Distance of Peritoneum to Inferior Mesenteric Artery Predicts the Operation Time During Laparoscopic Colectomy for Sigmoid or Rectosigmoid Colon Cancer.

Background/Aim: Obesity is a major technical limiting factor for laparoscopic surgery because abundant visceral fat is known to extend the operation time. However, special hardware is needed to assess it. We hypothesized that the depth from the peritoneum to the bifurcation of the inferior mesenteric artery (IMA) defined as 'peritoneum to IMA distance (PID)' might be a simple predictive factor for extended operation time during laparoscopic colectomy. Patients and Methods: One hundred twenty-four patients who were diagnosed with sigmoid or rectosigmoid colon cancer and underwent laparoscopic colectomy were included. The patients were divided into two groups based on the operation time (210 min). The vertical distance from the peritoneum to the bifurcation of the inferior mesenteric artery was defined as PID. The factors eliciting an operation time longer than 210 min were investigated. Results: There was significant difference in sex, BMI, cT, cN, and PID between the Early group (<210 min) and Late group (≥210 min). Less blood loss was observed in the Early group than in the Late group. Multivariate analysis showed that PID was the only independent factor that affected operation time (p<0.001). Conclusion: PID predicts the operation time during laparoscopic colectomy for sigmoid or rectosigmoid colon cancer.

Taking antithrombic therapy during emergency laparoscopic cholecystectomy for acute cholecystitis does not affect the postoperative outcomes: a propensity score matched study.

BACKGROUND: Continuing antithrombic therapy (ATT) during surgery increases the risk of bleeding. However, it is difficult to discontinue the ATT in emergency surgery. Therefore, safety of emergency laparoscopic cholecystectomy (LC) for acute cholecystitis (AC) is still unclear. We aimed to clarify the affect of ATT during emergency LC for AC. METHODS: Patients with AC were classified into ATT group (n = 30) and non-ATT group (n = 120). Postoperative outcomes were compared after propensity score matching (n = 22). RESULTS: Higher level of c-reactive protein level and shorter activated partial thromboplastin time (APTT) was observed in ATT group than in non-ATT group after matching. No significant difference was found between other patient characteristics and perioperative results. Blood loss over 100 mL was observed in 8 patients. Multivariate analyze showed that APTT was an independent risk factor for bleeding over 100 mL (P = 0.039), while ACT and APT was not. CONCLUSIONS: Taking ATT does not affect the blood loss or complications during emergency LC for AC. Controlling intraoperative bleeding is essential for a safe postoperative outcome.

Purse-string suture after ligating by endoloop for closing of the appendiceal stump is an alternative for endostapler in selected cases: A propensity score-matched study.

INTRODUCTION: The closure of the appendiceal stump is a crucial part of a laparoscopic appendectomy, and an endoloop or endostapler is generally used. The endoloop can be more cost effective than the endostapler. However, reports have shown that the endoloop has a higher postoperative abdominal abscess rate than the endostapler in complicated appendicitis. At our institution, we perform a purse-string suture after ligating by endoloop to reduce postoperative abdominal abscess risk. This study aimed to clarify whether this method could reduce the incidence of postoperative abdominal abscess compared with the endostapler. METHODS: Patients with acute appendicitis were classified into the purse-string suture group (n = 149) and the endostapler group (n = 82). Postoperative outcomes were compared after propensity score matching (n = 47). RESULTS: No significant difference was found between the two groups in terms of the patient characteristics and postoperative complications, including abdominal abscess. However, the purse-string suture group had more drain placement and a shorter hospital stay than the endostapler group (P = .04 and P = .02, respectively). In patients with complicated appendicitis, there was less drain placement and a shorter hospital stay in the purse-string suture group than in the endostapler group (P < .01 and P < .01, respectively). This might have reflected the difficulty of the operation. All postoperative abdominal abscesses occurred in complicated appendicitis cases. CONCLUSIONS: Endoloop with additional purse-string suture had a lower incidence of abscess than previous reports of using endoloop alone. Moreover, the postoperative abdominal abscess rate is similar between the two closure methods.

