RESUMEN
Methotrexate may cause methotrexate-associated lymphoproliferative disorder (MTX-LPD); however, this disease is uncommon in the gastrointestinal tract. We examined six patients with MTX-LPD in the gastrointestinal tract at our hospital. All of the lesions were ulcerative. Four cases regressed spontaneously, all of which were positive for Epstein-Barr virus-encoded small RNA by in situ hybridization. Two patients who did not regress were negative for Epstein-Barr virus RNA, one of whom received chemotherapy, and one underwent surgery. The prognosis of this disease is considered to be good. MTX-LPD should considered when ulcerative lesions are observed during endoscopy in patients receiving MTX.
RESUMEN
The need for antimicrobial therapy for uncomplicated acute diverticulitis of the colon remains controversial. We conducted a systematic review of the efficacy of antimicrobial agents against this disease, including new randomized controlled trials (RCTs) reported in recent years, and evaluated their efficacy using a meta-analytic approach. RCTs were searched using PubMed, EMBASE, Google Scholar, Cochrane Library, Ichushi-Web, and eight registries. Keywords were 'colonic diverticulitis', 'diverticulitis', 'antimicrobial agents', ''antibiotics, 'complication', 'abscess', 'gastrointestinal perforation', 'gastrointestinal obstruction', 'diverticular hemorrhage', and 'fistula'. Studies with antimicrobial treatment in the intervention group and placebo or no treatment in the control group were selected by multiple reviewers using uniform inclusion criteria, and data were extracted. Prevention of any complication was assessed as the primary outcome, and efficacy was expressed as risk ratio (RR) and risk difference (RD). A meta-analysis was performed using 5 RCTs of the 21 studies that were eligible for scrutiny in the initial search and which qualified for final inclusion. Three of these studies were not included in the previous meta-analysis. Subjects included 1039 in the intervention group and 1040 in the control group. Pooled RRâ =â 0.86 (95% confidence interval, 0.58-1.28) and pooled RDâ =â -0.01 (-0.03 to 0.01) for the effect of antimicrobial agents in reducing any complications. Recurrences, readmissions, and surgical interventions did not significantly show the efficacies of using antimicrobial agents. A meta-analysis of recently reported RCTs did not provide evidence that antimicrobial therapy improves clinical outcomes in uncomplicated acute diverticulitis of the colon.
Asunto(s)
Antiinfecciosos , Diverticulitis del Colon , Diverticulitis , Humanos , Diverticulitis del Colon/tratamiento farmacológico , Antiinfecciosos/uso terapéutico , Antibacterianos/efectos adversosRESUMEN
We herein report a rare case of primary retroperitoneal mucinous cystadenocarcinoma (PRMC) in a 60-year-old man. The patient, who had been treated with infliximab for Crohn's disease of the colon for 13 years, was referred to our hospital for lower back pain. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging revealed multiple cystic lesions in the right retroperitoneum, the calcification of the cyst, and bone lesions. Bone and CT-assisted biopsies of the retroperitoneal lesions revealed poorly differentiated adenocarcinoma. The patient was diagnosed with PRMC with bone metastases using immunohistochemical staining and positron emission tomography/CT.
