[Functional profile of cephalic arch stenosis]. / Perfil funcional de la estenosis del arco de la vena cefálica.

Cephalic arch stenosis (CAS) is a unique type of vascular access stenosis. For example, the etiology of CAS is under investigation and the prevalence of CAS can be lower in diabetic patients. Three cases of CAS were identified during our vascular access stenosis surveillance program by blood flow rate measurements using the Delta-H method. We evaluated the prevalence, etiology, relationship with diabetes and functional profile of CAS. To date, this is the first functional report published about this type of stenosis.

Functional profile of cephalic arch stenosis

Cephalic arch stenosis (CAS) is a unique type of vascular access stenosis. For example, the etiology of CAS is under investigation and the prevalence of CAS can be lower in diabetic patients. Three cases of CAS were identified during our vascular access stenosis surveillance program by blood flow rate measurements using the Delta-H method. We evaluated the prevalence, etiology, relationship with diabetes and functional profile of CAS. To date, this is the first functional report published about this type of stenosis (AU)

La estenosis del cayado o arco de la vena cefálica (EAC) es un tipo peculiar de estenosis del acceso vascular para hemodiálisis. Por ejemplo, y a diferencia de los restantes casos de estenosis, la etiopatogenia de la EAC no está totalmente esclarecida y su prevalencia parece ser inferior en el enfermo diabético. Presentamos tres casos de EAC diagnosticados en nuestra Unidad de Hemodiálisis mediante la aplicación de un programa de monitorización del flujo sanguíneo del acceso vascular utilizando el método Delta-H. Se revisa la prevalencia, la etiopatogenia, la relación con la diabetes mellitus y el perfil funcional de este tipo de estenosis. Hasta la fecha, es el primer estudio funcional efectuado sobre la EAC (AU)

[Prevalence and functional effect of arteriovenous fistula calcifications, evaluated by spiral CT in chronic haemodialysis patients]. / Prevalencia y efecto funcional de las calcificaciones de la fístula arteriovenosa evaluadas mediante TAC helicoidal en pacientes en hemodiálisis crónica.

INTRODUCTION: Vascular calcification is a common finding in patients (pts) with end-stage renal disease (ESRD). OBJECTIVE: The aim of this cross-sectional study was to investigate the prevalence and functional effect of native arteriovenous fistula AVF (feeding artery and/or arterialized vein) calcifications evaluated by spiral computed tomography (CT) in ESRD pts undergoing chronic hemodialysis (HD). PATIENTS AND METHOD: Forty-five upper limb AVF (radial 44.4% or brachial 55.6%, mean duration 65.3 +/- 80.9 months) without evidence of significant stenosis were evaluated by CT in 45 ESRD pts (mean age 63.8 +/- 13.1 yr; sex M: 71.1%, F: 28.9%; mean time on HD 53.1 +/- 51.9 months; diabetic nephropathy 15.6%). All AVF explorations were performed using the same multi-slice spiral CT scanner (HiSpeed Dual machine, GE Medical Systems). The severity of AVF calcifications was quantified by CT using the following criteria: grade I absence of calcifications, grade II isolated calcifications (<10 groups of calcification), grade III moderate calcifications (10-20 groups of calcification) and grade IV diffuse calcifications (>20 groups of calcification). Laboratory parameters analyzed: calcium, phosphorus, parathyroid hormone; calcium x phosphorus product was calculated. The same week of CT scanning, we evaluated AVF function measuring the blood flow rate (QA). We determined QA (1559.3 +/- 980.6 ml/min) by the Delta-H method (ABF-mode, HemaMetrics, USA) using the Crit-Line III monitor (68.9%) or by Doppler ultrasound (31.1%) performed by the same radiologist using a 5-8 MHz linear transducer (Sequoia machine, Siemens-Acuson); mean arterial pressure MAP (94.7 +/- 16.3 mmHg) was recorded simultaneous with QA. RESULTS: Most pts not showed AVF calcification by CT scan (grade I: 27/45, 60%). Forty percent of pts (18/45) demonstrated any degree of AVF calcification (grade II 13.3%, grade III 8.9%, grade IV 17.8%). Pts with brachial AVF showed higher mean QA compared to pts with radial AVF (1899.1 +/- 1131.8 versus 1134.5 +/- 516.4 ml/min, p=0.005), but MAP (91.2 +/- 15.8 versus 99.0 +/- 16.2 mmHg) and the prevalence of AVF calcification (32% versus 50%) were not different between both groups (p=0.11 and p=0.24, respectively). Pts with evidence of any calcification on CT scanning (grade II, III or IV) had higher time on HD (84.6 +/- 63.1 versus 24.6 +/- 20.0 months), higher AVF duration (97.7 +/- 89.3 versus 34.6 +/- 61.2 months) and similar QA (1488.3 +/- 678.9 versus 1606.6 +/- 1148.9 ml/min) compared with pts without AVF calcification (p=0.014, p=0.001 and p=0.69, respectively); no differences in MAP (95.4 +/- 13.8 versus 94.2 +/- 17.9 mmHg), prevalence of brachial AVF (44% versus 63%) or mineral metabolism parameters were found when comparing both groups (for all comparisons, p=NS). The same results were obtained when comparing pts with a high (grade III-IV: 26.7%) and a low (grade I-II: 73.3%) AVF calcification score, or when comparing pts with diffuse (grade IV) and without (grade I) AVF calcification. CONCLUSIONS: 1) The prevalence of AVF calcification by CT scan was 40%. 2) The AVF calcification was related with time on HD and AVF duration. 3) The function of fully developed AVF without stenosis and suitable for routine HD was not impaired by the presence of calcifications.

