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

Pancreatic cancer precursor lesions - Can immunotherapy prevent progression into pancreatic ductal adenocarcinoma?

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, with a 5-year survival rate of only 12.5 %. Early detection of PDAC or addressing risk factors for PDAC development are ways to improve outcomes. PDAC can arise from precursor lesions, including pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN), and less frequent, mucinous cystic neoplasm (MCN), and other rare precursor variants. High-risk precursor lesions harbor a substantial chance of evolving into PDAC. Such lesions can often be found in resected PDAC specimens adjacent to the cancer. Unfortunately, recognizing precursor lesions that need to be resected is often tricky, and resections frequently end in major surgical interventions. Thus, better ways to handle precursor lesions are desperately needed. We mapped the immune microenvironments (IMEs) of PanINs, IPMNs, and MCNs on a cellular level using multiplex immunofluorescence and computational imaging technology and compared the findings to PDACs and normal pancreatic tissues. We found distinct and potentially targetable mechanisms of immunosuppression between the two main precursor lesions, PanIN and IMPN. Immunosuppression in IPMNs seems partly mediated by programmed cell death protein 1 ligand (PD-L1) expression on antigen-presenting cells (APCs). By contrast, elevated numbers of regulatory T cells (Tregs) seem to be key players in the immunosuppression of PanINs. Thus, treating high-risk IPMNs with anti-PD-1 and high-risk PanINs with agents targeting Tregs, such as anti-lymphocyte associated protein 4 (anti-CTLA-4) antibodies, could reverse their immunosuppressive state. Reversal of immunosuppression will restore immunosurveillance and eventually prevent progression into PDAC. We also review relevant published and ongoing non-surgical treatment approaches for high-risk IPMNs and PanINs.

Role of Endoscopy in Clinical Management of Intraductal Papillary Mucinous Neoplasms

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a well-recognized precursor of pancreatic carcinoma. Along with cross-sectional abdominal imaging tests, endoscopic examinations remain the cornerstone in the diagnosis of pancreatic cysts, early detection of IPMN-derived carcinomas, and risk stratification of patients with IPMNs for subsequent surveillance strategies. In particular, endoscopic ultrasound (EUS) facilitates the optimal patient management by providing high-resolution morphological information, and the contrast-enhanced harmonic mode may further enhance diagnostic accuracy. EUS-guided fine-needle aspiration for solid mass and/or cyst fluid is considered for pathological and molecular examinations for the diagnosis of pancreatic cysts and malignancy. Emerging evidence suggests the usefulness of through-the-needle biopsy and confocal laser microendoscopy in this setting. In addition to the undoubtful diagnostic utility, recent studies have demonstrated the potential effect of endoscopic interventions (i.e., ablation) on the control of IPMNs. Despite the increasing role of endoscopy in the clinical management of IPMNs, there remains a gap in our understanding of how to utilize endoscopy in the personalized care for patients with IPMNs (e.g., the optimal interval of EUS) and the prevention of deaths due to pancreatic carcinomas developing concomitantly with IPMNs. This review summarizes the current evidence on the role of endoscopy in both the diagnostic and therapeutic landscapes of clinical management of IPMNs and identifies key clinical unmet needs that should be addressed in future research. Combined with emerging technologies (e.g., artificial intelligence and high-throughput molecular profiling), endoscopy would offer more effective and tailored management strategies for patients with IPMNs.

Endoscopic Ultrasound-Guided Chemoablation of an Acinar Cell Carcinoma as a Suppressive Strategy for Unresectable Disease

Acinar cell carcinoma is a relatively rare pancreatic neoplasm, typically treated with surgical resection and adjuvant chemotherapy; however, definitive treatment protocols are not well established. We describe endoscopic ultrasound-guided chemoablation with fine needle injection of paclitaxel/gemcitabine in conjunction with chemotherapy in a 78-year-old man with a 3.0 × 2.7-cm acinar cell carcinoma who was not a surgical candidate. At 12 months, the mass had reduced in size to 0.9 × 0.9 cm, followed by steady growth to 6 × 4.5 cm at 24 months when the patient died secondary to unrelated causes.

What Is the Latest in Pancreatic Cysts?

Pancreatic cysts are common incidental findings. The understanding of pancreatic cysts has evolved tremendously over the past few decades. Molecular diagnostic and endoscopic techniques have led to more precise characterization of cyst types and interventions to improve patient outcomes. This article outlines these recent innovations in pancreatic cyst diagnosis and management.

Reducing the incidence of pancreatic cancer through radiofrequency ablation of mucinous cystic neoplasms: What is the evidence?

Pancreatic cystic lesions are mostly discovered incidentally during cross-sectional imaging for other indications. They range from benign cysts to premalignant lesions, posing a risk for development of pancreatic cancer. Surveillance of cysts with low-risk features and surgical resection of high-risk ones has been the standard of care. However, the lack of consensus between national society guidelines results in discordant management and follow-up. One of the upcoming therapeutic modalities for pancreatic cysts, including mucinous cystic neoplasms (MCN), is endoscopic ultrasound (EUS)-guided interventions, including injection of chemotherapeutic agents or EUS-guided radiofrequency ablation (EUS-RFA). EUS-RFA is emerging as a promising minimally invasive tool with the need for further investigation to understand its clinical utility. This review discusses the physiology, clinical studies, adverse events, and future perspectives of RFA for various pancreatic lesions, with particular regard with MCN.

Short-Term Outcomes of Endoscopic Ultrasound-Guided Pancreatic Cyst Ablation: A Systematic Review and Meta-Analysis

Background and Aims

Pancreatic cysts (PCs) are increasingly detected through abdominal imaging, prompting exploration of alternatives such as endoscopic ultrasound-guided PC ablation due to the risks and costs associated with surgery. This study conducts a systematic review and meta-analysis of endoscopic ultrasound-guided PC ablation's short-term efficacy and complications for PC management.

