Re-examining the classification of abdominal pseudocysts as surgical site infections through review of broad-range polymerase chain reaction results

Background: The Hydrocephalus Clinical Research Network–quality group (HCRNq) historically defined all abdominal pseudocysts associated with a ventriculoperitoneal shunt as a surgical site infection regardless of culture result. Methods: We retrospectively reviewed broad-range polymerase chain reaction (BRPCR) results sent between January 2017 and July 2023 from abdominal pseudocyst fluid sent from hospitals around the country to a reference laboratory to help further characterize these collections. Results: A total of 19 samples were tested via BRPCR between 1/2017 and 7/2023. Two (10.5 %) had organisms identified; one with Staphylococcus epidermidis and one with Candida parapsilosis. No fastidious organisms that would be expected to not grow with typical culture techniques were identified. Conclusions: Few abdominal pseudocysts had organisms identified by BRPCR, suggesting that not all pseudocysts are due to infectious causes. Consideration should be given to alternate causes of pseudocyst development when cultures are negative.