Current Status of Robotic Hepatobiliary and Pancreatic Surgery.

Laparoscopic surgery is performed worldwide and has clear economic and social benefits in terms of patient recovery time. It is used for most gastrointestinal surgical procedures, but laparoscopic surgery for more complex procedures in the esophageal, hepatobiliary, and pancreatic regions remains challenging. Minimally invasive surgery that results in accurate tumor dissection is vital in surgical oncology, and development of surgical systems and instruments plays a key role in assisting surgeons to achieve this. A notable advance in the latter half of the 1990s was the da Vinci Surgical System, which involves master-slave surgical support robots. Featuring high-resolution three-dimensional (3D) imaging with magnification capabilities and forceps with multi-joint function, anti-shake function, and motion scaling, the system compensates for the drawbacks of conventional laparoscopic surgery. It is expected to be particularly useful in the field of hepato-biliary-pancreatic surgery, which requires delicate reconstruction involving complex liver anatomy with diverse vascular and biliary systems and anastomosis of the biliary tract, pancreas, and intestines. The learning curve is said to be short, and it is hoped that robotic surgery will be standardized in the near future. There is also a need for a standardized robotic surgery training system for young surgeons that can later be adapted to a wider range of surgeries. This systematic review describes trends and future prospects for robotic surgery in the hepatobiliary-pancreatic region.

Carbohydrate Antigen 19-9 Is an Invasive Malignancy Preoperative Prognostic Factor for Intraductal Papillary Mucinous Neoplasms.

INTRODUCTION: This study aimed to determine the preoperative clinicophysiological and postoperative clinicopathological predictors of malignancy in patients with intraductal papillary mucinous neoplasm (IPMN). METHODS: This was a retrospective observational study. We included 121 patients (73 men and 48 women; mean age: 68.7 years) who had undergone pancreatic resection for IPMN between 2007 and 2018. These patients were grouped into invasive carcinoma (IPMN-INV, N = 21) and low/high-grade IPMN (IPMN-LG/HG, N = 100) groups. Univariate and multivariate analyses of clinicophysiological parameters were carried out. These parameters were also compared between the IPMN-INV/HG (N = 53) and IPMN-LG (N = 68) groups. Survival analyses according to macroscopic type and IPMN subtypes were performed. RESULTS: On univariate analysis, age (p = 0.038), carbohydrate antigen (CA) 19-9 (p < 0.001), IPMN macroscopic type (p = 0.001), IPMN subtype (p < 0.001), pancreatic duct diameter (p < 0.001), and mural nodule (p = 0.042), between IPMN-INV and IPMN-LG/HG were found to be significant prognostic factors of malignancy. CA 19-9 was found to be an independent prognostic factor of IPMN malignancy on multivariate analysis (p = 0.035). The 1-, 3-, and 5-year overall survival (OS) rates of the IPMN-INV and IPMN-LG/HG groups were 94.4/100%, 94.4/100%, and 67.2/100%, respectively. The OS rate in the IPMN-LG/HG group was significantly higher than that in the IPMN-INV group (p < 0.001). On univariate analysis, platelet (p = 0.043), CA 19-9 (p = 0.039), prognostic nutritional index (p = 0.034), platelet/lymphocyte ratio (p = 0.01), IPMN macroscopic type (p < 0.001), IPMN subtype (p < 0.001), pancreatic duct diameter (p = 0.036), and mural nodule (p = 0.032) between IPMN-INV/HG and IPMN-LG were found to be significant prognostic factors of malignancy. On multivariate analysis, CA 19-9 was found to be an independent prognostic factor (p = 0.042) between IPMN-INV/HG and IPMN-LG of malignancy. The 1-, 3-, and 5-year OS rates of the IPMN-INV/HG and IPMN-LG groups were 97.9/100%, 97.9/100%, and 82.6/100%, respectively. The OS rate was significantly higher in the IPMN-LG group than in the IPMN-INV/HG group (p = 0.03). No significant differences in survival were observed in patients with macroscopic tumors (p= 0.544). CONCLUSION: CA 19-9 is an independent invasive malignancy predictor of IPMN.

