What are the peri‑operative risks and management considerations for a patient with moderate aortic regurgitation and mild pulmonary hypertension undergoing video‑assisted thoracoscopic surgery (VATS)?

Perioperative Risk and Management for Moderate AR with Mild PH Undergoing VATS

This patient can proceed with VATS surgery with appropriate perioperative optimization and monitoring, but faces significantly elevated risks of intraoperative hypotension (46% vs 35%) and myocardial injury (20% vs 12%) that require specialized hemodynamic management.

Risk Stratification

Your patient falls into a high-risk category based on two independent risk factors:

Moderate Aortic Regurgitation

• While moderate AR alone doesn't mandate valve intervention before noncardiac surgery 1, it creates hemodynamic vulnerability during the perioperative period
• The regurgitant lesion requires maintenance of forward flow and avoidance of bradycardia or excessive afterload 2

Mild Pulmonary Hypertension

• Even mild PH substantially increases perioperative risk during thoracoscopic surgery 3
• Recent data from 3,579 thoracoscopic lobectomy patients showed mildly elevated pulmonary artery systolic pressure (PASP) increased:
  • Intraoperative hypotension: 46.4% vs 35.2% (OR 1.525)
  • Myocardial injury after noncardiac surgery (MINS): 20.4% vs 12.4% (OR 1.803)
  • Both short (<15 min) and prolonged (≥15 min) hypotensive episodes occurred more frequently 3

The combination of AR and PH creates a particularly challenging hemodynamic scenario - the AR demands maintenance of forward flow while the PH limits the right ventricle's ability to accommodate changes in preload or afterload 4.

Preoperative Optimization

Mandatory Assessments

• Confirm AR severity and LV function with quantitative echocardiography - ensure LVEF >55%, LVESD index <25 mm/m², and no symptoms 1
• Document baseline PASP and right ventricular function - even mild PH warrants careful evaluation 5
• Assess functional capacity - symptom status is the key determinant of perioperative risk 1, 2

Consultation Requirements

Referral to or consultation with a specialized PH center is reasonable for patients with PH undergoing elevated-risk noncardiac surgery 5. VATS qualifies as elevated-risk given the thoracic nature, one-lung ventilation requirements, and your patient's dual pathology.

Medical Optimization

• Continue all baseline cardiac medications through the perioperative period
• If the patient is on PAH-targeted therapies, continuation is mandatory to reduce perioperative morbidity and mortality 5
• Optimize volume status carefully - avoid hypovolemia (worsens forward flow in AR) but also avoid volume overload (increases RV afterload in PH)

Intraoperative Management

Hemodynamic Goals - The Balancing Act

For the Aortic Regurgitation:

• Avoid bradycardia (target HR 80-100 bpm to maintain forward flow)
• Avoid excessive increases in afterload (worsens regurgitant fraction)
• Maintain adequate preload without volume overload
• Prevent acute increases in systemic vascular resistance 2

For the Pulmonary Hypertension:

• Prevent systemic hypotension at all costs (risk of RV ischemia) 4
• Prevent acute elevations in pulmonary artery pressure (risk of RV failure) 4
• Maintain adequate RV preload
• Avoid factors that increase PVR: hypoxia, hypercarbia, acidosis, hypothermia, pain, high airway pressures 6, 4

Monitoring Strategy

Invasive hemodynamic monitoring is reasonable in patients with severe PH undergoing elevated-risk noncardiac surgery 5. For your patient with mild PH and moderate AR:

• Arterial line: Mandatory for beat-to-beat blood pressure monitoring
• Central venous pressure monitoring: Consider for assessment of RV function and volume status
• Pulmonary artery catheter: May be reasonable given the dual pathology, though not absolutely required for mild PH 5
• Transesophageal echocardiography availability: Should be immediately accessible for hemodynamic instability 5

Anesthetic Technique

• Regional anesthesia with sedation is preferable when feasible 7, but VATS typically requires general anesthesia with one-lung ventilation
• Use anesthetic agents that preserve hemodynamic stability
• Avoid agents that cause significant myocardial depression or vasodilation
• Epidural analgesia can be beneficial for postoperative pain control and reducing sympathetic surge 7

Ventilation Strategy During One-Lung Ventilation

• Use lung-protective ventilation (tidal volumes 4-6 mL/kg predicted body weight)
• Minimize peak airway pressures to avoid increasing PVR
• Maintain normocapnia (hypercarbia increases PVR)
• Optimize oxygenation (hypoxia dramatically increases PVR)
• Consider recruitment maneuvers cautiously

Pharmacologic Management

If Hypotension Develops:

• First-line: Restore intravascular volume if hypovolemic
• Vasopressors of choice: Norepinephrine or vasopressin to maintain systemic pressure without significantly increasing PVR
• Avoid pure alpha-agonists in isolation if possible (increase afterload, worsen AR)
• Phenylephrine: Use cautiously - increases systemic afterload which worsens AR but may be necessary for RV perfusion

If RV Dysfunction or Acute PH Crisis:

• Inhaled pulmonary vasodilators may be reasonable: Inhaled nitric oxide or aerosolized prostacyclins to reduce RV afterload 5
• Inotropic support: Dobutamine or milrinone if RV failure develops (use cautiously as they cause systemic vasodilation)

Postoperative Management

Critical Care Considerations

Consideration of intensive care after noncardiac surgery is reasonable for patients with severe PH 5. For your patient with mild PH and moderate AR, ICU admission should be strongly considered given:

• The documented 20% risk of MINS in patients with mild PH undergoing thoracoscopic surgery 3
• Need for continued invasive monitoring
• Requirement for aggressive pain control to prevent PVR increases
• Risk of postoperative atrial fibrillation (catastrophic in AR with PH)

Monitoring Duration

• Continuous telemetry for 48-72 hours minimum
• Serial troponin measurements - elevated troponin occurred in 20% of similar patients 3
• Monitor for signs of RV failure: elevated JVP, peripheral edema, hypotension
• Watch for arrhythmias, particularly atrial fibrillation

Key Postoperative Interventions

• Aggressive multimodal analgesia to prevent pain-induced PVR increases
• Early mobilization while maintaining hemodynamic stability
• Supplemental oxygen to prevent hypoxic pulmonary vasoconstriction
• Avoid fluid overload but maintain adequate preload
• Continue all home cardiac medications without interruption

Common Pitfalls to Avoid

1. Underestimating the impact of "mild" PH - Recent evidence shows even mild PH significantly increases risk in thoracoscopic surgery 3

2. Aggressive fluid restriction - While you want to avoid RV volume overload, inadequate preload worsens both the AR (reduces forward flow) and RV function

3. Allowing intraoperative hypotension to persist - Even brief episodes increase MINS risk; maintain aggressive BP management 3

4. Using pure alpha-agonists reflexively - While needed for RV perfusion pressure, they increase afterload and worsen AR regurgitant fraction

5. Inadequate pain control postoperatively - Pain, anxiety, and sympathetic surge all increase PVR and can precipitate RV failure 4

6. Premature discontinuation of monitoring - The highest risk period extends 48-72 hours postoperatively when troponin elevation and complications manifest 3

Outcome Expectations

Based on the most recent evidence, your patient faces:

• 46% probability of intraoperative hypotension (vs 35% baseline) 3
• 20% probability of myocardial injury (vs 12% baseline) 3
• Increased risk of postoperative pulmonary complications
• Potential for new-onset atrial fibrillation

However, with appropriate perioperative management by an experienced team, successful outcomes are achievable 7. The key is meticulous attention to the hemodynamic principles outlined above and maintaining a low threshold for escalation of monitoring and intervention.