The Hit and Away technique: optimal usage of the ultrasonic scalpel in laparoscopic gastrectomy

Background Thermal injury and unexpected bleeding caused by ultrasonic scalpels can lead to fatal complications in laparoscopic gastrectomy (LG), such as postoperative pancreatic fistulas (POPF). In this study, we developed the Hit and Away protocol for optimal usage of the ultrasonic scalpel, which in essence involves dividing tissues and vessels in batches using the tip of the scalpel to control tissue temperature. Methods To assess the effectiveness of the technique, the surface temperature of the mesocolon of female swine after ultrasonic scalpel activations was measured, and tissue samples were collected to evaluate microscopic thermal injury to the pancreas. In parallel, we retrospectively surveyed 216 patients who had undergone LG before or after the introduction of this technique and assessed the ability of this technique to reduce POPF. Results The tissue temperature of the swine mesocolon reached 43 degrees C, a temperature at which adipose tissue melted but fibrous tissue, including vessels, remained intact. The temperature returned to baseline within 3 s of turning off the ultrasonic scalpel, demonstrating the advantage of using ultrasonic scalpel in a pulsatile manner. Tissue samples from the pancreas demonstrated that the extent of thermal injury post-procedure was limited to the capsule of the pancreas. Moreover, with respect to the clinical outcomes before and after the introduction of this technique, POPF incidence decreased significantly from 7.8 to 1.0 % (p = 0.021). Conclusion The Hit and Away technique can reduce blood loss and thermal injury to the pancreas and help to ensure the safety of lymph node dissection in LG.