Short-term Outcomes of Laparoscopic and Open Distal Pancreatectomy Using Propensity Score Analysis: A Real-world Retrospective Cohort Study.

OBJECTIVE: This study aimed to compare the short-term outcomes between laparoscopic and open distal pancreatectomy for lesions of the distal pancreas from a real-world database. BACKGROUND: Reports on the benefits of laparoscopic distal pancreatectomy include 2 randomized controlled trials; however, large-scale, real-world data are scarce. METHODS: We analyzed the data of patients undergoing laparoscopic or open distal pancreatectomy for benign or malignant pancreatic tumors from April 2008 to May 2020 from a Japanese nationwide inpatient database. We performed propensity score analyses to compare the inhospital mortality, morbidity, readmission rate, reoperation rate, length of postoperative stay, and medical cost between the 2 groups. RESULTS: From 5502 eligible patients, we created a pseudopopulation of patients undergoing laparoscopic and open distal pancreatectomy using inverse probability of treatment weighting. Laparoscopic distal pancreatectomy was associated with lower inhospital mortality during the period of admission (0.0% vs 0.7%, P <0.001) and within 30 days (0.0% vs 0.2%, P =0.001), incidence of reoperation during the period of admission (0.7% vs 1.7%, P =0.018), postpancreatectomy hemorrhage (0.4% vs 2.0%, P <0.001), ileus (1.1% vs 2.8%, P =0.007), and shorter postoperative length of stay (17 vs 20 d, P <0.001). CONCLUSIONS: The propensity score analysis revealed that laparoscopic distal pancreatectomy was associated with better outcomes than open surgery in terms of inhospital mortality, reoperation rate, postoperative length of stay, and incidence of postoperative complications such as postpancreatectomy hemorrhage and ileus.

The Prognostic Value of Preoperative Serum Markers and Risk Classification in Patients with Hepatocellular Carcinoma.

BACKGROUND: Complex hepatocellular carcinoma (HCC) prognostic biomarkers have been reported in various studies. We aimed to establish biomarkers that could predict prognosis, and formulate a simple classification using non-invasive preoperative blood test data. METHODS: We retrospectively identified 305 patients for a discovery cohort who had undergone HCC-related hepatectomy at four Japanese university hospitals between January 1, 2011 and December 31, 2013. Preoperative blood test parameter optimal cut-off values were determined using receiver operating characteristic curve analysis. Cox uni- and multivariate analyses were used to determine independent prognostic factors. Risk classifications were established using classification and regression tree (CART) analysis. Validation was performed with 267 patients from three other hospitals. RESULTS: In multivariate analysis, α-fetoprotein (AFP, p < 0.001), protein induced by vitamin K absence or antagonist-II (PIVKA-II, p = 0.006), and C-reactive protein (CRP, p < 0.001) were independent prognostic factors for overall survival (OS). AFP (p = 0.007), total bilirubin (p = 0.001), and CRP (p = 0.003) were independent recurrent risk factors for recurrence-free survival (RFS). CART analysis results formed OS (CRP, AFP, and albumin) and RFS (PIVKA-II, CRP, and total bilirubin) decision trees, based on machine learning using preoperative serum markers, with three risk classifications. Five-year OS (low risk, 80.0%; moderate risk, 56.3%; high risk, 25.2%; p < 0.001) and RFS (low risk, 43.4%; moderate risk, 30.8%; high risk, 16.6%; p < 0.001) risks differed significantly. These classifications also stratified OS and RFS risk in the validation cohort. CONCLUSION: Three simple risk classifications using preoperative non-invasive prognostic factors could predict prognosis.

Dorsal vs ventral approach to the middle hepatic vein during laparoscopic left hemihepatectomy: multicenter retrospective observational study.

