Aortic Aneurysm Surgery Research Articles

Features of Diagnosis and Surgical Treatment of Abdominal Aortic Aneurysms with a Horseshoe Kidney

Introduction. Reconstructive surgery of abdominal aortic aneurysms, despite significant international experience, remains one of the most complex issues of current vascular surgery, especially due to anatomical variability of arterial blood supply of the kidneys and abnormalities in their development, among which the most common is a horseshoe kidney. Features of vascularization, placement of the renal isthmus relative to the main vessels, the choice of the optimal method of abdominal aortic aneurysm reconstruction cause a high risk of surgery. The issues of open and endovascular aortic grafting, possibility of crossing the isthmus of the horseshoe kidney, feasibility of reconstruction of additional renal arteries still remain controversial.
 The aim. Improvement of the diagnosis and surgical treatment of abdominal aortic aneurysms with a horseshoe kidney.
 Case presentation. In our observation, in a 61-year-old patient, by clinical examination, laboratory and diagnostic imaging the diagnosis of two infrarenal abdominal aortic aneurysms with a horseshoe kidney was confirmed, that has become a direct indication for surgical intervention: exclusion of infrarenal aortic aneurysms from the blood flow, abdominal aortic prosthetic grafting with reimplantation of the renal isthmus arteries into the prosthetic graft. This clinical case confirms the advantages of open surgical technique, using transperitoneal approach, which not only provided sufficient exposure of the operating area, but also allowed to perform optimal reconstruction of the abdominal aorta without crossing the functioning isthmus of the horseshoe kidney with preservation of blood flow through additional renal arteries.
 Conclusion. Careful preoperative assessment of the peculiarities of the blood supply of the horseshoe kidney with coexistent abdominal aortic aneurysms allows to optimize the tactics of surgical treatment, prevent the development of severe complications and achieve complete recovery of the patient.

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

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

Long-Term Outcomes of Open and Endovascular Abdominal Aortic Repair in Younger Patients

Aim of this study is to evaluate long-term results in abdominal aortic aneurysm (AAA) surgery by either open aortic repair (OAR) or endovascular aortic repair (EVAR) in patients under 70years of age. A retrospective analysis of a prospectively collected database of patients with age under 70years old undergoing elective infrarenal AAA surgery between 2010 and 2018 was performed. The study population was divided into 2 groups: OAR and EVAR. Primary end points were overall survival and aneurysm-related death, while secondary outcomes were need for reintervention and development of minor and major complications. One hundred ninety-one patients younger than 70years old treated with elective AAA surgery were enrolled: 157 OAR (98% males, mean age 65±4years) and 34 EVAR (94% males, mean age 66±4years). Hospital stay, 30-day mortality, and need for reintervention were similar; OAR population presented higher incidence of postoperative major complications (18% vs. 2.9%; P = 0.01) while minor complications were 32% in the OAR versus 21% in the EVAR group (P = 0.08). Median follow-up was 69months for OAR (interquartile range [IQR] 53months) vs. 79months (IQR 51months) for EVAR (P = 0.9): long-term AAA-related reinterventions were more frequent after EVAR (1.9% OAR vs. 17% EVAR; P = 0.01) while AAA-related long-term mortality was similar in both subgroups (1.3% OAR and 3% EVAR; P = 0.8). At univariate analysis higher risk of reintervention was reported for conical necks in the EVAR group (P = 0.03) and for the concomitant presence of iliac aneurysms in both groups (P = 0.01). According to our data, EVAR in young patients is presenting an excessive rate of reintervention compared to OAR. The presence of conical neck is an independent predictor of EVAR failure and late reintervention, while it does not play a significant role in the OAR group. Open surgery should be considered the first option in younger patients with a long-life expectancy.

