Abdominal aortic calcification volume as a preoperative prognostic predictor for pancreatic cancer.

PURPOSE: Atherosclerosis and cancer may progress through common pathological factors. This study was performed to investigate the association between the abdominal aortic calcification (AAC) volume and outcomes following surgical treatment for pancreatic cancer. METHODS: The subjects of this retrospective study were 194 patients who underwent pancreatic cancer surgery between 2007 and 2020. The AAC volume was assessed through routine preoperative computed tomography. Univariate and multivariate analyses were performed to evaluate the impact of the AAC volume on oncological outcomes. RESULTS: A higher AAC volume (≥ 312 mm3) was identified in 66 (34%) patients, who were significantly older and had a higher prevalence of diabetes and sarcopenia. Univariate analysis revealed several risk factors for overall survival (OS), including male sex, an AAC volume ≥ 312 mm3, elevated carbohydrate antigen 19-9, prolonged operation time, increased intraoperative bleeding, lymph node metastasis, poor differentiation, and absence of adjuvant chemotherapy. Multivariate analysis identified an AAC volume ≥ 312 mm3, prolonged operation time, lymph node metastasis, poor differentiation, and absence of adjuvant chemotherapy as independent OS risk factors. The OS rate was significantly lower in the high AAC group than in the low AAC group. CONCLUSION: The AAC volume may serve as a preoperative prognostic indicator for patients with pancreatic cancer.

Long-term outcomes of choledochoduodenostomy for choledocholithiasis: increased incidence of postoperative cholangitis after total or distal gastrectomy.

PURPOSE: Choledochoduodenostomy (CDD) is performed to treat choledocholithiasis (CDL) cases where endoscopic stone removal is difficult. Recognizing CDD characteristics is important for CDL treatment planning. METHODS: A total of 116 patients, including 33 patients ≥ 80 years old (29 with previous total gastrectomy, 19 with previous distal gastrectomy, 20 with built-up stones, 19 with periampullary diverticulum, 10 with confluence stones, 8 with repetitive recurrent stones, 4 with hard stones, 3 with endoscopic retrograde cholangiography [ERC] not available due to lack of cooperation, 2 with a history of pancreatitis post-ERC, and 2 in whom ERC could not be performed due to a disturbed anatomy) underwent CDD for CDL. Postoperative complications and long-term outcomes were evaluated. RESULTS: The in-hospital mortality rate was 0%. The morbidity (grade ≥ IIIA according to the Clavien-Dindo classification) rates in the elderly (≥ 80 years old) and non-elderly (51-79 years old) patients were 3.0% (1/33) and 2.4% (2/83), respectively (p = 0.85). Long-term complications included cholangitis in eight (7%) patients, of which three cases were repetitive and seven had an operative history of total or distal gastrectomy. The incidence of postoperative cholangitis after total or distal gastrectomy was 15% (7/48), which was significantly higher than that involving other causes (1.5%, 1/68; p < 0.01). Two patients with cholangitis after total gastrectomy experienced early recurrence of lithiasis at 2 and 9 months after surgery. CONCLUSIONS: CDD is safe, even in elderly patients. However, a history of total gastrectomy or distal gastrectomy may increase the incidence of postoperative cholangitis.

Double cone-unit laparoscopic hepatic resection for tumors adjacent to the hepatic vein.

BACKGROUND: In tumor adjacent to the hepatic vein, it is important to treat two tertiary Glissonean pedicles that straddle to the hepatic vein in order to remove the tumor with a negative margin. The anatomical resection of the smallest unit may be considered to be the resection of the double cone-unit (DCU) in small tumor adjacent to the vein. PATIENTS AND METHODS: 127 patients who had undergone laparoscopic hepatectomy at the Jikei Medical University Hospital from 2020 through 2021. In 5 cases, Laparoscopic DCU resection was performed. If the CT image shows a hepatic vein near the tumor and the tumor is relatively small, less than 50 mm in size, DCU resection should be considered. After approaching the target Glissonean pedicles, the Bulldog Clamps were used to testing clamp it. After clamping it, the ICG was injected from peripheral veins. A few minutes later, the tumor-bearing portal territory could be identified as negative regions of fluorescence in the near infrared imaging system. The target hepatic vein, which runs between the two territories, was dissected where it transitions from the first to the second territory. RESULTS: The median operative time in these 5 patients was 279 min, and the median volume of blood loss was 290 g. The average tumor size was 33 mm and the average surgical margin was 4.5 mm. CONCLUSION: In small tumor adjacent to the hepatic vein, the anatomical hepatectomy of the smallest unit may be the Double Cone-Unit resection.

