In a patient undergoing repeat cardiac surgery, what peripheral cannulation approach and cannula sizes are recommended?

Peripheral Cannulation for Redo Cardiac Surgery

In redo cardiac surgery, peripheral cannulation via femoral vessels (femoral artery and femoral vein with or without internal jugular vein) before resternotomy is recommended for high-risk patients, but central cannulation after sternotomy should be the default approach when anatomically feasible, as peripheral cannulation is associated with increased long-term mortality. 1

Patient Selection for Peripheral vs. Central Cannulation

The decision to use peripheral cannulation before resternotomy should be based on specific high-risk anatomical and clinical features:

Indications for Peripheral Cannulation Before Resternotomy:

• Close adhesions between sternum and anterior cardiac structures (heart, ascending aorta, or patent bypass grafts) identified on CT imaging 2
• Hemodynamic or electrical instability requiring immediate circulatory support 2
• Severe functional tricuspid regurgitation that may worsen with surgical manipulation 2
• Severely depressed ejection fraction with limited cardiac reserve 2
• History of previous mediastinitis with expected dense adhesions 2
• Emergency situations requiring immediate bypass support (e.g., pulmonary embolectomy) 3

Central Cannulation is Preferred When:

• Lateral chest radiograph and CT imaging show adequate space between sternum and cardiac structures 3
• Patient is hemodynamically stable with adequate cardiac reserve 3
• No history of mediastinitis or severe adhesions expected 3

Recommended Cannulation Technique

Arterial Cannulation:

• Femoral artery cannulation using Seldinger technique is the primary peripheral arterial access site 2, 4
• Axillary artery serves as an alternative when femoral vessels are occluded from prior catheterizations 4, 5
• Abdominal aorta or right common iliac artery can be used when femoral vessels are not available 5
• Systolic blood pressure must be reduced below 100 mmHg before cannulation to minimize dissection risk (0.06-0.23% incidence) 6, 7

Venous Cannulation:

• Dual venous drainage is recommended: common femoral vein (via Seldinger technique) plus right internal jugular vein (percutaneous) 2
• Femoral venous cannula size: 15-18 French for adequate drainage 8
• Internal jugular cannula size: 15-18 French positioned into the SVC 8
• Transesophageal echocardiography should guide cannula positioning 2
• Vacuum-assisted venous drainage improves flow when using peripheral cannulation 8

Cannula Sizing Principles:

Selection must account for patient body surface area, anticipated CPB flow rate (target >2.5 L/min/m²), catheter flow characteristics, and vessel diameter 6, 9

Timing and Anticoagulation Strategy

Standard Approach:

• Peripheral cannulation is performed before sternotomy in selected high-risk patients 2, 4
• Cardiopulmonary bypass time before cardiotomy averages 35 ± 14.7 minutes 2
• Heparin-bonded circuits without systemic heparinization can be used during resternotomy, with full heparinization (200-300 U/kg, ACT >400 seconds) administered only after structures are isolated and before aortic cross-clamping 4

This approach minimizes prolonged anticoagulation, platelet dysfunction, and coagulopathy associated with early full heparinization 4

Critical Safety Considerations

Epiaortic Ultrasonography:

• Should be performed in patients >50-60 years or those with stroke history, peripheral arterial disease, or visible calcifications to detect atherosclerotic plaque before cannulation 6, 7, 9
• Can lead to relocation of cannulation sites in up to 29% of cases 9

Avoiding Femoral Cannulation Pitfalls:

• Retrograde arterial flow from femoral cannulation may worsen cerebral embolic risk in patients with aortic atherosclerosis 6, 7
• The Seldinger technique minimizes vascular trauma and maintains vessel patency 2
• No complications related to femoral cannulation were reported in the largest series (158 patients) 2

Outcomes Data

Short-Term Safety:

• Reentry injuries during resternotomy with peripheral bypass support are manageable: only 1.5% of patients sustained injuries (right ventricle, aorta, bypass grafts) with uneventful repair when bypass was already established 4
• Operative mortality ranges from 5.5-8.8% in redo cases with peripheral cannulation 2, 3
• Average postoperative bleeding is 264 ± 38 mL/m² 2

Long-Term Survival Concern:

After excluding operative mortality, peripheral cannulation is associated with significantly increased long-term mortality (HR 1.53,95% CI: 1.01-2.30, P=0.044) compared to central cannulation 1. This finding suggests that central cannulation should be the preferred approach whenever anatomically safe and feasible, reserving peripheral cannulation for truly high-risk scenarios where reentry injury risk is prohibitive.

Practical Algorithm

1. Preoperative imaging review (CT chest with contrast): Assess sternum-to-cardiac structure distance and identify patent grafts 2, 3
2. Risk stratification: Apply the indications listed above to determine peripheral vs. central approach 2, 3
3. If peripheral cannulation indicated: Perform femoral artery and vein cannulation plus internal jugular vein cannulation using Seldinger technique with TEE guidance 2
4. Initiate bypass before sternotomy in high-risk patients, allowing cardiac decompression and safer dissection 2, 4
5. If central cannulation feasible: Proceed with standard sternotomy and central cannulation after careful dissection 3, 1

Common Pitfalls

• Do not routinely use peripheral cannulation for all redo cases, as it increases long-term mortality without clear short-term benefit in low-risk patients 3, 1
• Do not rely on manual palpation alone to assess aortic atherosclerosis; use epiaortic ultrasonography in appropriate patients 6, 9
• Do not initiate full systemic heparinization before resternotomy when using heparin-bonded circuits, as this increases bleeding without improving safety 4