Precise highlighting of the pancreas by semantic segmentation during robot-assisted gastrectomy: visual assistance with artificial intelligence for surgeons.

BACKGROUND: A postoperative pancreatic fistula (POPF) is a critical complication of radical gastrectomy for gastric cancer, mainly because surgeons occasionally misrecognize the pancreas and fat during lymphadenectomy. Therefore, this study aimed to develop an artificial intelligence (AI) system capable of identifying and highlighting the pancreas during robot-assisted gastrectomy. METHODS: A pancreas recognition algorithm was developed using HRNet, with 926 training images and 232 validation images extracted from 62 scenes of robot-assisted gastrectomy videos. During quantitative evaluation, the precision, recall, intersection over union (IoU), and Dice coefficients were calculated based on the surgeons' ground truth and the AI-inferred image from 80 test images. During the qualitative evaluation, 10 surgeons answered two questions related to sensitivity and similarity for assessing clinical usefulness. RESULTS: The precision, recall, IoU, and Dice coefficients were 0.70, 0.59, 0.46, and 0.61, respectively. Regarding sensitivity, the average score for pancreas recognition by AI was 4.18 out of 5 points (1 = lowest recognition [less than 50%]; 5 = highest recognition [more than 90%]). Regarding similarity, only 54% of the AI-inferred images were correctly differentiated from the ground truth. CONCLUSIONS: Our surgical AI system precisely highlighted the pancreas during robot-assisted gastrectomy at a level that was convincing to surgeons. This technology may prevent misrecognition of the pancreas by surgeons, thus leading to fewer POPFs.

Color-coded laparoscopic liver resection using artificial intelligence: A preliminary study.

Tashiro and colleagues demonstrated for the first time that an artificial intelligence system can precisely identify intrahepatic vascular structures during laparoscopic liver resection in real time through color coding under bleeding and indocyanine green fluorescent imaging. The system supports real-time navigation and offers potentially safer laparoscopic or robotic liver surgery.

Development of a Novel Artificial Intelligence System for Laparoscopic Hepatectomy.

BACKGROUND/AIM: Laparoscopic hepatectomy (LH) requires accurate visualization and appropriate handling of hepatic veins and the Glissonean pedicle that suddenly appear during liver dissection. Failure to recognize these structures can cause injury, resulting in severe bleeding and bile leakage. This study aimed to develop a novel artificial intelligence (AI) system that assists in the visual recognition and color presentation of tubular structures to correct the recognition gap among surgeons. PATIENTS AND METHODS: Annotations were performed on over 350 video frames capturing LH, after which a deep learning model was developed. The performance of the AI was evaluated quantitatively using intersection over union (IoU) and Dice coefficients, as well as qualitatively using a two-item questionnaire on sensitivity and misrecognition completed by 10 hepatobiliary surgeons. The usefulness of AI in medical education was qualitatively evaluated by 10 medical students and residents. RESULTS: The AI model was able to individually recognize and colorize hepatic veins and the Glissonean pedicle in real time. The IoU and Dice coefficients were 0.42 and 0.53, respectively. Surgeons provided a mean sensitivity score of 4.24±0.89 (from 1 to 5; Excellent) and a mean misrecognition score of 0.12±0.33 (from 0 to 4; Fail). Medical students and residents assessed the AI to be very useful (mean usefulness score, 1.86±0.35; from 0 to 2; Excellent). CONCLUSION: The novel AI presented was able to assist surgeons in the intraoperative recognition of microstructures and address the recognition gap among surgeons to ensure a safer and more accurate LH.

Can Clinical Stage in the 8th Edition of the Union for International Cancer Control TNM Classification Stratify the Prognosis of Patients Undergoing Curative Surgery for Siewert Type II/III Adenocarcinoma of the Esophagogastric Junction?

