Assessing outcomes and complications of secondary hepatolithiasis after choledochoenterostomy: A nationwide survey in Japan.

BACKGROUND: This study aimed to evaluate the outcomes and complications of secondary hepatolithiasis following choledochoenterostomy to guide suitable management. METHODS: The study analyzed 127 patients from a 2017 national survey conducted by the Ministry of Health, Labor, and Welfare. The 2023 cohort study assessed residual stones, recurrences, cholangitis, cholangiocarcinoma, and prognosis. RESULTS: The median follow-up duration was 48 months. Balloon endoscopy-assisted endoscopic retrograde cholangiography (BE-ERC) was the most common treatment, achieving complete stone clearance in 84.4% of patients. Anatomical hepatectomy was the most common surgery. Predictors of residual stones were stone number ≥10 (odds ratio [OR], 7.480; p = .028) and stone diameter ≥10 mm (OR, 5.280; p = .020). Predictors of stone recurrence during follow-up were biliary strictures (hazard ratio [HR], 3.580; p = .005) and cholangitis (HR, 2.700; p = .037). Predictors of cholangitis during follow-up were biliary stricture (HR, 5.016; p = .006) and dilatation (HR, 3.560; p = .029). Any treatment for hepatolithiasis reduced cholangitis occurrence (HR, 0.168; p = .042). Balloon dilation combined with stenting for ≥3 months improved biliary strictures in 57.1% of patients. CONCLUSION: This study recommends BE-ERC as the first-choice treatment for secondary hepatolithiasis. Stone removal and relief of biliary strictures and dilatation are crucial to prevent stone recurrence and cholangitis after treatment.

Specialty-Certified Colorectal Surgeons Demonstrate Favorable Short-term Surgical Outcomes for Laparoscopic Low Anterior Resection: Assessment of a Japanese Nationwide Database.