Prevalencia y efecto funcional de las calcificaciones de la fístula arteriovenosa evaluadas mediante TAChelicoidal en pacientes en hemodiálisis crónica / No disponible

Introducción: se ha objetivado una mayor prevalencia, precocidad, extensión y velocidad de progresión de las calcificaciones vasculares en los pacientes en hemodiálisis crónica (HD) respecto a la población general .Objetivo: investigar la prevalencia y el efecto funcional de les calcificaciones de la fístula arteriovenosa FAVI (arteria nutricia o vena arterializada) evaluadas por TAC helicoidal (TACh) en pacientes en HD. Pacientes y método: cuarenta y cinco FAVI ( radial 44,4% o humeral 55,6%, duración media 65,3 ± 80,9 meses) sin evidencia de estenosis significativa se estudiaron por TACh en 45 pacientes (edad media 63,8 ± 13,1 años; género V: 71,1%, M: 28,9%; tiempo medio en HD 53,1 ±51,9 meses; nefropatía diabética 15,6%). Todas las exploraciones de la FAVI se efectuaron mediante el mismo aparato de TACh multidetector (..) (AU)

Introduction. Vascular calcification is a common finding in patients (pts) with end-stage renal disease(ESRD). Objective. The aim of this cross-sectional study was to investigate the prevalence and functional effect of native arteriovenous fistula AVF (feeding artery and/or arterialized vein) calcifications evaluated by spiral computed tomography (CT) in ESRD pts undergoing chronic hemodialysis (HD). Patients and method. Forty-five upper limb AVF (radial 44.4% or brachial55.6%, mean duration 65.3 ± 80.9 months) without evidence of significant stenos is were evaluated by CT in45 ESRD pts (mean age 63.8 ± 13.1 yr; sex M: 71.1%, F:28.9%; mean time on HD 53.1 ± 51.9 months; diabetic (..) (AU)

Exploración funcional del acceso vascular durante la hemodiálisis en 38 pacientes mediante la técnica de Termodilución. Estudio comparativo con el método Delta-H / No disponible

Introducción: La determinación periódica del flujo sanguíneo (QA) del acceso vascular (AV) es el método de elección para su monitorización en los pacientes (pts) con IRC. Objetivos: Determinar QA mediante la técnica de Termodilución (TDT) y comparar los resultados funcionales con el método Delta-H. Pacientes y método: Hemos determinado no invasivamente el QA de 38 AV (duración media 48,7 ± 69,8 meses) durante la HD en 38 pts (edad media 63,8 ± 15,1 años, tiempo medio en HD 47,6 ± 53,9 meses, nefropatía diabética 18,4%) con IRC mediante TDT. Catorce pts (36,8%) tenían el antecedente de algún AV previo, que fue ipsilateral al AV actual en la mayoría de los casos (11/14, 78,6%). Trece pts (34,2%) tenían el antecedente de alguna comorbilidad distinta de la diabetes (cardiopatía isquémica o enfermedad cerebrovascular o arteriopatía periférica). El QA se calculó a partir de los valores de recirculación obtenidos mediante el monitor de temperatura sanguínea (BTM), integrado en la máquina Fresenius Medical Care 4008-S, con las líneas sanguíneas de HD en configuración normal e invertida. El QA se determinó durante la primera hora de 2 sesiones consecutivas de HD (ambos valores se promediaron). La presión arterial media PAM y la distancia entre las agujas (DEA) se registraron simultáneamente con QA. Además, el flujo sanguíneo del AV se determinó nuevamente en un plazo no superior a 15 días mediante el método Delta-H utilizando el monitor Crit Line III (HemaMetrics, USA). Resultados: El QA medio fue 1.170,5 ± 464,2 ml/min (intervalo, 289,4-2.346,4 ml/min). La mayoría de AV (44,7%) presentaban un QA medio comprendido entre 1.000 y 1.500 ml/min. La DEA y PAM medios fueron 6,2 ± 2,9 cm y 91,9 ± 12,4 mmHg, respectivamente. El QA fue similar tanto para los pts con PAM inferior a 100 mmHg (n = 26) como para los pts con PAM igual o superior a 100 mmHg (n = 12) (p = 0,85). Los pts con nefropatía diabética presentaron un QA significativamente inferior (836,1 ± 395,8 ml/min) en relación a los restantes pts (1.245,9 ± 449,9 ml/min) (p = 0,62). Se objetivó la tendencia a un mayor QA de la FAVI humeral en relación a la FAVI radial (1.323,6 ± 465,3 versus 1.017,4 ± 447,3 ml/min) (p = 0,052). Los pts con antecedente de AV previo, presentaron un QA medio significativamente superior (1.410,6 ± 377,7 ml/min) en relación a los restantes pts (1.034,4 ± 458,7 ml/min) (p = 0,013). No hemos objetivado ninguna correlación entre el QA medio y: edad, DEA, PAM, índice Kt/V, tiempo en HD y duración del AV. El QA medio obtenido mediante TDT fue similar al flujo sanguíneo medio determinado con el método Delta-H (1.151,3 ± 479,0 ml/min) (p = 0,89). Los valores del flujo sanguíneo del AV obtenidos mediante TDT se correlacionaron significativamente con los determinados con el método Delta-H (coeficiente de correlación intraclase = 0,95, p < 0,001). Conclusiones: La TDT permite determinar QA durante la HD. El perfil funcional del AV fue peor en los pts con nefropatía diabética o sin antecedente de AV previo. Los valores de flujo sanguíneo del AV obtenidos mediante los métodos TDT y Delta-H se correlacionaron significativamente (AU)