BACKGROUND/AIM: Clinical staging in the eighth edition of the Union for International Cancer Control TNM classification (TNM8) is reported to predict the prognosis of patients with gastric cancer. However, there have been no reports on using the TNM8 for prognostic stratification of patients with adenocarcinoma of the esophagogastric junction (AEG). This study aimed to investigate whether it was possible to stratify the prognosis of patients who underwent curative surgery for Siewert type II/III AEG according to the TNM8 clinical stage (cStage). PATIENTS AND METHODS: This study included patients with Siewert type II/III AEG who underwent curative surgery between 2000 and 2019 at Kanagawa Cancer Center. Those who received neoadjuvant chemotherapy were excluded. We investigated the survival of patients with AEG of each TNM8 cStage. RESULTS: This study included 138 patients, among whom 102 (74%) had Siewert type II and 36 (26%) had Siewert type III AEG. A total of 50, 38, 43, and seven patients were classified with cStage I, II, III, and IV, respectively. The median duration of follow-up of the survivors was 54.7 months. The 5-year overall survival rate of the entire cohort was 65.8%, whereas for patients with cStage I, II, III and IV was 81.6%, 69.0%, 54.3% and 14.3%, respectively. The hazard ratio with reference to cStage I was 1.83, 3.07, and 8.13 for cStage I, III, and IV, respectively, increasing in a stepwise manner. CONCLUSION: TNM8 Clinical staging is able to stratify the prognosis of patients with Siewert type II/III AEG.

Clinical Significance of Pre-treatment Circumferential Tumor Location in Patients With cStage IB-III Esophageal Squamous Cell Cancer.

BACKGROUND/AIM: To determine the clinical significance of pre-treatment circumferential tumor location within the esophageal wall in patients with locally advanced esophageal squamous cell carcinoma who underwent curative resection after neoadjuvant chemotherapy. PATIENTS AND METHODS: Patients (n=96) with cStage IB-III esophageal squamous cell carcinoma who underwent curative resection after neoadjuvant chemotherapy were categorized into two groups based on the circumferential tumor location within the esophageal wall on diagnostic endoscopy: left or anterior wall group (L/A patients, n=49); right or posterior wall group (R/P patients, n=47). Analyses were conducted to examine the relationship between circumferential tumor location, clinicopathological characteristics, 3-year overall survival (3Y-OS), and 3-year recurrence-free survival (3Y-RFS). RESULTS: The lymph node status and recurrence rates of mediastinal lymph node metastases were significantly higher in patients with L/A than in patients with R/P. Furthermore, patients with L/A had significantly poorer 3Y-OS and 3Y-RFS than those with R/P. Tumor location within the esophageal wall was identified in multivariate analysis as an independent risk factor for 3Y-RFS (hazard ratio=2.92, 95% confidence interval=1.35-6.32, p=0.0064). CONCLUSION: Pre-treatment of circumferential tumor located within the esophageal wall may be a useful prognostic factor in patients with cStageIB-III esophageal squamous cell carcinoma who underwent curative resection after neoadjuvant chemotherapy.

Should the splenic hilar lymph node be dissected for the management of adenocarcinoma of the esophagogastric junction?

BACKGROUND: Splenic hilar lymphadenectomy is not recommended for advanced proximal gastric cancer that does not invade the greater curvature according to the results of the previous studies. The efficacy of splenic hilar lymphadenectomy for type II and type III adenocarcinomas of the esophagogastric junction and easy spread to the greater curvature of the stomach remains unclear. This study aimed to investigate the efficacy of splenic hilar lymphadenectomy and identify the risk factors for metastasis to splenic hilar nodes. METHODS: We examined patients who underwent R0/1 gastrectomy for Siewert types II and III at a single high-volume center in Japan. We analyzed the metastatic incidence, therapeutic value index, and risk factors for splenic hilar lymph node metastasis. RESULTS: We examined 126 patients (74, type II; 52, type III). Splenectomy was performed in 76 patients. Metastatic incidence and the therapeutic value index of splenic hilar lymph nodes in patients with type II and type III tumors were 4.5% and 0, and 21.9% and 9.4, respectively. In the patients who underwent splenectomy, we identified Siewert type III tumors (odds ratio: 6.93, 95% confidence interval: 1.24-38.8, p = 0.027) and tumor location other than the lesser curvature (odds ratio: 7.36, 95% confidence interval: 1.32-41.1, p = 0.023) to be independent risk factors. The metastatic incidence (46.2%) and therapeutic value index (15.4) were high in patients with both risk factors. CONCLUSIONS: Splenic hilar lymphadenectomy may contribute to the survival of patients with Siewert type III tumors, especially when the predominant location is not the lesser curvature.

