Risk factors for postoperative pancreatic fistula: Analysis of 539 successive cases of pancreaticoduodenectomy

AIM To analyze the risk factors for pancreatic fistula after pancreaticoduodenectomy.METHODS We conducted a retrospective analysis of 539 successive cases of pancreaticoduodenectomy performed at our hospital from March 2012 to October 2015. Pancreatic fistula was diagnosed in strict accordance with the definition of pancreatic fistula from the International Study Group on Pancreatic Fistula. The risk factors for pancreatic fistula were analyzed by univariate analysis and multivariate logistic regression analysis.RESULTS A total of 269(49.9%) cases of pancreatic fistula occurred after pancreaticoduodenectomy,including 71(13.17%) cases of grade A pancreatic fistula,178(33.02%) cases of grade B,and 20(3.71%) cases of grade C. Univariate analysis showed no significant correlation between postoperative pancreatic fistula(POPF) and the following factors: age,hypertension,alcohol consumption,smoking,history of upper abdominal surgery,preoperative jaundice management,preoperative bilirubin,preoperative albumin,pancreatic duct drainage,intraoperative blood loss,operative time,intraoperative blood transfusion,Braun anastomosis,and pancreaticoduodenectomy(with or without pylorus preservation). Conversely,a significant correlation was observed between POPF and the following factors: gender(male vs female: 54.23% vs 42.35%,P = 0.008),diabetes(non-diabetic vs diabetic: 51.61% vs 39.19%,P = 0.047),body mass index(BMI)(≤ 25 vs > 25: 46.94% vs 57.82%,P = 0.024),blood glucose level(≤ 6.0 mmol/L vs > 6.0 mmol/L: 54.75% vs 41.14%,P = 0.002),pancreaticojejunal anastomosis technique(pancreatic duct-jejunum double-layer mucosa-to-mucosa pancreaticojejunal anastomosis vs pancreatic-jejunum single-layer mucosa-tomucosa anastomosis: 57.54% vs 35.46%,P = 0.000),diameter of the pancreatic duct(≤ 3 mm vs > 3 mm: 57.81% vs 38.36%,P = 0.000),and pancreatic texture(soft vs hard: 56.72% vs 29.93%,P = 0.000). Multivariate logistic regression analysis showed that gender(male),BMI > 25,pancreatic duct-jejunum double-layer mucosa-to-mucosa pancreaticojejunal anastomosis,pancreatic duct diameter ≤ 3 mm,and soft pancreas were risk factors for pancreatic fistula after pancreaticoduodenectomy.CONCLUSION Gender(male),BMI > 25,pancreatic duct-jejunum double-layer mucosa-to-mucosa pancreaticojejunal anastomosis,pancreatic duct diameter ≤ 3 mm,and soft pancreas were risk factors for pancreatic fistula after pancreaticoduodenectomy.

Risk scoring system and predictor for clinically relevant pancreatic fistula after pancreaticoduodenectomy

AIM: To establish a scoring system to predict clinicallyrelevant postoperative pancreatic fistula(CR-POPF)after pancreaticoduodenectomy(PD).METHODS: The clinical records of 921 consecutive patients who underwent PD between 2008 and 2013 were reviewed retrospectively. Postoperative pancreatic fistula(POPF) was defined and classified by the international study group of pancreatic fistula(ISGPF).We used a logistic regression model to determine the independent risk factors of CR-POPF and developed a scoring system based on the regression coefficient of the logistic regression model. The optimal cut-off value to divide the risk strata was determined by the Youden index. The patients were divided into two groups(low risk and high risk). The independent sample t test was used to detect differences in the means of drain amylase on postoperative day(POD) 1, 2 and 3. The optimal cut-off level of the drain amylase to distinguish CR-POPF from non-clinical POPF in the two risk strata groups was determined using the receiver operating characteristic(ROC) curves.RESULTS: Grade A POPF occurred in 106(11.5%)patients, grade B occurred in 57(6.2%) patients,and grade C occurred in 32(3.5%) patients. A predictive scoring system for CR-POPF(0-6 points) was constructed using the following four factors: 1 point for each body mass index ≥ 28 [odds ratio(OR) = 3.86;95% confidence interval(CI): 1.92-7.75, P = 0.00],soft gland texture(OR = 4.50; 95%CI, 2.53-7.98, P =0.00), and the difference between the blood loss and transfusion in operation ≥ 800 mL(OR = 3.45; 95%CI,1.92-7.75, P = 0.00); and from 0 points for a 5 mm or greater duct diameter to 3 points for a less than 2 mm duct(OR = 8.97; 95%CI: 3.70-21.77, P = 0.00). The ROC curve showed that the area under the curve of this score was 0.812. A score of 3 points was suggested to be the best cut-off value(Youden index = 0.485). In the low risk group, a drain amylase level ≥ 3600 U/L on POD3 could distinguish CR-POPF from non-clinicalPOPF(the sensitivity and specificity were 75% and85%, respectively). In the high risk group, the best cutoff was a drain amylase level of 1600(the sensitivity and specificity were 77 and 63%, respectively).CONCLUSION: A 6-point scoring system accurately predicted the occurrence of CR-POPF. In addition, a drain amylase level on POD3 might be a predictor of this complication.

