EUS-guided pancreatic cyst ablation: a critical review (with video)

Endoscopic Ultrasound-Guided Ablation of Premalignant Pancreatic Cysts and Pancreatic Cancer

Pancreatic cancer is on the rise and expected to become the second leading cause of cancer-related death by 2030. Up to a one-fifth of pancreatic cancers may arise from mucinous pancreatic cysts, which are frequently present in the general population. Currently, surgical resection is the only curative approach for pancreatic cancer and its cystic precursors. However, only a dismal proportion of patients are eligible for surgery. Therefore, novel treatment approaches to treat pancreatic cancer and precancerous pancreatic cysts are needed. Endoscopic ultrasound (EUS)-guided ablation is an emerging minimally invasive method to treat pancreatic cancer and premalignant pancreatic cysts. Different ablative modalities have been used including alcohol, chemotherapy agents, and radiofrequency ablation. Cumulative data over the past two decades have shown that endoscopic ablation of mucinous pancreatic cysts can lead to cyst resolution in a significant proportion of the treated cysts. Furthermore, novel data are emerging about the ability to endoscopically ablate early and locally advanced pancreatic cancer. In this review, we aim to summarize the available data on the efficacy and safety of the different EUS-ablation modalities for the management of premalignant pancreatic cysts and pancreatic cancer.

An update on EUS-guided ablative techniques for pancreatic cystic lesions

Pancreatic cystic lesions (PCLs) are increasingly being recognized due to improvements and widespread use of cross-sectional imaging. With an estimated prevalence of 15% in general population, incidentally discovered PCLs represent a dilemma in management. While pancreatectomies offer a chance of cure, the morbidity is considerable in patients with high surgical risks. More recently, EUS-guided approaches for cyst ablation are being offered in clinical trials for the management of PCLs. EUS-chemoablation studies have progressed from first investigating safety and efficacy of EUS-guided alcohol lavage to single-agent paclitaxel ablation. Recent studies have shown that alcohol lavage may not be required, and long-term resolution can be achieved by chemoablation alone. EUS-guided lauromacrogol ablation and EUS-guided radiofrequency ablation (RFA) are new techniques that have shown promising results in a few small studies. Overall, the current literature suggests that EUS-guided paclitaxel ablation has better cyst resolution rates compared to other existing minimally invasive techniques including ethanol injection, lauromacrogol ablation, or RFA. This article will review EUS-guided PCL ablation approaches and future directions the field is headed into.

State-of-the-Art Update of Pancreatic Cysts

Andrew Canakis.

Long-term outcomes of EUS-guided lauromacrogol ablation for the treatment of pancreatic cystic neoplasms: 5 years of experience

BACKGROUND AND OBJECTIVES

We initially reported EUS-guided lauromacrogol ablation (EUS-LA) to treat pancreatic cystic neoplasms (PCNs); however, its long-term effectiveness remains unknown. This study was performed to further determine the effectiveness of EUS-LA in a larger population with a long-term follow-up based on 5 years of experience with EUS-LA.

MATERIALS AND METHODS

From April 2015 to April 2020, 279 patients suspected of having PCNs were prospectively enrolled, and seventy patients underwent EUS-guided ablation using lauromacrogol alone. Fifty-five patients underwent follow-up, 35 of whom had a follow-up duration of at least 12 months. The effectiveness of ablation was determined based on volume changes.

RESULTS

Among the fifty female and twenty male patients with an overall mean age of 50.3 years, cysts were located in the head/neck of the pancreas in 37 patients (52.9%) and in the body/tail of the pancreas in 33 patients (47.1%). The adverse events rate was 3.6% (3/84), with 14 patients undergoing a second ablation. Among the 55 patients who underwent follow-up, the median cystic volume sharply decreased from 11,494.0 mm3 to 523.6 mm3 (P < 0.001), and the mean diameter decreased from 32.0 mm to 11.0 mm (P < 0.001). Postoperative imaging showed complete resolution (CR) in 26 patients (47.3%) and partial resolution (PR) in 15 (27.3%) patients. CR was observed in 18 (51.4%), and PR was observed in 9 (25.7%) patients among the 35 patients followed for at least 12 months.

