Открытые и эндоваскулярные оперативные вмешательства при стенозе периферических отделов фистульных вен

Vascular access is the cornerstone of hemodialysis. With vascular access dysfunction, the results of treatment of patients with stage 5 chronic kidney disease significantly deteriorate. One of the most common causes of vascular access failure is peripheral venous stenosis. Despite the variety of initiating factors, the morphological substrate of stenotic damage to the arteriovenous fistula (or arteriovenous anastomosis) in most cases is neointimal hyperplasia. Stenotic lesions of the arterivenous fistula are strongly associated with an increased risk of thrombosis and loss of vascular access. There are 4 typical localizations of stenosis: arteriovenous or arteriograft anastomosis, stenosis of the juxta-anastomotic segment of the fistula, stenosis of the functional segment of the fistula, and stenosis of the cephalic arc.The most common indication for surgical treatment is vascular access failure; less common indications are clinical symptoms of venous insufficiency.There are various methods of open reconstruction of the stenotic segment of the fistula vein: resection, prosthetics with a synthetic vascular graft, prosthetics or plastic repair of the autologous vein wall, complete or partial drainage of the prestenotic segment of the vein, etc. Currently an alternative method of stenosis repair using endovascular interventions is gaining popularity. In contrast to central vein stenosis, where endovascular interventions are the gold standard, in peripheral vein stenosis it is only an adjuvant method. Complications of endovascular interventions are extremely rare.Despite the fact that endovascular interventions have almost absolute probability of technical success, the primary patency is not high and is about 50% in six months. The use of bare stents is not accompanied by an increase in primary patency. The use of stent-grafts can increase the primary patency, especially in the plastic repair of challenging stenoses of the graft-vein anastomosis or cephalic arch.Many issues related to endovascular interventions remain unresolved, which requires further research. Сосудистый доступ – краеугольный камень гемодиализа. При дисфункции сосудистого доступа значительно ухудшаются результаты лечения пациентов с хронической болезнью почек V стадии. Одной из наиболее частых причин дисфункции сосудистого доступа является стеноз периферического отдела фистульной вены. Несмотря на многообразие инициирующих факторов, морфологическим субстратом стенотического поражения фистульной вены (или артериовенозного анастомоза) в большинстве случаев является неоинтимальная гиперплазия. Стенотическое поражение фистульной вены сильно ассоциировано с повышенным риском тромбоза и утратой сосудистого доступа. Можно условно выделить четыре характерные локализации стеноза: артериовенозный или артериопротезный анастомоз, стеноз юкстаанастомотического сегмента фистульной вены, стеноз фистульной вены на протяжении «функционального» сегмента, стеноз «плечевой дуги».Показаниями к оперативному лечению в подавляющем большинстве случаев являются нарушение функции сосудистого доступа и гораздо реже – клиническая симптоматика венозной недостаточности.Известны различные методы открытой реконструкции стенозированного участка фистульной вены: резекция, протезирование синтетическим сосудистым протезом, протезирование или пластика стенки аутовеной, полное или частичное дренирование пристенотического сегмента вены и др. Постепенно набирает популярность альтернативный метод пластики стеноза при помощи эндоваскулярных вмешательств. В отличие от стенозов центральных вен, где эндоваскулярные вмешательства являются золотым стандартом, при стенозе периферических вен это лишь адъювантый метод. Осложнения при эндоваскулярных вмешательствах встречаются крайне редко.Несмотря на то, что эндоваскулярные вмешательства имеют практически абсолютную вероятность технического успеха, первичная проходимость невысока и составляет примерно 50% через полгода. Использование непокрытых стентов не сопровождается увеличением первичной проходимости. Применение стент-графтов позволяет увеличить первичную проходимость, особенно при пластике «проблемных» стенозов в области протезовенозного анастомоза и плечевой дуги.Множество вопросов, связанных с эндоваскулярными вмешательствами, остаются неразрешенными, что требует продолжения исследований в этом направлении.

