Hydrophilic
polymer coating of medical devices serves to lubricate the device and prevent device-related complications. The coating can be mechanically disrupted and result in downstream injury via presumed
thromboembolism. This process has been reported in the brain, heart, lung, and skin, and has been replicated through animal studies and in vitro histologic processing of the
polymer coating. We report the first description of hydrophilic
polymer-associated ischemic
enterocolitis in a series of 7 specimens (small bowel=2, colon=4, aortic
thrombus=1) from 3 patients. We report a 4% incidence among all patients with an ischemic bowel resection between April 29, 2014 and August 8, 2016. All patients developed bowel
ischemia within 1 day of aortic repair, and all bowel resection specimens showed
polymers, mainly in the submucosal vessels in areas of extensive
ischemia. The
polymers appeared as basophilic, intravascular, serpiginous structures. In a patient who developed acute
paralysis after the aortic repair, identical
polymers were identified in the aortic
thrombus and the ischemic bowel segment. We demonstrate that the
polymers display an altered morphology over time and with various graft types, and that the degrading
polymers are associated with a foreign body giant cell reaction. Special stains can aid in diagnosis, with the
polymers turquoise on a colloidal
iron stain, pink on von Kossa and
mucicarmine stains, and pale blue on trichrome. Clinical follow-up was available up
to 115 weeks: 1 patient died, and 2 are alive and well. In summary, we report a new diagnostic entity to be considered in the differential diagnosis of iatrogenic ischemic
injuries in the gastrointestinal tract. Awareness of this entity is important to elucidate the cause of
ischemia and to prevent misdiagnosis of the
polymers and their associated giant cell reaction as a
parasitic infection, granulomatous
vasculitis,
sarcoidosis, and idiopathic
inflammatory bowel disease.