Calcification of surgical aortic bioprostheses and its impact on clinical outcome.

AIMS: Aortic valve calcification (AVC) of surgical valve bioprostheses (BP) has been poorly explored. We aimed to evaluate in-vivo and ex-vivo BP AVC and its prognosis value. METHODS AND RESULTS: Between 2011 and 2019, AVC was assessed using in-vivo computed tomography (CT) in 361 patients who had undergone surgical valve replacement 6.4±4.3 years earlier. Ex-vivo CT scans were performed for 37 explanted BP. The in-vivo CT scans were interpretable for 342 patients (19 patients [5.2%], were excluded). These patients were 77.2±9.1 years old and 64.3% were male. Mean in-vivo AVC was 307±500 Agatston unit (AU). The AVC was 562±570 AU for the 183 (53.5%) patients with structural valve degeneration (SVD) and 13±43 AU for those without SVD (p<0.0001). In-vivo and ex-vivo AVC were strongly correlated (r=0.88, p<0.0001). An in-vivo AVC>100 AU (n=147, 43%) had a specificity of 96% for diagnosing Stage 2-3 SVD (area under the curve=0.92). Patients with AVC>100 AU had a worse outcome compared with those with AVC≤100 AU (n=195). In multivariable analysis, AVC was a predictor of overall mortality (hazard ratio [HR] and 95% confidence interval=1.16[1.04-1.29]; p=0.006), cardiovascular mortality (HR=1.22[1.04-1.43]; p=0.013), cardiovascular events (HR=1.28 [1.16-1.41]; p<0.0001), and re-intervention (HR=1.15 [1.06-1.25]; p<0.0001). After adjustment for Stage 2-3 SVD diagnosis, AVC remained a predictor of overall mortality (HR=1.20 [1.04-1.39]; p=0.015) and cardiovascular events (HR=1.25 [1.09-1.43]; p=0.001). CONCLUSION: CT scan is a reliable tool to assess BP leaflet calcification. An AVC>100 AU is tightly associated with SVD and it is a strong predictor of overall mortality and cardiovascular events.

Spinal Cord Protection During Thoracic and Thoracoabdominal Endovascular Aortic Repair: 5-Year Results of a Preventive Protocol Including Prophylactic Cerebrospinal Fluid Drainage in High-Risk Patients.

PURPOSE: Spinal cord injury (SCI) is a devastating complication of thoracoabdominal aortic (TAA) repair. The use of prophylactic cerebrospinal fluid drainage (CSFD) as part of a protective protocol during endovascular repair is controversial. This article reports the results of the prophylactic use of CSFD as part of the of a prevention protocol implemented in 2016. METHODS: Retrospective review of spinal cord outcomes (SCI rate and CSFD-related complications) in patients treated endovascularly for TAA disease at a single institution from 2016 (implementation of an institutional SCI risk reduction protocol) to 2021. Patients were classified as high risk (≥2 factors), intermediate risk (1 factor), or low risk (0 factor). Only high-risk patients without contraindications underwent a prophylactic CSFD placement. RESULTS: One hundred eighty-one patients were analyzed (124 males; 69.6 years): 130 (69%) aneurysms (n=24 thoracic, n=28 Crawford 1-2-3, and n=78 Crawford 4/pararenal), 35 (19.9%) chronic aneurysmal dissections, and 16 (8.8%) acute complicated type B dissections. Interventions were staged in 31 (17.2%) cases, and consisted of 74 (41%) Thoracic EndoVascular Aneurysm Repair (TEVAR) and 107 (59%) Fenestrated Branched EndoVascular Aneurysm Repair (F-BEVAR). Sixty-nine (38.1%) patients were identified as being at high risk of SCI and CSFD was used prophylactically in 64 of them (4 failures and 1 contraindication). Spinal cord injury occurred in 8 cases (4 paraparesis, 4 paraplegias including 2 permanent), of which 3 had a prophylactic CSFD and 5 underwent rescue drainage. In addition, 4 patients developed SCI related to prophylactic CSFD (intradural hematoma), resulting in 1 paraparesis and 3 paraplegias. Other CSFD-related complications were mild (6) or moderate (2), for a total of 12 complications (17%). Factors associated with major drain complications were: curative anticoagulation 36 hours after drain removal (n=1), multiple punctures (n=1), platelet count <100 000 at drain removal (n=1), and bipolar disorder (n=2). Overall, 4 patients had permanent paraplegia and 1 had sphincter dysfunction at the last follow-up. Mean follow-up was 17 months. Mortality was 4.4% at 30 days and 13.3% at 18 months, including 3 (1.6%) aortic-related deaths. CONCLUSIONS: With the protocol we used to protect the spinal cord, we report results comparable with the SCI literature and highlight the risks associated with prophylactic CSFD use, which requires a better understanding of contraindications.