Clinical Impact of Surgical Sarcopenia on Long-term Survival.

BACKGROUND/AIM: Preoperative sarcopenia is associated with various cancers and affects the long-term prognosis of patients. After gastrectomy for gastric cancer, dynamic changes in body composition occur, and sarcopenia becomes more apparent after surgery than before surgery. However, the relationship between sarcopenia in the early postoperative period and long-term survival is not fully understood. The aim of this study was to determine the effects of surgical sarcopenia on long-term outcomes of patents with gastric cancer. PATIENTS AND METHODS: We included 408 patients who underwent curative gastrectomy (distal or total gastrectomy) for gastric cancer at the Kanagawa Cancer Center from December 2013 to November 2017. Sarcopenia was defined using the skeletal muscle index (SMI), using computed tomography (CT) one month after gastrectomy. We compared the long-term outcomes between patients with and without sarcopenia. RESULTS: The 5-year overall survival (OS) rates were 83.2% and 91.4% in the surgical and non-surgical sarcopenia groups, respectively. The hazard ratio (HR) of surgical sarcopenia for OS was 2.410 (95% confidence interval (CI)=1.321-4.396). In addition, surgical sarcopenia was associated with non-cancer-related deaths and deaths from other cancers. CONCLUSION: Patients with surgical sarcopenia after gastrectomy should be carefully monitored not only for gastric cancer recurrence but also for the occurrence of other diseases, including other cancers.

Feasibility and Safety of Oral Nutritional Supplementation with High-Density Liquid Diet After Total Gastrectomy for Gastric Cancer.

INTRODUCTION: Patients requiring total gastrectomy for gastric cancer experience a decrease in food intake leading to severe body weight loss after surgery. This loss may be prevented using a high-density liquid diet of high caloric content and minimal volume. This phase II study evaluated the feasibility and safety of a high-density liquid diet (UpLead®; Terumo Corporation, Tokyo, Japan) after total gastrectomy. METHODS: UpLead® (1 pack, 100 mL, 400 kcal/day) was administered after surgery for 28 days. The primary endpoint was the % relative dose intensity of 28 days of UpLead intake®. The secondary endpoint was % body weight loss at 1 and 3 months after surgery. The sample size was 35 considering expected and threshold values of 80 and 60%, respectively, with a one-sided alpha error of 10% and statistical power of 80%. RESULTS: Among 35 patients enrolled before surgery between April 2018 and December 2019, 29 patients who could initiate UpLead® after surgery were analyzed. Seven patients had interrupted UpLead® intake due to taste intolerance (n = 6) and due to a duodenal stump fistula (n = 1). The remaining 22 patients completed 28 days of UpLead® intake, including temporary interruption, with no associated adverse events. The median relative dose intensity was 25.8% (95% confidence interval: 20.6-42.0%). The median body weight loss at 1 and 3 months after surgery was 7.2% (range: 3.2-13.9%) and 13.1% (range: 2.5-20.4%), respectively. CONCLUSIONS: Oral nutritional supplementation with a high-density liquid diet (UpLead®) was safely administered but was not feasible after total gastrectomy for gastric cancer. Clinical trial registration number UMIN000032291.

