Tumor location, clinicopathological features, and perioperative and prognostic outcomes in patients who underwent pancreatic resection following neoadjuvant chemoradiotherapy for resectable pancreatic cancer: A retrospective study.

BACKGROUND: /Objective: Preoperative treatment of resectable pancreatic ductal adenocarcinoma (PDAC) is gaining popularity worldwide. However, the characteristics of tumors located in the pancreatic head (Ph), or those in the body or tail (Pbt), after surgery following neoadjuvant chemoradiotherapy (NACRT) remain unclear. This study aimed to evaluate and compare the clinicopathological features, perioperative outcomes, and prognosis of patients with resectable PDAC who underwent NACRT followed by curative pancreatic resection, focusing on distinguishing between Ph and Pbt PDACs. METHODS: We included 107 patients with resectable PDAC who underwent curative resection following NACRT between 2009 and 2023. Clinicopathological features, perioperative and prognostic outcomes, recurrence patterns, and prognoses were compared between Ph and Pbt PDAC groups. RESULTS: Tumors were found in the Ph and Pbt in 64 and 43 patients, respectively. Albumin levels and lymphocyte-to-monocyte ratios after NACRT were significantly lower in the Ph group than in the Pbt group. The Pbt group showed significantly higher rates of positive peritoneal lavage cytology and serosal, arterial, and portal vein invasion than the Ph group did. Overall and recurrence-free survival were similar between the two groups. The most common site of initial postoperative recurrence was the lung only in both groups; however, the rate of peritoneal dissemination only was significantly higher in the Pbt group than in the Ph group. CONCLUSIONS: The prognoses based on tumor locations in the Ph and Pbt after surgery following NACRT are similar. Following the resection of resectable Pbt PDAC, the possibility of peritoneal dissemination recurrence should be considered.

A Novel Fluorescence-Based Leak Test Method for Rectal Anastomoses Using Aerosolized Indocyanine Green.

BACKGROUND: The intraoperative air leak test is commonly performed during rectal surgery to evaluate anastomotic integrity. However, its drawbacks include occasional difficulties in visualizing the exact point of the leak while maintaining the pelvis under saline, the need for repeat testing to identify the leak point, and a lack of continuous visualization of the leak point. OBJECTIVE: To evaluate the feasibility and clinical applicability of using aerosolized indocyanine green, a fluorescent tracer, for detecting rectal anastomotic leakage. DESIGN: Animal preclinical study. SETTING: Animal laboratory at Kagawa University. PATIENTS: Six healthy adult female beagles were included. INTERVENTIONS: An anastomotic leakage model with a single air leak point was created in each dog. Indocyanine green was aerosolized using a nebulizer kit with a stream of carbon dioxide flowing at 1.5 to 2.0 L/min. The aerosol was administered into the rectum transanally, and laparoscopic observations were performed. MAIN OUTCOME MEASURES: Air leak points were observed using a near-infrared fluorescence laparoscope, after which the presence of corresponding indocyanine green fluorescence was verified. RESULTS: Aerosolized indocyanine green was visualized laparoscopically at all anastomosis sites but not elsewhere. The median time from the administration of the aerosol to its visualization was 4.5 seconds. Pathological examinations were performed 4 weeks postsurgery in all dogs, and no histological abnormalities related to aerosolized indocyanine green administration were observed at the anastomosis sites. LIMITATIONS: The leak points were surgically created and did not occur naturally. CONCLUSIONS: Visualization of air leaks at the sites of rectal anastomosis was laparoscopically achievable by administering aerosolized indocyanine green transanally into the rectum in our canine model. This novel fluorescent leak test could be a valid alternative to established methods.

A combined score for predicting clinically relevant postoperative pancreatic fistula based on inflammatory parameters and drainage fluid culture results on postoperative day 3.

