02] and carotid endarterectomy [2.43 (1.03-5.73), P = 0.04], and with increased long-term risk of restenosis in endovascular treatment [hazard ratio 1.68 (1.12-2.53), P = 0.01]. The excess in restenosis after endovascular treatment compared with carotid endarterectomy was significantly greater in patients with long stenosis than with short stenosis at baseline (interaction P = 0.003). Results remained significant after multivariate adjustment. No associations were found for degree of stenosis and plaque surface. CONCLUSIONS: Increasing stenosis length is an independent risk factor for peri-procedural stroke or death in endovascular treatment and carotid endarterectomy, without favoring one treatment over the other. However, the excess restenosis rate after endovascular treatment compared with carotid endarterectomy increases with longer stenosis at baseline. Stenosis length merits further investigation in carotid revascularisation trials

A Survey of Experimental Research on Contests, All-Pay Auctions and Tournaments

Many economic, political and social environments can be described as contests in which agents exert costly efforts while competing over the distribution of a scarce resource. These environments have been studied using Tullock contests, all-pay auctions and rankorder tournaments. This survey provides a review of experimental research on these three canonical contests. First, we review studies investigating the basic structure of contests, including the contest success function, number of players and prizes, spillovers and externalities, heterogeneity, and incomplete information. Second, we discuss dynamic contests and multi-battle contests. Then we review research on sabotage, feedback, bias, collusion, alliances, and contests between groups, as well as real-effort and field experiments. Finally, we discuss applications of contests to the study of legal systems, political competition, war, conflict avoidance, sales, and charities, and suggest directions for future research. (author's abstract

Meglumine gadoterate: a new safe radiocontrast medium for endoscopic retrograde cholangiopancreatography?

The radiocontrast substance meglumine gadoterate (MG) is used in magnetic resonance imaging. It is characterized by its low rate of adverse drug reactions. In an open study we tested whether MG is useful in endoscopic retrograde cholangiopancreatography. The patients received in sequence MG and ioxotalamate. MG, in contrast to ioxotalamate, failed to visualize the proximal pancreatic and peripheral intrahepatic ducts. Thus, MG is not useful in routine endoscopic retrograde cholangiopancreatography. However, in patients with a history of severe allergic reactions to conventional contrast media, MG may be recommended when pathological findings of the extrahepatic bile duct or the area of the pancreatic head are suspected

Meningiomas involving the anterior clinoid process.

We report a series of 34 clinoidal meningiomas treated surgically and analyse the results according to cavernous sinus involvement. Fifteen tumours extended into the cavernous sinus. Only four of these could be resected completely, and global outcome was improved or stable in 10 cases. Overall, 20 tumours had a total resection and 14 had a partial resection. Complete removal of the sphenoid wing, including the anterior clinoid and part of the planum sphenoidale, allows early devascularization of the tumour and minimizes brain retraction when associated with resection of the zygomatic arch. The most frequent postoperative complication was transient CSF leak, occurring in three patients. Two patients died postoperatively, and three suffered permanent complications. There was no recurrence after total removal, but five patients showed signs of progressive tumour growth after partial removal, treated by radiotherapy in three and by surgery in two cases. Twenty patients showed preoperative visual impairment. Outcome of vision was improved or stable in 13 (68%) and worse in six cases (32%). We suggest that progressive visual impairment should lead to aggressive surgical treatment, especially when complete resection of cavernous sinus involvement can be performed

Endovascular coil placement compared with surgical clipping for the treatment of unruptured middle cerebral artery aneurysms: a consecutive series.

OBJECT: The goal of this study was to delineate the angioanatomical features that determine whether a patient with an unruptured middle cerebral artery (MCA) aneurysm is treated using endovascular coil placement or surgical clipping. METHODS: Thirty consecutive patients harboring 34 unruptured MCA aneurysms were evaluated. Patients with unruptured aneurysms are managed prospectively according to the following protocol: the primary treatment recommendation is endovascular packing with Guglielmi detachable coils (GDCs). Surgical clipping is recommended after failed attempts at coil placement or in the presence of angioanatomical features that contraindicate that type of endovascular therapy. Of 34 unruptured MCA aneurysms, two (6%) were successfully embolized and 32 (94%) were clipped. Of these 32 surgically treated aneurysms, in 11 (34%) an attempt at GDC embolization had failed, whereas in 21 (66%) primary clipping was performed because of unfavorable angioanatomy. Of the 13 aneurysms treated endovascularly, two (15%) were successfully excluded, whereas GDC treatment failed in 11 (85%). An unfavorable dome/neck ratio (< 2) and an arterial branch originating at the aneurysm base were the reasons for embolization failure. CONCLUSIONS: Careful evaluation of the angioanatomy of unruptured aneurysms allows selection of the most appropriate treatment. However, for unruptured MCA aneurysms, surgical clipping appears to be the most efficient treatment option. Series of unruptured aneurysms are ideal for comparing treatment results

Subarachnoid haemorrhage of unknown cause: Clinical, neuroradiological and evolutive aspects.

The clinical and radiological data of 52 patients with subarachnoid haemorrhage (SAH) and a negative panangiography were analysed with an average follow-up period of 3.8 years. Of these 52 patients, only one (1.9%) was subsequently found to have an aneurysm. Second angiography proved to be inconclusive in all 24 cases where it was performed. Of the 51 'true' non-aneurysmal SAH, 80% were in a good clinical grade on admission and 12% developed cerebral ischaemia. The mortality rate following SAH was 4%. There was one rebleeding. At follow-up examination, 87% of the patients had made a good recovery and 6% were left disabled due to SAH. Four patients with an aneurysmal pattern of SAH required a permanent shunt. All of the 22 patients with a perimesencephalic SAH were in a good neurological condition upon admission; one of them developed an angiography-induced transient cerebral ischaemia and another one suffered from a fatal rebleeding. None of the 21 survivors was disabled at follow-up examination. The clinical course of patients with SAH of unknown cause, especially those with a perimesencephalic pattern of haemorrhage, is good. Repeated angiography in this latter group is not useful. In the aneurysmal pattern SAH group, repeat angiography is advised only if there is strong computed tomographic (CT) scan suspicion of an aneurysm