Somatostatin vs. Octreotide for Prevention of Postoperative Pancreatic Fistula The PREFIPS Randomized Clinical Trial A FRENCH 007 - ACHBT Study.

OBJECTIVE: Pharmacological prevention of postoperative pancreatic fistula (POPF) after pancreatectomy is open to debate. The present study compares clinically significant POPF rates in patients randomized between somatostatin versus octreotide as prophylactic treatment. PATIENTS AND METHODS: Multicentric randomized controlled open study in patient's candidate for pancreaticoduodenectomy (PD) or distal pancreatectomy (DP) comparing somatostatin continuous intravenous infusion for 7 days versus octreotid 100 µg, every 8 hours subcutaneous injection for 7 days, stratified by procedure (PD vs. DP) and size of the main pancreatic duct (>4 mm) on grade B/C POPF rates at 90 days based on an intention-to-treat analysis. RESULTS: Of 763 eligible patients, 651 were randomized: 327 in the octreotide arm and 324 in the somatostatin arm, with comparable the stratification criteria - type of surgery and main pancreatic duct dilatation. Most patients had PD (n=480; 73.8%), on soft/normal pancreas (n=367; 63.2%) with a non-dilated main pancreatic duct (n=472; 72.5%), most often for pancreatic adenocarcinoma (n=311; 47.8%). Almost all patients had abdominal drainage (n=621; 96.1%) and 121 (19.5%) left the hospital with the drain in place (median length of stay=16 d). A total of 153 patients (23.5%) developed a grade B/C POPF with no difference between both groups: 24.1%: somatostatin arm and 22.9%: octreotide arm (Chi-2 test, P=0.73, ITT analysis). Absence of statistically significant difference persisted after adjustment for stratification variables and in per-protocol analysis. CONCLUSIONS: Continuous intravenous somatostatin is not statistically different from subcutaneous octreotide in the prevention of grade B/C POPF after pancreatectomy.

Keyhole-aware laparoscopic augmented reality.

Augmented Reality (AR) from preoperative data is a promising approach to improve intraoperative tumour localisation in Laparoscopic Liver Resection (LLR). Existing systems register the preoperative tumour model with the laparoscopic images and render it by direct camera projection, as if the organ were transparent. However, a simple geometric reasoning shows that this may induce serious surgeon misguidance. This is because the tools enter in a different keyhole than the laparoscope. As AR is particularly important for deep tumours, this problem potentially hinders the whole interest of AR guidance. A remedy to this issue is to project the tumour from its internal position to the liver surface towards the tool keyhole, and only then to the camera. This raises the problem of estimating the tool keyhole position in laparoscope coordinates. We propose a keyhole-aware pipeline which resolves the problem by using the observed tool to probe the keyhole position and by showing a keyhole-aware visualisation of the tumour. We assess the benefits of our pipeline quantitatively on a geometric in silico model and on a liver phantom model, as well as qualitatively on three patient data.

LARLUS: laparoscopic augmented reality from laparoscopic ultrasound.

PURPOSE: This research endeavors to improve tumor localization in minimally invasive surgeries, a challenging task primarily attributable to the absence of tactile feedback and limited visibility. The conventional solution uses laparoscopic ultrasound (LUS) which has a long learning curve and is operator-dependent. METHODS: The proposed approach involves augmenting LUS images onto laparoscopic images to improve the surgeon's ability to estimate tumor and internal organ anatomy. This augmentation relies on LUS pose estimation and filtering. RESULTS: Experiments conducted with clinical data exhibit successful outcomes in both the registration and augmentation of LUS images onto laparoscopic images. Additionally, noteworthy results are observed in filtering, leading to reduced flickering in augmentations. CONCLUSION: The outcomes reveal promising results, suggesting the potential of LUS augmentation in surgical images to assist surgeons and serve as a training tool. We have used the LUS probe's shaft to disambiguate the rotational symmetry. However, in the long run, it would be desirable to find more convenient solutions.

Augmented Reality Guided Laparoscopic Liver Resection: A Phantom Study With Intraparenchymal Tumors.

