An endovascular system for thoracoabdominal aortic aneurysm repair

A systematic review and meta-analysis of early outcomes after endovascular versus open repair of thoracoabdominal aortic aneurysms

OBJECTIVE

The objective of this study was to compare the early results of endovascular vs open thoracoabdominal aortic aneurysm (TAAA) repair.

METHODS

MEDLINE and Embase were searched for studies from January 2006 to March 2018 that compared endovascular vs open repair of TAAA using branched or fenestrated endografts. Data were subjected to a meta-analysis using a random-effects model. The outcomes of interest included early mortality, spinal cord injury, renal failure requiring dialysis, stroke, and hospital length of stay.

RESULTS

Eight comparative studies met inclusion criteria. There were two retrospective propensity-matched studies, two unadjusted single-center retrospective studies, and four unadjusted national population-based studies. Mortality in the matched studies was equivalent in both groups. Pooled analysis of all unmatched observational studies revealed a survival benefit for endovascular over open repair (relative risk [RR], 0.63; 95% confidence interval [CI],0.45-0.87); P < .01, I² = 47%). Endovascular repair was also associated with lower incidence of spinal cord injury (RR, 0.65; 95% CI, 0.42-1.01; P = .05; I² = 28%). For unmatched studies, pooled RR of renal failure requiring dialysis significantly favored endovascular repair (RR, 0.44; 95% CI, 0.23-0.85; P = .01; I² = 0%), although in the adjusted cohort, risk of dialysis was not different (RR, 1.00; 95% CI, 0.06-15.65; P = 1.00). Postoperative stroke rate was reported in three unadjusted studies and was not different between groups (RR, 0.81; 95% CI, 0.28-2.40; P = .71; I² = 77%). Hospital length of stay was reported in four studies and was shorter in the endovascular group (mean difference, -4.4 days; 95% CI, -6.6 to -1.7; P < .01; I² = 73%).

CONCLUSIONS

There are few reports comparing endovascular vs open repair of TAAAs. Short-term outcomes may be improved in patients undergoing endovascular treatment of TAAA on the basis of a limited number of studies with high risk of bias. These findings highlight the need for larger comparative studies with standardization of reporting.

Should endovascular approach be considered as the first option for thoraco-abdominal aortic aneurysms?

Open surgical repair has been the gold standard for treatment of thoracoabdominal aortic aneurysms (TAAAs). The technique of open TAAA repair has evolved from the use of "island" patch incorporation to separate branch vessel bypass, from "clamp and go" to routine use of distal perfusion, and towards more extensive repair in patients with connective tissue disorders. Open TAAA repair can be done with excellent results in highly specialized centers. However, these operations continue to carry excessive risk when performed outside large aortic centers, with 30-day mortality estimated on 20% according to statewide and national databases. In octogenarians, the mortality of elective open TAAA repair can be up to 40%. Endovascular repair was introduced as an alternative to open surgical repair in the elderly or higher risk patients using hybrid reconstruction, parallel grafts or fenestrated and branched endografts. Several large aortic centers have developed dedicated clinical programs to advance techniques of fenestrated-branched endovascular repair using patient-specific and off-the-shelf devices, offering a minimally invasive alternative to open repair allowing treatment of increasingly older and sicker TAAA patients. During the last decade, improvements in device design, patient selection, spinal cord injury protocols, and perioperative management have contributed to a continued decline in morbidity and mortality of fenestrated-branched endovascular aortic repair, challenging open surgical repair as the new "gold standard" for treatment of TAAAs. Despite the improved results, endovascular repair is a highly technical procedure that requires vast experience, involves a significant risk of complications, and also, has an impact on patients' physical quality of life. In this article, we review the current technical aspects of endovascular TAAA repair with the main focus on the evidence of open versus endovascular outcomes of TAAA repair.

Combination of Octopus and Periscope Techniques for the Management of Visceral Branches From Type V Thoracoabdominal Aortic Aneurysm: A Case Report

PURPOSE:

To describe an endovascular technique combining the octopus and periscope techniques for the treatment of a patient with type V thoracoabdominal aortic aneurysm in order to protect the patient's visceral circulation.

