What is robotic aortic valve replacement, its purpose, and associated care?

Robotic Aortic Valve Replacement (RAVR): Comprehensive Clinical Overview

System Classification

Robotic aortic valve replacement is a cardiovascular surgical procedure utilizing the da Vinci robotic surgical system (Intuitive Surgical) to perform aortic valve replacement through a minimally invasive right lateral thoracotomy approach. 1, 2, 3

• System: Cardiovascular/Cardiac Surgery 1, 2
• Robotic Platform: da Vinci Si or Xi robotic system with 3-4 port configuration 1, 2, 3
• Approach: Right lateral mini-thoracotomy (3-4 cm incision) with 3-port technique 3, 4

Purpose and Clinical Indications

RAVR provides a minimally invasive alternative to traditional surgical aortic valve replacement (SAVR) for patients requiring durable valve replacement who desire to avoid sternotomy, particularly addressing gaps left by transcatheter approaches. 5, 3

Primary Indications:

• Bicuspid aortic stenosis (56% of cases in recent series) where TAVR outcomes remain uncertain 3
• Severe aortic insufficiency (16% of cases) where TAVR is contraindicated 3, 4
• Young patients requiring mechanical valves (32% of cases) for lifelong durability without anticoagulation concerns from TAVR 3
• Patients requiring concomitant procedures (Cox maze, mitral repair, root enlargement) that cannot be addressed transcatheter 3, 4
• Low-risk patients preferring minimally invasive approach over sternotomy 5, 3
• Horizontal valve position making TAVR technically challenging 5

Required Supplies and Equipment

Robotic System Components:

• da Vinci Si or Xi robotic surgical system with patient-side cart 1, 2
• Three robotic ports: 1 endoscopic camera port (8-12mm) and 2 instrument arm ports 1, 2
• 3-4 cm right lateral working incision in 4th intercostal space 3
• Robotic instruments: needle drivers, forceps, scissors 1, 2

Cardiopulmonary Bypass Equipment:

• Peripheral cannulation supplies: femoral arterial and venous cannulas 1, 2
• Transthoracic aortic cross-clamp inserted through 2nd intercostal space stab wound 6
• Cardioplegia delivery system: antegrade cold crystalloid or blood cardioplegia catheter placed in ascending aorta 1, 2
• Vent cannula for placement through right superior pulmonary vein 1
• Vacuum-assisted venous drainage system 6

Valve Prostheses:

• Conventional SAVR prostheses: mechanical or bioprosthetic valves with interrupted braided sutures 3
• Sutureless valves (Perceval S) for facilitated deployment 1
• Valve sizers and deployment instruments 1

Additional Instruments:

• Long scissors for bedside surgeon assistance with calcified valve excision 1
• Decalcification instruments for annular preparation 1
• Defibrillator pads positioned outside operative field 6
• Transesophageal echocardiography (TEE) probe 6

Pre-Procedure Steps

Patient Selection and Evaluation:

• Multidisciplinary Heart Team evaluation involving cardiac surgery, interventional cardiology, imaging specialists, and anesthesia 6, 7
• Comprehensive echocardiographic assessment including valve morphology, annular size, and ventricular function 7
• CT angiography to evaluate chest anatomy, pleural adhesions, and peripheral vascular access 6
• Assessment for contraindications: significant right pleural adhesions, peripheral vascular disease precluding femoral access, porcelain aorta 6

Anesthesia Preparation:

• Dedicated anesthesia team with expertise in TEE and robotic cardiac surgery 6
• Single lung ventilation setup: double lumen endotracheal tube or single lumen with bronchial blocker 6
• Monitoring lines: arterial line, central venous access, pulmonary artery catheter (optional), percutaneous pulmonary artery vent 6

Patient Positioning:

• Supine position with right hemithorax elevated 30 degrees, hips flat 6
• Right arm tucked with shoulder slightly extended, elbow flexed, arm hanging supported below table 6
• Small pillow placed inferior to scapula 6
• Defibrillator pads applied outside operative field with consideration for potential sternotomy conversion 6

