Comparing the Efficacy of Endovascular Simulation Training in different Training Formats: a randomized controlled trial.

INTRODUCTION: High-fidelity endovascular simulators have demonstrated significant potential in enhancing interventionalists' performance metrics, including procedure time, fluoroscopy time, and contrast volume usage. However, it is less clear whether trainee performance, when assessed using both multidimensional global and procedure-specific rating scales, 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: 20 students were enrolled in this prospective, randomized, controlled, single-center trial. They were randomly divided into block and weekly training groups, each undergoing 6 hours 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 procedure time, fluoroscopy time, contrast volume usage, global rating scale scores, and performance-specific rating scale scores. However, no significant difference was observed between the two groups. The simulator training notably boosted the trainee's self-confidence. CONCLUSION: Simulator training not only enhances metric performance parameters, but also improves performance as assessed by both global rating scale and procedure-specific rating scale. 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.

Risk of Permanent Pacemaker Implantation Following Bentall Operation.

Conduction disorders following cardiac surgery are common complications with incidences of permanent pacemaker dependency up to 5%. However, data on pacemaker implantation rates in the long-term follow-up after Bentall operations are scarce. In a retrospective study, a mixed cohort of 260 patients including endocarditis and aortic dissection undergoing Bentall operation between March 1996 and December 2015 was analyzed. Median follow-up time was 60 (12-107) months. Early and late rates of permanent pacemaker implantation and associated risk factors were investigated. In the postoperative course 31 (11.9%) permanent pacemakers were implanted. The 30-day incidence of pacemaker implantations was 7.7% with operations performed after a median of 6 (3-12) days after the Bentall operation. After ten years, 21% of the Bentall patients were permanent pacemaker dependent. The risk factors for permanent pacemaker dependency included age above 75 years (16.1% vs 5.7%; P < 0.001), preoperative cardiac conduction disturbance (32.3% vs 22.7%, P = 0.018), aortic valve stenosis (38.7% vs 23.1, P = 0.008), infective endocarditis (19.4% vs 7.4%, P = 0.004), tricuspid valve reconstruction (6.5% vs 0.9%, P = 0.033), sepsis (12.9% vs 4.4%, P < 0.001) and non-cardiac reoperation (19.4% vs 8.7%, P = 0.004). Pacemaker implantation significantly increased the length of initial hospitalization (13 [8-26] days vs 8 [7-13] days; P = 0.003). In the long-term follow-up, mortality was not different between the groups. Permanent pacemaker dependency is a frequent complication in the short- and long-term follow-up after Bentall operations. Screening for cardiac conduction disturbances in the short- and long-term follow-up is recommended.

The impact of nitroglycerine and volume on gastric tube microperfusion assessed by indocyanine green fluorescence imaging.

The influence of hypervolemia and intraoperative administration of nitroglycerine on gastric tube microperfusion remains unclear The present study aimed to investigate the impact of different hemodynamic settings on gastric tube microperfusion quantified by fluorescence imaging with Indocyanine green (ICG-FI) as a promising tool for perfusion evaluation. Three groups with seven pigs each were formed using noradrenaline, nitroglycerin, and hypervolemia for hemodynamic management, respectively. ICG-FI, hemodynamic parameters, and transit-time flow measurement (TTFM) in the right gastroepiploic artery were continuously assessed. Fluorescent microspheres (FM) were administered, and the partial pressure of tissue oxygen was quantified. The administration of nitroglycerine and hypervolemia were both associated with significantly impaired microperfusion compared to the noradrenaline group quantified by ICG-FI. Even the most minor differences in microperfusion could be sufficiently predicted which, however, could not be represented by the mean arterial pressure measurement. Histopathological findings supported these results with a higher degree of epithelial damage in areas with impaired perfusion. The values measured by ICG-FI significantly correlated with the FM measurement. Using tissue oxygenation and TTFM for perfusion measurement, changes in microperfusion could not be comprehended. Our results support current clinical practice with restrictive volume and catecholamine administration in major surgery. Hypervolemia and continuous administration of nitroglycerine should be avoided.

