Investigation of the impact of COVID-19 on postoperative outcomes using a nationwide Japanese database of patients undergoing laparoscopic distal gastrectomy and low anterior resection for gastric cancer and rectal cancer

Background

The COVID-19 outbreak made conventional medical care impossible, forcing changes in both healthcare providers and patients. In Japan, COVID-19 infection began spreading in earnest in 2020 and exploded in 2021. There was concern that the medical impact of COVID-19 in 2021 would differ from that in 2020. We aimed to clarify the impact of COVID-19 on mortality and anastomotic leakage in laparoscopic surgery for gastric cancer and rectal cancer in Japan using the National Clinical Database (NCD).

Methods

We collected data from patients who underwent laparoscopic distal gastrectomy (LDG) and laparoscopic low anterior resection (LLAR) from January 2018 to December 2021 from the NCD, a web-based surgical registration system in Japan. The number of surgical cases, monthly incidence of mortality and morbidity (anastomotic leakage), standardized mortality ratio (SMR), and standardized morbidity-leakage ratio (SMLR [ratio of observed patients to expected patients calculated using the risk calculator established in the NCD]) were evaluated.

Results

The numbers of LDG and LLAR cases continued to decline in the first year of the pandemic in 2020 and were as low in 2021 as in 2020. Although the numbers of robot-assisted LDG and LLAR cases increased, the growth rate was lower than the rate of increase prior to the pandemic. Mortality and anastomotic leakage, two of the most important complications, as assessed by SMR and SMLR, did not worsen during the pandemic in comparison to the pre-pandemic period.

Conclusions

Laparoscopic surgeries were performed safely in Japan and were not affected by the COVID-19 pandemic.

Erratum forTreatment of Rectovaginal Fistula

[This corrects the article DOI: 10.23922/jarc.2023-007.].

The clinical impact of COVID-19 on endoscopic surgery in Japan: Analysis of data from the National Clinical Database

Aim

This study aimed to evaluate the impact of the coronavirus disease (COVID-19) pandemic on elective endoscopic surgeries in Japan using the National Clinical Database.

Methods

We retrospectively analyzed the clinicopathological factors and surgical outcomes of laparoscopic cholecystectomy (LC), laparoscopic distal gastrectomy (LDG), and laparoscopic low anterior resection (LLAR) and compared the monthly numbers of each procedure performed in 2020 with those in 2018 and 2019. The degree of infection in prefectures was classified into low and high groups.

Results

In 2020, the number of LCs (except for acute cholecystitis) was 76 079 (93.0% of that in 2019), the number of LDGs was 14 271 (85.9% of that in 2019), and the number of LLARs was 19 570 (88.1% of that in 2019). Although the number of robot-assisted LDG and LLAR cases increased in 2020, the growth rate was mild compared with that in 2019. There was little difference in the number of cases in the degree of infection in the prefectures. The numbers of LC, LDG, and LLAR cases decreased from May to June and recovered gradually. In late 2020, the proportion of T4 and N2 cases of gastric cancer and the number of T4 cases of rectal cancer increased compared with those in 2019. There was little difference between the proportions of postoperative complications and mortality in the three procedures between 2019 and 2020.

Conclusion

The number of endoscopic surgeries decreased in 2020 as a result of the COVID-19 pandemic. However, the procedures were performed safely in Japan.

Comparison of hand-sewn and circular stapled esophagogastric anastomoses in the neck after esophagectomy for thoracic esophageal cancer: a propensity score-matched analysis

Esophagectomy is a highly invasive surgical procedure; however, anastomotic leakage is one of the major surgical complications that should be prevented. Institutions have their own inherited or specialized anastomosis methods. The superior anastomosis procedure remains unknown despite the many studies to determine the optimal method. The present study enrolled 341 patients who underwent esophagectomy at Keio University Hospital, Tokyo, Japan, between January 2009 and January 2019. The anastomosis method was changed from circular stapled anastomosis to hand-sewn anastomosis in February 2014 to reduce the risk of anastomotic leakage. We retrospectively compared short-term results (anastomotic leakage and stricture) between hand-sewn and circular stapled anastomoses. Analysis of heterogeneity after propensity score matching between the 107 patients in the hand-sewn anastomosis group and 107 patients in the circular stapled anastomosis group revealed almost equal distributions. The incidence rate of anastomotic leakage was significantly lower in the hand-sewn anastomosis group than in the circular stapled anastomosis group (9 vs. 20%, hazard ratio: 2.521; 95% confidence interval: 1.112-5.716; P = 0.027). No significant difference was found in the incidence of anastomotic stricture (16 vs. 18%, P = 0.844). Furthermore, no significant difference was found in the incidence of anastomotic leakage in any of the tumor locations between the two anastomosis procedures. For esophagogastric anastomosis in the neck after esophagectomy, hand-sewn anastomosis is superior to circular stapled anastomosis with regard to reducing the risk of anastomotic leakage.

Treatment of Rectovaginal Fistula

Rectovaginal fistula (RVF) is a challenging complication with unsatisfactory success and a significant burden for the patients. With insufficient clinical data due to the rare entity, the present state of treatments for RVFs was reviewed especially form the point of factors to determine management, classifications, principle of treatment, conservative and surgical treatments with outcomes. Size, fistula localization and etiology, type of fistula; "simple" or "complex," status of anal sphincter complex and surrounding tissue, presence or absence of inflammation, presence of diverting stoma, previous attempted repair and radiation therapy, patient's condition with co-morbidities, and surgeon's experience are important factors to determine the management of RVF. The inflammation should initially subside in cases with infection. Starting with conservative surgical options and interposing healthy tissue for complex or recurrent fistulas, invasive procedures will be performed if conservative treatment failed. Conservative treatment may be effective in RVFs with minimal symptoms and should be done for small RVFs for a 36 months usual period. Anal sphincter damage might need a repair of sphincter muscles along with RVF repair. Diverting stoma can initially be constructed in patients with severe symptoms and larger RVFs to relief the patient's pain. Simple fistula is usually indicated for local repair. Local repairs to transperineal and transabdominal approaches can be used for complex RVFs. Interposition of healthy, well-vascularized tissue can be required for more complex fistulas and abdominal procedures for high RVFs.

Short-term outcomes of robot-assisted minimally invasive esophagectomy with extended lymphadenectomy for esophageal cancer compared with video-assisted minimally invasive esophagectomy: A single-center retrospective study

BACKGROUND

The safety and feasibility of robot-assisted minimally invasive esophagectomy (RAMIE) remain unclear. The aim of this study was to compare the short-term outcomes of RAMIE with extended lymphadenectomy and conventional minimally invasive esophagectomy (MIE) in order to investigate the safety and feasibility of RAMIE.

METHODS

A retrospective analysis of 87 patients who underwent minimally invasive esophagectomy at our institution between April 2018 and March 2020 was made, assigning 22 in the RAMIE group and 65 in the MIE group. Short-term clinical outcomes and clinical baseline data were compared.

RESULTS

The baseline characteristics were comparable. No significant difference in median thoracic phase blood loss and median number of dissected mediastinal lymph nodes were observed. The median operative time of thoracic approach was significantly longer in the RAMIE group than the MIE group (305 minutes [221-397] vs 227 minutes [133-365], P < .0001). With respect to postoperative complications such as recurrent laryngeal nerve paralysis (Clavien-Dindo ≥ grade II) (RAMIE 4.6% vs MIE 17%, P = .11) and postoperative pneumonia (Clavien-Dindo ≥ grade III) (RAMIE 9% vs MIE 23%, P = .13), no significant difference was observed. The patients in the RAMIE group had a better postoperative swallowing function (P = .023) and were able to start oral food intake significantly earlier (P = .007). The median hospital stay was significantly shorter in the RAMIE group than in the MIE (23 days vs 35 days, P = .009).

CONCLUSIONS

RAMIE with extended lymphadenectomy was safe and feasible for esophageal cancer and resulted in improved postoperative swallowing function and shorter postoperative hospital stay.

Current Status of Endoscopic Surgery in Japan: The 15th National Survey of Endoscopic Surgery by the Japan Society for Endoscopic Surgery

In Japan, the first endoscopic surgery, a laparoscopic cholecystectomy, was performed in 1990. Since then, operative procedures have been standardized, and the safety and efficacy of endoscopic surgery have been evaluated. In accordance with the social acceptance of endoscopic surgery as a less invasive type of surgery, the number of endoscopic procedures performed has increased in all surgical domains. The Japan Society for Endoscopic Surgery (JSES) has played an important role in the development of endoscopic surgery in Japan. Notably, a technical skills certification system for surgeons was established by the JSES to train instructors on how to teach safe endoscopic surgery. Furthermore, the JSES has conducted a national survey every 2 years. In 2019, 291,792 patients underwent endoscopic surgery in all surgical domains, such as abdominal, thoracic, mammary and thyroid gland, cardiovascular, obstetrics and gynecology, urologic, orthopedic, and plastic surgery. The 15th National Survey of Endoscopic Surgery conducted by the JSES demonstrated the status of laparoscopic surgery in Japan in 2018-2019.