Drain Lipase Levels and Decreased Rate of Drain Amylase Levels as Independent Predictors of Pancreatic Fistula with Nomogram After Pancreaticoduodenectomy.

BACKGROUND: Pancreaticoduodenectomy (PD) has recently been improved due to its increased safety. However, postoperative pancreatic fistula (POPF) remains a lethal complication of PD. Identifying novel clinicophysiological risk factors for POPF during the early post-PD period would help improve patient morbidity and mortality. Therefore, this retrospective study aimed to evaluate possible risk factors during the early postoperative period after pancreaticoduodenectomy (PD). METHODS: Data from 349 patients who underwent PD between 2007 and 2012 were examined retrospectively. All patients were classified into 2 groups: group A, patients without fistulae or biochemical leaks (288 patients), and group B, those with grade B or C POPF (61 patients). Data on various clinicophysiological parameters, including serum and drain laboratory data, were collected. Univariate and multivariate analyses were performed to evaluate POPF predictors. A predictive nomogram was established for these results. RESULTS: Univariate analysis showed that various serum and drain-related factors, such as white blood cell count, C-reactive protein levels, drain amylase (DAMY) levels, and drain lipase (DLIP) levels, were possible POPF risk factors. Multivariate analysis confirmed that postoperative day (POD) 1 DLIP levels (hazard ratio, 15.393; p = 0.037) and decreased rate (POD3/1) of DAMY levels (hazard ratio, 4.415; p = 0.028) were independent risk factors. Further, POD1 DLIP levels and decreased rate of DAMY levels were significantly lower in group A than in group B. The accuracy of nomogram was 0.810. CONCLUSIONS: POD1 DLIP levels (> 245 U/mL) and decreased rate of DAMY levels (> 0.44) were POPF risk factors, making them possible biomarkers for POPF.

Loss of antibodies to hepatitis E virus in organ transplant patients with hepatitis E.

AIM: Studies regarding changes in antibodies to hepatitis E virus (HEV) after HEV infection in organ transplant patients are limited. This study aimed to clarify HEV infection trends in organ transplant patients who contracted HEV using data from a previous Japanese nationwide survey. METHODS: This study was undertaken from 2012 to 2019. Among 4518 liver, heart, and kidney transplant patients, anti-HEV immunoglobulin G (IgG) antibodies were positive in 164; data were collected from 106 of these patients, who consented to participate in the study. In total, 32 liver transplant patients, seven heart transplant patients, and 67 kidney transplant patients from 16 institutions in Japan were examined for IgG, IgM, and IgM antibodies to HEV and the presence of HEV RNA in the serum. The χ2 -test was used to determine the relationship between the early and late postinfection groups in patients with anti-HEV IgG positive-to-negative conversion rates. The Mann-Whitney U-test was used to compare clinical factors. RESULTS: Anti-HEV IgG positive-to-negative conversion occurred in 25 (23.6%) of 106 organ transplant patients. Of eight patients with hepatitis E who tested positive for HEV RNA, one (14.0%) had anti-HEV IgG positive-to-negative conversion. Twenty-four (24.5%) of 98 patients negative for HEV RNA had anti-HEV IgG positive-to-negative conversion. CONCLUSIONS: This study revealed, for the first time, the changes in HEV antibodies in organ transplant patients. Loss of anti-HEV IgG could often occur unexpectedly in organ transplant patients with previous HEV infection.

What are the risk factors of conversion from total cholecystectomy to bailout surgery?