Open Abdominal Aortic Aneurysm Surgery and Renal Dysfunction; Association of Demographic and Clinical Variables with Proximal Clamp Location

While cross-clamp site is a known risk factor for postoperative acute and chronic renal dysfunction following open abdominal aortic aneurysm surgery (AAA), the additive impact of patient demographic and clinical factors is lacking. In this study, we investigated the impact of body mass index (BMI), surgical duration and aneurysm diameter on the association between proximal cross-clamp location and postoperative renal dysfunction. In this study, we conducted a retrospective analysis of 4,197 patients undergoing open AAA surgery between 2011 and 2018 using data housed in the American College of Surgeons National Safety Quality Improvement Program (ACS-NSQIP) database. The primary outcome was renal dysfunction, which was defined as patients requiring dialysis within 30days or patients with ≥2mg/dL rise in creatinine from baseline. We assessed the incidence of renal dysfunction with regard to clamp location and subsequently used multivariable logistic regression to assess clinical and demographic factors associated with renal dysfunction. We used a regression model to plot the association of BMI, surgical duration, and aneurysm diameter with an adjusted probability of postoperative acute and chronic renal dysfunction for individual cross-clamp locations. Of the 4,197 patients analyzed, 405 patients (9.6%) developed renal dysfunction within 30 days with 287 patients requiring dialysis. Patients with supraceliac clamp location had the highest incidence of renal dysfunction (20.4%). Our data showed a significant association of renal dysfunction with higher BMI patients [OR 1.04 (1.02, 1.07), P=0.001], longer operative times [OR1.01 (1.01, 1.02), P<0.001], clamp location between the superior mesenteric artery (SMA) and renal artery [OR 1.80 (1.17, 2.78), P=0.007] and supraceliac clamp location [OR 2.47 (1.62, 3.76), P<0.001]. The incidence of renal dysfunction increases with suprarenal clamps. Patients with higher BMI, longer operative times, and increasing aneurysm diameter, and a suprarenal clamp have a significantly increased risk of renal dysfunction compared to those who also had a suprarenal clamp but lower BMI, shorter operative times and smaller aneurysm diameter.

Efficacy of contrast-enhanced ultrasound in detection of type II endoleak after abdominal aortic aneurysm surgery: A prospective cohort study.

This study aimed to evaluate the efficacy of conventional contrast-enhanced ultrasound (CEUS) in detection of type II endoleak after endovascular abdominal aortic aneurysm repair (EVAR). From January 2015 to April 2018, 205 patients underwent EVAR were included. CEUS and computed tomography angiography (CTA) were performed at 1-month follow-up postoperatively to detect type II endoleak. CEUS was performed at 3- and 6-month follow-up to evaluate the development of type II endoleak. The diameter extension of type II endoleak increased greater than 5 mm was defined as enlarge group, and that increased less than 5 mm was defined as stable group. The difference of arrival time (AT) of contrast agent, maximum cross-sectional area (MCSA) of contrast agent and the blood flow velocity (BFV) of the abnormal blood around the stent graft were compared. At 1-month after EVAR, 65 cases of endoleak were detected by CEUS, including 25 cases of type I, 30 cases of type II endoleak and 10 cases of type III endoleak. Among them, 50 cases were also detected by CTA. The diameter extension of 12 cases of type II endoleak increased greater than 5 mm, and that of eight cases increased less than 5 mm. The average AT of the enlarge group was significantly shorter than that of the stable group, while the MCSA of contrast agent and the BFV were significantly higher than that of the stable group (p < 0.05). CEUS has predictive value for the natural outcome of type II endoleak.

Staged graft replacement with thoracic endovascular aneurysm repair for an extensive thoracoabdominal aortic aneurysm after total arch replacement

BackgroundOpen surgery for thoracoabdominal aortic aneurysm is highly invasive. Staged repair for extensive TAAA is effective because it has low morbidity and mortality, and preserves spinal cord perfusion. An initial total arch replacement can create a proximal landing zone for thoracic endovascular aneurysm repair.Case presentationWe performed a staged hybrid thoracoabdominal aortic aneurysm repair after total arch replacement, which consisted of a primary open repair procedure as Crawford Extent III and IV thoracoabdominal aortic aneurysms, and a secondary thoracic endovascular aneurysm repair for the residual lesions for four patients. No spinal cord injury was observed. In one patient, the residual descending aortic aneurysm ruptured six months after the primary open surgery.ConclusionsOverall, staged hybrid repair is effective and shows low morbidity and mortality. Secondary thoracic endovascular aneurysm repair should be performed as soon as possible to reduce the risk of residual aneurysm rupture.