A rare case of metastatic solitary fibrous tumor of the pancreas manifesting as a cystic neoplasm: a case report.

BACKGROUND: Solitary fibrous tumor (SFT) is a rare mesenchymal tumor that typically arises from the pleura. Although it may appear in other organs, it rarely develops in the pancreas. We report herein a rare case of metastatic SFT of the pancreas originating from an intracranial tumor and subsequently identified as a cystic neoplasm of the pancreas. CASE PRESENTATION: A 58-year-old woman with a past medical history of brain tumor visited the hospital for further investigation of a cystic tumor in the pancreas tail. Abdominal imaging showed a heterogeneously enhancing mass that was initially suspected as a neuroendocrine neoplasm, solid pseudopapillary neoplasm, or mucinous cystic neoplasm of the pancreas. Distal pancreatectomy was performed without any intraoperative and postoperative complications. Pathological findings confirmed a diagnosis of malignant SFT of the pancreas with hyperproliferative potential. A histopathological review of her brain tumor revealed that the pancreatic tumor was derived from her brain lesion. The patient developed recurrent brain disease 4 years after the pancreatectomy, but no recurrence has been observed in the abdominal cavity. CONCLUSIONS: SFT should be considered in the differential diagnosis of untypical hypervascular pancreatic mass, particularly in patients with a history of an intrathoracic or intracranial mesenchymal tumor. Immunohistochemical analysis is crucial in detecting this tumor entity. Hyperproliferative status indicates a malignant disease and requires careful postoperative observation.

[Adjuvant Chemotherapy for High-Risk Stage â ¡ Colon Cancer].

BACKGROUND: This study was designed to clarify effects of postoperative adjuvant chemotherapy for high-risk Stage Ⅱ colorectal cancer. METHOD: The subjects were 99 patients with high-risk Stage Ⅱcolorectal cancer who underwent surgery at our department from October 2013 to March 2018. Patients were classified into adjuvant chemotherapy group and nonadjuvant chemotherapy group. Overall survival(OS)and recurrence-free survival(RFS)were analyzed between the 2 groups. RESULTS: Thirty six patients(36.4%)underwent adjuvant chemotherapy. Adjuvant chemotherapy group were younger(p<0.010), had a better ASA-PS(p<0.010), good preoperative Hb(p<0.010), and preoperative Alb(p<0.010)compared to non-adjuvant chemotherapy group. There was no difference between the 2 groups in the high-risk factors for recurrence. Most patient had an oral medication as for adjuvant chemotherapy. There was no difference in OS and RFS between the 2 groups. CONCLUSION: Postoperative adjuvant chemotherapy for high-risk Stage Ⅱ colorectal cancer did not significantly improve the OS and RFS. Further study is necessary to asses the suitable regimen and patients eligible for chemotherapy.

[Preoperative Chemotherapy with DCF for Advanced Esophageal Cancer].

We conducted a retrospective study to evaluate the efficacy and the problem of the neoadjuvant chemotherapy using DCF for cStage Ⅲ/Ⅳ(squamous cell)esophageal cancer. Eleven patients from January 2017 to December 2018 were enrolled into this study. The median age was 67 years old, male/female ratio was 9:2, performance status was 0 in all patients, and UICC cStage Ⅲ/Ⅳa was 7:4. Cycles of chemotherapy was 2 in 1 patients, 3 in 5 patients and additional 2 courses in 1 patient. Four patients switched to FP therapy after a course of DCF. The efficacy of chemotherapy was evaluated by the clinical response rate, average tumor reduction rate, and histological therapeutic effect rate over Grade 2 which was 63.6%, 48.3%, and 40%, respectively. Neutropenia over Grade 3 was observed in all patients and Grade 4 was observed in 6 patients. In conclusion, preoperative chemotherapy with DCF therapy is useful for the treatment of cStage Ⅲ/Ⅳ(squamous cell) esophageal cancer as long as bone marrow suppression is managed.

