A systematic review of open, hybrid, and endovascular repair of aberrant subclavian artery and Kommerell's diverticulum treatment.

BACKGROUND: Aberrant subclavian artery (AScA) with or without associated Kommerell's diverticulum (KD) is the most frequently encountered anomaly of the aortic arch, it may be life threatening, especially when associated with aneurysmal degeneration. The best management is still debated and depends on many clinical and anatomical factors. A systematic review was conducted to assess the current evidence on the treatment options and their efficacy and safety for AscA and KD repairs. METHODS: A literature search in PubMed and Cochrane Library was performed, and articles that were published from January 1947 to August 2021 reporting on AscA and KD management were identified. Multicenter studies, single-center series, and case series with three or more patients were considered eligible in the present review. A comparison of outcomes of patients who underwent open surgery (OS), a hybrid approach (HA), and total endovascular repair (ER) (ie, 30-day mortality and stroke were analyzed when available and compared among the three groups (P < .05; Benjamini and Hochberg-adjusted P < .05; Bonferroni-adjusted P < .05). Titles, abstracts, and full texts were evaluated by two authors independently. Primary outcomes included survival rate, perioperative stroke, arm ischemia, and spinal cord ischemia. Endoleak, in the case of HA and ER, and reintervention rates were considered outcomes. RESULTS: Three hundred thirty-one articles were initially evaluated and 30 studies, totaling 426 patients treated for AScA with 324 KD, were included. Of the 426 patients, 241 were male (56.5%), and the mean patient age was 57.9 ± 12.0 years. The approach was OS in 228 patients, HA in 147 patients, and ER in 51. Dysphagia was the most common presentation in 133 cases. Aortic rupture was observed in 16 of the 426 patients (3.8%), including 14 AScA/KD (3.3%) aneurysm rupture. KD maximum diameter varied widely from 12.6 to 63.6 mm. The overall 30-day mortality was 20 (4.7%) (OS group 8/228 [3.5%]; HA group 10/147 [6.8%]; ER 2/51 [3.9%]; P = NS). The overall stroke rate was 4.9% (21/426) (OS group 10/228 [4.4%]; HA group 6/147 [4.1%]; ER group 5/51 [9.8%]; P = NS), including nine transient and nondisabling neurological deficits. Overall secondary procedures for complications were reported in 36 of the 426 cases (8.4%), mostly owing to endoleak. Follow-up varied from 13 to 74 months. CONCLUSIONS: This systematic review assessed the current outcomes of the three types of therapeutic management for AScA and KD and demonstrated that they are all relatively safe and effective, providing satisfactory early and midterm outcomes. Long-term outcomes are warranted, especially for total ERs since the long-term durability of stent grafts remains unknown.

Open and endovascular reinterventions after Candy Plug false lumen embolization of type B aortic dissection.

OBJECTIVE: In the majority of patients with chronic type B aortic dissection, there is persistent retrograde flow in the false lumen (FL) through distal re-entry tears. Among several endovascular techniques proposed for FL management, the "Candy Plug" (CP) technique has gained acceptance with good early results. The aim of this study is to report the types and outcomes of open and endovascular reinterventions and identify mechanisms of procedure failure as well as other causes for reinterventions. METHODS: All patients with type B aortic dissection submitted to thoracic endovascular aneurysm repair and CP implantation for FL embolization from January 2016 to December 2022 at our institution were included in this study. The preoperative, intraoperative, and postoperative data of the primary intervention and secondary reinterventions, when performed, were prospectively collected and retrospectively analyzed. Preoperative and postoperative computed tomography angiography were also analyzed. RESULTS: During the study period, 33 patients were submitted to thoracic endovascular aneurysm repair and CP implantation. Twenty-three patients (69.7%) showed thoracic FL complete thrombosis with aortic stability or positive remodeling at a mean follow-up of 45 ± 23.1 months. Ten patients (30.3%) underwent aortic reinterventions (male, n = 9; mean age, 60.5 ± 7.6 years). Of these 10 patients, in four patients, complete thrombosis of the FL was never achieved, leading to ongoing perfusion of the FL, defined as "primary failure." The other six patients underwent reinterventions for different causes: two patients, after initial sealing, showed a progressive enlargement of the abdominal FL leading to distal degeneration. One patient showed proximal degeneration, two patients showed a type II thoracoabdominal aortic aneurysm and CP implantation was used as a planned procedure to reduce the extent of the surgical procedure, and one patient had recurrent, intractable back pain despite complete thrombosis of the FL. Reinterventions were open in five cases and endovascular in five. One in-hospital death (postoperative day 27) after a type II thoracoabdominal aortic aneurysm open repair was recorded. In addition, two cases of delayed spinal cord ischemia after open reintervention were recorded: one resulting in permanent paraplegia and one transitory with complete recovery. CONCLUSIONS: The CP technique was safe and effective; however, a significant rate of aortic-related reintervention was observed. Several mechanisms led to reinterventions either in terms of "primary failure" of the CP or subsequent aneurysmal degeneration. Complex reinterventions were often necessary, with a high rate of major complications in case of open repair. Life-long and closer surveillance might be required in these patients.

