Nitric Oxide in Selective Cerebral Perfusion Could Enhance Neuroprotection During Aortic Arch Surgery

BackgroundHypothermic circulatory arrest (HCA) in aortic arch surgery has a significant risk of neurological injury despite the newest protective techniques and strategies. Nitric oxide (NO) could exert a protective role, reduce infarct area and increase cerebral perfusion. This study aims to investigate the possible neuroprotective effects of NO administered in the oxygenator of selective antegrade cerebral perfusion (SCP) during HCA.MethodsThirty male SD adult rats (450–550 g) underwent cardiopulmonary bypass (CPB), cooling to 22°C body core temperature followed by 30 min of HCA. Rats were randomized to receive SCP or SCP added with NO (20 ppm) administered through the oxygenator (SCP-NO). All animals underwent CPB-assisted rewarming to a target temperature of 35°C in 60 min. At the end of the experiment, rats were sacrificed, and brain collected. Immunofluorescence analysis was performed in blind conditions.ResultsNeuroinflammation assessed by allograft inflammatory factor 1 or ionized calcium-binding adapter molecule 1 expression, a microglia activation marker was lower in SCP-NO compared to SCP (4.11 ± 0.59 vs. 6.02 ± 0.18%; p < 0.05). Oxidative stress measured by 8oxodG, was reduced in SCP-NO (0.37 ± 0.01 vs. 1.03 ± 0.16%; p < 0.05). Brain hypoxic area extent, analyzed by thiols oxidation was attenuated in SCP-NO (1.85 ± 0.10 vs. 2.74 ± 0.19%; p < 0.05). Furthermore, the apoptotic marker caspases 3 was significantly reduced in SCP-NO (10.64 ± 0.37 vs. 12.61 ± 0.88%; p < 0.05).ConclusionsNitric oxide administration in the oxygenator during SCP and HCA improves neuroprotection by decreasing neuroinflammation, optimizing oxygen delivery by reducing oxidative stress and hypoxic areas, finally decreasing apoptosis.

A System for Accurate Deployment of Unconstrained Triple-Fenestrated Aortic Arch Endografts

Purpose: To achieve accurate rotational orientation and the axial position of unconstrained triple-fenestrated physician-modified endografts upon deployment in the aortic arch during total arch thoracic endovascular aortic repair (TA-TEVAR). Materials and Methods: Following a detailed study of reconstructed computerized tomography angiography images of patients’ arch anatomy, customized, sealable fenestrations with radio-opaque margins are created onsite on Valiant Captivia (Medtronic) endografts, transposing the arch branch ostial anatomic interrelationship onto the endograft precisely. Radio-opaque figure-of-8 markers, indicating the 12 o’clock (superior) position, are attached to the endograft on the surface and brought up to the surface under the endograft cover during resheathing. Resheathing without any twist in the endograft is achieved by lining up the welds in each endograft stent segment in a straight line. The fluoroscopic working view for arch endograft delivery and deployment is the left anterior oblique view that is orthogonal to the plane of the arch, which, in turn, is the right anterior oblique view in which parts of a stiff indwelling guidewire in the ascending and descending aorta precisely overlap. During introduction in the working view, the endograft delivery system is rotated in the descending thoracic aorta so that the 12 o’clock figure-of-8 markers are viewed on the edge and situated at the outer aortic curvature; continued advancement into the arch without any further rotation will ensure superior orientation of the figure-of-8 markers and, consequently, correct endograft rotational orientation. Proper axial endograft positioning requires locating the left common carotid artery (LCCA) fenestration just proximal to a taut externalized LCCA-femoral guidewire loop marking the posterior limit of the LCCA ostium. After endograft deployment during rapid cardiac pacing, the target arch branches are cannulated through their respective fenestrations using hydrophilic 0.035-inch guidewires that are externalized via distal sheaths to create femoral-arch branch (through-and-through) loops over which covered fenestrated stents are introduced and deployed. Results: This technique was used successfully in 31 consecutive patients undergoing TA-TEVAR; systemic blood pressure was obtained in all arch branches immediately after endograft deployment, indicating adequate blood flow. All arch branches were successfully cannulated and stented. Conclusion: This system enables accurate deployment of unconstrained triple-fenestrated arch endografts simply and reliably during TA-TEVAR.