INTRODUCTION: Augmented reality (AR) in laparoscopic liver resection (LLR) can improve intrahepatic navigation by creating a virtual liver transparency. Our team has recently developed Hepataug, an AR software that projects the invisible intrahepatic tumors onto the laparoscopic images and allows the surgeon to localize them precisely. However, the accuracy of registration according to the location and size of the tumors, as well as the influence of the projection axis, have never been measured. The aim of this work was to measure the three-dimensional (3D) tumor prediction error of Hepataug. METHODS: Eight 3D virtual livers were created from the computed tomography scan of a healthy human liver. Reference markers with known coordinates were virtually placed on the anterior surface. The virtual livers were then deformed and 3D printed, forming 3D liver phantoms. After placing each 3D phantom inside a pelvitrainer, registration allowed Hepataug to project virtual tumors along two axes: the laparoscope axis and the operator port axis. The surgeons had to point the center of eight virtual tumors per liver with a pointing tool whose coordinates were precisely calculated. RESULTS: We obtained 128 pointing experiments. The average pointing error was 29.4 ± 17.1 mm and 9.2 ± 5.1 mm for the laparoscope and operator port axes respectively (P = 0.001). The pointing errors tended to increase with tumor depth (correlation coefficients greater than 0.5 with P < 0.001). There was no significant dependency of the pointing error on the tumor size for both projection axes. CONCLUSIONS: Tumor visualization by projection toward the operating port improves the accuracy of AR guidance and partially solves the problem of the two-dimensional visual interface of monocular laparoscopy. Despite a lower precision of AR for tumors located in the posterior part of the liver, it could allow the surgeons to access these lesions without completely mobilizing the liver, hence decreasing the surgical trauma.

Comparing indications, complexity and outcomes of laparoscopic liver resection between centers with and without a liver transplant program: a French nationwide study.

BACKGROUND: There are no data to evaluate the difference in populations and impact of centers with liver transplant programs in performing laparoscopic liver resection (LLR). METHODS: This was a multicenter study including patients undergoing LLR for benign and malignant tumors at 27 French centers from 1996 to 2018. The main outcomes were postoperative severe morbidity and mortality. RESULTS: A total of 3154 patients were included, and 14 centers were classified as transplant centers (N = 2167 patients, 68.7 %). The transplant centers performed more difficult LLRs and more resections for hepatocellular carcinoma (HCC) in patients who more frequently had cirrhosis. A higher rate of performing the Pringle maneuver, a lower rate of blood loss and a higher rate of open conversion (all p < 0.05) were observed in the transplant centers. There was no association between the presence of a liver transplant program and either postoperative severe morbidity (<10 % in each group; p = 0.228) or mortality (1 % in each group; p = 0.915). CONCLUSIONS: Most HCCs, difficult LLRs, and cirrhotic patients are treated in transplant centers. We show that all centers can achieve comparable safety and quality of care in LLR independent of the presence of a liver transplant program.

Pancreatoduodenectomy Following Preoperative Biliary Drainage Using Endoscopic Ultrasound-Guided Choledochoduodenostomy Versus a Transpapillary Stent: A Multicenter Comparative Cohort Study of the ACHBT-FRENCH-SFED Intergroup.

BACKGROUND: It is unclear whether preoperative biliary drainage (PBD) by endoscopic retrograde cholangiopancreatography (ERCP) is equivalent to electrocautery-enhanced lumen-apposing metal stent (ECE-LAMS) before pancreatoduodenectomy (PD). METHODS: Patients who underwent PBD for distal malignant biliary obstruction (DMBO) followed by PD were retrospectively included in nine expert centers between 2015 and 2022. ERCP or endoscopic ultrasound-guided choledochoduodenostomy with ECE-LAMS were performed. In intent-to-treat analysis, patients drained with ECE-LAMS were considered the study group (first-LAMS group) and those drained with conventional transpapillary stent the control group (first-cannulation group). The rates of technical success, clinical success, drainage-related complications, surgical complications, and oncological outcomes were analyzed. RESULTS: Among 156 patients, 128 underwent ERCP and 28 ECE-LAMS in first intent. The technical and clinical success rates were 83.5% and 70.2% in the first-cannulation group versus 100% and 89.3% in the first-LAMS group (p = 0.02 and p = 0.05, respectively). The overall complication rate over the entire patient journey was 93.7% in first-cannulation group versus 92.0% in first-LAMS group (p = 0.04). The overall endoscopic complication rate was 30.5% in first-cannulation group versus 17.9% in first-LAMS group (p = 0.25). The overall complication rate after PD was higher in the first-cannulation group than in the first-LAMS group (92.2% versus 75.0%, p = 0.016). Overall survival and progression-free survival did not differ between the groups. CONCLUSIONS: PBD with ECE-LAMS is easier to deploy and more efficient than ERCP in patients with DMBO. It is associated with less surgical complications after pancreatoduodenectomy without compromising the oncological outcome.