A feasible and safe approach for repeat laparoscopic liver resection and patient selection based on standardized preoperative prediction of surgical difficulty.

PURPOSE: This study was performed to propose a strategy for repeat laparoscopic liver resection (RLLR) and investigate the preoperative predictive factors for RLLR difficulty. METHODS: Data from 43 patients who underwent RLLR using various techniques at 2 participating hospitals from April 2020 to March 2022 were retrospectively reviewed. Surgical outcomes, short-term outcomes, and feasibility and safety of the proposed techniques were evaluated. The relationship between potential predictive factors for difficult RLLR and perioperative outcomes was evaluated. Difficulties associated with RLLR were analyzed separately in two surgical phases: the Pringle maneuver phase and the liver parenchymal transection phase. RESULTS: The open conversion rate was 7%. The median surgical time and intraoperative blood loss were 235 min and 200 mL, respectively. The Pringle maneuver was successfully performed in 81% of patients using the laparoscopic Satinsky vascular clamp (LSVC). Clavien-Dindo class ≥III postoperative complications were observed in 12% of patients without mortality. An analysis of the risk factors for predicting difficult RLLR showed that a history of open liver resection was an independent risk factor for difficulty in the Pringle maneuver phase. CONCLUSION: We present a feasible and safe approach to address RLLR difficulty, especially difficulty with the Pringle maneuver using an LSVC, which is extremely useful in RLLR. The Pringle maneuver is more challenging in patients with a history of open liver resection.

Osteosarcopenia predicts poor prognosis for patients with intrahepatic cholangiocarcinoma after hepatic resection.

PURPOSE: The concept of osteosarcopenia, which is concomitant osteopenia and sarcopenia, has been proposed as a prognostic indicator for cancer patients. The aim of this study was to evaluate the prognostic significance of osteosarcopenia in patients with intrahepatic cholangiocarcinoma (IHCC). METHODS: The subjects of this retrospective study were 41 patients who underwent hepatic resection for IHCC. Osteopenia was assessed with pixel density in the mid-vertebral core of the 11th thoracic vertebra and sarcopenia was assessed by the psoas muscle areas at the third lumbar vertebra. Osteosarcopenia was defined as the concomitant occurrence of osteopenia and sarcopenia. We analyzed the association of osteosarcopenia with disease-free and overall survival and evaluated clinicopathologic variables in relation to the osteosarcopenia. RESULTS: Eighteen (44%) of the 41 patients had osteosarcopenia. Multivariate analysis identified osteosarcopenia (hazard ratio 3.38, 95% confidence interval: 1.49-7.68, p < 0.01) as an independent predictor of disease-free survival, and age ≥ 65 years (p = 0.03) and osteosarcopenia (hazard ratio 6.46, 95% confidence interval: 1.76-23.71, p < 0.01) as independent predictors of overall survival. CONCLUSIONS: Preoperative osteosarcopenia may be a predictor of adverse prognosis for patients undergoing hepatic resection for IHCC, suggesting that preoperative management to maintain muscle and bone intensity could improve the prognosis.

The significance of osteosarcopenia as a predictor of the long-term outcomes in hepatocellular carcinoma after hepatic resection.

BACKGROUND: Frailty, represented by sarcopenia and osteopenia, has been associated with worse survival after hepatectomy in patients with hepatocellular carcinoma. Recently, the concept and term "osteosarcopenia" have been proposed, which has been associated with worse outcome in several malignancies. METHODS: This study included 227 patients who underwent elective hepatic resection for hepatocellular carcinoma. Osteopenia was evaluated with computed tomographic measurement of pixel density in the midvertebral core of the 11th thoracic vertebra. The skeletal muscle index (SMI) was evaluated with psoas muscle areas at the third lumbar vertebra. Osteosarcopenia was defined as the concomitant occurrence of osteopenia and low SMI. We retrospectively investigated the relationship between osteosarcopenia and disease-free and overall survival. RESULTS: Osteosarcopenia was identified in 27 (12%) of the patients. Multivariate analysis showed that osteosarcopenia (P < .001), C-reactive protein-to-albumin ratio ≥0.02 (P = .002), and stage ≥III (P ≤ .001) were independent predictors of disease-free survival, while osteosarcopenia (P < .001), Child-Pugh grade B (P = .002), C-reactive protein-to-albumin ratio ≥0.02 (P = .001), low SMI (P ≤ .001), and stage ≥III (P ≤ .001) were independent predictors of overall survival. CONCLUSION: Preoperative osteosarcopenia may be a prognostic factor in patients with hepatocellular carcinoma after hepatic resection. Our results suggests that the preoperative maintenance of skeletal muscle and bone density may potentially improve prognosis.

