A New Needle Holder Design to Facilitate Intracorporeal Knot Tying

Understanding the ant's unique biting system can improve surgical needle holders

Mechanical grasping and holding devices depend upon a firm and controlled grip. The possibility to improve this gripping performance is severely limited by the need for miniaturization in many applications, such as robotics, microassembly, or surgery. In this paper, we show how this gripping can be improved in one application (the endoscopic needle holder) by understanding and imitating the design principles that evolution has selected to make the mandibles of an ant a powerful natural gripping device. State-of-the-art kinematic, morphological, and engineering approaches show that the ant, in contrast to other insects, has considerable movement within the articulation and the jaw´s rotational axis. We derived three major evolutionary design principles from the ant's biting apparatus: 1) a mobile joint axis, 2) a tilted orientation of the mandibular axis, and 3) force transmission of the adductor muscle to the tip of the mandible. Application of these three principles to a commercially available endoscopic needle holder resulted in calculated force amplification up to 296% and an experimentally measured one up to 433%. This reduced the amount of translations and rotations of the needle, compared to the needle's original design, while retaining its size or outer shape. This study serves as just one example showing how bioengineers might find elegant solutions to their design problems by closely observing the natural world.

Can a Fully Articulating Electromechanical Laparoscopic Needle Driver Compare with a Robotic Platform in Transabdominal Preperitoneal Inguinal Hernia Repair?

Background: Enhanced laparoscopic instruments are filling the gap between straight-stick laparoscopic equipment and robotic platforms. We sought to evaluate the performance and cost of the HandX™ device during mesh fixation and peritoneal flap closure of transabdominal preperitoneal (TAPP) inguinal hernia repairs. Methods: The video recordings of a consecutive series of TAPP surgeries using the articulated needle driver device were compared with a series of surgeries on the DaVinci robotic platform by a single surgeon. Two critical steps of the procedure were analyzed: mesh fixation and peritoneal closure. A cost analysis between the two platforms was completed. Results: We analyzed 27 cases using the new needle driver and 27 cases using the DaVinci Surgical Robotic system. To evaluate the learning curve (LC) with the HandX device, we created three groups (G1, G2, and G3). The two latter groups were combined and called after LC. Mean fixation time using the DaVinci system was 258.1 seconds (±100.4) compared with 391.5 (±95.9) using the articulating handheld laparoscopic needle driver after LC (P < .001). The average time for peritoneal closure was 418.6 (±192.1) seconds for DaVinci and 634.5 (±159.5) seconds for HandX (P < .001). When comparing the after-LC HandX cases and the DaVinci system stratified by side, there was no significant difference in peritoneal closure in the right side (520.1 seconds (84.3) with the HandX versus 444.2 seconds (229.7) using the DaVinci system (P = .353). When evaluating direct cost of the instruments, HandX cases had a lower cost (310 USD) when compared with the cost of using DaVinci (973 USD). Conclusions: The new smart articulating needle driver may be a cost-effective means of bringing some of the benefits of the robotic platform to laparoscopy.

Handheld robotic needle holder training: slower but better

BACKGROUND

Handheld robotic laparoscopic instruments fill the gap between robotic and conventional instruments, combining the advantages of degrees of freedom and low price. The difficulty and value in learning these new instruments require detailed investigation.

METHODS

Forty novice surgeons with no laparoscopic experience were randomly assigned to two groups: conventional instrument group (Group Conv) and robotic instrument group (Group Rob). The same training protocol was used in both groups: after viewing a standard operation film, laparoscopic suture training was administered using the corresponding instruments. After each training period, surgeons were tested using a force-sensing test platform. Maximum force (MF) and impulse (IMP) of operators through each ring were recorded. Learning curves based on MF and IMP for both instruments were compared. Institutional review board approval is not needed for this study.

RESULTS

MF and IMP of both groups decreased with increased training time; the learning curve of Group Conv decreased faster than that of Group Rob. When training time reached 13 h, the MF of Group Rob was significantly lower than that of Group Conv (P < 0.05), while IMP showed no significant difference between the two groups.

CONCLUSIONS

Effective training reduces operator MF and IMP, possibly decreasing damage to tissues with both conventional and handheld robotic needle holders. Group Rob took longer to reach a plateau, but subsequently had lower suture tension than did Group Conv. MF is more sensitive than IMP for measuring performance progress.

Validation of a Novel Needle Holder to Train Advanced Laparoscopy Skills to Novices in a Simulator Environment

Background. Our aim was to determine if a newly designed Najar needle holder (NNH) shortens the time for novices to improve advanced laparoscopy (AL) techniques (suturing/knot tying), compared with a conventional macro needle holder (MNH) in a simulator. Furthermore, we aimed to validate a new video scoring system determining AL skills. Methods. Forty-six medical students performed identical surgical tasks in a prospective, crossover study evaluating AL skills (NNH vs MNH). All subjects performed a double-throw knot, 2 single-throw knots following 3 running sutures in the Simball Box (SB) simulator. After resting, subjects switched needle holders. All tasks were videotaped and analyzed using SB software and by 2 independent reviewers using the Objective Video Evaluation Scoring Table (OVEST). Trial performance expressed as SB Overall Score (SBOS) and OVEST. Results. In the group starting with NNH (followed by MNH) OVEST was consistently high during both trials (median = 12.5, range = 6.5-18.0, and median = 13.5, range = 6.5-21.0; P = .2360). However, in the group starting with MNH, OVEST improved significantly when the participants changed to NNH (median = 10.0, range = 2.5-19.5, vs median = 14.5, range = 4.5-18.0; P = .0003); an improvement was also found with SBOS (median = 37%, range = 27% to 92%, vs median = 48%, range = 34% to 70%; P = .0289). In both trials, both independent reviewers' OVEST measures correlated well: Trial 1: β = 0.97, P < .0001; and Trial 2: β = 0.95, P < .0001. A correlation also existed between SBOS and OVEST in both trials (β = 2.1, P < .0001; and β = 1.9, P = .0002). Conclusions. This study indicates a significantly higher improvement in laparoscopic suturing skills in novices training AL skills using NNH compared with MNH. Starting early, AL training in novices using NNH is a feasible option. Furthermore, OVEST used in experimental settings as an evaluation tool is comparable with the validated SBOS.