Endoluminal aortic grafting with renal and superior mesenteric artery incorporation by graft fenestration

Fenestrated endovascular grafts for juxtarenal aortic aneurysms: A step by step technical approach

Fenestrated endovascular aortic aneurysm repair is a valuable alternative for patients who are at high risk for open surgery, but have unsuitable anatomy for infrarenal endovascular repair due to a short aneurysmal neck. Recognizing that this is an evolving and complex technology, we present a step by step approach to the surgical technique that may be useful for endovascular therapist interested in the management of these complex patients.

Fenestrated and Branched Stent-grafting After Previous Surgery Provides a Good Alternative to Open Redo Surgery

OBJECTIVE

To present our experience using fenestrated and branched endoluminal grafts for Para-anastomotic aneurysms (PAA) following prior open aneurysm surgery, and after previous endovascular aneurysm repair (EVAR) complicated by proximal type I endoleak.

METHODS

Fenestrated and/or branched EVAR was performed on eleven patients. Indications included proximal type I endoleak after EVAR and short infrarenal neck (n=4), suprarenal aneurysm after open AAA (n=4), distal type I endoleak after endovascular TAA (n=1), proximal anastomotic aneurysm after open AAA (n=1), and an aborted open AAA repair due to bleeding around a short infrarenal neck.

RESULTS

The operative target vessel success rate was 100% (28/28) with aneurysm exclusion in all patients. Mean hospital stay was 6.0 days (range 2-12 days, SD 3.5 days). Thirty day mortality was 0%. All cause mortality during 18 months mean follow-up (range 5-44 months, SD 16.7 months) was 18% (2/11) with no deaths from aneurysm rupture. Cumulative visceral branch patency was 96% (27/28) at 42 months. Average renal function remained unchanged during the follow-up period.

CONCLUSIONS

Our report highlights the potential of fenestrated and branched technology to improve re-operative aortic surgical outcomes. The unique difficulties of increased graft on graft friction hindering placement, short working distance, and increased patient co-morbidities should be recognized.

Repair of recurrent visceral aortic patch aneurysm after thoracoabdominal aortic aneurysm repair with a branched endovascular stent graft

Aneurysmal degeneration of the visceral aortic patch is an uncommon late complication of surgical replacement of the thoracoabdominal aorta. We report on a 70-year-old woman who had undergone previous open thoracoabdominal aortic aneurysm repair and subsequent revision surgery for a visceral aortic patch aneurysm. The patient presented with a recurrent asymptomatic 60-mm-diameter visceral aortic patch aneurysm involving the celiac axis and superior mesenteric artery. The lesion was successfully treated with a custom-designed Zenith branched endovascular stent graft. The patient remains well at 12 months.

Salvage of failed prior endovascular abdominal aortic aneurysm repair with fenestrated endovascular stent grafts

Three patients with type I proximal endoleak after previous endovascular abdominal aortic aneurysm (AAA) repair were treated with fenestrated endovascular stent grafts. Six renal arteries, three superior mesenteric arteries, and one coeliac axis were targeted for incorporation by graft fenestration. The fenestration-renal ostium interface was secured with balloon-expandable stents and completion angiography demonstrated no endoleaks and antegrade perfusion in all target vessels. All patients made an uncomplicated recovery. Fenestrated endovascular stent grafts can be used to salvage failed prior endovascular AAA repair in patients who are considered unsuitable for other endovascular or open surgical interventions.

Intentional Coverage of a Main Renal Artery During Endovascular Juxtarenal Aortic Aneurysm Repair in Symptomatic High-Risk Patients

PURPOSE

To describe the efficacy and morbidity of intentionally covering a main renal artery during symptomatic juxtarenal endovascular aneurysm repair (EVAR).

CASE REPORTS

Two patients with symptomatic juxtarenal abdominal aortic aneurysm (AAA) were felt to be at prohibitive risk for open repair. Each underwent EVAR with intentional coverage of 1 main renal artery to achieve adequate proximal hemostatic seal. One patient died at 24 months; the second is symptom-free at 10 months. Both aneurysms initially decreased in diameter. Both patients had increased serum creatinine and required increased therapy for hypertension, but neither required hemodialysis. Renal volume decreased 48.7% and 68.0%, respectively.

CONCLUSION

Intentional coverage of a main renal artery during EVAR for a symptomatic juxtarenal aneurysm resulted in effective short-term AAA repair with no need for dialysis. Despite the increased requirement for antihypertensive medications and the observed decline in renal function, this technique provides an option for treatment of this difficult patient subset.

