Histological mapping of porcine carotid arteries - An animal model for the assessment of artificial conduits suitable for coronary bypass grafting in humans.

BACKGROUND: Using animal models in experimental medicine requires mapping of their anatomical variability. Porcine common carotid arteries (CCA) are often preferred for the preclinical testing of vascular grafts due to their anatomical and physiological similarity to human small-diameter arteries. Comparing the microscopic structure of animal model organs to their human counterparts reveals the benefits and limitations of translational medicine. METHODS: Using quantitative histology and stereology, we performed an extensive mapping of the regional proximodistal differences in the fractions of elastin, collagen, and smooth muscle actin as well as the intima-media and wall thicknesses among 404 segments (every 1 cm) of porcine CCAs collected from male and female pigs (n = 21). We also compared the microscopic structure of porcine CCAs with segments of human coronary arteries and one of the preferred arterial conduits used for the coronary artery bypass grafting (CABG), namely, the internal thoracic artery (ITA) (n = 21 human cadavers). RESULTS: The results showed that the histological structure of left and right porcine CCA can be considered equivalent, provided that gross anatomical variations of the regular branching patterns are excluded. The proximal elastic carotid (51.2% elastin, 4.2% collagen, and 37.2% actin) transitioned to more muscular middle segments (23.5% elastin, 4.9% collagen, 54.3% actin) at the range of 2-3 centimeters and then to even more muscular distal segments (17.2% elastin, 4.9% collagen, 64.0% actin). The resulting morphometric data set shows the biological variability of the artery and is made available for biomechanical modeling and for performing a power analysis and calculating the minimum number of samples per group when planning further experiments with this widely used large animal model. CONCLUSIONS: Comparison of porcine carotids with human coronary arteries and ITA revealed the benefits and the limitations of using porcine CCAs as a valid model for testing bioengineered small-diameter CABG vascular conduits. Morphometry of human coronary arteries and ITA provided more realistic data for tailoring multilayered artificial vascular prostheses and the ranges of values within which the conduits should be tested in the future. Despite their limitations, porcine CCAs remain a widely used and well-characterized large animal model that is available for a variety of experiments in vascular surgery.

Hybrid and frozen elephant trunk for total arch replacement in DeBakey type I dissection.

OBJECTIVE: The study objective was to determine whether hybrid aortic repair yields superior outcomes compared with the conventional surgical approach for DeBakey type I aortic dissection. METHODS: A retrospective analysis of patients with DeBakey type I dissection admitted to Fuwai Hospital between January 2010 and December 2016 showed that 815 patients (86.9%) underwent open total arch replacement with frozen elephant trunk (frozen elephant trunk group) and 122 (13.1%) underwent hybrid aortic arch repair without deep hypothermic circulatory arrest (hybrid group). We selected 109 pairs of patients for propensity score matching. Outcomes included early postoperative death, a composite of complications, dissected aorta remodeling, long-term survival, and freedom from reoperation. RESULTS: Early mortality and complication rates were lower in the hybrid group, but the difference was not statistically significant (9.2% vs 17.4%, P = .073; 15.6% vs 25.7%, P = .066). The rates of postoperative renal insufficiency was significantly lower in the hybrid group than in the frozen elephant trunk group (22.9% vs 38.5%, P = .013); liver insufficiency and paraplegia were significantly lower in the hybrid group than in the frozen elephant trunk group (20.2% vs 33.9%, P = .022; 0% vs 6.4%, P = .014). After matched, the 1-year, 3-year, and 5-year survivals were 87.6%, 86.3%, and 82.2%, respectively, in the hybrid group and 80.7%, 76.5%, and 74.6% (P = .071), respectively, in the frozen elephant trunk group. CONCLUSIONS: Hybrid aortic arch repair is a viable alternative treatment for patients with DeBakey type I aortic dissection, which improves outcomes and promotes remodeling of the dissected thoracic aorta.

[Effectiveness of biological prosthesis for femoro-femoral bypass in high risk patients]. / Éffektivnost' biologicheskogo proteza pri bedrenno-bedrennom shuntirovanii u lits s vysokim operatsionnym riskom.