BACKGROUND: Clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreatic resection can lead to severe postoperative complications. POPF is defined based on postoperative day (POD) 3 drainage fluid amylase level. POPF correlates with inflammatory parameters as well as drainage fluid bacterial infection. However, a standardized model based on these factors for predicting CR-POPF remains elusive. We aimed to identify inflammatory parameter- and drainage fluid culture-related risk factors for CR-POPF on POD 3 after pancreatoduodenectomy (PD) and distal pancreatectomy (DP). METHODS: Data from 351 patients who underwent PD or DP between 2013 and 2022 at a single institution were retrospectively analyzed. Risk factors for CR-POPF were investigated using multivariate analyses, and a prediction model combining the risk factors for CR-POPF was developed. RESULTS: Of the 351 patients, 254 and 97 underwent PD and DP, respectively. Multivariate analyses revealed that drainage fluid amylase level ≥722 IU/L, culture positivity, as well as neutrophil count ≥5473/mm3 on POD 3 were independent risk factors for CR-POPF in PD group. Similarly, drainage fluid, amylase level ≥500 IU/L, and culture positivity on POD 3 as well as pancreatic thickness ≥11.1 mm were independent risk factors in the DP group. The model for predicting CR-POPF achieved the maximum overall accuracy rate when the number of risk factors was ≥2 in both the PD and DP groups. CONCLUSIONS: Inflammatory parameters on POD 3 significantly influence the risk of CR-POPF onset after pancreatectomy. The combined models based on these values can accurately predict the risk of CR-POPF after pancreatectomy.

Incidence and molecular characteristics of deficient mismatch repair conditions across nine different tumors and identification of germline variants involved in Lynch-like syndrome.

BACKGROUND: Based on molecular characteristics, deficient DNA mismatch repair (dMMR) solid tumors are largely divided into three categories: somatically MLH1-hypermethylated tumors, Lynch syndrome (LS)-associated tumors, and Lynch-like syndrome (LLS)-associated tumors. The incidence of each of these conditions and the corresponding pathogenic genes related to LLS remain elusive. METHODS: We identified dMMR tumors in 3609 tumors from 9 different solid organs, including colorectal cancer, gastric cancer, small-bowel cancer, endometrial cancer, ovarian cancer, upper urinary tract cancer, urinary bladder cancer, prostate cancer, and sebaceous tumor, and comprehensively summarized the characterization of dMMR tumors. Characterization of dMMR tumors were performed as loss of at least one of MMR proteins (MLH1, MSH2, MSH6, and PMS2), by immunohistochemistry, followed by MLH1 promotor methylation analysis and genetic testing for MMR genes where appropriate. Somatic variant analysis of MMR genes and whole exome sequencing (WES) were performed in patients with LLS. RESULTS: In total, the incidence of dMMR tumors was 5.9% (24/3609). The incidence of dMMR tumors and the proportion of the three categorized dMMR tumors varied considerably with different tumor types. One to three likely pathogenic/pathogenic somatic MMR gene variants were detected in 15 out of the 16 available LLS tumors. One patient each from 12 patients who gave consent to WES demonstrated non-MMR germline variants affect function (POLQ or BRCA1). CONCLUSIONS: Our data regarding the LS to LLS ratio would be useful for genetic counseling in patients who are suspected to have LS, though the genetic backgrounds for the pathogenesis of LLS need further investigation.

Tumor-to-blood pool ratio of 18F-fluorodeoxyglucose-positron emission tomography's standardized uptake value as a useful parameter indicating malignant transformation in pancreatic branch-duct intraductal papillary mucinous neoplasm compared to the international Fukuoka guidelines: a retrospective cohort study from surgical resections.

BACKGROUND: Identifying malignant transformation in pancreatic branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) remains challenging, but the standardized uptake value (SUV) obtained from 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT has the potential to become a valuable parameter for differentiation. This study aimed to assess the effectiveness of SUV of FDG-PET/CT in distinguishing low-grade dysplasia (LGD), high-grade dysplasia (HGD), and intraductal papillary mucinous carcinoma (IPMC) within BD-IPMNs. METHODS: We assessed 58 patients with confirmed BD-IPMN undergoing surgery between 2008 and 2022. Receiver operating characteristic curves were plotted using the tumor-to-blood pool ratio (TBR) of FDG-PET/CT in two scenarios: one considering HGD + IPMC as positive and the other considering only IPMC as positive. RESULTS: In the cohort of 58 cases, there were 39 females, and the median age was 71 years. The median TBR value was 1.45 (range, 0.35-25.44). The TBRs exhibited a significant correlation with each histopathology (p < 0.001). Furthermore, in the multivariate analysis, TBR was independently significant in both scenarios, with HGD + IPMC defined as malignant (p = 0.001) and with only IPMC defined as malignant (p = 0.024). CONCLUSIONS: TBR might have the potential to serve as a valuable parameter for indicating malignant transformation in pancreatic BD-IPMNs.

