Introduction

Diagnosis of chronic pancreatitis (CP) is challenging, especially in early stages when typical clinical signs and parenchymal changes are lacking. To date, evaluation by endoscopic ultrasound (EUS) using Rosemont criteria (RC) is the gold standard for the diagnosis of CP, but represents an invasive method with still suboptimal accuracy. Therefore, it is of crucial interest to develop non invasive, widely applicable tests for the diagnosis of CP. Recently the Gemelli chronic pancreatitis ultrasound score (USCP) has been developed to fill this gap (1). Comparable to liver stiffness measurement, transabdominal ultrasound (US) with 2D shear wave elastography (2D SWE) could represent an additional alternative for the diagnosis of CP. It uses measurement of tissue stiffness, which increases naturally with chronic inflammatory changes, present in CP (2).

Aims & Methods

We conducted a single center prospective case control study where all the included subjects underwent EUS first (for the suspicious of CP or other reasons such as lithiasis), with RC defined patient cohorts with chronic pancreatitis or absence of parenchymal changes. Patients with and without CP subsequently underwent US with evaluation of the pancreas using 2D SWE (in m/s) and characterization by the USCP score (LogiqE10, GE Healthcare). Primary outcome was agreement between the different evaluation techniques, namely RC and 2D SWE. Secondary outcome was the evaluation of a cut off value of SWE differentiating values in CP from normal values. Main exclusion criteria were patients with liver cirrhosis, acute pancreatitis and inability to visualize the pancreas with US.

Results

51 patients with CP and 51 without CP were included. Median SWE were statistically different between groups (no CP 1.50m/s; IQR 1.34-1.63 and with CP 1.83 m/s; IQR 1.68-2.08; p<0.0001). Patients with RC indeterminate for CP had lower SWE values compared to patients with RC consistent with CP (Median 1.67m/s, IQR 1.52-1.72 vs. 1.90 m/s, IQR 1.72-2.12, p<0.0001). Median USCP Score significantly differed between groups (no CP 0-1 points, with CP 3-9 points, p<0.0001). SWE values did not correlate with age, BMI, HbA1c or stool elastase levels, but correlated significantly with USCP score (p<0.001) and RC (p<0.001). USCP Score significantly correlated with BMI (p=0.011), stool elastase levels (p<0.001), HbA1c (p=0.002) as well as RC (p<0.0001). We defined a cutoff- SWE value of <1.42 m/s to rule out CP with a sensitivity of 97% (NPV 98%) and a SWE cut off >1.97 ms/s to diagnose CP with a specificity of 97% (PPV 92%).

Conclusion

Transabdominal ultrasound evaluation of the pancreas with 2D SWE is a promising, widely applicable and non-invasive tool for the diagnosis of CP. More studies with larger cohorts confirming the results are necessary.

References

1)Pagliari D, et al. A new ultrasound score for the assessment and follow-up of chronic pancreatitis: The 'Gemelli USCP score'. Dig Liver Dis. 2020 Jun;52(6):644-650.
2) Yashima Y et al. Acoustic radiation force impulse elastography for noninvasive assessment of chronic pancreatitis. J Gastroenterol. 2012 Apr;47(4):427-32.

Clinical Case Summary

We present a case of a 46-year-old female admitted to our clinic with a 6day history of nausea, vomiting around 10-15 times with blood clots, heartburn, regurgitation, retrosternal pain, loss of appetite, dizziness, generalized weakness, jaundiced skin and sclerae. The patient had previously been diagnosed with left-sided ulcerative colitis, currently in remission without medications. She mentioned alcohol abuse of around 300ml cognac per day for the past 2 years.
Physical examination t=36,6 ^oC, BP=70/40 mm Hg. Blood tests showed macrocytic anemia, thrombocytopenia, hypokalemia, elevated values of total bilirubin, especially direct, ALT, AST, GGT, and ALP, creatinine, urea, low albumin level and coagulopathy.
EGDS showed circumferential black discoloration of the esophagus, which bled on contact (Gurvits syndrome or black esophagus) and a coffee grounds resembling sediment in the stomach. PPI therapy was initiated.
An abdominal ultrasound found hepatomegaly, vena portae=11mm. A diagnosis of alcohol-related liver disease was made and corticosteroid therapy was initiated (32mg methylpredinosolone/day). Maddrey’s Discriminant Function was 41.9, and Lille score after 7 days of corticosteroid treatment was 0.021. Steroid therapy was continued, with an increase in serum creatinine levels. A diagnosis of AKI was made, and the patient was started on hemodialysis. Hallucinations started a few days after the initiation of hemodialysis. The differential diagnosis panel included hepatic, uremic, and Wernicke encephalopathies, which were deemed unlikely based on normal serum ammonia levels, unchanged status on hemodialysis, and absence of ataxia, nystagmus and confabulation, respectively. The patient was subsequently transferred to the intensive care unit, where the hallucinations were successfully treated with benzodiazepine therapy. Alcohol withdrawal syndrome was confirmed. A probable diagnosis of pre-renal injury was confirmed, although renal injury could not be ruled out.