Echo Endoscope Research Articles

Using Fuzzy Mathematical Model in the Differential Diagnosis of Pancreatic Lesions Using Ultrasonography and Echographic Texture Analysis.

Malignant tumors of the pancreas are the fourth leading cause of cancer-related deaths. This is mainly because they are often diagnosed at a late stage. One of the challenges in diagnosing focal lesions in the pancreas is the difficulty in distinguishing them from other conditions due to the unique location and anatomy of the organ, as well as the similarity in their ultrasound characteristics. One of the most sensitive imaging modalities of the pancreas is endoscopic ultrasonography. However, clinicians recognize that EUS is a difficult and highly operator-dependent method, while its results are highly dependent on the experience of the investigator. Hybrid technologies based on artificial intelligence methods can improve the accuracy and objectify the results of endosonographic diagnostics. Endoscopic ultrasonography was performed on 272 patients with focal lesions of the pancreatobiliary zone, who had been treated in the surgical section of the Kursk Regional Clinical Hospital in 2014-2023. The study utilized an Olympus EVIS EXERA II video information endoscopic system, along with an EU-ME1 ultrasound unit equipped with GF UM160 and GF UC140P-AL5 echo endoscopes. Out of the focal formations in the pancreatobiliary zone, pancreatic cancer was detected in 109 patients, accounting for 40.1% of the cases. Additionally, 40 patients (14.7%) were diagnosed with local forms of chronic pancreatitis. The reference sonograms displayed distinguishable focal pancreatic pathologies, leading to the development of hybrid fuzzy mathematical decision-making rules at the South-West State University in Kursk, Russian Federation. This research resulted in the creation of a fuzzy hybrid model for the differential diagnosis of chronic focal pancreatitis and pancreatic cancer. Endoscopic ultrasonography, combined with hybrid fuzzy logic methodology, has made it possible to create a model for differentiating between chronic focal pancreatitis and pancreatic ductal adenocarcinoma. Statistical testing on control samples has shown that the diagnostic model, based on reference endosonograms of the echographic texture of pancreatic focal pathology, has a confidence level of 0.6 for the desired diagnosis. By incorporating additional information about the contours of focal formations obtained through endosonography, the reliability of the diagnosis can be increased to 0.9. This level of reliability is considered acceptable in clinical practice and allows for the use of the developed model, even with data that is not well-structured.

APPLICATION OF ENDOSCOPIC ULTRASOUND GUIDED FNAC(EUS-FNAC) IN DIAGNOSING PANCREATIC MASS LESIONS

Introduction: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNAC) has become an important modality for identification of pancreatic masses. It is a minimally invasive procedure that provides excellent cell yield even in deep seated lesions. The preoperative diagnosis of pancreatic mass by EUS-FNAC can help the surgeons in early detection and confirmation of neoplasm as pancreatic mass lesions are highly concerning for pancreatic carcinoma. This study was aimed at application of EUS-FNAC in diagnosing pancreatic mass lesions. Methods: A study was conducted for 20 cases who underwent EUS guided FNAC for pancreatic mass lesions. EUS-FNAC was performed by using a curvilinear array echo endoscope. The technique was carried out by a skilled endoscopist, and the glass slides were used to make smears from fluid that was aspirated containing corpuscular fractions. The slides were air dried before being examined cytopathologically. Results: Out of 20 cases,10 were of pancreatic Ductal adenocarcinoma, 3 of Neuroendocrine tumor of pancreas, 2 of Acinar cell carcinoma, 1 of Solid pseudopapillary tumor, 2 of Serous cystadenoma and 2 of Mucinous cystadenoma. This was confirmed later, on further Immunocytochemical stains. Conclusions:Out of 20 cases, 16 were malignant and 4 were benign. EUS-FNAC can help in early diagnosis and can improve the patient outcome. It is safe, cost-effective and reliable. It not only gives precise cytological diagnosis, but it also allows for the exact site of tiny lesions.