CONCLUSIONS

EUS-LA was effective and safe for the treatment of PCNs with stable effectiveness based on at least 12 months of follow-up.

Pancreatitis kills cysts: A phenomenon that illustrates the potential role of immune activation in premalignant cyst ablation

Background and study aims  Pancreatic cystic lesions are being increasingly recognized on cross-sectional imaging and mucinous premalignant cysts represent one of the most prevalent types. Endoscopic ultrasound (EUS)-guided chemoablation offers a safe and minimally invasive ablation approach yet with limited efficacy. Patients who develop acute pancreatitis as a complication of chemoablation with alcohol however experience ablation rates up to 100 %. This evidence suggests that recruitment of the body's immune system may represent an avenue to significantly increase the efficacy of EUS-guided chemoablation. Here we illustrate this immune-mediated tumor killing phenomenon through a case presentation at our institution.

An updated review on ablative treatment of pancreatic cystic lesions

Pancreatic cysts are common and often incidentally detected on abdominal imaging. Their prevalence in asymptomatic individuals depends on the screening modality used. The incidence of these lesions increases with age and may be detected in nearly half of elderly patients undergoing high-resolution magnetic resonance imaging. Some, but not all, pancreas cysts have malignant potential. The overall risk is small but induces significant anxiety for the patient. When determining management options, it is important to consider the patient's age, medical comorbidities, and surgical risks as well as the wishes of the patient. Current strategies include imaging surveillance or surgical resection. Before embarking on cyst surveillance, a clinician must factor in patients' risk of developing malignancy, their life expectancy, medical comorbidities, and if they are a surgical candidate. Surgery poses significant adverse events and mortality, whereas radiographic surveillance imposes healthcare costs and psychological distress to patients with the looming possibility of malignancy. The development and use of endoscopic ultrasound cyst ablation is a minimally invasive alternative in treating pancreatic cystic lesions. This review focuses on the modalities of ethanol ablation, paclitaxel ablation, and radiofrequency ablation of pancreatic cystic lesions.

Pancreatic Cysts in the Elderly

PURPOSE OF REVIEW

Incidental pancreatic cysts are common, and management strategies continue to evolve. This review summarizes diagnostic and management recommendations in older patients with these lesions based on guidelines and best clinical evidence.

RECENT FINDINGS

Diagnosis of cyst type has been enhanced with improved imaging and cyst fluid analysis and visualization. Recent outcome studies indicate that certain cyst types should be followed independent of patient age as long as certain criteria which are reviewed are met. Differentiation of pancreatic cyst type is important as this dictates the need for long-term follow-up. Because most cyst-related neoplasia occurs in older patients, surveillance should continue within certain guidelines.

Safety of endoscopic ultrasound-guided ethanol ablation for pancreatic cystic lesions: A single-center experience of 214 patients

BACKGROUND

Endoscopic ultrasound-guided ethanol ablation (EUS-EA) for pancreatic cystic lesions (PCLs) has been used in recent years as a feasible treatment modality for low malignant probability PCLs or patients considered high-risk for surgery. The present study aimed to confirm the safety of EUS-EA and to find predictive factors for adverse event (AE).

METHODS

A retrospective review was performed from the prospectively maintained database of patients who underwent EUS-EA for PCLs from June 2006 to April 2018 at Seoul National University Hospital. The primary outcomes of the study were the rates of AEs and severe AEs by EUS-EA. The secondary outcome was the predictive factors of AEs including acute pancreatitis and abdominal pain.