Combined Endovascular and Surgical Procedure for Recurrent Thoracoabdominal Aortic Aneurysm

We report the case of an 85-year-old man with a recurrent thoracoabdominal aortic aneurysm who underwent two-staged combined endovascular and surgical procedure. First, two retrograde bypasses using saphenous vein grafts were implanted from the right common iliac artery to the celiac artery and superior mesenteric artery. Two weeks later the aneurysm was successfully excluded with a stent-graft. The postoperative course was uneventful. This two-staged combined endovascular and surgical approach may be a safe and effective alternative to open surgical repair of thoracoabdominal aortic aneurysm in high-risk patients.

Mid-term results of endovascular aneurysm repair with branched and fenestrated endografts

PURPOSE

The technique of fenestrated and branched endovascular aneurysm repair (EVAR) has been used for the treatment a variety of aortic aneurysms. Although technically successful, longer-term results have been lacking. This article reports on the mid-term results of aneurysm repair with fenestrated and branched endografts from a European center with a large endovascular experience.

METHODS

Between 2001 and 2005, 38 patients were prospectively enrolled in a single institution, investigational device protocol database. Indications for fenestrated or branched EVAR included unfavorable anatomy for traditional EVAR and an abdominal aortic aneurysm >5.5 cm in maximum diameter. Customized stent-grafts were either fenestrated or branched and based on the Zenith system. Data were analyzed on an intention-to-treat basis. Differences between groups were determined using analysis of variance with P < .05 considered significant.

RESULTS

The mean (SD) follow-up was 25.8 +/- 12.7 months (median, 25.0 months; range, 9 to 46 months), and no patients were lost to follow-up. All cause mortality was 13% (5/38), with all deaths occurring within the first postoperative year; 30-day mortality was 2.6%. No patient died during the operation. Completion angiography demonstrated successful sealing in 37 of 38 patients and an overall operative visceral vessel perfusion rate of 94% (82/87). Cumulative visceral branch patency was 92% at 46 months. Stent occlusions, when they did occur, all happened within the first postoperative year. All postoperative occlusions occurred in unstented fenestrations or scallops. No occlusions occurred in stented vessels. The difference in serum creatinine preoperatively and postoperatively at 6 months, 1, 2, and 3 years was not significant (P = NS). No patient required dialysis. The aneurysm sac size decreased significantly during the first year and then remained stable (P < .05). Limb perfusion as assessed by the ankle/brachial index was not affected by the presence of a fenestrated or branched endograft.

CONCLUSIONS

The intermediate-term results of fenestrated and branched endografts support their continued use in patients with anatomic contraindications for standard EVAR. Close surveillance is mandatory for early identification of visceral or branched vessel stenosis and preocclusion. All cases of failure appear to occur during the first year and then level off in subsequent longer-term follow-up. This includes death, secondary interventions, branch vessel patency, and complications. As the procedure matures, long-term results and randomized clinical trials will ultimately be required to determine the safety, efficacy, and stability of this system.

A Prospective Analysis of Fenestrated Endovascular Grafting: Intermediate-term Outcomes

PURPOSE

To assess the intermediate-term outcomes following fenestrated grafting for juxtarenal aneurysms.

MATERIALS AND METHODS

A prospective trial was conducted on patients with short proximal necks, who were considered to be high-risk for open repair and unacceptable for conventional endovascular repair. Devices were designed from reconstructed CT data. Follow-up studies included CT, duplex ultrasound, and KUB and occurred at hospital discharge, 1, 6, and 12 months and annually thereafter.

RESULTS

One hundred and nineteen patients were treated (2001-2005). Mean age and aneurysm size were 75 years and 65 mm, respectively, and 82% were male. A total of 302 visceral vessels were inferior to the fabric seal (a mean of 2.5 vessels per patient), with the most common design incorporating two renal arteries and the SMA (58%). All prostheses were implanted successfully without any acute visceral artery loss. The mean follow-up was 19 months (0-42 months). One patient died within 30 days of device implantation. Kaplan-Meier estimates of survival at 1, 12, 24, and 36 months are 0.99, 0.92, 0.83 and 0.79. There were no ruptures or conversions. Pre-discharge imaging noted 11 type I and type III endoleaks. The 30-day endoleak rate was 10% (all type II). Aneurysm sac size decreased (>5 mm) in 51, 79 and 77% at 6, 12 and 24 months, respectively. One patient had sac enlargement within the first year, associated with a persistent type II endoleak. In-stent stenoses occurred in 12 renal arteries and one SMA. Six renal arteries and the SMA stenosis were treated and two renal stenoses are awaiting treatment. Ten of 231 stented renal arteries occluded (three prior to discharge), one of which was recanalized. One component separation was treated with an extension at 2 years.

CONCLUSIONS

The placement of endovascular prostheses with graft material incorporating the visceral arteries is safe and appears to be effective at preventing rupture. Continued follow-up to assess the long-term benefit, aneurysm sac behavior and effect of stenting upon the visceral ostia remains critical.

