Control of Velocity-Constrained Stepper Motor-Driven Hilare Robot for Waypoint Navigation

Finding an optimal trajectory from an initial point to a final point through closely packed obstacles, and controlling a Hilare robot through this trajectory, are challenging tasks. To serve this purpose, path planners and trajectory-tracking controllers are usually included in a control loop. This paper highlights the implementation of a trajectory-tracking controller on a stepper motor-driven Hilare robot, with a trajectory that is described as a set of waypoints. The controller was designed to handle discrete waypoints with directional discontinuity and to consider different constraints on the actuator velocity. The control parameters were tuned with the help of multi-objective particle swarm optimization to minimize the average cross-track error and average linear velocity error of the mobile robot when tracking a predefined trajectory. Experiments were conducted to control the mobile robot from a start position to a destination position along a trajectory described by the waypoints. Experimental results for tracking the trajectory generated by a path planner and the trajectory specified by a user are also demonstrated. Experiments conducted on the mobile robot validate the effectiveness of the proposed strategy for tracking different types of trajectories.

National guidelines for the diagnosis and treatment of hilar cholangiocarcinoma

A consensus meeting of national experts from all major national hepatobiliary centres in the country was held on May 26,2023,at the Pakistan Kidney and Liver Institute&Research Centre(PKLI&RC)after initial consultations with the experts.The Pakistan Society for the Study of Liver Diseases(PSSLD)and PKLI&RC jointly organised this meeting.This effort was based on a comprehensive literature review to establish national practice guidelines for hilar cholangiocarcinoma(hCCA).The consensus was that hCCA is a complex disease and requires a multidisciplinary team approach to best manage these patients.This coordinated effort can minimise delays and give patients a chance for curative treatment and effective palliation.The diagnostic and staging workup includes high-quality computed tomography,magnetic resonance imaging,and magnetic resonance cholangiopancreato-graphy.Brush cytology or biopsy utilizing endoscopic retrograde cholangiopancreatography is a mainstay for diagnosis.However,histopathologic confirmation is not always required before resection.Endoscopic ultrasound with fine needle aspiration of regional lymph nodes and positron emission tomography scan are valuable adjuncts for staging.The only curative treatment is the surgical resection of the biliary tree based on the Bismuth-Corlette classification.Selected patients with unresectable hCCA can be considered for liver transplantation.Adjuvant chemotherapy should be offered to patients with a high risk of recurrence.The use of preoperative biliary drainage and the need for portal vein embolisation should be based on local multidisciplinary discussions.Patients with acute cholangitis can be drained with endoscopic or percutaneous biliary drainage.Palliative chemotherapy with cisplatin and gemcitabine has shown improved survival in patients with irresectable and recurrent hCCA.

“Hepatic hilum area priority,liver posterior first”:An optimized strategy in laparoscopic resection for type Ⅲ-Ⅳ hilar cholangiocarcinoma

BACKGROUND In recent years,pure laparoscopic radical surgery for Bismuth-Corlette type Ⅲ and Ⅳ hilar cholangiocarcinoma(HCCA)has been preliminarily explored and applied,but the surgical strategy and safety are still worthy of further improvement and attention.AIM To summarize and share the application experience of the emerging strategy of“hepatic hilum area dissection priority,liver posterior separation first”in pure laparoscopic radical resection for patients with HCCA of Bismuth-Corlette types Ⅲ and IV.METHODS The clinical data and surgical videos of 6 patients with HCCA of Bismuth-Corlette types Ⅲ and Ⅳ who underwent pure laparoscopic radical resection in our department from December 2021 to December 2023 were retrospectively analyzed.RESULTS Among the 6 patients,4 were males and 2 were females.The average age was 62.2±11.0 years,and the median body mass index was 20.7(19.2-24.1)kg/m^(2).The preoperative median total bilirubin was 57.7(16.0-155.7)μmol/L.One patient had Bismuth-Corlette type Ⅲa,4 patients had Bismuth-Corlette type Ⅲb,and 1 patient had Bismuth-Corlette type Ⅳ.All patients successfully underwent pure laparoscopic radical resection following the strategy of“hepatic hilum area dissection priority,liver posterior separation first”.The operation time was 358.3±85.0 minutes,and the intraoperative blood loss volume was 195.0±108.4 mL.None of the patients received blood transfusions during the perioperative period.The median length of stay was 8.3(7.0-10.0)days.Mild bile leakage occurred in 2 patients,and all patients were discharged without serious surgery-related complications.CONCLUSION The emerging strategy of“hepatic hilum area dissection priority,liver posterior separation first”is safe and feasible in pure laparoscopic radical surgery for patients with HCCA of Bismuth-Corlette types Ⅲ and Ⅳ.This strategy is helpful for promoting the modularization and process of pure laparoscopic radical surgery for complicated HCCA,shortens the learning curve,and is worthy of further clinical application.

