Debranching aortic surgery

Enabling supra-aortic vessels inclusion in statistical shape models of the aorta: a novel non-rigid registration method

Statistical Shape Models (SSMs) are well-established tools for assessing the variability of 3D geometry and for broadening a limited set of shapes. They are widely used in medical imaging due to their ability to model complex geometries and their high efficiency as generative models. The principal step behind these techniques is a registration phase, which, in the case of complex geometries, can be a critical issue due to the correspondence problem, as it necessitates the development of correspondence mapping between shapes. The thoracic aorta, with its high level of morphological complexity, poses a multi-scale deformation problem due to the presence of several branch vessels with varying diameters. Moreover, branch vessels exhibit significant variability in shape, making the correspondence optimization even more challenging. Consequently, existing studies have focused on developing SSMs based only on the main body of the aorta, excluding the supra-aortic vessels from the analysis. In this work, we present a novel non-rigid registration algorithm based on optimizing a differentiable distance function through a modified gradient descent approach. This strategy enables the inclusion of custom, domain-specific constraints in the objective function, which act as landmarks during the registration phase. The algorithm's registration performance was tested and compared to an alternative Statistical Shape modeling framework, and subsequently used for the development of a comprehensive SSM of the thoracic aorta, including the supra-aortic vessels. The developed SSM was further evaluated against the alternative framework in terms of generalisation, specificity, and compactness to assess its effectiveness.

Thoracic Aortic Aneurysms and Arch Disease

Aortic arch and descending thoracic pathology have historically remained in the realm of open surgical repair. Technology is quickly pushing to bring these under the endovascular umbrella, with lower morbidity repairs proving safe in their early experience. Much work remains particularly for acute aortic syndromes, however, to understand who is best treated medically, surgically, endovascularly, or with hybrid approaches.

Surgeon-modified fenestrated endograft for urgent an aortic arch aneurysm: case report

We report the case of an endovascular repair of an aortic arch aneurysm by a surgeon-modified fenestrated endograft with a single fenestration in a high-risk patient unfit for open surgery. A patient of 84 years, chronic ischemic cardiopathic, suffering from prostate adenocarcinoma in chemotherapy treatment, came to our hospital for post-traumatic fracture of the right femur. During the hospitalization, the patient exhibited dysphonia and respiratory disorders for several days, therefore, the patient performed Computed Tomography Angiography (CTA) that found the presence of voluminous aneurysm of the aortic arch with a maximum diameter of about 74 mm. The patient was treated with a hybrid-staged procedure; in the first instance, with a carotid-carotid-succlavium bypass to preserve the cerebral and upper limb vascularization and then, the procedure was completed by implanting the surgeon-modified fenestrated endograft with stent delivery to the patient with a fenestration on the anonymous trunk. This surgeon-modified fenestrated endograft was created by modifying a standard endograft by a single fenestration following the three-dimensional reconstructions of the CTA images. The procedure was successfully completed and postoperative course was uneventful. Computed Tomography Angiography demonstrated the exclusion of the aneurysm, patency of the implanted endograft modules, and absence of signs of endoleaks and / or cerebral or medullary ischemic complications.

Applicability of endovascular branched and fenestrated aortic arch repair devices to treat residual type A dissection after ascending replacement

OBJECTIVE

Endovascular repair of post-type-A aortic dissection after open ascending replacement (PTAD) has recently been shown as safe and feasible, but with limited anatomic applicability since only one stent graft was evaluated. We assessed anatomic and clinical applicability of six commercially available branched/fenestrated stent grafts for endovascular repair of PTAD.

METHODS

On postoperative CT-scans of 101 patients, we measured aortic diameter at: sino-tubular junction, supra-aortic vessels (SAV), and descending aorta, as well as the distances between these landmarks along the outer curvature of the arch and the diameters of the SAV. Anatomical applicability was evaluated according to the instructions-for-use, clinical applicability with regard to supra-aortic and iliac arteries. Assessed devices were: Cook aortic double branch; Terumo double branch; Najuta fenestrated; Endospan Nexus; Medtronic Mona LSA; and Gore TAG thoracic branch.

RESULTS

Single devices were anatomically and clinically applicable between 19/101 (Mona LSA) and 83/101 (Najuta) cases. Reasons for rejection varied considerably across devices. With all devices available, anatomical applicability was 97/101 and clinical applicability 95/101. Combinations of a fenestrated and a branched device showed the most favorable clinical applicability for a pair of two devices, ranging from 86/101 to 94/101.

