Neuraxial Blockade in Patients with Significant Aortic Stenosis: A Mini-Review of Literature

1. Abstract 1.1. Background:

Aortic stenosis (AS) is a prevalent and progressive valvular heart disease that poses significant risks during anesthesia, particularly for non-cardiac surgeries. Traditionally, neuraxial anaesthesia has been avoided in these patients due to concerns over hemodynamic instability and potential adverse clinical outcomes. However, recent studies and case studies have explored the feasibility of neuraxial blockade in patients with AS. This review synthesises evidence from key studies to evaluate the safety and efficacy of neuraxial anaesthesia in patients with significant AS, providing a comprehensive overview of current knowledge.

1.2. Methods:

A systematic search of the literature was conducted using the MEDLINE database via the PubMed search engine, employing search terms such as “aortic stenosis”, “neuraxial blockade”, “spinal anaesthesia”, “epidural anesthesia” and “noncardiac surgery”. The search was supplemented by manual reference checks of relevant articles to ensure comprehensive coverage. Studies included in this review range from systematic reviews and guidelines to case studies, each contributing to the understanding of neuraxial anaesthesia in AS patients.

1.3. Results:

The literature search identified no randomised controlled trials specifically examining neuraxial blockade in patients with AS. However, several retrospective studies, systematic reviews, and case studies provide valuable insights. These studies generally report that neuraxial anaesthesia can be safely administered in selected patients with careful peri-operative management. The evidence, while promising, is still limited by the small size and observational nature of most studies.

1.4. Conclusions:

Neuraxial anesthesia, traditionally contraindicated in patients with severe AS, may be a viable option in certain cases when administered with caution. The decision should be based on a comprehensive assessment of the patient’s cardiovascular status and surgical risk, coupled with vigilant intraoperative monitoring. Further large-scale, randomised studies are necessary to establish definitive guidelines and improve peri-operative clinical outcomes.

2. Introduction & Background 2.1. Introduction

Aortic stenosis (AS) is the most common valvular heart disease in the Western world, predominantly affecting older adults. Characterised by a narrowing of the aortic valve, AS leads to progressive obstruction of blood flow from the left ventricle to the aorta, ultimately resulting in left ventricular hypertrophy and decreased cardiac output. The prevalence of AS increases with age, with studies indicating that 2-7% of individuals over 65 years and 7-10% over 80 years suffer from this condition [1]. Given its impact on hemodynamics, AS presents unique challenges during anesthesia, especially for non-cardiac surgeries. The fixed obstruction caused by a stenotic aortic valve makes patients with AS highly sensitive to changes in preload, afterload, and heart rate. Historically, general anesthesia has been preferred for these patients due to the perceived risks of neuraxial blockade, which can lead to abrupt decreases in systemic vascular resistance and precipitate life-threatening hypotension. However, as the population ages and the number of elderly patients requiring surgery increases, the question of whether neuraxial anaesthesia can be safely used in this population has gained renewed interest. Aortic stenosis is a well-recognised risk factor for peri-operative complications, particularly in noncardiac surgery. Kertai et al. emphasised that the risks associated with aortic stenosis are often underestimated, necessitating heightened vigilance and tailored peri-operative management to minimise adverse clinical outcomes in these patients [2].

2.2. Pathophysiology of Aortic Stenosis

The pathophysiology of AS involves progressive calcification and narrowing of the aortic valve, which increases the afterload on the left ventricle. This results in compensatory left ventricular hypertrophy, which allows the heart to maintain stroke volume despite the increased resistance. Over time, however, this hypertrophy leads to diastolic dysfunction and reduced ventricular compliance. The hypertrophied ventricle becomes increasingly reliant on adequate preload and is highly sensitive to decreases in systemic vascular resistance [3]. Further insights into the impact of three-dimensional valve shape on the hemodynamics of AS have been provided by Gilon et al. using threedimensional echocardiographic stereolithography, which highlights the complex flow dynamics in AS patients and emphasises the importance of understanding valve morphology in clinical decision-making [4]. As AS progresses, the aortic valve area decreases, leading to increased transvalvular gradients and reduced cardiac output. The left ventricle becomes increasingly dependent on atrial contraction to maintain enddiastolic volume, making the maintenance of sinus rhythm critical. Any disruption in this delicate balance can lead to ischaemia, reduced cardiac output, and potentially fatal complications [5].

2.3. Hemodynamic Considerations During Neuraxial Blockade

Neuraxial anesthesia, which includes spinal and epidural techniques, induces a sympathetic blockade that results in vasodilation and a decrease in systemic vascular resistance. In patients with significant AS, this can lead to profound hypotension, compromising coronary perfusion and increasing the risk of myocardial ischaemia [6]. The hemodynamic effects of neuraxial blockade are particularly concerning in AS patients because they have a fixed cardiac output and are unable to compensate for sudden drops in blood pressure. Traditionally, these risks have led to the avoidance of neuraxial anaesthesia in AS patients. However, recent advances in monitoring and peri-operative management, as well as a growing body of literature, suggest that with careful patient selection and appropriate intraoperative care, neuraxial blockade may be a feasible option [7].

3. Methods

This review was conducted using a systematic approach to identify relevant literature on neuraxial blockade in patients with aortic stenosis. The primary search was performed using the PubMed database with the following search terms: “aortic stenosis,” “neuraxial blockade,” “spinal anaesthesia,” “epidural anesthesia,” “noncardiac surgery,” and “perioperative management.” The search was limited to studies published in English, French, and German. Additional articles were identified through manual reference checks of key papers and reviews. Inclusion criteria focused on studies and reports that specifically addressed the use of neuraxial anaesthesia in patients with AS. Excluded were articles that did not provide specific data on AS or focused solely on general anesthesia. The final selection included a mixture of systematic reviews, case series, case studies, and expert opinions.

