Lymph sampling and lymphangiography via EUS-guided transesophageal thoracic duct puncture in a swine model

New insights into acute pancreatitis

The incidence of acute pancreatitis continues to increase worldwide, and it is one of the most common gastrointestinal causes for hospital admission in the USA. In the past decade, substantial advancements have been made in our understanding of the pathophysiological mechanisms of acute pancreatitis. Studies have elucidated mechanisms of calcium-mediated acinar cell injury and death and the importance of store-operated calcium entry channels and mitochondrial permeability transition pores. The cytoprotective role of the unfolded protein response and autophagy in preventing sustained endoplasmic reticulum stress, apoptosis and necrosis has also been characterized, as has the central role of unsaturated fatty acids in causing pancreatic organ failure. Characterization of these pathways has led to the identification of potential molecular targets for future therapeutic trials. At the patient level, two classification systems have been developed to classify the severity of acute pancreatitis into prognostically meaningful groups, and several landmark clinical trials have informed management strategies in areas of nutritional support and interventions for infected pancreatic necrosis that have resulted in important changes to acute pancreatitis management paradigms. In this Review, we provide a summary of recent advances in acute pancreatitis with a special emphasis on pathophysiological mechanisms and clinical management of the disorder.

EUS-guided transesophageal study of the human thoracic duct diameter after instillation of intraduodenal fatty acids (EUS-TEST study)

INTRODUCTION

The accession of the thoracic duct (TD) may be vital for obtaining lymph samples, which may be potentially important for early detection of gastrointestinal cancers. The feasibility and safety of endoscopic ultrasound (EUS)-guided TD puncture were recently demonstrated in a swine model. However, the actual process of lymph aspiration is difficult because of small TD diameter (TDD) as well as sluggish flow. This study was designed to examine the change in TDD following intraduodenal instillation of fatty acids (Intralipid(®); manufactured by Fresenius Kabi [Uppsala, Sweden] for Baxter Healthcare [Deerfield, IL]) in patients undergoing diagnostic EUS.

PATIENTS AND METHODS

Ten patients undergoing EUS for routine indications were enrolled in this interventional study at a tertiary-care center in the United States. Baseline TDD was first recorded with EUS in the mediastinum, and the endoscope was advanced into the second part of the duodenum, where 20% Intralipid was instilled. Patients then underwent the complete EUS procedure, and TDD was again measured at 30, 45, 60, 75, and 90 minutes.

RESULTS

Mean age of the patients was 63 years (range, 46-83 years). The mean (±2 standard deviation) TDD at baseline was 0.17±0.04 cm (range, 0.11-0.23 cm). Values for TDD at 30 minutes (0.22±0.03 cm; P=.11), 60 minutes (0.35±0.08 cm; P=.0007), and 90 minutes (0.27±0.08 cm; P=.04) were all higher than the baseline measurement. Maximum increase in TDD was observed at 60 minutes, after which TD started returning toward baseline.

CONCLUSIONS

TDD increases after intraduodenal instillation of Intralipid in human subjects. This change was statistically most significant at 60 minutes. These observations may be critical for aspiration of lymph samples for early detection of gastrointestinal cancers in humans.

Present and future of endoscopic ultrasonography

Endoscopic ultrasonography and endoscopic ultrasonography-guided fine needle aspiration are well-established techniques, encompassing a variety of diagnostic and therapeutic applications. Along with traditional indications that constitute everyday clinical practice in all endoscopic ultrasonography centres, new indications are emerging that resemble the continuing research carried on in this field. Some of these are innovative applications, developed by highly experienced endosonographers and with a putative role for clinical practice in the near future. Others are merely experimental applications, carried out on in animal models or in highly selected groups of patients, opening up new fascinating areas of research but not for imminent introduction in clinical practice. The purpose of this review, after summarising the present indications of endoscopic ultrasonography, is to focus on the future applications and try to establish their possible advent, either in the near or in the far future.