Clinicopathologic differences of gastric neoplasms between Helicobacter pylori-infected and -naïve patients: a multicenter retrospective analysis.

BACKGROUND: The incidence of gastric neoplasms in Helicobacter pylori (Hp)-naïve patients has recently increased due to a remarkable decrease in the Hp-infected population in Japan. We investigated the clinicopathologic differences between Hp-infected gastric neoplasms (HpIGNs) and Hp-naïve gastric neoplasms (HpNGNs) that have not been fully elucidated so far. METHODS: This retrospective multicenter study investigated 966 consecutive patients with 1131 gastric dysplasia or cancers who underwent endoscopic or surgical treatment for the recent decade. Clinicopathologic features were compared between HpIGN and HpNGN cases. RESULTS: One thousand and sixty-eight HpIGNs in 916 patients included 877 differentiated types and 191 undifferentiated types. Sixty-three HpNGNs in 50 patients included 57 differentiated types (35 foveolar types, 15 intestinal types, 6 fundic-gland types, and 1 other differentiated type) and 6 undifferentiated types. HpNGNs occurred in younger (59.5 vs. 71.8 years, p < 0.05) and female patients (40.0% vs. 26.5%, p < 0.05), were found more frequently in the proximal compartment (p < 0.05), and had smaller size (median 4.0 vs. 20.0 mm, p < 0.05). Histologically, HpNGNs and HpIGNs both primarily consisted of differentiated type (90.5% vs. 82.1%, p = 0.089) and HpNGNs showed lower prevalence of invasive cancer (11.1% vs. 37.6%, p < 0.05) and lymphovascular invasion (1.6% vs. 31.6%, p < 0.05). Nearly all HpNGNs (62/63, 98.4%) were diagnosed in early pathological stage, while 16.1% (172/1068) of HpIGNs were diagnosed in advanced stage (p < 0.05). CONCLUSIONS: HpNGNs is recently on the increase but shows lower malignant nature regardless of histologic type than HpIGN. Endoscopic gastric cancer screening will be reviewed via cost effectiveness for Hp-naïve individuals in future.

Preoperative mechanical bowel preparation using conventional versus hyperosmolar polyethylene glycol-electrolyte lavage solution before laparoscopic resection for colorectal cancer (TLUMP test): a phase III, multicenter randomized controlled non-inferiority trial.

BACKGROUND: A hyperosmolar ascorbic acid-enriched polyethylene glycol-electrolyte (ASC-PEG) lavage solution ensures excellent bowel preparation before colonoscopy; however, no study has demonstrated the efficacy of this lavage solution before surgery. This study aimed to establish the non-inferiority of ASC-PEG to the standard polyethylene glycol-electrolyte solution (PEG-ELS) in patients undergoing laparoscopic resection for colorectal cancer. METHODS: This was a prospective, single-blind, multicenter, randomized, controlled, non-inferiority clinical trial. Overall, 188 patients scheduled for laparoscopic colorectal resection for single colorectal adenocarcinomas were randomly assigned to undergo preparation with different PEG solutions between August 2017 and April 2020 at four hospitals in Japan. Participants received ASC-PEG (Group A) or PEG-ELS (Group B) preoperatively. The primary endpoint was the ratio of successful bowel preparations using the modified Aronchick scale, defined as "excellent" or "good." RESULTS: After exclusion, 86 and 87 patients in Groups A and B, respectively, completed the study, and their data were analyzed. ASC-PEG was not inferior to PEG-ELS in terms of effective bowel preparation prior to laparoscopic colorectal resection (0.93 vs. 0.92; 95% confidence interval, - 0.078 to 0.099, p = 0.007). The total volume of cleansing solution intake was lower in Group A than in Group B (1757.0 vs. 1970.1 mL). Two and three severe postoperative adverse events occurred in Groups A and B, respectively. Patient tolerance of the two solutions was almost equal. CONCLUSIONS: ASC-PEG is effective for preoperative bowel preparation in patients undergoing laparoscopic resection for colorectal cancer and is non-inferior to PEG-ELS.

