President Kaiser, Dr. Pairolero, members and guests:
Descending thoracic aneurysms are still a life threatening situation and, although great strides have been achieved due to new surgical techniques, improved spinal cord monitoring, and better post-operative care, morbidity and mortality rates still remain high. Therefore, recent studies investigated the feasibility of endovascular stent graft placement in the descending aorta, a method primarily used in abdominal aortic aneurysms.
So the purpose of our study was to report our clinical experiences and results in endovascular stent graft placement and compare these results with the conventional treatment. If you look at our patients demography, we had a time frame of 8 years where we had 68 patients. Ten (10) patients received an endovascular stent, 58 patients were looked at retrospectively, in terms of same aneurysm extension based on CT andangiograms. They would have been suitable candidates for endovascular stent grafts, however, no stent graft material was available at the time of intervention. Most of the 58 patients were operated on by using profound hypothermic circulatory arrest. Diagnosis was confirmed by CT or MRI. Stent grafts were custom designed for each patient.
If you look on some pre-operative clinical characteristics in both groups, mean age in the conventional group was 62 years; stent patients were slightly over 68 years; male predominant in both groups. The most prevalent clinical characteristic was a history of smoking and hypertension followed by coronary heart disease, previous MI, and renal dysfunction.
If we focus on our 10 stent grafts patients, the youngest one was 41 years; the oldest one in the 70s. Nine of them were atherosclerotic aneurysms. One chronic dissection was performed where the false lumen was already thrombosed at the time of intervention. Pre-operative diameter of the aneurysm was between 6 and 8 cm and mean stent diameter was ranging in the 30s. Mean stent length was between 100 and 120 mm.
Operative technique: spinal cord or general anesthesia; marking of the left subclavian artery and celiac axis. Arterial access was performed by femoral, iliac artery or abdominal aorta. The device was then introduced through the sheath. Shortly before stent deployment, the blood pressure was lowered and the stent deployed. An angio was performed after deployment to confirm the position of the graft or to determine if there was any leakage present.
Here is the stent graft that we used in our series. It's a self-expanding stent graft with a Dacron prosthesis and flanges on each side. The device is introduced into the vascular system through the iliac artery in this picture. It is forwarded to the original aneurysmal site. Proximal stent deployment is achieved at the proximal neck. The sheath is withdrawn and that's how it looks when total stent deployment is achieved and the original site is excluded.
Here, an angio of a patient who had a proximal descending thoracic aneurysm with an aneurysm of the left subclavian artery. First the left subclavian artery was transposed and aneurysm exclusion was successfully achieved with two stent grafts.
If you look at the post-operative characteristics, two patients were operated on by spinal cord anesthesia. The location of the stent access was mostly achieved by the femoral or iliac artery. Transposition of the subclavian artery was performed in five patients and we had some complications: We had one rupture, where the patient died on the ward; two leakage, those patients had to be re-stented to get a total exclusion of the aneurysm sac; and one dissection of the iliac artery in a patient where the access was performed through the femoral artery.
Just briefly giving you some information on the comparison data. As you can see, the length of stent intervention was much shorter, same as the mean length of the ICU and the hospital stay. Furthermore, we could decrease spinal cord injury and operative mortality rate in the stent group.
Contraindication, if there are some: of course, kinking of the vascular access as well as kinking of the aneurysm; short neck, especially on the distal part of the aneurysm. It remains unknown whether patients with an acute or chronic dissection will benefit from this procedure.
Pitfalls: yes, there are pitfalls, especially technical pitfalls in terms of the device, the diameter and handling, the precision of stent deployment and postoperative leakage.
We can conclude in our early experience that endovascular stent graft placement is feasible and aneurysm exclusion can be achieved acutely. It might be an alternative method in selected patients with descending thoracic aneurysm. There is some improvement needed in the device, in terms of diameter, handling and deployment. Further studies need to be done in order to determine long-term effectiveness.
Once again I would like to thank the Society for the privilege of presenting our data.