Stereomicroscopic on-site evaluation in endoscopic ultrasound-guided tissue acquisition of upper gastrointestinal subepithelial lesions

Background/Aims@#In stereomicroscopic sample isolation processing, the cutoff value (≥4 mm) of stereomicroscopically visible white cores indicates high diagnostic sensitivity. We aimed to evaluate endoscopic ultrasound-guided tissue acquisition (EUS-TA) using a simplified stereomicroscopic on-site evaluation of upper gastrointestinal subepithelial lesions (SELs). @*Methods@#In this multicenter prospective trial, we performed EUS-TA using a 22-gauge Franseen needle in 34 participants with SELs derived from the upper gastrointestinal muscularis propria, requiring pathological diagnosis. The presence of stereomicroscopically visible white core (SVWC) in each specimen was assessed using stereomicroscopic on-site evaluation. The primary outcome was EUS-TA’s diagnostic sensitivity with stereomicroscopic on-site evaluation based on the SVWC cutoff value (≥4 mm) for malignant upper gastrointestinal SELs. @*Results@#The total number of punctures was 68; 61 specimens (89.7%) contained stereomicroscopically visible white cores ≥4 mm in size. The final diagnoses were gastrointestinal stromal tumor, leiomyoma, and schwannoma in 76.5%, 14.7%, and 8.8% of the cases, respectively. The sensitivity of EUS-TA with stereomicroscopic on-site evaluation based on the SVWC cutoff value for malignant SELs was 100%. The per-lesion accuracy of histological diagnosis reached the highest level (100%) at the second puncture. @*Conclusions@#Stereomicroscopic on-site evaluation showed high diagnostic sensitivity and could be a new method for diagnosing upper gastrointestinal SELs using EUS-TA.

Cholecystitis after Placement of Covered Self-Expandable Metallic Stents in Patients with Distal Malignant Biliary Obstructions

Background/Aims@#Cholecystitis can occur after the placement of covered self-expandable metallic stents for distal malignant biliary obstructions. We aimed to identify risk factors for cholecystitis following covered self-expandable metallic stent placement. @*Methods@#We investigated risk factors related to cholecystitis following covered self-expandable metallic stent placement in 118 patients with distal malignant biliary obstructions between January 1, 2015 and April 30, 2019. Endoscopic assessments and tumor invasion to the arteries feeding the gallbladder were determined by a pancreaticobiliary endoscopist and a radiologist, respectively. @*Results@#The median patient age was 72 years (men, 61.0%). The flow of the contrast agent into the gallbladder and tumor involvement in the orifice of the cystic duct were observed in 35 (29.7%) and 35 (29.7%) patients, respectively. During the observation period (median, 179 days), cholecystitis occurred in 18 (15.3%) patients. Multivariate analysis revealed the flow of the contrast agent into the gallbladder (p=0.023) and tumor involvement in the orifice of the cystic duct (p=0.005) as significant independent risk factors associated with cholecystitis. @*Conclusions@#The flow of the contrast agent into the gallbladder and tumor involvement in the orifice of the cystic duct are potential independent risk factors for cholecystitis following the placement of covered self-expandable metallic stents. A follow-up prospective study is warranted to validate their influence.

Confirming Whether Fine Needle Biopsy Device Shortens the Learning Curve of Endoscopic Ultrasound-Guided Tissue Acquisition Without Rapid Onsite Evaluation

Background/Aims@#Endoscopic ultrasonography (EUS)-guided tissue acquisition requires a long learning curve. We aimed to compare the skill maturation curves between fine needle aspiration (FNA) and biopsy (FNB) for tissue acquisition. @*Methods@#The initial 60 procedures performed by the trainee endosonographer (30 FNA vs. 30 FNB) were consecutively enrolled. The difference in procedure performance was compared between the two groups. Learning curves were assessed. Twenty additional cases were subsequently enrolled to assess the consistency of performance in the FNB group. @*Results@#The FNB group acquired larger tissue samples (2.35 vs. 0.70 mm2; p<0.001) with lower blood content (p=0.001) and higher tissue quality (p=0.017) compared with the FNA group. In addition, the FNB group required less needle pass to establish a diagnosis (2.43 vs. 2.97; p=0.006). A threshold diagnostic sensitivity of ≥80% was achieved after performing 10 FNB procedures. The number of needle passes significantly decreased after conducting 20 FNB procedures (1.80 vs. 2.70; p=0.041). The diagnostic sensitivity and number of needle passes remained the same in the subsequent FNB procedures. By contrast, this skill maturation phenomenon was not observed after performing 30 FNA procedures. @*Conclusions@#In EUS-guided tissue acquisition, the FNB needle was more efficient and thus shortened the learning curve of EUSguided tissue acquisition in trainee endosonographers.