The Fate of Target Visceral Vessels After Fenestrated Endovascular Aortic Repair—General Considerations and Mid-term Results

OBJECTIVE

To carry out a retrospective analysis of the short and mid-term target vessels (TV) patency following fenestrated endovascular aortic repair (f-EVAR) of abdominal aneurysm (AAA).

PATIENTS AND METHODS

Seventeen f-EVAR patients were analysed. The Zenith (Cook) fenestrated graft was used in all cases. Bare renal stents were used where good apposition existed between the stent graft and the aortic wall, and covered stents were chosen when this apposition appeared deficient.

RESULTS

A total of 35 TV were treated: twenty with small fenestration and 15 with a scallop. Procedural technical success was achieved in 16 out of 17 patients. All TV were perfused at the completion angiography. Access to TV through small fenestrations was achieved in 18 out of 20 vessels. After a mean follow-up of 20.5 months no type I endoleaks were detected. No late complications were observed in any of the stented TV. One patient with perioperative bilateral renal artery occlusion remains on haemodialysis. One non-target renal artery, opposite a scallop was unintentionally covered. One kidney, initially perfused via a un-stented scallop fenestration, was atrophied 14 months post surgery. One patient died from heart failure.

CONCLUSIONS

f-EVAR is a valid and safe treatment option. Our series and the world literature demonstrates a >90% TV preservation rate. Long-term intensive surveillance is required.

The Endowedge and Kilt Techniques to Achieve Additional Juxtarenal Seal during Deployment of the Gore Excluder Endoprosthesis

The proximal 4 mm of the Gore Excluder endoprosthesis are scalloped. Our purpose is to describe our initial experience of a novel technique, referred to as the "endowedge," that takes advantage of this scalloped configuration in aneurysms with short proximal necks. The technique utilizes a balloon in the renal artery to aid alignment of a scallop and allow additional juxtarenal seal. A retrospective review of aneurysms treated with the endowedge technique at our institution was initiated. Renal balloons were placed via the brachial approach. Excluder endografts were deployed by flowering the first one or two rings, then advancing upward against the inflated balloon during completion of deployment. In patients with dumbbell-shaped morphology, an aortic cuff was deployed in the distal seal zone prior to the main body (kilt technique). Eight patients were identified, three of whom underwent an adjuvant kilt procedure. Average preoperative proximal neck length was 8.5 mm (range 6-12). Average additional juxtarenal seal was 2.3 mm. Mean follow-up was 5 months (range 2.5 weeks to 9 months). There were no type I endoleaks. There were two type II endoleaks. Average aneurysm size decreased from 6.0 to 5.5 cm. No aneurysm has enlarged or ruptured. We conclude that the endowedge technique allows additional juxtarenal seal during endograft placement. Our early results suggest that this technique may allow for safe treatment of aneurysms with short necks.

Beyond the aortic bifurcation: Branched endovascular grafts for thoracoabdominal and aortoiliac aneurysms

OBJECTIVES

To evaluate the use of novel technology to treat complex aortic aneurysms involving branches that provide critical end-organ blood supply.

METHODS

A prospective study was conducted in patients with thoracoabdominal, suprarenal, or common iliac aneurysms (TAA, SRA, or CIA) at high risk for open surgical repair. An endovascular graft using the Zenith platform was customized to fit patient anatomy (TAA or SRA) and combined with Jomed balloon-expandable stent-grafts. Prefabricated hypogastric branches were used with a Zenith abdominal aortic aneurysm (AAA) or Fluency self-expanding fenestrated device in conjunction with a self-expanding stent-graft. Analyses were conducted in accordance with the endovascular aneurysm reporting standards document. Follow-up studies occurred at discharge, 1, 6, and 12 months, and included computed tomography and duplex ultrasound scans, and flat plate radiography.

RESULTS

Fifty patients were treated (9 TAA, 20 SRA, 21 CIA). The mean aneurysm size was 7.6 cm (TAA), 7.2 cm (SRA), and 6.1 cm AAA size associated with a mean CIA size of 3.8 cm. Bilateral CIA aneurysms were present in 86% (18/21) of patients with CIA aneurysms. Perioperative mortality was 2% (1/50) and resulted from a myocardial infarction after a planned conduit and iliac endarterectomy required for device access. Five late deaths occurred (2 TAA, 2 SRA, 1 CIA), three of which (2 TAA, 1 SRA) were aneurysm related. Failure to access internal iliac arteries occurred in three cases, and two late hypogastric branch thromboses occurred. No visceral branches were lost acutely or occluded during follow-up. Sac shrinkage (>5 mm) was noted in 65% of patients at 6 months and in all patients (10/10) by 12 months. There were no ruptures or conversions, but nine patients required secondary interventions.

