Recurrent intraoperative asystole induced by tumor manipulation in a cervical vagal schwannoma: a case report

<title>Abstract</title> <bold>Background:</bold> Vagal schwannomas are rare, benign tumors arising from Schwann cells of the vagus nerve. Surgical resection is the mainstay of treatment but carries significant risks, including intraoperative hemodynamic instability due to vagal nerve manipulation and postoperative cranial nerve deficits. <bold>Case presentation:</bold> We report the case of a 37‑year‑old previously healthy male who presented with an incidentally discovered right‑sided cervical mass during a routine health examination. Magnetic resonance imaging revealed a <bold>“string‑of‑beads”</bold> lesion, measuring approximately 6.8 cm in length and 1.0 cm in maximum anteroposterior diameter, located between the right common carotid artery and internal jugular vein, suggestive of a vagal schwannoma. The patient underwent complete microsurgical excision of the tumor. During dissection, manipulation of the tumor elicited <bold>three episodes of complete cardiac asystole</bold> , each lasting approximately 3–4 seconds, with spontaneous recovery upon cessation of traction. No atropine or temporary pacemaker was administered. The tumor was completely resected under microscopic visualization with meticulous hemostasis. Postoperatively, the patient exhibited <bold>no hoarseness, dysphagia, or Horner's syndrome</bold> , and was discharged on postoperative day 4 with an uneventful recovery. Pathological examination confirmed the diagnosis of schwannoma. <bold>Conclusion:</bold> This case highlights that intraoperative cardiac asystole induced by vagal schwannoma manipulation can be managed safely with immediate cessation of traction and close monitoring, even without pharmacological or pacemaker intervention. The absence of neurological deficits postoperatively underscores the importance of meticulous microsurgical technique and the potential value of considering traction‑induced bradycardia as a “physiological neuromonitoring” signal.