When the Sound Surmounts the Magnet: Pancreatic Cancer Imaging

Outcomes in the treatment of pancreatic cancer heavily depends on early detection. CT and MRI scans are common modalities employed in the initial diagnosis of pancreatic tumors. EUS has emerged as a valuable tool to aid in the early diagnosis of pancreatic malignancy and to detail their resectability. We present three patients with MRI and MRCP negative but EUS positive pancreatic cancer. All three patients presented with biliary dilatation where MRI/MRCP failed to detect any discrete pancreatic lesions. Subsequent EUS with core needle biopsy revealed pancreatic adenocarcinoma. The largest lesion was 3.4 cm in size. Two of these lesions resided in the head of pancreas and one in the uncinate process. EUS was performed using a linear array echo endoscope. All cases were performed by a single operator, who is a board certified gastroenterologist and fellowship trained in advanced interventional endoscopy. The mass/lesions were evaluated for its size, echogenicity, lymph node involvement, loco regional extension, ductal size, and major vessel abutment. Tissue samples from these pancreatic masses were harvested via a 22g Shark Core Fine Needle Biopsy (CNB). MRI/MRCP was performed using Philips Ingenia 1.5T MR system. Two of the three cases were presented at tumor board and images were reviewed at tumor board by a second radiologist. The primary impact of endosonography on the management of pancreatic cancer is in detection and cytologic diagnosis. The accuracy of EUS for T staging of pancreatic cancer is reported to be 80-85%, which is similar to that of MRI. The degree of certainty is dependent on the experience of the endoscopist. Most of the T1 lesions are < 2 cm and difficult to image by cross sectional methods. Unfortunately these are the patients who can have a favorable treatment outcome if instituted early in the course of the disease. EUS offer the advantage of detecting pancreatic masses earlier than cross sectional imaging in patients with early features of biliary obstruction. The ampulla and pancreatic portion of the CBD is very well visualized by EUS. More over EUS can provide an overall accuracy of 93% for vascular invasion thus defining resectability. We suggest a low threshold for EUS evaluation of patients with appropriate clinical symptoms in the setting of a negative cross sectional imaging for pancreatic cancer, than the practice of surveillance imaging which may widen the lag time and lead to an unfavorable outcome.1311_A.tif Figure 1: Patient and Imaging characteristics1311_B.tif Figure 2: tumor characteristics

Cervical esophageal perforation during endoscopic ultrasonography: A retrospective evaluation of frequency, outcome, and patient management

To analyze the indications and complications of diagnostic endoscopic ultrasonography (EUS) within a 12‐year period in our hospital. We retrospectively reviewed all patients who received upper gastrointestinal EUS at Keelung Chang Gung Memorial Hospital from January 2002 to December 2013. The examination was performed using a radial scanning echo endoscope (Olympus GF‐UMQ 240 before August 2011; Olympus GF‐UE 260‐AL5 after September 2011). The indications as well as complications were reviewed. A total of 839 patients underwent a total of 1036 procedures. Mean age of the patients was 59 years (range, 16‐102 years); 56.3% of patients were men. The indications for EUS were: evaluation of gastric submucosal tumors in 425 patients (41%), esophageal cancer staging in 247 patients (23.8%), evaluation of esophageal submucosal tumors in 91 patients (8.8%), evaluation of pancreatic lesions in 66 patients (6.4%), gastric cancer staging in 66 patients (6.4%), and evaluation of biliary lesions in 53 patients (5.1%). Only one patient (0.096%) developed a major complication (cervical esophageal perforation). Fortunately, the patient recovered smoothly after a surgical repair and felt well at 5‐year follow up. Cervical esophageal perforation is a rare but catastrophic complication of EUS. Advanced age, history of difficult intubation, cervical osteophytes, and less experienced doctors are documented to be the risk factors for perforation. In addition, surgeons should pay more attention to those who have a history of thyroidectomy. Immediate recognition of the perforation and urgent primary surgical repair results in a favorable outcome.

EUS-guided Gall Bladder Drainage in Severe Liver Disease: A Single-center Experience in Critically Ill Cirrhotics.