A comparison of thoracoabdominal aortic aneurysms open repair in patients with or without "shaggy aorta".

OBJECTIVE: In the field of thoracoabdominal aortic aneurysm (TAAA) open surgical repair (OSR), some preoperative characteristics are established risk factors for adverse outcomes, whereas others are supposed to be relevant, but their role still need to be defined; among them, the presence of "shaggy aorta" (SA), an extensive and irregular atheroma within the aorta. The aim of this study is to report the results of a single-center large cohort of patients treated with OSR for TAAA with SA, comparing the outcomes with patients affected by TAAA without SA, and analyzing the impact of the scores for SA on the outcomes. METHODS: All consecutive patients receiving OSR for TAAA between 2012 and 2021 were retrospectively analyzed. Clinical data from patients with degenerative TAAA were included and analyzed for preoperative characteristics and postoperative outcomes; patients with ruptured TAAA, and patients with aortic dissection were excluded from the analysis. Patients with degenerative aortic aneurysm, thrombus measurement in non-aneurysmal aortic segments (≤40 mm), atheroma thickness ≥5 mm, and finger-like thrombus projection were included in the SA group, whereas the others were included in the non-shaggy aorta group (NSA group). The SA group and NSA group were compared using a propensity-matched comparison. Preoperative computed tomography scans of patients in the SA group were also stratified according to SA grading scores. RESULTS: A total of 58 patients with SA were identified (male, n = 43 [74.1%], mean age 70.1 ± 7.8 years) among 497 patients with TAAA treated with open surgical repair. After propensity matching, there were 57 patients in the SA group and 57 in the NSA group with correction of all differences in baseline characteristics. Patients in the SA group presented significantly higher in-hospital mortality (SA group, 14.0% vs NSA group, 3.5%; P = .047), postoperative acute renal failure (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease [RIFLE], 3-5) (SA group, 21.1% vs NSA group, 5.3%; P = .013), and postoperative embolization (SA group, 28.1% vs NSA group, 8.8%; P = .008). Spinal cord ischemia and stroke rate were not significantly influenced by the presence of SA. In the SA group, 16 patients (27.6%) with end-organ embolization were compared with 42 patients (72.4%) without a documented embolization considering the grade of aortic "shagginess" and no significant difference was identified (P = .546). CONCLUSIONS: Despite a better knowledge of the SA disease, new classifications, and intraoperative adjuncts, TAAA patients with SA treated with OSR have worse postoperative outcomes if compared with patients without SA. The presence of SA is a risk factor itself, whereas the grade of "shagginess" seems not to impact on postoperative outcomes.

Approximate Autonomous Quantum Error Correction with Reinforcement Learning.

Autonomous quantum error correction (AQEC) protects logical qubits by engineered dissipation and thus circumvents the necessity of frequent, error-prone measurement-feedback loops. Bosonic code spaces, where single-photon loss represents the dominant source of error, are promising candidates for AQEC due to their flexibility and controllability. While existing proposals have demonstrated the in-principle feasibility of AQEC with bosonic code spaces, these schemes are typically based on the exact implementation of the Knill-Laflamme conditions and thus require the realization of Hamiltonian distances d≥2. Implementing such Hamiltonian distances requires multiple nonlinear interactions and control fields, rendering these schemes experimentally challenging. Here, we propose a bosonic code for approximate AQEC by relaxing the Knill-Laflamme conditions. Using reinforcement learning (RL), we identify the optimal bosonic set of code words (denoted here by RL code), which, surprisingly, is composed of the Fock states |2⟩ and |4⟩. As we show, the RL code, despite its approximate nature, successfully suppresses single-photon loss, reducing it to an effective dephasing process that well surpasses the break-even threshold. It may thus provide a valuable building block toward full error protection. The error-correcting Hamiltonian, which includes ancilla systems that emulate the engineered dissipation, is entirely based on the Hamiltonian distance d=1, significantly reducing model complexity. Single-qubit gates are implemented in the RL code with a maximum distance d_{g}=2.

