Incorporating Endoscopic Ultrasound and Elastography Towards Improving Outcomes of Pediatric Pancreatitis Management

Incorporating Endoscopic Ultrasound and Elastography Towards Improving Outcomes of Pediatric Pancreatitis Management

Incorporating Endoscopic Ultrasound and Elastography Towards Improving Outcomes of Pediatric Pancreatitis Management

The main reason for this research study is to find out more about acute recurrent pancreatitis and chronic pancreatitis in children. There are few studies on childhood pancreatitis, so diagnosis and treatment are based on adult studies. This limits our understanding and treatment of these disorders in children. Endoscopic ultrasound (EUS) is a tool used to assess and diagnose pancreatic disease. We can use ultrasound with shear wave elastography (SWE) to measure fibrosis (scarring) of the pancreas. We can use SWE on both EUS and transabdominal ultrasound (TUS) systems. Both TUS and EUS SWE have been studied for diagnosis of chronic pancreatitis in adult patients, however they have not been studied in children. We plan to use EUS SWE and TUS SWE information in this study to help us understand pancreatitis in children. Children with pancreatitis and children without pancreatitis (controls) will be invited to participate in this study.

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.

This arm includes two cohorts: Children with confirmed diagnosis of ARP or CP Controls (Children without a history of pancreatic disease)

TUS SWE will be performed using a Canon Aplio i800 ultrasound system and a curved 1-6 MHz transducer. 2D SWE will be performed with measurement of shear wave speed in the head, body and tail of the pancreas.

- Features Hyperechoic foci with shadowing (Major A) Lobularity with honeycombing (Major B) Lobularity without honeycombing (Minor) Hyperechoic foci without shadowing (Minor) Cysts (Minor) Stranding (Minor) Main pancreatic duct calculi (Major A) Irregular main pancreatic duct contour (Minor) Dilated side branches (Minor) Main pancreatic duct dilation (Minor) Hyperechoic main pancreatic duct margin (Minor)

Ductal calculi, dilated side branches, parenchymal calcifications found in any imaging (abdominal ultrasound (abd US), magnetic resonance imaging/magnetic resonance cholangiopancreatography (MRI/MRCP), computerized tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), endoscopic US (EUS). Ductal obstruction or stricture/dilatation/irregularities that are persistent (for >2 months) on any imaging. Surgical or pancreatic biopsy specimen demonstrating histopathologic features compatible with CP (acinar atrophy, fibrosis, protein plugs, infiltration with lymphocytes, plasma cells, macrophages).

Head (Vs m/s) median, IQR, # measurements Genu (Vs m/s) median, IQR, # measurements Body (Vs m/s) median, IQR, # measurements Tail (Vs m/s), median, IQR, # measurements

Head (Vs m/s) median, IQR, # measurements Body (Vs m/s) median, IQR, # measurements Tail (Vs m/s), median, IQR, # measurements

Four-stage scoring system: 0 = normal pancreas parenchyma, no fibrotic changes; 1 = mild fibrosis with thickening of periductal fibrous tissue; 2 = moderate fibrosis with marked sclerosis of interlobular septa, no evidence of architectural changes, and 3 = severe fibrosis with detection of architectural destruction.

Pancreas signal 1 _____ Pancreas signal 2 _____ Pancreas signal 3 _____ Spleen signal 1 _____ Spleen signal 2 _____ Spleen signal 3 _____ Muscle signal 1 _____ Muscle signal 2 _____ Muscle signal 3 _____

Pancreatitis Cohort: Inclusion criteria: Confirmed diagnosis of ARP or CP by INSPPIRE criteria ≤ 21 years of age, male and female Children undergoing EUS for clinical care For Aim 2.3 only: Children undergoing TPIAT or other pancreatic resection Exclusion criteria: Children <15 kg who cannot accommodate the size of endoscope Children with acute pancreatitis (AP) <6 weeks prior to EUS Control Cohort: Inclusion criteria: Children without a history of pancreatic disease undergoing EUS for other clinical indications ≤ 21 years of age, male and female Exclusion criteria: Children <15 kg who cannot accommodate the size of endoscope Children with AP, ARP or CP