the indications for simple procedures like upper endoscopy and advanced procedures such as endoscopic retrograde cholangiopancreatography ( ercp ) and endoscopic ultrasound ( eus ) in the pediatric age group are similar to those for adult endoscopy.12 adult gastroenterologists perform most of the eus procedures in the pediatric patients . lack of a dedicated pediatric eus scope forces the adult gastroenterologists to use adult eus scopes in pediatric population . the adult linear eus scope is however useful only in a subgroup of pediatric age group population , and the usage is limited due to a larger diameter ( 12 - 12.8 mm ) and difficulty in maneuvering the echoendoscope around the duodenal sweep . several case reports and series have reported successful use of eus in pediatric patients for upper gastrointestinal tract tumors , pancreatic disorders , characterization of esophageal strictures , and eosinophilic esophagitis.3456789 two case reports have used a smaller - diameter ( 7.4 mm ) echo - bronchoscope in young children to perform eus.1011 the utility and feasibility of eus in pediatric population , especially in infants and young children ( < 4 years ) are largely unclear . the aim of this case series was to evaluate indications , feasibility , safety , and impact of using the echo - bronchoscope for eus ( eb - eus)in the pediatric patient population below the age of 4 years . all eus procedures were performed by an experienced endosonographer who has independently performed more than 4000 eus procedures in adults . between september 2010 to august 2012 , 1800 eus studies were done , of which 46 were done in pediatric age group ( < 18 years ) . in 10 children ( 6 boys , 4 girls ) less than 4 years of age ( range 2 months to 4 years ) , eb - eus was done by a linear echo - bronchoscope ( eub-1970 uk ) . the indications for eb - eus included characterization of esophageal strictures in 3 cases , evaluation of pancreatobiliary tract in 4 cases , evaluation of abdominal cyst in 1 case , liver abscess in 1 case and fine needle aspiration ( fna ) cytology of abdominal lymphadenopathy in 1 case . after obtaining , appropriate informed consents procedures were performed on an outpatient basis with moderate conscious sedation in the left lateral decubitus position . the echo - bronchoscope was advanced up to stomach for evaluation of mediastinal diseases and to the duodenum for evaluation of pancreatobiliary disease . as there was no insufflation channel in the echo - bronchoscope , the gastrointestinal lumen was distended after manual insufflation of 50 - 100 ml of air into stomach by biopsy channel . in 3 patients of recurrent corrosive esophageal strictures who had undergone standard esophageal dilatation more than 5 times in last 1 year , eb - eus was done after balloon dilation of the esophageal stricture to 9 mm . a 22-g endobronchial ultrasound ( ebus ) needle occluded with a stylet ( echo - hd 22-ebus - p , wilson cook inc . ) the echo - bronchoscope was not advanced to the duodenum in 4 cases : 3 cases of esophageal strictures , and a 2-month old child with choledochal cyst . demographic profile , indication , findings and outcome in 10 cases of eus by echo - bronchoscope in 3 cases of corrosive stricture of esophagus , eb - eus showed peri - esophageal thickening . in a 3-year - old child with dysphagia after corrosive ingestion , who had undergone more than 30 sessions of stricture dilatation in last 1 and a half year ) , peri - esophageal thickening was seen in the entire circumference ( fig . this child was referred for surgery . in 2 cases where endoscopy after dilation had shown a short segment of stricture involving esophagus , eb - eus showed peri - esophageal thickening only in the lateral wall of esophagus ( fig . a barium swallow showed narrowing of a long segment of mid esophagus ( b ) . computed tomography scan showed circumferential thickening around the mid part of esophagus ( c , d , and e ) . eb - eus showed 17 mm thickening of the lateral wall of esophagus , 6 mm thickening of posterior wall esophagus ( between probe and aorta ) and 6.5 mm thickening of anterior wall of esophagus between probe and left atrium ( f , g and h ) . eb - eus showed a thickening of esophageal wall limited to lateral wall of esophagus . no thickening was seen at the level of left atrium in the anterior wall or in the posterior wall of esophagus . 3b and video 3 ) . computed tomography and magnetic resonance imaging / magnetic resonance cholangiopancreatography ( mri / mrcp ) of the bile duct eb - eus demonstrated dilated common bile duct of 2 cm in diameter in a 2-month - old child along with dilated intrahepatic biliary radicles ( ihbr ) and this case was referred for surgery ( video 4 ) . the second patient with choledochal cyst had a fusiform dilation of common bile duct involving the upper part of the bile duct ( fig . a : a 2-year - old child presented with recurrent abdominal pain and during the episodes of pain amylase levels were high . ultrasound revealed a bile duct diameter of 6 mm ( normal 3 mm for a 2-year - old child ) . ultrasound revealed a bile duct diameter of 8 mm . computed tomography scan and magnetic resonance cholangiopancreatography were normal . eb - eus showed dilated cbd in the upper part up to the neck of pancreas . the cbd in the intrapancreatic part abruptly narrowed down to a diameter of 5.4 mm . abdominal ultrasound revealed an abscess in the left lobe of liver in 1 child 2 cm away from the surface of liver . eb - eus showed that the abscess was only 3 mm away from the wall of the stomach ( fig . 