Methods

A systematic review and meta-analysis were carried out on PubMed, Ovid, Cochrane, and TRIP electronic databases. The primary outcome was cyst resolution (partial and complete) and persistence on imaging 12 months after ablation. The secondary outcome was procedure-related adverse events.

Results

Eight studies were eligible for analysis. Complete cyst resolution on imaging 12 months after endoscopic ultrasound ablation was 50% [95% CI 36‒63, I2 = 85.31%]. Partial cyst resolution was 27% [95% CI 15‒41, I2 = 87.07%], and cyst persistence was 17% [95% CI 11‒24, I2 = 62.11%]. The rate of complete resolution varied depending on the treatment agent (for ethanol 29% [95% CI 10‒53]; lauromacrogol 51% [95% Cl 36‒67]; ethanol and paclitaxel 63% [95% CI 48‒76]; paclitaxel and gemcitabine 67% [95% CI 45‒83]; and ethanol, paclitaxel, and gemcitabine 61% [95% CI 39‒80]). Postprocedure adverse events included abdominal pain in 4% [95% CI 0‒11], pancreatitis in 3% [95% CI 1‒5], and fever in 1% [95% CI 0‒3] of all patients.

Conclusion

The treatment of pancreatic cysts with endoscopic ultrasound ablation results in acceptable levels of complete resolution, and low incidence of severe adverse events. The effectiveness of this treatment is further enhanced when chemoablative agents are employed.

An Overview for Clinicians on Intraductal Papillary Mucinous Neoplasms (IPMNs) of the Pancreas

Currently, there is no reliable method of discerning between low-risk and high-risk intraductal papillary mucinous neoplasms (IPMNs). Operative resection is utilized in an effort to resect those lesions with high-grade dysplasia (HGD) prior to the development of invasive disease. The current guidelines recommend resection for IPMN that involve the main pancreatic duct. Resecting lesions with HGD before their progression to invasive disease and the avoidance of resection in those patients with low-grade dysplasia is the optimal clinical scenario. Therefore, the importance of developing preoperative models able to discern HGD in IPMN patients cannot be overstated. Low-risk patients should be managed with nonsurgical treatment options (typically MRI surveillance), while high-risk patients would undergo resection, hopefully prior to the formation of invasive disease. Current research is evolving in multiple directions. First, there is an ongoing effort to identify reliable markers for predicting malignant transformation of IPMN, mainly focusing on genomic and transcriptomic data from blood, tissue, and cystic fluid. Also, multimodal models of combining biomarkers with clinical and radiographic data seem promising for providing robust and accurate answers of risk levels for IPMN patients.

Long-Term Outcomes of Endoscopic Ultrasound-Guided Ablation Vs Surgery for Pancreatic Cystic Tumors

BACKGROUND & AIMS

Endoscopic ultrasound-guided pancreatic cyst ablation (EUS-PCA) is performed as an alternative to surgical resection in selected patients with pancreatic cystic tumors (PCTs). We aimed to directly compare the long-term outcomes between EUS-PCA and surgery for PCTs.

METHODS

We reviewed a PCT database to identify patients with unilocular or oligolocular PCTs who underwent EUS-PCA or surgery between January 2004 and July 2019. We performed 1:1 propensity score matching based on potential confounding factors. The primary outcome was long-term morbidities. Secondary outcomes included early (≤14 days) and late (>14 days) major adverse events (MAEs), development of diabetes mellitus, readmission, length of hospital stay, and therapeutic efficacy.

RESULTS

A total of 620 patients (EUS-PCA, n = 310; surgery, n = 310) were selected after propensity score matching. The EUS-PCA group showed a lower 10-year rate of cumulative long-term morbidities (1.6% vs 33.5%; P = .001) as well as lower rates of early MAE (1.0% vs 8.7%; P = .001), late MAE (0.3% vs 5.5%; P = .001), and readmission (1.0% vs 15.2%; P = .001). The EUS-PCA group had a shorter hospital stay (3.5 vs 10.3 d; P = .001) and a lower incidence of diabetes mellitus (2.2% vs 22.8%; P = .001), whereas the surgery group had a higher complete resolution rate (76.5% vs 100%; P = .001) and a lower relapse rate (4.6% vs 0.3%; P = .001).

CONCLUSIONS

For select patients with PCTs, EUS-PCA showed superior results to surgery in terms of long-term safety profile and preservation of pancreatic function.

Endoscopic Ultrasound-Guided Ablation of Pancreatic Mucinous Cysts

Endoscopic ultrasound (EUS) has rapidly evolved from a diagnostic to a therapeutic tool with applications for various pancreaticobiliary diseases. As part of this evolution, EUS-guided chemoablation for neoplastic pancreatic cysts is developing as a minimally invasive treatment option for appropriately selected mucinous cysts, which can spare patients major resective surgery and may reduce progression to pancreatic cancer. Chemotherapeutic cyst ablation has demonstrated encouraging complete resolution rates, while an alcohol-free chemoablation protocol has demonstrated a significant decrease in adverse events without a compromise to complete ablation rates when compared with previous alcohol-based protocols. Most pancreatic cysts are small, low risk, and best managed by surveillance per accepted guidelines. Cysts with features suggestive of overt malignancy are best discussed by a multidisciplinary committee, and surgery is considered if appropriate. However, for patients in the middle ground with cysts that are structurally suitable for chemoablation, alcohol-free chemoablation has been shown to allow effective, safe, and durable results especially for those who are not ideal operative candidates. EUS-guided alcohol-free chemoablation is promising and continues to evolve; however, as a relatively novel treatment option it has areas of uncertainty that will require further investigation and development.