Introduction: Periodic QA measurement is the preferred way for vascular access (VA) surveillance in end-stage renal disease (ESRD) patients (pts). Objective: The aims of this study were to measure QA by TDT and to compare the functional results with Delta-H method. Patients and methods: We measured QA non invasively in 38 VA (mean VA duration: 48.7 ± 69,8 months) during HD in 38 stable ESRD (mean age 63.8 ± 15.1 yr, mean time on HD 47.6 ± 53.9 months, diabetic nephropathy 18.4%) pts by the TDT. Fourteen pts (36.8%) had history of previous VA that were ipsilateral to the VA under study in most cases (11/14, 78.6%). Thirteen pts (34.2%) had history of any comorbidity other than diabetes mellitus (coronary artery or cerebrovascular or peripheral vascular diseases). QA was calculated from the recirculation values obtained by means of the blood temperature monitor (BTM), integrated into the Fresenius Medical Care 4008-S machine, at normal and reverse configurations of the HD blood lines. QA was measured within the first hour of two consecutive HD sessions (the values were averaged). Mean arterial pressure MAP and distance between needles (DBN) were measured simultaneous with QA. In addition, the VA blood flow was also determined by Delta-H method using Crit-Line III Monitor (ABF-mode, HemaMetrics, USA). Results: Mean QA was 1170.5 ± 464.2 ml/min (range, 289.4-2,346,4 ml/min). Most VA (44.7%) showed mean QA between 1,000 and 1,500 ml/min. The mean DBN and MAP were 6.2 ± 2.9 cm, 91.9 ± 12.4 mmHg, respectively. Mean QA was similar for pts with mean MAP < 100 mmHg (n = 26) and for pts with mean MAP 100 mmHg (n = 12) (p = 0.85). Pts with diabetic nephropathy showed lower mean QA (836.1 ± 395.8 ml/min) compared to the remaining pts (1,245.9 ± 449.9 ml/min) (p = 0.033). No differences in mean QA was found when pts with any comorbidity and without comorbidities were compared (p = 0.62). Brachial AVF tended to have higher mean QA (1,323.6 ± 465.3 ml/min) compared to radial AVF (1,017.4 ± 447.3 ml/min) (p = 0.052). Pts with history of previous VA showed higher mean QA (1,410.6 ± 377.7 ml/min) compared to the remaining pts (1,030.4 ± 458.7 ml/min) (p = 0.013). No correlation was found between mean QA and: mean age, DBN, MAP, Kt/V index, time on HD and VA duration. Mean QA obtained by TDT was not different when compared with mean ABF determined by Delta-H method (1,151.3 ± 479.0 ml/min) (p = 0.89). The calculated values of VA blood flow obtained by TDT were highly correlated with those determined by the Delta-H method (intraclass correlation coefficient = 0.95, p < 0.001). Conclusions: The TDT is an indicator of QA during HD. The functional profile of VA was worse in pts with diabetic nephropathy or without history of previous VA. The VA blood flow values obtained by TDT and Delta-H techniques correlated highly with each other (AU)

[Measurement of vascular access blood flow rate during hemodyalisis in 38 patients using the thermodilution technique. A comparative study with the Delta-H method]. / Exploración funcional del acceso vascular durante la hemodiálisis en 38 pacientes mediante la técnica de termodilución. Estudio comparativo con el método Delta-H.

INTRODUCTION: Periodic QA measurement is the preferred way for VA surveillance in end-stage renal disease (ESRD) patients (pts). OBJECTIVE: The aims of this study were to measure QA by TDT and to compare the functional results with Delta-H method. PATIENTS AND METHODS: We measured Q(A) non invasively in 38 VA (mean VA duration: 48.7 +/- 69.8 months) during HD in 38 stable ESRD (mean age 63.8 +/- 15.1 yr, mean time on HD 47.6 +/- 53.9 months, diabetic nephropathy 18.4%) pts by the TDT. Fourteen pts (36.8%) had history of previous VA that were ipsilateral to the VA under study in most cases (11/14, 78.6%). Thirteen pts (34.2%) had history of any comorbidity (coronary artery or cerebrovascular or peripheral vascular diseases). Q(A) was calculated from the recirculation values obtained by means of the blood temperature monitor (BTM), integrated into the Fresenius Medical Care 4008-S machine, at normal and reverse configurations of the HD blood lines. Q(A) was measured within the first hour of two consecutive HD sessions (the values were averaged). Mean arterial pressure MAP and distance between needles (DBN) were measured simultaneous with Q(A). In addition, the VA blood flow was also determined by Delta-H method using Crit-Line III Monitor (ABF-) between 1000 and 1500 ml/min. The mean DBN and MAP were 6.2 +/- 2.9 cm, 91.9 +/- 12.4 mmHg, respectively. Mean Q(A) was similar for pts with mean MAP<100 mmHg (n=26) and for pts with mean MAP>or=100 mmHg (n=12) (p=0.85). Pts with diabetic nephropathy showed lower mean Q(A) (836.1 +/- 395.8 ml/min) compared to the remaining pts (1,245.9 +/- 449.9 ml/min) (p=0.033). No differences in mean Q(A) was found when pts with any comorbidity and without comorbidities were compared (p=0.62). Brachial AVF tended to have higher mean Q(A) (1,323.6 +/- 465.3 ml/min) compared to radial AVF (1,017.4 +/- 447.3 ml/min) (p=0.052). Pts with history of previous VA showed higher mean Q(A) (1,410.6 +/- 377.7 ml/min) compared to the remaining pts (1,030.4 +/- 458.7 ml/min) (p=0.013). No correlation was found between mean Q(A) and: mean age, DBN, MAP, Kt/V index, time on HD and VA duration. Mean Q(A) obtained by TDT was not different when compared with mean ABF determined by Delta-H method (1,151.3 +/- 479.0 ml/min) (p=0.89). The calculated values of VA blood flow obtained by TDT were highly correlated with those determined by the Delta-H method (intraclass correlation coefficient =0.95, p<0.001). CONCLUSIONS: The TDT is an indicator of QA during HD. The functional profile of VA was worse in pts with diabetic nephropathy or without history of previous VA. The VA blood flow values obtained by TDT and Delta-H techniques correlated highly with each other.

[Noninvasive assessment of forearm vessels by color Doppler ultrasonography (CDU) before and after radiocephalic fistula (RCF) placement]. / Exploración vascular no invasiva del antebrazo mediante ecografía Doppler color (EDC) antes y después de la construcción de la fístula radiocefálica (FRC).

