Negligible procedure-related dissemination risk of mucosal incision-assisted biopsy for gastrointestinal stromal tumors versus endoscopic ultrasound-guided fine-needle aspiration/biopsy.

BACKGROUND: Mucosal incision-assisted biopsy (MIAB) is a valuable alternative to endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNAB) for sampling gastric subepithelial lesions (SELs). This study aimed to evaluate the potential risk of dissemination and impact on postoperative prognosis associated with MIAB, which has not yet been investigated. METHODS: Study 1: A prospective observational study was conducted to examine the presence or absence and growth rate of tumor cells in gastric juice before and after the procedure in patients with SELs who underwent MIAB (n = 25) or EUS-FNAB (n = 22) between September 2018 and August 2021. Study 2: A retrospective study was conducted to examine the impact of MIAB on postoperative prognosis in 107 patients with gastrointestinal stromal tumors diagnosed using MIAB (n = 39) or EUS-FNAB (n = 68) who underwent surgery between January 2001 and July 2020. RESULTS: In study 1, although no tumor cells were observed in gastric juice in MIAB before the procedure, they were observed in 64% of patients after obtaining samples (P < 0.001). In contrast, no tumor cells were observed in the gastric juice in EUS-FNAB before and after the procedure. In study 2, there was no significant difference in 5-year disease-free survival between MIAB (100%) and EUS-FNAB (97.1%) (P = 0.27). CONCLUSION: MIAB is safe, with little impact on postoperative prognosis, although the procedure releases some tumor cells after damaging the SEL's pseudocapsule.

Is a small-caliber or large-caliber endoscope more suitable for colonic self-expandable metallic stent placement? A randomized controlled study.

OBJECTIVES: The colonic self-expandable metallic stent (C-SEMS) with a 9-French (Fr) delivery system allows for a small-caliber endoscope (SCE) to be used to treat malignant colonic obstruction. Despite the lack of evidence, the SCE has become popular because it is considered easier to insert than the large-caliber endoscope (LCE). We aimed to determine whether the SCE is more suitable than the LCE for C-SEMS placement. METHODS: Between July 2018 and November 2019, 50 consecutive patients who were scheduled to undergo C-SEMS for colon obstruction were recruited in this study. Patients were randomized to the SCE or LCE group. The SCE and LCE were used with 9-Fr and 10-Fr delivery systems, respectively. The primary outcome was the total procedure time. Secondary outcomes were the technical success rate, complication rate, clinical success rate, insertion time, guidewire-passage time, stent-deployment time, and colonic obstruction-scoring-system score. RESULTS: Forty-five patients (SCE group, n = 22; LCE group, n = 23) were analyzed. The procedure time in the LCE group (median, 20.5 min) was significantly (p = 0.024) shorter than that in the SCE group (median, 25.1 min). The insertion time in the LCE group (median, 2.0 min) was significantly (p = 0.0049) shorter than that in the SCE group (median, 6.0 min). A sub-analysis of the procedure difficulties showed that the insertion time in the LCE group (median, 5.0 min) was significantly shorter than that in the SCE group (median, 8.5 min). CONCLUSION: Both LCE and SCE can be used for C-SEMS; however, LCE is more suitable than SCE as it achieved a faster and equally efficacious C-SEMS placement as that of SCE. CLINICAL TRIAL REGISTRATION NUMBER: University Hospital Medical Information Network Clinical Trials Registry (UMIN 32748).

Impact of the Concomitant Use of Immunomodulator and a Lower Week 8 Partial Mayo Score on the Persistence of Adalimumab in Refractory Ulcerative Colitis.