Analysis of risk factors for postoperative pancreatic fistula following pancreaticoduodenectomy

AIM:To explore the morbidity and risk factors of postoperative pancreatic fistula(POPF)following pancreaticoduodenectomy.METHODS:The data from 196 consecutive patients who underwent pancreaticoduodenectomy,performed by different surgeons,in the General Hospital of the People’s Liberation Army between January 1st,2013and December 31st,2013 were retrospectively collected for analysis.The diagnoses of POPF and clinically relevant(CR)-POPF following pancreaticoduodenectomy were judged strictly by the International Study Group on Pancreatic Fistula Definition.Univariate analysis was performed to analyze the following factors:patient age,sex,body mass index(BMI),hypertension,diabetes mellitus,serum CA19-9 level,history of jaundice,serum albumin level,blood loss volume,pancreatic duct diameter,pylorus preserving pancreaticoduodenectomy,pancreatic drainage and pancreaticojejunostomy.Multivariate logistic regression analysis was used to determine the main independent risk factors for POPF.RESULTS:POPF occurred in 126(64.3%)of the patients,and the incidence of CR-POPF was 32.7%(64/196).Patient characteristics of age,sex,BMI,hypertension,diabetes mellitus,serum CA19-9 level,history of jaundice,serum albumin level,blood loss volume,pylorus preserving pancreaticoduodenectomy and pancreaticojejunostomy showed no statistical difference related to the morbidity of POPF or CR-POPF.Pancreatic duct diameter was found to be significantly correlated with POPF rates by univariate analysis and multivariate regression analysis,with a pancreatic duct diameter≤3 mm being an independent risk factor for POPF(OR=0.291;P=0.000)and CR-POPF(OR=0.399;P=0.004).The CR-POPF rate was higher in patients without external pancreatic stenting,which was found to be an independent risk factor for CR-POPF(OR=0.394;P=0.012).Among the entire patient series,there were three postoperative deaths,giving a total mortality rate of 1.5%(3/196),and the mortality associated with pancreatic fistula was 2.4%(3/126).CONCLUSION:A pancreatic duct diameter≤3 mm is an independent risk factor for POPF.External stent drainage of pancreatic secretion may reduce CR-POPF mortality and POPF severity.

Preoperative differential diagnosis between intrahepatic biliary cystadenoma and cystadenocarcinoma:A single-center experience

AIM:To investigate preoperative differential diagnoses made between intrahepatic biliary cystadenoma and intrahepatic biliary cystadenocarcinoma.METHODS:A retrospective analysis of patient data was performed,which included 21 cases of intrahepatic biliary cystadenoma and 25 cases of intrahepatic biliary cystadenocarcinoma diagnosed between April 2003and April 2013 at the General Hospital of PLA.Potential patients were excluded whose diagnoses were not confirmed pathologically.Basic information(including patient age and gender),clinical manifestation,duration of symptoms,serum assay results(including tumor markers and the results of liver function tests),radiological features and pathological results were collected.All patients were followed up.RESULTS:Preoperative levels of cancer antigen 125(12.51±9.31 vs 23.20±21.86,P<0.05)and carbohydrate antigen 19-9(22.56±26.30 vs 72.55±115.99,P<0.05)were higher in the cystadenocarcinoma subgroup than in the cystadenoma subgroup.There were no statistically significant differences in age or gender between the two groups,or in pre-or post-operative levels of alanine aminotransferase,aspartate aminotransferase,total bilirubin(TBIL),and direct bilirubin(DBIL)between the two groups.However,eight of the 21 patients with cystadenoma and six of the 25 patients with cystadenocarcinoma had elevated levels of TBIL and DBIL.There were three cases in the cystadenoma subgroup and six cases in the cystadenocarcinoma subgroup with postoperative complications.CONCLUSION:Preoperative differential diagnosis relies on the integration of information,including clinical symptoms,laboratory findings and imaging results.