BACKGROUND: Left hemihepatectomy requires exposure of the middle hepatic vein (MHV) at the cutting-surface. Two procedures are used to approach the MHV: a conventional ventral approach and a laparoscopy-specific dorsal approach. This multicenter retrospective observational study aimed to evaluate the perioperative outcomes of these two procedures. METHODS: Clinical records of 38 consecutive patients that underwent laparoscopic left hemihepatectomy in four university hospitals between 2016 and 2021 were retrospectively reviewed. Outcome measurements were operative blood loss, operating time, trend of postoperative laboratory data within 7 days after hepatectomy, and postoperative complications. Quality of MHV exposure was also evaluated and compared by three-grade evaluation (excellent/good/poor) using recorded still images of the cut-surface of the remnant liver (n = 35). RESULTS: Dorsal and ventral approaches were performed in 9 and 29 patients, respectively. Median operating time was 316 min (dorsal) and 314 min (ventral) (P = 0.71). Median operative blood loss was 45 ml (dorsal) and 105 ml (ventral) (P = 0.10). Two patients in the ventral approach group had bleeding in excess of 500 ml, which was not seen in the dorsal approach group. Excellent/good/poor MHV appearance on the cutting-surface was observed in 5/3/1 patients in the dorsal approach group, respectively, and in 7/8/11 patients in the ventral approach group, respectively (P = 0.03). In the ventral approach group, significant increases of aspartate aminotransferase (on postoperative day 1 and day 4/5) and of alanine aminotransferase (on postoperative day 2/3 and 4/5) were observed (P < 0.05). Postoperative complications were observed only in the ventral approach group (n = 3). CONCLUSIONS: The dorsal approach could achieve safe and precise anatomical left hemihepatectomy with operation time and operative blood loss comparable to the conventional ventral approach.

Treatment strategy for resectable colorectal cancer liver metastases from the viewpoint of time to surgical failure.

PURPOSE: The efficacy of pre or postoperative chemotherapy for resectable colorectal cancer liver metastases (CRLM) is disputed. This study aimed to examine the risk factors for time to surgical failure (TSF) and analyze the efficacy of pre or postoperative chemotherapy prior to liver resection for CRLM. METHODS: The clinicopathological factors of 567 patients who underwent initial hepatectomy for CRLM at 7 university hospitals between April 2007 and March 2013 were retrospectively analyzed. The prognostic factors were identified and then stratified into two groups according to the number of preoperative prognostic factors: the high-score group (H-group, score 2-4) and the low-score group (L-group, score 0 or 1). RESULTS: Patients who experienced unresectable recurrence within 12 months after initial treatment had a significantly shorter prognosis than other patients (p < 0.001). Multivariate analysis identified age ≥ 70 (p = 0.001), pT4 (p = 0.015), pN1 (p < 0.001), carbohydrate antigen 19-9 ≥ 37 U/ml (p = 0.002), Clavien-Dindo grade ≥ IIIa (p = 0.013), and postoperative chemotherapy (p = 0.006) as independent prognostic factors. In the H-group, patients who received chemotherapy had a better prognosis than those who did not (p = 0.001). CONCLUSION: Postoperative chemotherapy is beneficial in colorectal cancer patients with more than two of the following factors: age ≥ 70, carbohydrate antigen 19-9-positivity, pT4, and lymph node metastasis.

Downregulation of miR-122-5p Activates Glycolysis via PKM2 in Kupffer Cells of Rat and Mouse Models of Non-Alcoholic Steatohepatitis.

Non-alcoholic steatohepatitis (NASH) has pathological characteristics similar to those of alcoholic hepatitis, despite the absence of a drinking history. The greatest threat associated with NASH is its progression to cirrhosis and hepatocellular carcinoma. The pathophysiology of NASH is not fully understood to date. In this study, we investigated the pathophysiology of NASH from the perspective of glycolysis and the Warburg effect, with a particular focus on microRNA regulation in liver-specific macrophages, also known as Kupffer cells. We established NASH rat and mouse models and evaluated various parameters including the liver-to-body weight ratio, blood indexes, and histopathology. A quantitative phosphoproteomic analysis of the NASH rat model livers revealed the activation of glycolysis. Western blotting and immunohistochemistry results indicated that the expression of pyruvate kinase muscle 2 (PKM2), a rate-limiting enzyme of glycolysis, was upregulated in the liver tissues of both NASH models. Moreover, increases in PKM2 and p-PKM2 were observed in the early phase of NASH. These observations were partially induced by the downregulation of microRNA122-5p (miR-122-5p) and occurred particularly in the Kupffer cells. Our results suggest that the activation of glycolysis in Kupffer cells during NASH was partially induced by the upregulation of PKM2 via miR-122-5p suppression.