Laparoscopic cholecystectomy with the Pringle maneuver for acute cholecystitis (with video).

Horiuchi and colleagues assessed the benefits of adding the Pringle maneuver to laparoscopic cholecystectomy for acute cholecystitis. Compared with laparoscopic cholecystectomy without the Pringle maneuver, including it reduced intraoperative bleeding. Laparoscopic cholecystectomy with the Pringle maneuver is a safe and feasible option that avoids conversion to open laparotomy and prevents serious complications.

The impact of postoperative exocrine index on non-alcoholic fatty liver disease following pancreaticoduodenectomy.

Background: To study exocrine function of the remnant pancreas after pancreatoduodenectomy (PD), we propose the use of an exocrine index (PEI) that combines the volume of the remnant pancreas and the intraoperative amylase activity of the pancreatic juice. Here, we aimed to determine whether the PEI can predict non-alcoholic fatty liver disease (NAFLD) following PD. Methods: Fifty-seven patients for whom pancreatic juice amylase activity was measured during PD were enrolled. NAFLD was defined as a liver-to-spleen attenuation ratio of <0.9 on plain CT 1 year following surgery. We retrospectively evaluated clinical parameters, including the PEI, to identify predictors of NAFLD. Results: Fifty-four patients (95%) were regularly administered 1200 mg of pancreatic lipase. NAFLD was diagnosed in 13 participants (23%) 1 year following surgery. NAFLD was associated with pancreatic ductal adenocarcinoma (P = .006), soft pancreas (P = .001), small main pancreatic duct (P = 0008), low remnant pancreatic volume (P < .001), low intraoperative amylase activity in the pancreatic juice (P = .001), high pancreatic fibrosis (P = .032), and large body weight loss (P = .015). The PEI was significantly lower in the participants with NAFLD than in those without (P < .001). The participants were then classified into tertiles of PEI: <5 × 106, 5-25 × 106, and >25 × 106. The prevalence of NAFLD in these groups was 53% (10/19), 11% (2/19), and 5% (1/19), respectively. In multivariable analyses, there was a significant association between NAFLD and the PEI (P value for trend = .042). Conclusion: The PEI, calculated using the remnant pancreatic volume and the intraoperative pancreatic juice amylase activity, predicts NAFLD development following PD.

Standardized and Feasible Laparoscopic Approach for Tumors Located in the Caudate Lobe.

BACKGROUND/AIM: Although laparoscopic hepatectomy has been widely used in the management of liver tumors for its reduced invasiveness and magnified view, in the caudate lobe it remains challenging especially for patients with cirrhosis. Thus, this study aimed to evaluate patients undergoing laparoscopic hepatectomy for hepatic tumors in the caudate lobe and establish strategies for performing such procedure. PATIENTS AND METHODS: Laparoscopic hepatectomy in the caudate lobe was performed in nine patients. We performed inflow control to reduce bleeding during hepatic transection and retraction of the left lateral section to the cranial side to obtain a sufficient surgical field using a Nathanson liver retractor. We approached tumors in the Spiegel lobe (SP) from caudal side for segment 1 (S1) partial hepatectomy and from caudal and left side for Spiegel lobectomy, the lower paracaval portion (PC) from caudal side for S1 partial hepatectomy, and the upper PC from caudal and bilateral side for total caudate lobectomy. RESULTS: In 6 cases the tumors were in the SP and in 3 cases in the PC. The types of laparoscopic hepatectomy performed were total caudate lobectomy (n=1), Spiegel lobectomy (n=2), and partial hepatectomy of segment 1 (n=6). All the tumors were curatively resected, and no patient had complications. Operative time for tumors located in the PC was significantly longer than that for tumors located in the SP. Laparoscopic hepatectomy in the caudate lobe was safely performed for five patients with liver cirrhosis. CONCLUSION: Laparoscopic hepatectomy in the caudate lobe may become the standard surgical technique with hepatic inflow control, sufficient surgical field exposure, and appropriate approach.

Phase II trial of nafamostat mesilate/gemcitabin/S-1 for unresectable pancreatic cancer.

