Endoscopic ultrasound-guided sampling in gastroenterology: European society of gastrointestinal endoscopy technical guidelines

Ultrasound imaging features of isolated pancreatic tuberculosis

Background and Objectives:

Isolated pancreatic tuberculosis (PTB) is extremely rare worldwide. The purpose of this multicenter retrospective study is to analyze imaging features of histologically confirmed isolated PTB in order to determine the diagnostic features of the new methods contrast enhanced ultrasound (CEUS), ultrasound elastography and contrast enhanced endoscopic ultrasound (CE-EUS).

Patients and Methods:

We report on a retrospective data collection of 12 cases of PTB confirmed by histology or cytology. All examinations were interpreted by two independent readers in consensus. CEUS, CE-EUS and ultrasound elastography were performed according to the European Federation of Societies for Ultrasound in Medicine and Biology guidelines.

Results:

In PTB patients the common bile duct was never dilated. Multiple retroperitoneal lymph nodes are the second important B-mode ultrasound feature detected in 75% of PTB patients. CE-EUS was performed in three PTB patients demonstrating hyperenhancement. On elastography, all PTB lesions were markedly stiffer than surrounding pancreatic parenchyma.

Conclusions:

Here we report the first time on CEUS and elastography features of PTB. PTB had some typical imaging features with iso- or hyperenhancement on CE(E) US. PTB is markedly stiffer on elastography. If clinicians are aware of clinical features of PTB and conduct appropriate investigations with multiple modalities including B-mode ultrasound, CEUS, and EUS guided fine needle aspiration, diagnosis of PTB without laparotomy is possible and the disease can be effectively treated with anti-tuberculous drugs.

B-mode and contrast-enhancement characteristics of small nonincidental neuroendocrine pancreatic tumors

BACKGROUND AND OBJECTIVES

Imaging of the pancreas for detection of neuroendocrine tumors is indicated as surveillance in multiple endocrine neoplasia type 1 (MEN1) or if typical clinical symptoms combined with hormone production raise the suspicion of a neuroendocrine tumor. Endoscopic ultrasound (EUS) is considered the best imaging modality to detect small pancreatic tumors. However, little is known about how small pancreatic neuroendocrine tumors (pNETs) present on EUS.

PATIENTS AND METHODS

In this multicenter study, we retrospectively analyzed the endosonographic characteristics of small pNETs which had been detected due to typical biochemistry and clinical symptoms or during surveillance of MEN 1. Only small pancreatic tumors ≤15 mm with histological confirmation as pNET were included. B-mode and contrast-enhanced ultrasound- and EUS patterns were analyzed.

RESULTS

Among 32 patients with histologically proven small pNETs, 7 patients had known MEN1. Among the pNETs, 20 were insulinoma, 2 gastrinoma, 3 glucagonoma, 6 nonfunctional in MEN1, and one PPoma. 94% of the pNET appeared hypoechogenic, only 1 isoechogenic and 1 hyperechogenic. After contrast injection, 90% of the pNETS showed hyperenhancement compared to the surrounding pancreatic parenchyma.

CONCLUSION

The high spatial resolution of EUS allows detection and even cytological confirmation of pNET <7 mm diameter. Hypoechogenicity in B-mode and hyperenhancement after injection of contrast agents are endosonographic characteristics of small pNET and present in >90% of pNETs.

Harmonic contrast-enhanced endoscopic ultrasound fine-needle aspiration: Fact or fiction?

The negative predictive value of endoscopic ultrasonography fine-needle aspiration is relatively low. To achieve the improvement of the diagnostic yield, the following were proposed: a higher number of passes, the presence of the rapid on-site cytopathologist evaluation, the fanning technique, or the repetition of the fine needle biopsy. Harmonic contrast-enhanced endosonography may better identify the targeted area in the lesions by avoiding the inside necrosis and the vessels of fibrosis, so it can guide the fine-needle aspiration. Both techniques are complementary, not competitive, and they can be done in the same session. The combined technique is simple, safe, and requires only a few minutes with minimal extra costs compared to standard fine-needle aspiration. It minimally increases the diagnostic rate, and it permits the decrease of the number of passes. However, we will know its real clinical impact only in the future and whether it will be incorporated into the lesion assessment process.