AIM: To compare synthetic and biological prostheses for femoral bypass surgery. MATERIAL AND METHODS: There were 40 patients with critical ischemia of lower extremities due to atherosclerotic lesion of aorto-iliac segment and severe comorbidities. They were divided into 2 groups by 20 patients. C-shaped femoro-femoral bypass with synthetic polytetrafluoroethylene and lavsan prostheses was performed in the first group and S-shaped bypass procedure with biological prosthesis from the internal thoracic arteries of the bull - in the second group. RESULTS: Biological prosthesis is associated with reduced early postoperative morbidity by 10%, late graft thrombosis incidence by 20% and increased physical and psychological health by 7.1%. CONCLUSION: S-shaped femoro-femoral bypass with a biological prosthesis from the internal thoracic arteries of the bull is pathogenetically substantiated and effective.

[Method of forming a distal anastomosis with an autovenous cuff]. / Sposob formirovaniia distal'nogo anastomoza s autovenoznoi manzhetoi.

Presented herein is a brief review of the world literature dedicated to methods of formation of composite arterial anastomoses in the femoropopliteal-tibial region The most justified is considered the use of a composite shunt formed proximally from a synthetic vascular graft made of polytetrafluoroethylene and distally with an extension from a portion of the suitable for reconstruction autovein (the so-called autovenous cuff of patch). The use of an autovenous cuff is more physiological since it provides closer correspondence of the diameters of the distal anastomosis being applied between the artery and autovenous extension, as well as contributes to creation of more adequate haemodynamic conditions in the shunt. Also analysed is the technique of performing the previously suggested anastomoses, demonstrating their main disadvantages. This is followed by describing a new original method of formation of a distal anastomosis using an autovenous insert, showing its advantages, with the main amongst them being the presence of only two vascular sutures and a decrease in the possibility of the onset and development of turbulence in the zone of the anastomosis. A conclusion is drawn that the suggested method contributes to decreasing the duration of the main stage of the operation, decreases the probability of technical defects and reduces the risk for the development of postoperative complications associated with impairments of the processes of haemodynamics in the zone of the anastomosis formed.

[In situ aortofemoral reconstructions in surgical treatment of infected aortofemoral grafts].

The article presents a review of literature sources covering possibilities of peiforming in situ aortofemoral reconstructions in surgical treatment of infected aortofemoral grafts. This methodology makes it possible to improve the outcomes of treatment for paraprosthetic infection at the expense of decreasing lethality and morbidity, increasing parameters of patency of grafts and lower limb salvage in the remote postoperative period. Mention should be made that in situ secondary aortofemoral reconstructions are fraught with danger of relapsing paraprosthetic infection, therefore many publications are dedicated to search for prostheses most resistant to infection. The article also presents the results of works devoted to the use of various types of prostheses for in situ secondary aortofemoral reconstructions: prostheses made of polytetrafluoroethylene (PTFE), synthetic grafts saturated with various antibacterial drugs and gelatine, cadaveric allografts, synthetic prostheses treated with silver ions, autovenous conduits based on the femoral and popliteal veins.

[Efficiency of bioprosthesis in case of axillary-femoral bypass in patients with high operative risk].

It was analyzed the treatment results of 60 male patients with critical limb ischemia in case of atherosclerotic lesions of the aorta-iliac segment and severe somatic diseases. All patients were divided into 2 groups. Every group consisted 30 patients. The first group included axillary-femoral bypass by using of synthetic polytetrafluoroethylene prosthesis. The second group - by using of bioprosthesis of bull's internal thoracic arteries. Using of bioprosthesis allows to reduce early postoperative complications in intermediate postoperative period on 13.3%, late bypass thrombosis on 30%. Also there was elongation of average time of bypasses functioning in 1.8 times. Physical health was increased on 12.8%, mental - on 9.1%.

[Ways to improve patency of the femoral-popliteal-crural bypass grafts].

Chronic obliterating diseases of lower-limb arteries account for more than 20% of all manifestations of cardiovascular pathology. A surgical method of treatment for this pathology remains most effective. The types of operations below the inguinal fold currently used are as follows: bypass grafting, endarterectomy, and angioplasty. The vein is the material of choice and if it is not easily available allografts may be used. Differing elastic properties of the artery and prosthesis lead to progression of the neointima thus negatively affecting patency of bypass grafts. This article describes venous bypass grafts, their efficacy, methods of improving patency of allografts, as well as variants of combined operations.