Superiority of CRP-albumin-lymphocyte index (CALLY index) as a non-invasive prognostic biomarker after hepatectomy for hepatocellular carcinoma.

BACKGROUND: We aimed to investigate whether a novel biomarker incorporating albumin, lymphocytes, and CRP can predict the prognosis for hepatocellular carcinoma (HCC) after hepatectomy. METHODS: Between January 2011 and December 2013, 384 patients who underwent hepatectomy in four university hospitals in Japan were investigated as a discovery cohort. The CRP-Albumin-Lymphocyte (CALLY index) was defined as (Albumin × Lymphocyte)/(CRP × 104). Patients with a CALLY index ≥5 (n = 200) were compared to those with an index <5 (n = 184). Next, validation was performed using 267 patients from three other university hospitals (external validation cohort). RESULTS: The number of TNM Stage III and IV patients was significantly higher in the CALLY <5 group than the ≥5 group (p = 0.003). There was a significant difference in the 5-year survival rate (CALLY ≥5: 71% vs. <5: 46%; p < 0.001). Multivariate analysis identified the CALLY index as an independent factor of overall survival. Similarly, there was a significant difference in the 5-year survival rate between the CALLY ≥5 (73%) and <5 (48%) groups (p < 0.001), and the CALLY index was identified as an independent prognostic factor in the external validation cohort. CONCLUSION: The CALLY index derived from CRP, albumin, and lymphocyte values is a promising predictive biomarker for postoperative prognosis of patients with HCC.

Preoperative Risk Assessment for Loss of Independence Following Hepatic Resection in Elderly Patients: A Prospective Multicenter Study.

OBJECTIVE: To establish a preoperative risk assessment method for loss of independence after hepatic resection. SUMMARY BACKGROUND DATA: Hepatic resection often results in loss of independence in preoperatively self-sufficient elderly people. Elderly patients should therefore be carefully selected for surgery. METHODS: In this prospective, multicenter study, 347 independently-living patients aged ≥65 years, scheduled for hepatic resection, were divided into study (n = 232) and validation (n = 115) cohorts. We investigated the risk factors for postoperative loss of independence in the study cohort and verified our findings with the validation cohort. Loss of independence was defined as transfer to a rehabilitation facility, discharge to residence with home-based healthcare, 30-day readmission for poor functionality, and 90-day mortality (except for cancer-related deaths). RESULTS: In the study cohort, univariate and multivariate analyses indicated that frailty, age ≥ 76 years, and open surgery were independent risk factors for postoperative loss of independence. Proportions of patients with postoperative loss of independence in the study and validation cohorts were respectively 3.0% and 0% among those with no applicable risk factors, 8.1% and 12.5% among those with 1 applicable risk factor, 25.5% and 25.0% among those with 2 applicable risk factors, and 56.3% and 50.0% among those with all 3 factors applicable (P < 0.001 for both cohorts). Areas under the receiver operating characteristic curves for the study and validation groups were 0.777 and 0.783, respectively. CONCLUSIONS: Preoperative risk assessments using these 3 factors may be effective in predicting and planning for postoperative loss of independence after hepatic resection in elderly patients.

Association Between Neoadjuvant Chemoradiotherapy and Intractable Serous Ascites After Pancreaticoduodenectomy for Pancreatic Cancer.

BACKGROUND: Intractable serous (not chylous) ascites (IA) that infrequently develops early following pancreaticoduodenectomy (PD) for pancreatic cancer is a life-threatening problem. The relationship between neoadjuvant chemoradiotherapy (NACRT) for pancreatic cancer and the incidence of IA following PD has not been evaluated. This study aims to identify the risk factors associated with IA that develops early after PD for pancreatic cancer. METHODS: We retrospectively identified 94 patients who underwent PD for pancreatic cancer at the Department of General and Gastroenterological Surgery, Osaka Medical College Hospital, Osaka, Japan, from April 2012 to March 2020. Data on 29 parameters were obtained from medical records. Univariate and multivariate analyses were conducted to identify independent risk factors. Levels of serum albumin were compared before and after NACRT to analyze its effect. Survival analysis was also conducted. RESULTS: Of the 92 patients included in this study, 8 (8.70%) were categorized into the IA group. Multivariate analysis identified NACRT [odds ratio (OR) 27, 95% confidence interval (CI) 1.87-394, p = 0.016)] and hypoalbuminemia (≤ 1.6 g/dl) just after the operation (OR 50, 95% CI 1.68-1516, p = 0.024) as risk factors. The level of serum albumin was significantly decreased following NACRT. The IA group had poorer prognosis than the control group. CONCLUSIONS: IA is a serious problem that aggravates patient's prognosis. Postoperative lymphatic leak might be a trigger of IA. NACRT was a major risk factor, followed by hypoalbuminemia caused by various reasons. These factors may act synergistically and cause IA.