Cholecystitis after Placement of Covered Self-Expandable Metallic Stents in Patients with Distal Malignant Biliary Obstructions

Background/Aims@#Cholecystitis can occur after the placement of covered self-expandable metallic stents for distal malignant biliary obstructions. We aimed to identify risk factors for cholecystitis following covered self-expandable metallic stent placement. @*Methods@#We investigated risk factors related to cholecystitis following covered self-expandable metallic stent placement in 118 patients with distal malignant biliary obstructions between January 1, 2015 and April 30, 2019. Endoscopic assessments and tumor invasion to the arteries feeding the gallbladder were determined by a pancreaticobiliary endoscopist and a radiologist, respectively. @*Results@#The median patient age was 72 years (men, 61.0%). The flow of the contrast agent into the gallbladder and tumor involvement in the orifice of the cystic duct were observed in 35 (29.7%) and 35 (29.7%) patients, respectively. During the observation period (median, 179 days), cholecystitis occurred in 18 (15.3%) patients. Multivariate analysis revealed the flow of the contrast agent into the gallbladder (p=0.023) and tumor involvement in the orifice of the cystic duct (p=0.005) as significant independent risk factors associated with cholecystitis. @*Conclusions@#The flow of the contrast agent into the gallbladder and tumor involvement in the orifice of the cystic duct are potential independent risk factors for cholecystitis following the placement of covered self-expandable metallic stents. A follow-up prospective study is warranted to validate their influence.

Confirming Whether Fine Needle Biopsy Device Shortens the Learning Curve of Endoscopic Ultrasound-Guided Tissue Acquisition Without Rapid Onsite Evaluation

Background/Aims@#Endoscopic ultrasonography (EUS)-guided tissue acquisition requires a long learning curve. We aimed to compare the skill maturation curves between fine needle aspiration (FNA) and biopsy (FNB) for tissue acquisition. @*Methods@#The initial 60 procedures performed by the trainee endosonographer (30 FNA vs. 30 FNB) were consecutively enrolled. The difference in procedure performance was compared between the two groups. Learning curves were assessed. Twenty additional cases were subsequently enrolled to assess the consistency of performance in the FNB group. @*Results@#The FNB group acquired larger tissue samples (2.35 vs. 0.70 mm2; p<0.001) with lower blood content (p=0.001) and higher tissue quality (p=0.017) compared with the FNA group. In addition, the FNB group required less needle pass to establish a diagnosis (2.43 vs. 2.97; p=0.006). A threshold diagnostic sensitivity of ≥80% was achieved after performing 10 FNB procedures. The number of needle passes significantly decreased after conducting 20 FNB procedures (1.80 vs. 2.70; p=0.041). The diagnostic sensitivity and number of needle passes remained the same in the subsequent FNB procedures. By contrast, this skill maturation phenomenon was not observed after performing 30 FNA procedures. @*Conclusions@#In EUS-guided tissue acquisition, the FNB needle was more efficient and thus shortened the learning curve of EUSguided tissue acquisition in trainee endosonographers.

Development of the Asian EUS Group consensus in pancreatic pseudocyst drainage

Drainage of pseudocyst and walled-off pancreatic necrosis has traditionally been achieved by surgical means. Recently, there has been a progressive shift in paradigm to performing endoscopic drainage for these conditions. Endoscopic ultrasound (EUS)-guided drainage is the preferred approach for drainage of pancreatic pseudocyst. However, many controversies still exist on the optimal management and wide variations in techniques exist. There is a pressing need for establishment of a consensus for safe practices in EUS-guided pseudocyst drainage.

Recent Advances of Biliary Stent Management

Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Even we employed metallic stents which contributed to higher rates and longer durations of patency, and occlusion of covered metallic stents now occurs in about half of all patients during their survival. We investigated the complication and patency rate for the removal of covered metallic stents, and found that the durations were similar for initial stent placement and re-intervention. In order to preserve patient quality of life, we currently recommend the use of covered metallic stents for patients with malignant biliary obstruction because of their removability and longest patency duration, even though uncovered metallic stents have similar patency durations.