BACKGROUND: There are few studies on the impact of a colorectal-specific technically certified surgeon on good surgical outcomes for laparoscopic low anterior resection in the real world. OBJECTIVE: To evaluate the short-term outcomes of laparoscopic low anterior resection with the participation of a certified colorectal surgeon. DESIGN: This was a retrospective cohort study using a Japanese nationwide database. SETTING: This study was conducted as a project for the Japan Society of Endoscopic Surgery and the Japanese Society of Gastroenterological Surgery. PATIENTS: This study included 41,741 patients listed in the National Clinical Database who underwent laparoscopic low anterior resection performed by certified, noncertified, and colorectal-specific certified surgeons, according to the Endoscopic Surgical Skill Qualification System, from 2016 to 2018. MAIN OUTCOME MEASURES: Operative mortality rate and anastomotic leak rate were the primary outcome measures. RESULTS: Overall 30-day mortality and operative mortality were 0.2% and 0.3%, respectively, without significant differences between all kinds of certified and noncertified surgeon groups. Overall anastomotic leak rate was 9.3%, with a significant difference between the 2 groups. Colorectal- and stomach-certified groups had lower 30-day mortality and operative mortality than the biliary-certified and noncertified groups. The anastomotic leak rate was the lowest in the colorectal-certified group. Based on a logistic regression analysis using the risk-adjusted model, operative mortality was significantly higher in the biliary-certified group than in the colorectal-certified group. Moreover, anastomotic leak rate was significantly lower in the colorectal-certified group than in the stomach-certified and noncertified groups. LIMITATIONS: This study was a retrospective study, and there was a possibility of different definitions of anastomotic leak due to the use of a nationwide database. CONCLUSIONS: The participation of a colorectal-specific certified surgeon may decrease the risk of operative mortality and anastomotic leak for laparoscopic low anterior resection. CIRUJANO COLORRECTAL ALTAMENTE CALIFICADO PROVOCA RESULTADOS QUIRRGICOS FAVORABLES A CORTO PLAZO PARA LA RESECCIN ANTERIOR BAJA LAPAROSCPICA EVALUACIN DE LA BASE DE DATOS NACIONAL JAPONESA: ANTECEDENTES:Hay pocos estudios sobre el impacto de un cirujano certificado técnicamente especializado en cáncer colorrectal con un buen resultado quirúrgico para la resección anterior baja laparoscópica en el mundo real.OBJETIVO:Evaluar los resultados a corto plazo de la resección anterior baja laparoscópica con la participación de un cirujano colorrectal certificado.DISEÑO:Este fue un estudio de cohorte retrospectivo que utilizó una base de datos nacional japonesa.AJUSTE:Este estudio se realizó como un proyecto para la Sociedad Japonesa de Cirugía Endoscópica y la Sociedad Japonesa de Cirugía Gastroenterológica.PACIENTES:este estudio incluyó a 41 741 pacientes incluidos en la base de datos clínica nacional que se sometieron a una resección anterior baja laparoscópica realizada por cirujanos certificados, no certificados y certificados específicamente colorrectales, según el Sistema de calificación de habilidades quirúrgicas endoscópicas de 2016 a 2018.PRINCIPALES MEDIDAS DE RESULTADO:La tasa de mortalidad operatoria y la tasa de fuga anastomótica fueron los resultados primarios.RESULTADOS:La mortalidad general a los 30 días y la mortalidad operatoria fueron del 0,2 % y el 0,3 %, respectivamente, sin diferencias significativas entre los grupos de todos los tipos de cirujanos certificados y no certificados. La tasa global de fuga anastomótica fue del 9,3 %, con una diferencia significativa entre los dos grupos. Los grupos con certificación colorrectal y estomacal tuvieron una mortalidad a los 30 días y una mortalidad operatoria más bajas que los grupos con certificación biliar y sin certificación. La tasa de fuga anastomótica fue la más baja en el grupo certificado colorrectal. Con base en un análisis de regresión logística utilizando el modelo ajustado por riesgo, la mortalidad operatoria fue significativamente más alta en el grupo con certificación biliar que en el grupo con certificación colorrectal. Además, la tasa de fuga anastomótica fue significativamente más baja en el grupo con certificación colorrectal que en los grupos con certificación estomacal y sin certificación.LIMITACIONES:Este estudio fue retrospectivo y existía la posibilidad de diferentes definiciones de fuga anastomótica debido al uso de una base de datos nacional.CONCLUSIONES:La participación de un cirujano certificado en video específico colorrectal puede disminuir el riesgo de mortalidad operatoria y fuga anastomótica para la resección anterior baja laparoscópica. (Traducción-Dr. Mauricio Santamaria ).

Skill-qualified surgeons positively affect short-term outcomes after laparoscopic gastrectomy for gastric cancer: a survey of the National Clinical Database of Japan.

BACKGROUND: Proficiency of the operating surgeon is one of the most critical factors potentially associated with reductions in complications and surgery-related mortality. With video-rating systems having shown potential for assessing laparoscopic surgeons' proficiency, the Endoscopic Surgical Skill Qualification System (ESSQS) was developed by the Japan Society for Endoscopic Surgery to subjectively assess the proficiency of laparoscopic surgeons by rating applicants' non-edited case videos. We conducted a study to evaluate how ESSQS skill-qualified (SQ) surgeon involvement influences short-term outcomes of laparoscopic gastrectomy performed for gastric cancer. METHODS: Data from the National Clinical Database regarding laparoscopic distal and total gastrectomy performed for gastric cancer between January 2016 and December 2018 were analyzed. Operative mortality, defined as 30-day mortality or 90-day in-hospital mortality, and anastomotic leakage rates were compared per involvement vs. non-involvement of an SQ surgeon. Outcomes were also compared per involvement of a gastrectomy-, colectomy-, or cholecystectomy-qualified surgeon. The association between the area of qualification and operative mortality/anastomotic leakage was also analyzed with a generalized estimating equation logistic regression model used to account for patient-level risk factors and institutional differences. RESULTS: Of 104,093 laparoscopic distal gastrectomies, 52,143 were suitable for inclusion in the study; 30,366 (58.2%) were performed by an SQ surgeon. Of 43,978 laparoscopic total gastrectomies, 10,326 were suitable for inclusion; 6501 (63.0%) were performed by an SQ surgeon. Gastrectomy-qualified surgeons outperformed non-SQ surgeons in terms of both operative mortality and anastomotic leakage. They also outperformed cholecystectomy- and colectomy-qualified surgeons in terms of operative mortality or anastomotic leakage in distal and total gastrectomy, respectively. CONCLUSION: The ESSQS appears to discriminate laparoscopic surgeons who can be expected to achieve significantly improved gastrectomy outcomes.