CASE REPORT:

An 84-year-old male patient was hospitalized for type V thoracoabdominal aortic aneurysm involving celiac axis, superior mesenteric artery, and both renal arteries. The patient's aneurysm was successfully treated by combining the octopus technique and periscope techniques. The 1-year follow-up computed tomography angiography showed that the endograft and the branches were patent. The gutters had thrombosed with no signs of endoleak. No spinal cord ischemia or impairment of the renal function was observed during the follow-up.

CONCLUSIONS:

This case is an example of the successful usage of the combined octopus and periscope techniques in protecting the renovisceral arteries arising from a type V thoracoabdominal aortic aneurysm; this combined technique might be applicable in carefully selected patients.

A prospective observational trial of fusion imaging in infrarenal aneurysms

OBJECTIVE

Use of three-dimensional fusion has been shown to significantly reduce radiation exposure and contrast material use in complex (fenestrated and branched) endovascular aneurysm repair (EVAR). Cydar software (CYDAR Medical, Cambridge, United Kingdom) is a cloud-based technology that can provide imaging guidance by overlaying preoperative three-dimensional vessel anatomy from computed tomography scans onto live fluoroscopy images both in hybrid operating rooms and on mobile C-arms. The aim of this study was to determine whether radiation dose reduction would occur with the addition of fusion imaging to infrarenal repair in all imaging environments.

METHODS

All patients who consented to involvement in the trial and who were treated with EVAR in our center from March 2016 until April 2017 were included. A teaching session about radiation protection and Cydar fusion software use was provided to all operators before the start of the fusion group enrollment. This group was compared with a retrospective cohort of patients treated in the same center from March 2015 to March 2016, after a dedicated program of radiation awareness and reduction was introduced. Ruptured aneurysms and complex EVAR were excluded. Preoperative and perioperative characteristics were recorded, including parameters of radiation dose, such as air kerma and dose-area product. Results were expressed in median and interquartile range.

RESULTS

Forty-four patients were prospectively enrolled and compared with 21 retrospective control patients. No significant differences were found in comparing sex, body mass index, and age at repair. The median operation time (wire to wire) and fluoroscopy time were 90 (75-105) minutes and 30 (22-34) minutes, respectively, without significant differences between groups (P = .56 and P = .36). Dose-area product was nonsignificantly higher in the control group, 21.7 (8.9-85.9) Gy cm², compared with the fusion group, 12.4 (7.5-23.4) Gy cm² (P = .10). Air kerma product was significantly higher in the control group, 142 (61-541) mGy, compared with 82 (51-115) mGy in the fusion group (P = .03). The number of digital subtraction angiography runs was significantly lower in the fusion group (8 [6-11]) compared with the control group (10 [9-14]); (P = .03). There were no significant differences in the frequency of adverse events, endoleaks, or additional procedures required.

CONCLUSIONS

When it is used in simple procedures such as infrarenal aneurysm repair, image-based fusion technology is feasible both in hybrid operating rooms and on mobile systems and leads to an overall 50% reduction in radiation dose. Fusion technology should become standard of care for centers attempting to maximize radiation dose reduction, even if capital investment of a hybrid operating room is not feasible.

Complications and Reinterventions After Fenestrated and Branched EVAR in Patients with Paravisceral and Thoracoabdominal Aneurysms

The application of endovascular strategies to treat aneurysms involving the abdominal and thoracoabdominal aorta has evolved significantly since the inception of endovascular aneurysm repair. Advances in endograft technology and operator experience have enabled the management of a wider spectrum of challenging aortic anatomy. Fenestrated endovascular and branched endovascular aneurysm repair represent two technical innovations, which have expanded endovascular treatment options to include patients with paravisceral and thoracoabdominal aortic aneurysms. Although similar in many ways to standard aortic endografts, fenestrated and branched endografts have specific short- and long-term complications due to their unique modular endograft design and their sophisticated deployment mechanisms. This article aims to examine the commonly encountered complications with these devices and the endovascular reintervention strategies.

A Novel Off-the-Shelf Technique for Endovascular Repair of Type III and IV Thoracoabdominal Aortic Aneurysms Using the Gore Excluder and Viabahn Branches

BACKGROUND

The aim of this study is to describe the use of a novel off-the-shelf technique to repair type III and type IV thoracoabdominal aortic aneurysms (TAAAs) in the absence of available prefabricated branched devices.