Ultrasound-guided central vascular interventions, comments on the European Federation of Societies for Ultrasound in Medicine and Biology guidelines on interventional ultrasound

Central venous access has traditionally been performed on the basis of designated anatomical landmarks. However, due to patients' individual anatomy and vessel pathology and depending on individual operators' skill, this landmark approach is associated with a significant failure rate and complication risk. There is substantial evidence demonstrating significant improvement in effectiveness and safety of vascular access by realtime ultrasound (US)-guidance, as compared to the anatomical landmark-guided approach. This review comments on the evidence-based recommendations on US-guided vascular access which have been published recently within the framework of Guidelines on Interventional Ultrasound (InVUS) of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) from a clinical practice point of view.

Endobronchial ultrasound elastography

Elastographic techniques have recently become available as advanced diagnostic tools for tissue characterization. Strain elastography is a real-time technique used with transcutaneous ultrasound (US) and endoscopic US. Convincing evidence is available demonstrating a significant value of strain elastography for the discrimination of benign and malignant lymph nodes (LNs). This paper reviews preliminary data demonstrating the feasibility of performing real-time elastography during endobronchial US (EBUS) and a potential application of this technique for selection of LNs for EBUS-guided transbronchial needle aspiration in patients with lung cancer and extrathoracic malignancies.

Mapping international practice patterns in EUS-guided tissue sampling: outcome of a global survey

BACKGROUND AND STUDY AIMS

Although Endoscopic Ultrasound (EUS)-guided tissue sampling is widely used, the optimal sampling strategy remains subject of debate. We evaluated practice patterns within the international endosonographic community.

PATIENTS AND METHODS

An online questionnaire was sent to 400 endosonographers from the United States, Europe, and Asia.

RESULTS

A total of 186 (47 %) endosonographers participated: United States 54 (29 %), Europe 85 (46 %), and Asia 47 (25 %). European (75 %) and Asian (84 %) respondents routinely check coagulation status, whereas US respondents only check on indication (64 %, P = 0.007). While propofol sedation is standard in the United States (83 %), conscious sedation is still widely used in Europe (52 %) and Asia (84 %, P < 0.001). Overall, the 22-gauge needle is most commonly used (52 %). For fine-needle aspiration (FNA) of solid pancreatic lesions, 22-gauge (45 %) and 25-gauge (49 %) needles are used equally. For fine-needle biopsy (FNB) of solid masses, the 25-gauge device is less favored than the 22-gauge FNA device (49 % versus 21 %). The 19-gauge needle is generally used for FNB of submucosal masses (62 %). Rapid on-site pathological evaluation (ROSE) is utilized more often by US (98 %) than by European and Asian respondents (51 %, P < 0.001). Cytolyt (52 %), formalin (15 %) and alcohol (15 %) are used for FNA specimen preservation in the United States and Europe, while saline (27 %) and alcohol (38 %) are widely used in Asia (P < 0.001).

CONCLUSIONS

EUS-guided tissue sampling practices vary substantially within the international endosonographic community and differ considerably from recommendations expressed in guidelines. Because the clinical relevance of these variations is largely unknown, the outcome of this survey suggests a need for further studies.

The safety of endoscopic ultrasound-guided fine-needle aspiration of pancreatic cystic lesions

Endoscopic ultrasound (EUS) is widely used in the evaluation of various pancreatic diseases including pancreatic cystic lesions (PCLs). EUS-guided fine-needle aspiration (EUS-FNA) of PCLs provides cyst fluid, which is used for the differentiation of PCLs. EUS-FNA of PCLs is a safe procedure with a low complication rate. Contrary to the concerns expressed by some investigators, preoperative EUS-FNA of mucinous PCLs is unlikely to increase the frequency of postoperative peritoneal seeding.

Evaluation of transabdominal ultrasound after oral administration of an echoic cellulose-based gastric ultrasound contrast agent for gastric cancer

Background

With the remarkable improvements in ultrasound equipment, transabdominal ultrasound after oral administration of an echoic cellulose-based gastric ultrasound contrast agent (TUS-OCCA) has recently been suggested to be effective in initial screening of gastric cancer. The aim of this study was to evaluate the diagnostic value of TUS-OCCA for gastric cancer.

Methods

Consecutive patients with gastric cancers who underwent resection in our hospital were enrolled. Before the lesion was resected, TUS-OCCA examination was performed by a skilled examiner who was blinded to the site, size, and endoscopy diagnosis of the lesion. TUS-OCCA findings were compared with those of endoscopy and pathological diagnoses as the gold standard.