Background and Aims: Acute calculous cholecystitis with impending gall bladder perforation in severe liver diseases including decompensated cirrhosis and acute-on-chronic liver failure (ACLF) is difficult to manage, due to the procedures such as cholecystectomy and per cutaneous cholecystostomy being associated with high risk and complications in these patients.Methods: Four cases of severe liver disease with acute calculous cholecystitis who presented to the Institute of Liver and Biliary Sciences (New Delhi, India) for further management were included in the study if they underwent endoscopic ultrasound-guided gall bladder drainage (EUS-GBD). The patients were followed up for a minimum of 3 months and outcomes were recorded.Results: Four cases of severe liver disease (three ACLF and one decompensated cirrhosis), with model for end-stage liver disease scores of 24, 26, 23 and 25 respectively, presented with acute calculous cholecystitis (Tokyo grade III) and systemic sepsis (high total leukocyte counts). Their international normalized ratios were 2.3, 2.6, 2.2 and 2.9 respectively, and two were in shock, requiring inotropes at presentation. Ultrasonography of the abdomen confirmed hugely distended gall bladder with stone impacted at the neck and moderate ascites. All these cases underwent EUS-GBD by linear echo endoscope, and had the gastric wall punctured in the antrum using a 19G access needle followed by dilatation of the tract using controlled radial expansion balloon and Sohendra dilator. In three cases, the plastic stents were placed. In the fourth case, a Nagi stent was placed. All the patients recovered and were discharged within a week.Conclusions: EUS-GBD is challenging in severe liver disease but represents a life-saving procedure, and hence can be attempted in such critically ill patients with utmost care and precaution.

First Case of ROLL Technique for Mesorectal Recurrence Excision

The radio-guided occult lesion localization (ROLL) technique has been in use since the mid-1990s, mainly in breast surgery. Today, ROLL is used for numerous oncologic pathologies, including parathyroid lesions, melanomas, and colorectal tumors. We report a patient with an 11-mm left mesorectal solitary recurrence of a primary ovarian cancer in whom the ROLL technique was used to identify the implant. A radioisotope was introduced through a 22-gauge needle with endoscopic ultrasound technique using an linear echo endoscope. On the day of surgery, the patient's perianal region was scanned with a gamma probe to identify the area of maximal radioactivity, to determine the optimal placement of the incision over the lesion. After macroscopic excision of the lesion, radioactivity was measured in the lesion bed to ensure complete removal of affected tissues. In our case, the ROLL technique was performed safely for the detection and excision of a recurrent lesion of difficult identification. To our knowledge, this is the first reported case involving use of the ROLL technique to aid the excision of a mesorectal lesion.

Endoscopic Ultrasound-Guided Pancreatic Pseudocyst Drainage in Children

Background: Endoscopic drainage of pancreatic pseudocysts is well established in adults and known to be associated with complications including perforation and hemorrhage. One reason for this is that endoscopic drainage is a blind procedure and to overcome this, EUS guided drainage was established. However, there are limited data regarding this procedure in the pediatric age group. The reasons for this are the limited number of cases seen in children and the lack of experienced pediatric gastroenterologist with this technique. Add to this another technical limitation with EUS is that the therapeutic echo endoscope is 14.6 mm in diameter and has a rigid tip that restricts its use in young children. Patients, methods and results: This report describes a 4-year old child weighing 14 kg with a large pancreatic pseudocyst (8x8x12cm) that was treated successfully using adult endoscopic ultrasound scope (The Olympus EVIS LUCERA Ultrasound Gastrovideoscope GF-UCT 260, 14.6 mm distal tip). Conclusion: Endoscopic drainage of symptomatic pancreatic pseudocysts can be achieved safely and effectively in children using the adult EUS scope.