Accurate resection of hilar cholangiocarcinoma using eOrganmap 3D reconstruction and full quantization technique

BACKGROUND For treatment of hilar cholangiocarcinoma(HCCA),the rate of radical resection is low and prognosis is poor,and preoperative evaluation is not sufficiently accurate.3D visualization has the advantage of giving a stereoscopic view,which makes accurate resection of HCCA possible.AIM To establish precise resection of HCCA based on eOrganmap 3D reconstruction and full quantification technology.METHODS We retrospectively analyzed the clinical data of 73 patients who underwent HCCA surgery.All patients were assigned to two groups.The traditional group received traditional 2D imaging planning before surgery(n=35).The eOrganmap group underwent 3D reconstruction and full quantitative technical planning before surgery(n=38).The preoperative evaluation,anatomical classification of hilar hepatic vessels,indicators associated with surgery,postoperative complications,liver function,and stress response indexes were compared between the groups.RESULTS Compared with the traditional group,the amount of intraoperative blood loss in the eOrganmap group was lower,the operating time and postoperative intestinal ventilation time were shorter,and R0 resection rate and lymph node dissection number were higher(P<0.05).The total complication rate in the eOrganmap group was 21.05%compared with 25.71%in the traditional group(P>0.05).The levels of total bilirubin,Albumin(ALB),aspartate transaminase,and alanine transaminase in the eOrganmap group were significantly different from those in the traditional group(intergroup effect:F=450.400,79.120,95.730,and 13.240,respectively;all P<0.001).Total bilirubin,aspartate transaminase,and alanine transaminase in both groups showed a decreasing trend with time(time effect:F=30.270,17.340,and 13.380,respectively;all P<0.001).There was an interaction between patient group and time(interaction effect:F=3.072,2.965,and 2.703,respectively;P=0.0282,0.032,and 0.046,respectively);ALB levels in both groups tended to increase with time(time effect:F=22.490,P<0.001),and there was an interaction effect between groups and time(interaction effect:F=4.607,P=0.004).In the eOrganmap group,there was a high correlation between the actual volume of intraoperative liver specimen resection and the volume of preoperative virtual liver resection(t=0.916,P<0.001).CONCLUSION The establishment of accurate laparoscopic resection of hilar cholangiocarcinoma based on preoperative eOrganmap 3D reconstruction and full quantization technology can make laparoscopic resection of hilar cholangiocarcinoma more accurate and safe.

Precise mapping of hilar cholangiocarcinoma with a skip lesion by SpyGlass cholangioscopy:A case report