RESULTS

A total of 214 patients were evaluated and the diagnoses of PCLs according to cystic fluid analysis and clinical features were as follows: serous cystic neoplasm (32.2%), mucinous cystic neoplasm (26.6%), branch duct type intraductal papillary mucinous neoplasm (BD-IPMN) (29.4%), and pseudocyst (11.7%). Three patients (1.4%) experienced severe AEs. Overall, AEs occurred in 71 (33.2%) patients. BD-IPMN (OR: 2.87; 95% CI: 1.05-7.84; P = 0.040), multilocular cysts (OR: 3.59; 95% CI: 1.09-11.85; P = 0.036), suspected ethanol leakage during procedure (OR: 10.68; 95% CI: 1.98-57.53; P = 0.006), and sticky cystic fluid (OR: 3.83; 95% CI: 1.20-12.24; P = 0.024) were predictive factors for post-procedural acute pancreatitis. PCLs of uncinate process (OR: 2.99; 95% CI: 1.22-7.35; P = 0.017) and PCLs with exophytic portion (OR: 3.70; 95% CI: 1.96-7.01; P < 0.001) were predictive factors for post-procedural abdominal pain.

CONCLUSIONS

EUS-EA is a safe procedure with a very low rate of severe AEs. It seems possible to predict the AEs according to the features of the procedure and PCLs.

Position statement on EUS-guided ablation of pancreatic cystic neoplasms from an international expert panel

Background and aim  Recently, several guidelines with divergent recommendations on management of pancreatic cystic neoplasm have been published but the role of endoscopic ultrasound (EUS)-guided pancreatic cyst ablation has not been thoroughly addressed. The aim of the current paper is to explore the issues surrounding EUS-guided pancreatic cyst ablation by generating a list of clinical questions and providing answers based on best scientific evidence available. Methods  An expert panel in EUS-guided pancreatic cyst ablation was recruited from members of the Asian EUS group and an international expert panel. A list of clinical questions was created and each question allocated to one member to generate a statement in response. The statements were then discussed in three Internet conference meetings between October 2016 and October 2017. The statements were changed until consensus was obtained. Afterwards, the complete set of statements was sent to all the panelist to vote on strength of the statements, classification of the statement sand grading of the evidence. Results  Twenty-three statements on EUS-guided drainage of pancreatic cyst ablation were formulated. The statements addressed indications for the procedures, technical aspects, pre-procedure and post-procedure management, management of complications, and competency and training in the procedures. Conclusion  The current set of statements on EUS-guided pancreatic cyst ablation are the first to be published by any endoscopic society. Clinicians interested in developing the technique should reference these statements and future studies should address the key issues raised in the document.

Duodenal Stricture due to Necrotizing Pancreatitis following Endoscopic Ultrasound-Guided Ethanol Ablation of a Pancreatic Cyst: A Case Report

The frequency of incidental detection of pancreatic cystic lesions (PCLs) is increasing because of the frequent use of cross-sectional imaging. The appropriate treatment for PCLs is challenging, and endoscopic ultrasound-guided ablation for PCLs has been reported in several studies. Although the feasibility and efficacy of this therapeutic modality have been shown, the safety issues associated with the procedure are still a concern. We present a case of a 61-year-old man who underwent ultrasound-guided ethanol ablation for PCL and needed repeated endoscopic balloon dilatation for severe duodenal stricture caused by necrotizing pancreatitis after the cyst ablation therapy.

EUS-Guided Pancreatic Cyst Ablation: a Clinical and Technical Review

PURPOSE OF REVIEW

Pancreatic cystic lesions represent a growing public health dilemma, particularly as our population ages and cross-sectional imaging becomes more sensitive. Mucinous cysts carry a clinically significant risk of developing pancreatic cancer, which carries an extremely poor prognosis. Determining which cysts will develop cancer may be challenging, and surgical resection of the pancreas carries significant morbidity. The goal of this paper is to review the rationale for cyst ablation and discuss prior and current research on cyst ablation techniques and efficacy. Indications, contraindications, and factors related to optimal patient selection are outlined.

RECENT FINDINGS

Endoscopic ultrasound-guided chemoablation of pancreatic cysts has been performed in neoplastic cysts, with varying levels of efficacy. Safety concerns arose due to the risk of pancreatitis in alcohol-based treatments; however, the most recent data using a non-alcohol chemoablation cocktail suggests that ablation is effective without the need for alcohol, resulting in a significantly more favorable adverse event profile. Endoscopic ultrasound-guided chemoablation of neoplastic pancreatic cysts is a promising, minimally invasive approach for treatment of cysts, with recent significant advances in safety and efficacy, suggesting that it should play a role in the treatment algorithm.