CONCLUSIONS

Branch vessel technology has made it technically feasible to preserve critical end-organ perfusion in the setting of CIA, SRA, and TAA aneurysms. The relatively low acute mortality rate and lack of short-term branch vessel loss are encouraging and merit further investigation. These advances have the potential to markedly diminish the complications associated with conventional management of complex aneurysms.

Repair of juxtarenal para-anastomotic aortic aneurysms after previous open repair with fenestrated and branched endovascular stent grafts

Three patients with juxtarenal para-anastomotic aortic aneurysms after previous open abdominal aortic aneurysm repair were treated with custom-designed fenestrated and branched Zenith endovascular stent grafts. Six renal arteries and two superior mesenteric arteries were targeted for incorporation by graft fenestrations and branches. The fenestration/renal ostium interface was secured with balloon-expandable Genesis stents (n = 5) or Jostent stent grafts (n = 1). Completion angiography demonstrated no endoleaks and antegrade perfusion in all target vessels. During follow-up, one patient developed asymptomatic renal artery occlusion and underwent further endovascular intervention for type I distal endoleak. Computed tomography at 12 months demonstrated complete aneurysm exclusion in all patients with antegrade perfusion in the remaining target vessels. Fenestrated and branched endovascular stent grafts may be an acceptable alternative to conventional open repair in this group of patients.

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.

Transrenal fixation of aortic stent-grafts: current status and future directions

Aortic stent-graft repair has been widely used in clinical practice for more than a decade, achieving satisfactory results compared to open surgical techniques. Transrenal fixation of stent-grafts is designed to obtain secure fixation of the proximal end of the stent-graft to avoid graft migration and to prevent type I endoleak. Unlike infrarenal deployment of stent-grafts, transrenal fixation takes advantage of the relative stability of the suprarenal aorta as a landing zone for the uncovered struts of the proximal stent. These transostial wires have sparked concern about the patency of the renal arteries, interference with renal blood flow, and effects on renal function. Although short to midterm results with suprarenal stent-grafts have not shown significant changes in renal function, long-term effects of this technique are still not fully understood. This review will explore the current status of transrenal fixation of aortic stent-grafts, potential risks of stent struts relative to the renal ostium, alternative methods to preserve blood flow to the renal arteries, and future directions or developments in stent-graft design to prevent myointimal proliferation around the stent struts.

Fenestrated endovascular grafting: The renal side of the story

BACKGROUND

Fenestrated endovascular aneurysm repair uses the visceral aortic segment, in the setting of a suboptimal proximal neck, for sealing and fixation. This technique requires the placement of visceral stents and might be hampered by the deleterious effects of such interventions. This study was performed to define outcomes related to renal events.

MATERIALS AND METHODS

Consecutive clinical records and radiographic studies of patients treated primarily with an endovascular approach with a fenestrated endograft were reviewed. The population was divided into groups with and without baseline renal dysfunction based on the National Kidney Foundation definition of chronic kidney disease. Morphologic measurements and the detection of postoperative renal events such as renal artery stenosis or occlusion, need for dialysis, deterioration of renal function by using estimated glomerular filtration rate (GFR), and secondary interventions related to the renal arteries were assessed. Preoperative and postprocedural factors predictive for the development of renal dysfunction were assessed by using a Fisher exact test, t test, and logistic regression.

RESULTS

A total of 72 patients were treated between 2001 and 2004 with a mean age, aneurysm size, and follow-up of 75 years, 6.2 cm, and 6 months (range, 1 to 24 months), respectively. No ruptures and five deaths (two procedure-related) were observed. There were 23 patients with baseline renal insufficiency and 49 patients without insufficiency. Twenty-four patients had deterioration in GFR >30% during the follow-up period, and 17 patients experienced 19 renal-related events (more common in patients with baseline insufficiency, 39% vs 16.3%; P = .04; relative risk, 2.4). Four patients required dialysis (two permanent), and all had preoperative renal dysfunction ( P = .002); similarly, death was also more common in this group (17.4% vs 2%; P = .02; relative risk, 8.52). Renal events in most patients occurred within the first postoperative month (59%). However, mean GFR stabilized after 6 months.

CONCLUSION

Aneurysm repair with fenestrated endovascular grafts is associated with a significant risk for adverse renal events (16% in those without renal dysfunction, although none developed a creatinine >2 mg/dL, and 39% for patients with preoperative renal dysfunction). These patients must be meticulously followed, particularly within the first month after such a procedure. When renal artery restenosis is suspected or diagnosed, aggressive approach might be warranted to limit the extent of late renal dysfunction.