Transaxillary Tri-Branch Aortic Endovascular Graft Repair of Recurrent Thoracoabdominal Aneurysm With Pararenal Aortic Occlusion.

The absence of an adequate ileo-femoral access is usually considered an absolute contraindication to fenestrated and branched aortic repairs. Alternative routes and dedicated stent-graft designs have been advocated. Hereby, we describe the case of a 73-year-old man with a recurrent type IV thoracoabdominal aortic aneurysm and complete thrombotic pararenal aortic occlusion treated successfully with a tri-branch custom-made endograft deployed via a transaxillary access.

Spinal Cord Ischemia After Thoracoabdominal Aortic Aneurysms Endovascular Repair: From the Italian Multicenter Fenestrated/Branched Endovascular Aneurysm Repair Registry.

PURPOSE: The aim of this study is to report an Italian multicenter experience analyzing the incidence and the risk factors associated with spinal cord ischemia (SCI) in a large cohort of thoracoabdominal aortic aneurysms (TAAAs) treated by fenestrated-branched endovascular aneurysm repair (F-/B-EVAR). MATERIALS AND METHODS: All consecutive patients undergoing F-/B-EVAR in 4 Italian university centers between 2008 and 2019 were prospectively recorded and retrospectively analyzed. Spinal cord ischemia, 30 day/in-hospital adverse events, and mortality were assessed as early outcomes. Risk factors for SCI were determined by multivariable analysis. RESULTS: A total of 351 patients received F-/B-EVAR for a TAAA. Twenty-eight (8.0%) patients died within 30 postoperative days or during the hospitalization. Regarding SCI, 47 patients (13.4%) developed neurological symptoms related to spinal cord impaired perfusion. Among them, 17 (4.8%) had a major permanent impairment. The multivariable analysis identified that SCI was associated with Crawford extent I to III (odds ratio [OR]: 20.90, p=0.004, 95% confidence interval [CI]=2.69-162.57), and with endovascular procedures performed for ruptured TAAA (OR: 5.74, p=0.010, 95% CI=1.53-21.57). Spinal cord ischemia was also significantly associated with a grade 3 bleeding during the visceral stage (OR: 4.34, p=0.005, 95% CI=1.55-12.16) and a grade 2 renal insufficiency at 30 days (OR: 7.45, p=0.002, 95% CI=2.12-26.18). CONCLUSION: The present study indicates that SCI is still an open issue after extent I to III TAAA endovascular repair, while its incidence in extent IV TAAA and pararenal/juxtarenal aneurysms is rare. Thoracoabdominal aortic aneurysms extension, urgent TAAA repair for rupture, severe bleeding, and 30 day renal insufficiency have been identified as significant risk factors for SCI. In the presence of such factors, adjunctive strategies may be considered to reduce SCI rates, while in low-risk patients invasive or potentially-risky maneuvers might not be justified.

Single-center midterm results with the low-profile Zenith Alpha thoracic endovascular stent graft.

OBJECTIVE: The analysis of endovascular treatment of thoracic aortic diseases using new low-profile stent grafts in large series is crucial to understanding the durability of these devices. The present study reports the midterm outcomes of a single-center experience using the Zenith Alpha thoracic endovascular stent graft. METHODS: The outcomes of 270 procedures performed on 262 patients (197 men; mean age, 70.5 ± 9.5 years) using the Zenith Alpha thoracic endovascular stent graft from November 2013 to December 2019 for different thoracic aortic diseases were analyzed. The primary endpoints were 30-day clinical success and midterm (5-year) clinical success. The secondary endpoints were the adverse event rate at 30 days and midterm and access- and device-related complications. The follow-up of surviving patients was performed using computed tomography angiography and office visits at 1, 6, and 12 months and annually thereafter. Kaplan-Meier analysis was performed for overall survival, and freedom from thoracic aortic endovascular repair-related mortality and related reinterventions. RESULTS: The overall 30-day mortality was 5.2% (2.5% for elective and 30.8% for nonelective cases). Type I endoleaks were identified in six patients. The 30-day primary technical and clinical success rates were 97.8% and 92.6%, respectively. Femoral cutdown was used in 41.1% of cases and percutaneous access in 58.5%. The rate of femoral artery complications after the percutaneous approach was 5.1%, with the need for surgical conversion in 1.9%. The stroke rate was 4.1% (major stroke, 2.2%), and the spinal cord ischemia rate was 3.7% (permanent paraplegia, 0.7%). Of the 248 survivors, 239 complied with the follow-up protocol with adequate computed tomography angiograms available images. Overall follow-up survival was 94.0% at 1 year, 91.6% at 2 years, 88.9% at 3 years, and 88.5% at 5 years. The unplanned secondary endovascular procedure rate was 5.3%. No stent fractures or new-onset type I endoleaks due to stent graft migration were observed in the study cohort. CONCLUSIONS: The midterm outcomes of this new generation of low-profile devices were satisfactory. The reported low incidence of secondary procedures and the absence of migrations are promising for the long-term durability of these devices.