Augmented reality technology for preoperative planning and intraoperative navigation during hepatobiliary surgery: A review of current methods

Background: Augmented reality(AR) technology is used to reconstruct three-dimensional(3D) images of hepatic and biliary structures from computed tomography and magnetic resonance imaging data, and to superimpose the virtual images onto a view of the surgical field. In liver surgery, these superimposed virtual images help the surgeon to visualize intrahepatic structures and therefore, to operate precisely and to improve clinical outcomes.Data Sources: The keywords "augmented reality", "liver", "laparoscopic" and "hepatectomy" were used for searching publications in the Pub Med database. The primary source of literatures was from peer-reviewed journals up to December 2016. Additional articles were identified by manual search of references found in the key articles.Results: In general, AR technology mainly includes 3D reconstruction, display, registration as well as tracking techniques and has recently been adopted gradually for liver surgeries including laparoscopy and laparotomy with video-based AR assisted laparoscopic resection as the main technical application. By applying AR technology, blood vessels and tumor structures in the liver can be displayed during surgery,which permits precise navigation during complex surgical procedures. Liver transformation and registration errors during surgery were the main factors that limit the application of AR technology.Conclusions: With recent advances, AR technologies have the potential to improve hepatobiliary surgical procedures. However, additional clinical studies will be required to evaluate AR as a tool for reducing postoperative morbidity and mortality and for the improvement of long-term clinical outcomes. Future research is needed in the fusion of multiple imaging modalities, improving biomechanical liver modeling,and enhancing image data processing and tracking technologies to increase the accuracy of current AR methods.

Clinical analysis of surgical treatment of portal hypertension

AIM: To review the experience in surgery for 508 patients with portal hypertension and to explore the selection of reasonable operation under different conditions.METHODS: The data of 508 patients with portal hypertension treated surgically in 1991-2001 in our centers were analyzed. Of the 508 patients, 256 were treated with portaazygous devascularization (PAD),167 with portasystemic shunt (PSS), 62 with selective shunt (SS), 11 with combined portasystemic shunt and portaazygous devascularization (PSS+PAD), 9 with liver transplantation (LT), 3 with union operation for hepatic carcinoma and portal hypertension (HCC+PH).RESULTS: In the 167 patients treated with PSS, free portal pressure (FPP) was significantly higher in the patients with a longer diameter of the anastomotic stoma than in those with a shorter diameter before the operation (P＜0.01). After the operation, FPP in the former patients markedly decreased compared to the latter ones (P＜0.01).The incidence rate of hemorrhage in patients treated with PAD, PSS, SS, PSS+PAD, and HCC+PH was 21.09% (54/256), 13.77 (23/167), 11.29 (7/62), 36.36% (4/11),and 100% (3/3), respectively. The incidence rate of hepatic encephalopathy was 3.91% (10/256), 9.58% (16/167),4.84% (3/62), 9.09% (1/11), and 100% (3/3), respectively while the operative mortality was 5.49% (15/256), 4.22% (7/167), 4.84% (3/62), 9.09% (1/11), and 66.67% (2/3) respectively. The operative mortality of liver transplantation was 22.22% (2/9).CONCLUSION: Five kinds of operation in surgical treatment of portal hypertension have their advantages and disadvantages. Therefore, the selection of operation should be based on the actual needs of the patients.

Comprehensive application of modern technologies in precise liver resection

BACKGROUND: Liver surgery has gone through the phases of wedge liver resection, regular resection of hepatic lobes, irregular and local resection, extracorporeal hepatectomy, hemi-extracorporeal hepatectomy and Da Vinci surgical system-assisted hepatectomy. Taking advantage of modern technologies, liver surgery is stepping into an age of precise liver resection. This review aimed to analyze the comprehensive application of modern technologies in precise liver resection. DATA SOURCE: PubMed search was carried out for English-language articles relevant to precise liver resection, liver anatomy, hepatic blood inflow blockage, parenchyma transection, and down-staging treatment. RESULTS: The 3D image system can imitate the liver operation procedures, conduct risk assessment, help to identify the operation feasibility and confirm the operation scheme. In addition, some techniques including puncture and injection of methylene blue into the target Glisson sheath help to precisely determine the resection. Alternative methods such as Pringle maneuver are helpful for hepatic blood inflow blockage in precise liver resection. Moreover, the use of exquisite equipment for liver parenchyma transection, such as cavitron ultrasonic surgical aspirator, ultrasonic scalpel, Ligasure and Tissue Link is also helpful to reduce hemorrhage in liver resection, or even operate exsanguinous liver resection without blocking hepatic blood flow. Furthermore, various down-staging therapies including transcatheter arterial chemoembolization and radio-frequency ablation were appropriate for unresectable cancer, which reverse the advanced tumor back to early phase by local or systemic treatment so that hepatectomy or liver transplantation is possible.CONCLUSIONS: Modern technologies mentioned in this paper are the key tool for achieving precise liver resection and can effectively lead to maximum preservation of anatomical structural integrity and functions of the remnant liver. In addition, large randomized trials are needed to evaluate the usefulness of these technologies in patients with hepatocellular carcinoma who have undergone precise liver resection.