Exploratory prospective study of the influence of radical esophagectomy on perioperative physical activity in patients with thoracic esophageal cancer

Sarcopenia, which involves two important aspects, namely skeletal muscle loss and decreased physical function, was suggested as a poor prognostic factor in esophageal cancer surgery. The purpose of this study was to clarify the perioperative change in daily physical activity and propose effective preventive strategies. We prospectively enrolled patients with esophageal cancer who were scheduled to undergo radical esophagectomy. Their daily physical activities were recorded using an accelerometer before surgery, immediately after discharge, and 6 months after surgery. The relationships of physical activity level and the perioperative factors, especially skeletal muscle change, with the risk factors of low daily activity level were investigated. The data of 20/28 enrolled patients were analyzed. The mean activity level of the 20 patients decreased after discharge and subsequently recovered on postoperative month 6. The percentage of activity levels >1.5 metabolic equivalents/day after discharge significantly correlated to the change rate in total muscle cross-sectional area from baseline to POM 6 (r = 0.452, P = 0.045). In a stepwise multiple regression analysis, age, neoadjuvant chemotherapy, and anastomotic leakage were identified as negative associated factors of activity time at >1.5 metabolic equivalents at postoperative month 6. Activity level immediately after discharge was significantly associated with skeletal muscle loss at postoperative month 6 in patients with esophageal cancer who underwent esophagectomy. Elderly patients and patients who received neoadjuvant chemotherapy and had an anastomotic leakage might require intensive prevention. Prospective interventions aimed at increasing daily activity can prevent sarcopenia.

Preoperative maximum phonation time as a predictor of pneumonia in patients undergoing esophagectomy

PURPOSE

Esophagectomy is a highly invasive procedure, associated with several postoperative complications including pneumonia, anastomotic leakage, and sepsis, which may result in multiorgan failure. Pneumonia is considered a major predictor of poor long-term prognosis, so its prevention is important for patients undergoing surgery for esophageal cancer.

METHODS

The subjects of this study were 137 patients who underwent esophagectomy at Keio University Hospital, Tokyo, Japan, between January, 2012 and December, 2016. Patients who underwent R0 or R1 resection or esophagectomy with organ excision were included. Patients who underwent salvage surgery or resection of recurrent laryngeal nerve, and those with preoperative recurrent laryngeal nerve palsy, were excluded. We investigated the effect of the maximum phonation time on the development of postoperative pneumonia.

RESULTS

Pneumonia developed more frequently in patients with a long operative time, clinically left recurrent nerve lymph node metastasis, and a short preoperative maximum phonation time (p = 0.074, 0.046, and 0.080, respectively). Pneumonia was also more common in men with an abnormal maximum phonation time (p = 0.010).

CONCLUSIONS

The maximum phonation time is a significant predictor of postoperative pneumonia after esophagectomy in men.

Association of anastomotic leakage with long-term oncologic outcomes of patients with esophagogastric junction cancer

BACKGROUND

Despite improvements in surgical procedures and peri-operative patients management, the postoperative complications in esophagogastric junction (EGJ) cancer remain high because of technical aspects. Several studies have indicated the negative influence of postoperative infectious complications on long-term survival after gastrointestinal surgery. However, no study has shown the association between postoperative complications and long-term survival of patients with EGJ cancer.

AIM

To elucidate influence of postoperative complications on the long-term outcomes of patients with EGJ cancer.

METHODS

A total of 122 patients who underwent surgery for EGJ cancer at the Keio University were included in this study. We examined the association between complications and long-term oncologic outcomes.

RESULTS

In all patients, the 3-year overall survival (OS) rate was 71.9%, and the recurrence-free survival (RFS) rate was 67.5%. Compared with patients without anastomotic leakage, those with anastomotic leakage had poor median OS (8 mo vs not reached, P = 0.028) and median RFS (5 mo vs not reached, P = 0.055). Among patients with cervical anastomosis, there were not significant differences between patients with and without anastomotic leakage. However, among patients who underwent intrathoracic anastomosis, patients with anastomotic leakage had significantly worse OS (P = 0.002) and RFS (P = 0.005).

CONCLUSION

Anastomotic leakage was significantly associated with long-term oncologic outcomes of patients with EGJ cancer, especially those who underwent intrathoracic anastomosis. Cervical anastomosis with subtotal esophagectomy may be an option for the patients who are at high risk for anastomotic leakage.

Clinical usefulness of sputum culture on the first postoperative day to predict early postoperative pneumonia after esophagectomy for esophageal cancer

BACKGROUND

Postoperative pneumonia is a serious prognostic problem that can appear after esophagectomy in patients with esophageal cancer. The past reports have considered the usefulness of perioperative culture examinations for predicting postoperative pneumonia; however, the direct relationship between these examinations and postoperative complications remains unclear.

METHODS

This study retrospectively analyzed esophageal cancer patients who underwent esophagectomy followed by sputum culture on the first postoperative day. The bacterial species that frequently cause hospital-acquired pneumonia were chosen as the target species in this study. The relationship between culture examination and postoperative pneumonia within one week (7 days) after esophagectomy was investigated.

RESULTS

Sputum cultures on the first postoperative day were investigated in 238 patients who underwent esophagectomy for esophageal cancer. Forty-one patients developed pneumonia within one week after surgery. The target bacterial species were detected in 26 of 238 sputum cultures (10.9%). In the univariate analysis, a Brinkman index, detection of target bacterial species, detection of Gram-positive cocci, and Gram-negative rods were significantly associated with postoperative pneumonia. In the three independent multivariate analyses, the target bacterial species, Gram-positive cocci, and Gram-negative rods (p = 0.001, 0.042, and < 0.001) were individually identified as independent risk factors of postoperative pneumonia in addition to a Brinkman index.

CONCLUSIONS

Detection of target bacterial species by sputum culture on the first postoperative day after esophagectomy was an independent risk factor of postoperative pneumonia within 7 days after surgery. Prospective studies for the prevention of early postoperative pneumonia using sputum culture on the first postoperative day can be considered.

Association of preoperative sarcopenia with postoperative dysphagia in patients with thoracic esophageal cancer

BACKGROUND

The purpose of the current study was to clarify the relationship between clinical features of dysphagia after esophagectomy and preoperative sarcopenia.

METHODS

A total of 187 cases were included in the current study. The psoas cross-sectional area on pre-treatment computed tomography was measured in thoracic esophageal cancer patients who underwent curative resection. The psoas muscle index (PMI) cut-off levels for sarcopenia were 6.36 cm2/m2 for men and 3.92 cm2/m2 for women. Swallowing function was evaluated using videofluoroscopic swallowing study (VFSS) and fiberoptic endoscopic evaluation of swallowing (FEES) at postoperative days 7-15, and classified according to the food intake level scale (FILS). Perioperative swallowing rehabilitation was performed in all cases.

RESULTS

In the 187 included patients, the median PMI was 5.42 cm2/m2 for men and 3.43 cm2/m2 for women, and 133 cases (71%) met the sarcopenia criteria. The FILS <4 (no oral intake) was 15% in the non-sarcopenia group, and 38% in the sarcopenia group (P = 0.003). There was no significant difference in the incidence of postoperative complications, including pneumonia and re-admission due to pneumonia, between the two groups. Preoperative sarcopenia and recurrent laryngeal nerve palsy were be independent risk factors for postoperative dysphagia.

CONCLUSIONS

Sarcopenic patients with esophageal cancer develop postoperative dysphagia more often than non-sarcopenic patients. Prehabilitation and nutritional support for patients with preoperative sarcopenia could play an important role to mitigate postoperative dysphagia.

The Results of Sentinel Node Mapping for Patients with Clinically Early Staged Gastric Cancer Diagnosed with pT2/deeper Tumors

BACKGROUND

Sentinel node (SN) mapping based on the SN concept has been applied to early gastric cancer. However, it is still controversial whether or not the oncological safety is ensured in case pathological stage was advanced in these patients. The aim of this study was to investigate the validity of SN mapping in patients with clinically early staged gastric cancer diagnosed with pT2/deeper tumors.

METHODS

We retrospectively analyzed 40 patients with a diagnosis of cT1N0 or cT2N0 single-lesion gastric cancer who were shown to have pT2 or deeper tumors after gastrectomy with SN mapping. We adopted a dual-tracer method using a radioactive colloid and blue dye to detect SNs. The diagnostic accuracy and distribution of SNs at each tumor site were analyzed.

RESULTS

Of the 40 patients, 24 (60%) were postoperatively diagnosed as pT2, and 16 (40%) as pT3 or T4. SNs were detected in all patients. The false negative rate was 9% (1/11), and in that patient, the non-SN metastasis was observed within the SN basin. Diagnostic accuracy was 98% (39/40). Overall distribution of SNs was similar to that for patients with early gastric cancer. No significant differences in overall and recurrence-free survival were observed between the patients who underwent standard gastrectomy and those who underwent function-preserving gastrectomy, based on the results of SN mapping.

