Surgical correction of descending thoracic aortic aneurysms under simple aortic cross-clamping

Thoracic stent graft versus surgery for thoracic aneurysm

BACKGROUND

Thoracic aortic aneurysm (TAA) is an uncommon disease with an incidence of 10.4 per 100,000 inhabitants. It occurs mainly in older individuals and is evenly distributed among both sexes. There are no signs or symptoms indicative of the presence of the disease. Progressive but unpredictable enlargement of the dilated aorta is the natural course of the disease and can lead to rupture. Open chest surgical repair using prosthetic graft interposition has been a conventional treatment for TAAs. Despite improvements in surgical procedures perioperative complications remain significant. The alternative option of thoracic endovascular aneurysm repair (TEVAR) is considered a less invasive and potentially safer technique, with lower morbidity and mortality compared with conventional treatment. Evidence is needed to support the use of TEVAR for these patients, rather than open surgery. This is an update of the review first published in 2009.

OBJECTIVES

This review aimed to assess the efficacy of TEVAR versus conventional open surgery in patients with thoracic aortic aneurysms.

SEARCH METHODS

For this update the Cochrane Vascular Information Specialist searched the Specialised Register (last searched January 2016) and CENTRAL (2015, Issue 12).

SELECTION CRITERIA

Randomised controlled trials in which patients with TAAs were randomly assigned to TEVAR or open surgical repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified and evaluated potential trials for eligibility. Excluded studies were further checked by another author. We did not perform any statistical analyses as no randomised controlled trials were identified.

MAIN RESULTS

We did not find any published or unpublished randomised controlled trials comparing TEVAR with conventional open surgical repair for the treatment of thoracic aortic aneurysms.

AUTHORS' CONCLUSIONS

Stent grafting of the thoracic aorta is technically feasible and non-randomised studies suggest reduction of early outcomes such as paraplegia, mortality and hospital stay. High quality randomised controlled trials assessing all clinically relevant outcomes including open-conversion, aneurysm exclusion, endoleaks, and late mortality are needed.

Cohort comparison of thoracic endovascular aortic repair with open thoracic aortic repair using modern end-organ preservation strategies

BACKGROUND

Pivotal trials showed that thoracic endovascular aortic repair (TEVAR) has improved outcomes compared with open surgery for treating descending thoracic aortic aneurysms. However, those trials included historical open controls in which modern end-organ preservation strategies were not routinely employed. To create a more level assessment, we compared our outcomes of elective TEVAR with modern open thoracic aortic repair (OTAR) controls.

METHODS

A retrospective review of thoracic aortic aneurysm patients undergoing TEVAR was compared with a contemporaneous cohort of OTAR patients. Partial bypass or hypothermic circulatory arrest was used in all OTAR patients. Cerebrospinal fluid drain placement was attempted in all patients. Preoperative characteristics, operative variables, and outcomes were recorded, and the Kaplan-Meier method was used for survival estimates.

RESULTS

The main outcome was mortality. Secondary outcomes included postoperative spinal cord ischemia (SCI) or stroke, and any persistent neurologic deficit 30 days following the operation. During the study period, 62 patients underwent TEVAR and 56 underwent OTAR with median follow-up of 23.7 months and 36.4 months, respectively. No difference existed between the TEVAR and OTAR with respect to overall neurologic complications (8.1% vs. 12.5%, P = 0.55) as well as any residual neurologic deficit at 30 days (0% vs. 5.4%, P = 0.10). TEVAR patients had fewer complications including pneumonia (P = 0.02), rebleeding (P = 0.02), and acute kidney injury (P = 0.001). There was no difference in 30-day mortality (1.6% vs. 8.9%, P = 0.10), 1-year mortality (12.2% vs. 14%, P = 0.80), or 5-year mortality (53.9% vs. 44%, P = 0.48) between TEVAR and OTAR, respectively.

CONCLUSIONS

TEVAR continues to show improved perioperative outcomes with a trend toward decreased 30-day mortality and fewer major adverse events compared with OTAR. However, with the routine use of end-organ preservation strategies during OTAR, neurologic deficits, particularly SCI, can be safely reduced to comparable levels with those of TEVAR and 1-year all-cause mortality rates are similar between the groups. These OTAR results may serve as a benchmark as TEVAR is increasingly applied for other aortic pathologies, such as chronic dissection, wherein long-term efficacy is not proven.

Thoracic stent graft versus surgery for thoracic aneurysm

BACKGROUND

Thoracic aortic aneurysm (TAA) is an uncommon disease with an incidence of 10.4 per 100,000 inhabitants. It occurs mainly in older individuals and is evenly distributed among both sexes. There are no signs or symptoms indicative of the presence of the disease. Progressive but unpredictable enlargement of the dilated aorta is the natural course of the disease and can lead to rupture. Open chest surgical repair using prosthetic graft interposition has been a conventional treatment for TAAs. Despite improvements in surgical procedures perioperative complications remain significant. The alternative option of thoracic endovascular aneurysm repair (TEVAR) is considered a less invasive and potentially safer technique, with lower morbidity and mortality compared with conventional treatment. Evidence is needed to support the use of TEVAR for these patients, rather than open surgery.

OBJECTIVES

The aim of this review is to assess the efficacy of TEVAR versus conventional open surgery in patients with TAAs.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched March 2013) and CENTRAL (2013, Issue 2).

SELECTION CRITERIA

Randomised controlled trials in which patients with TAAs were randomly assigned to TEVAR or open surgical repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified and evaluated potential trials for eligibility. Excluded studies were further checked by another author. We did not perform any statistical analyses as no randomised controlled trials were identified.