Successful EUS-guided pancreatic cyst chemoablation safely allows reduction in the frequency of radiographic surveillance: long-term follow-up of randomized prospective data

BACKGROUND AND AIMS

Endoscopic ultrasound-guided pancreatic cyst chemoablation is safe and effective for appropriately selected patients; however, the proper frequency of radiographic surveillance after successful chemoablation is unknown. Here we report the long-term follow-up of 2 randomized prospective Chemotherapy for Ablation and Resolution of Mucinous Pancreatic Cysts (ChARM) clinical trials. In addition, the performance of a postablation-reduced radiographic surveillance protocol was evaluated according to clinical and economic outcomes and patient experience metrics.

METHODS

Patients who successfully completed 1 of the 2 ChARM randomized control trials were evaluated for durability of response and clinical outcomes. Patients were eligible if 2 years or more of follow-up were available and complete. We calculated economic outcomes according to Medicare allowable costs applicable to endoscopic ultrasound, magnetic resonance imaging, and outpatient clinic visits. We modeled costs of a patient followed by the ChARM Post-treatment Reduced Radiographic Surveillance Protocol compared with a similar patient followed under Fukuoka or American College of Gastroenterology (ACG) guidelines over 5 years. In addition, patients under long-term surveillance in our clinic were interviewed via a 4-question Likert-type questionnaire.

RESULTS

A total of 52 patients were eligible and included in the study. At the most recent follow-up of the 52 patients, 36 (69.2%) achieved complete response, an additional 11 (21.2%) showed partial response, and only 5 (9.6%) showed nonresponse. All patients were successfully reduced to annual or less surveillance without recurrence or the development of cyst-associated malignancy. Compared with Fukukoa or ACG guidelines, a patient treated and followed under the ChARM Post-treatment Reduced Radiographic Surveillance Protocol incurred a Medicare allowable cost of $7200.00 versus $19,437.44 and $12,526.52 if untreated and observed under Fukukoa and ACG guidelines, respectively. The patient experience questionnaire was returned completed by 49 participants.

CONCLUSIONS

The ChARM Post-treatment Reduced Radiographic Surveillance Protocol safely allows a reduction in radiographic surveillance. A reduction in cost associated with cyst management under the ChARM protocol, compared with management following Fukukoa or ACG guidelines, was shown. According to the questionnaire, most patients reported a moderate level of logistical and emotional burden associated with magnetic resonance imaging surveillance, and a majority were in favor of reducing the frequency of radiographic surveillance if it could be done without a marked increase in oncologic risk.

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.

International evidence-based Kyoto guidelines for the management of intraductal papillary mucinous neoplasm of the pancreas

This study group aimed to revise the 2017 international consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, and mainly focused on five topics; the revision of high-risk stigmata (HRS) and worrisome features (WF), surveillance of non-resected IPMN, surveillance after resection of IPMN, revision of pathological aspects, and investigation of molecular markers in cyst fluid. A new development from the prior guidelines is that systematic reviews were performed for each one of these topics, and published separately to provide evidence-based recommendations. One of the highlights of these new "evidence-based guidelines" is to propose a new management algorithm, and one major revision is to include into the assessment of HRS and WF the imaging findings from endoscopic ultrasound (EUS) and the results of cytological analysis from EUS-guided fine needle aspiration technique, when this is performed. Another key element of the current guidelines is to clarify whether lifetime surveillance for small IPMNs is required, and recommends two options, "stop surveillance" or "continue surveillance for possible development of concomitant pancreatic ductal adenocarcinoma", for small unchanged BD-IPMN after 5 years surveillance. Several other points are also discussed, including identifying high-risk features for recurrence in patients who underwent resection of non-invasive IPMN with negative surgical margin, summaries of the recent observations in the pathology of IPMN. In addition, the emerging role of cyst fluid markers that can aid in distinguishing IPMN from other pancreatic cysts and identify those IPMNs that harbor high-grade dysplasia or invasive carcinoma is discussed.

Comparison of outcomes of EUS-guided ablation and surveillance only for pancreatic cystic lesions: a propensity score-matching study (with videos)

BACKGROUND AND AIMS

EUS-guided ethanol ablation is a recently introduced treatment approach for pancreatic cystic lesions (PCLs), including branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs). However, the utility of this procedure is limited because of its relatively low efficacy in treating PCLs.

METHODS

We retrospectively reviewed patients with PCLs, including those with enlarging suspected BD-IPMNs or those with PCLs measuring >3 cm, who were suboptimal candidates for surgery and had been managed using EUS-guided rapid ethanol lavage (EUS-REL; immediate ethanol lavage performed 4 times, 2015-2022) or surveillance only (SO; 2007- 2022). Propensity score matching (PSM) was performed to minimize bias. The primary outcome was the cumulative incidence rate of BD-IPMN progression. Secondary outcomes were the efficacy and safety of EUS-REL, surgical resection rate (SR), overall survival (OS), and disease-specific survival (DSS) in both groups.

RESULTS

Overall, 169 and 610 patients were included in the EUS-REL and SO groups, respectively. PSM created 159 matched pairs. The radiologic complete resolution rate after EUS-REL was 74%. Procedure-related pancreatitis in the EUS-REL group was 13.0% (n = 22; 19 mild and 3 moderate grade); no severe adverse events were reported. The 10-year cumulative incidence rate of BD-IPMN progression was significantly lower in the EUS-REL group than in the SO group (1.6% vs 21.2%; hazard ratio, 12.35; P = .003). EUS-REL showed a lower tendency of SR compared with that associated with SO. The rates of 10-year OS and 10-year DSS were comparable in both groups.

