Geometry of laparoscopic suturing and knotting techniques

Area of Science:

• Minimally Invasive Surgery
• Surgical Technology
• Surgical Simulation

Background:

• Spatial limitations and fixed trocar positions in laparoscopy restrict instrument maneuverability.
• Geometric factors like trocar distance, instrument length, and angles critically impact endoscopic reconstruction.
• This study experimentally investigates these geometric factors in reconstructive laparoscopy.

Purpose of the Study:

• To determine the impact of specific geometric factors on the efficiency of intracorporeal suturing during reconstructive laparoscopy.
• To identify optimal instrument and trocar configurations for improved laparoscopic surgical performance.
• To provide data-driven recommendations for planning laparoscopic procedures.

Main Methods:

• An in vitro model using porcine intestine for end-to-end anastomoses was developed.
• Standardized intracorporeal suturing was performed with variations in trocar distance (6-12 cm), object/camera position, instrument angles (15-90 degrees), instrument length (10-25 cm), and working space (4-25 cm).
• Suturing efficiency was assessed before and after training in reconstructive surgery.

Main Results:

• Training decreased overall suturing time by 30-50% and non-suturing tasks by 50-70%.
• Optimal angles (<55 degrees with horizontal, <45 degrees between instruments) and lateral camera positioning simplified suturing in confined spaces.
• Shorter suture filaments (<10 cm) reduced time by 30% in maximally narrowed spaces (4 cm diameter).

Conclusions:

• An isosceles triangle configuration with instrument angles between 25-45 degrees and <55 degrees relative to the horizontal is suggested for optimal intracorporeal suturing.
• These geometric parameters should guide trocar alignment and table positioning in reconstructive laparoscopic surgery.
• Further studies are needed to validate these preliminary findings in clinical settings.