MAIN RESULTS

We did not find any published or unpublished randomised controlled trials comparing TEVAR with conventional open surgical repair for the treatment of thoracic aortic aneurysms.

AUTHORS' CONCLUSIONS

Though stent grafting of the thoracic aorta is technically feasible and non-randomised studies suggest reduction of early outcomes such as paraplegia, mortality and hospital stay, high quality randomised controlled trials assessing all clinically relevant outcomes including open-conversion, aneurysm exclusion, endoleaks, and late mortality are needed.

Emergency procedures on the descending thoracic aorta in the endovascular era

BACKGROUND

Thoracic endovascular aortic repair (TEVAR), initially developed for the treatment of degenerative aneurysms of the descending thoracic aorta, has been applied to the entire spectrum of descending thoracic aortic pathology in both the elective and emergent settings. This single center study evaluates the effectiveness of TEVAR for the treatment of acute surgical emergencies involving the descending thoracic aorta, including traumatic aortic disruption (TAD), ruptured descending thoracic aneurysm (RDTA), and acute complicated Type B dissection (cTBD).

METHODS

A retrospective review of the medical records of all patients undergoing emergent TEVAR at the University of Mississippi Medical Center between August 2007 and November 2010 was undertaken. Patients were studied for 30-day survival, complications, type of device used for the repair, and technical aspects of the procedure.

RESULTS

A total of 44 patients (59% male) with an average age of 49 years (range, 16-87 years) underwent emergent TEVAR during the study period. The technical success rate was 100%, with no patient requiring emergent open surgery for conditions involving the descending thoracic aorta at our institution during the study period. The majority (73%) of the repairs were accomplished using commercially available thoracic stent grafts. Abdominal endograft proximal extension cuffs were used in 12 (38%) of the 32 patients undergoing repair of TAD. Twenty-one patients (48%) required coverage of the left subclavian artery, two (10%) of whom subsequently required subclavian artery revascularization. Procedure-related complications included two strokes, one spinal cord ischemia, one unintentional coverage of the left carotid artery, one episode of acute renal failure, and three access site injuries. One patient undergoing repair of TAD had collapse of the stent graft in the early postoperative period. He was successfully treated by placement of an additional stent graft. Seven patients (16%) died within 30 days of surgery. Three of the deaths occurred in patients who had successfully undergone repair of a TAD and died of associated injuries.

CONCLUSIONS

Emergent TEVAR has become the treatment of choice for acute surgical emergencies involving the descending thoracic aorta. Short-term morbidity and mortality compare favorably with historic results for emergent open surgical procedures on the descending thoracic aorta. Survival is highest in patients undergoing repair of TAD. Using current endograft technology, nearly all emergent conditions of the descending thoracic aorta can be successfully treated with TEVAR.

The effects of operative indication and urgency of intervention on patient outcomes after thoracic aortic endografting

BACKGROUND

Endovascular repair for complex thoracic aortic pathology has emerged over the past decade as an alternative to open surgical repair. Reports suggest lower morbidity and mortality rates associated with endovascular interventions. The purpose of this report was to analyze a large single institution experience in endovascular thoracic aortic repair based on clinical presentation as well as within and outside specific instructions for use.

METHODS

Records of all patients undergoing thoracic aortic endografting at our institution were retrospectively reviewed for demographics, interventional indications and acuity, operative details, and clinical outcomes. Study outcomes were analyzed by clinical presentation (urgent/emergent vs elective) and aneurysm morphology that was within and outside specific instructions for use as recommended by the manufacturer.

RESULTS

Between March 2006 and October 2009, 96 patients underwent thoracic endografting for aneurysm (n = 43), transection (n = 7), penetrating ulcer (n = 11), dissection (n = 19; acute = 9, chronic = 10), pseudoaneurysm (n = 11), or miscellaneous indications (n = 5). Endografting was performed with various endografts (Gore TAG: 59; Medtrontic Talent: 26; Zenith-TX2: 7; Combination: 4.Involvement of the arch (n = 42, 43.75%) was treated with subclavian artery coverage without revascularization in 13 (13.5%), debranching in 20 (20.8%), and fenestration/stenting in 9 (9.38%). Involvement of the visceral vessels (n = 24, 25%) was treated with debranching in 15 (15.6%) or fenestration/stenting in 9 (9.4%). Patients had a mean follow-up of 11.5 ± 10.96 (range: 0-38) months. Overall mortality was 6.25% (n = 6). Mean intensive care unit stay was 6.26 ± 8.55 (range: 1-63, median: 4) days, and hospital stay was 9.97 ± 10.31 (range: 1-65, median: 65) days. Major complications were infrequent and included: spinal cord ischemia (n = 6, 6.25%), stroke (n = 6, 6.25%), myocardial infarction (n = 3, 3.15%), renal failure (n = 6, 6.25%), and wound complications (n = 9, 9.38%). Reoperation was required in 13 (13.54%), with early intervention in 2 (2.1%). The vast majority of patients were discharged directly to home (n = 66, 68.8%). There were no significant differences between death (1/49 [2%] vs 5/47 [10.6%], P = .07), stroke (3/49 [6%] vs 3/47 [6%], P = 1.0), or spinal cord ischemia (3/49 [6%] vs 3/47 [6%], P = 1.0) when comparing urgent/emergent presentation to elective cases, respectively. However, there were significant differences in death (6/58 [10.5%] vs 0/38 [0%], P = .04) and spinal cord ischemia (6/58 [10.5%] vs 0/38 [0%], P = .04) but not stroke (5/58 [8.8%] vs 1/38 [2.5%], P = .24] when procedures were performed outside the specific instructions for use.

