Controversies in EUS-guided treatment of walled-off necrosis.

This review gives an overview of different techniques in the treatment of post-acute complications of acute pancreatitis. The endoscopic treatment of those complications is currently standard of care. EUS opened up the broad implementation of internal drainage methods to make them safe and effective. Due to different endoscopic approaches worldwide, controversies have arisen that are pointed out in this paper. The main focus was placed on weighing up evidence to find the optimal approach. However, if no evidence can be provided, the authors, experienced in the field, give their personal advice.

Clinical impact of strain histogram EUS elastography and contrast-enhanced EUS for the differential diagnosis of focal pancreatic masses: A prospective multicentric study.

BACKGROUND: Recent advances in EUS techniques (real-time EUS elastography and contrast-enhanced EUS) have allowed a better characterization of focal pancreatic masses. Mean strain histograms (SHs) are considered a good parameter for the semi-quantitative evaluation of focal pancreatic masses, alongside complementary contrast-enhanced EUS parameters which can be quantified during both the early arterial and late venous phase. MATERIALS AND METHODS: The study design was prospective, blinded, and multicentric, assessing real-time EUS elastography and contrast-enhanced EUS results for the characterization of focal pancreatic masses using parametric measurements, in comparison with pathology which is the gold standard. SHs were performed based on the embedded software of the ultrasound system, with the values being reversed as opposed to our initially published data on hue histograms. Consequently, a cutoff of 80 was derived from previous multicentric trials. Contrast-enhanced EUS also allowed the focal masses to be classified as hyper-, iso-, or hypoenhanced in comparison with the normal pancreatic parenchyma. EUS-FNA was then performed for all patients, with a positive cytological diagnosis taken as a final proof of malignancy for the pancreatic masses. The diagnoses obtained by EUS-FNA were verified further either by surgery or during a clinical follow-up of at least 6 months. RESULTS: A total number of 97 consecutive patients with focal pancreatic masses were included in the study. Based on previously defined cutoffs of 80, the values of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the mean SHs for the diagnosis of pancreatic cancer were 100%, 29.63%, 78.65%, 100%, and 80.41%, respectively. Corresponding values for contrast-enhanced EUS (taking into consideration hypoenhencement as a predictive factor of malignancy) were 98.57%, 77.78%, 92%, 95.45%, and 92.78%, respectively. Combining contrast enhancement-EUS (hypoenhencement) and semi-quantitative EUS elastography (SH cutoffs <80), the resulting values corresponding for sensitivity, specificity, and accuracy were 98.57%, 81.48%, and 93.81%, respectively. CONCLUSION: The current study using objective parametric tools for both EUS elastography and contrast-enhanced EUS confirmed the results of previous studies and meta-analyses that indicated a complementary role for the differential diagnosis of focal pancreatic masses. Moreover, the best values for the receiver operating curves were obtained using a sequential clinical algorithm based on the initial use of elastography, followed by contrast enhancement.

Transcutaneous partial pressure of carbon dioxide monitoring during EUS-guided drainage of peripancreatic fluid collections using carbon dioxide insufflation: A prospective study.

BACKGROUND: Carbon dioxide (CO2) insufflation has become more commonly used in EUS-guided interventions in recent years. However, there is a paucity of information regarding methods by which to monitor in vivo CO2 levels. This study aimed to assess the feasibility of a novel noninvasive method to monitor transcutaneous partial pressure of CO2 [INSIDE:1] levels during EUS-guided drainage of peripancreatic fluid collections (PFCs). The safety of CO2 insufflation in EUS-guided interventions was also investigated. PATIENTS AND METHODS: Patients who underwent EUS-guided PFC drainage between September 2015 and December 2016 at Shengjing Hospital of China Medical University were prospectively enrolled in this study. [INSIDE:2] was measured in all patients using a noninvasive sensor throughout the procedure. RESULTS: There were 25 patients eligible to be included in this study. The mean procedure time was 53.1 min. The mean [INSIDE:2] level was 40 ± 4 mmHg and 48 ± 5 mmHg before and after the procedure, respectively. The mean peak [INSIDE:2] during the procedure was significantly higher at 53 ± 6 mmHg (P < 0.0001). No complications associated with CO2 insufflation such as CO2 narcosis, gas embolism, or arrhythmias were encountered. CONCLUSIONS: [INSIDE:2] monitoring can accurately reflect the level of [INSIDE:3] continuously and noninvasively. CO2 insufflation is safe for patients undergoing relatively complicated EUS-guided drainage of PFCs.