Contemporary Results of Carotid Artery Stenting Using Low-Profile Dual-Metal Layer Nitinol Micromesh Stents in Relation to Single-Layer Carotid Stents.

PURPOSE: To evaluate patients characteristics, procedural details, perioperative outcomes, and midterm results of carotid artery stenting (CAS) performed with the Roadsaver/Casper stent (Terumo Corp, Tokyo, Japan) as compared to concurrent patients treated with other commercially available carotid stents. MATERIALS AND METHODS: This is a single-center, retrospective, nonrandomized study including 200 consecutive patients who underwent a total of 205 elective CAS procedures due to severe internal carotid artery stenosis between April 2015 and December 2018. Procedural data and outcomes for patients treated with the Roadsaver/Casper stent implantation (100 procedures, in 97 patients) vs first-generation carotid stents implantations (90 procedures, in 88 patients) were compared. Fifteen patients were treated with CGuard carotid stent (InspireMD, Tel Aviv, Israel), and outcomes were reported separately. Primary endpoints were the occurrence of major adverse cerebrovascular events (MACE), including death, ipsilateral stroke, and transitory ischemic attack (TIA). Secondary endpoints were the rate of intrastent stenosis, the need for reintervention, and the occurrence of adverse cardiovascular events, including myocardial infarction, arrhythmias, and need for inotropic support. RESULTS: No difference in demographics and preoperative risk factors were observed between patients treated with and without the Roadsaver/Casper stent. The mean procedure time was shorter in the Roadsaver/Casper group (40.7±16.9 vs 49.4±27.3 minutes; p=0.008), while radial percutaneous access was more frequent (24% vs 5%; p<0.001). The rate of stroke/TIA/death at 30 days was 3% in the Roadsaver group vs 1% in the first-generation stent group (p=0.623). The primary patencyrate was 100% and 93.4% at 1- and 3-year of follow-up in the Roadsaver/Casper groupand 99% and 94.3% in the other stent group, respectively (p=0.95). CONCLUSIONS: In this real-world cohort of patients undergoing CAS, the Roadsaver/Casper stent was used to treat more symptomatic and vulnerable carotid plaques as compared to other carotid stents. Nevertheless, patients treated with this low-profile dual-layer micromesh stent showed low events rates at both 30 days and follow-up, similar to that observed for other stents.

Thoracic Endovascular Aortic Repair With Additional Distal Bare Stents in Type B Aortic Dissection Does Not Prevent Long-Term Aneurysmal Degeneration.

PURPOSE: TEVAR (thoracic endovascular aortic repair) + PETTICOAT (Provisional ExTension to Induce COmplete ATtachment) technique has been selectively employed since 2005 at our institution during endovascular treatment of type B aortic dissection (TBD). The aim of this study is to evaluate the long-term (>5 years) clinical results and the evolution of aortic volume. MATERIALS AND METHODS: All the patients receiving an endovascular treatment for TBD with the PETTICOAT technique were collected in a prospectively maintained database and follow-up computed tomography scan were retrospectively analyzed. Study endpoints included short- and long-term clinical success (absence of need for reintervention) and any major adverse event. The volumes of thoracic and abdominal aorta at long-term follow-up were also analyzed. RESULTS: Twenty-eight patients received a TEVAR + PETTICOAT and were followed up (median follow-up 85 months). Primary 30-day clinical success rate was 82% with an adverse event rate of 31%; 4 type I endoleak and 1 retrograde dissection were recorded. Secondary mid-term clinical success was 96% while the long-term clinical success rate was 79%. Six cases (21%) received either an open repair or an endovascular repair for a significant distal aortic enlargement at follow-up. With regards to volumetric analysis, an increase of overall (thoracic and abdominal) aortic volume was observed in 8 cases mainly related to an increase (mean: +31%) of the abdominal volume that was observed in 11 cases. CONCLUSIONS: PETTICOAT technique does not protect from long-term significant aneurysmal degeneration that may require aortic open or endovascular reinterventions. Aortic growth occurs mainly in the bare-stented aorta and thus, life-long surveillance is advisable in these patients.