Стеноз центральных вен и методы его лечения у больных на гемодиализе

There is no doubt that the optimal vascular access is arteriovenous fistula (AVF). However, the proportion of patients receiving hemodialysis using central venous catheters is very high. Largely due to this, the incidence of central venous stenosis (CVS) in this category of patients is one of the highest: the prevalence ranges from 2 to 40%. Against the background of functioning AVF from the ipsilateral side, CVS proceeds with much more pronounced symptoms than in the general population of patients with this pathology. There is no doubt that stenosis of the central veins is a precursor of AVF thrombosis, recurrent infections, reduction of blood flow in the limb in general and AVF in particular, and consequently - increase in recirculation and decrease in the effectiveness of HD. Endovascular surgery is the «gold standard» treatment for CVS. Technical success is at least 80-90% of the cases. As a rule, endovascular operations not only lead to the immediate reduction of symptoms of venous hypertension, but also allow the use of fistulas for hemodialysis in the near future after the intervention. At the same time, clinical success is achieved much less frequently. Primary patency in six months is about 50%, secondary patency in two years - 60-80%. The use of cutting balloon catheters may be associated with greater secondary patency than using standard balloon catheters, but slightly increases the risk of complications. An effective way to improve the results of CVS plastic is the use of stents, which allow to increase the patency after surgery. Indications for the primary use of stents is a debatable issue. However, stenting is undoubtedly effective in the case of rapid occurrence of recurrent stenosis or rigid stenosis and recoil immediately after surgery. In addition, one of the problems associated with the use of stents is the risk of their migration. This risk increases in patients with functioning AVF. Skepticism about the use of stents in patients on hemodialysis is also added by the fact that in randomized controlled studies, when comparing isolated balloon angioplasty and angioplasty using uncovered stents, there was no significant difference in the recurrence of stenosis. At the same time, the use of covered stents provides a significant increase in access survival. In addition, the use of drug-coated balloon catheters may provide some advantage over standard uncoated balloon catheters. Open surgical interventions have slightly better results in the treatment of CVS (annual primary patency of 80-90%) compared to endovascular methods. Nevertheless, open reconstructions are associated with a much greater risk of intra- and postoperative complications, in most cases require clavicle section or sternotomy, general anesthesia, and are associated with greater postoperative mortality. In this regard, percutaneous transluminal angioplasty is deservedly considered to be a common method of treatment of CVS. Open surgery can be used in case of unsuccessful attempts to resolve stenosis endovascular while maintaining a pronounced clinical symptoms. On the face of the fact that the available methods of treatment of this pathology in patients on hemodialysis with functioning vascular access do not fully meet the clinical needs. Currently, there is no consensus on many aspects of the use of endovascular interventions for the correction of vascular access dysfunction, which requires additional research.Общепризнано, что оптимальным сосудистым доступом является артериовенозная фистула (АВФ). Тем не менее доля больных, получающих гемодиализ с использованием центральных венозных катетеров, весьма высока. Во многом благодаря этому частота встречаемости стенозов центральных вен (СЦВ) у этой категории больных одна из самых высоких: распространенность колеблется в пределах от 2 до 40%. На фоне функционирующей АВФ с ипсилатеральной стороны стенозы центральных вен протекают со значительно более выраженной симптоматикой, чем в общей популяции больных с этой патологией. Нет сомнений в том, что стеноз центральных вен является предвестником тромбоза АВФ, рецидивирующих инфекций, снижения кровотока по конечности в целом и АВФ - в частности, а следовательно - увеличения рециркуляции и снижения эффективности ГД. «Золотым стандартом» лечения СЦВ являются эндоваскулярные хирургические вмешательства. Технический успех составляет как минимум 80-90% случаев. Как правило, эндоваскулярные операции не только приводят к немедленному разрешению симптоматики венозной гипертензии, но и позволяют использовать фистульную вену для гемодиализа в ближайшие сроки после вмешательства. В то же время клинический успех достигается значительно реже. Первичная проходимость через полгода составляет примерно 50%, вторичная проходимость через два года - 60-80%. Использование режущих баллонов может быть ассоциировано с большей вторичной проходимостью по сравнению с использованием стандартных баллонных катетеров, но несколько повышает риск осложнений. Эффективным способом улучшения результатов пластики СЦВ является использование стентов, которые позволяют увеличить показатели проходимости после операции. Показания для первичного использования стентов - вопрос дискутабельный. Однако стентирование бесспорно эффективно в случае быстрого возникновения возвратного стеноза или ригидного стеноза и рекойла (recoil) сразу после операции. Помимо этого, одной из проблем, связанных с применением стентов, является опасность их миграции. Этот риск возрастает у больных с функционирующей АВФ. Скепсиса в отношении использования стентов у больных на гемодиализе также добавляет тот факт, что в рандомизированных контролируемых исследованиях при сравнении изолированной баллонной ангиопластики и ангиопластики с использованием непокрытых стентов достоверной разницы в рецидивировании стеноза не выявлено. В то же время использование покрытых стентов дает значимое увеличение выживаемости доступа. Кроме того, использование баллонных катетеров с лекарственным покрытием может обеспечить некоторое преимущество по сравнению со стандартными баллонами. Открытые хирургические вмешательства имеют несколько лучшие результаты лечения СЦВ (годовая первичная проходимость 80-90%) по сравнению с эндоваскулярными методами. Тем не менее открытые реконструкции сопряжены со значительно большим риском интра- и послеоперационных осложнений, в большинстве случаев требуют пересечения ключицы или стернотомии, наркоза, а также сопряжены с большей послеоперационной летальностью. В связи с этим общепринятым методом лечения стеноза центральных вен заслуженно считается чрескожная транслюминальная ангиопластика. Открытые оперативные вмешательства могут применяться в случае безуспешных попыток разрешить стеноз эндоваскулярно при сохранении выраженной клинической симптоматики. Налицо факт того, что имеющиеся методы лечения этой патологии у пациентов на гемодиализе с функционирующим сосудистым доступом не в полной мере удовлетворяют клинические потребности. В настоящее время нет единого мнения относительно многих аспектов применения эндоваскулярных вмешательств для коррекции дисфункции постоянного сосудистого доступа, что требует проведения дополнительных исследований

