Remimazolam-Based Anesthetic Management in a Patient with Severe Aortic Stenosis and Myelodysplastic Syndrome-Related Thrombocytopenia: A Case Report

<b>Background/Objectives:</b> Severe aortic stenosis (AS) poses major anesthetic challenges because cardiac output is highly dependent on preload and heart rate, and abrupt afterload reduction or tachycardia may precipitate ischemia and cardiovascular collapse. Coexisting myelodysplastic syndrome (MDS) with severe thrombocytopenia further increases the perioperative bleeding risk, which we considered particularly important in the anesthetic planning for this patient. We report a case of laparoscopic anterior resection in a patient with severe AS and thrombocytopenia, highlighting a transfusion strategy adjusted according to the patient's response and remimazolam-based anesthesia. To the best of our knowledge, there have been no previous reports describing remimazolam-based total intravenous anesthesia achieving stable hemodynamics without vasopressor support in a patient with severe AS and MDS-related thrombocytopenia. <b>Method:</b> A 78-year-old man with previously diagnosed MDS and chronic pancytopenia, whose baseline platelet counts (PLTs) ranged from 20,000 to 40,000/μL, was found to have severe AS (aortic valve area, 0.73 cm²; mean pressure gradient, 42 mmHg) during preoperative evaluation for laparoscopic anterior resection. After platelet transfusions titrated to his response, the patient's PLT increased to 93,000/μL before surgery. Anesthesia was induced and maintained with remimazolam and remifentanil, which were chosen to prevent afterload reduction associated with propofol. <b>Results:</b> Hemodynamics, including arterial pressure, cardiac index, systemic vascular resistance index, and cerebral oxygen saturation, remained stable without vasopressor support. Transient systolic hypertension during surgical stimulation was controlled using remifentanil titration and esmolol. Recovery and the postoperative course were uneventful, and the patient was discharged in a stable condition. <b>Conclusions:</b> Remimazolam-based total intravenous anesthesia can provide hemodynamic stability without vasopressors in high-risk patients with severe AS, and a transfusion strategy adjusted step by step according to the patient's response can be effective for optimizing PLTs while minimizing the transfusion-related risks of MDS-associated thrombocytopenia.