Side-branched modular endograft system for thoracoabdominal aortic aneurysm repair

Thoracic Stent Grafts with a Distal Fenestration for the Celiac Axis

Descending thoracic aneurysms can be treated with a stent graft provided that there is sufficient proximal and distal aortic neck length above the celiac axis. One of the options for the treatment of thoracic aneurysms with a too short distal neck is described in this report. For this purpose, a stent graft was constructed with a scallop for the celiac axis. Three cases are presented, and the technical details are described.

Comparison of Blood Flow in Branched and Fenestrated Stent-Grafts for Endovascular Repair of Abdominal Aortic Aneurysms

Purpose: To report a computational study assessing the hemodynamic outcomes of branched stent-grafts (BSGs) for different anatomic variations. Methods: Idealized models of BSGs and fenestrated stent-grafts (FSGs) were constructed with different visceral takeoff angles (ToA) and lateral aortic neck angles. ToA was defined as the angle between the centerlines of the main stent-graft and side branch, with 90° representing normal alignment, and 30° and 120° representing angulated side branches. Computational simulations were performed by solving the conservation equations governing the blood flow under physiologically realistic conditions. Results: The largest renal flow recirculation zones (FRZs) were observed in FSGs at a ToA of 30°, and the smallest FRZ was also found in FSGs (at a ToA of 120°). For straight-neck stent-grafts with a ToA of 90°, mean flow in each renal artery was 0.54, 0.46, and 0.62 L/min in antegrade BSGs, retrograde BSGs, and FSGs, respectively. For angulated stent-grafts, the corresponding values were 0.53, 0.48, and 0.63 L/min. All straight-neck stent-grafts experienced equal cycle-averaged displacement forces of 1.25, 1.69, and 1.95 N at ToAs of 30°, 90°, and 120°, respectively. Angulated main stent-grafts experienced an equal cycle-averaged displacement force of 3.6 N. Conclusion: The blood flow rate in renal arteries depends on the configuration of the stent-graft, with an FSG giving maximum renal flow and a retrograde BSG resulting in minimum renal flow. Nevertheless, the difference was small, up to 0.09 L/min. Displacement forces exerted on stent-grafts are very sensitive to lateral neck angle but not on the configuration of the stent-graft.

Thoracic stent graft with distal fenestration for the superior mesenteric artery for treatment of thoracic aortic aneurysm

An 86-year-old man with a 75-mm TAA that terminated just above the celiac artery was treated with a customized Zenith stent graft that had a distal fenestration for the superior mesenteric artery (SMA). Because angiography demonstrated a type IB endoleak, an additional extension stent graft was deployed, and coil embolization of the aneurysmal sac was performed. Three months later, there was no endoleak and good visceral blood flow. Placement of a fenestrated thoracic stent graft with a scallop-like fenestration for the SMA is a promising procedure for the treatment of TAAs with a short distal neck.

The Risks of Celiac Artery Coverage During Endoluminal Repair of Thoracic and Thoracoabdominal Aortic Aneurysms

The risks of purposeful celiac artery coverage during endovascular thoracic aortic aneurysm repair (TEVAR) to obtain an adequate distal landing zone have received scant scientific attention. Patients undergoing TEVAR at 6 tertiary centers from January 2000 to June 2007 were identified (n = 434); cases requiring celiac artery exclusion (n = 19; 4.4% of the total) were analyzed. The mean follow-up was 8.7 months (range, 0.2-21.2). The mean patients' age was 73.6 years (range, 56-86); 57.9% were men. The mean aneurysm diameter was 6.7 cm (range, 5-8.6). In 2 patients, the celiac artery balloon occlusion test was performed prior to TEVAR. In both, intact collateral foregut circulation was seen. Both underwent TEVAR without celiac artery revascularization; 1 did well, whereas the other developed foregut ischemia. In 16 cases (84.2%), the celiac artery was not revascularized prior to TEVAR. In those patients, 19 complications were reported (3 deaths; 2 paraplegia). No similar events occurred in those who underwent celiac artery revascularization (n = 3). Celiac artery coverage during TEVAR is required in 4.4% of cases. TEVAR correlated with a nonnegligible number of major complications. Complications were more frequent and severe in patients who did not have celiac artery revascularization prior to TEVAR. Specific celiac artery coverage complications are rare and not readily predictable based on preprocedure arteriography.

Hybrid procedures for thoracoabdominal aortic aneurysms and chronic aortic dissections - a single center experience in 28 patients

OBJECTIVE

We report our 6-year experience with the visceral hybrid procedure for high-risk patients with thoracoabdominal aortic aneurysms (TAAA) and chronic expanding aortic dissections (CEAD).