CONCLUSIONS

EUS-REL was associated with a significantly lower 10-year cumulative incidence rate of BD-IPMN progression and a lower tendency of SR, whereas its 10-year OS and DSS rates were similar to those of SO for PCLs. EUS-REL may be a viable alternative to SO for managing patients with enlarging suspected BD-IPMNs or those with PCLs >3 cm who are suboptimal candidates for surgery.

Interventional Endoscopic Ultrasound: Current Status and Future Frontiers

Interventional endoscopic ultrasound has fueled remarkable advancements in the field of therapeutic procedures, revolutionizing minimally invasive interventions for a diverse range of conditions. This review highlights the latest breakthroughs and advancements in therapeutic endoscopic ultrasound, showcasing its potential to transform patient care.

Endoscopic Interventions in Pancreatic Cystic Neoplasms

During the past two decades, there has been a significant evolution in endoscopic interventions in pancreatic cystic neoplasms (PCNs), ranging from diagnostic intervention (endoscopic ultrasound-guided through-the-needle biopsy [EUS-TTNB]) to therapeutic intervention (endoscopic ultrasound-guided pancreatic cystic ablation [EUS-PCA]). They have received attention as alternatives to conventional diagnostic and therapeutic modalities. EUS-TTNB can categorize PCN types accurately by providing histologic diagnoses that conventional diagnostic modalities cannot provide. As pancreatectomy entails high morbidities, EUS-PCA can be performed safely to treat PCNs in patients who refuse surgery or have high surgical risks.

Therapeutic Endoscopic Ultrasound: Current Indications and Future Perspectives

The transcendence of endoscopic ultrasound (EUS) from diagnostic to therapeutic tool has revolutionized management options in the field of gastroenterology. Through EUS-guided methods, pancreaticobiliary obstruction can now be utilized as an alternative to surgical and percutaneous approaches. This modality also allows for gallbladder drainage in patients who are not ideal operative candidates. By utilizing its unique imaging capabilities, EUS also allows for drainage access points in cases of gastric outlet obstruction as well as windows to ablate pancreatic cystic lesions. As technical progress continues to evolve, interventional gastroenterology continues to push the envelope of minimally invasive therapeutic procedures in a multidisciplinary setting. In this comprehensive review, we set out to describe current indications and innovations through EUS.

Evolution of interventional endoscopic ultrasound

Endoscopic ultrasound (EUS) has become an indispensable modality for the assessment of the gastrointestinal tract and adjacent structures since its origin in the 1980s. Following the development of the linear echoendoscope, EUS has evolved from a purely diagnostic modality to a sophisticated tool for intervention, with numerous luminal, pancreaticobiliary, and hepatic applications. Broadly, these applications may be subdivided into three categories: transluminal drainage or access procedures, injection therapy, and EUS-guided liver interventions. Transluminal drainage or access procedures include management of pancreatic fluid collection, EUS-guided biliary drainage, EUS-guided bile duct drainage, EUS-guided pancreatic duct drainage, and enteral anastomosis formation. Injection therapies include therapeutic EUS-guided injections for management of malignancies accessible by EUS. EUS-guided liver applications include EUS-guided liver biopsy, EUS-guided portal pressure gradient measurement, and EUS-guided vascular therapies. In this review, we discuss the origins of each of these EUS applications, evolution of techniques leading to the current status, and future directions of EUS-guided interventional therapy.

Endoscopic Ultrasound-Guided Local Ablative Therapies for the Treatment of Pancreatic Neuroendocrine Tumors and Cystic Lesions: A Review of the Current Literature

Since its emergence as a diagnostic modality in the 1980s, endoscopic ultrasound (EUS) has provided the clinician profound access to gastrointestinal organs to aid in the direct visualization, sampling, and subsequent identification of pancreatic pathology. In recent years, advancements in EUS as an interventional technique have promoted the use of local ablative therapies as a minimally invasive alternative to the surgical management of pancreatic neuroendocrine tumors (pNETs) and pancreatic cystic neoplasms (PCNs), especially for those deemed to be poor operative candidates. EUS-guided local therapies have demonstrated promising efficacy in addressing a spectrum of pancreatic neoplasms, while also balancing local adverse effects on healthy parenchyma. This article serves as a review of the current literature detailing the mechanisms, outcomes, complications, and limitations of EUS-guided local ablative therapies such as chemical ablation and radiofrequency ablation (RFA) for the treatment of pNETs and PCNs, as well as a discussion of future applications of EUS-guided techniques to address a broader scope of pancreatic pathology.

Performance and Safety of EUS Ablation Techniques for Pancreatic Cystic Lesions: A Systematic Review and Meta-Analysis

BACKGROUND

Pancreatic cystic lesions (PCL) represent an increasingly diagnosed condition with significant burden to patients' lives and medical resources. Endoscopic ultrasound (EUS) ablation techniques have been utilized to treat focal pancreatic lesions. This systematic review with meta-analysis aims to assess the efficacy of EUS ablation on PCL in terms of complete or partial response and safety.

METHODS

A systematic search in Medline, Cochrane and Scopus databases was performed in April 2023 for studies assessing the performance of the various EUS ablation techniques. The primary outcome was complete cyst resolution, defined as cyst disappearance in follow-up imaging. Secondary outcomes included partial resolution (reduction in PCL size), and adverse events rate. A subgroup analysis was planned to evaluate the impact of the available ablation techniques (ethanol, ethanol/paclitaxel, radiofrequency ablation (RFA), and lauromacrogol) on the results. Meta-analyses using a random effects model were conducted and the results were reported as percentages with 95% confidence intervals (95%CI).