Treatment Outcome Trends for Non-Ruptured Abdominal Aortic Aneurysms: A Nationwide Prospective Cohort Study

The Dutch Surgical Aneurysm Audit (DSAA) initiative was established in 2013 to monitor and improve nationwide outcomes of aortic aneurysm surgery. The objective of this study was to examine whether outcomes of surgery for intact abdominal aortic aneurysms (iAAA) have improved over time.

Risk Factors of Long‐Term Incisional Hernia after Open Surgery for Abdominal Aortic Aneurysm: A Bicentric Study

Conventional open surgery is still important beside endovascular surgery in the management of abdominal aortic aneurysms, with less reinterventions in the long-term follow-up. Incisional hernias are the major complication open surgery in the mid- and long term. The occurrence of this late complication could be due to the choice of the incision, median or transverse. The objectives of our retrospective and bicentric study were to characterize the long-term risk factors for incisional hernias after open surgery for abdominal aortic aneurysms, in particular by comparing the 2 types of laparotomy, and to determine the prevalence of the operated and not operated incisional hernias. Between January 2009 and December 2011, all the patients having elective open surgery for abdominal aortic aneurysm (AAA) by midline laparotomy at the University hospital of Besancon or by transversal laparotomy at the University Hospital of Strasbourg were included retrospectively. The demographic data, the time of diagnosis of the incisional hernia and the parietal reinterventions were collected during a 5-year postoperative follow-up. A univariate and multivariate Cox model was used for the statistical analysis to determine the long-term risk factors for the appearance of an incisional hernia. During the study period, 223 patients presenting with AAA were included, 112 of them were operated by a midline laparotomy and 111 by a transverse laparotomy. The mean age of the patients was 69 ± 8,4years and 208 (93.3%) were men. The 5-year prevalence of incisional hernias was 14.3% (32), and 20 of these hernias (9%) had to be operated. Eighteen hernias (16.1%) occurred after a midline laparotomy and 14 (12.6%) after a transverse incision (P=0.30). In univariate analysis, obstructive chronic pulmonary disease was the only significant risk factor for incisional hernia (P=0.01) and an age over 65 years appeared to protect against this risk (P=0.049). These results were confirmed by multivariate analysis, which showed that obstructive chronic pulmonary disease was an independent risk factor for incisional hernia (HR=2.35, 95% CI 1.16-4.75), and that an age over 65 years was a protective factor (HR=0.49 95% IC 0.00-0.99). The type of laparotomy did not modify the rate of incisional hernias. We showed that only 9% of the patients had to be operated to treat an incisional hernia during the first 5 years after surgery for AAA in our bicentric study. Chronic obstructive pulmonary disease was the only independent risk factor for the occurrence of an incisional hernia.

Male-Female Differences in Ascending Aortic Aneurysm Surgery: 25-Year Single Center Results

The aim of this study was to improve insight into male-female differences in patients undergoing ascending aortic aneurysm surgery. Consecutive patients that underwent ascending aortic aneurysm surgery between January 1991-December 2016 were retrospectively analyzed. Patient and procedural characteristics, 30-day mortality, and survival were compared between male and female patients. Multivariable Cox-regression analysis was performed to explore differences in factors associated with long-term mortality. Of 631 included patients, 36% were female patients. They were older (66 (55.9-72.9) vs 56 (44.1-67.3) years, p < 0.001), had a higher logistic EuroSCORE (12 (8-17) vs 8 (5-12), p < 0.001), and underwent concomitant arch surgery more often (74% vs 54%, p < 0.001). Aortic diameter (5.5 (5.0.6.5) vs 5.5 (5.0-6.0) cm, p=0.025) and Aortic Size Index (3.15 (2.80-3.65) vs 2.70 (2.42-3.00) cm/m2, p < 0.001) were larger in female patients. Early mortality was 0.9% in female patients and 2.0% in male patients (p=0.51). Adjusted 15-year survival was comparable between male and female patients. Multivariable Cox-regression did not identify an independent association between female sex and mortality. In males a larger aortic diameter (HR1.38 per centimeter increase, 95%-CI 1.03-1.85, p=0.003) was an independent factor associated with mortality, and in female patients a larger BSA (HR0.08 per 1kg/m2 increase, 95%-CI 0.01-0.49, p=0.007) was an independent risk-reducing factor. Female patients presented at older age and with more advanced disease. Increased awareness for ascending aortic pathology and timely referral may result in better preoperative profiles in female patients. This may improve outcomes after ascending aortic aneurysm surgery.

