Present and Future of Branched Stent Grafts in Thoraco-abdominal Aortic Aneurysm Repair: A Single-centre Experience

Thoracoabdominal Aortic Aneurysm Repair Using Fenestrated and Branched Endovascular Grafts for High-Risk Patients: Evolving yet Safe

PURPOSE

The purpose was to investigate outcomes of high-risk patients undergoing thoracoabdominal aortic aneurysm (TAAA) repair using fenestrated or branched endovascular aneurysm repair (F/BEVAR) devices at a single center in Canada.

MATERIALS AND METHODS

A retrospective review of all patients undergoing endovascular TAAA repair with F/BEVAR from June 2007 to July 2020. Imaging and clinical endpoints of interest including death, reintervention, and target vessel patency were reported.

RESULTS

Ninety-five consecutive patients underwent endovascular TAAA repair using F/BEVAR stent grafts (63 males, median age 74 [interquartile range 70, 78] years). Repairs included 81 elective and 14 urgent/emergent cases (6 ruptures and 8 symptomatic). Graft deployment was 100% successful. Intraoperative target vessel revascularization was successful in 336/355 (94.6%) vessels with the celiac having the lowest success rate 72/82 (87.8%). In-hospital mortality was 9.5% (7.4% elective and 21.4% urgent/emergent, p=0.125) and permanent paraplegia was 4.2% (3.7% elective and 7.1% urgent/emergent, p=0.458). In-hospital complications included stroke in 5.3%, acute myocardial infarction in 8.4%, and bowel ischemia in 5.3%. No patients required permanent dialysis or tracheostomy during their hospital stay. However, 22 (23.2%) patients required additional unplanned procedures for various indications (branch occlusion, endoleaks, realignment) during their hospital stay. Patients were followed up for a mean of 3.6 ± 3.0 years. Clinical follow-up was 100%, with 80/86 (93%) having surveillance imaging. On follow-up imaging, 43 (50%) patients had at least 1 endoleak identified and 337/341 (98.8%) of the target vessels were found to be patent. At 5 years, cumulative probability of reintervention was 46.3% (95% confidence interval [CI], 36.1-56.4). Survival at 5 and 8 years was 50.1% (95% CI, 38.4-65.4) and 34.4% (95% CI, 22.5-52.8), respectively. Progression of aneurysmal disease leading to rupture on follow-up was confirmed in 1 patient at 10 years.

CONCLUSION

Endovascular TAAA repair provides a safe treatment option with a high technical success rate and low pulmonary and renal complications. Long-term survival is similar to previous literature; however, high rates of secondary reintervention reaffirm the need for ongoing patient follow-up and further technical improvements.

CLINICAL IMPACT

This study demonstrates that endovascular repair of TAAAs can be performed in a high-risk elderly population with acceptable rates of mortality, TALE and SCI, using evolving technology. The incidences of post-operative respiratory failure and renal dysfunction were lower in patients who underwent endovascular repair compared with open repair. Future technical and procedural refinements in addition to increasing surgical experience are expected to lead to further improvements in short- and long-term outcomes exceeding those of open repair.

A Novel Bypass Technique to Prevent Vexing Spinal Cord Ischemia in Endovascular Thoracoabdominal Aortic Intervention

BACKGROUND

Spinal cord ischemia remains a devastating complication when treating patients with complex thoracoabdominal aortic aneurysms using fenestrated endovascular aortic repair. This approach is progressively deployed. However, to date, no strategy has been identified to reduce the feared risk of spinal cord ischemia.

OBJECTIVE

To introduce a novel bypass technique using a customized composite graft to create a direct extra-anatomic revascularization before fenestrated endovascular aortic repair in patients with high-risk of spinal cord ischemia.

METHODS

To demonstrate this novel concept, we present here a clinical case that reports the strategy of this novel concept in detail. An 83-year-old man with medical history of endovascular repair of an abdominal aortic aneurysm and thoracic aorta presented with a type IA endoleak, located along the posterior superior aspect of the aortic stent graft adjacent to the lumbar arteries. A multidisciplinary plan was developed, which included a novel bypass from the profunda femoris to the left L1 radicular artery before fenestrated endovascular aortic repair to prevent spinal cord ischemia.

RESULTS

The patient successfully receives the novel extra-anatomic revascularization bypass before fenestrated endovascular aortic repair. During the first implementation of this strategy, no intraoperative difficulties and postoperative complications were observed.

CONCLUSION

This case demonstrates a novel surgical technique before fenestrated endovascular aortic repair for prevention of spinal cord ischemia. In addition, this concept provides a promising direction to not only complement the existing surgical techniques but also to generate more future innovations.