Automated segmentation by deep learning of loose connective tissue fibers to define safe dissection planes in robot-assisted gastrectomy.

The prediction of anatomical structures within the surgical field by artificial intelligence (AI) is expected to support surgeons' experience and cognitive skills. We aimed to develop a deep-learning model to automatically segment loose connective tissue fibers (LCTFs) that define a safe dissection plane. The annotation was performed on video frames capturing a robot-assisted gastrectomy performed by trained surgeons. A deep-learning model based on U-net was developed to output segmentation results. Twenty randomly sampled frames were provided to evaluate model performance by comparing Recall and F1/Dice scores with a ground truth and with a two-item questionnaire on sensitivity and misrecognition that was completed by 20 surgeons. The model produced high Recall scores (mean 0.606, maximum 0.861). Mean F1/Dice scores reached 0.549 (range 0.335-0.691), showing acceptable spatial overlap of the objects. Surgeon evaluators gave a mean sensitivity score of 3.52 (with 88.0% assigning the highest score of 4; range 2.45-3.95). The mean misrecognition score was a low 0.14 (range 0-0.7), indicating very few acknowledged over-detection failures. Thus, AI can be trained to predict fine, difficult-to-discern anatomical structures at a level convincing to expert surgeons. This technology may help reduce adverse events by determining safe dissection planes.

Comparison of the Dietary Intake Loss Between Total and Distal Gastrectomy for Gastric Cancer.

BACKGROUND/AIM: The changes of dietary intake (DI) after gastrectomy have not been objectively reported. It has not been clear how much DI loss is experienced after total gastrectomy (TG) in comparison to after distal gastrectomy (DG). This study quantified the changes of DI after gastrectomy, and clarified how much DI loss is experienced after TG. PATIENTS AND METHODS: This was a prospective observational study. Patients who underwent gastrectomy for gastric cancer were enrolled. The DI loss was evaluated at 1 and 3 months postoperatively. RESULTS: Thirty-three patients underwent TG, and 117 patients underwent DG. The median %DI loss of the overall study population at 1 and 3 months after surgery was -9.3% and -3.6%. The median %DI loss at 1 and 3 months postoperatively was -15.6% and -5.3% in TG group, -8.9% and -3.3% in DG group (p=0.10 and 0.49, respectively). CONCLUSION: The patients experienced DI loss of approximately 10% at 1 month after gastrectomy. Patients who received TG tended to show a greater %DI loss at 1 month postoperatively.

Effect of Prognostic Nutrition Index in Gastric or Gastro-oesophageal Junction Cancer Patients Undergoing Nivolumab Monotherapy.

BACKGROUND/AIM: We hypothesised that the prognostic nutrition index (PNI) is useful for evaluating host immunity and response to immune checkpoint inhibitors. We investigated the effect of PNI on nivolumab monotherapy efficacy in advanced or recurrent gastric cancer (GC) or gastro-oesophageal junction cancer (GOC) patients. PATIENTS AND METHODS: We retrospectively examined 110 patients, divided them into a high-PNI group and a low-PNI group, and compared treatment efficacy, adverse events (AEs), and survival between the groups. RESULTS: Median overall survival (OS) was significantly longer in the high-PNI group than in the low-PNI group (205 vs. 109 days; p<0.001). Multivariate analysis revealed that low PNI was an independent risk factor for OS (hazard ratio=2.398; 95% confidence interval=1.384-4.154; p=0.002). The overall response rate and frequency of AEs were not significantly different between the groups. CONCLUSION: PNI could be a useful prognostic factor in GC or GOC patients undergoing nivolumab monotherapy.

Risk factors analysis and stratification for microscopically positive resection margin in gastric cancer patients.

