Goal-directed colloid versus crystalloid therapy and microcirculatory blood flow following ischemia/reperfusion.

OBJECTIVE: Ischemia/reperfusion can impair microcirculatory blood flow. It remains unknown whether colloids are superior to crystalloids for restoration of microcirculatory blood flow during ischemia/reperfusion injury. We tested the hypothesis that goal-directed colloid - compared to crystalloid - therapy improves small intestinal, renal, and hepatic microcirculatory blood flow in pigs with ischemia/reperfusion injury. METHODS: This was a randomized trial in 32 pigs. We induced ischemia/reperfusion by supra-celiac aortic-cross-clamping. Pigs were randomized to receive either goal-directed isooncotic hydroxyethyl-starch colloid or balanced isotonic crystalloid therapy. Microcirculatory blood flow was measured using Laser-Speckle-Contrast-Imaging. The primary outcome was small intestinal, renal, and hepatic microcirculatory blood flow 4.5 h after ischemia/reperfusion. Secondary outcomes included small intestinal, renal, and hepatic histopathological damage, macrohemodynamic and metabolic variables, as well as specific biomarkers of tissue injury, renal, and hepatic function and injury, and endothelial barrier function. RESULTS: Small intestinal microcirculatory blood flow was higher in pigs assigned to isooncotic hydroxyethyl-starch colloid therapy than in pigs assigned to balanced isotonic crystalloid therapy (768.7 (677.2-860.1) vs. 595.6 (496.3-694.8) arbitrary units, p = .007). There were no important differences in renal (509.7 (427.2-592.1) vs. 442.1 (361.2-523.0) arbitrary units, p = .286) and hepatic (604.7 (507.7-701.8) vs. 548.7 (444.0-653.3) arbitrary units, p = .376) microcirculatory blood flow between groups. Pigs assigned to colloid - compared to crystalloid - therapy also had less small intestinal, but not renal and hepatic, histopathological damage. CONCLUSIONS: Goal-directed isooncotic hydroxyethyl-starch colloid - compared to balanced isotonic crystalloid - therapy improved small intestinal, but not renal and hepatic, microcirculatory blood flow in pigs with ischemia/reperfusion injury. Whether colloid therapy improves small intestinal microcirculatory blood flow in patients with ischemia/reperfusion needs to be investigated in clinical trials.

A Free-Floating Aortic Thrombus: An Uncommon Approach to Handle a Rare Clinical Entity.

BACKGROUND: Thrombotic material in the non-aneurysmatic and non-atherosclerotic aorta is a rare entity without any recommended standard treatment so far. We present a successful treatment strategy for patients who do not fit into any of the common approaches. CASE REPORT: A free-floating thrombus in the descending aorta was found as source of embolism in an 82-year-old female patient with lower limb ischemia. After initial heparinization of the patient without relevant reduction of the thrombotic mass, the thrombus was removed using an interdisciplinary approach. Under echocardiographic guidance to locate the thrombus, the AngioVac device, usually licensed to remove floating thrombi from the venous system, was used off-label to remove the thrombus by a transfemoral approach. To avoid rebuilding of a new thrombus, the attachment point with an exulcerated plaque in the descending aorta was covered by a stent graft via the same femoral access. The patient did not experience any further embolic events, and the postoperative course was uncomplicated. CONCLUSION: Patients with uncommon aortic diseases, such as the reported free-floating thrombus, should be treated by an individualized, interdisciplinary approach. Besides the recommended treatment options, there are other uncommon approaches that might offer an alternative in complex cases. CLINICAL IMPACT: Evidence is rare for the treatment of a free-floating thrombus in the descending aorta and the treatment strategy remains discussed controversially. We present a rather uncommon approach of successful off-label treatment for patients who do not fit into any of the common approaches (operative, endovascular, or conservative treatment based on patient's comorbidities). The AngioVac System has already been successfully used off-label in the arterial system but not in the above presented way of treating a free-floating thrombus in a patient with high embolization risk and treatment-limiting comorbidities.

Comparing the Efficacy of Endovascular Simulation Training in Different Training Formats: A Randomized Controlled Trial.