Results

There were a total of 288 consecutive patients enrolled in the study, including 228 with advanced gastric cancers (T2–T4 stage), 50 with early gastric cancer (26 with stage T1b and 24 with stage T1a), and 10 with high-grade intraepithelial neoplasia. TUS-OCCA had a detection rate of 100 % (228/228) for advanced gastric cancers, 77 % (20/26) for stage T1b, 67 % (16/24) for stage T1a, and 60 % (6/10) for high-grade intraepithelial neoplasia. The majority of patients with undetectable neoplasms using TUS-OCCA were obese (body mass index, 28.7–31.8 kg/m²). The overall accuracy of TUS-OCCA in determining the T stage of gastric cancer was 77.3 % (62.5 % for T1a, 70 % for T1b, 71.1 % for T2, 85.2 % for T3, and 73.3 % for T4).

Conclusions

These findings indicate that TUS-OCCA achieved a high detection rate for gastric cancers and was useful in assessing the degree of gastric cancer invasion.

Endoscopic ultrasound: Elastographic lymph node evaluation

Different imaging techniques can bring different information which will contribute to the final diagnosis and further management of the patients. Even from the time of Hippocrates, palpation has been used in order to detect and characterize a body mass. The so-called virtual palpation has now become a reality due to elastography, which is a recently developed technique. Elastography has already been proving its added value as a complementary imaging method, helpful to better characterize and differentiate between benign and malignant masses. The current applications of elastography in lymph nodes (LNs) assessment by endoscopic ultrasonography will be further discussed in this paper, with a review of the literature and future perspectives.

Endoscopic Ultrasound in the Diagnosis and Staging of Pancreatic Cancer

Pancreatic cancer is one of the digestive cancers with the poorest prognosis, so an early and correct diagnosis is of utmost importance. With the development of new therapeutic options an accurate staging is essential. Endoscopic ultrasonography (EUS) has a major role in all stages of the management of these patients. EUS has a high accuracy in the diagnosis of pancreatic adenocarcinoma and the possibility to perform fine-needle aspiration/biopsy (FNA/FNB) increases the diagnostic yield of EUS. There is still no consensus on the several technical aspects of FNA, namely on the rapid on-site evaluation (ROSE), the diameter and type of needle, the number of passes and the use of stylet and suction. Contrast-enhanced EUS (CE-EUS) and EUS elastography (EUS-E) have been used in recent years as an adjunct to EUS-FNA. Given the higher sensitivity of these techniques a negative cytology by EUS-FNA should not exclude malignancy when CE-EUS and/or EUS-E are suggestive of pancreatic neoplasia. EUS remains one of the main methods in the staging of pancreatic adenocarcinoma, namely to further evaluate patients with non-metastatic disease that appears resectable on initial imaging. EUS is crucial for an accurate preoperative evaluation of pancreatic cancer which is essential to choose the correct management strategy. The possibility to obtain samples from suspicious lesions or lymph nodes, by means of EUS-guided fine-needle aspiration as well as the use of contrast-enhanced and elastography, makes EUS an ideal modality for the diagnosis and staging of pancreatic cancer.

Basic technique in endoscopic ultrasound-guided fine needle aspiration for solid lesions: How many passes?

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has evolved to become an indispensable tool for tissue acquisition in patients with luminal and extra luminal gastrointestinal cancers. Despite the extensive use of EUS-FNA, there still exists a wide variation in the number of samples required to ensure acquisition of diagnostic material from different kind of lesions. There are several factors that may influence the number of fine needle passes made during EUS-FNA, but the main factor seems to be the presence of a Cytopathologist during the EUS procedure. The diagnostic yield of EUS-FNA with rapid on-site evaluation (ROSE) in most studies exceeds 90%. Nevertheless, ROSE is not available in many centers. Various studies have investigated the adequate number of needle passes that should be performed if ROSE is not used. Differences exist based on the nature of the target lesion: Five to seven passes for pancreatic masses, three passes for lymphnodes, only one pass for pancreatic cystic lesions. Consider using a core biopsy needle or a 19-G FNA needle for histology could improve the diagnostic yield. Even though EUS-FNA is widely available, some patients still do not receive conclusive diagnoses upon initial EUS-FNA. One way to maximize the benefits for patients might be to centralize cases to several well-equipped, high-volume centers with experienced endosonographers that have universal availability of ROSE.