RESULTS

Fifteen studies (840 patients) were eligible for analysis. Complete cyst resolution after EUS ablation was achieved in 44% of cases (95%CI: 31-57; 352/767; I2 = 93.7%), and the respective partial response rate was 30% (95%CI: 20-39; 206/767; I2 = 86.1%). Adverse events were recorded in 14% (95%CI: 8-20; 164/840; I2 = 87.2%) of cases, rated as mild in 10% (95%CI: 5-15; 128/840; I2 = 86.7%), and severe in 4% (95%CI: 3-5; 36/840; I2 = 0%). The subgroup analysis for the primary outcome revealed rates of 70% (95%CI: 64-76; I2 = 42.3%) for ethanol/paclitaxel, 44% (95%CI: 33-54; I2= 0%) for lauromacrogol, 32% (95%CI: 27-36; I2 = 88.4%) for ethanol, and 13% (95%CI: 4-22; I2 = 95.8%) for RFA. Considering adverse events, the ethanol-based subgroup rated the highest percentage (16%; 95%CI: 13-20; I2 = 91.0%).

CONCLUSION

EUS ablation of pancreatic cysts provides acceptable rates of complete resolution and a low incidence of severe adverse events, with chemoablative agents yielding higher performance rates.

Approach to Cystic Lesions of the Pancreas: Review of Literature

Pancreatic cystic lesions (PCL) have a wide range of demographical, clinical, morphological and histological characteristics. The distinction between these lesions is of paramount importance due to the risk of malignancy in specific categories of PCL. Considering the malignant potential for pancreatic cystic neoplasm (PCN) lesions, guidelines have been made to balance unnecessary treatment and manage the progression to malignancy. Various surgical procedures can be done for PCN depending on the location and size of the cyst; pancreatoduodenectomy is done for PCN located in the head of the uncinate process, whereas distal pancreatectomy is done for PCN in the body or tail. In the neck and proximal body of the pancreas, less extensive resections such as central pancreatectomy can be performed. Active surveillance of PCN is typically offered to asymptomatic PCNs of subtype intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN) without any concerning features. In recent years, numerous guidelines have been created to augment PCN diagnosis, classification and management. Despite this, the management of PCNs remains complex. Thus, discussions with multidisciplinary teams involving surgeons, gastroenterologists, pathologists, and radiologists are required to ensure optimum care for the patient.

A Review of Endoscopic Ultrasound-Guided Chemoablative Techniques for Pancreatic Cystic Lesions

Pancreatic cystic lesions (PCLs) are known precursors to pancreatic cancer, one of the deadliest types of cancer worldwide. Surgical removal or pancreatectomies remain the central approach to managing precancerous high-risk PCLs. Endoscopic ultrasound (EUS)-guided therapeutic management of PCLs is a novel management strategy for patients with prohibitive surgical risks. Various ablation techniques have been explored in previous studies utilizing EUS-guided fine needle injection (FNI) of alcohol and chemotherapeutic agents. This review article focuses on EUS-FNI and chemoablation, encompassing the evolution of chemoablation, pancreatic cyst selection, chemotherapy drug selection, including novel agents, and a discussion of its safety and efficacy.

EUS-guided intra-tumoral therapies

EUS-guided treatments for focal tumor lesions has been developed since 20 years using at onset of the technique mainly local and guided alcohol injection [1-4]. Pancreatic tumors are the most assessed targeted lesions for EUS treatment because of their accessibility and because EUS management could be a safe alternative to surgery. More and more pancreatic tumors are discovered mainly fortuitously due to the advances in conventional imaging (abdominal ultrasound, CT, MRI) resulting in the question of surgical management of an asymptomatic pancreatic lesion ("incidentaloma") [5-8]. The lesions detected include mostly pancreatic cystic neoplasms (PCN) and neuroendocrine tumors (NET) mainly well differentiated. Clinically, NET are mostly non-functional and do not induce secretory disorders [5-8]. Once their nature is yielded by diagnostic tests like EUS-FNA, incidental nonfunctional NET currently lead to difficult management when their largest diameter is less than 2 cm [2,4,9,10]. EUS-guided treatment for pancreatic adenocarcinoma have also been developed with recent prospective observational study and randomized control study [11,12]. Thus, therapeutic surgical choices could be challenged by EUS- guided treatment [2,4,9].

Early phase trial of intracystic injection of large surface area microparticle paclitaxel for treatment of mucinous pancreatic cysts

Background and study aims  Mucinous pancreatic cystic lesions (PCLs) have the potential for malignant transformation, for which the only accepted curative modality is surgery. A novel intracystic therapy with large surface area microparticle paclitaxel (LSAM-PTX) may treat PCLs without local or systemic toxicities. Safety and preliminary efficacy of LSAM-PTX for the treatment of PCLs administered by endoscopic ultrasound-guided fine-needle injection (EUS-FNI) was evaluated. Patients and methods  Ten subjects with confirmed PCLs (size > 1.5 cm) received intracystic LSAM-PTX via EUS-FNI at volumes equal to those aspirated from the cyst in sequential cohorts at 6, 10, and 15 mg/mL in a standard "3 + 3" dose-escalation protocol. The highest dose with acceptable safety and tolerability was taken into the confirmatory phase where nine additional subjects received two injections of LSAM-PTX 12 weeks apart. Subjects were followed for 6 months after initial LSAM-PTX treatment for endpoints including: adverse events (AEs), tolerability, pharmacokinetic analysis of systemic paclitaxel drug levels, and change in cyst volume. Results  Nineteen subjects completed the study. No dose-limiting toxicities, treatment-related serious AEs, or clinically significant laboratory changes were reported. Systemic paclitaxel concentrations did not exceed 3.5 ng/mL at any timepoint measured and fell below 1 ng/mL by Week 2, supporting the lack of systemic toxicity. By Week 24 a cyst volume reduction (10-78 %) was seen in 70.6 % of subjects. Conclusions  Intracystic injection of LSAM-PTX into mucinous PCLs resulted in no significant AEs, a lack of systemic absorption, and resulted in reduction of cyst volume over a 6 month period.

