Segmental liver resection assisted by HIFU: tissue precauterization using a toroidal‐shaped HIFU transducer Available to Purchase

The development of new cauterization techniques for hepatic resection is critical for improving the safety of the procedure. Previous studies showed the feasibility of using HIFU or radiofrequency precoagulation to limit blood loss during dissection of the organ. Here we report a new therapeutic modality using high intensity focused ultrasound (HIFU) to perform a bloodless hepatic resection that could represent a promising alternative. A comparative study was performed to evaluate the interest of using this complementary tool to improve surgical resection in the liver. This study used a 3 MHz HIFU toroidal‐shaped phased array transducer which allows the generation of a single conical lesion of $7 cm3$ in 40 seconds. In order to minimize blood loss and dissection time, a barrier of coagulative necrosis was generated with the HIFU device before hepatectomy, by juxtaposing single conical lesions on the line of dissection. Resection assisted by HIFU (RA‐HIFU) was compared with classical dissections with clamping (RC) and without clamping (Control). For each technique 14 partial liver resections were performed in seven pigs. The parameters examined were vascular control and times of treatment. Precoagulation allowed the vascular isolation of small vessels and surgical clips were mainly used for the control of vessels>5 mm in diameter. The number of clips used per unit of liver surface dissected in RA‐HIFU $(0.8±0.3 cm−2)$ was significantly lower than in the other groups (RC: $1.6±0.4 cm−2,$ Control: $1.8±0.8 cm−2,$ p<0.01). In addition, blood loss was lower in RA‐HIFU $(7.4±6.5 ml.cm−2)$ than in RC $(11.2±4.5 ml.cm−2)$ and Control $(14.0±6.7 ml.cm−2).$ The time of dissection in RA‐HIFU $(13±5 min)$ was shorter than in RC $(23±8 minutes)$ and Control $(18±5 minutes).$ The feasibility and the efficiency of RA‐HIFU using a toroidal‐shaped HIFU transducer without additional devices were demonstrated. This technique enhances the resection procedure and will be able to be tested in clinic.