BACKGROUND: High-fidelity endovascular simulators have demonstrated significant potential in enhancing interventionalists' performance metrics, including procedure time (PT), fluoroscopy time (FT), and contrast volume (CV) usage. However, it is less clear whether trainee performance, when assessed using both multidimensional global and procedure-specific rating scales (PSRS), improves in a manner consistent with these metric parameters. This study aimed to determine whether the structure of the training-conducted in block sessions or weekly intervals-impacts the effectiveness of the training. METHODS: Twenty students were enrolled in this prospective, randomized, controlled, single-center trial. They were randomly divided into block and weekly training groups, each undergoing 6 hrs of supervised endovascular training on a Mentice simulator over a span of 3 weeks. At the outset and conclusion of their training, students performed a predefined peripheral endovascular intervention, which was assessed by an experienced interventionalist. Furthermore, participants were prompted to complete a survey at both the beginning and the end of the study. RESULTS: Both groups exhibited significant improvements in PT, FT, CV usage, global rating scale (GRS) scores, and performance-specific rating scale scores. However, no significant difference was observed between the 2 groups. The simulator training notably boosted the trainee's self-confidence. CONCLUSIONS: Simulator training not only enhances metric performance parameters but also improves performance as assessed by both GRS and PSRS. Whether the training is conducted in block sessions or weekly intervals did not affect its efficacy. As such, the training format can be tailored to best fit the specific circumstances and setting.

Experimental Atherosclerosis Research on Large and Small Animal Models in Vascular Surgery.

Animal models have significantly advanced our understanding of the mechanisms of atherosclerosis formation and the evaluation of therapeutic options. The current focus of research is on preventive strategies and includes pharmacologic and biologic interventions directed primarily against smooth-muscle cell proliferation, endovascular devices for recanalization and/or drug delivery, and an integrated approach using both devices and pharmacobiologic agents. The experience over many decades with animal models in vascular research has established that a single, ideal, naturally available model for atherosclerosis does not exist. The spectrum ranges from large animals such as pigs to small animal experiments with genetically modified rodents such as the ApoE-/- mouse with correspondingly differently pronounced changes in their lipid and lipoprotein levels. The development of transgenic variants of currently available models, e.g., an ApoE-deficient rabbit line, has widened our options. Nevertheless, an appreciation of the individual features of natural or stimulated disease in each species is of importance for the proper design and execution of relevant experiments.

Effects of fluids vs. vasopressors on spinal cord microperfusion in hemorrhagic shock induced ischemia/reperfusion.

OBJECTIVE: Spinal cord injury induced by ischemia/reperfusion is a devastating complication of aortic repair. Despite developments for prevention and treatment of spinal cord injury, incidence is still considerably high majorly impacting patient outcome. Microcirculation is paramount for tissue perfusion and oxygen supply and often dissociated from macrohemodynamic parameters used to guide resuscitation. Effects of fluids vs. vasopressors in the setting of hemodynamic resuscitation on spinal cord microperfusion are unknown. Aim of this study was to compare the effects of vasopressor and fluid resuscitation on spinal cord microperfusion in a translational acute pig model of hemorrhagic shock induced ischemia/reperfusion injury. METHODS: We designed this study as prospective randomized explorative large animal study. We induced hemorrhagic shock in 20 pigs as a model of global ischemia/reperfusion injury. We randomized animals to receive either fluid or vasopressor resuscitation. We measured spinal cord microperfusion using fluorescent microspheres as well as laser-Doppler probes. We monitored and analyzed macrohemodynamic parameters and cerebrospinal fluid pressure. RESULTS: Spinal cord microperfusion decreased following hemorrhagic shock induced ischemia/reperfusion injury. Both fluids and vasopressors sufficiently restored spinal cord microperfusion. There were no important changes between groups (percentage changes compared to baseline: fluids 14.0 (0.31-27.6) vs. vasopressors 24.3 (8.12-40.4), p = .340). However, cerebrospinal fluid pressure was higher in animals receiving fluid resuscitation (percentage changes compared to baseline: fluids 27.7 (12.6-42.8) vs. vasopressors -5.56 ((-19.8)-8.72), p = .003). Microcirculatory resuscitation was in line with improvements of macrohemodynamic parameters. CONCLUSIONS: Both, fluids and vasopressors, equally restored spinal cord microperfusion in a porcine acute model of hemorrhagic shock induced ischemia/reperfusion injury. However, significant differences in cerebrospinal fluid pressure following resuscitation were present. Future studies should evaluate these effects in perfusion disruption induced ischemia/reperfusion conditions of microcirculatory deterioration.