Objective Real-world data of adalimumab (ADA) in the treatment of ulcerative colitis (UC) are scarce. We aimed to study the ADA response rates and predictors of response in UC treatment. Methods This observational, prospective and multi-center study assessed the clinical outcome of refractory UC patients treated with ADA who previously had an inadequate response to either conventional therapies or other anti-TNF antibodies or tacrolimus. The primary endpoint was the proportion of UC patients achieving a clinical response and remission at 8 and 52 weeks. We also evaluated the parameters which were associated with a clinical response at 8 and 52 weeks. Results A total of 35 patients were enrolled from 11 centers. The clinical responses at 8 and 52 weeks were 60.0% and 51.4%, respectively. The clinical remission rates at 8 and 52 weeks were 45.7% and 48.6%, respectively. Positive predictors for week 52 response were combination of ADA with immunomodulator (IM) (OR: 27.229; 95% CI; 1.897-390.76; p=0.015) and a week 8 lower partial Mayo score (OR: 0.406; 95% CI; 0.204-0.809; p=0.010). A receiver operation characteristic curve analysis revealed the optimal week 8 partial Mayo score to be 2.5, therefore a partial Mayo score of ≤2 was a positive predictor for the continuation of ADA. No malignancy or death occurred during this study. Conclusion ADA was effective for inducing and maintaining both a clinical response and remission in patients with refractory UC. It remains possible that the concomitant use of IM and a week 8 partial Mayo score of ≤2 may predict the long-term response of ADA.

Efficacy of Early Endoscopic Ultrasound-Guided Transluminal Drainage for Postoperative Pancreatic Fistula.

Background: Endoscopic ultrasound-guided transluminal drainage (EUS-TD) is generally performed 4 weeks after disease onset for evacuating pancreatic fluid collections. However, the optimal timing for conducting the procedure in those diagnosed with postoperative pancreatic fistula (POPF) has not been established. We aimed to elucidate the efficacy and safety of early EUS-TD procedures for treating POPF. Methods: We retrospectively reviewed patients diagnosed with POPF who underwent EUS-TD in the Kyushu University Hospital between 2008 and 2019. Clinical features were comparatively analyzed between the two patient groups who underwent either early (≤15 days postoperatively) or late (>15 days postoperatively) EUS-TD. Factors prolonging hospital stay were also analyzed using Cox proportional hazard models. Results: Thirty patients (median age, 64.5 years) were enrolled. The most common initial operation was distal pancreatectomy with splenectomy (60.0%). Median size of POPF was 69.5 (range, 38-145) mm, and median time interval between surgery and EUS-TD was 17.5 (range, 3-232) days. Totally, 47% patients underwent early EUS-TD. Rates of technical success, clinical success, and complications were 100%, 97%, and 6.9%, respectively. No recurrence of POPF occurred during a median follow-up period of 14 months. Clinical characteristics and outcomes were comparable between the early and late drainage patient groups, except for the rates of infection and nonencapsulation of POPF, which were significantly higher in the early drainage group. Performing simultaneous internal and external drainage (hazard ratio (HR): 0.31; 95% confidence interval (CI): 0.11-0.93, p=0.04) and conducting ≥2 treatment sessions (HR: 0.26; 95% CI: 0.08-0.84, p=0.02) were significantly associated with prolonged hospitalization after EUS-TD. Conclusions: EUS-TD is a safe and effective method for managing POPF, regardless of when it is performed in the postoperative period. Once infected POPF occurs, clinicians should not hesitate to perform EUS-TD even within 15 days of the initial operation.

Endoscopic mucosal resection vs endoscopic submucosal dissection for superficial non-ampullary duodenal tumors.

BACKGROUND: The selection of endoscopic treatments for superficial non-ampullary duodenal epithelial tumors (SNADETs) is controversial. AIM: To compare the efficacy and safety of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) for SNADETs. METHODS: We retrospectively analyzed the data of patients with SNADETs from a database of endoscopic treatment for SNADETs, which included eight hospitals in Fukuoka, Japan, between April 2001 and October 2017. A total of 142 patients with SNADETs treated with EMR or ESD were analyzed. Propensity score matching was performed to adjust for the differences in the patient characteristics between the two groups. We analyzed the treatment outcomes, including the rates of en bloc/complete resection, procedure time, adverse event rate, hospital stay, and local or metastatic recurrence. RESULTS: Twenty-eight pairs of patients were created. The characteristics of patients between the two groups were similar after matching. The EMR group had a significantly shorter procedure time and hospital stay than those of the ESD group [median procedure time (interquartile range): 6 (3-10.75) min vs 87.5 (68.5-136.5) min, P < 0.001, hospital stay: 8 (6-10.75) d vs 11 (8.25-14.75) d, P = 0.006]. Other outcomes were not significantly different between the two groups (en bloc resection rate: 82.1% vs 92.9%, P = 0.42; complete resection rate: 71.4% vs 89.3%, P = 0.18; and adverse event rate: 3.6% vs 17.9%, P = 0.19, local recurrence rate: 3.6% vs 0%, P = 1; metastatic recurrence rate: 0% in both). Only one patient in the ESD group underwent emergency surgery owing to intraoperative perforation. CONCLUSION: EMR has significantly shorter procedure time and hospital stay than ESD, and provides acceptable curability and safety compared to ESD. Accordingly, EMR for SNADETs is associated with lower medical costs.