Poor prognosis for hepatocellular carcinoma with transarterial chemoembolization pre-transplantation:Retrospective analysis

AIM: To investigate whether transarterial chemoembolization(TACE) before liver transplantation(LT) improves long-term survival in hepatocellular carcinoma(HCC) patients.METHODS: A retrospective study was conducted among 204 patients with HCC who received LT from January 2002 to December 2010 in PLA General Hospital. Among them, 88 patients received TACE before LT. Prognostic factors of serum α-fetoprotein(AFP), intraoperative blood loss, intraoperative blood transfusion, disease-free survival time, survival time with tumor, number of tumor nodules, tumor size, tumor number, presence of blood vessels and bile duct invasion, lymph node metastasis, degree of tumor differentiation, and preoperative liver function were determined in accordance with the Child-TurcottePugh(Child) classification and model for end-stage liver disease. We also determined time of TACE before transplant surgery and tumor recurrence and metastasis according to different organs. Cumulative survival rate and disease-free survival rate curves were prepared using the Kaplan-Meier method, and the logrank and χ2 tests were used for comparisons.RESULTS: In patients with and without TACE before LT, the 1, 3 and 5-year cumulative survival rate was 70.5% ± 4.9% vs 91.4% ± 2.6%, 53.3% ± 6.0% vs 83.1% ± 3.9%, and 46.2% ± 7.0% vs 80.8% ± 4.5%, respectively. The median survival time of patients with and without TACE was 51.857 ± 5.042 mo vs 80.930 ± 3.308 mo(χ2 = 22.547, P < 0.001, P < 0.05). The 1, 3 and 5-year disease-free survival rates for patients with and without TACE before LT were 62.3% ± 5.2% vs98.9% ± 3.0%, 48.7% ± 6.7% vs 82.1% ± 4.1%, and 48.7% ± 6.7% vs 82.1% ± 4.1%, respectively. The median survival time of patients with and without TACE before LT was 50.386 ± 4.901 mo vs 80.281 ± 3.216 mo(χ2 = 22.063, P < 0.001, P < 0.05). TACE before LT can easily lead to pulmonary or distant metastasis of the primary tumor. Although there was no significant difference between the two groups, the chance of metastasis of the primary tumor in the group with TACE was significantly higher than that of the group without TACE.CONCLUSION: TACE pre-LT for HCC patients increased the chances of pulmonary or distant metastasis of the primary tumor, thus reducing the long-term survival rate.

Ex-situ liver surgery without veno-venous bypass

AIM:To evaluate the results of hepatic resection with ex-situ hypothermic perfusion and without veno-venous bypass.METHODS:In 3 patients with liver tumor,the degree of the inferior vena cava and/or main hepatic vein involvement was verified when the liver was dissociated in the operation.It was impossible to resect the tumors by the routine hepatectomy,so the patients underwent ex-situ liver surgery,vein cava replacement and hepatic autotransplantation without veno-venous bypass.All surgical procedures were carried out or supervised by a senior surgeon.A retrospective analysis was performed for the prospectively collected data from patients with liver tumor undergoing ex-situ liver surgery,vein cava replacement and hepatic autotransplantation without veno-venous bypass.We also compared our data with the 9 cases of Pichlmayr's group.RESULTS:Three patients with liver tumor were analysed.The first case was a 60-year-old female with a huge haemangioma located in S1,S4,S5,S6,S7 and S8 of liver;the second was a 64-year-old man with cholangiocarcinoma in S1,S2,S3 and S4 and the third one was a 55-year-old man with a huge cholangiocarcinoma in S1,S5,S7 and S8.The operation time for the three patients were 6.6,6.4 and 7.3 h,respectively.The anhepatic phases were 3.8,2.8 and 4.0 h.The volume of blood loss during operation were 1200,3100,2000 mL in the three patients,respectively.The survival periods without recurrence were 22 and 17 mo in the first two cases.As for the third case complicated with postoperative hepatic vein outflow obstruction,emergency hepatic vein outflow extending operation and assistant living donor liver transplantation were performed the next day,and finally died of liver and renal failure on the third day.Operation time(6.7 ± 0.47 h vs 13.7 ± 2.6 h) and anhepatic phase(3.5 ± 0.64 h vs 5.7 ± 1.7 h) were compared between Pichlmayr's group and our series(P = 0.78).CONCLUSION:Ex-situ liver resection and liver autotransplantation has shown a potential for treatment of complicated hepatic neoplasms that are unresectable by traditional procedures.