Comparison of Prosthetic and Vein Bypass with Nitinol Stents in Long Femoropopliteal Lesions.

BACKGROUND: Guidelines for the treatment of long femoropopliteal lesions are not based on a high level of evidence and recent randomized controlled trials (RCTs) challenge vein bypass (VBP) as the recommended therapy. This study compared prosthetic (PTFE) bypass, VBP and angioplasty with nitinol stents in long femoropopliteal lesions. METHODS: Pooled data from a RCT and a retrospective database with the same inclusion criteria were analyzed with primary and secondary patency as well as freedom from target lesion revascularization (TLR) as primary endpoints. RESULTS: Between 2016 and 2018 a total of 172 lesions were treated in three groups (PTFE: n = 62, VBP: n = 55, stent: n = 55). Clinical and lesion characteristics were similar with mean lesion lengths between 260 and 279mm. Technical success rate in the stent group was 87%. There were no significant differences between the groups in patency rates, freedom from TLR, limb salvage and survival during 2-year follow-up. The primary patency rates for the PTFE, VBP and stent groups were 50%, 56% and 60% at 2 years. The PTFE group had significantly less complications compared to the other groups and a shorter hospital-stay compared to the VBP group. Clinical improvement was significantly better in the PTFE and VBP group compared to the stent group. CONCLUSIONS: The 2-year results indicate that the role of VBP as the recommended therapy for long femoropopliteal lesions may not be unchallenged due to the similar results in all three groups. Further RCTs are needed to determine the best revascularization modality for long femoropopliteal lesions.

Quantification of gastric tube perfusion following esophagectomy using fluorescence imaging with indocyanine green.

INTRODUCTION: Anastomotic leakage (AL) remains a prevalent and life-threatening complication after esophagectomy. Gastric tube perfusion assessment using indocyanine green fluorescence imaging (ICG-FI) has been published in several studies and appears to be a promising tool to reduce AL rates by changing the surgical approach, namely by an intraoperative evaluation of the anastomosis localization. METHODS: In this study, gastric tube perfusion was quantified by using ICG-FI in 20 high-risk patients undergoing esophagectomy. From a time-dependent fluorescence intensity curve, the following three parameters were evaluated: slope of fluorescence intensity (SFI), background subtracted peak fluorescence intensity (BSFI), and time to slope (TTS). RESULTS: The values between pyloric region and tip showed a similar downward trend and SFI and BSFI significantly correlated with the distance to the pyloric region. SFI and BSFI were significantly decreased at the tip of the gastric tube. The placement of anastomosis in an area with homogenous fluorescence pattern was correlated with no AL in 92.9% of cases. An inhomogeneous fluorescence pattern at anastomotic site was a risk factor for the occurrence of an AL (p < 0.05). Reduction of perfusion up to 32% using SFI and up to 23% using BSFI was not associated with AL. CONCLUSION: ICG-FI can be used to quantify the gastric tube perfusion by calculating SFI, BSFI, and TTS. The anastomosis should be created in areas with homogeneous fluorescence pattern. A reduction in blood flow of up to 32% can be accepted without causing an increased rate of insufficiency.

Long-Term Results of Endovascular Treatment with Nitinol Stents for Femoropopliteal TASC II C and D Lesions.