BACKGROUND Cholangiocarcinoma(CC)is a very aggressive cancer with a poor prognosis.As surgery is the only curative therapy,preoperative evaluation of the tumor extent is essential for surgical planning.Although high-quality image modalities such as computed tomography and magnetic resonance imaging have been used extensively in preoperative evaluation,the accuracy is low.To obtain precise localization of tumor spread arising from the hilar region preoperatively,the development of an acceptable imaging modality is still an unmet need.CASE SUMMARY A 52-year-old female presented to our emergency department with jaundice,abdominal pain,and fever.Initially,she was treated for cholangitis.Endoscopic retrograde cholangiopancreatography with the cholangiogram showed long segment filling defect in the common hepatic duct with dilatation of bilateral intrahepatic ducts.Transpapillary biopsy was performed,and the pathology suggested intraductal papillary neoplasm with high-grade dysplasia.After treatment of cholangitis,contrasted-enhanced computed tomography revealed a hilar lesion with undetermined Bismuth-Corlette classification.SpyGlass cholan gioscopy showed that the lesion involved the confluence of the common hepatic duct with one skip lesion in the posterior branch of the right intrahepatic duct,which was not detected by previous image modalities.The surgical plan was modified from extended left hepatectomy to extended right hepatectomy.The final diagnosis was hilar CC,pT2aN0M0.The patient has remained disease-free for more than 3 years.CONCLUSION SpyGlass cholangioscopy may have a role in precision localization of hilar CC to provide surgeons with more information before the operation.

Real-time continuous image guidance for endoscopic retrograde cholangiopancreatography based on 3D/2D registration and respiratory compensation

BACKGROUND It has been confirmed that three-dimensional(3D)imaging allows easier identification of bile duct anatomy and intraoperative guidance of endoscopic retrograde cholangiopancreatography(ERCP),which reduces the radiation dose and procedure time with improved safety.However,current 3D biliary imaging does not have good real-time fusion with intraoperative imaging,a process meant to overcome the influence of intraoperative respiratory motion and guide navigation.The present study explored the feasibility of real-time continuous image-guided ERCP.AIM To explore the feasibility of real-time continuous image-guided ERCP.METHODS We selected 23D-printed abdominal biliary tract models with different structures to simulate different patients.The ERCP environment was simulated for the biliary phantom experiment to create a navigation system,which was further tested in patients.In addition,based on the estimation of the patient’s respiratory motion,preoperative 3D biliary imaging from computed tomography of 18 patients with cholelithiasis was registered and fused in real-time with 2D fluoroscopic sequence generated by the C-arm unit during ERCP.RESULTS Continuous image-guided ERCP was applied in the biliary phantom with a registration error of 0.46 mm±0.13 mm and a tracking error of 0.64 mm±0.24mm.After estimating the respiratory motion,3D/2D registration accurately transformed preoperative 3D biliary images to each image in the X-ray image sequence in real-time in 18 patients,with an average fusion rate of 88%.CONCLUSION Continuous image-guided ERCP may be an effective approach to assist the operator and reduce the use of X-ray and contrast agents.

A systematic review of robot-assisted partial nephrectomy outcomes for advanced indications:Large tumors(cT2-T3),solitary kidney,completely endophytic,hilar,recurrent,and multiple renal tumors

Objective:Robot-assisted partial nephrectomy(RAPN)has become widely used for treatment of renal cell carcinoma and it is expanding in the field of complex renal masses.The aim of this systematic review was to analyze outcomes of RAPN for completely endophytic renal masses,large tumors(cT2-T3),renal cell carcinoma in solitary kidney,recurrent tumors,completely endophytic and hilar masses,and simultaneous and multiple tumors.Methods:A comprehensive search in the PubMed,Scopus,Web of Science,and Cochrane Central Register of Controlled Trials databases was performed in December 2022 for English language papers.The primary endpoint was to evaluate the role of RAPN in the setting of each category of complex renal masses considered.The secondary endpoint was to evaluate the surgical and functional outcomes.Results:After screening 1250 records,43 full-text manuscripts were selected,comprising over 8500 patients.Twelve and thirteen studies reported data for endophytic and hilar renal masses,respectively.Five and three studies reported outcomes for cT2-T3 and solitary kidney patients,respectively.Four studies focused on redo-RAPN for recurrent tumors.Two studies investigated simultaneous bilateral renal masses and five reports focused on multiple tumor excision in ipsilateral kidney.Conclusion:Over the past decade,evidence supporting the use of RAPN for the most challenging nephron-sparing surgery indications has continuously grown.Although limitations remain including study design and lack of detailed long-term functional and oncological outcomes,the adoption of RAPN for the included advanced indications is associated with favorable surgical outcomes with good preservation of renal function without compromising the oncological result.Certainly,a higher likelihood of complication might be expected when facing extremely challenging cases.However,none of these indications should be considered per se an exclusion criterion for performing RAPN.Ultimately,a risk-adapted approach should be employed.