Vascular Surgery During COVID-19 Emergency in Hub Hospitals of Lombardy: Experience on 305 Patients.

OBJECTIVE: During the most aggressive phase of the COVID-19 outbreak in Italy, the Regional Authority of Lombardy identified a number of hospitals, named Hubs, chosen to serve the whole region for highly specialised cases, including vascular surgery. This study reports the experience of the four Hubs for Vascular Surgery in Lombardy and provides a comparison of in hospital mortality and major adverse events (MAEs) according to COVID-19 testing. METHODS: Data from all patients who were referred to the Vascular Surgery Department of Hubs from 9 March to 28 April 2020 were collected prospectively and analysed. A positive COVID-19 polymerase chain reaction swab test, or symptoms (fever > 37.5 °C, upper respiratory tract symptoms, chest pain, and contact/travel history) associated with interstitial pneumonia on chest computed tomography scan were considered diagnostic of COVID-19 disease. Patient characteristics, operative variables, and in hospital outcomes were compared according to COVID-19 testing. A multivariable model was used to identify independent predictors of in hospital death and MAEs. RESULTS: Among 305 included patients, 64 (21%) tested positive for COVID-19 (COVID group) and 241 (79%) did not (non-COVID group). COVID patients presented more frequently with acute limb ischaemia than non-COVID patients (64% vs. 23%; p < .001) and had a significantly higher in hospital mortality (25% vs. 6%; p < .001). Clinical success, MAEs, re-interventions, and pulmonary and renal complications were significantly worse in COVID patients. Independent risk factors for in hospital death were COVID (OR 4.1), medical treatment (OR 7.2), and emergency setting (OR 13.6). COVID (OR 3.4), obesity class V (OR 13.5), and emergency setting (OR 4.0) were independent risk factors for development of MAEs. CONCLUSION: During the COVID-19 pandemic in Lombardy, acute limb ischaemia was the most frequent vascular disease requiring surgical treatment. COVID-19 was associated with a fourfold increased risk of death and a threefold increased risk of major adverse events.

Emergency management of the COVID-19 pandemic in a vascular surgery department of a large metropolitan hospital in Italy. Preparation, escalation, de-escalation, and normal activity.

BACKGROUND: During the first phase of coronavirus disease-2019 (COVID-19) pandemic in Italy, several strategies have been taken to deal with the pandemic outbreak. AIM OF THE STUDY: To report the remodeling of the Vascular Surgery Department of San Raffaele Hospital as regards the strategies of preparation, escalation, and return to normal activities during the COVID-19 pandemic. PREPARATION, ESCALATION, DE-ESCALATION: The Regional Authority of Lombardy remodeled the hospitalization system to allocate appropriate resources to treat patients with COVID-19 and to identify "Hub/Spoke" hospitals for highly specialized medical activities. The Hubs hospitals were required to guarantee full-time evaluation of all patients presenting with cardiovascular diseases with an independent pathway for patients with suspect or confirmed COVID-19 infection. San Raffaele Hospital was identified as Hub for cardiovascular emergencies and the Vascular Surgery Department was remodeled to face this epidemic situation. Surgical treatment was reserved only to symptomatic, urgent, or emergent cases. Large areas of the hospital were simultaneously reorganized to assist patients with COVID-19. RESULTS: During this period, 135 patients were referred to San Raffaele Vascular Surgery Department. COVID-19 was diagnosed in 24 patients and, among them, acute limb ischemia was the most common cause of admission. At this time, the COVID-19 trend is in decline in Italy, and the local authorities reorganized the healthcare system to return to normal activities avoiding new escalations of COVID-19 cases. The COVID-19 pandemic will be remembered in Lombardy as a cataclysm. Nevertheless, the HUB/spoke system has proven to be a valid model in the management of ischemic emergencies. Continuous surveillance, cooperation, coordination, and communication to effectively respond to COVID-19 pandemic is crucial because COVID-19 reference centers could face similar issues in the near future.

External iliac artery endofibrosis in an elite female endurance cyclist.