Open conversion after failed endovascular aneurysm repair is increasing and its 30-day mortality is higher than that after primary open repair

BACKGROUND

Endovascular aneurysm repair (EVAR) has become the preferred treatment of abdominal aortic aneurysms (AAAs). Recent studies have demonstrated that cases of EVAR failure repair and subsequent open conversion have increased. The aim of the present study was to evaluate the national trend of annual cases and assess the 30-day outcomes of conversion to open repair after failed EVAR compared with primary open repair.

METHODS

The National Surgical Quality Improvement Program database was queried for relevant Current Procedural Terminology and International Classification of Diseases, Ninth and Tenth Revision, codes to identify patients who had undergone conversion to open repair or primary open repair of nonruptured AAAs from 2009 to 2018. The annual trend of cases was assessed, and the perioperative outcomes of both procedures were compared. Multivariable logistic regression analyses were conducted to identify independent perioperative factors associated with mortality.

RESULTS

Of the 9635 patients with nonruptured AAAs included in the present analysis, 9250 had undergone primary repair and 385 had required open conversion. During the 10-year period, the annual number of cases of open conversion had steadily increased and that of primary repair had decreased. The incidence of postoperative complications was similar between both groups, except for cardiac arrest, which had occurred more frequently in the open conversion group. The 30-day mortality was higher in the open conversion group than in the primary group (9.6% vs 3.9%; P < .0001). Open conversion was also independently associated with higher odds of death (adjusted odds ratio [OR], 2.1; 95% confidence interval [CI], 1.8-2.4; P < .0001). When the average mortality in both groups was compared between the first and last 5 years, no difference was found (open conversion: 9.8% vs 9.5% [P = 1.00]; primary repair: 3.6% vs 4.2% [P = .19]). Other perioperative factors independently associated with mortality included increased age (OR, 1.8; 95% CI, 1.5-2.1; P < .0001), American Society of Anesthesiologists class ≥III (OR, 2.7; 95% CI, 1.1-6.6; P = .029), insulin-dependent diabetes (OR, 2.0; 95% CI, 1.2-3.3; P = .005), chronic obstructive pulmonary disease (OR, 1.4; 95% CI, 1.1-1.8; P = .006), the presence of dyspnea at rest (OR, 3.3; 95% CI, 1.8-6.1; P < .0001), and a high preoperative hematocrit (OR, 0.94; 95% CI, 0.93-0.97; P < .0001).

CONCLUSIONS

Open conversion to treat nonruptured AAAs after failed EVAR was independently associated with higher mortality. Also, the annual cases of open conversion have continued to increase without any significant changes in postoperative mortality. This highlights the danger of open conversion and stresses the need for better solutions to prevent and manage EVAR failure.

Extrathoracic collaterals to critical segmental arteries after endovascular thoraco-abdominal aneurysm repair

OBJECTIVES

The risk of spinal cord injury after thoraco-abdominal aortic aneurysm repair increases when the segmental arteries (SAs) in the critical segment are sacrificed. Such critical SAs cannot be reconstructed when performing thoracic endovascular aortic repair (TEVAR). We aimed to elucidate extrathoracic collaterals to the critical SAs (T9-L1) that develop after TEVAR.

METHODS

Between 2006 and 2018, the critical SAs (T9-L1) of 38 patients were sacrificed during TEVAR. Nineteen of these patients who underwent multidetector row computed tomography 6 months after surgery were included (mean age 60 ± 13 years; 10 male; Crawford extent II:III, 14:5). We retrospectively assessed extrathoracic collaterals to the sacrificed critical SAs.

RESULTS

Ninety-four collaterals to the critical SAs were observed, originating from the subclavian (26/94), external iliac (50/94) and internal iliac (18/94) arteries. Twenty-five of the 26 (96%) collaterals from the subclavian artery were from its lateral descending branch, and 19 of the 26 (73%) collaterals fed into T9. Forty-three of the 50 (86%) collaterals from the external iliac artery were from its lateral ascending branch, and 25 of the 50 (50%) collaterals communicated with T11. Patients with a history of left thoracotomy (no collaterals in 6 patients) had fewer collaterals via the lateral descending branch of the left subclavian artery in comparison with the patients without (10 collaterals in 13 patients) (P = 0.009).

CONCLUSIONS

After critical SAs were sacrificed, extrathoracic collaterals developed with certain regularity. Previous left thoracotomy could influence the development of extrathoracic collaterals from the left subclavian artery.

Branched Endograft Partial Deployment to Save Space for Vessel Cannulation When Treating Aneurysms with Narrow Aortic Lumen

PURPOSE

To describe a novel technique developed for the treatment of patients with thoracoabdominal aortic aneurysms having narrow aortic lumens using branched endografts.