Using multiple images and contours for deformable 3D-2D registration of a preoperative CT in laparoscopic liver surgery.

PURPOSE: Laparoscopic liver resection is a challenging procedure because of the difficulty to localise inner structures such as tumours and vessels. Augmented reality overcomes this problem by overlaying preoperative 3D models on the laparoscopic views. It requires deformable registration of the preoperative 3D models to the laparoscopic views, which is a challenging task due to the liver flexibility and partial visibility. METHODS: We propose several multi-view registration methods exploiting information from multiple views simultaneously in order to improve registration accuracy. They are designed to work on two scenarios: on rigidly related views and on non-rigidly related views. These methods exploit the liver's anatomical landmarks and texture information available in all the views to constrain registration. RESULTS: We evaluated the registration accuracy of our methods quantitatively on synthetic and phantom data, and qualitatively on patient data. We measured 3D target registration errors in mm for the whole liver for the quantitative case, and 2D reprojection errors in pixels for the qualitative case. CONCLUSION: The proposed rigidly related multi-view methods improve registration accuracy compared to the baseline single-view method. They comply with the 1 cm oncologic resection margin advised for hepatocellular carcinoma interventions, depending on the available registration constraints. The non-rigidly related multi-view method does not provide a noticeable improvement. This means that using multiple views with the rigidity assumption achieves the best overall registration error.

Augmented reality in laparoscopic liver resection evaluated on an ex-vivo animal model with pseudo-tumours.

BACKGROUND: The aim of this study was to assess the performance of our augmented reality (AR) software (Hepataug) during laparoscopic resection of liver tumours and compare it to standard ultrasonography (US). MATERIALS AND METHODS: Ninety pseudo-tumours ranging from 10 to 20 mm were created in sheep cadaveric livers by injection of alginate. CT-scans were then performed and 3D models reconstructed using a medical image segmentation software (MITK). The livers were placed in a pelvi-trainer on an inclined plane, approximately perpendicular to the laparoscope. The aim was to obtain free resection margins, as close as possible to 1 cm. Laparoscopic resection was performed using US alone (n = 30, US group), AR alone (n = 30, AR group) and both US and AR (n = 30, ARUS group). R0 resection, maximal margins, minimal margins and mean margins were assessed after histopathologic examination, adjusted to the tumour depth and to a liver zone-wise difficulty level. RESULTS: The minimal margins were not different between the three groups (8.8, 8.0 and 6.9 mm in the US, AR and ARUS groups, respectively). The maximal margins were larger in the US group compared to the AR and ARUS groups after adjustment on depth and zone difficulty (21 vs. 18 mm, p = 0.001 and 21 vs. 19.5 mm, p = 0.037, respectively). The mean margins, which reflect the variability of the measurements, were larger in the US group than in the ARUS group after adjustment on depth and zone difficulty (15.2 vs. 12.8 mm, p < 0.001). When considering only the most difficult zone (difficulty 3), there were more R1/R2 resections in the US group than in the AR + ARUS group (50% vs. 21%, p = 0.019). CONCLUSION: Laparoscopic liver resection using AR seems to provide more accurate resection margins with less variability than the gold standard US navigation, particularly in difficult to access liver zones with deep tumours.

Liver Venous Deprivation or Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy?: A Retrospective Multicentric Study.

OBJECTIVE: To compare 2 techniques of remnant liver hypertrophy in candidates for extended hepatectomy: radiological simultaneous portal vein embolization and hepatic vein embolization (HVE); namely LVD, and ALPPS. BACKGROUND: Recent advances in chemotherapy and surgical techniques have widened indications for extended hepatectomy, before which remnant liver augmentation is mandatory. ALPPS and LVD typically show higher hypertrophy rates than portal vein embolization, but their respective places in patient management remain unclear. METHODS: All consecutive ALPPS and LVD procedures performed in 8 French centers between 2011 and 2020 were included. The main endpoint was the successful resection rate (resection rate without 90-day mortality) analyzed according to an intention-to-treat principle. Secondary endpoints were hypertrophy rates, intra and postoperative outcomes. RESULTS: Among 209 patients, 124 had LVD 37 [13,1015] days before surgery, whereas 85 underwent ALPPS with an inter-stages period of 10 [6, 69] days. ALPPS was mostly-performed for colorectal liver metastases (CRLM), LVD for CRLM and perihilar cholangiocarcinoma. Hypertrophy was faster for ALPPS. Successful resection rates were 72.6% for LVD ± rescue ALPPS (n = 6) versus 90.6% for ALPPS (P < 0.001). Operative duration, blood losses and length-of-stay were lower for LVD, whereas 90-day major complications and mortality were comparable. Results were globally unchanged for CRLM patients, or after excluding the early 2 years of experience (learning-curve effect). CONCLUSIONS: This study is the first 1 comparing LVD versus ALPPS in the largest cohort so far. Despite its retrospective design, it yields original results that may serve as the basis for a prospective study.