A multicenter survey of effects and challenges of an 8K ultra-high-definition endoscopy system compared to existing endoscopy systems for endoscopic surgery.

INTRODUCTION: 8K ultra-high-definition (UHD) images enabling clearer recognition of anatomical structures could contribute to further development of surgical techniques and advanced applications in endoscopic surgery fields. This study aimed to clarify effects and challenges of endoscopic surgery with 8K UHD endoscopy compared to existing endoscopy systems. METHODS: In this multicenter, cross-sectional, questionnaire survey, data were collected from surgical participants who newly used and observed 8K UHD endoscopy in patients undergoing surgery from February 2020 to February 2021. Survey items included sense of presence, reality, depth perception, visibility of tissue, eyestrain, and degree of satisfaction for operators and observers, and weight, operability, focus adjustment, physical fatigue, eyestrain, and satisfaction for camera assistants. Participants rated each 8K UHD endoscopic surgery on a one-to-five scale (definitively inferior, relatively inferior, equivalent, relatively superior, definitively superior) compared to the existing endoscopy system of each facility. RESULTS: Overall, questionnaire responses from 139 participants assessing 8K UHD endoscopic surgery were collected from surgeries performed in 46 patients. Respective ratings of operators and observers included sense of presence: "superior or relatively superior", 97.8% and 91.5%; reality: "superior or relatively superior", 76.1% and 72.3%; and visibility of tissue: "superior or relatively superior", 93.5% and 87.2%. Weight was rated as "inferior or relatively inferior" by 73.9% of camera assistants and focus adjustment as "inferior" by 60.9% of them. CONCLUSIONS: 8K UHD endoscopic surgery enabled identification of surgical anatomies more clearly, provided a sense of presence and reality, and might improve educational effect. Technological development is expected to reduce the burden of camera assistants.

Predictive factors for subsequent intrahepatic cholangiocarcinoma associated with hepatolithiasis: Japanese National Cohort Study for 18 years.

BACKGROUND: Predictive factors for intrahepatic cholangiocarcinoma in long-term follow-up of hepatolithiasis are unknown. We thus conducted a cohort study to investigate the predictive factors for developing intrahepatic cholangiocarcinoma in hepatolithiasis. METHODS: This cohort is comprised of 401 patients registered in a nationwide survey of hepatolithiasis for 18 years of follow-up. Cox regression analysis was used to elucidate predictive factors for developing intrahepatic cholangiocarcinoma. RESULTS: The median follow-up period of patients was 134 months. Twenty-two patients developed intrahepatic cholangiocarcinoma and all died. Identified independent significant factors were as follows: age 63 years or older (hazard ratio [HR] 3.344), residual stones at the end of treatment (HR 2.445), and biliary stricture during follow-up (HR 4.350). The incidence of intrahepatic cholangiocarcinoma in patients with three factors was significantly higher than that in patients with one or two factors. The incidence in the groups with one or two predictive factors was not different. In 88.9% of patients with both biliary stricture and intrahepatic cholangiocarcinoma, the duration between the diagnoses of biliary stricture and intrahepatic cholangiocarcinoma was ≥ 5 years. However, once intrahepatic cholangiocarcinoma developed, 77.8% of patients died within 1 year. Of 24 patients with no symptoms, no previous choledocoenterostomy, no signs of malignancy, no biliary stricture, and no treatment for hepatolithiasis during follow-up, only one developed intrahepatic cholangiocarcinoma. CONCLUSIONS: Regarding carcinogenesis, complete stone clearance and releasing biliary stricture can prevent the development of intrahepatic cholangiocarcinoma and improve the prognosis of hepatolithiasis.

