K.T. Den Boer

Sensitivity of laparoscopic dissectors. What can you feel

AbstractBackground: Sensory feedback is reduced considerably in minimally invasive procedures by the interposition of instruments, causing loss of direct manual contact with the tissue. The purpose of this study was to evaluate the feedback quality of commercially available reusable and disposable laparoscopic dissectors. Methods: A total of 31 participants were asked to feel a simulated arterial pulse with their bare fingers and through laparoscopic dissectors, tweezers, an orthopedic forceps, and a laparoscopic low-friction prototype. The absolute sensory threshold was determined by the psychophysical method of limits. Results: The sensory feedback quality was significantly better for the reusable dissectors tested than for the disposable dissector (p < 0.001). Nevertheless, the reusable dissectors were at least eight times less sensitive than bare fingers. Furthermore, sensitivity qualities were highly variable, depending on the dissector tested. Conclusions: This study showed that the overall sensitivity loss through instruments could be accurately assessed, proving that the sensory feedback for commercially available instruments was low compared to bare fingers. The good sensory feedback results of the prototype indicated that careful design could decrease the overall sensitivity loss.

Problems with laparoscopic instruments: opinions of experts.

INTRODUCTION Laparoscopic surgery is particularly known for its complex technique, which calls for operative analysis of laparoscopic instruments. This study investigates the opinion of experts about clinical problems with instruments occurring during laparoscopic surgery. METHODS A questionnaire was used to obtain the opinions of expert laparoscopic surgeons about difficulties experienced operatively using laparoscopic instruments. RESULTS The laparoscopic surgeons indicated that coagulators were especially prone to cause complications of the gastro-intestinal tract, vascular injuries, and bile duct injuries. Dissectors were considered to play a role in the occurrence of solid organ and bile duct injuries, and retractors to cause solid organ injuries. Insufficient functionality of the instruments and insufficient quality of the image were indicated to contribute to the instruments risks. CONCLUSION The questionnaire identified technological deficiencies prone to cause operative complications. The results provide a basis for the interaction between surgeons and engineers, and serve as pilot information on which to base an in-depth object evaluation of instrument problems.

Peroperative analysis of the surgical procedure

The increased technological complexity of surgery and the growing importance of quality assessment demand objective analysis of the surgical process. However, until now no standard method existed for analyzing the peroperative process. In this article, a methodology is discussed to describe and to analyze the surgical process. A method is given to measure the correctness and efficiency of task performance, protocols, and instruments used. In addition, reference values are defined so as to compare new instruments, alternative protocols, and the performance of new tasks with a standard. Finally, recommendations are given for improving new surgical tasks, the development of clinically driven instrument design, and new protocols.

Analysis of the quality and efficiency in learning laparoscopic skills

ObjectivesThis study demonstrates the application of time-action analysis to the evaluation of task performance of diagnostic laparoscopy with laparoscopic ultrasonography.MethodsThe first 25 diagnostic laparoscopies with laparoscopic ultrasonography performed by a surgical resident were analyzed and compared with the outcomes of these procedures performed by an experienced surgeon. The time, actions, and correctness of task performance were evaluated. Furthermore, outcome correctness and postoperative complications were assessed.ResultsNo postoperative complications occurred. The resident made one wrong diagnosis, for which the cause was detected by peroperative analysis. Additionally, 1% of the subtasks were performed only partially, 4% not at all, and 2% using the wrong technique. The efficiency for most diagnostic tasks remained significantly lower than that of the experienced surgeon (p<0.001).ConclusionsTime-action analysis can be used to provide detailed insight into the quality and efficiency of learning surgical skills. It enables objective measurement of correctness in task performance as well as time and action efficiency.

Establishment of Pneumoperitoneum with a Modified Blunt Trocar

Veress needle and trocar-related accidents have caused many surgeons to adopt the Hasson technique for establishment of pneumoperitoneum, but this technique also has drawbacks. A modification of the sharp trocar has been developed that overcomes the disadvantages of the Veress needle and Hasson trocar.

Design and Evaluation of Laparoscopic Forceps with Accurate Force Feedback

Abstract This paper presents newly designed laparoscopic forceps and describes the evaluation of the man-machine interface performance. Careful mechanical design has led to a purely mechanical instrument with excellent intrinsic feedback capacity, thus omitting the need for an electronic feedback system. This concept has relevance for the design of all manually operated instruments and tools.