Неоднозначные результаты баллонной ангиопластики при стенозах центральных вен у пациентов на гемодиализе с нативной артериовенозной фистулой

Objective: to conduct comprehensive comparative analysis of the patency rate of native arteriovenous fistula (AVF) for central vein stenosis (CVS) after endovascular balloon angioplasty and palliative surgery. Materials and methods. The retrospective study included 80 patients with confirmed central vein stenosis: subclavian, brachiocephalic veins, inferior vena cava, or multiple lesions. The experimental group included 39 patients who underwent percutaneous balloon angioplasty. The control group included 41 patients who, for various reasons, did not do balloon angioplasty, but underwent palliative interventions: thrombectomy, proximalization of arteriovenous anastomosis, AVF blood flow-reducing surgical procedures. Results. Primary patency (time interval between the first intervention for CVS and the second intervention) in the experimental group was 61.5% [95% CI 44.5; 74.7] and 15.4% [95% CI 6.2; 28.3] at 6 and 12 months, respectively. In the control group, it was 39% [95% CI 24.3; 53.4] and 0% respectively. Hazard ratio (HR) 0.5337 [95% CI 0.3381; 0.8427], log-rank test p = 0.0011. No differences in functional primary patency (time interval between the start of using AVF and the first intervention for CVS) were found: 89.7% [95% CI 74.9; 96] and 30.8% [95% CI 17.3; 45.4] at 1 year and 3 years, respectively, in the experimental group, and 80.5% [95% CI 64.8; 89.7] and 24.4% [95% CI 12.7; 38.2] in the control group. There were no differences between the groups HR 0.7695 [95% CI 0.4952; 1.196], log-rank p = 0.2259. In the experimental group, strong negative correlation between primary patency and functional primary patency was detected: r = –0.627 [95% CI –0.787; –0.388], p < 0.0001. In the control group, no such correlation was found: r = 0.049 [95% CI –0.262; –0.351], p = 0.7599. Thus, the later CVS developed, the less effective balloon angioplasty was. Balloon angioplasty significantly increased duration of AVF use after first intervention for CVS (secondary patency): 84.6% [95% CI 68.9; 92.8], 66.7% [95% CI 49.6; 79.1] and 17.9% [95% CI 7.9; 31.3] at 6, 12 and 24 months, respectively in the experimental group. In the control group, it was 56.1% [95% CI 39.7; 69.6], 19.5% [95% CI 9.2; 32.7] and 0%. HR 0.4009 [95% CI 0.2481; 0.6477], log-rank p < 0.0001. Functional secondary patency (total duration of AVF use) was: 100%, 74.4% [95% CI 57.6; 85.3] and 12.8% [95% CI 4.7; 25.2] at 1, 3 and 5 years in the experimental group, and 95.1% [95% CI 81.9; 98.8], 36.6% [95% CI 22.3; 51] and 4.9% [95% CI 0.9; 14.5] in the control group. HR 0.5661 [95% CI 0.3598; 0.8906], log-rank p = 0.0067. Conclusions. 1. Central vein stenosis inevitably cuts vascular access from the ipsilateral side. 2. Balloon angioplasty allows to slightly prolong AVF use but it cannot radically change the long-term results of CVS treatment. 3. The outcome of balloon angioplasty greatly depends on the length of the period from the time the use of AVF started to the time CVS developed. 4. Multiple repeated balloon angioplasties are apparently justified in patients for whom creating a new vascular access might not be possible. 4. AVF volumetric blood flow velocity is an important factor determining the severity of CVS clinical manifestations and whether repeated surgical interventions are needed.