Thoracic aortic aneurysm repair with endovascular stent-grafts

Evaluation of the diameter of the proximal descending thoracic aorta with age: implications for thoracic aortic stent grafting

BACKGROUND

Long-term anatomical changes of the thoracic aorta which may affect long-term outcome of blunt aortic injuries treated with endovascular stent grafts are unknown. The purpose of this study was to examine the natural history of thoracic aortic diameter with progressing age.

METHODS

One thousand consecutive thoracic computed tomographic scans performed for nonthoracic aortic pathology on patients aged 15-99 (mean 59.4) were examined, and thoracic aortic diameter immediately adjacent to the left subclavian artery was measured. Factors possibly influencing diameter, including age by decade of life, race, gender, history of hypertension (HTN), diabetes mellitus (DM), chronic obstructive pulmonary disease (COPD), and tobacco use, were examined. Factors were compared using Student's t-test.

RESULTS

The differences in mean diameters of the thoracic aorta by gender (male=27.1 vs. female=26.0, p=0.87), race (Caucasian=26.6 vs. non-Caucasian=26.3, p=0.10), presence of HTN (yes=25.8 vs. no=24.9, p=0.36), COPD (yes=26.3 vs. no=25.4, p=0.21), DM (yes=26.1 vs. no=25.3, p=0.12), and tobacco use (yes=26.3 vs. no=25.0, p=0.18) were not significant. However, differences in mean diameter increased significantly over time with age. Patients under 40 years old had mean aortic diameters of 22.92 mm compared to 27.09 mm (p<0.001) for patients over 40. The mean aortic isthmus diameter showed an approximately 1cm increase when comparing octogenarians to teenagers.

CONCLUSION

The diameter of the aortic isthmus increases substantially with age. These findings suggest that long-term surveillance is warranted for trauma patients with aortic stent grafts, to monitor the natural history and to assess for possible late complications.

Contemporary Analysis of Descending Thoracic and Thoracoabdominal Aneurysm Repair

Background— Endovascular repair of thoracic aneurysm has demonstrated low risks of mortality and spinal cord ischemia (SCI), but few large series have been published on endovascular thoracoabdominal aneurysm repair, and reports suffer from a lack of accurate comparison with similar open surgical procedures.

Methods and Results— A consecutive cohort of patients with thoracic and thoracoabdominal aneurysms treated electively with endovascular repair (ER) or surgical repair (SR) techniques between 2001 and 2006 were analyzed. The association between repair technique and SCI was evaluated with univariable analysis. Adjustments for potential confounders and for the propensity to receive ER or SR were also performed in multivariable analysis. A total of 724 patients (352 ER, 372 SR) underwent repair. The mean age was 67 years, and 65% were male. ER patients were on average 9 years older ( P <0.001), had more comorbid conditions, and more frequently had prior distal repair ( P <0.001) or underwent a type I or IV repair. SR patients more commonly had chronic dissection or required type II or type III repairs ( P <0.001). Mortality at 30 days (5.7% ER versus 8.3% SR, P =0.2) and 12 months (15.6% ER versus 15.9% SR, P =0.9) was similar. A borderline difference in SCI was found between repair techniques: 4.3% of ER and 7.5% of SR patients ( P =0.08) had SCI. In patients with ER, prior distal aortic operation was associated with the development of SCI in univariable analysis (odds ratio 4.1, 95% confidence interval 1.4 to 11.7). Multivariable analysis showed that the type of required repair (type I, II, III, or IV) was the primary factor associated with the development of SCI in ER and SR patients.

Conclusion— No significant difference in the incidence of mortality or SCI was found between ER and SR techniques. The strongest factor associated with SCI remains the extent of the disease. Further studies are indicated to compare ER with patients considered eligible for SR.