BACKGROUND: Laparoscopic cholecystectomy (LC) is regarded as the first choice for patients with gallbladder diseases, but biliary injury (BDI) still poses serious risks upon implementation of LC. Recently, bailout surgery (BOS; partial cholecystectomy or subtotal cholecystectomy) has been proposed to avoid not only BDI but also major vessels injuries. In this retrospective study, we evaluated the preoperative and perioperative risk factors regarding conversion from total cholecystectomy (TC) to BOS. METHODS: A total of 584 patients who underwent elective LC for gallbladder diseases between January 2006 and April 2018 were analyzed. The patients were divided into the TC group (including conversion open TC) and the BOS group. Univariate and multivariate analyses using preoperative and perioperative clinicolaboratory characteristics were performed to investigate the most significant risk factors associated with conversion to BOS. RESULTS: There were a total of 33 patients in the BOS group (35 men and 18 women), with 19 patients who underwent open BOS and 14 patients who underwent laparoscopic BOS. From the univariate analyses, age, albumin level, CRP level, WBC, lymph. ratio, neutro. ratio, platelet count (PLt), neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, CRP-to-alb ratio, intercurrent acute cholecystitis (AC), and previous biliary tract drainage (PBTD) were considered as risk factors for the conversion to BOS. Multivariate analysis using the 13 parameters selected from the univariate analyses demonstrated that AC (p = 0.04), albumin level (p = 0.01) and age (p = 0.04) were significant risk factors. CONCLUSION: Patients with PBTD and AC have a high risk upon conversion from LTC to BOS, and for such patients, LC should be performed cautiously.

Leiomyosarcoma of the transverse colon with lymph node metastasis and malignant transformation: a case report.

BACKGROUND: The concept of GIST was established in 1998, clearly differentiating between gastrointestinal leiomyosarcoma and GISTs among gastrointestinal mesenchymal tumors. Lymph node metastasis is extremely rare in true gastrointestinal leiomyosarcoma, and there are no reports of malignant transformation from leiomyoma. CASE PRESENTATION: The patient was an old woman who had undergone endoscopic mucosal resection for an Is polyp on the left side of the transverse colon at the age of 73. She was diagnosed with leiomyoma with positive surgical margins. Subsequently, she presented to our institution with a sensation of pressure in the upper abdominal region as a chief complaint at the age of 76 years. Abdominal computed tomography and colorectal endoscopy showed a tumor lesion with invagination of the intestines in the transverse colon, the same site as that of the previously resected leiomyoma. A biopsy suggested a smooth muscle tumor, and we performed partial left transverse colectomy and lymph node dissection under a diagnosis of recurrence and enlargement of the previously incompletely resected leiomyoma. Histopathological examination revealed spindle-shaped tumor cells, and the mitotic activity was 30-40/10 high-power field. Tumor cells were immunohistologically positive for α-smooth muscle actin and h-caldesmon; partially positive for desmin; negative for c-kit, CD34, DOG-1, and the S-100 protein; and showed a Ki-67 labeling index of 70-80%. She was diagnosed with leiomyosarcoma malignantly transformed from leiomyoma. Metastasis was found in 1 of the 14 resected lymph nodes. The patient did not undergo adjuvant chemotherapy, but has survived with no recurrence at 2 years after the surgery. CONCLUSIONS: We have reported a case of leiomyosarcoma of the transverse colon with lymph node metastasis that was malignantly transformed from a leiomyoma.

Urinary titin N-terminal fragment concentration is an indicator of preoperative sarcopenia and nutritional status in patients with gastrointestinal tract and hepatobiliary pancreatic malignancies.

