Foreign Body Granuloma After Cranial Surgery: A Systematic Review of Reported Cases.

BACKGROUND: In cranial surgery, different foreign body (FB) materials are used and may be left intentionally or unintentionally in the surgical field after closure, inducing a foreign body granuloma (FBG). This is a rare complication in neurosurgery, but it may be a diagnostic dilemma, with sometimes medicolegal implications.

METHODS: We performed a systematic review of the English literature between 1965 and 2018 and found a total of 77 articles concerning 100 cases of FBG caused by retained material located within the cranium or surrounding soft tissues.

RESULTS: There were 60 females and 40 males, with ages ranging from 1 to 77 years. Most initial diagnoses were cranial/intracranial tumors, trigeminal neuralgia, hemifacial spasm, intracranial aneurysm, hydrocephalus, head injury, infectious disease, and nontraumatic intracerebral hematoma. The interval from the causative surgical operation to presentation of the FBG ranged from 2 weeks to 20 years. Various radiologic modalities were used and histologic study confirmed the presence of FBG in all patients. Intentional FB was used and left in 77 patients, and unintentional FB was found postoperatively in 23 patients. Associated infection was found in 13 patients. Complete recovery was seen in 47.6% of patients with sufficient data.

CONCLUSIONS: Despite being unusual, a retained FBG should be considered in the differential diagnosis of any patient after cranial surgery. A history of surgery, clinical symptoms, physical examination findings, laboratory results, and the use of appropriate neuroimaging explorations may provide a correct preoperative diagnosis. In addition, unintentionally retained FBs are preventable errors in the operating room.