Cysts or necrotic components in pancreatic ductal adenocarcinoma is associated with the risk of EUS-FNA/B complications including needle tract seeding.

BACKGROUND: EUS-FNA/B for pancreatic ductal adenocarcinoma (PDAC) is generally considered to be safe; however, while the incidence is low, there are occurrences of complications. Among these complications, there are serious ones like needle tract seeding (NTS), and it is not known than which types of tumors have the risks of EUS-FNA/B complications. This study aimed to evaluate the risk of EUS-FNA/B complications in patients with PDAC, focusing on morphological features. METHODS: Overall, 442 patients who underwent EUS-FNA/B for solid pancreatic masses between January 2018 and May 2022 in four institutions were retrospectively surveyed. Finally, 361 patients histopathologically diagnosed with PDAC were analyzed. Among these patients, 79 tumors with cysts or necrotic components were compared with 282 tumors without cysts or necrotic components. The incidence and risk of EUS-FNA/B complications including NTS were evaluated. RESULTS: There were 9 (2.4 %) of total EUS-FNA/B complications and 3 (0.8 %) of NTS. The incidence of total complication rate and NTS in tumors with cysts or necrotic components were significantly higher than in those without cysts or necrotic components (total complication 6.3 % vs. 1.4 %, p = 0.026, NTS 3.7 % vs. 0 %, p = 0.01). The transgastric route of puncture (OR: 93.3, 95 % CI: 3.81-2284.23) and the existence of cysts or necrotic components (OR: 7.3, 95 % CI: 1.47-36.19) were risk factors for EUS-FNA/B complications identified by the multivariate analysis. CONCLUSIONS: We should pay attention to the risks of EUS-FNA/B complications, including NTS, when the tumor has cysts or necrotic components.

The efficacy of non-anesthesiologist-administered propofol sedation with a target-controlled infusion system during double-balloon endoscopic retrograde cholangiopancreatography.

BACKGROUND: The sedation method used during double-balloon endoscopic retrograde cholangiopancreatography (DB-ERCP) differs among countries and/or facilities, and there is no established method. This study aimed to evaluate the efficacy of non-anesthesiologist-administered propofol (NAAP) sedation using a target-controlled infusion (TCI) system during DB-ERCP. METHODS: This retrospective study was conducted between May 2017 and December 2020 at an academic center. One hundred and fifty-six consecutive patients who underwent DB-ERCP were sedated by gastroenterologists using diazepam (n = 77) or propofol with a TCI system (n = 79), depending on the period. The primary endpoint was a comparison of poor sedation rates between the two groups. Poor sedation was defined as a condition requiring the use of other sedative agents or discontinuation of the procedure. Secondary endpoints were sedation-related adverse events and risk factors for poor sedation. RESULTS: Poor sedation occurred significantly more often in the diazepam sedation group (diazepam sedation, n = 12 [16%] vs. propofol sedation, n = 1 [1%]; P = 0.001). Vigorous body movements (3 or 4) (diazepam sedation, n = 40 [52%] vs. propofol sedation, n = 28 [35%]; P = 0.038) and hypoxemia (< 85%) (diazepam sedation, n = 7 [9%] vs. propofol sedation, n = 1 [1%]; P = 0.027) occurred significantly more often in the diazepam sedation group. In the multivariate analysis, age < 70 years old (OR, 10.26; 95% CI, 1.57-66.98; P = 0.015), BMI ≥ 25 kg/m2 (OR, 11.96; 95% CI, 1.67-85.69; P = 0.014), and propofol sedation (OR, 0.06; 95% CI, 0.01-0.58; P = 0.015) were associated factors for poor sedation. CONCLUSIONS: NAAP sedation with the TCI system during DB-ERCP was safer and more effective than diazepam sedation.

Risk Factors for Ceftriaxone-Associated Pseudolithiasis in Adults.