Feasibility and Effectiveness of Gastrectomy for Elderly Gastric Cancer Patients.

BACKGROUND/AIM: The benefits of gastrectomy for elderly gastric cancer (GC) patients remain unknown. The aim of this study was to evaluate the validity of gastrectomy. PATIENTS AND METHODS: Patients who had R0 or R1 resection and diagnosed as pathological Stage I-III GC were enrolled in this study. Patients were classified according to age: Elderly group (≥80 years old), non-Elderly group (70-79 years old), Standard group (≤69 years old). RESULTS: As the age raised, the number of comorbidities increased and patients had a worse physical status. Operative procedure and postoperative complications of the Elderly group were similar to that of the non-Elderly group. The overall survival was similar in pathological Stages I and III between the Elderly and non-Elderly groups, while the Stage II Elderly group had shorter overall survival. Also, the Elderly group did not undergo adjuvant chemotherapy compared to other groups. CONCLUSION: Gastrectomy can be performed safely in elderly patients following gastrectomy, survival of elderly patients was similar to non-elderly patients. Therefore, gastrectomy is an acceptable treatment for elderly patients in good condition.

A Prospective Phase II Trial of Neoadjuvant S-1 with Concurrent Hypofractionated Radiotherapy in Patients with Resectable and Borderline Resectable Pancreatic Ductal Adenocarcinoma.

BACKGROUND: The ideal neoadjuvant treatment protocol for patients with pancreatic cancer (PDAC) remains unclear. We evaluated the efficacy and safety of neoadjuvant hypofractionated chemoradiotherapy with S-1 for patients with resectable (R) and borderline resectable (BR) PDAC. METHODS: Eligibility criteria included patients with R and BR PDAC, performance status 0-1, and age 20-85 years. Hypofractionated external-beam radiotherapy (30 Gy in 10 fractions) with concurrent S-1 (60 mg/m2) was delivered 5 days/week for 2 weeks prior to pancreatectomy. RESULTS: Fifty-seven patients were enrolled in this study, including 33 R and 24 BR [19 BR tumors with portal vein contact (BR-PV) and 5 BR tumors with arterial contact (BR-A)]. The total rates of protocol treatment completion and resection were 91% (50/57) and 96% (55/57), respectively. Seven patients failed to complete S-1 due to cholangitis (n = 5) or neutropenia (n = 2). The most common grade 3 toxicities [Common Terminology Criteria for Adverse Events (CTCAE) version 4.0] were anorexia (7%), nausea (5%), neutropenia (4%), and leukopenia (4%). No patient experienced grade 4 toxicity. Pathologically negative margins (R0) were achieved in 54 of 55 patients (98%) who underwent pancreatectomy. Pathological response was classified as Evans grade I in 8 patients (15%), IIa in 31 patients (56%), IIb in 14 patients (25%), III in 1 patient (2%), and IV in 1 patient (2%), and operative morbidity (Clavien-Dindo grade IIIb or less) was observed in 4 patients (8%). The 1- and 2-year overall survival (OS) rates were 91 and 83% in R patients, respectively, and 77 and 58% in BR patients, respectively (p = 0.03). CONCLUSION: Neoadjuvant S-1 with concurrent hypofractionated radiotherapy is tolerable and appears promising for patients with R and BR PDAC.

Successful laparoscopic distal gastrectomy with D2 lymph node dissection preserving the common hepatic artery branched from the left gastric artery for advanced gastric cancer with an Adachi type VI (group 26) vascular anomaly.