TECHNIQUE

When treating patients with a narrow aortic inner diameter with branched endografts, we propose a partial graft deployment leaving the distal portion of the device inside the delivery system with the aim of spare space and facilitate target vessel cannulation.

CONCLUSIONS

Partial endograft deployment could be considered in the case of expected difficulty associated with encumbrance deriving from the distal straight graft portion. This technique could be useful to avoid target vessel loss and therein save procedural and fluoroscopy time.

Systematic review of contemporary outcomes of endovascular and open thoracoabdominal aortic aneurysm repair

OBJECTIVE

The purpose of the study was to provide a systematic review of the literature reporting the contemporary early outcomes after endovascular and open repair of thoracoabdominal aortic aneurysms (TAAAs).

METHODS

MEDLINE and Embase were searched for studies from January 2006 to March 2018 that reported either endovascular (using branched or fenestrated endografts) or open repair of TAAA in at least 10 patients. Outcomes of interest included perioperative mortality, spinal cord injury (SCI), renal failure requiring dialysis, and stroke. Pooled proportions were determined using a random-effects model.

RESULTS

The analysis included 71 studies, of which 24 and 47 reported outcomes after endovascular and open TAAA repair, respectively. Endovascular cohort patients were older and had higher rates of coronary artery disease, chronic obstructive pulmonary disease, and diabetes. Endovascular repair was associated with higher rates of SCI (13.5%; 95% confidence interval [CI], 10.5%-16.7%) compared with open repair (7.4%; 95% CI, 6.2%-8.7%; P < .01) but similar rates of permanent paralysis (5.2% [95% CI, 3.8%-6.7%] vs 4.4% [95% CI, 3.3%-5.6%]; P = .39), lower rates of postoperative dialysis (6.4% [95% CI, 3.2%-9.5%] vs 12.0% [95% CI, 8.2%-16.3%]; P = .03) but similar rates of being discharged on permanent dialysis (3.7% [95% CI, 2.0%-5.9%] vs 3.8% [95% CI, 2.9%-5.3%]; P = .93), a trend to lower stroke (2.7% [95% CI, 1.9%-3.6%] vs 3.9% [95% CI, 3.0%-4.9%]; P = .06), and similar perioperative mortality (7.4% [95% CI, 5.9%-9.1%] vs 8.9% [95% CI, 7.2%-10.9%]; P = .21).

CONCLUSIONS

This systematic review summarizes the contemporary literature results of endovascular and open TAAA repair. Endovascular repair studies included patients with more comorbidities and were associated with higher rates of SCI but similar rates of permanent paraplegia, whereas open repair studies had higher rates of postoperative dialysis but similar rates of being discharged on permanent dialysis. Perioperative mortality rates were similar. Universally adopted reporting standards for patient characteristics, outcomes, and the conduct of contemporary comparative studies will allow better assessment and comparisons of the risks associated with the two surgical treatment options for TAAA.

Chimney Stent Graft Technique for Endovascular Repair of Penetrating Atherosclerotic Ulcers of Abdominal Aorta with Bilateral Common Iliac Artery Aneurysms and Ectopic Right Renal Artery Stenosis

Ectopic renal artery (RA), a rare congenital anomaly, presents a challenge in open surgery and endovascular repair for abdominal aortic lesions. To preserve the abnormal main blood supply and renal function complicates the procedures requiring careful imaging measurement and well-designed therapeutic strategy. We report on a 68-year-old man with abdominal aortic atherosclerotic ulcers, bilateral common iliac artery aneurysms, and right ectopic RA stenosis that was successfully managed with antegrade chimney technique, resulting in well-excluded lesions and well-reconstructed renal blood supply without any complication. This endovascular procedure may be useful for repair of abdominal aortic lesions with ectopic RA in high-risk surgical patients.

Correlations Between Branch Vessel Catheterization and Procedural Complexity in Fenestrated and Branched Endovascular Aneurysm Repair

Introduction:

The use of fenestrated and branched endovascular technologies in complex aortic aneurysm repair (F/BEVAR) is increasing, with a trend toward using longer sealing zones and incorporating more target vessels. Successful aneurysm exclusion and prevention of long-term treatment failure need to be balanced against the increased complexity of more extensive procedures. The aim of this study was to analyze relationships between the number of catheterized vessels and multiple operative variables as a means for evaluating procedural complexity.

Methods:

Operative data from consecutive F/BEVAR procedures performed at a single center from 2012 to 2015 were analyzed. An equal number of EVAR procedures, randomly selected, from this period were also analyzed. Only intact aneurysms were included. Complex aneurysms were grouped based on the required number of target vessel catheterization. Ten procedural variables, categorized as perioperative, postoperative, and radiologic-related, were compared. Pearson correlation analysis and regression analysis were performed. The correlation coefficients, r, were classified using Cohen boundaries, r ≥ 0.5 indicating a strong relationship.