OBJECTIVES: Recent reports indicate that preoperative patients with gastrointestinal malignancies often have sarcopenia. The diagnosis of sarcopenia is generally done by evaluation of walking speed, grip strength, and skeletal muscle volume of the limbs on computed tomography (CT). However, these parameters are objective indices, and new indicators for diagnosis, such as molecular biomarkers, have been anticipated. The aim of this study was to investigate whether titin, a muscular contractile protein present in sarcomeres, is an indicator of sarcopenia. METHODS: We analyzed 39 patients with gastrointestinal tract and hepatobiliary pancreatic malignancies who underwent surgery. We compared urinary titin n-terminal fragment concentration (UTF) with clinical factors, subcutaneous fat volume, and skeletal muscle volume index, and also compared UTF levels between patients with and without sarcopenia. RESULTS: The patients comprised 24 men and 15 women, with a mean age of 72 y (range: 35-85 y). Cancer locations were the pancreas (n = 17), liver (n = 9), stomach (n = 5), colorectum (n = 5), and esophagus (n = 3). UTF was significantly higher in patients with sarcopenia (P = 0.04), and showed statistically significant negative correlations with albumin (r = -2.61, P = 0.001), pre-albumin (r = -2.14, P = 0.02), body mass index (r = -0.49, P = 0.007), cholinesterase (r = -0.02, P = 0.01, skeletal muscle volume index (r = -0.16, P = 0.04), and subcutaneous fat volume (r = -0.03, P = 0.007). CONCLUSION: UTF may be a new index for preoperative nutritional assessment in patients with gastrointestinal malignancies.

Investigation of morphological and functional changes in the liver and pancreas during bevacizumab treatment.

Objectives: Recently, there have been reports regarding the atrophy of various organs caused by molecular targeted drugs. We investigated morphological and clinical changes in the liver and pancreas caused by treatment with bevacizumab.Methods: We investigated 30 patients with colorectal cancer who received bevacizumab-containing chemotherapy (study group) and 11 patients with colorectal cancer who received chemotherapy without bevacizumab (control group) from 2010 to 2014. We obtained computed tomography data of the liver and pancreas and performed three-dimensional image analysis and volumetry. Laboratory data before and after chemotherapy were analyzed.Results: There was no significant difference in liver volume before and after bevacizumab-containing chemotherapy, but the pancreatic volume was found to be significantly reduced after bevacizumab-containing chemotherapy (57.9 ± 16 mL versus 47.4 ± 15.3 mL; p = .005). The liver and pancreatic volume did not change statistically in the control group. With regard to complete blood cell counts and laboratory data, no significant differences were observed in the leukocyte count and hemoglobin, hemoglobin A1c, triglyceride, albumin, and C-reactive protein levels. In contrast, there was a significant decrease in the platelet count, total cholesterol level and a significant increase in the amylase level. A chemotherapy regimen that included bevacizumab reduced pancreatic volume and significantly altered the morphology of the pancreas.Conclusions: Although bevacizumab caused atrophy of the pancreas and reduced pancreatic volume, pancreatic endocrine function showed no change. Future studies should investigate the survival rate and functional changes caused by bevacizumab treatment.

A Nationwide Survey of Hepatitis E Virus Infection and Chronic Hepatitis in Heart and Kidney Transplant Recipients in Japan.

BACKGROUND: Recently, chronic hepatitis E has been reported in solid organ transplant (SOT) recipients in European countries. Previously, we clarified the prevalence of hepatitis E virus (HEV) infection in Japanese liver transplant recipients and identified 2 chronic hepatitis E patients infected by blood transfusion. However, the rate of HEV infection in recipients of SOTs other than liver in Japan remains unclear, so we conducted a nationwide survey to clarify the prevalence of chronic HEV infection in Japanese heart and kidney transplant recipients. METHODS: A total of 99 heart and 2526 kidney transplant recipients in 17 hospitals in Japan were examined for the presence of the IgG class of anti-HEV antibodies as well as for serum HEV RNA. RESULTS: The prevalence of anti-HEV IgG among heart and kidney transplant recipients was 7.07% (7/99) and 4.08% (103/2526), respectively. One heart transplant patient (1.01%) and 11 kidney transplant patients (0.44%) were found to be positive for HEV RNA. The HEV isolates from all viremic patients were typed as genotype 3. Four patients developed chronic hepatitis E after transplantation. Three patients were treated with ribavirin; their liver enzymes normalized, and HEV RNA became negative immediately. Sustained virologic response was achieved in all cases. CONCLUSIONS: This is the first nationwide survey of HEV infection in Japanese heart and kidney transplant recipients. The prevalence of anti-HEV IgG and HEV RNA in heart and kidney transplant recipients in Japan was lower than that in European countries. Of note, 42% of viremic transplant patients developed chronic hepatitis.