Surgical Field Preparation:

• Sterile prep and drape from neck to groin, including entire right chest and both groins for peripheral access 6
• Positioning verification to avoid robotic arm collision with head, endotracheal tube, abdomen, or pelvis 6

Procedure Steps

Phase 1: Access and Cannulation (Time: 30-45 minutes)

1. Peripheral vascular access: femoral artery and vein cannulation for cardiopulmonary bypass 1, 2
2. Port placement:
   • Camera port in medial aspect of 4th intercostal space 6
   • Robotic arm ports in 2nd-3rd intercostal space (anterior axillary line) and 5th-6th intercostal space 6
   • 3-4 cm working incision in 4th intercostal space 3
3. Robot docking: patient-side cart positioned and instruments inserted 1, 2

Phase 2: Cardiopulmonary Bypass Initiation (Time: 15-20 minutes)

1. Vent cannula placement through right superior pulmonary vein 1
2. Cardioplegia cannula insertion in ascending aorta with robotic purse-string suture 1, 2
3. Transthoracic aortic cross-clamp inserted through 2nd intercostal space stab wound, 8-10 cm posterior to left robotic arm 6
4. Cardiopulmonary bypass initiation with mild-moderate hypothermia (28-33°C) 6
5. Cardioplegic arrest following aortic cross-clamping 1, 2

Phase 3: Aortic Valve Exposure (Time: 10-15 minutes)

1. Clam shell aortotomy performed robotically with excellent exposure 1
2. Valve visualization under direct camera view 1, 2

Phase 4: Valvectomy and Annular Preparation (Median: 4 minutes)

1. Native valve excision using robotic instruments 3
2. Calcified cusp removal with assistance from bedside surgeon using long scissors for severely calcified valves 1
3. Annular decalcification to ensure proper prosthesis seating 1
4. Annular sizing to determine appropriate prosthesis size 1

Phase 5: Prosthesis Implantation (Median: 20 minutes for sutures, 31 minutes for aortotomy closure)

1. Interrupted braided sutures placed circumferentially around annulus robotically (for conventional valves) 3
2. Prosthesis parachuting and seating:
   • Conventional valves: sutures passed through sewing ring, valve lowered and tied 3
   • Sutureless valves: 3 guiding sutures placed, Perceval S valve parachuted and deployed 1
3. Valve position confirmation via direct visualization and TEE 1

Phase 6: Closure and De-airing (Time: 30-40 minutes)

1. Aortotomy closure with running polypropylene or polytetrafluoroethylene suture 6, 3
2. De-airing maneuvers: ascending aortic vent, left ventricular vent, Trendelenburg positioning 6
3. Cross-clamp removal after adequate de-airing 2, 3
4. Rhythm management: defibrillation if needed (only after removing robotic instruments and re-expanding lungs) 6

Phase 7: Separation from Bypass and Closure (Time: 20-30 minutes)

1. Weaning from cardiopulmonary bypass with TEE confirmation of valve function 3
2. Decannulation and hemostasis 2
3. Port site inspection for bleeding 6
4. Chest tube placement: 1-2 tubes through robotic arm ports (one high pleural, one pericardial soft drain) 6
5. Port closure with absorbable suture 6

Median procedural times: Total procedure 166-231 minutes, CPB 121-166 minutes, cross-clamp 98-117 minutes 1, 2, 3

Post-Procedure Care

Immediate Post-Operative (0-4 hours):

• Operating room extubation in 84% of patients; remaining 16% extubated within 4 hours 3
• ICU admission with continuous hemodynamic monitoring 3
• TEE or transthoracic echo to confirm valve function and rule out perivalvular leak 3

Early Recovery (4-24 hours):

• Chest tube output monitoring: expect <100 mL/hour initially, decreasing progressively 6
• Hemodynamic stability assessment: maintain adequate preload, avoid excessive vasodilation 6
• Rhythm monitoring: atrial fibrillation occurs in approximately 20% (1 in 5 patients in reported series) 1
• Pain management: multimodal analgesia with reduced opioid requirements compared to sternotomy 5

