More on lumbo-sacral spine surgery and bradycardia

Unexpected Bradycardia Related to Surgical Manipulation During Thoracolumbar Spinal Surgery

BACKGROUND

Although spinal surgery can offer pain relief and functional improvements in daily life, it is often associated with various perioperative complications. The incidence of cardiac complications associated with spinal surgery is relatively low. We evaluated frequency and causes for bradycardia incidents in posterior thorocolumbar spinal surgeries.

METHODS

We retrospectively evaluated posterior thoracolumbar spinal surgeries between 2018-2022 for bradycardic events in our tertiary general hospital. Patients operated for degenerative changes or disk herniations are included, other cases for tumors, trauma, arteriovenous (AV) fistulae or previously operated are excluded.

RESULTS

The study reached 6 eligible patients (4 female and 2 male) aged between 45-75 years (mean: 63.3) among 550 patients operated between 2018-2022. The rate of bradycardia was 1.09%. Of these, 5 patients (lumbar discectomy: one; posterior stabilization:4) exhibited it following L2 and L3 root manipulation and one presented it following L4-5 discectomy. In each of these cases, bradycardia occurred during surgical manipulation and ceased upon removal of the insult. None of the cases exhibited accompanying hypotension. The patient's heart rates were seen to drop to lowest the of 30 beats/min, and all patients exhibited favorable outcomes and no postoperative cardiac complications over a mean follow-up period of 20 months (range: 10-40 months).

CONCLUSIONS

The current study examines the occurrence of unexpected bradycardia events associated with thoracolumbar spinal surgery during surgical handling of the dura mater. Awareness of such incidents among surgeons and anesthesiologists can help prevent catastrophic outcomes caused by adverse cardiac events.

Negative Chronotropic Cardiovascular Changes in Lumbar Spine Surgery: A Potential Spinal-Cardiac Reflex?

Cardiovascular changes following lumbar spine surgery in a prone position are exceedingly rare. Over the past 20 years, a total of six cases have been published where patients experienced varying degrees of bradycardia, hypotension, and asystole, which could be attributed to intraoperative dural manipulation. As such, there is emerging evidence for a potential neural-mediated spinal-cardiac reflex. The authors report their experience of negative chronotropy during an elective lumbar spine surgery that coincided with dural manipulation and review the available literature. A 34-year-old male presented with a long-standing history of lower back pain recently deteriorating to bilaterally radiating leg pain, with restricted left leg raise, and numbness at the left L5 dermatomal territory. The patient was an athletic police officer with no comorbidities or past medical history. Magnetic resonance imaging lumbosacral spine revealed spinal stenosis most pronounced at L4/L5 and disc bulges at L3/L4 and L5/S1. The patient opted for lumbar decompression surgery. After an unremarkable comprehensive preoperative workup, including cardiac evaluation (electrocardiogram, echocardiogram), the patient was induced general anesthesia in a prone position. A lumbar incision was made from L2 to S1. When the left L4 nerve root was retracted while removing the prolapsed disc at L4/L5, the anesthetist cautioned the surgeon of bradycardia (34 beats per minute [bpm]), and the surgery was immediately stopped. The heart rate improved to 60 bpm within 30 seconds. When the root was later retracted again, a second episode of bradycardia occurred for 4 minutes with heart rate declining to 48 bpm. The surgery was stopped, and after 4 minutes, the anesthetist administered 600 µg of atropine. The heart rate then rose to 73 bpm within 1 minute. Other potential causes for bradycardia were excluded. The total blood loss was estimated to be 100 mL. He remains well at his 6-month follow-up and has returned to work as normal. Akin to previously published cases, each episode of bradycardia coincided with dural manipulation, which may indicate a possible reflex between the spinal dura mater and the cardiovascular system. Such a rare adverse event may occur even in seemingly healthy, young individuals, and anesthetists should caution the operating surgeon of bradycardias to exclude operative manipulation of the dura as the cause. While this phenomenon is only reported in a handful of lumbar spine surgery cases, it provides evidence for a potential spinal-cardiac physiological reflex in the lumbar spine that may be neural mediated and should be investigated further.