Development of new software enabling automatic identification of the optimal anatomical liver resectable region, incorporating preoperative liver function.

Determining the resectable region and volume of the liver prior to anatomical resection is important. The synapse Vincent (SV) system is the current method for surgical liver resection that relies on the surgeon's individual experience and skill. Additionally, in cases involving abnormal liver function, the resectable region is limited due to deteriorating liver function, thus making the determination of the hepatectomy region challenging. The current study outlines a novel 3D Hariyama-Shimoda Soft (HSS) simulation software that can be used to automatically simulate the optimal hepatectomy region under a limited resectable liver volume. The current study recruited patients with hepatic malignant tumors that were scheduled for anatomical resection. The influence of the tumor on each portal vein point was quantified in accordance with the tumor domination ratio (TDR). The resectable region was subsequently determined so that the sum of the TDR was the maximum estimated resectable liver volume (ERLV). The maximum ERLV settings utilized were within Makuuchi's criteria. ERLV was compared with the actual resected liver volume (ARLV) using SV and HSS. A total of 15 patients were included in the present study. The median ERLV was not significantly different between the two groups (P=0.15). However, the correlation between ERLV and ARLV, for SV and HSS, was statistically significant [SV ERLV (ml) = 1.139 × HSS ERLV (ml) + 30.779 (P=0.001)]. In conclusion, HSS may be an effective 3D simulation system. TDR and ERLV were indicated to be novel factors that may be incorporated into simulation software for use in anatomical resection surgery.

Remnant pancreatic volume as an indicator of poor prognosis in pancreatic cancer patients after resection.

BACKGROUND: Remnant pancreatic volume (RPV) is a well-known marker for short-term outcomes in pancreatic cancer patients after resection. However, in terms of the long-term outcomes, the significance of the RPV value remains unclear. Here, we address whether the RPV value is a predictor of the long-term outcomes in pancreatic cancer patients after resection by comparing various cancer-, patient-, and surgery-related prognostic factors and systemic inflammatory response markers in a retrospective cohort. METHODS: The RPV was measured on a three-dimensional (3D) image, revealing the actual pancreatic parenchymal remnant volume. Ninety-one patients who underwent pancreaticoduodenectomy were retrospectively enrolled. We divided the cohort into high- and low-RPV groups based on a cut-off value (>31.5 cm3, n = 66 and ≤31.5 cm3, n = 25, respectively). The median survival times (MSTs) were compared between the two groups. Using multivariate analysis, the RPV and other well-known prognostic factors were independently assessed. RESULTS: The MSTs (days) were significantly different between the two groups (high, 823 vs. low, 482, p = 0.001). Multivariate analysis identified the RPV (≤31.5 cm3) (hazard ratio [HR], 2.015; p = 0.011), lymph node metastasis (HR, 8.415; p = 0.002), lack of adjuvant chemotherapy (HR, 5.352; p < 0.001), stage III/IV disease (HR, 2.352; p = 0.029), and pathological fibrosis (HR, 1.771; p = 0.031) as independent prognostic factors. CONCLUSIONS: The present study suggests that the RPV value is also useful for predicting long-term outcomes in pancreatic cancer patients after resection.

Number of positive lymph nodes and lymphatic invasion are significant prognostic factors after pancreaticoduodenectomy for distal cholangiocarcinoma.