Involvement of a skill-qualified surgeon favorably influences outcomes of laparoscopic cholecystectomy performed for acute cholecystitis.

OBJECTIVE: The Endoscopic Surgical Skill Qualification System (ESSQS) was developed by the Japan Society for Endoscopic Surgery as a means of subjectively assessing the proficiency of laparoscopic surgeons. We conducted a study to evaluate how involvement of an ESSQS skill-qualified (SQ) surgeon influences short-term outcomes of laparoscopic cholecystectomy performed for acute cholecystitis. Previous reports suggest that assessment of the video-rating system is a potential tool to discriminate laparoscopic surgeons' proficiency and top-rated surgeons face less surgical mortality and morbidity in bariatric surgery. METHODS: Data from the National Clinical Database regarding laparoscopic cholecystectomy performed for acute cholecystitis between January 2016 and December 2018 were analyzed. Outcomes were compared between patients grouped according to involvement vs. non-involvement of an SQ surgeon. Outcomes were also compared between patients grouped according to whether their operation was performed by biliary tract-, stomach-, or colon-qualified surgeon. RESULTS: Of the 309,998 laparoscopic cholecystectomies during the study period, 65,295 were suitable for inclusion in the study and 13,670 (20.9%) were performed by an SQ surgeon. Patients' clinical characteristics did not differ between groups. Thirty-day mortality was significantly lower in the SQ group (0.1%) 16/13,670 than in the non-SQ group (0.2%) 140/51,625 (P = 0.001). Thirty-day mortality was [0.1% (9/7173)] in the biliary tract-qualified group, [0.2% (5/3527)] in the stomach-qualified group, and [0.1% (2/3240)] in the colon-qualified group. CONCLUSION: Surgeons with ESSQS certification outperform the non-skilled surgeons in terms of surgical mortality in 30 and 90 days. Further verification of the value of the ESSQS is warranted and similar systems may be needed in countries across the world to ensure patient safety and control the quality of surgical treatments.

Parenchymal-sparing approaches for resection of tumors located in the paracaval portion of the caudate lobe of the liver-utility of limited resection and central hepatectomy.

PURPOSE: Resection of liver cancer involving the paracaval portion (PC) of the caudate lobe is challenging because the PC is located deepest in the liver. This study aimed to elucidate the utility of two parenchymal-sparing approaches of limited resection and central hepatectomy for resecting tumors located in the PC. METHODS: In 2018 and 2020, 12 out of 143 patients underwent hepatectomy for tumors located in the PC of the liver. In six patients, limited resection (LR) of the PC after full mobilization of the liver off the inferior vena cava (IVC) was performed for tumors excluding the hilar plate or large hepatic veins (large HVs), including major hepatic veins or thick short hepatic veins. In six patients, central hepatectomy (CH) using liver tunnel was performed for tumors involving or close to the hilar plate and/or large HVs. RESULTS: During CH, the surgical view of the cranial side of the hilar plate was wide enough to perform combined resection of the large HVs in front of the IVC. Five of the six CHs were performed with resection of the LHVs. No LRs were accompanied with resection of the LHVs. The CH was associated with longer Pringle's time (76 min vs. 29.5 min, p = 0.015) and blood loss (1104 ml vs. 370 ml, p = 0.041). The preserved liver parenchyma volumes were 82% and 95% of the total liver volume after CH and LR, respectively. CONCLUSION: Our parenchymal-sparing approach for resection of liver cancer located in the PC is feasible for curative resection.

Direct splenic vein reconstruction combined with resection of the portal vein/superior mesenteric vein confluence during pancreaticoduodenectomy.