Asunto(s)
Enfermedad de Crohn , Cistadenocarcinoma Mucinoso , Neoplasias Retroperitoneales , Masculino , Humanos , Persona de Mediana Edad , Cistadenocarcinoma Mucinoso/diagnóstico por imagen , Cistadenocarcinoma Mucinoso/tratamiento farmacológico , Cistadenocarcinoma Mucinoso/patología , Infliximab/efectos adversos , Enfermedad de Crohn/complicaciones , Enfermedad de Crohn/tratamiento farmacológico , Neoplasias Retroperitoneales/diagnóstico por imagen , Neoplasias Retroperitoneales/tratamiento farmacológico , Tomografía Computarizada por Rayos XAsunto(s)
Resección Endoscópica de la Mucosa , Tracción , Humanos , Endoscopía , Instrumentos Quirúrgicos , LigaduraRESUMEN
Objectives: Endoscopic submucosal dissection (ESD) is effective for the resection of colorectal intramucosal lesions. This study was performed to examine the safety and effectiveness of using dexmedetomidine (DEX) in the anesthesia regimen of patients with colorectal lesions undergoing ESD. Methods: We retrospectively examined 287 consecutive patients who underwent ESD for colorectal lesions in our institution from January 2015 to December 2021. Outcomes including the frequency of intraprocedural pain and adverse events were compared between the DEX and no DEX groups. Moreover, univariate and multivariate analyses were conducted for each clinical factor of intraprocedural pain. Intraprocedural pain was defined as patient-reported abdominal pain or body movement during the procedure. Results: The incidence of intraprocedural pain was significantly lower in the DEX than in the no DEX group (7% vs. 17%, p = 0.02). The incidence of hypotension was also significantly higher in the DEX group (7% vs. 0%, p = 0.01), but no cerebrovascular or cardiac ischemic events occurred. In the univariate analyses, the diameter of the resected specimen, procedure time, no use of DEX, and total midazolam dose was associated with intraprocedural pain. The midazolam dose and DEX administration were significantly negatively correlated and the diameter of resected specimen and procedure time were significantly positively correlated. Multivariate logistic regression showed that no use of DEX was independently associated with intraprocedural pain (p = 0.02). Conclusions: Adding DEX to the anesthesia regimen in patients undergoing colorectal ESD appears to be safe and effective for reducing intraprocedural pain.
RESUMEN
Herein, we report two rare basaloid squamous cell carcinoma (BSCC) cases. Esophagogastroduodenoscopy revealed a submucosal tumor-like lesion and a biopsied specimen showed a finding suspected of BSCC in both cases. Both lesions underwent endoscopic submucosal dissection with en bloc resection, and long-term survival was achieved using additional chemoradiotherapy. The standard treatment for BSCC has not been determined, and there are few reports of esophageal BSCC treated using endoscopic resection. Endoscopic submucosal dissection and additional chemoradiotherapy for superficial BSCC may be effective treatment options.
RESUMEN
Background and study aims Underwater endoscopic mucosal resection (UEMR) is effective for colorectal intramucosal lesions. The aim of this study was to evaluate whether a longly-attached cap in UEMR improves the en bloc resection rate for 20-30âmm lesions. Patients and methods We performed a retrospective study at a tertiary institute. Candidates for the study were systematically retrieved from an endoscopic and pathological database from October 2016 to December 2020. We assessed the procedural outcomes with UEMR for lesions ≥ 20âmm in size and the clinical factors contributing to en bloc resection. Results A total of 52 colorectal lesions that underwent UEMR were included. The median procedure time was 271 (66-1264) seconds. The en bloc resection rate and R0 resection rate were 75â% and 73â%, respectively. Intraprocedural perforation occurred in one (1.9â%) case, but no bleeding occurred. Delayed bleeding occurred in one (1.9%) case, but no delayed perforation occurred. Regarding tumor size, macroscopic type, tumor location, and the presence or absence of a history of abdominal operation, there was no significant difference between the en bloc resection and piecemeal resection groups. The visibility of the whole lesion, a longly-attached cap, and sessile serrated lesions were more frequently observed in the en bloc resection group than in the piecemeal resection group ( P â<â0.001, P â=â0.01, and P â=â0.04, respectively). Multivariate analysis showed that a longly-attached cap was the only independent factor associated with en bloc resection ( P â=â0.02). Conclusions A longly-attached cap might contribute to en bloc resection.
RESUMEN
Background and Aim: Whether administration of antispasmodics as a component of premedication contributes to detection of lesions by screening esophagogastroduodenoscopy (EGDS) remains unclear. Our primary aim was to investigate this possibility. Methods: The cohort in this retrospective study comprised consecutive asymptomatic individuals who had undergone screening EGDS as part of a health check-up at the Japanese Red Cross Wakayama Medical Center from October 2015 to September 2020. The investigated lesions comprised esophageal squamous cell carcinoma or adenocarcinoma, gastric adenoma or adenocarcinoma, and duodenal adenoma or adenocarcinoma. Results: Targeted lesions were detected in 72 of 31 484 participants (0.23%), 18 260 and 13 224 of whom had received and not received pre-procedure antispasmodics, respectively. The rates of detection of lesions in these groups were 0.21% (38/18260) and 0.26% (34/13224), respectively (P = 0.40). Multivariate logistic regression analysis showed no association between administration of antispasmodics and rates of detection of targeted lesions [P = 0.24, Odds ratio (95% CI): 1.46 (0.78-2.75)]. Conclusions: Antispasmodics, which were administered to more than half of the study cohort, did not improve the rate of detection of targeted lesions.
