This prospective, randomized clinical study aims to compare the analgesic efficacy of serratus plane block (SPB) and rhomboid intercostal plane block (RIPB) for postoperative analgesia in patients undergoing elective bilateral breast reduction surgery under general anesthesia. All patients will receive standardized general anesthesia. Before induction of anesthesia, while patients are awake, Group SPB will receive an ultrasound-guided serratus anterior plane block and Group RIPB will receive an ultrasound-guided rhomboid intercostal plane block. Postoperative analgesia will be maintained with intravenous patient-controlled analgesia (PCA) with opioids. Primary outcomes include postoperative pain scores and opioid consumption at 1, 6, 12, and 24 hours. Secondary outcomes include time to first analgesic demand, patient satisfaction, and block-related complications.