Effect of Continuous Box-trainer Training on Laparoscopic Skills of Surgical Residents: A Prospective, Observational Study.

BACKGROUND/AIM: As opportunities for hands-on surgical training during residency have decreased, off-the-job training before surgery is gaining importance. We developed a training program using a box-trainer for surgical residents. This study aimed to verify the effectiveness of the program. Using task-achievement time, we demonstrated the learning curve through continuous task training and verified the efficiency of our training tasks. In addition, we examined the circularity of the cut circle to evaluate the task accuracy and summarized the questionnaire results. PATIENTS AND METHODS: A prospective, observational study was conducted at a single center with five trainees from April 2019 to March 2020. The training consisted of four tasks based on the Fundamentals of Laparoscopic Surgery module. The trainees had to achieve expert proficiency time targets. The task-achievement time and circularity of the cut circle were used for objective assessment; subjective evaluation was done using a questionnaire. RESULTS: Although the learning curves of the task-achievement time seemed to reach a plateau between the third and the fifth skills lab, all the trainees achieved expert proficiency times for the three tasks. Circularity of the cut circle tended to be more accurate after training. All trainees perceived an improvement in their skills after the training program. The level of satisfaction of the training program was rated as 'very satisfied' or 'satisfied'. CONCLUSION: Continuous box-trainer training for 1 year may be effective for improvement in preoperative laparoscopic surgical skills of surgical residents.

[A Case of Pathological Complete Response of Advanced Rectal Cancer with Direct Invasion of the Prostate and Extra-Regional Lymph Node Metastasis after Chemotherapy].

A 62-year-old man was diagnosed as having advanced rectal cancer with an invasive carcinoma of the prostate and the right inguinal lymph node metastasis. He received chemotherapy consisting of combination of 5-FU, oxaliplatin, Leucovorin (mFOLFOX6)and bevacizumab. After 5 courses of the chemotherapy, CT and MRI findings revealed the tumor shrinkage. After 6 courses of the chemotherapy, a laparoscopic abdominoperineal resection, bilateral lymph node dissection and a resection of right inguinal lymph node were performed. The pathological findings showed a pCR. NAC with mFOLFOX6 and bevacizumab may contribute to the reduction of the surgical stress for the patients and be an effective treatment for advanced rectal cancer with distant lymph node metastasis.

Interischial Spine Distance Is a Simple Index of the Narrow Pelvis That Can Predict Difficulty During Laparoscopic Low Anterior Resection.

BACKGROUND: A narrow pelvis makes laparoscopic rectal resection difficult. This study aimed to evaluate whether a simple measurement on computed tomography can predict procedural difficulty. METHODS: A total of 62 patients with low rectal cancer underwent conventional laparoscopic low anterior resection. The interischial spine (IS) distance (ie, the distance between the ischial spines) was measured on an axial computed tomography slice. The operative time, blood loss, and time from the insertion of linear staplers to completion of clamping on the distal end of the rectum (clamp time) were compared between patients with narrow or wide pelvises. RESULTS: Overall, 42 men and 20 women with low rectal cancer were assessed. The mean tumor size was 34.5 mm. Total or tumor-specific mesorectal excisions were performed in all cases; high ligation and resection of the inferior mesenteric arteries were carried out in 92% of patients. The mean operative time and blood loss were 206 minutes and 15 mL, respectively. Four patients (6.5%) experienced postoperative complications, including 2 anastomotic leaks (3.2%). The mean IS distance was 93.3 mm. In simple linear regression analysis, a shorter IS distance correlated with a longer operative time ( R2 =0.08, P =0.030) and the clamp time ( R2 =0.07, P =0.046). Using a receiver operating characteristic curve, a narrow pelvis was defined as an IS distance <94.7 mm. Multivariate regression analysis revealed that an IS distance <94.7 mm (odds ratio: 3.51; P =0.04) was independently associated with a longer clamp time. CONCLUSIONS: The IS distance is a simple and useful measurement for predicting the difficulty of laparoscopic low anterior resection.

Exploration of the advantages of minimally invasive surgery for clinical T4 colorectal cancer compared with open surgery: A matched-pair analysis.

