At SITE 2005 Dr Germano Melissano, Chair of Vascular Surgery, San Raffaele University, Milan, Italy, made a presentation discussing the 'Hybrid treatment of thoracoabdominal aortic disease'. He began by stating that the feasibility of endovascular repair for infrarenal and descending thoracic aortic aneurysms have been well documented, even for patients who are at high-risk for open repair. Moreover, an endovascular approach to thoracoabdominal aortic disease is still an investigational procedure, as there are several technical limitations, experience is limited and follow-up is too short to draw any conclusions on the durability of the procedure. He stated that an adequate endovascular technology with fenestrated or side-branched modular endograft systems to save the visceral vessels is not yet easily available. Melissano reported that a hybrid approach to complex aortic disease like arch aneurysm or thoraco abdominal aneurysm (TAAA), open surgery and endovascular grafting may be complementary in order to repair the aorta with reduced invasiveness. He cited seven cases and reported on the outcomes of each.
Melissano claims that hybrid open-endovascular repair for thoracoabdominal pathology is a new attractive investigational procedure, as it takes advantage of both the lower invasiveness of endovascular techniques and the direct surgical control of open technique and may be particularly appealing in selected cases.
From 2001, seven patients at high-risk for open conventional repair, underwent an hybrid treatment of a TAAA. The first four patients treated were unsuitable for conventional open repair due to previous thoracic aortic surgery resulting in frozen chest in one case because of severe chronic respiratory failure and old age. In three cases the aneurysm involved the origin of celiac trunk and superior mesenteric artery and the researchers performed a retrograde revascularisation of visceral vessels from the abdominal aorta or the iliac arteries and endovascular treatment of the aneurysm just above the renal arteries. In one case the aneurysm involved visceral, renal arteries and the infrarenal aorta. As a result, an inferenal aortic open repair was performed with a tube graft (Dacron 34mm) and from this graft the researcher reperfused the visceral and renal vessels with retrograde four vessels bypass (6 and 8mm Dacron grafts). The procedure was completed excluding the thoracoabdominal aneurysm from the left subclavian artery to the surgical graft.
The fifth patient presented with Marfan's syndrome and dissecting Type I TAAA extending from the left subclavian artery to the infrarenal aorta and considered for endovascular repair. Two straight self expandable endogarfts were deployed from the left subclavian artery to the distal proximal thoracic aorta. After one year complete healing of the proximal thoracic aorta was observed, while below the diaphragm, the patient had developed an enlarging dissecting aneurysm sustained by multiple re-entry tears at the level of visceral vessels. As a result a traditional Type IV thoracoabdominal repair was carried out with left heart bypass, cerebrospinal fluid drainage and minimal diaphragm incision. The proximal anastomosis was accomplished at the level of distal thoracic aorta with a transaortic suture line including endograft and aortic wall, whilst a Carrel patch was performed for visceral arteries revascularisation.
The sixth patient presented with previous open repair Type III TAAA, five years after surgery had developed a 7cm aneurysm of the visceral aortic patch associated with atrophy of the left kidney. A retrograde revascularisation of the celiac trunk, superior mesenteric artery and right renal artery from the infrarenal renal aorta was performed followed by endovascular exclusion of the aneurysm with two conic devices from the proximal graft to the intrarenal native aorta.
In the final case, the patient presented with idiopathic retroperitoneal fibrosis, was referred for a contained pararenal aortic rupture. Intraoperative findings revealed chronic inflammatory status of the retroperitoneum associated to a large aortic pseudoaneurysm. A safe proximal aortic clamping site could not be found. A retrograde bypass to the right renal artery was performed, by means of a right laterocolic access. It was discovered that the left renal artery was involved in the fibrosis and haematoma and revascularisation was impossible. The aorta was repaired endoluminally by means of a tube stent deployed immediately below the superior mesenteric artery and covering the renal arteries ostia.
The results showed that technical success was achieved in all cases, with no morbidity related to the open procedure and all stent grafts were patent at post-operative CT scans. There were two in-hospital deaths due to coagulopathy and respiratory failure, with no cases of paraplegia recorded. The mean length of hospital stay was 9.5 days. At a mean follow-up for 14 months there were no aneurysm related deaths, endoleaks, graft migration or visceral revascularisation related morbidly.
Melissano said that the main variables affecting surgical outcome of thoracoabdominal repair were surgical access with thoraco-phreno-laparotomy, proximal aortic cross clamping, extension of the diseased aorta, perioperative haemodynamic changes and organ ischaemia. He also stated that the hybrid approach should not be considered for any patient with TAAA. However, with greater experience and a new generation of endografts, Melissano believes that the hybrid approach will broaden the range of critical patients that may be treated with reduced invasiveness.
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