Thoracoabdominal aortic aneurysm: hybrid repair outcomes

Open, closed or a bit of both: a systematic review and meta-analysis of staged thoraco-abdominal aortic aneurysm repair

Background

Staged procedures are one strategy found to be beneficial for medium- to high-risk Crawford extent I-III thoraco-abdominal aortic aneurysm (TAAA) repair patients and may be performed through a variety of techniques. This review sought to compare the primary outcomes of spinal cord ischemia (SCI) and long-term mortality between three cohorts grouped by approach: open, endovascular, and hybrid.

Methods

In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a total of 919 references were extracted from a search of three online databases (Embase, PubMed, Scopus). Following application of inclusion/exclusion criteria and data extraction, quantitative meta-analysis was undertaken utilizing a random effects model. Kaplan-Meier (KM) curves were digitized and aggregated to graph estimated survival.

Results

A total of 20 studies representing 924 patients were included. SCI was highest in the endovascular group, at 9.8% of weighted means, followed by hybrid, and open groups at 3.2% and 1.4%, respectively. However, 30-day mortality was highest in the open group at 6.0%, followed by the hybrid group at 3.8%, and endovascular at 3.6%. Aggregated long-term survival estimations are shown graphically, extending to 5 years for open and endovascular cohorts, and 3 years for the smaller hybrid cohort.

Conclusions

While all cases incorporated spinal drainage, monitoring and staging for spinal protection, there is innate difference in approach when examining for cord ischemia. This systematic review and meta-analysis of staged TAAA repair describes the first comparison between cohorts of open and endovascular approach, revealing the increased risk of SCI and long-term mortality in endovascular repair.

Unusual hybrid repair of a thoracoabdominal and mesenteric aneurysm with aberrant right hepatic artery

Hybrid approaches for the treatment of thoracoabdominal aortic aneurysms that combine visceral debranching and endovascular repair are feasible alternatives to open surgery for certain high-risk patients. A 70-year-old man was admitted with a rapidly expanding thoracoabdominal aneurysm involving the superior mesenteric artery, associated with an aberrant hepatic artery. An iliovisceral debranching was performed, followed by the endovascular repair of the thoracoabdominal aorta with a standard thoracic device. The ostial aneurysm was excluded by retrograde implantation of a covered stent from the superior mesenteric artery. Such approach can be considered as a viable alternative in the management of complex thoracoabdominal aneurysms.

Successful Surgical Abdominal Aortic Debranching Preceding Stent Graft Implantation: A Case Report

Background  Acute endovascular aneurysm repair with stent grafts (thoracic endovascular aortic repair [TEVAR]) is safe and feasible.

Case Description  A 64-year-old female presented with a perforated aortic aneurysm of the thoracic descending aorta. Primary TEVAR resulted in good management of the perforation but a type Ib endoleakage remained postoperatively. To place another stent, abdominal debranching with saphenous vein bypass to the celiac trunk was required. In the same session, another endograft was inserted successfully.

Conclusion  Abdominal debranching is a safe alternative to open aortic repair in acute thoracic and abdominal aneurysms, instead of waiting for a custom-made device.

Thoracoabdominal aortic aneurysm repair: open, endovascular, or hybrid?

Successful repair of complex thoracoabdominal aortic aneurysms requires careful surgical planning based on anatomic and patient considerations. Not only are surgical considerations key, but also post-operative care, regardless of surgical approach, can dramatically impact both short- and long-term outcomes. While open repair has been the gold standard for decades, the technical challenges associated with operative repair, a specialty approach requisite for good outcomes, and the unique challenges in the post-operative care of these patients have given providers pause when considering operative intervention. The relatively recent development of elegant endovascular and hybrid approaches to this problem has shown improved short-term morbidity and reasonable durability. Here, we discuss these three techniques for correction of complex thoracoabdominal aortic aneurysms to provide some guidance for optimization of outcomes based on individual patient anatomy and comorbid conditions.