The indications of minimally invasive surgery (MIS) for T4 colorectal cancer are controversial because the advantages of MIS are unclear. Therefore, we compared overall survival (OS) and recurrence-free survival (RFS) as the primary endpoint, and short-term outcome, alteration in perioperative laboratory data, and the interval of postoperative chemotherapy from operation as secondary endpoints, between MIS and open surgery (OPEN) using a matched-pair analysis. We explored the advantages of MIS for T4 colorectal cancer. In this retrospective single-institution study, we included 125 patients with clinical T4 colorectal cancer who underwent curative-intent surgery of the primary tumor between October 2010 and September 2019. Conversion cases were excluded. MIS patients were matched to OPEN patients (ratio of 1:2) according to tumor location, clinical T stage, and preoperative treatment. We identified 25 and 50 patients who underwent OPEN and MIS, respectively, including 31 with distant metastasis. Both groups had similar background characteristics. The rate of major morbidities (Clavien-Dindo grade > III) was comparable between the 2 groups (P = .597), and there was no mortality in either group. MIS tended to result in shorter postoperative hospitalization than OPEN (P = .073). Perioperative alterations in laboratory data revealed that MIS suppressed surgical invasiveness better compared to OPEN. Postoperative chemotherapy, especially for patients with distant metastasis who underwent primary tumor resection, tended to be started earlier in the MIS group than in the OPEN group (P = .075). OS and RFS were comparable between the 2 groups (P = .996 and .870, respectively). In the multivariate analyses, MIS was not a significant prognostic factor for poor OS and RFS. MIS was surgically safe and showed similar oncological outcomes to OPEN-with the potential of reduced invasiveness and enhanced recovery from surgery. Therefore, patients undergoing MIS might receive subsequent postoperative treatments earlier.

Transabdominal Ultrasonography for Preoperative Diagnosis of Lymph Node Metastasis in Colon Cancer: A Retrospective Cohort Study.

Background/Aim: Although computed tomography (CT) is the standard modality for diagnosing lymph node metastasis (LNM), transabdominal ultrasonography (US) can be useful due to its high spatial resolution and use of Doppler signals to precisely analyse lymph nodes. This study aimed to evaluate the accuracy of US for lymph node assessment, establish US-based diagnostic criteria for LNM, and compare the capability of US with that of CT for the diagnosis of LNM. Patients and Methods: This retrospective, single-institution, cohort study included patients who underwent radical surgery for clinical stage 0-III colon cancer, between March 2012 and February 2019. Results: Overall, 34.9% (66/189) of patients had pathological LNM. The optimal US diagnostic criteria were 1) short axis ≥7 mm and short/long ratio ≥0.75 and 2) at least two of the following: the absence of hilar echoes, expansive appearance, or peripheral/mixed vascularity by the colour Doppler and/or contrast-enhanced method. Compared to CT, US showed a higher diagnostic sensitivity (54.5% vs. 43.9%; p=0.296), higher concordance with the number of pathological LNM (correlation coefficient: US, 0.42; CT, 0.27) and pathological N diagnosis (weighted ĸ: US, 0.35; CT, 0.18), and higher sensitivity for advanced LNM, including multiple LNMs (47.4% vs. 18.4%; p=0.014) and N2 stage (27.8% vs. 5.6%; p=0.177). Conclusion: US has higher sensitivity than CT for diagnosing LNM in colon cancer, along with a more accurate preoperative diagnosis of the N stage. Additionally, US may be more helpful than CT alone for preoperatively deciding the appropriateness of neoadjuvant treatment in colon cancer with advanced LNM.

Intestinal-type gastric dysplasia in Helicobacter pylori-naïve patients.