The European Study Group on Cystic Tumours of the Pancreas. European evidence-based guidelines on pancreatic cystic neoplasms

Evidence-based guidelines on the management of pancreatic cystic neoplasms (PCN) are lacking. This guideline is a joint initiative of the European Study Group on Cystic Tumours of the Pancreas, United European Gastroenterology, European Pancreatic Club, European-African Hepato-Pancreato-Biliary Association, European Digestive Surgery, and the European Society of Gastrointestinal Endoscopy. It replaces the 2013 European consensus statement guidelines on PCN. European and non-European experts performed systematic reviews and used GRADE methodology to answer relevant clinical questions on nine topics (biomarkers, radiology, endoscopy, intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), serous cystic neoplasm, rare cysts, (neo)adjuvant treatment, and pathology). Recommendations include conservative management, relative and absolute indications for surgery. A conservative approach is recommended for asymptomatic MCN and IPMN measuring <40 mm without an enhancing nodule. Relative indications for surgery in IPMN include a main pancreatic duct (MPD) diameter between 5 and 9.9 mm or a cyst diameter ≥40 mm. Absolute indications for surgery in IPMN, due to the high-risk of malignant transformation, include jaundice, an enhancing mural nodule >5 mm, and MPD diameter >10 mm. Lifelong follow-up of IPMN is recommended in patients who are fit for surgery. The European evidence-based guidelines on PCN aim to improve the diagnosis and management of PCN.

New treatment of the pancreatic cystic neoplasm: Endoscopic ultrasonography-guided radiofrequency ablation combined with lauromacrogol ablation

Pancreatic cystic neoplasms (PCNs) are being increasingly detected because of rapid advances in radiologic technology and an increased imaging demand. The management of PCNs is challenging as most of these neoplasms are asymptomatic, but have malignant potential, and surgical resection has substantial perioperative morbidity and mortality. Endoscopic ultrasonography (EUS)-guided ablation, as a minimally invasive treatment, has received increasing attention in the past few years. However, the resolution after EUS-guided ablative therapy still needs to be improved. In this case report, EUS-guided radiofrequency ablation combined with lauromacrogol ablation was applied for the first time in the treatment of PCN, and it showed complete resolution at a 3-month follow-up.

The Safety and Efficacy of an Alcohol-Free Pancreatic Cyst Ablation Protocol

BACKGROUND & AIMS

Endoscopic ultrasound (EUS)-guided chemoablation with ethanol lavage followed by infusion of paclitaxel is effective for the treatment of mucinous pancreatic cysts. However, complications arise in 3%-10% of patients, presumably linked to the inflammatory effects of ethanol. We aimed to determine whether alcohol is required for effective pancreatic cyst ablation, if removing alcohol from the ablation process would improve complication rates, and whether a multi-agent chemotherapeutic cocktail could increase the rate of complete cyst resolution compared with findings reported from previous trials using alcohol followed by paclitaxel alone.

METHODS

Between November 2011 and December 2016, we conducted a single-center, prospective, double-blind trial of 39 patients with mucinous-type pancreatic cysts. Patients were randomly assigned to 1 of 2 groups that underwent EUS-guided pancreatic cyst lavage with either 80% ethanol (control) or normal saline (alcohol-free group). Cysts in both groups were then infused with an admixture of paclitaxel and gemcitabine. Primary outcomes were the rates of complete ablation 12 months after the procedure, and rates of serious and minor adverse events within 30 days of the procedure.

RESULTS

At 12 months, 67% of patients who underwent alcohol-free EUS-guided cyst chemoablation had complete ablation of cysts compared with 61% of patients in the control group. Serious adverse events occurred in 6% of patients in the control group vs none of the patients in the alcohol-free group. Minor adverse events occurred in 22% of patients in the control group and none of the patients in the alcohol-free group. The overall rate of complete ablation was 64%.