4a ) . in absence of availability of a thick needle for eb - eus - guided aspiration it resulted in shrinkage of the size of the abscess , and on a repeat eb - eus the abscess wall had moved 1 cm away from the wall of the stomach ( fig . 4b ) . a : a 3-year - old child presented with complain of pain in abdomen . ultrasound revealed an abscess in left lobe of liver 2 cm away from the surface . eb - eus showed that the abscess was only 3 mm away from the stomach wall . b : after aspiration the wall of the abscess had moved 1 cm away from the wall of the stomach . eb - eus showed a cyst with mature cyst wall related to head of the pancreas in a child who had a history of blunt injury of abdomen 3 months back ( fig . possible consideration was given to surgical intervention , but conservative management resulted in resolution of the cyst in 4 months . in the final case , multiple enlarged lymph nodes inaccessible for percutaneous aspiration or biopsy were seen near the abdominal aorta . eb - eus demonstrated the presence of lymph nodes posterior to pancreas and anterior to aorta ( fig . immunocytochemical markers were positive for cd15 and cd30 , and the child was referred to pediatric oncology unit ( fig . the computed tomography ( ct ) scan and magnetic resonance imaging ( mri ) has shown a cyst located between the liver and pancreas . the exact origin and nature of the cyst was suggested to be from pancreatic origin by ct scan and mri . eb - eus supplemented by providing the information that the cyst was related to pancreas . a , b : a three year old child presented with pyrexia of unknown origin . the lymph nodes were seen lying anterior to aorta and posterior to pancreas on eb - eus . c : an eb - eus guided fine needle aspiration cytology was done from the para - aortic lymph node . our case series shows that eb - eus is safe , successful and feasible in the pediatric patient population below the age of 4 years . besides the large external diameter , another factor to consider is the difficulty of passage of an adult echoendosocpe across the oro - pharynx and maneuvering around the duodenal sweep . due to the size of the transducer and limited flexibility of the tip of the echoendoscope , this can be restricted . in our series , because of the small caliber of the echoendoscope and higher flexibility of the tip , these limitations were easily overcome . eb - eus evaluation provided a definite diagnosis in 2 cases with microlithiasis and common bile duct stones . the diameter of common bile duct in these 2 children was more than normal ( ~3.3 mm ) . eb - eus allowed a definite diagnostic evaluation by fna cytology in 1 case of abdominal lymphadenopathy and suggested long - term management in 3 cases of esophageal stricture12 . in 1 case of liver abscess , eb - eus guided aspiration was considered because of close proximity of abscess ( < 5 mm ) to the wall of stomach , but a satisfactory window ultimately allowed easy aspiration from the percutaneous route . in 1 case of pancreatic cyst , the findings on eb - eus collaborated with computed tomography and mri findings . although the usefulness of eus in children has been only recently appreciated , published studies remain limited to a few patients and single center experiences.345678 the current series illustrates the experience of eb - eus at a large volume , single center with 10 children from 2 months age to 4 years for management of pediatric pathologies involving the gastrointestinal tract , pancreatobiliary system , and mediastinum . the average duration of procedure was less than 15 min and the information obtained helped in ultimate management . in the present series of pediatric eb - eus all of the procedures were performed on an outpatient basis and eb - eus may prove to be preferable to mri , especially if it is easier to obtain , more affordable , and/or better tolerated . this may open the door to the possibility of replacing mri studies with eb - eus studies , or at least , using the two modalities to maximize the information obtained in a particular patient and to avoid more invasive interventions . in conclusion , eb - eus appears to be a feasible and safe technique in children and provides clinically useful information with a significant impact on the management of gastrointestinal , pancreatobiliary and mediastinal diseases . larger studies are needed to further evaluate a more widespread role for eb - eus in the assessment of young children .
the practical use of eus in small children below the age of 4 years is not described . 
 the aim of the study was to evaluate the feasibility , safety , and clinical utility of smaller caliber echo - bronchoscope in the management of gastrointestinal , pancreatobiliary , and mediastinal disease in children below 4 years . 
 consecutive children of age younger than 4 years where eus was clinically considered useful were evaluated by echo - bronchoscopes . 
 the findings showed that eus by echo - bronchoscopes is feasible and safe in young children .