CONCLUSIONS

Our results confirmed validity of SN mapping for patients with clinically early staged gastric cancer diagnosed with pT2/deeper tumors after gastrectomy. Closed surveillance without additional surgical treatment is an option for these patients.

Prognostic impact of thoracic duct lymph node metastasis in esophageal squamous cell carcinoma

AIM

We have previously reported the existence of lymph nodes surrounding the thoracic duct ( TDLN) and transthoracic esophagectomy (TTE) with thoracic duct (TD) resection increased the number of lymph nodes (LNs) retrieved. The current study aims to evaluate the prognostic impact of TDLN metastasis in esophageal cancer patients subdivided by its location and comparing the patients' survival with those with extra-regional LN metastasis.

METHODS

Patients who underwent TTE with TD resection for esophageal squamous cell carcinoma (ESCC) were reviewed. Patients were classified into those with or without TDLN metastasis, and clinicopathological factors were compared between groups. TDLN was further divided into TDLN-Ut/Mt/Lt based on the location in the mediastinum. The relapse-free survival (RFS) and overall survival (OS) were compared between groups.

RESULTS

Of 232 patients, TDLN metastasis was observed in 17 (7%). RFS and OS were significantly worse in the TDLN metastasis group. TDLN metastasis was shown to be an independent prognostic factor for RFS and OS in the multivariate analysis. The negative prognostic impact of TDLN metastasis was evident in TDLN-Mt/Lt. The RFS and OS of patients with TDLN metastasis were almost identical to those with positive LN metastasis in extra-regional LNs.

CONCLUSION

TDLN metastasis was proven to be a strong prognostic indicator. Although the TDLN has been included in the classification of regional LN in the current staging systems, it could be independently classified from the current regional LNs. Given that neoadjuvant therapy has been a standard, we might need to introduce adjuvant therapy when TDLN metastasis is observed.

A case of synchronous intramucosal gastric carcinoma with multiple lymph node metastases

Background

In Japan, the prevalence of synchronous multiple intramucosal gastric carcinoma is reported to be 5–15%. Here is a case of a synchronous small gastric carcinoma fulfilling the definite indication and curative criteria for endoscopic submucosal dissection with multiple lymph node metastases.

Case presentation

A Japanese woman in her fifties with a history of endoscopic resection for mucosal poorly differentiated adenocarcinoma was evaluated, with the UICC TNM classification stage being cT1aN0M0 cStageIA. She had undergone total gastrectomy with D1 + lymph node dissection. Histopathological examination revealed 16 individual sporadic lesions in the gastric body, with maximum diameter 3 mm and localization in the lamina propria. Twenty-seven nodes were resected, and metastasis of the carcinoma was revealed in 24 nodes.

Conclusions

Undifferentiated intramucosal gastric cancer has a relatively high probability of lymph node metastasis; however, synchronous early lesions are often overlooked. Frequent follow-up examinations may increase the detection of multiple gastric cancers.

Relationship Between Early Postoperative Change in Total Psoas Muscle Area and Long-term Prognosis in Esophagectomy for Patients with Esophageal Cancer

PURPOSE

Postoperative sarcopenia following esophagectomy for esophageal cancer has become a severe problem due to the increasing number of elderly patients undergoing surgery. This study aimed to clarify the relationship between early postoperative skeletal muscle change and cancer prognosis, and propose effective interventions to prevent sarcopenia.

METHODS

This study retrospectively analyzed 152 patients who underwent esophagectomy for esophageal cancer. Total psoas muscle area (TPA) was measured before surgery as baseline and on postoperative day 7 (± 2). The effect of early postoperative skeletal muscle loss on 5-year survival was investigated. Moreover, 5-year survival in patients with postoperative complications and a high inflammatory status, which were previously reported as poor prognostic factors of esophageal cancer, was also investigated.

RESULTS

Among the 152 patients, 52 (34.2%) showed a decrease in TPA, while 100 (65.8%) maintained their TPA. The TPA decreasing group exhibited poor 5-year overall survival (OS) (p = 0.003) and 5-year recurrence-free survival (RFS) (p < 0.001). The TPA decreasing group also showed a poor 5-year OS in patients who developed severe postoperative complications (p = 0.015). Multivariate analyses showed that decreased TPA was found to be independently associated with OS (p = 0.017) as well as RFS (p = 0.002).

CONCLUSIONS

Our findings suggested a relationship between decreased TPA within 1 week after esophagectomy and long-term prognosis among patients with esophageal cancer. If TPA can be maintained, the prognosis was better even in cases with serious complications.

Prognostic Significance of the Number and Extent of Metastatic Lymph Nodes in Patients with Esophageal Cancer: Comparison of the Union for International Cancer Control 8th Edition and Japan Esophageal Society Japanese Classification of Esophageal Cancer 11th Edition Classifications for Esophageal Cancer

BACKGROUND

The tumor, node, metastasis staging system of the Union for International Cancer Control (UICC) has been used worldwide for esophageal cancer, and, in Japan, the Japan Esophageal Society Japanese Classification of Esophageal Cancer (JES) has also been used; however, there is a big difference between the two classifications with regard to node staging. We hypothesized that these two node staging systems may lead to different outcome predictions in terms of tumor location.

METHODS

This study enrolled 409 patients who underwent esophagectomy at Keio University Hospital, Tokyo, Japan, between January 2005 and December 2017. We included those who underwent R0 or R1 resection or esophagectomy with additional organ excision, and excluded those who underwent salvage surgery. Thereafter, we investigated how the number or spread of metastatic lymph nodes affected the prognosis.

RESULTS

For all 409 patients, the 5-year overall survival rate was 64.1% and the 5-year recurrence-free survival rate was 58.4%. The concordance indices were 0.756 for UICC 8th edition pathological node staging and 0.732 for JES 11th edition pathological node staging (p = 0.06). Based on tumor location, the difference in the concordance indices between these two classifications was greatest for lower thoracic esophageal tumors (p = 0.02).

CONCLUSIONS

For all patients, the UICC 8th edition node staging system tended to reflect survival more precisely than that of the JES 11th edition. For lower thoracic esophageal tumors in particular, the former node staging system could be more useful.

Usefulness of Neutrophil to Lymphocyte Ratio at Recurrence for Predicting Long-Term Outcomes in Patients with Recurrent Esophageal Squamous Cell Carcinoma

BACKGROUND

Although radical esophagectomy with multifield lymph node dissection is a promising treatment to achieve long-term survival for resectable esophageal cancer, survival after postoperative recurrence remains poor. To select the optimal treatment for patients with recurrent esophageal cancer, simple, objective indicators for predicting of long-term outcomes are needed.

PATIENTS AND METHODS

We conducted a single-institution, retrospective cohort study between 2004 and 2019, wherein 586 patients underwent transthoracic esophagectomy for primary esophageal squamous cell carcinoma. Of these, 133 patients with postoperative recurrence were included in this analysis. Several predictors of survival after recurrence were investigated.

RESULTS

Among all patients, the 1- and 3-year survival rates after recurrence were 48.0% and 23.1%, respectively. On multivariate analysis, the neutrophil to lymphocyte ratio (NLR) at recurrence was identified as a significant predictor of death after recurrence (hazard ratio 1.061; 95% confidence interval 1.002-1.125; p = 0.043). Time-dependent receiver operating characteristics curves showed that the area under the curve value of the NLR at recurrence was superior to the modified Glasgow Prognostic Score at recurrence in all terms. To simulate the clinical decision process, we set the cut-off NLR at recurrence for survival using survival classification and regression tree (CART) and defined the optimal cut-off value as 3.374.

CONCLUSIONS

NLR at recurrence was a significant indicator of survival after recurrence in patients with recurrent esophageal cancer. CART analysis was used to determine the optimal cut-off value for the prediction of survival, allowing the NLR to be used clinically to facilitate decision making.

Essential updates 2019/2020: Perioperative and surgical management of gastric cancer

Perioperative and surgical management of gastric cancer have been changing as pivotal phase II trials and landmark phase III trials offer new insights to the existing knowledge. The results of many landmark trials have been published or presented in the past year, many of which have changed or will change current clinical practice. For example, FLOT4 has completely changed the regimen of perioperative chemotherapy in Europe. Furthermore, evidence for minimally invasive surgery for clinical Stage I was firmly established by KLASS-01 and JCOG0912 for distal gastrectomy and CLASS-02, KLASS-03, and JCOG1401 for total gastrectomy. Moreover, promising results were provided by CLASS-01 and KLASS-02 for locally advanced gastric cancer. For adjuvant chemotherapy, JACCRO GC-07 (START-2) has provided a new doublet regimen for pathological Stage III, which is often refractory to chemotherapy. Conversely, JCOG0501 poses a significant challenge for advanced tumors, such as large type 3 and scirrhous (type 4) tumors. In this review, we briefly review recent updates and discuss future perspectives of gastric cancer treatment.