Background and Objectives: The feasibility of endovascular treatment (EVT) for Trans-Atlantic Inter-Society Consensus (TASC) II C and D femoropopliteal artery lesions has been described, but no prospective study has performed a long-term follow-up. The aim of this study was to report the long-term results of nitinol stents (NS) for the treatment of long femoropopliteal lesions. Materials and Methods: A single-center prospective, randomized controlled trial (RCT) comparing EVT with NS and vein bypass surgery was previously performed. The EVT group's follow-up was extended and separately analyzed with primary patency as the primary endpoint. The secondary endpoints were technical success, secondary patency, reinterventions, limb salvage, survival, complications, and clinical improvement. Results: Between 2016 and 2020, 109 limbs in 103 patients were included. A total of 48 TASC II C and 61 TASC II D lesions with a mean lesion length of 264 mm were reported. In 53% of limbs, the indication for treatment was chronic limb-threatening ischemia. The median follow-up was 45 months. Technical success was achieved in 88% of cases, despite 23% of the lesions being longer than 30 cm (retrograde popliteal access in 22%). At four-year follow-up, primary patency, secondary patency, and freedom from target lesion revascularizations were 35%, 48%, and 58%, respectively. Limb salvage and survival were 90% and 80% at 4 years. Clinical improvement of at least one Rutherford category at the end of follow-up was achieved in 83% of limbs. Conclusions: This study reports the longest follow-up of endovascular treatment with nitinol stents in femoropopliteal TASC II C and D lesions. The results emphasize the feasibility of an endovascular-first strategy, even in lesions beyond 30 cm in length, and clarify its acceptable long-term durability and good clinical outcomes. Large multicenter RCTs with mid- and long-term follow-up are needed to investigate the role of different endovascular techniques in long femoropopliteal lesions.

The Role of Mitochondrial Function in Peripheral Arterial Disease: Insights from Translational Studies.

Recent evidence demonstrates an involvement of impaired mitochondrial function in peripheral arterial disease (PAD) development. Specific impairments have been assessed by different methodological in-vivo (near-infrared spectroscopy, 31P magnetic resonance spectroscopy), as well as in-vitro approaches (Western blotting of mitochondrial proteins and enzymes, assays of mitochondrial function and content). While effects differ with regard to disease severity, chronic malperfusion impacts subcellular energy homeostasis, and repeating cycles of ischemia and reperfusion contribute to PAD disease progression by increasing mitochondrial reactive oxygen species production and impairing mitochondrial function. With the leading clinical symptom of decreased walking capacity due to intermittent claudication, PAD patients suffer from a subsequent reduction of quality of life. Different treatment modalities, such as physical activity and revascularization procedures, can aid mitochondrial recovery. While the relevance of these modalities for mitochondrial functional recovery is still a matter of debate, recent research indicates the importance of revascularization procedures, with increased physical activity levels being a subordinate contributor, at least during mild stages of PAD. With an additional focus on the role of revascularization procedures on mitochondria and the identification of suitable mitochondrial markers in PAD, this review aims to critically evaluate the relevance of mitochondrial function in PAD development and progression.

Fenestrated or branched endovascular aortic repair for postdissection thoracoabdominal aortic aneurysm.

OBJECTIVE: Fenestrated or branched endovascular aortic repair (FB-EVAR) usually represents the last stage in endovascular treatment of postdissection aneurysm after thoracic endograft coverage of entry tear and false lumen embolization. METHODS: The study was a retrospective analysis of all patients with postdissection thoracoabdominal aneurysm treated with FB-EVAR in a single center. Short-term outcomes included technical success, operative mortality, and morbidities. Midterm outcomes included secondary intervention, false lumen thrombosis rate, aneurysm size regression, and subsequent survival. RESULTS: Twenty patients (95% male with a mean age of 64 ± 9 years) were treated between January 2014 and December 2017. The technical success was 100%. There was one death (5%) within 30 days. Postoperative complications included two patients with spinal cord ischemia (10%; one partial and one full). The median follow-up period was 12 months (range, 0-31 months). A secondary intervention was required in six patients, including thoracic stent graft relining for type III endoleak (n = 2), covered stent relining for junctional leak between main body and renal stent (n = 2), and iliac false lumen embolization (n = 2). Twelve patients completed the 1-year follow-up computed tomography angiogram, and their mean aneurysm diameters were 71 ± 18, 66 ± 19, and 62 ± 19 mm preoperatively, immediate postoperatively, and at 1 year, respectively; the corresponding false lumen thrombosis rates were 0% (0/20), 58% (7/12), and 92% (11/12), respectively. One more patient died during follow-up from a non-aneurysm-related cause. The estimated overall survival rates were 95 ± 5%, 88 ± 8%, and 88 ± 8% at 6, 12, and 18 months, respectively. CONCLUSIONS: FB-EVAR was feasible for postdissection thoracoabdominal aneurysm. Despite the associated perioperative risk and high probability of planned or unplanned reintervention, the procedure led to favorable aortic remodeling with false lumen thrombosis and aneurysm regression.