PURPOSE: To assess the efficacy of combination chemotherapy with nafamostat mesilate, gemcitabine and S-1 for unresectable pancreatic cancer patients. MATERIALS AND METHODS: The study was conducted as a single-arm, single center, institutional review board-approved phase II trial. Patients received nafamosntat mesilate (4.8 mg/kg continuous transregional arterial infusion) with gemcitabine (1000 mg/m2 transvenous) on days 1 and15, and with oral S-1 [(80 mg/day (BSA<1.25 m2), 100 mg/day (1.25 ≤ BSA<1.5 m2), or 120 mg/day (BSA ≥1.5 m2)] on days 1-14 or, days 1-7 and 15-21. This regimen was repeated at 28-day intervals. RESULTS: Forty-seven evaluable patients (Male/Female: 31/16, Age (median): 66 (range 35-78) yrs, Stage III/IV 10/37.) were candidates in this study. Two patients in stage III (20%) could undergo conversion surgery. Twenty-four patients (51%) underwent subsequent treatment (1st line/ 2nd line / 4th line, 13/ 10/ 1, FOLFIRINOX: 12, GEM/nab-PTX: 18, TAS-118: 3, chemoradiation with S-1: 2, GEM/Erlotinib: 1, nal-IRI: 1, surgery: 2). Median PFS and OS were 9.7 (95% CI, 8.9-14.7 mo) and 14.2 months (99% CI, 13.3-23.9 mo), respectively. Median PFS in stage IV patients was 9.2 months (95% CI, 8.4-12.0 mo). Median OS in patients without subsequent treatment was 10.8 months (95% CI, 9.1-13.8 mo). Median OS in patients with subsequent treatment was 19.3 months (95% CI, 18.9-31.9 mo). Grade 4 treatment-related hematological toxicities were encountered in 7 patients. Two patients developed grade 3 allergic reaction after 6 cycles or later. No febrile neutropenia has been observed. CONCLUSION: NAM/GEM/S-1 therapy is safe and could be promising option for unresectable pancreatic cancer, especially for stage IV cancer.

Effects of an enteral nutrient-rich therapy with omega-3 fatty acids in patients with unresectable or recurrent biliary tract cancer or pancreatic cancer during chemotherapy: a case-control study.

To evaluate omega-3 fatty acid-rich enteral nutrient effects in patients with unresectable or recurrent biliary tract or pancreatic cancers during chemotherapy. Enteric nutritional supplements containing omega-3 fatty acids (Racol®) was administered to aforementioned patients with cancers during chemotherapy. The skeletal muscle mass and blood test data were obtained pre-administration and 28 and 56 days after. Patients with pancreatic cancer were administered the digestive enzyme supplement pancrelipase (LipaCreon®) 28 days after the start of Racol® administration. The number of chemotherapies skipped due to neutropenia was recorded for 2 months before and after enteral nutrient initiation. In all 39 patients, the skeletal muscle mass increased on day 56 versus baseline (median 17.3 kg vs. 14.8 kg, p < 0.01), number of chemotherapies skipped decreased (mean: 0.65 times/month vs. 1.3 times/month, p = 0.03), and retinol-binding protein (mean: 2.56 mg/dL vs. 2.42 mg/dL, p = 0.05) increased. Patients with pancreatic cancer showed increased blood eicosapentaenoic acid concentration on day 56 versus baseline (median: 48.1 µg/mL vs. 37.0 µg/mL, p = 0.04) and increased skeletal muscle mass (median 16.8 kg vs. 14.4 kg, p = 0.006). Baseline median neutrophil count increased significantly from 2200/µL at baseline to 2500/µL (p = 0.04). Patients with biliary tract cancer during chemotherapy also exhibited increased skeletal muscle mass following omega-3 supplementation (median 17.3 kg vs. 15.8 kg, p = 0.01). In patients undergoing chemotherapy for unresectable or post-recurrence pancreatic and biliary tract cancers, high-omega-3 fatty acid nutrition therapy use improved skeletal muscle maintenance and chemotherapy dosing intensity.

Conversion surgery for undifferentiated carcinoma with osteoclast-like giant cells of the pancreas: a case report.