Treatment Outcome Trends for Non-Ruptured Abdominal Aortic Aneurysms: A Nationwide Prospective Cohort Study

<h3>Objective</h3> The Dutch Surgical Aneurysm Audit (DSAA) initiative was established in 2013 to monitor and improve nationwide outcomes of aortic aneurysm surgery. The objective of this study was to examine whether outcomes of surgery for intact abdominal aortic aneurysms (iAAA) have improved over time. <h3>Methods</h3> Patients who underwent primary repair of an iAAA by standard endovascular (EVAR) or open surgical repair (OSR) between 2014 and 2019 were selected from the DSAA for inclusion. The primary outcome was peri-operative mortality trend per year, stratified by OSR and EVAR. Secondary outcomes were trends per year in major complications, textbook outcome (TbO), and characteristics of treated patients. The trends per year were evaluated and reported in odds ratios per year. <h3>Results</h3> In this study, 11 624 patients (74.8%) underwent EVAR and 3 908 patients (25.2%) underwent OSR. For EVAR, after adjustment for confounding factors, there was no improvement in peri-operative mortality (aOR [adjusted odds ratio] 1.06, 95% CI 0.94 – 1.20), while major complications decreased (2014: 10.1%, 2019: 7.0%; aOR 0.91, 95% CI 0.88 – 0.95) and the TbO rate increased (2014: 68.1%, 2019: 80.9%; aOR 1.13, 95% CI 1.10 – 1.16). For OSR, the peri-operative mortality decreased (2014: 6.1%, 2019: 4.6%; aOR 0.89, 95% CI 0.82 – 0.98), as well as major complications (2014: 28.6%, 2019: 23.3%; aOR 0.95, 95% CI 0.91 – 0.99). Furthermore, the proportion of TbO increased (2014: 49.1%, 2019: 58.3%; aOR 1.05, 95% CI 1.01 – 1.10). In both the EVAR and OSR group, the proportion of patients with cardiac comorbidity increased. <h3>Conclusion</h3> Since the establishment of this nationwide quality improvement initiative (DSAA), all outcomes of iAAA repair following EVAR and OSR have improved, except for peri-operative mortality following EVAR which remained unchanged.

Intraoperative neurophysiologic monitoring in thoracoabdominal aortic aneurysm surgery can provide real-time feedback for strategic decision making

ObjectivesDespite the introduction of several adjuncts to improve spinal perfusion, spinal cord ischemia (SCI) remains a devastating complication of thoracoabdominal aortic aneurysm (TAAA) repair. Our aim was to assess the effects on clinical outcome of interventions triggered by motor evoked potentials (MEP) alerts. Furthermore, we want to assess whether a multimodal intraoperative neurophysiologic monitoring (IONM) protocol is helpful for stratifying patients according to the risk of SCI at the end of the vascular phase of surgery. MethodsWe prospectively studied one-hundred consecutive patients who underwent TAAA repair. We applied a multimodal IONM including MEP, somatosensory evoked potentials (SEP) and peripheral nerve monitoring techniques. Signal deteriorations were classified as reversible/irreversible according to whether they recovered or not at the end of monitoring (EOM), set at the end of the vascular phase of surgery. Significant MEP changes drove a series of corrective measures aimed to improve spinal perfusion. ResultsThe rate of immediate postoperative motor deficits consistent with SCI was significantly higher with irreversible MEP deteriorations compared to reversible ones. The interpretation of MEP findings at the EOM led to the development of risk categories for SCI, based on the association between MEP results and motor outcome. ConclusionsOur data seem to justify interventions made to reverse MEP deterioration in order to improve the clinical outcome. A multimodal IONM protocol could improve MEP interpretation at the end of the vascular phase of surgery, supporting the surgeon in their decision-making, before concluding vascular maneuvers.