Debranching aortic surgery

Conventional open surgery still remains as the gold standard of care for aortic arch and thoracoabdominal pathology. In centers of excellence, open repair of the arch has been performed with 5% immediate mortality and a low rate of complications; however overall mortality rates are around 15%, being up to 40% of all patients rejected for treatment due to their age or comorbidities. For thoracoabdominal aortic pathology, data reported from centers of excellence show immediate mortality rates from 5% to 19%, spinal cord ischemia from 2.7% to 13.2%, and renal failure needing dialysis from 4.6% to 5.6%. For these reasons, different alternatives that use endovascular techniques, including debranching procedures, have been developed. The reported results for hybrid debranching procedures are controversial and difficult to interpret because series are retrospective, heterogenic and including a small number of patients. Clearly, an important selection bias exists: debranching procedures are performed in elderly patients with more comorbidities and with thoracoabdominal aortic aneurysms that have more complex and extensive disease. Considering this fact, debranching procedures still remain a useful alternative: for aortic arch pathology debranching techniques can avoid or reduce the time of extracorporeal circulation (ECC) or cardiac arrest which may be beneficial in high-risk patients that otherwise would be rejected for treatment. And compared to pure endovascular techniques, they can be used in emergency cases with applicability in a wide range of anatomies. For thoracoabdominal aortic aneurysms, they are mainly useful when other lesser invasive endovascular options are not feasible due to anatomical limitations or when they are not available in cases where delaying the intervention is not an option.

Complementary roles of open and hybrid approaches to thoracoabdominal aortic aneurysm repair

OBJECTIVE

Thoracoabdominal aortic aneurysm (TAAA) repair remains a significant challenge with considerable perioperative morbidity and mortality. A hybrid approach utilizing visceral debranching with endovascular aneurysm exclusion has been used to treat high-risk patients and therefore allow repair in more patients. Limited data exist regarding long-term outcomes with this procedure as well as comparison to conventional open repair. This study describes our institutional algorithmic approach to TAAA repair using both open and hybrid techniques.

METHODS

Hybrid and open TAAA repairs performed between July 2005 and August 2015 were identified from a prospectively maintained institutional aortic surgery database. Perioperative morbidity and mortality, freedom from reintervention, and long-term and aorta-specific survival were calculated and compared between the two groups.

RESULTS

During the study period, 165 consecutive TAAA repairs were performed, including 84 open repairs and 81 hybrid repairs. Patients in the hybrid repair group were significantly older, were more frequently female, and had a generally greater comorbid disease burden, including significantly more chronic kidney disease. Despite the older and sicker cohort, there was no difference in in-hospital mortality between the two groups (9.9% hybrid vs 7.1% open; P = .59). Major morbidity rates differed by procedure, with patients undergoing open repair having a significantly higher rate of postoperative stroke (9.5% open vs 0% hybrid; P = .017), whereas patients undergoing hybrid repair had a higher rate of new permanent dialysis (14.8% hybrid vs 3.6% open; P = .043). There was no difference between groups in the rate of postoperative permanent paraplegia/paresis (8.3% open vs 7.4% hybrid; P = .294). There was a significantly increased rate of reintervention in the hybrid repair group (12.3% hybrid vs 1.2% open, P = .004), with all hybrid reinterventions performed because of endoleak. One-year survival was similar between groups at 69% in hybrid repairs vs 77% in open repairs. Long-term survival was worse in the hybrid group (5-year survival, 32% hybrid vs 56% open), although late survival appeared to be influenced mainly by comorbid disease burden, given the similar long-term aorta-specific survival between groups.

CONCLUSIONS

Use of an algorithmic approach whereby higher risk patients with TAAA are treated by a hybrid approach and lower risk patients with conventional open repair yields satisfactory short- and long-term outcomes. The availability of multiple options for TAAA repair within a single center likely allows repair in more patients with consequent decrease in the risk of aorta-related death, at the expense of increased reinterventions for endoleak.

[Endovascular versus conventional vascular surgery - old-fashioned thinking? Part 1: interventions on the aorta]

Endovascular therapy has widely replaced conventional open vascular surgical reconstruction. For this reason both techniques were widely considered to be competing approaches. Evidence-based data from randomized prospective trials, meta-analyses and clinical registries, however, demonstrated that both techniques should be used to complement each other. It became increasingly more evident that the use of either procedure depends on the underlying disease and the anatomical conditions, whereby a combination of both (hybrid approach) may be the preferred option in certain situations. This review focuses on the treatment of complicated acute type B aortic dissection, descending thoracic aortic aneurysms, thoracoabdominal aortic aneurysms as well as asymptomatic and ruptured abdominal aortic aneurysms.

Fiber-optic Monitoring of Spinal Cord Hemodynamics in Experimental Aortic Occlusion

BACKGROUND

Spinal cord ischemia occurs frequently during thoracic aneurysm repair. Current methods based on electrophysiology techniques to detect ischemia are indirect, non-specific, and temporally slow. In this article, the authors report the testing of a spinal cord blood flow and oxygenation monitor, based on diffuse correlation and optical spectroscopies, during aortic occlusion in a sheep model.

METHODS

Testing was carried out in 16 Dorset sheep. Sensitivity in detecting spinal cord blood flow and oxygenation changes during aortic occlusion, pharmacologically induced hypotension and hypertension, and physiologically induced hypoxia/hypercarbia was assessed. Accuracy of the diffuse correlation spectroscopy measurements was determined via comparison with microsphere blood flow measurements. Precision was assessed through repeated measurements in response to pharmacologic interventions.

