Performance of the forward-viewing linear echoendoscope for fine-needle aspiration of solid and cystic lesions throughout the gastrointestinal tract: a large single-center experience

Diagnostic Endoscopic Ultrasound (EUS) of the Luminal Gastrointestinal Tract

The purpose of this review is to focus on the diagnostic endoscopic ultrasound of the gastrointestinal tract. In the last decades, EUS has gained a central role in the staging of epithelial and sub-epithelial lesions of the gastrointestinal tract. With the evolution of imaging, the position of EUS in the diagnostic work-up and the staging flow-chart has continuously changed with two extreme positions: some gastroenterologists think that EUS is absolutely indispensable, and some think it is utterly useless. The truth is, as always, somewhere in between the two extremes. Analyzing the most up-to-date and strong evidence, we will try to give EUS the correct position in our daily practice.

Colonoscopic Ultrasound-Guided Fine-Needle Aspiration Using a Curvilinear Array Transducer: A Single-Center Retrospective Cohort Study

BACKGROUND

Curvilinear array ultrasound transducers enable tissue sampling and have therapeutic capabilities. Nevertheless, colonic intubation and maneuvering with these transducers is technically challenging and is therefore typically limited to the rectosigmoid area. This retrospective cohort study aimed to evaluate the safety, feasibility, and diagnostic yield of colonoscopic ultrasound-guided fine-needle aspiration in deep colonic intubation.

IMPACT OF INNOVATION

The impact of this innovation is to enable tissue sampling of colonic and extracolonic lesions guided by endoscopic ultrasound.

TECHNOLOGY, MATERIALS, AND METHODS

Curvilinear array ultrasound is used in the evaluation of luminal and extraluminal colonic diseases. Thirteen patients underwent colonoscopic ultrasound with a curvilinear array ultrasound endoscope in a single center for subepithelial lesions, cancer staging, and extracolonic lesions from July 2015 to February 2021. Endosonography was performed using an Olympus EU-ME1 and GF-UCT 180 with a 5-12MHz curvilinear array transducer. The primary outcome was the percentage of patients who were successfully scanned with the endoscopic ultrasound. The secondary outcomes included the success rate of fine-needle aspiration, the diagnostic yield of the tissue samples, and the adverse events related to the procedure.

PRELIMINARY RESULTS

A total of 13 female patients underwent colonoscopic ultrasound. All patients (100%, 13/13) were successfully scanned. Fine-needle aspiration was deemed necessary and successfully performed in 100% (5/5) of the patients. Tissue samples collected by fine-needle aspiration resulted in a diagnostic yield of 60%, and no adverse events resulted from this intervention.

CONCLUSIONS

This study demonstrates the feasibility of performing colonoscopic ultrasound with a curvilinear array transducer. Fine-needle aspiration for subepithelial, colonic, and extracolonic lesions is feasible and safe in this setting with no adverse events reported in our study.

FUTURE DIRECTIONS

Future research should be directed toward validating colonoscopic ultrasound with a curvilinear array transducer technique in prospective randomized trials. Studies evaluating the feasibility and safety of endoscopic ultrasound-guided interventions in the colon, such as abscess drainage and enteral anastomosis, should be considered.

Performance of the forward-view echoendoscope for pancreaticobiliary examination in patients with status post-upper gastrointestinal surgery

BACKGROUND AND OBJECTIVES

Failures of endoscopic ultrasound (EUS) imaging of the head of the pancreas (HOP) and the common bile duct (CBD) have been reported in up to 50% of patients with status postsurgery (e.g., Billroth II and Roux-en-Y). This is attributable to inability to intubate the afferent limb or the duodenum. Recently, a forward-view (FV) echoendoscope has become available. The frontal endoscopic and ultrasound field of view theoretically allow easier manipulation throughout the gastrointestinal tract compared to the traditional echoendoscopes. The aim of our study was to evaluate the safety and performance of the FV echoendoscope for the investigation of the biliary tree and the pancreas, including fine-needle aspiration (FNA), in patients with surgically altered upper gastrointestinal anatomy.

PATIENTS AND METHODS

This was a retrospective evaluation of a prospectively maintained database. All EUS procedures were performed at our institution by one experienced endosonographer from March to September 2009 under conscious sedation. The FV echoendoscope was used for all procedures.

RESULTS

Twenty-five (25) out of 37 presented status post-Billroth II and 12 out of 37 with status post-Roux-en-Y surgery. Overall, HOP and CBD were adequately visualized in 28 out of 37 (75.7%). All the failures occurred in the Roux-en-Y patients. EUS-FNA was successfully performed in 16 patients. No adverse events were observed.

CONCLUSIONS

The FV echoendoscope proved to be safe and effective in reaching the periampullary area in patients with previous Billroth II, allowing complete exploration of the HOP and the CBD and performance of EUS-FNA. However, FV EUS was unsuccessful in the majority of patients with Roux-en-Y, which still remains a challenging condition.

Endoscopic ultrasonography-guided endoscopic treatment of pancreatic pseudocysts and walled-off necrosis: New technical developments

In the last decades, the treatment of pancreatic pseudocysts and necrosis occurring in the clinical context of acute and chronic pancreatitis has shifted towards minimally invasive endoscopic interventions. Surgical procedures can be avoided in many cases by using endoscopically placed, Endoscopic ultrasonography-guided techniques and drainages. Endoscopic ultrasound enables the placement of transmural plastic and metal stents or nasocystic tubes for the drainage of peripancreatic fluid collections. The development of self-expanding metal stents and exchange free delivering systems have simplified the drainage of pancreatic fluid collections. This review will discuss available therapeutic techniques and new developments.

Forward-viewing linear echoendoscope: a new option in the endoscopic ultrasound armamentarium (with video)

The forward-viewing linear echoendoscope (FV-EUS) has been developed with the aim of overcoming limitations of standard curved linear-array echoendoscopes (CLA-EUS) and to further expand interventional applications of EUS. The main characteristic of the FV-EUS is a shifting in the orientation of both endoscopic and ultrasound views from oblique to forward, with the exit of the working channel at the tip of the instrument. This allows exit of the devices parallel to the longitudinal axis of the endoscope, thus resulting in a more direct and stable access to the lesion while increasing the precision and force applied to the target. Accumulating evidence has shown that the FV-EUS can be used instead of the standard CLA-EUS scope for routine fine needle aspiration, with extremely good performance for subepithelial lesions and for difficult to reach locations. Several areas of use of this echoendoscope are yet to be better defined, such as its potential for therapeutic and interventional procedures, as well as for natural orifice transluminal endoscopic surgery. The current report provides an updated overview of the available evidence for both diagnostic and interventional uses of the FV-EUS.