Clinical Report: Robot-Assisted Laparoscopic Sigmoid Resection Using ANSUR System

Overview

This report details the first clinical case of robot-assisted laparoscopic sigmoid resection for colon cancer using the ANSUR surgical system. The procedure demonstrated the system's capability to replace the first assistant and scopist, potentially enhancing surgical efficiency and surgeon autonomy.

Background

Laparoscopic surgery offers benefits such as reduced trauma, blood loss, and recovery time compared to open surgery. Since its introduction in 1991, laparoscopic colonic resection has been validated by randomized controlled trials as non-inferior to open surgery for colon cancer outcomes. However, limited human resources in some regions restrict minimally invasive surgery availability, highlighting the need for technological innovations like surgical robots. The ANSUR surgical unit, approved in Japan in 2023, is a novel robotic system designed to assist surgeons by replacing human assistants during endoscopic surgeries.

Data Highlights

The ANSUR system weighs 350 kg and measures 110 cm (width) × 126 cm (depth) × 168 cm (height). It features a camera arm and two tool arms with 5-mm diameter tool units capable of ±360° rotation and bending joints ranging from −4° to 75°. The system uses surgical instrument sensors and trocar sensors to transmit instrument position and movement, controlled by the operating surgeon via sensors and foot switches without a dedicated surgeon console. The reported patient was a 69-year-old woman with BMI 24.0 kg/m2 and stage IIIB sigmoid colon adenocarcinoma (T3N1bM0).

Key Findings

• The ANSUR system successfully replaced the first assistant and scopist roles during laparoscopic sigmoid resection.
• No additional trocars beyond those used in conventional laparoscopic surgery were required.
• The system allowed precise manipulation of surgical instruments and laparoscope, enabling effective mesenteric dissection and vessel ligation.
• The procedure was performed by an experienced laparoscopic surgeon trained in robotic surgery, ensuring safe operation of the system.
• The surgical unit's mobility and compact size facilitated positioning parallel to the operating table and efficient docking.
• The specimen was extracted through the umbilical wound without complications.

Clinical Implications

The ANSUR surgical system may enhance surgical efficiency by reducing dependence on human assistants, which is particularly valuable in settings with limited surgical staff. Its design allows surgeons to control both the laparoscope and instruments directly, potentially improving ergonomics and precision. Adoption of such robotic systems could expand access to minimally invasive surgery globally.

Conclusion

The first clinical use of the ANSUR system for robot-assisted laparoscopic sigmoid resection demonstrated its feasibility and potential to improve surgical workflow by substituting human assistance. Further studies are warranted to evaluate its broader clinical benefits and outcomes.

References

1. Jacobs et al. 1991 -- First report of laparoscopic colonic resection
2. Multicenter RCTs 2000s -- Laparoscopic vs open surgery for colon cancer
3. ASAHI SURGICAL ROBOTICS Co., Ltd. 2023 -- ANSUR surgical system approval and description