Recent advances in thoraco-abdominal aortic aneurysm repair

Thoraco-abdominal aortic aneurysm repair remains a formidable challenge to vascular surgeons. The traditional repair of thoraco-laparotomy with aortic cross-clamping is associated with a high morbidity and mortality despite significant advances in perioperative critical care, anaesthetic and surgical techniques. The advent of the endovascular revolution has shown a marked paradigm in the approach to all aneurysm repairs. As a logical progression from the open repair, the St Mary's visceral hybrid repair combines traditional open techniques (retrograde visceral and renal revascularisation via mid-line laparotomy) with endovascular stent grafting, thereby avoiding the need for thoracotomy and aortic cross-clamping. In specialist centres, the results have been encouraging and easily comparable to the open repair. The technique has been used in several centres around the world and represents a robust, transferrable method of repairing thoraco-abdominal aortic aneurysms. Stent-grafting technologies have reached a point of sophistication that wholly endovascular methods of repairing thoraco-abdominal aortic aneurysms are being performed in several centres around the world. Although these stent grafts have to be customised to the individual patient and are only suitable for certain types of aneurysmal anatomies, they represent the future of thoraco-abdominal aortic aneurysm repair. We review the history of thoraco-abdominal aortic aneurysm repair, the exciting advances in their treatment and discuss our approach to the management of thoraco-abdominal aortic aneurysms in the 21st century.

Hybrid Open-endovascular Repair for Thoracoabdominal Aortic Aneurysms: Current Status and Level of Evidence

PURPOSE

To report the results of a systematic review of the literature and to provide evidence for the hybrid open-endovascular repair (HOER) in patients with thoracoabdominal aortic aneurysms (TAAAs).

METHODS

A comprehensive literature review was performed and all studies identified that reported the results of HOER in patients with TAAA and information about primary technical and clinical success in evaluating the immediate and long-term complications such as neurological, renal and respiratory morbidity. All studies were reviewed by two independent observers for the above mentioned parameters.

RESULTS

After careful selection according to the given criteria, 13 studies were included in our statistical analysis. The number of reported patients totalled 58. Of those, 37 were men (64.4%) and the mean age of the patients was 68.1 years (range 35-80, 95%CI [72.8, 64.9]). All patients were unfit for open repair with severe comorbidities. The mean follow-up period was 14.5+/-8.7 months (range 4-36, 95%CI [18.7, 9.9]) and the mean aneurysm diameter was 7.15cm (range 5 to 12, 95%CI [7.87, 6.69]). 229 (97.8%) of the 234 visceral vessel grafts remained patent during the follow-up period. Reintervention was necessary in one (1.6%) of the five patients with an occluded graft. The overall long-term endoleak rate was 20.6% (12/58 patients) and the reintervention rate was 13.7% (8/58 patients). No patients developed procedure-related neurological deficits. The overall early and long-term mortality rate for completed procedures was 15.5% (9/58).

CONCLUSIONS

HOER shows promising mid-term results for high-risk patients who have TAAA, however, present evidence does not allow robust conclusions.

Hybrid-procedures for the Treatment of Thoracoabdominal Aortic Aneurysms and Dissections

AIM

The conventional open repair of thoracoabdominal aneurysms and dissections remains complex and demanding and is associated with significant morbidity and mortality. We present our experience of hybrid open and endovascular treatment of thoracoabdominal aneurysms and dissections.

METHODS

Within an experience of 226 aortic stent-grafts between 1998 and April 2006, 6 of the patients (median age 60 years, range 35 to 68 years) with thoracoabdominal aneurysms (Crawford type I, II, III, and V) were treated with a combined endovascular and open surgical approach. Five men and one woman, with median aneurysm diameter of 75 mm (range 70-100 mm), received revascularization of the renal arteries, the superior mesenteric artery, and the coeliac trunk accomplished via transperitoneal bypass grafting. Aneurysmal exclusion was then performed by stent-graft deployment.

RESULTS

The entire procedure was technically successful in all patients. The patients were discharged a median of 9 days after the operation, while the postoperative studies revealed the patency of the vessels and no evidence of type I endoleak or secondary rupture of the aneurysm. During follow up (1 to 22 months) spiral-CT scanning revealed distinct shrinkage of the aneurysm, no graft migration or endoleak and patency of all revascularised vessels, except one renal artery in two patients. No patient experienced any temporary or permanent neurological deficit, and no dialysis was necessary.

CONCLUSION

The combined endovascular and open surgical approach is feasible, without cross clamping of the aorta and with minimized ischemia time for renal and visceral arteries, and seems to be an appropriate strategy for patients with a thoraco-abdominal aortic aneurysm or dissection.

Combining open and endovascular approaches to complex aneurysms

Patients with aortic aneurysms commonly present with anatomic issues that preclude them from receiving purely endovascular repairs. In these situations, open surgical procedures can be used to manage anatomic problems and facilitate endovascular aneurysm repair. This report focuses on combined approaches that enable repair of abdominal or thoracoabdominal aortic aneurysms that involve the mesenteric and/or renal circulation. Current experience with combined open/endovascular repairs is essentially anecdotal. The common feature among the open procedures is establishment of extra-anatomic perfusion of the visceral arteries to enable ligation and subsequent coverage of their ostia during endograft placement. The existing reports are notable for the marked variability in many factors including extent of aneurysm repair, surgical approach, mode of visceral revascularization, conduit for bypass, and type of endovascular device used. Overall, current reports demonstrate that patients with limited physiologic reserve and complex aortic anatomy can be treated successfully by combining open and endovascular repairs. As endograft design and endovascular techniques continue to improve, combined approaches are likely to play an increasingly important role in the treatment of extensive aortic disease.