BACKGROUND: Cancer cells are often found postoperatively at surgical resection margins (RM) in patients with gastric cancer because of submucosal infiltration or hesitation to secure adequate RM. This study was designed to evaluate risk factors for microscopic positive RM and to clarify which patients should undergo intraoperative frozen section diagnosis (IFSD). METHODS: Patients who underwent R0/1 gastrectomy for gastric adenocarcinoma between 2000 and 2018 in a single cancer center in Japan were studied. We divided the patients into a positive RM group and negative RM group according to the results of definitive histopathological examinations. We performed multivariate analysis to analyze risk factors for positive RM by and used the identified risk factors to risk stratify the patients. RESULTS: A total of 2757 patients were studied, including 49 (1.8%) in the positive RM group. The risk factors significantly associated with positive RM were remnant gastric cancer (odds ratio [OR] 4.7), esophageal invasion (OR 6.3), tumor size ≥80 mm (OR 3.9), and a histopathological diagnosis of undifferentiated type (OR 3.6), macroscopic type 4 (OR 3.7), or pT4 disease (OR 4.6). On risk stratification analysis, the incidence of positive RM was 0.1% without any risk factors, increasing to 0.4% with one risk factor, 3.1% with two risk factors, 5.3% with three risk factors, 21.3% with four risk factors, and 85.7% with five risk factors. CONCLUSIONS: The risk of macroscopically positive RM increased in patients who have risk factors. IFSD should be performed in patients who have four or more risk factors.

The Prognostic Value of the Perioperative Systemic Inflammation Score for Patients With Advanced Gastric Cancer.

AIM: We examined whether the perioperative systemic inflammation score (SIS), which describes systemic inflammation and/or malnutrition, affected the tumor recurrence and survival in advanced gastric cancer patients. PATIENTS AND METHODS: The study retrospectively analyzed 160 patients with stage II/III gastric cancer who underwent curative resection at the Kanagawa Cancer Center. The SIS was evaluated before surgery, one week after surgery and one month after surgery, as determined by the serum albumin level (cut-off value=4.0 g/dl) and lymphocyte-to-monocyte ratio (cut-off value=4.44). RESULTS: A high SIS at one month after surgery was identified as an independent predictor for overall survival [hazard ratio (HR)=2.143, p=0.020] and showed a marginal significance for the relapse-free survival (HR=1.814, p=0.053) in multivariate analyses. CONCLUSION: The SIS at one month after surgery is a useful biomarker for predicting the long-term outcome in patients with advanced gastric cancer.

Relationship Between the Waiting Times for Surgery and Survival in Patients with Gastric Cancer.

BACKGROUND: Surgery for gastric cancer should be performed as soon as possible after diagnosis. However, sometimes the waiting time for surgery tends to be longer. The relation between the waiting time for surgery and survival in patients with gastric cancer remains to be fully investigated. METHODS: This retrospective, single-center cohort study evaluated patients with gastric cancer who underwent curative surgery from 2006 through 2012 at Kanagawa Cancer Center in Japan. Patients who received neoadjuvant chemotherapy were excluded. The waiting time for surgery was defined as the time between the first visit and surgery. We investigated whether the waiting time for surgery has a linear negative impact on outcomes by using a Cox regression model with clinical prognostic factors. RESULTS: In total, 801 patients were eligible. The median waiting time was 45 days (range 10-269 days). The restricted cubic spline regression curve showed that the adjusted time-specific hazard ratios of waiting times did not indicate a linear negative trend on survival between 20 and 100 days (p = 0.759). In the Cox model with a quartile of waiting times, waiting times in the 32-44-day group, 43-62-day group, and ≥63 day groups were not associated with poorer overall survival as compared with the ≤31 day group (HR: 1.01, 95% CI 0.63-1.60, p = 0.984, HR: 1.17, 95% CI 0.70-1.94, p = 0.550, HR: 1.06, 95% CI 0.60-1.88, p = 0.831, respectively). CONCLUSIONS: There was no negative relation between the waiting time for surgery (within 100 days) and survival in patients with gastric cancer.