We report a case of successful laparoscopic distal gastrectomy with D2 lymph node dissection preserving the common hepatic artery branched from the left gastric artery for advanced gastric cancer with an Adachi type VI (group 26) vascular anomaly. A 76-year-old female patient was admitted with a diagnosis of advanced gastric cancer at the anterior wall to the lesser curvature of the antrum (cT3N0M0 cStage IIA). Dynamic computed tomography showed the ectopia of the common hepatic artery branched from the left gastric artery. We made a diagnosis of an Adachi type VI (group 26) vascular anomaly and performed the abovementioned operation. In this anomaly pattern, scrupulous attention is required to remove the suprapancreatic lymph nodes because the portal vein is located immediately dorsal to those lymph nodes and is at increased risk for the injury in this situation. The common hepatic artery is branched from the left gastric artery, and the hepatic perfusion from the superior mesenteric artery is not present in group 26. Planning to preserve the artery will improve safety when it is possible oncologically. There were no postoperative complications, and the patient was discharged 9 days after the operation. To our knowledge, the present case is the first reported case of a laparoscopic distal gastrectomy with D2 lymph node dissection with an Adachi type VI (group 26) vascular anomaly. Preoperative diagnostic imaging is very important to prevent surgical complications because the reliable identification of vascular anomaly during an operation is very difficult.

Comparing the short-term outcomes of laparoscopic distal gastrectomy with D1+ and D2 lymph node dissection for gastric cancer.

INTRODUCTION: Laparoscopic distal gastrectomy (LDG) with D1+ lymph node dissection (LND) for early gastric cancer has been widely accepted. However, LDG with D2 LND for advanced gastric cancer remains in limited use. The aim of this retrospective study was to clarify the safety of LDG with D2 LND for gastric cancer. METHODS: From January 2010 to September 2014, 296 patients underwent LDG; those who received D1+ LND (n = 230) or D2 LND (n = 66) were included in this study. The clinicopathological characteristics and short-term outcomes of both groups were investigated and compared. RESULTS: There were no significant differences in the incidence of postoperative complications between the two groups. However, the frequency of infectious intra-abdominal complications was higher in the D2 LND group than in the D1+ LND group. Additionally, a lower risk of infectious intra-abdominal complications was seen with certified than with uncertified operators. CONCLUSION: The evaluation of short-term outcomes demonstrated that LDG with D2 LND is generally feasible. However, the risk of infectious intra-abdominal complications is higher with D2 LND than with D1+ LND. Also, D2 LND should be performed by trained operators.

[A case of stage IV b pancreatic head cancer that was resected because of a good response to chemotherapy].

The prognosis of Stage IV b pancreatic cancer is extremely poor; the mean survival time is 2-4 months. However, new anticancer agents can improve the outcome of advanced pancreatic cancer. We present the case of a 50-year-old female patient with Stage IV b pancreatic head cancer with invasion to the superior mesenteric vein(SMV)and multiple liver metastases. The patient received S-1 as first-line chemotherapy. Three months later, a further CT scan showed reduction of the pancreatic tumor, disappearance of the liver metastases, and reduction in SMV invasion. Therefore, a subtotal stomach-preserving pancreatoduodenectomy with partial SMV resection was performed. Following surgery, the patient received S-1 chemotherapy again. However, lung metastasis appeared. Despite the initiation of gemcitabine(GEM)treatment, the patient developed metastases in other parts of the lung and the abdominal wall. She died 46 months after surgery, but it is noteworthy that the liver metastases were manageable. The combination of chemotherapy and surgery was effective in prolonging survival in this patient with Stage IV b pancreatic head cancer.

Hand-assisted laparoscopic splenectomy for thrombocytopenia in patients with cirrhosis.