Traditional surgical planning of liver surgery is modified by 3D interactive quantitative surgical planning approach： a single-center experience with 305 patients

BACKGROUND： Decision making and surgical planning are to achieve the precise balance of maximal removal of target lesion, maximal sparing of functional liver remnant volume, and minimal surgical invasiveness and therefore, crucial in liver surgery. The aim of this prospective study was to validate the accuracy and predictability of 3D interactive quantitative surgical planning approach （IQSP）, and to evaluate the impact of IQSP on traditional surgical plans based on 2D images. METHODS： A total of 305 consecutive patients undergoing hepatectomy were included in this study. Surgical plans were created by traditional 2D approach using picture archiving and communication system （PACS） and 3D approach using IQSP respectively by two groups of physicians who did not know the surgical plans of the other group. The two surgical plans were submitted to the chief surgeon for selection before operation. The specimens were weighed. The two surgical plans were compared and analyzed retrospectively based on the operation results. RESULTS： The two surgical plans were successfully developed in all 305 patients and all the 3D IQSP surgical plans were selected as the final decision. Total 278 patients successfully underwent surgery, including 147 uncomplex hepatectomy and 131 complex hepatectomy. Twenty-seven patients were withdrawn from hepatectomy. In the uncomplex group, the two surgical plans were the same in all 147 patients and no statistically significant difference was found among 2D calcu- lated resection volume （2D-RV）, 3D IQSP calculated resection volume （IQSP-RV） and the specimen volume. In the complex group, the two surgical plans were different in 49 patients （49/131, 37.4%）. According to the significance of differences, the 49 different patients were classified into three grades. No statistically significant difference was found between IQSP-RV and specimen volume. The coincidence rate of territory analy- sis of IQSP with operation was 92.1% （93/101） for 101 patients of anatomic hepatectomy. CONCLUSIONS： The accuracy and predictability of 3D IQSP were validated. Compared with traditional surgical planning, 3D IQSP can provide more quantitative information of anatomic structure. With the assistance of 3D IQSP, traditional surgical plans were modified to be more radical and safe.

Hepatectomy for hepatocellular carcinoma in the era of liver transplantation

The aim of management of hepatocellular carcinoma(HCC)is to improve the prognosis of the patients by radical resection and preserve remnant liver function.Although liver transplantation is associated with a lower tumor recurrence rate,this benefit is counteracted by long-term complications.Therefore,hepatectomy could be the first choice of treatment in selected patients with HCC.However,the higher frequency of tumor recurrence and the lower rate of resectability after hepatectomy for HCC led to an unsatisfactory prognosis.New strategies are required to improve the long-term outcome of HCC after hepatectomy.In this paper,we introduce some strategies to increase the low rate of resectability and reduce the high rate of tumor recurrence.Some aggressive treatments for tumor recurrence to extend long-term survival are also involved.We believe that hepatectomy combined with other therapies,such as portal vein embolization,transarterial chemoembolization,radioembolization,antiviral treatment,radiofrequency ablation and salvage transplantation,is a promising treatment modality for HCC and may improve survival greatly.

Inhalation of hydrogen gas reduces liver injury during major hepatotectomy in swine

AIM:To study the effect of H2 gas on liver injury in massive hepatectomy using the Intermittent Pringle maneuver in swine. METHODS:Male Bama pigs (n = 14) treated with ketamine hydrochloride and Sumianxin Ⅱ as induction drugs followed by inhalation anesthesia with 2% isoflurane, underwent 70% hepatotectomy with loss of bleeding less than 50 mL, and with hepatic pedicle occlusion for 20 min, were divided into two groups:Hydrogen-group (n = 7), the pigs with inhalation of 2% hydrogen by the tracheal intubation during major hepatotectomy; Contrast-group (n = 7), underwent 70% hepatotectomy without inhalation of hydrogen. Hemo-dynamic changes and plasma concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and malondialdehyde (MDA) in liver tissue were measured at pre-operation, post-hepatotectomy (PH) 1 h and 3 h. The apoptosis and proliferating cell nuclear antigen (PCNA) expression in liver remnant were evaluated at PH 3 h. Thenwe compared the two groups by these marks to evaluate the effect of the hydrogen in the liver injury during major hepatotectomy with the Pringle Maneuver in the swine. RESULTS: There were no significant differences in body weight, blood loss and removal liver weight between the two groups. There was no significant difference in changes of portal vein pressure between two groups at pre-operation, PH 30 min, but in hydrogen gas treated-group it slightly decrease and lower than its in Contrast-group at PH 3 h, although there were no significant difference (P = 0.655). ALT and AST in Hydrogen-group was significantly lower comparing to Contrast-group (P = 0.036, P = 0.011, vs P = 0.032, P = 0.013) at PH 1 h and 3 h, although the two groups all increased. The MDA level increased between the two group at PH 1 h and 3 h. In the hydrogen gas treated-group, the MDA level was not significantly significant at pre-operation and significantly low at PH 1 h and 3 h comparing to Contrast-group (P = 0.0005, P = 0.0004). In Hydrogen-group, the HA level was also significantly low to Contrast-group (P = 0.0005, P = 0.0005) although the two groups all increased at PH 1 h and 3 h. The expression of cluster of differentiation molecule 31 molecules Hydrogen-group was low to Contrast-group. However, PCNA index (%) was not statistically significant between the two groups (P = 0.802). Microphotometric evaluation of apoptotic index (AI) in terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-stained tissue after hepatotectomy for 3h, the AI% level in the hydrogen was significantly low to Contrast-group (P = 0.012). There were no significant difference between Hydrogen-group and Contrastgroup at pre-operation (P = 0.653, P = 0.423), but after massive hepatotectomy, the TNF-α and IL-6 levels increase, and its in Hydrogen-group was significantly low compared with Contrast-group (P = 0.022, P = 0.013, vs P = 0.016, P = 0.012), respectively. Hydrogen-gas inhalation reduce levels of these markers and relieved morphological liver injury and apoptosis.CONCLUSION: H2 gas attenuates markedly ischemia and portal hyperperfusion injury in pigs with massive hepatotectomy, possibly by the reduction of inflammation and oxidative stress, maybe a potential agent for treatment in clinic.

