Hybrid Open Endovascular Technique for Aortic Thoracoabdominal Pathologies

Management of acute aortic syndrome with evolving individualized precision medicine solutions: Lessons learned over two decades and literature review

Background

Thoracoabdominal acute aortic syndrome is associated with high morbidity and mortality. We aim to scrutinize our evolving strategies for acute aortic syndrome (AAS) management using minimally invasive and adaptive surgical techniques over two decades.

Methods

This is a longitudinal observational study at our tertiary vascular centre from 2002 to 2021. Out of 22,349 aortic referrals, we performed 1,555 aortic interventions over twenty years. Amongst 96 presented with symptomatic aortic thoracic pathology, 71 patients had AAS. Our primary endpoint is combined aneurysm-related and cardiovascular-related mortality.

Results

There were 43 males and 28 females (5 Traumatic Aortic Transection (TAT), 8 Acute Aortic Intramural Hematoma (IMH), 27 Symptomatic Aortic Dissection (SAD) and 31 Thoracic Aortic Aneurysm (TAA) post-SAD) with a mean age of 69. All the patients with AAS received optimal medical therapy (OMT), but TAT patients underwent emergency thoracic endovascular aortic repair (TEVAR). Fifty-eight patients had an aortic dissection, of which 31 developed TAA. These 31 patients with SAD and TAA received OMT initially and interval surgical intervention with TEVAR or sTaged hybrId sinGle lumEn Reconstruction (TIGER). To increase our landing area, we performed a left subclavian chimney graft with TEVAR in twelve patients. The average follow-up duration was 78.2 months, and eleven patients (15.5%) had combined aneurysm and cardiovascular-related mortality. Twenty-six percentage of the patients developed endoleaks (EL), of which 15% required re-intervention for type II and III. Four patients who had paraplegia (5.7%) and developed renal failure died. None of our patients had a stroke or bowel ischaemia. Twenty patients had OMT, eight of these were patients with acute aortic hematoma, and all eight died within 30 days of presentation.

Conclusion

Acute aortic hematoma is a sinister finding, which must be closely monitored, and consideration is given to early intervention. Paraplegia and renal failure result in an increased mortality rate. TIGER technique with interval TEVAR has salvaged complex situations in young patients. Left subclavian chimney increases our landing area and abolishes SINE. Our experience shows that minimally invasive techniques could be a viable option for AAS.

Hemodynamic analysis of hybrid treatment for thoracoabdominal aortic aneurysm based on Newtonian and non-Newtonian models in a patient-specific model

The accuracy of the Newtonian model used in retrograde visceral revascularization (RVR) of hybrid surgery for thoracoabdominal aortic aneurysm (TAAA) hemodynamic simulation remains unclear. Noting that an appropriate blood viscosity model is a significant factor to capture hemodynamic changes in numerical studies. Therefore, both Newtonian and non-Newtonian blood viscosity models were adopted in this study to investigate the importance of hemodynamics when non-Newtonian blood property was accounted for in a patient-specific RVR simulation. The results revealed that disturbed flow and unfavorable WSS distribution can be observed in the anastomosis region under both blood viscosity models due to the retrograde flow pattern in the RVR model. However, although the non-Newtonian blood model has negligible effect on flow pattern and pressure drop, there were of significance quantitative and qualitative difference of local normalized helicity and wall shear stress distribution under pulsatile flow condition. In particular, the unfavorable WSS indicators distribution was better matched with a patient-specific follow-up report when non-Newtonian blood viscosity was accounted for. To conclude, the use of a Newtonian blood model is a reasonable approximation to obtain the general features of the flow field under steady flow condition. However, to study the hemodynamic parameters within retrograde flow under pulsatile flow condition, a non-Newtonian model may be more appropriate.

Double-Cuff Bidirectional Branch in Endovascular Aortic Repair: A New Way of Increasing the Flexibility of Inner Branch Endografting

PURPOSE

The purpose of the study was to describe the design and implantation of a branched stent-graft during endovascular aortic repair incorporating double-cuff bidirectional inner branch.

TECHNIQUE

A new double-cuff bidirectional antegrade and retrograde inner branched stent-graft with large diamond-shaped fenestration was designed for incorporation of a splenic artery. The inner cuffs of the branch were accessible using brachial and/or femoral access. The splenic artery was originating from an aortic segment with narrow inner aortic luminal diameter in a patient with extent IV thoracoabdominal aortic aneurysm with bilobed configuration. The retrograde, more distal inner cuff of the branch was extended into the splenic artery using a self-expandable bridging stent-graft from the femoral approach, whereas the antegrade, more proximal inner cuff of the branch was intentionally occluded using an endovascular plug. The recovery was uneventful and a computed tomography angiography 30 days postoperatively showed patency of all the target vessels without signs of endoleaks.

CONCLUSION

This is the first design of a double-cuff bidirectional inner branched stent-graft. The technique can potentially expand the applications of directional branches to patients with more difficult anatomy in the thoracoabdominal or aortic arch segments. Potential indications are patients with target arteries that are not ideally suited for caudally-oriented branches, patients with accessory vessels, or targets with early branch bifurcations.

CLINICAL IMPACT

This report describes the use of a branched endograft with a new double-cuff bidirectional branch that can potentially address many of the limitations of current BEVAR solutions, such as early bifurcations, double arteries with adjacent origins and arteries with less favorable trajectories for the traditional caudally-oriented branches.

Results of the North American Complex Abdominal Aortic Debranching (NACAAD) Registry

BACKGROUND

Hybrid debranching repair of pararenal and thoracoabdominal aortic aneurysms was initially designed as a better alternative to standard open repair, addressing the limitations of endovascular repair involving the visceral aorta. We reviewed the collective outcomes of hybrid debranching repairs using extra-anatomic, open surgical debranching of the renal-mesenteric arteries, followed by endovascular aortic stenting.