Changes in tumor vascularity depicted by contrast-enhanced EUS as a predictor of prognosis and treatment efficacy in patients with unresectable pancreatic cancer (PEACE): A study protocol.

Patients with unresectable pancreatic cancer have a poor prognosis. The analysis of prognostic factors before treatment may be helpful in determining the best therapeutic strategies. The aim of the PEACE study is to assess the vascularity of pancreatic malignant tumors using contrast-enhanced harmonic EUS (CEH-EUS) and to clarify the prognostic value of tumor vascularity in patients with locally advanced and metastatic pancreatic cancer. Hereby, we present the protocol of a prospective, nonrandomized, single-arm, multicenter study aiming to assess changes in tumor vascularity using CEH-EUS before and 2 months after treatment initiation in patients with unresectable, locally advanced/metastatic pancreatic cancer and to examine the correlation between vascular changes and treatment response, progression-free survival, and overall survival.

The role of hemoclips reinforcement in the ligation-assisted endoscopic enucleation for small GISTs in gastric fundus.

BACKGROUND: Endoscopic ultrasonography- (EUS-) assisted band ligation has been proven to be a safe and effective procedure for the treatment of small gastrointestinal stromal tumors (GISTs) apart from the relatively high risk of the postligation perforation of the gastric fundus. The aim of this study is to investigate the efficacy of hemoclip reinforcement in treating small GISTs in the gastric fundus. METHOD: During a standard endoscopy, a transparent cap attached to the endoscopic tip was placed over the lesion to exert sustained maximal aspiration before a rubber band was released. Once a definite ligation was confirmed by EUS, the tumor was enucleated. Four to 6 hemoclips were placed on the folds around the ligation band to reduce the tension of the ligation site. RESULTS: The small GISTs were resected completely in 192 patients. Two cases of delayed perforation were found 72 hours after the procedure and successfully treated with an ordinary conservative method. CONCLUSION: Hemoclip-reinforced endoscopic band ligation with systematic follow-up using EUS appears to be a simple and effective technique for the resection of small GISTs in the gastric fundus.

Combined EUS-Guided Abdominal Cavity Drainage and Cystogastrostomy for the Ruptured Pancreatic Pseudocyst.

Background. Endoscopic-Ultrasonography- (EUS-) guided puncture and drainage of pancreatic pseudocyst is currently one of the most widely accepted nonsurgical treatments. To date, this technique has only been used for pancreatic pseudocysts adhesive to the gastric wall. This study introduces the technique of EUS-guided pseudocyst drainage and additional EUS-guided peritoneal drainage for the ruptured pseudocyst. Methods. Transmural puncture and drainage of the cyst were performed with a 19 G needle, cystotome, and 10 Fr endoprosthesis. Intraperitoneal drainage was performed with a nasobiliary catheter when rupture of pseudocyst occurred. The entire procedure was guided by the echoendoscope. Results. A total of 21 patients, 8 men and 13 women, with a mean age of 36 years, were included in this prospective study. All of the pseudocysts were successfully drained by EUS. Peritoneal drainage was uneventfully performed in 4 patients. There were no severe complications. Complete pseudocyst resolution was established in all patients. Conclusion. The technique of EUS-guided transmural puncture and drainage, when combined with abdominal cavity drainage by a nasobiliary catheter, allows successful endoscopic management of pancreatic pseudocysts without adherence to gastric wall.