Endovascular Repair of Traumatic Thoracic Aortic Injuries: A Critical Appraisal

Blunt trauma to the thoracic aorta is life-threatening, with instant fatality in at least 75% of victims. If left untreated, nearly half of those who survive the initial injury will die within the first 24 hours. Surgical repair has been the standard treatment of blunt aortic injury, but immediate operative intervention is frequently difficult due to concomitant injuries. Although endovascular treatment of traumatic aortic disruption is less invasive than conventional repair via thoracotomy, this strategy remains controversial in young patients due to anatomical considerations and device limitations. This article reviews the likely advantages of endovascular interventions for blunt thoracic aortic injuries. Potential limitations and clinical outcomes of this minimally invasive technique are also discussed.

Endovascular repair of the descending thoracic aorta: evidence for the change in clinical practice

The purpose was to review outcome data following endovascular repair of the descending thoracic aorta from reports published between 1994 and 2004. To accomplish this task, 1,518 patients underwent endovascular repair for thoracic aortic disease; 810 thoracic aortic aneurysms, 500 type B thoracic aortic dissections, and 106 traumatic ruptures. The 30-day mortality rate was 5.5% and 6% for late postoperative deaths. The primary technical success rate was 97%, with only 15 patients requiring open conversion. Neurologic deficits occurred in 29 patients. In total, 118 endoleaks were reported; 29 were restented, and the remainder required surgical intervention. Graft infection occurred in 6 cases, and migrations were detected in 10. The conclusion reached is that endovascular repair of descending thoracic aortic disease is feasible and can be achieved with low rates of perioperative morbidity and mortality. As few long-term data exist on the durability of thoracic stent grafts, lifelong surveillance remains necessary.

Mid-term Survival and Costs of Treatment of Patients with Descending Thoracic Aortic Aneurysms; Endovascular vs. Open Repair: a Case-control Study

OBJECTIVES

To evaluate the results of open surgery or endovascular stent graft repair of descending thoracic aortic aneurysm (TAA).

DESIGN, MATERIALS AND METHODS

This is a retrospective multicenter study of 95 patients undergoing TAA repair (42 stent grafts, 53 open repair). The median age was 67 years. Post-operative complications, mid-term survival and costs were assessed. The results were pooled with data in the literature.

RESULTS

After a mean follow up of 26 months (open group) and 15 months (endovascular group) survival was similar for patients treated by either repair method. Post-operative pneumonia was more in the open group (p <0.02). The hospital costs of open treatment were 40% more than that of the endovascular procedure. Combining the present results with pooled data from the literature the peri-operative mortality and paraplegia rate was less in the endovascular group (p <0.05).

CONCLUSIONS

These retrospective data suggest that endografting of descending thoracic aneurysms can be performed with less peri-operative morbidity, at lower hospital costs, but with equal mid-term life expectancy, compared with open grafting.

Combined open and endovascular repair of a syphilitic aortic aneurysm

The use of endovascular stent grafts in the repair of thoracic aortic aneurysms has provided an alternative means of treatment, particularly in the high-risk patient who may not tolerate conventional open repair. The combination of conventional surgery and endovascular repair may allow for successful treatment in patients with anatomy unsuitable for repair entirely by endovascular means alone. We present the case of a patient with a syphilitic thoracic aortic aneurysm involving the aortic arch and descending thoracic aorta. He underwent a staged repair with an elephant trunk reconstruction of the aortic arch followed by endovascular repair of the descending thoracic aorta. This is the first reported case of the repair of a syphilitic aneurysm by means of endovascular techniques.

Endovascular treatment of thoracic aortic aneurysms

Endovascular repair of thoracic aortic aneurysms is a promising modality that may someday replace open surgical repair. While stent grafts have been used with moderate success in small to moderate-sized retrospective series, there have been no completed multicenter clinical trials directed at gaining approval from the U.S. Food and Drug Administration. The available data suggest that morbidity and mortality of the procedure may be lowered with endovascular techniques. Paraplegia occurs, but despite the inability to maintain perfusion of intercostal vessels, the rate is at least as low as that associated with open repair. Similar to the minimally invasive repair of infrarenal aneurysms, the trade-off between the open and endovascular approach rests in the necessity to follow patients closely with after endovascular repair. The long-term durability of available devices is unproved, and serial imaging studies must be followed in order to detect device failure prior to the development of devastating clinical sequelae.