A Second-Stage Surgery for Thoracoabdominal Aortic Aneurysm after Ascending Aorta-Abdominal Aorta Bypass for Atypical Coarctation Due to Takayasu Arteritis

Although aortic aneurysms associated with Takayasu arteritis are not rare, a total occlusion of the thoracoabdominal aorta with enlargement is rare. We have experienced a 60-year-old man who underwent a second-stage surgery for thoracoabdominal aortic aneurysm nine years after the prior operation of an ascending aorta-abdominal aorta bypass for atypical coarctation due to Takayasu arteritis. We present a successful case of the treatment result after 4 years’ follow-up.

Narrative review: open surgery for thoracoabdominal aortic aneurysm—is it still a horrible surgery?

Narrative review: open surgery for thoracoabdominal aortic aneurysm—is it still a horrible surgery?

Mini-David procedure. Procedural considerations.

The main goal of minimally invasive surgery is to reduce the perioperative trauma, accelerate patient mobilization and reduce the length of hospital stay. Due to the development of modern technology, these treatments can be offered to a wider group of patients. For many years, aortic root surgery consisted of mechanical conduit implantation and, therefore, necessitated life-long anticoagulation. At present, in patients with aortic root aneurysm and significant aortic valve regurgitation, it is possible to perform minimal-access valve sparing surgical procedures. The current paper is a brief description of the surgical technique for aortic root aneurysm surgery with preservation of the patient's own valve using the David procedure.

Continuous Epidural Block and Balanced General Anesthesia in Abdominal Aortic Aneurysm Surgery in a General Hospital. Case Report

Introduction: Abdominal Aortic Aneurysms (AAA) are becoming more frequent in our population; the surgical management of this pathology represents a highly complex surgery which must be performed in a well-equipped medical unit, with implements and suitable personnel, since morbidity and mortality depends a lot on the preoperative evaluation of these patients with high coronary risk. Peripheral locoregional anesthesia techniques occupy an important place in anesthetic treatment and postoperative resuscitation due to the frequent possibility of cardiovascular, respiratory, renal complications or mesenteric ischemia, which justifies a treatment adapted to the high surgical risk, therefore, postoperative management should generally be in an Intensive Care Unit. Objective: Present the case of a patient with Abdominal Aortic Aneurysm (AAA) with acute abdomen urgently operated in a second-level hospital using mixed anesthesia. Case: Octogenarian patient with a diagnosis of infrarenal AAA, undergoing emergency surgery for abdominal pain, which was under balanced general anesthesia plus epidural block a bifurcated Dacron synthetic graft was interposed, with postoperative management in general surgery hospitalization area because there was no availability in the Intensive Care Unit (ICU), evolving properly. Conclusion: Evolution depends a lot on the anesthetic technique, which must be directed towards a multimodal strategy, where hemodynamic stability is a priority.

Surgical repair of abdominal aortic aneurysms on the public health system in the largest city in Brazil: a descriptive analysis of in-hospital data on 2693 procedures over 10 years.

