EUS-guided Ablation of Pancreatic Cyst Neoplasms

Visit 1 for all participants will consist of going over the Informed Consent form and talking
with the patient about the study. If the patient agrees to participate, he/she will be asked
to sign the form, and a copy will be given to him/her for his/her records. This will be
conducted during the day of the endoscopic procedure before the participant is under
anesthesia. The treatment provided will be standard-of-care that is offered to patients with
pancreatic cyst lesions (PCL) interested in undergoing EUS-guided ethanol ablation.

An MRI of the abdomen will be obtained as baseline measure to determine the size of the
pancreatic cyst and confirm diagnosis.

Prior to undertaking any ablation, the cyst fluid will be sampled at a prior EUS session to
check for mucin, viscosity, carcinoembryonic antigen (CEA) (>200U/L=mucinous cyst), amylase
and if required molecular marker analysis. Once a PCL is determined to have a malignant
potential the patient will be selected for EUS-guided ablation. All patients will receive a
dose of intravenous ciprofloxacin 500mg 30 minutes prior to the ablation. These evaluation
and treatment measures are standard-of-care for any patient with pancreatic cyst lesion
undergoing EUS-guided ethanol ablation.

Procedural Technique: All procedures will be undertaken using a curvilinear echoendoscope.
Once a cyst is identified for ablation it will be punctured using a 22G needle. After
subtotal evacuation of the cyst, injection is performed with a volume of alcohol that is
equal to the quantity aspirated, and the cyst will be lavaged for 3 to 5 minutes,
alternatively filling and emptying the cavity. The injected ethanol will then be evacuated at
the end of lavage, leaving just enough fluid to outline the cavity. A second ablative agent
such as paclitaxel is then injected and left in the cyst cavity; the volume injected should
not exceed the volume of aspirated fluid. The needle tip must be carefully maintained within
the cyst to avoid parenchymal injury or cyst wall leak. At the completion of the procedure,
the needle will be removed from the cyst cavity. When a cyst is not restored to its original
size during ethanol injection, vigorous lavage and aspiration must be avoided because of
probable communication with the main pancreatic duct.

In patients with multi-loculated cysts, a single injection may not provide sufficient drug
delivery to all locules within a cyst. It is important to determine the optimal angle at
which the needle can be introduced into the maximum number of targeted locules. When all
punctured locules cannot be visualized on endosonographic image, needle passage across a
septation may be indicated. The simultaneous collapse of locules across the septum during
cyst fluid evacuation and spread of echogenic bubbles across the septation during injection
of ablative agents are indication of good distribution of the ablative agent into the
locules. This is important as a missed locule may result in cyst regrowth and treatment
failure. While additional needle passes through different angles may increase the
effectiveness of cyst ablation it will also increase the incidence of adverse events.
Therefore a second needle puncture may be considered only when the risk of adverse events
appears low.

The relative effectiveness of the procedure is related to the degree of contact between the
ablative agent and the cyst epithelium. However, it is important to maintain the needle in
the visual plane and within the cyst cavity during the entire procedure. All techniques
described above are standard-of-care treatment measures offered to patients undergoing
EUS-guided ethanol ablation of pancreatic cysts.

Ablative agents:

1. Ethanol: concentration of 80-99% may be used.

2. Paclitaxel: Because of the high viscosity of its cosolvent (castor oil) the paclitaxel
solution must be diluted 1:1 in 0.9% normal saline to yield a final dose concentration
of 3mg/mL. However, if the agent is available in a less viscous format (polymeric
micelle) it can be used without dilution (a dose concentration of 6mg/mL).

Follow-up:

1. Patients will be admitted overnight for observation and kept nil by mouth. A complete
blood count and serum amylase level will be checked the next day and patients will be
discharged home if clinically well, with no evidence of pancreatitis or other adverse
events and can tolerate a low fat diet. Patients will be prescribed oral ciprofloxacin
500 mg to be taken twice a day for three days. This will be standard-of-care follow-up.

2. A CT of the abdomen will be obtained at 3 months to assess treatment response. If there
is no change in size of the cyst, further CT scans will be scheduled at 3-month
intervals with another attempt at EUS-guided cyst ablation. If there is complete or
partial cyst resolution, follow-up CT scans will be obtained at 6-month intervals. If
complete resolution is documented on two CT scans, then the patient will be scheduled
for annual CT scans. This will be standard-of-care follow-up. 3. Patients with
persistent or only partial cyst resolution despite two ablative treatment sessions will
be referred to a pancreatic surgeon for consultation. If the patients are high-risk
surgical candidates, surveillance by EUS and cross-sectional imaging will be continued
per International Society of Pancreatology guidelines. This will be standard-of-care
follow-up. 4. Definitions: Using multi-detector CT scans and specialized software the
original volume (OV) of the cyst will be calculated by the radiologist. Complete
resolution will be defined as the cyst being nonvisible or less than 5% of the OV on
follow-up CT; Partial resolution of the cyst will be defined as decrease in size by
5-25% of the OV and the cyst will be defined as Persistent if > 25% the OV.

Inclusion Criteria:

1. Benign branch-duct intraductal papillary mucinous neoplasm (IPMN) or mucinous cyst
neoplasm (MCN) measuring >2 and up to 4cm in size and located in the head or body of
the pancreas.

2. Benign branch-duct IPMN or MCN measuring > 2 and up to 4cm in size and located in the
tail of the pancreas in a high-risk surgical candidate.

3. A branch-duct IPMN or MCN with high-risk features (mural nodule or enlarging in size)
in a high-risk surgical patient.

4. Indeterminate cyst lesions

Exclusion Criteria:

1. Cysts measuring <2cm or >4cm.

2. Multiloculated cysts (>4 locules).

3. Cysts with vascular supply.

4. Cysts communicating with the main pancreatic duct via an obvious side-branch measuring
2mm or more in diameter.

5. Cysts with hypoechoic mass lesions that on fine needle aspiration (FNA)reveal
malignant cells.

6. Recent history of pancreatitis and EUS findings suggestive of a pseudocyst.

7. Bleeding tendency; international normalized ratio (INR) >1.4 or platelet count
<70,000.