Impact of EUS-FNA on Patient Management, Resource Use, and Clinical Outcomes in Patients With Lung Cancer

Introduction: Lung cancer is the most common cause of cancer death in the United States. The initial management is to confirm the diagnosis and to assess the stage of the disease. Unfortunately, about half of the patients at the time of the presentation have mediastinal lymph node involvement. Computed tomography (CT) scanning remains the initial method in staging of patient with suspected lung cancer, but it has limited sensitivity and specificity for detecting nodal involvement. EUS has been increasingly recognized as a valuable tool for mediastinal staging lung cancer. If EUS is not available the alternative is mediastinoscopy. The purpose of this paper is to study the impact of EUS on patient management, resource use, and clinical outcomes in patients with suspected lung cancer. Methods: We studied 64 consecutive patients with suspected lung cancer who underwent EUS-FNA for lung staging or diagnosis in a retrospective study from 2003 to 2014. In 52 patients Olympus echo endoscope was used, while in 12 patients Pentax echo endoscope was used. FNA was performed using 22 g needle in 32 patients, 25 g needle in 13 patients and 19 g needle in 8 patients. A 25 g pro-core needle was used in 11 patients. Patients found to have operable disease underwent thoracotomy. We assumed that in the absence of EUS, patients with operable disease on CT will undergo thoracotomy. If suspicious lymph node were noted on computed tomography (CT), mediastinoscopy will be performed in the absence of EUS. Results: Final diagnosis was available for each patient (lung cancer n= 40, lymphoma n=8, benign n=9, cyst n=5). Benign included 5 sarcoidosis, 2 reactive lymphadenopathy and 2 TB. Clinical management was altered due to the results from EUS-FNA in 48 of 64 patients, these include 35 patients with lung cancer, 8 with lymphoma, and 5 with a benign biopsy. EUS-FNA ($1,614) was less expensive than mediastinoscopy ($2,548). In 26 patients, an unnecessary thoracotomy was avoided. No complications were observed in EUS-FNA group of patients. Conclusion: The use of EUS-FNA for mediastinal staging of suspected lung cancer appears to be a safe and cost-effective approach. In our study, EUS-FNA changed clinical management in most patients by avoiding unnecessary thoracotomy or mediastinoscopy, reducing hospital stay, and improving patient outcomes. The introduction of EBUS should supplant the use of EUS-FNA, making mediastinoscopy unnecessary in the staging of lung cancer.

Imaging of peritoneal ligament by endoscopic ultrasound

Double layered peritoneal folds, variously named as ligaments, omenta and mesenteries connect the intraperitoneal organs to the abdominal wall. Some of these ligaments contain blood vessels and lymph nodes while others are avascular. The peritoneal folds not only act as conduits for the passage of blood vessels from the retroperitoneum to reach intraperitoneal organs, but also provide a pathway for the spread of disease processes. It is difficult to identify these normal peritoneal folds at imaging. Computed tomography is the most common imaging modality used to detect diseases of the peritoneum to fully delineate peritoneal anatomy and the extent of disease. The endoscopic ultrasound (EUS) can be used to image peritoneal ligaments with the advantage of lack of ionizing radiation and lower cost. Though EUS is being increasingly used both for diagnostic and interventional purposes in the abdomen, it has not been used to assess the peritoneal ligaments till now. We did this study in 50 patients using linear echo endoscope to delineate various peritoneal ligaments. The technique of evaluation of ligament has been described in this review. The peritoneal ligaments can be delineated with accuracy by EUS.

Evolving role of endoscopic ultrasonography–guided fine-needle aspiration in tumor staging and treatment of patients with carcinomas of the upper gastrointestinal tract

