Partial Renal Transplant Torsion as a Cause of Abdominal Pain

Allograft torsion is a rare but potentially devastating outcome of renal transplantation. Patients typically present with an acute onset of abdominal pain, though symptoms are non-specific and can easily be missed in favor of more common diagnoses. Imaging, in particular ultrasound and computed tomography, can aid in the diagnosis of renal transplant torsion by demonstrating characteristic features, and once recognized immediate surgery is typically performed in an attempt to salvage the allograft. However, renal transplant torsion needs not be an acute event; patients can instead present with chronic, waxing, and waning symptoms if the allograft undergoes partial or intermittent torsion. The aforementioned characteristic imaging findings may not be present in this situation. It is essential to recognize partial, intermittent torsion as well, for which imaging can again play a role.