Distribution of splenic artery lymph nodes and splenic hilar lymph nodes

BACKGROUND Total gastrectomy with splenectomy is the standard treatment for advanced proximal gastric cancer with greater-curvature invasion.As an alternative to splenectomy,laparoscopic spleen-preserving splenic hilar lymph node(LN)dissection(SPSHLD)has been developed.With SPSHLD,the posterior splenic hilar LNs are left behind.AIM To clarify the distribution of splenic hilar(No.10)and splenic artery(No.11p and 11d)LNs and to verify the possibility of omitting posterior LN dissection in laparoscopic SPSHLD from an anatomical standpoint.METHODS Hematoxylin&eosin-stained specimens were prepared from six cadavers,and the distribution of LN No.10,11p,and 11d was evaluated.In addition,heatmaps were constructed and three-dimensional reconstructions were created to visualize the LN distribution for qualitative evaluation.RESULTS There was little difference in the number of No.10 LNs between the anterior and posterior sides.For LN No.11p and 11d,the anterior LNs were more numerous than the posterior LNs in all cases.The number of posterior LNs increased toward the hilar side.Heatmaps and three-dimensional reconstructions showed that LN No.11p was more abundant in the superficial area,while LN No.11d and 10 were more abundant in the deep intervascular area.CONCLUSION The number of posterior LNs increased toward the hilum and was not neglectable.Thus,surgeons should consider that some posterior No.10 and No.11d LNs may remain after SPSHLD.

Proposal of a modified classification for hilar cholangiocarcinoma

Hilar cholangiocarcinoma is a malignant tumor that originates from the left and right hepatic ducts and their confluence.It is highly malignant and associated with a poor prognosis.Surgical resection is the only available curative treatment option.A scientific classification system can aid in the preoperative assessment of resectability and guide the development of appropriate surgical strategies.Several classification systems are available,with the Bismuth-Corlette(BC)classification being the earliest and most widely used.Similar to many other classifications,the BC classification relies on the secondary branching of the bile ducts as an important anatomical landmark,making it unsuitable for cases with variations in the bile duct anatomy.With advances in understanding the hepatic plate and anatomical structures at the hilum,the secondary bile ducts are no longer considered important anatomical landmarks.Therefore,modifications to the BC classification are needed to align with modern anatomical improvements and advancements in surgical techniques.Herein,we propose a modification to the BC classification.In this new system,the boundary of the hilar plate is considered as limit of the proximal ductal margin and used as an anatomical landmark,rather than the concept of“secondary bile ducts”in the BC classification.

Hilar Cholangiocarcinoma with Synchronous Metastases to Breast and Skeletal Muscle: A Case Report and Literature Review

Hilar cholangiocarcinoma has been reputed as a slow growth tumor in the past. Skeletal muscle is one of the most unusual sites of metastasis from any malignancy. We report herein a case of hilar cholangiocarcinoma with synchronous metastases to skeletal muscle and breast, and review the literature. The patient was a 48-year-old woman who presented with jaundice and weight loss. An inoperable hilar cholangiocarcinoma was diagnosed. She was treated with a combination of endoscopic plastic stent biloiary drainage and three-dimensional conformal radiotherapy （3DCRT）. Good response was achieved. Ten months later, she exhibited with a painful metastatic mass in the muscle rectus femoris of left thigh and a painless mass in the left breast. She underwent operation to relieve the pain, but died from liver failure after 8 months. The literature only offers isolated cases of cholangiocarcinoma with distant metastases, of which the common sites were cervical lymph node, bone, and portal venous system. Most patients were presented with multiple metastases with extensive local disease.