Efficacy of neoadjuvant chemoradiotherapy followed by pancreatic resection for older patients with resectable and borderline resectable pancreatic ductal adenocarcinoma.

BACKGROUND: The benefit of preoperative treatment followed by pancreatic resection in older patients with pancreatic ductal adenocarcinoma (PDAC) remains unclear. In this retrospective analysis of prospectively collected data, we evaluated the significance and safety of preoperative treatment followed by curative resection for older PDAC patients. METHODS: We evaluated 122 patients with resectable and borderline resectable PDAC who received neoadjuvant chemoradiotherapy (NACRT) followed by curative resection between 2009 and 2019. Changes in the prognostic nutritional indices during NACRT, surgical outcomes, and prognosis were compared between older (≥75 years, n = 44) and younger patients (<75 years, n = 78). RESULTS: The completion rate, adverse event rate, changes in prognostic nutritional indices during NACRT, and prognosis were similar between the groups. In multivariate analysis, an elevated C-reactive protein/albumin ratio (CRP/Alb) ≥ 33.1% during NACRT (p = 0.035) and no postoperative adjuvant chemotherapy (p = 0.041) were identified as significant predictors of overall survival. CONCLUSIONS: NACRT followed by pancreatic resection could be safely performed in older patients, with a similar prognosis as that of younger patients, despite an increased frequency of postoperative complications. Elevated CRP/Alb during NACRT and no postoperative adjuvant chemotherapy were poor prognostic factors for older patients.

Tumor metabolic alterations after neoadjuvant chemoradiotherapy predict postoperative recurrence in patients with pancreatic cancer.

OBJECTIVE: We investigated the metabolic changes in pancreatic ductal adenocarcinoma to identify the mechanisms of treatment response of neoadjuvant chemoradiation therapy. METHODS: Frozen tumor and non-neoplastic pancreas tissues were prospectively obtained from 88 patients with pancreatic ductal adenocarcinoma who underwent curative-intent surgery. Sixty-two patients received neoadjuvant chemoradiation therapy and 26 patients did not receive neoadjuvant therapy (control group). Comprehensive analysis of metabolites in tumor and non-neoplastic pancreatic tissue was performed by capillary electrophoresis-mass spectrometry. RESULTS: Capillary electrophoresis-mass spectrometry detected 90 metabolites for analysis among more than 500 ionic metabolites quantified. There were significant differences in 27 tumor metabolites between the neoadjuvant chemoradiation therapy and control groups. There were significant differences in eight metabolites [1-MethylnNicotinamide, Carnitine, Glucose, Glutathione (red), N-acetylglucosamine 6-phosphate, N-acetylglucosamine 1-phosphate, UMP, Phosphocholine] between good responder and poor responder for neoadjuvant chemoradiation therapy. Among these metabolites, phosphocholine, Carnitine and Glutathione were associated with recurrence-free survival only in the neoadjuvant chemoradiation therapy group. Microarray confirmed marked gene suppression of choline transporters [CTL1-4 (SLC44A1-44A4)] in pancreatic ductal adenocarcinoma tissue of neoadjuvant chemoradiation therapy group. CONCLUSION: The present study identifies several important metabolic consequences and potential neoadjuvant chemoradiation therapy targets in pancreatic ductal adenocarcinoma. Choline metabolism is one of the key pathways involved in recurrence of the patients with pancreatic ductal adenocarcinoma who received neoadjuvant chemoradiation therapy.

Outcomes of Patients with Left-Sided Obstructive Colorectal Cancer: Comparison between Self-Expandable Metallic Stent and Other Treatment Methods.

INTRODUCTION: This multi-institutional retrospective study aimed to evaluate the efficacy of preoperative self-expandable metallic stent (SEMS) placement for patients with left-sided obstructive colorectal cancer (OCRC). METHODS: Overall, 520 consecutive patients who received treatment for OCRC were enrolled. Of these, the data of 253 patients who underwent primary tumour resection for left-sided OCRC were reviewed. The short- and long-term outcomes were compared between the SEMS group and other three groups: transanal decompression tube (TaDT), decompressing stoma (DS), and emergency resection (ER). RESULTS: The SEMS group had a higher frequency of laparoscopic surgery (p < 0.001), lesser frequency of postoperative stoma (p < 0.001), and more dissected lymph nodes (p < 0.001) than the other groups. Moreover, the SEMS group had shorter postoperative hospital stays than the TaDT, DS, and ER groups (p = 0.005, p = 0.037, and p < 0.001, respectively). The Kaplan-Meier survival curves of recurrence-free survival and overall survival did not differ significantly between the SEMS group and the other three groups in patients with stage II and III diseases. DISCUSSION/CONCLUSION: Elective surgery after SEMS placement may improve short-term outcomes compared to other treatment strategies, with similar long-term outcomes.