Acute recurrent bradycardia with evoked potential loss during transforaminal lumbar interbody fusion

During a transforaminal lumbar interbody fusion a patient experienced acute intermittent bradycardia with manipulation of the intervertebral body space, followed by loss of somatosensory evoked potentials that did not recover. Postoperative evaluation revealed new bilateral lower extremity sensory and motor deficits. We postulate an afferent reflex arc to explain this and other reported instances of bradycardia and asystole during transforaminal lumbar interbody fusion surgery. Awareness of the association between bradycardia during lumbar spine surgery may alert anaesthetists, surgeons and neuromonitoring teams to impending neurological harm.

Hemodynamically significant cardiac arrhythmias during general anesthesia for spine surgery: A case series and literature review

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Although multiple factors have been implicated, our case series highlights SSEP stimulation as a common etiology of arrhythmia.

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Significant bradycardia and CA during spine surgery does not always require termination of the surgical procedure.

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Decision making should be undertaken in each case individually based on patient condition and circumstances of each event.

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Surgeons and anesthesiologists should be aware of and prepared to treat significant cardiac arrhythmias during spine surgery even in otherwise healthy patients without known risk factors.

Background context

Hemodynamically significant bradycardia and cardiac arrest (CA) are rare under general anesthesia (GA) for spine surgery. Although patient risks are well defined, emerging data implicate surgical, anesthetic and neurologic factors which should be considered in the immediate management and decision to continue or terminate surgery.

Purpose

To characterize causes and contributors to significant arrhythmias during spine surgery. We also provide an updated literature review to inform spine care teams and aid in the management of intraoperative bradycardia and CA.

Study design

Case series and literature review

Patient sample

Six patients who underwent spine surgery from 03/2016 to 01/2020 at a single institution and developed unexpected hemodynamically significant arrhythmia

Outcome measures

Our primary outcome was to identify potential risk factors of interest for significant arrhythmia during spine surgery.

Methods

Medical records of patients who underwent spine surgery from 03/2016 to 01/2020 at a single institution and developed unexpected hemodynamically significant arrhythmia during spine surgery were identified from a departmental Quality Assurance Database. We evaluated the presence/absence of patient, surgical, anesthetic and neurologic risk factors and estimated the most likely etiology of the event, immediate and subsequent management, whether surgery was postponed or continued and outcomes.

Results

We found a temporal relationship of bradyarrhythmia and CA after somatosensory evoked potential (SSEP) stimulation in 4/6 cases and pharmacy/polypharmacy in 2/6. Surgery was completed in 4/6 patients, and terminated in 2/6 (subsequently completed in both). We found no adverse outcomes in any patients. Our literature review predominately identified case reports for guidance to support decision making. New literaure suggests peripheral nerve blocks and opioid-sparing anesthetic agents should also be considered.

Conclusions

Significant bradycardia and CA during spine surgery does not always require termination of the surgical procedure. Decision making should be undertaken in each case individually, with an updated awareness of potential causes. The study also suggests the need for large prospective studies to adequately assess incidence, risk factors and outcomes.

Cardiovascular Changes and Lumbar Spine Surgery: A Neglected Entity

Cardiovascular changes following lumbar spine surgeries in the prone position have been less commonly described. Here, we report a case of an elderly male patient undergoing lumbar spine decompression and transforaminal interbody fusion who developed multiple but transient episodes of hypotension and bradycardia. Anesthesiologist should be vigilant while monitoring such patients and should use invasive blood pressure monitoring if possible, so as to detect transient cardiovascular episodes which may progress and results in a dreadful outcome.

Cardiac Arrest During Spine Surgery in the Prone Position: Case Report and Review of the Literature

OBJECTIVE

Intraoperative cardiac arrest (CA) is usually attributable to pre-existing disease or intraoperative complications. In rare cases, intraoperative stress can demask certain genetic diseases, such as catecholaminergic polymorphic ventricular tachycardia (CPVT). It is essential that neurosurgeons be aware of the etiologies, risk factors, and initial management of CA during surgery with the patient in the prone position.

METHODS

We present a case of CA directly after spinal fusion for lumbar spondylolisthesis and review the literature on cardiac arrests during spinal neurosurgery in the prone position. We focus on etiologies of CA in patients with structurally normal hearts.

