Olsen Kevin R, LaGrew Joseph E, Awoniyi Caleb A, Goldstein J Christopher
Department of Anesthesiology, University of Florida College of Medicine, Gainesville, Florida, USA.
North Florida/South Georgia Veterans Affairs Medical Center, 1601 SW Archer Road, Gainesville, Florida, 32608, USA.
J Med Case Rep. 2018 Dec 18;12(1):372. doi: 10.1186/s13256-018-1904-8.
Transcatheter aortic valve replacement is indicated for severe symptomatic aortic stenosis in patients who have a very high or prohibitive surgical risk as assessed pre-procedurally by the Society of Thoracic Surgery Risk Score, EuroSCORE (II), frailty testing, and other predictors. When combined with another left ventricular outflow tract obstruction, careful consideration must be taken prior to proceeding with transcatheter aortic valve replacement because an additional masked left ventricular outflow tract pathology can lead to challenging hemodynamics in the peri-deployment phase, as reported in this case.
A 56-year-old Caucasian man with multiple comorbidities and severe aortic stenosis underwent transcatheter aortic valve replacement under monitored anesthesia care. During the deployment phase, he developed dyspnea that progressed to pulmonary edema requiring emergent conversion to general anesthesia, orotracheal intubation, acute respiratory distress syndrome-type ventilation, and vasopressor medications. Intraoperative transesophageal echocardiography was performed and hypertrophic obstructive cardiomyopathy with systolic anterior motion of the mitral valve was discovered as an underlying pathology, undetected on preoperative imaging. After treatment with beta blockers, fluid resuscitation, and alpha-1 agonists, he stabilized and was eventually discharged from our hospital without any lasting sequelae.
Patients with aortic stenosis most often develop symmetric hypertrophy; however, a small subset has asymmetric septal hypertrophy leading to left ventricular outflow tract obstruction. In cases of severe aortic stenosis, however, evidence of left ventricular outflow tract obstruction via both symptoms and echocardiographic findings may be minimized due to extremely high afterload on the left ventricle. Diagnosing a left ventricular outflow tract obstruction as the cause of hemodynamic instability during transcatheter aortic valve replacement, in the absence of abnormal findings on echocardiogram preoperatively, requires a high index of clinical suspicion. The management of acute onset left ventricular outflow tract obstruction intraoperatively consists primarily of medical therapy, including rate control, adequate volume resuscitation, and avoidance of inotropes. With persistently elevated gradients, interventional treatments may be considered.
经导管主动脉瓣置换术适用于严重症状性主动脉瓣狭窄患者，这些患者经胸外科医师协会风险评分、欧洲心脏手术风险评估系统（II）、衰弱测试及其他预测指标评估，手术风险非常高或无法承受。当合并其他左心室流出道梗阻时，在进行经导管主动脉瓣置换术前必须谨慎考虑，因为额外隐匿的左心室流出道病变可能导致部署期血流动力学出现问题，本病例即有报道。
一名患有多种合并症且严重主动脉瓣狭窄的56岁白人男性在麻醉监测下接受经导管主动脉瓣置换术。在部署阶段，他出现呼吸困难，进而发展为肺水肿，需要紧急转为全身麻醉、经口气管插管、急性呼吸窘迫综合征型通气及使用血管升压药物。术中进行经食管超声心动图检查，发现潜在病理为肥厚性梗阻性心肌病伴二尖瓣收缩期前向运动，术前影像学检查未发现。经β受体阻滞剂、液体复苏及α-1激动剂治疗后，他病情稳定，最终从我院出院，无任何持久后遗症。
主动脉瓣狭窄患者最常出现对称性肥厚；然而，一小部分患者有不对称性室间隔肥厚导致左心室流出道梗阻。然而，在严重主动脉瓣狭窄病例中，由于左心室后负荷极高，通过症状和超声心动图检查发现左心室流出道梗阻的证据可能会减少。在术前超声心动图无异常发现的情况下，诊断经导管主动脉瓣置换术中血流动力学不稳定的原因是左心室流出道梗阻，需要高度的临床怀疑。术中急性发作的左心室流出道梗阻的处理主要包括药物治疗，包括心率控制、充分的容量复苏及避免使用正性肌力药物。对于梯度持续升高的情况，可考虑介入治疗。