RESUMEN
An 82-year-old man with fever and back pain was referred to our hospital and was thus found to be thrombocytopenic. A bone marrow biopsy revealed the diffuse infiltration of poorly differentiated neuroendocrine carcinoma (NEC). Computed tomography revealed a large hepatic mass. Considering the risk of bleeding due to thrombocytopenia, a needle biopsy was not performed. The patient rapidly deteriorated and died 10 days after presentation. An autopsy confirmed the diagnosis of primary hepatic NEC, with diffuse metastasis to the spleen, bone marrow, and systemic lymph nodes. This is an extremely rare case of NEC presenting with thrombocytopenia due to extensive bone marrow and splenic infiltration.
Asunto(s)
Anemia , Carcinoma Neuroendocrino , Trombocitopenia , Masculino , Humanos , Anciano de 80 o más Años , Médula Ósea/patología , Autopsia , Bazo/patología , Trombocitopenia/complicaciones , Anemia/patología , Carcinoma Neuroendocrino/complicaciones , Carcinoma Neuroendocrino/diagnóstico , Carcinoma Neuroendocrino/patologíaRESUMEN
BACKGROUND AND AIM: A multicenter randomized controlled trial reported a better R0 resection rate for intermediate-sized (10-20 mm) colorectal polyps with underwater endoscopic mucosal resection (UEMR) than conventional endoscopic mucosal resection (CEMR). To clarify whether UEMR removes enough submucosal tissue in the removal of unpredictable invasive cancers, we investigated the cutting plane depth with UEMR versus CEMR. METHODS: This was a post-hoc analysis of a randomized controlled trial in which 210 intermediate-sized colorectal polyps were removed in five Japanese hospitals. One pathologist and two gastroenterologists independently reviewed all resected specimens and measured the cutting plane depth. The cutting plane depth was evaluated as (i) maximum depth of submucosal layer and (ii) mean depth of submucosal layer, calculated using a virtual pathology system. RESULTS: We identified 168 appropriate specimens for the evaluation of the cutting plane depth, resected by UEMR (n = 88) and CEMR (n = 80). The median resection depth was not significantly different between UEMR and CEMR specimens, regardless of the measurement method ([i] 1317 vs 1290 µm, P = 0.52; [ii] 619 vs 545 µm, P = 0.32). All specimens in the UEMR and CEMR groups contained substantial submucosa and no muscularis propria. CONCLUSIONS: The cutting plane depth with UEMR was comparable with that with CEMR. UEMR can be a viable alternative method that adequately resects the submucosal layer for the histopathological assessment of unpredictable submucosal invasive cancers.
Asunto(s)
Neoplasias Colorrectales , Resección Endoscópica de la Mucosa , Colonoscopía/métodos , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/cirugía , Resección Endoscópica de la Mucosa/métodos , Humanos , Mucosa Intestinal/patología , Mucosa Intestinal/cirugía , Recurrencia Local de Neoplasia/patologíaAsunto(s)
Aneurisma de la Aorta Abdominal , Pólipos del Colon , Coagulación Intravascular Diseminada , Aneurisma de la Aorta Abdominal/complicaciones , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/cirugía , Colonoscopía , Coagulación Intravascular Diseminada/etiología , Hemorragia , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND AND AIMS: Endoscopic resection of nonampullary duodenal adenoma is often challenging, and its technique has not yet been standardized. To overcome the practical difficulty of conventional endoscopic mucosal resection, underwater endoscopic mucosal resection (UEMR) was recently developed; therefore, we investigated the effectiveness and safety of UEMR for nonampullary duodenal adenoma. METHODS: A multicenter, prospective cohort study was conducted at 21 institutions in Japan. We enrolled patients with no more than 2 nonampullary duodenal adenomas ≤20 mm in size, who were planned to undergo UEMR. After UEMR, follow-up endoscopies were scheduled at 2 and 12 months after the procedure, and biopsy specimens were taken from the post-UEMR scars. The primary endpoint was the proportion of patients with histologically proven nonrecurrence at follow-up endoscopy and biopsy. RESULTS: A total of 155 patients with 166 lesions underwent UEMR. One patient with a non-neoplastic lesion in the resected specimen and 10 patients with 10 lesions who were lost to follow-up were excluded. Finally, 144 patients with 155 lesions who received all follow-up endoscopies were analyzed for the primary endpoint. The proportion of patients with proven nonrecurrence was 97.2% (n = 140 of 144; 95% confidence interval, 92.8%-99.1%) which exceeded the predefined threshold value (92%). Two cases of delayed bleeding (1.2%) occurred and they were successfully managed by clips. All recurrences were successfully treated by additional endoscopic treatment. CONCLUSIONS: This multicenter, prospective cohort study demonstrated effectiveness and safety of UEMR for nonampullary duodenal adenomas ≤20 mm in size. (University Hospital Medical Network Clinical Trials Registry, Number: UMIN000030414).