Treatments such as neoadjuvant chemotherapy and endoscopic mucosal resection for upper gastrointestinal carcinomas (UGC) necessitates preoperative staging evaluation of lymph nodes. Endoscopic ultrasonography (EUS)-guided fine-needle aspiration (FNA) of lymph nodes provides more accurate staging than EUS alone. Our study investigates the role of EUS-FNA in the staging/treatment of patients with UGC. We searched our database for patients who had EUS-FNA staging of lymph nodes for UGC over 1 year. The cytologic diagnoses were compared with clinical, radiographic, EUS-determined staging, and patient follow-up data. All EUS/EUS-FNA procedures used a standard radial and/or linear echo endoscope. Direct smears from the aspirated material were stained by Papanicolaou and Diff-Quik methods. We studied 84 patients with esophageal or gastroesophageal junction carcinomas and 15 patients with gastric carcinomas. EUS-FNA confirmed N0 status for 100% of patients with T1 and T2 tumors and for 93% of patients with T3 tumors. Patients with T1N0 carcinomas confirmed by EUS were selected for endoscopic mucosal resection. All patients with gastric carcinomas had EUS-determined stage T3 and above tumors. Based on primary tumor stage, all patients with gastric carcinomas received neoadjuvant chemotherapy. Cytologic diagnosis by EUS-FNA agreed with EUS nodal staging in 77% of the patients with UGC. EUS-FNA was useful to select patients with T1N0 esophageal or gastroesophageal junction carcinomas for endoscopic mucosal resection. EUS-FNA did not contribute significantly in treatment of patients with higher stage tumors whose disease was down-staged to N0 by EUS-FNA. These patients received neoadjuvant chemotherapy based on the status of the primary tumor.

Lymph node characterization in vivo using endoscopic ultrasound spectrum analysis with electronic array echo endoscopes

Our purpose was to demonstrate the use of radiofrequency spectral analysis to distinguish between benign and malignant lymph nodes with data obtained using electronic array echo endoscopes, as we have done previously using mechanical echo endoscopes. In a prospective study, images were obtained from eight patients with benign-appearing lymph nodes and 11 with malignant lymph nodes, as verified by fine-needle aspiration. Midband fit, slope, intercept, correlation coefficient, and root-mean-square (RMS) deviation from a linear regression of the calibrated power spectra were determined and compared between the groups. Significant differences were observable for mean midband fit, intercept, and RMS deviation (t test P < 0.05). For benign (n = 16) vs. malignant (n = 12) lymph nodes, midband fit and RMS deviation provided classification with 89 % accuracy and area under receiver operating characteristic (ROC) curve of 0.95 based on linear discriminant analysis. We concluded that the mean spectral parameters of the backscattered signals from electronic array echo endoscopy can provide a noninvasive method to quantitatively discriminate between benign and malignant lymph nodes.

Fine needle aspiration using forward-viewing endoscopic ultrasonography

A prototype forward-viewing instrument has been developed for therapeutic endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA). We had the opportunity to use this forward-viewing echo endoscope and to study its clinical usefulness, mainly for diagnostic EUS-FNA. The prototype forward-viewing echo endoscope was used for 15 months between November 2006 and March 2010, in a study group comprising 47 consecutive patients. Diagnostic EUS-FNA was done in 38 patients and the diagnostic accuracy of the forward-viewing device was compared with that from an oblique-viewing echo endoscope in reference patients who were matched by disease and puncture route. Therapeutic EUS was done in nine patients (pseudocyst drainage in six; celiac ganglia neurolysis, biliary drainage, and pancreatic duct drainage in one each). Diagnostic EUS-FNA provided a correct diagnosis in 97.4 % (37/38 patients), which was not significantly different from the 94.7 % (36/38) in the reference patients. Lesions considered difficult to access with an oblique-viewing scope, such as those located at the fornix, or the head of the pancreas, or associated with strictures, were easily punctured, as were those located at the body or tail of the pancreas or at the porta hepatis. Treatment was successful in all nine patients who underwent therapeutic EUS procedures. None of the 47 patients had any complications. A forward-viewing echo endoscope that allows target sites to be punctured more perpendicularly with minimal effort, can be used for diagnostic EUS-FNA and this may be advantageous, depending on the site of target lesions.

