50th Annual Regional Anesthesiology and Acute Pain Medicine Meeting

Introduction

Neuraxial anesthesia (NA) has historically been considered a relative contraindication for patients with severe aortic stenosis (AS) due to sympathetic block and potential for hypotension.
This precautionary recommendation has not been backed by significant published scientific evidence.
Recent research suggests that NA may be a viable option for severe AS patients, considering individual factors, and a literature review on its use in AS shows no reported cases of cardiovascular collapse or mortality.1,2

Case Presentation

A 76-year-old female with hypertension, severe bicuspid AS, and moderate aortic aneurysm presented for elective left total knee arthroplasty (TKA).

severe AS (peak valve velocity 4.28 m/s, mean gradient 41 mmHg, aortic valve area 0.97 cm², index 0.48 cm²/m²)
preserved left ventricular ejection fraction (67%).

Exercise stress echocardiogram revealed no ischemia or symptomatic angina identified at the achieved heart rate (141 bpm, 92% maximum predicted heart rate).
No significant changes in aortic valve characteristics were noted between anesthetics.

60mg of 2% mepivacaine injected intrathecally at the L3-L4 level
Sedation was maintained with propofol infusion with a native airway and oxygen supplementation via simple mask. Under NA, hemodynamics were supported with ephedrine and phenylephrine boluses and a phenylephrine infusion.
No opioids were required for this procedure.
Adductor canal catheter was placed postoperatively with no complications.
Hemodynamically stable and oxygenated well in PACU.

Discussion

This report directly compares GA and NA for TKA in a single patient with severe AS.
Despite traditional avoidance of NA in AS, this case comparison highlights its potential to enhance hemodynamic stability and minimize opioid use.
General anesthetics carry their own risk of hypotension similar to neuraxial anesthesia.
Hemodynamic parameters (Table 1), including heart rate and mean arterial pressure were more tightly controlled with NA.
AS is not a singular diagnosis but encompasses a spectrum of acuity, requiring individualized anesthetic evaluation.
We suggest NA be included in potential anesthetic choices based on individual patient factors and surgery type.
The use of 2% mepivacaine for spinal anesthesia was well tolerated, something that has not been previously reported.

Conclusion

NA can offer additional hemodynamic stability over GA in a patient with AS undergoing TKA.
Mepivacaine can be used as a spinal anesthetic for select cases and offers an advantage for its relative isobaricity and shorter duration compared to bupivacaine.
Future research should focus on larger patient cohorts to refine best practices for the use of neuraxial anesthesia in severe AS.

DIRECT COMPARISON OF GENERAL ANESTHESIA AND NEURAXIAL ANESTHESIA IN A SINGLE PATIENT WITH SEVERE AORTIC STENOSIS