Asunto(s)
Adenoma , Neoplasias Duodenales , Resección Endoscópica de la Mucosa , Adenoma/patología , Adenoma/cirugía , Neoplasias Duodenales/patología , Neoplasias Duodenales/cirugía , Resección Endoscópica de la Mucosa/efectos adversos , Resección Endoscópica de la Mucosa/métodos , Humanos , Mucosa Intestinal/patología , Estudios Prospectivos , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Pyogenic granuloma (PG) is a benign inflammatory vascular lesion rarely seen in the gastrointestinal tract and a possible cause of bleeding. Polypectomy using a detachable snare for esophageal PG with active bleeding is an effective treatment.
RESUMEN
BACKGROUND: Endoscopic removal of colorectal adenoma is considered an effective treatment for reducing the mortality rates associated with colorectal cancer. Warfarin, a type of anticoagulant, is widely used for the treatment and prevention of thromboembolism; however, bleeding may increase with its administration after polypectomy. In recent times, a high incidence of bleeding after endoscopic polypectomy has been reported in patients receiving heparin bridge therapy. However, previous studies have not compared the bleeding rate after endoscopic colorectal polypectomy between patients who continued with anticoagulant therapy and those who received heparin bridge therapy. We hypothesised that endoscopic colorectal polypectomy under the novel treatment with continuous warfarin is not inferior to endoscopic colorectal polypectomy under standard treatment with heparin bridge therapy with respect to the rate of postoperative bleeding. This study aims to compare the efficacy of endoscopic colorectal polypectomy with continuous warfarin administration and endoscopic colorectal polypectomy with heparin bridge therapy with respect to the rate of postoperative bleeding. METHODS: We will conduct a prospective multicentre randomised controlled non-inferiority trial of two parallel groups. We will compare patients scheduled to undergo colorectal polypectomy under anticoagulant therapy with warfarin. There will be 2 groups, namely, a standard treatment group (heparin bridge therapy) and the experimental treatment group (continued anticoagulant therapy). The primary outcome measure is the rate of postoperative bleeding. On the contrary, the secondary outcomes include the rate of cumulative bleeding, rate of overt haemorrhage (that does not qualify for the definition of haemorrhage after endoscopic polypectomy), incidence of haemorrhage requiring haemostasis during endoscopic polypectomy, intraoperative bleeding during endoscopic colorectal polypectomy requiring angiography, abdominal surgery and/or blood transfusion, total rate of bleeding, risk factors for postoperative bleeding, length of hospital stay, incidence of thromboembolism, prothrombin time-international ratio (PT-INR) 28 days after the surgery, and incidence of serious adverse events. DISCUSSION: The results of this randomised controlled trial will provide valuable information for the standardisation of management of anticoagulants in patients scheduled to undergo colorectal polypectomy. TRIAL REGISTRATION: UMIN-CTR UMIN000023720 . Registered on 22 August 2016.
