Description

The aims of the proposed study are as follows:

Aim 1: Characterize endoscopic ultrasound (EUS) findings of pediatric acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP).

Adult criteria for EUS diagnosis of CP exist, but no such criteria exist for children. As such, the applicability of current diagnostic criteria to pediatric patients is unknown.

1.1: Catalogue grayscale EUS findings of ARP and CP in a pediatric cohort and compare to healthy controls. Hypothesis: EUS findings of ARP and CP in pediatric patients will differ from those of adult ARP and CP and will be characteristically different from healthy controls. Exp1: We will catalogue grayscale EUS findings in 40 pediatric

patients with known history of ARP or CP undergoing clinically indicated EUS and will compare those with findings in 20 patients without a history of pancreatitis who are undergoing EUS for other indications.

1.2: Benchmark grayscale EUS against other imaging modalities for diagnosis of CP, particularly early CP, in children. Hypothesis: Grayscale EUS findings will be more sensitive than other imaging modalities in all stages of CP. Exp2: We will test associations, in blinded fashion, of grayscale EUS findings catalogued under S.A1.1 in enrolled children with findings on alternative pancreas imaging modalities performed for clinical indications. Specifically, we will correlate to endoscopic retrograde cholangiopancreatography (ERCP), magnetic resonance cholangiopancreatography (MRCP) and computed tomography (CT) performed for clinical indications within +/- 3 months of the EUS.

Aim 2: Define the diagnostic performance of ultrasound elastography for CP and pancreatic stiffness as a measure of fibrosis in pediatric patients.

2.1: Define the diagnostic performance of EUS and TUS elastography for pediatric CP. Hypothesis: EUS and TUS elastography will have high specificity for CP with increased stiffness in patients compared to controls. Exp 1: Patients enrolled under Aim 1 will undergo shear wave elastography (SWE) measurement of the pancreas during EUS. These same patients will undergo research TUS with SWE of the pancreas. SWE results by both EUS and TUS will be evaluated for diagnostic performance for CP.

2.2: Define agreement between EUS and TUS measurement of pancreatic parenchymal stiffness in pediatric patients. Hypothesis: EUS and TUS measures of pancreatic parenchymal stiffness will agree with minimal bias. Exp2: EUS and TUS SWE data obtained under S.A2.1 will be evaluated for agreement and divergent cases will be investigated to define causes.

2.3: Define the diagnostic performance of elastography for pancreatic fibrosis. Hypothesis: SWE is a sensitive indicator of pancreatic fibrosis as identified by histology. Exp3: Patients undergoing clinically indicated total pancreatectomy and islet auto transplant (TPIAT) or other pancreatic surgical resection at our institution (approximately 20 per year) will be approached to undergo pre-operative TUS SWE. These SWE measurements, along with EUS SWE measurements obtained preoperatively, will be compared to binary and semi-quantitative assessments of pancreatic parenchymal fibrosis by histology.