State of the art in robotic liver surgery: a meta-analysis

Prince and princesses: The current status of robotic surgery in surgical oncology

Robotic surgery has experienced a dramatic increase in utilization across general surgery over the last two decades, including in surgical oncology. Although urologists and gynecologists were the first to show that this technology could be utilized in cancer surgery, the robot is now a powerful tool in the treatment of gastrointestinal, hepato-pancreatico-biliary, colorectal, endocrine, and soft tissue malignancies. While long-term outcomes are still pending, short-term outcomes have showed promise for this technologic advancement of cancer surgery.

Validity of the Institut Mutualiste Montsouris classification system for robotic liver resection

BACKGROUND

The Institut Mutualiste Montsouris (IMM) classification system is one of several widely accepted difficulty scoring systems for laparoscopic liver resections. Nothing is yet known about the applicability of this system for robotic liver resections.

METHODS

We conducted a retrospective review of 359 patients undergoing robotic hepatectomies between 2016 and 2022. Resections were classified into low, intermediate, and high difficulty level. Data were analyzed utilizing ANOVA of repeated measures, 3 x 2 contingency tables, and area under the receiving operating characteristic (AUROC) curves. Data are presented as median (mean ± SD).

RESULTS

Of the 359 patients, 117 were classified as low-difficulty level, 92 as intermediate, and 150 as high. The IMM system correlates well with tumor size (p = 0.002). The IMM system was a strong predictor of intraoperative outcomes including operative duration (p<0.001) and estimated blood loss (EBL) (p<0.001). The IMM system also showed a strong calibration for predicting an open conversion (AUC=0.705) and intraoperative complications (AUC=0.79). In contrast, the IMM system was a poor predictor of postoperative complications, mortality, and readmission.

CONCLUSION

The IMM system provides a strong correlation with intraoperative, but not postoperative outcomes. A dedicated difficulty scoring system should be developed for robotic hepatectomy.

Robotic Versus Laparoscopic Hepatectomy: A Single Surgeon Experience of 629 Consecutive Minimally Invasive Liver Resections

BACKGROUND

Robotic surgery has the potential to broaden the indications for minimally invasive liver surgery owing to its technical advantages. This paper compares our experience with robotic liver surgery (RLS) with conventional laparoscopic liver surgery (LLS).

METHODS

All consecutive liver resections between October 2011 and October 2022 were selected from our prospective database to be included in this cohort study. Patients who underwent RLS were compared with a LLS group for operative and postoperative outcomes.

RESULTS

In total, 629 patients were selected from our database, including 177 patients who underwent a RLS and 452 patients who had LLS. Colorectal liver metastasis was the main indication for surgery in both groups. With the introduction of RLS, the percentage of open resections decreased significantly (32.6% from 2011 to 2020 vs. 11.5% from 2020 onward, P < 0.001). In the robotic group, redo liver surgery was more frequent (24.3% vs. 16.8%, P = 0.031) and the Southampton difficulty score was higher (4 [IQR 4 to 7] vs. 4 [IQR 3 to 6], P = 0.02). Median blood loss was lower (30 vs. 100 ml, P < 0.001), and postoperative length of stay (LOS) was shorter in the robotic group (median 3 vs. 4 days, P < 0.001). There was no significant difference in postoperative complications. Cost related to the used instruments and LOS was significantly lower in the RLS group (median €1483 vs. €1796, P < 0.001 and €1218 vs. €1624, P < 0.001, respectively), while cost related to operative time was higher (median €2755 vs. €2470, P < 0.001).

CONCLUSIONS

RLS may allow for a higher percentage of liver resections to be completed in a minimally invasive way with lower blood loss and a shorter LOS.