RESULTS

The fiber-optic probe can be placed percutaneously and is capable of continuously measuring spinal cord blood flow and oxygenation preoperatively, intraoperatively, and postoperatively. The device is sensitive to spinal cord blood flow and oxygenation changes associated with aortic occlusion, immediately detecting a decrease in blood flow (-65 ± 32%; n = 32) and blood oxygenation (-17 ± 13%, n = 11) in 100% of trials. Comparison of spinal cord blood flow measurements by the device with microsphere measurements led to a correlation of R = 0.49, P < 0.01, and the within-sheep coefficient of variation was 9.69%. Finally, diffuse correlation spectroscopy is temporally more sensitive to ischemic interventions than motor-evoked potentials.

CONCLUSION

The first-generation spinal fiber-optic monitoring device offers a novel and potentially important step forward in the monitoring of spinal cord ischemia.

Splenic artery as a conduit to facilitate visceral arterial reconstruction

Splenic-to-superior mesenteric artery transposition was used to treat proximal celiac in-stent occlusion in one patient and to prepare a landing zone for thoracic endograft treatment of a dissection in another. The proximal splenic artery was used as a conduit to facilitate visceral aortic debranching in four patients. Using the splenic artery as a conduit to preserve or restore celiac perfusion without interrupting liver perfusion is feasible.

Visceral Debranching for the Treatment of Thoracoabdominal Aortic Aneurysms: Based on a Presentation at the 2013 VEITH Symposium, November 19-23, 2013 (New York, NY, USA)

Surgical repair of thoracoabdominal aortic aneurysms (TAAA) is associated with significant morbidity and mortality. Hybrid approaches that involve visceral debranching and aortic endografting allow for an alternative approach in certain high-risk patients. In most circumstances the visceral vessels can be bypassed in a retrograde manner from the iliac arteries via a midline laparotomy, and the aortic aneurysm subsequently excluded with standard aortic endografts. These procedures avoid the extensive two-cavity exposure, aortic cross-clamping, and mechanical circulatory support that comprise open TAAA repair, and offer the theoretical advantage of being less invasive. Despite this, outcomes have been mixed with reported perioperative mortality rates of 0% and 34% and permanent paraplegia rates of 0% to 13% in most major series. The reported outcomes, as well as the variation between centers, highlight the importance of patient selection in undertaking hybrid repair. In practice, the best outcomes are achieved in patients who have high-risk anatomy, rather than high-risk comorbidities.

Visceral debranching thoracic endovascular aneurysm repair for chronic dissecting thoracoabdominal aortic aneurysm

Type II chronic dissecting thoracoabdominal aortic aneurysms are a surgically challenging disease. The conventional thoracoabdominal aortic aneurysm repair technique using cardiopulmonary bypass is a high-risk procedure. However, a recently developed endovascular technique may be an alternative treatment for the disease, but faces the obstacle of lesional restriction. This new technique uses a hybrid strategy to overcome the limits of endovascular thoracoabdominal aortic aneurysm repair. Herein, we report on a successful outcome after performing the hybrid visceral debranching procedure.

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.

Possible graft-related complications in visceral debranching for hybrid B dissection repair

BACKGROUND

Hybrid repair (HR) of thoracoabdominal aortic aneurysm (TAAA) and dissection (TAAD), consisting of rerouting renovisceral branches followed by endograft aortic repair, has been shown to be a feasible option. It is especially appealing in patients unfit for both open and total endovascular repair. In order to determine the role of dissecting etiology and intraoperative variables as risk factors for graft-related complications in visceral debranching, we retrospectively analyzed the clinical outcomes, patency rate and hemodynamic alterations of the renovisceral debranching grafts in our series.

METHODS

We analyzed 55 consecutive patients who underwent thoracoabdominal aortic HR between 2001 and 2013 in our center. Forty-four procedures were performed for TAAA and 11 procedures for TAAD. In TAAD patients, dissection involved 9/44 (20.5%) renovisceral vessels. One hundred and fifty-nine visceral bypasses were made (156 retrograde; three anterograde).