Hospital Course (1-5 days):

• Chest tube removal when output <200 mL/24 hours and no air leak 6
• Early mobilization facilitated by minimal incision 5, 3
• 30-day echocardiography to document valve function (no valvular or perivalvular abnormalities in reported series) 3
• Anticoagulation initiation for mechanical valves; aspirin for bioprosthetic valves 8

Discharge Planning:

• Typical length of stay: 3-5 days (shorter than traditional sternotomy) 5, 3
• Wound care instructions for small incisions 3
• Activity restrictions: avoid heavy lifting >10 lbs for 6 weeks 5
• Follow-up echocardiography at 30 days, 6 months, and annually 7, 8

Nursing Responsibilities

Pre-Operative:

• Verify informed consent including discussion of potential conversion to sternotomy 6
• Ensure availability of conversion equipment: sternotomy tray immediately accessible 6
• Coordinate with perfusion team for peripheral cannulation setup 6
• Position patient according to protocol with pressure point padding 6

Intra-Operative:

• Assist with robotic system setup and port placement 1, 2
• Monitor for robotic arm conflicts with patient anatomy or external equipment 6
• Maintain sterile field around working incision and port sites 6
• Communicate with surgical team regarding suture management and instrument needs 6
• Prepare for potential emergencies: rapid conversion to sternotomy, bleeding control 6

Post-Operative:

• Continuous hemodynamic monitoring: arterial pressure, central venous pressure, cardiac output 6
• Chest tube assessment: output volume, character, air leak 6
• Respiratory support: incentive spirometry, early mobilization to prevent pneumonia 1
• Pain assessment and management: multimodal analgesia protocol 5
• Cardiac rhythm monitoring: detect and manage atrial fibrillation 1
• Anticoagulation management for mechanical valves (INR goal 2.5-3.5) 8
• Wound assessment: monitor port sites and working incision for infection or bleeding 6

Normal Parameters

Hemodynamic:

• Mean arterial pressure: 65-90 mmHg 6
• Central venous pressure: 8-12 mmHg 6
• Cardiac index: >2.2 L/min/m² 6
• Heart rate: 60-100 bpm (may require temporary pacing) 6

Valve Function (Post-Operative Echo):

• Peak gradient: <20 mmHg for appropriately sized prosthesis 7
• Mean gradient: <10 mmHg 7
• No perivalvular leak or trace only 3
• Normal leaflet/disc motion 3

Laboratory:

• Hemoglobin: >8 g/dL (transfusion threshold) 6
• INR: 2.5-3.5 for mechanical valves (once therapeutic) 8
• Creatinine: return to baseline within 48-72 hours 6

Chest Tube Output:

• First 4 hours: <100 mL/hour 6
• 24 hours: <200 mL total 6
• Character: serosanguinous, not bright red 6

Alarms and Troubleshooting

Intra-Operative Complications:

Robotic System Malfunction:

• Alarm: Loss of instrument control, system error messages 6
• Action: Immediately undock robot, convert to direct visualization through working incision or sternotomy 6

Inadequate Exposure:

• Problem: Cannot visualize valve adequately 1
• Action: Reposition camera, adjust retraction, consider enlarging working incision 6, 1

Severe Annular Calcification:

• Problem: Difficulty with decalcification using robotic instruments 1
• Action: Bedside surgeon assists with long instruments through working incision 1

Bleeding from Aortotomy:

• Alarm: Excessive bleeding obscuring field 6
• Action: Increase suction, verify cross-clamp position, consider additional sutures, prepare for conversion 6

Endoaortic Balloon Migration:

• Problem: Balloon migrates distally (obstructs arch vessels) or proximally (impairs exposure) 6
• Action: Reposition under TEE guidance, consider conversion to transthoracic clamp 6

Inadequate Venous Drainage:

• Problem: Right heart distention, poor myocardial protection 6
• Action: Increase vacuum-assisted drainage, verify cannula position, consider bicaval cannulation 6

Post-Operative Complications:

Excessive Chest Tube Output (>100 mL/hour):