Safety validation of decision trees for hepatocellular carcinoma

AIM: To evaluate a different decision tree for safe liver resection and verify its efficiency.METHODS: A total of 2457 patients underwent hepatic resection between January 2004 and December 2010 at the Chinese PLA General Hospital,and 634 hepatocellular carcinoma(HCC) patients were eligible for the final analyses. Post-hepatectomy liver failure(PHLF) was identified by the association of prothrombin time < 50% and serum bilirubin > 50 μmol/L(the "50-50" criteria),which were assessed at day 5 postoperatively or later. The Swiss-Clavien decision tree,Tokyo University-Makuuchi decision tree,and Chinese consensus decision tree were adopted to divide patients into two groups based on those decision trees in sequence,and the PHLF rates were recorded.RESULTS: The overall mortality and PHLF rate were 0.16% and 3.0%. A total of 19 patients experienced PHLF. The numbers of patients to whom the SwissClavien,Tokyo University-Makuuchi,and Chinese consensus decision trees were applied were 581,573,and 622,and the PHLF rates were 2.75%,2.62%,and 2.73%,respectively. Significantly more cases satisfied the Chinese consensus decision tree than the Swiss-Clavien decision tree and Tokyo University-Makuuchi decision tree(P < 0.01,P < 0.01); nevertheless,the latter two shared no difference(P = 0.147). The PHLF rate exhibited no significant difference with respect to the three decision trees.CONCLUSION: The Chinese consensus decision tree expands the indications for hepatic resection for HCC patients and does not increase the PHLF rate compared to the Swiss-Clavien and Tokyo UniversityMakuuchi decision trees. It would be a safe and effective algorithm for hepatectomy in patients with hepatocellular carcinoma.

Outcomes of liver transplantation for end-stage biliary disease: A comparative study with end-stage liver disease

AIM: To evaluate the outcomes of patients with endstage biliary disease(ESBD) who underwent liver transplantation, to define the concept of ESBD, the criteria for patient selection and the optimal operation for decision-making.METHODS: Between June 2002 and June 2014, 43 patients with ESBD from two Chinese organ transplantation centres were evaluated for liver transplantation. The causes of liver disease were primary biliary cirrhosis(n = 8), cholelithiasis(n = 8), congenital biliary atresia(n = 2), graft-related cholangiopathy(n = 18), Caroli's disease(n = 2), iatrogenic bile duct injury(n = 2), primary sclerosing cholangitis(n = 1), intrahepatic bile duct paucity(n = 1) and Alagille's syndrome(n = 1). The patients with ESBD were compared with an end-stage liver disease(ESLD) case control group during the same period, and the potential prognostic values of multiple demographic and clinical variables were assessed. The examined variables included recipient age, sex, pre-transplant clinical status, pre-transplant laboratory values, operation condition and postoperative complications, as well as patient and allograft survival rates. Survival analysis was performed using Kaplan-Meier curves, and the rates were compared using log-rank tests. All variables identified by univariate analysis with P values < 0.100 were subjected to multivariate analysis. A Cox proportional hazard regression model was used to determine the effect of the study variables on outcomes in the study group.RESULTS: Patients in the ESBD group had lower model for end-stage liver disease(MELD)/paediatric end-stage liver disease(PELD) scores and a higher frequency of previous abdominal surgery compared to patients in the ESLD group(19.2 ± 6.6 vs 22.0 ± 6.5, P = 0.023 and 1.8 ± 1.3 vs 0.1 ± 0.2, P = 0.000). Moreover, theoperation time and the time spent in intensive care were significantly higher in the ESBD group than in the ESLD group(527.4 ± 98.8 vs 443.0 ± 101.0, P = 0.000, and 12.74 ± 6.6 vs 10.0 ± 7.5, P = 0.000). The patient survival rate in the ESBD group was not significantly different from that of the ESBD group at 1, 3 and 5 years(ESBD: 90.7%, 88.4%, 79.4% vs ESLD: 84.9%, 80.92%, 79.0%, χ2 = 0.194, P = 0.660). The graftsurvival rates were also similar between the two groups at 1, 3 and 5 years(ESBD: 90.7%, 85.2%, 72.7% vs ESLD: 84.9%, 81.0%, 77.5%, χ2 = 0.003, P = 0.958). Univariate analysis identified MELD/PELD score(HR = 1.213, 95%CI: 1.081-1.362, P = 0.001) and bleeding volume(HR = 0.103, 95%CI: 0.020-0.538, P = 0.007) as significant factors affecting the outcomes of patients in the ESBD group. However, multivariate analysis revealed that MELD/PELD score(HR = 1.132, 95%CI: 1.005-1.275, P = 0.041) was the only negative factor that was associated with short survival time.CONCLUSION: MELD/PELD criteria do not adequately measure the clinical characteristics and staging of ESBD. The allocation system based on MELD/PELD criteria should be re-evaluated for patients with ESBD.