METHODS

All patients undergoing endovascular repair of type III and IV TAAAs using this technique were included from a prospectively maintained registry at a regional aortic referral center. The proximal bifurcated Gore C3 Excluder device is positioned in the descending thoracic aorta with the contralateral gate 2-3 cm above the celiac artery. From an axillary approach, the contralateral gate renovisceral branches are sequentially cannulated and simultaneously stented using Viabahn covered stents. In cases were the celiac artery could not be excluded, a parallel stent (snorkel) was added adjacent to the proximal endograft. All branches are simultaneously balloon dilated to ensure proximal gutter seal in the contralateral gate. Via the ipsilateral limb, the device can then be extended with a flared iliac extension and/or additional bifurcated device to obtain seal in the distal aorta (previous open repair) or common iliac arteries.

RESULTS

Eight patients (male = 6, mean 78 years of age) were treated in this manner since January 2015. All patients underwent repair using Gore C3 device with 3 (n = 5) or 4 (n = 3) renovisceral branches. The celiac artery was sacrificed in 4 patients and 1 renal artery in 1 patient. Mean fluoroscopy time was 88.7 min with a mean of 92.3 cc contrast utilized. Median length of stay was 7 days with 3 days spent in the intensive care unit. No major cardiac, respiratory, renal, neurologic, or wound complications occurred. Three patients had early endoleaks treated with additional endovascular techniques (n = 2) or open surgical ligation (n = 1) during the index hospitalization. Two late endoleaks were identified; 1 type II with stable sac size and 1 type III requiring iliac limb relining. All limbs and branches remain patent at the time of the last imaging study (mean 6.8 months).

CONCLUSIONS

We present an endovascular technique for repair of type III and IV TAAAs which appears to be both feasible and safe with good short-term outcomes.

Management of Abdominal Aortic Aneurysm: A Decade of Progress

Since the world was first introduced to the concept of endovascular aneurysm repair by Parodi's landmark procedures in 1990, stent-grafts have assumed a prominent role in the management of abdominal aortic aneurysm. Most modern systems are trackable, accurate, and secure. The resulting endovascular procedure is safe, durable, effective, and versatile. Perhaps the most significant increment in the applicability of the endovascular technique was achieved by the development of bifurcated stent-grafts, which dispensed with inadequate distal aortic implantation sites. Additional branches and fenestrations now permit endovascular repair in cases of thoracoabdominal, pararenal, juxtarenal, and bilateral iliac aneurysms. These advances in device performance have been accompanied by a rapid dissemination of necessary skills, leading to the development of a new superspecialty of vascular therapy, with elements of vascular surgery, interventional radiology, and interventional cardiology.

Retrograde Fenestration of Endoluminal Grafts from Target Vessels: Feasibility, Technique, and Potential Usage

Purpose:

To report initial experiments involving a new method for percutaneous intraprocedural stent-graft fenestration from the target vessel.

Technique:

In bench and canine models, the fabric of an implanted Zenith endograft was punctured easily using the stiff end of a coronary 0.014-inch guidewire delivered through the target vessel (e.g., renal or iliac artery). A 20-G cutting needle was passed over the coronary wire to enlarge the puncture site, followed by a cutting balloon to create a fenestration that was of sufficient size to allow deployment of a stent.

Conclusions:

In vivo endograft fenestration of a Zenith endograft is feasible. In addition to providing a percutaneous means of intentionally fenestrating a stent-graft from the artery to be perfused, the technique has potential application as a bailout maneuver after inadvertent side branch occlusion. Although the time to achieve successful fenestration in the experimental model was long, refinement may achieve performance times adequate to maintain viability of the end organ.

Endovascular Exclusion of Leaking Thoracic Aortic Aneurysms

Purpose:

To describe the endovascular exclusion of leaking thoracic aortic aneurysms (TAA).

Case Report:

Two elderly patients with leaking TAAs who were at high risk for surgical intervention were transferred to our institution for possible endovascular treatment. Both patients underwent successful endovascular exclusion of the leaking TAAs using multiple stacked AneuRx thoracic endoprostheses. One patient remains alive and well at 1 year with an excluded aneurysm; the other patient died from heart failure 2 months after endografting.