[Surgical treatment of leiomyosarcoma of the inferior vena cava].

The presented review of the literature is generalization of the currently existing data of foreign and Russian literature concerning treatment of a rare non-organic retroperitoneal tumour from smooth-muscle tissue, i. e., leiomyosarcoma of the inferior vena cava. The authors also formulate and lay down the basic principles of surgical interventions depending on the scope and level of the lesion, as well statistical analysis of the outcomes of surgical management of the this severely ill patient cohort.

[Restenosis of carotid arteries after carotid endarterectomy: current aspects of the problem: (local and systemic risk factors). Part 1].

Carotid endarterectomy is currently the most effective surgical means of preventing ischaemic stroke. Despite the fact that this type of intervention is widely used, there seems to be no tendency toward decreased incidence of such a complication as restenosis of carotid arteries.The present review deals with the results of analyzing the literature on the problem concerning carotid artery restenosis after carotid endarterectomy. Considered herein are the problems of epidemiology and prevalence of the complication involved. Special attention is paid to local and systemic risk factors for the development of restenosis. Studying risk factors of restenosis after carotid endarterectomy is of considerable importance for both prevention and choice of pathogenetically targeted treatment of patients presenting with atherosclerotic lesions of brachiocephalic vessels.

Graft selection for aortic root replacement in complex active endocarditis: does it matter?

BACKGROUND: Endocarditis affecting the aortic valve, with abscess formation and root destruction, remains a challenge to treat. Aortic root homografts have been advocated because of a perceived lower risk of infective complications than with other root replacement grafts. However, the theoretical advantage of homografts has not been re-evaluated in the modern era. This report is based on an examination of our results for all aortic root replacements in complex, active endocarditis affecting the aortic valve. METHODS: From 2000 to 2010, 134 patients (70.9% male; mean age 58.3±14.8 years) at our institution underwent aortic root replacement for active endocarditis. Ninety of the patients (67.2%) had a previously implanted prosthetic aortic valve. Our findings for these patients included one or more of the following: abscess (n=110, 82.1%), valve vegetation (n=98, 73.1%), and pseudoaneurysm or rupture or both (n=62, 46.3%). We retrospectively reviewed data for the patients from hospital records and the social security data base. RESULTS: A mechanical composite graft (MC) was used in 43 of the patients (32.1%), a non-homograft biologic valve conduit (BC) in 55 patients (41.0%), and a homograft (HG) valve in 36 patients (26.9%). There was no significant difference among the groups in the incidence of major complications or in-hospital mortality. During a mean follow-up of 32.1±29.4 months, the rates of readmission, reinfection, and reoperation were similar for the three groups. The mean 5-year survival in the study was 58±9% for the MC group, 62±7% for the BC group, and 58 ± 9% for the HG group, respectively (p=0.48). CONCLUSIONS: Aortic root replacement in the presence of complex active infection is associated with significant morbidity and mortality. We report that the rates of major complications and late mortality were similar among MC, BC, and HG groups in our study.

Endovascular repair of an aorto-iliac aneurysm succeeded by kidney transplantation / Tratamento endovascular de aneurisma aorto-ilíaco sucedido por transplante renal

We present the case of aorto-iliac aneurysm in a patient with chronic renal failure requiring dialysis who were treated with an endovascular stent graft and, later on, submitted to kidney transplantation. A 53-year-old male with renal failure requiring dialysis presented with an asymptomatic abdominal aorto-iliac aneurysm measuring 5.0cm of diameter. He was treated with endovascular repair technique, being used an endoprosthesis Excluder®. After four months, he was successfully submitted to kidney transplantation (dead donor), with anastomosis of the graft renal artery in the external iliac artery distal to the endoprosthesis. The magnetic resonance imaging, carried out 30 days after the procedure, showed a good positioning of the endoprosthesis and adequate perfusion of the renal graft. In the follow-up, the patient presented improvement of nitrogenous waste, good positioning of the endoprosthesis without migration or endoleak. The endovascular repair of aorto-iliac aneurysm in a patient with end-stage renal failure under hemodialysis treatment showed to be feasible, safe and efficient, as it did not prevent the success of the posterior kidney transplantation.