Superiority of mucosal incision-assisted biopsy over ultrasound-guided fine needle aspiration biopsy in diagnosing small gastric subepithelial lesions: a propensity score matching analysis.

BACKGROUND: Gastric subepithelial lesions, including gastrointestinal stromal tumors, are often found during routine gastroscopy. While endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) has been the gold standard for diagnosing gastric subepithelial lesions, alternative open biopsy procedures, such as mucosal incision-assisted biopsy (MIAB) has been reported useful. The aim of this study is to evaluate the efficacy of MIAB for the diagnosis of gastric SELs compared with EUS-FNAB. METHODS: We retrospectively analyzed medical records of 177 consecutive patients with gastric SELs who underwent either MIAB or EUS-FNAB at five hospitals in Japan between January 2010 and January 2018. Diagnostic yield, procedural time, and adverse event rates for the two procedures were evaluated before and after propensity-score matching. RESULTS: No major procedure-related adverse events were observed in either group. Both procedures yielded highly-accurate diagnoses once large enough samples were obtained; however, such successful sampling was more often accomplished by MIAB than by EUS-FNAB, especially for small SELs. As a result, MIAB provided better diagnostic yields for SELs smaller than 20-mm diameter. The diagnostic yields of both procedures were comparable for SELs larger than 20-mm diameter; however, MIAB required significantly longer procedural time (approximately 13 min) compared with EUS-FNAB. CONCLUSIONS: Although MIAB required longer procedural time, it outperformed EUS-FNAB when diagnosing gastric SELs smaller than 20-mm diameter.

Learning Effect of Diagnosing Depth of Invasion Using Non-Extension Sign in Early Gastric Cancer.

BACKGROUND: Determining the depth of invasion is important when considering therapeutic strategies for early gastric cancer (EGC). We determined the effects of learning the non-extension sign, that is, an index of T1b2 in EGC, on identifying its depth of invasion. METHODS: Endoscopic images of 40 EGC cases (20 showing positive non-extension sign on endoscopy as T1b2 and 20 showing negative non-extension sign on endoscopy as T1a-T1b1) were randomly displayed on PowerPoint. Participants read endoscopy findings (pretest) and attended a 60-min lecture on how to read the non-extension sign. Then, they read the same images using the non-extension sign as the marker (posttest). The primary endpoint was a change in accuracy rate for determining the depth of invasion before and after attending the lecture, for nonexperts (< 80%). RESULTS: Among 35 endoscopists, 12 were nonexperts; their test results were used for analyses. Accuracy rates for pretest and posttest among nonexperts were 75.2 and 82.5%, respectively, showing a significant increase in the accuracy rate after learning to read the non-extension sign (p = 0.003). CONCLUSION: Nonexperts' diagnostic ability to determine the depth of invasion of EGC improved by learning to read the non-extension sign. Thus, the non-extension sign is considered a simple and useful diagnostic marker.

Mucosal incision-assisted biopsy versus endoscopic ultrasound-guided fine-needle aspiration with a rapid on-site evaluation for gastric subepithelial lesions: A randomized cross-over study.

OBJECTIVES: This study aimed to compare the diagnostic yield of mucosal incision-assisted biopsy (MIAB) and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) with a rapid on-site evaluation (ROSE) for gastric subepithelial lesions (SEL) suspected of being gastrointestinal stromal tumors (GIST) with an intraluminal growth pattern. METHODS: This was a prospective randomized, cross-over multicenter study. The primary outcome was the diagnostic yield of EUS-FNA and MIAB. The secondary outcomes were the technical success rate, complication rate, procedure time and biopsy frequency. RESULTS: A total of 47 patients were randomized to the MIAB group (n = 23) and EUS-FNA group (n = 24). There was no significant difference in the diagnostic yield of MIAB and EUS-FNA (91.3% vs 70.8%, P = 0.0746). The complication rates of MIAB and EUS-FNA did not differ to a statistically significant extent. The mean procedure time in the MIAB group was significantly longer than that in the EUS-FNA group (34 vs 26 min, P = 0.0011). CONCLUSIONS: The diagnostic yield of MIAB was satisfactorily as high as EUS-FNA with ROSE for gastric SEL with an intraluminal growth pattern.