Risk of spinal cord ischemia after fenestrated or branched endovascular repair of complex aortic aneurysms.

OBJECTIVE: The aim of our study was to analyze the incidence of spinal cord ischemia (SCI) in patients presenting with complex aortic aneurysms treated with endovascular aneurysm repair (EVAR) and to identify risk factors associated with this complication. METHODS: A retrospective study was undertaken of prospectively collected data including patients presenting with complex aortic aneurysm (pararenal abdominal aortic aneurysm and thoracoabdominal aortic aneurysm) treated with fenestrated EVAR (F-EVAR) or branched EVAR (B-EVAR). The primary end point was the incidence of SCI and the assessment of any associated factors. RESULTS: Between January 2011 and August 2017, a total of 243 patients (mean aneurysm diameter, 65.2 ± 15.3 mm; mean age, 72.4 ± 7.5 years; 73% male) were treated with F-EVAR or B-EVAR. Asymptomatic patients were treated in 73% of the cases (177/243, in contrast to 27% urgent), and 52% (126/243) were treated for thoracoabdominal aortic aneurysm (in contrast to 48% for pararenal abdominal aortic aneurysm). F-EVAR (mean number of fenestrations, 3.3/case) and B-EVAR (mean number of branches, 3.7/case) were undertaken in 67% (164/243) and 33% (79/243), respectively. The total incidence of SCI was 17.7% [43/243; paraplegia in 4% (10/243) and paraparesis in 13.7% (33/243)]. Most of the patients with SCI presented with immediate postoperative symptoms (72% [31/43]). A spinal drain was preoperatively placed in 53% (130/243) and was associated with the prevention of SCI (SCI with spinal drainage, 12% [16/130]; SCI without spinal drainage, 24% [27/113]; P = .018). The 30-day mortality rate was 9% (21/243). After multiple logistic regression analysis, SCI was associated with preoperative renal function (SCI with preoperative glomerular filtration rate <60 mL/min/1.73 m2: odds ratio [OR], 2.43; 95% confidence interval [CI], 1.18-4.99; P = .016) and the number of vertebral segments covered (SCI with higher position of proximal stent in terms of vertebra: OR, 1.2; 95% CI, 1.1-1.3; P = .000). A similar outcome was derived when the height of the proximal end of the stent graft was replaced by the total length of aortic coverage (SCI with preoperative glomerular filtration rate <60 mL/min/1.73 m2: OR, 2.36 [95% CI, 1.11-5.00; P = .025]; SCI with longer length of aortic coverage: OR, 1.01 [95% CI, 1.003-1.009; P = .000]). CONCLUSIONS: The majority of SCI incidence after F-EVAR or B-EVAR of complex aortic aneurysms is manifested immediately postoperatively. The use of preoperative spinal drainage may prevent SCI. Patients with GRF <60 mL/min/1.73 m2 and with longer aortic stent graft coverage are at higher risk of SCI.

Cervical Debranching in the Endovascular Era: A Single Centre Experience.

OBJECTIVE/BACKGROUND: Debranching of the supra-aortic arteries is a common practice either as part of a hybrid treatment of aortic arch pathology or owing to arterial occlusive disease. Results of the debranching techniques have not been reported frequently. METHODS: This was a retrospective single centre study of all consecutive patients with cervical debranching procedures as part of hybrid aortic arch repair. RESULTS: Between 2010 and 2017, 201 patients underwent 211 cervical debranching procedures in a tertiary centre. Mean ± SD patient age was 67.7 ± 10.7 years (70.6% males; n = 142/201) and mean ± SD body mass index (BMI) was 26.3 ± 5. In 78.7% of the cases carotid-subclavian bypass was performed alone (n = 166/211) followed by transposition of the subclavian artery to the ipsilateral carotid (n = 17/211; 8.1%) and in 28 cases (13.3%) a combination of procedures was performed. Twenty-four cases (11.4%) were complicated with local bleeding and 21 cases required re-intervention (10.4%). Nineteen patients (9.5%) developed local peripheral neurological damage post-operatively. Eight patients (3.8%) developed a chylous fistula and five (2.4%) presented with a local wound infection. One patient (0.5%) developed a bypass graft infection. The thirty day mortality was 7.6% (n = 16/211): one death occurred after isolated debranching without thoracic endovascular aneurysm repair (TEVAR; 0.5%). Whether the hybrid procedures were undertaken in a single stage (simultaneous TEVAR and cervical debranching) or two stage fashion appeared to have a significant impact on 30 day mortality (single stage n = 9/60 [15%] vs. debranching alone or two stage hybrid procedures n = 7/144 [4.9%]; p = .018). The major stroke incidence was 4.3% (n = 9/211); no strokes occurred after isolated debranching. Stroke was correlated with longer operating times (odds ratio [OR] 1.006; 95% confidence interval [CI] 1.000-1.011; p = .045) and higher BMI (OR 1.195; 95% CI 1.009-1.415; p = .039). Mean ± SD follow up was 15 ± 17 months (range 0-89 months). Primary cumulative graft patency during follow up was 98.1% (n = 207/211) and secondary patency was 100%. CONCLUSION: The results of cervical debranching procedures showed not only excellent patency rates, but also a significant rate of local complications. Carotid-subclavian bypass appeared to be safer with significantly fewer post-operative complications. Staged hybrid procedures also seemed to be safer.