肝门部胆管癌手术热点浅析

肝门部胆管癌（hilar cholangiocarcinoma,HCCA）是指累及肝总管、左右肝管及其汇合部的胆管黏膜上皮癌,亦称高位胆管癌、近端胆管癌或Klatskin肿瘤,是胆管癌中最常见的类型,约占50%~60%[1]。根治性手术切除（R_0切除）是可能治愈肝门部胆管癌的唯一选择。

经皮肝穿胆管内金属支架置入联合伽玛刀立体定向放射治疗肝门部胆管癌

目的探讨经皮肝穿胆管内金属支架置入联合伽玛刀立体定向放射治疗肝门部胆管癌的疗效及安全性。方法 2005年10月—2007年1月对不愿意手术或不能手术治疗的21例肝门部胆管癌患者,给予经皮肝穿胆管内金属支架置入联合伽玛刀立体定向放射治疗。肿瘤边缘剂量4～8Gy/次,隔日1次,总剂量为40～60 Gy,10～20 d完成。结果患者行经皮肝穿胆管内支架置入术后,血总胆红素及直接胆红素水平均有显著下降。治疗后1~3月复查,1例出现再梗阻,其余血胆红素水平基本上接近正常。肿瘤病灶CR 2例,PR 14例,PD 1例,SD 3例,总有效率(CR+PR)为80%。胆道支架植入术中及术后,出现血压下降4例,放疗不良反应以消化道反应多见,均为I^II度。患者中位生存期为14.5月,1、2年生存率分别为47.6%、14.2%。结论经皮肝穿胆管内支架置入术联合伽玛刀立体定向放射治疗是肝门部胆管癌的一种有效方法,并发症及不良反应少。

Evaluation of MRI in Diagnosing Hilar Cholangiocarcinoma

Objective： To investigate the clinical application of MRI in the diagnosis and preoperative evaluation of hilar cholangiocarcinoma （HC）. Methods： Thirty-four cases of HC were examined with 1.5T super-conduct MR unit. The plain MRI and MRCP were followed by dynamic Gd-DTPA （0.1 mmol/kg） contrast-enhanced scanning, which was repeated at 30 s intervals in the first 3 min with the patient being remained in the same position. Delayed scanning was done at 5, 8, 10, 12 and 15 min respectively. 3D- DCE-MRA was performed in arterial and portal venous phase with an additional bolus injection of 15-20 mL Gd-DTPA （0.15-0.20 mmol/kg）. The contrast time-signal curve of both the liver and the tumor was drawn from DCE imaging, and both arterial and portal venous phase imaging were reconstructed with MIP. MRI findings were compared with surgical findings and pathology. Results： Hilar lesion, intrahepatic ducts dilatation and disconnect of main hepatic duct were shown in all cases. Thirty-one cases had tumor-delayed enhancement. In 3D-DCE-MRA, spiral artery deformed was displayed in 6 cases, infiltration, encasement or occlusion of portal vein was displayed in 18 cases. The accuracy of assessing tumor unresectability and resectability by preoperative MRI was 95.0% （19/20） and 78.6% （11/14） respectively. The total accuracy rate of MRI assessing was 88.2% （30/34）. Conclusion： All-in-one MR, including plain MR, MRCP, MR DCE and 3D-DCE-MRA, can accurately show the lesions and involvement of neighbouring tissues. It was of great value in diagnosis and preoperative evaluation of HC.