The Mini-Cross Prefenestration for Endovascular Repair of Aortic Arch Pathologies

Objective: To examine the feasibility, integrity, efficacy, and safety of endovascular repair of the aortic arch pathologies with the mini-cross prefenestration (MCPF) on stent grafts.Methods: First, to prove the feasibility of the MCPF, an in-vitro prefenestration experiment was conducted. Second, to examine the integrity of the MCPF stent grafts, a fatigue test was conducted. Then, the membranes and metal structures of stent grafts were examined by light microscopy and scanning electron microscopy (SEM). Third, a clinical experiment was conducted to investigate the efficacy and safety of this novel technique (ClinicalTrials.gov Identifier: NCT04544579).Results: All the 12 branch stents were successfully implanted and flared in vitro. After the fatigue test stimulating a 5-year cardiac cycle, no obvious disintegration or fracture was found in light microscopy or SEM. From December 2017 to February 2020, 26 patients with left subclavian arteries and/or left common carotid arteries involved received the novel technique. The endovascular repair with the MCPF was successfully performed on all the 26 (100%) patients. Eighteen (69.2%) patients underwent the reconstruction of the left subclavian artery (LSCA) only. The fenestrations of both the LSCA and left common carotid artery (LCCA) were conducted in 8 (30.8%) patients. Median operative time was 120 [interquartile range (IQR), 95–137.5] min and median revascularization time of the LSCA and LCCA was 30.5 (IQR, 22.8–42.0) s and 20.0 (IQR, 18.0–32.0) s separately. During the median follow-up duration of 38.9 (range, 18.8–44.2) months, one case needed an open surgery because of retrograde type A aortic dissection 3 months after implantation and no other complications or mortality occurred. The maximum aortic diameters were significantly decreased in patients with thoracic aortic dissection and thoracic aortic aneurysm (p < 0.05).Conclusion: The existing evidence demonstrated the safety, rapid branch artery revascularization, and positive aortic remodeling of the novel technique. Long-term observation is warranted to prove the durability.

Preliminary results of single centre experience with the “release and perfuse technique” during aortic arch surgery.

Background and aim of the study To evaluate whether the release and perfuse technique implies a circulatory arrest time comparable with or shorter than those of standard Frozen Elephant Trunk technique in aortic arch surgery. Methods We retrospectively reviewed the records of patients who had undergone aortic arch repair with Release and Perfuse Technique (RPT) or standard Frozen Elephant Trunk (FET) at our Institution between January 2018 and May 2021. Primary endpoints were the comparison of circulatory arrest time, perioperative variables, and complications between two groups. A propensity score weighting approach was used for data analysis. Results A total of 41 patients underwent aortic arch surgery were analyzed:15 (37%) and 26 (63 %) in RPT and FET group, respectively. The use of RPT showed a significant shorter circulatory arrest times than FET: 9 min vs 58 min (P < 0.001), respectively. The median lactates peak in the first 24h post intervention was 2.6 for RPT group and 5.4 mmol/L for FET group, (P <0.0001). When compared with the FET, RPT is associated with significant reduction in the use of packed red blood cells (P <0.0001), fresh frozen plasma (P <0.0001), platelet concentrate (P <0.0001), and fibrinogen (P <0.004). The median ICU stay was 3 and 9 days (P = 0.011), whereas the median hospital stay was 12 and 18.5 days (P=0.004) in the RPT and FET groups, respectively. Thirty-day mortality and postoperative outcomes were comparable between the two groups. Conclusions Considering the anatomical limitations related to the use of this technique, the RPT appears to be safe, feasible, and effective in reducing the circulatory arrest time during aortic arch surgery. Nevertheless, further studies are required to demonstrate its safety and efficacy.

Multi-Branched Thoracoabdominal Endovascular Aortic Repair With Branch Access Through a Left Thoracotomy and Descending Thoracic Aortic Conduit: A Novel and Effective Alternative Access

Purpose: To demonstrate an alternative access to perform directional branch catheterization during complex endovascular aortic repair. Technique: Urgent endovascular aortic repair was indicated to treat a symptomatic post dissection thoracoabdominal aneurysm with large infrarenal dilatation with an off-the-shelf t-Branch endograft (Cook Medical, Bloomington, IN, USA). Traditional proximal arterial accesses were not suitable due to a previous aortic arch endograft. A novel approach was performed through a left postero-lateral thoracotomy, isolation of the descending thoracic aorta and anastomosed a polyester graft conduit to allow sheaths passage to the thoracoabdominal aorta with subsequently directional branch catheterization. Conclusion: The descending thoracic aortic conduit technique is an effective alternative for directional branch catheterization and should be considered whenever traditional proximal arterial accesses are not suitable and other endografts configurations not considered due to anatomic limitations.

Using self -suture branching artificial vesssels in aortic arch surgery at Hanoi Heart Hospital

Background: For aortic arch surgery, the improvement of anastomosis technique, and the improvement of using self-suture branching artificial vessels have shortened the time and reduced the cost of surgery. The study aimed to evaluate the improved results of using self-suture branched artificial vessels in aortic arch surgery. Methods: A retrospective descriptive study of the use of self-suture branching artificial vessels in aortic arch surgery at Hanoi Heart Hospital from October 2018 to May 2021. Results: There were 33 cases of aortic arch replacement using self-suture branching artificial vessels. The rate of postoperative bleeding was 6.06%. The rate of artificial vessel infection is 0%. Conclusion: Using self-suture branching artificial vessels in aortic arch surgery is a safe and effective technique.