Indocyanine green fluorescence imaging during laparoscopic rectal cancer surgery could reduce the incidence of anastomotic leakage: a single institutional retrospective cohort study.

BACKGROUND: There is insufficient evidence on whether indocyanine green (ICG) fluorescence angiography can reduce the incidence of anastomotic leakage (AL). This retrospective cohort study aimed to evaluate the effect of ICG fluorescence angiography on AL rates in laparoscopic rectal cancer surgery at a single institution. METHODS: Patients who underwent laparoscopic low anterior resection or intersphincteric resection with ICG fluorescence angiography (ICG group; n = 73) and patients who underwent a similar surgical procedure for rectal cancer without ICG fluorescence (non-ICG group; n = 114) were enrolled consecutively in this study. ICG fluorescence angiography was performed prior to transection of the proximal colon, and anastomosis was performed with sufficient perfusion using ICG fluorescence imaging. AL incidence was compared between both groups, and the risk factors for AL were analyzed. RESULTS: AL occurred in 3 (4.1%) and 14 (12.3%) patients in the ICG and non-ICG groups, respectively. In the ICG group, the median perfusion time from ICG injection was 34 s, and 5 patients (6.8%) required revision of the proximal transection line. None of the patients requiring revision of the proximal transection line developed AL. In univariate analysis, longer operating time (odds ratio: 2.758; 95% confidence interval: 1.023-7.624) and no implementation of ICG fluorescence angiography (odds ratio: 3.266; 95% confidence interval: 1.038-11.793) were significant factors associated with AL incidence, although the creation of a diverting stoma or insertion of a transanal tube was insignificant. CONCLUSION: ICG fluorescence angiography was associated with a significant reduction in AL during laparoscopic rectal cancer surgery. Changes in the surgical plan due to ICG fluorescence visibility may help improve the short-term outcomes of patients with rectal cancer.

Immunohistochemically Detected Expression of ATRX, TSC2, and PTEN Predicts Clinical Outcomes in Patients With Grade 1 and 2 Pancreatic Neuroendocrine Tumors.

OBJECTIVE: The goal of this retrospective study was to clarify the clinical implications of immunohistochemically detected protein expression for genes that are frequently mutated in pancreatic neuroendocrine tumors (PNETs). BACKGROUND: The clinical management of PNETs is hindered by their heterogenous biological behavior. Whole-exome sequencing recently showed that 5 genes (DAXX/ATRX, MEN1, TSC2, and PTEN) are frequently mutated in PNETs. However, the clinical implications of the associated alterations in protein expression remain unclear. METHODS: We collected Grade 1 and 2 (World Health Organization 2017 Classification) primary PNETs samples from 100 patients who underwent surgical resection. ATRX, DAXX, MEN1, TSC2, and PTEN expression were determined immunohistochemically to clarify their relationships with prognosis and clinicopathological findings. RESULTS: Kaplan-Meier analysis indicated that loss of TSC2 (n = 58) or PTEN (n = 37) was associated with significantly shorter overall survival, and that loss of TSC2 or ATRX (n = 41) was associated with significantly shorter recurrence-free survival. Additionally, loss of ATRX or TSC2 was significantly associated with nodal metastasis. In a multivariate analysis, combined loss of TSC2 and ATRX (n = 31) was an independent prognostic factor for shorter recurrence-free survival (hazard ratio 10.1, 95% confidence interval 2.1-66.9, P = 0.003) in G2 PNETs. CONCLUSIONS: Loss of ATRX, TSC2, and PTEN expression might be useful as a method of clarifying the behavior and clinical outcomes of Grade 1 and 2 PNETs in routine clinical practice. Combined loss of TSC2 and ATRX had an especially strong, independent association with shorter recurrence-free survival in patients with G2 PNETs. Loss of pairs in ATRX, TSC2, or PTEN would be useful for selecting the candidate for postoperative adjuvant therapy.

