EUS-guided fine needle injection (FNI) and anti-tumor therapy

Endoscopic foregut surgery and interventions: The future is now. The state-of-the-art and my personal journey

In this paper, I reviewed the emerging field of endoscopic surgery and present data supporting the contention that endoscopy can now be used to treat many foregut diseases that have been traditionally treated surgically. Within each topic, the content will progress as follows: "lessons learned", "technical considerations" and "future opportunities". Lessons learned will provide a brief background and update on the most current literature. Technical considerations will include my personal experience, including tips and tricks that I have learned over the years. Finally, future opportunities will address current unmet needs and potential new areas of development. The foregut is defined as "the upper part of the embryonic alimentary canal from which the pharynx, esophagus, lung, stomach, liver, pancreas, and part of the duodenum develop". Foregut surgery is well established in treating conditions such as gastroesophageal reflux disease (GERD), achalasia, esophageal diverticula, Barrett's esophagus (BE) and esophageal cancer, stomach cancer, gastric-outlet obstruction, and obesity. Over the past decade, remarkable progress in interventional endoscopy has culminated in the conceptualization and practice of endoscopic foregut surgery for various clinical conditions summarized in this paper. Regarding GERD, there are now several technologies available to effectively treat it and potentially eliminate symptoms, and the need for long-term treatment with proton pump inhibitors. For the first time, fundoplication can be performed without the need for open or laparoscopic surgery. Long-term data going out 5-10 years are now emerging showing extended durability. In respect to achalasia, per-oral endoscopic myotomy (POEM) which was developed in Japan, has become an alternative to the traditional Heller's myotomy. Recent meta-analysis show that POEM may have better results than Heller, but the issue of post-POEM GERD still needs to be addressed. There is now a resurgence of endoscopic treatment of Zenker's diverticula with improved technique (Z-POEM) and equipment; thus, patients are choosing flexible endoscopic treatment as opposed to open or rigid endoscopy options. In regard to BE, endoscopic submucosal dissection (ESD) which is well established in Asia, is now becoming more mainstream in the West for the treatment of BE with high grade dysplasia, as well as early esophageal cancer. In combination with all the ablation technologies (radiofrequency ablation, cryotherapy, hybrid argon plasma coagulation), the entire spectrum of Barrett's and related dysplasia and early cancer can be managed predominantly by endoscopy. Importantly, in regard to early gastric cancer and submucosal tumors (SMTs) of the stomach, ESD and full thickness resection (FTR) can excise these lesions en-bloc and endoscopic suturing is now used to close large defects and perforations. For treatment of patients with malignant gastric outlet obstruction (GOO), endoscopic gastro-jejunostomy is now showing better results than enteral stenting. G-POEM is also emerging as a treatment option for patients with gastroparesis. Obesity has become an epidemic in many western countries and is becoming also prevalent in Asia. Endoscopic sleeve gastroplasty (ESG) is now becoming an established treatment option, especially for obese patients with body mass index between 30 and 35. Data show an average weight loss of 16 kg after ESG with long-term data confirming sustainability. Finally, in respect to endo-hepatology, there are many new endoscopic interventions that have been developed for patients with liver disease. Endoscopic ultrasound (EUS)-guided liver biopsy and EUS-guided portal pressure measurement are exciting new frontiers for the endo-hepatologists.

Contrast-enhanced endoscopic ultrasonography: advance and current status

Endoscopic ultrasonography (EUS) technology has undergone a great deal of progress along with the color and power Doppler imaging, three-dimensional imaging, electronic scanning, tissue harmonic imaging, and elastography, and one of the most important developments is the ability to acquire contrast-enhanced images. The blood flow in small vessels and the parenchymal microvasculature of the target lesion can be observed non-invasively by contrast-enhanced EUS (CE-EUS). Through a hemodynamic analysis, CE-EUS permits the diagnosis of various gastrointestinal diseases and differential diagnoses between benign and malignant tumors. Recently, mechanical innovations and the development of contrast agents have increased the use of CE-EUS in the diagnostic field, as well as for the assessment of the efficacy of therapeutic agents. The advances in and the current status of CE-EUS are discussed in this review.

Comparison of diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration with 22- and 25-gauge needles in the same patients