Volume Based Resuscitation and Intestinal Microcirculation after Ischaemia/Reperfusion Injury: Results of an Exploratory Aortic Clamping Study in Pigs.

OBJECTIVES: In the presence of ischaemia/reperfusion (I/R) induced endothelial injury, volume administration may not correlate with increased microcirculation. The aim of this study was to evaluate intestinal microcirculation after standardised sequential volume loading in an animal model of I/R injury following supracoeliac aortic clamping. METHODS: This was a prospective exploratory pilot animal study. Intestinal I/R injury was induced in eight pigs during experimental thoraco-abdominal aortic repair. After 6 h of I/R, microcirculatory blood flow (mFlux, measured in the ileum using direct laser speckle contrast imaging) and macrohaemodynamic parameters (using trans-cardiopulmonary thermodilution) were measured and measurements were repeated after each of four sequential volume loading steps (VLS1 - 4). Each load was administered over 5 min followed by another 5 min for equilibration. RESULTS: All animals survived until after VLS4. After 6 h of I/R cardiac output (CO) (p < .001) and mFlux (p < .001) had both decreased. CO increased again after VLS1 (p < .001) and VLS2 (p = .036), whereas mFlux did not change. In contrast, mFlux further decreased after VLS3 (p < .01) and VLS4 (p < .001), whereas CO did not change anymore. Extravascular lung water continued to increase after VLS2 (p = .046) and VLS4 (p = .049). CONCLUSIONS: I/R leads to impaired intestinal microcirculation, which was not restored by volume administration in spite of improved CO. In contrast, further volume administration exceeding preload reserves was associated with additional decreases in the intestinal microcirculation. The potentially negative effect of excessive volume resuscitation after I/R injury should encourage further translational research.

Fenestrated-branched endografts and visceral debranching plus stenting (hybrid) for complex aortic aneurysm repair.