Laparoscopic hand-sewn esophagojejunal anastomosis in laparoscopic proximal gastrectomy for early gastric cancer.

PURPOSE: In Asian countries, proximal gastrectomy is a standard treatment option for early primary gastric cancer located in the upper third of the stomach. However, laparoscopic proximal gastrectomy (LPG) is not widely employed due to the technical difficulty of laparoscopic esophagojejunal anastomosis. Therefore, we began performing laparoscopic hand-sewn esophagojejunal anastomosis. In this report, we describe the technique of this method and the short-term surgical outcomes. METHODS: Between February 2016 and June 2020, 18 patients underwent LPG with double-tract reconstruction at our institution. Laparoscopic hand-sewn esophagojejunal anastomosis was attempted for all patients. RESULTS: The median operative time for the 18 patients was 431 min (range: 301-549 min), and the estimated blood loss was 100 mL (range: 0-1524 mL). The median time for the hand-sewn esophagojejunostomy was 42 min (range: 26-81 min). Only one case was converted to open surgery after the reconstruction due to bleeding from an artery of the lesser curvature. No anastomotic leakage was observed in any patients (0/18, 0 %); however, two patients developed anastomotic stenosis (2/18, 11%). The mean length of postoperative hospital stay was 10 days (range: 8-28 days). CONCLUSION: The laparoscopic hand-sewn esophagojejunal anastomosis in LPG is a simple, cost-effective, and safe procedure. We believe that our method is a feasible choice. However, careful and longer follow-up of more patients is necessary to determine the advantages of our method.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2020 for the Clinical Practice of Hereditary Colorectal Cancer.

Hereditary colorectal cancer (HCRC) accounts for < 5% of all colorectal cancer cases. Some of the unique characteristics commonly encountered in HCRC cases include early age of onset, synchronous/metachronous cancer occurrence, and multiple cancers in other organs. These characteristics necessitate different management approaches, including diagnosis, treatment or surveillance, from sporadic colorectal cancer management. There are two representative HCRC, named familial adenomatous polyposis and Lynch syndrome. Other than these two HCRC syndromes, related disorders have also been reported. Several guidelines for hereditary disorders have already been published worldwide. In Japan, the first guideline for HCRC was prepared by the Japanese Society for Cancer of the Colon and Rectum (JSCCR), published in 2012 and revised in 2016. This revised version of the guideline was immediately translated into English and published in 2017. Since then, several new findings and novel disease concepts related to HCRC have been discovered. The currently diagnosed HCRC rate in daily clinical practice is relatively low; however, this is predicted to increase in the era of cancer genomic medicine, with the advancement of cancer multi-gene panel testing or whole genome testing, among others. Under these circumstances, the JSCCR guidelines 2020 for HCRC were prepared by consensus among members of the JSCCR HCRC Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR guidelines 2020 for HCRC.

Early gastric cancer with an Adachi type VI (group 26) vascular anomaly diagnosed preoperatively and treated by laparoscopic surgery: a case report.

BACKGROUND: It is important to understand the branching pattern of the celiac artery for a safe surgery. Various branching anomalies of the celiac artery were classified by Adachi in 1928. In Adachi's classification, type VI (group 26) is a rare anatomical anomaly (0.4%) that requires care when carrying out a surgery in gastric cancer patients with this anomaly. Herein, we reported a case treated successfully with laparoscopic distal gastrectomy with D1+ lymph node dissection for early gastric cancer. CASE PRESENTATION: An 84-year-old female was referred to our division for an additional surgical treatment for early gastric cancer that was resected by endoscopic submucosal dissection. A three-dimensional computed tomography angiography revealed an angioplany of the common hepatic artery branching from the left gastric artery. According to Adachi's classification, the anomaly of this patient corresponded to type VI (group 26). Preoperative anatomical information of this rare anomaly helped us to safely perform a laparoscopic distal gastrectomy and lymph node dissection with common hepatic artery preservation. The patient had an uneventful postoperative course and was discharged on postoperative day 11. CONCLUSIONS: We consider that Group 26 anomalies require the most precise anatomical understanding among Adachi classification type VIs, since it affects hepatic blood flow and can cause serious complications. In this time, we reported a successful case to perform laparoscopic distal gastrectomy with safety and accuracy by preoperative understanding of the precise vascular anatomy.

Japanese Society of Medical Oncology Clinical Guidelines: Molecular Testing for Colorectal Cancer Treatment, 4th edition.

