Purpose or Case Report: Idiopathic thickening of the pyloric muscle can occur in young infants, causing projectile vomiting, electrolyte abnormalities, and necessity for surgical intervention to relieve the gastric outlet obstruction. Case reports have been published describing infants with HPS who also have portal venous gas (PVG) visualized within the liver. The presence of PVG in other clinical scenarios often indicates a severe and potentially life threatening bowel condition. The purpose of this study was to determine the incidence of infants with hypertrophic pyloric stenosis (HPS) and concurrent portal venous gas (PVG), as well as whether there are unique clinical features or different outcomes in the HPS patients with PVG versus without PVG.
Methods & Materials: IRB approval with waiver of consent was granted for this retrospective study. Institutional report search was performed for infant ultrasound reports containing the words “pyloric stenosis”, excluding a negative descriptor. Attending pediatric radiologists reviewed sonographic reports and images to confirm positive diagnosis of HPS and collect imaging data. Imaging data recorded included: length of pylorus, thickness of pylorus, sonographic evaluation of liver, presence of portal venous gas, and whether any additional imaging was performed. Clinical data included demographic information, days of symptomatology, presence of electrolyte abnormality, and length of hospital stay.
Results: Between 11/2010-9/2017, 559 ultrasounds were found to be positive for pyloric stenosis at our institution. 343 studies were deemed to have sufficient hepatic imaging to evaluate for portal venous gas. 6 out of the 343 HPS cases demonstrated PVG (1.8%). Pyloric thickness and length measured 4.4 mm and 18.9 mm respectively in HPS patients without PVG, versus 4.2 mm and 19.9 mm with PVG. Male gender predominance was seen in both groups. Average length of stay for both groups was approximately 2 days, with average length of symptoms and electrolyte abnormalities slightly decreased for the 6 patients with PVG than the group without PVG.
Conclusions: Our retrospective study showed an incidence of PVG in approximately 1.8% of our patient population with HPS. Imaging and clinical characteristics were similar between the HPS patients without and with PVG, suggesting that the presence of portal venous gas does not portend overall worse clinical condition or outcome in HPS patients.