Background: Early recurrence of distal cholangiocarcinoma (DCC) may result in a poorer prognosis. This study aimed to evaluate the clinicopathological factors that predict survival and recurrence in patients with DCC. Methods: Fifty-five patients with DCC who underwent pancreaticoduodenectomy between 2005 and 2015 were studied retrospectively. The following clinicopathological parameters were analyzed as predictors of disease-free survival (DFS) and overall survival (OS): sex, age, body mass index, presence of biliary tract decompression, macroscopic type, histological type, tumor size, TNM classification, lymph node metastasis ratio, number of positive lymph nodes (PLNs), lymphatic invasion, venous invasion, perineural invasion, proximal bile duct margin, dissected margin, portal system invasion, arterial system invasion, stage, and residual tumor. Results: Univariate analysis showed that contiguous extension of the primary tumor, PLN, lymphatic invasion, venous invasion, perineural invasion, and stage were significant prognostic factors for DFS and OS. Multivariate analysis revealed that PLN and lymphatic invasion were prognostic for DFS and OS (P<0.001). Significant differences in OS and DFS were found in analyses stratified by PLN (0, 1, 2 vs ≥3) and lymphatic invasion (0 vs 1, 2, 3). Conclusion: Among the clinicopathological parameters analyzed, PLN and lymphatic invasion were confirmed as prognostic factors for DCC.

Three-Dimensional Remnant Pancreatic Volumetry Predicts Postoperative Pancreatic Fistula in Pancreatic Cancer Patients after Pancreaticoduodenectomy.

BACKGROUND: Postoperative pancreatic fistula (POPF) is a serious complication that can occur following pancreaticoduodenectomy (PD). Recent studies suggest that remnant pancreatic volume (RPV) values from preoperative multidetector computed tomography (MDCT) are highly predictive of POPF. We performed three-dimensional (3D) surgical simulation of PD including RPV measurements. The aim of this study was to determine whether 3D-measured RPV is predictive of POPF after PD. METHODS: We used the SYNAPSE VINCENT® medical imaging system (Fujifilm Medical Co., Ltd., Tokyo, Japan) to construct 3D images after integrating MDCT and magnetic resonance cholangiopancreatography images. RPV was measured using this 3D image, which simulated actual intraoperative pancreatic parenchymal remnant volume. Ninety-one patients who underwent PD were retrospectively enrolled. Using multivariate analysis, RPV and other well-known POPF risk factors were independently assessed. RESULTS: Multivariate analysis identified high RPV values (hazard ratio [HR] = 8.41, p = 0.01), pancreatic duct diameter < 3.0 mm (HR = 5.48, p < 0.01), no pathological fibrosis (HR = 3.41, p < 0.01), and body mass index > 25 kg/m2 (HR = 1.53, p = 0.02) as independent risk factors for POPF. CONCLUSION: The present study indicates that preoperative 3D-measured RPV is predictive of POPF after PD.

Prevalence and characteristics of hepatitis E virus infection in kidney transplant recipients: A single-center experience in Japan.

BACKGROUND: Hepatitis E virus (HEV) infection can lead to chronic hepatitis in solid organ transplant recipients. To investigate whether HEV infection influences outcomes following kidney transplantation, we examined the prevalence of HEV infection and clinical characteristics of kidney transplant recipients in our hospital. METHODS: Our cross-sectional study included 184 kidney transplant recipients. Blood samples were obtained from all patients to detect anti-HEV immunoglobulin (Ig)A, IgM, and IgG by enzyme-linked immunosorbent assay and HEV RNA by reverse transcription polymerase chain reaction. Clinical data were collected from medical charts for all patients. RESULTS: The prevalence of anti-HEV IgG was 8/184 (4.3%). Anti-HEV IgA, anti-HEV IgM, and HEV RNA were not detected in any patients. Compared to their anti-HEV IgG-negative counterparts, anti-HEV IgG-positive patients were significantly older at the time of transplantation, and they were more likely to receive kidneys from deceased donors. No significant differences in other characteristics such as the prevalence of primary cause of end-stage renal disease, blood transfusion, and immunosuppressive therapy use; liver and renal function; and the frequencies of hepatitis B and hepatitis C virus infection were observed according to the patients' anti-HEV IgG status. CONCLUSION: HEV infection had no significant influence on the outcomes of kidney transplantation at our institution. However, HEV infection should be recognized in kidney transplant recipients similarly as hepatitis B and hepatitis C virus infection in cases of liver dysfunction.