Conclusions:

While the early results of the endovascular exclusion of leaking TAAs are promising, the use of thoracic endoprostheses remains investigational.

Combined Endovascular and Surgical Approach (Hybrid Treatment) for Management of Type IV Thoracoabdominal Aneurysm

The purpose of this article is to report successful hybrid treatment of a sovraprosthetis type IV thoracoabdominal aneurysm.

This technique was used in a 65-year-old man with chronic rupture of a type IV thoracoabdominal aneurysm not suitable for aortic cross-clamping because of a severe cardiopathy (left ventricular ejection fraction 20%); the patient underwent previous repairs of aortic arch and infrarenal abdominal aortic aneurysms. Perioperative complications were absent. Postoperative day 21 computed tomography and monthly duplex ultrasonography confirmed the complete exclusion of the aneurysm with proper perfusion of visceral vessels. At the seventh postoperative month, the patient died of a massive recurrence of myocardial infarction.

Hybrid treatment for thoracoabdominal aneurysms may represent a valid solution for those patients with poor cardiac and respiratory reserve, reducing cardiac stress and the duration of visceral ischemia, which are still the main causes of morbidity and mortality for this type of intervention.

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.

Editor's Choice - Ten-year Experience with Endovascular Repair of Thoracoabdominal Aortic Aneurysms: Results from 166 Consecutive Patients

OBJECTIVE

To present a 10 year experience with endovascular thoracoabdominal aortic aneurysm (TAAA) repair using fenestrated and branched stent grafts.

MATERIALS AND METHODS

Consecutive patients with TAAA treated with fenestrated and branched stent grafts within the period January 2004-December 2013. Data were collected prospectively.

RESULTS

166 patients (125 male, 41 female, mean age 68.8 ± 7.6 years) were treated. The mean TAAA diameter was 71 ± 9.3 mm. Types of TAAA were: type I, n = 12 (7.2%), type II, n = 50 (30.1%), type III, n = 53 (31.9%), type IV, n = 41 (24.8%), and type V, n = 10 (6%). Fifteen (9%) patients had an acute TAAA (11 contained rupture, 4 symptomatic). One hundred and eight (65%) patients were refused for open surgery earlier. Seventy eight (47%) patients had previously undergone one or more open/endovascular aortic procedures. Technical success was 95% (157/166). Thirty day operative mortality was 7.8% (13/166), with an in hospital mortality of 9% (15/166). Peri-operative spinal cord ischemia (SCI) was observed in 15 patients (9%), including permanent paraplegia in two (1.2%). Mean follow up was 29.2 ± 21 months. During follow up 40 patients died, two of them probably from aneurysm related cause. Re-intervention, mostly by endovascular means, was needed in 40 (24%) patients. Estimated survival at 1, 2, and 5 years was 83% ± 3%, 78% ± 3.5%, and 66.6% ± 6.1%, respectively. Estimated target vessel stent patency at 1, 2, and 5 years was 98% ± 0.6%, 97% ± 0.8%, and 94.2% ± 1.5%, respectively. Estimated freedom from re-intervention at 1 and 3 years was 88.3% ± 2.7%, and 78.4% ± 4.5%, respectively.

CONCLUSIONS

Endovascular repair of TAAA with fenestrated and branched stent grafts in high volume centers appears safe and effective in the mid-term in a high risk patient cohort. A considerable reintervention rate should be acknowledged, however.

Contemporary outcomes of open repair of thoracoabdominal aortic aneurysm in young patients

Background

Endovascular technology now permits total endovascular thoracoabdominal aortic aneurysm (TAAA) repair with high volume centres reporting encouraging results. The long-term durability of such stent grafts is unknown, leading to concerns regarding their use in younger patients. This study reports contemporary outcomes of open repair in young patients.

Methods

Outcomes for patients age 60 or younger undergoing open TAAA repair between June 1999 and August 2013 with prospective collected data were analysed retrospectively.

