Maximizing the endosonography: The role of contrast harmonics, elastography and confocal endomicroscopy

New technologies in endoscopic ultrasound(EUS) evaluation have been developed because of the need to improve the EUS and EUS-fine needle aspiration(EUS- FNA) diagnostic rate. This paper reviews the principle, indications, main literature results, limitations and future expectations for each of the methods presented. Contrast-enhanced harmonic EUS uses a low mechanical index and highlights slowflow vascularization. This technique is useful for differentiating solid and cystic pancreatic lesions and assessing biliary neoplasms, submucosal neoplasms and lymph nodes. It is also useful for the discrimination of pancreatic masses based on their qualitative patterns; however, the quantitative assessment needs to be improved. The detection of small solid lesions is better, and the EUS-FNA guidance needs further research. The differentiation of cystic lesions of the pancreas and the identification of the associated malignancy features represent the main indications. Elastography is used to assess tissue hardness based on the measurement of elasticity. Despite its low negative predictive value, elastography might rule out the diagnosis of malignancy for pancreatic masses. Needle confocal laser endomicroscopy offers useful information about cystic lesions of the pancreas and is still under evaluation for use with solid pancreatic lesions of lymph nodes.

Stage and size using magnetic resonance imaging and endosonography in neoadjuvantly-treated rectal cancer

AIM: To assess the stage and size of rectal tumours using 1.5 Tesla (1.5T) magnetic resonance imaging (MRI) and three-dimensional (3D) endosonography (ERUS). METHODS: In this study, patients were recruited in a phaseⅠ/Ⅱ trial of neoadjuvant chemotherapy for biopsy-proven rectal cancer planned for surgical resection with or without preoperative radiotherapy. The feasibility and accuracy of 1.5T MRI and 3D ERUS were compared with the histopathology of the fixed surgical specimen (pathology) to determine the stage and size of the rectal cancer before and after neoadjuvant chemotherapy. A Philips Intera 1.5T with a cardiac 5-channel synergy surface coil was used for the MRI, and a B-K Medical Falcon 2101 EXL 3D-Probe was used at 13 MHz for the ERUS. Our hypothesis was that the staging accuracy would be the same when using MRI, ERUS and a combination of MRI and ERUS. For the combination, MRI was chosen for the assessment of the lymph nodes, and ERUS was chosen for the assessment of perirectal tissue penetration. The stage was dichotomised into stageⅠ and stage Ⅱ or greater. The size was measured as the supero-inferior length and the maximal transaxial area of the tumour. RESULTS: The staging feasibility was 37 of 37 for the MRI and 29 of 36 for the ERUS, with stenosis as a limiting factor. Complete sets of investigations were available in 18 patients for size and 23 patients for stage. The stage accuracy by MRI, ERUS and the combination of MRI and ERUS was 0.65, 0.70 and 0.74, respectively, before chemotherapy and 0.65, 0.78 and 0.83, respectively, after chemotherapy. The improvement of the post-chemotherapy staging using the combination of MRI and ERUS compared with the staging using MRI alone was significant (P = 0.046). The post-chemotherapy understaging frequency by MRI, ERUS and the combination of MRI and ERUS was 0.18, 0.14 and 0.045, respectively, and these differences were non-significant. The measurements of the supero-inferior length by ERUS compared with MRI were within 1.96 standard deviations of the difference between the methods (18 mm) for tumours smaller than 50 mm. The agreement with pathology was within 1.96 standard deviations of the difference between imaging and pathology for all tumours with MRI (15 mm) and for tumours that did not exceed 50 mm with ERUS (22 mm). Tumours exceeding 50 mm in length could not be reliably measured by ERUS due to the limit in the length of each recording. CONCLUSION: MRI is preferable to use when assessing the size of large or stenotic rectal tumours. However, staging accuracy is improved by combining MRI with ERUS.