Hepatocellular Carcinoma with Blood Supply from Parasitized Omental Artery: Angiographic Appearance And Chemoembolization

Objective： To analyze angiographic appearance of hepatocellular carcinoma （HCC） with blood supply from parasitized omental artery （POA）, and evaluate the technical feasibility, safety and therapeutic efficacy of chemo-embolization via the POAs. Methods： A total of 1,221 HCC patients who had undergone chemoembolization procedures were evaluated retrospectively. The evaluated indexes included the incidence rate of POAs, success rate of superselective catheterization, post-reaction after chemoembolization, and the cumulative survival rates. Results： Totally 1,221 HCC patients had undergone 3,639 chemoembolization procedures, and 32 patients with POAs were enrolled, with 97 POAs found in 76 angiography procedures, giving an incidence rate of 2.09%. POA was observed mostly at the right lobe and left medial lobe except the segment II, and 62 POAs underwent superselective catheterization with microcatheter, giving a success rate of 63.9%. The angiographic appearance was： （1） hypertrophic POAs participating in tumor staining （n=28）; （2） stiff and distorted POA （n=11）, displaced due to tumor＇s oppression （n=8）; and （3） defective tumor staining close to either gastrocolic omentum distribution or liver capsule （n=7）. In 19 patients, chemoembolization via POAs was performed successfully （A group）, while the remaining 13 patients failed （B group）. Except 1 acute edema pancreatitis case, no serious complication was recorded. The cumulative survival rates of 6-, 12-, 18- and 24-month were 78.9%, 47.4%, 31.6% and 21.1% respectively for A group; correspondingly, 61.5%, 30.8%, 15.4% and 7.7%% for B group, in which 2 patients died of ruptured HCC. Conclusion： Chemoembolization with microcatheter via POAs is a relatively safe, feasible and valuable method.

Tolerance limit of rats to normothermic hepatic inflow occlusion under portal blood bypass

Objective: To evaluate the tolerance limit of rats tonormothermic hepatic inflow occlusion under portalblood bypass.Methods: A new rat model of normothermic hepaticinflow occlusion under portal blood bypass was estab-lished by clamping temporarily the pedicles of all liverlobes while the caudal lobe was kept as a passage ofthe portal blood flow. After hepatic blood flow re-stored, the caudal lobe was cut off. On the 7th postop-erative day, survival rate, hepatic morphological changes,and the severity and reversibility of the injured energymetabolism of the liver were investigated.Results: All rats that had been subjected to 30, 60 and90 minutes of hepatic inflow occlusion under portalblood bypass survived on the 7th postoperativeday. Ischemia-reperfusion injury of the liver was re-versible and compensatory in rats with hepatic inflowocclusion within 90minutes. However, the survivalrates of rats with 100, 110 and 120 minutes of hepaticinflow occlusion were 50%, 30% and 20% respective-ly. Liver injury of rats with 120 minutes of hepatic in-flow occlusion was severe and irreversible.Conclusions: The tolerance limit of rats to normother-mic hepatic inflow occlusion is enhanced significantlyunder portal blood bypass and the upper limit is 90minutes.