RESULTS

Thirty-day mortality was 12.7% (n=7). Potential graft-related complications included four cases of pancreatitis (7.3%) and five of peri-operative renal failure (9.1%). At a mean follow-up of 36.1 months, the global rate of visceral graft occlusion was 9.4% (15/159), leading to fatal bowel infarction in two patients and kidney loss in seven patients. Actuarial primary patency in renovisceral grafts at 12, 24, and 36 months was 96.3%, 92.6%, and 90.2% respectively. At the level of the anastomosis of the graft to the superior mesenteric artery, significant flow alterations (systolic peak velocity >250 cm/s) were observed during computed flow dynamics analysis in 18.5% of cases. Overall, an additional procedure to ensure patency was required in 19 bypasses intraoperatively and three during follow-up. The presence of aortic dissection had no significant impact on debranching graft-related complications. During multivariate analysis, retropancreatic routing to CT was the only independent predictor of graft-related complications (P=0.006).

CONCLUSIONS

Specific visceral graft-related complications were not uncommon in our series and were often associated with clinical consequences. Hemodynamic alterations of debranching grafts were observed in particular at the level of the anastomosis with the superior mesenteric artery. Careful follow-up is mandatory in order to monitor visceral bypasses and facilitate patency when required.

Current management and outcome of chronic type B aortic dissection: results with open and endovascular repair since the advent of thoracic endografting

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) has become the preferred treatment for chronic type B aortic dissection (CTBAD) at our institution. However, it remains incapable of treating all patients with CTBAD. The present study aims to review our contemporary results with open and endovascular CTBAD repairs since the advent of thoracic endografting.

METHODS

The records of all patients undergoing index repair of CTBAD (chronic DeBakey type IIIA, IIIB and repaired type I) at our institution between June 2005 and December 2013, were retrospectively reviewed.

RESULTS

A total of 107 patients underwent CTBAD repair, of whom 70% (n=75) underwent endovascular-based procedures [44 TEVAR, 27 hybrid arch and four hybrid thoracoabdominal aortic aneurysm (TAAA) repair] and 30% (n=32) underwent open procedures (nine open descending and 23 open TAAA). Connective tissue disease (CTD), prior aortic surgery and DeBakey dissection type were strongly associated with the choice of operation. The rates of stroke, paraplegia and operative mortality following endovascular-based repairs were 0%, 0% and 4% (n=3), respectively. Adverse neurologic events were higher following open repair, and rates of stroke, paraplegia, and operative mortality were 16% (n=5), 9% (n=3), and 6% (n=2), respectively. However, 1- and 5-year survival rates were similar for endovascular-based repairs (86% and 65%, respectively), and open repairs (88% and 79%, respectively). Over a median follow-up interval of 34 months, the rate of descending aortic reintervention was 24% (n=18) following endovascular-based repairs and 0% following open repairs (P=0.001). Forty-four percent (n=8) of descending aortic reinterventions were required to treat stent graft complications (five endoleak, two stent graft collapse and one stent graft-induced new entry tear) and the remainder were required to treat metachronous pathology (n=2) or progressive aneurysmal disease related to persistent distal fenestrations (n=8).

CONCLUSIONS

Endovascular repair of CTBAD was associated with excellent procedural and survival outcomes, but at the expense of further reinterventions. Open repair remains relevant for patients who are not candidates for endovascular repair and was associated with higher procedural morbidity but similar overall survival and fewer reinterventions.

Insurance status predicts acuity of thoracic aortic operations

OBJECTIVE

Nonelective case status is the strongest predictor of mortality for thoracic aortic operations. We hypothesized that underinsured patients were more likely to require nonelective thoracic aortic surgery because of reduced access to preventative cardiovascular care and elective surgical services.

METHODS

Between June 2005 and August 2011, 826 patients were admitted to a single aortic referral center and underwent 1 or more thoracic aortic operations. Patients with private insurance or Medicare (insured group, n=736; 89%) were compared with those with Medicaid or no insurance (underinsured group, n=90; 11%).

RESULTS

The proportion of patients requiring nonelective surgery was higher for underinsured than insured patients (56% vs 26%, P<.0001). Multivariable analysis revealed underinsurance to be the strongest independent predictor of nonelective case status (odds ratio [OR], 2.67; P<.0001). Preoperative use of lipid-lowering medications (OR, 0.63; P<.009) or a history of aortic surgery (OR, 0.48; P<.001) was associated with a decreased risk of nonelective operation. However, after adjustment for differences in preoperative characteristics and case status, underinsurance did not confer an increased risk of procedural morbidity or mortality (adjusted OR, 0.94; P=.83) or late death (adjusted hazard ratio, 0.83, P=.58) when compared with insured patients.

CONCLUSIONS

Underinsured patients were at the greatest risk of requiring nonelective thoracic aortic operation, possibly because of decreased use of lipid-lowering therapies and aortic surveillance. These data imply that greater access to preventative cardiovascular care may reduce the need for nonelective thoracic aortic surgery and lead to improved survival from thoracic aortic disease.