Chymase as a Novel Therapeutic Target in Acute Pancreatitis.

Acute pancreatitis is still a life-threatening disease without an evidenced therapeutic agent. In this study, the effect of chymase in acute pancreatitis and the possible effect of a chymase inhibitor in acute pancreatitis were investigated. Hamsters were subcutaneously administered 3.0 g/kg of L-arginine to induce acute pancreatitis. Biological markers were measured 1, 2, and 8 h after L-arginine administration. To investigate the effect of a chymase inhibitor, a placebo (saline) or a chymase inhibitor TY-51469 (30 mg/kg) was given 1 h after L-arginine administration. The survival rates were evaluated for 24 h after L-arginine administration. Significant increases in serum lipase levels and pancreatic neutrophil numbers were observed at 1 and 2 h after L-arginine administration, respectively. Significant increases in pancreatic neutrophil numbers were observed in the placebo-treated group, but they were significantly reduced in the TY-51469-treated group. A significant increase in the pancreatic tumor necrosis factor-α mRNA level was observed in the placebo-treated group, but it disappeared in the TY-51469-treated group. Chymase activity significantly increased in the placebo-treated group, but it was significantly reduced by treatment with TY-51469. The survival rate significantly improved in the TY-51469-treated group. A chymase inhibitor may become a novel therapeutic agent for acute pancreatitis.

Is Postoperative Adjuvant Transcatheter Arterial Infusion Therapy Effective for Patients with Hepatocellular Carcinoma who Underwent Hepatectomy? A Prospective Randomized Controlled Trial.

BACKGROUND: The effectiveness of adjuvant transcatheter arterial chemo- or/and chemoembolization therapy after curative hepatectomy of initial hepatocellular carcinoma (HCC) is controversial. This study aimed to evaluate whether hepatectomy combined with adjuvant transcatheter arterial infusion therapy (TAI) for initial HCC has better long-term survival outcomes than hepatectomy alone. METHODS: From January 2012 to December 2014, a prospective randomized controlled trial of patients with initial HCC was conducted. Then, 114 initial HCC patients were recruited to undergo hepatectomy with adjuvant TAI (TAI group, n = 55) or hepatectomy alone (control group, n = 59) at our institution. The TAI therapy was performed twice, at 3 and 6 months after curative hepatectomy (UMIN 000011900). RESULTS: The patients treated with TAI had no serious side effects, and operative outcomes did not differ between the two groups. No significant differences were found in the pattern of intrahepatic recurrence or time until recurrence between the two groups. Moreover, no significant differences were found in the relapse-free survival or overall survival. Low cholinesterase level (< 200) had been identified as a risk factor affecting relapse-free survival. Furthermore, compared with surgery alone, adjuvant TAI with hepatectomy improved the overall survival for lower-cholinesterase patients. CONCLUSIONS: Adjuvant TAI is safe and feasible, but it cannot reduce the incidence of postoperative recurrence or prolong survival for patients who underwent curative hepatectomy for initial HCC.

Validation and performance of three-level procedure-based classification for laparoscopic liver resection.