INTRODUCTION: Ceftriaxone (CTRX) is known to occasionally cause pseudolithiasis. This condition is often observed in children; however, few studies have reported the incidence and risk factors for CTRX-associated pseudolithiasis. METHODS: In this single-center retrospective study, we investigated the incidence of and risk factors for CTRX-associated pseudolithiasis in adults. All patients underwent computed tomography to confirm pseudolithiasis before and after CTRX administration. RESULTS: The study included 523 patients. Pseudolithiasis was detected in 89 patients (17%). Data analysis showed that abdominal area-related biliary diseases at the site of infection (odds ratio [OR] 0.19, 95% confidence interval [CI] 0.064-0.53, p = 0.0017), CTRX administration for >3 days (OR 5.0, 95% CI: 2.5-9.9, p < 0.0001), CTRX dose of 2 mg (OR 5.2, 95% CI: 2.8-9.6, p < 0.0001), fasting period >2 days (OR 3.2, 95% CI: 1.6-6.4, p = 0.0010), and estimated glomerular filtration rate <30 mL/min/1.73 m2 (OR 3.4, 95% CI: 1.6-7.5, p = 0.0022) were independent factors for pseudolithiasis. CONCLUSIONS: CTRX-associated pseudolithiasis may occur in adults and should be considered in the differential diagnosis in patients who develop abdominal pain or liver enzyme elevation after CTRX administration, particularly in patients with chronic kidney disease, in those who are fasting, in and those who receive high-dose CTRX therapy.

Endocrinological Changes after Anamorelin Administration in Patients with Gastrointestinal Cancer.

Changes in hormone levels in patients with cancer cachexia after anamorelin administration have not been fully investigated. This study aimed to determine how anamorelin affects the endocrine system in patients with gastrointestinal cancer and cachexia. We prospectively enrolled 13 patients and comprehensively investigated their body weight and levels of serum albumin, hemoglobin A1c (HbA1c), and hormones before (week 0) and 3 and 12 weeks after anamorelin administration. The variables were evaluated at week 3 in 9 patients and at week 12 in 5 patients. At week 3, anamorelin administration resulted in body weight gain and increased the levels of growth hormone and HbA1c, as well as insulin-like growth factor-1 standard deviation scores (IGF-1 SD scores). At the same time, negative correlations were observed between ΔIGF-1 SD score and Δthyroidstimulating hormone (TSH) and between ΔIGF-1 SD score and Δfree testosterone. ΔBody weight and ΔIGF-1 SD score correlated positively at week 12. These results suggest that TSH and free testosterone levels can be affected 3 weeks after anamorelin administration; however, those variables tend to return to a state of equilibrium, and anabolic effects of anamorelin appear in long-term (≥ 12 weeks) users.

A Comparison of the Efficacy of Plastic Stent Placement Above and Across the Sphincter of Oddi for Benign Biliary Hilar Stricture.

We investigated the efficacy and safety of endoscopic plastic stent (PS) placement for hilar benign biliary strictures (BBSs) and compared cases with PS placement above (inside stent, IS) and across (usual stent, US) the sphincter of Oddi. Patients who underwent initial endoscopic PS placement for hilar BBSs between August 2012 and December 2021 were retrospectively analyzed. Hilar BBSs in 88 patients were investigated. Clinical success was achieved in 81 of these cases (92.0%), including 38 patients in the IS group and 43 patients in the US group. Unexpected stent exchange (uSE) before the first scheduled PS exchange occurred in 18 cases (22.2%). The median time from first stent placement to uSE was 35 days. There was no significant difference in the rate and median time to uSE between the two groups. The rates of adverse events such as pancreatitis or cholangitis in the two groups did not significantly differ. However, the rate of difficult stent removal in the IS group (15.8%) was significantly higher than that in the US group (0%) (p=0.0019). US placement is preferable to IS placement for scheduled stent exchange, as it offers the same effectiveness and risk of adverse events with easier stent removal.

Association between BRCA Gene Variants and the Response to Modified FOLFIRINOX in Patients with Unresectable Pancreatic Cancer.

We investigated the effect of modified FOLFIRINOX (mFFX) in unresectable pancreatic cancer by retrospectively analyzing the cases of 43 patients who underwent BRCA testing (germline, n=11; somatic, n=26; both germline and somatic, n=6). The association between BRCA mutations and therapeutic effect was clarified. Six patients tested positive for germline pathogenic variants. Familial pancreatic cancer (33% vs. 3%, p=0.006) and peritoneal disseminated lesions (66% vs. 8%, p<0.001) were significantly more common in patients with germline pathogenic variants. The partial response (PR) rate was 100% in the germline BRCA-positive patients, and 27% in the germline BRCA-negative patients (p<0.001). The median progression-free survival (PFS) was not reached for any germline BRCA-positive patients but was 9.0 months for the germline BRCA-negative patients (p=0.042). Patients with stage IV BRCA-associated pancreatic cancer had better overall survival than those with non-BRCA-associated pancreatic cancer, although the difference was nonsignificant (not reached vs. 655 days, p=0.061). Our results demonstrate that a PR and prolonged PFS can be expected in germline BRCA-positive patients after treatment with mFFX. Our findings also suggest that germline BRCA pathogenic variants may be useful as biomarkers for the therapeutic effect of mFFX in patients with pancreatic cancer.