Endoscopic ablation therapy for the pancreatic neoplasms

Recently, endoscopic ultrasound (EUS)-guided ablation therapy has been reported as a less invasive therapy for patients with pancreatic neoplasms. Some ablation techniques, including injective ablation (using ethanol or other ablative agents), radiofrequency ablation (RFA), photodynamic therapy, and laser ablation, have been described in the literature. Among these, injective ablation and RFA are more frequently used for treating pancreatic neoplasms. Few studies have evaluated the effectiveness of EUS-guided ethanol ablation (EUS-EA) for potentially malignant solid neoplasms (neuroendocrine neoplasms or solid pseudopapillary neoplasms) and have reported a complete response (CR) rate of 60-80%. In addition, the CR rate after EUS-RFA for these lesions has been reported to be 55-100%, with no additional procedure-related adverse events (AEs). Regarding the amelioration of the symptoms of an insulinoma, the success rates of both the therapies were found to be excellent. Regarding complete tumor ablation, EUS-RFA appeared to be superior to EUS-EA. Although EUS-RFA has been reported as a safe treatment for pancreatic cancers, its effectiveness remains inadequate. Some studies have examined the effectiveness of EUS-guided injection ablation therapy for pancreatic cystic neoplasms (PCNs) and have reported CR rates that range from 35% to 79%. Alcohol-free chemotherapeutic agent ablation appears to be effective, with a low risk of AEs. However, studies on the effectiveness of EUS-RFA for PCNs are limited. In the future, EUS-guided ablation therapy could become a more widely used approach for potentially malignant and malignant pancreatic lesions.

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.

Pancreatic Cystic Neoplasms

Early detection of high-risk pancreatic cystic lesions enables potentially curative surgical resection, and early detection of lesions without worrisome features may lead to appropriate surveillance. Regrettably, differentiating premalignant and malignant cysts from nonmalignant ones remains challenging. However, emerging additional diagnostic tools, including the needle biopsy with microforceps and needle-based confocal laser endomicroscopy, are of exciting potential along with cyst fluid analysis".

State-of-the-Art Update of Pancreatic Cysts

Andrew Canakis.

Incidence and Risk Factors for New-Onset Diabetes Mellitus After Surgical Resection of Pancreatic Cystic Lesions: A MarketScan Study

OBJECTIVES

There is a paucity of literature evaluating new-onset diabetes mellitus (NODM) after resection of pancreatic cystic lesions (PCLs). We sought to characterize the incidence and risk factors associated with NODM after partial pancreatectomy for PCLs.

METHODS

We utilized the IBM MarketScan Database (2012-2018) to identify all nondiabetic adults who underwent partial pancreatectomy for PCLs. Patients with any other pancreatic disease were excluded. We performed Kaplan-Meier analysis and multivariable Cox proportional hazards regression to define the incidence and risk factors of postoperative NODM.

RESULTS

Among 311 patients, the overall risk (95% confidence interval) of NODM was 9.1% (6.3-12.9%), 15.1% (11.3-20.2%), and 20.2% (15.3-26.4%) at 6, 12 and 24 months, respectively. Multivariable analysis (adjusted hazard ratio; 95% confidence interval) revealed that older age (1.97; 1.04-3.72; 55-64 vs 18-54 years), obesity (2.63; 1.35-5.12), hypertension (1.79; 1.01-3.17), and cardiovascular disease (2.54; 1.02-6.28) were independent predictors of NODM. Rates of NODM were similar after distal pancreatectomy versus pancreaticoduodenectomy.

CONCLUSIONS

Within 2 years, 1 in 5 patients without any other pancreatic disease will develop NODM after partial pancreatectomy for PCLs. Those with advanced age, metabolic syndrome features, and/or cardiovascular disease may benefit from preoperative counseling and intensive postoperative monitoring, education, and treatment for diabetes mellitus.

Endotherapy in Pancreatic Diseases

Interventional endoscopy is now considered an effective minimally invasive treatment modality for the management of pancreatic diseases. It is important for the clinician to know the indications and contraindications as well as the timing of various endoscopic interventions. This will help in its safe and effective use and consequently decrease morbidity and mortality from various pancreatic diseases. This review will provide a broad overview of the indications, techniques, and outcomes of pancreatic endotherapy.

The Durability of EUS-Guided Chemoablation of Mucinous Pancreatic Cysts: A Long-Term Follow-Up of the CHARM trial

Pancreatic cancer has known precursor lesions with potential to develop into malignancy over time. At least 20% of pancreatic cancer evolves from mucinous cystic neoplasms and intraductal papillary mucinous neoplasms, which are often discovered incidentally.^1,2 Current guidelines for the management of mucinous cystic neoplasms and intraductal papillary mucinous neoplasms include long-term surveillance, which is expensive and nontherapeutic, or surgical resection, which is associated with major risk and may not be an option for patients with significant concomitant illness.³.

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.