Short- and long-term outcomes of endoscopic resection of rectal neuroendocrine tumours: analyses according to the WHO 2010 classification.

OBJECTIVE: Although the World Health Organisation (WHO) defined a novel classification of gastroenteropancreatic neuroendocrine tumours (NETs) in 2010, indications for endoscopic resection of rectal NETs in the guidelines were based on evidence accumulated for carcinoid tumours defined by a previous classification. This study was designed to clarify indications for endoscopic resection of rectal NETs corresponding to the new WHO classifications. MATERIAL AND METHODS: One hundred-seventy rectal NETs resected endoscopically from April 2001 to March 2012 were histologically re-classified according to the WHO 2010 criteria. The clinicopathological features of these lesions were analysed, and the short- and long-term outcomes of endoscopic resection were evaluated. RESULTS: Of the 170 rectal NETs, 166 were histopathologically diagnosed as NET G1 and four as NET G2. Thirty-eight tumours (22.4%) were positive for lymphovascular invasion, a percentage higher than expected. Although the curative resection rate was low (65.3%), en bloc (98.8%) and complete (85.9%) resection rates were high. Modified endoscopic mucosal resection (88.0%) and endoscopic submucosal dissection (92.2%) resulted in significantly higher complete resection rates than conventional endoscopic mucosal resection (36.4%). No patient experienced tumour recurrence, despite the low curative resection rate. CONCLUSION: Despite the low curative resection rate, prognosis after endoscopic resection of rectal NETs was excellent. Prospective large-scale, long-term studies are required to determine whether NET G2 and tumours >1 cm should be included in the indication for endoscopic resection and whether tumours with lymphovascular invasion can be followed up without additional surgery.

[Synchronous gastrointestinal stromal tumors of the rectum and duodenum: a case report].

An 85-year-old woman with anemia underwent colonoscopy, which revealed a 25-mm submucosal tumor with ulceration in the lower rectum. Histological examination of a biopsy showed that the lesion was a gastrointestinal stromal tumor (GIST). Subsequent esophagogastroduodenoscopy revealed a submucosal tumor in the duodenum, and examination of a biopsy obtained by endoscopic ultrasound-guided fine-needle aspiration also confirmed that this lesion was a GIST. The rectal lesion was surgically resected to control bleeding and was confirmed as a GIST histologically. Simultaneous development of GISTs in the rectum and duodenum is extremely rare.

[Three cases of pedunculated gastric hamartomatous inverted polyps resected endoscopically].

We report three cases of pedunculated gastric hamartomatous inverted polyps (HIPs) that were successfully treated by endoscopic polypectomy. The first case involved an 87-year-old woman with mild anemia. Esophagogastroduodenoscopy (EGD) revealed a pedunculated, reddish polyp located at the greater curvature of the upper stomach. The second case involved a 34-year-old woman in whom a pedunculated polyp was found at the gastric fundus during routine EGD. The third patient was a 59-year-old woman with epigastric discomfort. EGD revealed a pedunculated polyp in the gastric fundus. Polypectomy was successfully performed in all three cases. Histological examination revealed that the tumors comprised submucosal proliferation of cystically dilated gastric glands and hyperplastic glands;thus, we diagnosed gastric HIPs, which are rare and typically difficult to diagnose. Gastric HIPs should be considered in the differential diagnosis of elevated gastric lesions.

Key endoscopic ultrasound features of pancreatic ductal adenocarcinoma smaller than 20 mm.