Endovascular stent-graft repair of pararenal and type IV thoracoabdominal aortic aneurysms with adjunctive visceral reconstruction

OBJECTIVE

Pararenal and type IV thoracoabdominal aortic aneurysms (TAAA) are not currently considered as indications for endovascular repair given unfavorable neck anatomy or aneurysm involvement of the visceral vessels. Open repair of these aneurysms is associated with significant morbidity and mortality, particularly postoperative renal dysfunction. In selective high-risk patients, debranching of the visceral aorta to improve the proximal neck region can be used to facilitate endovascular exclusion of the aneurysm.

METHODS

Between October 2000 and July 2003, 10 patients were treated with open visceral revascularization and endovascular repair of pararenal and type IV TAAAs at a single institution. Patient demographics and procedural characteristics were obtained from medical records.

RESULTS

Overall 13 visceral bypasses were performed in 10 patients: 6 patients with a single iliorenal bypass, 3 with a hepatorenal bypass, and 1 patient with complete visceral revascularization. Juxtarenal aneurysms occurred in 5 patients (50%), suprarenal aneurysms in 3 patients (30%), and type IV TAAAs in 2 patients (20%). All patients had successful endovascular aneurysm exclusion. Mean follow-up was 8.7 months. There were no perioperative deaths, neurologic deficits coagulopathies, or renal dysfunction. Follow-up spiral computed tomography scans demonstrated patency of all bypass grafts with only one patient requiring a secondary intervention for late type I leak which was sealed with placement of a proximal cuff.

CONCLUSION

These initial results suggest that are similar to infrarenal AAA endovascular repair. This combined approach to repair of pararenal and type IV TAAAs reduces the morbidity and mortality of open repair, and represents an attractive option in high-risk patients while endoluminal technology continues to evolve.

Abdominal Aortic Aneurysm:. A Review of Endoluminal Treatment

Abdominal aortic aneurysm (AAA) carries a high mortality if left untreated. Until recently, most patients with AAA were treated with surgical repair. However, endoluminal graft treatment is rapidly becoming an alternative to surgical repair due to lower morbidity and comparable perioperative mortality rates. Despite this optimism patients and operators should keep in mind the palliative nature of these endovascular repairs and the lifelong need for surveillance, before embarking on these procedures. Endoleaks remain to be a significant problem leading to aneurysm expansion and occasionally rupture. Durability of the existing endograft devices remains to be seen. Careful patient selection is critical to success with these procedures. With future advancements in the endograft device technology, methods of patient surveillance, and patient care, there may be a shift from conventional surgical approaches to endovascular repair for the treatment of AAA.

Effect of improved endograft design on outcome of endovascular aneurysm repair

OBJECTIVE

This study was undertaken to identify factors that lead to improvements in the results of endovascular aneurysm repair, with particular focus on new endograft design.

METHODS

We analyzed data for patients enrolled in the European Collaborators on Stent Graft Techniques for Abdominal Aortic Aneurysm Repair (EUROSTAR) registry, and compared those for endografts now withdrawn from the market with those for endografts currently in use. Patients in whom a variety of endograft types were used in small numbers were excluded. Postoperative and long-term outcomes were initially compared with univariate analyses, and subsequently multivariate tests were used to adjust for baseline differences between the 2 groups. The main outcome measures were freedom from a variety of secondary interventions, aneurysm rupture, and death.

RESULTS

Some 1224 patients received "withdrawn" endografts, and 2768 patients received "current" endografts. The 2 groups were generally similar, but patients with current devices were more often men, significantly older, more frequently unfit for open surgery, and had larger aneurysms with wider necks. Of no surprise, current endografts were also more often used by experienced (>60 previous cases) surgical teams (44% vs 20%; P <.0001). Thirty-day clinical outcomes were comparable in the 2 groups, although patients with withdrawn devices were less likely to have type II endoleak (9.2% vs 5.5%; P <.0001), and those with current devices had a shorter mean hospital stay (5.4 vs 6.8 days; P <.0001). At 3 years more patients with current devices were free from secondary transfemoral intervention (88.4% vs 76%; P <.0001) and conversion to open repair (95.4% vs 93.4%; P =.007). Aneurysm-related mortality at 3 years, defined as death due to aneurysm rupture or within 30 days of a secondary intervention, was also less frequent with current endografts (2.7% vs 4.4%; P =.02). Aneurysm rupture at 3 years was infrequent (0.8% vs 1.8%; P =.07). At multivariate analysis the use of current devices was a protective factor against late conversion to open repair (hazard ratio, 0.49; 95% confidence interval, 0.28-0.86; P =.014) and aneurysm-related death (hazard ratio, 0.51, 95% confidence interval, 0.34-0.75; P =.0008). Larger aneurysm or neck diameter and shorter neck length were also associated with late conversion to open repair; larger aneurysm diameter, older age, and unfitness for open surgery were predictive of aneurysm-related death.