Management of Patients with Pancreatic Ductal Adenocarcinoma in the Real-Life Setting: Lessons from the French National Hospital Database.

Pancreatic ductal adenocarcinoma (PDAC) remains a major public health challenge, and faces disparities and delays in the diagnosis and access to care. Our purposes were to describe the medical path of PDAC patients in the real-life setting and evaluate the overall survival at 1 year. We used the national hospital discharge summaries database system to analyze the management of patients with newly diagnosed PDAC over the year 2016 in Auvergne-Rhône-Alpes region (AuRA) (France). A total of 1872 patients met inclusion criteria corresponding to an incidence of 22.6 per 100,000 person-year. Within the follow-up period, 353 (18.9%) were operated with a curative intent, 743 (39.7%) underwent chemo- and/or radiotherapy, and 776 (41.4%) did not receive any of these treatments. Less than half of patients were operated in a high-volume center, defined by more than 20 PDAC resections performed annually, mainly university hospitals. The 1-year survival rate was 47% in the overall population. This study highlights that a significant number of patients with PDAC are still operated in low-volume centers or do not receive any specific oncological treatment. A detailed analysis of the medical pathways is necessary in order to identify the medical and territorial determinants and their impact on the patient's outcome.

Pancreaticoduodenectomy following endoscopic ultrasound-guided choledochoduodenostomy with electrocautery-enhanced lumen-apposing stents an ACHBT - SFED study.

BACKGROUND: After ERCP failure or if ERCP is declined for preoperative biliary drainage before pancreaticoduodenectomy, endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) with electrocautery-enhanced lumen-apposing stents (ECE-LAMS) might be needed. The aim of the present study was to assess the technical feasibility and short-term outcomes of pancreaticoduodenectomy (PD) following endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) with electrocautery-enhanced lumen-apposing stents (ECE-LAMS). METHODS: A retrospective study of all EUS-CDS procedures with ECE-LAMS followed by PD performed in France since the availability of the device in 2016. RESULTS: 21 patients underwent PD in 9 departments of surgery following EUS-CDS with ECE-LAMS. The median bilirubin level at endoscopic procedure was 292 µmol/L. A 6 mm diameter stent was used in 20 cases. No complications occurred during the procedure. During the waiting time, 1 patient had an acute pancreatitis post ERCP and 3 patients developed cholangitis, treated by either an additional percutaneous biliary drainage, or an endoscopic procedure to extract a bezoar occluding the stent, or antibiotics, respectively. PD with a curative intent was performed in all cases. Overall, postoperative mortality was nil and postoperative morbidity occurred in 17 patients (81%), including 3 with severe complications (14%). No patient developed postoperative biliary fistula. In the 21 patients followed at least 6 months, no biliary complications occurred, and no tumor recurrence developed on the hepaticojejunostomy/hepatic pedicle. CONCLUSION: Pancreaticoduodenectomy following EUS-CDS with ECE-LAMS is technically feasible with acceptable short-term postoperative outcome, including healing of biliary anastomosis.

A case series study of augmented reality in laparoscopic liver resection with a deformable preoperative model.

BACKGROUND: Previous work in augmented reality (AR) guidance in monocular laparoscopic hepatectomy requires the surgeon to manually overlay a rigid preoperative model onto a laparoscopy image. This may be fairly inaccurate because of significant liver deformation. We have proposed a technique which overlays a deformable preoperative model semi-automatically onto a laparoscopic image using a new software called Hepataug. The aim of this study is to show the feasibility of Hepataug to perform AR with a deformable model in laparoscopic hepatectomy. METHODS: We ran Hepataug during the procedures, as well as the usual means of laparoscopic ultrasonography (LUS) and visual inspection of the preoperative CT or MRI. The primary objective was to assess the feasibility of Hepataug, in terms of minimal disruption of the surgical workflow. The secondary objective was to assess the potential benefit of Hepataug, by subjective comparison with LUS. RESULTS: From July 2017 to March 2019, 17 consecutive patients were included in this study. AR was feasible in all procedures, with good correlation with LUS. However, for 2 patients, LUS did not reveal the location of the tumors. Hepataug gave a prediction of the tumor locations, which was confirmed and refined by careful inspection of the preoperative CT or MRI. CONCLUSION: Hepataug showed a minimal disruption of the surgical workflow and can thus be feasibly used in real hepatectomy procedures. Thanks to its new mechanism of semi-automatic deformable alignment, Hepataug also showed a good agreement with LUS and visual CT or MRI inspection in subsurface tumor localization. Importantly, Hepataug yields reproducible results. It is easy to use and could be deployed in any existing operating room. Nevertheless, comparative prospective studies are needed to study its efficacy.

