A novel Veress needle mechanism that reduces overshooting after puncturing the abdominal wall

The relevance of reducing Veress needle overshooting

Safe insertion of the Veress needle during laparoscopy relies on the surgeons' technical skills in order to stop needle insertion just in time to prevent overshooting in the underlying organs. To reduce this risk, a wide variety of Veress needle systems were developed with safety mechanisms that limit the insertion speed, insertion depth or decouple the driving force generated by the surgeon's hand on the needle. The aim of this study is to evaluate current surgeons' perceptions related to the use of Veress needles and to investigate the relevance of preventing overshooting of Veress needles among members of the European Association of Endoscopic Surgery (EAES). An online survey was distributed by the EAES Executive Office to all active members. The survey consisted of demographic data and 14 questions regarding the use of the Veress needle, the training conducted prior to usage, and the need for any improvement. A total of 365 members residing in 58 different countries responded the survey. Of the responding surgeons, 36% prefer the open method for patients with normal body mass index (BMI), and 22% for patients with high BMI. Of the surgeons using Veress needle, 68% indicated that the reduction of overshoot is beneficial in normal BMI patients, whereas 78% indicated that this is beneficial in high BMI patients. On average, the members using the Veress needle had used it for 1448 (SD 3031) times and felt comfortable on using it after 22,9 (SD 78,9) times. The average years of experience was 17,6 (SD 11,1) and the surgeons think that a maximum overshoot of 9.4 (SD 5.5) mm is acceptable before they can safely use the Veress needle. This survey indicates that despite the risks, Veress needles are still being used by the majority of the laparoscopic surgeons who responded. In addition, the surgeons responded that they were interested in using a Veress needle with an extra safety mechanism if it limits the risk of overshooting into the underlying structures.

The MISLI-Drive, a modular sterilizable robotic driver for steerable laparoscopic instruments

Introduction: Based on the success of the former "Shaft-Actuated, Tip-Articulated" SATA-Drive, a prototype robotic instrument driver for modular, steerable, laparoscopic instruments, a new driver is designed and tested to improve previously lacking features concerning cleanability, instrument adaptation, practical application and control. The design of the driver engages these issues with a modular design aimed at re-use of both the instrument and the driver, for which a set of design requirements are established. Methods: A new modular design has been developed to improve cleanability through separation of the electro-motors and the instrument mechanism which clutches the instrument. Contamination of the driver's robotic side is prevented though a combination of a drape and a Sterile barrier interface, while the instrument side is made sterilizable. A novel instrument clutching mechanism enables quick-release features, while a motor-axis latching mechanism enables plug-and-play assembly. Embedded sensors allow precise and fast control. A user-experiment was conducted on instrument exchange and assembly time, while mechanical and electrical tests were conducted on the driver's responsiveness. Results: The driver has proven its ability to control the instrument, after which it can be disassembled for cleaning and inspection. The driver is designed for re-use through disassembled sterilization where all possibly contaminated surfaces are exposable for cleaning and inspection. The new standardized instrument clutches allow easy instrument (dis-)assembly. Instrument exchange is possible in two methods, the fastest of which is a median of 11 (6.3-14.6) seconds. The driver's instrument mechanism is separated in a median of 3.7 (1.8-8.1) seconds. After assembly, the driver is operational in less than 2 s. Discussion: Instrument exchange times are similar to the semi-reusable Da Vinci systems, yet the MISLI-Drive is designed for sterilization, inspection and continual re-use. The modular build of the driver also allows easier parts replacement during maintenance, and requires minimal adaptation to different future scenarios, which is expected to reduce the overall cost of use.

A negative pressure-based visualization technique for abdominal Veress needle insertion

PURPOSE

Abdominal Veress needle insertion is commonly performed to generate a pneumoperitoneum during laparoscopy. Various safety tests are conducted to confirm accurate needle tip positioning into the abdominal cavity. However, these occasionally yield unclear results and do not help directly visualize the peritoneum puncture. We validated a negative pressure-based technique that helps instantly visualize the moment of the Veress needle entry into the abdominal cavity.

METHODS

This study included 761 patients who underwent laparoscopic hernioplasty between 2003 and 2021 that entailed pneumoperitoneum creation using a Veress needle. They were divided into conventional technique (CON) and negative pressure visualization technique (NPV) groups. The patients were propensity score-matched (1:1) to minimize selection bias. To determine whether the technique gave a clear result to the surgeon and precisely informed the moment of entry, failed entry and emphysematous complications were compared between the groups.

RESULTS

The propensity score-matching yielded 105 pairs in the matched CON and NPV groups. Failed entry did not occur in the NPV group, whereas it occurred in 8 patients (7.6%) in the CON group (p = 0.004). No patient experienced extraperitoneal emphysema in the matched NPV group, whereas 7 patients (6.7%) in the CON group did (p = 0.007). The groups did not differ in the incidence of omental or mesenteric emphysema.

CONCLUSION

The NPV eliminated the incidence of failed entry and decreased the incidence of extraperitoneal emphysema, indicating that it could simply and adequately inform the moment of needle entry into the abdominal cavity.

Needle-Probe Optical Coherence Tomography for Real-Time Visualization of Veress Peritoneal Needle Placement in a Porcine Model: A New Safety Concept for Pneumoperitoneum Establishment in Laparoscopic Surgery

The safe establishment of pneumoperitoneum is a critical step in all laparoscopic surgeries. A closed pneumoperitoneum is usually obtained by inserting a Veress needle into the peritoneal cavity. However, there is no definite measure to visually confirm the position of the Veress needle tip inside the peritoneal cavity. This study aimed to describe a method of real-time visual detection of peritoneal placement of the Veress needle using an incorporated optical coherence tomography (OCT) probe in a porcine model. A 14-gauge Veress needle was incorporated with a miniature fiber probe to puncture the piglet’s abdominal wall into the peritoneal cavity. A total of 80 peritoneal punctures were attempted in four piglets. For each puncture, continuous two-dimensional OCT images of the abdominal wall were acquired for real-time visual detection of the needle placement into the peritoneal cavity. Characteristic OCT image patterns could be observed during the puncturing process, especially a deep V-shaped concave pattern before the peritoneum puncture, which was a crucial feature. A statistical difference in the OCT signal standard deviation value also indicated the differentiability of images between the peritoneum and extra-peritoneal tissue layers. A success rate of 97.5% could be achieved with the guidance of the OCT images. OCT images translate the blind closed technique of peritoneal access into a visualized procedure, thus improving peritoneal access safety.