METHODS

Data from patients who underwent hybrid repair in 14 North American institutions during 10 years were retrospectively reviewed. Society of Vascular Surgery scores were used to assess comorbidity risk. Early and late outcomes, including mortality, morbidity, reintervention, and patency were analyzed.

RESULTS

A total of 208 patients (118 male; mean age, 71±8 years old) were treated by hybrid repair with extraanatomic reconstruction of 657 renal and mesenteric arteries (mean 3.2 vessels/patient). Mean aneurysm diameter was 6.6±1.3 cm. Thoracoabdominal aortic aneurysms were identified in 163 (78%) patients and pararenal aneurysms in 45 (22%). A single-stage repair was performed in 92 (44%) patients. The iliac arteries were the most common source of inflow (n=132; 63%), and most (n=150; 72%) had 3 or more bypasses. There were 30 (14%) early deaths, ranging widely across sites (0%-21%). A Society of Vascular Surgery comorbidity score >15 was the primary predictor of early mortality (P<0.01), whereas mortality was 3% in a score ≤9. Early complications occurred in 140 (73%) patients and included respiratory complications in 45 patients (22%) and spinal cord ischemia in 22 (11%), of whom 10 (45%) fully recovered. At 5 years, survival was 61±5%, primary graft patency was 90±2%, and secondary patency was 93±2%. The most significant predictor of late mortality was renal insufficiency (P<0.0001).

CONCLUSIONS

Mortality after hybrid repair and visceral debranching is highly variable by center, but strongly affected by preoperative comorbidities and the centers' experience with the technique. With excellent graft patency at 5 years, the outcomes of hybrid repair done at centers of excellence and in carefully selected patients may be comparable (or better) than traditional open or even totally endovascular approaches. However, in patients already considered as high-risk for surgery, it may not offer better outcomes.

Thoracoabdominal Aortic Disease and Repair: JACC Focus Seminar, Part 3

Thoracoabdominal aortic disease is a rare but life-threatening condition that requires expert multidisciplinary collaborative management. Intervention is indicated in patients with symptomatic aneurysms or when an aneurysm reaches a certain threshold of diameter or rate of expansion. The strategies for spinal cord and end-organ protection have evolved over several decades, resulting in improved outcomes after repair. Open repair, although invasive, provides definitive and durable repair. Endovascular approaches are rapidly evolving, and the results with fenestrated and branched endografts are promising. Both open repair and endovascular repair require highly specialized expertise, and outcomes are best when repair is undertaken in an elective setting by a dedicated team. Patients with degenerative thoracoabdominal aortic aneurysms and chronic dissections should be followed up closely and referred for elective repair when indicated.

Endovascular and Hybrid Repair in Patients with Heritable Thoracic Aortic Disease

OBJECTIVE

In individuals with heritable thoracic aortic disease (HTAD), endovascular repair for treatment of aortic aneurysm and dissection may be lifesaving but is associated with increased risk of failure of endovascular repair and adverse outcomes. This study reports our experience with early and late outcomes of endovascular aortic and branch vessel repair in patients with HTAD.

METHODS

A retrospective case series was performed by chart review of individuals with HTAD followed at Washington University School of Medicine/Barnes-Jewish Hospital who underwent endovascular aortic and/or branch vessel repair. Clinical features, imaging characteristics, and short- and long-term outcomes were collected.

RESULTS

Twenty-nine patients with HTAD (20 male; mean age 45 ± 13 years) underwent thirty-seven endovascular procedures between 2006 and 2020 with mean follow up of 54 ± 41 months. Seven patients underwent two or more separate endovascular procedures. Each procedure was considered separate for data collection and analysis. Underlying conditions included Marfan syndrome (n=16 procedures), Loeys-Dietz syndrome (n=14 procedures), vascular Ehlers-Danlos syndrome (n=3 procedures), and nonsyndromic HTAD (n=4 procedures). Twenty patients (69%) had prior open surgical aortic repair. Indications for endovascular aortic repair (n=31) included urgent repairs of acute complications of aortic dissection (n=10) or aneurysm rupture (n=3), and elective aortic repair (n=18; 10 chronic dissections and 8 chronic aneurysms). Six patients underwent elective endovascular repair of six branch vessel aneurysms or dissections. Six patients underwent hybrid open surgical and endovascular repair. Of the 37 procedures, twenty-five (68%) proximal landing zones were in the native aorta or branch vessel, eleven (30%) were in a surgical graft or elephant trunk and one was in a previously placed endograft. Thirty-six (97%) procedures were technically successful, and none required emergency surgical conversion. Two patients died: one from sepsis and one from presumed late pseudoaneurysm rupture, for a 5% per-procedure mortality rate. Two procedures were complicated by stroke and one patient developed paraparesis. Of the 31 aortic procedures, seven aortic endografts (23%) developed a stent-induced new entry (SINE) discovered with imaging at 20 ± 15 days post-procedure. Seven endografts (23%) developed a Type I endoleak and eight (26%) developed a Type II endoleak. No Type III endoleaks were seen. Within 30 days, two endografts (of 37, 5%) required reintervention. After 30 days, fifteen additional endografts (of 37, 41%) required reintervention. Two patients (of 6, 33%) who underwent hybrid repair required reintervention.

CONCLUSIONS

This study is the largest single-center case series examining outcomes of HTAD patients following endovascular repair. Urgent and elective endovascular repairs in patients with HTAD can manage acute and chronic complications of aortic aneurysm and dissection with relatively low risk. However, risk of early and late endoleaks and SINE is high. Close post-procedural surveillance is required, and many individuals will require additional interventions. Hybrid repair shows promise and requires further investigation.

Fenestrated and Branched Stent-Grafts for the Treatment of Thoracoabdominal Aortic Aneurysms: A Systematic Review and Meta-Analysis

Purpose

To investigate the safety and efficacy of total endovascular repair for thoracoabdominal aortic aneurysms (TAAAs) with fenestrated and branched stent-grafts.