Comparison of Short and Midterm Aortic Reinterventions in Acute Type A Aortic Dissection Treated by Frozen Elephant Trunk or Conventional Arch Repair.

BACKGROUND: Long-term outcomes after acute type A aortic dissection (ATAAD) are related to remodelling of the descending thoracic aorta and aortic reinterventions. We compared the impact of an extensive repair at the index procedure using the Frozen Elephant Trunk (FET) technique, versus a conventional arch repair, on long-term remodelling of the descending thoracic and reintervention related to the aorta. METHODS: Consecutive patients who underwent conventional arch repair (conventional group) or FET repair (FET group) for an ATAAD from September 2018 to November 2021 were included. Patients who died before discharge or were lost to follow-up prior to the first appointment were excluded from the analysis. Preoperative and postoperative computed tomography angiography was reconstructed and diameter of the true/false lumen of the remaining aorta was compared up to 1 year. Negative (increased total diameter ≥ 5 mm) aortic remodelling was collected for each computed tomography angiography, as well as aortic reinterventions. Comparison of demographic, anatomical, and perioperative complications data were performed using Wilcoxon test for continuous variables or Chi-square test for categorical covariates. The Kaplan-Meier method estimator was used to assess survival rates. The Log rank test was used to compare survival curves between the 2 groups. RESULTS: Thirty nine patients were included, 22 in the conventional group and 17 in the FET group (82% males, mean age 60 ± 12 years). In the FET group, distal anastomosis was performed in zone 0 or 1 for 82% of patients using the simplified delivery technique. Median maximum preoperative descending aortic diameter was larger in the FET group (33 mm [30; 37] vs. 30 mm [28; 32] [P = 0.0172]). At 30 days, the rate of negative remodelling on the descending thoracic aorta was significantly higher in the conventional group (50%) than in the FET group (8%, P = 0.02). At 1 year, Kaplan-Meier analysis shown a freedom from descending aortic negative remodeling of 35.1% (95% confidence interval (CI) 18.7-66.1%) in conventional group and 44.9% (CI 95% 26.1-77.2%) in FET group with no significant difference. However, early negative remodelling was observed for the conventional group. Within a year, freedom from reintervention was observed for 74.4% (95% CI 57.1-97%) of patients in the conventional group and 75.5 (95% CI 57.1-99.7%) of patients in the FET group with no significant difference. CONCLUSIONS: Negative evolution of descending aorta remains a challenge after ATAAD. An extensive repair using the FET technique during the index procedure seems to be associated with satisfying short-term remodelling of descending aorta.

Obesity is Not Associated with Adverse Perioperative or Poorer Clinical Outcomes following Thoracic and Fenestrated-Branched Endovascular Aortic Repair.

BACKGROUND: Obesity is a risk factor for higher morbidity and mortality following open aortic repair but currently there is limited literature on its impact on clinical and procedural outcomes following thoracic endovascular aortic repair (TEVAR) and branched-fenestrated endovascular aortic repair (B-FEVAR). METHODS: We conducted a retrospective case-control analysis of a prospectively collected nonrandomized database to evaluate the effects of obesity on procedural and clinical outcomes after B-FEVAR/TEVAR in treatment of pararenal/thoracoabdominal aortic aneurysm and dissection at the University hospital of Nantes (France) between January 2016 and December 2021. Patients were divided in 2 groups according to their body mass index (BMI) and the rate of technical success, complications (renal, pulmonary, cardiac, and neurological events), 30-day and long-term survival, freedom from target vessel instability and reintervention were compared. RESULTS: 195 patients were included (mean age 69.6 DS±11.2; n = 135, 69.2% men; mean BMI: 26.6 kg/m2 range 19-41) totalling n = 72 (36.8%) TEVAR, n = 107 (55.4%) FEVAR and n = 14 (7.3%) BEVAR. Patients were divided in 2 groups [obese: BMI≥30 kg/m2n = 52 (26.7%); and nonobese, BMI<30 kg/m2, n = 143 (73.3%) that statistically differed only in terms of coronary artery disease (obese 42.3% vs. 26.6% nonobese, P = 0.035) and diabetes (obese 25% vs. 12.6% nonobese, P = 0.03). No statistical differences were noted in primary technical (94.2% vs. 94.4%, P = 1.00) and clinical (92.3% vs. 95.1%, P = 0.49) success. Overall morbidity (30.8% vs. 21.1%, P = 0.16), visceral vessels instability (1.9% vs. 1.4% P = 1.00), reintervention rate within 30 days (9.6% vs. 5.6% P = 0.33), 90 days (7.7% vs. 9.8%, P = 0.78) and during follow-up (9.8% vs. 20%, P = 0.14) were comparable. No statistical difference were noted in 30-day mortality (3.8% vs. 4.9%, P = 1.00) and the 2-year follow-up survival (86.8% vs. 78.4%, P = 0.180) between the 2 groups. CONCLUSIONS: In this series, obesity was not associated to worst clinical outcomes or higher mortality rate following TEVAR/B-FEVAR. However, considering our small patient sample, a conclusive analysis on obesity as risk factors for adverse events after endovascular treatment is not possible. A larger sample from the collaboration of multiple centers will be required to obtain definitive conclusions.