Цель: провести комплексный сравнительный анализ показателей проходимости нативной артериовенозной фистулы (АВФ) при стенозе центральных вен (СЦВ) после эндоваскулярной баллонной ангиопластики и паллиативных оперативных вмешательств. Материалы и методы. В ретроспективное исследование включены 80 пациентов с подтвержденным стенозом центральных вен: подключичных, брахиоцефальных вен, нижней полой вены или множественным поражением. К основной группе были отнесены 39 пациентов, у которых выполнена чрескожная баллонная ангиопластика. К группе сравнения были отнесены 41 пациент, у которых по различным причинам баллонная ангиопластика не выполнялась, а проводились паллиативные вмешательства: тромбэктомия, проксимализация артериовенозного анастомоза, редукция кровотока по АВФ. Результаты. Первичная проходимость (интервал времени между первым вмешательством по поводу СЦВ и повторным вмешательством) составила 61,5% [95%ДИ 44,5; 74,7] и 15,4% [95%ДИ 6,2; 28,3] через 6 и 12 месяцев соответственно в основной группе, 39% [95%ДИ 24,3; 53,4] и 0% – в группе сравнения, HR 0,5337 [95%ДИ 0,3381; 0,8427], log-rank p = 0,0011. Мы не отметили различий в функциональной первичной проходимости (интервал времени между началом использования АВФ и первым вмешательством по поводу СЦВ): 89,7% [95%ДИ 74,9; 96] и 30,8% [95%ДИ 17,3; 45,4] через год и три года соответственно в основной группе, 80,5% [95%ДИ 64,8; 89,7] и 24,4% [95%ДИ 12,7; 38,2] – в группе сравнения. Различий между группами не было, HR 0,7695 [95%ДИ 0,4952; 1,196], log-rank p = 0,2259. В основной группе между первичной проходимостью и функциональной первичной проходимостью выявлена сильная отрицательная связь: r = –0,627 [95%ДИ –0,787; –0,388], p < 0,0001. В группе сравнения такой зависимости не выявлено: r = 0,049 [95%ДИ –0,262; –0,351], p = 0,7599. Таким образом, чем позднее развился СЦВ, тем меньше была эффективность баллонной ангиопластики. Баллонная ангиопластика позволила значительно увеличить продолжительность использования АВФ после первой операции по поводу СЦВ (вторичная проходимость): 84,6% [95%ДИ 68,9; 92,8], 66,7% [95%ДИ 49,6; 79,1] и 17,9% [95%ДИ 7,9; 31,3] через 6 и 12 и 24 месяца соответственно в основной группе, 56,1% [95%ДИ 39,7; 69,6], 19,5% [95%ДИ 9,2; 32,7] и 0% – в группе сравнения, HR 0,4009 [95%ДИ 0,2481; 0,6477], log-rank p < 0,0001. Функциональная вторичная проходимость составила (общая продолжительность использования АВФ): 100%, 74,4% [95%ДИ 57,6; 85,3] и 12,8% [95%ДИ 4,7; 25,2] через один, три и пять лет в основной группе, 95,1% [95%ДИ 81,9; 98,8], 36,6% [95%ДИ 22,3; 51] и 4,9% [95%ДИ 0,9; 14,5] – в группе сравнения, HR 0,5661 [95%ДИ 0,3598; 0,8906], log-rank p = 0,0067. Выводы. 1. Стеноз центральных вен неизбежно приводит к утрате сосудистого доступа с ипсилатеральной стороны. 2. Баллонная ангиопластика позволяет несколько продлить период использования АВФ, не способна радикально изменить долгосрочные результаты течения СЦВ. 3. На результаты баллонной ангиопластики значительное влияние оказывает продолжительность периода от момента начала использования АВФ до развития СЦВ. 4. Многократные повторные баллонные ангиопластики, по-видимому, оправданы у пациентов, возможность создания нового устойчивого сосудистого доступа у которых сомнительна. 4. Объемная скорость кровотока по АВФ является важным фактором, определяющим выраженность клинических проявлений СЦВ и потребность в повторных оперативных вмешательствах

