The occlusion mechanism of hepatic vessels covered by connective tissue

Laparoscopic liver surgery is the primary choice for the treatment of various liver diseases, because of its significant advantages, including less trauma and fast recovery. Currently, the Pringle manoeuvre remains the major clinical method employed for controlling bleeding during liver surgery. However, despite its widespread application, the Pringle method is limited by its inability to achieve accurate and quantitative haemostasis. Moreover, surgical tools might cause damage to liver tissues. Therefore, investigation of the deformation behaviour and occlusion mechanism of the hepatic vessels, as well as the influence of covering connective tissues, is required. In this research, a type of artificial liver blood vessel made of silicone rubber was designed. This vessel was wrapped by artificial connective tissues made of rubbery sponges. The occlusion mechanism of the artificial liver vessel was characterized using an in situ observation platform, and the results were validated via finite element simulation. The quantitative relationship between the force exerted on the artificial liver vessel and the blocking ratio was obtained and then used as the basis for the design of a quantitative occlusion indicator device and the corresponding surgical procedure for controlling bleeding from hepatic vessels. Finally, the effectiveness of the new haemostasis method was verified by liver resection surgeries in live pigs. This study provides a scientific theoretical basis and technical support for the effective control of bleeding in laparoscopic liver surgery.