Indocyanine green fluorescence-navigated laparoscopic metastasectomy for peritoneal metastasis of hepatocellular carcinoma: a case report.

BACKGROUND: Indocyanine green (ICG) can selectively accumulate in primary hepatocellular carcinoma (HCC) and its extrahepatic metastases. ICG fluorescence imaging is an extremely sensitive intraoperative tool for detecting HCC foci and can be used to detect impalpable tumors in laparoscopic surgery. Here, we report a case of a 75-year-old man who underwent peritoneal metastasis resection of HCC using a laparoscopic near-infrared imaging system and ICG fluorescence-navigated surgery. CASE PRESENTATION: A 75-year-old man was referred to our department for peritoneal metastasis resection of HCC. Two years before admission, he had undergone transarterial embolization and segmentectomy of segment 6 with open surgery for ruptured HCC. Computed tomography revealed a 12-mm peritoneal metastatic lesion on the abdominal wall near the cut surface of the liver. No other metastases were observed; resection of the solitary metastasis was scheduled. ICG (0.5 mg/kg body weight) was intravenously injected, 72 h preoperatively. An endoscopic, ICG near-infrared fluorescence imaging system revealed clear green fluorescence, indicating peritoneal metastasis of HCC on the abdominal wall. The tumor was resected with adequate surgical margin by partially resecting the liver and diaphragm, followed by histological confirmation as peritoneal metastasis of HCC. No recurrence was observed after 12 months of follow-up. CONCLUSIONS: ICG fluorescence can be useful in laparoscopic surgery for identifying peritoneal metastasis.

Predictive Early Recurrence Factors of Preoperative Clinicophysiological Findings in Pancreatic Cancer.

BACKGROUND: We aimed to evaluate the use of preoperative clinicophysiological parameters as predictive risk factors for early recurrence of pancreatic ductal adenocarcinoma (PDAC) after curative resection. METHODS: A total of 260 patients who underwent pancreatic resection for PDAC between 2007 and 2015 were examined retrospectively. We divided the patients into those with early recurrence (within 6 months; group A, n = 52) and those with relapse within ≥6 months or without recurrence (group B, n = 208). Data regarding clinicophysiological parameters were analyzed as predictors of disease-free survival (DFS). These factors were analyzed by χ2 tests on univariate analysis and Cox proportional hazard models on multivariate analyses. Kaplan-Meier survival curves were generated using log-rank tests. RESULTS: Groups A and B had significantly different preoperative carbohydrate antigen 19-9 (CA19-9) levels, carcinoembryonic antigen (CEA) levels, and curability. Univariate and multivariate analysis showed that CA19-9 and CEA were independent prognostic factors for early recurrence. Patients with CA19-9 levels > 124.65 U/mL had significantly shorter DFS than those with lower levels, as did patients with CEA levels > 4.45 ng/mL. CONCLUSIONS: Our results show that elevated CA19-9 (> 124.65 U/mL) and CEA (> 4.45 ng/mL) were independent predictors of early recurrence after pancreatic resection in PDAC patients.

Three-dimensional surgical simulation of the bile duct and vascular arrangement in pancreatoduodenectomy: A retrospective cohort study.