The Mangled Extremity Severity Score (MESS) does not predict amputation in popliteal artery injury.

PURPOSE: Vascular injuries in lower extremity trauma, especially with involvement of the popliteal artery, are associated with considerably high rates of limb loss, especially with blunt trauma mechanisms. The aim of this study was to evaluate the risk of amputation in patients with traumatic popliteal artery lesions with special focus on the validity of the Mangled Extremity Severity Score (MESS). METHODS: In this retrospective study, all patients treated for isolated lesions of the popliteal artery following trauma between January 1990 and December 2020 at a high-volume level I trauma center were included. Primary outcome was limb salvage dependent on MESS and the influence of defined parameters on limb salvage was defined as secondary outcome. The extent of trauma was assessed by the MESS. RESULTS: A total of 50 patients (age 39.2 ± 18.6 years, 76% male) with most blunt injuries (n = 47, 94%) were included. None of the patients died within 30 days and revascularization was attempted in all patients with no primary amputation and the overall limb salvage rate was 88% (44 patients). A MESS ≥ 7 was observed in 28 patients (56%) with significantly higher rates of performed fasciotomies (92.9% vs. 59.1%; p < 0.01) in those patients. MESS did not predict delayed amputation within our patient cohort (MESS 8.4 ± 4.1 in the amputation group vs. 8.1 ± 3.8 in the limb salvage group; p = 0.765). CONCLUSION: Revascularization of limbs with isolated popliteal artery injuries should always be attempted. MESS did not predict delayed amputation in our cohort with fasciotomy being an important measure to increase limb salvage rates.

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.

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.

[Establishment of a new research concept at a university location]. / Die Etablierung eines neuen Forschungskonzepts an einem universitären Standort.

Apart from daily clinical work and patient care, research and student teaching are essential assignments of a university hospital. The implementation of a completely new research laboratory at the Department of Vascular Surgery at the Medical University of Innsbruck led to the creation of a novel infrastructure for the design and set-up of a newly founded research focus. The cooperation with national as well as international research collaborators was essential for this process. The construction of a research network is not only important for the design and conception of a new research laboratory but also for the development of new study protocols and exchange and discussion of results. After the successful implementation of Experimental Vascular Surgery in Innsbruck, the realization of basic research projects as well as translational research projects is possible at this university location. Moreover, simulation training is an emerging field of research that aims to add more realistic surgical skills to residency programs, attract future residents and teach more complex novel techniques.

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.

Risk factors for major amputation after arterial vascular trauma of the lower extremity.

BACKGROUND & OBJECTIVE: Arterial vascular trauma bears a great risk of poor functional outcome or limb loss. The aim of this study was to analyze amputation rates of patients after vascular trauma and to perform a predictor analysis for the risk of major amputation. METHODS: In a single-center retrospective analysis of 119 extremities treated for arterial vascular injury between 1990 and 2018 amputation rates and factors associated with limb loss were assessed. All patients were treated for traumatic vascular injuries; iatrogenic injuries were not included in the study. RESULTS: During the study period, a total of 119 legs in 118 patients were treated after arterial vascular trauma. The in-hospital major amputation rate was 16.8% and the mortality rate was 2.5%. In the predictors analysis, vascular re-operation (amputation rate 53.8% vs 12%, odds ratio = 8.56), a Rutherford category ⩾IIb (25.4% vs 4.2%, odds ratio = 6.43), work-related or traffic accidents (28.2% vs 0%, odds ratio = 4.86), concomitant soft tissue or bone injuries (26.7% vs 7.3%, odds ratio = 4.64), polytrauma (33.3% vs 12%, odds ratio = 3.68), and blunt trauma (18.9% vs 0% for penetrating trauma, odds ratio = 1.64) were found to be associated with amputation. CONCLUSIONS: Lower extremity arterial vascular trauma was associated with a significant major amputation rate. Several predictors for limb loss were identified, which could aid in identifying patients at risk and adapting their treatment.

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.

The use of pulse pressure variation for predicting impairment of microcirculatory blood flow.