PURPOSE: Although splenectomy plays an important role in the management of patients with liver cirrhosis, the optimal technique, open surgery, total laparoscopic surgery or hand-assisted laparoscopic surgery (HALS), has not yet been defined. The present study evaluated the outcomes of HALS splenectomy for cirrhotic patients. METHODS: A total of 28 consecutive patients with cirrhosis that underwent HALS splenectomy were enrolled into this study. The preoperative laboratory and morphometric data, intraoperative variables and postoperative outcomes were reviewed from the hospital charts. RESULTS: The postoperative platelet count was remarkably elevated in all cases. A re-operation was required in 1 patient complicated with postoperative hemorrhage. Enhanced CT on POD 7 revealed a high incidence of portal or splenic vein thrombosis (PSVT; 22 patients, 78.6 %). PSVT was significantly associated with higher serum bilirubin, higher indocyanine green retention value at 15 min (ICG R-15), and larger splenic vein diameter. CONCLUSION: HALS splenectomy was a very feasible and appropriate procedure for cirrhotic patients with hypersplenism. PSVT was a frequent complication and large splenic vein diameter, high serum bilirubin, and high ICG R-15 were found to be significant risk factors for PSVT after HALS splenectomy in cirrhotic patients.

Pancreatic thickness as a predictive factor for postoperative pancreatic fistula after distal pancreatectomy using an endopath stapler.

PURPOSE: No consistent risk factor has yet been established for the development of pancreatic fistula (PF) after distal pancreatectomy (DP) with a stapler. METHODS: A total of 31 consecutive patients underwent DP with an endopath stapler between June 2006 and December 2010 using a slow parenchymal flattening technique. The risk factors for PF after DP with an endopath stapler were identified based on univariate and multivariate analyses. RESULTS: Clinical PF developed in 7 of 31 (22 %) patients who underwent DP with a stapler. The pancreata were significantly thicker at the transection line in patients with PF (19.4 ± 1.47 mm) in comparison to patients without PF (12.6 ± 0.79 mm; p = 0.0003). A 16-mm cut-off for pancreatic thickness was established based on the receiver operating characteristic (ROC) curve; the area under the ROC curve was 0.875 (p = 0.0215). Pancreatic thickness (p = 0.0006) and blood transfusion (p = 0.028) were associated with postoperative PF in a univariate analysis. Pancreatic thickness was the only significant independent factor (odds ratio 9.99; p = 0.036) according to a multivariate analysis with a specificity of 72 %, and a sensitivity of 85 %. CONCLUSION: Pancreatic thickness is a significant independent risk factor for PF development after DP with an endopath stapler. The stapler technique is thus considered to be an appropriate modality in patients with a pancreatic thicknesses of <16 mm.

Hand-assisted laparoscopic partial splenectomy using an endopath monopolar sealer.

A partial splenectomy is a good way to prevent postsplenectomy infections by preservation of the immune role of the spleen for select patients. Although a laparoscopic total splenectomy is a safe and feasible treatment modality, the laparoscopic approach has not been generally adopted for a partial splenectomy because of technical difficulties. The hand-assisted technique provides an excellent means to explore, to retract safely, and to apply immediate hemostasis in solid organ resection. The hand-assisted laparoscopic partial splenectomy using an endopath monopolar sealer (Salient EndoSH2.0 Monopolar Sealer) was performed successfully. The segmental arteries and veins were isolated and divided using a tactile feedback. Splenic parenchyma was dissected and sealed using an endopath monopolar sealer. The surgical field was almost bloodless during the parenchymal transection and the transection time was around 15 minutes. The hand-assisted laparoscopic approach allows partial splenectomy as a safe and bloodless surgery for select patients.

Surgical approach for extrahepatic metastasis of HCC in the abdominal cavity.