An easy and reliable method to close Petersen's defect using barbed suture to prevent internal hernia from developing after gastrectomy with Roux-en-Y reconstruction.

INTRODUCTION: We propose a novel technique to close Petersen's defect using barbed sutures and evaluate the safety and usefulness of this technique by assessing postoperative complications and measuring the time required to close Petersen's defect. MATERIALS AND SURGICAL TECHNIQUE: Petersen's defect was closed laparoscopically with running non-absorbable barbed sutures (V-loc®) after a nodal dissection and reconstruction procedure. First, the transverse colon was elevated cranially, making the dorsal side of the transverse mesocolon a flattened surface. The intersection of the transverse mesocolon and Roux limb mesentery was then identified, and closure was started from this point. We continued to sew the transverse mesocolon and Roux limb mesentery toward the transverse colon with a running suture. At the end of suturing, we placed one or two stitches in the fatty appendices of the transverse colon and cut the free tail of thread as short as possible. DISCUSSION: We investigated postoperative complications and measured the time required to close Petersen's defect in 64 patients who underwent this technique. The results showed that this closure technique could be performed promptly and safely regardless of the patient, surgical procedure, and the experience of the operator.

Feasibility and safety of laparoscopy-assisted distal gastrectomy performed by trainees supervised by an experienced qualified surgeon.

BACKGROUND: Laparoscopic gastrectomy is becoming more commonly performed, but acquisition of its technique remains challenging. We investigated whether laparoscopy-assisted distal gastrectomy (LDG) performed by trainees (TR) supervised by a technically qualified experienced surgeon (QS) is feasible and safe. METHODS: The short-term outcomes of LDG were assessed in patients with gastric cancer between 2008 and 2018. We compared patients who underwent LDG performed by qualified experienced surgeons (QS group) with patients who underwent LDG performed by the trainees (TR group). RESULTS: The operation time was longer in the TR group than in the QS group (median time: 270 min vs. 239 min, p < 0.001). The median duration of the postoperative hospital stay was 9 days in the QS group and 8 days in the TR group (p = 0.003). The incidence of postoperative complications did not differ significantly between the two groups. Grade 2 or higher postoperative complications occurred in 18 patients (12.9%) in the QS group and 47 patients (11.7%) in the TR group (p = 0.763). Grade 3 or higher postoperative complications occurred in 9 patients (6.4%) in the QS group and 17 patients (4.2%) in the TR group (p = 0.357). Multivariate analysis showed that the American Society of Anesthesiologist Physical Status was an independent predictor of grade 2 or higher postoperative complications and that gender was an independent predictor of grade 3 or higher postoperative complications. The main operator (TR/QS) was not an independent predictor of complications. CONCLUSIONS: Laparoscopy-assisted distal gastrectomy performed by trainees supervised by an experienced surgeon is a feasible and safe procedure similar to that performed by experienced surgeons.

Postoperative D-dimer elevation affects tumor recurrence and the long-term survival in gastric cancer patients who undergo gastrectomy.

INTRODUCTION: We retrospectively evaluated the blood coagulation activity using the D-dimer level in the early period after gastrectomy and investigated whether postoperative hypercoagulation affects tumor recurrence and long-term survival in gastric cancer patients. METHODS: The study involved 650 patients who underwent curative resection for gastric cancer at Kanagawa Cancer Center between July 2009 and July 2013. They were divided into a low-D-dimer group (LD group) and high-D-dimer group (HD group) according to the median D-dimer level on postoperative day (POD) 7. The risk factors for overall survival (OS) and relapse-free survival (RFS) were identified. RESULTS: Of the 448 enrolled patients, 218 were classified into the LD group and 230 into the HD group. The 5-year OS rates after surgery were 90.8% and 81.3% in the LD and HD groups, respectively (p < 0.001). The 5-year RFS rates after surgery were 89.9% and 76.1% in the LD and HD groups, respectively (p < 0.001). A high D-dimer level on POD 7 (≥ 4.9 µg/ml) was identified as an independent predictive factor for both the OS (hazard ratio [HR] 1.955, 95% confidence interval [CI] 1.158-3.303, p = 0.012) and RFS (HR 2.182, 95% CI 1.327-3.589, p = 0.002). Furthermore, hematological recurrence was significantly more frequent in the HD group than in the LD group (p = 0.014). CONCLUSION: A high D-dimer level on POD 7 may predict tumor recurrence and the long-term survival in patients who undergo gastrectomy for locally advanced gastric cancer. Patients with an elevated postoperative D-dimer level need careful observation and diagnostic imaging to timely detect tumor recurrence.