• Action: Check coagulation parameters, consider re-exploration if >200 mL/hour for 2 consecutive hours 6
• Escalation threshold: Hemodynamic instability, >500 mL in first hour 6

Hemodynamic Instability:

• Hypotension with low filling pressures: Volume resuscitation, rule out bleeding 6
• Hypotension with high filling pressures: Inotropic support, rule out tamponade 6
• Action: Urgent echocardiography to assess valve function and pericardial effusion 6

New Murmur or Abnormal Echo:

• Problem: Perivalvular leak, prosthetic dysfunction 3
• Action: Immediate cardiology consultation, consider re-exploration if severe 3

Atrial Fibrillation:

• Incidence: ~20% of patients 1
• Action: Rate control, anticoagulation, consider cardioversion if hemodynamically unstable 1

Pneumonia:

• Risk factor: Single lung ventilation, elderly patients 1, 2
• Action: Aggressive pulmonary toilet, early mobilization, antibiotics if indicated 1

Red Flags and Escalation Criteria

Immediate Surgical Re-Exploration Required:

• Cardiac tamponade: hypotension, elevated CVP, equalization of pressures, echo confirmation 6
• Massive bleeding: chest tube output >500 mL in first hour or >200 mL/hour for 2+ hours 6
• Acute prosthetic valve dysfunction: severe perivalvular leak, leaflet/disc immobility 3
• Acute myocardial ischemia: ST elevation, new wall motion abnormalities suggesting coronary ostial obstruction 6

Urgent Cardiology/Cardiac Surgery Consultation:

• New stroke symptoms: focal neurological deficits (stroke rate 0% in recent series but remains risk) 6, 3
• Hemodynamic instability not responding to initial resuscitation 6
• New significant perivalvular leak on echocardiography 3
• Prosthetic valve endocarditis: fever, positive blood cultures, new murmur 8

Conversion to Sternotomy (Intra-Operative):

• Unexpected right chest adhesions preventing safe dissection 6
• Inability to achieve adequate exposure of aortic valve 6, 1
• Uncontrolled bleeding from aorta or cardiac structures 6
• Aortic dissection during cannulation or clamping 6
• Inability to wean from cardiopulmonary bypass requiring mechanical support 6
• Robotic system failure that cannot be immediately resolved 6

Critical Monitoring Thresholds:

• STS-PROM >8%: High-risk patients require intensive monitoring 6, 7
• LVEF <40%: Increased risk of post-operative heart failure 6
• Frailty indicators: Prolonged recovery, increased complication risk 6

Documentation Requirements

Pre-Operative:

• Heart Team consensus on RAVR as optimal approach 6, 7
• Informed consent including risks of conversion to sternotomy, stroke, bleeding, valve dysfunction 6
• STS-PROM score and risk stratification 6, 7
• Echocardiographic measurements: valve area, gradients, LVEF, annular size 7
• CT findings: chest anatomy, vascular access suitability 6

Intra-Operative:

• Procedural times: total procedure, CPB, cross-clamp, valvectomy, suturing, closure 1, 2, 3
• Valve details: type (mechanical vs. bioprosthetic), size, manufacturer, lot number 3
• Complications: bleeding, conversion, technical difficulties 6, 1
• Concomitant procedures: Cox maze, root enlargement, mitral repair 3, 4
• De-airing maneuvers performed 6
• TEE findings: valve function, perivalvular leak assessment 3

Post-Operative:

• 30-day echocardiography: valve gradients, perivalvular leak, ventricular function 3
• Complications: mortality, stroke, bleeding requiring re-exploration, pneumonia, atrial fibrillation, pacemaker requirement 6, 1, 3
• Length of stay and discharge disposition 5, 3
• Anticoagulation plan for mechanical valves 8
• Follow-up schedule: 30 days, 6 months, annually with echocardiography 7, 8

Registry Reporting:

• STS Database submission for all SAVR procedures including RAVR 6
• Device-specific registry participation if required by manufacturer 6
• Outcomes tracking: mortality, stroke, valve dysfunction, reoperation rates 6, 3