Introduction: Outcomes from endovascular procedures are highly dependent on the experience and skill of the operating physician. The multi-disciplinary CREST-2 Interventional Management Committee (IMC) was charged with credentialing a cohort of skilled interventionists with adequate contemporary case volumes. Methods: Applicants were required to submit 25 consecutive cases completed within 5 years as primary operator out of a required total experience of ≥ 50 cases (≥ 20 for operators completing training). Interventionists not approved on initial review were asked to submit additional cases (with procedural angiograms), the number depending on quality and recent-quantity of the cases. Results: The IMC has had 102 meetings, and 283 interventionists have been evaluated: 104 (37%) interventionists were cardiologists, 64 (23%) vascular surgeons, 42 (15%) neurosurgeons, 32 (11%) neuroradiologists, 26 (9%) neurologists, 9 (3%) interventional radiologists, and 6 (2%) other. The mean total experience among the 226 interventionists with available information was 220±263 carotid stent cases (median 135; range 10-2500). A total of 7037 cases have been reviewed by the IMC, dating from August 2001 to April 2016, with 3366 symptomatic, 3541 asymptomatic and 130 undetermined. The range of cases reviewed per interventionist was 5 to 50. Of the 251 interventionists with sufficient periprocedural follow-up data, no stroke events were reported by 152 (60.5%), and at least one or more stroke events were reported by 99 (39.5%). The IMC has approved 115 interventionists, 29 at the first review and 86 subsequently, based upon submission and review of 631 additional contemporary cases (mean=7 cases per interventionist); 122 have approval pending submission of additional cases; 33 have been denied; 8 have been deferred; 4 have been approved for the CREST-2 Companion Registry only; and 1 is pending decision. Discussion: Rigorous evaluation and credentialing of carotid stenters in CREST-2 has been demanding, for the candidates and for the evaluators. Yet the cohort of interventionists so selected should be able to provide the high-quality stenting outcomes necessary for acceptance of the trial results.
Validation of frontal near-infrared spectroscopy as noninvasive bedside monitoring for regional cerebral blood flow in brain-injured patients
Object Near-infrared spectroscopy (NIRS) offers noninvasive bedside measurement of direct regional cerebral arteriovenous (mixed) brain oxygenation. To validate the accuracy of this monitoring technique, the authors analyzed the statistical correlation of NIRS and CT perfusion with respect to regional cerebral blood flow (CBF) measurements. Methods The authors retrospectively reviewed all cases in which NIRS measurements were obtained at a single, academic neurointensive care unit from February 2008 to June 2011 in which CT perfusion was performed at the same time as NIRS data was collected. Regions of interest were obtained 2.5 cm below the NIRS bifrontal scalp probe on CT perfusion with an average volume between 2 and 4 ml, with mean CBF values used for purposes of analysis. Linear regression analysis was performed for NIRS and CBF values. Results The study included 8 patients (2 men, 6 women), 6 of whom suffered subarachnoid hemorrhage, 1 ischemic stroke, and 1 intracerebral hemorrhage and brain edema. Mean CBF measured by CT perfusion was 61 ml/100 g/min for the left side and 60 ml/100 g/min for the right side, while mean NIRS values were 75 on the right and 74 on the left. Linear regression analysis demonstrated a statistically significant probability value (p < 0.0001) comparing NIRS frontal oximetry and CT perfusion–obtained CBF values. Conclusions The authors demonstrated a linear correlation for frontal NIRS cerebral oxygenation measurements compared with regional CBF on CT perfusion imaging. Thus, frontal NIRS cerebral oxygenation measurement may serve as a useful, noninvasive, bedside intensive care unit monitoring tool to assess brain oxygenation in a direct manner.