PURPOSE: Splenic vein (SV) ligation combined with portal vein (PV)/superior mesenteric vein (SMV) confluence resection during pancreaticoduodenectomy (PD) is reported to cause left-side portal hypertension (LPH). The purpose of this study was to present our technique of the SV reconstruction and to evaluate the surgical outcomes with/without SV ligation during PD. METHODS: Twenty-four patients undergoing PD with PV and/or SMV resection and being followed over 4 months after surgery between March 2013 and December 2019 in our hospital were evaluated. Resection of the PV/SMV confluence were performed in 14, and SV reconstruction was successfully performed in 3. Presence of LPH was assessed by examining changes in splenic volume, newly venous collateral formation, and platelet counts before and 4-8 months after PD. Surgical technique is the direct anastomosis between SV and PV. RESULTS: Splenic volume ratio was significantly higher in the SV ligation group (n = 11) than in the SV preservation group (n = 13) (median (range) 1.11 (0.57-1.62) vs. 1.68 (1.05-2.22), p < 0.01), but no significant differences were found in the incidence of newly formed venous collaterals or platelet counts between groups. CONCLUSION: SV ligation may represent the cause of LPH after PD combined with resection of PV/SMV confluence. Our simple procedure may help decrease the incidence of LPH.

Current status of laparoscopic bariatric/metabolic surgery in Japan: The sixth nationwide survey by the Japan Consortium of Obesity and Metabolic Surgery.

INTRODUCTION: Laparoscopic bariatric procedures have been performed in Japan since 2000. Laparoscopic sleeve gastrectomy (LSG) has been fully covered by National Health Insurance since 2014, and it has been increasingly performed recently. The Japan Consortium of Obesity and Metabolic Surgery conducts a nationwide survey on laparoscopic bariatric/metabolic surgery every 2 years. METHODS: The survey was sent by post or email to 97 Japanese institutions in January 2020. RESULTS: From 2000 to 2019, a total of 3669 laparoscopic bariatric/metabolic procedures were performed in 64 institutions. The most popular procedure was LSG (n = 2866), followed by LSG with duodenojejunal bypass (LSG-DJB, n = 337) and laparoscopic Roux-en-Y gastric bypass (LRYGB, n = 280). Morbidity and reoperation rates were, respectively, 29.8% and 11.8% for LRYGB, 16.8% and 2.8% for LSG, and 13.6% and 6.6% for LSG-DJB. At 5 years after the procedures, the percentage of excess weight loss was 78% for LRYGB, 66% for LSG, and 80% for LSG-DJB. CONCLUSION: This nationwide survey clearly showed that laparoscopic bariatric/metabolic surgery has been safely and effectively performed for 20 years in Japan.

Optimal Lymphadenectomy of the Mesopancreas Based on Fluorescence Imaging During Pancreaticoduodenectomy.

BACKGROUND: Excision of the mesopancreas with lymphadenectomy is an important component of pancreatoduodenectomy. However, the optimal extent of lymphadenectomy remains unclear. Furthermore, accurate description of the mesopancreatic lymphatic pathways is difficult, probably because of the complex anatomy. Intestinal derotation simplifies the anatomy and facilitates both examination of lymphatic flow and the surgical procedure. The aim of this study was to evaluate lymphatic flow in the mesopancreas using indocyanine green fluorescence imaging with an intestinal derotation technique, and to clarify the optimal extent of mesopancreas excision and lymphadenectomy in pancreatoduodenectomy. METHODS: Indocyanine green solution (2.5 × 10-3 mg) was injected into the pancreatic head parenchyma. After intestinal derotation, the spread of indocyanine green was observed using near-infrared imaging. RESULTS: Participants comprised 10 patients who underwent pancreatoduodenectomy for periampullary neoplasms. With indocyanine green fluorescence imaging, 9 of the 10 patients showed lymphatic flow from the pancreatic head to the superior mesenteric artery via the inferior pancreaticoduodenal artery and first jejunal artery (but not via the second and more distant arteries), with eventual drainage into the paraaortic region. CONCLUSIONS: Lymphatic pathways from the pancreatic head were connected to the superior mesenteric artery via the inferior pancreaticoduodenal artery and first jejunal artery. Excision of the mesopancreas with the inferior pancreaticoduodenal artery and first jejunal artery while preserving the second or more distant arteries appears optimal in pancreatoduodenectomy for periampullary malignancies.

Double-Volume Intraoperative Lavage Reduce Bacterial Contamination After Pancreaticoduodenectomy.