Gastric dysplasia and gastric cancer in Helicobacter pylori (Hp)-naïve patients usually exhibit a gastric phenotype, reflecting gastric mucosa without intestinal metaplasia (IM). We showed that intestinal-type gastric dysplasia (IGD) rarely occurs in the Hp-naïve stomach. In the last 10 years, we treated 1760 gastric dysplasia and gastric cancer patients, with 3.6% (63/1760) being Hp-naïve. Among these, ten were diagnosed with 14 IGDs and enrolled in this retrospective analysis. All lesions were observed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). We analyzed their endoscopic and microscopic features and patient demographics. Five men and five women aged 64 ± 21 years were included. WLE showed the depressed lesions mimicking a benign raised erosion in the prepyloric compartment. Multiple growths were confirmed in 30% (3/10) of patients. NBIME showed a near-regular microstructure and capillaries in 50% (7/14) of lesions with a gastritis-like appearance. Histologically, background mucosa was non-atrophic pyloric gland tissue, but 40.0% of samples (4/10) contained sporadic IM. Most of the lesions (8/14) were low-grade dysplasia, and others had a high-grade component, with one progressing to intramucosal carcinoma. The neoplastic surface was widely covered with foveolar epithelium in 57.1% (8/14). Immunohistochemically, neoplastic cells expressed CDX2 in all patients (14/14), MUC2 and CD10 in 92.9% (13/14), MUC5AC in 14% (2/14), and no expression of MUC6, showing an intestinal phenotype. Ki-67 was overexpressed with a mean labeling index of 58.3 ± 38.5%, and p-53 was overexpressed in 92.9% (13/14), regardless of the dysplastic grade. The IGD rarely occurs in Hp-naïve patients with distinctive clinicopathologic characteristics.

Modified complete mesocolic excision with central vascular ligation by the squeezing approach in laparoscopic right colectomy.

PURPOSE: Complete mesocolic excision (CME) and central vascular ligation (CVL) are becoming the standard procedure in laparoscopic right-sided colectomy. However, the approach to CME and CVL has not been established, although several useful approaches have been reported. The squeezing approach described herein is a novel procedure to perform modified CME and CVL in laparoscopic right colectomy. METHODS: The squeezing approach features retroperitoneal mobilization followed by cranial mesocolic mobilization and lymph node dissection using a cranial approach followed by a caudal approach. Dissection of the regional lymph nodes along with central vascular ligation was performed along the anterior wall of the superior mesenteric vein. In total, 177 patients (mean age, 70.6 years; male-to-female ratio, 90:87) who underwent laparoscopic right-sided colectomy were retrospectively assessed. Descriptive statistics for patient characteristics were calculated. RESULTS: The mean operative time and blood loss were 169 min and 37 mL, respectively. Seven patients (4.0%) required conversion to open surgery, and major postoperative complications occurred in five patients (2.8%) with no anastomotic leakage. Histological R0 resection was achieved in all cases of stages 0-III colon cancer. The 5-year recurrence-free survival rates were 100% (n = 19), 100% (n = 40), 87% (n = 46), and 81% (n = 43) in pathological stages 0, I, II, and III, respectively. Node recurrence occurred in one case near the root of the middle colic artery. CONCLUSION: The novel squeezing approach in laparoscopic right colectomy could be safely performed in terms of the technical and oncological aspects.

Ursodeoxycholic Acid Triggers Primary Enterolith Growth in a Crohn's Disease Patient with Jejunal Stenosis.

Primary enteroliths associated with Crohn's disease have been considered to be rare and are most likely caused by severe ileal stenosis. Herein, we report the case of a primary enterolith possibly caused by mild jejunal stenosis in a Crohn's disease patient who received oral administration of ursodeoxycholic acid (UDCA). A 62-year-old woman with a 6-year history of Crohn's disease, currently in clinical remission, was on UDCA prescription for liver dysfunction. Magnetic resonance imaging and double-balloon endoscopy, which were performed to examine epigastric pain, revealed mild jejunal stenosis and an enterolith on the oral side. Since it was difficult to remove or crush the enterolith endoscopically, we decided to remove it surgically with the stenotic jejunum. Component analysis revealed that more than 98% of the enterolith was composed of UDCA; subsequently, oral administration of UDCA was discontinued. This case demonstrated that primary enterolith might develop in Crohn's disease patients with mild intestinal stenosis, and oral administration of UDCA can trigger an enterolith in such patients. Therefore, routine follow-up imaging is necessary for early detection. Oral UDCA should be administered with caution for Crohn's disease patients with stenosis of the proximal small intestine.