Kontrastverstärkter harmonischer Ultraschall bei soliden Pankreasläsionen: Ergebnisse einer Pilotstudie

Hintergrund und Studienziele: Die Unterscheidung zwischen einem Adenokarzinom des Pankreas und anderen Pankreasraumforderungen bleibt mit zur Zeit verfügbaren Bildgebungstechniken eine Herausforderung. Diese prospektive Studie hat das Ziel, die Genauigkeit einer neuen Methode der Abbildung des Mikrozirkulationsmusters des Pankreas mithilfe des kontrastverstärkten harmonischen endoskopischen Ultraschalls (CEH-EUS), durchgeführt mit einem neuen Ultraschall-Endoskop Prototyp der Firma Olympus, zu untersuchen. Patienten und Methoden: 35 Patienten mit soliden Pankreasläsionen wurden prospektiv in die Studie einbezogen. Bei allen Patienten war ein konventioneller B-Mode- und ein Power-Doppler-EUS durchgeführt worden. Nach der intravenösen Bolusgabe von 2,4 ml eines Ultraschallkontrastmittels der zweiten Generation (SonoVue) wurde die CEH–EUS mit einem neuen Echoendoskop Prototyp der Firma Olympus (xGF-UCT 180) durchgeführt. Das Mikrozirkulationsmuster wurde mit der Enddiagnose verglichen, die auf der pathologischen Untersuchung von während einer Operation gewonnenen Proben oder der EUS-gestützten Feinnadelaspiration (EUS-FNA) oder durch ein Follow-up von mindestens 12 Monaten beruhte. Ergebnisse: Enddiagnosen waren: 18 Adenokarzinome, 9 neuroendokrine Tumoren, 7 chronische Pankreatitis und 1 Stromatumor. Der Power-Doppler konnte keine Mikrozirkulation darstellen, dies war mit dem „harmonic imaging“ in allen Fällen möglich. Von 18 Läsionen mit einem hypointensen Signal bei der CEH-EUS, waren 16 Adenokarzinome. Die Sensitivität, Spezifität, der negative prädiktive Wert (NPV), der positive prädiktive Wert (PPV) und die Genauigkeit (accuracy) der Hypointensität bei der Diagnostik des Pankreaskarzinoms betrug 89, 88, 89 und 88,5 %, verglichen mit den korrespondierenden Ergebnissen der EUS-FNA von 72, 100, 77, 100 und 86 %. Von 5 Adenomkarzinomen mit falsch negativem Resultat bei der EUS-FNA hatten vier ein hypodenses Echosignal bei der CEH-EUS. Schlussfolgerung: Die CEH-EUS mit dem neuen Prototyp der Firma Olympus stellt zuverlässig das Mikrozirkulationsmuster in soliden Pankreasläsionen dar. Es kann hilfreich bei der Unterscheidung eines Adenokarzinoms von anderen Pankreasraumforderungen sein.

Contrast-enhanced harmonic endoscopic ultrasound in solid lesions of the pancreas: results of a pilot study

Distinguishing pancreatic adenocarcinoma from other pancreatic masses remains challenging with current imaging techniques. This prospective study aimed to evaluate the accuracy of a new procedure, imaging the microcirculation pattern of the pancreas by contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) with a new Olympus prototype echo endoscope. 35 patients presenting with solid pancreatic lesions were prospectively enrolled. All patients had conventional B mode and power Doppler EUS. After an intravenous bolus injection of 2.4 ml of a second-generation ultrasound contrast agent (SonoVue) CEH-EUS was then performed with a new Olympus prototype echo endoscope (xGF-UCT 180). The microvascular pattern was compared with the final diagnosis based on the pathological examination of specimens from surgery or EUS-guided fine-needle aspiration (EUS-FNA) or on follow-up for at least 12 months. The final diagnoses were: 18 adenocarcinomas, 9 neuroendocrine tumors, 7 chronic pancreatitis, and 1 stromal tumor. Power Doppler failed to display microcirculation, whereas harmonic imaging demonstrated it in all cases. Out of 18 lesions with a hypointense signal on CEH-EUS, 16 were adenocarcinomas. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy of hypointensity for diagnosing pancreatic adenocarcinoma were 89 %, 88 %, 88 %, 89 %, and 88.5 %, compared with corresponding values of 72 %, 100 %, 77 %, 100 %, and 86 % for EUS-FNA. Of five adenocarcinomas with false-negative results at EUS-FNA, four had a hypointense echo signal at CEH-EUS. CEH-EUS with the new Olympus prototype device successfully visualizes the microvascular pattern in pancreatic solid lesions, and may be useful for distinguishing adenocarcinomas from other pancreatic masses.