Сосудистый доступ и выживаемость пациентов на гемодиализе: особенности причинно-следственной связи

Aim: to analyze features of the causal relationship between the vascular access type at the time of hemodialysis (HD) start and survival rates of patients, taking into account the cause of chronic kidney disease (CKD) and comorbidity.Materials and methods. The retrospective analysis included 604 HD patients divided into three groups: «AVF» (n = 336) patients started and continued HD with AVF; «CVC-AVF» (n = 152) patients started HD with CVC and later successfully converted to AVF; «CVC» (n = 116) patients who started and continued HD with CVC only. Patients with other types of conversions were not included in the analysis. The mean follow-up period since the beginning of HD was 38 [interquartile range 19; 48] months.Results. Unadjusted survival rate after 5 years in the AVF group was 61% [95%CI 51.8; 71.9], that in the CVC-AVF group - 53.9% [95%CI 42.5; 67], and that in the CVC group - 31.6% [95% CI 21.4; 41.4]. Survival rate in the CVC group varied from that in the AVF (p < 0.0001) and CVC-AVF (p < 0.0001) groups. CVC-AVF and CVC groups patients had significantly worse comorbidity than that of AVF group patients. After adjustment for comorbidity, age, sex, and cause of CKD, the survival rate in the groups after 5 years came to the following: 56.7% [95%CI 51.1; 62.8] in the AVF group, 51.7% [95%CI 42.5; 61.7] in the CVC-AVF group, 33.3% [95%CI 24; 42.8] in the CVC group. The results in the AVF group differed significantly from that in the CVC group (p < 0.001), but not from that in the CVC-AVF group (p = 0.425). The results in the CVC-AVF group are also statistically significantly varied from that in the CVC group (p = 0.009). Diabetes mellitus and systemic diseases were important risk factors. In the 5 years’ time period the survival rate of the group of patients with diabetes mellitus within in the AVF group adjusted (for sex, age, cause of CKD and comorbidity) was 38.1% [95% CI 29; 47.1], that in the CVC-AVF group - 29.7% [95% CI 18.9; 41.2] and that in the CVC group - 20.3% [95% CI 11.6; 31.8]. The results in the AVF group statistically significantly differed from that in the CVC group (p = 0.001), and from that in the CVC-AVF group (p = 0.011). The results in the CVC-AVF group are also statistically significantly varied from that in the CVC group (p = 0.021). In the 5 years’ time period the adjusted survival rate within the patients in the AVF group with systemic processes, was 34.2% [95% CI 18.8; 50.3], that in the CVC-AVF group - 23.9% [95% CI 10.5; 40.3], and that in the CVC group - 20.5 % [95% CI 7.3; 38.5]. We did not note statistically significant differences between the groups (p > 0.05 in all cases).Conclusion. The HD beginning with the use of CVC does not increase the risk of death in case of successful conversion to AVF. The use of CVC as the only vascular access is associated with a significant increase in the adjusted risk of death. Within the patients with diabetes mellitus, the use of CVC is associated with a deterioration of the adjusted survival rate even with subsequent successful conversion to functional AVF. Patients with systemic processes (vasculitis, myeloma, HIV-associated nephropathy, renal neoplasms, etc.) have low predicted survival rate disregarding the type of vascular access (there are no significant differences between the types of vascular access). The differences in survival rates are determined not only by the types of vascular access, but also by the comorbid background.Цель: проанализировать особенности причинно-следственной связи типа сосудистого доступа на момент начала гемодиализа (ГД) и выживаемости пациентов с учетом причины хронической болезни почек (ХБП) и коморбидного фона.Материалы и методы. В ретроспективный анализ было включено 604 пациента на программном гемодиализе, которые были разделены на три группы: «АВФ» (n = 336) - пациенты, начавшие и продолжившие ГД с использованием АВФ; «ЦВК-АВФ» (n = 152) - пациенты, начавшие ГД с использованием ЦВК с последующей успешной конверсией на АВФ; «ЦВК» (n = 116) - пациенты, начавшие и продолжившие ГД с использованием ЦВК. Пациенты с иными видами конверсий не включались в анализ. Средний период наблюдения с момента начала ГД составил 38 [интерквартильный размах 19; 48] месяцев.Результаты. Нескорректированная выживаемость через 5 лет в группе «АВФ» была 61% [95% ДИ 51,8; 71,9], в группе «ЦВК-АВФ» - 53,9% [95% ДИ 42,5; 67], в группе «ЦВК» - 31,6% [95% ДИ 21,4; 41,4]. Выживаемость в группе «ЦВК» отличалась от групп «АВФ» (р < 0,0001) и «ЦВК-АВФ» (р < 0,0001). Пациенты групп «ЦВК-АВФ» и «ЦВК» имели значительно худший коморбидный фон, чем больные группы «АВФ». После коррекции на коморбидность, возраст, пол и причину ХБН выживаемость в группах через 5 лет была: в группе «АВФ» - 56,7% [95% ДИ 51,1; 62,8], в группе «ЦВК-АВФ» - 51,7% [95% ДИ 42,5; 61,7], в группе «ЦВК» - 33,3% [95% ДИ 24; 42,8]. Группа «АВФ» статистически значимо отличалась от группы «ЦВК» (р < 0,001), но не группы «ЦВК-АВФ» (р = 0,425). Группа «ЦВК-АВФ» также статистически значимо отличалась от группы «ЦВК» (р = 0,009). Важными факторами риска были сахарный диабет и системные заболевания. У больных сахарным диабетом через 5 лет скорректированная (на пол, возраст, причину ХБП и коморбидность) выживаемость в группе АВФ была 38,1% [95% ДИ 29; 47,1], в группе «ЦВК-АВФ» - 29,7% [95% ДИ 18,9; 41,2], в группе «ЦВК» - 20,3% [95% ДИ 11,6; 31,8]. Группа «АВФ» статистически значимо отличалась от группы «ЦВК» (р = 0,001), а также от группы «ЦВК-АВФ» (р = 0,011). Группа «ЦВК-АВФ» также статистически значимо отличалась от группы «ЦВК» (р = 0,021). У больных с системными процессами через 5 лет скорректированная выживаемость в группе АВФ была 34,2% [95% ДИ 18,8; 50,3], в группе «ЦВК-АВФ» - 23,9% [95% ДИ 10,5; 40,3], в группе «ЦВК» - 20,5% [95% ДИ 7,3; 38,5]. Мы не отметили статистически значимых различий между группами (р > 0,05 во всех случаях).Заключение. Начало ГД с использованием ЦВК не ухудшает прогноз при условии последующей успешной конверсии на АВФ. Использование ЦВК в качестве единственного сосудистого доступа ассоциировано со значительным повышением скорректированного риска смерти. У больных сахарным диабетом использование ЦВК ассоциировано с ухудшением скорректированной выживаемости даже при условии последующей успешной конверсии на функциональную АВФ. У больных с системными процессами (васкулиты, миеломная болезнь, ВИЧ-ассоциированная нефропатия, новобразования почек и др.) отмечается низкая прогнозируемая выживаемость при любых типах сосудистого доступа (значимых различий между типами сосудистого доступа нет). Различия в выживаемости детерминированы не только типом сосудистого доступа, но и во многом коморбидным фоном

