Minimally invasive anatomic liver resection: Results of a survey of world experts

BACKGROUND

Although the number of minimally invasive liver resections (MILRs) has been steadily increasing in many institutions, minimally invasive anatomic liver resection (MIALR) remains a complicated procedure that has not been standardized. We present the results of a survey among expert liver surgeons as a benchmark for standardizing MIALR.

METHOD

We administered this survey to 34 expert liver surgeons who routinely perform MIALR. The survey contained questions on personal experience with liver resection, inflow/outflow control methods, and identification techniques of intersegmental/sectional planes (IPs).

RESULTS

All 34 participants completed the survey; 24 experts (70%) had more than 11 years of experience with MILR, and over 80% of experts had performed over 100 open resections and MILRs each. Regarding the methods used for laparoscopic or robotic anatomic resection, the Glissonean approach (GA) was a more frequent procedure than the hilar approach (HA). Although hepatic veins were considered essential landmarks, the exposure methods varied. The top three techniques that the experts recommended for identifying IPs were creating a demarcation line, indocyanine green negative staining method, and intraoperative ultrasound.

CONCLUSION

Minimally invasive anatomic liver resection remains a challenging procedure; however, a certain degree of consensus exists among expert liver surgeons.

Image-Guided Surgical Simulation in Minimally Invasive Liver Procedures: Development of a Liver Tumor Porcine Model Using a Multimodality Imaging Assessment

Background: Image-guided liver surgery and interventions are growing as part of the current trend to translate liver procedures into minimally invasive approaches. Hands-on surgical training in such techniques is required. Consequently, a meaningful and realistic liver tumor model using multi-imaging modalities, such as ultrasound (US), computed tomography (CT), magnetic resonance (MR), cone beam-CT (CBCT), is mandatory. The first aim of this study is to develop a novel tumor-mimic model and assess it with multi-imaging modalities. The second aim is to evaluate the usefulness of the model during image-guided liver procedures. Materials and Methods: The tumor-mimic model is made of a composition of hydrogel, smashed muscle, and gadolinium contrast solution. Five ex vivo livers and three pigs were included in the study. Procedures were performed in an experimental hybrid operating room. Under general anesthesia, US guidance was required to inject the biotumor formula into the pig's liver. US, CT, CBCT, and MR acquisitions were then performed after the initial injection. In vivo models were then used to perform liver procedures, including US-guided biopsy, radiofrequency ablation, and laparoscopic resection. Results: The formula developed is easily injected generating a tissue-like material. Visualization using multi-imaging modalities was appropriate, thereby allowing to perform image-guided techniques. Conclusion: A novel design of an in vivo and ex vivo tissue-like tumor liver model is presented. Due to the multimodality imaging appraisal, it may provide a realistic and meaningful model allowing to perform image-guided liver procedures.

Landmarks and techniques to perform minimally invasive liver surgery: A systematic review with a focus on hepatic outflow

PURPOSE

In this systematic review, we aimed to clarify the useful anatomic structures and assess available surgical techniques and strategies required to safely perform minimally invasive anatomic liver resection (MIALR), with a particular focus on the hepatic veins (HVs).

METHODS

A systematic review was conducted using MEDLINE/PubMed for English articles and Ichushi databases for Japanese articles through September 2020. The quality assessment of the articles was performed in accordance with the Scottish Intercollegiate Guidelines Network (SIGN).

RESULTS

A total of 3372 studies were obtained, and 59 were selected and reviewed. Due to the limited number of published comparative studies and case series, the degree of evidence from our review was low. Thirty-two articles examined the anatomic landmarks and crucial structures for approaching HVs. Regarding the direction of HV exposure, 32 articles focused on the techniques and advantages of exposing HVs from either the root or the periphery. Ten articles focused on the techniques to perform a segmentectomy 8 in particularly difficult cases of MIALR. In seven articles, bleeding control from HVs was also discussed.

CONCLUSIONS

This review may help experts reach a consensus regarding the best approach to the management of hepatic veins during MIALR.

Fluoroless intravascular ultrasound image-guided liver navigation in porcine models

Background

An intravascular ultrasound catheter (IVUSc) was developed for intracardiac ultrasound to assess interventions with compelling results. However, intrahepatic vascular exploration was rarely tested and was always associated with X-ray techniques. The aim of this study was to demonstrate the feasibility to navigate through the whole liver using an IVUSc, providing high-quality images and making it unnecessary to use ionizing radiation.

Methods

An ex vivo pig visceral block and an in vivo pig model were used in this study. The IVUS equipment was composed of an US system, and of an 8 French lateral firing IVUSc capable of producing 90-degree sector images in the longitudinal plane. After accessing the intravascular space with the IVUSc into the models, predetermined anatomical landmarks were visualized from the inferior vena cava and hepatic veins and corroborated.

Results

IVUS navigation was achieved in both models successfully. The entire navigation protocol took 87 and 48 min respectively, and 100% (21/21) and 96.15% (25/26) of the landmarks were correctly identified with the IVUSc alone in the ex vivo and in vivo models respectively. IVUS allowed to clearly visualize the vasculature beyond third-order branches of the hepatic and portal veins.

Conclusions

A complete IVUS liver navigation is feasible using the IVUSc alone, making it unnecessary to use ionizing radiation. This approach provides high-definition and real-time images of the complex liver structure and offers a great potential for future clinical applications during diagnostic and therapeutic interventions.