Post-pancreaticoduodenectomy hemorrhage:risk factors, managements and outcomes

BACKGROUND： Post-pancreaticoduodenectomy（PD） hemorrhage（PPH） is an uncommon but serious complication. This retrospective study analyzed the risk factors, managements and outcomes of the patients with PPH.METHODS： A total of 840 patients with PD between 2000 and2010 were retrospectively analyzed. Among them, 73 patients had PPH： 19 patients had early PPH and 54 had late PPH.The assessment included the preoperative history of disease,pancreatic status and surgical techniques. Other postoperative complications were also evaluated.RESULTS： The incidence of PPH was 8.7%（73/840）. There were no independent risk factors for early PPH. Male gender（OR=4.40, P0.02）, diameter of pancreatic duct（OR=0.64,P0.01）, end-to-side invagination pancreaticojejunostomy（OR=5.65, P0.01）, pancreatic fistula（OR=2.33, P0.04）and intra-abdominal abscess（OR=12.19, P0.01） were the independent risk factors for late PPH. Four patients with early PPH received conservative treatment and 12 were treated surgically. As for patients with late PPH, the success rate of medical therapy was 27.8%（15/54）. Initial endoscopy was operated in 12 patients（22.2%）, initial angiography in 19（35.2%）,and relaparotomy in 15（27.8%）. Eventually, PPH resulted in 19 deaths. The main causes of death were multiple organ failure,hemorrhagic shock, sepsis and uncontrolled rebleeding.CONCLUSIONS： Careful and ongoing observation of hemorrhagic signs, especially within the first 24 hours after PD or within the course of pancreatic fistula or intra-abdominal abscess, is recommended for patients with PD and a prompt management is necessary. Although endoscopy and angiography are the standard procedures for the management of PPH,surgical approach is still irreplaceable. Aggressive prevention of hemorrhagic shock and re-hemorrhage is the key to treat PPH.

Integrin αvβ6 sustains and promotes tumor invasive growth in colon cancer progression

AIM: To detect the mechanism by which colon tumor escapes the growth constraints imposed on normal cells by cell crowding and dense pericellular matrices.METHODS: An immunohistochemical study of integrin αvβ6 and matrix metalloproteinase-9(MMP-9) was performed on tissue microarrays of 200 spots, including 100 cases of colon tumors. RESULTS: High immunoreactivity for αvβ6(73.7%; 28/38) and MMP-9(76.5%; 52/68) was observed in invasive tumor portions. Furthermore, the effects of integrin αvβ6 on tumor invasive growth in nude mice were detected. Tumor invasive growth and high expression of both αvβ6 and MMP-9 were only seen in tumors resulting from Wi Dr cells expressing αvβ6 in the tumorigenicity assay. Flow cytometry was applied to analyze αvβ6 expression in colon cancer Wi Dr and SW480 cells. The effects of cell density on αvβ6 expression and MMP-9 secretion were also detected by Biotrak MMP-9 activity assay and gelatin zymography assay. High cell density evidently enhanced αvβ6 expression and promoted MMP-9 secretion compared with low density. CONCLUSION: Integrin αvβ6 sustains and promotes tumor invasive growth in tumor progression via a selfperpetuating mechanism. Integrin ανβ6-mediated MMP-9 secretion facilitates pericellular matrix degradation at high cell density, which provides the basis of invasive growth.

Graft cholangiopathy: etiology, diagnosis, and therapeutic strategies

BACKGROUND: Graft cholangiopathy has been recognized as a significant cause of morbidity, graft loss, and even mortality in patients after orthotopic liver transplantation. The aim of this review is to analyze the etiology, pathogenesis, diagnosis and therapeutic strategies of graft cholangiopathy after liver transplantation. DATA SOURCE: A PubMed database search was performed to identify articles relevant to liver transplantation, biliary complications and cholangiopathy. RESULTS: Several risk factors for graft cholangiopathy after liver transplantation have been identified, including ischemia/ reperfusion injury, cytomegalovirus infection, immunological injury and bile salt toxicity. A number of strategies have been attempted to prevent the development of graft cholangiopathy, but their efficacy needs to be evaluated in large clinical studies. Non-surgical approaches may offer good results in patients with extrahepatic lesions. For most patients with complex hilar and intrahepatic biliary abnormalities, however, surgical repair or re-transplantation may be required. CONCLUSIONS: The pathogenesis of graft cholangiopathy after liver transplantation is multifactorial. In the future, more efforts should be devoted to the development of more effective preventative and therapeutic strategies against graft cholangiopathy.

Modified hepatic outflow tract reconstruction in piggyback liver transplantation

OBJECTIVE: To summarize the experience in modified reconstruction of the hepatic outflow tract during piggyback liver transplantation at our hospital. METHODS: The clinical data on 67 patients undergoing piggyback liver transplantation with modified hepatic outflow tract reconstruction from January 1999 to October 2002 were analyzed retrospectively. RESULTS: In this group, 7 patients (10. 45%) died perioperatively. Complications included: pulmonary infection (38 patients); multiple organ system failure (10), intraperitoneal bleeding (6), acute respiratory distress syndrome (14), thrombosis of the hepatie artery (1), and bile leakage (1). No hepatic outflow occluded. Two recipients survived for over 3 years, 8 over 2 years, and 19 over a year. CONCLUSION: Modified hepatic outflow reconstruction in piggyback live transplantation may increase the success rate of liver transplantation and decrease technical complications.