External iliac artery endofibrosis is a rare pathology that affects high-level endurance athletes, especially cyclists. Classical symptoms include pain, loss of power, and/or cramp in the affected limb while training at maximal effort. The patient's lack of atherosclerotic risk factors makes clinical suspicion of arteriopathy challenging. Moreover, the best management of such patients is still a subject of discussion. We report the case of a 36-year-old professional female endurance cyclist who presented with lower extremity pain during training. Right external iliac artery endofibrosis was diagnosed and the patient underwent surgical treatment. At two-months follow-up, she reported significant improvement in symptoms. This case highlights the importance of diagnosing peripheral vascular disease in young patients and athletes, who do not fit the ordinary profile of patients with atherosclerotic risk factors.

A endofibrose da artéria ilíaca externa é uma doença rara que afeta atletas de resistência (endurance) de nível competitivo, principalmente ciclistas. Os sintomas clássicos incluem dor, perda de força e/ou câimbras no membro afetado ao fazer esforço máximo durante o treino. A ausência de fatores de risco ateroscleróticos nesses pacientes torna a suspeita clínica de arteriopatia desafiadora. Além disso, o melhor manejo ainda é motivo de debate. Relatamos o caso de uma ciclista de resistência profissional, de 36 anos, que apresentou dor nos membros inferiores durante o treino. Foi diagnosticada endofibrose da artéria ilíaca externa, e a paciente foi submetida a tratamento cirúrgico. Após seguimento por dois meses, a paciente relatou melhora significativa dos sintomas. Este caso destaca a importância do diagnóstico de doença vascular periférica em pacientes jovens e atletas, os quais não se encaixam no perfil comum do paciente com fatores de risco ateroscleróticos.

Critical Point for Bifurcation Cascades and Featureless Turbulence.

In this Letter we show that a bifurcation cascade and fully sustained turbulence can share the phase space of a fluid flow system, resulting in the presence of competing stable attractors. We analyze the toroidal pipe flow, which undergoes subcritical transition to turbulence at low pipe curvatures (pipe-to-torus diameter ratio) and supercritical transition at high curvatures, as was previously documented. We unveil an additional step in the bifurcation cascade and provide evidence that, in a narrow range of intermediate curvatures, its dynamics competes with that of sustained turbulence emerging through subcritical transition mechanisms.

A Modified Proximal Stent-Graft for Spinal Cord Preconditioning During Staged Endovascular Repair of Thoracoabdominal Aortic Aneurysms.

Purpose: To describe a new custom-made thoracic device able to seal against the aortic wall and occlude intercostal arteries for spinal cord preconditioning during the first thoracic stage of a thoracoabdominal endovascular repair. Technique: The custom-made device, based on the Zenith Alpha stent-graft, combines different features from 2 previously described devices: the outer part is designed with a bell-bottom configuration similar to the "Embo" stent-graft, while the inner part mimics the "2 in 1" design. The outer stent-graft is designed to span the entire length of the thoracic aorta and cover as many intercostal arteries as possible during the first stage to effectively precondition the spinal cord. The sutured inner component is customizable in diameter and 20 to 40 mm shorter than the outer stent-graft. The technique has been used in 5 patients. Conclusion: The use of this new custom-made thoracic stent-graft might represent an additional tool for effectively preconditioning the spinal cord during fenestrated and branched staged procedures whenever a proximal thoracic proximal component is needed.

Elective Multistaged Endovascular Repair of Thoraco-abdominal Aneurysms with Fenestrated and Branched Endografts to Mitigate Spinal Cord Ischaemia.