Robotic versus laparoscopic versus open major hepatectomy - an analysis of costs and postoperative outcomes in a single-center setting

PURPOSE

In the era of minimal-invasive surgery, the introduction of robotic liver surgery (RS) was accompanied by concerns about the increased financial expenses of the robotic technique in comparison to the established laparoscopic (LS) and conventional open surgery (OS). Therefore, we aimed to evaluate the cost-effectiveness of RS, LS and OS for major hepatectomies in this study.

METHODS

We analyzed financial and clinical data on patients who underwent major liver resection for benign and malign lesions from 2017 to 2019 at our department. Patients were grouped according to the technical approach in RS, LS, and OS. For better comparability, only cases stratified to the Diagnosis Related Groups (DRG) H01A and H01B were included in this study. Financial expenses were compared between RS, LS, and OS. A binary logistic regression model was used to identify parameters associated with increased costs.

RESULTS

RS, LS and OS accounted for median daily costs of 1,725 €, 1,633 € and 1,205 €, respectively (p < 0.0001). Median daily (p = 0.420) and total costs (16,648 € vs. 14,578 €, p = 0.076) were comparable between RS and LS. Increased financial expenses for RS were mainly caused by intraoperative costs (7,592 €, p < 0.0001). Length of procedure (hazard ratio [HR] = 5.4, 95% confidence interval [CI] = 1.7-16.9, p = 0.004), length of stay (HR [95% CI] = 8.8 [1.9-41.6], p = 0.006) and development of major complications (HR [95% CI] = 2.9 [1.7-5.1], p < 0.0001) were independently associated with higher costs.

CONCLUSIONS

From an economic perspective, RS may be considered a valid alternative to LS for major liver resections.

Venous thromboembolism (VTE) after open hepatectomy compared to minimally invasive liver resection: a systematic review and meta-analysis

BACKGROUND

Even though the risk of postoperative venous thromboembolism (VTE) after liver resection is well recognized, the association between surgical approach and VTE risk is unknown. This study aims to compare VTE rates following open liver resection (OLR) and minimally invasive liver resection (MILR).

METHODS

MEDLINE, Web Of Sciences and EMBASE databases were interrogated to identify eligible studies published between February 2016 and August 2022. Studies were considered suitable if they reported a comparison between OLR and MILR (including laparoscopic liver resection [LLR] or robotic liver resection [RLR]).

RESULTS

Fourteen studies including 11 356 patients met the inclusion criteria. 5622 patients underwent OLR and 5734 patients underwent MILR. The VTE rate was higher among patients who underwent OLR compared to MILR (2.8% vs 1.4%, OR (95% CI) = 1.84, p=<00001). Similarly, the subgroup analysis showed a higher rate of deep venous thrombosis (DVT) (1.4% vs 0.7%, OR (95% CI) = 1.98, p = 0.02) and pulmonary embolism (PE) (1.3% vs 0.7%, OR (95% CI) = 1.88, p = 0.002) in patients who underwent OLR compared to MILR.

DISCUSSION

Patients who undergo open hepatectomy have a higher incidence of postoperative VTE when compared to those undergoing minimally invasive liver resection. This finding was consistent for both DVT and PE.

[Treatment concepts for hepatic echinococcosis]

The incidence of both cystic (CE) and alveolar echinococcosis (AE) is increasing in Germany. The CE can often be managed with drug treatment and interventional strategies. In contrast, AE shows characteristics of a malignant disease with a high morbidity and mortality. Benzimidazoles are potent drugs for both entities but with the necessity for a lifelong follow-up and the risk of side effects as well as progression under treatment. Therefore, the indications for surgical resection have to be carefully considered; however, the combination of drug treatment and surgery is the only curative approach. Recently, the use of minimally invasive surgery with reduced morbidity and mortality has justified surgical resection for a broader set of patients; however, minimally invasive surgery requires a high level of expertise and optimal perioperative planning. Therefore, treatment strategies, especially for AE require an individual stratified risk-benefit assessment in an interdisciplinary consensus.