BACKGROUND: A procedure-based laparoscopic liver resection (LLR) classification (IMM classification) stratified 11 different LLR procedures into 3 grades. IMM classification assessed the difficulty of LLR differently than an index-based LLR classification (IWATE criteria), which scored each procedure on an index scale of 12. We validated the difference of 3 IMM grades using an external cohort, evaluated the IMM classification using the scores of the IWATE criteria, and compared the performance of IMM classification with the IWATE criteria and the minor/major classification. METHODS: Patients undergoing LLR without simultaneous procedures were selected from a prospectively maintained database at the Institut Mutualiste Montsouris (IMM cohort) and from the database of 43 Japanese institutions (JMI cohort). Surgical and postoperative outcomes were evaluated according to the 3 IMM grades using the JMI cohort. The 11 LLR procedures included in the IMM classification were scored according to the IWATE criteria. The area under the curves (AUCs) for surgical and postoperative outcomes were compared. RESULTS: In the JMI (n = 1867) cohort, operative time, blood loss, conversion rate, and major complication rate were significantly associated with a stepwise increase in grades from I to III (all, P < 0.001). In the IMM (n = 433) and JMI cohorts, IMM grades I, II, and III corresponded to three low-scoring, two intermediate-scoring, and six high-scoring LLR procedures as per the IWATE criteria, respectively. Mean ± standard deviation among the IMM grades were significantly different: 3.7 ± 1.4 (grade I) versus 7.5 ± 1.7 (grade II) versus 10.2 ± 1.0 (grade III) (P < 0.001) in the IMM cohort and 3.6 ± 1.4 (grade I) versus 6.7 ± 1.5 (grade II) versus 9.3 ± 1.4 (grade III) (P < 0.001) in the JMI cohort. The AUCs for surgical and postoperative outcomes are higher for the 3-level IMM classification than for the minor/major classification. CONCLUSIONS: The difference of 3 IMM grades with respect to surgical and postoperative outcomes was validated using an external cohort. The 3-level procedure-based IMM classification was in accordance with the index-based IWATE criteria. The IMM classification performed better than the minor/major classification for stratifying LLR procedures.

Laparoscopic versus open liver resection for hepatocellular carcinoma in elderly patients: a multi-centre propensity score-based analysis.

BACKGROUND: The frequency of liver resection in elderly patients has been increasing. However, data are limited regarding the safety of laparoscopic liver resection (LLR) compared with that of open liver resection (OLR) for hepatocellular carcinoma (HCC) in elderly patients. The present study aimed to compare short-term outcomes between LLR and OLR in elderly patients with HCC using propensity score matching. METHODS: The study included 630 patients (age, ≥ 75 years) who underwent liver resection for HCC at nine liver centres between April 2010 and December 2017. Patients were divided into LLR and OLR groups, and perioperative outcomes were compared between the groups. In addition, subgroup analysis was performed according to age (75-79 and ≥ 80 years). RESULTS: Of the 630 patients, 221 and 409 were included in the LLR and OLR groups, respectively. After propensity score matching, 155 patients were included in each group. Intraoperative blood loss and the transfusion, post-operative overall complication and major complication rates were lower in the matched LLR than the matched OLR group (P < 0.001, P = 0.004, P < 0.001 and P < 0.001, respectively). Moreover, post-operative pulmonary and cardiovascular complications were less frequent in the matched LLR group (P = 0.008 and P = 0.014, respectively). In subgroup analysis, among octogenarians, the post-operative major complication rate was lower and hospital stay was shorter in the matched LLR than the matched OLR group (P < 0.001 and P < 0.001, respectively). CONCLUSION: LLR for HCC is associated with good short-term outcomes in patients aged ≥ 75 years compared with OLR. LLR is safe and feasible in selected octogenarians with HCC.

The Management of Recurrence within Six Months after Hepatic Resection for Colorectal Liver Metastasis.

BACKGROUND: Hepatectomy is currently recommended as the most reliable treatment for colorectal liver metastases. However, the association between the choice of treatment for recurrence and the timing of recurrence remains controversial. METHODS: Two-hundred ninety-five patients who underwent hepatectomy were retrospectively analyzed for the risk factors and the outcomes for early recurrence within 6 months. The remnant liver volumes (RLVs) and laboratory data were measured postoperatively using multidetector computed tomography on days 7 and months 1, 2, and 5 after the operation. RESULTS: Early recurrence developed in 88/295 patients (29.8%). Colorectal cancer lymph node metastasis, synchronous liver metastasis, and multiple liver metastases were independent risk factors for the occurrence of early recurrence (p < 0.001, 0.032, and 0.019, respectively). Patients with early recurrence had a poorer prognosis than did patients who developed later recurrence (p < 0.001). Patients who underwent surgery or other local treatment had better outcomes. The changes in RLV and laboratory data after postoperative month 2 were not significantly different between the 2 groups. CONCLUSION: Patients with early recurrence within 6 months had a poorer prognosis than did patients who developed later recurrence. However, patients who underwent repeat hepatectomy for recurrence had a better prognosis than did those who underwent other treatments, with good prospects for long-term survival.