Results:

There were 63 EVAR, 40 FEVAR, and 22 BEVAR procedures. There was no significant difference in patient comorbidities between conventional EVAR and complex procedure groups. The complex procedures included 23 two-vessel, 20 three-vessel, and 19 four-vessel catheterizations. Strong linear relationships between the number of branch vessel catheterizations and the following variables were identified: accumulated skin dose ( r = .504), contrast volume ( r = .652), fluoroscopy duration ( r = .598), number of angiography series ( r = .650), anesthesiology duration ( r = .742), procedure duration ( r = .554), and total length of stay ( r = .533).

Conclusion:

The complexity of FEVAR and BEVAR procedures reveals strong correlations between multiple peri- and postoperative variables. These exposures and risks should be borne in mind when considering treatment of complex abdominal aortic aneurysms as well as long-term clinical outcomes.

Open abdominal aortic aneurysm repair is still necessary in an era of advanced endovascular repair

OBJECTIVE

Recent advances in endovascular aneurysm repair have overcome substantial anatomic barriers associated with short and challenging necks. With greater range to treat more difficult anatomy from an endovascular approach, one would assume the need of open surgical repair (OSR) would be diminished. The purpose of our study was to determine the need for OSR for abdominal aortic aneurysms, in a tertiary academic setting, with a moderate volume (10-15 cases/year) of fenestrated endografting being performed.

METHODS

An Institutional Review Board approved retrospective review was performed of all patients who underwent elective aortic aneurysm repair between January 2010 and July 2014. Computed tomography scans for patients who underwent OSR were reviewed and anatomic characteristics obtained. Instructions for use of (IFU) a commercially available fenestrated device (Cook Medical, Bloomington, Ind) were used to determine if open repair patients had anatomy amenable to advanced endovascular repair.

RESULTS

During the study interval, 415 patients underwent abdominal aortic aneurysm repair. Of those patients who underwent elective aneurysm repair, 105 patients had OSR. The study subsequently excluded 11 patients because they underwent secondary interventions after a failed endovascular repair and thus were not further evaluated. Also excluded were 18 patients who had OSR for an emergency intervention. The remaining 76 patients (35 female, 41 male; average age, 72 ± 8 years) had OSR and were outside the IFU of the fenestrated endovascular aneurysm repair (FEVAR) device. The average diameter of the abdominal aorta was 5.9 cm. Indications for OSR were an aneurysm neck <4 mm (71%), inclusion of at least 1 visceral vessel (69.7%), unilateral iliac artery aneurysms (15.5%), bilateral iliac artery aneurysms (14.3%), iliac artery tortuosity >40° of angulation (37.6%), extensive aortic thrombus (23.2%), and aortic neck angulation >45° (11.8%). Rejected patients had an average of 1.7 ± 0.8 anatomic constraints (range 1-4) that prevented use of the FEVAR device.

CONCLUSIONS

With evidence to support the strict adherence to IFU protocols of the FEVAR device in patients, our institution's practice has been to continue to perform open abdominal aortic aneurysm repair for patients with anatomy outside device protocols. Although it was thought that the decreased requirement of aortic neck required to deploy an endograft would lead to an increased patient population amenable to endovascular repair, there is still a clinically significant need for open aortic surgery.

Multibranched Stent-Grafts for the Treatment of Thoracoabdominal Aortic Aneurysms

Purpose: To evaluate the available literature on endovascular repair of thoracoabdominal (TAAA) and pararenal aortic aneurysms (PRAA) using multibranched stent-grafts. Methods: MEDLINE, EMBASE, and Cochrane databases were searched between January 2001 and June 2015 to identify articles related to the use of multibranched stent-grafts for the treatment of TAAA and PRAA. Articles with <4 cases and those on juxtarenal aortic aneurysms were excluded. Meta-analyses were conducted to evaluate 30-day mortality, all-cause mortality, spinal cord ischemia, renal insufficiency, endoleak, target vessel patency, and reintervention. Of 370 articles screened, only 4 articles encompassing 185 patients (mean age 71.1 years; 137 men) were aligned with the inclusion criteria. There were 23 PRAAs; the mean aneurysm diameter was 64.5 mm. The Crawford TAAA classification was 10 type I, 47 type II, 37 type III, 58 type IV, and 9 type V; there was 1 Stanford type B dissection in association with a large TAAA. Results of the meta-analyses are reported as proportions and 95% confidence interval (CI). Results: Pooled analysis indicated a technical success rate of 98.9%. As study heterogeneity was significant, random effects models were used for meta-analysis. The rate for 30-day mortality was 9% (95% CI 3% to 19%), for all-cause mortality 27% (95% CI 17% to 38%), endoleaks 10% (95% CI 1% to 25%), target vessel patency 98% (95% CI 95% to 99%), SCI 17% (95% CI 1% to 26%), irreversible SCI 6% (95% CI 3% to 10%), renal insufficiency 15% (95% CI 0.8% to 41%), and reinterventions 21% (95% CI 4% to 47%). Conclusion: Use of multibranched stent-grafts in the treatment of TAAAs and PRAAs appears to be feasible and safe based on satisfactory early outcomes in the limited literature available to date. Long-term surveillance and further studies are essential to determine the durability of this technique.