INTRODUCTION: The CDU is a noninvasive vascular access (VA) monitoring technique that provides both structural and hemodynamic information from vessels. OBJECTIVE: The aim of this prospective study was to analyze some parameters of forearm vessels by CDU before and after RCF creation at the wrist. PATIENTS AND METHODS: We explored by CDU the vessels of forearm in 34 CRF patients (pts) (mean age 63.915.1 yr, sex M:76.5%;F:23.5%, 26.5% diabetes, 73.5% already on HD at the time of RCF placement). Forearm CDU evaluation was planned twice: before RCF creation (first exploration FE) and after two months of successful RCF cannulation for HD by 2 needles at Qb>250 ml/min (second exploration SE). All CDU examinations were performed by the same radiologist with 5-10 MHz linear transducer (Doppler angle < or = 60 degrees) at two proximal and distal points of the forearm (the values were averaged) using the Aspen machine (Siemens-Acuson, Mountain View, CA). We measured by CDU parameters from radial artery RA (diameter RAd, peak systolic velocity PSV, resistive index RI, blood flow rate RAflow), cephalic vein CV (diameter CVd) and arterialized vein AV (diameter AVd, blood flow rate AVflow). RAflow or AVflow calculation by CDU: time average velocity (mean of three cardiac cycles) (m/s) x cross-sectional area (mm2) x 60. RCF outcome: functioning RCF (FRCF) suitable for routine HD 61.8% (mean age 61.214.5 yr, 23.8% diabetes), or non-functioning RCF 38.2% (mean age 68.215.5 yr, 30.8% diabetes) due to: early thrombosis (within 24 hours after operation, ETRCF) 14.7%, lack of RCF maturation (LMRCF) 5.9%, last thrombosis (between 24 hours after operation and SE by CDU, LTRCF) 17.6%. RESULTS: Between FE and SE by CDU at RA, overall mean RAd (3.2 +/- 0.3 vs 5.5 +/- 1.0 mm), mean PSV (59.9 +/- 12.4 vs 166.6 +/- 58.2 cm/s) and mean RAflow (67.9 +/- 27.4 vs 1297.1 +/- 683.1 ml/min) increased significantly (for all comparisons, p<0.001), and mean RI (0.9 +/- 0.2 vs 0.40. +/- 0.1) decreased significantly (p<0.001); we also found a significant difference when overall mean CVd (2.9 +/- 0.6 mm) and mean AVd (5.7 +/- 1.1 mm) were compared (p<0.001). Overall and distal mean RAflow at FE by CDU were lower in pts with ETRCF (33.6 +/- 19.6 and 26.0 +/- 16.7 ml/min, respectively) compared to pts with FRCF (67.9 +/- 27.4 and 48.0 +/- 21.3 ml/min, respectively) (p=0.015 and p=0.029, respectively). Pts with ETRCF and LMRCF considered together (20.6%), had lower overall mean RAd (2.80.4 mm) and distal mean RAflow (28.1 +/ 15.2 ml/min) at FE by CDU compared to pts with FRCF (3.2 +/ 0.3 mm and 48.0 +/- 21.3 ml/min, respectively) (p=0.015 and p=0.031, respectively). No significant differences between pts with LTRCF and FRCF were found when overall and distal mean RAd, PSV, RI, RAflow and CVd obtained at FE by CDU were compared (for all comparisons, p=NS), but all pts with LTRCF underwent HD at the time of RCF creation compared to 57.1% of pts with FRCF (p=0.049). Pts with FRCF who had overall mean AVflow = 800 ml/min (38.1%, mean AVflow: 602.5167.3 ml/min) showed lower overall mean RAflow at SE by CDU compared to pts with FRCF who had overall mean AVflow>800 ml/min (61.9%, mean AVflow: 1113.9 +/- 160.1 ml/min): 820.1 +/- 188.7 vs 1590.7 +/- 715.4 ml/min (p=0.002). We found a positive correlation between overall mean AVflow and mean RAflow obtained at SE by CDU (r = 0.52, p = 0.016). CONCLUSIONS: 1) All parameters of forearm vessels measured by CDU changed after RCF placement. 2) Preoperative mean RAflow is predictive of RCF outcome. 3) Mean AVflow is related to mean RAflow obtained at SE by CDU.

Exploración vascular no invasiva del antebrazo mediante ecografía Doppler color (EDC) antes y después de la construcción de la fístula radiocefálica (FRC) / Noninvasive assessment of forearm vessels by color doppler ultrasonography (CDU) before and after radiocefalic fistula (RCF) placement

Introducción: La EDC permite efectuar un estudio anatómico y funcional del árbol vascular. Objetivos: Analizar diferentes parámetros de los vasos sanguíneos del antebrazo por EDC antes y después de la construcción de la FRC en el carpo. Material y métodos: Hemos explorado prospectivamente el antebrazo de 34 pacientes (pts) con IRC (edad 63,9 ± 15,1, sexo H: 76,5%; M: 23,5%, 26,5% diabetes, 73,5% ya efectuaban HD en el momento de efectuar la FRC) mediante EDC. La evaluación por EDC se planificó por duplicado: antes de la creación de la FRC (primera exploración PE) y dos meses después de la punción sin problemas de la FRC con 2 agujas y Qb > 250 ml/min (segunda exploración SE). Todas las exploraciones se efectuaron por el mismo radiólogo mediante un transductor lineal de 5-10 MHz (monitor de EDC Aspen, Siemens-Acuson, Mountain View, CA) aplicado sobre 2 puntos diferentes (proximal y distal) del antebrazo (ambos valores se promediaron). Se determinaron por EDC parámetros de la arteria radial AR (diámetro d AR, velocidad máxima sistólica VMS, índice de resistencia IR, flujo sanguíneo flujo AR), vena cefálica VC (diámetro d VC) y vena arterializada VA (diámetro dVA, flujo sanguíneo flujoVA). Cálculo de flujoAR o flujoVA por EDC (ml/min): curva tiempo-velocidad (media de 3 ciclos cardíacos) (m/s) x área transversal (mm2) x 60. Seguimiento de la FRC: FRC funcionante (FRCF) 61,8%, o FRC no funcionante 38,2% por: trombosis inicial (durante las 24 horas siguientes a la intervención, TIFRC) 14,7%, falta de maduración (FMFRC) 5,9%, trombosis tardía (entre las 24 horas post-intervención y la SE por EDC, TTFRC) 17,6%. Resultados: Entre PE y SE por EDC sobre la AR, los valores globales de dAR (3,2 ± 0,3 vs 5,5 ± 1,0 mm), VMS (59,9 ± 12,4 vs 166,6 ± 58,2 cm/s) y flujo- AR (67,9 ± 27,4 vs 1297,1 ± 683,1 ml/min) aumentaron (para todas las comparaciones, p 800 ml/min (61,9%, flujoVA: 1113,9 ± 160,1 ml/min): 820,1 ± 188,7 vs 1590,7 ± 715,4 ml/min (p = 0,002). Hemos objetivado una correlación positiva entre flujoVA y flujoAR medio global obtenidos en la SE por EDC (r = 0,52, p = 0,016). Conclusiones: 1) Todos los parámetros vasculares del antebrazo determinados por EDC cambian tras la construcción de la FRC. 2) El flujoAR obtenido antes de la intervención es predictivo de funcionamiento de la FRC. 3) El flujoVA está en relación con el flujoAR obtenido en la SE por EDC

