Arkadiusz Kazimierczak

Electrical Potentials between Stent-grafts Made from Different Metals Induce Negligible Corrosion

OBJECTIVE Evaluation of the risk of galvanic corrosion in various stent-grafts in current practice, when devices with unmatched alloy compositions are deployed together. METHOD Five nitinol (NT) and two steel (SS) stent-grafts produced by different companies were used in different combinations to create 21 samples (NT:NT, n = 10; NT:SS, n = 10; SS:SS, n = 1). Electric potential was measured between the metal couplings after immersion in 0.9% NaCl at a temperature of 37 °C. Subsequently, the same samples were incubated for 24 months in 0.9% NaCl at 37-39 °C under hermetic conditions and examined under a scanning electron microscope in order to search for any evidence of corrosion. RESULTS Electric potentials between different metals alloys were found (means: NT:SS, 181 μV; NT:NT, 101 μV; SS:SS, 160 μV). The mean electrical potential between stainless steel and nitinol samples was significantly higher than between NT:NT couplings (p < .001). During the final scanning electron microscope examination, only one spot of pitting corrosion (>10 μm) on a nitinol surface was found (associated with previous mechanical damage) in an NT:SS sample after 24 months of incubation in vitro and no sign of mechanical failure of the wires was found. CONCLUSION Direct contact between the stainless steel and the nitinol alloys does indeed create electrical potential but with a minimal risk of galvanic corrosion. No evidence was found for significant galvanic corrosion when two endovascular implants (stent-grafts) made from different metal composition were used in the same procedure.

A 3-Dimensional Printed Aortic Arch Template to Facilitate the Creation of Physician-Modified Stent-Grafts

Purpose: To demonstrate the utility of a 3-dimensional (3D) printed template of the aortic arch in the construction of a fenestrated and scalloped physician-modified stent-graft (PMSG). Case Report: A 73-year-old woman with descending thoracic aneurysm was scheduled for thoracic endovascular aortic repair after being disqualified for open surgery. Computed tomography angiography (CTA) revealed no proximal landing zone as the aneurysm began from the level of the left subclavian artery, so a fenestrated/scalloped PMSG was planned. To facilitate accurate placement of the openings in the graft, a 3D printed aortic arch template was prepared from the CTA data and gas sterilized. In the operating room, a Valiant stent-graft was inserted into the 3D printed template and deployed. Using ophthalmic cautery, a fenestration and a scallop were created; radiopaque markers were added. The PMSG was successfully deployed with no discrepancy between the openings and the target vessels. Conclusion: A 3D printed aortic arch template facilitates handmade fenestrations and scallops in PMSGs and may improve accuracy and quality.

Association between Asymptomatic Unilateral Internal Carotid Artery Stenosis and Electrophysiological Function of the Retina and Optic Nerve

Purpose. This study was designed to assess retinal and optic nerve bioelectrical function in patients with unilateral asymptomatic but hemodynamically significant internal carotid artery stenosis (ICAS). Methods. Forty-two subjects with a diagnosis of unilateral ICAS and 34 controls were analyzed. Full-field electroretinogram (ERG), pattern electroretinogram (PERG), and pattern visual-evoked potentials, as well as optical coherence tomography and ophthalmological examination, were performed. Data analysis included eyes ipsilateral to ICAS (EIS) and eyes contralateral to ICAS (ECS). Results. Intraocular pressure was significantly decreased in EIS and ECS compared to that in the controls. In the macula, both the cube average thickness and cube volume values were significantly reduced both in EIS and ECS compared to those in the controls. Similarly, PERG P50 and N95 wave amplitudes were significantly smaller in EIS and ECS compared to those in the controls. The ERG rod b-wave and rod-cone a-wave amplitudes were decreased, and implicit times were significantly prolonged, whereas the OP wave index was reduced in EIS compared to that in the controls. No differences in IOP, OCT, or ERG and PERG parameters were identified between EIS and ECS. Conclusions. Our study demonstrated that retinal bioelectrical function is negatively affected by ICAS despite the absence of objective clinical signs and symptoms of ocular ischemia.