Endosonography-guided cholangiopancreatography as a salvage drainage procedure for obstructed biliary and pancreatic ducts

Endoscopic ultrasound allows transmural access to the bile or pancreatic ducts and subsequent contrast injection to provide ductal drainage under fluoroscopy using endoscopic retrograde cholangiopancreatography (ERCP)-based techniques.Differing patient specifics and operator techniques result in six possible variant approaches to this procedure,known as endosonography-guided cholangiopancreatography(ESCP). ESCP has been in clinical use for a decade now,with over 300 cases reported.It has become established as a salvage procedure after failed ERCP in the palliation of malignant biliary obstruction.Its role in the management of clinically severe chronic/relapsing pancreatitis remains under scrutiny.This review aims to clarify the concepts underlying the use of ESCP and to provide technical tips and a detailed step-by-step procedural description.

Endosonography with linear array instead of endoscopic retrograde cholangiography as the diagnostic tool in patients with moderate suspicion of common bile duct stones

AIM: To evaluate the diagnostic efficiency of endoscopic ultrasound (EUS) as the main imaging modality in patients with moderate suspicion of common bile duct stones (CBDS).METHODS: 55 patients with moderate clinical suspicion of CBDS were prospectively included to the study and evaluated with EUS. This study was done in single blind method in the clinical and biochemical data of patients. EUS was done with echo-endoscope Pentax FG 32-UA (f=5-7,5 MHz) and Hitachi EUB 405 ultrasound machine. Patients diagnosed with CBDS by EUS were excluded from this study and treated with ERC. All the other patients were included to the follow up study obtained by mail every 6 months for clinical evaluation (need of ERC or surgery).RESULTS: CBDS was found in 4 patients by EUS. Diagnosis was confirmed in all cases on ERC. The remaining 51 patients without CBDS on EUS were followed up for 6-26 months (meanly 13 months) There were: 40 women, 42cholecystectomized patients, aged: 55 (mean). Biochemical values (mean values) were as follows: bilirubin: 14,9 μmol.L-1,alkaline phosphatase: 95 IU.L-,1 γ-GTP: 131 IU.L-1, ALT: 50IU.L-1, AST: 49 IU.L-1, Only 1 patient was lost for follow up.In the remaining 50 patients with follow up, there was only 1 (2 %) patient with persistent biliary symptoms in whom CBDS was finally diagnosed by ERC with ES. All other patients remained symptoms free on follow up and did not require ERC or biliary surgery.CONCLUSION: Vast majority of patients with moderate suspicion of CBDS and no stones on EUS with linear array can avoid invasive evaluation of biliary tree with ERC.

Histological changes at an endosonography-guided biliary drainage site:A case report

Endosonography-guided biliary drainage (ESBD) is a new method enabling internal drainage of an obstructed bile duct. However,the histological conditions associated with fistula development via the duodenum to the bile duct have not been reported. We performed ESBD 14 d preoperatively in a patient with an ampullary carcinoma and histologically confirmed changes in and around the fistula. The female patient developed no complications relevant to ESBD. Levels of serum bilirubin and hepatobiliary enzymes declined quickly,and pancreatoduodenectomy was carried out uneventfully. The resected specimen was sliced and stained with hematoxylin-eosin. Histological evaluation of the puncture site in the duodenum and bile-duct wall,and the sinus tract revealed no hematoma,bile leakage,or abscess in or around the sinus tract. Little sign of granulation,fibrosis,and inflammatory cell infiltration was observed. Although further large-scale confirmatory studies are needed,the findings here may encourage more active use of ESBD as a substitute for percutaneous transhepatic drainage in cases with failed/difficult endoscopic biliary stenting.

Different options of endosonography-guided biliary drainage after endoscopic retrograde cholangiopancreatography failure

AIM To investigate the success rates of endosonography(EUS)-guided biliary drainage(EUS-BD) techniques after endoscopic retrograde cholangiopancreatography(ERCP) failure for management of biliary obstruction.METHODS From Feb/2010 to Dec/2016, ERCP was performed in 3538 patients, 24 of whom(0.68%) suffered failure to cannulate the biliary tree. All of these patients were initially submitted to EUS-guided rendez-vous(EUS-RV) by means of a transhepatic approach. In case of failure, the next approach was an EUS-guided anterograde stent insertion(EUS-ASI) or an EUS-guided hepaticogastrostomy(EUS-HG). If a transhepatic approach was not possible or a guidewire could not be passed through the papilla, EUS-guided choledochoduodenostomy(EUS-CD) was performed.RESULTS Patients were submitted to EUS-RV(7), EUS-ASI(5), EUS-HG(6), and EUS-CD(6). Success rates did not differ among the various EUS-BD techniques. Overall,technical and clinical success rates were 83.3% and 75%, respectively. Technical success for each technique was, 71.4%, 100%, 83.3%, and 83.3%, respectively(P = 0.81). Complications occurred in 3(12.5%) patients. All of these cases were managed conservatively, but one patient died after rescue percutaneous transhepatic biliary drainage(PTBD).CONCLUSION The choice of a particular EUS-BD technique should be based on patient's anatomy and on whether the guidewire could be passed through the duodenal papilla.