Visceral branch occlusion following aneurysm repair using multibranched thoracoabdominal stent-grafts

PURPOSE

To identify risk factors for late-occurring branch occlusion following multibranched endovascular repair of thoracoabdominal and pararenal aortic aneurysm.

METHOD

Out of 120 patients who underwent multibranched endovascular aneurysm repair between September 2005 and May 2013, 100 (78 men; mean age 72.4 ± 7.4 years) met the criteria for inclusion in the current retrospective analysis. Demographic data were gleaned from a prospectively maintained database. Mean aneurysm diameter was 66.7 ± 11.7 mm. Multiplanar reconstructions of postoperative computed tomographic angiography were used to measure 6 parameters of renal branch morphology.

RESULTS

All 100 patients had undergone successful placement of multibranched aortic stent-grafts with a total of 95 celiac branches, 100 superior mesenteric artery (SMA) branches, and 187 renal branches. During a mean follow-up of 25.6 months, there were no stent fractures or stent separations, no SMA occlusions, and only 2 (2.1%) celiac artery occlusions, neither of which required reintervention. In contrast, there were 18 (9.6%) renal branch occlusions in 16 patients, all men (p=0.02). Patients with renal branch occlusions were significantly more likely to have a history of myocardial infarction (p=0.004). The mean renal artery length was significantly greater in the occlusion group compared to the non-occlusion group (47.5 ± 13.6 vs. 39.4 ± 14.2, p=0.03). No other aspect of branch morphology was significantly different between the occlusion and non-occlusion groups.

CONCLUSION

Renal branch occlusion was by far the commonest late failure mode after multibranched endovascular aneurysm repair. The current study provides no basis for a change in patient selection or stent-graft design, only a change in the components used to construct renal branches. It is too early to tell the effect this will have.

Outcomes of fenestrated/branched endografting in post-dissection thoracoabdominal aortic aneurysms

OBJECTIVES

Fenestrated/branched thoracic endovascular repair (F/Br-TEVAR) is increasingly applied for atherosclerotic thoracoabdominal aortic aneurysm (TAAA); however, use in post-dissection TAAAs is still very limited. Experience with F/Br-TEVAR in the treatment of post-dissection TAAA is presented.

METHODS

Data were analysed from prospectively maintained databases including all patients with post-dissection TAAAs that underwent F/Br-TEVAR within the period January 2010 to July 2013 in two vascular institutions. Evaluated outcomes included initial technical success, operative mortality and morbidity, late survival, endoleak, aneurysm diameter regression, renal function, and reintervention during follow-up (FU).

RESULTS

A total of 31 patients (25 male, mean age 65 ± 11.4 years) were treated. Technical success was 93.5% and 30-day mortality 9.6%. Temporary spinal cord ischaemia occurred in four (12.6%) patients, with no case of permanent paraplegia. Mean FU was 17.0 ± 10 months. There were seven late deaths, all aneurysm unrelated. Estimated overall survival rates were 83.9 ± 6.7, 76.4 ± 7.9 and 71.6 ± 8.7% at 6, 12, and 18 months, respectively. Impairment of renal function occurred in two (6.4%) patients. Endoleaks were diagnosed in 12 patients during FU, including six type IB endoleaks and six type II endoleaks. Reintervention was required in seven (22.5%) patients. Mean aneurysm sac regression was 9.3 ± 8.7 mm, with a false lumen thrombosis rate of 66.7% and 88.2% for patients with a FU longer than 6 and 12 months respectively.

CONCLUSIONS

F/Br-EVAR is feasible for patients with a post-dissection TAAA. Although associated with additional technical challenges, and a significant need for reintervention, it leads to favourable aneurysm morphologic changes, and may play a more prominent role in the future for this type of pathology if long-term results confirm the good initial outcome.

