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although major complications following endoscopic ultrasonography procedures are rare ; we all , as examiners , could be faced with the hypothetical situation of intraprocedural perforation . therefore , careful consideration of each imaging detail and step of the procedure is of utmost importance in the early identification and management of such an incident .
a 75-year - old male patient presented for endoscopic palliation of the jaundice secondary to an invasive pancreaticobiliary malignancy .
endoscopic retrograde cholangiopancreatography ( ercp ) went well and a plastic 10 fr , 7 cm stent was placed through the papilla , with consecutive improvement in the patient 's clinical status and biochemical tests .
cytopathologic confirmation of the neoplasia was attempted 4 days later using a linear echoendoscope ( olympus gf - uct180 , olympus europe gmbh , hamburg , germany ) with the patient under propofol sedation , but under endoscopic ultrasound ( eus ) guidance it was impossible to advance the 22-g needle ( ez shot , olympus europe gmbh , hamburg , germany ; the only type of needle available ) into the tumor from the duodenum , despite multiple attempts .
after the first needle pass into one peritumoral lymph node , a small quantity of free fluid , not seen before , appeared in the view [ figure 1 ] .
a couple of minutes were spent ruling out ongoing hemorrhage , after which more needle passes were performed , and the procedure ended apparently without major incidents .
there were no alterations in the monitored parameters or requirement of extra sedation or analgesia during the procedure .
a small quantity of free fluid ( red arrow ) is seen during eus - fna of a peritumoral lymph node ( not clearly seen ) ; the puncturing needle is also shown ( yellow arrow ) .
eus - fna = endoscopic ultrasound - guided fine - needle aspiration after the eus procedure , despite marked attenuation of jaundice , the patient under close follow - up gradually developed peritoneal signs , marked leukocytosis , and elevated c - reactive protein . in this context , a computer tomography ( ct ) abdomen was emergently performed and revealed the distal end of the previously inserted biliary plastic stent passing through the wall of the inferior genu of the duodenum [ figures 2 and 3 ] ; ascites , but no pneumoperitoneum was present .
the findings were confirmed during surgery [ figure 4 ] that besides removing the plastic stent and the bile from the peritoneal cavity , also carried out a primary duodenal repair and coledocho - jejuno - anastomosis .
there was no blood in the peritoneal cavity , confirming the supposition that the small quantity of free fluid seen during the eus examination was in fact bile .
unfortunately , the patient recovered slowly , being discharged 40 days afterwards , and succumbed 1 month later due to tumor progression .
ct = computed tomography distal extremity of the plastic stent penetrating the duodenal wall ( yellow arrow ) confirmatory picture taken from the surgical intervention , revealing the stent penetrating through the inferior genu of the duodenum
bleeding is the most common complication of eus - guided fine - needle aspiration ( eus - fna ) ; extraluminal bleeding following eus - fna is clearly visualized on eus as an expanding hyperechoic or hypoechoic region adjacent to the sampled lesion , this being initially considered in the presented case
. however , the most feared complication related to eus is perforation , with a reported incidence between 0.075% following diagnostic procedures to 0.25% following interventions .
duodenal perforation is the most common type , accounting for 6 out of 10 cases in a german study , the most important responsible factors being , besides the physical characteristics of the echoendoscopes ( lack of forward viewing , higher rigidity and stiffness of the scope tip , larger diameter compared to gastroscopes or even duodenoscopes , longer nonflexible section just proximal to the transducer , and presence of a rigid segment containing the transducer that extends beyond the optical lens ) , also the significantly longer duration of the eus examination compared with standard upper digestive endoscopy .
moreover , patients who undergo eus - fna are approximately 10 times more likely to suffer complications following eus compared to patients undergoing diagnostic noninterventional eus , with most of the fatal complications occurring after examinations by endoscopists who have performed fewer than 300 eus procedures . as there are several published case reports of stent - induced perforations of the duodenal wall , none of them is reported to have occurred immediately after a eus examination .
we think that the duodenal perforation in this case was induced by the multiple attempts at puncturing the primary tumor , somehow determining pushing of the distal end of the stent through the wall of the duodenum , even if the water - filled balloon was not used for the eus examination .
although it is thought that the balloon technique could protect against perforation induced by the tip of the scope , we think that a wider pressure surface might favor pushing a plastic stent from the common bile duct . despite these considerations
, a retrospective study showed that pre - eus stenting of biliary obstructions due to pancreatic cancer did not increase the eus - fna complication rate , and the accuracy of tissue diagnosis was not impaired if ercp and endoscopic stenting were performed more than 1 day prior to eus - fna , once more proving that our case was singular .
still , the duodenal perforation in the presented case could have been recognized early , given the sudden appearance of free fluid during the procedure ( which was thought to represent bleeding ) , fact that could have majorly altered the therapeutic attitude in this case .
there is in fact one published case report that describes an iatrogenic duodenal perforation during eus managed successfully by endoscopic closure followed by conservative treatment .
besides that , one recent retrospective study shows that early identification of duodenal perforations is associated with a much better outcome , possibly avoiding surgery by using endoscopic treatment ( usually clipping ) and conservative management alone .
therefore , we think that a careful eus investigation must always be carried out prior to eus - fna , so that any changes occurring afterwards could be recognized easily . we also suggest that if there is the slightest suspicion of a perforation during eus in patients with biliary stents , the correct position of the stent ( s ) should be confirmed at the end of the examination , in order to avoid the morbidity and mortality related to a stent - induced perforation .
during endoscopic ultrasound - guided fine - needle aspiration ( eus - fna ) of a pancreatic malignancy , a small quantity of free fluid , not seen before , suddenly appeared in the view , and time was spent ruling out ongoing hemorrhage . 
 however , during follow - up , the patient gradually developed peritoneal signs and was referred for surgery . 
 the images presented elucidate the diagnosis and raise the question of a theoretical change in diagnostic and therapeutic approach .