Outcomes and Patient Selection in Laparoscopic vs. Open Liver Resection for HCC and Colorectal Cancer Liver Metastasis

Hepatocellular carcinoma (HCC) and colorectal liver metastasis (CRLM) are the two most common malignant tumors that require liver resection. While liver transplantation is the best treatment for HCC, organ shortages and high costs limit the availability of this option for many patients and make resection the mainstay of treatment. For patients with CRLM, surgical resection with negative margins is the only potentially curative option. Over the last two decades, laparoscopic liver resection (LLR) has been increasingly adopted for the resection of a variety of tumors and was found to have similar long-term outcomes compared to open liver resection (OLR) while offering the benefits of improved short-term outcomes. In this review, we discuss the current literature on the outcomes of LLR vs. OLR for patients with HCC and CRLM. Although the use of LLR for HCC and CRLM is increasing, it is not appropriate for all patients. We describe an approach to selecting patients best-suited for LLR. The four common difficulty-scoring systems for LLR are summarized. Additionally, we review the current evidence behind the emerging robotically assisted liver resection technology.

Laparoscopic and Robot-Assisted Hepatic Surgery: An Historical Review

Hepatic surgery is a rapidly expanding component of abdominal surgery and is performed for a wide range of indications. The introduction of laparoscopic cholecystectomy in 1987 was a major change in abdominal surgery. Laparoscopic surgery was widely and rapidly adopted throughout the world for cholecystectomy initially and then applied to a variety of other procedures. Laparoscopic surgery became regularly applied to hepatic surgery, including segmental and major resections as well as organ donation. Many operations progressed from open surgery to laparoscopy to robot-assisted surgery, including colon resection, pancreatectomy, splenectomy thyroidectomy, adrenalectomy, prostatectomy, gastrectomy, and others. It is difficult to prove a data-based benefit using robot-assisted surgery, although laparoscopic and robot-assisted surgery of the liver are not inferior regarding major outcomes. When laparoscopic surgery initially became popular, many had concerns about its use to treat malignancies. Robot-assisted surgery is being used to treat a variety of benign and malignant conditions, and studies have shown no deterioration in outcomes. Robot-assisted surgery for the treatment of malignancies has become accepted and is now being used at more centers. The outcomes after robot-assisted surgery depend on its use at specialized centers, the surgeon's personal experience backed up by extensive training and maintenance of international registries. Robot-assisted hepatic surgery has been shown to be associated with slightly less intraoperative blood loss and shorter hospital lengths of stay compared to open surgery. Oncologic outcomes have been maintained, and some studies show higher rates of R0 resections. Patients who need surgery for liver lesions should identify a surgeon they trust and should not be concerned with the specific operative approach used. The growth of robot-assisted surgery of the liver has occurred in a stepwise approach which is very different from the frenzy that was seen with the introduction of laparoscopic cholecystectomy. This approach allowed the identification of areas for improvement, many of which are at the nexus of engineering and medicine. Further improvements in robot-assisted surgery depend on the combined efforts of engineers and surgeons.

Study: International Multicentric Minimally Invasive Liver Resection for Colorectal Liver Metastases (SIMMILR-CRLM)

(1) Background: Here we report on a retrospective study of an international multicentric cohort after minimally invasive liver resection (SIMMILR) of colorectal liver metastases (CRLM) from six centers. (2) Methods: Resections were divided by the approach used: open liver resection (OLR), laparoscopic liver resection (LLR) and robotic liver resection (RLR). Patients with macrovascular invasion, more than three metastases measuring more than 3 cm or a solitary metastasis more than 5 cm were excluded, and any remaining heterogeneity found was further analyzed after propensity score matching (PSM) to decrease any potential bias. (3) Results: Prior to matching, 566 patients underwent OLR, 462 LLR and 36 RLR for CRLM. After PSM, 142 patients were in each group of the OLR vs. LLR group and 22 in the OLR vs. RLR and 21 in the LLR vs. RLR groups. Blood loss, hospital stay, and morbidity rates were all highly statistically significantly increased in the OLR compared to the LLR group, 636 mL vs. 353 mL, 9 vs. 5 days and 25% vs. 6%, respectively (p < 0.001). Only blood loss was significantly decreased when RLR was compared to OLR and LLR, 250 mL vs. 597 mL, and 224 mL vs. 778 mL, p < 0.008 and p < 0.04, respectively. (4) Conclusions: SIMMILR indicates that minimally invasive approaches for CRLM that follow the Milan criteria may have short term advantages. Notably, larger studies with long-term follow-up comparing robotic resections to both OLR and LLR are still needed.

