Success of endoscopic ultrasound-guided ethanol ablation of pancreatic cysts: a meta-analysis and systematic review

Intracystic injection of large surface area microparticle paclitaxel for chemoablation of intraductal papillary mucinous neoplasms: Insights from an expanded access protocol

AIMS

A novel large surface area microparticle paclitaxel (LSAM-PTX) has unique properties of long retention in cystic spaces while maintaining high drug concentration. We prospectively evaluated the safety and response of EUS-guided fine needle injection (EUS-FNI) of LSAM-PTX to chemoablate branch duct (BD)-IPMNs.

METHODS

Subjects diagnosed with BD-IPMNs exhibiting at least one worrisome criteria and considered non-surgical were enrolled in a multicenter clinical trial (NCT03188991) and subsequently included in an Expanded Access Protocol (EAP) where they received EUS-FNI of LSAM-PTX (15 mg/mL).

RESULTS

Six BD-IPMNs measuring (mean ± SD) 3.18 ± 0.76 cm in diameter among 5 subjects (mean age: 66 years) were treated by EUS-FNI of LSAM-PTX. A mean of 4 doses of LSAM-PTX (mean dose/cyst: 73 ± 31 mg) were administered, and subjects were followed for up to 32 months. The mean volume reduction/cyst ranged from 42 to 89% (9.58 ± 5.1 ml to 2.2 ± 1.1 ml (p = 0.016)). The mean surface area reduction ranged from 31 to 83% (21.9 ± 8.7 cm2 to 5.7 ± 2.5 cm2 (p = 0.009)). Higher dosing-frequency of EUS-FNI of LSAM-PTX significantly correlated with a reduction in cyst volume (R2 = 0.87, p = 0.03) and surface area (R2 = 0.83, p = 0.04). Comparing pre- and post-ablation samples, molecular analysis of the cyst fluid revealed a loss of IPMN-associated mutations in 5 cases (83.3%), while reemergence was observed in 1 case and persistence in 1 case. Intracystic changes (fibrosis/calcification) were observed in 83.3% (n = 5). One subject developed mild acute pancreatitis (1 of 22 EUS-FNIs of LSAM-PTX).

CONCLUSION

In this EAP, EUS-FNI of LSAM-PTX into BD-IPMNs was safe and resulted in volume and surface area reduction, morphological changes, and loss of pathogenic mutations.

Efficacy and safety of endoscopic ultrasound-guided radiofrequency ablation for management of pancreatic lesions: a systematic review and meta-analysis

BACKGROUND

Radiofrequency ablation (RFA) has been used to treat various abdominal tumors including pancreatic tumors. Multiple approaches such as laparoscopic, open, and percutaneous have been used for pancreatic tissue ablation. More recently, endoscopic ultrasound (EUS)-guided RFA has emerged as a new technique for pancreatic tissue ablation. The role of EUS-RFA in management of pancreatic lesions is still not well-established. In this study, our aim is to assess efficacy and safety of EUS-RFA for management of pancreatic lesions.

METHODS

MEDLINE, Scopus, and Cochrane Library databases were searched to identify studies reporting EUS-RFA of pancreatic lesions with outcomes of interest. Studies with <5 patients were excluded. Clinical success was defined as symptom resolution, decrease in tumor size, and/or evidence of necrosis on radiologic imaging. Efficacy was assessed by the pooled clinical response rate whereas safety was assessed by the pooled adverse events rate. Heterogeneity was assessed using I2. Pooled estimates and the 95% CI were calculated using random-effect model.

RESULTS

Ten studies (5 retrospective and 5 prospective) involving 115 patients with 125 pancreatic lesions were included. 152 EUS-RFA procedures were performed. The lesions comprised of 37.6% non-functional neuroendocrine tumors (NFNETs), 15.4% were insulinomas, 26.5% were pancreatic cystic neoplasms (PCNs), and 19.7% were pancreatic adenocarcinomas. The majority were present in the pancreatic head (40.2%), 38.3% in the body, 11.2% in the tail, and 10.3% in the uncinate process. Pooled overall clinical response rate was 88.9% (95% CI: 82.4-93.7, I2=38.1%). Pooled overall adverse events rate was 6.7% (95% CI: 3.4-11.7, I2=34.0%). The most common complication was acute pancreatitis (3.3%) followed by pancreatic duct stenosis, peripancreatic fluid collection, and ascites (2.8%) each. Only one case of perforation was reported with pooled rate of (2.1%).

DISCUSSION

This study demonstrates that EUS-RFA is an effective treatment modality for pancreatic lesions, especially functional neuroendocrine tumors such as insulinomas.

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.

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.

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.

[Endoscopic Treatment for Pancreatic Cystic Lesions]

The decision of the appropriate treatment for pancreatic cystic lesions (PCLs) is becoming increasingly important as the number of incidentally found PCLs increases. A range of modalities have been attempted because there has been an increasing demand for minimally invasive treatment for PCLs due to the large burden of a surgical resection. Endoscopic treatment using endoscopic ultrasonography (EUS), a representative of minimally invasive therapy, can be categorized into two types: ablation therapy by the injection of drugs and topical thermal coagulative therapy through the high topical energy. A number of studies reported the feasibility and efficacy of these treatments; the most common is EUS-guided ablation for PCLS with ethanol alone or in combination with anticancer drugs. Although ablation therapies with drug injection have proven safety and feasibility, there is no consensus regarding the actual treatment effects and indications of these modalities. EUS-guided radiofrequency ablation was recently attempted as a representative method of local thermal coagulation, but further studies will be needed because of the lack of evidence of its feasibility and safety. In addition, a range of treatments for malignant tumors rather than PCLs have been attempted, such as EUS-guided photodynamic therapy, EUS-guided neodymium-doped yttrium aluminum garnet laser, and high-intensity focused ultrasound, based on the data from animal experiments. Through further study, endoscopic treatment is expected to become established as a useful treatment modality for PCLs.