Role of endosonography in non-malignant pancreatic diseases

Endoscopic ultrasound (EUS) has emerged as a valuable tool in the evaluation of benign and malignant pancreatic diseases. The ability to obtain high quality images and perform fine-needle aspiration (FNA) has led EUS to become the diagnostic test of choice when evaluating the pancreas. This article will review the role of EUS in benign pancreatic diseases.

Pancreatic cancer–Endosonography

EUS is the most sensitive imaging procedure for the detection of small solid pancreatic masses and is accurate in determining vascular invasion of the portal venous system. Even compared to the new CT-techniques EUS provides excellent results in preoperative staging of solid pancreatic tumors. Compared to helical CT-techniques EUS is less accurate in detecting tumor involvement of superior mesenteric artery. EUS staging and EUS-guided FNA can be performed in a single-step procedure, to establish the diagnosis of cancer. There is no known negative impact of tumor cell seeding due to EUS-FNA. Without FNA EUS and additional methods are not able to reliably distinguish between inflammatory and malignant masses.

Diagnostic approach using endosonography guided fine needle aspiration for lymphadenopathy in primary sclerosing cholangitis

We report a case of primary sclerosing cholangitis (PSC) with benign lyphadenopathy which was diagnosed with endosonography guided fine needle aspiration (EUS-FNA). A 65-year-old woman was admitted to Jikei University Hospital with severe jaundice. Although endoscopic retrograde cholangiography and liver biopsy revealed the findings consistent with PSC, abdominal computed tomography revealed numerous large perihepatic lymph nodes with a maximum diameter of more than 3 cm. Therefore, EUS-FNA was done in order to exclude malignant lymphadenopathy, and adequate specimens obtained by EUS-FNA showed reactive hyperplasia of lymphnode. The patients were scheduled to undergo liver transplantation.

Machine learning-based decision tool for selecting patients with idiopathic acute pancreatitis for endosonography to exclude a biliary aetiology

BACKGROUND Biliary microlithiasis/sludge is detected in approximately 30%of patients with idiopathic acute pancreatitis(IAP).As recurrent biliary pancreatitis can be prevented,the underlying aetiology of IAP should be established.AIM To develop a machine learning(ML)based decision tool for the use of endosonography(EUS)in pancreatitis patients to detect sludge and microlithiasis.METHODS We retrospectively used routinely recorded clinical and laboratory parameters of 218 consecutive patients with confirmed AP admitted to our tertiary care hospital between 2015 and 2020.Patients who did not receive EUS as part of the diagnostic work-up and whose pancreatitis episode could be adequately explained by other causes than biliary sludge and microlithiasis were excluded.We trained supervised ML classifiers using H_(2)O.ai automatically selecting the best suitable predictor model to predict microlithiasis/sludge.The predictor model was further validated in two independent retrospective cohorts from two tertiary care centers(117 patients).RESULTS Twenty-eight categorized patients’variables recorded at admission were identified to compute the predictor model with an accuracy of 0.84[95%confidence interval(CI):0.791-0.9185],positive predictive value of 0.84,and negative predictive value of 0.80 in the identification cohort(218 patients).In the validation cohort,the robustness of the prediction model was confirmed with an accuracy of 0.76(95%CI:0.673-0.8347),positive predictive value of 0.76,and negative predictive value of 0.78(117 patients).CONCLUSION We present a robust and validated ML-based predictor model consisting of routinely recorded parameters at admission that can predict biliary sludge and microlithiasis as the cause of AP.