Methods

The MEDLINE, EMBASE, and Cochrane databases were searched between January 2001 and December 2021 to identify literature relevant to the use of fenestrated and branched endografts for the treatment of TAAAs. Studies with <4 cases and those on juxtarenal or pararenal aortic aneurysms were excluded. Meta-analyses were conducted to evaluate spinal cord ischemia (SCI), irreversible SCI, renal insufficiency, dialysis, endoleak, reintervention, target vessel patency, 30-day mortality and overall mortality. Fourteen studies comprising 1,114 patients (mean age 72.42 years, 847 men) were selected. The mean TAAA diameter was 67 mm. The Crawford TAAA classification was type I-III in 759 cases, type IV in 344 cases, and type V in 10 cases. Outcomes of the meta-analysis are reported as proportions and 95% confidence intervals (CIs).

Results

The pooled rates for 30-day mortality and overall mortality were 6% and 18%, respectively. The pooled rate for technical success was 94% (95% CI, 93–96%), for SCI was 8% (95% CI, 7–10%), for irreversible SCI was 6% (95% CI, 4–7%), for reversible SCI was 5% (95% CI, 4–6%), for reversible SCI was 2% (95% CI, 2–3%), for renal insufficiency was 7% (95% CI, 5–10%), for dialysis was 3% (95% CI, 2–4%), for target vessel patency was 98% (95% CI, 97–99%), and for reintervention was 15% (95% CI, 9–24%).

Conclusion

Fenestrated and branched endografts for the treatment of TAAAs are safe and effective with acceptable early results. Lifelong regular follow-up and additional prospective studies are necessary to substantiate whether this technique is valid.

Single Stem Visceral Debranching for Complex Aortic Disease

Objective

The treatment of complex aortic disease has been described with various retrograde visceral bypass techniques. An original technique with a single stem retrograde visceral graft (SSRVG) is presented.

Methods

This was a single centre retrospective study including 16 patients between 2015 and 2019. Patients were treated for aortic dissection (AD; type A and acute or chronic type B), thoraco-abdominal aortic aneurysms (TAAAs), and visceral occlusive disease. Surgery consisted of visceral vessel debranching from the native infrarenal aorta or from an aortic graft. In the case of AD, surgical fenestration was performed. Additional thoracic endovascular aneurysm repair (TEVAR) completed the treatment when indicated, during the same procedure or later. Patient outcomes and reconstruction patency were studied.

Results

The mean patient age was 64 years (median 68 ± 12.6). Ten (62%) patients were treated for AD, three (19%) for TAAA, and three (19%) for occlusive disease. Sixty-nine target vessels were debranched with this SSRVG technique. Aortic surgical fenestration was performed in eight cases and TEVAR in four. During their hospital stay, three (19%) TAAA patients died, seven cases of renal insufficiency (44%), four cases of pneumonia (25%), and three colonic ischaemia cases (19%) were noted. After a mean follow up of 21 months, no other deaths occurred. All vessels (except two inferior mesenteric arteries) were patent and no endoleak was noted.

Conclusion

The SSRVG technique can be offered in various complex aortic diseases. The use of a single graft is feasible and reduces the volume of multiple branch assembly in the retroperitoneal space. The observed patency rate is high.

•

Not all patients with complex aortic disease are amenable to open surgery or total endovascular repair.

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Hybrid surgery with visceral vessel debranching may represent an alternative.

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Various techniques using several grafts to debranch visceral vessels have been published.

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The use of a single conduit for total visceral debranching is relatively straightforward and provides excellent patency results.

Endovascular Treatment of Aortic Pathologies in Patients With Marfan Syndrome: Single-Center Experience

OBJECTIVES

To study the outcome of endovascular treatment of aortic pathologies in patients with Marfan syndrome (MFS) at a single institution.

METHODS

Consecutive MFS patients who underwent endovascular repair or hybrid procedures for aortic pathologies from January 2010 to May 2020 were identified. Several endovascular and hybrid strategies have been used. Technical success, short- and mid-term survival, complications, and re-interventions were retrospectively analyzed.

RESULTS

During the study period, 24 patients with MFS (median age, 48 [13-78] years; 58% males) were treated. Indications for intervention were chronic aortic dissection with aneurysm degeneration in 16 patients (67%), acute type B aortic dissection in 4 patients (17%), aortic aneurysm without any dissection in 3 patients (13%), and aortic intramural hematoma in 1 patient (4%). Most patients were asymptomatic (83%), three (13%) were symptomatic and one (4%) had a contained rupture. The median aneurysm diameter was 56 (35-86) mm. Hybrid procedures were performed in 7 (29%) patients. Thoracic endovascular repair was performed in 12 (50%) patients, a fenestrated or branched endovascular aortic repair in 4 (17%) patients, and placement of an iliac artery stent-graft in 1 (4%) patient. Procedures were staged in 12 (50%) patients. Technical success was achieved in all patients. The median intensive care unit stay was 6 (range, 1-30) days, and the median hospital stay was 23 (range, 3-112) days. Early mortality was reported in 1 (4%) patient. Wound infection was seen in 7 (29%) patients and gastrointestinal complications in 3 (13%) patients. The median follow-up was 42 (range, 1-127) months. The cumulative survival rate was 87% at 24 months. The cumulative freedom from re-intervention was 77% at 12 months.

CONCLUSIONS

Endovascular treatment of aortic pathologies in patients with MFS appears feasible with acceptable early and mid-term outcomes in terms of mortality and re-intervention rates. Endovascular therapy plays an increasing role in MFS patients with aortic pathology.