Dynamic parameters of preload have been widely recommended to guide fluid therapy based on the principle of fluid responsiveness and with regard to cardiac output. An equally important aspect is however to also avoid volume-overload. This accounts particularly when capillary leakage is present and volume-overload will promote impairment of microcirculatory blood flow. The aim of this study was to evaluate, whether an impairment of intestinal microcirculation caused by volume-load potentially can be predicted using pulse pressure variation in an experimental model of ischemia/reperfusion injury. The study was designed as a prospective explorative large animal pilot study. The study was performed in 8 anesthetized domestic pigs (German landrace). Ischemia/reperfusion was induced during aortic surgery. 6 h after ischemia/reperfusion-injury measurements were performed during 4 consecutive volume-loading-steps, each consisting of 6 ml kg-1 bodyweight-1. Mean microcirculatory blood flow (mean Flux) of the ileum was measured using direct laser-speckle-contrast-imaging. Receiver operating characteristic analysis was performed to determine the ability of pulse pressure variation to predict a decrease in microcirculation. A reduction of ≥ 10% mean Flux was considered a relevant decrease. After ischemia-reperfusion, volume-loading-steps led to a significant increase of cardiac output as well as mean arterial pressure, while pulse pressure variation and mean Flux were significantly reduced (Pairwise comparison ischemia/reperfusion-injury vs. volume loading step no. 4): cardiac output (l min-1) 1.68 (1.02-2.35) versus 2.84 (2.15-3.53), p = 0.002, mean arterial pressure (mmHg) 29.89 (21.65-38.12) versus 52.34 (43.55-61.14), p < 0.001, pulse pressure variation (%) 24.84 (17.45-32.22) versus 9.59 (1.68-17.49), p = 0.004, mean Flux (p.u.) 414.95 (295.18-534.72) versus 327.21 (206.95-447.48), p = 0.006. Receiver operating characteristic analysis revealed an area under the curve of 0.88 (CI 95% 0.73-1.00; p value < 0.001) for pulse pressure variation for predicting a decrease of microcirculatory blood flow. The results of our study show that pulse pressure variation does have the potential to predict decreases of intestinal microcirculatory blood flow due to volume-load after ischemia/reperfusion-injury. This should encourage further translational research and might help to prevent microcirculatory impairment due to excessive fluid resuscitation and to guide fluid therapy in the future.

Validation of quantitative assessment of indocyanine green fluorescent imaging in a one-vessel model.

OBJECTIVES: Evaluation of intestinal perfusion remains subjective and depends on the surgeon´s individual experience. Intraoperative quality assessment of tissue perfusion with indocyanine green (ICG) fluorescence using a near-infrared camera system has been described in different ways and for different indications. The aim of the present study was to evaluate fluorescent imaging (FI) in the quantitative assessment of intestinal perfusion in a gastric tube model in pigs and to compare the results to results obtained with florescent microspheres (FM), the gold standard for tissue perfusion. METHODS: Seven pigs (56.0±3.0 kg), both males and females, underwent gastric tube formation after transection and ligation of the gastric arteries, except the right gastroepiploic artery, to avoid collateral blood flow. After baseline assessment (T0), hypotension (T1) was induced by propofol (Karampinis et al 2017) (< 60 mmHg). Then, propofol was paused to obtain normotension (T2, Mean arterial pressure (MAP) 60-90 mmHg). Finally, hypertension (T3, MAP>90 mmHg) was induced by norepinephrine. Measurements were performed in three regions of interest (ROIs) under standardized conditions: the fundus (D1), corpus (D2), and prepyloric area (D3). Hemodynamic parameters and transit-time flow measurement (TTFM) in the right gastroepiploic artery were continuously assessed. FI, FM and the partial pressure of tissue oxygen (TpO2) were quantified in each ROI. RESULTS: The study protocol could successfully be performed during stable hemodynamics. Flow in the gastroepiploic artery measured by transit time flow measurement (TTFM) was related to hemodynamic changes between the measurements, indicating improved blood flow with increasing MAP. The distal part of the gastric tube (D1) showed significantly (p<0.05) impaired perfusion compared to the proximal parts D3 and D2 using FM. ICG-FI also showed the highest values in D3 and the lowest values in D1 at all hemodynamic levels (T1-T3; p<0,05). CONCLUSION: Visual and quantitative assessment of gastric tube perfusion is feasible in an experimental setting using ICG-FI. This might be a promising tool for intraoperative assessment during visceral surgery in the future.