BACKGROUND/AIMS: Despite recent development of therapeutic strategies for intrahepatic lesions, standard guidelines for treatment of extrahepatic metastases of hepatocellular carcinoma have not been established. METHODOLOGY: Surgical resection for intra-abdominal extrahepatic metastases of hepatocellular carcinoma was performed on 10 patients at our institution between 1992 and 2008. We retrospectively examined the clinicopathologic features and significance of a surgical approach in these patients. RESULTS: Nine of the 10 patients received treatment for primary hepatocellular carcinoma before surgery for intra-abdominal extrahepatic metastasis. A simultaneous intrahepatic lesion was detected in half of the patients when the extrahepatic metastasis was resected. Extrahepatic recurrent organs included adrenal glands, lymph nodes, abdominal wall, stomach and diaphragm. The mean survival period after resection was 36.1 months. Two patients are still alive without further recurrence. One patient died of retroperitoneal recurrence and 7 died of intrahepatic recurrence or liver failure after resection. CONCLUSIONS: With careful case selection, considering that not all extrahepatic metastases suggest systemic spread of hepatocellular carcinoma, surgical treatment for metastatic lesions in the abdominal cavity can provide a relatively good prognosis.

Persisting ratio of total amylase output in drain fluid can predict postoperative clinical pancreatic fistula.

BACKGROUND/PURPOSE: A consistent predictor for pancreatic fistula (PF) development in the early period after pancreatic resection is still lacking. PATIENTS AND METHODS: A total of 54 consecutive patients undergoing pancreatic resection were enrolled between June 2007 and April 2010. Pancreaticoduodenectomy (PD) and distal pancreatectomy (DP) were performed in 38 and 16 patients, respectively. For the purpose of finding an early predictor for PF development, we investigated drain amylase levels (d-Amy, IU/mL), drain output volume (d-Vol, mL/day) and drain amylase output (Amy-V, IU/day) on postoperative days (POD) 1 and 3. Amy-V was calculated as the product of d-Amy and d-Vol, and was expressed as the sum of values obtained from all drains. In addition, the ratio of d-Amy or Amy-V on POD3 to that on POD1 was calculated as the persisting ratio in each patient. RESULTS: The overall incidence of clinical PF (International Study Group on Pancreatic Fistula Grade B and C) was 16.7%, occurring in 13.1% after PD and 25% after DP. All PF occurred in cases with a remnant pancreas of soft texture. There was no significant difference in d-Amy, d-Vol, or Amy-V on POD1 and POD3 between patients with and without clinical PF. The persisting ratio of Amy-V was significantly lower in patients without clinical PF compared to those with clinical PF (p = 0.029). Furthermore, the persisting ratio of Amy-V was significantly lower in patients with Grade A PF compared to those with Grade B PF (p = 0.03). CONCLUSION: The persisting ratio of drain amylase output is a new significant predictive factor for clinical PF development.

Hepatic preconditioning using lipopolysaccharide: association with specific negative regulators of the Toll-like receptor 4 signaling pathway.

BACKGROUND: Preconditioning using lipopolysaccharide (LPS), a Toll-like receptor (TLR)-4 ligand, has been demonstrated to attenuate ischemia-reperfusion injury (IRI) in several organs but has not been sufficiently elucidated in the liver. We investigated the molecular mechanism of protection induced by LPS preconditioning against hepatic IRI. METHODS: BALB/c mice underwent 70% hepatic ischemia for 90 min. LPS was injected intraperitoneally 20 hr before ischemia at a range of 1 to 1000 µg/kg. Hepatic injury was evaluated based on serum alanine aminotransferase levels and histopathology. Inflammatory cytokine expression, nuclear factor-κB activation, and c-Jun N-terminal kinase phosphorylation were investigated after reperfusion. Additionally, preischemic expression of negative feedback inhibitors of the TLR4 cascade was examined. RESULTS: Only the 100 µg/kg LPS pretreatment significantly reduced serum alanine aminotransferase levels and histopathologic damage 6 hr after reperfusion; there was no difference among other LPS concentrations. In mice pretreated with LPS, intrahepatic expression of tumor necrosis factor-α and interleukin (IL)-6 as well as activation of nuclear factor-κB and c-Jun N-terminal kinase were inhibited 1 hr after reperfusion, whereas expression of IL-10, an anti-inflammatory cytokine, was induced. Suppressor of cytokine signaling (SOCS)-1, SOCS-3 and IL-1 receptor-associated kinase-M were upregulated by LPS exposure in the preischemic period. CONCLUSIONS: Hepatic LPS preconditioning elicited the upregulation of specific negative regulators in the TLR4 signaling pathway. Preischemic induction of these regulators plays an important role as immunologic preparation for the subsequent ischemia-reperfusion and produces resistance to liver injury. Preoperative modulation of the TLR4 pathway might become an alternative therapeutic strategy against hepatic IRI.