Introduction: The CDU is a noninvasive vascular access (VA) monitoring technique that provides both structural and hemodynamic information from vessels. Objective: The aim of this prospective study was to analyze some parameters of forearm vessels by CDU before and after RCF creation at the wrist. Patients and methods: We explored by CDU the vessels of forearm in 34 CRF patients (pts) (mean age 63.9 ± 15.1 yr, sex M:76.5%; F:23.5%, 26.5% diabetes, 73.5% already on HD at the time of RCF placement). Forearm CDU evaluation was planned twice: before RCF creation (first exploration FE) and after two months of successful RCF cannulation for HD by 2 needles at Qb>250 ml/min (second exploration SE). All CDU examinations were performed by the same radiologist with 5-10 MHz linear transducer (Doppler angle 800 ml/min (61.9%, mean AVflow: 1113.9 ± 160.1 ml/min): 820.1 ± 188.7 vs 1590.7 ± 715.4 ml/min (p = 0.002). We found a positive correlation between overall mean AVflow and mean RAflow obtained at SE by CDU (r = 0.52, p = 0.016). Conclusions: 1) All parameters of forearm vessels measured by CDU changed after RCF placement. 2) Preoperative mean RAflow is predictive of RCF outcome. 3) Mean AVflow is related to mean RAflow obtained at SE by CDU

Catéteres tunelizados para hemodiálisis tipo «sistema Tesio de catéteres gemelos» mediante técnica ecodirigida. Análisis retrospectivo de 210 catéteres / P

Objetivo: Revisar nuestra experiencia en la colocación del «Sistema Tesio de catéteres gemelos » tunelizados con cuff y evaluar sus resultados como acceso vascular para hemodiálisis. Material y métodos: Hemos revisado retrospectivamente nuestra base de datos clínicos de pacientes con IRC que han sido remitidos desde dos unidades de hemodiálisis para la colocación de catéter tunelizado como acceso vascular para hemodiálisis, entre marzo de 1996 y julio del 2005. Se ha utilizado la técnica ecodirigida para la localización, punción y canalización del vaso. El catéter utilizado durante todo el estudio fue el conocido sistema Tesio de catéteres gemelos de 10-F. Los pacientes con sospecha de bacteriemia relacionada con el catéter y/o disfunción del mismo siguieron protocolos establecidos. Para la disfunción y trombosis del catéter se utilizaron dosis bajas de uroquinasa. Para evaluar dosis de hemodiálisis se registraron los flujos de bomba de sangre (Qb) y el Kt/v, calculado por la formula de 2ª generación de Daugirdas. Resultados: Durante un periodo de seguimiento de 112 meses se han insertado 210 catéteres en 148 pacientes (93 hombre y 55 mujeres, edad media de 68,6 ± 4,95 años), 101 catéteres en vena yugular interna, 84 en femoral y 25 en subclavia. El índice de éxito con un solo pase de aguja fue del 87,8%, la tasa de complicaciones inmediatas del procedimiento fue del 4,7%. El tiempo total de permanencia de todos los catéteres fue de 18.324 días con una media de 87,2 días y rango de (4-1.280 días), la tasa media de Qb fue 252 ± 42,4 mL/min. El Kt/v medio fue de 1,21 ± 0,07. Setenta y siete catéteres presentaron trombosis durante el periodo de seguimiento, en 55 casos la uroquinasa fue efectiva en recuperar Qb >= 250 mL/min. En 25 casos no fue efectiva siendo necesaria la retirada del catéter y la reinserción de otro. La incidencia de infección ha sido del 11,9% con una tasa de bacteriemia relacionada con el catéter de 2,8 por 1.000 catéteres-día, los gérmenes Gram positivos fueron responsables de la infección en el 84% de los casos, los Gram negativos en 12% y otros en el 4%. Conclusión: La inserción de catéteres tunelizados del sistema Tesio de catéteres gemelos como accesos vasculares para hemodiálisis utilizando la técnica ecodirigida constituye un procedimiento con un alto grado de éxito, seguridad y eficacia. Además ofrece aceptables resultados de efectividad y desarrollo de la hemodiálisis