IL-8/CXCR2 Signalling Promotes Cell Proliferation in Oesophageal Squamous Cell Carcinoma and Correlates With Poor Prognosis

BACKGROUND/AIM

The inflammatory cytokine IL-8 and its receptor CXCR2 are key signalling pathway molecules in cancer development. We hypothesized that IL-8/CXCR2 signalling promotes tumour progression in oesophageal squamous cell carcinoma (ESCC) patients.

MATERIALS AND METHODS

We examined the relationship between IL-8/CXCR2 expression and clinicopathological factors by immunohistochemistry in samples from 63 patients with resectable ESCC. The effects of IL-8/CXCR2 signalling on cell proliferation and gene expression were examined in vitro and in vivo using ESCC cell lines.

RESULTS

Increased IL-8/CXCR2 signalling was associated with shorter overall survival (p<0.05) and recurrence-free survival (p<0.05) in ESCC patients. Multivariate analysis identified IL-8/CXCR2 expression as a prognostic factor for surgically treated ESCC (p<0.05). In vitro, IL-8 exposure or over-expression significantly enhanced ESCC cell proliferation. SB225002, a CXCR2-specific antagonist, and IL-8 siRNA significantly suppressed cell proliferation.

CONCLUSION

IL-8/CXCR2 expression is an independent prognostic factor for surgically treated ESCC, and IL-8/CXCR2 signalling contributes to ESCC cell proliferation.

Validation Study of Fibrinogen and Albumin Score in Esophageal Cancer Patients Who Underwent Esophagectomy: Multicenter Prospective Cohort Study

PURPOSE

To arrange multidisciplinary treatment for esophageal cancer, a simple and accurate predictive marker for prognosis is required. The current multicenter prospective study aims to validate the prognostic significance of fibrinogen and albumin score (FA score) for esophageal cancer patients.

PATIENTS AND METHODS

Patients who were planned to undergo surgical resection for esophageal cancer at four participating institutions were enrolled in this study. Patient background, clinicopathological factors, and blood concentration of plasma fibrinogen and albumin were collected. Patients with elevated fibrinogen and decreased albumin levels were allocated a score of 2; those with only one of these abnormalities were allocated a score of 1; and those with neither of these abnormalities were allocated a score of 0. Recurrence-free survival (RFS) and overall survival (OS) were evaluated as a primary endpoint.

RESULTS

From four participating institutions, 133 patients were registered for the current analysis. The distribution of FA score of 0/1/2 was 84 (63%)/34 (26%)/15 (11%), respectively. In the analysis of primary endpoint, the preoperative FA score significantly classified RFS (FA score 1/2: HR 2.546, p = 0.013/6.989, p < 0.001) and OS (FA score 1/2: HR 2.756, p = 0.010/6.970, p < 0.001). We further evaluated the prognostic significance of FA score under stratification by pStage. As a result, with increasing FA score, RFS and OS were significantly worse in both pStage 0-I and II-IV groups.

CONCLUSIONS

The prognostic impact of preoperative FA score was confirmed for esophageal cancer patients in the current multicenter prospective trial. FA score can be considered to predict postoperative survival and rearrange the treatment strategy before esophagectomy.

Successful minimally invasive two-stage operation for rare synchronous cancers of the esophagus and the pancreatic head: A case report

We report the case of a 70-year-old woman with synchronous advanced esophageal cancer and pancreatic head cancer. To reduce the surgical invasiveness, we performed a two-stage operation that included percutaneous endoscopic gastrostomy and minimally invasive esophagectomy. In the first stage, we performed a percutaneous endoscopic gastrostomy, a thoracoscopic esophagectomy with cervical and mediastinal lymph node dissection, and an esophagostomy without a laparotomy. The second stage, which was performed 28 days after the first operation, consisted of a total gastrectomy, pancreaticoduodenectomy, colonic reconstruction, and jejunostomy. Fifty days after the second operation, the patient was discharged from the hospital. A two-stage operation that includes minimally invasive esophagectomy seems to be useful for avoiding serious postoperative complications, even in patients with rare, synchronous advanced cancers of the esophagus and the pancreatic head.

Clinical significance of preoperative serum concentrations of interleukin-6 as a prognostic marker in patients with esophageal cancer

BACKGROUND

Although the clinical outcome of esophageal cancer has recently improved, the relapse rate remains high for all disease stages. At present, there is no diagnostic method to predict the long-term outcome for esophageal cancer. In this study, we evaluated serum preoperative proinflammatory cytokine levels and investigated the correlation between preoperative interleukin-6 (IL-6) and IL-8 levels and survival of patients with esophageal cancer.

METHODS

Between 2008 and 2015, we evaluated preoperative serum cytokine levels in 122 patients who underwent esophagectomy for esophageal cancer. Serum IL-6 and IL-8 levels were measured by enzyme-linked immunosorbent assays. We investigated the relationship between serum cytokine levels and the response to chemotherapy and survival.

RESULTS

The preoperative IL-6 levels were significantly associated with shorter recurrence-free survival (RFS, p = 0.001) and overall survival (OS, p = 0.001) after esophagectomy. Higher IL-8 levels were significantly associated with RFS (p = 0.018). In the multivariate analysis, age, preoperative chemotherapy, lymph node metastasis, serum C-reactive protein (CRP) levels and serum IL-6 levels (hazard ratio (HR), 2.888; p = 0.049) were significantly independent prognostic factors of RFS. Additionally, age, pathological stage, and serum IL-6 levels (HR, 3.247; p = 0.027) were shown to be significantly independent prognostic factors of OS. Serum IL-6 levels were significantly higher in the non-responder group (pathological response pGrade0 and pGrade1) after neoadjuvant therapy.

CONCLUSIONS

High preoperative serum IL-6 levels are associated with a poor response to chemotherapy or chemoradiotherapy and poor prognosis after esophagectomy. Preoperative serum IL-6 levels may be a useful independent prognostic marker for esophageal cancer patients.

Laparoscopic and endoscopic cooperative surgery for gastric cancer mimicking a submucosal tumor

Abstract

Background

Gastric cancer that mimics a submucosal tumor (SMT) is infrequently encountered in routine clinical settings, and histopathological analysis is often negative for malignant cells. In such cases, excisional biopsy of the entire tumor may be necessary to make a definitive pathological diagnosis, and laparoscopic and endoscopic cooperative surgery (LECS) is a viable method of excisional biopsy.

Case presentation

An 80-year-old male patient diagnosed with stomach wall irregularities at routine medical check-up was referred to our facility, and consequent endoscopic examination detected a 20-mm protruded lesion in the greater curvature at the middle third of the stomach. Endoscopic ultrasound (EUS) showed a thick, low echoic lesion with an irregular margin in the second layer of the gastric wall. Further, a nodular part of the lesion had infiltrated into the submucosa, with an appearance similar to that of linitis plastica of the stomach. The lesion was highly suspected to be a gastric carcinoma with submucosal invasion. However, mucosal-incision-assisted biopsy revealed no malignant cells. Computed tomography (CT) identified no metastatic lymph nodes. Therefore, an excisional biopsy using LECS was performed, and to avoid peritoneal dissemination, we used a modified version, namely, combination of laparoscopic and endoscopic approaches to neoplasia with non-exposure technique (CLEAN-NET). The procedure ended without any complications, and post-operative course was uneventful. As histopathology returned a diagnosis of adenocarcinoma pT4a, we performed radical gastrectomy and D2 lymphadenectomy. Post-operative course was unremarkable and the patient underwent follow-up examinations without adjuvant chemotherapy because of old age.

Conclusions

Local resection using LECS for gastric tumors with a high suspicion of malignancy is useful and feasible. LECS could be used in similar cases.

Utility of the one-step nucleic acid amplification assay in sentinel node mapping for early gastric cancer patients

BACKGROUND

To safely perform minimized gastrectomy based on sentinel node (SN) concept for early gastric cancer patients, intraoperative diagnostic accuracy is indispensable. This study aimed to evaluate the clinical utility of the one-step nucleic acid amplification (OSNA) assay in the intraoperative diagnosis of SN metastasis in early gastric cancer patients compared with that of histopathological examination.

METHODS

We conducted a prospective study using the OSNA assay for 43 patients with cT1N0M0 gastric cancer undergoing gastrectomy with SN mapping. All the SNs and selected non-SNs were examined by routine histopathological diagnosis, and the OSNA assay.

RESULTS

We performed permanent histopathology (PH) in 1732 lymph nodes (LNs) (286 SNs and 1446 non-SNs) obtained from 43 patients. We also evaluated 439 LNs (286 SNs and 153 non-SNs) with the OSNA assay in addition to PH. Intraoperative histopathology (IH) was performed in 214 LNs (213 SNs and 1 non-SN). PH revealed LN metastasis in 6 patients (14%), all of whom showed positive SNs by PH. The diagnostic accuracy to predict the LN status based on the SN concept by histological examination was 100%. The concordance rate between the OSNA assay and the PH and IH were 0.970 and 0.981 respectively. Discordant results between PH and OSNA assay were observed in 13 LNs. The sensitivity and specificity of the OSNA assay compared with those of PH were 0.636, and 0.988, and compared with those of IH were 0.800, and 0.995.