CONCLUSIONS

Results of this single-institution report suggest that endovascular thoracic aortic repair is a safe and effective treatment option for a variety of thoracic pathology including both elective and emergent cases. However, off-label usage of the devices is associated with a significantly higher risk of mortality and spinal cord ischemia, but the risk still appears acceptable given the majority of cases were emergent.

Thoracic stent graft versus surgery for thoracic aneurysm

BACKGROUND

Thoracic aortic aneurysm (TAA) is an uncommon disease with an incidence of 10.4 per 100,000 inhabitants. It occurs mainly in older individuals and is evenly distributed among both sexes. There are no signs or symptoms indicative of the presence of the disease. Progressive but unpredictable enlargement of the dilated aorta is the natural course of the disease and can lead to rupture. Open chest surgical repair using prosthetic graft interposition has been a conventional treatment for TAAs. Despite improvements in surgical procedures perioperative complications remain significant. The alternative option of thoracic endovascular aneurysm repair (TEVAR) is considered a less invasive and potentially safer technique, with lower morbidity and mortality compared with conventional treatment. Evidence is needed to support the use of TEVAR for these patients, rather than open surgery.

OBJECTIVES

The aim of this review is to assess the efficacy of TEVAR versus conventional open surgery in patients with TAAs.

SEARCH STRATEGY

The Cochrane Peripheral Vascular Diseases Group searched their Trials Register (last searched 10 October 2008), the Cochrane Central Register of Controlled Trials database (CENTRAL) (last searched The Cochrane Library 2008, Issue 4).

SELECTION CRITERIA

Randomised controlled trials in which patients with TAAs were randomly assigned to TEVAR or open surgical repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified and evaluated potential trials for eligibility. Excluded studies were further checked by another author. We did not perform any statistical analyses as no randomised controlled trials were identified.

MAIN RESULTS

We did not find any published or unpublished randomised controlled trials comparing TEVAR with conventional open surgical repair for the treatment of thoracic aortic aneurysms.

AUTHORS' CONCLUSIONS

Though stent grafting of the thoracic aorta is technically feasible and non-randomised studies suggest reduction of early outcomes such as paraplegia, mortality and hospital stay, high quality randomised controlled trials assessing all clinically relevant outcomes including open-conversion, aneurysm exclusion, endoleaks, and late mortality are needed.

Predictors of morbidity and mortality with endovascular and open thoracic aneurysm repair

BACKGROUND

Open and endovascular thoracic aneurysm repairs are associated with significant complications including paraplegia, stroke, vascular insufficiency, and death. Predictors of adverse outcomes are not well-defined in this patient population.

METHODS

The database of the GORE TAG (W.L. Gore, Flagstaff, Ariz) Pivotal Trial comparing the TAG endograft to open repair was interrogated. Univariate (UVA) and multivariate analyses (MVA) of demographic, clinical, anatomic, and procedural variables were conducted to discover possible predictors of serious adverse events for the whole group and for the TAG and open cohort groups separately. Early adverse outcomes occurred within 30 days or the initial hospitalization. P value of < or = .05 was significant.

RESULTS

A total of 140 TAG and 94 open descending thoracic aneurysm (DTA) patients were analyzed, consisting of 128 men and 106 women. Perioperative deaths were 9/94 for open surgery and 3/140 for TAG patients, with 10/12 (7 open, 3 TAG) deaths occurring in men. Two female deaths were both after open surgery. Multivariate analysis showed predictors of death for all patients were symptomatic aneurysms and male gender. Analysis of a combined morbidity/mortality endpoint (stroke/paralysis/MI/death) showed elevated creatinine predicted these events for the whole group. Open surgery (P < .001) and increasing aneurysm diameter (P < .001) predicted an increased likelihood of any major adverse event. Open surgery was significantly associated with an increased risk of paraplegia (P = .002). Vascular complications were more frequent in the TAG (19%) than in open DTA patients (9%) (P = .038). Female gender (P = .01) predicted vascular complications within the endovascular group. For all analyses, long procedure times were correlated with adverse events. Women were noted to have longer procedure times for both TAG and open repairs.

CONCLUSION

Elevated creatinine levels and symptomatic aneurysms predict morbidity and mortality, respectively, regardless of repair type. Male gender predicted death after open surgery, and since most deaths (9 of 12) were in this group, male gender predicted death overall, despite women's more difficult endovascular TAA repairs as evidenced by longer procedure times and higher vascular complication rates. All major adverse events and paraplegia were more common for open surgery patients.

Stent graft treatment for transverse arch and descending thoracic aorta aneurysms

PURPOSE OF REVIEW

The aim of this article is to review the recent relevant literature on endovascular repair of thoracic aortic aneurismal disease.

RECENT FINDINGS

The introduction of endovascular stent graft technology has ushered in a new era in therapy for diseases of the aortic arch and descending thoracic aorta. The technical challenges of stent graft deployment in the descending thoracic aorta, such as proximity to the great vessels and arch tortuosity, have been and remain a device engineering focus. More recently, repair of aortic arch aneurysms has been accomplished using both 'hybrid' (open and endovascular) and totally endovascular techniques.

SUMMARY

Endovascular stent grafting of aneurismal disease processes of the thoracic aorta is feasible and relatively safe. Exquisite judgment is essential for good results. These results generally rest on a broad knowledge base of thoracic aortic disease processes and experience in both open and endovascular surgery. Careful attention to patient anatomy and device specifications must be maintained. The key to the successful implementation of this technology lies in careful preoperative planning, intraoperative execution with safe device delivery, and prevention of central nervous system injury. Routine follow-up imaging is imperative to better understand the long-term results and indications for these new procedures.