Central venous stenosis and methods of its treatment in hemodialysis patients

There is no doubt that the optimal vascular access is arteriovenous fistula (AVF). However, the proportion of patients receiving hemodialysis using central venous catheters is very high. Largely due to this, the incidence of central venous stenosis (CVS) in this category of patients is one of the highest: the prevalence ranges from 2 to 40%. Against the background of functioning AVF from the ipsilateral side, CVS proceeds with much more pronounced symptoms than in the general population of patients with this pathology. There is no doubt that stenosis of the central veins is a precursor of AVF thrombosis, recurrent infections, reduction of blood flow in the limb in general and AVF in particular, and consequently - increase in recirculation and decrease in the effectiveness of HD. Endovascular surgery is the «gold standard» treatment for CVS. Technical success is at least 80-90% of the cases. As a rule, endovascular operations not only lead to the immediate reduction of symptoms of venous hypertension, but also allow the use of fistulas for hemodialysis in the near future after the intervention. At the same time, clinical success is achieved much less frequently. Primary patency in six months is about 50%, secondary patency in two years - 60-80%. The use of cutting balloon catheters may be associated with greater secondary patency than using standard balloon catheters, but slightly increases the risk of complications. An effective way to improve the results of CVS plastic is the use of stents, which allow to increase the patency after surgery. Indications for the primary use of stents is a debatable issue. However, stenting is undoubtedly effective in the case of rapid occurrence of recurrent stenosis or rigid stenosis and recoil immediately after surgery. In addition, one of the problems associated with the use of stents is the risk of their migration. This risk increases in patients with functioning AVF. Skepticism about the use of stents in patients on hemodialysis is also added by the fact that in randomized controlled studies, when comparing isolated balloon angioplasty and angioplasty using uncovered stents, there was no significant difference in the recurrence of stenosis. At the same time, the use of covered stents provides a significant increase in access survival. In addition, the use of drug-coated balloon catheters may provide some advantage over standard uncoated balloon catheters. Open surgical interventions have slightly better results in the treatment of CVS (annual primary patency of 80-90%) compared to endovascular methods. Nevertheless, open reconstructions are associated with a much greater risk of intra- and postoperative complications, in most cases require clavicle section or sternotomy, general anesthesia, and are associated with greater postoperative mortality. In this regard, percutaneous transluminal angioplasty is deservedly considered to be a common method of treatment of CVS. Open surgery can be used in case of unsuccessful attempts to resolve stenosis endovascular while maintaining a pronounced clinical symptoms. On the face of the fact that the available methods of treatment of this pathology in patients on hemodialysis with functioning vascular access do not fully meet the clinical needs. Currently, there is no consensus on many aspects of the use of endovascular interventions for the correction of vascular access dysfunction, which requires additional research

Open and endovascular surgery for stenosis of the peripheral regions of arteriovenous fistula

Vascular access is the cornerstone of hemodialysis. With vascular access dysfunction, the results of treatment of patients with stage 5 chronic kidney disease significantly deteriorate. One of the most common causes of vascular access failure is peripheral venous stenosis. Despite the variety of initiating factors, the morphological substrate of stenotic damage to the arteriovenous fistula (or arteriovenous anastomosis) in most cases is neointimal hyperplasia. Stenotic lesions of the arterivenous fistula are strongly associated with an increased risk of thrombosis and loss of vascular access. There are 4 typical localizations of stenosis: arteriovenous or arteriograft anastomosis, stenosis of the juxta-anastomotic segment of the fistula, stenosis of the functional segment of the fistula, and stenosis of the cephalic arc.The most common indication for surgical treatment is vascular access failure; less common indications are clinical symptoms of venous insufficiency.There are various methods of open reconstruction of the stenotic segment of the fistula vein: resection, prosthetics with a synthetic vascular graft, prosthetics or plastic repair of the autologous vein wall, complete or partial drainage of the prestenotic segment of the vein, etc. Currently an alternative method of stenosis repair using endovascular interventions is gaining popularity. In contrast to central vein stenosis, where endovascular interventions are the gold standard, in peripheral vein stenosis it is only an adjuvant method. Complications of endovascular interventions are extremely rare.Despite the fact that endovascular interventions have almost absolute probability of technical success, the primary patency is not high and is about 50% in six months. The use of bare stents is not accompanied by an increase in primary patency. The use of stent-grafts can increase the primary patency, especially in the plastic repair of challenging stenoses of the graft-vein anastomosis or cephalic arch.Many issues related to endovascular interventions remain unresolved, which requires further research