The blood flow channel index as novel predictor of abdominal aortic aneurysm impending rupture based on the intraluminal thrombus angio-CT study

OBJECTIVE In this study the hypothesis that the thickness of the thinnest part of the thrombus, combined with bleeding into the intraluminal thrombus (ILT), is associated with a possible higher risk of abdominal aortic aneurysm (AAA) rupture was investigated, independently of aneurysm diameter, by using angio-CT. This article describes blood flow channel index based on the CT imaging findings that may help identify impending rupture prior to complete rupture. METHODS Computed tomographic images of 310 hospitalized patients with infrarenal AAA, were collected over a three-year period. They were divided into two main groups: 125 with bleeding into the ILT and control group 185 without the presence of blood in the thrombus. Patients were also analyzed in subgroups with ruptured, symptomatic and asymptomatic AAAs. A blood flow channel index was formulated as: maximal/minimal thickness ratio of thrombus from the same CT scan. RESULTS In dissected ILT group blood flow channel index was over a twofold higher than in group with intact ILT (19.0 [1.2-89.3] vs. (9.7 [1.3-38.9]; p<0.001), respectively. Median thickness at the thinnest part of the ILT in dissected thrombus group was lower (1.3mm [0.3-16.0]) than in group with intact ILT (1.7 mm [0.2-23.4]; p<0.003). CONCLUSION An association between a high blood flow channel index and bleeding into the ILT based on angio-CT study was demonstrated, and can suggest the aneurysm propensity for rupture.

Cosmetic effects of skin-crease camouflage incision versus longitudinal incision following carotid endarterectomy

Introduction Despite the increasing use of carotid angioplasty and stenting (CAS), carotid endarterectomy (CEA) nonetheless remains a more medically beneficial method of treatment for carotid artery stenosis. Therefore, one possibility for progress within this procedure may be to use minimally invasive carotid surgery, especially when the scar is in plain sight: the use of the natural wrinkles (skin crease) as a camouflage of the skin incision provides significant cosmetic improvements. Aim To compare the cosmetic effects of classic and trans-wrinkle CEA. To assess the distance between the carotid artery bifurcation (CAB) and the skin-crease incision whilst attempting CEA. Material and methods It was a randomized prospective study with two groups: patients undergoing classic surgery (control group; n = 100) and skin-crease trans-wrinkle camouflaged CEA (study group; n = 100). Follow-up was at 2 months and 1 year. Results The medical results of the treatment were similar in both groups. The cumulative count of strokes and myocardial infarctions was 0.5% within 30 days, and after one year 3.5% (and 5.5% including cases of death). The superiority of the transverse crease being hidden compared to the conventional longitudinal technique was proven in the Patient and Observer Scar Assessment Scale (POSAS) score, respectively 11.4 ±1.0 vs. 14.1 ±3.4 (p = 0.0001) after 2 months and 13.5 ±2.8 vs. 14.1 ±3.4 (p = 0.039) after a year. Conclusions Trans-wrinkle incision gives better cosmetic results, can be safely performed in most cases, and offers a comfortable approach during CEA.

Relationship between aortic wall oxidative stress/proteolytic enzyme expression and intraluminal thrombus thickness indicates a novel pathomechanism in the progression of human abdominal aortic aneurysm