Endovascular stent grafting versus open surgical repair of descending thoracic aortic aneurysms in low-risk patients: A multicenter comparative trial

OBJECTIVE

Results are presented from the first completed multicenter trial directed at gaining approval from the US Food and Drug Administration of endovascular versus open surgical repair of descending thoracic aortic aneurysms.

METHODS

Between September 1999 and May 2001, 140 patients with descending thoracic aneurysms were enrolled at 17 sites and evaluated for a Gore TAG Thoracic Endograft. An open surgical control cohort of 94 patients was identified by enrolling historical and concurrent subjects. Patients were assessed before treatment, at treatment, and at hospital discharge and returned for follow-up visits at 1 month, 6 months, and annually thereafter.

RESULTS

One hundred thirty-seven of 140 patients had successful implantation of the endograft. Perioperative mortality in the endograft versus open surgical control cohort was 2.1% (n = 3) versus 11.7% (n = 11, P < .001). Thirty-day analysis revealed a statistically significant lower incidence of the following complications in the endovascular cohort versus the surgical cohort: spinal cord ischemia (3% vs 14%), respiratory failure (4% vs 20%), and renal insufficiency (1% vs 13%). The endovascular group had a higher incidence of peripheral vascular complications (14% vs 4%). The mean lengths of intensive care unit stay (2.6 +/- 14.6 vs 5.2 +/- 7.2 days) and hospital stay (7.4 +/- 17.7 vs 14.4 +/- 12.8 days) were significantly shorter in the endovascular cohort. At 1 and 2 years' follow-up, the incidence of endoleaks was 6% and 9%, respectively. Through 2 years of follow-up, there were 3 reinterventions in the endograft cohort and none in the open surgical control cohort. Kaplan-Meier analysis revealed no difference in overall mortality at 2 years.

CONCLUSIONS

In this multicenter study early outcomes with descending aortic endovascular stent grafting were very encouraging when compared with those of a well-matched surgical cohort. However, at 2 years' follow-up, there is an incidence of endoleaks and reinterventions associated with endovascular versus open surgical repair. Continued vigilant surveillance of patients treated with an endograft is important.

Stent-graft versus open-surgical repair of the thoracic aorta: Mid-term results

OBJECTIVE

Pivotal and comparative trial data are emerging for stent graft (SG) vs open repair of the thoracic aorta. We reviewed procedure-related perioperative morbidity, mortality, and mid-term outcomes in a contemporary series of patients treated with SG of the thoracic aorta. The data were compared with those of a patient cohort concurrently treated with open surgical repair confined to the descending aorta.

METHODS

A review of patients undergoing SG procedures and open surgery of the thoracic aorta from January 1, 1996, to November 30, 2005, was performed from a prospectively compiled database. Study end points included perioperative complications, late survival, freedom from reinterventions, and graft-related complications. Multivariate methods were used to assess variables potentially associated with study end points; late outcomes were compared with actuarial methods.

RESULTS

In 105 patients (mean age, 70 years; 66 male [62.9%]) SG repairs were done for 68 degenerative aneurysms (64.7%), 12 penetrating ulcers (11.4%), 15 pseudoaneurysms (14.3%), 9 traumatic tears (8.6%), and 1 acute dissection (0.9%). Mean follow-up was 22 months (range, 0 to 101 months). Eighty-nine (84.8%) SG patients were asymptomatic at presentation and underwent elective repair, whereas 16 (15.2%) presented with acute conditions and underwent urgent repair. Perioperative mortality was 7.6% (8/105), and actuarial survival at 48 months was 54% +/- 7%. The perioperative mortality rate among SG patients treated for degenerative pathology was 10.4% (8/77). Seven (6.7%) of 105 patients experienced spinal cord ischemic complications, including 2 patients with transient paraparesis that resolved by the time of discharge. Reinterventions were performed in 10.5% of patients (11/105), with freedom from reintervention approaching 81% by 48 months. Over the same interval, 93 patients were treated with open-surgical repair for descending thoracic aneurysm (anastomosis cephalad to the celiac axis). Perioperative mortality in the open cohort was 15.1% (14/93; P = .09 vs SG repair), and the 48-month actuarial survival was 64% +/- 6%. The incidence of spinal cord ischemic complications was 8.6% (8/93), including 4 patients with transient paraparesis (P = .44 vs SG repair). Nine patients (9.7%) required surgical reintervention during the follow-up period, with 48-month freedom from reintervention approaching 79% (P = .73 vs SG repair).

CONCLUSIONS

Operative mortality was halved with SG, with similar late survival for both cohorts. Reinterventions were required at a nearly identical rate for open repair and SG, and both groups experienced similar rates of spinal cord ischemic complications.

Combined surgical and endovascular treatment of aortic arch aneurysms

BACKGROUND

Traditional repair of aortic arch aneurysms requires cardiopulmonary bypass, hypothermia, and circulatory arrest and is associated with considerable morbidity and mortality. Endovascular stent-graft placement has developed as a safe and effective treatment for various diseases of the descending aorta and, recently, even in delicate anatomic regions such as the aortic arch. The aim of this study is to review our clinical experience with endovascular treatment of aortic arch aneurysms after surgical transposition of supra-aortic vessels.