CONCLUSION

Our results suggest that the OSNA assay is a useful and convenient tool for the intraoperative detection of SN metastasis in early gastric cancer patients.

Role of FOXO3A in Trastuzumab Combination Chemotherapy in Esophageal Squamous Cell Carcinoma

BACKGROUND/AIM

Targeting of the human epidermal growth factor receptor 2 (HER2) is suggested to be beneficial for esophageal squamous cell carcinoma (ESCC) patients with HER2 amplification. In this study, we evaluated the effects of combination chemotherapy with HER2-targeted drug trastuzumab in ESCC cells and examined the underlying mechanism contributing to these effects.

MATERIALS AND METHODS

HER2 expression was verified, and the efficacy of chemotherapy with and without trastuzumab was investigated in vitro and in vivo.

RESULTS

The combination of trastuzumab and a combined-modality therapy stimulated the PI3K/Akt pathway in ESCC cells overexpressing HER2. Trastuzumab treatment resulted in the intranuclear accumulation of FOXO3A in ESCC xenografts overexpressing HER2. The combination of trastuzumab and a combined-modality therapy enhanced antitumor effects in HER2-overexpressing ESCC xenografts.

CONCLUSION

FOXO3A plays an important role in mediating the effects of trastuzumab, and combination chemotherapy may be a promising treatment for patients with HER2-overexpressing ESCC.

An experimental setup for creating and imaging 4He2 * excimer cluster tracers in superfluid helium-4 via neutron-3He absorption reaction

For the purpose of future visualization of the flow field in superfluid helium-4, clusters of the triplet state excimer ⁴He₂ ^* are generated along the micro-scale recoil tracks of the neutron-absorption reaction n + ³He → ³T + p. This reaction is induced by neutron irradiation of the ³He fraction contained in natural isotopic abundance liquid helium with neutron beams either from the Japan Proton Accelerator Research Complex, Materials and Life Science Experimental Facility (JPARC)/Materials and Life Science Experimental Facility or from the Kyoto University Institute for Integrated Radiation and Nuclear Science. These ⁴He₂ ^* clusters are expected to be ideal tracers of the normal-fluid component in superfluid helium with several advantageous properties. Evidence of the excimer generation is inferred by detection of laser induced fluorescence emitted from the ⁴He₂ ^* clusters excited by a purpose-built short pulse gain-switched titanium:sapphire (Ti:sa) laser operating at a wavelength of 905 nm. The setup and performance characteristics of the laser system including the Ti:sa and two continuous wave re-pumping lasers are described. Detection at the fluorescence wavelength of 640 nm is performed by using optical bandpass filtered photomultiplier tubes (PMT). Electrical noise in the PMT acquisition traces could successfully be suppressed by post-processing with a simple algorithm. Despite other laser-related backgrounds, the excimer was clearly identified by its fluorescence decay characteristics. Production of the excimer was found to be proportional to the neutron flux, adjusted via insertion of different collimators into the neutron beam. These observations suggest that the apparatus we constructed does function in the expected manner and, therefore, has the potential for groundbreaking turbulence research with superfluid helium.

Minimally invasive oesophagectomy with extended lymph node dissection and thoracic duct resection for early-stage oesophageal squamous cell carcinoma

BACKGROUND

Oesophageal squamous cell carcinoma is an aggressive disease owing to early and widespread lymph node metastases. Multimodal therapy and radical surgery may improve prognosis. Few studies have investigated the efficacy of radical lymph node and thoracic duct resection.

METHODS

Patients with oesophageal squamous cell carcinoma who underwent transthoracic minimally invasive oesophagectomy (TMIE) for cancer at Keio University Hospital between January 2004 and December 2016 were selected. Between 2004 and 2008, TMIE was performed in the lateral decubitus position without thoracic duct resection (standard TMIE). From 2009 onwards, TMIE with extended lymph node and thoracic duct resection was introduced (extended TMIE). Demographics, co-morbidity, number of retrieved lymph nodes, pathology, postoperative complications and recurrence-free survival (RFS) were compared between groups.

RESULTS

Forty-four patients underwent standard TMIE and 191 extended TMIE. There were no significant differences in clinical and pathological tumour stage or postoperative complications. The extended-TMIE group had more lymph nodes removed at nodal stations 106recL and 112. Among patients with cT1 N0 disease, RFS was better in the extended-TMIE group (P < 0·001), whereas there was no difference in RFS between groups in patients with advanced disease.

CONCLUSION

Extended TMIE including thoracic duct resection increased the number of lymph nodes retrieved and was associated with improved survival in patients with cT1 N0 oesophageal squamous cell carcinoma.

Relationship between perioperative change of total psoas muscle area and cancer prognosis in esophageal carcinoma

314

Background: As surgery for esophageal carcinoma in the elderly people has been increasing, sarcopenia is a severe problem not only in complications, but also in long-term prognosis. However, the relationship between perioperative skeletal muscle loss especially in the early postoperative period and long-term prognosis has not been clarified. Methods: This study retrospectively analyzed 152 patients with thoracic esophageal carcinoma who had underwent radical esophagectomy in our institution from April 2008 to March 2015 (Patients with postoperative hospital stay longer than 6 weeks were excluded). As an index of perioperative sarcopenia, total psoas muscle area (TPA) was measured before surgery (as baseline), at postoperative day (POD) 7 and postoperative month (POM) 6 from CT images. We investigated the correlation between the change of TPA and the postoperative survival. Results: Of 152 patients, 52 (34.2%) showed a TPA decrease from baseline to POD 7, and 98 (64.5%) showed a TPA decrease from baseline to POM 6. At the time of POD 7, overall survival (OS) decreased significantly in a TPA decrease group (P = 0.008, 5-year survival rate: non-decrease group 82.3% / decrease group 56.8%). Recurrence free survival (RFS) was also significantly decreased in a TPA decrease group (P < 0.001, 5-year recurrence free survival rate: non-decrease group 73.7% / decrease group 44.9%). On the other hand, at the time of POM 6, OS and also RFS had no significant difference between decrease and non-decrease groups. In univariate analysis for OS, pStage ≥3 and TPA decrease at POD 7 had poor prognosis. In multivariate analysis for OS, pStage ≥3 (HR:5.516, P < 0.001, 95%CI:2.634-11.551) and TPA decrease at POD 7 (HR:2.036, P = 0.047, 95%CI:1.010-4.103) were also independent poor prognostic factors. In the univariate analysis for RFS, pStage ≥3, TPA decrease at POD 7 and age ≥60 years had poor prognosis. In multivariate analysis, pStaeg ≥3 (HR:3.831, P < 0.001, 95%CI:2.182-6.728) and TPA decrease at POD 7 (HR:1.942, P = 0.021, 95%CI:1.104-3.416) were independent poor prognostic factors. Conclusions: Our findings suggest that the TPA decrease early in a postoperative period has poor prognosis on OS and also RFS.

Prediction of lymph node metastasis in early gastric cancer using artificial intelligence technology

289

Background: Early gastric cancer shows lymph node involvement in about 10-15% of patients. Despite the fact, we perform radical lymphadenectomy for all patients because predicting lymph node metastasis has yet to be successful. In this study, we hypothesize that image analysis using artificial intelligence (AI) technology may help solve the problem. Methods: We retrospectively collected 82 patients with clinical T1N0 and pathological node negative and 82 patients with clinical T1N0 and pathological node positives and then divided the 164 patients into a training:validation set in ratio of 9:1. Endoscopic images of the early tumors were analyzed by transfer learning using AlexNet, a deep neural network containing 5 convolutional layers and 3 fully-connected layers. The model was validated with newly-collected 40 images from 20 clinical T1N0 and pathological node negative and 20 patients with clinical T1N0 and pathological node positives as a test set. For comparison, three methods of prediction were implemented: prediction at random, by logistic regression, and by skilled endoscopists. Results: The AI predicted LNM with accuracy of 80.9% in the validation set and 66.9% in the test set. (48.3% for node negative cancers and 85.4% for node positive cancers) On the other hand, prediction at random, by logistic regression, and by 2 endoscopists resulted in 50.3%, 50.0%, and 47.5%, respectively. Conclusions: Although the accuracy still needs to be improved, image analysis using the AI technology resulted in the best prediction of lymph node metastasis, indicating that AI is a promising technology for the diagnosis of lymph node metastasis in early gastric cancer.

Determination of the optimal surgical procedure by identifying risk factors for pneumonia after transthoracic esophagectomy

BACKGROUND

Esophagectomy is associated with a high risk of postoperative complications, and the respiratory complications are the most common. Therefore, stratification of patients based on preoperative risk factors is essential. This study aimed to identify the risk of postoperative pneumonia (POP) based on the preoperative factors and determine the optimal perioperative surgical management strategy.