BackgroundFrom 1990 to 2015, mortality from aortic aneurysms increased 16.8% in Brazil. São Paulo is the largest city in Brazil and about 5 million people depend on the public health system there.ObjectivesTo conduct an epidemiological analysis of abdominal aortic aneurysm surgeries in the city of São Paulo.MethodsInfra-renal aortic aneurysm procedures performed over a decade (from 2008 to 2017) were studied using publicly-available platforms from the Unified Health System and DATASUS.Results2693 procedures were analyzed; 66.73% were endovascular; 78.7% of patients were male; 70.7% were aged 65 years or more; 64.02% were elective hospital admissions. There were 288 in-hospital deaths (mortality: 10.69%). In-hospital mortality was lower for endovascular surgery than for open surgery; both for elective (4.13% versus 14.42%) and urgent (9.73% versus 27.94%) (p = 0.019) admissions. The highest volume hospital (n = 635) had the lowest in-hospital mortality (3.31%). USD 24,835,604.84 was paid; an average of $ 2,318.63 for elective open, $ 3,420.10 for emergency open, $ 12,157.35 for elective endovascular and $ 12,969.12 for urgent endovascular procedures. Endovascular procedure costs were statistically higher than the values paid for open surgeries (p <0.001).ConclusionsEndovascular surgeries were performed twice as often as open surgeries; they had shorter hospital stays and lower mortality.

Editor’s foreword

Welcome to the third issue of the Journal of Vascular Societies Great Britain and Ireland (JVSGBI). The journal is certainly going from strength to strength, and I hope that you find the May edition both informative and enjoyable. On behalf of the Editorial Board, thank you to all authors who have submitted articles. This issue includes two editorials. The first is a personal journey with respect to equality, diversity and inclusion from Mr Neeraj Bhasin, a Consultant Vascular Surgeon, in West Yorkshire. The second editorial examines what the recently published Vascular PAD-QIF CQUIN, means for vascular patients, clinicians and patients. The full report is also a supplement to this issue, and can be located on the JVSGBI website, for easy reference. This issue includes four original research articles, which cover a variety of research topics including: outcomes of revascularisation in elderly CLTI patients; a study of the reliability of WIfI risk stratification in the diabetic foot clinic; factors associated with delays to carotid endarterectomy in the Republic of Ireland; and a study of training in open aortic aneurysm surgery. We also have two trial protocols: the first (VENUM) aims to evaluate the provision of undergraduate vascular teaching in UK medical schools, whilst the second (WALKSTRONG) aims to test the feasibility of a novel home exercise programme for patients with intermittent claudication. Finally, this issue also contains the JVSGBI's first case report and literature review – distal venous arterialisation for 'no-option' CLTI. It is particularly pleasing to see such a wide variety of study designs, research topics and our first publication from a non UK centre. Recently, the JVSGBI Editorial Board took the decision to acknowledge the sterling and essential input of article reviewers. Therefore from this point forward each article will include a note of gratitude to the individual article reviewers. A list of reviewers will also be published in each November edition. Additionally, as Editor in Chief, I am proud to advise that time from article submission to on-line publication at www.jvsgbi.com is taking approximately eight weeks and that all articles have free, open access. A Twitter notification is sent out when articles are published online via @VSjournalGBI. Our Twitter following is growing – if you are not yet following us on social media please visit and follow to receive the latest news from the journal. Finally, I hope that you enjoy reading this issue of JVSGBI. Please do continue to submit your work for publication, and follow us on social media.

Exosome miR-23a-3p from Osteoblast Alleviates Spinal Cord Ischemia/Reperfusion Injury by Down-Regulating KLF3-Activated CCNL2 Transcription

Background: Spinal cord ischemia/reperfusion injury (SCIRI) is usually caused by spinal surgery or aortic aneurysm surgery and can eventually lead to paralysis or paraplegia and neurological dysfunction. Exosomes are considered as one of the most promising therapeutic strategies for SCIRI as they can pass the blood-spinal barrier. Previous studies have proved that exosomes secreted by osteocytes have a certain slowing effect on SCIRI. Aim: We aimed to explore the effect of osteoblast secreted exosomes on SCIRI. Methods: First, neurons and osteoblasts were co-cultured under different conditions. GEO database was utilized to detect the expression of miR-23a-3p in osteoblast exosomes. SCIRI cells were treated with exosomes, and the detection was taken to prove whether miR-23a-3p could slow the progression of SCIRI. Downstream gene and the potential regulatory mechanism were explored through database and functional experiments. Results: MiR-23a-3p was highly expressed in exosomes and it slowed down the process of SCIRI. Downstream mRNA KLF3 could bind to miR-23a-3p and was highly expressed in IRI. Moreover, CCNL2 was regulated by KLF3 and was highly expressed in IRI. Rescue experiments verified that miR-23a-3p suppressed the transcription of CCNL2 by targeting KLF3. Conclusion: Exosome miR-23a-3p from osteoblast alleviates SCIRI by down-regulating KLF3-activated CCNL2 transcription.