4. Review 4.1. Review of Literature 4.1.1. Echocardiographic Assessment and Risk Stratification

The accurate assessment of AS severity is crucial for peri-operative planning. According to Ring et al. echocardiography is the gold standard for assessing aortic valve area (AVA), mean gradient, and peak aortic jet velocity, all of which are critical for risk stratification [6]. The guideline emphasises the need for thorough preoperative evaluation, which should inform anesthetic planning. Bohbot et al. demonstrated the importance of using peak aortic jet velocity as a predictor of clinical outcomes in patients with severe AS and preserved ejection fraction [5]. This study highlights the need for detailed echocardiographic evaluation to guide anesthetic decisions, particularly in high-risk patients

4.1.2. Neuraxial Blockade in Aortic Stenosis Patients

The traditional contraindication of neuraxial blockade in AS patients has been increasingly challenged. Johansson & Lind conducted a systematic review of central regional anesthesia in AS patients and found that, with careful management, neuraxial techniques could be safely employed [8]. Their review highlighted the need for vigilant intraoperative monitoring and the potential benefits of neuraxial anaesthesia in reducing the risks associated with general anesthesia. Kim et al. reported a successful case of combined spinal-epidural anesthesia in a patient with severe asymptomatic AS undergoing lumbar discectomy [9]. This case underscores the importance of individualised care and careful intraoperative management. Goel et al. examined the use of graded epidural anesthesia in patients with severe AS undergoing noncardiac surgery [7]. Their findings support the feasibility of neuraxial techniques in AS patients, provided that the anesthetic plan is tailored to the patient’s specific cardiovascular status. O’Keefe et al. explored the risks associated with noncardiac surgical procedures in patients with AS and emphasised the importance of understanding patient-specific risks when considering anesthesia options [10]. Similarly, McDonald questioned the absolute contraindication of neuraxial blockade in AS patients, suggesting that with modern techniques and careful monitoring, neuraxial anaesthesia may be reconsidered [11]. Tabrizi et al. provided a more recent systematic review of neuraxial anaesthesia in AS patients, reinforcing the idea that, while neuraxial blockade carries risks, it can be safely administered in selected patients under controlled conditions [12].

5. Discussion

The use of neuraxial anaesthesia in patients with significant AS remains controversial. The risks associated with sympathetic blockade and subsequent hypotension are well-documented, yet recent literature suggests that these risks can be mitigated with careful peri-operative management. The absence of large-scale randomised trials limits the strength of current recommendations, but the accumulating evidence from case studies and smaller studies indicates that neuraxial blockade may be a viable alternative to general anesthesia in select patients. The traditional approach to managing patients with aortic stenosis during labor has often involved the avoidance of neuraxial anaesthesia due to hemodynamic concerns. However, Van de Velde et al. demonstrated the successful use of continuous spinal analgesia in a parturient with aortic stenosis, highlighting that with careful monitoring and individualised care, neuraxial techniques may be feasible in this population [13]. Patient selection is critical, with a thorough preoperative assessment being essential to identify those who may benefit from neuraxial anaesthesia without undue risk. The use of advanced monitoring techniques, such as continuous intra-arterial blood pressure monitoring, is recommended to detect and address hemodynamic instability early. Multidisciplinary collaboration, involving anesthesiologists, cardiologists, and surgeons, is also vital to optimise clinical outcomes.

6. Conclusions

Neuraxial anesthesia in patients with significant AS, though traditionally contraindicated, may be a feasible option in carefully selected cases. The current body of literature, while limited in size and scope, suggests that with appropriate precautions, the benefits of neuraxial blockade may outweigh the risks. However, the need for larger, prospective studies is evident to establish clearer guidelines and improve peri-operative care for this high-risk population.

References

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2. Kertai MD, Bountioukos M, Boersma E, et al. Aortic stenosis: an underestimated risk factor for perioperative complications in patients undergoing noncardiac surgery. Am J Med . 2004, Jan 1;116(1):8-13. 10.1016/j.amjmed.2003.07.012

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5. Bohbot Y, Rusinaru D, Delpierre Q, et al. Risk stratification of severe aortic stenosis with preserved left ventricular ejection fraction using peak aortic jet velocity: an outcome study. Circ Cardiovasc Imaging. 2017, 10:006760. 10.1161/circimaging.117.006760

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7. Goel N, Kumar MG, Barwad P: Noncardiac surgery in two severe aortic stenosis patients: General or epidural anesthesia?. Saudi J Anaesth.. 2018, Apr-Jun; 12(2):367-369. 10.4103/sja.SJA_648_17

8. Johansson S, Lind MN.Central regional anaesthesia in patients with aortic stenosis—a systematic review. Dan Med J. 2017, Sep;64(9):A5407.

9. Kim YS, Park JH, Lee SY, et al. Combined spinal-epidural anesthesia for lumbar discectomy in a patient with asymptomatic severe aortic stenosis: a case report. Korean J Anesthesiol. 2014, Aug; 67(2):129- 132. 10.4097/kjae.2014.67.2.129

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13. Van de Velde M, Budts W, Vandermeersch E: Continuous spinal analgesia for labor pain in a parturient with aortic stenosis. Int J Obstet Anesth. 2003, Jan;12(1):51-4. 10.1016/s0959-289x(02)00163-2

Citation

Peter Nielsen. Neuraxial Blockade in Patients with Significant Aortic Stenosis: A Mini-Review of Literature. Annals of Clinical and Medical Case Reports 2024