Effect of Anastomosis Angles on Retrograde Perfusion and Hemodynamics of Hybrid Treatment for Thoracoabdominal Aortic Aneurysm

BACKGROUND

Hemodynamic effects on the retrograde visceral reconstruction (RVR) for thoracoabdominal aortic aneurysms treatment by anastomotic angle remains unclear. This study aims to qualitatively and quantitatively investigate the effects of different anastomotic angles on hemodynamics and patency.

METHODS

Three RVR models with 45°, 60° and 90° anastomotic angles were reconstructed respectively by manipulating apostoperative patient-specific model. The manipulated models of the RVRs were numerically simulated and analyzed in terms of hemodynamics including theinstant and cumulative patency, flow pattern and indicators based on wall shear stress (WSS).

RESULTS

Although a smaller anastomotic angle may decrease the patency rate of common iliac arteries, it can improve the visceral perfusion during a cardiac cycle. More importantly, RVR with the smallest anastomotic angle experienced a minimal low time-averaged wall shear stress, high oscillatory shear index and relative residence time in the anastomosis region, whereas the largest anastomotic angle can introduce more unfavorable WSS in the graft trunk. Furthermore, a spiral flow pattern was observed in the proximal graft trunk of all three models, where no high-risk shear distribution was detected in this region.

CONCLUSION

A smaller anastomotic angle may have more benefits of hemodynamic environment in RVR, especially the WSS distribution and flow pattern in the graft trunk. We may also suggest that additional stents or an extended cuff for the graft can be used to induce spiral flow intentionally, which can further improve local hemodynamic environment and long-term prognosis.

[Visceral debranching in hybrid surgery of thoracoabdominal aortic aneurysms]

Presented herein is a review of the literature dedicated to the method of visceral debranching, i. e., switching of the visceral and renal branches of the abdominal aorta to its intact portion, using synthetic vascular prostheses as the first stage of hybrid surgical treatment of thoracoabdominal aortic aneurysms prior to endovascular aortic aneurysm repair. This is accompanied and followed by describing the history of the problem, operative technique, results of studies, as well as the data from registries and meta-analyses. Also discussed are the main complications of the method and measures of their prevention. We conclude that hybrid surgery of the thoracoabdominal portion of the aorta is a promising method in a particular cohort of patients, especially those at high surgical risk of 'open' aortic surgery.

Endovascular Outcomes in Aortic Arch Repair with Double and Triple Parallel Stent Grafts

PURPOSE

To report early and midterm outcomes of treating thoracic aortic aneurysm (TAA) and aortic dissection (AD) involving zone 1 and zone 0 with multiple parallel stent grafts (PSGs).

MATERIALS AND METHODS

From February 2011 to August 2018, 31 of 1,806 patients (1.7%) who underwent thoracic endovascular aortic repair (TEVAR) with double PSGs (DPSGs) (n = 20) or triple PSGs (TPSGs) (n = 11) were retrospectively reviewed. Procedures were performed in high-risk patients who had TAA or AD involving zone 1 or zone 0.

RESULTS

Fifteen patients (48.4%) who presented with symptomatic or impending rupture underwent urgent or emergent TEVAR with DPSGs or TPSGs. Nineteen patients (61.3%) were treated for zone 0 disease. Technical and clinical success rates were 70.0% for DPSG cohort and 45.5% for TPSG cohort. Intraoperative type Ia endoleak was observed in 30% of DPSG cohort and 45.5% of TPSG cohort. One patient in the DPSG cohort died of aortic sinus rupture intraoperatively. Minor stroke during the 30-day postoperative period was more frequent in the TPSG cohort (P = .042). Mean duration of follow-up was 28.9 months ± 17.7. The TPSG cohort had a higher incidence of major adverse events (72.7% vs 25.0%, P = .021). The most common adverse events were endoleaks (12.9%), endograft migration (9.7%), PSG stenosis or occlusion (6.5%), retrograde dissection (6.5%), and stroke (3.2%). Endograft migrations were more common in TPSG cohort (27.3%, P = .037). Overall mortality rate was 16.1% (5/31) perioperatively and during follow-up. There were no statistical differences in overall survival and reintervention-free survival.

CONCLUSIONS

In the context of TEVAR with multiple PSGs for aortic arch repair, TPSGs may have a high risk of major complications.

Multi-stage open surgical and endovascular treatment of progressive aortic degeneration in a patient with Marfan syndrome

Aortic interventions in patients with underlying connective tissues disorders present a unique challenge. The inevitable degeneration of the native aorta can lead to the need for multiple staged interventions with significant risk of complications associated with reoperative aortic procedures. We present a challenging case of progressive aortic degeneration in a patient with Marfan syndrome treated with multi-staged open surgical and endovascular procedures.

Comparison of Physician-Modified Fenestrated/Branched Stent-Grafts and Hybrid Visceral Debranching Plus Stent-Graft Placement for Complex Thoracoabdominal Aortic Aneurysm Repair