Molecular testing to select the appropriate targeted and standard of care therapies is essential for managing patients with colorectal cancer (CRC). The Japanese Society of Medical Oncology previously published clinical guidelines for molecular testing in CRC. In the third edition published in 2018, RAS and BRAF V600E mutations should be tested prior to first-line chemotherapy to assess the benefit of anti-epidermal growth factor receptor (EGFR) antibody therapy in patients with unresectable CRC. Microsatellite instability (MSI) testing was recommended in patients with curatively resected stage II CRC because deficient mismatch repair is associated with low risk of recurrence. MSI testing was also recommended in patients with CRC suspected to be Lynch syndrome. The main aim of this fourth edition is to reflect recent advances in comprehensive genomic profiling (CGP) tests and liquid biopsy. Here, CGP tests performed on tumor tissues are strongly recommended to assess the benefit of molecular targeted drugs in patients with CRC. Circulating tumor DNA (ctDNA)-based CGP tests are also proposed. ctDNA testing is recommended to determine the optimal treatment based on the risk of recurrence for curatively resected CRC and evaluate the suitability and monitor the therapeutic effects of anti-EGFR antibodies in patients with unresectable CRC. While both MSI testing and immunohistochemistry are strongly recommended to determine the indication of immune checkpoint inhibitors in patients with unresectable CRC, next-generation sequencing-based tests are weakly recommended because these tests have not been validated in clinical trials.

New Concept Air Conditioning System for the Operating Room to Minimize Patient Cooling and Surgeon Heating: A Historical Control Cohort Study.

BACKGROUND: Intraoperative hypothermia is a common adverse event. For avoiding the complication due to hypothermia, many warming devices and methods have been used in perioperative period. It has been reported that more patients undergoing laparoscopic surgery tend to have hypothermia than with open surgery. To avoid intraoperative hypothermia, many kinds of warming tools have been used. But, it was also reported that some warming methods increased perceptions of distraction and physical demand. METHODS: To achieve both patients' normothermia and surgeons' comfort, new air conditioning (AC) system was designed with considering the characteristics of laparoscopic surgery. The temperature of the airflows to the patient and to the surgeons can be adjusted independently in this new system. The new system has two parts. One controls the temperature of the central area over the operation table. The air from this part falls on the patients. The other part is the lateral area beside the operating table; the air from this part falls on the surgeons. The subjects of this study were 160 gastric cancer patients and 316 colorectal cancer patients undergoing laparoscopic surgery. The temperature of the central flow was set 23.5 °C, and the temperature of the lateral flow was set 22 °C just after the anesthesia. The number of timepoints the patient spent in hypothermic state, defined as a temperature cooler by 0.5 °C or more than that at the starting point of surgery, was determined in each patient. RESULTS: In the results, the rate of hypothermic state in old operation rooms was 23.8% and that in new operation rooms was 2.7% in male gastric cancer patients (p < 0.01). And those were 37.1% in old operation rooms and 0.9% in new operation rooms in female gastric cancer patients (p < 0.01). The rate of hypothermic state in old operation rooms was 30.0% and that in new operation rooms was 9.5% in male colorectal cancer patients (p < 0.01). And those were 41.6% in old operation rooms and 8.9% in new operation rooms in female colorectal cancer patients (p < 0.01). The similar results were showed in the study, which subjects were limited the patients undergoing surgery in 2015 and 2016; which were the last year the old operation rooms were used and the first year the new operation rooms were used. CONCLUSIONS: Thus, the usefulness of the new air conditioning system for achieving both patients' normothermia and comfort of surgeons could be verified in this study.

Correction to: Purse-string approximation vs. primary closure with a drain for stoma reversal surgery: results of a randomized clinical trial.

In the original publication, surname of first author is misspelt as "Amamo". It should be "Amano" as given in this Correction.

Purse-string approximation vs. primary closure with a drain for stoma reversal surgery: results of a randomized clinical trial.