Endovascular exclusion of thoracic aortic aneurysms: mid-term results of elective treatment and in contained rupture

PURPOSE

The purpose is to present results of endovascular exclusion (stent-graft treatment) of aneurysms of the descending thoracic aorta both in elective cases and in emergencies.

METHODS

Indications for stent-graft treatment were dependent on multislice angio-CT evaluation revealing a proximal neck of at least 10 mm between the left common carotid artery and the onset of aneurysm. All stent grafts were inserted in the operating room; 43 transfemoral, 2 transiliac. The stent grafts used were Corvita, Stenford, Vanguard, AneuRx, Talent, and Excluder. Deployment was achieved under fluoroscopic control, endoleaks were checked for with D S A on the operating table and postoperatively by angio-CT. Long-term follow-up consisted of evaluation with angio-CT after 6 and 12 months, and from there on once a year and with plain chest X-rays. Follow-up was achieved in all patients.

RESULTS

Mean follow-up is 21 months (1-66); 30-day mortality is 3/45, no permanent neurologic deficit. Thirty patients were treated electively, 15 with contained rupture. Left subclavian artery overstenting proved to be necessary in 12 patients for proper proximal sealing of the aneurysm, type I endoleaks were observed in 10 patients, one early conversion, 7 proximal extension cuffs, one sealed spontaneously, one still at risk. Among patients where LSA had been overstented only one wanted a transposition, all others did well without left-hand ischemia or subclavian steal syndrome.

CONCLUSION

Endovascular treatment is less invasive and has reasonable mortality and morbidity but is limited to well-defined morphologies. Mid-term results are promising but it has to be observed whether these will translate into long-term durability.

Endovascular treatment of thoracic aortic pathology: feasibility and mid-term results

OBJECTIVE

to report our experience with 21 consecutive patients treated with a thoracic stent-graft.

DESIGN

retrospective analysis.

MATERIALS AND METHODS

Between October 1998 and February 2002, 21 patients (12 male), mean age 55.6 years (range 19-86 years), were treated for aorticortic pathology localized to the descending aorta (18 patients), the aortic arch (2 patients) and the ascending aorta (1 patient) and comprising true aneurysms (8 patients), false aneurysms (6 patients), traumatic rupture (4 patients), mycotic aneurysms (2 patients), and ruptured aneurysm (1 patient). Plain chest X-rays and computed tomography was performed at 3, 6 and 12 months postoperatively and then annually.

RESULTS

the median (range) operation time was 85min (50-305min), hospital stay 6 days (3-63 days) and follow-up 24 months (5-44 months). Complications occurred in 5 patients and comprised intraoperative migration (1), type I endoleak (1), type II endoleak (1), ischemic myelopathy (1), pneumonia (2), suture granuloma (1) and common femoral artery dissection (1).

CONCLUSIONS

stent-grafting can be successfully employed to treat a wide range of thoracic aortic pathologies with a mortality, morbidity and resource utilization that is considerably less than that associated with conventional surgery. However, long term follow-up on safety and efficacy is needed.

Management of traumatic rupture of the thoracic aorta in pediatric patients

BACKGROUND

Traumatic rupture of the thoracic aorta (TRA) in the pediatric population is uncommon. Management of TRA in general has evolved to include selective nonoperative and endovascular stent graft approaches, although operative repair remains the standard.

METHODS

We conducted a retrospective chart review of patients younger than 16 years of age admitted to a single institution between March 1985 and February 2002.