Double guidewire technique stabilization procedure for endoscopic ultrasound-guided hepaticogastrostomy involving modifying the guidewire angle at the insertion site.

BACKGROUND AND AIMS: Endoscopic ultrasonography-guided hepaticogastrostomy (EUS-HGS) is often performed using a single guidewire (SGW), but the efficacy of the double guidewire (DGW) technique during endoscopic ultrasonography-guided biliary drainage has been reported. We evaluated the efficacy of the DGW technique for EUS-HGS, focusing on the guidewire angle at the insertion site. METHODS: This retrospective cohort study included consecutive patients who underwent EUS-HGS between April 2012 and March 2021. We measured the guidewire angle at the insertion site using still fluoroscopic imaging. We compared the clinical outcomes of EUS-HGS with the DGW and SGW techniques. The factors associated with successful cannula insertion, need for additional fistula dilation and adverse event rate were assessed by a logistic regression multivariable analysis. RESULTS: The DGW group showed higher technical (p = 0.020) and clinical success rates (p = 0.016) than the SGW group, which showed more adverse events (p = 0.017) than the DGW group. Successful cannula insertion was associated with a guidewire angle > 137° and an uneven double-lumen cannula. The DGW technique made the guidewire angle obtuse at the insertion site (p < 0.0001). A guidewire angle ≤ 137° (OR, 35.6; 95% CI, 1.70-744; p = 0.0045) and intrahepatic bile duct diameter of the puncture site ≤ 3.0 mm (OR, 14.4; 95% CI, 1.37-152; p = 0.0056) were risk factors for needing additional fistula dilation in a multivariate analysis, and additional dilation was a significant predictive factor for adverse events (OR, 8.3; 95% CI, 0.9-77; p = 0.026). CONCLUSIONS: The DGW technique can modify the guidewire angle at the insertion site and facilitate stent deployment with few adverse events.

Randomized trial comparing the 25G and 22G Franseen needles in endoscopic ultrasound-guided tissue acquisition from solid pancreatic masses for adequate histological assessment.

BACKGROUND: The effects of the Franseen needle size in endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) of solid pancreatic masses remain unclear. This study aimed to compare 25G and 22G Franseen needles in terms of adequate tissue acquisition from solid pancreatic masses. METHODS: In this single-center, crossover, randomized noninferiority trial, eligible patients underwent EUS-FNB with both 25G and 22G Franseen needles in a randomized order between November 2018 and August 2020. Tissue specimens from each pass were separately evaluated based on the cellularity scoring system. The primary outcome was the proportion of acquired specimens allowing adequate histological assessment (cellularity score ≥3). A -15% noninferiority margin was assumed. RESULTS: Data from 88 patients were analyzed, which showed malignant and benign lesions in 84 (95.5%) and four (4.5%) patients, respectively. Of the 88 specimens, 62 (70.5%) and 69 (78.4%) acquired using 25G and 22G needles, respectively, allowed adequate histological assessment. The adjusted proportion difference was -6.6% (95% confidence interval -8.8% to -4.5%), indicating noninferiority of the 25G Franseen needle (P < 0.001). The diagnostic accuracies of the 25G and 22G needles were 86.4% and 89.8%, respectively, with no significant difference (P = 0.180). Adverse events occurred in one patient. CONCLUSIONS: The 25G Franseen needle showed a noninferior adequate tissue acquisition and similar diagnostic performance compared to that of the 22G Franseen needle. However, a 15% noninferiority margin was high for clinical use; thus, further consideration is needed (Clinical Trial Registry no. UMIN000034596).

[A case of Peutz-Jeghers syndrome that developed triple cancers during the course].