17例肝门部胆管癌患者的诊治分析

肝门部胆管癌（hilar cholangiocarcinoma,HCCA）是指发生于左右肝管、肝总管及其汇合部的恶性肿瘤,占肝外胆管癌的40%-60%。其特殊的解剖位置、毗邻关系和多极化浸润转移的生物学特性,致其手术切除率和长期生存率极低,使得HCCA诊断和治疗成为外科疑难问题之一。本文分析2008年1月至2013年12月于我科行手术治疗的17例肝门部胆管癌患者的临床资料,

Preoperative biliary drainage in patients with hilar cholangiocarcinoma undergoing major hepatectomy

AIM:To investigate the effect of preoperative biliary drainage(PBD)in jaundiced patients with hilar cholangiocarcinoma(HCCA)undergoing major liver resections.METHODS:An observational study was carried out by reviewing a prospectively maintained database of HCCA patients who underwent major liver resection for curative therapy from January 2002 to December 2012.Patients were divided into two groups based on whether PBD was performed:a drained group and an undrained group.Patient baseline characteristics,preoperative factors,perioperative and short-term postoperative outcomes were compared between the two groups.Risk factors for postoperative complications were also analyzed by logistic regression test with calculating OR and 95%CI.RESULTS:In total,78 jaundiced patients with HCCA underwent major liver resection:32 had PBD prior to operation while 46 did not have PBD.The two groups were comparable with respect to age,sex,body mass index and co-morbidities.Furthermore,there was no significant difference in the total bilirubin(TBIL)levels between the drained group and the undrained group at admission(294.2±135.7 vs 254.0±63.5,P=0.126).PBD significantly improved liver function,reducing not only the bilirubin levels but also other liver enzymes.The preoperative TBIL level was significantly lower in the drained group as compared to the undrained group(108.1±60.6 vs 265.7±69.1,P=0.000).The rate of overall postoperative complications(53.1%vs 58.7%,P=0.626),reoperation rate(6.3%vs 6.5%,P=1.000),postoperative hospital stay(16.5 vs 15.0,P=0.221)and mortality(9.4%vs 4.3%,P=0.673)were similar between the two groups.In addition,there was no significant difference in infectious complications(40.6%vs 23.9%,P=0.116)and noninfectious complications(31.3%vs 47.8%,P=0.143)between the two groups.Univariate and multivariate analyses revealed that preoperative TBIL>170μmol/L(OR=13.690,95%CI:1.275-147.028,P=0.031),Bismuth-Corlette classification(OR=0.013,95%CI:0.001-0.166,P=0.001)and extended liver resection(OR=14.010,95%CI:1.130-173.646,P=0.040)were independent risk factors for postoperative complications.CONCLUSION:Overall postoperative morbidity and mortality rates after major liver resection are not improved by PBD in HCCA patients with jaundice.Preoperative TBIL>170μmol/L,Bismuth-Corlette classification and extended liver resection are independent risk factors linked to postoperative complications.

Prognostic factors and long-term outcomes of hilar cholangiocarcinoma:A single-institution experience in China

AIM: To evaluate the prognostic factors of hilar cholangiocarcinoma in a large series of patients in a single institution.METHODS: Eight hundred and fourteen patients with a diagnosis of hilar cholangiocarcinoma that were evaluated and treated between 1990 and 2014, of which 381 patients underwent curative surgery, were included in this study. Potential factors associated with overall survival(OS) and disease-free survival(DFS) were evaluated by univariate and multivariate analyses.RESULTS: Curative surgery provided the best long-term survival with a median OS of 26.3 mo. The median DFS was 18.1 mo. Multivariate analysis showed that patients with tumor size > 3 cm [hazard ratio(HR) = 1.482, 95%CI: 1.127-1.949; P = 0.005], positive nodal disease(HR = 1.701, 95%CI: 1.346-2.149; P < 0.001), poor differentiation(HR = 2.535, 95%CI: 1.839-3.493; P < 0.001), vascular invasion(HR = 1.542, 95%CI: 1.082-2.197; P = 0.017), and positive margins(HR = 1.798, 95%CI: 1.314-2.461; P < 0.001) had poor OS outcome. The independent factors for DFS were positive nodal disease(HR = 3.383, 95%CI: 2.633-4.348; P < 0.001), poor differentiation(HR = 2.774, 95%CI: 2.012-3.823; P < 0.001), vascular invasion(HR = 2.136, 95%CI: 1.658-3.236; P < 0.001), and positive margins(HR = 1.835, 95%CI: 1.256-2.679; P < 0.001). Multiple logistic regression analysis showed that caudate lobectomy [odds ratio(OR) = 9.771, 95%CI: 4.672-20.433; P < 0.001], tumor diameter(OR = 3.772, 95%CI: 1.914-7.434; P < 0.001), surgical procedures(OR = 10.236, 95%CI: 4.738-22.116; P < 0.001), American Joint Committee On Cancer T stage(OR = 2.010, 95%CI: 1.043-3.870; P = 0.037), and vascular invasion(OR = 2.278, 95%CI: 0.997-5.207; P = 0.051) were independently associated with tumorfree margin, and surgical procedures could indirectly affect survival outcome by influencing the tumor resection margin. CONCLUSION: Tumor margin, tumor differentiation, vascular invasion, and lymph node status were independent factors for OS and DFS. Surgical procedures can indirectly affect survival outcome by influencing the tumor resection margin.