ENDOSONOGRAPHY‐GUIDED PANCREATIC DUCT DRAINAGE FOR CHRONIC PANCREATITIS

Although endoscopic transpapillary treatment of chronic pancreatitis (CP) is gaining acceptance, it is not always possible, especially in patients with inflammatory stenosis of the duodenum due to CP or with a history of a Whipple's procedure. Linear array echoendoscopes (ES) provide high-quality images of the pancreas along with adjacent organs and allow therapeutic applications. echoendoscope-related procedures, such as ES-guided pancreatic duct drainage (ESPD) are feasible and useful in selected patients with CP suffering from PD stricture in whom conventional endoscopic retrograde cholangiopancreatography (ERCP) is impossible.

EUS-guided Trucut needle biopsies as first-line diagnostic method for patients with intestinal or extraintestinal mass lesions

Fine-needle aspiration (FNA) is a well-established technique to obtain cytological specimens, but it does not permit the extraction of histological tissue-core samples, which, if available, may increase the yield and accuracy of the histopathological diagnosis. This prospective study was designed to assess the yield and diagnostic accuracy of endoscopic ultrasound (EUS)-guided Trucut needle biopsy (TNB) as first-line diagnostic method for suspected malignant lesions identified by upper gastrointestinal EUS. In a prospective case series, 24 consecutive patients (14 women; median age, 68 (range, 38-84) years) with suspected malignancy underwent EUS-TNB with a 19-gauge needle. EUS was performed with a linear scanning echo endoscope. When the EUS-TNB device did not collect adequate samples, subsequent EUS-FNA was performed. The presence or absence of malignancy was confirmed by postoperative histopathology or diagnostic imaging follow-up for at least 9 months. Adequate tissue specimens were obtained in 20 of 24 (83%) patients by TNB. An accurate diagnosis was achieved in 19 of 20 (95%) patients in whom TNB was successful with a sensitivity and specificity of 93% and 100%, respectively. In 11 patients malignant disease was found, whereas 8 patients showed benign lesions on TNB-obtained histopathology. Thirteen patients underwent additional EUS-FNA. The diagnosis by TNB was confirmed in seven of nine (78%) patients with additional FNA. In three of four patients with inadequate TNB, the diagnosis was established by FNA. The overall accuracy of EUS-TNB was 79% (19/24) for all patients and 92% (22/24) with subsequent FNA. The positive and negative predictive values for the diagnosis of a malignant lesion by EUS-TNB were 57.9% and 88.9%, respectively. Neither method had any procedure-related complications. EUS-guided TNB is a safe and accurate technique to obtain core specimen for histopathologic diagnosis in patients with suspected malignancies on upper gastrointestinal EUS. FNA can serve as rescue technique and should be performed if TNB fails to obtain adequate tissue samples.

Komplikationen der Endosonografie und endosonografischer Interventionen – Ergebnisse einer Umfrage an deutschen Zentren

Endoscopic ultrasonography is a widely used technique in Germany and not restricted to highly specialised centres. Complementary to the traditional radial scanners, longitudinally scanning echo endoscopes have gained considerable acceptation. Multicentre data on the complications of endoscopic ultrasound and endoscopic ultrasound-guided interventions at German centres do not exist. From 2004 to 2006 all German centres performing endoscopic ultrasonography were surveyed and asked to report on their complications. From 1991 to 2006 100 604 endosonographic procedures had been performed in 67 centres (85,084 diagnostic endosonographies without any intervention, 13,223 endoscopic ultrasound-guided finde-needle aspiration biopsies, 2297 endoscopic ultrasound-guided therapeutic interventions). 38 centres reported on 104 complications, of which 88 were considered to be severe (overall complication rate 0.1 %). Complications of diagnostic endoscopic ultrasound occurred at a rate of 0.034 %, almost all of them were duodenal and oesophageal perforations. There had been complications in 0.29 % of all endoscopic ultrasound-guided fine-needle aspiration biopsies and subsequent to 1.61 % of all endoscopic ultrasound-guided therapeutic interventions. The overall mortality of non-interventional and interventional endosonographic procedures was 0.01 %. Under the specific circumstances in Germany, endoscopic ultrasound, both conventional and interventional, was confirmed to be a safe diagnostic and therapeutic technique. In future, the prospective assessment of complications should become an essential part of quality management of endoscopic ultrasound.