Initial pulmonary metastasis after pancreatectomy for pancreatic ductal adenocarcinoma.

Patients who undergo pancreatectomy for pancreatic ductal adenocarcinoma (PDA) develop relatively early recurrence, but pulmonary metastasis from PDA is rare. Between January 2008 and December 2016, a total of 120 consecutive patients underwent pancreatectomy for primary PDA at Osaka Medical College Hospital. Among these, 13 patients developed pulmonary metastasis and 6 patients underwent pulmonary metastasectomy. Among these patients, the median disease-free survival following initial pancreatic surgery was 26.1 months, and the median overall survival (OS) interval was 39 months. On the other hand, seven patients did not undergo pulmonary resection. The median OS interval of these patients was 33 months. The 1-, 3-, and 5-year OS rates were 100%, 80%, and 60%, respectively, for patients who underwent pulmonary metastasectomy and 100.0%, 42.8%, and 0%, respectively, for those who did not undergo the procedure. Our experience has shown that surgical resection may lengthen the survival time of patients who tolerate surgery.

Surgical treatment of gastric venous congestion in association with extended resection of pancreas: a case report.

BACKGROUND: Total pancreatectomy is performed for chronic pancreatitis, tumors involving the entire pancreas or remnant pancreas after pancreatectomy. Gastric venous congestion and bleeding may be associated with total pancreatectomy. We report the case of a patient who underwent left gastric vein to splenic vein bypass to relieve gastric venous congestion during total pancreatectomy for remnant pancreatic cancer. CASE PRESENTATION: A 60-year-old woman underwent subtotal stomach-preserving pancreaticoduodenectomy for cancer of the pancreatic head. A follow-up computed tomography revealed a low-density tumor of the remnant pancreas. The pathological diagnosis was adenocarcinoma on endoscopic ultrasound-fine needle aspiration. Total resection of the remnant pancreas was performed for the tumor 3 years after the initial surgery. We ligated the splenic vein at the point of distal side of the left gastric vein confluent. Immediately, the vein congestion around the stomach was confirmed. We found the stenosis of the confluent between the left gastric vein and splenic vein. We subsequently anastomosed the left gastric vein and splenic vein, following which the gastric venous congestion was relieved. CONCLUSION: In cases wherein all the drainage veins from the stomach are removed, an anastomosis between the left gastric vein and splenic vein can be effectively used to prevent gastric venous congestion and bleeding after total pancreatectomy.

Surgical Outcome and Hepatic Regeneration after Hepatic Resection for Hepatocellular Carcinoma in Elderly Patients.

INTRODUCTION: The rising proportion of elderly patients (aged 80 yearsor above) in our population means that more elderly patients are undergoing hepatectomy. METHODS: Five-hundred and thirty patients who underwent hepatectomy for hepatocellular carcinoma (HCC) were retrospectively analyzed with respect to their preoperative status and perioperative results, including remnant liver regeneration. The remnant liver volume was postoperatively measured with multidetector CT on postoperative day 7 and 1, 2, 5, and 12 months after surgery. An elderly group (aged 80 or older) was compared with a non-elderly group (aged less than 80 years). RESULTS: Underlying diseases of the cardiovascular system were significantly more common in the elderly group (57.8%, p = 0.0008). The postoperative incidence of Clavien-Dindo Grade IIIa or higher complications was 20.0% in the elderly group and 24.3% in the non-elderly group, and this difference was not significant. As for regeneration of the remnant liver after resection, this was not morphologically delayed compared to the non-elderly group. CONCLUSIONS: In this study, we have demonstrated that safe, radical hepatectomy, similar to procedures performed on non-elderly patients, can be performed on patients with HCC aged 80 and older with sufficient perioperative care.