Combining Visual Cues with Interactions for 3D-2D Registration in Liver Laparoscopy.

Augmented Reality (AR) in monocular liver laparoscopy requires one to register a preoperative 3D liver model to a laparoscopy image. This is a difficult problem because the preoperative shape may significantly differ from the unknown intraoperative shape and the liver is only partially visible in the laparoscopy image. Previous approaches are either manual, using a rigid model, or automatic, using visual cues and a biomechanical model. We propose a new approach called the hybrid approach combining the best of both worlds. The visual cues allow us to capture the machine perception while user interaction allows us to take advantage of the surgeon's prior knowledge and spatial understanding of the patient anatomy. The registration accuracy and repeatability were evaluated on phantom, animal ex vivo and patient data respectively. The proposed registration outperforms the state of the art methods both in terms of accuracy and repeatability. An average registration error below the 1 cm oncologic margin advised in the literature for tumour resection in laparoscopy hepatectomy was obtained.

Study Protocol of the PreFiPS Study: Prevention of Postoperative Pancreatic Fistula by Somatostatin Compared With Octreotide, a Prospective Randomized Controlled Trial.

Background: Pancreatic fistula (PF), i. e., a failure of the pancreatic anastomosis or closure of the remnant pancreas after distal pancreatectomy, is one of the most feared complications after pancreatic surgery. PF is also one of the most common complications after pancreatic surgery, occurring in about 30% of patients. Prevention of a PF is still a major challenge for surgeons, and various technical and pharmacological interventions have been investigated, with conflicting results. Pancreatic exocrine secretion has been proposed as one of the mechanisms by which PF occurs. Pharmacological prevention using somatostatin or its analogs to inhibit pancreatic exocrine secretion has shown promising results. We can hypothesize that continuous intravenous infusion of somatostatin-14, the natural peptide hormone, associated with 10-50 times stronger affinity with all somatostatin receptor compared with somatostatin analogs, will be associated with an improved PF prevention. Methods: A French comparative randomized open multicentric study comparing somatostatin vs. octreotide in adult patients undergoing pancreaticoduodenectomy (PD) or distal pancreatectomy with or without splenectomy. Patients with neoadjuvant radiation therapy and/or neoadjuvant chemotherapy within 4 weeks before surgery are excluded from the study. The main objective of this study is to compare 90-day grade B or C postoperative PF as defined by the last ISGPF (International Study Group on Pancreatic Fistula) classification between patients who receive perioperative somatostatin and octreotide. In addition, we analyze overall length of stay, readmission rate, cost-effectiveness, and postoperative quality of life after pancreatic surgery in patients undergoing PD. Conclusion: The PreFiPS study aims to evaluate somatostatin vs. octreotide for the prevention of postoperative PF.

Combined biembolization induces higher hypertrophy than portal vein embolization before major liver resection.

BACKGROUND: Combined preoperative portal and hepatic vein embolization (biembolization, BE) has been recently described and may further enhance preoperative FLR growth. The objective of this study was to compare the efficacy of combined preoperative biembolization and portal vein embolization (PVE). METHODS: This study was performed between 2010 and 2017. From 2010 to 2014, patients only underwent preoperative PVE. After 2014, BE was proposed as an alternative to PVE. Liver volumetry was assessed by a CT-scan before BE or PVE and then three weeks later. RESULTS: During the study period, 72 patients underwent radiological procedures that included 41 PVE (PVE group) and 31 BE (BE group). The time elapsing between the procedure and surgery was similar (p = 0.760). The mean percentage of FLR ratio hypertrophy in the PVE group was 31.9% (±34), but reached 51.2% (±42) in the BE group (p = 0.018) and this difference remained significant under multivariate analysis that included age, gender, body mass index, diabetes mellitus, cirrhosis and NASH. The kinetic growth rates were 19% (±17%) and 8% (±13%) in the BE and PVE groups, respectively (p = 0.026). CONCLUSION: This study shows that BE induces higher hypertrophy than portal vein embolization before major liver resection with no more morbidity.