METHODS

This retrospective study involved 207 patients who underwent esophagectomy. The patients were divided into two groups, namely, with POP and without POP. To identify the risk factors for POP, the pre- and perioperative characteristics were analyzed. A receiver operating characteristics curve was used to determine a cutoff value of 2.40 L for the forced expiratory volume in 1 s (FEV1.0) and the cohort was divided into a high- and low-FEV1.0 group. A second analysis was then performed to determine the optimal surgical management for patients at a high risk for POP.

RESULTS

POP occurred in 45 (21.7%) patients. A multiple logistic regression analysis showed that FEV1.0 was significantly lower in the POP (+) group (P = 0.020); thus, a low FEV1.0 was found to be a risk factor for POP. Multiple logistic regression analysis showed that open thoracotomy was a significant risk factor for POP in low FEV1.0 patients (P = 0.013).

CONCLUSIONS

A low FEV1.0 and an open thoracotomy are risk factors for POP. Therefore, patients with low FEV1.0 should be managed carefully and video-assisted thoracic surgery should be considered.

Clinical outcomes of non-exposed endoscopic wall-inversion surgery for gastric submucosal tumors: long-term follow-up and functional results

BACKGROUND AND AIMS

To avoid the risk of iatrogenic dissemination during procedures, we have developed a combined laparoscopic and endoscopic surgery with a nonexposure technique for resection of gastric tumors. The study aim was to evaluate the feasibility and safety of non-exposed endoscopic wall-inversion surgery (NEWS) for gastric submucosal tumors (SMTs).

METHODS

Between August 2013 and February 2018, NEWS was performed for 42 patients with gastric SMTs ≤ 3 cm in diameter at our institution. We retrospectively investigated the patients' backgrounds, operative and perioperative outcomes, tumor pathological characteristics, and follow-up data.

RESULTS

All tumors were resected with negative margins by NEWS. The median operation time was 198 min, and the median estimated blood loss was 5.0 mL. Adverse events occurred in one patient with pneumonia. All patients were alive without recurrence within the median follow-up period of 29.2 months. The average body weight loss rate was 0.3 ± 4.0%. No food residue was observed at endoscopic follow-up.

CONCLUSIONS

On the basis of slight body weight loss and the absence of food residue observed in the postoperative endoscopy, NEWS appeared to be safe and feasible for gastric SMTs and to preserve function of the remnant stomach.

Current status of endoscopic surgery in Japan: The 14th National Survey of Endoscopic Surgery by the Japan Society for Endoscopic Surgery

In Japan, the first endoscopic surgery, a laparoscopic cholecystectomy, was performed in 1990. Since then, operative procedures have been standardized, and the safety and efficacy of endoscopic surgery have been evaluated. In accordance with the social acceptance of endoscopic surgery as a less invasive type of surgery, the number of endoscopic procedures performed has increased in all surgical domains. The Japan Society for Endoscopic Surgery (JSES) has played an important role in the development of endoscopic surgery in Japan. Notably, a technical skills certification system for surgeons was established by the JSES to train instructors on how to teach safe endoscopic surgery. Furthermore, the JSES has conducted a national survey every two years to evaluate the status of endoscopic surgery over time. In 2017, 248 743 patients underwent endoscopic surgery in all surgical domains, such as abdominal, thoracic, mammary and thyroid gland, cardiovascular, obstetrics and gynecology, urologic, orthopedic, and plastic surgery. The 14th National Survey of Endoscopic Surgery conducted by the JSES demonstrated the status of laparoscopic surgery in Japan in 2016-2017.

THUMP domain containing 2 protein possibly induces resistance to cisplatin and 5-fluorouracil in in vitro human esophageal squamous cell carcinoma cells as revealed by transposon activation mutagenesis

BACKGROUND

Although chemotherapy is a core treatment for esophageal cancer, some patients develop drug resistance. Gene screening with transposons (i.e. mobile genetic elements) is a novel procedure for identifying chemotherapy-resistant genes. Transposon insertion can randomly affect nearby gene expression. By identifying the affected genes, candidate genes can be found. The present study aimed to identify cisplatin (CDDP)/5-fluorouracil (5-FU)-resistant genes in in vitro human esophageal squamous cell carcinoma with transposons.

METHODS

After establishing transposon-tagged cells, we obtained CDDP/5-FU-resistant colonies. A polymerase chain reaction and sequencing were used to identify the transposon inserted site and candidate CDDP/5-FU resistant genes. Focusing on one candidate gene, we confirmed CDDP/5-FU resistance by comparing the IC₅₀ between drug-resistant and wild-type cells. Furthermore, we investigated gene expression by a real-time polymerase chain reaction. Finally, we mediated the candidate gene level with small interfering RNA to confirm the resistance.

RESULTS

Thirty-nine candidate genes for CDDP/5-FU resistance were identified. Nineteen were for CDDP resistance and 27 were for 5-FU resistance. Seven genes, THUMP domain-containing protein 2 (THUMPD2), nuclear factor interleukin-3-regulated protein (NFIL3), tyrosine-protein kinase transmembrane receptor 2 (ROR2), C-X-C chemokine receptor type 4 (CXCR4), thrombospondin type-1 domain-containing protein 2 (THSD7B) alpha-parvin (PARVA) and TEA domain transcription factor 1 (TEAD1), were detected as candidate genes in both colonies. Regarding THUMPD2, its expression was downregulated and knocking down THUMPD2 suggested drug resistance in both drugs.

CONCLUSIONS

Thirty-nine candidate genes were identified with transposons. The downregulation of THUMPD2 was suggested to play a role in multidrug resistance in in vitro esophageal squamous cell carcinoma.

P732Maternal high-fat diet promotes the expansion of abdominal aortic aneurysm in adult offspring by enhancing osteoclast-like macrophage differentiation

Background and objective

Maternal high-fat diet (HFD) has been shown to modulate vascular function and remodeling in adult offspring. Here, we investigated the impact of maternal HFD on abdominal aortic aneurysm (AAA) formation.

Methods and results

Eight-week-old female wild-type mice (C57BL/6) were fed a HFD or normal diet (ND) one week prior to mating and received during pregnancy and lactation. In eight-week-old offspring of both genders, AAA was induced with the application of 0.5M calcium chloride (CaCl2) on the infrarenal aorta. Male offspring of HFD-fed dams (O-HFD) showed a significant increase in maximum outer diameter of AAA at 1, 4 and 8 weeks after surgery compared with offspring of ND-fed dams (O-ND) (P<0.05). The lengths of outer circumference assessed by histological analysis were increased in O-HFD (P<0.05). Likewise, female O-HFD showed a greater length of outer circumference than female O-ND (P<0.05). While the number of F4/80-positive cells at 1 wk after surgery was comparable between the male O-HFD and O-ND, the percentage of MMP-9/F4/80 double-positive cells was significantly increased in male O-HFD. Consistently, fluorescent image of abdominal aorta taken by IVIS at 1 wk after surgery revealed a 2-fold increase in MMP activity (P<0.01). Intriguingly, F4/80-positive cells in male O-HFD showed a 2.5-fold increase in co-staining with tartrate-resistant acid phosphate (TRAP), typical marker of osteoclast-like macrophages which abundantly secrete proteases than classically activated macrophages (M1), while the percentage of TNF-α/F4/80 double-positive cells was comparable between the 2 groups. Pharmacological inhibition of osteoclastogenesis by zoledronic acid (ZA) (100μg/kg) completely abolished the exaggerated AAA development in male O-HFD to a similar extent of that in male O-ND, while AAA development in male O-ND mice did not change even after ZA treatment. Furthermore, in vitro TNF-α-induced osteoclast differentiation of bone marrow-derived macrophages (BMDMs) showed a significantly higher number of TRAP-positive cells, accompanied by increased calcitonin receptor mRNA expression. Western blotting analysis showed that protein expression level of NFATc1, master regulator of osteoclastogenesis, was significantly higher in BMDM of O-HFD than O-ND.

Conclusion

Our findings demonstrate that maternal HFD accelerates CaCl2-induced AAA expansion, accompanied by the exaggerated accumulation of osteoclast-like macrophages and augmented activity of MMPs. Inhibition of macrophages skewing toward osteoclast-like cells could be a potential therapeutic target for preventing AAA development.

Thyroid and Parathyroid Functions After Pharyngo-Laryngo-Esophagectomy for Cervical Esophageal Cancer

BACKGROUND

Cervical esophageal cancer (CEC) patients whose larynx function cannot be preserved often undergo chemoradiotherapy, whereas those with residual or recurrent lesions undergo a pharyngo-laryngo-esophagectomy (PLE); however, some need to undergo a pharyngolaryngectomy with total esophagectomy (PLTE) for synchronous or metachronous esophageal cancer. We retrospectively evaluated the relationship between preoperative irradiation (or the extent of esophageal resection) and postoperative endocrine complications in CEC, including hypothyroidism and hypoparathyroidism.

