Laparoscopic living donor nephrectomy (LLDN) is a safe procedure and rapid wound healing, affecting the quality of life. The physiology of postoperative pain after LLDN has been attributed to reasons such as tissue damage, residual pneumoperitoneum, and diaphragm irritation. In terms of patient comfort after LLDN, pain control is provided by IV analgesics, local anesthetic injection instead of incision, and regional techniques. Regional anesthesia techniques for postoperative pain control have become popular in recent years. Today, many blocks are performed with ultrasonography (USG) to reduce the severity of pain after laparoscopic and open surgeries. In 2016, Forero et al. erector spinae plane block (ESPB) had been defined and used successfully in thoracic and abdominal surgeries. In our clinic, peripheral nerve blocks such as intravenous patient-controlled analgesia (PCA) and ESPB are applied for postoperative analgesia. The method of analgesia is suitable for the surgery and explained to the patients. This study; In LLDN operations, it was aimed to compare the bilateral ESP block performed with USG in terms of postoperative pain scores and opioid analgesic consumption compared to patients without any block. Before the operation, the anesthesiologist in charge of the anesthesia outpatient clinic provides information about both anesthesia and postoperative pain management methods suitable for surgery. This is the standard practice in our clinic. Before anesthesia, anesthesia and analgesia methods will be briefly reminded to the patient who has come for the operation. He/she will be asked if he/she wants to apply postoperative analgesia. Block procedure will be applied to patients who want ESP block. Standard analgesia will be applied to all patients. Regardless of the study, patients who underwent LLDN operation will be interviewed in the postoperative period with or without an ESP block for postoperative analgesia. The data and postoperative evaluations of the patients who agreed to participate in the study will be recorded for study purposes. The patient data will be taken from the hospital registration system.

Inclusion Criteria:

• All patients aged 18-75 who were operated on under general anesthesia for LLDN surgery and agreed to participate in the study will be included.

Exclusion Criteria:

• Participants who did not accept the study, had intraoperative complications, and whose laparoscopic operation was canceled will not be included in the study.