Role of endoscopic ultrasound in anticancer therapy: Current evidence and future perspectives

The digestive system is one of the most common sites of malignancies in humans. Since gastrointestinal tumors represent a massive global health burden both in terms of morbidity and health care expenditures, scientists continuously develop novel diagnostic and therapeutic methods to ameliorate the detrimental effects of this group of diseases. Apart from the well-established role of the endoscopic ultrasound (EUS) in the diagnostic course of gastrointestinal and hepatobiliary malignancies, we have recently become acquainted with a vast array of its therapeutic possibilities. A multitude of previously established, evidence-based methods that might now be guided by the EUS emerged: Radiofrequency ablation, brachytherapy, fine needle injection, celiac plexus neurolysis, and endoscopic submucosal dissection. In this review we endeavored to provide a comprehensive overview of the role of these methods in different malignancies of the digestive system, primarily in the treatment and symptom control in pancreatic cancer, and additionally in the management of hepatic, gastrointestinal tumors, and pancreatic cysts.

Interventional endoscopic ultrasound

PURPOSE OF REVIEW

To update on recent advances in interventional endoscopic ultrasound (INVEUS) techniques.

RECENT FINDINGS

The introduction of linear echoendoscopes with larger instrument channels and the combined development of new tools and devices have enabled various new applications of minimally invasive endoscopic ultrasound (EUS)-guided transluminal interventions of the pancreas, biliary system and peri-gastrointestinal structures. In this review, EUS-guided interventions are discussed and evaluated: drainage of peripancreatic fluid collections, access and drainage of bile ducts, gallbladder and pancreatic duct, treatment of gastrointestinal haemorrhage, coeliac plexus block and coeliac plexus neurolysis, fiducial placement, solid and cystic tumour ablation, drug delivery and brachytherapy, gastroenterostomy, angiotherapy and other EUS-guided applications. The EUS-guided interventions are classified based on the available evidence as established or experimental, standardized or nonstandardized procedures in common or rare diseases with well or little known complications and their established or nonestablished treatment.

SUMMARY

Some EUS-guided interventions have sparse published evidence with only single-centre studies, case series or individual case reports, others like drainage of peripancreatic fluid collections have become widely accepted practice. INVEUS has been accepted as an alternative to several surgical approaches, EUS-guided techniques result in faster recovery times, shorter hospital stay and lower costs.

Pancreatic Cysts after Endoscopic Ultrasonography-Guided Ethanol and/or Paclitaxel Ablation Therapy: Another Mimic of Pancreatic Pseudocysts

BACKGROUND

Endoscopic ultrasound-guided ablation (EUS-A) therapy is a minimally invasive procedure for pancreatic-cystic tumors in patients with preoperative comorbidities or in patients who are not indicated for surgical resection. However, histopathologic characteristics of pancreatic cysts after ablation have not been well-elucidated.

METHODS

Here, we analyzed pathological findings of 12 surgically resected pancreatic cysts after EUS-A with ethanol and/or paclitaxel injection.

RESULTS

Mean patient age was 49.8 ± 13.6 years with a 0.3 male/female ratio. Clinical impression before EUS-A was predominantly mucinous cystic neoplasms. Mean cyst size before and after ablation therapy was similar (3.7 ± 1.0 cm vs. 3.4 ± 1.6 cm; p = 0.139). Median duration from EUS-A to surgical resection was 18 (range, 1-59) months. Mean percentage of the residual neoplastic lining epithelial cells were 23.1 ± 37.0%. Of the resected cysts, 8 cases (67%) showed no/minimal (<5%) residual lining epithelia, while the remaining 4 cases (33%) showed a wide range of residual mucinous epithelia (20-90%). Ovarian-type stroma was noted in 5 cases (42%). Other histologic features included histiocytic aggregation (67%), stromal hyalinization (67%), diffuse egg shell-like calcification along the cystic wall (58%), and fat necrosis (8%).

CONCLUSION

Above all, diffuse egg shell-like calcification along the pancreatic cystic walls with residual lining epithelia and/or ovarian-type stroma were characteristics of pancreatic cysts after EUS-A. Therefore, understanding these histologic features will be helpful for precise pathological diagnosis of pancreatic cystic tumor after EUS-A, even without knowing the patient's history of EUS-A.

EUS-guided ablation of pancreatic neoplasms

Ablative therapies for locoregional treatment of pancreatic neoplastic lesions developed over the last decade to be applied during surgery are now becoming also available to be utilized under endoscopic ultrasound (EUS) guidance. The advantage of this approach is clear because of the close proximity of the EUS transducer to the target lesion, coupled with developments of specifically designed ablation devices, making the procedure minimally invasive, and potentially sparing patients from the morbidity of this method when performed surgically. EUS-guided ablative techniques that have been applied to pancreatic neoplastic cysts, pancreatic functional and non-functional neuroendocrine neoplasms and pancreatic ductal adenocarcinoma include ethanol injection, radiofrequency ablation (RFA), a combination of bipolar RFA and cryoablation, laser therapy (LT) and photodynamic therapy (PDT). Up to now, most of these procedures have been applied to patients at high surgical risk or who refused surgery. However, more studies evaluating some of these treatments also in selected patients not at surgical risk are becoming available. These studies will pave the road to apply this therapeutic approach to a more extensive number of patients, alone or in association with other therapies, such as immunomodulating drugs. The present manuscript will critically review the available evidence in the field of EUS-guided local ablative treatment of solid and cystic pancreatic neoplasms.

A Review of the Diagnosis and Management of Premalignant Pancreatic Cystic Lesions

Pancreatic cystic lesions are an increasingly common clinical finding. They represent a heterogeneous group of lesions that include two of the three known precursors of pancreatic cancer, intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN). Given that approximately 8% of pancreatic cancers arise from these lesions, careful surveillance and timely surgery offers an opportunity for early curative resection in a disease with a dismal prognosis. This review summarizes the current evidence and guidelines for the diagnosis and management of IPMN/MCN. Current pre-operative diagnostic tests in pancreatic cysts are imperfect and a proportion of patients continue to undergo unnecessary surgical resection annually. Balancing cancer prevention while preventing surgical overtreatment, continues to be challenging when managing pancreatic cysts. Cyst fluid molecular markers, such as KRAS, GNAS, VHL, PIK3CA, SMAD4 and TP53, as well as emerging endoscopic technologies such as needle-based confocal laser endomicroscopy and through the needle microbiopsy forceps demonstrate improved diagnostic accuracy. Differences in management and areas of uncertainty between the guidelines are also discussed, including indications for surgery, surveillance protocols and if and when surveillance can be discontinued.