Detrimental effects of cerebrospinal fluid pressure elevation on spinal cord perfusion: first-time direct detection in a large animal model.

OBJECTIVES: Cerebrospinal fluid (CSF) drainage is routinely utilized to mitigate perioperative and postoperative spinal cord ischaemia in open and endovascular thoraco-abdominal aortic aneurysm repair to prevent permanent paraplegia. Clinical decision-making in the vulnerable perioperative period, however, is still based on limited clinical and experimental data. Our aim was to investigate the isolated effect of CSF pressure elevation on spinal cord perfusion in an established large animal model. METHODS: Ten juvenile pigs with normal (native) arterial inflow (patent segmental arteries and collaterals) underwent iatrogenic CSF pressure elevation (×2, ×3, ×4 from their individual baseline pressure). Each pressure level was maintained for 30 min to mimic clinical response time. After the quadrupling of CSF pressure, the dural sac was slowly depressurized against gravity allowing CSF pressure to passively return to baseline values. Measurements were taken 30 and 60 min after normalization, and microspheres for regional blood flow analysis were injected at each time point. RESULTS: Spinal cord perfusion decreased significantly at all mid-thoracic to lumbar cord segments at the doubling of CSF pressure and declined to values <53% compared to baseline when pressure was quadrupled. Normalizing CSF pressure led to an intense hyperperfusion of up to 186% at the cervical level and 151% within the lumbar region. CONCLUSIONS: CSF pressure elevation results in a relevant impairment of spinal cord blood supply. Close perioperative and postoperative monitoring of CSF pressure is crucial for maintaining sufficient spinal cord perfusion. Radical and rapid withdrawal of CSF is followed by significant hyperperfusion in all spinal cord segments and may lead to 'drainage-related' iatrogenic reperfusion injury-aggravating the risk of delayed spinal cord injury-and should therefore be avoided.

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.

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.

Impact of hybrid thoracoabdominal aortic repair on visceral and spinal cord perfusion: The new and improved SPIDER-graft.

OBJECTIVES: SPIDER-graft for thoracoabdominal aortic aneurysm repair avoiding thoracotomy and extracorporeal circulation was modified, enabling reimplantation of lumbar arteries to prevent spinal cord ischemia and compared with open aortic repair (control) in a pig model. METHODS: Graft implantation was performed in 7 pigs per group (75-85 kg). For SPIDER-graft (groups I and II), the infra-diaphragmatic aorta was exposed through retroperitoneal access. The right iliac branch was first temporarily anastomosed end-to-side to the distal aorta maintaining periprocedural retrograde visceral perfusion. SPIDER-graft was deployed in the descending thoracic aorta via the celiac artery ostium. The celiac, superior mesenteric, and renal arteries were successively connected to the corresponding side branches of the graft. In group II, the lumbar arteries were reimplanted into the former access branch. For control, complete thoracoabdominal exposure of the aorta was required. After crossclamping, proximal anastomosis was performed, and the celiac artery, superior mesenteric artery, renal arteries, and iliac arteries were reattached. Technical feasibility, ischemic times, blood flow, and visceral and spinal cord perfusion in the related organs were evaluated before implantation and 3 and 6 hours after implantation using transit-time flow measurement and fluorescent microspheres. RESULTS: Technical success was achieved in all animals in all groups. Total aortic clamping time and selective ischemic times of related organs were significantly longer during open aortic repair compared with groups I and II (P < .0001). Fluorescent microspheres confirmed best spinal cord perfusion in group II. CONCLUSIONS: SPIDER-graft reduced ischemic time, avoided extracorporeal circulation and thoracotomy, and improved spinal cord perfusion during thoracoabdominal aortic aneurysm repair in a pig model.

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.