CONCLUSIONS

In this prospective, randomized, controlled trial, we found that alcohol is not required for effective EUS-guided pancreatic cyst ablation, and when alcohol is removed from the ablation process, there is a significant reduction in associated adverse events. A multi-agent chemotherapeutic ablation admixture did not appear to significantly improve rates of complete ablation compared with the current standard of alcohol lavage followed by paclitaxel alone. ClinicalTrials.gov ID: NCT01475331.

Clinical Approach to Incidental Pancreatic Cystic Neoplasm in Outpatient Clinics

Cystic lesions of the pancreas are increasingly observed due to increased use of abdominal images. The malignant rate of pancreas cystic lesion varies widely between various types. Identification of malignant or high-risk lesions is important when determining the appropriate course of management. Using these image findings, including cyst size, presence of solid components, and pancreatic duct involvement, the 2012 International Association of Pancreatology (IAP) and the 2015 American Gastroenterological Association (AGA) guidelines provide a rationale in identifying higher risk patients requiring further workups using an endoscopic ultrasound (EUS). EUS with fine needle aspiration and cytology allows confirmation of the cyst type and determines the risk of malignancy. Small cysts with no suspicious features may undergo the regular imaging study for regular surveillance due to low risk for malignancy. In this review, the differences between the 2012 IAP and 2015 AGA guidelines are presented, In addition to possible recommendations for management and surveillance.

Pancreatic Cysts and Guidelines

Pancreatic cysts, especially incidental asymptomatic ones seen on noninvasive imaging such as CT or MR imaging, remain a clinical challenge. The etiology of such cysts may range from benign cysts without any malignant potential such as pancreatic pseudocysts and serous cystadenomas to premalignant or frankly malignant cysts such as mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, cystic degeneration associated with solid tumors such as pancreatic ductal adenocarcinoma or pancreatic endocrine neoplasms, and solid pseudopapillary neoplasms. The clinical challenge in 2017 is to accurately preoperatively diagnose them and their malignant potential before deciding about surgery, surveillance or doing nothing. This review will focus on the currently available clinical guidelines for doing so.

Sonographic and cyst fluid cytologic changes after EUS-guided pancreatic cyst ablation

BACKGROUND AND AIMS

The effect of EUS-guided pancreatic cyst ablation (PCA) on sonographic morphology and cyst fluid cytology is unknown. The aim of this study was to evaluate morphologic, cytologic, and change in cyst fluid DNA after PCA.

METHODS

In a prospective single-center study, consecutive patients with suspected benign 10- to 50-mm pancreatic cysts underwent baseline EUS-FNA and EUS-PCA followed 2 to 3 months later by repeat EUS, cyst fluid analysis, and possible repeat PCA. Surveillance imaging after ablation was performed at least annually and classified as complete response (CR), partial response, or persistent, with <5%, 5% to 25%, and 25% of the original cyst volume, respectively.

RESULTS

Thirty-six patients underwent EUS-PCA with ethanol alone (n = 8) or ethanol and paclitaxel (n = 28), and CR occurred in 19 patients (56%). After EUS-PCA, EUS showed an increase in wall diameter in 68%, decreased number of septations in 24%, increased debris in 24%, loss of mural nodule or novel calcification in 21%, and alteration of fluid viscosity in 48%. Follow-up cytology showed increased epithelial cellularity in 27%, loss or decreased cellular atypia in 15%, increased or appearance of macrophages in 24%, and inflammatory cells in 15%. Postablation DNA amount increased and quality decreased in 71% each. Between the CR and non-CR patients, there was no significant difference in frequency of sonographic or cytologic features. In the CR group, mean DNA quantity was significantly increased after ablation (P = .023) without a change in quality (P = .136).

CONCLUSIONS

EUS-PCA induces morphologic and cytologic changes of pancreatic cysts, none of which appears to predict overall imaging-defined response to ablation. (Clinical trial registration numbers: NCT00233038 and NCT01643460.).