Combined Laparoscopic and Transperineal Endoscopic Pelvic Tumor Resection with Sacrectomy for Locally Recurrent Rectal Cancer.

Pelvic tumor resection with sacrectomy for locally recurrent rectal cancer is a challenging operation with a high complication rate and poor prognosis. We report a case of pelvic tumor resection with sacrectomy by transperineal endoscopy following laparoscopic dissection for locally recurrent rectal cancer. A 70-year-old man underwent laparoscopic abdominoperineal resection for rectal cancer and was diagnosed with local pelvic recurrence on follow-up computed tomography (CT) three years postoperatively. As the recurrence was in contact with the front of the sacrum, we concluded that distal sacrectomy was necessary to ensure a surgical margin. We safely performed combined laparoscopic and transperineal endoscopic pelvic tumor resection with sacrectomy by exposing the surface of the sacrum from both abdominal and transperineal approach. The operative time was 200 minutes, with minimal blood loss. There was no tumor exposure on the surgically dissected surface, and the patient was discharged without complications 14 days postoperatively. Transperineal endoscopy may be useful for pelvic tumor resection with sacrectomy for locally recurrent rectal cancer.

Novel Prognostic Stratification Factor Based on the Pathological Profile of the Invasive Front in Colorectal Cancer.

BACKGROUND/AIM: This study aimed to develop a new pathological finding, namely, invasion front grade and verify its clinical usefulness. MATERIALS AND METHODS: We re-examined haematoxylin-eosin-stained specimens in 162 stage II-III colorectal cancer patients who underwent radical resection. We assessed the desmoplastic reaction, Klintrup grade, and poorly differentiated cluster. These three findings were combined to form the invasion front grade (good prognosis group; Grade A, poor prognosis group; Grade B), and its reproducibility and prognostic stratification ability were statistically analysed. RESULTS: Invasion front grade was Grade A in 116 cases and Grade B in 46 cases, and its kappa coefficient was 0.81 for interobserver and 0.74 for intraobserver variability. The 3-year recurrence-free survival rates of Grade A and Grade B were 90.4% and 55.9%. Multivariate analysis showed that invasion front grade was an independent prognostic factor. CONCLUSION: Invasion front grade is useful as a prognostic stratification factor for stage II-III colorectal cancer.

Transperineal total mesorectal excision for rectal cancer on the residual rectum after multiple abdominal surgeries in a patient with Crohn's disease: a case report.

BACKGROUND: The improved prognosis of Crohn's disease may increase the opportunities of surgical treatment for patients with Crohn's disease and the risk of development of colorectal cancer. We herein describe a patient with Crohn's disease and a history of multiple surgeries who developed rectal stump carcinoma that was treated laparoscopically and transperineally. CASE PRESENTATION: A 51-year-old man had been diagnosed with Crohn's disease 35 years earlier and had undergone several operations for treatment of Crohn's colitis. Colonoscopic examination was performed and revealed rectal cancer at the residual rectum. The patient was then referred to our department. The tumor was diagnosed as clinical T2N0M0, Stage I. We treated the tumor by combination of laparoscopic surgery and concomitant transperineal resection of the rectum. While the intra-abdominal adhesion was dissected laparoscopically, rectal dissection in the correct plane progressed by the transperineal approach. The rectal cancer was resected without involvement of the resection margin. The duration of the operation was 3 h 48 min, the blood loss volume was 50 mL, and no intraoperative complications occurred. The pathological diagnosis of the tumor was type 5 well- and moderately differentiated adenocarcinoma, pT2N0, Stage I. No recurrence was evident 3 months after the operation, and no adjuvant chemotherapy was performed. CONCLUSION: The transperineal approach might be useful in patients with Crohn's disease who develop rectal cancer after multiple abdominal surgeries.

Ischemic proctitis 6 months after laparoscopic sigmoidectomy: a case report.

