Development and Dry-Lab Evaluation of a Novel Clothoid Curve Needle for Laparoscopic Suturing

Intracorporeal suturing in minimally invasive surgery remains technically demanding due to limited maneuverability and confined working space. Conventional suturing needles with fixed curvature can cause excessive tissue stress and irregular suture lines. We developed a novel surgical needle incorporating a clothoid (Euler spiral) curve, designed to provide smoother penetration and improved tip control.

A prospective, single-center, crossover study was conducted using a laparoscopic dry-lab simulator to compare a clothoid curve needle with a conventional curved needle. Sixteen surgeons (6 experts, 10 nonexperts) performed standardized laparoscopic suturing tasks with both needles. Objective evaluation of tissue displacement was recorded by internal sensors, capturing maximum deviation in three axes: X (left-right), Y (anterior-posterior), and Z (vertical). Subjective usability was assessed using an 8-item Likert scale.

Objective analysis revealed that experts showed reduced displacement with the clothoid needle in the Z direction (p = 0.031), while nonexperts showed less deviation in the Y direction (p = 0.019). In the overall cohort, Y-axis deviation was also significantly lower with the clothoid needle (p = 0.038). The clothoid needle showed significantly higher Likert scores in thread pulling (p < 0.001), smoothness of needle driving (p = 0.031), tip control (p = 0.008), tissue penetration resistance (p = 0.045), and overall satisfaction (p < 0.001).

The clothoid needle may offer potential advantages in selected aspects of laparoscopic suturing performance, although the effects differed according to operator experience and displacement axis.