Purpose: To evaluate the immediate postoperative and midterm outcomes of complex thoracoabdominal aortic aneurysm (TAAA) treatment with fenestrated/branched physician-modified endovascular grafts (PMEGs) or open debranching of the visceral aorta with bypass graft revascularization plus endovascular aneurysm exclusion (hybrid repair). Materials and Methods: A retrospective analysis was conducted of 88 patients (mean age 70.0±10.6 years; 73 men) with complex TAAAs who underwent treatment with PMEGs (60, 68%) or a hybrid technique (28, 32%) between 2016 and 2019. The mean aneurysm diameter was 64.5±11.7 mm, and 37 patients (42%) were symptomatic. The Zenith TX2 and Ankura were the main stent-grafts used in the PMEG group. The hybrid technique involved visceral debranching with extra-anatomical bypass graft revascularization and subsequent stent-graft deployment (1- or 2-stage procedure). Results: In the PMEG group, 35 patients received modified stent-grafts with 4 fenestrations, 8 patients had 4 branches per device, and 17 patients had combinations (50 fenestrations and 18 branches) that successfully revascularized 228 of the 240 targets (95%). In the 28 hybrid cases, all 110 target vessels were successfully revascularized with bypass grafts. The overall 30-day mortality was 3.4% (2 PMEG and 1 hybrid), and the early rate of target vessel stenosis/occlusion was 3.3% (5 in PMEG group and 6 in the hybrid repair group). The 30-day morbidity was mainly attributed to pulmonary complications (15%), lower limb ischemia (8%), or spinal cord ischemia with paraplegia (6%). Eleven patients (13%) had deteriorated renal function with a >30% decrease in the glomerular filtration rate. The mean follow-up was 22.3±4.9 months, and mortality was 4.5% (3.3% in the PMEG group vs 7.1% in the hybrid repair group). Conclusion: PMEGs and hybrid techniques seem to be feasible treatment options for aortic aneurysms necessitating visceral vessel revascularization. PMEGs may have a lower morbidity than the hybrid technique, which nonetheless remains an important option available for complex aortic aneurysms.

Current status of endovascular treatment for thoracoabdominal aortic aneurysms

Open surgical repair (OSR) for thoracoabdominal aortic aneurysms (TAAAs) is maximally invasive and associated with high rates of operative mortality and perioperative complications including spinal cord ischemia (SCI), despite improvements in surgical techniques and perioperative care. Elderly patients, patients with a history of aortic surgery, and patients with severe comorbidities are often considered ineligible for this surgery and endovascular treatment may be their only treatment option. Total endovascular aneurysm repair (t-EVAR) without debranching surgery does not require thoracotomy and laparotomy and could improve the outcomes of these patients. t-EVAR includes fenestrated EVAR (f-EVAR), multi-branched EVAR (b-EVAR), and physician-modified fenestration endograft (PMFG). Although these techniques have achieved lower mortality rates than OSR, there are concerns about perioperative complications including limb ischemia, SCI, and long-term outcomes such as endograft migration and endoleaks (ELs). This article provides an overview of available endovascular devices for TAAAs and reviews the short and mid-term results of t-EVAR, as well as alternative options.

FEATURES OF DEBRANCHING TECHNIQUE FOR AORTIC DISSECTIONS AND ANEURYSMS IN THORATIC AND THORACO-ABDOMINAL AORTAS

This article describes a hybrid surgical technique for high-risk patients with thoraco-abdominal aortic dissections and aneurysms. The technical aspects of the first stage of surgical treatment - visceral and brachiocephalic debranching are described in detail. 17 surgical interventions for chronic dissection and aneurysm in the thoracic and thoracoabdominal aortas were performed at the Vishnevsky National Medical Research Center of Surgery of Ministry of Health of the Russian Federation in the period from 2014 to 2019. In two cases, we observed postoperative pancreatitis after surgical treatment of the abdominal aorta branches, which we managed using conservative therapy. After open surgery, all patients were discharged in a satisfactory condition. The selected technique made it possible to prepare patients for the following stage of treatment - endografting of the aorta - without developing serious complications.

Precise plan of hybrid treatment for thoracoabdominal aortic aneurysm: Hemodynamics of retrograde reconstruction visceral arteries from the iliac artery

Hybrid visceral-renal debranching procedures with endovascular repair have been proposed as a less invasive alternative to conventional thoracoabdominal aortic aneurysm or dissection (TAAA or TAAD) surgery. Up to now, there has been no information about the hemodynamic effects of retrograde visceral reconstruction (RVR) for Crawford type II/III/IV TAAA patients undergoing hybrid treatment. The aim is to provide insights in the abnormal hemodynamics of RVR from unilateral or bilateral common iliac arteries (CIAs). Idealized three-dimensional AAs with RVR from unilateral CIA or bilateral CIAs were generated and computationally simulated. The results show that RVRs from CIA lead to a dramatic decrease in flow to the visceral organs compared with a healthy AA and that the anastomosis region is most dangerous to graft occlusion and the initiation of an aneurysm. In addition, compared with a quar-furcated graft, the employment of bilateral bi-furcated grafts have better performance in terms of the wall shear stress (WSS) and flow filed but result in less flow to the celiac and mesenteric arteries. This study has revealed the potential risks after an RVR operation, and points out the advantages and disadvantages of different approaches for the visceral reconstruction, which the vascular surgeons are not fully aware of. According to our results, bilateral bi-furcated grafts are recommended to the TAAA patients when the CIAs are unique inflow sites for visceral reconstruction. A precise plan with patient specific for TAAA or TAAD will be designed for better long-term outcome.

[Staged approach for hybrid thoracoabdominal aortic replacement]

AIM

To generalize our experience of step-by-step hybrid thoracoabdominal aortic replacement.

MATERIAL AND METHODS

Twenty-three patients were enrolled who underwent staged hybrid treatment of thoracoabdominal aortic aneurysm. There were 5 (21.7%) women and 18 (78.3%) men aged 61.4±8.3 years (37-74 years). The first stage was proximal debranching, the second - distal (abdominal) procedure and the third - stenting of the thoracoabdominal aorta.

RESULTS

There were no any complications after proximal debranching and aortic stenting. Abdominal debranching was followed by lethal outcome in 3 (13.0%) patients and early postoperative occlusion of the prosthesis brunch in 3 out of 87 cases.

CONCLUSION

Staged approach for hybrid surgical treatment is optimal solution, especially in high risk patients. In our opinion no necessity for cardiopulmonary bypass is the main advantage of this technique.

Outcomes of thoracic endovascular aortic repair using aortic arch chimney stents in high-risk patients

BACKGROUND

Aortic arch disease is a challenging clinical problem, especially in high-risk patients, in whom open repair can have morbidity and mortality rates of 30% to 40% and 2% to 20%, respectively. Aortic arch chimney (AAC) stents used during thoracic endovascular aortic repair (TEVAR) are a less invasive treatment strategy than open repair, but the current literature is inconclusive about the role of this technology. The focus of this analysis is on our experience with TEVAR and AAC stents.