Placement, Performance and complications of The Tesio Twin Tunnelled Catheter System for hemodialysis Purpose: Review a large experience in the placement of tunnelled catheters to assess the outcomes with Twin catheter System as hemodialysis access. Material and Methods: We retrospectively reviewed clinical and hemodialysis data regarding of ESRD patients who were referred from 2 dialysis facilities for placement of tunnelled catheter as hemodialysis access between 1996 march and 2005 july. For catheter insertion it was used a real-time sonography technique (Site Rite II Dymax corporation) in performing vascular access procedure. The twin catheter system available during the study period consisted of 2x10-F12. Patients suspected to present bacteraemia related to catheter were followed with established protocols. Catheter suspected malfunction or thrombosis was treated with low dose Urokinase. To evaluated dialysis dose and adequacy, blood flow rates were recorded and Kt/v calculated by Daugirdas 2nd generation formula. Results: Over all study period of 112 months, 210 catheters were inserted in 148 patients (93 males and 55 females, mean age 68,6 ± 4,95 years). 101 catheters were inserted in internal jugular vein, 84 in femoral and 25 in subclavian. The successful insertion rate with only single needle pass was 87,8%, immediate procedural complications rate was 4.7%. The catheters were in place a total of 18,324 days during the study period (mean 87,2 days; range 4-1,280 days). The mean flow blood rate was 252,4 DS ± 42.4 mL/min, Mean Kt/v was 1,21 DS ± 0,07. Seventy —seven Catheters malfunctioned during study period, in 55 cases urokinase was effective in recovering blood flow rate over 250 mL/min and 25 were necessitated removal for ineffective urokinase. Infection incidence was 11.9% with bacteraemia related catheter rate of 2.8 episodes per 1,000 catheter- days, Gram positive bacteria was found in (84%), Gram negative in (12%) and others (4%). Conclusion: Placement of Tunnelled twin catheters system using real-time sonografy technique can be performed with excellent technical success, safety and acceptable catheter performance and outcomes for effective hemodialysis

[Prevalence and functional profile of unsuspected radial artery stenosis in native radiocephalic fistula dysfunction. Diagnosis by vascular access flow monitoring using Delta-H method]. / Prevalencia y perfil functional de la estenosis de la arteria radial. Diagnóstico mediante la monitorización del flujo sanguíneo de la fístula arteriovenosa radiocefálica para hemodiálisis utilizando el método Delta-H.

OBJECTIVE: The aim of this study was to know the prevalence and functional profile of RA stenosis in RCF dysfunction detected as a result of our surveillance programme. PATIENTS AND METHODS: We prospectively monitored QA of 116 VA (arteriovenous fistula 81% or graft 19%; mean VA duration 28.2 +/- 52.9 months) during hemodiaysis (HD) in 102 ESRD (mean age 63.0 +/- 13.0 yr; sex M: 56.9%, F: 43.1%; mean time on HD 31.4 +/- 44.0 months; 15.5% diabetes) patients (pts) over 4 yr period. QA was measured at least every 4 months by the Delta-H method using the Crit-Line III monitor (overall mean QA 1,193.4 +/- 490.3 ml/min) Forty-three VA (43/116, 37%) met criteria of positive evaluation (absolute QA < 700 ml/min: 48.8%; NQA > 20% from baseline: 51.2%) and were referred for angiography. Most VA explored by angiography showed stenosis > or = 50% (36/40, 90%) that were mainly located in RCF (25/36, 69.4%: RA 11/25, arterialized vein AV 14/25). RESULTS: Eleven cases of RA stenosis (prevalence: 11/36, 30.5%; mean degree: 83.5 +/- 15.8%) were found in 11 RCF (mean VA duration 48.9 +/- 76.7 months) of 11 pts (mean age 67.5 +/- 11.5 yr; mean time on HD 54.0 +/- 75.8 months; 18.2% diabetes). Cause of positive evaluation: absolute QA < 700 ml/min 81.8%; NQA > 20% from baseline 18.2%. Mean QA of RCF just before angiography: 532.9 +/- 99.8 ml/min (range, 418-699 ml/min). Stenosis type: Type I (multiple stenoses) 9.1%, type II (isolated stenosis but critical > 90-95%) 36.4% and type III (isolated stenosis 50-90% with normal haemodynamic status of RCF) 54.5%. Followup: stenosis not reparable 36.4% (4/11), elective intervention by surgery 36.4% (4/11), lost of follow-up before intervention 27.3% (2/11 died, 1/11 transplantation). Mean QA of RCF tended to increase from 547.0 +/- 100.6 ml/min just before surgery to 872.3 +/- 526.5 ml/min just after surgery (n = 4, mean DQA = 325.2 +/- 431.3 ml/min (p = 0.068). Comparative study with 14 AV stenosis (mean degree 76.4 +/- 7.4%) in 11 RCF (mean VA duration 16.4 +/- 22.8 months) of 11 pts (mean age 64.3 +/- 10.5 yr; mean time on HD 17.0 +/- 18.9 months; 50% diabetes): higher prevalence of intervention (85.8%) compared to RA stenosis (p =0.011); without differences in degree of stenosis (p = 0.12) and QA before angiography (p = 0.78) or surgery (p = 1.00); mean QA increased significantly after surgery (n = 6 AV, 549.8 +/- 86.4 vs 1,033.0 +/- 216.6 ml/min) (p = 0.028). CONCLUSIONS: 1) One third of cases of VA dysfunction were related to feeding artery stenosis. 2) No differences in functional profile were found between RA and AV stenosis before angiography and surgery. 3) The functional results of elective surgery in RA stenosis were worse compared to AV stenosis.

Prevalencia y perfil funcional de la estenosis de la arteria radial. Diagnóstico mediante la monitorización del flujo sanguíneo de la fístula arteriovenosa radiocefálica para hemodiálisis utilizando el método Delta-H / Prevalence and functional profile of unsuspected radial artery stenosis in native radiocephalic fistula dysfunction. Diagnosis by vascular access flow monitoring using Delta-h method