RESULTS

Of 160 patients admitted with TRA, 11 were younger than 16 (11.9 +/- 3.5) years of age. Concomitant injuries included closed head injury (5 patients) and acute lung injury (6 patients). All were started on beta-blockers when the diagnosis was suspected. Laparotomy was required in 3 patients and orthopedic procedures in 5 patients. Six underwent operative repair (two primary repairs), with no mortality. Cross-clamp time was 30.4 +/- 2.6 minutes. One patient (operated on without bypass) was partially paralyzed. Two patients were managed nonoperatively, 1 with an intimal arch injury, who on subsequent follow-up has demonstrated healing, and 1 who died of head injury. Three patients were managed by endovascular stent grafts, 2 who died of closed head injury and 1 who at 1-year follow-up has fully recovered. The endovascular stent grafts were placed through the femoral artery in 2 patients and through an iliac conduit in 1 patient. No patient died of rupture.

CONCLUSIONS

The approach to pediatric TRA should be identical to the adult, with early institution of beta-blockers. Depending on the clinical setting, a spectrum of options should be considered, including operation, non-operation, and endovascular stent graft, although the choice of the latter must be tempered by the lack of long-term follow-up data.

Transient paraplegia after stent grafting of a descending thoracic aortic aneurysm treated with cerebrospinal fluid drainage

We present a case of descending thoracic aortic aneurysm repair using an endovascular stent graft, complicated by postoperative paraplegia, which was successfully treated by placing a spinal drain. The case highlights the importance of the concept of collateral flow to the spinal cord and of choosing an anesthetic technique that allows immediate postoperative evaluation of lower extremity neurologic function.

Endovascular repair of thoracic aortic aneurysms: a paradigm shift in standard of care

The standard open surgical treatment of thoracic aortic aneurysms is associated with significant morbidity and mortality. Endovascular repair is less invasive and potentially less morbid for patients with multiple risk factors. The authors report their results in 9 consecutive high-risk patients treated with endovascular grafts from January 1998 through June 2000. There were 7 men and 2 women patients with an average age of 75 years. Mean aneurysm diameter was 7.1 cm. All aneurysms were repaired with Gianturco Z-stent polytetrafluoroethylene prostheses. There were no perioperative deaths. Mean length of stay was 6.3 days. Technical success was achieved in all 9 patients. Two patients had neurologic complications following repair (1 patient with transient lower extremity numbness related to spinal arthritis and 1 patient with bowel and bladder incontinence). Both patients were independent with ambulation. Mean follow-up was 15.8 months. There was no evidence of endoleak or stent migration during the follow-up period. These findings support endovascular treatment of high-risk patients with thoracic aneurysm.

Thoracic aortic stent grafts--early experience from two centres using commercially available devices

OBJECTIVES

open surgical intervention for aneurysms of the distal arch and descending thoracic aorta is associated with high morbidity and mortality. Stent grafts offer an attractive alternative treatment for these aneurysms. The aim of this study was to assess the morbidity and mortality of endovascular treatment for these aneurysms with stent grafts.

DESIGN, PATIENTS AND METHODS

a prospective observational study was performed of 37 consecutive patients treated from July 1997 to October 2000 (30 at Guy's and St. Thomas' and 7 at Sheffield). Indications included degenerative aneurysms (n=18), false aneurysm (5), acute dissection (4), aortic transection (4), aneurysm related to previous surgery for coarctation (3), chronic dissection (2) and traumatic dissection (1). Nineteen were performed as elective and 18 as non-elective procedures.

RESULTS

three non-elective patients died in hospital (in-hospital and 30-day mortality 8%) and one suffered a stroke with spontaneous full recovery. No elective patient died. One patient with a persistent proximal endoleak required conversion to open repair at 6 weeks. Two patients with persistent flow into the sac at 24 h spontaneously thrombosed at subsequent 3 month follow-up. Two further patients developed new distal endoleaks at 3 months and required distal extension cuffs. One patient died at 28 months of aortic rupture. Serial CT scans had shown prolapse of the stent graft into the aneurysm sac and the patient died just before planned endovascular repair. No patient suffered paraplegia or renal failure. Intensive care facilities were only required for patients who needed them preoperatively.

CONCLUSIONS

thoracic stent grafts can be performed with low morbidity and mortality. They offer a realistic alternative to open surgery. Long term follow up is required to assess their durability.