OBJECTIVE: To evaluate the safety and effectiveness of a multistaged approach for elective thoraco-abdominal aneurysm (TAAAs) repair by means of endovascular fenestrated and/or branched (F/B-EVAR) grafts. METHODS: Between 2013 and 2018, 80 high risk surgical patients received elective F/B-EVAR for TAAAs with a protocolled multistaged approach (thoracic, visceral, and limb steps) and were enrolled in an ambispective single centre study called STEAR (STaged Endovascular Aortic Repair - NCT03342755). Data regarding all study participants, single step mortality and morbidity (systemic complications) rates were recorded and the overall results were considered for statistical analysis. RESULTS: Previous aortic interventions (61/80 cases, 76.3%) combined with the TAAA extents resulted in different staging strategies: 58 patients (73%) had a thoracic step and 33 (41%) a limb step. The median TAAA treatment time was 77 days (50-107). The overall mortality was six cases (8%) and 30 day clinical success rate 64 cases (80%). The overall rate of grade 2 or 3 (including death) systemic complications was 19 cases (24%) and 20 patients (25%) experienced grade 1 complications. Three patients with type II or III TAAAs (4%) had permanent and fatal spinal cord (SC) impairment. On multivariable analysis, SC ischaemia was associated with an aortic coverage ≥350 mm (OR: 9.15, p = .03, 95% CI: 1.3-66.4) and bovine arch (OR: 10.6, p = .01, 95% CI: 1.6-68.6). The overall short term (six month) clinical success was 72 cases (90%) and none experienced SC ischaemia after late endoleak resolution or treatment. At mid term (mean follow up: 13.3 ± 15.4 months), the overall freedom from conversions, re-interventions, late rupture, or type I and III endoleaks was 57 of 72 survivors (79%). CONCLUSION: A multistaged approach with a third limb step in case of TAAAs is safe and technically feasible, with an acceptable rate of permanent spinal cord ischaemia. Different staging methods and protocols have been proposed and standardisation is required, especially for type I-II-III aneurysms.

Single-Center Vascular Hub Experience after 7 weeks of COVID-19 Pandemic in Lombardy (Italy).

BACKGROUND: The aim of this study was to report the experience of one of the major "hubs" for vascular surgery in Lombardy, Italy, during the first 7 weeks after total lockdown due to COVID-19 pandemic. METHODS: Data from all patients treated at our Department since the decision of the regional healthcare authorities of Lombardy to centralize surgical specialties creating a hub/spoke system (March 9, 2020) were prospectively collected and compared with a retrospectively collected cohort from the same period of year 2019. Primary study end point was defined as primary clinical success. Secondary end points were defined as in-hospital mortality and/or any in hospital major adverse event or lower limb amputation. RESULTS: One hundred sixteen patients were treated (81 men, 70%; median age: 71 years, IQR 65-81). Thirty-two patients (28%) were addressed from spoke hospitals directly referring to our hub, 19 (16%) from hospitals belonging to other hub/spoke nets, 48 (41%) came directly from our emergency department, and 17 (15%) were already hospitalized for COVID-19 pneumonia. Acute limb ischemia was the most observed disease, occurring in 31 (26.7%), 12 (38.7%) of whom were found positive for COVID-19 pneumonia on admission, whereas 3 (9.7%) became positive during hospitalization. Chronic limb ischemia was the indication to treatment in 24 (20.7%) patients. Six (5.2%) patients underwent primary amputation for irreversible ischemia. Aortic emergencies included 21 cases (18.1%), including 13 (61.9%) symptomatic abdominal aortic or iliac aneurysms, 4 (19.0%) thoracoabdominal aortic aneurysms, 2 (9.5%) cases of acute type B aortic dissection (one post-traumatic). Seventeen (14.7%) patients were admitted for symptomatic carotid stenosis (no COVID-19 patients); all of them underwent carotid endarterectomy. Seventeen (14.7%) cases were treated for other vascular emergencies. Overall, at a median follow-up of 23 ± 13 days, primary clinical success was 87.1% and secondary clinical success was 95.9%. We recorded 3 in-hospital deaths for an overall mortality rate of 2.6%. Compared with the 2019 cohort, "COVID era" patients were older (72 vs. 63 years, P = 0.002), more frequently transferred from other hospitals (44% vs. 21%, P = 0.014) and more frequently with decompensated chronic limb threatening ischemia (21% vs. 3%, P = 0.015); surgical outcomes were similar between the 2 cohorts. CONCLUSIONS: Since its appearance, SARS-CoV-2 has been testing all national healthcare systems which founds themselves facing an unprecedented emergency. Late referral in the pandemic period could seriously worsen limb prognosis; this aspect should be known and addressed by health care providers. Vascular surgical outcomes in pre-COVID and COVID era were comparable in our experience.

Neutron-Antineutron Oscillations from Lattice QCD.