METHODS

All TEVAR procedures performed from 2002 to 2015 were reviewed to identify those with AAC stents. Primary end points were technical success and 30-day and 1-year mortality. Secondary end points included complications, reintervention, and endoleak. Technical success was defined as a patient's surviving the index operation with deployment of the AAC stent at the intended treatment zone with no evidence of type I or type III endoleak on initial postoperative imaging. The Kaplan-Meier method was used to estimate survival.

RESULTS

Twenty-seven patients (age, 69 ± 12 years; male, 70%) were identified, and all were described as being at prohibitive risk for open repair by the treating team. Relevant comorbidity rates were as follows: coronary artery disease/myocardial infarction, 59%; oxygen-dependent emphysema, 30%; preoperative creatinine concentration >1.8 mg/dL, 19%; and congestive heart failure, 15%. Presentations included elective (67%; n = 18), symptomatic (26%; n = 7), and ruptured (7%; n = 2). Eleven patients (41%) had prior endovascular or open arch/descending thoracic repair. Indications were degenerative aneurysm (49%), chronic residual type A dissection with aneurysm (15%), type Ia endoleak after TEVAR (11%), postsurgical pseudoaneurysm (11%), penetrating ulcer (7%), and acute type B dissection (7%). Thirty-two brachiocephalic vessels were treated: innominate (n = 7), left common carotid artery (LCCA; n = 24), and left subclavian artery (n = 1). Five patients (19%) had simultaneous innominate-LCCA chimneys. Brachiocephalic chimney stents were planned in 75% (n = 24), with the remainder placed for either LCCA or innominate artery encroachment (n = 8). Overall technical success was 89% (one intraoperative death, two persistent type Ia endoleaks in follow-up). The 30-day mortality was 4% (n = 1; intraoperative death of a patient with a ruptured arch aneurysm), and median length of stay was 6 (interquartile range, 4-9) days. Seven (26%) patients experienced a major complication (stroke, three [all with unplanned brachiocephalic chimney]; respiratory failure, three; and death, one). Nine (33%) patients underwent aorta-related reintervention, and no chimney occlusion events occurred during follow-up (median follow-up, 9 [interquartile range, 1-23] months). The 1-year and 3-year survival is estimated to be 88% ± 6% and 69% ± 9%, respectively.

CONCLUSIONS

TEVAR with AAC can be performed with high technical success and acceptable morbidity and mortality in high-risk patients. Unplanned AAC placement during TEVAR results in an elevated stroke risk, which may be related to the branch vessel coverage necessitating AAC placement. Acceptable midterm survival can be anticipated, but aorta-related reintervention is not uncommon, and diligent follow-up is needed.

A Novel Method for the Treatment of Bilateral Hypogastric Aneurysms Using Hybrid Polytetrafluoroethylene Graft

Open aortic aneurysm repair in the setting of bilateral hypogastric aneurysms is technically challenging. We present a novel technique for open surgical repair for bilateral hypogastric aneurysms using the Gore hybrid vascular graft (GVHG; W. L. Gore and Associates Inc, Flagstaff, Arizona). The GVHG is an expanded polytetrafluoroethylene graft with a nitinol stent at 1 end designed for hemodialysis access. The GVHG has been also been used for aortic debranching and treatment of occlusive disease. We describe the first report using GVHG to repair hypogastric aneurysms.

Reversed Frozen Elephant Trunk Technique to Treat a Type II Thoracoabdominal Aortic Aneurysm

Purpose: To describe a hybrid technique of reversed frozen elephant trunk to treat thoracoabdominal aortic aneurysms (TAAA) through an abdominal only approach. Technique: The technique is demonstrated in a 29-year-old Marfan patient with a chronic type B aortic dissection previously treated with a thoracic stent-graft who presented with a thoracoabdominal false lumen aneurysm. Through an open distal retroperitoneal approach to the abdominal aorta, a frozen elephant trunk graft was implanted over a super-stiff wire upside down with the stent-graft component in the thoracic aorta. Following deployment of the stent-graft proximally and preservation of renovisceral perfusion in a retrograde manner, the renovisceral vessels were sequentially anastomosed to the elephant trunk graft branches, thus reducing the ischemia time of the end organs. The aortic sac was then opened, and the distal part of the hybrid graft was anastomosed with a further bifurcated graft to the iliac vessels. Conclusion: The reversed frozen elephant trunk technique is feasible for hybrid treatment of TAAAs via an abdominal approach only. This has the benefit of substantially reducing the trauma of thoracic exposure, thus preserving major benefits of open thoracoabdominal surgery, such as the presence of short bypasses to the renovisceral vessels and reimplantation of lumbar arteries to reduce spinal cord ischemia.

Hybrid Repair of Thoracoabdominal Aortic Aneurysms Is a Durable Option for High-Risk Patients in the Endovascular Era

Objective:

To report our long-term experience in using the hybrid technique in complex thoracoabdominal aortic aneurysms (TAAAs).

Methods:

Between March 2005 and September 2013, 10 patients with TAAA underwent hybrid procedures with open renovisceral revascularization and thoracoabdominal aortic endografting. Patients were analyzed retrospectively.