Changes in aneurysm morphology and stent-graft configuration after endovascular repair of aneurysms of the descending thoracic aorta

OBJECTIVE

We sought to study changes in morphology and stent-graft configuration of descending thoracic aortic aneurysms after endovascular repair.

METHODS

Twenty-three patients treated with custom-made stent-grafts were studied. The stent-graft consisted of continuous, stainless-steel Z stents mounted within a polyester graft. In the last 11 cases the stents were interconnected with 3 longitudinal wires. Contrast-enhanced spiral computed tomography was performed preoperatively and at 1, 3, and every 6 months postoperatively. Angiography was used preoperatively and at 1-year follow-up. Proximal and distal necks were assessed for diameter and length. Aneurysm diameter, endoleaks, stent-graft migration, and changes in stent-graft configuration were evaluated.

RESULTS

During follow-up (median, 18 months; range, 1-48 months), excluded aneurysms decreased in diameter by 4 mm (0.5-10 mm, P =.0018). Endoleaks prevented size decrease. Five patients displayed neck dilatation, 4 at both the proximal and distal fixation sites and 1 only distally. In 7 (30%) patients there was proximal migration of the distal end of the stent-graft. Three (13%) patients displayed both distal migration of the proximal end of the stent-graft and proximal migration of the distal end of the stent-graft. There was a significant correlation between stent-graft kinking and appearance of proximal or distal stent-graft migration (P =.05 and P =.0007, respectively). In no case did the migration lead to appearance of an endoleak before intervention was performed.

CONCLUSION

Excluded descending thoracic aortic aneurysms decrease in size on midterm follow-up. A subgroup of patients prone to neck dilatation might exist. A combination of neck dilatation and vector forces acting on stent-grafts in the tortuous thoracic aorta might lead to stent-graft migration.

Midterm results of stent-graft repair for thoracic aortic aneurysms: computed tomographic evaluation

Midterm observation of endovascular surgery using a fabric-covered stent graft for thoracic aortic aneurysms is discussed with postoperative follow-up findings based on regularly performed thoracic computed tomography (CT). From 1996 to 1999, 20 patients with thoracic aortic aneurysm underwent stent-graft placement in our hospital. One year follow-up CT results after placement were obtained for 17 patients. The CT scans found that there were both thrombosis and size reduction of aneurysm in 8 patients (46%), thrombosis without size reduction in 2 (13%), a new ulcerlike projection (ULP) in 3 (19%), persistent minor endoleakage in 2 (13%), a new endoleak in 1 (6%), and a recurrent endoleak from intercostal arteries in 1 (6%). The new ULP formation seemed to be a peculiar problem stemming from an intimal injury caused by edges of the stent. Therefore, we recently adopted a new spiral stent instead of the previous stent to avoid the injury. The new endoleak suggested that aneurysmal thrombosis without size reduction could cause the aneurysm to develop recurrent endoleaks. From these findings, we concluded that midterm observation of stent-graft repair for thoracic aortic aneurysms did not give satisfactory results. In order to improve the results of endovascular surgery using stent-grafts, we need to develop safer stent grafts with a reliable design to prevent endoleaks and to avoid intimal injury of the aorta. We also hope to develop effective technologies that can accelerate organization of thrombus in the aortic aneurysm after stent-graft placement.

Staged thoracic and abdominal aortic aneurysm repair using stent graft technology and surgery in a patient with acute renal failure

A 52-year-old male presented with severe hypertension and acute renal failure. Carbon dioxide (CO(2)) angiography identified a saccular thoracic aortic aneurysm, right renal artery stenosis, left renal artery occlusion, an infrarenal aortic aneurysm, celiac artery, and inferior mesenteric artery (IMA) orificial stenoses. Via an anterior retroperitoneal approach, bilateral renal artery thromboendarterectomy, infrarenal aortic aneurysmectomy, and IMA reimplantation were performed. The patient's tortuous iliac arteries were straightened to permit future passage of a thoracic stent graft by mobilizing the aortic bifurcation and anastomosing it to a Dacron graft within 4 cm of the renal vessels. Two weeks later, a stent graft was placed via a femoral incision utilizing CO(2) angiography, successfully excluding the saccular thoracic aneurysm. Recovery from both procedures was quick, with rapid return of renal function, and alleviation of the hypertension. At 8 months follow-up, his renal arteries and aorta are patent.

