Endoscopic Ultrasound-Fine Needle Aspiration versus Core Biopsy for the Diagnosis of Subepithelial Tumors

Magnetically Actuated Soft Capsule Endoscope for Fine-Needle Biopsy

Wireless capsule endoscopes have revolutionized diagnostic procedures in the gastrointestinal (GI) tract by minimizing discomfort and trauma. Biopsy procedures, which are often necessary for a confirmed diagnosis of an illness, have been incorporated recently into robotic capsule endoscopes to improve their diagnostic functionality beyond only imaging. However, capsule robots to date have only been able to acquire biopsy samples of superficial tissues of the GI tract, which could generate false-negative diagnostic results if the diseased tissue is under the surface of the GI tract. To improve their diagnostic accuracy for submucosal tumors/diseases, we propose a magnetically actuated soft robotic capsule robot, which takes biopsy samples in a deep tissue of a stomach using the fine-needle biopsy technique. We present the design, control, and human-machine interfacing methods for the fine-needle biopsy capsule robot. Ex vivo experiments in a porcine stomach show 85% yield for the biopsy of phantom tumors located underneath the first layers of the stomach wall.

Endoscopic ultrasound guided fine-needle aspiration vs core needle biopsy for solid pancreatic lesions: Comparison of diagnostic accuracy and procedural efficiency

BACKGROUND

Endoscopic ultrasound (EUS) guided core needle biopsies (CNB) are increasingly being performed to diagnose solid pancreatic lesions. However, studies have been conflicting in terms of CNB improving diagnostic accuracy and procedural efficiency vs fine-needle aspiration (FNA), which this study aims to elucidate.

METHODS

Data were prospectively collected on consecutive patients with solid pancreatic or peripancreatic lesions at a single tertiary care center from November 2015 to November 2016 that underwent either FNA or CNB. Patient demographics, characteristics of lesions, diagnostic accuracy, final and follow-up pathology, use of rapid on-site evaluation (ROSE), complications, and procedure variables were obtained.

RESULTS

A total of 75 FNA and 48 CNB were performed; of these, 13 patients had both. Mean passes were lower with CNB compared to FNA (2.4 vs 2.9, P = .02). Use of ROSE was higher for FNA (97.3% vs 68.1%, P = .001). Mean procedure time was shorter with CNB (34.1 minutes vs 51.2 minutes, P = .02) and diagnostic accuracy was similar (89.2% vs 89.4%, P = .98). There was no difference in diagnostic accuracy when ROSE was performed for CNB vs not performed (93.5% vs 85.7%, P = .58). Additionally, diagnostic accuracy of combined FNA and CNB procedures was 92.3%, which was comparable to FNA (P = .73) or CNB (P = .52) alone.

CONCLUSION

FNA and CNB had comparable safety and diagnostic accuracy. Use of CNB resulted in less number of passes and shorter procedure time as compared to FNA. Moreover, diagnostic accuracy for CNB with or without ROSE was similar.

Via mucosa incision EUS-guided sampling for the diagnosis of conventional endoscopic biopsy-negative gastric wall thickening

Abnormal thickened lesions of the gastric wall are usually covered with normal mucosa. Conventional endoscopic biopsies often do not yield sufficient positive histological results for clinical treatment. To increase the rate of diagnosis of conventional endoscopic biopsy-negative gastric wall thickening, we used an endoscopic submucosal dissection (ESD)-like sampling method under endoscopic ultrasound (EUS) guidance to obtain tissue of gastric wall-thickening lesions. Between 2012 and 2016, patients with gastric wall thickening (as identified by computed tomography (CT), EUS or other imaging methods that showed no positive findings in repeating conventional endoscopic biopsy) underwent via mucosa incision EUS-guided sampling. Final diagnosis was determined after surgical or biopsy pathology. A total of 10 patients with gastric wall thickening were included in this study. Eight cases received definite results, whereas in two cases the biopsy results were ambiguous and in these two patients poorly differentiated adenocarcinoma was determined by postoperative pathology. The results of the cases presented in this study demonstrated that via mucosa incision EUS-guided sampling provided a complementary option for the diagnosis of conventional endoscopic biopsy-negative gastric wall thickening.

Echoendoscopic ablative therapy for solid pancreatic tumors

Initially, endoscopic ultrasound (EUS) was developed to inspect the pancreas and other organs adjacent to the gastrointestinal tract. After introduction of curvilinear-array echoendoscopes, EUS has been used for a variety of interventions in gastroenterology, including fine needle aspiration, pancreatobiliary drainage and tumor ablation. EUS-guided ablation of pancreatic cystic tumors with ethanol and with or without cytotoxic agents has been studied, showing its potential to become an alternative to surgery. However, only few attempts at using ethanol ablation to treat solid pancreatic tumors have been reported. Recently, EUS-guided radiofrequency ablation was introduced and has been cautiously applied for pancreatic cancer. This article focuses on the clinical application of EUS for the ablation of solid pancreatic tumors.

Current endoscopic ultrasound-guided approach to incidental subepithelial lesions: optimal or optional?

Subepithelial lesions (SEL) are identified during endoscopic procedures on a regular basis. They can occur anywhere in the gastrointestinal (GI) tract and are located beneath the normal epithelial layer, which explains why a tissue diagnosis is difficult to obtain with routine biopsies. Endoscopic ultrasound (EUS) is used to further characterize these lesions. EUS can distinguish intramural lesion from extramural compression. Furthermore, it allows allocation of intramural lesions to a specific layer of the GI wall and offers additional information as to whether a lesion could be benign or malignant. EUS also assists in choosing the optimal means of tissue acquisition. The choice of tissue acquisition is based on a number of factors, such as tumor size, EUS features, and location within the GI tract or within a specific layer of the GI wall. Furthermore, local expertise and patient factors should be considered when deciding whether tissue acquisition, surgical intervention or follow up is recommended. In this review we offer an EUS-guided approach to the evaluation of incidental SEL based on current evidence and point out areas of uncertainty, which explain why the proposed algorithmic approach may be optional rather than optimal.