CONCLUSION

Modern endograft design has improved the results of endovascular aneurysm repair.

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.

Treatment of short-necked infrarenal aortic aneurysms with fenestrated stent-grafts: short-term results

INTRODUCTION

A proximal neck of 15 mm length is usually required to allow endovascular repair of abdominal aortic aneurysms (EVAR). Many patients have been refused EVAR due to a short neck. By customising fenestrated grafts to the patients' anatomy, we can offer an endovascular solution, especially for patients who are unsuitable for open repair.

METHODS

Eighteen patients were selected for fenestrated stent-grafting if they presented with an abdominal aneurysm of at least 55 mm in diameter, a short neck (less than 15 mm), plus contra-indications for open repair (cardiopulmonary impairment or a hostile abdomen). The stent-graft used was a customised fenestrated model based on the Cook Zenith composite system. We used additional stents to ensure apposition of the fenestrations with the side branches.

RESULTS

All endovascular procedures were successful. Out of the 46 targeted side branches (10 superior mesenteric arteries, 36 renal arteries), 45 were patent at the end of the procedure. One accessory renal artery became occluded by the stent-graft. There was one possible proximal type I endoleak, which later proved to be a type II endoleak. There was no mortality, but complications occurred in six patients: two cardiac complications, three urinary complications and one occlusion of a renal artery. At follow-up (mean 9.4 months, range 1-18), there were no additional renal complications and all the remaining targeted vessels stayed patent.

DISCUSSION

By customizing fenestrated stent-grafts, it is possible to position the first covered stent completely inside the proximal neck, thus achieving a more stable position. The additional side-stents may also contribute to a better fixation. This technique may become a valuable alternative for patients who are at high risk from open surgery.

Primary Endovascular Repair of Juxtarenal Aneurysms with Fenestrated Endovascular Grafting

PURPOSE

To evaluate outcomes of an endovascular graft incorporating the visceral aortic segment with graft material in the setting of juxtarenal aneurysms.

MATERIALS AND METHODS

A prospective analysis of patients undergoing implantation of an endovascular device with graft material proximal to the renal arteries was conducted. All patients were deemed unacceptable candidates for open surgical repair and had proximal neck length=<10 mm, or =<15 mm with a compromising morphology (funnel or thrombus). Fenestrations were customized to accommodate aortic branch anatomy based upon CT and intravascular ultrasound data. Selective visceral ostia were treated with balloon expandable stents following endograft deployment. All patients were evaluated with CT, duplex ultrasound, and abdominal radiograph at discharge, 1, 6, 12 and 24 months.

RESULTS

A total of 32 patients were enrolled in the trial. Short proximal necks (3-10 mm) were present in 22, and 10 had necks 10-15 mm in length with concomitant angulation or thrombus compromising neck quality. Endograft design included bifurcated (30) and aortic tube (2) systems. A total of 83 visceral vessels were incorporated (mean of 2.6 per patient). These most commonly included both renal arteries and the SMA. All prostheses were implanted successfully without the acute loss of any visceral arteries. The mean follow-up was 9.2 months (range 0-24 months). One patient died within 30 days of device implantation and hypogastric bypass following the development of aspiration pneumonia. Three early (<30 days) and three late secondary interventions were performed. The 30-day endoleak rate was 6.5%. The aneurysm sac decreased greater than 5 mm in 58% of patients at 6 months and in 75% of patients at 12 months. One patient, with a persistent type II endoleak had 5 mm of sac growth over 12 months. Six patients had transient or permanent elevation of serum creatinine (>30% from baseline), with one requiring hemodialysis. Of the 83 vessels incorporated, three late stenoses (all successfully treated with an endovascular approach) and two renal occlusions were detected during follow-up. Three patients died of unrelated causes during the follow-up period.

CONCLUSIONS

The placement of endovascular prostheses with graft material incorporating the visceral arteries is technically feasible. The incidence of endoleaks is exceptionally low. It remains critical to follow the status of stented visceral vessels, and establish the long-term efficacy of this type of repair.

In Situ Stent-Graft Fenestration to Preserve the Left Subclavian Artery

PURPOSE

To report our first clinical application of a new technique for in situ fenestration of a thoracic stent-graft.

CASE REPORT

After completing a series of in vitro and in vivo experiments, in situ stent-graft fenestration was employed during endograft repair of a saccular thoracic aortic aneurysm in a 77-year-old woman. Because the stent-graft would have covered the left subclavian artery ostium, a modified Zenith TX1 thoracic stent-graft was deployed then fenestrated transluminally using a guidewire followed by serial cutting balloons, which created a fenestration over the LSA sufficiently large to accommodate a Jomed covered stent on an 8-mm balloon. Completion angiography showed exclusion of the aneurysm and brisk flow into the LSA. Following the procedure, the arm pressures were nearly equal. The 6-month CT scan showed no endoleak and a patent subclavian artery stent.