Contribution of endosonography in an uncommon case of pancreatic cysts

Here we present the case of a 35-year-old female patient with long standing dyspepsia and imaging studies showing the presence of multiple cysts in the head and tail of the pancreas. The patient underwent endosonography that confirmed the presence of multiple simple cysts throughout the entirety of the pancreas without dilation of the pancreatic duct. The majority of the cysts were less than one centimeter in size, and the largest cyst showed a honeycomb appearance.Cytology of aspirates from the two largest cysts was compatible with benign pancreatic cysts. Endosonography also revealed cysts within the left kidney and spleen. Genetic testing confirmed Von Hippel-Lindau disease. We highlight this case because it is unusual for Von Hippel-Lindau disease, a rare clinical entity, to present solely with cysts in the absence of more common manifestations, such as hemangioblastomas in the central nervous system and malignancy.

Why is endosonography insufficient for residual diagnosis after neoadjuvant therapy for esophageal cancer?Solutions using muscle layer evaluation

BACKGROUND The diagnosis of residual tumors using endoscopic ultrasound(EUS)after neoadjuvant therapy for esophageal cancer is considered challenging.However,the reasons for this difficulty are not well understood.AIM To investigate the ultrasound imaging features of residual tumors and identify the limitations and potential of EUS.METHODS This exploratory prospective observational study enrolled 23 esophageal squamous cell carcinoma patients receiving esophagectomy after neoadjuvant therapy[15 patients after neoadjuvant chemotherapy(NAC)and 8 patients after chemoradiotherapy(CRT)]at the Department of Surgery,Chiba University Hospital,between May 2020 and October 2021.We diagnosed the T stage for specimens using ultrasound just after surgery and compared ultrasound images with the cut surface of the fixed specimens of the same level of residual tumor.The ratio of esophageal muscle layer defect measured by ultrasound was compared with clinicopathological factors.Furthermore,the rate of reduction for the muscle layer defect was evaluated using EUS images obtained before and after neoadjuvant therapy.RESULTS The accuracy of T stage rate was 61%(n=14/23),which worsened after CRT(38%,n=3/8)than after NAC(73%,n=11/15)because of overstaging.Moreover,pT0 could not be diagnosed in all cases.The detection rate of residual tumor for specimens using ultrasound retrospectively was 75%(n=15/20).There was no correlation between after-NAC(79%,n=11/14)and after-CRT(67%,n=4/6)detection rate.The detection of superficial and submucosal types was poor.The pathologic tumor size and pathological response were correlated.Tumor borders were irregular and echogenicity was mixed type after CRT.There was a correlation between the pT stage(pT0/1 vs pT2/3)and the length of muscle layer circumference(P=0.025),the length of muscle layer defect(P<0.001),and the ratio of muscle layer defect(P<0.001).There was also a correlation between the pT stage and the rate of muscle layer defect reduction measured by EUS(P=0.001).CONCLUSION Compared to pathological images,some tumors are undetectable by ultrasound.Focusing on the esophageal muscle layer might help diagnose the depth of the residual tumor.

Redefining endoluminal biliary drainage:Challenges and innovations in endosonography-guided techniques

Endoscopic retrograde cholangiopancreatography is considered the gold standard for treating benign and malignant biliary obstructions.However,its use in complex biliary obstructions is limited.Over the past decades,therapeutic endosonography(EUS)and emerging technologies such as lumen-apposing metal stents have enabled endoscopic treatment of conditions previously requiring nonendoscopic or surgical approaches.Studies show that EUS-guided choledochoduodenostomy is a reliable alternative to endoscopic retrograde cholangiopancreatography in the treatment of distal malignant biliary obstructions and can be considered a primary drainage modality in centers with adequate expertise.For malignant hilar biliary obstructions,draining at least 50%of viable liver tissue often requires combining different modalities.The treatment strategy in these patients should be individualized,depending on the Bismuth classification,patient physical status,and intended systemic therapy.Due to the lack of evidence,general recommendations cannot be made for EUS-guided hepaticoduodenostomy or combined procedures with transhepatic bridging stents.These novel techniques should be limited to selected palliative cases where conventional methods have failed and conducted within clinical trials to generate evidence before broader application.