18F-fluorodeoxyglucose positron emission tomography in the diagnosis of small pancreatic cancer.

AIM: To investigate the role of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the diagnosis of small pancreatic cancer. METHODS: This study involved 31 patients with proven invasive ductal cancer of the pancreas. The patients were divided into 3 groups according to the maximum diameter of the tumor: TS1 (maximum tumor size ≤ 2.0 cm), TS2 (> 2.0 cm and ≤ 4.0 cm) or TS3-4 (> 4.0 cm). The relationships between the TS and various diagnostic tools, including FDG-PET with dual time point evaluation, were analyzed. RESULTS: The tumors ranged from 1.3 to 11.0 cm in diameter. Thirty of the 31 patients (97%) had a positive FDG-PET study. There were 5 patients classified as TS1, 15 as TS2 and 11 as TS3-4. The sensitivity of FDG-PET, computed tomography (CT) and magnetic resonance imaging (MRI) were 100%, 40%, 0% in TS1, 93%, 93%, 89% in TS2 and 100%, 100%, 100% in TS3-4. The sensitivity of FDG-PET was significantly higher in comparison to CT and MRI in patients with TS1 (P < 0.032). The mean standardized uptake values (SUVs) did not show a significant difference in relation to the TS (TS1: 5.8 ± 4.5, TS2: 5.7 ± 2.2, TS3-4: 8.2 ± 3.9), respectively. All the TS1 tumors (from 13 to 20 mm) showed higher SUVs in FDG-PET with dual time point evaluation in the delayed phase compared with the early phase, which suggested the lesions were malignant. CONCLUSION: These results indicate that FDG-PET with dual time point evaluation is a useful modality for the detection of small pancreatic cancers with a diameter of less than 20 mm.

Protective effect of lipopolysaccharide preconditioning in hepatic ischaemia reperfusion injury.

BACKGROUND: Preconditioning using lipopolysaccharide (LPS), a toll-like receptor 4 (TLR4) ligand, has been demonstrated to reduce ischaemia/reperfusion injury (IRI) in some organs, but its effect in the liver has not been elucidated. We examined the liver protective mechanism and correlated signalling pathway of LPS preconditioning in mice. METHODS: BALB/c and TLR4 mutant mice underwent 90 min of 70% hepatic ischaemia. Lipopolysaccharide (100 µg/kg) was injected intraperitoneally 20 h or 30 min before ischaemia. Liver damage after reperfusion was examined using serum samples and liver specimens. To analyse the mechanism of preconditioning in detail, phosphorylation of representative signalling mediators to nuclear factor-κB (NF-κB) activation, Akt and interleukin-1 receptor-associated kinase-1 (IRAK-1), and expression of a negative feedback inhibitor, suppressor of cytokine signalling-1 (SOCS-1), were evaluated by Western blotting. RESULTS: Pretreatment with LPS only 20 h before ischaemia elicited a preconditioning effect; however, preconditioning was absent in TLR4 mutant mice. Lipopolysaccharide significantly decreased serum alanine aminotransferase, tumour necrosis factor-α, hepatocyte necrosis and NF-κB activity after reperfusion. Phosphorylated IRAK-1 was suppressed by LPS, whereas no difference was observed in phosphorylated Akt. Pre-ischaemic LPS provided early induction of SOCS-1. DISCUSSION: Late-phase LPS preconditioning provided liver protection against IRI through the downregulation of the TLR4 cascade derived from early induction of SOCS-1 during ischaemia/reperfusion.