Surgical Conversion After Endovascular Grafting for Abdominal Aortic Aneurysms

Conversion to open repair after endografting for abdominal aortic aneurysm: a review of causes, incidence, results, and surgical techniques of reconstruction

PURPOSE

To review the incidence, causes, and mortality rates of early and late conversion to open surgery after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA).

METHODS

A systematic search of the English-language literature from 2002 to 2009 was performed by interrogation of the PubMed, MEDLINE, and EMBASE databases. Studies were included if they: (1) had >100 patients treated with EVAR and (2) provided adequate data to calculate incidence and associated mortality rates. The search yielded 13 articles with sufficient data to analyze early conversion (12,236 patients, 178 conversions) and 15 articles with available data for late conversion (14,298 patients, 279 conversions).

RESULTS

The rate of early conversion among the 13 articles reviewed ranged from 0.8% to 5.9%; more recent studies carried lower rates of early conversion. Mortality rates of early conversion varied between 0% and 28.5%. Overall, there were 178 (1.5%) early conversions among the 12,236 AAAs treated with EVAR, with an average mortality of 12.4%. The rates of late conversion ranged from 0.4% to 22%. Of the 14,289 AAA patients undergoing endovascular repair, 279 (1.9%) required late conversion; the mortality rate was 10%.

CONCLUSION

Though the incidence is gradually declining, secondary interventions persist as the Achilles' heel of EVAR. A lifelong follow-up strategy for AAA patients treated with EVAR is essential for early detection and treatment of complications of the procedure. Vascular surgeons should be familiar with the complex open conversion procedures.

Late Surgical Conversion After Thoracic Endograft Failure due to Fracture of the Longitudinal Support Wire

PURPOSE

To report complications from a thoracic endograft wire fracture and early experience with elective conversion after thoracic endografting.

CASE REPORT

A 43-year-old man underwent urgent endovascular repair of a symptomatic post-traumatic thoracic aneurysm in 1999. The patient had been involved in a car accident 14 years before. He developed clinical and radiological signs of graft infection 46 months after stent-graft implantation. Multidetector computed tomography confirmed a fracture of the longitudinal support wire in the Excluder thoracic stent-graft. Additionally, radiological signs of suspected endograft infection were described. Due to concerns over a potential chronic infection, the stent-graft was successfully excised, and a polyester graft was implanted 50 months after primary endovascular repair.

CONCLUSIONS

Recognition or strong suspicion of endograft infection requires conversion with removal of the device. Long-term follow-up after endografting is necessary to assess material fatigue that undermines the durability of these implants.

Endovascular treatment of failed prior abdominal aortic aneurysm repair

Failure of endovascular or conventional abdominal aortic aneurysm (AAA) repair may occur as a result of attachment site endoleak (type I) or paraanastomotic aneurysm and pseudoaneurysm formation. This study examined the results of the use of secondary endovascular grafts for the treatment of failed prior infrarenal AAA repair procedures. Forty-seven patients were treated with endovascular grafts. These included 14 patients with type I endoleaks (5 proximal, 8 distal, 1 proximal and distal) and 33 patients with paraanastomotic aneurysms after standard open surgical AAA repair (3 proximal aorta, 5 distal aorta, 21 iliac, 4 proximal and distal). The interval between the primary aortic procedure and the endovascular repair was significantly shorter for failed endovascular procedures (mean, 18.2 months; range, 1-42 months) than for failed conventional procedures (mean, 108.9 months; range, 12-216 months) (p <0.01). The endovascular devices used for correction of the failed AAA repairs were Talent (23), physician-made (19), AneuRx (2), Vanguard (2), and Excluder (1). Transrenal fixation was used for repair of all proximal anastomotic failures. Mean follow-up after reintervention was 12.2 months in patients with failed endovascular grafts and 10.6 months in patients with failed conventional grafts. Patient demographics were as follows: average age, 78 years; 36 male and 11 female; and 4.1 comorbid medical conditions per patient. The endovascular graft was successfully deployed in all 47 cases; 1 patient experienced a persistent proximal attachment site endoleak after endograft deployment. Endovascular grafts may be used to treat previously failed endovascular and conventional AAA repair procedures with good short- and intermediate-term results. Endovascular treatments in these cases may avoid the difficulties of aortic reoperation or AAA repair in the setting of prior endovascular aortic grafting.