Is neoadjuvant chemotherapy appropriate for patients with resectable liver metastases from colorectal cancer?

PURPOSE: Neoadjuvant chemotherapy (NAC) for resectable liver metastasis from colorectal cancer (CRLM) is used widely, but its efficacy lacks clear evidence. This study aimed to clarify its worth and develop appropriate treatment strategies for CRLM. METHODS: We analyzed, retrospectively, the clinicopathological factors and outcomes of 137 patients treated for resectable CRLM between 2006 and 2015, with upfront surgery (NAC- group; n = 117) or initial NAC treatment (NAC+ group; n = 20). RESULTS: The time to surgical failure (TSF) and overall survival (OS) after initial treatment were significantly worse in the NAC+ group than in the NAC- group (P = 0.002 and P = 0.032, respectively). At hepatectomy, the NAC+ group had a lower median prognostic nutrition index (PNI), higher rates of a positive Glasgow Prognostic Score (P = 0.002) and more perioperative blood transfusions (P = 0.027) than the NAC- group. Moreover, the serum albumin (P = 0.006), PNI (P ≤ 0.001) and lymphocyte-to-monocyte ratio (P ≤ 0.001) were significantly decreased and the GPS positive rate was increased from 15 to 35% in the NAC+ group. The OS rates did not differ significantly according to the NAC response (5-year OS rates-CR/PR 67%, SD 60%, PD 38%). CONCLUSIONS: Patients with resectable CRLM should undergo upfront hepatectomy because NAC did not improve OS after initial treatment in these patients.

A Concealed "Natural Orifice": Umbilicus Anatomy for Minimally Invasive Surgery.

INTRODUCTION: A recent development in minimally invasive surgery (MIS) is single-port surgery, where a single large multiport trocar is placed in the umbilicus. All medical schools require that students complete an anatomy course as part of the medical curriculum. However, there is limited instruction regarding the detailed parts of the "umbilicus." In several famous anatomy atlases, the umbilicus is not dissected at all and is merely represented as a button. Until now, the true nature of the umbilicus has not been anatomically demonstrated. METHODS: Five cadavers were obtained from the Osaka Medical College medical student anatomy class. The umbilicus was dissected in the anatomy laboratory, to demonstrate all the layers. A detailed dissection was performed, focusing on the exact center of the umbilicus, in order to ascertain whether there exists a "natural orifice" or a fascial defect. RESULTS: In all cadavers, a small defect of fascia was identified just below the center of the umbilicus. Yellow fatty tissue was present just below the skin in the exact center of the umbilicus. A probe placed exactly in the middle of this defect passes easily through into the abdominal cavity. CONCLUSIONS: With the widespread use of MIS, umbilical incision is commonly used to reduce pain and improve cosmetic results. This study consistently revealed a natural defect of fascia in the center of the umbilicus. Therefore, the umbilicus can be called a concealed "natural orifice." It is important to recognize and utilize this defect effectively to minimize unnecessary tissue trauma during MIS.

Comparison of Regeneration of Remnant Liver After Hemihepatectomy with or Without the Middle Hepatic Vein.

BACKGROUND: There is no consensus about remnant liver regeneration associated with middle hepatic vein (MHV) resecting. METHODS: Seventy-five patients who underwent hemihepatectomy were retrospectively analysed with respect to remnant liver regeneration. The liver remnant volume (LRV) and each sectional volume were postoperatively measured with multidetector computed tomography at day 7 and months 1, 2, 5, and 12 after the operation. RESULTS: In right hemihepatectomy cases, the regeneration rate of LRV in the MHV preservation group was significantly higher than that of the MHV resection group at months 5 and 12. In particular, the regeneration rate of remnant segment IV peaked at day 7 and was shrunk after 1 month, and was significant higher in the MHV preservation group. In left hemihepatectomy cases, the regeneration rate of LRV at month 12 was significantly higher in the MHV preservation group. The regeneration rate of the remnant anterior section peaked at 1 month and was shrunk. CONCLUSION: In this study, the MHV should be preserved or reconstructed whenever possible during hepatic hemihepatectomy. Hepatic regeneration in the MHV perfusion region becomes poor within 7 days to 1 month after surgery (UMIN000023714).