BACKGROUND: Various factors, such as the optimal number of passes, aspiration pressure, and the use of 19-gauge and Trucut biopsy needles, have been studied to improve the diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). We retrospectively compared the diagnostic accuracy of EUS-FNA between 25- and 22-gauge needles, which have been widely used recently. SUBJECTS AND METHODS: The study group comprised 47 consecutive patients who underwent EUS-FNA with both 22- and 25-gauge needles from October 2007 through March 2010. Their underlying diseases were pancreatic cancer in 24 patients, submucosal tumors in 11, other pancreatic tumors in 4, chronic pancreatitis in 4, enlarged lymph nodes in 3, and gall bladder cancer in 1. Tissue specimens, which were pushed out of the puncture needle, were placed into physiological saline solution. Gray-whitish, worm-like specimens were used for histologic diagnosis. The remaining specimen was centrifuged, and the sediment was plated on slides and examined by a cytopathologist to obtain the cytologic diagnosis. RESULTS: A total of 75 punctures (mean, 1.6) were performed with 25-gauge needles, and 69 punctures (mean, 1.4) were performed with 22-gauge needles. The overall tissue-sampling rate for cytology was 100% (47/47), which was significantly (p=0.01) superior to 83% (39/47) for histology. The overall diagnostic accuracy on the cytologic and histologic examinations was 79% (37/47) and 85% (33/39) (p=0.48). According to needle type, the tissue-sampling rate for cytology and histology on each puncture was 97% (73/75) and 56% (42/75) with 25-guage needles, and was 97% (67/69) and 58% (40/69) with 22-guage needles, the accuracy of cytologic diagnosis on each puncture was 73% (53/73) with 25-gauge needles and 66% (44/67) with 22-gauge needles (p=0.37); the accuracy of histologic diagnosis on each puncture was 60% (25/42) and 75% (30/40) (p=0.14), respectively. No patient had complications. CONCLUSIONS: The tissue-sampling rate and diagnostic accuracy did not differ significantly between 22- and 25-gauge needles in patients with pancreatic or gastrointestinal diseases who underwent EUS-FNA.

Therapeutic endoscopic ultrasound for biliary and pancreatic disorders

The role of endoscopic ultrasound (EUS) has greatly expanded since the first clinical examination performed nearly 30 years ago. The introduction of linear instruments allowed tissue sampling (Kulesza and Eltoum Clin Gastroenterol Hepatol 5:1248-1254, 2007; Levy and Wiersema Gastrointest Endosc 62:417-426, 2005) and therapeutic interventions applications, including celiac plexus and ganglia blockade and neurolysis (Wiersema and Wiersema Gastrointest Endosc 44:656-662, 1996; Levy and Wiersema Gastroenterol Clin North Am, 35:153-165, 2006; Levy et al. Am J Gastroenterol 103:98-103, 2008), pancreatic fluid drainage (Lopes et al. Arq Gastroenterol 45:17-21, 2008; Norton et al. Mayo Clin Proc 76:794-798, 2001; Kruger et al. Gastrointest Endosc 63:409-416, 2006; Seifert et al.: Endoscopy 32:255-259, 2000), cholecystenterostomy (Kwan et al. Gastrointest Endosc 66:582-586, 2007), and delivery of cytotoxic agents (eg, chemotherapy, radioactive seeds, and gene therapy) (Chang et al.: Cancer 88:1325-1335, 2000; Chang Endoscopy 38(Suppl 1):S88-S93, 2006). The continued need to develop less invasive alternatives to surgical and interventional radiologic therapies drove the development of EUS-guided methods for biliary and pancreatic intervention. This article reviews existing data and focuses on established and emerging EUS techniques for accessing and draining the bile and pancreatic ducts.

Preliminary experience of a prototype forward-viewing curved linear array echoendoscope in a training phantom model

Oblique-viewing curved linear array (OV-CLA) echoendoscopes have been widely used to perform endoscopic ultrasonography-guided fine needle aspiration and interventional endoscopic ultrasonography. Recently a prototype forward-viewing curved liner array (FV-CLA) echoendoscope was developed. In the present trial, 11 endoscopists participated in a hands-on trial and a questionnaire survey to evaluate the operation performance and visualization performance of a prototype FV-CLA scope in a phantom model designed for training of endoscopic ultrasonography. The results of our trial suggested that the FV-CLA scope is slightly inferior or equivalent to the conventional OV-CLA scope in operation performance, and that the FV-CLA scope is equivalent to the OV-CLA scope with regard to the visualization performance in a phantom model.

Endoscopic ultrasound in the evaluation of pancreaticobiliary disorders

The close proximity of the endoscopic ultrasound probe to the pancreas coupled with the ability to perform fine needle aspiration has made endoscopic ultrasound an extremely important technique for the evaluation of both benign and malignant pancreaticobiliary disorders. In parallel to the widespread importance of diagnostic endoscopic ultrasound, the therapeutic and interventional applications of this procedure are expanding and may become a major breakthrough in the management of pancreaticobiliary diseases. This article focuses on the utility and recent advances of endoscopic ultrasound in the diagnostic evaluation pancreaticobiliary disorders and analyses the data of well established interventional procedures such as celiac plexus neurolysis and pseudocyst drainage. Moreover, the more innovative procedures, such endoscopic ultrasound-guided biliary and pancreatic ducts access and drainage and the experimental use of direct endoscopic ultrasound-guided therapy of both solid and cystic pancreatic lesions will also be reviewed.

EUS-guided radiofrequency ablation with a prototype electrode array system in an animal model (with video)

BACKGROUND

Although previously reported in an animal model, the development of EUS-guided radiofrequency ablation (EUS-RFA) has been impeded because of a lack of a retractable needle electrode array that could safely and effectively ablate large areas.