Robotic-Assisted Surgery for Primary Hepatobiliary Tumors-Possibilities and Limitations

Simple Summary

Primary liver malignancies are some of the most common and fatal tumors today. Robotic-assisted liver surgery is becoming increasingly interesting for both patients and surgeons alike. Up to date, prospective comparative studies around the topic are scarce. This leads us to an ever existing controversy about the efficacy, safety, and economic benefits of robotic surgery as an extension of traditional minimally invasive surgery over open liver surgery. However, there is evidence that robotic-assisted surgery is, after passing the learning curve, equivalent in terms of feasibility and safety, and in some cases superior to traditional laparoscopic hepatic resection. With this work, we want to provide an overview of the latest and most significant reviews and meta-analyses focusing on robotic hepatectomy in primary liver malignancies. We outline the technical aspects of robotic-assisted surgery and place them into the context of technical, surgical, and oncological outcomes compared with laparoscopic and open resection. When chosen per case individually, any hepatic resection can be performed robotically to overcome limitations of laparoscopic surgery by an experienced team. In this paper, we propose that prospective studies are needed to prove efficacy for robotic-assisted resection in liver malignancy.

Abstract

Hepatocellular and cholangiocellular carcinoma are fatal primary hepatic tumors demanding extensive liver resection. Liver surgery is technically challenging due to the complex liver anatomy, with an intensive and variant vascular and biliary system. Therefore, major hepatectomies in particular are often performed by open resection and minor hepatectomies are often performed minimally invasively. More centers have adopted robotic-assisted surgery, intending to improve the laparoscopic surgical limits, as it offers some technical benefits such as seven degrees of freedom and 3D visualization. The da Vinci^® Surgical System has dominated the surgical robot market since 2000 and has shown surgical feasibility, but there is still much controversy about its economic benefits and real benefits for the patient over the gold standard. The currently available retrospective case studies are difficult to compare, and larger, prospective studies and randomized trials are still urgently missing. Therefore, here we summarize the technical, surgical, and economic outcomes of robotic versus open and laparoscopic hepatectomies for primary liver tumors found in the latest literature reviews and meta-analyses. We conclude that complex robotic liver resections (RLR) are safe and feasible after the steep learning curve of the surgical team has plateaued. The financial burden is lower in high volume centers and is expected to decrease soon as new surgical systems will enter the market.

Augmented Reality and Image-Guided Robotic Liver Surgery

Artificial intelligence makes surgical resection easier and safer, and, at the same time, can improve oncological results. The robotic system fits perfectly with these more or less diffused technologies, and it seems that this benefit is mutual. In liver surgery, robotic systems help surgeons to localize tumors and improve surgical results with well-defined preoperative planning or increased intraoperative detection. Furthermore, they can balance the absence of tactile feedback and help recognize intrahepatic biliary or vascular structures during parenchymal transection. Some of these systems are well known and are already widely diffused in open and laparoscopic hepatectomies, such as indocyanine green fluorescence or ultrasound-guided resections, whereas other tools, such as Augmented Reality, are far from being standardized because of the high complexity and elevated costs. In this paper, we review all the experiences in the literature on the use of artificial intelligence systems in robotic liver resections, describing all their practical applications and their weaknesses.