BACKGROUND: Undifferentiated carcinoma with osteoclast-like giant cells (UCOGCs) is a rare subtype of pancreatic cancer (PC), and its clinicopathological characteristics are still unclear. Herein, we report a case of initially unresectable UCOGC that was successfully resected after FOLFIRINOX therapy. CASE PRESENTATION: A 63-year-old man was referred to us for evaluation of a pancreatic mass detected by computed tomography (CT) during a medical checkup. Computed tomography showed a 7.5-cm tumor located in the pancreatic head and body, which involved the common hepatic artery (CHA), gastroduodenal artery (GDA), and main portal vein (PV) with tumor thrombus. UCOGC was suspected by endoscopic ultrasonography-guided fine needle aspiration, and the patient was diagnosed with unresectable locally advanced pancreatic cancer. After ten cycles of FOLFIRINOX, the tumor size decreased to 3 cm and the tumor thrombus in the main portal trunk had disappeared in the follow-up CT scan. However, the patient experienced severe adverse drug reactions, including neutropenia and liver dysfunction. Therefore, we performed pancreatoduodenectomy with portal vein resection. The pathological diagnosis was UCOGC with a negative tumor margin. He was treated with FOLFIRINOX, and remains recurrence-free for 6 months after surgery. CONCLUSIONS: We experienced a case undergoing conversion surgery for unresectable UCOGC, which resulted in R0 resection. FOLFIRINOX could be a possible regimen to achieve conversion surgery for UCOGC.

Safe perioperative management of major hepatectomy in a patient with portal hypertension after elimination of hepatitis C: a case report.

BACKGROUND: The administration of direct-acting antiviral agents in patients with liver cirrhosis and hepatitis C has been shown to improve liver function and long-term prognosis after sustained virological response (SVR) is achieved. However, in patients with portal hypertension (PH) at the time of SVR, PH may persist despite improvement in liver function. CASE PRESENTATION: An 82-year-old woman with liver cirrhosis due to hepatitis C was treated with direct-acting antiviral agents and achieved SVR. During follow-up, computed tomography revealed a low-density tumor in the left lateral region of the liver with dilation of the left intrahepatic bile duct. Considering the patient's advanced age and PH persistence with a mild decrease in liver reserve function after SVR, preoperative percutaneous transhepatic portal embolization (PTPE) and partial splenic embolization (PSE) were performed concomitantly. Laparoscopic left hemihepatectomy was performed 8 days after the PTPE and PSE. The patient was discharged 8 days after surgery without any postoperative complications. CONCLUSIONS: Laparoscopic left hemihepatectomy after preoperative management of PH was performed safely in a patient after the elimination of hepatitis C.

Risk Factors and Overcoming Strategies of Surgical Site Infection After Hepatectomy for Colorectal Liver Metastases.

BACKGROUND/AIM: The aim of this study was to investigate the risk factors of surgical site infection (SSI) in patients who underwent liver resection for colorectal liver metastases (CRLM). PATIENTS AND METHODS: A total of 151 patients who underwent liver resection for CRLM were included in this study. We investigated the relationship between the patient characteristics and perioperative factors and the incidence of SSI. RESULTS: Nineteen (13%) of these patients developed SSI. Multivariate analysis revealed that modified Glasgow Prognostic Score (mGPS) (1 or 2, odds ratio 3.86, p=0.03) and presence of an enterostomy (yes, odds ratio 3.93, p=0.04) were significant and independent risk factors for SSI. CONCLUSION: A higher mGPS and an enterostomy were risk factors for SSI in patients who underwent a liver resection for CRLM.

Feasible laparoscopic left trisectionectomy by Arantius' ligament approach (with video).

BACKGROUND: Laparoscopic trisectionectomy is a technically challenging procedure with high rate of postoperative morbidity [1,2]. Arantius' ligament approach is useful to expose the root of middle hepatic vein, which is required in left trisectionectomy [3]. METHODS: This video illustrates laparoscopic left trisectionectomy using Arantius' ligament approach. A 63-year-old man, with chronic kidney disease, had intrahepatic cholangiocarcinoma with a diameter of 8 cm, located in the segment 4 and anterior section of the liver. The tumor was close to the umbilical portion of the left portal vein and future liver remnant was 770 ml (49.5% of the whole liver) after left trisectionectomy. VIDEO: After the pneumoperitoneum and the mobilization of the left lateral segment, the root of left and middle hepatic vein was exposed by division of Arantius' ligament and parenchymal transection of dorsal surface around the root of left hepatic vein. Next, the left Glissonian pedicle was controlled and divided. The Glissonean pedicle for the anterior section was then isolated and divided. Demarcation line was then observed using indocyanine green negative counterstaining. Parenchymal transection was completed followed by the division of the common trunk of the left and middle hepatic veins. RESULTS: The operation time was 294 min, and the blood loss was 400 g. The patient was discharged on postoperative day 16 after conservative treatment for temporary kidney injury. Pathological examination revealed intrahepatic cholangiocarcinoma with negative surgical margin. CONCLUSION: The Arantius' ligament approach could be a feasible procedure for left trisectionectomy.

