with “complete and final discretionary authority to interpret the plans and maintain control over the operation and administration of the plans.” Accordingly, the Chevron Plan, via the Services Agreement and the SPD, delegates authority to Aetna regarding benefit eligibility for the Medical Plan. Moreover, in this situation, Aetna made a factual determination that certain diagnostic testing and IVIG treatments were not medically necessary. “[F]actual determinations made by [an] administrator during the course of a benefits review will be rejected only upon the showing of an abuse of discretion.” Meditrust Fin. Servs. Corp. v. Sterling Chems., Inc., 168 F.3d 211, 213 (5th Cir.1999); see also Chandler v. Hartford Life, No. 05-50688, 2006 WL 1209363, at *3 (5th Cir. Apr.28, 2006) (<HOLDING>) (quoting Meditrust Fin. Servs. Corp., 168 F.3d
holding that the admission or exclusion of evidence is within discretion of the trial court and that such determinations will not be disturbed on appeal absent clear abuse of discretion holding that a denial of benefits will not be reviewed de novo where the language of an erisa plan gives the administrator or fiduciary discretionary authority to determine eligibility for benefits or to construe the terms of the plan holding that arbitrary and capricious standard applies to section 1132a1b denial ofbenefits claims if the benefit plan gives the administrator or fiduciary discretionary authority to determine eligibility for benefits or to construe the terms of the plan holding that rulings on admissibility of evidence are within the discretion of the trial court and will not be disturbed absent a showing of abuse of that discretion holding that  rjegardless of the administrators ultimate authority to determine benefit eligibility  factual determinations made by the administrator during the course of a benefits review will be rejected only upon the showing of an abuse of discretion 