Objetivo: Conocer la prevalencia y perfil funcional de la estenosis de la arteria radial (AR) diagnosticada mediante la aplicación de un programa de monitorización del acceso vascular (AV). Material y métodos: Hemos monitorizado prospectivamente durante 4 años el flujo sanguíneo (QA) de 116 AV (fístula arteriovenosa 81% o prótesis 19%; duración del AV 28,2 ± 52,9 meses) en 102 pacientes (pts) (edad 63,0 ± 13,0 años; sexo H: 56,9%, M: 43,1%; tiempo en hemodiálisis HD 31,4 ± 44,0 meses; 15,5% diabetes). El QA se determinó durante la HD cada 4 meses como mínimo mediante el método Delta-H utilizando el monitor Crit- Line III (QA global 1193,4 ± 490,3 ml/min). Cuarenta y tres AV (37%) presentaron evaluación positiva (QA absoluto 20% respecto al valor basal: 51,2%) y se remitieron para efectuar angiografía. La mayoría de AV explorados por angiografía presentaron estenosis >= 50% (36/40, 90%) que se localizó en la arteria nutricia 30,5% (11/36: todos los casos en fístulas radiocefálicas FRC) o vena eferente 69,5% (25/36: vena arterializada VA de 14 FRC y 7 fístulas humerales; anastomosis venosa de 4 prótesis). Resultados: Once casos de estenosis de la AR (prevalencia: 11/36, 30,5%; grado medio: 83,5 ± 15,8%) se diagnosticaron en 11 FRC (duración del AV 48,9 ± 76,7 meses) en 11 pts (edad 67,5 ± 11,5 años; tiempo en HD 54,0 ± 75,8 meses; 18,2% diabetes). Causa de evaluación positiva: QA absoluto 20% respecto al valor basal 8,2%. QA medio de la FRC justo antes de la angiografía: 532,9 ± 99,8 ml/min (intervalo, 418-699 ml/min). Clasificación de la estenosis: Tipo I (estenosis múltiple) 9.1%, tipo II (estenosis única pero crítica > 90-95% que altera la hemodinámica normal de la FRC) 36,4% y tipo III (estenosis única entre el 50 y el 90%) 54,5%. Seguimiento: estenosis no reparable 36,4% (4/11), intervención electiva mediante cirugía 36,4% (4/11), exitus (2/11) o trasplante (1/11) antes de la intervención 27,3%. El QA medio de la FRC tiende a aumentar desde 547,0 ± 100,6 ml/min justo antes de la cirugía hasta 872,3 ± 526,5 ml/min justo después de la cirugía (n = 4, DeltaQA = 325,2 ± 431,3 ml/min) (p = 0,068). Estudio comparativo con 14 estenosis de la VA (grado medio 76,4 ± 7,4%) de 11 FRC (duración del AV 16,4 ± 22,8 meses) en 11 pts (edad 64,3 ± 10,5 años; tiempo en HD 17,0 ± 18,9 meses; 50% diabetes): alta prevalencia de intervención (85,8%) en relación con los casos de estenosis de la AR (p = 0,011); sin diferencias en el grado de estenosis (p = 0,12), DeltaQA (p = 0,20) ni en el QA antes de la angiografía (p = 0,78) y de la cirugía (p = 1,00); el QA se incrementó significativamente después de la cirugía (n = 6, 549,8 ± 86,4 vs 1033,0 ± 216,6 ml/min) (p = 0,028). Conclusiones: 1) Un tercio de los casos de disfunción de la AV se deben a la afectación de la arteria nutricia. 2) No hemos encontrado diferencias en el perfil funcional al comparar los casos de estenosis de la AR y de la VA antes de la angiografía y de la cirugía. 3) Los resultados funcionales de la cirugía electiva de la estenosis de la AR son peores en relación con los de la estenosis de la VA

Objective: The aim of this study was to know the prevalence and functional profile of RA stenosis in RCF dysfunction detected as a result of our surveillance programme. Patients and methods: We prospectively monitored QA of 116 VA (arteriovenous fistula 81% or graft 19%; mean VA duration 28.2 ± 52.9 months) during hemodiaysis (HD) in 102 ESRD (mean age 63.0 ± 13.0 yr; sex M: 56.9%, F: 43.1%; mean time on HD 31.4 ± 44.0 months; 15.5% diabetes) patients (pts) over 4 yr period. QA was measured at least every 4 months by the Delta-H method using the Crit-Line III monitor (overall mean QA 1193.4 ± 490.3 ml/min) Forty-three VA (43/116, 37%) met criteria of positive evaluation (absolute QA 20% from baseline: 51.2%) and were referred for angiography. Most VA explored by angiography showed stenosis >= 50% (36/40, 90%) that were mainly located in RCF (25/36, 69.4%: RA 11/25, arterialized vein AV 14/25). Results: Eleven cases of RA stenosis (prevalence: 11/36, 30.5%; mean degree: 83.5 ± 15.8%) were found in 11 RCF (mean VA duration 48.9 ± 76.7 months) of 11 pts (mean age 67.5 ± 11.5 yr; mean time on HD 54.0 ± 75.8 months; 18.2% diabetes). Cause of positive evaluation: absolute QA 20% from baseline 18.2%. Mean QA of RCF just before angiography: 532.9 ± 99.8 ml/min (range, 418-699 ml/min). Stenosis type: Type I (multiple stenoses) 9.1%, type II (isolated stenosis but critical > 90-95%) 36.4% and type III (isolated stenosis 50-90% with normal haemodynamic status of RCF) 54.5%. Followup: stenosis not reparable 36.4% (4/11), elective intervention by surgery 36.4% (4/11), lost of follow-up before intervention 27.3% (2/11 died, 1/11 transplantation). Mean QA of RCF tended to increase from 547.0 ± 100.6 ml/min just before surgery to 872.3 ± 526.5 ml/min just after surgery (n = 4, mean DeltaQA = 325.2 ± 431.3 ml/min (p = 0.068). Comparative study with 14 AV stenosis (mean degree 76.4 ± 7.4%) in 11 RCF (mean VA duration 16.4 ± 22.8 months) of 11 pts (mean age 64.3 ± 10.5 yr; mean time on HD 17.0 ± 18.9 months; 50% diabetes): higher prevalence of intervention (85.8%) compared to RA stenosis (p = 0.011); without differences in degree of stenosis (p = 0.12), QA (p = 0.20) and QA before angiography (p = 0.78) or surgery (p = 1.00); mean QA increased significantly after surgery (n = 6 AV, 549.8 ± 86.4 vs 1033.0 ± 216.6 ml/min) (p = 0.028). Conclusions: 1) One third of cases of VA dysfunction were related to feeding artery stenosis. 2) No differences in functional profile were found between RA and AV stenosis before angiography and surgery. 3) The functional results of elective surgery in RA stenosis were worse compared to AV stenosis

Functional vascular access evaluation after elective intervention for stenosis.