Results:

Six men and 4 women with a mean age of 66 years (range 54-81 years) were treated electively during the study period. All 4 visceral vessels were revascularized in 8 patients, whereas 1 patient underwent 3-vessel revascularization and another 2-vessel revascularization. The primary technical success rate was 100%. Eight of the procedures were single staged, and the 2 most recent cases were performed in 2 stages. Perioperative and 30-day mortality was 0%. The mean follow-up was 55 months (4-133 months). None of the patients died due to aortic complications. Major complications included paraplegia (10%, n = 1) and bowel ischemia (n = 1). Postoperative cerebrospinal fluid (CSF) pressure and mean arterial pressure measurements were systematically monitored and corrected. The CSF drainage solved another 4 cases of paraparesis. Three patients required postoperative dialysis, but none of them required permanently. Postoperative spinal cord ischemia and renal complications accumulated in extensive TAAA cases. One renal graft was occluded 45 days after the initial procedure but was successfully treated with thrombolysis. One type I and 1 type III endoleak were noted and successfully treated with an additional stent graft. Two cases of type II endoleak were detected—one with a growing aneurysm sac was treated successfully and another showed no growth and further procedures were abandoned after 2 embolization attempts. In long-term follow-up, 90% of the aneurysms showed shrinkage by a mean of 23 mm (range 7-45 mm).

Conclusion:

The results of hybrid repair on high-risk patients with complex TAAAs are encouraging, and this approach is a valuable alternative when branched and fenestrated endovascular techniques are not considered 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.

Three-Year Outcomes With the Multilayer Flow Modulator for Repair of Thoracoabdominal Aneurysms

Purpose: To evaluate midterm outcomes of endovascular repair of types II and III thoracoabdominal aortic aneurysms (TAAA) using the Multilayer Flow Modulator (MFM) in patients unsuitable for open surgery or fenestrated stent-grafts. Methods: In the prospective, multicenter, nonrandomized STRATO trial (EudraCT registration: 2009-013678-42; ClinicalTrials.gov identifier NCT01756911), 23 patients (mean age 75.8 years; 19 men) with Crawford type II and III TAAA (mean diameter 6.5 cm) were implanted between April 2010 and February 2011. Outcomes included all-cause mortality and stable aneurysm thrombosis with associated branch vessel patency. Results: Through 36 months, there were 7 deaths (none confirmed as aneurysm-related), and no cases of spinal cord injury, device migration or fracture, or respiratory, renal, or peripheral complications. Three patients were lost to follow-up and 2 devices were explanted. The device was patent in the 11 remaining patients at 3 years. Stable aneurysm thrombosis was achieved for 15 of 20 patients at 12 months, 12 of 13 at 24 months, and 10 of 11 at 36 months. The rate of branch patency was 96% at 12 months (primary patency), 100% at 24 months, and 97% at 36 months. Nine patients suffered from endoleaks (attachment site or device overlap); 9 patients underwent 11 reinterventions (3 surgical). Maximum aneurysm diameter was stable for 18 of 20 patients at 12 months, 11 of 13 at 24 months, and 9 of 11 at 36 months. For 10 patients with computed tomography at 36 months, the mean ratio of aneurysm flow volume to total volume had decreased by 83%; the mean ratio of thrombus volume to total volume increased by 159%. Conclusion: Through 3 years, endovascular repair with the MFM appears to be safe and effective while successfully maintaining branch vessel patency.

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.

Endovascular Treatment of Thoracoabdominal Aorta Aneurysm by the Combination of a Stent Graft with Multiple Overlapping Bare Stents

A 41-year-old male diagnosed with Crawford III thoracoabdominal aorta aneurysm (TAAA) was treated using a completely endovascular approach. After the combined implementation of 4 overlapping bare stents and a stent graft, TAAA was excluded while the 4 visceral arteries were reserved. Follow-up computed tomography scans at 3 and 6 months showed that the aneurysm had almost disappeared, while the vital branches remained open. This case may provide an acceptable alternative choice for treating TAAA in selected patients.

Ruptured Juxtarenal Abdominal Aortic Aneurysm Treated With a Fenestrated EVAR Graft Intended for a Different Patient

Treatment of juxtarenal abdominal aortic aneurysms (AAAs) remains challenging. A 79-year-old male who had infrarenal endovascular repair of abdominal aortic aneurysm (EVAR) 13 years previously presented with leaking juxtarenal AAA. Emergency fenestrated EVAR (FEVAR) was performed utilizing a stent graft designed and built for a different patient. Despite the need to embolize the celiac artery prior to covering it with the stent graft in order to achieve adequate proximal seal, the patient had uneventful recovery.

A computational simulation of the effect of hybrid treatment for thoracoabdominal aortic aneurysm on the hemodynamics of abdominal aorta

Hybrid visceral-renal debranching procedures with endovascular repair have been proposed as an appealing technique to treat conventional thoracoabdominal aortic aneurysm (TAAA). This approach, however, still remained controversial because of the non-physiological blood flow direction of its retrograde visceral revascularization (RVR) which is generally constructed from the aortic bifurcation or common iliac artery. The current study carried out the numerical simulation to investigate the effect of RVR on the hemodynamics of abdominal aorta. The results indicated that the inflow sites for the RVR have great impact on the hemodynamic performance. When RVR was from the distal aorta, the perfusion to visceral organs were adequate but the flow flux to the iliac artery significantly decreased and a complex disturbed flow field developed at the distal aorta, which endangered the aorta at high risk of aneurysm development. When RVR was from the right iliac artery, the abdominal aorta was not troubled with low WSS or disturbed flow, but the inadequate perfusion to the visceral organs reached up to 40% and low WSS and flow velocity predominated appeared at the right iliac artery and the grafts, which may result in the stenosis in grafts and aneurysm growth on the host iliac artery.

Results of the Gore Hybrid Vascular Graft in Challenging Aortic Branch Revascularization during Complex Aneurysm Repair

BACKGROUND

Prolonged organ ischemia during complex aortic surgery is associated with increased morbidity and mortality. A novel hybrid graft (Gore Hybrid Vascular Graft) as composite of expanded polytetrafluorethylene vascular prosthesis that has a section reinforced with nitinol was investigated for feasibility and effectiveness during aortic repair.