METHODS

Hybrid procedure includes debranching of the visceral and renal arteries followed by endovascular exclusion of the aneurysm. A series of 28 patients (20 male, mean age 66 years) were treated between January 2001 and July 2007. Sixteen patients had TAAAs type I-III, one type IV, four thoracoabdominal placque ruptures, and seven patients CEAD. Patients were treated for asymptomatic, symptomatic, and ruptured aortic pathologies in 20, and 4 patients, respectively. Two patients had Marfan's syndrome; 61% had previous infrarenal aortic surgery. The infrarenal aorta was the distal landing zone in 70%. In elective cases, simultaneous approach (n = 9, group I) and staged approach (n = 11, group II) were performed. Mean follow-up is 22 months (range 0.1-78).

RESULTS

Primary technical success was achieved in 89%. All stent grafts were implanted in the entire thoracoabdominal aorta. Additionally, three patients had previous complete arch vessel revascularization. Left subclavian artery was intentionally covered in three patients (11%). Thirty-day mortality rate was 14.3% (4/28). One patient had a rupture before the staged endovascular procedure and died. Overall survival rate at 3 years was 70%, in group I 80%, and in group II 60% (P = .234). Type I endoleak rate was 8%. Permanent paraplegia rate was 11%. Three patients required long-term dialysis (11%). Peripheral graft occlusion rate was 11% at 30 days. Gut infarction with consecutive bowel resection occurred in two patients. There was no significant difference between group I and II regarding paraplegia and complications.

CONCLUSIONS

Early results of visceral hybrid repair for high-risk patients with complex and extended TAAAs and CEADs are encouraging in a selected group of high risk patients in whom open repair is hazardous and branched endografts are not yet optional.

Wholly endovascular repair of thoracoabdominal aneurysm

Background

The aim was to evaluate a wholly endovascular approach to the repair of thoracoabdominal aortic aneurysm (TAAA).

Methods

Six patients (median age 71 years) underwent wholly endovascular repair of TAAA (maximum diameter 56–85 mm) employing individually customized endografts. Procedures were performed under general anaesthesia, with spinal drainage in five patients. Patients were followed by serial computed tomography, plain radiography and duplex imaging for a median of 17 (range 8–44) months.

Results

All grafts were deployed as intended, with preservation of all target vessels. There were no postoperative deaths, strokes or paraplegia. One patient suffered a silent myocardial infarction. In two patients a persistent paraostial endoleak was treated by further balloon dilatation of the stent within the endograft fenestration. Imaging before discharge confirmed aneurysm exclusion in all patients. Two patients required late secondary intervention to abolish endoleaks due to side-branch disconnection. One patient suffered late occlusion of the coeliac axis without clinical sequelae, and late occlusion of a solitary renal artery in another resulted in dependence on dialysis. There have been no late deaths and all aneurysms remain excluded.

Conclusion

Wholly endovascular TAAA repair is relatively safe, but long-term follow-up is required to establish its durability.

Anatomic exclusion from endovascular repair of thoracic aortic aneurysm

OBJECTIVES

We sought to define the current anatomic barriers to thoracic aortic aneurysm (TAA) stent grafting to guide future device development.

METHODS

All patients presenting with TAA requiring repair were evaluated for endovascular repair during a 4-year period (2000 to 2004). The TAAs evaluated were those beginning distal to the left common carotid artery (LCCA) and ending proximal to the celiac artery. All patients in whom endovascular repair was indicated underwent cross-sectional imaging by computed tomography angiography and three-dimensional modeling of their thoracic and abdominal arterial anatomy. Patients were evaluated for endovascular TAA repair in the context of the inclusion/exclusion criteria of pivotal United States Food and Drug Administration trials of the Gore TAG and Medtronic Talent devices. Anatomic requirements included >or=20 mm of suitable proximal and distal neck length, and proximal and distal neck diameters of 20 to 42 mm. These trials allowed the use of femoral or iliac access, including the use of conduits, and permitted stent graft coverage of the left subclavian artery (LSA) after preliminary carotid-subclavian bypass. Patients rejected for medical reasons or who died during evaluation were not included in the review.

RESULTS

A total of 126 patients (73 men, 53 women) with TAA located between the LCCA and celiac artery were screened for endovascular repair, and 33 (26%) were rejected for anatomic reasons. The remaining 93 patients underwent endografting (59 Talent, 34 TAG). Rejection was not significantly different by gender (16/73 men, 17/53 women, P = .22, NS). Most patients (28/33) were rejected for more than one criterion. Hostile proximal neck characteristics were the most prevalent reason for disqualification, despite the ability to cover the LSA to extend the proximal seal zone. Many of these patients (16/28) also had distal neck anatomy unsuitable for grafting. Overall, 19 patients had hostile distal necks. Difficulties with vascular access (diseased or tortuous iliac arteries, or a small caliber aorta) that could not be overcome even by use of conduits occurred in a significant fraction of patients (10/33).