How to Perform Curative Laparoscopic Hepatectomy for Intraoperatively Unidentified Hepatocellular Carcinoma.

BACKGROUND/AIM: Detection of hepatocellular carcinoma using intraoperative ultrasonography (IOUS) is indispensable for successful laparoscopic hepatectomy (LH). This study was performed to evaluate patients with intraoperatively unidentified tumours undergoing LH. PATIENTS AND METHODS: Seven patients who underwent LH for hepatocellular carcinoma and whose tumours were not detected using IOUS were included in this study. Clinical features, preoperative imaging, intraoperative imaging, surgical procedures, and pathological findings were evaluated. RESULTS: Using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging, all the tumours were enhanced in the arterial phase and rapidly washed out, becoming hypointense to the remainder of the liver. All tumours except one were <2 cm in size. Severe liver fibrosis was observed in all cases. Tumours that were invisible on preoperative ultrasonography also could not be detected using IOUS or indocyanine green fluorescence imaging. Five patients underwent hepatectomy based on anatomical landmarks and achieved curative resection, whereas curative resection failed in two patients. CONCLUSION: When tumours cannot be identified by IOUS, LH based on anatomical landmarks should be preferred. Importantly, invisible tumours on preoperative ultrasonography may not be identified intraoperatively during LH.

The Significance of the Rapid Turnover Protein Score as a Predictor of the Long-Term Outcomes in Hepatocellular Carcinoma After Hepatic Resection.

BACKGROUND: Nutritional status assessment is essential in cancer patients because a poor nutritional status has been associated with poor outcomes; however, the impact of rapid turnover proteins (RTPs), such as prealbumin, transferrin, and retinol-binding protein, on the outcomes of hepatocellular carcinoma (HCC) has not been well-investigated. We therefore examined the prognostic significance of RTPs in patients with HCC after curative resection. METHODS: This study included 150 patients who underwent elective hepatic resection for HCC between January 2011 and December 2018. The prealbumin, transferrin, and retinol-binding protein levels were classified into two groups (high vs. low); the RTP score (0-3) was calculated as the sum of each RTP measurement (high = 0; low = 1). We retrospectively investigated the relationship between the RTP score and disease-free and overall survival. RESULTS: Multivariate analysis showed that a high RTP score (P = 0.022), presence of sarcopenia (P = 0.001), and stage III or higher (P = 0.005) were independent predictors of disease-free survival, while a high RTP score (P < 0.001), presence of sarcopenia (P = 0.017), and stage III or higher (P = 0.012) were independent predictors of overall survival. In patients with high RTP scores, positive hepatitis B and C viral infection, high indocyanine green (ICG) at 15 min (ICGR15), Child-Pugh grade B, poorly differentiated carcinoma, and postoperative ascites were more common than in patients with low RTP scores. CONCLUSION: The preoperative RTP score may be a prognostic factor in patients with hepatocellular carcinoma after hepatic resection, suggesting an important role of RTP in the assessment of nutritional status in cancer patients.

Development of recognised position-guided navigation system.

BACKGROUND: Previously, we developed an image-guided navigation system (IG-NS) incorporating augmented reality technology. Nevertheless, the system could still only aid the operator by presenting imagery and was short of achieving the goal of developing a real navigation system. Therefore, we developed a recognised position-guided navigation system (RP-NS) and herein reported the functionality and usefulness of this system in a phantom model for clinical applications. METHODS: We developed RP-NS which was reconstructed by adding the positional recognition and instruction functions with the cautions by displaying the images on the monitor with a voice to the IG-NS. We evaluated accuracy of positional recognition and instruction functions using phantom model. By utilising the chronological recording of the tip position of the surgical apparatus, the surgical precision of the operators was assessed. Finally, the feasibility of improvements in surgical precision using this system was evaluated. RESULTS: The RP-NS indicated an accuracy of the position recognition functions with an error of 2.7 mm. The surgeons could perform partial hepatectomies within mean value of 7.5% error as compared with calculated volume according to the instruction. Improvements in surgical precision using this system were obtained on the surgeons with different levels. CONCLUSIONS: The RP-NS was highly effective as a navigation system owing to precise positional recognition and adequate instruction functions. Therefore, these results indicate that the use of this system may complement differences in proficiency, and numerically evaluate surgical skills and analyse tendencies of surgeons.