Citation Nr: 21075329 Decision Date: 12/20/21 Archive Date: 12/20/21 DOCKET NO. 18-48 139 DATE: December 20, 2021 REMANDED Entitlement to service connection for carotid artery disease is remanded. REASONS FOR REMAND The Veteran served on active duty from March 1958 to November 1977. This matter comes before the Board of Veterans' Appeals (Board) on appeal from a December 2014 rating decision issued by a Department of Veterans Affairs (VA) Regional Office (RO). The Veteran testified before the undersigned at a hearing in April 2019. The Board remanded this matter in August 2019, August 2020, February 2021, June 2021, and September 2021 for additional development. The matter is now returned to the Board for further appellate review. This appeal is advanced on the Board's docket pursuant to 38 C.F.R. § 20.902(c); 38 U.S.C. § 7107(a)(2). Entitlement to service connection for carotid artery disease is remanded. VA has a duty to ensure any medical examination or opinion it provides is adequate. Barr v. Nicholson, 21 Vet. App. 303, 312 (2007) (overruled on other grounds, Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013)). A medical opinion is adequate where it is based upon consideration of the full medical history and describes a disability in sufficient detail so that the Board's evaluation will be fully informed. Stefl v. Nicholson, 21 Vet. App. 120, 123 (2007). The Veteran contends his carotid artery disease is secondary to his service-connected obstructive sleep apnea (OSA). Following the Board's September 2021 remand, an October 2021 VA etiology opinion was obtained to evaluate this claim. The examiner opined carotid artery disease was less likely than not caused or aggravated by OSA because "there is no credible medical evidence of any pathological mechanism" to support such a relationship. The October 2021 opinion is inadequate. The evidence of record includes a June 2018 VA etiology opinion (evaluating whether OSA was causally related to the Veteran's active service) noting medical literature shows OSA is "an important disorder because patients are at increased risk for . . . adverse medical outcomes" and "severe untreated OSA has been associated with increased all-cause and cardiovascular mortality." In August 2020, the Veteran's representative submitted an informal hearing brief. The brief included links to online medical information from the Centers for Disease Control (CDC), WebMD, and Harvard Medical School which described poor sleep as being associated with multiple chronic medical conditions, including cardiovascular disease. Additionally, in November 2020, a VA examiner observed "there is evidence in the medical literature that OSA can contribute to the development of . . . carotid atherosclerosis." The October 2021 examiner did not discuss the medical literature and evidence identified within the claims file. She did not offer any rationale explaining why this evidence was not credible. Her opinion is not based on a complete and cogent rationale. Although the Board regrets the additional delay, a new opinion must be provided. See Stefl, supra. The matters are REMANDED for the following action: Obtain an addendum opinion from an appropriate clinician. After reviewing the complete claims file, the clinician should opine whether it is at least as likely as not (50 percent or greater probability) that the carotid artery disease is (a) caused by; or (b) aggravated (i.e., worsened beyond the normal progression of the disease) by the Veteran's service-connected OSA. If aggravation is found, the clinician must attempt to establish a baseline level of severity of the carotid artery disease prior to aggravation by the service-connected sleep apnea. Please note, causation and aggravation are separate concepts and MUST be addressed independently. In providing this opinion the clinician must fully review and address the statements, medical literature, and medical evidence referenced in the June 2018 VA etiology opinion for OSA, the August 2020 informal hearing brief submitted by the Disabled American Veterans, and the November 2020 VA etiology opinion for carotid artery disease. The clinician is also advised that if a negative etiology opinion is provided, the rationale must go beyond simply noting that the carotid artery disease was diagnosed before the sleep apnea as there is no temporal requirement inherent in secondary service connection claims. (Continued on the next page) All findings must be reported in detail and all opinions must be accompanied by a clear rationale. If any of the above issues cannot be resolved without resorting to speculation, then a detailed medical explanation as to why this is so must be provided. If the clinician is unable to provide the requested opinion without an additional examination, an examination should be provided. In scheduling such an examination every effort should be made to accommodate the Veteran's medical requirements. M. HYLAND Veterans Law Judge Board of Veterans' Appeals Attorney for the Board Jeanne Celtnieks The Board's decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.