METHODS

Fifteen patients received thoracic stent-graft implants after aortic debranching for repair of aortic arch aneurysms during the 3-year period ending December 31, 2005. All patients were not candidates for standard endovascular repair due to inadequate proximal landing zones on the aortic arch. Device design and implant strategy were determined by an evaluation of aortic morphology with angiography and computed tomography (CT) scanning. Stent-grafts were used to repair the arch after supra-aortic vessel transposition was performed. The endografts were implanted transfemorally or via an iliac Dacron conduit graft using standardized endovascular techniques. Follow-up was 100% complete (mean, 18 +/- 2.5 months; range, 12 to 36 months). Outcome variables included death and treatment failure (endoleak, aortic rupture, reintervention, or aortic-related or sudden death). Follow-up included clinical examination, chest radiograph, and CT at discharge, 6 months after stent-graft placement, and yearly thereafter.

RESULTS

Stent-graft deployment success was 100% after staged supra-aortic vessel transposition. Patency of all endografts and conventional bypasses was 100%. No endoleak or graft migration was observed. There were no neurologic complications. One patient died 2 months after the procedure from pulmonary complications.

CONCLUSION

Repair of aortic arch aneurysms by sequential transposition of the supra-aortic branches and endovascular stent-graft placement is feasible. Extended application of this technique will enable safe and effective treatment of a highly selected subgroup of patients with aortic aneurysms by avoiding conventional arch aneurysm repair in deep hypothermia and circulatory arrest.

Thoracic aortic stent grafting: Improving results with newer generation investigational devices

OBJECTIVE

Six years ago an endovascular program for repair of descending thoracic aneurysms was established at the University of Pennsylvania. We report on the hypothesis that results are improving with new stent design iterations and describe our experience and lessons learned.

METHODS

From April 1999 to March 2005, 99 patients with descending thoracic aneurysms underwent repair with a first or second-generation commercially produced endograft; 24 patients had an early-generation device, and 75 patients had a late-generation device. Each patient was enrolled as part of 3 distinct Phase I or Phase II Food and Drug Administration-approved clinical trials in accordance with strict inclusion and exclusion criteria.

RESULTS

Mean age was 73.1 years. Symptomatic aneurysms accounted for 42% of the cohort. Mean aneurysm size was 63.7 mm (range: 30-105 mm). Twenty percent of the patients underwent a subclavian carotid transposition or bypass preoperatively to obtain an adequate proximal landing zone. No procedures had to be aborted. In-hospital or 30-day mortality was 5.0%. The incidence of permanent spinal ischemia was 2%. Perioperative vascular complications requiring interposition graft, stent repair, or patch angioplasty occurred in 27% and seemed to be less frequent in the late-generation cohort than the early-generation cohort (22.7% vs 41.7%, respectively, P = .069). At the 30-day follow-up, 23 endoleaks were detected in 22 patients (14.7% in late-generation cohort vs 45.8% in early-generation cohort, P = .001). During the follow-up period, 3 new endoleaks were detected, 3 patients died of aortic rupture, and 10 patients underwent aneurysm-related reintervention. Kaplan-Meier estimated 1, 3, and 5-year survival was 84.5%, 70.5%, and 52.4%, respectively. Freedom from aneurysm-related event, defined as freedom from endoleak, aortic rupture, dissection, or any reintervention on the aorta, was 73%, 69%, and 64% at 1, 3, and 5 years, respectively.

CONCLUSION

Thoracic aortic stent grafting is a safe procedure in selected patients with the added benefit of a low incidence of paraplegia. However, there is an incidence of late complications and reinterventions. This risk requires further quantification and must be balanced against the benefits of a minimally invasive approach with low perioperative morbidity and mortality. Results are improving as technology evolves and our level of experience increases. Radiologic follow-up is mandatory.

Endovascular treatment of thoracic aortic aneurysms: Results of the phase II multicenter trial of the GORE TAG thoracic endoprosthesis

OBJECTIVE

A decade after the first report of descending thoracic aortic aneurysm (DTA) repair with endografts, a commercial device is yet to be approved in the United States. The GORE TAG endoprosthesis, an investigational nitinol-supported expanded polytetrafluoroethylene tube graft with diameters of 26 to 40 mm, is the first DTA device to enter phase II trials in the United States and has been used worldwide for a host of thoracic pathologies.

METHODS

A multicenter prospective nonrandomized phase II study of the GORE TAG endoprosthesis was conducted at 17 sites. Enrollment was from September 1999 to May 2001. Preoperative workup included arteriography and spiral computed tomography scans of the chest, abdomen, and pelvis. Follow-up radiographs and computed tomography scans were obtained at 1, 6, and 12 months and yearly thereafter.

RESULTS

A total of 139 (98%) of 142 patients had a successful implantation of the device. Inadequate arterial access was responsible for the 3 failures. The mean DTA size was 64.1 +/- 15.4 mm. Men slightly outnumbered women (57.7%), with an average age of 71 years, and 88% of the patients were white. Ninety percent were American Society of Anesthesiologists category III or IV. One device was used in 44% of patients, and 56% required two or more devices to bridge the thoracic aorta. The left subclavian artery was covered in 28 patients, with planned carotid-subclavian transposition. The procedure time averaged 150 minutes, estimated blood loss averaged 506 mL, intensive care unit stay averaged 2.6 days, and hospital stay averaged 7.6 days. Within 30 days, 45 (32%) patients had at least 1 major adverse event: 5 (4%) experienced a stroke, 4 (3%) demonstrated temporary or permanent paraplegia, 20 (14%) experienced vascular trauma or thrombosis, and 2 (1.5%) died. Mean follow-up was 24.0 months. Four patients had aneurysm-related deaths. Three patients underwent endovascular revisions for endoleak. No ruptures have been reported. Twenty wire fractures have been identified in 19 patients; 18 (90%) of these occurred in the longitudinal spine, and only 1 patient required treatment. At 2 years, aneurysm-related and overall survival rates are 97% and 75%, respectively.