CONCLUSIONS

Anatomical and clinical applicability of endovascular devices for the repair of PTAD is high for fenestrated and branched devices, and very high for the combination of fenestrated and branched devices. Manufacturers should amend specific device requirements for PTAD. Surgeons should emphasize the need for a sufficiently long and straight graft as a potential landing zone.

[Use of temporary arterial shunt in surgery of dissection of the aorta and brachiocephalic arteries]

BACKGROUND

Unsolved problems of cerebral protection in operations on the aortic arch, especially in a combination with extension of dissection to the brachiocephalic arteries determine search for variants making it possible to carry out adequate cerebral perfusion.

AIM

To propose a new technique and initial experience of using cerebral perfusion through a temporary shunt from the basin of the left subclavian artery at the stage of prosthetic repair of brachiocephalic arteries.

PATIENTS AND METHODS

At the Department of Reconstructive Surgery and Aortic Root of A.N. Bakulev National Medical Research Centre of Cardiovascular Surgery, a total of 6 patients (5 men) with type A aortic dissection underwent a stage of restoration of brachiocephalic arteries with the use of a temporary arterial shunt. The mean age was 48±15 years. The patients had chronic aortic dissection involving brachiocephalic arteries, primary fenestration in the aortic arch. All were found to have signs of chronic cerebrovascular insufficiency (dizziness, loss of consciousness); 2 patients had a history of transitory focal impairments. All patients were subjected to prosthetic repair of the ascending portion, aortic arch and all brachiocephalic arteries in conditions of adaptive perfusion with the use of adaptive loop from arterial lines. Supracoronary reconstruction of the ascending aorta was performed in 4 patients, Bentall operation in 2 subjects, with all undergoing total aortic arch replacement according to the elephant trunk technique. Brachiocephalic arteries were repaired using a trifurcated vascular grafts.

RESULTS

Mean duration of cerebral perfusion along the temporary shunt amounted to 34±12 min. At all stages of operation, the level of haemoglobin oxygen saturation (rSO2) according to cerebral oximetry was within the reference values. All patients were discharged averagely on POD 12.

CONCLUSION

A novel technique of cerebral perfusion along a temporary shunt will make it possible to extend the capabilities of heart surgeons in complicated combined interventions on the aortic arch and brachiocephalic arteries.

Pre-fenestration endovascular repair of aortic diseases in patients with zone 2 segment: A single-center experience

OBJECTIVE

The present study aims to analyze the outcomes of three cases of pre-fenestration and branch stent-graft endovascular repair of aortic disease with zone 2 aortic lesions.

METHODS

From August 2017 to June 2018, three patients with zone 2 aortic lesions underwent thoracic endovascular repair with innominate artery, left common carotid artery, and left subclavian artery recannulation using pre-fenestration and branched stent-grafts to preserve the patency of the aortic arch branches.

RESULTS

The technical success rate was 100%. One patient had a proximal type I endoleak with no need for additional treatment. The overall mortality was 0%. All branches were patent. The follow-up period lasted for 2-15 months, with one patient lost to follow-up. There were no conversions to open surgical repair, aortic rupture, paraplegia, or retrograde type A aortic dissection.

CONCLUSION

The use of a pre-fenestration and branch stent-graft for the thoracic endovascular repair of zone 2 aortic lesions is a feasible and effective method for aortic arch branch revascularization. The risk of this surgical procedure is high, requiring significant expertise. The procedure should be conducted only in experienced centers. Durability concerns should be assessed in future studies with long-term follow-up.

Zone 1 Aortic Arch Hybrid Endovascular Repair with Extra-anatomical Bypass: A Meta-analysis

BACKGROUND

The aim of this meta-analysis is to determine the morbidity and mortality outcomes of adult patients with aortic arch disease managed with extra-anatomical bypass avoiding median sternotomy and cardiopulmonary bypass, with simultaneous or staged hybrid zone 1 endovascular aortic repair.

METHODS

Systematic literature searches of the MEDLINE, EMBASE, and Cochrane databases were carried out to identify relevant studies on zone 1 hybrid arch repair. Extracted data were analyzed by random effects models. Primary outcomes included 30-day or in-hospital mortality. Longitudinal survival was analyzed up to 7 years from date of operation. Secondary outcomes included in-hospital morbidity, as well as late endoleak and reintervention.