At the time of colon polyp follow-up, a 46-year-old Japanese woman with a history of invagination, colon polyps, cervical cancer, and breast cancer was suspected of Peutz-Jeghers syndrome and referred. Multiple polyposes of the jejunum were discovered by capsule endoscopy and double-balloon endoscopy, and the resected specimen was diagnosed with hamartoma. During the follow-up, advanced pancreatic cancer-derived from IPMN developed. It is important to remember that multiple cancers can develop in Peutz-Jeghers syndrome.

Endoscopic ultrasonography findings of pancreatic parenchyma for predicting subtypes of intraductal papillary mucinous neoplasms.

BACKGROUND AND AIMS: The subtypes of intraductal papillary mucinous neoplasms (IPMNs) are closely associated with the clinicopathological behavior and recurrence after surgical resection. However, there are no established non-invasive methods to confirm the subtypes of IPMNs without surgery. The aim of this study is to predict the subtypes of IPMNs using the findings of endoscopic ultrasonography (EUS). METHODS: Sixty-two consecutive patients with IPMNs who underwent EUS before surgery were retrospectively reviewed. The following EUS findings were analyzed and their relationship with the subtypes was evaluated: diameter of the main pancreatic duct, cyst size, number of cysts, height of mural nodule, early chronic pancreatitis (CP) finding, fatty parenchyma and atrophic parenchyma. RESULTS: The subtypes of IPMNs were as follows: gastric (G)-type 38 (61%), intestinal (I) -type 14 (23%) and pancreatobiliary (PB) -type 10 (16%). Fatty parenchyma was significantly associated with G-type (P < 0.0001). Early CP findings ≥2 and atrophic parenchyma were significantly correlated with I-type (P < 0.0001). PB-type was significantly associated with pancreatic parenchyma without early CP findings or fatty degeneration in comparison to the other subtypes (P < 0.0001). Using the above characteristic EUS findings, the sensitivity, specificity, and accuracy were as follows: 63%, 92% and 74%, respectively, in G-type, 57%, 96% and 87% in I-type, and 90%, 94% and 94% in PB-type. CONCLUSIONS: The evaluation of EUS findings, especially focused on the pancreatic parenchyma, has the potential to predict the subtypes of IPMN.

Outcomes of endoscopic treatment for malignant biliary obstruction in patients with surgically altered anatomy: analysis of risk factors for clinical failure.

BACKGROUND: To evaluate the outcomes of endoscopic retrograde cholangiopancreatography (ERCP) for malignant biliary obstruction (MBO) using short-type double-balloon enteroscope (sDBE) in patients with surgically altered anatomy. METHODS: A total of 45 patients with surgically altered anatomy underwent ERCP using sDBE for the treatment of MBO between April 2011 and March 2019. We retrospectively evaluated the clinical and technical success (insertion and biliary intervention success), adverse events, and risk factors for clinical failure. RESULTS: The scope was successfully inserted in the target site in 82.2% of patients (37/45), and among them, biliary intervention success was achieved in 86.4% (32/37). The overall technical success rate was 71.1% (32/45) and clinical success rate was 68.9% (31/45), with an adverse event rate of 11.1%. In multivariate analysis, the presence of peritoneal dissemination (odds ratio, 7.3; 95% confidence interval, 1.5-43.5, p = 0.02) was as an independent risk factor for clinical failure. The clinical success rate was 38.5% in patients with peritoneal dissemination and 81.3% in those without peritoneal dissemination. CONCLUSION: Endoscopic treatment using sDBE in patients without peritoneal dissemination provided favorable outcomes, and it can be an initial treatment for MBO in patients with surgically altered anatomy.

Treatment outcomes, including risk factors of stone recurrence, for hepatolithiasis using balloon-assisted endoscopy in patients with hepaticojejunostomy (with video).

