Ultrasound-guided Paravertebral Block Versus Mid-point Transverse Process Pleura Block in Mastectomy Surgery

This study was performed to analyze the postoperative analgesic effects of the paravertebral block (PVB) and Mid-Point Transverse Process Pleura (MTP) block after a unilateral mastectomy surgery. This study included 64 women aged 18-65 years, American Society of Anesthesiologists score I-III, who were scheduled for unilateral simple mastectomy operation due to breast cancer. Patients were randomly assigned to Group 1 (Patients undergoing PVB) or Group 2 (Patients undergoing MTP block) for a ratio of 1:1, including 32 patients each, using a computer-generated table of random numbers and concealed sealed opaque envelopes. Patients were placed in the prone position. The linear ultrasound probe was fixed to the T3-T4 vertebra level. The skin and subcutaneous tissue were anaesthetized with 2% lidocaine, then 22 gauge 100 mm needle was led in a cranial-cephalic direction to the paravertebral gap. Trapezius, rhomboid, erector spinae muscles were crossed by seeing the tip of the needle. Transverse processes were reached and the intercostal muscles were passed. When the needle reached the paravertebral level in Group 1, and the midpoint level between the transverse process and pleura in Group 2, it was observed that there was no blood or air by aspiration. Then, the needle location was confirmed with 0.5-1 mL of saline, and a 20 mL of 0.25% bupivacaine was applied. Thirty minutes after block application, the sensorial block level was evaluated by pinprick test at the midclavicular line, and the blocked dermatome area was recorded as front and back. Complications developed during the process (such as hypotension, vascular injury, local anaesthetic toxicity) were recorded.Routine general anesthesia protocol was performed to all patients.At the end of the surgery, neuromuscular block antagonization was performed with 4 mg/kg sugammadex. All of the patients were extubated and taken to the postanesthetic care unit (PACU). In the PACU, a patient-controlled analgesia device (PCA)