Pancreaticoduodenectomy with right gastric vessels preservation: impact on intraoperative and postoperative outcomes.

BACKGROUND: Sympathetic denervation of the antropyloric area combined with relative devascularization from division of the right gastric vessels (RGV) during pancreaticoduodenectomy (PD) could predispose to delayed gastric emptying (DGE). Therefore, some authors advocated for RGV preservation (RGVP), where feasibility and utility for the prevention of post-operative DGE have never been investigated. METHODS: From 2011 to 2014, patients who underwent classic Whipple PD (CWPD, n = 34), standard pylorus-preserving PD (PPPD, n = 44) or PPPD with RGVP (n = 22) were retrospectively analysed. RESULTS: RGVP was not possible in 12% of the cases because of an intraoperative injury of the RGV. There was no difference between CWPD, standard PPPD and PPPD with RGVP in terms of intraoperative blood loss, operative time, number of lymph node harvested and resection margins. Post-operative morbidity and mortality were comparable between the three groups, including rate (27%, 34% and 32%, P = 0.77) and severity of DGE, delay in removing nasogastric tube and use of prokinetics. Hospital stay was similar in all the compared groups. CONCLUSION: This is the first study comparing post-operative outcomes after PPPD with RGVP, standard PPPD and CWPD. Although feasible and safe, RGVP during PPPD appeared to offer no obvious clinical benefit in terms of preventing post-operative complications, especially DGE.

Preoperative liver registration for augmented monocular laparoscopy using backward-forward biomechanical simulation.

PURPOSE: Augmented reality for monocular laparoscopy from a preoperative volume such as CT is achieved in two steps. The first step is to segment the organ in the preoperative volume and reconstruct its 3D model. The second step is to register the preoperative 3D model to an initial intraoperative laparoscopy image. To date, there does not exist an automatic initial registration method to solve the second step for the liver in the de facto operating room conditions of monocular laparoscopy. Existing methods attempt to solve for both deformation and pose simultaneously, leading to nonconvex problems with no optimal solution algorithms. METHODS: We propose in contrast to break the problem down into two parts, solving for (i) deformation and (ii) pose. Part (i) simulates biomechanical deformations from the preoperative to the intraoperative state to predict the liver's unknown intraoperative shape by modeling gravity, the abdominopelvic cavity's pressure and boundary conditions. Part (ii) rigidly registers the simulated shape to the laparoscopy image using contour cues. RESULTS: Our formulation leads to a well-posed problem, contrary to existing methods. This is because it exploits strong environment priors to complement the weak laparoscopic visual cues. CONCLUSION: Quantitative results with in silico and phantom experiments and qualitative results with laparosurgery images for two patients show that our method outperforms the state-of-the-art in accuracy and registration time.

Preliminary trial of augmented reality performed on a laparoscopic left hepatectomy.

BACKGROUND: Laparoscopic liver surgery is seldom performed, mainly because of the risk of hepatic vein bleeding or incomplete resection of the tumour. This risk may be reduced by means of an augmented reality guidance system (ARGS), which have the potential to aid one in finding the position of intrahepatic tumours and hepatic veins and thus in facilitating the oncological resection and in limiting the risk of operative bleeding. METHODS: We report the case of an 81-year-old man who was diagnosed with a hepatocellular carcinoma after an intraabdominal bleeding. The preoperative CT scan did not show metastases. We describe our preferred approach for laparoscopic left hepatectomy with initial control of the left hepatic vein and preliminary results of our novel ARGS achieved postoperatively. In our ARGS, a 3D virtual anatomical model is created from the abdominal CT scan and manually registered to selected laparoscopic images. For this patient, the virtual model was composed of the segmented left liver, right liver, tumour and median hepatic vein. RESULTS: The patient's operating time was summed up to 205 min where a blood loss of 300 cc was recorded. The postoperative course was simple. Histopathological analysis revealed the presence of a hepatocellular carcinoma with free margins. Our results of intrahepatic visualization suggest that ARGS can be beneficial in detecting the tumour, transection plane and medial hepatic vein prior to parenchymal transection, where it does not work due to the substantial changes to the liver's shape. CONCLUSIONS: As of today, we have performed eight similar left hepatectomies, with good results. Our ARGS has shown promising results and should now be attempted intraoperatively.