BACKGROUND AND STUDY AIMS: Endoscopic treatment outcomes for hepatolithiasis in patients with altered anatomy are not well known. The aim of this study was to evaluate the treatment outcomes of hepatolithiasis in patients with hepaticojejunostomy (HJ) using short-type double-balloon endoscopy (sDBE) and to assess the risk factors for stone recurrence. PATIENTS AND METHODS: This was a retrospective cohort study that consisted of 73 patients with hepatolithiasis who underwent bowel reconstruction with HJ at an academic center. Stone removal was performed using sDBE. After balloon-occluded cholangiography using sDBE, peroral direct cholangioscopy (PDCS) using ultraslim endoscopy was performed to check for residual stones, depending on the bowel reconstruction method. Recurrence was defined as the development of cholangitis from stones. RESULTS: The success rate of reaching the HJ site was 92% (67/73), and the complete stone removal rate was 93% (62/67) with multiple sessions (mean number 1.5 ± 0.9). The occurrence rate of procedure-related adverse events was 6.8%. Among 58 patients evaluated for stone recurrence, 13 (22%) developed recurrence during a median follow-up period of 2.7 years (interquartile range: 1.5-4.8). Multivariate analyses determined that a stone diameter ≥ 8 mm [odds ratio (OR), 5.57; 95% confidence interval (CI), 1.39-37.2; p = 0.013] and performing PDCS (OR, 0.16; 95% CI, 0.0084-0.90; p = 0.036) were significant factors for stone recurrence. CONCLUSIONS: Endoscopic treatment using sDBE for hepatolithiasis was effective and safe. PDCS might reduce the rate of stone recurrence by detecting stones that are too small to confirm on fluoroscopic images.

Efficacy of low dose rectal diclofenac for preventing post-endoscopic retrograde cholangiopancreatography pancreatitis: Propensity score-matched analysis.

BACKGROUND: Acute pancreatitis is a major adverse event of endoscopic retrograde cholangiopancreatography (ERCP). Rectal administration of non-steroidal anti-inflammatory drugs (NSAIDs) decreases the incidence of post-ERCP pancreatitis (PEP). However, the efficacy of low dose rectal NSAIDs for preventing PEP remains controversial. METHODS: We performed a retrospective study of 301 patients with native papilla and a body weight of <50 kg who underwent ERCP between September 2010 and October 2019. After July 2016, a 25 mg dose of rectal diclofenac was routinely administered within 15 min before ERCP (NSAIDs group, n = 72) and the control group (n = 229) consisted of patients undergoing ERCP before this date without treatment. We compared the incidence of PEP between the two groups using propensity score matching. RESULTS: A total of 66 pairs of patients in each group were selected. The patients and procedural-related factors were similar in both groups. In total, 15 patients (11.4%) developed PEP: 12.1% (8/66) in the NSAIDs group and 10.6% (7/66) in the control group (Odds ratio (OR) 1.2; 95% confidence interval (CI) 0.4-3.5; P = 0.78). There was no significant difference in incidence of other adverse events related to ERCP between the two groups. CONCLUSIONS: Prophylactic administration of a 25 mg dose of rectal diclofenac did not reduce the incidence of PEP in patients with a native papilla and a body weight of <50 kg in this study and a certain dose of rectal NSAIDs, such as a 100-mg dose, should be administered regardless of body weight to prevent PEP.

The efficacy of pancreatic juice cytology with liquid-based cytology for evaluating malignancy in patients with intraductal papillary mucinous neoplasm.

BACKGROUND: Pancreatic juice cytology (PJC) is a tool for diagnosing malignant intraductal papillary mucinous neoplasm (IPMN); however, the accuracy is insufficient using the conventional method. Liquid-based cytology (LBC) improves the cell recovery rate, and almost all cells can be evaluated. We evaluated the efficacy of PJC with LBC for malignant IPMN. METHODS: We retrospectively analyzed 90 patients with suspected malignant IPMN who underwent PJC before pancreatectomy. PJC with smear and LBC methods was conducted in 52 patients (between June 2003 to December 2011) and 38 patients (between January 2012 to December 2018). Based on the imaging studies, all of the patients were classified according to the international consensus guidelines for IPMN revised in 2017. RESULTS: Of the 90 patients, 43 (48%) had malignant IPMN (high-grade dysplasia or invasive carcinoma), and the remaining patients had non-malignant IPMN (intermediate- or low-grade dysplasia). LBC increased the accuracy of PJC for the diagnosis of malignant IPMN (smear method: 56% [29/52] vs. LBC method: 76% [29/38]; P = 0.044). In a multivariate analysis, LBC was a significant factor influencing the accurate diagnosis of PJC (odds ratio: 3.52; P = 0.021). Furthermore, LBC increased the accuracy of PJC for malignant IPMN in patients with worrisome features (smear method: 66% [19/29] vs. LBC method: 93% [14/15]; P = 0.043). CONCLUSIONS: LBC increases the accuracy of PJC for diagnosing malignant IPMN compared with the conventional smear method.