METHODS

Retrospective analysis of all consecutive patients treated with the hybrid vascular graft (HVG). Indication for graft implantation was surgeon's preference for branch revascularization in challenging aortic repair.

RESULTS

Within 26 months, 25 Gore HVGs and 17 conventional grafts were implanted in 12 patients (age, 73 years; range, 33-79 years, 8 men). Eleven patients were treated for thoracoabdominal aortic aneurysms and one for aortoiliac aneurysm (elective = 6, urgent = 6). Nine visceral debranching procedures, 2 Crawford procedures, and 1 repair of an internal iliac aneurysm were performed. The distribution of HVG use was left renal artery = 10, right renal artery = 9, superior mesenteric artery = 4, celiac trunk = 1, and internal iliac artery = 1. Time to restore visceral blood flow during visceral debranching was 7 ± 4 min for the Gore HVG vs. 12 ± 6 min for conventional grafts (P < 0.01).Technical success was achieved in all cases. At 12 months of median follow-up, cumulative patency of the HVGs was 96%.

CONCLUSIONS

The Gore HVG offers a new, simplified, and time-sparing technique for visceral anastomoses during complex aneurysm repair. However, long-term results are still lacking and need to be awaited.

["Debranching" -- a new surgical option for the aortic arch and thoracoabdominal aorta hybrid interventions]

INTRODUCTION

Endovascular techniques in vascular surgery are frequently applied to treat aortic diseases. These minimally invasive procedures changed aortic interventions remarkably. We have to be familiar with new terminology and methods.

METHOD

New and old surgical procedures gained new role in preparation of endograft implantations. Transforming anatomy of aortic branches - "debranching" - is aimed to create a sufficient fixation of the endografts at safe "landing zones".

CONCLUSIONS

Knowing the option of hybrid procedures is a fundamental requirement for the vascular surgeon. Equally important is to know the biomechanical characteristics of the available endografts, the possible complications during and after implantation and the treatment options. We have to be aware of the limitations of these new methods and the role of traditional open surgery in the new era. Our intention in this paper is to summarize methods of debranching.

The "terrace technique"--totally endovascular repair of a type IV thoracoabdominal aortic aneurysm

BACKGROUND

As an alternative to branched or fenestrated aortic stent grafts, the "snorkel" or "chimney graft" strategy is a feasible endovascular option, particularly for juxtarenal aneurysms. When more than 2 visceral vessels require revascularization, however, the summative displacement of the main body endograft theoretically increases gutter formation with subsequent endoleak. The "terrace" strategy, or "sandwich", stacks the snorkel grafts into separate layers, and we describe a case using 4 snorkel grafts during endovascular aneurysm repair of a type IV thoracoabdominal aortic aneurysm (TAAA).

METHODS

A 76-year-old man with prohibitive operative risk has been followed for years with an asymptomatic TAAA that grew to 6.2 cm. Endovascular strategy consisted of celiac and superior mesenteric artery snorkel stents deployed and molded adjacent to a 36-mm proximal thoracic cuff (Cook TX2).

RESULTS

Through the proximal thoracic endograft, both renals were then accessed, and in this second layer, or "terrace configuration," bilateral renal snorkels were deployed and molded adjacent to a 36-mm bifurcated abdominal stent-graft system (Cook Zenith). "Quadruple kissing" balloon angioplasty was then performed to mold the lower part of the devices. Operative time was 4 hr, the patient was extubated immediately and recovered quickly on the floor, being discharged in 3 days. Postoperative imaging at 6 months, 1 year, and 2 years have revealed patent aortic components without evidence of stent-graft migration or significant endoleak. The terrace snorkel stents were all patent to the celiac, superior mesenteric, and right renal arteries, while the left renal artery stent shows some stent compression.

CONCLUSIONS

In select high-risk patients opting for an all-endovascular approach of type IV TAAAs, up to 4 snorkel grafts can be deployed in a "terrace" or "sandwich" configuration to successfully revascularize all visceral branches and provide aneurysm exclusion. Long-term follow-up is necessary to understand the overall success of this strategy.

A novel hybrid approach using antegrade visceral debranching from both axillary arteries for thoracoabdominal aneurysm repair

Hybrid aortic surgery combining visceral debranching and stent grafting is an alternative to conventional open surgery and branched stent grafting for thoracoabdominal aneurysm repair. Visceral aortic branch bypasses are usually performed from the iliac arteries or the infrarenal or ascending aorta. Herein, we describe a new debranching technique to treat a painful Crawford type III thoracoabdominal aneurysm in a high-risk patient who was deemed unsuitable for open, endovascular, or traditional hybrid repair. The superior mesenteric artery and the right renal arteries were exposed via a right retroperitoneal approach and revascularized from the right axillary artery. Splenic and left renal arteries were exposed via a left retroperitoneal approach and revascularized from the left axillary artery.

The chimney-graft technique for preserving supra-aortic branches: a review

Evolution in the endovascular era has influenced the management of aortic arch pathologies. "Chimney" or "snorkel" graft technique has been used as an alternative in high risk patients unfit for open repair. We reviewed the published literature on the chimney graft technique for preservation of the supra-aortic branches in order to provide an extensive insight of its feasibility and efficacy and investigate its outcomes. 18 reports were identified, with a total of 124 patients and 136 chimney. Primary technical success was achieved in 123/124 patients (99.2%). The perioperative mortality rate was 4.8% and the stroke rate was 4%, while events of spinal cord ischemia were rare. The overall endoleak rate was 18.5%; 13 patients (10.5%) developed a type I endoleak and 10 (8%) patients a type II endoleak. During a median follow-up period of 11.4 months (range, 0.87-20.1 months) all implanted chimney grafts remained patent. From this, we conclude that endovascular aortic arch repair with chimney grafts is associated with a lower mortality rate compared to totally open or hybrid reconstruction. However, the stroke rate remains noteworthy, and requires longterm data to elucidate.