Table 1. Position statements on EUS-guided pancreatic cyst ablation.
| No. | Question | Statement | Classification of statement | Quality of evidence |
| Indications for the procedure | ||||
| 1 | When should we perform pancreatic cyst ablation? | In patients who are not surgical candidates or refuse surgery with a reasonable life expectancy and suffering from either:
|
B | Moderate |
| 2 | What size and configuration of the pancreatic cyst respond best to ablation? | Pancreatic cysts with 6 or less locules and measuring 2 to 6 cm in diameter respond best to ablation. | B | Moderate |
| 3 | What are the contraindications to the procedure? | Absolute contraindications
|
B | Moderate |
| 4 | What level of certainty of diagnosis is required before the procedure? | The treating physician should be reasonably certain that the cyst is not a benign asymptomatic pancreatic cyst with no or low malignant potential. The degree of pre-procedure testing required to diagnose other types of pancreatic cysts will vary among physicians to ensure a proper diagnosis for patient counselling and the planned treatment for the patient. | B | Moderate |
| Procedural preparations | ||||
| 5 | What investigational modalities are required before EUS cyst ablation is performed? | We recommend all patients to be evaluated with contrast enhanced computed tomography (pancreatic protocol) or enhanced magnetic resonance imaging with cholangiopancreatography (MRCP) and/or endoscopic ultrasonography (EUS-FNA) before ablation. Anatomic and morphological features of the pancreatic cysts should be evaluated and EUS-FNA may be performed for biochemical and cytological examination to aid in diagnosis of the cyst. | B | Moderate |
| 6 | Are prophylactic antibiotics required? | Prophylactic antibiotics (fluoroquinolones or beta-lactamase) are recommended to prevent post-procedural infection. | C | Moderate |
| 7 | How long does antibiotics need to be continued if given? | Antibiotics if given, should be continued for 3 to 5 days. | C | Moderate |
| Procedural considerations | ||||
| 8 | What size of the needle should be used? | A 19G or 22G needle should be used for aspiration and injection. | B | Moderate |
| 9 | Should the fluid be aspirated completely or not before ablation? | We suggest leaving a small rim of fluid around the tip of the needle within the cyst (after the initial aspiration) before the ablation process. | C | Very low |
| 10 | What should be done if the cyst fluid is too viscous to be aspirated out during EUS-FNA? | We suggest using a 19-gauge needle under high suction pressure to aspirate the viscous fluid. The viscosity of the cyst can then be lowered by injection of equal volumes of normal saline or alcohol that were aspirated out. The process is repeated to allow the majority of the cyst fluid to be aspirated for ablation. | C | Very low |
| 11 | What are the available agents for the procedure? | Use of ethanol lavage only, ethanol lavage followed by the infusion of paclitaxel, an alcohol-free saline lavage followed by an admixture of paclitaxel-gemcitabine, and use of lauromacrogol have been reported in clinical trials. | A | High |
| 12 | Is ethanol required for effective pancreatic cyst ablation? | Ethanol is the traditional agent used for ablation, however, two recent trials have shown that ethanol is not required for effective cyst ablation when a chemotherapeutic agent appropriate for cyst ablation is used. | A | High |
| 13 | What is the difference between aspiration, lavage and retention? Are there any differences between the practices? | Aspiration refers to the removal of cyst fluid by the aspiration needle. Lavage is the repetitive aspiration and reinjection of the lavage agent for 3 to 5 minutes. Retention is to retain the injected ethanol for 20 minutes to 40 minutes while rotating patient position, particularly for large cyst. After a retention period, the injected ethanol is aspirated completely. Infusion refers to replacement of the cyst content with an ablation agent (eg paclitaxel or gemcitabine-paclitaxel) which is then left in place. | C | Low |
| Outcomes of EUS-guided pancreatic cyst ablation | ||||
| 14 | How should a response to therapy be defined as after the procedure? | Completeness of response is defined by the amount of reduction in volume of the cyst (4 /3 π r3) where r is the cyst radius as measured by the primary imaging modality at initial and 6-month follow-up. Complete response is defined as 95 % or greater reduction in volume of the cyst. Partial response is then a 75 % to 95 % reduction in volume of the cyst and non-response would be defined as < 75 % reduction in volume of the cyst. |
C | Very low |
| 15 | What are the results of pancreatic cyst ablation? | Complete cyst resolution with ethanol alone occurs in about 30 % of treated cysts. The addition of paclitaxel infusion following ethanol lavage increases complete resolution to 60 %-79 %. | A | High |
| 16 | What are the effects of ablation on cyst epithelium? | Surgery is rarely performed after cyst ablation. However, reported histologic epithelial ablation rates after endoscopic therapy of pancreatic cysts ranges from 0 % to 100 % but are generally between 50 % and 100 %. | C | Low |
| 17 | What are the cytological and genetic changes after the procedure? | Data are limited data suggesting that genetic changes revert to normal after cyst ablation. | C | Low |
| Follow-up and monitoring | ||||
| 18 | How should these patients be followed up and monitored? | Patients treated with pancreatic cyst ablation and followed non-operatively should undergo cross-sectional imaging at 6-month intervals for the first year and then annually until no longer warranted due to patient age and medical conditions. This is to monitor for recurrences after ablation and possible incomplete histologic ablation following treatment. | B | Moderate |
| Potential AEs and management | ||||
| 19 | What are the potential adverse events of the procedure? | It is assumed that EUS-guided pancreatic cyst ablation carries the baseline risks of standard EUS-FNA procedures, which are considered safe and rarely associated with adverse events. Specific AEs associated with the ablation itself include self-limiting abdominal pain, acute pancreatitis, and VTE. | A | Moderate |
| 20 | Are there systemic effects from the chemotherapeutic agent during and after the procedure? | Paclitaxel in doses used for pancreatic cyst ablation has been shown to be safe when injected into pancreatic cysts without identifiable blood levels of the agent post-procedure. | B | Moderate |
| Competency and training | ||||
| 21 | Who should learn the procedure? | EUS-guided cyst ablation is a technically challenging procedure. Physicians undertaking this procedure are expected to have completed an accredited, standardized training program in interventional endoscopy, as outlined by the appropriate national society governing that center. They should be competent in EUS-FNA and also EUS interventional procedures. | C | Low |
| 22 | How should training of the procedure be undertaken? | Only physicians who have completed training in EUS and EUS-FNA with appropriate credentialing should perform pancreatic cyst ablation. Performance of five procedures under supervision is recommended to gain appropriate experience for an endoscopist fluent in EUS to gain competency. | C | Very low |
| 23 | Which centers should provide training of the procedure? | Training should be obtained in a high-volume training center. The center should possess a multi-disciplinary team including the expert endosonographer, surgical oncologist and radiologist for discussion of each patient’s condition and treatment strategy. | B | Very low |
EUS, endoscopic ultrasound; MRCP, magnetic resonance imaging with cholangiopancreatography; EUS-FNA, endoscopic ultrasound-guided fine-needle aspiration; AE, adverse event; VTE, venous thromboembolism.