This prospective randomized controlled trial was conducted to compare the effectiveness of two ultrasound-guided regional anesthesia techniques, erector spinae plane block (ESPB) and serratus posterior superior intercostal plane block (SPSIPB), with standard patient-controlled analgesia (PCA) for postoperative pain management after video-assisted thoracoscopic surgery (VATS).

Adult patients undergoing elective VATS were randomly assigned to receive ESPB, SPSIPB, or PCA alone. The primary objective was to evaluate postoperative pain intensity during the first 48 hours after surgery. Secondary outcomes included opioid consumption, rescue analgesia requirements, patient satisfaction, and postoperative complications.

Video-assisted thoracoscopic surgery (VATS) is a minimally invasive surgical technique; however, postoperative pain remains clinically significant and may delay recovery and increase opioid consumption. Ultrasound-guided fascial plane blocks have been increasingly incorporated into multimodal analgesia strategies in thoracic surgery.

This single-center, prospective, randomized controlled study included adult patients aged 18-75 years with ASA physical status I-III who were scheduled for elective VATS. After obtaining written informed consent and ethics committee approval, patients were randomly assigned in a parallel design to one of three groups: ESPB group, SPSIPB group, or control group receiving morphine patient-controlled analgesia (PCA) alone.

Both ESPB and SPSIPB were performed preoperatively under ultrasound guidance by an experienced anesthesiologist prior to induction of general anesthesia. Standardized general anesthesia and postoperative analgesia protocols were applied to all patients.

The primary outcome was postoperative pain intensity assessed using the Numeric Rating Scale (NRS, 0-10) at predefined time points up to 48 hours postoperatively. Secondary outcomes included cumulative morphine consumption, number of morphine demands, rescue analgesia requirements, patient satisfaction, and opioid-related adverse events.

The study aimed to determine whether SPSIPB provides analgesic efficacy comparable to ESPB and whether both regional techniques reduce opioid consumption compared with PCA alone.

Inclusion Criteria:

• Age between 18 and 75 years
• American Society of Anesthesiologists (ASA) physical status I-III
• Scheduled for elective video-assisted thoracoscopic surgery (VATS)
• Ability to understand and use patient-controlled analgesia device
• Provided written informed consent

Exclusion Criteria:

• - Coagulation disorders or current anticoagulant therapy
• Infection at the block application site
• Known allergy to local anesthetic agents
• Anatomical abnormalities interfering with ultrasound-guided block
• Severe cardiac, renal, or hepatic failure
• Neurological or cognitive impairment preventing reliable pain assessment
• Emergency surgery

Postoperative pain assessments were performed by clinicians who were blinded to group allocation in order to minimize assessment bias.