Endovascular management of chronic post-dissection aneurysms

Open repair is still the gold standard in acute type A dissection. Endovascular repair is advocated for complicated acute type B dissections. Recent evidence also supports the role of endovascular repair in a larger proportion of uncomplicated acute type B dissections. The role of endovascular repair in chronic post-dissection aneurysms, however, is still unclear. Most commonly, post-dissection aneurysms involve the thoracoabdominal aorta, making the use of fenestrated/branched stent-grafts to achieve complete aneurysm exclusion mandatory. These fenestrated/branched stent-grafts have been used with success in atherosclerotic thoracoabdominal aortic aneurysms (TAAAs). In chronic post-dissection aneurysms, however, additional technical challenges arise. The usually narrow true lumen makes the use of branches more tedious and overall planning difficult. A second technical challenge relates to the fact that visceral branches can also originate from the false lumen. In such cases, perforation of the stiff chronic dissection flap is required to obtain access to the vessel. During the period January 2010 to November 2013, 17 patients (13 males, mean age 65±7.8 years) with chronic thoracoabdominal aneurismal degeneration following acute dissection were treated in our department with the use of fenestrated/branched stent-grafts. Technical success was achieved in all cases (100%). Perioperative mortality was two (11.8%) patients. One patient died due to multiple organ failure and one due to cardiac failure. No case of paraplegia was observed. During a 12-month median follow-up (range, 4-28 months) no aneurysm-related deaths were observed. Reintervention was required in three cases to repair a type Ib endoleak from a side branch. Endovascular treatment with fenestrated/branched stent-grafts is feasible for chronic post-dissection aneurysms. Standard thoracic stent-grafting is an option in a minority of patients, when the aneurysm is limited to the thoracic segment. Fenestrated and branched devices can successfully be used for aneurysms extending to the thoracoabdominal aorta.

Impact of intraoperative adverse events during branched and fenestrated aortic stent grafting on postoperative outcome

Objective

Fenestrated and branched endovascular devices are increasingly used for complex aortic diseases, and despite the challenging nature of these procedures, early experiences from pioneering centers have been encouraging. The objectives of this retrospective study were to report our experience of intraoperative adverse events (IOAEs) during fenestrated and branched stent grafting and to analyze the impact on clinical outcomes.

Methods

Consecutive patients treated with fenestrated and branched stent grafting in a tertiary vascular center between February 2006 and October 2013 were evaluated. A prospectively maintained computerized database was scrutinized and updated retrospectively. Intraoperative angiograms were reviewed to identify IOAEs, and adverse events were categorized into three types: target vessel cannulation, positioning of graft components, and intraoperative access. Clinical consequences of IOAEs were analyzed to ascertain whether they were responsible for death or moderate to severe postoperative complications.

Results

During the study period, 113 consecutive elective patients underwent fenestrated or branched stent grafting. Indications for treatment were asymptomatic complex abdominal aortic aneurysms (CAAAs, n = 89) and thoracoabdominal aortic aneurysms (TAAAs, n = 24). Stent grafts included fenestrated (n = 79) and branched (n = 17) Cook stent grafts (Cook Medical, Bloomington, Ind), Ventana (Endologix, Irvine, Calif) stent grafts (n = 9), and fenestrated Anaconda (Vascutek Terumo, Scotland, UK) stent grafts (n = 8). In-hospital mortality rates for the CAAA and TAAA groups were 6.7% (6 of 89) and 12.5% (3 of 24), respectively. Twenty-eight moderate to severe complications occurred in 21 patients (18.6%). Spinal cord ischemia was recorded in six patients, three of which resolved completely. A total of 37 IOAEs were recorded in 34 (30.1%) patients (22 CAAAs and 12 TAAAs). Of 37 IOAEs, 15 (40.5%) resulted in no clinical consequence in 15 patients; 17 (45.9%) were responsible for moderate to severe complications in 16 patients, and five (13.5%) led to death in four patients. The composite end point death/nonfatal moderate to severe complication occurred more frequently in patients with IOAEs compared with patients without IOAEs (20 of 34 vs 12 of 79; P < .0001).

Conclusions

In this contemporary series, IOAEs were relatively frequent during branched or fenestrated stenting procedures and were often responsible for significant complications.

Hyperbaric oxygen preconditioning induces tolerance against oxidative injury and oxygen-glucose deprivation by up-regulating heat shock protein 32 in rat spinal neurons

OBJECTIVE

Hyperbaric oxygen (HBO) preconditioning (HBO-PC) has been testified to have protective effects on spinal cord injury (SCI). However, the mechanisms remain enigmatic. The present study aimed to explore the effects of HBO-PC on primary rat spinal neurons against oxidative injury and oxygen-glucose deprivation (OGD) and the relationship with heat shock proteins (HSPs).