Fundamental symmetry tests of baryon number violation in low-energy experiments can probe beyond the standard model (BSM) explanations of the matter-antimatter asymmetry of the Universe. Neutron-antineutron oscillations are predicted to be a signature of many baryogenesis mechanisms involving low-scale baryon number violation. This Letter presents first-principles calculations of neutron-antineutron matrix elements needed to accurately connect measurements of the neutron-antineutron oscillation rate to constraints on |ΔB|=2 baryon number violation in BSM theories. Several important systematic uncertainties are controlled by using a state-of-the-art lattice gauge field ensemble with physical quark masses and approximate chiral symmetry, performing nonperturbative renormalization with perturbative matching to the modified minimal subtraction scheme, and studying excited state effects in two-state fits. Phenomenological implications are highlighted by comparing expected bounds from proposed neutron-antineutron oscillation experiments to predictions of a specific model of postsphaleron baryogenesis. Quantum chromodynamics is found to predict at least an order of magnitude more events in neutron-antineutron oscillation experiments than previous estimates based on the "MIT bag model" for fixed BSM parameters. Lattice artifacts and other systematic uncertainties that are not controlled in this pioneering calculation are not expected to significantly change this conclusion.

Satisfactory short-term outcomes of the STABILISE technique for type B aortic dissection.

OBJECTIVE: The aim of this study was to evaluate the perioperative and short-term results in a cohort of patients treated during the last year at our institution with the stent-assisted balloon-induced intimal disruption and relamination in aortic dissection repair (STABILISE) technique for acute complicated aortic dissection. METHODS: Between June 2016 and June 2017, 10 patients (all male; mean age, 62.6 ± 7.4 years) received treatment for acute complicated aortic dissection with the STABILISE technique. After a standard provisional extension to induce complete attachment procedure using the commercially available endovascular dissection system (Cook Medical, Bloomington, Ind), the distal stent graft area and the bare stent area were ballooned to completely exclude the thoracic false lumen (FL) and to obtain a single-channeled abdominal aorta. Computed tomography was routinely performed within the first postoperative week before discharge and then at 3 months, at 6 months, and yearly thereafter. The technical and clinical success rates were analyzed. RESULTS: The 30-day technical and clinical success rates were 100%, with complete thrombosis of the thoracic FL and no type I endoleak. Malperfusion was resolved in all cases. No aortic ruptures were recorded, and no open conversion was required. One case of delayed spinal cord ischemia fully resolved within the discharge period. Predischarge computed tomography showed complete thrombosis of the thoracic FL in all cases. In two cases, some degree of patency of the abdominal FL was observed. At short-term follow-up, the overall aortic diameters remained stable with no further dilation. CONCLUSIONS: The STABILISE technique was safe and feasible in this cohort of patients, with complete thrombosis of the thoracic FL and creation of a single-channeled aorta in most cases. Further studies are needed to ascertain the long-term behavior of the treated aorta.

Results from the Multicenter Study on Aortoenteric Fistulization After Stent Grafting of the Abdominal Aorta (MAEFISTO).

OBJECTIVE: This study investigated the frequency, clinical features, therapeutic options, and results of aortoenteric fistulas (AEFs) developing after endovascular abdominal aortic repair (EVAR). METHODS: Eight Italian centers with an EVAR program participated in this retrospective multicenter study and collected data on AEFs that developed after a previous EVAR. RESULTS: A total of 3932 patients underwent EVAR between 1997 and 2013 at the participating centers. During the same period, 32 patients presented with an AEF during EVAR follow-up, 21 with original EVAR performed for atherosclerotic aneurysmal disease (ATS group) and 11 with the original EVAR performed for a postsurgical pseudoaneurysm (PSA group). The incidence of AEF development after EVAR was 0.46% in the ATS group and 3.9% in the PSA group. Anastomotic PSA as the indication to EVAR (P < .0001) and urgent/emergency EVAR (P = .01) were significantly associated with AEF development. Median time between EVAR and the AEF diagnosis was 32 months (interquartile range, 11-75 months) for the ATS group and 14 months (interquartile range, 10.5-21.5 months) for the PSA group. Among five AEF patients treated conservatively, two (40%) died, at 7 and 15 months, and the remaining three were alive at a median follow-up of 12 months. The AEF was treated surgically in 27 patients, including aortic stent graft explantation in all cases, in situ aortic reconstruction in 14 (52%), and extra-anatomic bypass in 13 (48%). Perioperative mortality was 37% (10 of 27). No additional aortic-related death was recorded in operated-on patients at a median follow-up of 28 months. CONCLUSIONS: Late AEFs rarely occur during EVAR follow-up, but the risk is significantly increased when EVAR is performed for PSA after previous aortic surgery and EVAR is performed as an emergency. Conservative and surgical treatment of post-EVAR AEF are both associated with high mortality. However, beyond the perioperative period, surgical correction of AEFs appears to be durable at midterm follow-up.