Mini-probe ultrasound of the upper gastrointestinal tract--1995 state of the art and perspectives. Workshop on Mini-Probe Ultrasound in Gastroenterology, Münster, 28 October 1995

Endoscopic ultrasound (EUS) allows for intraluminal sonographic imaging of the oesophagus, stomach, pancreatobiliary duct system, the papilla of Vater, as well as the colon and rectum. EUS has proved valuable for diagnosis and staging of tumours of the upper intestinal tract. EUS can also provide valuable additional information concerning lesions that cannot be immediately classified. As doing this involves, first, removal of the conventional endoscope and, second, insertion of the echo endoscope, EUS is not suitable for routine examinations. Therefore EUS has remained an independent endoscopic diagnostic modality. Moreover, due to their diameter conventional echoendoscopes cannot be inserted into the pancreatobiliary duct system. Fine calibre high frequency ultrasound probes promise a resolution of less than 2 mm in diameter. The following report is a summary of a one-day workshop which took place in Muenster, Germany on Oct. 28, 1995. Its goal was to define the current state of the art of miniaturised endoscopic ultrasound probes in the field of gastroenterology. During this workshop, possible clinical applications for diagnosis, therapy, as well as follow-up were described and discussed. The potential of miniaturised endoscopic ultrasound probes was explored in terms of possible future technical developments.

Endoscopic ultrasound visibility of celiac ganglia

Gleeson and colleagues must be congratulated on their large series evaluating the visibility at EUS of celiac ganglia, recently published in this journal [1]. Their findings confirm that celiac ganglia can be detected by EUS in the majority of patients. However, we would like to correct their statement that ”this is the first study that has evaluated the frequency of visualization of celiac ganglia by EUS.” Our first description of the EUS characteristics of celiac ganglia [2] included a small series of 22 patients who were prospectively evaluated with a linear echo endoscope, and we were able to visualize celiac ganglia in 16 (73 %). The study by Gleeson and colleagues now validates these results in a large number of patients.

EUS training in a live pig model: does it improve echo endoscope hands-on and trainee competence?

The learning curve for endoscopic ultrasonography (EUS) is known to be difficult, especially in the field of pancreatic and biliary diseases. The aim of this study was to assess the impact of a live pig model developed for EUS credentialing in France. A total of 17 trainees obtained hands-on EUS experience using a live pig model. Trainees were asked to visualize anatomical structures, to carry out fine-needle aspiration (FNA) on lymph nodes in the liver hilum, and to perform celiac neurolysis. Assessment of the FNA procedure or celiac neurolysis included measurement of time (seconds), evaluation of the precision of the puncture (mm), and existence of technical errors. A significant improvement between a pre-test and post-test was observed for diagnostic procedures in the following anatomical areas: splenic mesenteric vein, vena cava, splenic mesenteric artery, celiac tree, pancreatic gland, and bile duct. For lymph node FNA, a significant improvement was observed in the duration of the procedure (84 seconds vs. 60 seconds; P = 0.01), and precision (4.2 mm vs. 1.8 mm; P = 0.009), but not for the rate of technical error (29% vs. 6%; not significant [n. s.]). For celiac neurolysis, a significant improvement was observed in procedure time (150 seconds vs. 84 seconds; P = 0.003), but not in the rate of technical error (6% vs. 6%; n. s.) or precision (4.2 mm vs. 2.8 mm; n. s.). Teaching EUS with a live pig model significantly increased competence in diagnostic procedures with regard to visualizing anatomical structures, performance of FNA and, to a lesser extent, EUS-guided celiac neurolysis.