METHODS

Primary rat spinal neurons after 7 days of culture were used in this study. HSPs were detected in rat spinal neurons following a single exposure to HBO at different time points by Western blot. Using lactate dehydrogenase release assay and cell counting kit-8 assay, the injuries induced by hydrogen peroxide (H2O2) insult or OGD were determined and compared among neurons treated with HBO-PC with or without HSP inhibitors.

RESULTS

The results of Western blot showed that HSP27, HSP70 and HSP90 have a slight but not significant increase in primary neurons following HBO exposure. However, HSP32 expression significantly increased and reached highest at 12 h following HBO exposure. HBO-PC significantly increased the cell viability and decreased the medium lactate dehydrogenase content in cultures treated with H2O2 or OGD. Pretreatment with zinc protoporphyrin IX, a specific inhibitor of HSP32, significantly blocked the protective effects of HBO-PC.

CONCLUSIONS

These results suggest that HBO-PC could protect rat spinal neurons in vitro against oxidative injury and OGD mostly by up-regulating of HSP32 expression.

Image guidance for endovascular repair of complex aortic aneurysms: comparison of two-dimensional and three-dimensional angiography and image fusion

PURPOSE

To evaluate the feasibility of image fusion (IF) of preprocedural arterial-phase computed tomography with intraprocedural fluoroscopy for roadmapping in endovascular repair of complex aortic aneurysms, and to compare this approach versus current roadmapping methods (ie, two-dimensional [2D] and three-dimensional [3D] angiography).

MATERIALS AND METHODS

Thirty-seven consecutive patients with complex aortic aneurysms treated with endovascular techniques were retrospectively reviewed; these included aneurysms of digestive and/or renal arteries and pararenal and juxtarenal aortic aneurysms. All interventions were performed with the same angiographic system. According to the availability of different roadmapping software, patients were successively placed into three intraprocedural image guidance groups: (i) 2D angiography (n = 9), (ii) 3D rotational angiography (n = 14), and (iii) IF (n = 14). X-ray exposure (dose-area product [DAP]), injected contrast medium volume, and procedure time were recorded.

RESULTS

Patient characteristics were similar among groups, with no statistically significant differences (P ≥ .05). There was no statistical difference in endograft deployment success between groups (2D angiography, eight of nine patients [89%]; 3D angiography and IF, 14 of 14 patients each [100%]). The IF group showed significant reduction (P < .0001) in injected contrast medium volume versus other groups (2D, 235 mL ± 145; 3D, 225 mL ± 119; IF, 65 mL ± 28). Mean DAP values showed no significant difference between groups (2D, 1,188 Gy · cm(2) ± 1,067; 3D, 984 Gy · cm(2) ± 581; IF, 655 Gy · cm(2) ± 457; P = .18); nor did procedure times (2D, 233 min ± 123; 3D, 181 min ± 53; IF, 189 min ± 60; P = .59).

CONCLUSIONS

The use of IF-based roadmapping is a feasible technique for endovascular complex aneurysm repair associated with significant reduction of injected contrast agent volume and similar x-ray exposure and procedure time.

Endovascular repair of thoracoabdominal aortic aneurysm (TAAA): early experience

BACKGROUND

Repair of thoracoabdominal aortic aneurysms (TAAA) represents a considerable technical challenge. Since its first description in 1955, open repair of TAAA has been considered the gold standard of repair. Despite improvements in surgical techniques, spinal cord protection and post-operative critical care support, patients who undergo open repair are faced with a mortality rate of 5-35 %. We report the first Irish experience of endovascular management of TAAAs.

RESULTS

To date five patients have undergone endovascular repair; four had hybrid repair and one a fenestrated graft. The mean age of the patients was 66.8 ± 3.4 and the mean aneurysm diameter was 6.74 ± 0.6 cm. All patients were ASA III. Two-stage hybrid repair was associated with an increased risk of complications, prolonged intensive care unit and overall hospital stay. One patient died in the perioperative period due to rupture of their aneurysm between the two stages of their hybrid repair.

CONCLUSION

The role of endovascular techniques in the treatment of TAAA continues to evolve. Hybrid and complete endovascular repairs do not replace conventional repair, but provide an alternative for high-risk patients who might otherwise be denied treatment.

Treatment of acute visceral aortic pathology with fenestrated/branched endovascular repair in high-surgical-risk patients

OBJECTIVE

The safety and feasibility of fenestrated/branched endovascular repair of acute visceral aortic disease in high-risk patients is unknown. The purpose of this report is to describe our experience with surgeon-modified endovascular aneurysm repair (sm-EVAR) for the urgent or emergent treatment of pathology involving the branched segment of the aorta in patients deemed to have prohibitively high medical and/or anatomic risk for open repair.