Endovascular repair of descending thoracic aortic aneurysms: an early experience with intermediate-term follow-up

PURPOSE

The purpose of this study was to report an initial experience with the endovascular repair of descending thoracic aortic aneurysm. Complications and intermediate-term morphologic changes were identified with the intent of altering patient selection and device design.

METHODS

Endografts were placed into 25 patients at high-risk for conventional surgical repair over a 3(1/2)-year period. Devices were customized on the basis of preoperative imaging information. Follow-up computed tomography scans were obtained at 1, 3, 6, and 12 months and yearly thereafter. Additional interventions occurred in the setting of endoleaks, migration, and aneurysm growth.

RESULTS

The overall 30-day mortality rate was 20% (12.5% for elective cases; 33% for emergent cases). There were 3 conversions to open repair. Neurologic deficits developed in 3 patients; 1 insult resulted in permanent paraplegia. Neurologic deficits were associated with longer endografts (P =.019). Three endoleaks required treatment, and 1 fatal rupture of the thoracic aneurysm treated occurred 6 months after the initial repair. Migrations were detected in 4 patients. The maximal aneurysm size decreased yearly by 9.15% (P =.01) or by 13.5% (P =.0005) if patients with endoleaks (n = 3 patients) were excluded. Both the proximal and distal neck dilated slightly over the course of follow-up (P =.019 and P =.001, respectively). The length of the proximal neck was a significant predictor of the risk for endoleakage (P =.02).

CONCLUSION

The treatment of descending thoracic aortic aneurysms with an endovascular approach is feasible and may, in some patients, offer the best means of therapy. Early complications were primarily related to device design and patient selection. All aneurysms without endoleaks decreased in size after treatment. Late complications were associated with changing aneurysm morphologic features and device migration. The morphologic changes remain somewhat unpredictable; however, alterations in device design may result in improved fixation and more durable aneurysm exclusion.

The use of endovascular stents in the treatment of penetrating ulcers of the thoracic aorta

Penetrating atheromatous ulcers of the aorta are increasingly recognized as a distinct entity. Although their natural history remains ill-defined, such ulcers may lead to pseudoaneurysmal formation, dissection, rupture, or embolization. Given the morbidity associated with open repair, endovascular repair of penetrating atheromatous ulcers may be the treatment of choice. Although stent-graft replacement of acute aortic dissections has recently been described, endovascular repair of penetrating thoracic aortic ulcers has not previously been reported. We report two cases of successful endovascular repair of penetrating atheromatous ulcers that previously ruptured.

Management of aortobronchial fistula with an aortic stent-graft

Aortobronchial fistula presenting as massive hemoptysis is a rapidly fatal process that is extremely difficult to manage. We report a case in which endovascular occlusion of a fistula between a thoracic aortic pseudoaneurysm and lung was successfully managed by placement of an aortic endovascular stent-graft. Stent-grafting is a promising technique in managing complications of thoracic aneurysms and grafts.

New imaging techniques in endovascular surgery

Imaging requirements for endovascular surgery are quite different from imaging requirements for open surgical procedures. As with the entire field of endovascular surgery, imaging techniques and recommendations are changing rapidly. Preoperative imaging is crucial--once deployed, an endograft cannot be retrieved without conversion to open surgical repair. As with any surgical procedure, patient selection and preoperative planning are at least as important as technical skills and at least as difficult to learn. Nonetheless, good imaging technology is no substitute for good judgement. Endovascular procedures are also unique because intraoperative and postoperative imaging are also keys to the success of the procedure. Postoperative imaging techniques are evolving more slowly as long-term data are gathered but seem to be vitally important.