Vascular access and survival of patients with hemodialysis: features of cause-effect relationship

Aim: to analyze features of the causal relationship between the vascular access type at the time of hemodialysis (HD) start and survival rates of patients, taking into account the cause of chronic kidney disease (CKD) and comorbidity.Materials and methods. The retrospective analysis included 604 HD patients divided into three groups: «AVF» (n = 336) patients started and continued HD with AVF; «CVC-AVF» (n = 152) patients started HD with CVC and later successfully converted to AVF; «CVC» (n = 116) patients who started and continued HD with CVC only. Patients with other types of conversions were not included in the analysis. The mean follow-up period since the beginning of HD was 38 [interquartile range 19; 48] months.Results. Unadjusted survival rate after 5 years in the AVF group was 61% [95%CI 51.8; 71.9], that in the CVC-AVF group - 53.9% [95%CI 42.5; 67], and that in the CVC group - 31.6% [95% CI 21.4; 41.4]. Survival rate in the CVC group varied from that in the AVF (p < 0.0001) and CVC-AVF (p < 0.0001) groups. CVC-AVF and CVC groups patients had significantly worse comorbidity than that of AVF group patients. After adjustment for comorbidity, age, sex, and cause of CKD, the survival rate in the groups after 5 years came to the following: 56.7% [95%CI 51.1; 62.8] in the AVF group, 51.7% [95%CI 42.5; 61.7] in the CVC-AVF group, 33.3% [95%CI 24; 42.8] in the CVC group. The results in the AVF group differed significantly from that in the CVC group (p < 0.001), but not from that in the CVC-AVF group (p = 0.425). The results in the CVC-AVF group are also statistically significantly varied from that in the CVC group (p = 0.009). Diabetes mellitus and systemic diseases were important risk factors. In the 5 years’ time period the survival rate of the group of patients with diabetes mellitus within in the AVF group adjusted (for sex, age, cause of CKD and comorbidity) was 38.1% [95% CI 29; 47.1], that in the CVC-AVF group - 29.7% [95% CI 18.9; 41.2] and that in the CVC group - 20.3% [95% CI 11.6; 31.8]. The results in the AVF group statistically significantly differed from that in the CVC group (p = 0.001), and from that in the CVC-AVF group (p = 0.011). The results in the CVC-AVF group are also statistically significantly varied from that in the CVC group (p = 0.021). In the 5 years’ time period the adjusted survival rate within the patients in the AVF group with systemic processes, was 34.2% [95% CI 18.8; 50.3], that in the CVC-AVF group - 23.9% [95% CI 10.5; 40.3], and that in the CVC group - 20.5 % [95% CI 7.3; 38.5]. We did not note statistically significant differences between the groups (p > 0.05 in all cases).Conclusion. The HD beginning with the use of CVC does not increase the risk of death in case of successful conversion to AVF. The use of CVC as the only vascular access is associated with a significant increase in the adjusted risk of death. Within the patients with diabetes mellitus, the use of CVC is associated with a deterioration of the adjusted survival rate even with subsequent successful conversion to functional AVF. Patients with systemic processes (vasculitis, myeloma, HIV-associated nephropathy, renal neoplasms, etc.) have low predicted survival rate disregarding the type of vascular access (there are no significant differences between the types of vascular access). The differences in survival rates are determined not only by the types of vascular access, but also by the comorbid background

Ambiguous results of balloon angioplasty for central vein stenosis in hemodialysis patients with native arteriovenous fistula