Contrast-enhanced guided endoscopic ultrasound procedures

Contrast-enhanced endoscopic ultrasound(CH-EUS)can overcome the limi-tations of endoscopic ultrasound-guided acquisition by identifying microvessels inside inhomogeneous tumours and improving the characterization of these tumours.Despite the initial enthusiasm that oriented needle sampling under CH-EUS guidance could provide better diagnostic yield in pancreatic solid lesions,further studies did not confirm the supplementary values in cases of tissue acquisition guided by CH-EUS.This review details the knowledge based on the available data on contrast-guided procedures.The indications for CH-EUS tissue acquisition include isoechoic EUS lesions with poor visible delineation where CH-EUS can differentiate the lesion vascularisation from the surrounding parenchyma and also the mural nodules within biliopancreatic cystic lesions,which occur in select cases.Additionally,the roles of CH-EUS-guided therapy in patients whose pancreatic fluid collections or bile ducts that have an echogenic content have indications for drainage,and patients who have nonvisualized vessels that need to be highlighted via Doppler EUS are presented.Another indication is represented if there is a need for an immediate assessment of the post-radiofrequency ablation of pancreatic neuroendocrine tumours,in which case CH-EUS can be used to reveal the incomplete tumour destruction.

Endo-hepatology: Why should we do endoscopic ultrasound-guided interventions to the liver that we could do through the skin?

Endoscopic ultrasound(EUS)-guided interventions on the liver such as diffuse biopsy and portal pressure gradient measurement are emerging as potential alternatives to percutaneous procedures.The purpose of this editorial was to address all the indications that could potentially make an EUS-guided approach a possible alternative to the percutaneous procedures with respect to the proce-dures that could join the EUS examination such as upper endoscopy for gastro-esophageal varices,pancreaticobiliary investigation with EUS,and other potential advantages in terms of patient safety.The issue of a holistic gastroenterologist approach was also discussed along with the potential for developing clinical research.

Young patient with a giant gastric bronchogenic cyst:A case report and review of literature

BACKGROUND Gastric bronchogenic cysts(BCs)are extremely rare cystic masses caused by abnormal development of the respiratory system during the embryonic period.Gastric bronchial cysts are rare lesions that were first reported in 1956;as of 2023,only 33 cases are available in the PubMed online database.BCs usually have no clinical symptoms in the early stage,and imaging findings also lack specificity.Therefore,they are difficult to diagnose before histopathological examination.CASE SUMMARY A 34-year-old woman with respiratory distress presented at our hospital.Endoscopic ultrasound revealed an anechoic mass between the spleen,left kidney and gastric fundus,with hyperechogenic and soft elastography textures and with a size of approximately 6.5 cm×4.0 cm.Furthermore,a computed tomography scan demonstrated high density between the posterior stomach and the spleen and the left kidney,with uniform internal density and a small amount of calcification.The maximum cross section was approximately 10.1 cm×6.1 cm,and the possibility of a cyst was high.Because the imaging findings did not suggest a malignancy and because the patient required complete resection,she underwent laparotomy surgery.Intraoperatively,this cystic lesion was found to be located in the posterior wall of the large curvature of the fundus and was approximately 8 cm×6 cm in size.Finally,the pathologists verified that the cyst in the fundus was a gastric BC.The patient recovered well,her symptoms of chest tightness disappeared,and the abdominal drain was removed on postoperative day 6,after which she was discharged on day 7 for 6 months of follow-up.She had no tumor recurrence or postoperative complications during the follow-up.CONCLUSION This is a valuable report as it describes an extremely rare case of gastric BC.Moreover,this was a very young patient with a large BC in the stomach.

Endoscopic ultrasound-guided biliary drainage after failed endoscopic retrograde cholangiopancreatography: The road is open for almighty biliopancreatic endoscopists!

Commentary on the article written and published by Peng et al,investigating the role of endoscopic ultrasound(EUS)-guided biliary drainage for palliation of malignant biliary obstruction after failed endoscopic retrograde cholangiopan-creatography(ERCP).For 40 years endoscopic biliary drainage was synonymous with ERCP,and EUS was used mainly for diagnostic purposes.The advent of therapeutic EUS has revolutionized the field,especially with the development of a novel device such as electrocautery-enhanced lumen-apposing metal stents.Complete biliopancreatic endoscopists with both skills in ERCP and in interven-tional EUS,would be ideally suited to ensure patients the best drainage technique according to each individual situation.

