Evaluating the technical experience of transmuscular quadratus lumborum block in prone position: a retrospective observational study.

Background: Traditionally quadratus lumborum block has been performed in lateral or supine positions. We propose that transmuscular or anterior quadratus lumborum block performed in a prone position may offer comparable or improved technical conditions, image quality and also aid in resident training. This study aimed to assess the technical ease of performing Tm-QLB in the prone position.

Methods: This retrospective study included female patients undergoing elective gynecologic oncology surgery via midline incision, who received bilateral preoperative prone-position transmuscular quadratus lumborum block. Block performance was evaluated using a composite score derived from normalized ultrasound image quality, time taken, number of attempts, and redirections. Blocks were categorized into five difficulty levels based on the composite score.

Results: Ninety blocks were analyzed. Mean age was 40.18 ± 12.05 years; BMI was 23.90 ± 1.86 kg/m². The median composite score was 0.81 (IQR: 0.17). Over 50% of blocks were rated "Very Easy" or "Easy," reflecting high image quality, low redirection rates, and brief procedure times.

Conclusion: Prone-position Tm-QLB is technically easy and operator-friendly, making it a viable alternative for training and clinical practice in suitable patients.