Objective: to conduct comprehensive comparative analysis of the patency rate of native arteriovenous fistula (AVF) for central vein stenosis (CVS) after endovascular balloon angioplasty and palliative surgery. Materials and methods. The retrospective study included 80 patients with confirmed central vein stenosis: subclavian, brachiocephalic veins, inferior vena cava, or multiple lesions. The experimental group included 39 patients who underwent percutaneous balloon angioplasty. The control group included 41 patients who, for various reasons, did not do balloon angioplasty, but underwent palliative interventions: thrombectomy, proximalization of arteriovenous anastomosis, AVF blood flow-reducing surgical procedures. Results. Primary patency (time interval between the first intervention for CVS and the second intervention) in the experimental group was 61.5% [95% CI 44.5; 74.7] and 15.4% [95% CI 6.2; 28.3] at 6 and 12 months, respectively. In the control group, it was 39% [95% CI 24.3; 53.4] and 0% respectively. Hazard ratio (HR) 0.5337 [95% CI 0.3381; 0.8427], log-rank test p = 0.0011. No differences in functional primary patency (time interval between the start of using AVF and the first intervention for CVS) were found: 89.7% [95% CI 74.9; 96] and 30.8% [95% CI 17.3; 45.4] at 1 year and 3 years, respectively, in the experimental group, and 80.5% [95% CI 64.8; 89.7] and 24.4% [95% CI 12.7; 38.2] in the control group. There were no differences between the groups HR 0.7695 [95% CI 0.4952; 1.196], log-rank p = 0.2259. In the experimental group, strong negative correlation between primary patency and functional primary patency was detected: r = –0.627 [95% CI –0.787; –0.388], p < 0.0001. In the control group, no such correlation was found: r = 0.049 [95% CI –0.262; –0.351], p = 0.7599. Thus, the later CVS developed, the less effective balloon angioplasty was. Balloon angioplasty significantly increased duration of AVF use after first intervention for CVS (secondary patency): 84.6% [95% CI 68.9; 92.8], 66.7% [95% CI 49.6; 79.1] and 17.9% [95% CI 7.9; 31.3] at 6, 12 and 24 months, respectively in the experimental group. In the control group, it was 56.1% [95% CI 39.7; 69.6], 19.5% [95% CI 9.2; 32.7] and 0%. HR 0.4009 [95% CI 0.2481; 0.6477], log-rank p < 0.0001. Functional secondary patency (total duration of AVF use) was: 100%, 74.4% [95% CI 57.6; 85.3] and 12.8% [95% CI 4.7; 25.2] at 1, 3 and 5 years in the experimental group, and 95.1% [95% CI 81.9; 98.8], 36.6% [95% CI 22.3; 51] and 4.9% [95% CI 0.9; 14.5] in the control group. HR 0.5661 [95% CI 0.3598; 0.8906], log-rank p = 0.0067. Conclusions. 1. Central vein stenosis inevitably cuts vascular access from the ipsilateral side. 2. Balloon angioplasty allows to slightly prolong AVF use but it cannot radically change the long-term results of CVS treatment. 3. The outcome of balloon angioplasty greatly depends on the length of the period from the time the use of AVF started to the time CVS developed. 4. Multiple repeated balloon angioplasties are apparently justified in patients for whom creating a new vascular access might not be possible. 4. AVF volumetric blood flow velocity is an important factor determining the severity of CVS clinical manifestations and whether repeated surgical interventions are needed

Vascular access in patients on chronic hemodialysis in the Moscow Region: current state and outlook

Background: The prevalence of chronic kidney disease (CKD) is annually growing worldwide. Stable functioning arteriovenous fistula (AVF) is one of the main prerequisites of survival for patients on chronic hemodialysis (HD). As a rule, available clinical guidelines for creation and maintenance of HD vascular access do not give a clear answer to some important questions. We have summarized and analyzed our experience of the creation and maintenance of the vascular access. Aim: To analyze the results of the creation and maintenance of vascular access in a large population of patients on chronic HD (in the Moscow Region). Materials and methods: We analyzed the results of 3837 surgeries for creation and reconstruction of the vascular access in 1862  patients, performed from 2012 to 2016. Results: The CKD stage 5D incidence has increased from 239 to 391 over the last three years. Currently, 2204  patients are followed up and receiving treatment in 38 outpatient centers. Almost one half of all interventions, 43.5% (1668/3837), has been performed to create AVF. Only one third, i.e. 33% (1266/3837) of them was de novo operations, whereas 10.5% (403/3837) were done to create a new AVF in HD patients after thrombosis of the existing AVF. 15.4%  (590/3837) of the interventions were performed for AVF reconstruction, 4% (154/3837) for AVF closure after successful kidney transplantation, 3.2%  (121/3837) for creation of AVF with vascular graft, 3%  (115/3837) for thrombectomy from the graft, 14.6%  (559/3837) to implant a  permanent central venous catheter (CVC), and 13.6%  (520/3837) for placement of a  temporary CVC. 54.4%  (1012/1862) of the patients had their functional AVF, 2.2% (41/1862) had a vascular graft at the beginning of HD, and one year later, there were 73.8% (1152/1561) and 5.3% (83/1561) of such patients, respectively. The type of vascular access at the start of HD strongly depended on the cause of CKD. 60.4% (192/318) of patients with polycystic kidney disease and 65.1% (181/278) with systemic disease or cancer started HD with the CVC. Oneyear survival of patients who started HD with AVF, who started HD with CVC and switched to AVF, and those who initiated and continued HD with CVC only, was 87.5% (95% confidence interval [CI] 83.5– 90.6), 79.6% [95% CI 72.3–82.5], and 66.4% (95% CI 57–74.2), respectively. The 5-year survival in these groups was 61% (95% CI 51.8–71.9), 53.9% (95% CI 42.5–67), and 31.6%  (95%  CI 21.4–41.4), respectively. At one year, primary and secondary AVF patency amounted to 77.2%  (95%  CI 71.7–81.8) and 87% (95% CI 83.7–89.7), respectively, at 5 years 34.1% (95% CI 27.8–40.5) and 60.9% (95% CI 56.4– 65.1), respectively. Conclusion: A more detailed analysis is necessary to identify risk factors for complications of the vascular access and to optimize approaches to its creation and reconstruction. An effective way to achieve this goal is to establish a local registry of CKD patients