BACKGROUND/AIMS: We evaluated the usefulness of three-dimensional (3D) images for pancreatoduodenectomy (PD), including the classification of the bile duct and vascular arrangement, i.e., hepatic artery, inferior mesenteric vein (IMV) and left gastric vein (LGV). We evaluated the extent to which this simulation affected the perioperative outcomes of PD. METHODS: In all, 117 patients who underwent PD were divided into the without-3D (n = 53) and with-3D (n = 64) groups, and perioperative outcomes were compared. We evaluated the arrangement of the accessory bile duct and the hepatic artery (type I: the right hepatic artery arising from the superior mesenteric artery, type II: the left hepatic artery arising from the left gastric artery, type III: the most common pattern) and the confluence pattern of the LGV and the IMV [type i: portal vein (PV):splenic vein (SV), type ii: PV:superior mesenteric vein (SMV), type iii: SV:SV, and type iv: SV:SMV] between the two groups. RESULTS: Two patients had an accessory bile duct. The 3D images were classified as type I (n = 4), type II (n = 10), type III (n = 48) and other patterns (n = 2); type ii (n = 27) was the most frequent confluence pattern (p < 0.05). Intraoperative blood loss was reduced in the with-3D group (p < 0.05). CONCLUSIONS: We propose that the 3D imaging technique is useful for preoperative assessment in PD.

[Current Situations and Prospects of Preoperative 3D Simulation in Gastrointestinal Surgery].

Recently, three-dimensional(3D)simulation in liver surgery has become common in Japan because it is covered by medical insurance. The benefits of 3D simulation for liver surgery, such as an enhanced understanding of tumor anatomy, estimation of liver volume and assessment of irrigation area, have been previously reported. However, in the conventional system, the reconstructed 3D liver model is fixed and rigid. In addition, we were not able to observe every moment of cutting or the intrahepatic vessels. Therefore, we have developed a novel real-time virtual hepatectomy simulation software program, Liversim, to present the real-time motion and deformation of the liver. Recently, the usefulness of 3D-printed organ models based on preoperative computed tomography(CT)for hepatectomy has been reported. We have developed a novel 3D-printed liver frame model for hepatectomy, which made the procedure easier, reduced the production cost, and improved the visibility. Recently, indocyanine green(ICG)has been used for surgical navigations because it emits fluorescence upon exposure to near-infrared illumination. In addition, research and development of real-time navigation surgery like car navigation is expected.

Impact of Three-Dimensional Surgical Simulation on Pancreatic Surgery.

BACKGROUND/AIMS: Anatomical variations are frequently encountered during hepato-biliary-pancreatic surgeries, requiring surgeons to have a precise understanding of the surgical anatomy in order to perform a safe surgery. We evaluated the impact of novel three-dimensional (3D) surgical simulation on pancreatic surgeries to enhance surgical residents' understanding. METHODOLOGY: Between January 2013 and May 2014, 61 preoperative 3D surgical simulations were performed. The consistency (0-10, with 10 representing 100% consistency) among the 15 surgical residents' anatomical drawings from multidetector computed tomography images and the simulated 3D images by SYNAPSE VINCENT® was assessed. We divided the surgical residents into two groups - first- to fifth-year postgraduate doctors (group A) and sixth- to tenth-year postgraduate doctors (group B) - and compared the self-assessment scores between these two groups. RESULTS: In terms of the self-assessment scores, a statistically significant difference was observed between the two groups (p < 0.001). CONCLUSIONS: In this study, 3D surgical simulation was useful for preoperative assessments prior to pancreatic surgery, especially in younger postgraduate surgeons.

Encountered-Type Haptic Interface for Representation of Shape and Rigidity of 3D Virtual Objects.

This paper describes the development of an encountered-type haptic interface that can generate the physical characteristics, such as shape and rigidity, of three-dimensional (3D) virtual objects using an array of newly developed non-expandable balloons. To alter the rigidity of each non-expandable balloon, the volume of air in it is controlled through a linear actuator and a pressure sensor based on Hooke's law. Furthermore, to change the volume of each balloon, its exposed surface area is controlled by using another linear actuator with a trumpet-shaped tube. A position control mechanism is constructed to display virtual objects using the balloons. The 3D position of each balloon is controlled using a flexible tube and a string. The performance of the system is tested and the results confirm the effectiveness of the proposed principle and interface.