BACKGROUND: Ischemic colitis is a common disease; however, its pathophysiology remains unclear, especially in ischemic proctitis after sigmoidectomy. We present a rare case of ischemic proctitis 6 months after laparoscopic sigmoidectomy. CASE PRESENTATION: The patient was a 60-year-old man with hypertension, type 2 diabetes, and hyperlipidemia. He was a smoker. He underwent laparoscopic sigmoidectomy for pathological stage I sigmoid colon cancer and was followed up without any adjuvant therapy. Six months after his surgery, he complained of lower abdominal discomfort, bloody stools, and tenesmus. Colonoscopy showed extensive rectal ulcers between the anastomotic site and the anal canal, which was particularly severe on the anal side several centimeters beyond the anastomosis. We provided non-surgical management, including hyperbaric oxygen therapy. The rectal ulcers had healed 48 days after the therapeutic intervention. He has not experienced any recurrence for 3.5 years. CONCLUSIONS: While performing sigmoidectomy, it is important to consider the blood backflow from the anal side of the bowel carefully, especially for patients with risk factors of ischemic proctitis.

Intestinal anisakiasis with severe intestinal ischemia caused by extraluminal live larvae: a case report.

BACKGROUND: Anisakiasis is a parasitic infection caused by Anisakis worms found in raw fish. Most cases of anisakiasis occur in the stomach and rarely occur in the intestine. It is extremely rare for live larvae to break through the intestine into the mesentery and cause severe intestinal ischemia. Anisakiasis can be treated conservatively, because the larvae will die in approximately 1 week, but, sometimes, a serious condition can arise, as in this case. We report the first case of extraluminal anisakiasis in which a live Anisakis worm caused severe intestinal ischemia. CASE PRESENTATION: The patient was a 26-year-old woman who ate squid a week prior. She had abdominal pain and was admitted to our emergency department. On physical examination, abdominal guarding and rebound tenderness were present in her lower abdomen. Contrast-enhanced computed tomography showed ascites, the whirl sign, localized submucosal edema of the intestinal wall, and a dilated small bowel segment with edema. We suspected the strangulated small bowel obstruction based on the CT-scan findings. To rule out the strangulated small bowel obstruction, laparoscopic exploration was performed. Bloody ascites in the pouch of Douglas and severe inflammation in 20 cm of the ileum were observed. An Anisakis larva had perforated the intestinal wall and was found alive in the mesentery. The ileum had developed a high degree of ischemia, so the affected section was resected. Histopathological examination revealed that the Anisakis worm body was in the inflamed mesentery and caused a high degree of ischemia in the intestinal tract. The patient was discharged 9 days after surgery. CONCLUSIONS: A living Anisakis larva punctured the mesentery of the small intestine, resulting in severe intestinal ischemia. As seen in this case, intestinal anisakiasis may cause serious symptoms, and a low threshold for performing diagnostic laparoscopy for the early diagnosis of bowel ischemia secondary to anisakiasis can be useful in determining the definite diagnosis and indications for resection.

Evaluating Health Impact at High Altitude in Antarctica and Effectiveness of Monitoring Oxygen Saturation.

BACKGROUND: The Japanese Antarctic Research Expedition (JARE) has been conducting research activities in inland Antarctica, which is extremely cold dryland covered with a thick ice sheet. This environment may cause a health disorder called acute mountain sickness (AMS). To improve the safety of expedition members, we evaluated the impact of extreme environmental conditions on human health and the effectiveness of monitoring of hypoxia for the early detection of AMS. METHODS: In total, 9 members from JARE 59 were studied. Dome Fuji Station (Dome F), located 3,810 m above sea level (ASL), was the destination of the research party. We analyzed daily AMS scores (higher values correspond to more severe AMS-related symptoms), physiological findings, and percutaneous arterial blood oxygen saturation (SpO2) during the inland activity. We also determined the factors related to AMS scores. RESULTS: The average AMS score on arrival at Dome F was significantly higher than that at the departure point (560 m ASL). The average SpO2 level was significantly lower than that at other points. The SpO2 level correlated negatively with the AMS score in Spearman's rank correlation. Generalized estimating equations analysis showed that the AMS score was negatively associated with SpO2 level and positively associated with age. CONCLUSION: Hypoxia is a contributory factor to AMS which we can easily assess by measuring the SpO2 level with a pulse oximeter. SpO2 monitoring is a potentially useful health management tool for members in inland Antarctic expeditions. In addition, our results are helpful for understanding physiological responses and health issues in extreme environments.

