Cath Lab Digest

Diagnosis of SAA can be easily accomplished with clinical history and physical examination. The advances in duplex scan have enabled clinicians to use noninvasive methods to isolate and identify these aneurysms. CT scanning is also useful, but routine CT scan does not provide sufficient detail for complete diagnosis. Reconstruction techniques using 3-D imaging can be used to demonstrate the entire cervical vasculature allowing visualization of all arteries connecting to the aneurysm.¹⁷ Conventional angiography is the gold standard and has always been mandatory for planning surgical management. This may not completely or always demonstrate the distal subclavian artery in some cases because of contrast medium dilution.¹⁷ MRI/MRA is also useful and transesophageal echocardiogram has also been utilized.¹⁸ A conventional angiogram was not done in this case.

Open surgery is the classic method of therapy for SAA. The surgical approach to the extrathoracic SAA is often feasible through the combined supra- and infraclavicular incisions. In our case, a single supraclavicular approach was successfully used. Right-sided intrathoracic SAA is approached through a median sternotomy, whereas left-sided aneurysms can be approached through a high left posterolateral thoracotomy.

In TOS, removal of a cervical rib or resection of the first rib should be performed prior to the procedure for an aneurysm. The axillary approach is suitable for distal aneurysm. Other neurological structures are preserved along with the thoracic duct. Several authors have successfully described treatment using endovascular techniques.^19,20,21 Others have reported using a combined open and endovascular approach.²² Reports on stent graft treatment of SAA have dealt mostly with pseudoaneurysms in the setting of iatrogenic or penetrating traumatic injuries. The advantages of this procedure include a minimally invasive approach, shortened hospitalization, and cost effectiveness. While this treatment modality is technically feasible, widespread utilization is not employed because of the rarity of the problem and the scarcity of information regarding long-term outcomes of stent grafts in this area.

In the early reports, operations for SAA were limited to simple ligation without revascularization.²³ Repair of these aneurysms has been attempted by several other techniques, which include partial excision of the sac and repair by aneurysmorrhaphy or a patch repair with prosthetic material. Resection of the aneurysm and revascularization is currently the common procedure. Arterial reconstruction options include anatomic reconstruction with interposition graft, primary end-to-end anastomosis, and extra-anatomic reconstruction such as carotid-subclavian transposition or bypass grafting.

Conclusion

A right SAA was successfully repaired using an open technique with a single supraclavicular incision. The ease of recognition, appropriate investigations, and proper surgical technique ensure a good clinical outcome. Although the endovascular approach is becoming more feasible, long-term outcome data are limited and so this must be used with caution and experience.