PURPOSE: Stoma reversal carries a risk of surgical site infection (SSI). Purse-string approximation (PSA) has been reported as an attractive alternative to conventional primary wound closure for stoma reversal, but its efficacy is still under debate. METHODS: Patients undergoing elective stoma reversal were randomized to undergo PSA or primary closure with a drain (PCD). All patients received preoperative bowel cleansing and antimicrobial prophylaxis. The primary endpoint was the incidence of wound healing at the stoma site 30 days after surgery. The secondary endpoint was the 30-day SSI rate after surgery. RESULTS: A total of 159 patients (PCD group, n = 79; PSA group, n = 80) were eligible for this study. The incidence of wound healing at the stoma site was 92.4% in the PCD group and 62.5% in the PSA group [difference (95% confidence interval - 29.9% (- 42.9 to - 16.9%)]. The 30-day SSI rate at the stoma site, as the secondary endpoint, was 8.9% in the PCD group and 5.0% in the PSA group (P = 0.35). CONCLUSIONS: These results suggest that PCD may remain the standard procedure for stoma reversal surgery.

Histological Comparison of Cold versus Hot Snare Resections of the Colorectal Mucosa.

BACKGROUND: Delayed postpolypectomy bleeding occurs more frequently after hot resection than after cold resection. OBJECTIVE: To elucidate the underlying mechanism, we performed a histological comparison of tissue after cold and hot snare resections. DESIGN: This is a prospective study, registered in the University Hospital Medical Information Network (UMIN000020104). SETTING: This study was conducted at Aizu Medical Center, Fukushima Medical University, Japan. PATIENTS: Fifteen patients scheduled to undergo resection of colorectal cancer were enrolled. INTERVENTION: On the day before surgery, 2 mucosal resections (hot and cold) of normal mucosa were performed on each patient using the same snare without saline injection. The difference was only the application of electrocautery or not. Resection sites were placed close to the cancer to be included in the surgical specimen. MAIN OUTCOME MEASURES: The primary outcome measure was the depth of destruction. Secondary outcome measures included the width of destruction, depth of the remaining submucosa, and number of vessels remaining at the resection sites. The number and diameter of vessels in undamaged submucosa were also evaluated. RESULTS: All cold resections were limited to the shallow submucosa, whereas 60% of hot resections advanced to the deep submucosa and 20% to the muscularis propria (p < 0.001). There was no significant difference in the width of destruction. The number of remaining large vessels after hot resections trended toward fewer (p = 0.15) with a decreased depth of remaining submucosa (p = 0.007). In the deep submucosa, the vessel diameter was larger (p < 0.001) and the number of large vessels was greater (p = 0.018). LIMITATIONS: Histological assessment was not blinded to the 2 reviewers. Normal mucosa was used instead of adenomatous tissue. CONCLUSIONS: Hot resection caused damage to deeper layers involving more large vessels. This may explain the mechanism for the reduced incidence of hemorrhage after cold snare polypectomy. See Video Abstract at http://links.lww.com/DCR/A631.

Prevalence and molecular characteristics of defective mismatch repair epithelial ovarian cancer in a Japanese hospital-based population.

BACKGROUND: The prevalence and molecular characteristics of defective mismatch repair epithelial ovarian cancers in the Japanese population have scarcely been investigated. METHODS: Immunohistochemistry for mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) was performed in formalin-fixed paraffin-embedded sections prepared from resected primary epithelial ovarian cancers in patients who underwent oophorectomy at our institution between April 2005 and September 2014. Genetic and/or epigenetic alterations of the mismatch repair genes were investigated in patients with loss of any mismatch repair proteins in the tumor. RESULTS: There were 305 patients with a median age of 54 years (range, 18-83 years). Loss of expression in the ovarian tumor of one or more mismatch repair proteins was observed in 3 of the 305 patients (0.98%): 2 patients MLH1/PMS2 loss and 1 patient showed MSH2/MSH6 loss. Genetic testing of these three patients failed to reveal any pathogenic germline mutations of MLH1 or MSH2. One patient with MLH1/PMS2 loss showed hypermethylation of the promoter region of MLH1. Somatic mutations were found in each of the alleles of MLH1 (c.545dupG and deletion of exons 2-19) in the other patient with MLH1/PMS2 loss. In the patient with MSH2/MSH6 loss, two somatic mutations were detected in MSH2 (c.229_230delAG and c.1861C>T), although we could not determine whether these mutations were biallelic or not. CONCLUSIONS: The prevalence of defective mismatch repair epithelial ovarian cancer in the Japanese hospital-based population was extremely low. Molecular mechanism involved in such defective mismatch repair ovarian cancers seems to be epigenetic events through MLH1 promotor hypermethylation or somatically mutated mismatch repair genes without germline mismatch repair mutation.