The R4U Planes for the Zonal Demarcation for Safe Laparoscopic Cholecystectomy

Rouvière's Sulcus as a Landmark for a Safe Laparoscopic Cholecystectomy: An Interim Analysis of a Multicenter Cross-sectional Study on the Prevalence and Morphologic Type of Rouvière's Sulcus in the Italian Population

BACKGROUND

Laparoscopic cholecystectomy is the gold standard in the treatment of symptomatic gallstones. The large number of gallbladders removed every year is not fully consistent with the excessively high incidence of iatrogenic bile duct injury (IBDI). Several strategies have been suggested to reduce this risk. Among them, the use of extra biliary anatomic structures, such as the Rouvière's sulcus, as a landmark to guide the surgeon during dissection has been proposed as a means to prevent IBDI. The main aim of the present paper is the evaluation of the prevalence of Rouvière's sulcus (RS) and its anatomic variants in a given population.

MATERIALS AND METHODS

This observational, cross-sectional, and multicenter study has been conducted at the Department of Digestive and Emergency Surgery of the "Azienda Ospedaliera Santa Maria," Terni (Italy), at the Department of Surgical Sciences of the "Azienda Ospedaliera Perugia," Perugia (Italy) and at the Department of Emergency and Trauma Surgery of the "Policlinico Umberto I," Rome (Italy). Intraoperative images of 111 patients undergoing laparoscopic cholecystectomy were analyzed to identify the presence and type of RS, according to the Singh-Prasad classification and the Dahmane classification.

RESULTS

RS was present in 93 (83.8%) patients. Singh-Prasad type 1A is present in 48.4% of patients, type 1B in 25.8%, type 2 in 12.9% and type 3 in 12.9%. Dahmane's open type is present in 48.4% of patients and fused type in 51.6%.

CONCLUSION

Due to its high prevalence, RS can be used as an anatomic landmark and probably reduces the incidence of IBDI during laparoscopic cholecystectomy.

Prevalence of Rouvière's sulcus and its anatomical variations: our experience and systematic review/meta-analysis

INTRODUCTION

Rouvière's sulcus, an anatomical landmark, has been proposed as a potential aid in enhancing surgical safety. This study aims to assess the prevalence of RS and its anatomical variations both in the existing literature and within our clinical practice.

EVIDENCE ACQUISITION

A systematic literature search was conducted, and relevant studies were identified.

EVIDENCE SYNTHESIS

Fourteen studies were obtained from literature search and we added data extracted during our clinical practice, considering them as the fifteenth study (1802 patients enrolled). In the 15 studies analyzed, the overall pooled prevalence estimate of the Rouvière's sulcus was 82.6%. The study heterogeneity was high, I2=87.8%. The subgroup analysis showed negligible difference between studies with cadaveric dissection (PPE=82.6%) and laparoscopic dissection (PPE=82.6%). The analysis of variations according to Singh and Prasad criteria shows that the Type 1A was the most common variation (60.1%). The prevalence of other types was lower:14.2% in Type 1B, 17.3% in Type 2 and 8.5% in Type 3.

CONCLUSIONS

Rouvière's sulcus is identified in the majority of patients undergoing LC, and starting the dissection after its recognition can represent a method to reduce IBDI. Considerable heterogeneity exists in the anatomical variations and further research is ongoing to evaluate an association between the variations and technical complexity associate at risk of iatrogenic bile duct injuries.

Development of deep learning framework for anatomical landmark detection and guided dissection line during laparoscopic cholecystectomy

Background

Bile duct injuries during laparoscopic cholecystectomy can arise from misinterpretation of biliary anatomy, leading to dissection in improper areas. The integration of a deep learning framework into laparoscopic procedures offers the potential for real-time anatomical landmark recognition, ensuring accurate dissection. The objective of this study is to develop a deep learning framework that can precisely identify anatomical landmarks, including Rouviere's sulcus and the liver base of segment IV, and provide a guided dissection line during laparoscopic cholecystectomy.

Methods

We retrospectively collected 40 laparoscopic cholecystectomy videos and extracted 80 images form each video to establish the dataset. Three surgeons annotated the bounding boxes of anatomical landmarks on a total of 3200 images. The YOLOv7 model was trained to detect Rouviere's sulcus and the liver base of segment IV as anatomical landmarks. Additionally, the guided dissection line was generated between these two landmarks by the proposed algorithm. To evaluate the performance of the detection model, mean average precision (mAP), precision, and recall were calculated. Furthermore, the accuracy of the guided dissection line was evaluated by three surgeons. The performance of the detection model was compared to the scaled-YOLOv4 and YOLOv5 models. Finally, the proposed framework was deployed in the operating room for real-time detection and visualization.

