The Clip-Pulley Maneuver: Atraumatic and Adjustable Retraction in Robotic Liver Resection

Precise liver retraction is essential in robotic hepatectomy. Conventional retraction methods using barbed sutures^1,2 or hook-needle systems³ are penetrative and traumatic, risking diaphragmatic injury or tension pneumothorax. We developed a nonpenetrating Clip-Pulley Maneuver (CPM) to achieve safe and adjustable retraction.

From February to November 2025, 26 robotic hepatectomies were performed using CPM. A 3-0 polydioxanone monofilament (PDS; Ethicon, Inc., Bridgewater, NJ, USA) was placed on the liver surface at the resection margin. After suture placement, a triangular clip from the Internal Organ Retractor system (Aesculap, Inc., Center Valley, PA, USA) was introduced and the suture passed through its loop. The clip was then positioned on the diaphragm using a dedicated applicator. The suture was exteriorized through the abdominal wall using an Endo Close device (MC Medical Inc., Tokyo, Japan), forming a pulley-like system. The surgeon adjusted the traction force externally, and the assistant could reposition the clips to modify retraction direction. The direction of traction is determined by the spatial relationship between the suture placement on the liver surface and the clip position, rather than by the direction of external pulling. This setup allowed real-time, atraumatic retraction without additional punctures to the diaphragm or peritoneum. In most cases, two clips were sufficient; additional clips may be used for larger anatomical resections.

There were no CPM-related complications or Clavien-Dindo grade III or higher events. The diaphragm remained intact in all cases.

CPM offers a safe, effective, and reusable liver retraction method for robotic hepatectomy.