Real time ultrasound guided insertion of Veress needle in obese patients

Computer-aided Veress needle guidance using endoscopic optical coherence tomography and convolutional neural networks

During laparoscopic surgery, the Veress needle is commonly used in pneumoperitoneum establishment. Precise placement of the Veress needle is still a challenge for the surgeon. In this study, a computer-aided endoscopic optical coherence tomography (OCT) system was developed to effectively and safely guide Veress needle insertion. This endoscopic system was tested by imaging subcutaneous fat, muscle, abdominal space, and the small intestine from swine samples to simulate the surgical process, including the situation with small intestine injury. Each tissue layer was visualized in OCT images with unique features and subsequently used to develop a system for automatic localization of the Veress needle tip by identifying tissue layers (or spaces) and estimating the needle-to-tissue distance. We used convolutional neural networks (CNNs) in automatic tissue classification and distance estimation. The average testing accuracy in tissue classification was 98.53 ± 0.39%, and the average testing relative error in distance estimation reached 4.42 ± 0.56% (36.09 ± 4.92 μm).

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.