OBJECTIVE

To evaluate the feasibility and safety of performing EUS-RFA with a 19-gauge FNA needle fitted with an umbrella-shaped retractable needle electrode array.

DESIGN AND SETTING

Endoscopic experimental study in a porcine survival model at a tertiary referral center animal laboratory.

MAIN OUTCOME MEASURES

Evaluate the safety and efficacy of the retractable needle electrode array for performing EUS-RFA.

INTERVENTIONS

A 19-gauge EUS-FNA needle was modified and fitted with a retractable echogenic umbrella-shaped monopolar electrode array at its tip. The FNA needle was connected to a 200-W generator that has an impedance-based feedback system. EUS-RFA of the liver was attempted on 5 Yorkshire pigs. Although 1 pig was euthanized immediately after RFA to assess for immediate complications and pathological examination, the 4 others were kept alive for 7 days.

RESULTS

At EUS, the needle electrode was well visualized and could be deployed in the liver without technical difficulty. During ablation, a round hyperechoic focus gradually surrounded the electrode tip. Tissue ablation was attained within 7 minutes, and the electrode array could be easily withdrawn into the needle assembly. The vital signs of all pigs remained stable throughout the procedure and until they were euthanized. Histopathology in all pigs revealed a discrete, well-demarcated spherical focus of complete coagulation necrosis measuring 2.6 cm in diameter and without damage to the surrounding liver parenchyma or vasculature.

CONCLUSIONS

In this experimental study, EUS-RFA of the liver was performed safely by using the retractable umbrella-shaped electrode array with effective coagulation necrosis of large areas.

Endoscopic ultrasound in pancreatic disease--its influence on surgical decision-making. An update 2008

Endoscopic ultrasonography (EUS) was introduced about 25 years ago with the primary aim of better visualization of the pancreas as compared to transabdominal ultrasonography. This review discusses the current evidence in 2008 concerning the role of EUS in the clinical management of patients, with a special emphasis on its impact on surgical therapy. According to the literature, good indications are detection of common bile duct stones (e.g. in acute pancreatitis), the detection of small exo- and endocrine pancreatic tumors, the performance of fine-needle aspiration in pancreatic masses depending on therapeutic consequences. In other areas such as diagnosis of chronic pancreatitis and cystic pancreatic lesions, the contribution of EUS seems limited. Pancreatic cancer staging is discussed controversially due to conflicting evidence and certainly has lost grounds due to improvements in CT technology. Therapeutic EUS is, however, more widely accepted and may replace other techniques, e.g. in pancreatic cyst drainage and celiac plexus neurolysis; further techniques of interest are being developed.

Endoscopic ultrasound: moving from diagnostics to therapeutics

Endoscopic ultrasound was initially introduced in the 1980s as a diagnostic modality using echoendoscopes with radial scanning that permitted reconstruction of cross-sectional images similar to computed tomography The close proximity of the ultrasound transducer to the gastrointestinal wall and retroperitoneal structures allowed a detailed examination that is not possible with cross-sectional imaging such as computed tomography and magnetic resonance imaging. It proved to be highly accurate and useful in the staging of gastrointestinal malignancies, as well as in characterizing the nature of subepithelial lesions and disorders of the pancreaticobiliary system. The introduction of linear echoendoscopes facilitated fine needle aspiration because, with linear scanning, it was able to trace the path of the tip of the needle during the puncture process. In addition to being very useful for tissue acquisition for diagnostic purposes, the principles behind endoscopic ultrasound-guided fine needle aspiration paved the way for the development of therapeutic endoscopic ultrasound. Substances could now be delivered by endoscopic ultrasound into targeted areas, an example being an endoscopic ultrasound-guided celiac plexus block and neurolysis. In addition, the endoscopic ultrasound-guided puncture of fluid collections, abscesses and obstructed biliary and pancreatic ductal systems facilitated the passage of guidewires, thus allowing therapeutic drainage procedures to be performed using the Seldinger technique. This review summarizes the diagnostic capability of endoscopic ultrasound and then moves on to elaborate in detail its therapeutic capability and potential.

Esophageal endoscopic ultrasound fine-needle aspiration as a diagnostic tool

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) may be employed for procurement of a tissue diagnosis in a minimally invasive fashion. In many cases, EUS-FNA excludes the need for more invasive diagnostic procedures when a tissue diagnosis is required. In patients with esophageal neoplasms, EUS-FNA is a safe and accurate tool for the preoperative diagnosis of metastatic spread to the paraesophageal and celiac lymph nodes. EUS-FNA is also increasingly recognized as an accurate, cost-effective and safe means of evaluating and staging patients with lung cancer. EUS-FNA is useful in providing tissue confirmation of cancer in cases in which bronchoscopy or computed tomography-guided approaches has been non-diagnostic. EUS-guided therapies are paving the way for therapeutic/interventional EUS. The interventional endoscopist will now play a more central role in the diagnosis and treatment of various gastrointestinal malignancies by delivering antitumor agents.