BACKGROUND: To clarify whether double-volume peritoneal lavage can decrease the risk of clinically relevant postoperative pancreatic fistula after pancreaticoduodenectomy. MATERIALS AND METHODS: Forty-nine patients who underwent pancreaticoduodenectomy and intraoperative peritoneal lavage using 6000 mL of saline before abdominal closure were studied retrospectively. Bacterial cultures of the lavage fluid were taken twice, after irrigation using 3000 mL of saline and then after an additional 3000 mL of saline. Bacterial culture of the drainage fluid was taken on day 1, and the relationship between the results of bacterial cultures and clinically relevant postoperative pancreatic fistula was examined. RESULTS: Double amount of peritoneal lavage significantly decreased the incidence of positive bacterial cultures than single amount of peritoneal lavage (45% vs. 29%, P < .05). Multivariate analysis showed that positive bacterial culture of drainage fluid on day 1 and main pancreatic duct size (<3 mm) were independent risk factors for clinically relevant postoperative pancreatic fistula. A positive bacterial culture of the final lavage fluid and preoperative biliary drainage were independent factors related to a positive bacterial culture on day 1. DISCUSSION: A positive bacterial culture on day 1 is an independent risk factor for clinically relevant postoperative pancreatic fistula during pancreaticoduodenectomy. Double-volume intraperitoneal lavage may be effective for reducing the incidence of clinically relevant postoperative pancreatic fistula.

Clinical impact of Endoscopic Surgical Skill Qualification System (ESSQS) by Japan Society for Endoscopic Surgery (JSES) for laparoscopic distal gastrectomy and low anterior resection based on the National Clinical Database (NCD) registry.

AIM: This study aimed to evaluate the association between surgeons certified via the Endoscopic Surgical Skill Qualification System (ESSQS) of the Japan Society for Endoscopic Surgery (JSES) and surgical outcomes of laparoscopic distal gastrectomy (LDG) and laparoscopic low anterior resection (LLAR). METHODS: Japanese National Clinical Database data on the patients undergoing LDG and LLAR between 2014-2016 were analyzed retrospectively. The proportion of cases performed by ESSQS-certified surgeons was calculated for each procedure, and clinicopathological factors with or without participation of ESSQS-certified surgeons as an operator were assessed. Then, effects of operations performed by ESSQS-certified surgeons on short-term patient outcomes were analyzed using generalized estimating equations logistic regression analysis. RESULTS: There were 110 610 and 65 717 patients who underwent LDG and LLAR, respectively. The operations performed by ESSQS-certified surgeons in each procedure totaled 28 467 (35.3%) and 12 866 (31.2%), respectively. A multivariable logistic regression model showed that odds ratios of mortality for LDG and LLAR performed by ESSQS-certified surgeons were 0.774 (95% CI, 0.566-1.060, P = 0.108) and 0.977 (0.591-1.301, P = 0.514), respectively. Odds ratios for secondary endpoints of anastomotic leakage in LDG and LLAR performed by ESSQS-certified surgeons were 0.835 (95% CI, 0.723-0.964, P = 0.014) and 0.929 (0.860-1.003, P = 0.059), respectively, whereas that of ileus/bowel obstruction for LLAR performed by ESSQS-certified surgeons was 1.265 (1.132-1.415, P < 0.001). There were no significant associations between the two operations performed by ESSQS-certified surgeons and other factors such as mortality and overall complications. CONCLUSIONS: ESSQS certification did not affect postoperative mortality following LDG and LLAR, but annual experience of laparoscopic surgery was associated with it. ESSQS certification may contribute to favorable outcomes regarding anastomotic leakage following LDG and LLAR.

Fe-N-C Artificial Enzyme: Activation of Oxygen for Dehydrogenation and Monoxygenation of Organic Substrates under Mild Condition and Cancer Therapeutic Application.