METHODS

The cancers of 35 (5.4%) of 678 esophageal cancer patients with esophagectomy treated in 2000-2017 were CECs. We also analyzed the 17 cases of CEC patients who underwent PLE with thyroid lobectomy-11 with irradiation before PLE and 6 without irradiation. Seven patients underwent a PLTE.

RESULTS

Hypothyroidism and hypoparathyroidism occurred in 14 and 12 patients, respectively. The hypothyroidism rate was significantly higher in patients with irradiation versus those without irradiation (100% vs. 50%; p = 0.010), and the hypoparathyroidism rate was significantly higher in the PLTE versus non-PLTE patients (100% vs. 50%; p = 0.026). The mean levothyroxine dosage was 1.60 μg/kg/day in the PLE patients post-irradiation.

CONCLUSIONS

Irradiation appears to be a risk factor for hypothyroidism after PLE with thyroid lobectomy, while PLTE might have some effect on hypoparathyroidism. Due to vocal function loss, PLE patients may experience symptoms from endocrine complications. Levothyroxine treatment soon after PLE for post-irradiation patients and patients requiring as-needed calcium or vitamin D supplementation based on biochemical hypocalcemia for PLE (especially PLTE), may be effective in preventing symptomatic endocrine complications.

P740Repeated social defeat exaggerates fibrin-rich clot formation in FeCl3-induced arterial thrombosis mice model by enhancing NETs formation

Background and objective

Depression is an independent risk factor of cardiovascular disease (CVD). We have recently shown that repeated social defeat (RSD) precipitates depressive-like behaviorsin apoE−/− mice and exaggerates atherosclerosis development by enhancing neutrophil extracellular traps (NETs) formation (BBRC 2018; 500:490). Here, we investigated the impact of RSD on arterial thrombosis.

Methods and results

Eight-week-old male WT mice were exposed to RSDby housing with a larger CD-1 mouse in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days. Control mice were housed in the same gage without physical contact. After social interaction testto confirm depressive-like behaviors, defeated mice (19 of 31) and control mice (12 of 14) were underwent arterial injury at 10 wks of age. A filter paper saturated with 10% FeCl3was applied on the adventitial surface of left carotid artery for 3 min and analyzed 3 hrs later. The volume of thrombi calculated by summing8–15 frozen cross-sectional images, each separated by 200 μm, was comparable between the 2 groups. However, fibrinogen/fibrin-positive areas in immunofluorescent images were significantly increased in defeated mice (27.8% vs. 48.8%, Control vs. Defeat, P<0.01).The numberof Ly-6G-positive cells in thrombi was markedly higher in defeated mice (144/mm2 vs. 878/mm2, Control vs. Defeat, P<0.05). Further, Ly-6G-positive cells were almost accumulated at the inner surface of injured artery, which were co-localized with neutrophil elastase, Cit-H3, and CD41-positive staining. Treatment with DNase Icompletely diminished the exaggerated fibrin-rich clot formation in defeated miceto a similar extent of control mice (25.7% vs. 22.3%, Control vs. Defeat, P= NS), while the volume of thrombi and number of Ly-6G-positive cells in thrombi were comparable between the 2 groups even afterDNase I treatment. Platelet aggregations induced by ADP or collagen were comparable between the 2 groups, suggesting that NETs formation primarily contributes to the exaggerated fibrin-rich clot formation in defeated mice.

Conclusions

Our findings demonstrate for the first time that repeated social defeat enhances fibrin-rich clot formation after arterial injury by enhancing NETs formation, suggesting that NETosis could be a new therapeutic target in depression-related CVD development.

5220Maternal high-fat diet exaggerates the development of diet-induced insulin resistance in adult offspring by enhancing pyroptosis through augmented gasdermin D-mediated pore formation

Background

Maternal high-fat diet (HFD) has been shown to promote the development of insulin resistance (IR) in adult offspring; however, the underlying mechanisms remain unclear.

Approach and results

Eight-week-old female wild-type mice (C57BL/6) were fed a HFD or normal diet (ND) one week prior to mating, and received during pregnancy and lactation. Eight-week-old male offspring of both groups were fed a HFD for 8 weeks. Offspring of HFD-fed dams (O-HFD) showed significantly enhanced IR compared with offspring of ND-fed dams (O-ND). There was no difference in body weight, epidydimal white adipose tissue (eWAT) weight, and cumulative caloric intake between the 2 groups. However, eWAT adipocyte size was significantly increased in O-HFD, accompanied by the abundant crown-like structures. Flow cytometric analysis revealed an increased percentage of M1, but not M2, macrophages. Serum and eWAT concentrations of IL-1β, but not TNF-α, were significantly higher in O-HFD than O-ND (3.7-fold and 2.0-fold, respectively, P<0.05). Treatment with NLRP3 inflammasome inhibitor MCC950 completely abrogated the enhanced IR in O-HFD to a similar extent of that in O-ND, although IR was modestly, but not significantly, ameliorated in O-ND even after MCC950 treatment. Consistent with in vivo findings, in vitro polarization of bone marrow-derived macrophages (BMDMs) did not show any difference in TNF-α mRNA expression after conventional stimulation. In contrast, palmitate acid (PA)-mediated metabolic activation of BMDMs following LPS priming showed a significantly higher concentration of IL-1β in culture supernatants from O-HFD (45%, P<0.05). However, protein expression levels of NLRP-3, ASC, and procaspase-1 after LPS priming were equivalent between the 2 groups. Consistently, intracellular flow cytometric analysis of caspase-1 activity after PA activation did not show any difference, which was compatible with the finding that ex vivo caspase-1 activity of eWAT assessed by fluorescent image of IVIS revealed no difference between the 2 groups. To further examine the mechanism of augmented IL-1β release in BMDM of O-HFD, we examined the cleavage of caspase substrate gasdermin D (GSDMD) and subsequent pore formation. Protein and gene expression levels of GSDM-D after LPS priming were significantly higher in O-HFD (50% and 381%, respectively, P<0.05). At 2 hrs after PA stimulation following LPS priming, cleaved GSDM-D was significantly increased in O-HFD (80%, P<0.01). Consistently, percentage of pore formation assessed by ethidium bromide staining was significantly higher in O-HFD (60%, P<0.05), while LDH release could not be observed.

Conclusions

Our findings demonstrate that maternal HFD exaggerates diet-induced insulin resistance in adult offspring by enhancing pyroptosis through augmented GSDM-D-mediated pore formation.

A low surgical Apgar score is a predictor of anastomotic leakage after transthoracic esophagectomy, but not a prognostic factor

BACKGROUND

The surgical Apgar score (SAS) has been a useful predictor of postoperative complications in several types of cancer. However, there are few reports about the correlation of SAS and esophageal cancer. This study aimed to examine the utility of SAS as a predictor of major complications, particularly anastomotic leakage, in patients who underwent transthoracic esophagectomy, and investigate the correlation between SAS and patient prognosis.

METHODS

This is a single-center, retrospective observational study. A total of 190 patients who underwent esophagectomy for esophageal cancer in 2012-2016 were reviewed to find the correlation between SAS and postoperative complications (Clavien-Dindo classification III or higher). SAS was calculated based on intraoperative estimated blood loss, lowest mean arterial pressure, and lowest heart rate. Major complications included anastomotic leakage, respiratory, cardiac, recurrent nerve palsy, chylothorax, and other complications. We also reviewed how SAS was correlated with 3 year overall survival (OS) and recurrence-free survival (RFS). A high SAS was defined as ≥ 6, and a low SAS as < 6.

RESULTS

On univariate analysis, SAS showed a statistical significance in all major complications and anastomotic leakage. On multiple logistic regression analysis, a low SAS was detected as a risk factor of the major complications and anastomotic leakage, with a significant difference. Moreover, we conducted survival analysis with SAS; however, we could not detect that a low SAS had a negative impact on OS and RFS.

CONCLUSIONS

A low SAS can be a predictor of postoperative complications, especially anastomotic leakage. However, SAS was not correlated with OS or RFS.

The Benefits of Docetaxel Plus Cisplatin and 5-Fluorouracil Induction Therapy in Conversion to Curative Treatment for Locally Advanced Esophageal Squamous Cell Carcinoma

BACKGROUND

Definitive chemoradiotherapy (CRT), used for treatment of patients with an initial diagnosis of unresectable locally advanced esophageal cancer, has led to unsatisfactory long-term prognosis. Moreover, CRT can lead to esophageal fistula, perforation, and strictures. Therefore, strong induction chemotherapeutic treatments are necessary to reduce the tumor volume for subsequent radical esophagectomy. This study aimed to determine the oncological utility of docetaxel plus cisplatin and 5-fluorouracil (DCF) and the technical feasibility of subsequent esophagectomy for locally advanced esophageal cancer.