Apresentamos o caso de aneurisma aortoilíaco em um paciente com insuficiência renal crônica dialítica tratado com uma endoprótese vascular, sendo, após, submetido a transplante renal. Um homem de 53 anos com insuficiência renal dialítica apresentava um aneurisma abdominal aortoilíaco assintomático com 5,0cm de diâmetro. Foi tratado com técnica endovascular com uma endoprótese Excluderâ. Após quatro meses, foi submetido a transplante renal (doador cadáver) com sucesso, com anastomose da artéria renal do enxerto na artéria ilíaca externa distal à endoprótese. A ressonância magnética 30 dias após o procedimento mostrou a endoprótese bem posicionada e o enxerto renal bem perfundido. No seguimento, o paciente evoluiu com melhora das escórias nitrogenadas, bom posicionamento da endoprótese, sem migração ou endoleak. O reparo endovascular do aneurisma aortoilíaco em paciente com insuficiência renal terminal em hemodiálise mostrou-se exequível, seguro e eficaz, e não comprometeu o sucesso do transplante renal posterior.

Configurations and classifications of composite arterial grafts in coronary bypass surgery.

The aim of this review is to present the configurations and classifications of composite arterial grafts in coronary bypass surgery. Articles were collected by tracking references cited in the literature with regard to the configurations of composite arterial grafts in coronary bypass surgery. Figures of the configurations were drawn in accordance to the schematic drawings, angiograms, photographs, table contents or written captions of the literature. According to their structural nature, composite arterial grafts can be classified as: (i) alphabetical (Y, T, I, U, K, X and H) and (ii) complex grafts (TY, loop, pi and sling grafts). According to the conduits that form the composite graft, they can be classified as: (i) definite (all standard alphabetical grafts, classic pi and sling grafts); (ii) varying [internal mammary artery (IMA) loop, modified pi graft]; and (iii) indefinite conduit graft (TY graft). According to their application in coronary artery bypass grafting (CABG), they can be divided into complete arterial revascularization for: (i) triple vessel disease (T, Y, K, X, TY, pi and sling grafts); (ii) two vessel disease (U, right Y, and two-thirds right IMA T grafts); and (iii) single vessel disease, mainly the left anterior descending artery with or without the diagonal branch (H, I, IMA loop and left IMA T grafts). According to the CABG method, they can be classified as: (i) for conventional CABG (sling graft); (ii) for minimally invasive direct coronary artery bypass (H graft); and (iii) for both conventional CABG and off-pump coronary artery bypass (T, Y, U, K, I, TY, IMA loop, and pi grafts). Standard Y and T grafts have been accepted as the common figurations of composite arterial grafts to maximum graft length for the bypass of triple vessel disease. Composite arterial grafts overcome the limited availability of arterial conduits for performing total arterial myocardial revascularization, allow a gain in conduit length, and minimize the ascending aorta manipulation.

Estenosis de carótida interna. Tipos de stent empleados en el stenting carotídeo / No disponible

No disponible

The Valiant thoracic endograft.

Thoracic aortic pathology is common, but conventional surgery carries with it a significant risk of mortality and morbidity due to thoracotomy, extensive surgical dissection, partial left lung collapse, proximal aortic cross-clamping and blood loss necessary for open thoracic aortic replacement. Endovascular techniques have the potential to remove much of this harm. However, endograft delivery to the thoracic aorta brings its own challenges; the graft and delivery system must be conformable to follow the aortic arch, flexible to track through tortuous calcified vessels, of low profile for access through the iliac arteries, and deploy accurately and with minimal force to avoid accidental side branch occlusion. The endoprosthesis must also prove to be durable. This paper reviews current indications for thoracic aortic stent grafts and the properties of an ideal endograft for deployment in the arch and descending aorta. The Medtronic Valiant TM endoprosthesis with Xcelerant TM Delivery System is a third-generation system designed specifically for the treatment of a range of thoracic aortic pathologies, including but not exclusively, aneurysms and dissections. The design of the Valiant endoprosthesis and delivery system are described in detail, and compared to the second-generation Talent system. Our early experience of using Valiant in 28 patients with a range of pathologies is described. The graft achieved an initial technical success in 93% and was easy to position and deploy. Long-term data is now required; the Virtue Registry is a prospective multicenter European registry collecting clinical and health economics data on Valiant in the management of aortic dissections.