The role of antibody responses against glycans in bioprosthetic heart valve calcification and deterioration.

Bioprosthetic heart valves (BHVs) are commonly used to replace severely diseased heart valves but their susceptibility to structural valve degeneration (SVD) limits their use in young patients. We hypothesized that antibodies against immunogenic glycans present on BHVs, particularly antibodies against the xenoantigens galactose-α1,3-galactose (αGal) and N-glycolylneuraminic acid (Neu5Gc), could mediate their deterioration through calcification. We established a large longitudinal prospective international cohort of patients (n = 1668, 34 ± 43 months of follow-up (0.1-182); 4,998 blood samples) to investigate the hemodynamics and immune responses associated with BHVs up to 15 years after aortic valve replacement. Early signs of SVD appeared in <5% of BHV recipients within 2 years. The levels of both anti-αGal and anti-Neu5Gc IgGs significantly increased one month after BHV implantation. The levels of these IgGs declined thereafter but anti-αGal IgG levels declined significantly faster in control patients compared to BHV recipients. Neu5Gc, anti-Neu5Gc IgG and complement deposition were found in calcified BHVs at much higher levels than in calcified native aortic valves. Moreover, in mice, anti-Neu5Gc antibodies were unable to promote calcium deposition on subcutaneously implanted BHV tissue engineered to lack αGal and Neu5Gc antigens. These results indicate that BHVs manufactured using donor tissues deficient in αGal and Neu5Gc could be less prone to immune-mediated deterioration and have improved durability.

Sapien 3 Embolization From Ventricle to Aorta in the Setting of Noncalcified Aortic Regurgitation.

Transcatheter aortic valve replacement is currently used off-label for noncalcified aortic valve regurgitation and therefore is restricted to selected cases. In this setting we describe a rare complication of Sapien 3 (Edwards Lifesciences, Irvine, California) embolization from the left ventricle to the descending aorta. Given their technical challenges, such procedures require specific considerations and management. (Level of Difficulty: Advanced.).

A simplified delivery frozen elephant trunk technique to reduce circulatory arrest time in hybrid aortic arch surgery.

A simplified delivery technique for the frozen elephant trunk procedure allows the distal suture to be performed on a perfused and loaded aorta in moderate hypothermia-or even normothermia-reducing circulatory arrest time to just a few minutes. Two surgical sealing tourniquets are placed around the aortic arch, usually between the brachiocephalic trunk (BCT) and the left common carotid artery and the aorta is cross-clamped and cardioplegia started. Once in mild hypothermia, the BCT is disconnected and circulatory arrest is initiated while cerebral perfusion is maintained. This modified technique can be used in all pathologies, including dissections.

Carotid versus femoral access for transcatheter aortic valve replacement: comparable results in the current era.