Advanced endoscopic ultrasound management techniques for preneoplastic pancreatic cystic lesions

Pancreatic cystic lesions can be benign, premalignant or malignant. The recent increase in detection and tremendous clinical variability of pancreatic cysts has presented a significant therapeutic challenge to physicians. Mucinous cystic neoplasms are of particular interest given their known malignant potential. This review article provides a brief but comprehensive review of premalignant pancreatic cystic lesions with advanced endoscopic ultrasound (EUS) management approaches. A comprehensive literature search was performed using PubMed, Cochrane, OVID and EMBASE databases. Preneoplastic pancreatic cystic lesions include mucinous cystadenoma and intraductal papillary mucinous neoplasm. The 2012 International Sendai Guidelines guide physicians in their management of pancreatic cystic lesions. Some of the advanced EUS management techniques include ethanol ablation, chemotherapeutic (paclitaxel) ablation, radiofrequency ablation and cryotherapy. In future, EUS-guided injections of drug-eluting beads and neodymium:yttrium aluminum agent laser ablation is predicted to be an integral part of EUS-guided management techniques. In summary, International Sendai Consensus Guidelines should be used to make a decision regarding management of pancreatic cystic lesions. Advanced EUS techniques are proving extremely beneficial in management, especially in those patients who are at high surgical risk.

Prevalence, Diagnosis and Management of Pancreatic Cystic Neoplasms: Current Status and Future Directions

Cystic neoplasms of the pancreas are found with increasing prevalence, especially in elderly asymptomatic individuals. Although the overall risk of malignancy is very low, the presence of these pancreatic cysts is associated with a large degree of anxiety and further medical investigation due to concerns about malignancy. This review discusses the different cystic neoplasms of the pancreas and reports diagnostic strategies based on clinical features and imaging data. Surgical and nonsurgical management of the most common cystic neoplasms, based on the recently revised Sendai guidelines, is also discussed, with special reference to intraductal papillary mucinous neoplasm (IPMN; particularly the branch duct variant), which is the lesion most frequently identified incidentally. IPMN pathology, its risk for development into pancreatic ductal adenocarcinoma, the pros and cons of current guidelines for management, and the potential role of endoscopic ultrasound in determining cancer risk are discussed. Finally, surgical treatment, strategies for surveillance of pancreatic cysts, and possible future directions are discussed.

Is alcohol required for effective pancreatic cyst ablation? The prospective randomized CHARM trial pilot study

BACKGROUND AND STUDY AIMS

In this study, we aim to determine the safety and feasibility of an alcohol-free approach to pancreatic cyst ablation using a chemotherapeutic ablation cocktail.

PATIENTS AND METHODS

In this prospective, randomized, double-blinded pilot study, 10 patients with known mucinous type pancreatic cysts underwent endoscopic ultrasound (EUS)-guided fine needle aspiration and then lavage with either 80 % ethanol or normal saline. Both groups were then treated with a cocktail of paclitaxel and gemcitabine. Primary outcomes were reduction in cyst volume and rates of complications.

RESULTS

At 6 months, patients randomized to the alcohol arm had an 89 % average volume reduction, with a 91 % reduction noted in the alcohol-free arm. Complete ablation was achieved in 67 % of patients in the alcohol-free arm at both 6 and 12 months, whereas the alcohol group recorded complete ablation rates of 50 % and 75 % at 6 and 12 months, respectively. One patient in the alcohol arm developed acute pancreatitis (20 %) with no adverse events in the alcohol-free arm.

CONCLUSIONS

This study revealed similar ablation rates between the alcohol ablation group and the alcohol-free arm and demonstrates the safety and feasibility of an alcohol-free ablation protocol. This pilot study suggests that alcohol may not be required for effective cyst ablation.

Endoscopic ultrasound-fine needle injection for oncological therapy

The minimal invasiveness and precision of endoscopic ultrasound (EUS) has lead to both its widespread use as a diagnostic and staging modality for gastrointestinal and pancreaticobiliary malignancies, and to its expanding role as a therapeutic modality. EUS-guided celiac plexus neurolysis is now a well-accepted modality for palliation of pain in patients with pancreatic cancer. EUS-guided ablation, brachytherapy, fiducial marker placement, and antitumor agent injection have been described as methods of performing minimally invasive oncological therapy. EUS-fine needle injection may be performed as adjunctive, alternative, or palliative treatment. This review summarizes the studies to date that have described these methods. A literature search using the PubMed/MEDLINE databases was performed. While most published studies to date are limited with disappointing outcomes, the concept of a role of EUS in oncological therapy seems promising.