Results

Thirty-seven patients (31 men, 84%) with a median age of 56 (range 22–60) were identified with a median TAAA diameter of 6.9 cm (range 5.6-11). Aneurysm aetiology included degenerative change (18), dilation of chronic dissection (10), connective tissue disease (7) and mycotic degeneration (2). Crawford Type IV TAAA were most commonly treated (17), followed by Type II (10), Type III (7) and Type I (3). Two (5%) patients died in hospital, one from multiple organ failure and one from respiratory failure. Three patients (8%) developed temporary paraplegia, all of whom made a complete recovery and 4 (11%) patients required temporary renal replacement therapy. Median critical care stay was 5 days (range 2–28) with an in-hospital stay of 14 days (range 7–83). During a median follow-up of 72 months (range 13–171), no patient subsequently required any further aneurysm related surgical or radiological intervention. The mean (SEM) survival time was 138.5 (11) months. The 5 year survival was 79.7% (8.3) including early deaths, with no aneurysm related complications.

Conclusions

The outcome of open TAAA repair in patients aged less than 60 years is favorable. It is against these results that evolving endovascular interventions must be compared.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-014-0195-4) contains supplementary material, which is available to authorized users.

Abdominal aortic aneurysm-repair devices

Traditional open aneurysm repair is associated with significant perioperative morbidity. The development of abdominal aneurysm-repair devices has provided a minimally invasive alternative to open repairs. The field of aneurysm-repair devices is burgeoning since the approval of the first device in 1999. A clear perioperative survival advantage and lower perioperative morbidity has been reported by multiple studies. In addition to benefiting the normal risk aortic aneurysm patient, this new technology is making the repair of aneurysms in older patients with high operative risk factors possible. Modifications to devices are introduced rapidly to overcome anatomical limitations and to improve on device-related complications such as endoleaks and migration. Limited long-term outcomes are available for newer devices, and life-long surveillance is still recommended for all patients. Patient selection and preoperative planning are the cornerstones to successful endovascular repair of abdominal aortic aneurysms.

A New Technique of Branched Stent Graft Treatment for Ruptured Thoracoabdominal Aortic Aneurysms

Endovascular repair of thoracoabdominal aortic aneurysms (TAAAs) using a branched stent graft is a technically challenging procedure. A 64-year-old man with multiple medical problems, including severe renal impairment, is presented with a ruptured type IV TAAA. He underwent emergency repair using an off-the-shelf branched stent graft and carbon dioxide as the exclusive contrast agent.

Preservation of aortic arch branches using chimney and sandwich stent grafts

PURPOSE

To share our hybrid endovascular experiences using chimney or sandwich stent grafts for acute aortic arch pathologies.

METHODS

Hybrid procedures for a distal aortic arch aneurysm and an ascending anastomotic aortic aneurysm rupture were reported. Right to left common carotid and left axillar artery bypasses were located. Covered stents were inserted into the inominate artery, with the flow-proximal end located in the ascending (standard chimney) or the descending aortic stent graft (retrograde sandwich).

RESULTS

Both cases had no signs of brain ischemia. Aneurysms are decreasing in size.

CONCLUSION

Chimney and sandwich techniques were technically feasible in the complex and acute situations.

Endovascular device design in the future: transformation from trial and error to computational design

Endovascular devices have been designed by trial and error, with bench and animal testing followed by human clinical trials to determine whether the devices are safe and effective. Despite remarkable advances over the past 15 years, there are persistent concerns regarding the long-term durability of endovascular devices. This may be due to deficiencies in device design, which has lagged behind other industries in adopting computational methods that are now routinely used to design, develop, and test new aircraft and automobiles. Similar computational design and failure mode simulations that evaluate performance under stress conditions have not been widely applied in the development of endovascular devices. Advances in medical imaging and computational modeling now allow simulation of physiological conditions in patient-specific 3-dimensional vascular models, which can provide a framework to design and test the next generation of endovascular devices. This modeling will allow the prospective design of devices that can withstand the force variations in the cardiovascular system that occur during bending, coughing, and varying degrees of exercise, as well as the extremes encountered during sudden impact in contact sports. Utilization of computational design methodology that takes into consideration the physiology of the cardiovascular system will improve future endovascular devices so that they are safer and more effective and durable.