OBJECTIVES: The carotid approach for transcatheter aortic valve replacement (TAVR) has been shown to be feasible and safe. The goal of this study was to compare the 30-day outcomes of trans-carotid (TC) and transfemoral (TF) TAVR. METHODS: This retrospective study enrolled 500 consecutive patients treated by TC-TAVR (n = 100) or TF-TAVR (n = 400) with percutaneous closure between January 2018 and January 2020 at the Nantes University Hospital. The primary end-point was the occurrence of cardiovascular death and cerebrovascular events at 30 days. RESULTS: The mean age was 79.9 ± 8.1 in the TC group and 81.3 ± 6.9 (P = 0.069) in the TF group. The TC group had more men (69% vs 50.5%; P = 0.001) and more patients with peripheral vascular disease (86% vs 14.8%; P < 0.0001). Cardiac characteristics were similar between the groups, and the EuroSCORE II was 3.8 ± 2.6% vs 4.6 ± 6.0%, respectively (P = 0.443). The 30-day mortality was 2% in the TC group versus 1% in the TF group (P = 0.345). TC-TAVR was not associated with an increased risk of stroke (2% vs 2.5%; P = 0.999) or major vascular complications (2% vs 4%; P = 0.548). More permanent pacemakers were implanted in the TF group (14.9% vs 5.6%; P = 0.015), and no moderate or severe aortic regurgitation was observed in the TC group (0 vs 3.3%; P = 0.08). TC-TAVR was not associated with an increased risk of mortality or stroke at 30 days (odds ratio 1.32; 95% confidence interval 0.42-4.21; P = 0.63) in the multivariable analysis. CONCLUSIONS: No statistically significant differences between TC-TAVR and TF-TAVR were observed; therefore, TC-TAVR should be the first alternative in patients with anatomical contraindications to the femoral route.

Celsior® crystalloid cardioplegia versus standard hyperkalemic normothermic blood cardioplegia: Analysis of myocardial protection in elective mitral valve repair.

INTRODUCTION: With the increase and refinement of video assisted mitral valve surgery, cristalloïd cardioplegia started regaining popularity. The aim of our study was to evaluate the effectiveness of Celsior®, a crystalloid cardioplegic solution, on myocardial protection in elective surgical mitral valve repair in comparison to blood based hyperkalemic cardioplegia. METHODS: In this observational retrospective study, all consecutive elective isolated surgical mitral valve repair where Celsior® or normothermic hyperkalemic blood cardioplegia were used were included. Primary endpoint was any sign of myocardial protection failure (troponin levels, need for inotropic or mechanical support, rhythm disturbances, mortality). Secondary endpoint was Celsior® safety (allergic reactions, bleeding, organ toxicities). RESULTS: From January 2009 to August 2016, 382 patients underwent elective isolated mitral valve repair in whom normothermic hyperkalemic blood cardioplegia (n = 181) or Celsior® (n = 201) were used. There were no statistically significant differences in baseline characteristics including Euroscore 2. Peak troponin (pg/ml) release and 30-days mortality were not statistically different. Need for cardioversion was significantly more frequent in the Celsior® group (47% vs 13%, p < 0.001). There was no statistical difference in post-operative atrial fibrillation, permanent pacemaker implantation, reoperation for bleeding, transfusion, acute kidney injury, haemoglobin at discharge or length of stay. No allergic reaction to Celsior® occurred. CONCLUSION: Effective myocardial protection was achieved with the Celsior® cardioplegic solution with no unexpected toxicity. Celsior® may be an efficacious and safe cardioprotective strategy in mitral valve repair.

Results of large pulmonary homograft implantation for right ventricular outflow tract reconstruction.

BACKGROUND: To evaluate the long-term results of implantation of homogeneous large size of pulmonary homograft (PH) for reconstruction of the right ventricular outflow tract (RVOT). METHODS: Between January 2000 and December 2017, 107 patients were implanted with PH for reconstruction of the RVOT. Data were collected retrospectively in this single-center study. PH failure was defined as a peak of gradient greater than 40 mmHg and/or as a pulmonary regurgitation greater than Grade 2. Primary endpoint was the reoperation of the RVOT during follow-up. Secondary endpoints were overall survival, occurrence of PH failure and the rate of reoperation for all cause. RESULTS: Mean age of the recipients was 26.1 ± 13.6 years. Median follow-up interval was 2.99 years (interquartile range [IQR]: 6.2). Mean size of PH was 24.9 ± 1.9 mm. Reoperation of the RVOT occurred in eight patients (7.8%). Time before reoperation was 2.74 years (IQR: 6.4). Freedom from reoperation for RVOT at 5 and 10 years was respectively 95.7% and 90.0%. Overall survival at 10 years was 95.2%. PH failure occurred in 13 patients (12.0%). Median time before PH failure was 6.7 years (IQR: 9.6). Freedom from PH failure at 10 years was 81.6%. Reoperation for PH failure occurred in four patients (3.9%). Concomitant tricuspid surgery (p = .01; 95% confidence interval [CI]: 1.9-319.6) and undersized PH (p = .01; 95% CI: 2.06-719.8) were independent risk factors of late reoperation. CONCLUSION: Implantation of large PH for RVOT reconstruction provides excellent midterm results in terms of reoperation.