[A Case of Liver Metastasis 14 Years after Total Gastrectomy for Advanced Gastric Cancer].

We report a rare case of liver recurrence of gastric cancer 14 years and 3 months after curative gastrectomy. An 81-yearold man underwent total gastrectomy, D2 lymphadenectomy, Roux-en-Y reconstruction, and cholecystectomy for advanced gastric cancer in November 2002. H e was diagnosed pathologically with M, Type 5, 53×42 mm, tub2>tub1, pT4a, ly2, v2, pN1, pPM0, pDM0, M0, pStage ⅢA(JGCA 15th). Postoperative adjuvant therapy was not administered. He was followed up for 5 years after surgery without adjuvant therapy, and he did not exhibit recurrence. In February 2017, he experienced difficulties in swallowing and visited our hospital. Abdominal contrast-enhanced CT showed an 8×5 cm liver tumor in the lateral segment. Part of the tumor protruded to outside of the liver, and the tumor invaded and pushed the jejunum in the Roux limb. We performed liver biopsy and diagnosed him with liver metastasis of recurrent gastric cancer. Late relapse after gastrectomy, especially after 10 years or more, is very rare.

[Local Resection of Gastric Tube Cancer with a Gastrointestinal Endoscope].

An 81-year-old man with esophageal cancer had undergone subtotal thoracic esophagectomy and retrosternal reconstruction using a gastric tube. He developed anemia. Gastrointestinal endoscopy was performed, which revealed a tumor in the posterior wall of the lower part of the gastric tube. Biopsy revealed well-differentiated adenocarcinoma. There was no lymph node metastasis and no distal metastasis on CT. We performed partial resection of the stomach tube because of his age and physical condition. We identified the position of the tumor by upper gastrointestinal series CT and gastrointestinal endoscopy. The tumor was located on the posterior wall of the lower part of the gastric tube and the back of the sternum lower border. Marking was performed by gastrointestinal endoscopy before operation. We simulated the operation and decided to perform laparostomy without sternotomy incision. We cut the anterior wall of the gastric tube in front of the tumor using the endoscope. We could then confirm the diagnosis of cancer, and clipped and removed the tumor from the posterior wall. The resected site was sutured with 4-0 absorbable thread. The pathological diagnosis was T1a(M)N0M0, ly0, v0, PM0, DM0, pStage ⅠA.

[A Case of Mediastinal Lymph Node Recurrence after Endoscopic Submucosal Dissection of Esophageal Cancer].

We report a case of mediastinal lymph node recurrence of esophageal cancer after endoscopic submucosal dissection (ESD). We first administered chemotherapy and then performed esophagectomy. A 78-year-old man underwent ESD for early esophageal cancer at a different hospital in January 2015. H e was diagnosed pathologically with scc, pSM1, pHM1, pVM0, ly0, v0. Additional treatment was not administered because of his age. In June 2017, chest enhanced CT showed swollen mediastinal lymph nodes. This was diagnosed as a recurrence of esophageal cancer, and he presented at our hospital. We first performed chemotherapy for that lesion, because the swollen lymph node was large and may have invaded the surrounding organs. We then performed esophagectomy.