BACKGROUND AND STUDY AIMS. Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis compared with other solid pancreatic tumors. Diagnosis of PDAC in the earliest possible stage is important to improve the prognosis. Although endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been the gold-standard modality for diagnosing pancreatic lesions, its diagnostic yield is not satisfactory for pancreatic tumors smaller than 20 mm. The purpose of this study was to determine the EUS findings that are useful for differentiating PDAC from other solid pancreatic tumors when the lesions are smaller than 20 mm. PATIENTS AND METHODS. We performed a retrospective review of 126 patients with pancreatic tumors smaller than 20 mm who had undergone EUS. According to the final pathological diagnoses, they were categorized into either the PDAC or non-PDAC group. We, then, compared the EUS findings between the two groups. RESULTS. Among the 126 patients, we diagnosed PDAC in 75 patients and non-PDAC in the remaining patients, including neuroendocrine tumor in 43 patients, intraductal papillary mucinous carcinoma in 3 patients, solid pseudopapillary neoplasm in 2 patients, and inflammatory pseudotumor in 3 patients. Of all EUS findings, three factors were significantly indicative of PDAC: an irregular tumor edge, main pancreatic duct dilation, and tumor location in the pancreatic head. The predicted probability for PDAC was 80%, 92.6%, and 74.1%, respectively. CONCLUSIONS. EUS could be a useful modality for differentiating PDAC from other solid pancreatic tumors, when the diagnostic yield of EUS-FNA is unsatisfactory, even for lesions smaller than 20 mm.

Prospective, randomized, double-blind, placebo-controlled trial of ulinastatin for prevention of hyperenzymemia after double balloon endoscopy via the antegrade approach.

BACKGROUND: Double balloon endoscopy (DBE) allows the entire small intestine to be viewed using a combination of antegrade and retrograde approaches. Acute pancreatitis is a serious complication of antegrade DBE with no effective prophylactic treatment currently available. Ulinastatin has been shown to be effective for the prevention of pancreatitis following endoscopic retrograde cholangiopancreatography. We therefore assessed the efficacy of ulinastatin for hyperenzymemia after antegrade DBE. PATIENTS AND METHODS: Forty-four patients were enrolled in this prospective, randomized, double-blind, placebo-controlled trial. Patients in the ulinastatin group received 150 000 U ulinastatin by i.v. drip infusion for 2 h from the start of the procedure. Serum concentrations of pancreatic amylase and lipase were measured before and 3 and 18 h after antegrade DBE. RESULTS: The study was terminated after interim analysis. Of the 44 patients, 23 were randomized to ulinastatin and 21 to placebo.The groups were similar with regard to sex ratio, age, type of endoscope, insertion time, total procedure time, number of endoscope pull-back procedures, and baseline pancreaticamylase and lipase concentrations. Post-DBE hyperenzymemia was observed in 35.0% and 47.8% of patients in the placebo and ulinastatin groups, respectively. The higher frequency of hyperenzymemia in the ulinastatin group was unexpected, but the difference was not statistically significant. One patient in the placebo group (5.0%) and none in the ulinastatin group experienced acute pancreatitis, but the difference was not statistically significant. CONCLUSION: The results of this trial suggest that ulinastatin does not prevent hyperenzymemia following antegrade DBE.

[A case of lymph node metastasis from esophageal small-cell-type endocrine cell carcinoma diagnosed by endoscopic ultrasound-guided fine-needle aspiration].

A 70-year-old man presented with a 0-IIc lesion in the lower esophagus. He underwent esophageal endoscopic submucosal dissection (ESD). The pathological diagnosis was squamous cell carcinoma with small cell carcinoma. The patient received chemoradiotherapy after ESD, but this was interrupted because of myelosuppression. Follow-up endoscopic ultrasonography (EUS) at 5 months after the ESD revealed paracardial lymph node swelling (17mm). He underwent EUS-guided fine-needle aspiration (FNA), and lymph node metastasis of small-cell-type endocrine cell carcinoma was diagnosed. He received VP-16 chemotherapy but died 22 months after the ESD.

Predictive factors for colonic diverticular rebleeding: a retrospective analysis of the clinical and colonoscopic features of 111 patients.