Management of hilar cholangiocarcinoma in the North of England: Pathology, treatment, and outcome

AIM: To assess the management and outcome of hilar cholangiocarcinoma (Klatskin tumor) in a single tertiary referral center.METHODS: The notes of all patients with a diagnosis of hilar cholangiocarcinoma referred to our unit for over an 8-year period were identified and retrospectively reviewed. Presentation, management and outcome were assessed.RESULTS: Seventy-five patients were identified. The median age was 64 years (range 34-84 years). Male to female ratio was 1:1. Eighty-nine percent of patients presented with jaundice. Most patients referred were under Bismuth classification 3a, 3b or 4. Seventy patients required biliary drainage, 65 patients required 152percutaneous drainage procedures, and 25 had other complications. Forty-one patients had 51 endoscopic drainage procedures performed (15 failed). Of these,36 subsequently required percutaneous drainage. The median number of drainage procedures for all patients was three, 18 patients underwent resection (24%), nine had major complications and three died post-operatively.The 5-year survival rate was 4.2% for all patients, 21%for resected patients and 0% for those who did not undergo resection (P = 0.0021). The median number of admissions after diagnosis in resected patients was two and three in non-resected patients (P＜0.05).Twelve patients had external-beam radiotherapy, seven brachytherapy, and eight chemotherapy. There was no significant benefit in terms of survival (P = 0.46) or hospital admissions.CONCLUSION: Resection increases survival but carries the risk of significant morbidity and mortality.Percutaneous biliary drainage is almost always necessary and endoscopic drainage should be avoided if possible.

Risk factors and classifications of hilar cholangiocarcinoma

Cholangiocarcinoma is the second most common primary malignant tumor of the liver.Perihilar cholangiocarcinoma or Klatskin tumor represents more than 50% of all biliary tract cholangiocarcinomas.A wide range of risk factors have been identified among patients with Perihilar cholangiocarcinoma including advanced age,male gender,primary sclerosing cholangitis,choledochal cysts,cholelithiasis,cholecystitis,parasitic infection(Opisthorchis viverrini and Clonorchis sinensis),inflammatory bowel disease,alcoholic cirrhosis,nonalcoholic cirrhosis,chronic pancreatitis and metabolic syndrome.Various classifications have been used to describe the pathologic and radiologic appearance of cholangiocarcinoma.The three systems most commonly used to evaluate Perihilar cholangiocarcinoma are the Bismuth-Corlette(BC) system,the Memorial Sloan-Kettering Cancer Center and the TNM classification.The BC classification provides preoperative assessment of local spread.The Memorial Sloan-Kettering cancer center proposes a staging system according to three factors related to local tumor extent:the location and extent of bile duct involvement,the presence or absence of portal venous invasion,and the presence or absence of hepatic lobar atrophy.The TNM classification,besides the usual descriptors,tumor,node and metastases,provides additional information concerning the possibility for the residual tumor(R) and the histological grade(G).Recently,in 2011,a new consensus classification for the Perihilar cholangiocarcinoma had been published.The consensus was organised by the European Hepato-PancreatoBiliary Association which identified the need for a new staging system for this type of tumors.The classification includes information concerning biliary or vascular(portal or arterial) involvement,lymph node status or metastases,but also other essential aspects related to the surgical risk,such as remnant hepatic volume or the possibility of underlying disease.