[IgA vasculitis with massive hemorrhage from the jejunum after steroid administration].

A 45-year-old Japanese man presenting with leg purpura, abdominal pain, and arthralgia was diagnosed with IgA vasculitis. His symptoms resolved after the intravenous administration of prednisolone. However, on day 20 of admission, he experienced bloody discharge and hypovolemic shock. The bleeding point was not identified on contrast-enhanced computed tomography scanning. The blood loss was approximately 10800ml and the patient received transfusions of 48 units of concentrated red blood cells, 18 units of fresh frozen plasma, and 30 units of concentrated platelets. Laparotomy and enteroscopy were performed through the incision of the jejunum to detect the bleeding source. Spurting bleeding was observed during the enteroscopy and partial resection of the jejunum was performed. Histopathological examination of the resected specimen revealed large vessels beneath the jejunal ulcer scar, suggesting bleeding from a Dieulafoy's lesion. Leukocytoclastic vasculitis or cytomegalovirus infection was not observed in the resected specimen. Gastrointestinal symptoms in patients with IgA vasculitis usually improve with bowel rest and conservative treatment. Administration of steroids or factor XIII is recommended for patients with severe abdominal pain refractory to conservative management. Rarely, massive bleeding, perforation, intussusception, and/or intestinal obstruction occur in the gastrointestinal tract and these complications affect patients' prognoses. The clinical course in the present patient indicated that severe bleeding from the gastrointestinal tract can occur even after symptom remission in patients with IgA vasculitis. In such cases, prompt treatment, including laparotomy and/or enteroscopy, is essential.

A Granulation Polyp in the Colon Masquerading as Metastatic Cancer.

A 60-year-old Caucasian male was diagnosed with lung adenocarcinoma and multiple metastases to the bone, spleen, and brain. He underwent radiotherapy for the brain and lumbar spine metastases, plus chemotherapy (cisplatin and pemetrexed). The chemotherapy was discontinued due to vomiting and hyponatremia, and nivolumab was then administered. Eight months later, 18F-fluorodeoxyglucose positron emission tomography showed tracer uptake in the colon. Colonoscopy revealed a reddish multinodular polyp in the sigmoid colon. The polyp showed irregular microvessels. No colonic mucosal surface structures were observed. Colonic metastasis of the lung carcinoma was highly suspected; the polyp was therefore surgically removed. The histological analysis revealed granulation tissue and suppurative inflammation without neoplastic changes. We diagnosed the lesion as a granulation polyp. Despite the difficulty in diagnosing these lesions due to their rarity and similarity to metastatic colon tumors, we suggest that recognizing the endoscopic features of the polyp surface may allow a preoperative diagnosis.

Safety of cold polypectomy for small colorectal neoplastic lesions: a prospective cohort study in Japan.

BACKGROUND: Cold polypectomy has been widely accepted for removal of small colorectal polyps. However, no large-scale prospective study exists as for its safety in Japan. We investigated this issue in this single-center, prospective cohort study in a total of 1198 colorectal polyps resected with cold polypectomy. PATIENTS AND METHODS: Four hundred and seventy-four patients who underwent cold polypectomy for colorectal neoplastic lesions less than 10-mm diameter between September 2014 and October 2016 were enrolled. Primary outcome was the incidence of delayed bleeding within 2 weeks after the procedure. Secondary outcomes were the rate of immediate bleeding, perforation, endoscopic en bloc resection, and advanced histology. RESULTS: Cold polypectomy was performed on 1198 polyps in the 474 patients. No delayed bleeding or colonic perforation was observed. Immediate bleeding during the procedure, requiring endoscopic hemostasis, occurred in 97 lesions (8.1%), and all of them were successfully managed endoscopically. The endoscopic en bloc resection rate was 97.2%. Twenty-eight lesions (2.3%) were histologically diagnosed as advanced neoplasia; among them, three lesions were well-differentiated adenocarcinomas, and in two of them, a negative margin was not histologically confirmed. CONCLUSIONS: Cold polypectomy for small colorectal polyps is a safe technique without significant complication, but careful endoscopic diagnosis at cold polypectomy is necessary to identify advanced neoplasia. The reliability of cold polypectomy in excision of polyps with high-grade neoplasia should be established before the procedure becomes standard in the excision of small colorectal polyps. CLINICAL TRIAL REGISTRATION NUMBER: UMIN000014812.