CONCLUSIONS

The GORE TAG thoracic endoprosthesis provides a safe alternative for the treatment of DTAs, with low mortality, relatively low morbidity, and excellent 2-year freedom from aneurysm-related death. Longitudinal spine fractures have so far been associated with rare clinical events.

The effects of intraoperative fenoldopam on renal blood flow and tubular function following suprarenal aortic cross-clamping

This study evaluated the effect of fenoldopam, a selective dopamine (DA1) agonist, on renal blood flow and renal tubular function following renal ischemia induced by suprarenal aortic cross-clamping. Twenty anesthetized research pigs received either fenoldopam (10 micro g/kg/min; n = 10) or saline ( n = 10) beginning 20 min before suprarenal aortic cross-clamping and continuing for 20 min after clamp release, for a total infusion time of 160 min (120-min cross-clamp). Recordings of renal blood flow, mean arterial pressure, and heart rate were taken at baseline, during cross-clamping, and immediately postclamp. Ischemic renal injury was evaluated by serum creatinine and by histologic grading of acute tubular necrosis. Treatment with fenoldopam increased renal blood flow in comparison to that in the control group ( p = 0.03). The mean creatinine increase from baseline at 6 hr and 18 hr after cross-clamp removal for the fenoldopam-treated group was significantly less than that in the control group ( p < 0.001). On histologic evaluation, the mean score for the degree of tubular necrosis was significantly higher in the control group ( p = 0.02), indicating less derangement of tubular morphology in the fenoldopam group. This study demonstrated that the intraoperative use of a continuous infusion of fenoldopam during suprarenal aortic cross-clamping results in increased renal blood flow, less postoperative rise in creatinine, and better preservation of tubular histology in the pig model.

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.

Distal aortic arch replacement for aneurysmal disease: the value of preparatory carotid subclavian reconstruction

Between November 2000 and January 2002, two patients with aneurysms that involved the distal part of the aortic arch including the left subclavian artery were treated at our institution. Patient 1 had an aneurysm of 5.8 cm extending to the proximal descending aorta. Patient 2 had a 6.8 cm type II thoracoabdominal aneurysm extending proximal to the aortic bifurcation. Both patients had left subclavian-to-carotid transposition in preparation for distal aortic arch replacement. Complete replacement of the descending thoracic and abdominal aorta was carried out in patient 2. Both cases were done with distal aortic perfusion, spinal catheter drainage, and dual lumen endotracheal anesthesia. There was no mortality. There were no cerebrovascular complications in spite of the fact that patient 1 required aortic cross-clamping between the innominate and left carotid artery. There was no paraplegia, renal failure, or mesenteric or lower extremity complications. Patient 1 had postoperative vocal cord palsy, eventually requiring medialization procedure. He recovered normal voice. Both patients remain alive and well at the time of last follow-up (7 to 20 months). Carotid subclavian reconstruction in preparation for distal aortic arch replacement facilitates the performance of the proximal anastomosis and attempts to maintain flow through the left vertebral system during aortic cross-clamping. This may reduce the risk of stroke during distal aortic arch replacement.

Clinical application of a curved nitinol stent-graft for thoracic aortic aneurysms

PURPOSE

To evaluate the clinical efficacy of a curved nitinol stent-graft for repair of thoracic aortic aneurysms.

METHODS

The Matsui-Kitamura stent-graft (MKSG), composed of a self-expanding nitinol stent and polyester fabric, was shaped to match the aortic curvature of 11 patients (6 men; mean age 72.6 years, range 33-90) with 6 true and 5 false aneurysms of the distal arch or proximal descending aorta. The delivery system was an 18 or 20-F J-shaped sheath combined with a preloader-type introducer. The original mean proximal neck length was 16.4 mm, but 4 patients received an axilloaxillary bypass to lengthen the neck. Although the mean corrected proximal neck length was 21.9 mm (overall), 5 cases still had proximal necks <15 mm long.

RESULTS

All curved MKSGs were successfully deployed in the correct position and fitted to the curvature of the aortic arch, achieving complete aneurysm exclusion in 8 (73%) cases. The other 3 repairs displayed early endoleaks; 1 received an additional MKSG, but the other 2 are being observed. Thirty-day mortality was 0%. One patient developed transient renal failure requiring hemodialysis; no neurological complications were observed.

CONCLUSIONS

Endovascular repair of thoracic aortic aneurysms using curved MKSGs appears to be feasible and clinically effective. A tighter fit of the device to the curvature of the aortic arch may exclude distal arch aneurysms despite a short proximal neck.

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 treatment of descending thoracic aortic aneurysms and dissections

Various endovascular techniques have become viable therapeutic alternatives in the treatment of patients with many types of descending thoracic aortic pathology and aortic dissections. Descending thoracic aortic aneurysms can be successfully treated using stent grafts. This technique is less invasive and is associated with acceptable morbidity and mortality rates. Patients who are particularly likely to benefit include the very elderly population; those with markedly compromised cardiac, pulmonary, or renal status; and individuals who have previously undergone complex operations on the thoracic aorta. Other endovascular methods, such as aortic flap fenestration, stent, or covering of the primary intimal tear in the descending thoracic aorta with a stent graft, have also been effectively employed in the treatment of peripheral arterial complications of aortic dissection. Despite the reported early success of these endovascular percutaneous methods, true assessment of the effectiveness of these various techniques awaits long-term follow-up evaluation in large patient populations.