Developing highly efficient biomimetic catalysts that directly use O2 as the terminal oxidant to dehydrogenate and monoxygenate substrates with high selectivity under mild conditions has long been pursued but rarely achieved yet. Herein, we report that heterogeneous Fe-N-C, which is commonly used as an electrocatalyst for oxygen reduction reaction, had unusual biomimetic catalytic activity in both dehydrogenation and monoxygenation of a series of organic molecules (∼100% selectivity) by directly using O2. The Fe-N x center was verified to be the active site that reductively activated O2 by spontaneously generating specific reactive oxygen species (ROS) (1O2, O2•-, and H2O2). Aided by these ROS, under physiological conditions, the Fe-N-C was further successfully exampled to kill proliferative lung cancer cells. Fe-N-C had several striking superior features with respect to natural enzymes, classical heterogeneous nanozymes, and homogeneous artificial enzymes incapable of working under harsh conditions (extreme pH and high temperature), ease of separation and recycling, and direct use of O2. It would open up a new vista of Fe-N-C as an artificial enzyme in biomimetic catalysis, ranging from fundamental simulation of oxidase/oxygenase metabolism to industrial oxidation processes and to disease treatment.

Gastric washing by distilled water can reduce free gastric cancer cells exfoliated into the stomach lumen.

PURPOSE: Intragastric free cancer cells in patients with gastric cancer have rarely been studied. The purpose of this study was to investigate the detection rate of intragastric free cancer cells in gastric washes using two types of solutions during endoscopic examination. We further clarified risk factors affecting the presence of exfoliated free cancer cells. METHODS: A total of 175 patients with gastric cancer were enrolled. Lactated Ringer's solution (N = 89) or distilled water (DW; N = 86) via endoscopic working channel was sprayed onto the tumor surface, and the resultant fluid was collected for cytological examination. We compared the cancer-cell positivity rate between the two (Ringer and DW) groups. We also tested the correlation between cancer-cell positivity and clinicopathological factors in the Ringer group to identify risk factors for the presence of exfoliated cancer cells. RESULTS: The cancer-cell positivity rate was significantly higher in the Ringer group than that in the DW group (58 vs 6%). Cytomorphology in the Ringer group was well maintained, but not in the DW group. The larger tumor size (≥ 20 mm) and positive lymphatic involvement were significant risk factors of exfoliated free cancer cells. CONCLUSIONS: Cancer cells can be highly exfoliated from the tumor surface into the gastric lumen by endoscopic irrigation in large gastric cancer with lymphatic involvement. Gastric washing by DW can lead to cytoclasis of free cancer cells; therefore, it may minimize the possibility of cancer-cell seeding in procedures carrying potential risks of tumor-cell seeding upon transluminal communication, such as endoscopic full-thickness resection and laparoscopy-endoscopy cooperative surgery.

Comparison between endoscopic and laparoscopic removal of gastric submucosal tumor.

BACKGROUND AND AIM: A retrospective study was conducted to compare two resection methods, namely, endoscopic resection (ER) procedures (endoscopic submucosal dissection [ESD], endoscopic muscularis dissection [EMD], and endoscopic full-thickness resection [EFTR]) and laparoscopic resections (LR) (laparoscopic endoscopic cooperative surgery [LECS] and laparoscopic wedge resection). METHODS: Seventy-three patients who underwent ER (N = 33: ESD, N = 4; EMD, N = 15; EFTR, N = 14) or LR (N = 39: LECS, N = 16; wedge resection, N = 23) for gastric submucosal tumor (G-SMT) smaller than 50 mm were included in this study. Patient/tumor characteristics and intra/postoperative factors were compared between the ER and LR groups. RESULTS: The ER group had a significantly higher percentage of intraluminal growing type of tumor (100% vs 41%) and smaller tumor size (23 vs 33 mm) than the LR group. The ER group had a significantly shorter operative time (93 vs 145 min) and less blood loss (13 vs 30 mL) than the LR group. In the ER group, three patients who had tumors located on the anterior wall of the stomach required laparoscopic closure after EFTR because of difficulty in endoscopic closure of the gastric-wall defect. Postoperative complication rates and duration of postoperative hospital stays did not differ between the two groups. CONCLUSIONS: ER may be technically feasible, safe, less invasive, and oncologically appropriate options for selected patients with the intraluminal growing type of G-SMT smaller than 30 mm. EFTR may be more reasonable alternatives to LR in selected patients with a small G-SMT located on the lesser curvature side.

