Living liver donor hepatectomy at our institution routinely includes ultrasound-guided interfascial plane blocks as part of postoperative analgesia. Although these blocks have become increasingly used in donor hepatectomy, their cutaneous sensory distributions and block-related dermatomal coverage have not been systematically evaluated, with only anecdotal reports available in the literature.

This prospective observational study aims to assess both the sensory blockade patterns and the early postoperative analgesic performance of interfascial plane blocks administered to living liver donors. Following surgery, all consenting donors receive the institution's standard block protocol. Cutaneous sensory mapping is performed in the post-anesthesia care unit (PACU) at the second postoperative hour. Pain intensity and analgesic requirements within the first 24 hours are also recorded.

The study is designed to provide objective data on the dermatomal coverage and postoperative analgesic effects of contemporary ultrasound-guided interfascial plane blocks used in living liver donor surgery.

Inclusion Criteria:

• Adult living liver donors undergoing elective donor hepatectomy
• Age 18 to 65 years
• ASA physical status I-II
• Patients who have received ultrasound-guided interfascial plane blocks as part of their postoperative analgesia
• Ability to cooperate with postoperative sensory mapping procedures
• Patients who agree to participate and provide written informed consent

Exclusion Criteria:

• Patients who refuse to participate or do not provide written informed consent
• Patients who have not received any ultrasound-guided interfascial plane block
• ASA physical status > II
• Presence of surgical incisions or wound complications preventing reliable sensory mapping
• Prior major abdominal surgery that may alter cutaneous innervation patterns
• Cognitive impairment limiting the ability to cooperate with sensory testing
• Known psychiatric disorders (e.g., major depression, mania, schizophrenia) that may interfere with postoperative assessment
• Local infection, skin disease, or dermatologic condition preventing accurate cutaneous mapping
• Allergy or contraindication to local anesthetics used in the block

The study population consists of adult living liver donors undergoing elective donor hepatectomy at a tertiary care center. All participants receive ultrasound-guided interfascial plane blocks as part of the institution's routine postoperative analgesia protocol. Eligible donors are aged 18 to 65 years, classified as ASA physical status I-II, and able to cooperate with postoperative cutaneous sensory mapping procedures. Individuals with contraindications to regional anesthesia, conditions preventing accurate sensory assessment, or those who decline participation are excluded.