Endoscopic ultrasound-guided ablation therapy for pancreatic cysts

Pancreatic cysts are being encountered frequently because of rapid advances in radiologic technology and an increased cross-sectional imaging demand. Management of pancreatic cystic tumors is challenging because most of them are asymptomatic; they are potentially malignant, and surgery has substantial morbidity and mortality. Endoscopic ultrasound (EUS)-guided fine-needle aspiration of pancreatic cystic tumors is accepted as a minimally invasive technique, which also enables injection of ablative agents into cysts under EUS guidance. In this review, the basic procedural steps and technical considerations of cyst ablation and their clinical issues including safety, feasibility, and therapeutic outcome will be summarized.

Endoscopic Ultrasound-Guided Treatment of Pancreatic Cystic and Solid Masses

Pancreatic tumor is one of the most difficult diseases to diagnose and treat because of its anatomical location and characteristics. Recently, there have been several innovative trials on the treatment of pancreatic tumors using endoscopic ultrasound (EUS) because it allows selective access to the difficult to reach target organ along the gastrointestinal tract and can differentiate vessels by color Doppler. Among these trials, several have investigated EUS-guided ethanol lavage with or without paclitaxel for pancreatic cystic tumors. These studies show a 33% to 79% complete resolution rate with a favorable safety profile. Compared to EUS-guided ethanol lavage for pancreatic cystic tumors, EUS-guided radiofrequency ablation is considered a less invasive treatment method for pancreatic cancer. Although there are still several difficulties and concerns about complications, one clinical study reported 72.8% feasibility with favorable safety, and therefore, we anticipate the results of ongoing studies with these new less invasive techniques.

Management of serous cystic neoplasms of the pancreas

Pancreatic serous cystadenomas are uncommon benign tumours that are often found incidentally on routine imaging examinations. Radiological imaging techniques alone have proven to be suboptimal to fully characterize cystic pancreatic lesions. Endoscopic ultrasound, with the addition of fine-needle aspiration in difficult cases, has showed greater diagnostic accuracy than conventional imaging techniques. The best management strategy of these neoplasms is still debated. Surgery should be limited only to symptomatic and highly selected cases and most of the patients should only be strictly monitored. In the current paper, we provide an updated overview on pancreatic serous cystadenomas, focusing our attention on epidemiology, clinical characteristics and diagnostic evaluation; finally, we also discuss different management strategies and areas for future research.

Endoscopic ultrasound in the diagnosis and treatment of pancreatic disease

Endoscopic ultrasound (EUS) is an important part of modern gastrointestinal endoscopy and now has an integral role in the diagnostic evaluation of pancreatic diseases. Furthermore, as EUS technology has advanced, it has increasingly become a therapeutic procedure, and the prospect of multiple applications of interventional EUS for the pancreas is truly on the near horizon. However, this review focuses on the established diagnostic and therapeutic roles of EUS that are used in current clinical practice. In particular, the diagnostic evaluation of acute pancreatitis, chronic pancreatitis, cystic pancreatic lesions and solid masses of the pancreas are discussed. The newer enhanced imaging modalities of elastography and contrast enhancement are evaluated in this context. The main therapeutic aspects of pancreatic EUS are then considered, namely celiac plexus block and celiac plexus neurolysis for pain control in chronic pancreatitis and pancreas cancer, and EUS-guided drainage of pancreatic fluid collections.

Systemic effect of endoscopic ultrasonography-guided pancreatic cyst ablation with ethanol and paclitaxel

BACKGROUND

Endoscopic ultrasonography (EUS)-guided pancreatic cyst ablation is a minimally invasive treatment modality. Local injection of ablative agents may rarely cause systemic effects in patients.