METHODS

A retrospective review was performed on all patients treated with sm-EVAR for acute indications. Planning was based on three-dimensional computed tomographic angiogram reconstructions and graft configurations included various combinations of branch, fenestration, or scallop modifications.

RESULTS

Sixteen patients (mean age [± standard deviation], 68 ± 10 years; 88% male) deemed high risk for open repair underwent urgent or emergent repair using sm-EVAR. Indications included degenerative suprarenal or thoracoabdominal aneurysm (six), presumed or known mycotic aneurysm (four), anastomotic pseudoaneurysm (three), false lumen rupture of type B dissection (two), and penetrating aortic ulceration (one). Nine (56%) had previous aortic surgery and all patients were either American Society of Anesthesiologists class IV (n = 9) or IV-E (n = 7). A total of 40 visceral vessels (celiac, 10; superior mesenteric artery, 10; right renal artery, 10; left renal artery, 10) were revascularized with a combination of fenestrations (33), directional graft branches (six), and graft scallops (one). Technical success was 94% (n = 15/16), with one open conversion. Median contrast use was 126 mL (range, 41-245) and fluoroscopy time was 70 minutes (range, 18-200). Endoleaks were identified intraoperatively in four patients (type II, n = 3; type IV, n = 1), but none have required remediation. Mean length of stay was 12 ± 15 days (median, 5.5; range, 3-59). Single complications occurred in five (31%) patients as follows: brachial sheath hematoma (one), stroke (one), ileus (one), respiratory failure (one), and renal failure (one). An additional patient experienced multiple complications including spinal cord ischemia (one) and multiorgan failure resulting in death (n = 1; in-hospital mortality, 6.3%). The majority of patients were discharged to home (63%; n = 10) or short-term rehabilitation units (25%; n = 4), while one patient required admission to a long-term acute care setting. There were no reinterventions at a median follow-up of 6.2 (range, 1-16.1) months. Postoperative computed tomographic angiogram was available for all patients and demonstrated 100% branch vessel patency, with one type III endoleak pending intervention. There were two late deaths at 1.4 and 13.4 months due to nonaortic-related pathology.

CONCLUSIONS

Urgent or emergent treatment of acute pathology involving the visceral aortic segment with fenestrated/branched endograft repair is feasible and safe in selected high-risk patients; however, the durability of these repairs is yet to be determined.

Endovascular repair with chimney technique of abdominal aortic aneurysm with hostile aortic neck

Abdominal aortic aneurysm (AAA) with hostile aortic neck is not a good candidate for conventional endovascular aneurysm repair (EVAR), and a recent paper showed that EVAR with chimney technique (Ch-EVAR) yielded reasonable outcome. We report here a case of successful Ch-EVAR treatment of AAA with hostile neck. An 81-year-old man presented with a 71-mm AAA during evaluation of a gastric ulcer. Aortic neck was 30 mm in diameter, 10-15 mm in length and angulated by 100°. EVAR was performed with chimney stenting to both renal arteries, and the patient recovered after transient hematuria. At one-year follow-up, AAA had increased by 7 mm with delayed type I endoleak control without renal insufficiency. The patient needed close follow-up.

The chimney graft, a systematic review

BACKGROUND

Approximately 20% to 30% of the patients are considered not eligible for standard endovascular aneurysm repair because of aortic neck morphology. Most of these patients have an aortic neck situated in the vicinity of the aortic side branches, requiring extensive open surgery. The introduction of fenestrated and branched stent grafts has made endovascular branch preservation possible, but these procedures are time-consuming and expensive. The chimney procedure offers a readily available endovascular alternative for the treatment in patients with acute aneurysms and challenging anatomy. We conducted a systematic review to evaluate the short- and long-term results of the chimney procedure.

METHODS

A comprehensive literature search for studies describing the chimney procedure was performed using MEDLINE and Excerpta Medica Database. All articles were critically appraised and included, based on relevance, validity, and outcome measures. Patient characteristics, details of the surgical intervention, and short- and long-term outcomes were studied.

RESULTS

A total of 75 patients were included who underwent a chimney procedure for the preservation of a total of 96 branches. Used operating techniques differed considerably between all studies, with an overall technical success rate of 98.9%. Three perioperative deaths were reported, of which one patient died from intervention-related complication. The follow-up duration ranged from 2 days to 54 months. Late complications included three deaths, none of which was device or aneurysm related. Three chimney grafts occluded during follow-up, of which two required reintervention.

CONCLUSION

The chimney procedure appears as an acceptable alternative for patients in an emergency setting, although data regarding long-term follow-up are not yet available.