Diagnostic accuracy of endoscopic ultrasound in pancreatic neuroendocrine tumors: A systematic review and meta analysis

AIM: To detect pancreatic neuroendocrine tumors (PNETs) has been varied. This study is undertaken to evaluate the accuracy of endoscopic ultrasound (EUS) in detecting PNETs.METHODS: Only EUS studies confirmed by surgery or appropriate follow-up were selected. Articles were searched in Medline, Ovid journals, Medline nonindexed citations, and Cochrane Central Register of Controlled Trials and Database of Systematic Reviews. Pooling was conducted by both fixed and random effects model). RESULTS: Initial search identified 2610 reference articles, of these 140 relevant articles were selected and reviewed. Data was extracted from 13 studies (n = 456) which met the inclusion criteria. Pooled sensitivity of EUS in detecting a PNETs was 87.2% (95%CI: 82.2-91.2). EUS had a pooled specificity of 98.0% (95%CI: 94.3-99.6). The positive likelihood ratio of EUS was 11.1 (95%CI: 5.34-22.8) and negative likelihood ratio was 0.17 (95%CI: 0.13-0.24). The diagnostic odds ratio, the odds of having anatomic PNETs in positive as compared to negative EUS studies was 94.7 (95%CI: 37.9-236.1). Begg-Mazumdar bias indicator for publication bias gave a Kendall's tau value of 0.31 (P = 0.16), indication no publication bias. The P for χ2 heterogeneity for all the pooled accuracy estimates was > 0.10. CONCLUSION: EUS has excellent sensitivity and specificity to detect PNETs. EUS should be strongly considered for evaluation of PNETs.

Comparative analysis of ERCP,IDUS,EUS and CT in predicting malignant bile duct strictures

AIM: To compare endoscopic retrograde cholangio-pancreatography (ERCP), intraductal ultrasound (IDUS), endosonography (EUS), endoscopic transpapillary forceps biopsies (ETP) and computed tomography (CT) with respect to diagnosing malignant bile duct strictures.

Endoscopic ultrasound-guided fine-needle aspiration cytology diagnosis of solid pseudopapillary tumor of the pancreas: A case report and literature review

We describe the clinical, imaging and cytopathological features of solid pseudopapillary tumor of the pancreas (SPTP) diagnosed by endoscopic ultrasound- guided (EUS-guided) fine-needle aspiration (FNA). A 17-year-old woman was admitted to our hospital with complaints of an unexplained episodic abdominal pain for 2 mo and a short history of hypertension in the endocrinology clinic. Clinical laboratory examinations revealed polycystic ovary syndrome, splenomegaly and low serum amylase and carcinoembryonic antigen (CEA) levels. Computed tomography (CT) analysis revealed a mass of the pancreatic tail with solid and cystic consistency. EUS confirmed the mass, both in body and tail of the pancreas, with distinct borders, which caused dilation of the peripheral part of the pancreatic duct (major diameter 3.7 mm). The patient underwent EUS-FNA. EUS-FNA cytology specimens consisted of single cells and aggregates of uniform malignant cells, forming microadenoid structures, branching, papillary clusters with delicate fibrovascular cores and nuclear overlapping. Naked capillaries were also seen. The nuclei of malignant cells were round or oval, eccentric with fine granular chromatin, small nucleoli and nuclear grooves in some of them. The malignant cells were periodic acid Schiff (PAS)-Alcian blue (+) and immunocytochemically they were vimentin (+), CA 19.9 (+), synaptophysin (+), chromogranin (-), neuro-specific enolase (-), a1- antitrypsin and a1-antichymotrypsin focal positive. Cytologic findings were strongly suggestive of SPTP. Biopsy confirmed the above cytologic diagnosis. EUS- guided FNA diagnosis of SPTP is accurate. EUS findings,cytomorphologic features and immunostains of cell block help distinguish SPTP from pancreatic endocrine tumors, acinar cell carcinoma and papillary mucinous carcinoma.