BACKGROUND/AIMS: Colonic diverticular bleeding can stop spontaneously or be stopped by endoscopic hemostasis. We analyzed the clinical and colonoscopic features of patients with colonic diverticular bleeding to establish the predictive factors for rebleeding. METHODS: A total of 111 patients (median age, 72 years) with colonic diverticular bleeding in Aso Iizuka Hospital between April 2007 and July 2010 were enrolled. Age, sex, body mass index (BMI), comorbidity, medication, location of bleeding, colonoscopic findings and hemostatic methods were analyzed retrospectively from the hospital records. RESULTS: The most common sites of bleeding were the ascending (39.6%) and sigmoid (29.7%) colon. Overt rebleeding occurred in 30 patients (27.0%). Spontaneous hemostasis was seen in 81 patients (73.0%), and endoscopic hemostatic treatment was performed in 30 patients. The BMI in the patients with colonic diverticular rebleeding was significantly higher than in patients without rebleeding. Colonoscopic findings of actively bleeding or nonbleeding visible vessels in the responsible diverticula were more frequent in the group with rebleeding. CONCLUSIONS: A higher BMI and colonoscopic findings of actively bleeding or nonbleeding visible vessels can be used as predictive factors for colonic diverticular rebleeding. Patients with such findings should be carefully followed up after hemostasis of the initial colonic diverticular bleeding.

Endoscopic submucosal dissection for esophageal granular cell tumor using the clutch cutter.

Endoscopic submucosal dissection (ESD) with a knife is a technically demanding procedure associated with a high complication rate. The shortcomings of this method are the deficiencies of fixing the knife to the target lesion, and of compressing it. These shortcomings can lead to major complications such as perforation and bleeding. To reduce the risk of complications related to ESD, we developed a new grasping type scissors forceps (Clutch Cutter®, Fujifilm, Japan) which can grasp and incise the targeted tissue using an electrosurgical current. Esophagogastroduodenoscopy on a 59-year-old Japanese man revealed a 16mm esophageal submucosal nodule with central depression. Endoscopic ultrasonography demonstrated a hypoechoic solid tumor limited to the submucosa without lymph node involvement. The histologic diagnosis of the specimen obtained by biopsy was granular cell tumor. It was safely and accurately resected without unexpected incision by ESD using the CC. No delayed hemorrhage or perforation occurred. Histological examination confirmed that the granular cell tumor was completely excised with negative resection margin.We report herein a case of esophageal granular cell tumor successfully treated by an ESD technique using the CC.

[A case of rectal implantation cyst diagnosed by EUS and EUS-guided FNA].

A 73-year-old woman was referred to our hospital complaining of bloody stool. She had undergone high anterior resection with the double stapling technique for a sigmoid colon cancer 2 years prior to this admission. Colonoscopy revealed a soft submucosal tumor, 4cm in size, on the anal side of the previous anastomosis in the rectum. EUS revealed a cystic lesion located in the third and fourth layers of the rectal wall. EUS-FNA was performed, and the content of the cystic lesion was transparent mucinous liquid. Histologically, the specimen revealed PAS and Alcian blue-positive mucinous material and a small number of inflammatory cells such as foamy macrophages. Therefore, this cystic lesion was diagnosed as a rectal implantation cyst.

Low-frequency of bacteremia after endoscopic submucosal dissection of the stomach.

BACKGROUND: Mainstream therapy for early gastric cancer in Japan has now shifted from endoscopic mucosal resection (EMR) to endoscopic submucosal dissection (ESD). Although bacteremia is reported as being infrequent and transient in gastric EMR, there are no reports of it being investigated in gastric ESD. This study aimed to determine the frequency of bacteremia in gastric ESD. PATIENTS AND METHODS: A prospective study, in 46 consecutive patients who underwent gastric ESD, investigated the frequency of bacteremia before and after the procedure. RESULTS: The median time for the total ESD procedure was 105min (range 30-400). The median volume of the submucosal injection was 80ml (range 20-260). The mean size of the resected specimen was 40±9.7mm. Blood cultures obtained before ESD were positive in 4.4% (2/45) of cases. Bacillus subtilis and Bacillus spp. were the isolated microorganisms. Blood cultures obtained 10min after ESD were positive in 4.3% (2/46) of cases; with the same microorganisms being isolated. Blood cultures obtained 3h after ESD were all negative. No signs of sepsis were seen in the two patients with a positive blood culture 10min after ESD. CONCLUSIONS: The frequency of bacteremia after gastric ESD was low and transient. ESD for gastric lesions is thought to have a low risk of infectious complications; therefore, prophylactic administration of antibiotics may not be warranted.