A prospective study of endoscopic ultrasonography features, cyst fluid carcinoembryonic antigen, and fluid cytology for the differentiation of small pancreatic cystic neoplasms

Background and Objectives

With improvements in imaging technologies, pancreatic cystic lesions (PCLs) have been increasingly identified in recent years. However, the imaging modalities used to differentiate the categories of pancreatic cysts remain limited, which may cause confusion when planning treatment. Due to progress in endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) technology, auxiliary diagnosis by the detection of cystic fluid has become a recent trend.

Methods

From March 2015 to April 2016, 120 patients with PCLs were enrolled in this study. According to the results of EUS, cyst fluid carcinoembryonic antigen (CEA) analysis, and cystic fluid cytology, the patients were divided into two groups: a nonmucinous and a mucinous group. Of those, 61 patients who had undergone surgical resection were included in the analysis. The clinical features, biochemical and tumor markers of cyst fluid as well as the cytological test results of the patients were compared with histopathology results.

Results

A cyst size of 4.0 cm was used as the boundary value; a cyst ≤4.0 cm was defined as a small PCL. 87 (72.5%) lesions were ≤4.0 cm, and 33 (27.5%) lesions were >4.0 cm. Regarding the analysis of CEA and carbohydrate antigens 19-9 (CA19-9), significant differences were found between the nonmucinous and mucinous groups (P < 0.05) according to nonparametric independent samples tests. The EUS, cystic fluid CEA, and cystic fluid cytology results were compared with the tissue pathology findings using McNemar's test (P < 0.05) and showed a sensitivity of 90% and a specificity of 84%.

Conclusion

A diagnostic combination of EUS, cyst fluid CEA, and cystic fluid cytology could be used to differentiate small pancreatic cystic neoplasms. Cystic fluid cytology analysis is helpful for planning treatment for pancreatic cystic tumors that pose a surgical risk.

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.

Endoscopic Management of Pancreatic Cysts

Management of pancreatic cystic lesions relies on patients' clinical presentation, imaging, and endoscopic ultrasound. Current research in basic science, radiology, and endoscopy is evolving and making progress in this condition which is relatively common in the general population. This review focuses on the recent endoscopic ultrasound approaches to the diagnosis of these pancreatic disorders.

Therapeutic Approach to Cystic Neoplasms of the Pancreas

Management of cystic neoplasms of the pancreas is challenging as it relies on radiologic and cyst fluid markers to discriminate between benign and pre-cancerous lesions, however their ability to predict malignancy is limited. While asymptomatic serous cystadenomas can be managed conservatively, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms are more difficult to manage. A selective approach, based on the preoperative likelihood of high-grade dysplasia or invasive disease, is the standard of care. Research is focusing on the development of pre-operative markers for identifying high risk lesions, which will spare patients with low-risk or benign lesions the risks of pancreatectomy.

Role of Endoscopic Ultrasonography and Endoscopic Retrograde Cholangiopancreatography in the Clinical Assessment of Pancreatic Neoplasms

Accurate diagnosis and staging of pancreatic neoplasms is essential for surgical planning and identification of locally advanced and metastatic disease that is incurable by surgery. The ability to position the endoscopic ultrasonography (EUS) transducer close to the pancreas combined with the use of fine-needle aspiration enables the accurate diagnosis of pancreatic cysts and solid masses. EUS is also increasingly being used to procure core tissue for molecular analysis that facilitates personalized treatment of pancreatic cancer. Various therapeutic interventions can be undertaken under EUS guidance. This article focuses on the applications of EUS and endoscopic retrograde cholangiopancreatography in pancreatic neoplasms.

State-of-the-art endoscopic procedures for pancreatic cancer

Pancreatic cancer is the twelfth most common cancer worldwide, taking the fourth place in cancer-related mortality in western countries. Despite significant efforts in understanding the tumor biology of pancreatic cancer and introducing new technologies and therapies to improve the detection, staging and treatment of this disease, pancreatic cancer continues to have a high and almost unchanged mortality. In the last few decades, the development of techniques such as endoscopic retrograde cholangio pancreatography and endoscopic ultrasound have allowed us to directly access the pancreaticobiliary system and fight pancreatic cancer and its complications from different fronts. Our goal with this review is to discuss the most cutting-edge endoscopic techniques available in our armamentarium to diagnose, stage and treat pancreatic cancer.

New developments in endoscopic ultrasound-guided therapies

Endoscopic ultrasound (EUS) has opened new horizons in minimally invasive therapies for diverse gastrointestinal pathologies. Digestive Disease Weak 2015 held in Washington, DC., USA featured exciting research articles on EUS-guided therapeutic procedures. EUS-guided biliary drainage has been attempted and described for many years. There seems to be a lot of interest among various international groups to compare this technique with other alternatives in terms of efficacy and safety. Similarly, EUS-guided pancreatic drainage of cysts and fluid collections continues to evolve with new stents and devices being developed specifically for deployment under endosonographic guidance. EUS-guided ablation of cystic pancreatic tumors is innovative but not always effective. Combining alcohol ablation with injecting chemotherapeutic agents may improve long-term results regarding efficacy. Similarly, for solid pancreatic tumors there appears to be ongoing interest and continuing efforts in injecting different chemotherapeutic or ablative agents, delivering fiducials for radiation guidance and even attempting ablation with radiofrequency. Gastric variceal treatment and EUS-guided anastomoses also continue to be investigated. This review article is focused on the recent developments in EUS-guided therapies presented at Digestive Disease Week (DDW) 2015.