What is Crawford inclusion reconstructive endoaneurysmorrhaphy?

Crawford Inclusion Reconstructive Endoaneurysmorrhaphy

Crawford inclusion reconstructive endoaneurysmorrhaphy is a specific open surgical technique for thoracoabdominal aortic aneurysm (TAAA) repair where the aneurysmal aortic wall is opened longitudinally, the graft is sewn inside the aneurysm sac, and visceral/renal arteries are reimplanted as buttons or patches into the graft, with the native aneurysm wall then wrapped around the reconstruction.

Surgical Technique and Anatomic Approach

The procedure is performed through a thoracoabdominal incision (typically posterolateral thoracotomy) to access the descending thoracic and abdominal aorta 1. The technique involves:

• Opening the aneurysm sac longitudinally rather than completely excising it, which differs from traditional exclusion techniques 2
• Placing an interposition graft within the opened aneurysm (hence "inclusion" technique) 1
• Reimplanting visceral arteries (celiac, superior mesenteric, and renal arteries) directly into the graft as Carrel patches or individual buttons 1
• Wrapping the native aneurysm wall around the completed reconstruction for hemostasis and structural support 1

Organ Protection During Repair

Critical adjuncts to reduce morbidity include:

• Cold crystalloid renal perfusion is superior to normothermic blood for renal protection during aortic cross-clamping 1
• Partial cardiopulmonary bypass via femoral arterial and venous cannulation provides distal perfusion to visceral organs and lower extremities 3
• Minimizing aortic cross-clamp time is independently associated with reduced operative mortality 4

Crawford Classification and Surgical Risk

The extent of aortic involvement (Crawford classification) significantly impacts outcomes 1:

• Crawford Extent II (most extensive, involving entire descending thoracic and abdominal aorta to bifurcation) carries the highest surgical risk
• Crawford Extent IV (confined below diaphragm) has lower operative mortality of 6.8% in contemporary series 4
• Extent I-III repairs demonstrate 18.4% one-year mortality even with modern techniques 5

Contemporary Outcomes and Complications

Open TAAA repair using inclusion technique demonstrates 1, 4:

• Operative mortality: 6-20% depending on Crawford extent and patient comorbidities
• Spinal cord injury risk requiring careful perfusion management
• Renal failure requiring dialysis: 6% in extent IV repairs 4
• Independent mortality predictors include chronic kidney disease, previous myocardial infarction, urgent/emergency status, and prolonged cross-clamp times 4

Comparison to Alternative Techniques

Exclusion technique (ligating aneurysm without opening, bypassing with separate graft) shows reduced blood loss (703 ml vs 1031 ml) and fewer complications (10.2% vs 23.5%) compared to open endoaneurysmorrhaphy in infrarenal aneurysms 2. However, for complex TAAA requiring visceral reimplantation, the inclusion technique remains necessary 1.

Endovascular and hybrid approaches are increasingly utilized for high-risk patients, though open repair remains the gold standard for suitable candidates 1, 6, 7, 3. Staged hybrid repair (proximal TEVAR followed by distal open repair) demonstrates 0% mortality in selected series of extent I-II TAAAs secondary to chronic dissection 3.

Critical Pitfalls

• Inadequate organ perfusion during cross-clamping leads to renal failure and visceral ischemia 1
• Prolonged cross-clamp times independently predict mortality and must be minimized through efficient technique 4
• Posterior aneurysm location is technically more challenging and associated with higher perioperative mortality (though confounded by more severe heart failure in these patients) 8
• Emergency or ruptured presentation dramatically increases operative mortality compared to elective repair 4