CONCLUSIONS

Most patients with a TAA located between the LCCA and the celiac artery can be treated by endovascular repair. Patients excluded from TAA stent graft protocols for anatomic reasons most commonly have hostile proximal neck features that preclude endovascular repair with currently available devices. Transposition of arch vessels to facilitate greater use of existing stent grafts or development of new stent graft designs are needed to expand the applicability of TAA endovascular repair.

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.

Successful endovascular repair of an aneurysm of the ductus diverticulum with a branched stent graft: Case report and review of literature

Aneurysm of the ductus diverticulum rarely has been reported in adults, and the reported aneurysms were treated with conventional open surgery or were diagnosed at autopsy. We report a successful endovascular repair of an aneurysm of the ductus diverticulum with the Inoue branched stent graft. In a 78-year-old woman, an abnormal shadow was noted at the aortopulmonary window on a chest x-ray film. A computed tomography scan demonstrated a 3.8-cm saccular aneurysm, which protruded inferiorly from the distal end of the aortic arch. The aneurysm was considered an aneurysm of the ductus diverticulum, and surgery was required. However, the patient was considered at high risk for respiratory dysfunction with conventional open surgery. Endovascular repair with an Inoue single-branched stent graft was performed with the patient under local anesthesia, successfully and without complication or endoleak. To our knowledge, this is the first report of endovascular treatment of an aneurysm of the ductus diverticulum.

Ten years experience of thoracic and thoracoabdominal aortic aneurysm surgical repair: lessons learned

In the last few years, advances in surgical techniques and in organ protection adjuncts have improved outcomes in thoracic (TAA) and thoracoabdominal aortic aneurysm (TAAA) surgical repair, although mortality and morbidity are still noteworthy. The aim of the current retrospective study is to determine whether the use of adjuncts influenced mortality and morbidity rates. From 1993 to 2003 we performed 353 procedures for TAA (175 cases) and TAAA (178 cases). This series has been divided into two consecutive groups: in group I (from 1993 to 1997), distal aortic perfusion with left atriofemoral bypass and cerebrospinal fluid drainage were used selectively, and in group II (from 1998 to 2003), the adjuncts were used routinely (together with surgical techniques of less invasive approach in selected cases). Total in-hospital mortality rates were significantly different ( p < 0.05): 15.9% in group I and 8.6% in group II. The overall incidence of paraplegia or paraparesis in group I was 8.3% and in Group II it was 5.1%. Renal failure occurred in 9.6% of group I and in 4.1% of group II. The incidence of respiratory failure in group I was 28%, and was 17.9% in group II. Respiratory failure was significantly lower ( p < 0.05) in group II. The reduction in the incidence of renal failure and paraplegia in the two groups was nonsignificant. In conclusion, the use of adjuncts and our improved experience allowed us to achieve a significant improvement in mortality and major morbidity rates in the group of patients operated on after 1998.

Endovascular grafting of complex aortic aneurysms with a modular side branch stent-graft system in a porcine model

OBJECTIVES

To evaluate and refine a stent-graft system with side branches for treatment of aneurysms with essential branch arteries.

METHODS

In a porcine model (n=4) supra- and juxta-renal aortic aneurysms were created by suturing an artificial patch onto an anterior aortotomy. Angiography was performed to determine the exact location of the renal arteries. Accordingly, fenestrations were created in an appropriately sized aortic stent-graft. Initial deployment of the aortic graft is partial, whereby the top stent is secured in a cap and distal stents are being restrained, thus ensuring longitudinal and rotational manoeuvrability during alignment of the branch arteries. Separate branch grafts with silicone flanges for connection with the main stent-graft are subsequently placed in the renal arteries followed by full deployment of the main stent-graft. Outcome was evaluated by postoperative angiography and autopsy results and by measuring operating time, blood loss and use of contrast agent.

RESULTS

Branched grafts were placed successfully in all trials. The median endovascular procedure time was 126 min (90-160), with 575 ml (400-800) blood loss and 65 ml (50-80) contrast agent use. Angiographically, all aneurysms were excluded without signs of endoleak and all renal arteries were patent. At autopsy, the main stent-graft and all side branches were adequately placed with intact connections between main stent-graft and branch grafts.

CONCLUSIONS

In this model, endovascular repair of complex aneurysms using a modular branch graft system is feasible in a reliable, predictable and timely fashion.