Asunto(s)
Neoplasias Colorrectales , Warfarina , Anticoagulantes/efectos adversos , Neoplasias Colorrectales/cirugía , Heparina/efectos adversos , Humanos , Estudios Multicéntricos como Asunto , Hemorragia Posoperatoria/inducido químicamente , Hemorragia Posoperatoria/prevención & control , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto , Warfarina/efectos adversosRESUMEN
Sedation in gastroenterological endoscopy has become an important medical option in routine clinical care. Here, the Japan Gastroenterological Endoscopy Society and the Japanese Society of Anesthesiologists together provide the revised "Guidelines for sedation in gastroenterological endoscopy" as a second edition to address on-site clinical questions and issues raised for safe examination and treatment using sedated endoscopy. Twenty clinical questions were determined and the strength of recommendation and evidence quality (strength) were expressed according to the "MINDS Manual for Guideline Development 2017." We were able to release up-to-date statements related to clinical questions and current issues relevant to sedation in gastroenterological endoscopy (henceforth, "endoscopy"). There are few reports from Japan in this field (e.g., meta-analyses), and many aspects have been based only on a specialist consensus. In the current scenario, benzodiazepine drugs primarily used for sedation during gastroenterological endoscopy are not approved by national health insurance in Japan, and investigations regarding expense-related disadvantages have not been conducted. Furthermore, including the perspective of beneficiaries (i.e., patients and citizens) during the creation of clinical guidelines should be considered. These guidelines are standardized based on up-to-date evidence quality (strength) and supports on-site clinical decision-making by patients and medical staff. Therefore, these guidelines need to be flexible with regard to the wishes, age, complications, and social conditions of the patient, as well as the conditions of the facility and discretion of the physician.
Asunto(s)
Gastroenterología , Sedación Consciente , Endoscopía Gastrointestinal , Humanos , JapónRESUMEN
Papillary adenocarcinomas of the stomach are rare and associated with a high rate of lymphovascular invasion and distant metastasis. However, the association between papillary adenocarcinoma and bone metastasis in gastric cancer remains largely unexplored. We report a rare case of bone metastasis as a recurrence of early papillary adenocarcinoma of the stomach after curative surgery. A 75-year-old man with a pedunculated polyp at the pylorus of the stomach was diagnosed with papillary adenocarcinoma after biopsy of the lesion, and the polyp was surgically resected. Pathohistological examination revealed intramucosal cancer without lymphovascular invasion or lymph node metastasis. Eight months after surgery, imaging studies showed osteolysis in the right sacrum, and the lesion was diagnosed as a bone metastasis after biopsy. The patient received palliative chemotherapy and radiotherapy for the bone metastasis, which resulted in relief of his leg pain. Subsequently, he was provided supportive care when his condition deteriorated, and he died 8 months after the diagnosis of bone metastasis. Our case shows that bone metastasis should not be overlooked, even though it is rare in gastric cancer patients. Papillary adenocarcinoma of the stomach should be carefully followed up through imaging examinations, even after curative resection.
Asunto(s)
Adenocarcinoma Papilar/patología , Neoplasias Óseas/secundario , Recurrencia Local de Neoplasia/patología , Neoplasias Gástricas/patología , Anciano , Neoplasias Óseas/diagnóstico por imagen , Endoscopía del Sistema Digestivo , Humanos , Masculino , Tomografía de Emisión de Positrones , Sacro/diagnóstico por imagen , Estómago/patologíaRESUMEN
Background: Management of anticoagulants for patients undergoing polypectomy is still controversial. Cold snare polypectomy (CSP) is reported to cause less bleeding than hot snare polypectomy (HSP). Objective: To compare outcomes between continuous administration of anticoagulants (CA) with CSP (CA+CSP) and periprocedural heparin bridging (HB) with HSP (HB+HSP) for subcentimeter colorectal polyps. Design: Multicenter, parallel, noninferiority randomized controlled trial. (University Hospital Medical Information Network Clinical Trials Registry: UMIN000019355). Setting: 30 Japanese institutions. Patients: Patients receiving anticoagulant therapy (warfarin or direct oral anticoagulants) who had at least 1 nonpedunculated subcentimeter colorectal polyp. Intervention: Patients were randomly assigned to undergo HB+HSP or CA+CSP and followed up 28 days after polypectomy. Measurements: The primary end point was incidence of polypectomy-related major bleeding (based on the incidence of poorly controlled intraprocedural bleeding or postpolypectomy bleeding requiring endoscopic hemostasis). The prespecified inferiority margin was -5% (CA+CSP vs. HB+HSP). Results: A total of 184 patients were enrolled: 90 in the HB+HSP group, 92 in the CA+CSP group, and 2 who declined to participate after enrollment. The incidence of polypectomy-related major bleeding in the HB+HSP and CA+CSP groups was 12.0% (95% CI, 5.0% to 19.1%) and 4.7% (CI, 0.2% to 9.2%), respectively. The intergroup difference for the primary end point was +7.3% (CI, -1.0% to 15.7%), with a 0.4% lower limit of 2-sided 90% CI, demonstrating the noninferiority of CA+CSP. The mean procedure time for each polyp and the hospitalization period were longer in the HB+HSP than in the CA+CSP group. Limitation: An open-label trial assessing 2 factors (anticoagulation approach and polypectomy procedure type) simultaneously. Conclusion: Patients having CA+CSP for subcentimeter colorectal polyps who were receiving oral anticoagulants did not have an increased incidence of polypectomy-related major bleeding, and procedure time and hospitalization were shorter than in those having HB+HSP. Primary Funding Source: Japanese Gastroenterological Association.