Thoracic aortic aneurysm repair with an endovascular stent graft: the "first generation"

OBJECTIVE

The feasibility and efficacy trial of an endovascular stent-grafting system for the treatment of aneurysms of the descending thoracic aorta was investigated.

METHODS

After Institutional Review Board approval, 103 patients (mean age 69 years) underwent stent graft repair of a descending thoracic aortic aneurysm between July 1992 and November 1997. The stent graft was fabricated using self-expanding "Z" stents covered by a woven Dacron tube graft. Follow-up, which averaged 22 months, was 100% complete. Simultaneous open abdominal aortic aneurysm repair was performed in 19 patients.

RESULTS

Complete aneurysm thrombosis was achieved in 86 patients (83%). Early mortality, defined as a death during the same hospitalization or in less than 30 days, was 9 +/- 3%, and was significantly associated with preoperative cerebrovascular accident (CVA) or myocardial infarction. Major perioperative morbidity occurred in 31 patients, and included paraplegia in 3, CVA in 7, and respiratory insufficiency in 12 patients each. Actuarial survival was 81 +/- 4% at 1 year, and 73 +/- 5% at 2 years. Treatment failure (including all late, sudden, unexplained deaths) occurred in 38 patients, and only 53 +/- 10% of patients were free of treatment failure at 3.7 years. Five patients required late operative therapy for endoleaks associated with aneurysm enlargement.

CONCLUSIONS

Satisfactory results were achieved using this "first-generation" homemade stent graft device. Mortality and morbidity occurred frequently, but may have been associated with the high-risk character of this patient population. Medium-term results were acceptable, but continued aortic enlargement, with the late development of endoleaks, is a significant concern. Second-generation devices with commercial development, coupled with this initial experience, should allow improved clinical results in the future. Longer term follow-up is still necessary to fully define the efficacy of this endovascular approach.

Strategies to prevent neurologic deficit based on motor-evoked potentials in type I and II thoracoabdominal aortic aneurysm repair

PURPOSE

Motor-evoked potentials (MEPs) were monitored during thoracoabdominal aortic aneurysm (TAAA) repair to assess spinal cord ischemia and evaluate the subsequent protective strategies to prevent neurologic deficit.

METHODS

Between January 1996 and December 1997, 52 consecutive patients with type I (n = 24) and type II (n = 28) TAAA underwent surgery (mean patient age, 60 years; range, 21-78 years). The surgical protocol included left heart bypass, cerebrospinal fluid drainage, and monitoring transcranial myogenic MEPs. When spinal cord ischemia was detected, distal aortic pressure and mean arterial pressure were increased. By means of sequential crossclamping, MEPs were used to identify critical intercostal or lumbar arteries.

RESULTS

Reproducible MEPs could be recorded in all patients, and spinal cord ischemia was detected within 2 minutes. During distal aortic perfusion, 14 patients (27%) showed rapid decrease in the amplitude of MEPs to less than 25% of baseline, indicating spinal cord ischemia, which could be corrected by increasing distal aortic pressure. The mean distal aortic pressure to maintain adequate cord perfusion was 66 mm Hg; however, it varied among individuals between 48 and 110 mm Hg. In 24 patients (46%), MEPs disappeared after segmental clamping and returned after reattachment of intercostal arteries. In 9 patients (17%), MEPs disappeared completely, but no intercostal arteries were found. After aortic endarterectomy, 6 or 8 mm Dacron grafts were anastomosed to intercostal arteries, and MEPs returned after reperfusion. Using this aggressive surgical approach based on MEPs, no early or late paraplegia occurred in this series.

CONCLUSION

Monitoring of MEPs is an effective technique to assess spinal cord ischemia. Operative strategies based on MEPs prevented neurologic deficits in patients treated for type I and II TAAA.

The "first generation" of endovascular stent-grafts for patients with aneurysms of the descending thoracic aorta

OBJECTIVE

Our goal was to determine whether endovascular stent-grafting is feasible and effective for patients with aneurysms of the descending thoracic aorta.

METHODS

Starting in July 1992, we conducted a prospective, uncontrolled clinical trial in 103 patients (mean age 69 years [range 34-89 years]) who underwent endovascular treatment of aneurysms of the descending thoracic aorta using a custom-fabricated, self-expanding stent-graft device. Follow-up was 100% complete and averaged 22 months. Sixty-two patients (60%) were judged not to be reasonable candidates for a conventional "open" surgical procedure.

RESULTS

Complete thrombosis of the aneurysm was ultimately achieved in 86 (83%) patients. The early mortality rate was 9% +/- 3% (+/- 70% CL). Multivariable analysis revealed that myocardial infarction or stroke was linked with a higher likelihood of early death (P = .001). Early serious complications included paraplegia in 3% +/- 2% and stroke in 7% +/- 3%. Actuarial survival estimates at 1 year and 2 years were 81% +/- 4% and 73% +/- 5% (+/- 1 SE), respectively; being judged not to be a surgical candidate portended a higher probability of death (P = .003). According to the intent-to-treat principle, "treatment failure" (including all late sudden unexplained deaths) occurred in 38 patients; 53% +/- 10% of patients were free from treatment failure at 3.7 years. Stent-graft related complications occurred commonly and were linked with several anatomic, technical, and patient-related risk factors.

CONCLUSIONS

This 5-year clinical trial involving use of a "first generation" device indicates that endovascular stent-grafting of descending thoracic aortic aneurysms is feasible with acceptable medium-term results. More refined, commercially developed devices available today offer less traumatic and more precise stent-graft deployment; these major technical advantages, coupled with important lessons we have learned over time and better patient selection, should be associated with more salutary clinical results in the future.