The possibility that oxidative stress promotes degradation of the extracellular matrix and a relationship between intraluminal thrombus (ILT) thickness and proteolytic activity within the abdominal aortic aneurysm (AAA) wall has been suggested. In the present study, the hypothesis that thin ILT is correlated with an increase in oxidative stress–related enzymes and matrix metalloproteinase‐9 (MMP‐9) expression within the human AAA wall was investigated. We also studied the antioxidant activity of superoxide dismutases, catalase, glutathione peroxidase, glutathione reductase, and thioredoxin within the full‐thickness AAA wall and through fluoroimmunohistochemical staining of catalase and MMP‐9 expression within the inner and outer media, in relation to ILT thickness. Reactive oxygen species control the degradation and remodeling of the extracellular matrix by up‐regulating proteolytic enzymes, such as MMPs. Results showed that oxidative stress and proteolytic enzyme expression were simultaneously, significantly higher within thin thrombus (≤10 mm)‐covered aneurysm wall when compared with the wall covered by thick thrombus (≥25 mm). These findings provide the first demonstration, to our knowledge, of a causative link between oxidative stress instigating proteolytic enzyme expression at the tissue level and human AAA development. Presence of a thin circumferential thrombus should always be considered as a risk factor for the greatest increase in aneurysm growth rate and rupture, giving an indication for surgery timing.—Wiernicki, I., Parafiniuk, M., Kolasa‐Wołosiuk, A., Gutowska, I., Kazimierczak, A., Clark, J., Baranowska‐Bosiacka, I., Szumilowicz, P., Gutowski, P. Relationship between aortic wall oxidative stress/proteolytic enzyme expression and intraluminal thrombus thickness indicates a novel pathomechanism in the progression of human abdominal aortic aneurysm. FASEB J. 33, 885–895 (2019). www.fasebj.org

A 3D Printed Aortic Arch Template to Facilitate Decision-Making Regarding the Use of an Externalized Transapical Wire during Thoracic Endovascular Aneurysm Repair

Thoracic endovascular aortic repair (TEVAR) is an established treatment option, although some anatomical challenges require a through-and-through wire technique, and subsequently transapical access via minithoracotomy can be required. It is clear that an objective tool to facilitate decision-making is needed. A 3D print of a severely angulated aortic arch was used as a template to advance a stent graft, and this was achieved after pulling the top of the wire. This simulation assisted in decision-making relating to transapical access with a wire externalization. A 3D aortic print could be used in advance to simulate the TEVAR procedure and facilitate any other decisions regarding additional transapical access.

An unusual case of aortic rupture after deployment of a bare stent in the treatment of aortic dissection in a patient with giant-cell arteritis

Giant-cell arteritis is associated with a higher risk of aortic aneurysm and aortic dissection formation. We present a women with aortic dissection type B treated with a stent graft and bare-metal stent implantation. After the stent deployment we noticed aortic rupture, which was successfully treated with implantation of an additional stent graft. This report highlights the difficulty of endovascular therapy in patients with giant-cell arteritis. We have to bear in mind that chronic inflammation of the aorta leads to a more fragile aortic wall than normal. We recommend the use of a stent graft over a bare-metal stent and gentle use of a balloon catheter.

Significant changes in combined consistent biomarkers and CTAngiography revealed during an interval of 6 months before abdominal aortic aneurysm rupture

The most commonly used predictor of rupture of abdominal aortic aneurysm (AAA) is the diameter, but this does not correlate well with the risk of rupture. Therefore, in order to make further improvements in clinical decisions regarding AAA patients, the development of additional predictive tools other than aneurysm size alone is needed. We herein report a case of a 72-year-old man with AAA that underwent rupture transformation during six months. We review the morphological features changes detected by computed tomography and also observe several alters circulating biomarkers at the same time. In the study presented essentially an association of those combined parameters with the risk of AAA impending rupture.

JATROGENNY TĘTNIAK RZEKOMY TĘTNICY RAMIENNEJ U CZTEROMIESIĘCZNEGO DZIECKA – OPIS PRZYPADKU

We present a rare case of an iatrogenic pseudoaneurysm of the brachial artery in a 4-month-old child. As there are reports of such lesions in children that undergo invasive treatment such as sophisticated cardiovascular or radiological interventions and have preexisting risk factors, our patients had no history of vessel caniulation in hospital conditions and no systemic problems. A simple ambulatory blood draw caused a tear in the brachial artery wall, that later formed a pseudoaneurysm, a month before parents suddenly noticed mass on their child’s arm. A microsurgical repair was performed. A significant increase in endovascular treatment options has been observed over last decades. Successful treatment was a result of fast radiological diagnostic and effective co-operation between paediatric and general vascular surgeons. Our case should raise awareness of paediatric practitioners about iatrogenic trauma of vessels in the differential diagnosis of tumours and vascular lesions.