The Impact of Ultrasound-Guided Superficial and Deep Paravertebral Nerve Blocks at the Superior Costotransverse Ligament on Hemodynamics During the Induction Phase of Thoracoscopic Lung Lobectomy: A Multicenter, Double-Blind, Randomized Controlled Trial

Inclusion Criteria: * Patients scheduled for elective two-port video-assisted thoracoscopic lobectomy * Age: ≥18 years * ASA classification: I-III * BMI: 18-30 kg/m² Exclusion Criteria: * Severe hypertension (SBP ≥180 mmHg or DBP ≥110 mmHg) * MAP \<70 mmHg before anesthesia induction * Emergency surgery * Severe cardiovascular disease, including history of cerebral or thoracic/abdominal aortic aneurysm * Congestive heart failure (New York Heart Association class III or IV) * Untreated or unstable ischemic heart disease * Severe aortic or mitral valve disease * Pregnancy or lactation * Coagulation disorders * Bacteremia, sepsis, or infection at the puncture site * Allergy to study-related drugs * Severe liver and kidney dysfunction * Neurological disorders, spinal disease (deformity or trauma), history of spinal surgery, or abnormal skin sensation in the thoracic or back region * Existing or anticipated difficult airway management * Other conditions deemed unsuitable for inclusion by the investigators Forty patients who required CT (3D) imaging technology to observe drug diffusion after the implementation of the two methods were included as follows: patients who were scheduled to undergo double-hole thoracoscopic lobectomy, aged ≥18 years, ASA grade I to III, BMI 18 to 30kg/m2, and required preoperative CT localization. Exclusion criteria In addition to the above conditions, patients with a history of anaphylaxis induced by contrast agents should be excluded.