Interventional Endoscopic Ultrasound: Current Status and Future Directions

The evolution of endoscopic ultrasound (EUS) from a diagnostic to a therapeutic procedure has resulted in a paradigm shift toward endoscopic management of disease states that previously required percutaneous or surgical approaches. The past few years have seen additional techniques and devices that have enabled endoscopists to expand its diagnostic and therapeutic capabilities. Some of these techniques initially were reported more than a decade ago; however, with further device development and refinement in techniques there is potential for expanding the application of these techniques and new technologies to a broader group of interventional gastroenterologists. Lack of formalized training, devices, and prospective data regarding their use in addition to a scarcity of guidelines on implementation of these technologies into clinical practice are contributing factors impeding the growth of the field of interventional EUS. In April 2019, the American Gastroenterological Association's Center for Gastrointestinal Innovation and Technology conducted its annual Tech Summit and a key session focused on interventional EUS. This article is a White Paper generated from the conference, discusses the published literature pertaining to the topic of interventional EUS, and outlines a proposed framework for the implementation of interventional EUS techniques into clinical practice. Three primary areas of interventional EUS are addressed: (1) EUS-guided access; (2) EUS-guided tumor ablation; and (3) endohepatology. There was general agreement among participants on several key components. The introduction of these novel interventions requires better tools, more data on safety/outcomes, and improved training for endoscopists. Participants also agreed that widespread implementation and use of these techniques will require support from Gastrointestinal Societies and other key stakeholders including payers. Continued work by the Gastrointestinal Societies and manufacturers to provide training programs, appropriate equipment/work environments, and policies that motivate endoscopists to adopt new techniques is essential for growing the field of interventional EUS.

Endoscopic Ultrasound-Guided Ablation of Focal Pancreatic Lesions: The GRUPUGE Perspective

Focal pancreatic lesions include a heterogeneous group of solid and cystic lesions, with different natures and variable clinical, imagiological, and pathological characteristics. Several endoscopic ultrasound (EUS)-guided ablative techniques have been tested during the last decade for the treatment of these pancreatic lesions, mostly consisting of the injection of ablative agents and, more recently, radiofrequency ablation. The most encouraging EUS-guided ablation outcomes are being reached in the treatment of some pancreatic cystic neoplasms and small (≤2 cm) pancreatic neuroendocrine tumours (pNETs). Data supporting a potential role of ablative therapies in the treatment of pancreatic ductal adenocarcinoma is still lacking. In this article, GRUPUGE presents an updated perspective of the potential role of EUS-guided ablation for the treatment of pancreatic cystic neoplasms and pNETs, addressing the selection criteria and technical issues of different techniques and analysing recent data on their safety and efficacy.

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.

Endosonography-guided Radiofrequency Ablation in Pancreatic Diseases: Time to Fill the Gap Between Evidence and Enthusiasm

Over the past 20 years, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has generated interest as a novel minimally invasive tool in the multimodal treatment of pancreatic malignant and premalignant lesions. However, although optimization of probes and settings has made EUS-RFA relatively safe, questions on the ideal positioning of this treatment in a multimodal strategy remain unanswered. This review will summarize the technical aspects of EUS-RFA and available clinical experiences for each pancreatic indication (pancreatic cancer, neuroendocrine neoplasms, cystic lesions, and celiac ganglia neurolysis). Established indications will be discussed along those requiring additional clinical data or even proof-of-concept studies. A dedicated session will further discuss evidence expected to emerge from ongoing registered trials, together with issues that must be addressed in future research, including the possible combination with immunotherapy, and the personalization of this treatment on the basis of genetic profiling. Despite the great clinical enthusiasm and scientific fervor, while evidence-based answers are produced, EUS-RFA must be centralized in high-volume centers of recognized expertise, where multidisciplinary discussions of indications and actively recruiting research protocols are available.

Endoscopic ultrasound-guided injective ablative treatment of pancreatic cystic neoplasms

With the development of cross-sectional imaging modalities and the increasing attention being paid to physical examinations, the prevalence of pancreatic cystic neoplasms (PCNs) has increased. PCNs comprise a broad differential spectrum with some PCNs having low or no malignant potential and others having high malignant potential. The morbidity and mortality rates related to major pancreatic surgical resection are high. Long-term surveillance may not only increase the financial burden and psychological stress for patients but also result in a missed malignancy. Minimally invasive endoscopic ultrasound (EUS)-guided ethanol ablation was first reported in 2005. Several other agents, such as paclitaxel, lauromacrogol, and gemcitabine, were reported to be effective and safe for the treatment of PCNs. These ablative agents are injected through a needle inserted into the cyst via transgastric or transduodenal puncture. This treatment method has been substantially developed in the last 15 years and is regarded as a promising treatment to replace surgical resection for PCNs. While several reviews of EUS-guided ablation have been published, no systematic review has evaluated this method from patient preparation to follow-up in detail. In the present review, we systematically describe EUS-guided injective ablation with regard to the indications, contraindications, preoperative treatment, endoscopic procedure, postoperative care and follow-up, evaluation method, treatment efficiency, safety profile, tips and tricks, and current controversies and perspectives.

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.

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.