RESULTS

Twenty studies incorporating 348 patients were included. In-hospital or 30-day mortality was 10.1% (95% confidence interval, 6.7-14.9%). Overall operative technical success was 89.8% (83.7-93.8%). Early type 1 endoleak rate was 14.0% (7.4-24.7%). Stroke prevalence was 9.5% (6.1-14.3%). Spinal cord paraplegia prevalence was 3.8% (1.9-7.6%). Retrograde aortic dissection prevalence was 4.1% (1.5-10.6%). Survival at 1 year postoperatively was 77.2% (66.1-85.4%). Survival at 3 years postoperatively was 73.7% (59.2-84.4%). Survival beyond 4 years postoperatively (range 58-80 months) was 65.9% (53.6-76.4%). Late type 1 endoleak prevalence was 11.8% (5.5-23.7%). Overall rate of reintervention was 11.6% (6.4-20.1%).

CONCLUSIONS

Zone 1 hybrid repair has evidence for satisfactory short- and long-term morbidity/mortality outcomes and may be considered as an alternative approach to aortic arch disease.

Application of an extracorporeal prefenestrated stent graft in endovascular repair of ascending aorta and aortic arch lesions

OBJECTIVES

Aortic dissection involving the ascending aorta and aortic arch is a serious condition. Treatment using traditional surgical methods has certain disadvantages. This study investigated the effectiveness of thoracic endovascular repair of aortic dissection using an external prefenestrated stent.

METHODS

We present a series of aortic dissection cases involving the ascending aorta and aortic arch treated with an external prefenestrated stent.

RESULTS

Postoperative follow-up of the patients showed that all stents were released at the proper position and that branch vessels were not occluded, and there were no instances of type I endoleak. One patient died suddenly one week after surgery; another experienced retrograde type A aortic dissection in the second week; and type I endoleak occurred in one patient in the first week, although this resolved within six months. No serious complications such as cerebrovascular events, acute spinal cord ischemia, and paraplegia occurred during the perioperative period. All patients had false lumen thrombosis in the ascending aorta and aortic arch.

CONCLUSION

Prefenestrated stent grafting is a feasible treatment option for repairing an entry tear in the ascending aorta.

Intravenous hydrogen sulfide does not induce neuroprotection after aortic balloon occlusion-induced spinal cord ischemia/reperfusion injury in a human-like porcine model of ubiquitous arteriosclerosis

Objective

In rodents, intravenous sulfide protected against spinal cord ischemia/reperfusion (I/R) injury during aortic balloon occlusion. We investigated the effect of intravenous sulfide on aortic occlusion-induced porcine spinal cord I/R injury.

Methods

Anesthetized and mechanically ventilated “familial hypercholesterolemia Bretoncelles Meishan” (FBM) pigs with high-fat-diet-induced hypercholesterolemia and atherosclerosis were randomized to receive either intravenous sodium sulfide 2 h (initial bolus, 0.2 mg kg body weight (bw)⁻¹; infusion, 2 mg kg bw⁻¹ h⁻¹; n = 4) or vehicle (sodium chloride, n = 4) prior to 45 min of thoracic aortic balloon occlusion and for 8 h during reperfusion (infusion, 1 mg kg bw⁻¹ h⁻¹). During reperfusion, noradrenaline was titrated to maintain blood pressure at above 80% of the baseline level. Spinal cord function was assessed by motor evoked potentials (MEPs) and lower limb reflexes using a modified Tarlov score. Spinal cord tissue damage was evaluated in tissue collected at the end of experiment using hematoxylin and eosin and Nissl staining.

Results

A balloon occlusion time of 45 min resulted in marked ischemic neuron damage (mean of 16% damaged motoneurons in the anterior horn of all thoracic motor neurons) in the spinal cord. In the vehicle group, only one animal recovered partial neuronal function with regain of MEPs and link motions at each time point after deflating. All other animals completely lost neuronal functions. The intravenous application of sodium sulfide did not prevent neuronal cell injury and did not confer to functional recovery.

Conclusion

In a porcine model of I/R injury of the spinal cord, treatment with intravenous sodium sulfide had no protective effect in animals with a pre-existing arteriosclerosis.