Spinal cord complications of thoracoabdominal aneurysm surgery

BACKGROUND

Although rare, paralysis secondary to spinal cord ischaemia after aortic aneurysm surgery is a devastating complication. Many papers have been published on this topic but without a clear consensus on the best way of minimizing the problem. Recent articles have included advanced pharmacological approaches and the literature has been reviewed in light of these.

METHODS

Relevant papers were identified by an extensive text word search of the Medline database and a review of quoted articles.

RESULTS

Spinal cord complications are commoner after the repair of Crawford type II aneurysms than less extensive aneurysms. The presence of dissection, rupture and prolonged clamp times are associated with an increased incidence. About a quarter of all cord problems develop over 24 h after surgery and this may be due to a reperfusion type injury, although the exact mechanisms are by no means clear.

CONCLUSION

A combination of rapid surgery, left heart bypass for the repair of more extensive aneurysms, free spinal drainage and the avoidance of postoperative hypoxia and hypotension help to minimize spinal cord ischaemia. No pharmacological agent has yet been shown conclusively to improve outcome in the clinical setting.

Simultaneous abdominal aortic replacement and thoracic stent-graft placement for multilevel aortic disease

PURPOSE

Patients with aneurysmal disease involving both the descending thoracic and abdominal aorta have historically required simultaneous or sequential conventional operations, but the morbidity rate is high with either approach in these patients, who often exhibit coexisting cardiopulmonary disease. Transluminally placed endovascular grafts have recently been developed for repair of aortic aneurysms, and we have implemented these techniques to eliminate the need for a thoracotomy in patients with multilevel aortic disease.

METHODS

Since January 1994, 18 patients have undergone conventional abdominal aortic replacement with endovascular stent-graft placement into the descending thoracic aorta under fluoroscopic guidance through a 10 mm Dacron side limb off the abdominal graft. Abdominal aortic replacement required a tube graft in eight patients and bifurcated grafts in 10 patients. Thoracic stent-grafts (custom fabricated, woven Dacron covered, self-expandable stents) averaged 12.2 +/- 4.2 cm (mean +/- SD) in length.

RESULTS

One patient died, resulting in a hospital mortality rate of 6%. No patients required further surgical intervention to treat their aortic disease. Seventeen patients (94%) are currently well 14 +/- 8 months after surgery (range, 3 to 29 months) with completely excluded thoracic aortic disease, no stent migration, and no change in stent configuration documented by serial radiologic examinations.

CONCLUSIONS

Simultaneous abdominal aortic replacement and deployment of a thoracic stent-graft can safely exclude multilevel aortic aneurysmal disease and may be a valuable treatment option for these otherwise high-risk patients.

Surgical and long-term outcome of graft replacement of aneurysms of the descending thoracic aorta. Analysis of 28 consecutive cases

A consecutive series of 28 patients operated on at the Oulu University Hospital during the years 1974-1994 for aneurysms of the descending thoracic aorta is presented. Twenty-five cases were elective and three were operated on as emergencies. Their mean age was 58 years. During the aortic cross-clamp, circulatory support of the lower body, was used in 27 cases as follows: a direct aorto-femoral shunt without a pump (12/28), left-heart bypass (11/28) or femoro-femoral perfusion (4/28). Hospital mortality was 14% (4/28). One patient with a ruptured aneurysm died of renal failure, but there were no other renal complications. None had paraplegia postoperatively. Three had symptoms of paraparesis, but only one of them had a slight permanent discomfort while walking. The mean follow-up time was 100 months, range 2-242 months. Late actuarial survival including hospital mortality, was 65% at 5 years and 41% at 10 years, reflecting the generalized aortic disease with a high risk of very late rupture (4) and other manifestations of atherosclerosis with myocardial infarction (6) or cerebral atherosclerosis (1), the remaining late deaths being unrelated. The efficacy of lower body circulatory support in avoiding peroperative renal and spinal cord ischaemic complications is demonstrated.

[Mechanisms and prediction of hemorrhagic complications during surgery of thoraco-abdominal aortic aneurysms]

This study, including 33 consecutive patients was designed to assess the haemostatic alterations occurring during repair of thoracoabdominal aneurysms. The surgical procedure consisted in Dacron graft replacement of the diseased aorta, using neither cardiopulmonary bypass, nor any shunting technique, nor any heparin. Blood samples were drawn before anaesthesia, before and 30 min after unclamping, and on the first postoperative day. The measured parameters were: haematocrit, platelet count, bleeding, activated cephalin, thrombin and prothrombin times, and concentrations of fibrinogen, factors V, VII, X and II, anti-thrombin III, proteins C and S, fibrin degradation products, D-dimers, alpha 2-antiplasmin, plasminogen, tissue plasminogen activator, plasminogen activator inhibitor, and serum protein. Eight patients developed severe multiple haemorrhages; 3 of them died during the procedure because of uncontrollable bleeding. Although the measured parameters were similar in the "bleeding" and control (n = 25) groups before surgery, there was, before unclamping in the first group, an important increase in activated cephalin and thrombin times, with a fall in concentrations of factor II and V, protein C, fibrinogen, and alpha 2-antiplasmin, and in platelet numbers. After unclamping, these changes worsened further, with an increase in prothrombin time and in fibrinogen levels (0,8 g.l-1), without any increase in fibrin degradation products. Abnormal bleeding started about 30 min after this in all the patients of the "bleeding" group. These changes, involving the fibrinolytic system as well as a fall in concentration of all the coagulation factors, can probably be partly explained by the clamping and unclamping of mesenteric vessels.(ABSTRACT TRUNCATED AT 250 WORDS)