Anaphylaxis after injecting a hemostatic agent containing gelatin into vertebral bone under pressure-a warning

Case series.

The use of topical hemostatic agents is common in spinal deformity surgery. While beneficial, emerging case data shows gelatin-containing agents causing intra-operative complications. We present two patients who developed anaphylaxis after injection of these gelatin-containing hemostatic agents into the vertebral body using manual pressure. In the literature, while anaphylactic reactions associated with the use of animal-derived gelatin has been implicated; the risk of injecting these products into the closed vascular cavity of the vertebral body with subsequent embolization into systemic circulation bears emphasis. This report is to meant to make the surgical team aware of the risks of injecting hemostatic agents using manual pressure into the vertebral body and to highlight a plausible mechanism for the phenomenon.

Two children with spinal deformity undergoing posterior spinal fusion procedures with the use of gelatin-containing hemostatic agents injected into the vertebral body through the pedicle are described.

Both patients had gelatin-containing hemostatic agent solution injected under manual pressure through the vertebral pedicle to prevent excessive bleeding. Anaphylaxis occurred soon thereafter, resulting in emergent cessation of the surgery and initiation of medical resuscitation. In both cases, tryptase levels obtained just after the event were elevated.

Patients with an allergy to or prior history of exposure to zoologic products undergoing spine surgery may be at risk of anaphylaxis if the gelatin-containing hemostatic agent is injected under manual pressure into the closed space of the vertebral body. This allows rapid entry into the venous circulation. We recommend that the surgeon perform a thorough history of a patient's allergies and use extreme caution when injecting these topical hemostatic products into the vertebral body.

IV.