AIMS

This study aimed to evaluate the systemic effect of ablative agents by analyzing the plasma drug concentration.

METHODS

Ten patients with pancreatic cysts were enrolled. Cyst ablation was performed by 99 % ethanol lavage (2.5-70 mL) and paclitaxel (Genexol-polymeric micelle, 6.0-24.0) injection. Blood samples were collected at 0, 2, 4, 7 and 24 h. Plasma paclitaxel concentration was analyzed by a liquid chromatography-tandem mass spectrometry with the lowest limit of quantitation of 0.1 ng/mL. Procedure-related complications were closely monitored.

RESULTS

Pancreatic cysts were located at the head in two, body in seven and tail in one patient. Eight cysts were septated. Median diameter and original volume were 39.5 mm (range 2.7-21.8) and 14.79 mL (3.42-343.30). Median cyst fluid CEA and amylase values were 17.10 ng/mL (0.5-14127.5) and 73.50 U/L (3.1-91,590). Peak plasma paclitaxel concentration values were observed between 2 and 7 h, ranging from 0.45 to 14.73 ng/mL. The highest concentration (17.10 ng/mL at 0 h) was observed in a patient who had intracystic bleeding. Mild abdominal pain occurred in five patients and vomiting in one patient during the first 48-h monitoring.

CONCLUSION

Plasma paclitaxel concentration after EUS-guided pancreatic cyst ablation was nearly as low as the undetectable value and rarely caused systemic side-effect.

Interventional endoscopic ultrasonography

OPINION STATEMENT

Endoscopic ultrasound (EUS) is not only a diagnostic tool but also an interventional and therapeutic procedure. Indeed, in addition to tissue acquisition, it can also drain fluid collections adjacent to the gastrointestinal tract, provide access to biliary and pancreatic ducts, biliary, pancreatic, and gallbladder drainage, pancreatic cyst ablation, and, finally, provide anti-tumoral treatments and interventional vascular procedures. Although several improvements have been made in the last decade, the full potential of interventional EUS is yet to be completely explored. Future areas of research are the development of dedicated tools and accessories, the standardization of the interventional procedures, and the widening of the use of EUS, while increasing the expertise worldwide. In addition, more data, based on well-performed, possibly randomized clinical trials, are needed to accurately determine the risks and long-term outcomes of these interventions. We firmly believe that interventional EUS can play a pivotal role in anti-tumor treatments, by the fine-needle injection of anti-tumoral agents, tumor ablation, and assisting radiation treatment with gold fiducial placement and the implantation of intralesional seeds. The goal of the near future will be to offer targeted therapy and monitoring of tumor treatment response in a more biologically driven manner than has been available in the past. Interventional EUS will be an essential part of the multidisciplinary approach to cancer treatment.

Role of endoscopic ultrasonography in pancreatic cystic neoplasms: where do we stand and where will we go?

We increasingly encounter pancreatic cystic neoplasms (PCN) in clinical practice and the differential diagnoses vary widely from benign to malignant. There is no 'one and only' diagnostic procedure for PCN. Multiple modalities including computed tomography, magnetic resonance imaging, endoscopic retrograde cholangiopancreatography and endoscopic ultrasound (EUS) are widely used, but EUS has the advantage of anatomical proximity to the pancreas and upper gastrointestinal tract. In addition, EUS-guided fine-needle aspiration (EUS-FNA) provides both cytological evaluation and cyst fluid analysis. Although the role of EUS-FNA for PCN is established, the sensitivity of cytology is low and cyst fluid analysis is only useful for differentiation between mucinous and non-mucinous cysts. Recently, novel through-the-needle imaging under EUS-FNA, such as confocal laserendomicroscopy, is expected to attribute to a better diagnostic yield. Moreover, feasibility of cyst ablation has been reported and the role of EUS has expanded from diagnosis to treatment. However, clinical impact of cyst ablation in terms of safety, efficacy and cost-effectiveness should be validated further. In summary, EUS and EUS-guided intervention does and will play a central role in the management of PCN from surveillance to treatment, but many clinical questions remain unanswered, which warrants well-designed prospective clinical trials.