Impact of Relative Change in Temperature and Atmospheric Pressure on Acute Aortic Syndrome Occurrence in France.

Acute aortic syndromes (AAS) have been related to significant circadian and seasonal conditions. We used time series analyses to study the impact of meteorological variations on AAS occurrence. We retrospectively assessed 140 patients presenting with AAS over a 6-year period in a French university hospital. Average daily temperature (T) and atmospheric pressure (AP) at the location of the event were collected within the previous 10 days, and their association with AAS investigated with generalized additive models. A decrease in temperature of more than 5 °C within the previous seven days was significantly associated with an increased risk of AAS occurrence (OR equal to 1.86 [1.06; 3.44]). Subgroup analysis revealed that the risk was only significant among normotensive individuals (n = 41) free from blood pressure lowering medication (OR equal to 2.3 [1.05; 5.37]), but not among hypertensive individuals under blood pressure lowering medication despite a larger patient number (n = 99). Similarly, only among the subgroup of normotensive individuals a decrease of AP between 2 and 4 kPa within the previous 3 days was associated with an increased risk of AAS (OR equal to 2.93 [1.1; 8.15]) and an increased between 2 and 4 kPa was associated with a decreased risk (OR equal to 0.59 [0.36; 1.00]). Variations of meteorological conditions (temperature and AP) within the previous week seem to have effects on triggering AAS especially among the population free from blood pressure lowering medication.

Romiplostim as a transfusion saving strategy in 20 patients after heart or lung transplantation: a single centre before-after pilot study.

BACKGROUND: Thrombocytopenia is a common disorder after heart or lung transplantation. Platelet transfusion is often required to maintain haemostasis but represents a specific cause of morbidity and mortality in this setting including alloimmunisation and graft rejection. STUDY DESIGN AND METHODS: As part of a health-care quality improvement project, in a single-centre before-after pilot study, the relevance of a platelet transfusion saving strategy based on romiplostim administration after transplantation was assessed in patients with platelet count <100 × 109/L. Transfusions on days 28 and 90 were compared using propensity matched score for adjustment of demographic characteristics at baseline. The primary outcome was platelet transfusion until day 28 after transplantation. RESULTS: Ninety-three patients were analysed (73 before vs. 20 after). The median [interquartile range] number of platelet concentrate was 1 [0;4.0] before versus 0.5 [0;2.0] in the after period, mean difference 0.5 confidence interval 95% [-0.7 to 1.7], p = 0.39. On day 28, median [interquartile range] red blood cell transfusion was significantly higher in the before versus the after period, 7 [2.0;13.5] versus 6 [1.5;8.5], mean difference 3.2 CI 95% [0.4-6.0], p = 0.02. At 6 months, the rate of patients with de novo anti-human leukocyte antigen alloimmunisation was 45% before versus 53% in the after period (p = 0.56). Deep venous thrombosis was detected in nine patients (12%) before versus seven patients (35%) in the after period (p = 0.04). CONCLUSION: Romiplostim did not significantly reduce platelet transfusion after heart or lung transplantation. Its relevance and safety in a global transfusion strategy remains to be studied in this setting in a large randomised study.

