SPSIP block is the intervention used in this study. It was performed when the patient is in lateral decubitis position. A high frequency (7-12 MHz) linear transducer of the ultrasound device is placed at the spinae scapula level in the transverse plane, and the upper medial border of the scapula, the trapezius muscle, rhomboid muscle, serratus posterior superior muscle (SPSM) and the second and third ribs are visualized. The sonovisible needle is then advanced immediately medial to the scapula, aiming for the area between the second and third ribs in order to reach the fascial plane between the SPSM and intercostal muscles. After contact of the needle with the rib gently, and a total of 30 mL of 0.25% bupivacaine is administered to the superficial to the intercostal muscle. All patients had 3x400 mg ibuprofen intravenous (i.v.) in postoperative 24 hours. 50 mg tramadol was given as a rescue analgesic drug to the patients who had numerical rating scale (NRS) 4 or higher.

Control group patients were not subjected to any block or local infiltration anesthesia (local anesthetic administration around the incision). Their postoperative pain was relieved with ibuprofen 3x400mg intravenous (i.v.) in postoperative 24 hours. The patients had NRS score 4 or higher were given 50 mg tramadol as a rescue analgesic.

Serratus posterior superior intercostal plane block is the intervention used in this study. It was performed when the patient is in lateral decubitis position. A high frequency (7-12 MHz) linear transducer of the ultrasound device is placed at the spinae scapula level in the transverse plane, and the upper medial border of the scapula, the trapezius muscle, rhomboid muscle, serratus posterior superior muscle (SPSM) and the second and third ribs are visualized. The sonovisible needle is then advanced immediately medial to the scapula, aiming for the area between the second and third ribs in order to reach the fascial plane between the SPSM and intercostal muscles. After contact of the needle with the rib gently, 1-2mL of saline is used to confirm the correct plane, and a total of 30 mL of 0.25% bupivacaine is administered to the superficial to the intercostal muscle.

Numerical rating scale is used for pain assessment. The scores of the numerical rating scale changes between 0 to 10 points. 10 points mean "the most severe pain that the patient ever had". 0 point means "there is no pain." Higher scores mean worse outcome.

Postoperative total analgesic need was recorded as "milligram" in unit.