Creation of an Analytical Model of Spinal Cord Cooling by Epidural Catheter for Preventing Paraplegia.

IntroductionParaplegia is a serious complication after thoracic and thoracoabdominal aortic aneurysm surgery. The aortic cross-clamp blocks blood flow to the intercostal artery as a feeding blood vessel, so the spinal cord is at risk of being exposed to ischemia. Hypothermia with systemic cooling is a useful means of avoiding spinal ischemia caused by aortic blockade but has various side effects. Theoretically, local cooling by epidural cooling catheter is an effective method to reduce the side effects. However, the use of needle sensors to measure the temperature of the human spinal cord is not ethically applicable in the real clinical field. The purpose of the study is to build computer modeling of human-sized spinal cords and a basic platform for simulating spinal cord cooling. This is being done to prove that local cooling can cool the human spinal cord in the same way, even in human spinal cords larger than laboratory animals.MethodsWe tried to model a horizontal cross-section of tissue near the spinal cord at a size equivalent to that of an adult human. The tissue around the spinal cord was decomposed into many small matrices for analysis using the finite element method. Next, the analysis was performed using a high-speed computer on the assumption that the matrix exchanges heat with the adjacent matrix over time according to Pennes' bio-heat equation. Repeated calculations were performed on a high-speed computer to calculate temperature changes in the central part of the spinal cord.ResultBy setting the temperature of the cooling catheter to 20°C, temperatures at the center of the spinal cord after 5, 10, 15, 20 and 25 minutes were 34.08°C, 33.64°C, 33.48°C, 33.40°C, and 33.36°C, respectively. After stopping the cooling, the temperature at the center of the spinal cord recovered to baseline temperature within 10 minutes.ConclusionResults were similar to those of previous animal studies using our local cooling system, suggesting that evaluation of cooling catheter's performance by computational simulation (CS) is effective.

Autophagy of Spinal Microglia Affects the Activation of Microglia through the PI3K/AKT/mTOR Signaling Pathway

Delayed paralysis occurs within some patients suffered from ischemic spinal cord injury (ISCI) due to the aorta occlusion during the repair surgery of thoracic and thoracoabdominal aortic aneurysms. Although mild hypothermia has been reported to improve ISCI and prolong the tolerance of rats to ISCI without inducing immediate paralysis, the mechanism remains unclear. Herein, the study revealed that the mild hypothermia treatment indeed partially improved the ISCI in rats caused by cross-clamping at the descending aorta. ISCI induced the excessive activation of microglia and moderate autophagy in the spinal cord tissues of rats, while mild hypothermia significantly induced autophagy and reversed the excessive activation of microglia in the spinal cord tissues of rats. In OGD-stimulated mouse microglia BV-2 cells, the excessive activation of microglia and moderate autophagy were also observed; in the rapamycin-treated OGD model in BV-2 cells, autophagy was significantly enhanced whereas the excessive activation of microglia was reversed. In both in vivo ISCI model in rats and in vitro OGD model in BV-2 cells, the PI3K/AKT/mTOR pathway showed to be inhibited, whereas the PI3K/AKT/mTOR pathway was further inhibited by mild hypothermia in ISCI rats or rapamycin treatment in OGD-stimulated BV-2 cells. In conclusion, enhanced autophagy might be the mechanism of inhibited microglia activation by hypothermia treatment in ISCI rats and by rapamycin treatment in OGD-stimulated BV-2 cells. Autophagy could be enhanced through inhibiting the PI3K/AKT/mTOR pathway.