METHODS

Eighty-seven patients with clinical borderline unresectable T3 and T4 esophageal squamous cell carcinoma without distant metastases were included in this study. There were 44 patients in primary DCF group and 43 patients in definitive CRT group, and perioperative and long-term oncological outcomes were compared between the two groups.

RESULTS

Twenty-two patients (50%) achieved R0 resection in the DCF group. Albeit not significant, the rate of curative treatment was higher in the DCF group than the definitive CRT group (p = 0.099). The overall survival (OS) and progression-free survival (PFS) were better with DCF than with definitive CRT (median OS, 29 vs. 17 months, p = 0.206; median PFS, 10 vs. 6 months, p = 0.020). Specifically, the OS of patients with a Charlson score of less than 3 among the DCF-treated patients tended to be better than those among the definitive CRT-treated patients.

CONCLUSION

DCF and subsequent esophagectomy achieved R0 resection in 50% of the patients and was associated with better long-term oncological outcomes in patients with initially unresectable esophageal cancer if their systemic status is acceptable.

Analysis of the Effect of Early Versus Conventional Nasogastric Tube Removal on Postoperative Complications After Transthoracic Esophagectomy: A Single-Center, Randomized Controlled Trial

BACKGROUND

Although esophagectomy is the only curative option for esophageal cancer, the associated invasiveness is high. Nasogastric (NG) tube use may prevent complications; however, its utility remains unclear, and the decompression period depends on the doctor. This study aimed to reveal the effect of conventional versus early NG tube removal on postoperative complications after esophagectomy.

METHODS

This single-center prospective randomized controlled clinical trial enrolled patients aged 20-80 years with histologically proven primary esophageal squamous cell carcinoma. Eighty patients admitted for transthoracic first-stage esophagectomy reconstructed with gastric conduit were randomly assigned (1:1) to the conventional and early NG tube removal groups. In the conventional NG tube removal group, the tube was removed on postoperative day (POD) 7; in the other, it was removed on POD 1. The occurrence rate of major complications, length of postoperative hospital stay, and NG tube reinsertion rate were compared between the groups.

RESULTS

The incidence of postoperative major complications such as pneumonia, anastomotic leakage, recurrent nerve palsy and gastrointestinal bleeding, and the NG tube reinsertion rate was not different between the groups. However, recurrent nerve palsy was more commonly observed in the conventional removal group; this difference was not significant. In terms of postoperative pneumonia, tumor location and field of lymph node dissection were significant risk factors.

CONCLUSION

Although early NG tube removal did not reduce the rate of postoperative pneumonia, it could be performed safely. Hence, the NG tube can be removed earlier than conventional methods.

Discrepancy Between the Clinical and Final Pathological Findings of Lymph Node Metastasis in Superficial Esophageal Cancer

BACKGROUND

Recent advances in endoscopic examinations have resulted in the detection of a larger number of early esophageal cancers; however, there have been many cases with clinically negative but pathologically positive lymph node metastasis (LNM). In this study, we aimed to evaluate the discrepancy between the clinical and pathological diagnoses of LNM in patients with cT1a-MM/cT1b N0M0 esophageal cancer, and assess LNM size in these patients to clarify the presence of LNM that cannot be detected with current modalities.

METHODS

This study included 50 patients who underwent surgery for cT1a-MM/cT1b N0M0 thoracic esophageal squamous cell carcinoma between January 2012 and November 2016 at our institution. The maximum size of involved LNs and metastatic nests were measured, and the distribution of LNM was investigated.

RESULTS

Of the 50 patients, 13 (26%) had LNM on pathological examination. Lymphatic invasion was significantly more frequent in the LNM-positive group than in the LNM-negative group (p = 0.005). The median sizes of 28 involved LNs and metastatic nests were 3 and 1.6 mm, respectively. Of these LNs, 20 (71%) were classified as micrometastases (≤ 2 mm). The involved nodes were distributed across three fields.

CONCLUSIONS

There was a discrepancy between the clinical and final pathological findings of LNM in patients with cT1a-MM/cT1b N0M0 esophageal cancer. The detection of involved nodes with current modalities in these patients was difficult because of the small size of LNM. Therefore, continued strong consideration for extended LN dissection is necessary in these patients to ensure appropriate diagnosis and treatment.

Comparison of olanexidine versus povidone-iodine for preventing surgical site infection in gastrointestinal surgery: study protocol for a multicentre, single-blind, randomised controlled clinical trial

INTRODUCTION

The prevalence of surgical site infection (SSI) remains higher in gastrointestinal surgery than in other surgeries. Although several guidelines have indicated the efficacy of chlorhexidine and povidone-iodine in reducing the SSI rate, the optimal recommendation has still not been established. Therefore, it is necessary to determine the more effective antiseptic for surgical site preparation. Olanexidine (1.5% olanedine, Otsuka Pharmaceutical Factory, Tokushima, Japan), which is a new antiseptic in Japan, has antimicrobial activity against a wide range of bacteria, including Gram-positive and Gram-negative bacteria. Our study will contribute to determining a new antiseptic for use in gastrointestinal and other surgeries.

METHODS AND ANALYSIS

We propose a multicentre, randomised controlled clinical trial for comparing two treatments, that is, 1.5% olanexidine or 10% povidone-iodine, for surgical skin preparation to prevent SSI in clean-contaminated gastrointestinal surgeries with surgical wounds. Patients aged ≥20 years at the time of consent will be included. The primary outcome measure is the 30-day postoperative SSI rate. For the primary analysis, which is aimed at comparing the treatment effects, the adjusted risk ratio and its 95% CI will be estimated using the Mantel-Haenszel method.

ETHICS AND DISSEMINATION

The protocol was first approved by the Institutional Review Board of Keio University School of Medicine, followed by the institutional review board of each participating site. Participant recruitment began in June 2018. The final results will be published in international peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

UMIN 000031560; Pre-results.

Perioperative risk calculator for distal gastrectomy predicts overall survival in patients with gastric cancer

BACKGROUND

Although some predictive factors of long-term survival after a distal gastrectomy for gastric cancer have been reported, only few studies have predicted long-term outcomes based on preoperative parameters. We aimed to evaluate the reliability of perioperative risk calculator for predicting overall survival (OS) after distal gastrectomy in patients with gastric cancer.

METHODS

Overall, 337 patients (225 males, 112 females) who had undergone a distal gastrectomy for gastric cancer at the Keio University Hospital, Tokyo, Japan, between January 2009 and December 2013 were enrolled in this study. We investigated the reliability of a risk calculator for the prediction of OS.

RESULTS

In multivariate analysis, the risk models for operative mortality and 30-day mortality were identified as predictors of death. Time-dependent receiver operating characteristics (ROC) curve analysis indicated that the estimated area under the curve (AUC) value of the risk model for operative mortality was > 0.870 during the first postoperative 3 years. We set optimal cutoff values of the risk model operative mortality for OS using the Cutoff Finder online tool. The cutoff values of 4.117% were significant risk factors of death. Similar results were observed in the external validation set.

CONCLUSIONS

We elucidated the associations among risk calculator values and OS rates of patients with gastric cancer. Time-dependent ROC curve analysis suggested that the AUC value of the risk model for operative mortality was high, indicating that this risk calculator would be useful for not only short-term outcomes, but also long-term outcomes.

Influence of Neoadjuvant Therapy on Poor Long-Term Outcomes of Postoperative Complications in Patients with Esophageal Squamous Cell Carcinoma: A Retrospective Cohort Study

BACKGROUND

Postoperative complications have a negative impact on overall survival after esophagectomy because systemic inflammation may induce residual cancer cell growth. A solution that could suppress micrometastasis is neoadjuvant therapy; however, to date, no study has shown that neoadjuvant therapy suppresses proliferation of cancer cells due to postoperative complications after esophagectomy. The aim of this study is to investigate the influence of neoadjuvant therapy on poor long-term outcomes of postoperative complications in patients with esophageal carcinoma.

PATIENTS AND METHODS

In total, 431 patients who underwent esophagectomy for esophageal squamous cell carcinoma were included in this study. We investigated the relationship between complications, such as pneumonia, and long-term oncologic outcomes with and without neoadjuvant therapy.

RESULTS

Among the patients, the 3-year overall survival (OS) rate was 69.5% and the disease-free survival (DFS) rate was 59.0%. The patients were categorized into two groups: the neoadjuvant therapy (+) group (n = 217) and neoadjuvant therapy (-) group (n = 214). Among patients not undergoing neoadjuvant therapy, patients with pneumonia or pyothorax had significantly poorer OS and DFS than patients without these complications. However, among patients undergoing neoadjuvant therapy, there were no significant differences in long-term outcomes, regardless of presence of complications. On multivariate analysis, pneumonia (p = 0.003), pyothorax (p < 0.001), and chylothorax (p = 0.002) were identified as predictors of death in the neoadjuvant therapy (-) group.

CONCLUSION

The negative impact of postoperative complications on long-term prognoses can be reduced by performing neoadjuvant therapy in patients with esophageal carcinoma.