Results

The overall performance of the YOLOv7 model on validation set and testing set were 98.1 % and 91.3 %, respectively. Surgeons accepted the visualization of guide dissection line with a rate of 95.71 %. In the operating room, the well-trained model accurately identified the anatomical landmarks and generated the guided dissection line in real-time.

Conclusions

The proposed framework effectively identifies anatomical landmarks and generates a guided dissection line in real-time during laparoscopic cholecystectomy. This research underscores the potential of using deep learning models as computer-assisted tools in surgery, providing an assistant tool to accommodate with surgeons.

When Critical View of Safety Fails: A Practical Perspective on Difficult Laparoscopic Cholecystectomy

The incidence of common bile duct injuries following laparoscopic cholecystectomy (LC) remains three times higher than that following open surgery despite numerous attempts to decrease intraoperative incidents by employing better training, superior surgical instruments, imaging techniques, or strategic concepts. This paper is a narrative review which discusses from a contextual point of view the need to standardise the surgical approach in difficult laparoscopic cholecystectomies, the main strategic operative concepts and techniques, complementary visualisation aids for the delineation of anatomical landmarks, and the importance of cognitive maps and algorithms in performing safer LC. Extensive research was carried out in the PubMed, Web of Science, and Elsevier databases using the terms "difficult cholecystectomy", "bile duct injuries", "safe cholecystectomy", and "laparoscopy in acute cholecystitis". The key content and findings of this research suggest there is high intersocietal variation in approaching and performing LC, in the use of visualisation aids, and in the application of safety concepts. Limited papers offer guidelines based on robust data and a timid recognition of the human factors and ergonomic concepts in improving the outcomes associated with difficult cholecystectomies. This paper highlights the most relevant recommendations for dealing with difficult laparoscopic cholecystectomies.

How to achieve the critical view of safety for safe laparoscopic cholecystectomy: Technical aspects

Laparoscopic cholecystectomy is associated with a higher incidence of biliary/vasculobiliary injuries than open cholecystectomy. Anatomical misperception is the most common underlying mechanism of such injuries. Although a number of strategies have been described to prevent these injuries, critical view of safety method of structural identification seems to be the most effective preventive measure. The critical view of safety can be achieved in the majority of cases during laparoscopic cholecystectomy. It is highly recommended by various guidelines. However, its poor understanding and low adoption rates among practicing surgeons have been global problems. Educational intervention and increasing awareness about the critical view of safety can increase its penetration in routine surgical practice. In this article, a technique of achieving critical view of safety during laparoscopic cholecystectomy is described with the aim to enhance its understanding among general surgery trainees and practicing general surgeons.

Anatomical appraisal of safe cholecystectomy: a prospective study

BACKGROUND

Principles of safe cholecystectomy include dissection of the hepatocystic triangle and identification of the bilio-vascular structures to achieve critical view of safety. The aim of the present study was to document the variations in anatomical landmarks and bilio-vascular structures exposed during laparoscopic cholecystectomy.

METHODS

All consecutive patients who underwent laparoscopic cholecystectomy were included in the study. Recommended techniques of safe cholecystectomy were followed. Rouviere's sulcus was classified into four types. Cystic duct was assessed for its length and diameter. A new classification was suggested for cystic artery.

RESULTS

Five hundred patients were included in the study. Critical view of safety was achieved in 463 (92.6%) patients. Type1 Rouviere's sulcus was the most common variant found in 263 (52.6%). Normal cystic duct was present in 339 (67.8%). Wide cystic duct of normal length was the most common variant found in 71 (14.2%). Single cystic artery supero-medial to cystic duct (type1-s) was the most common variant found in 384 (76.8%). Inferior cystic artery i.e. artery infero-lateral to cystic duct (type-2) was the second most common variant, found in 40 (8%). Multiple cystic arteries in the hepatocystic triangle were due either to early division of single cystic artery (type-1m) or double cystic artery (type-3). Aberrant right hepatic artery giving off a small cystic artery (type-4) was seen in 12 (2.4%).

CONCLUSION

Wide variation in the anatomical structures is noted when principles of safe laparoscopic cholecystectomy is followed. Awareness is paramount to avoid bilio-vascular injury during surgery.

[Modern principles of safety in laparoscopic cholecystectomy]

Laparoscopic cholecystectomy has many advantages over open surgery. Nevertheless, incidence of intraoperative bile duct injury is consistently higher for laparoscopic technique. This review is devoted to modern principles of identifying the anatomical elements in hepatoduodenal ligament and rules for safe tissue dissection in this area. The last ones mainly consist in formation of «critical view of safety» before clipping and transection of tubular structures. The key for «critical view of safety» is mobilization of fatty and fibrous tissues of hepatocystic triangle starting from the lower third of the gallbladder.