RESULTS

After resuscitation, a 53-years-old female patient achieved return of spontaneous circulation after 17 minutes, without any neurologic deficits and with substantial improvement of functional disability and pain scores. Extensive imaging, stress testing, and genetic screening ruled out common etiologies of CA. In this patient with a structurally normal heart, CPVT was established as the most likely cause. We identified 18 additional cases of CA associated with spinal neurosurgery in the prone position. Most cases occurred during deformity or fusion procedures. Commonly reported etiologies of CA were air embolism, hypovolemia, and dural traction leading to vasovagal response. In patients with structurally normal hearts, inherited arrhythmia syndromes including CPVT, Brugada syndrome, and long QT syndrome should be included in the differential diagnosis and specifically included in testing.

CONCLUSIONS

Although intraoperative CA is rare during spine surgery, neurosurgeons should be aware of the etiologies and the specific difficulties in the management associated with the prone position.

The negative chronotropic effect during lumbar spine surgery: A systemic review and aggregation of an emerging model of spinal cardiac reflex

BACKGROUND

Hemodynamic perturbations in spine surgeries are predominantly reported in cervical and thoracic level procedures. The literature related to negative cardiovascular changes (decrease of heart rate and blood pressure) in lumbar spine procedures is still scarce and only highlighted in few case reports/letters until now.

METHODS

With the help of a systematic literature review with predefined criteria, we, therefore, examined and synthesized here the probable underlying common cause of these hemodynamic disturbances in lumbar spine surgeries. Data aggregation to a model was done by a case survey method and established by a cause-effect relationship.

RESULTS

There are only 5 cases that met our strict predefined criteria and that were aggregated to an emergent model of an autonomous reflex arc.

CONCLUSION

This review and consecutive data aggregation provides, for the first time, a concept of spinal cardiac reflex in lumbar spine surgeries.

Dural Traction a Possible Cause of Hemodynamic Changes During Single-Level Transforaminal Lumbar Interbody Fusion

BACKGROUND

Lumbar spinal surgery may be associated with electrophysiologic and hemodynamic abnormalities during the procedure.

CASE DESCRIPTION

A 58-year-old man with grade II L4-5 spondylolisthesis and degenerative changes underwent single-level transforaminal lumbar interbody fusion. During decompression of the L4 foramina, distraction of the disc space, and placement of the interbody cage and pedicle screws, episodes of extreme bradycardia with up to 5 seconds of asystole were detected on electrocardiogram and invasive hemodynamic monitoring. The events correlated with and possibly could have been a result of traction on the dura mater.

CONCLUSIONS

Anesthesia providers should be aware of electrophysiologic and hemodynamic abnormalities during lumbar spinal surgery and the need to respond appropriately with sympathomimetic or vagolytic interventions.

Perioperative cardiopulmonary complications after cervical spine surgery in the prone position: the relationship between age and preoperative testing

BACKGROUND

Cardiac arrest during spine surgery in the prone position is difficult to manage as poor access makes cardiopulmonary resuscitation and defibrillation difficult. Advanced age is the maximal risk factor for cardiac arrest. Therefore, we wanted to determine the relationship between age and cardiac risk factors/pre-operating tests for cervical spine surgery in the prone position.

METHODS

The inclusion criteria for this study specified 88 patients scheduled should undergo cervical spine surgery in the prone position. The patients were divided into two groups: Paients in group A (50 patients) were aged 69 and under, Group B (38 patients) 70 and above. All patients responded to a medical interview about eight cardiac risk factors including past history, chest symptoms, diabetes mellitus, hypertension, hyperlipidemia, obesity, smoking, and family history. All patients underwent physical examination and 24-h Holter ECG and echocardiography performed by two cardiologists before surgery. We analyzed relationships between cardiac risk factors and ECG/echocardiography and investigated intra- and postoperative cardiovascular complications.

RESULTS

Although there were no significant differences in the number of cardiac risk factors between the two groups, the frequency of hypertension was significantly greater in Group B than in Group A. The frequency of abnormal ECG and echocardiography findings especially was significantly greater in Group B than in Group A. In ECG and echocardiography, three patients in Group B who had no cardiac risk factors before surgery showed abnormal findings, and one of the three patients had the amalgamation of arrhythmia after the operation. Also, in Group B, cardiovascular complications occurred in one case during operation.

CONCLUSION

These results suggested that patients aged 70 and above should undergo ECG and echocardiography examination before cervical spine surgery in the prone position whether they have cardiac risk factors or not . A prospective, randomized multi-center study with a larger patient sample is warranted to ultimately demonstrate how patients should be tested before spine surgery in the prone position.