Asunto(s)
Anticoagulantes/administración & dosificación , Pólipos del Colon/cirugía , Electrocoagulación/métodos , Heparina/administración & dosificación , Hemorragia Posoperatoria/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Colonoscopía , Femenino , Hemostasis Quirúrgica , Humanos , Incidencia , Japón/epidemiología , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Tempo Operativo , Hemorragia Posoperatoria/cirugíaRESUMEN
Background and study aims We developed an e-learning program for endoscopic diagnosis of invasion depth of early gastric cancer (EGC) using a simple diagnostic criterion called non-extension sign, and the contribution of self-study quizzes to improvement of diagnostic accuracy was evaluated. Methods We conducted a prospective randomized controlled study that recruited endoscopists throughout Japan. After completing a pretest, the participants watched video lectures and undertook post-test 1. The participants were then randomly allocated to either the self-study or non-self-study group, and participants in the first group completed the self-study program that comprised 100-case quizzes. Finally, participants in both groups undertook post-test 2. The primary endpoint was the difference in post-test 2 scores between the groups. The perfect score for the tests was set as 100 points. Results A total of 423 endoscopists completed the pretest and were enrolled. Post-test 1 was completed by 415 endoscopists and 208 were allocated to the self-study group and 207 to the non-self-study group.âTwo hundred and four in the self-study group and 205 in the non-self-study group were included in the analysis. Video lectures improved the mean score of post-test 1 from 72 to 77 points. Participants who completed the self-study quizzes showed significantly better post-test 2 scores compared with the non-self-study group (80 vs. 76 points, respectively, P â<â0.0001). Conclusions Our e-learning program showed that self-study quizzes consolidated knowledge of the non-extension sign and improved diagnostic ability of endoscopists for invasion depth of EGC.
RESUMEN
BACKGROUND & AIMS: Endoscopic mucosal resection (EMR) with submucosal injection is an established method for removing colorectal polyps, although the en bloc resection rate decreases when polyp size exceeds 10 mm. Piecemeal resection increases local recurrence. Underwater EMR (UEMR) is an effective technique for removal of sessile colorectal polyps and we investigated whether it is superior to conventional EMR (CEMR). METHODS: We conducted a multicenter randomized controlled trial at 5 institutions in Japan. Patients with endoscopically diagnosed, intermediate-size (10-20 mm) sessile colorectal lesions were randomly assigned to undergo UEMR or CEMR. Only the most proximal lesion was registered. The UEMR procedure included immersion of the entire lumen in water and snare resection of the lesion without submucosal injection of normal saline. We analyzed outcomes of 108 colorectal lesions in the UEMR group and 102 lesions in the CEMR group. R0 resection was defined as en bloc resection with a histologically confirmed negative resection margin. The primary endpoint was the difference in the R0 resection rates between groups. RESULTS: The proportions of R0 resections were 69% (95% confidence interval [CI] 59%-77%) in the UEMR group vs 50% (95% CI 40%-60%) in the CEMR group (P = .011). The proportions of en bloc resections were 89% (95% CI 81%-94%) in the UEMR group vs 75% (95% CI 65%-83%) in the CEMR group (P = .007). There was no significant difference in median procedure time (165 vs 175 seconds) or proportions of patients with adverse events (2.8% in the UEMR group vs 2.0% in the CEMR group). CONCLUSIONS: In a multicenter randomized controlled trial, we found that UEMR significantly increased the proportions of R0 resections for 10- to 20-mm sessile colorectal lesions without increasing adverse events or procedure time. Use of this procedure should be encouraged. Trials registry number: UMIN000018989.