Background: Total en bloc spondylectomy (TES) is a lengthy, physically demanding procedure that entails circumferential removal of the affected vertebra, typically performed for selected primary spinal malignancies. Negative chronotropy during spinal surgery has been recognized in very few literature reports, citing possible connection to an apparent spinal cord-brainstem-heart loop that can trigger sudden cardiovascular collapse. We report, to the best of our knowledge, the first TES case that involved sudden supraventricular tachycardia that progressed to hypotension, then pulseless electrical activity within one minute, during closure of surgical site.

Case presentation: A 24-year-old male presented with progressively enlarging mass on the back, accompanied by paraplegia. MR and CT imaging described large mass arising from T12 vertebra that extended to left 11th and 12th ribs, posterior columns of T11 and L1, and paraspinal soft tissues, measuring 8.6 x 10 x 13.9 cm. Core-needle biopsy with immunohistochemical sstudies yieldedundifferentiated pleiomorphic sarcoma, while PET/CT found no evidence of other primary or metastatic lesions. Patient underwent 4 cycles of neoadjuvant chemotherapy (AIM), then preoperative 3-level arterial embolization (T11-L1) 24 hours prior to surgery. Patient subsequently underwent TES with en bloc removal of both T12 vertebral body and paraspinal mass involving left 11th and 12th ribs and posterior columns of T11 to L1, along with thoracotomy, circumferential spinal stabilization, and unilateral chest tube insertion. During skin closure, negative suction tube was connected to surgical site drain, right after which abrupt supraventricular tachycardia occurred that progressed to hypotension, then pulseless electrical activity, within a minute. Cardiopulmonary resuscitation resulted in return of hemodynamic circulation after 2 cycles, and patient recovered with no new-onset neurologic deficits.

Conclusion: The report concludes that cardiovascular collapse during TES, although multifactorial, can possibly be sudden and connected to an apparent spinal cord-brainstem-heart loop triggering negative chronotropy following excessive dural manipulation. The authors recommend vigilance by both surgical and anesthetic teams throughout whole conduct of TES, as mechanical stretching of spinal cord not only occurs during removal of tumor but also when applying negative-pressure surgical site drain.