Optical trocar access for initial trocar placement in laparoscopic gastrointestinal surgery: A propensity score-matching analysis

Learning curve of optical trocar access during laparoscopic pelvic surgery: A prospective study

INTRODUCTION

The optical trocar access (OTA) is a modified closed technique that aims to minimize the risk of vascular or bowel injuries while reducing the likelihood of gas leakage. A learning curve (LC) effect for OTA has been invoked with n = 30 procedures being considered as a threshold to define expertise. We aim to evaluate the impact of the LC within the first thirty cases of OTA performed by a trainee.

METHODS

This is a prospective randomized study on 60 patients elected to laparoscopic gynecological surgery. Patients were randomized to have OTA insertion by a junior surgeon or by an expert. LC was evaluated by: 1) insertion time; number of: 2) corrections by the senior; 3) times the tip of the trocar stopped in the preperitoneal layer; 4) mistakes of skin incision; 5) times the tip of the trocar ends under the omentum; 6) complications. To analyze the LC within the first 30 cases, procedures were stratified in 3 groups (cases 1-10; 11-20; 21-30) for both trainee and expert and LC variables were compared.

RESULTS

Overall, mean OTA insertion time was 56 s. No major intra- and post-operative complications were recorded. Mean insertion time was statistically significantly longer for the trainee compared to the expert within the first 10 cases (91 vs 33 s respectively, P = .01). For cases 11-20 and 21-30, time advantage of the senior surgeon is less evident (P = .05). The number of times the tip of the trocar stopped in the preperitoneal layer was similar between groups, as well as times the tip of the trocar ends under the omentum.

CONCLUSIONS

OTA is a fast and simple way to achieve the pneumoperitoneum and first trocar insertion as a single step. The current series confirms the effectiveness of the technique since the beginning of the LC.

Intraoperative visualization of morphological patterns of the thoracic duct by subcutaneous inguinal injection of indocyanine green in esophagectomy for esophageal cancer

To prevent chylothorax after esophageal cancer surgery, it is important to recognize morphological patterns of the thoracic duct intraoperatively. The present study aimed to evaluate the safety and usefulness of near-infrared (NIR) fluorescence imaging with subcutaneous inguinal injection of indocyanine green (SII-ICG) to detect the thoracic duct during thoracoscopic esophagectomy for esophageal cancer. Patients (n = 16) who underwent thoracoscopic esophagectomy in the prone position with SII-ICG at Shinshu University Hospital between June 2020 and January 2022 were enrolled in the present study and retrospectively reviewed. Immediately prior to thoracoscopic esophagectomy, we injected 0.2-0.5 mg/kg ICG into the subcutaneous tissue in the bilateral inguinal region. The identification rate of the thoracic duct was 93.8% (n = 15), and the success rate of fluorescence using SII-ICG was 87.5% (n = 14). The visible thoracic ducts had four patterns: a typical pattern in 50% (n = 8), duplication pattern in 18.8% (n = 3), branching pattern in 12.5% (n = 2), and plexiform pattern in 12.5% (n = 2). In all cases, ICG fluorescence did not disappear and was visible during the thoracic surgery. No SII-ICG-related complications were observed. Intraoperative NIR fluorescence imaging of the thoracic duct using SII-ICG is a simple and safe method with very high detection sensitivity. This method can be a powerful tool for avoiding thoracic duct injuries during esophageal cancer surgery.

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

BACKGROUND

Complications that occur in laparoscopic surgery are often associated with the initial entry into the peritoneal cavity. The literature reported incidences of Veress needle (VN) injuries of e.g. 0.31% and 0.23%. In a 2010 national survey of laparoscopic entry techniques in the Canadian General Surgical practice, 57.3% of respondents had either experienced or witnessed a serious laparoscopic entry complication like bowel perforation and vascular injury. As those complications are potentially life threatening and should be avoided at all costs, improving safety of this initial action is paramount.

METHODS

Based on a bare minimum design approach with focus on function expansion of existing components, a new Safety mechanism was developed for the VN that decreases the risks of VN overshooting. The mechanism works by preventing the puncturing acceleration of the tip of the VN by decoupling the surgeon's hand from the VN immediately after entering the abdomen.

RESULTS

Based on a set of requirements, a first prototype of the VN+ with force decoupling safety mechanism is presented and evaluated on an ex vivo porcine abdominal wall tissue model in a custom setup. The experiments conducted by two novices and one experienced surgeon indicated a significant difference between the attempts with a standard, conventional working VN (41.4 mm [37.5-45 mm]) and VN+ with decoupling mechanism (20.8 mm [17.5-22.5 mm]) of p < 0.001.

CONCLUSION

A new decoupling safety mechanism was integrated successfully in a standard VN resulting in a VN+ . The results from the pilot study indicate that this new VN+ reduces overshooting with a minimum of 50% in a standardised ex vivo setting on fresh porcine abdominal wall specimens.

Optimizing first trocar access for robot-assisted radical prostatectomy: Optical trocar access through the upper abdominal quadrant using the Kii Fios First Entry trocar

OBJECTIVES

A pre-equipped metal trocar is required to use as a camera trocar due to a specification change in the da Vinci X/Xi system (Intuitive Surgical). We observed slight slippage of a trocar placed by the open method. With optical trocar access (OTA), the initial trocar is viewed directly with a laparoscope during placement. Reports regarding OTA for robotic surgery are limited, particularly for robot-assisted radical prostatectomy (RARP). We modified the OTA procedure such that it was appropriate for RARP.

PATIENTS AND METHODS

A total of 158 patients were enrolled in this study. The first trocar placement time (FTPT) was compared between the open and OTA groups. In the OTA group, the trocar was mainly placed through the upper abdominal quadrant. We also analyzed the differences between the conventional and modified OTA procedures using the Kii Fios First Entry trocar (Applied Medical). We examined the factors affecting the FTPT using linear regression models. A P value <.05 was considered significant.

RESULTS

The FTPT was significantly shorter in the OTA group than the open group (P < .0001). The modified method was associated with a shorter FTPT (P = .0001). None of the patient characteristics affected the FTPT in either group. No major complications were observed.

CONCLUSIONS

OTA was applied successfully during RARP. Use of the Kii Fios First Entry trocar with upper abdominal quadrant placement was suitable for RARP.