CONCLUSIONS

In situ graft fenestration to preserve the left subclavian artery after deliberate coverage during endovascular repair of a thoracic aortic aneurysm appears feasible in this initial clinical application. There are uncertainties regarding the long-term stability of the fabric tears that are an inherent part of this technique.

Retrograde visceral vessel revascularization followed by endovascular aneurysm exclusion as an alternative to open surgical repair of thoracoabdominal aortic aneurysm

Staged visceral artery revascularization with occlusion of the proximal lumen enables endovascular exclusion of the entire thoracoabdominal aneurysm from a femoral approach. This technique has been successfully used in three patients at high risk for conventional repair.

Endovascular management of juxtarenal aneurysms with fenestrated endovascular grafting

PURPOSE

To evaluate the technical feasibility and short-term results of juxtarenal aneurysm repair with an endovascular graft that incorporated the visceral aortic segment with graft material.

METHODS

Patients were studied prospectively after the implantation of an endovascular device with graft material extending proximal to the renal arteries, variably incorporating the superior mesenteric and celiac arteries. All patients were deemed to be high risk with respect to open surgical repair and had compromised proximal neck anatomy. Proximal neck lengths were <or=10 mm, or <or=15 mm with a challenging morphology (funnel shape or extensive thrombus). Fenestrations within the graft material were customized to accommodate visceral and renal vessels on the basis of computerized tomography (CT), angiography, or intravascular ultrasound data. Selected visceral ostia were protected with balloon-expandable stents after partial endograft deployment. All patients were evaluated with CT and kidney, ureters, and bladder x-ray at discharge and at 1, 6, and 12 months. Visceral duplex scan studies were performed at 1, 6, and 12 months.

RESULTS

A total of 22 patients were enrolled in the study. Sixteen patients had short proximal necks (3-10 mm), and six had compromised necks of 10 to 15 mm in length. Endograft design included bifurcated (20) and tube (2) systems. All prostheses were implanted successfully without the acute loss of any visceral arteries. A total of 58 visceral vessels were incorporated (mean, 2.6 per patient) and most commonly included both renal arteries and the superior mesenteric artery. The mean follow-up was 6 months. There were no deaths within 30 days and no aneurysm-related deaths during the follow-up period. Two early (<30 days) and two late secondary interventions were performed, inclusive of two visceral artery stenoses detected with duplex scanning. The 30-day endoleak rate was 4.5%. The aneurysm sac decreased greater than 5 mm in 53 % of patients at 6 months and three of four patients at 12 months. Three patients developed renal insufficiency, only one of which required temporary hemodialysis.

CONCLUSIONS

The placement of an endovascular prosthesis with graft material that incorporates the visceral arteries is technically feasible. The occurrence of endoleaks appears to be relatively low. The increased sealing and fixation zones in this patient population should limit the late development of proximal endoleak or migration; however, this situation will require more patients and extended follow-up.

Cine MRI assessment of aortic aneurysm dynamics before and after endovascular repair

PURPOSE

To evaluate stent-graft and aneurysm wall motions during the cardiac cycle using cine magnetic resonance imaging (MRI) to identify mechanisms of long-term failure of endovascular aneurysm repair (EVAR).

METHODS

Prior to and after EVAR in 7 patients with abdominal aortic aneurysms (AAA), 12 MRI images per cardiac cycle were acquired in transverse, sagittal, and coronal planes of the aneurysm. Two independent observers blinded to the aim of the study manually traced stent-graft and aneurysm wall contours. Translation was defined as the maximal displacement of the contours in the peak-systolic image compared to the end-diastolic image. Aneurysm wall motions before and after repair were compared. Stent-graft and aneurysm configuration changes during the cardiac cycle were evaluated. The relation between translation and the degree of angulation of the stent-graft was calculated.

RESULTS

The anteroposterior translation of the aneurysm decreased from a median 1.05 mm (range <0.5-1.29) before EVAR to within pixel size (<0.5 mm) after EVAR (p=0.04). The cranial-caudal translation of the aneurysm increased from a median 1.01 mm (range <0.5-1.51) before to 1.69 mm (range 1.1-1.99) after EVAR (p=0.02). In 4 stent-grafts, bending during cardiac systole was observed at the site of maximal angulation of the device. In transverse sections, 2-dimensional pulsatile wall motion of the aneurysm was 0.25 cm(2) (range 0.07-0.29) before and 0.17 cm(2) (range 0.07-0.42) after EVAR (p=0.79). No pulsatility of the stent-graft itself was observed. The correlation coefficient between angulation of the stent-graft and the increase in cranial-caudal translation after EVAR was 0.67 (p>0.05).