OBJECTIVE: The aim of this study was to assess the immediate postoperative and midterm outcome of complex aortic aneurysm treatment necessitating four-vessel revascularization with either a total endovascular approach (fenestrated-branched stent graft [FBSG]) or a hybrid technique of visceral debranching plus stenting. METHODS: The clinical data of consecutively treated patients presenting with a complex aortic aneurysm that necessitated four-vessel revascularization between 2010 and 2015 were retrospectively analyzed. RESULTS: There were 98 patients (65 men [68%]) with a mean age of 70.65 ± 4 years who presented with aortic aneurysm (Crawford type I, 12; type II, 18; type III, 12; type IV, 24; type V, 6; and juxtarenal and suprarenal, 26) and were treated with either FBSG (76/98 [77.5%]) or hybrid repair (22/98 [22.4%]). Twenty-six patients were symptomatic (16, pain; 10, contained rupture). The mean maximum aneurysm diameter was 65 ± 15 mm, and 53% of the patients had a prior aortic intervention. In FBSG-treated patients, 15 off-the-shelf multibranched stent grafts, 3 surgeon-modified fenestrated stent grafts, and 58 custom-made devices tailored to the patient's anatomy were used. Four fenestrations, four branches, and their combination were used in 38 cases, 30 cases, and 8 cases, respectively. A total of 304 target vessels were addressed, with technical success rate of 96% (292/304). In most hybrid cases (18/22 [82%]), a two-stage procedure was undertaken. All target vessels were successfully revascularized with 88 bypasses. The 30-day mortality was 15.3% (15/98), and the early target vessel occlusion was 9.1% (2 in FBSG, 7 in hybrid). After multivariate analysis, type of procedure (hybrid) was independently associated with higher early mortality (odds ratio, 6.3; P = .01). The morbidity was mainly attributed to pulmonary complications (16.3%), lower extremity weakness (16.3%), mesenteric ischemia (6.1%), dialysis on discharge (6.1%), and complete paraplegia (4.3%). Acute renal failure (2.6% vs 18%; P = .03) and mesenteric ischemia (3% vs 23%; P = .001) presented more commonly in the hybrid group. The mean follow-up was 16.4 ± 5 months, and the mortality rate was 19.4% (12% in the FBSG group vs 45% in the hybrid group; P = .05). The graft and stent graft patency rate was 87.8% (three branches and nine bypasses were occluded). CONCLUSIONS: FBSG and hybrid technique seem to be feasible treatment options for complex aortic aneurysms that necessitate four-vessel revascularization. FBSG may be associated with lower mortality and morbidity rates in comparison to the hybrid procedure. FBSG should be the treatment of choice for complex aneurysms in patients with comorbidities, whereas hybrid repair should be considered for acute cases unsuitable for endovascular repair.

Physician-Modified Thoracic Stent-Graft With Low Distal Radial Force to Prevent Distal Stent-Graft-Induced New Entry Tears in Patients With Genetic Aortic Syndromes and Aortic Dissection.

PURPOSE: To describe a novel modification technique to lower the distal radial force of a thoracic stent-graft so as to avert stent-graft-induced new entry tears (SINE) in the fragile aorta of patients with genetic aortic disease and aortic dissection. TECHNIQUE: A commercially available thoracic stent-graft is partially deployed on a back table. The most distal Z-stent is removed, the distal fabric is marked by vascular clips, and the modified stent-graft is reloaded and deployed in the true lumen of an aortic dissection. The technique is demonstrated in 3 patients with aortic dissection related to genetic aortic diseases. CONCLUSION: Creating a low distal radial force stent-graft is easy and can be done in a short time. Endovascular implantation appears feasible and safe.

Feasibility Study of a Novel Thoraco-abdominal Aortic Hybrid Device (SPIDER-graft) in a Translational Pig Model.

BACKGROUND: The hybrid SPIDER-graft consists of a proximal descending aortic stent graft and a conventional six branched Dacron graft for open abdominal aortic repair. Technical feasibility with regard to avoiding thoracotomy and extracorporeal circulation (ECC) during thoraco-abdominal aortic hybrid repair and peri-procedural safety of this novel device are unknown. MATERIAL AND METHODS: This was a feasibility and safety study in domestic pigs (75-85 kg). The abdominal aorta including iliac bifurcation, left renal artery, and visceral arteries were exposed via retroperitoneal access. The right iliac branch was first temporarily anastomosed end to side to the distal aorta via partial clamping. During inflow reduction and infra-coeliac cross-clamping, the coeliac trunk (CT) was divided and the proximal stent graft portion of the SPIDER-graft was deployed into the descending aorta via the CT ostium. Retrograde visceral and antegrade aorto-iliac blood flow was maintained via the iliac side branch. The visceral, renal, and iliac arteries were sequentially anastomosed, finally replacing the first iliac end to side anastomosis. Technical success, blood flow, periods of ischaemia, and peri-procedural complications were evaluated after intra-operative completion angiography and post-operative computed tomography angiography. RESULTS: Six animals underwent successful thoracic stent graft deployment and distal open reconstruction without peri-operative death. The median thoracic graft implantation time was 4.5 min, and the median ischaemia times before reperfusion were 10 min for the CT, 8 min for the superior mesenteric artery, 13 min for the right renal artery, and 22 min for the left renal artery. Angiography demonstrated appropriate graft implantation and blood flow measurements confirmed sufficient blood flow through all side branches. CONCLUSION: In this translational pig model, thoraco-abdominal hybrid repair using the novel SPIDER-graft was successful in avoiding thoracotomy and ECC. Technical feasibility and safety appear promising, but need to be reassessed in humans.