Prognostic impact of blood product transfusion in VA and VV ECMO.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is an accepted and reliable technique to provide temporary circulatory and/or respiratory support. Our objective was to describe the transfusion requirements in ECMO recipients. Secondarily, we addressed the effect of indications for ECMO on transfusion requirements and the baseline factors associated with worse survival. METHODS: We reviewed the prospectively collected data of 509 patients receiving venoarterial (VA) or venovenous (VV) ECMO therapy (2005-2016). Follow-up was prospectively conducted. Data were prospectively entered in the Rennes ECMO database. RESULTS: VA ECMO was employed in 81% of cases; indications were post-cardiotomy myocardial failure in 28% of cases, post-heart transplantation (early graft failure) in 13.2% and cardiogenic shock in 149 (36.4%). VV ECMO was employed in the remaining patients. Average follow-up was 80.25 ± 85.13 days and was 100% complete. In the VA and VV groups, survival at the 30th post-implantation day was 58.3% and 71.1%, respectively, and survival at 6 months was 40.5% and 50.5%, respectively. Platelets and prothrombin time (PT) levels were significantly lower in the VA ECMO group at implantation (p<0.001). VA ECMO patients had a higher rate of thrombotic/haemorrhagic complications (p<0.001) and received both fresh frozen plasma (FFP) (60.5% vs. 31.8% p<0.001) and platelet units (Plt) (61.7% vs. 34.1% p<0.001) more frequently than VV ECMO patients. Post-cardiotomy and post-transplantation patients had significantly higher rates of transfusion of packed red blood cells (pRBC), FFP and Plt than other VA ECMO cases (p<0.001, all). Mortality was equal or greater than 80% among patient subgroups who received more than 19 pRBC, 5 Plt and/or 12 FFP. CONCLUSIONS: An ECMO program is associated with important consumption of blood products. VA ECMO patients have a greater transfusion burden than VV ECMO patients. Mortality is greater in the case of extreme transfusion requirements.

A prospective observational trial of fusion imaging in infrarenal aneurysms.

OBJECTIVE: Use of three-dimensional fusion has been shown to significantly reduce radiation exposure and contrast material use in complex (fenestrated and branched) endovascular aneurysm repair (EVAR). Cydar software (CYDAR Medical, Cambridge, United Kingdom) is a cloud-based technology that can provide imaging guidance by overlaying preoperative three-dimensional vessel anatomy from computed tomography scans onto live fluoroscopy images both in hybrid operating rooms and on mobile C-arms. The aim of this study was to determine whether radiation dose reduction would occur with the addition of fusion imaging to infrarenal repair in all imaging environments. METHODS: All patients who consented to involvement in the trial and who were treated with EVAR in our center from March 2016 until April 2017 were included. A teaching session about radiation protection and Cydar fusion software use was provided to all operators before the start of the fusion group enrollment. This group was compared with a retrospective cohort of patients treated in the same center from March 2015 to March 2016, after a dedicated program of radiation awareness and reduction was introduced. Ruptured aneurysms and complex EVAR were excluded. Preoperative and perioperative characteristics were recorded, including parameters of radiation dose, such as air kerma and dose-area product. Results were expressed in median and interquartile range. RESULTS: Forty-four patients were prospectively enrolled and compared with 21 retrospective control patients. No significant differences were found in comparing sex, body mass index, and age at repair. The median operation time (wire to wire) and fluoroscopy time were 90 (75-105) minutes and 30 (22-34) minutes, respectively, without significant differences between groups (P = .56 and P = .36). Dose-area product was nonsignificantly higher in the control group, 21.7 (8.9-85.9) Gy cm2, compared with the fusion group, 12.4 (7.5-23.4) Gy cm2 (P = .10). Air kerma product was significantly higher in the control group, 142 (61-541) mGy, compared with 82 (51-115) mGy in the fusion group (P = .03). The number of digital subtraction angiography runs was significantly lower in the fusion group (8 [6-11]) compared with the control group (10 [9-14]); (P = .03). There were no significant differences in the frequency of adverse events, endoleaks, or additional procedures required. CONCLUSIONS: When it is used in simple procedures such as infrarenal aneurysm repair, image-based fusion technology is feasible both in hybrid operating rooms and on mobile systems and leads to an overall 50% reduction in radiation dose. Fusion technology should become standard of care for centers attempting to maximize radiation dose reduction, even if capital investment of a hybrid operating room is not feasible.

Structural relaxation dynamics and annealing effects of sodium silicate glass.

Here we report high-precision measurements of structural relaxation dynamics in the glass transition range at the intermediate and short length scale for a strong sodium silicate glass during long annealing times. We evidence for the first time the heterogeneous dynamics at the intermediate range order by probing the acoustic longitudinal frequency in the GHz region by Brillouin light scattering spectroscopy. Or, from in-situ Raman measurements, we show that relaxation is indeed homogeneous at the interatomic length scale. Our results show that the dynamics at the intermediate range order contains two distinct relaxation time scales, a fast and a slow component, differing by about a 10-fold factor below Tg and approaching to one another past the glass transition. The slow relaxation time agrees with the shear relaxation time, proving that Si-O bond breaking constitutes the primary control of structural relaxation at the intermediate range order.