CONCLUSIONS

After EVAR, increased longitudinal translation of both the aneurysm and stent-graft was observed, indicating downward pulling forces at the proximal fixation site. Secondly, increased bending was seen at the site of maximal angulation, which implies a risk of metal fatigue and fabric damage at sites of stent-graft angulation.

Side-branched modular endograft system for thoracoabdominal aortic aneurysm repair

PURPOSE

To describe a side-branched modular endograft system that provides adequate visceral artery perfusion with perfect seal during thoracoabdominal aortic aneurysm (TAAA) repair.

CASE REPORT

A 76-year-old man with a 57-mm TAAA involving the celiac artery was treated with a customized Talent endograft consisting of a 46-mm x 18-cm stented main body and a 6-mm x 30-mm nonstented Dacron side branch. The graft was delivered through a surgical exposure of the left common femoral artery. A 6-mm x 10-cm Hemobahn stent-graft was introduced in the 30-mm side branch from the aorta to the celiac trunk through a long 8-F sheath via the left brachial artery. The patient recovered uneventfully except for a mild reactive inflammatory syndrome. Postoperative computed tomography demonstrated total exclusion of the TAAA sac and good antegrade perfusion of the celiac and superior mesenteric arteries, which has been maintained at the 6-month follow-up.

CONCLUSIONS

Endovascular treatment of TAAA is feasible with further technical refinements of available technology.

Simultaneous stent-graft repair of thoracic and infrarenal abdominal aortic aneurysms

PURPOSE

To describe a technique for concomitant endovascular stent-graft repair of thoracic and infrarenal abdominal aortic aneurysms.

CASE REPORT

A 68-year-old man was found to have concomitant thoracic and abdominal aortic aneurysms. Both of the aneurysms were excluded successfully in one procedure using Talent stent-grafts. The patient tolerated the procedure well and was discharged on postoperative day 4. Aside from an infected groin wound, the patient did not have any complications. Computed tomographic scans at 6, 12, and 18 months showed proper position of both stents without evidence of endoleak.

CONCLUSIONS

Simultaneous endovascular treatment of thoracic and infrarenal abdominal aortic aneurysms may represent a viable alternative for therapy in some patients.

Migration of a bifurcated endovascular graft into an iliac aneurysm: endovascular salvage and future prevention--a case report

The FDA approval of endovascular grafts for the treatment of abdominal aortic aneurysms has been associated with a dramatic increase in the use of these devices. Major referral centers are reporting the treatment of 75% to 80% of their patients with infrarenal abdominal aortic aneurysms with endovascular devices. The large quantity of endovascular devices being used has produced a growing number of management issues that are often not predictable during the preoperative assessment. These issues require complex intraoperative decision making and innovative techniques for their management as reflected by the subsequent case report. An 82-year-old patient presented with a 7.8-cm abdominal aortic aneurysm. The aneurysm extended into the common iliac arteries bilaterally. The right common iliac artery was 6.5 cm and the left common iliac artery was 2.0 cm in maximal diameter. The preoperative work-up, including a computed tomography scan and arteriogram, suggested that he would be a potential candidate for endovascular repair. The plan was to extend the graft into the right external iliac artery after embolization of the right hypogastric artery and to seal the left limb in the ectatic left common iliac artery using an aortic extender cuff. During the endovascular repair of the aortoiliac aneurysms using the AneuRx bifurcated graft, the main device became dislodged from its infrarenal attachment site and migrated into the large right common iliac artery aneurysm with the iliac limb ending in the distal external iliac artery. A new bifurcated device was deployed from the left side to attempt an endovascular salvage of the difficult situation. The new graft was partially deployed down to the iliac limb. This allowed cannulation of the contralateral stump through the original endovascular graft that had migrated distally. The two grafts were connected with a long iliac limb. This allowed stabilization of the endovascular reconstruction by increasing its columnar strength. The deployment of the second bifurcated graft was completed and the central core with the runners removed safely without migration of the second bifurcated component. The reconstruction was completed with an aortic cuff in the left common iliac artery. The use of the aortic cuff was useful to preserve the left hypogastric artery. No intraoperative endoleak was noted. The patient did well and was discharged the day following the procedure. The follow-up computed tomography scan shows the abdominal aortic aneurysm excluded by the endovascular graft with a defunctionalized portion of one bifurcated graft within the right common iliac aneurysm. There is no evidence of endoleak and the abdominal aortic aneurysm had decreased in size at 6 months. This case demonstrates one of the unique management problems that may arise during endovascular graft placement. Events that initially would suggest failure of the endoluminal treatment may be corrected using advanced endovascular techniques by an experienced surgeon. However, there will be times that the prudent decision will be conversion to open repair. Only good clinical judgement and adequate training will prevent catastrophic outcomes.