Repair of thoracoabdominal aortic aneurysms with fenestrated and branched endovascular stent grafts

OBJECTIVE

To report the repair of thoracoabdominal aortic aneurysms (TAAAs) with fenestrated and branched endovascular stent grafts (EVSGs).

METHODS

Four patients with asymptomatic TAAAs were treated with custom-designed Zenith fenestrated and branched EVSGs. Three patients had undergone previous open aortic aneurysm repair. Thirteen visceral vessels in four patients were targeted for incorporation by graft fenestrations and branches.

RESULTS

The fenestration/orifice interface was secured with balloon-expandable Genesis stents or Jostent stent grafts in 9 of 13 target vessels. Completion angiography demonstrated antegrade perfusion in 12 of 13 target vessels. One renal artery occluded because of graft rotation during deployment. There were no endoleaks. Three patients required additional surgical procedures related to access vessels. One patient required reoperation for bleeding from an extra-anatomic bypass graft and subsequently died from multisystem organ failure. Three patients made an uncomplicated recovery. No patient developed spinal cord ischemia. Computed tomography at 12 months in the 3 survivors demonstrated complete aneurysm exclusion with antegrade perfusion in all 10 target vessels.

CONCLUSIONS

TAAA repair with fenestrated and branched EVSGs is feasible and provides an acceptable and promising alternative to conventional surgical repair in selected patients.

Two-Stage Combined Endovascular and Surgical Approach for Recurrent Thoracoabdominal Aortic Aneurysm

PURPOSE

To present a 2-stage combined endovascular and surgical approach for recurrent thoracoabdominal aortic aneurysm (TAAA).

CASE REPORT

A 78-year-old man with previous surgical repairs of infrarenal abdominal and descending thoracic aortic aneurysms was referred for dysphagia due to an enlarging 9-cm aneurysm extending from the mid thoracic to the suprarenal aorta. Because no suitable endograft was available, an open repair was attempted, but the presence of a "frozen" chest made the redo procedure extremely difficult. A 2-stage treatment was thus decided upon. First, a retrograde bifurcated bypass graft was implanted from the abdominal aortic graft to the superior mesenteric and celiac arteries. Twenty days later, the TAAA was successfully excluded with a stent-graft, during which spinal fluid drainage was performed to prevent paraplegia. At 6 months, computed tomography showed patency of the endoprosthesis and visceral grafts. At 1 year, the patient remains asymptomatic.

CONCLUSIONS

This case illustrates that a 2-stage combined endovascular and surgical approach may be a safe and effective alternative to reoperation for recurrent TAAA.

Thoracovisceral segment aneurysm repair after previous infrarenal abdominal aortic aneurysm surgery

OBJECTIVE

Repair of thoracovisceral aortic aneurysms (TVAA) after previous open repair of an infrarenal abdominal aortic aneurysm (AAA) poses significant challenges. We sought to better characterize such recurrent aneurysms and to evaluate their operative outcome.

METHODS

We reviewed the records and radiographs of 49 patients who underwent repair of TVAAs between 1988 and 2002 after previous repair of an AAA. Visceral artery reconstructions were completed with combinations of beveled anastomoses, inclusion patches, and side arm grafts. In 14 patients visceral endarterectomy was required to treat associated occlusive disease. Sixteen patients had cerebrospinal fluid drainage, and 10 patients had distal perfusion during cross-clamping.

RESULTS

Patient mean age was 72 years, and 80% were men. Fifty-one percent of patients had symptomatic disease, and average TVAA diameter was 6.2 cm. Mean time between AAA and TVAA repair was 77 months. Twenty-six percent of aneurysms were restricted to the lower visceral aortic segment, 35% extended to the diaphragm, another 35% extended to the distal or middle thoracic aorta, and 4% involved the entire remaining visceral and thoracic aorta. The 30-day operative mortality rate was 4.1% in patients with nonruptured aneurysms and 50% in patients with ruptured aneurysms, for an overall mortality rate of 8.2%. Fifteen patients (30.6%) had major morbidity, including paresis in two patients and dialysis-dependent renal failure in five patients. At late follow-up, three patients required further aortic operations to treat additional aneurysms, and four patients had fatal aortic ruptures. Two-year and 5-year cumulative survival rates were 61% (+/-7.5%) and 37% (+/-7.8%), respectively. At univariate analysis, operative blood loss was the sole significant predictor of major morbidity (P <.023), and rupture (P <.030, P <.0001) and aneurysm extent (P <.0007, P <.0001) correlated with both operative death and long-term survival. Only aneurysm extent (P <.010, relative risk 37.3) remained a significant predictor of long-term survival at multivariate analysis.

CONCLUSION

Elective repair of TVAAs after previous AAA repair can be performed with an acceptable level of operative mortality, though with considerable operative morbidity. Limited long-term survival mandates careful patient selection, and the high mortality associated with ruptured TVAA underscores the need for post-AAA surveillance.