Clinical benefit of radiation therapy and metallic stenting for unresectable hilar cholangiocarcinoma

AIM： To determine the efficacy of external beam radiotherapy （EBRT）, with or without intraluminal brachytherapy （ILBT）, in patients with non-resected locally advanced hilar cholangiocarcinoma.METHODS： We analyzed 64 patients with locally advanced hilar cholangiocarcinoma, including 25 who underwent resection （17 curative and 8 non-curative）, 28 treated with radiotherapy, and 11 who received best supportive care （BSC）. The radiotherapy group received EBRT （50 Gy, 30 fractions）, with 11 receiving an ad- ditional 24 Gy （4 fractions） ILBT by iridium-192 with remote after loading. ILBT was performed using percu-taneous transhepatic biliary drainage （PTBD） route. Uncovered metallic stents （UMS） were inserted into nonresected patients with obstructive jaundice, with the exception of four patients who received percutaneous transhepatic biliary drainage only. UMS were placed endoscopically or percutaneously, depending on the initial drainage procedure. The primary endpoints were patient death or stent occlusion. Survival time of patients in the radiotherapy group was compared with that of patients in the resection and BSC groups. Stent patency was compared in the radiotherapy and BSC groups.RESULTS： No statistically significant differences in patient characteristics were found among the resection, radiotherapy, and BSC groups. Three patients in the radiotherapy group and one in the BSC group did not receive UMS insertion but received PTBD alone; cholangitis occurred after endoscopic stenting, and patients were treated with PTBD. A total of 16 patients were administered additional systemic chemotherapy （5-fluorouracil-based regimen in 9, S-1 in 6, and gemcitabine in 1）. Overall survival varied significantly among groups, with median survival times of 48.7 mo in the surgery group, 22.1 mo in the radiotherapy group, and 5.7 mo in the BSC group. Patients who underwent curative resection survived significantly longer than those who were not candidates for surgery （P = 0.0076）. Cumulative survival in the radiotherapy group was significantly longer than in the BSC group （P = 0.0031）, but did not differ significantly from those in the non-resection group. Furthermore, the median survival time of patients in the radiotherapy group who were considered for possible resection （excluding the seven patients who were not candidates for surgery due to comorbid disease or age） was 25.9 mo. Stent patency was evaluated only in the 24 patients who received a metallic stent. Stent patency was significantly longer in the radiotherapy than in the BSC group （P = 0.0165）. Biliary drainage was not eliminated in any patient. To determine the efficacy of ILBT, we compared

Infiltrative xanthogranulomatous cholecystitis mimicking aggressive gallbladder carcinoma: A diagnostic and therapeutic dilemma

Xanthogranulomatous cholecystitis(XGC) is an uncommon variant of chronic cholecystitis. The perioperative findings in aggressive cases may be indistinguishable from those of gallbladder or biliary tract carcinomas. Three patients presented mass lesions that infiltrated the hepatic hilum,provoked biliary dilatation and jaundice,and were indicative of malignancy. Surgical excision was performed following oncological principles and included extirpation of the gallbladder,extrahepatic bile duct,and hilar lymph nodes,as well as partial hepatectomy. Postoperative morbidity was minimal. Surgical pathology demonstrated XGC and absence of malignancy in all three cases. All three patients are alive and well after years of follow-up. XGC may have such an aggressive presentation that carcinoma may only be ruled out on surgical pathology. In such cases,the best option may be radical resection following oncological principles performed by expert surgeons,in order that postoperative complications may be minimized if not avoided altogether.