Spontaneous regression of colorectal liver metastasis.

A 72-year-old woman with advanced ascending colon cancer and an intraductal papillary mucinous neoplasm (IPMN) of the pancreatic head was treated by right hemicolectomy (RHC) and pylorus-preserving pancreaticoduodenectomy (PpPD). Adjuvant chemotherapy was not administered. Multimodal examinations at 5 months after surgery detected a solitary metastatic liver tumor derived from cancer of the ascending colon. Liver resection proceeded at 7 months after the first surgery. A pathological study of a surgical specimen of the liver identified a necrotic nodule that did not contain viable tumor cells. However, an immunohistological study of the hepatic mass indicated metastasis derived from cancer of the ascending colon. These findings were consistent with total necrosis of a liver metastasis of colorectal cancer. The mechanism of spontaneous regression of tumors remains unexplained. In our case, pancreaticoduodenectomy was performed at the same time as right hemicolectomy, which involved a risk of continuous biliary infection after biliary tract reconstruction. A host immune response to chronic biliary tract infection might have been involved in the spontaneous regression of liver metastasis. Spontaneous regression of colorectal liver metastasis is rare, and the mechanism remains unknown. This needs to be investigated in more tissues from patients who have experienced this phenomenon.

Effect of Reprimo Down-regulation on Malignant Transformation of Intraductal Papillary Mucinous Neoplasm.

OBJECTIVES: Reprimo gene is a cytoplasmic protein belonging to a family of molecules controlled by p53 that inhibits cell cycle progression. Ectopic expression of Reprimo results in cell cycle arrest at the G2 phase. The aim of this study was to investigate the impact of Reprimo expression on tumorigenesis of intraductal papillary mucinous neoplasm (IPMN). METHODS: Thirty-seven surgical cases of IPMN were collected retrospectively. Twenty-eight patients had benign IPMNs (low-grade dysplasia, n = 18; intermediate-grade dysplasia, n = 10), and the remaining 9 had malignant IPMNs (high-grade dysplasia, n = 4; invasive carcinoma, n = 5). DNA from tumor samples was extracted. DNA methylation patterns of Reprimo were determined by the methods of methylation-specific polymerase chain reaction and immunohistochemistry. The methylation status of Reprimo was compared between benign IPMNs and malignant IPMNs. RESULTS: The incidence of aberrant DNA methylation of Reprimo was significantly higher in malignant IPMNs than in benign IPMNs (78% vs 32%, P = 0.016). Furthermore, the incidence of immunohistochemical Reprimo expression was significantly lower in malignant IPMNs than in benign IPMNs (22% vs 82%, P = 0.002). CONCLUSIONS: Reprimo methylation was found more frequently in malignant IPMNs. Reprimo methylation is involved in malignant transformation of IPMNs.

Endoscopic self-expandable metal stent placement for malignant afferent loop obstruction caused by peritoneal recurrence after total gastrectomy.

Afferent loop obstruction (ALO) caused by cancer recurrence after total gastrectomy (TG) can be managed by either surgical or non-surgical treatment. The general condition of patients with recurrent gastric cancer is often poor, so a less invasive non-surgical treatment is desirable. We report the case of a 75-year-old male who had undergone TG for gastric cancer 6 months previously and who presented at our hospital with abdominal pain and vomiting. Abdominal computed tomography scan showed a dilated afferent loop, and additionally a low-density lesion around jejunojejunal anastomosis, suggesting that ALO is associated with peritoneal recurrence. A self-expandable metal stent (SEMS) was endoscopically placed to treat ALO after decompression of the dilated afferent loop using an intestinal tube. He retained a good quality of life until his death due to cancer progression 5 months after the SEMS placement. Our case indicates that SEMS could be a less invasive alternative to surgery, and may confer a better quality of life for patients with ALO due to cancer recurrence after TG. This is the valuable report of case in which endoscopic metallic stent placement succeeded for ALO caused by peritoneal recurrence after TG.