Outcomes of Endoscopic Submucosal Dissection for Subepithelial Lesions Localized Within the Submucosa, Including Neuroendocrine Tumors: A Multicenter Prospective Study.

BACKGROUND AND AIMS: Endoscopic submucosal dissection (ESD) seems to be a reasonable option for gastrointestinal subepithelial lesions (SELs) localized within the submucosa. Indications for ESD include small neuroendocrine tumors (NETs) and indeterminate SELs. However, the prospective data regarding ESD and surveillance remain unclear. This study was performed to prospectively investigate the outcomes of ESD, including organ-specific outcomes and the mid-term prognosis. METHODS: This prospective multicenter study included 57 patients who underwent ESD for SELs localized within the submucosa [definite NETs (n = 42) and indeterminate SELs (n = 15)]. The efficacy and safety of ESD were evaluated in the whole cohort and in subgroups (NETs and indeterminate SELs). All patients were followed up. RESULTS: The rates of en bloc resection, curative resection, and complications were 98.2%, 66.7%, and 7.7% for the overall population (n=57); 100%, 61.9%, and 2.4% for NETs (n=42); and 93.3%, 80.0%, and 20.0% for indeterminate SELs (n=15), respectively. The rates of curative resection for NETs were poorer in the stomach (20%, n=5) and duodenum (33%, n=3) than in the rectum (71%, n=34). Including 11 of 16 patients with NETs who underwent a conservative approach resulting in non-curative resection, no patients developed tumor recurrence during the follow-up period (median, 24.5 months; range, 1-60 months). ESD followed by surveillance demonstrated acceptable mid-term outcomes for non-curative NETs. CONCLUSIONS: ESD can be an efficient therapy for SELs localized within the submucosa. However, gastric and duodenal ESD for NETs may be limited in terms of its curative and technical aspects. Clinicians should be aware of the potential complications of ESD for indeterminate SELs.

Prospective multicenter study of the esophageal triamcinolone acetonide-filling method in patients with subcircumferential esophageal endoscopic submucosal dissection.

BACKGROUND AND AIM: The esophageal triamcinolone acetonide (TA)-filling method is a novel local approach for stenosis prevention after extensive esophageal endoscopic submucosal dissection (ESD). We evaluated this method after subcircumferential ESD. METHODS: We enrolled 20 patients with esophageal cancer requiring subcircumferential ESD in a prospective multicenter study. Esophageal TA filling was carried out 1 day and 1 week after ESD, with follow-up endoscopy every 2 weeks. We treated severe stenosis preventing endoscope passage with endoscopic balloon dilatation (EBD) and additional TA filling, and mild stenosis allowing endoscope passage with additional TA filling only. Primary endpoint was incidence of severe stenosis; secondary endpoints were total number of EBD, rate of additional TA filling, time to stenosis and complete re-epithelialization, dysphagia score, and adverse events. Horizontal resection grade was divided into grades 1 (≥ 9/12 and <10/12 of the circumference), 2 (≥ 10/12 and <11/12), and 3 (≥ 11/12 but not circumferential) and analyzed statistically for correlation with endpoints. RESULTS: Incidence of severe stenosis was 5.0% (1/20; 0.1-24.8%) and was treated with three EBD. Six patients showed mild stenosis. Additional TA filling was carried out in these seven patients: 0% (0/9) for grade 1 resection, 40% (2/5) for grade 2, and 83% (5/6) for grade 3 (P < 0.05). Median time to stenosis and re-epithelialization was 3 and 7 weeks, respectively. Dysphagia score deteriorated in one patient. No adverse events occurred. CONCLUSIONS: The esophageal TA-filling method prevented stenosis after subcircumferential ESD. Grade ≥2 resection showed a high risk for stenosis, but additional TA filling for mild stenosis inhibited stenosis progression (UMIN000024384).