Gender differences in abdominal aortic aneurysm therapy - a systematic review.

This article analyses if and to what extent gender differences exist in abdominal aortic aneurysm (AAA) therapy. For this purpose Medline (PubMed) was searched from January 1999 to January 2018. Keywords were: "abdominal aortic aneurysm", "gender", "prevalence", "EVAR", and "open surgery of abdominal aortic aneurysm". Regardless of open or endovascular treatment of abdominal aortic aneurysms, women have a higher rate of complications and longer hospitalizations compared to men. The majority of studies showed that women have a lower survival rate for surgical and endovascular treatment of abdominal aneurysms after both elective and emergency interventions. Women receive less surgical/interventional and protective medical treatment. Women seem to have a higher risk of rupture, a lower survival rate in AAA, and a higher rate of complications, regardless of endovascular or open treatment. The gender differences may be due to a higher age of women at diagnosis and therapy associated with higher comorbidity, but also because of genetic, hormonal, anatomical, biological, and socio-cultural differences. Strategies for treatment in female patients must be further defined to optimize outcome.

Outcome of Surgeon-Modified Fenestrated/Branched Stent-Grafts for Symptomatic Complex Aortic Pathologies or Contained Rupture.

PURPOSE: To analyze the outcome of surgeon-modified fenestrated and branched stent-grafts (sm-FBSG) in high-risk patients with symptomatic complex aortic pathology or contained rupture. METHODS: A single-center retrospective analysis was conducted of 21 consecutive patients (mean age 70 years, range 58-87; 16 men) treated with a sm-FBSG from April 2014 to September 2016. The indications included 11 thoracoabdominal and 10 pararenal aortic pathologies, which presented as symptomatic in 8 and as contained rupture in 13 patients. The mean aneurysm diameter was 7.4±2.3 cm. RESULTS: Technical success was 100%. From 1 to 4 (mean 3) renovisceral branch vessels were targeted with fenestrations. The mean length of in-hospital stay was 19 days (range 1-78). There was 1 death within 30 days and 2 further in-hospital deaths. Two patients suffered permanent spinal cord injury, 2 developed respiratory failure, and 2 had renal failure requiring temporary or permanent dialysis. No myocardial infarction, stroke, or bowel ischemia occurred. Six early endoleaks (3 type II and 3 minor type III) were detected. Mean follow-up was 11.2 months (range 2-33) in 17 patients. One late aneurysm-related death occurred. All 13 follow-up imaging studies showed patent target renovisceral vessels, with 1 type I and 2 type II endoleaks. CONCLUSION: Sm-FBSG can be utilized for urgent treatment of complex abdominal and thoracoabdominal aortic pathologies in high-risk patients with anatomy unsuitable for commercially available stent-grafts.

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.

Acute Type A Aortic Dissection Treated Using a Tubular Stent-Graft in the Ascending Aorta and a Multibranched Stent-Graft in the Aortic Arch.

PURPOSE: To describe the combined use of a tubular stent-graft for the ascending aorta and an inner-branched arch stent-graft for patients with acute type A aortic dissection. TECHNIQUE: The technique to deploy these modular, custom-made stent-grafts is demonstrated in 2 patients with acute DeBakey type I aortic dissections and significant comorbidities precluding open surgery. Both emergent procedures were made possible by the availability of suitable devices manufactured for elective repair in other patients. After preliminary carotid-subclavian bypass, a long Lunderquist guidewire was introduced from the right femoral artery to the left ventricle for delivery of the Zenith Ascend and Zenith Branched Arch Endovascular Grafts under inflow occlusion. Bridging stent-grafts were delivered to the innominate and left common carotid arteries to connect to the 2 inner branches; the left subclavian artery was occluded. Both cases were technically successful and resulted in exclusion of the false lumen in the ascending aorta. The operating and fluoroscopy times did not exceed those of comparable elective procedures. The patients were rapidly extubated shortly after the procedure and without serious immediate complications. One patient survived 11 months with a satisfactory repair; the other succumbed to complications of recurrent pneumonia after 23 days. CONCLUSION: Endovascular treatment of patients with acute type A aortic dissection using a combination of tubular and branched stent-grafts in the ascending aorta is feasible and offers an alternative strategy to open surgery.