Reconstrucción endovascular con stents en el tratamiento de aneurismas cerebrales / Reconstruction endovascular stents in the treatment of brain aneurysms

Obejtivo: Presentamos nuestra experiencia clínica y los resultados del seguimiento a mediano plazo de las lesiones aneurismáticas complejas tratadas mediante stenting intracraneal. Material y Métodos: Entre junio de 1996 y junio del 2004, 259 pacientes con aneurisma complejos de la circulación cerebral fueron tratados mediante técnica de stenting intracraneal. Los pacientes se dividieron en dos grupos: 1.- Pacientes tratados con stents balón expandibles (SBE), 2.- Pacientes con stents auto-expandibles (SAE). Resultados: Grupo 1: fueron implantados 172 stents. El 50.5% de los casos fueron aneurismas pequeños; 32.5% grandes y 18.6% gigantes. El 33% se trató solo con stent, el 66% con stent y coils y el 1% con stent y Onyx. La morbilidad del procedimiento fue de 4.3% y la mortalidad del 2.1%. Grupo2: el 102 stents implantados: 55.8% pequeños, 31.3% grandes y 12.7% gigantes. En el 29.4% fueron tratados exclusivamente con stent y en el 70.5% con stent y coils. La morbilidad del procedimiento fue de 2.8% con una mortalidad del 2.7%. Conclusión: los resultados de nuestra serie indican que el tratamiento con stents es una técnica segura, factible y efectiva para la reconstrucción endovascular de lesiones aneurismáticas complejas, y defectos arteriales segmentarios, pudiéndose utilizar como único tratamiento o combinado con coils. La disponibilidad de stent diseñados para uso neurológico permite realizar satisfactoriamente el tratamiento endovascular sin importar la tortuosidad vascular.

[Aortic dissection type B with aortic arch involvement surgically treated--a case report]. / Rozwarstwienie aorty typu B z objeciem luku leczone operacyjnie.

A case of a 56-year-old male with acute aortic dissection type B is presented. The patient underwent successful surgery which was very difficult due to the extent of aortic dissection.

Use of stent grafts to repair hemodialysis graft-related pseudoaneurysms.

PURPOSE: To review the author's early experience with stent grafts to repair hemodialysis graft-related pseudoaneurysms. MATERIALS AND METHODS: Eleven patients had undergone insertion of a stent graft to repair a pseudoaneurysm arising from a PTFE hemodialysis graft. The study group consists of seven women and four men with a mean age of 50.7 years. The primary indications for stent graft placement were: rapid enlargement of a pseudoaneurysm in four patients, difficulty with cannulating the graft in two patients, high risk of acute rupture in three patients, persistent bleeding from the pseudoaneurysm in one patient, and one was incidentally discovered during diagnostic fistulography. In 10 of the 11 patients, the pseudoaneurysm arose from the arterial limb of a loop-configuration graft. A stent graft was successfully deployed in all patients. The radiological and surgical records were reviewed. RESULTS: The Viabahn endoprosthesis was successfully inserted and deployed in all 11 patients. Six patients underwent subsequent interventions, which ended primary patency at 39 days, 40 days, 63 days, 104 days, 120 days, and 327 days after insertion of the stent graft. However, no additional interventions have been performed in five patients and primary patency continues. In these five patients the interval of continuing primary patency is 55 days, 92 days, 103 days, 139 days, and 196 days. In this small group of patients the primary patency rate is 71% at 3 months and 20% at 6 months. DISCUSSION: Early experience has demonstrated that a stent graft can successfully exclude a pseudoaneurysm from a hemodialysis graft and may prevent further enlargement and decrease the likelihood of rupture. However, in two of these 11 patients, the large pseudoaneurysm remained problematic and required subsequent surgical repair.