PURPOSE: To evaluate the functional effects of preventive vascular access (VA) intervention through periodic blood flow (Q A ) measurements during hemodialysis (HD) by the delta-H method. METHODS: We prospectively monitored the blood flow rate (Q A ) of 100 VA (arteriovenous fistula (AVF) 81% or AV graft (AVG) 19%; mean VA duration 24.6 +/- 42.3 months) during HD in 89 end-stage renal disease patients (mean age 62.7 +/- 13.6 yrs; mean time on HD 30.9 +/- 43.9 months; 18% with diabetes) over a 3-yr period. Q A was measured at least every 4 months by the delta-H method (Yarar (6)) using the Crit Line III Monitor (overall mean Q A 1247.6 +/- 519.7 ml/min). The mean arterial pressure (MAP) and Kt/V index were measured simultaneously with Q A . Thirty-eight VA (38%) met the positive evaluation criteria (absolute Q A <700 ml/min 50%, Q A decreased >20% from baseline 50%). Most cases with positive evaluation underwent angiography (36/38, 95%) and had stenosis >/=50% (34/36, 94%). Of VA with significant stenosis, 17 (17/34, 50%) VA (AVF 76.5%, AVG 23.5%; mean VA duration 12.5 +/- 22.4 months, mean percentage of VA stenosis 75.8%) in 15 patients (mean age 68.4 +/- 9.8 yrs; mean time on HD 14.2 +/- 18.2 months; 33.3% with diabetes) underwent corrective intervention by angioplasty, 35.3% (6/17), and revision surgery, 64.7% (11/17). RESULTS: Short-term results: Elective intervention was successful in 88% of treated VA (15/17). Mean Q A increased from 563.8 +/- 115.4 ml/min just before intervention (Q A pre) to 975.7 +/- 351.8 ml/min just after intervention (Q A post) (mean delta Q A = 411.8 +/- 290.1 ml/min) (p < 0.001). We found a significant difference between the overall mean Q A before (689.6 +/- 227.0 ml/min) vs after intervention (965.9 +/- 396.8 ml/min) (p = 0.011). No difference was found when the highest recorded mean Q A before intervention (877.7 +/- 415.4 ml/min) and mean Q A post were compared (p = 0.25). Mean MAP did not change after intervention (91.5 +/- 12.5 vs 92.7 +/- 14.2 mmHg, p = 0.46). Mean Kt/V index improved from 1.44 +/- 0.24 just before intervention to 1.49 +/- 0.23 just after intervention without any change in dialyzer type or HD duration (p = 0.025). Mean delta Q A was similar for diabetic patients vs non-diabetic patients (p = 0.34), for younger patients (age <65 yrs) vs older patients (age >/=65 yrs) (p = 0.64) and for AVF vs AVG (p = 0.39). We found a positive correlation between mean delta Q A and mean Q A post (r = 0.95, p < 0.001) or between mean delta Q A and overall mean Q A after intervention (r = 0.77, p < 0.001). Long-term results: Prevalence of VA thrombosis during the follow-up period (354.4 +/- 293.1 days): 17.6% (3/17). Five (29.4%) treated VA showed restenosis and two of them (40%) underwent reintervention by surgery. Mean restenosis period and mean decrease in Q A were 232.6 +/- 74.1 days and 2.8 +/- 0.6 ml/min/day, respectively. No significant correlation was found between mean delta Q A or Q A pre and mean restenosis period or decrease in Q A (p = ns). CONCLUSIONS: 1) Monitoring Q A by the delta-H method is useful in assessing the hemodynamic response to elective VA intervention. 2) Mean Q A post was similar to the highest recorded mean Q A before intervention. 3) Mean delta Q A was related to mean Q A post and overall mean Q A after intervention. 4) The HD effectiveness (Kt/V index) improved after intervention.

[Tesio twin catheter system for hemodialysis tunnelized using an echo-guided technique. Retrospective analysis of 210 catheters]. / Catéteres tunelizados para hemodiálisis tipo "sistema Tesio de catéteres gemelos" mediante técnica ecodirigida. Análisis retrospectivo de 210 catéteres.

PURPOSE: Review a large experience in the placement of tunnelled catheters to assess the outcomes with twin catheter system as hemodialysis access. MATERIAL AND METHODS: We retrospectively reviewed clinical and hemodialysis data regarding of ESRD patients who were referred from 2 dialysis facilities for placement of tunnelled catheters hemodialysis access between 1996 March and 2005 July. For catheter insertion a real-time sonography technique was used (Site Rite II Dymax corporation) in performing vascular access procedure. The twin catheter system available during the study period consisted of 2 x 10-F12. Patients suspected to present bacteraemia related to catheter were followed with established protocols. Catheter suspected malfunction or thrombosis was treated with low dose Urokinase. To evaluated dialysis dose and adequacy, blood flow rates were recorded and Kt/v calculated by Daugirdas 2nd generation formula. RESULTS: Overall study period of 112 months, 210 catheters were inserted in 148 patients(93 males and 55 females, mean age 68,6 +/- 4,95 years). 101 catheters were inserted in internal jugular vein, 84 in femoral and 25 in subclavian. The successful insertion rate with only single needle pass was 87.8%, immediate procedural complications rate was 4.7%. The catheters were in place a total of 18,324 days during the study period (mean 87.2 days; range 4-1,280 days). The mean flow blood rate was 252,4 DS +/- 42.4 mL/min, Mean Kt/v was 1,21 DS +/- 0,07. Seventy-seven catheters malfunctioned during study period, in 55 cases urokinase was effective in recovering blood flow rate over 250 mL/min and 25 necessitated removal for ineffective urokinase. Infection incidence was 11.9% with bacteraemia related catheter rate of 2.8 episodes per 1,000 catheter-days, Gram positive bacteria was found in (84%), Gram negative in (12%) and others(4%). CONCLUSION: Placement of tunnelled twin catheters system using real-time sonography technique can be performed with excellent technical success, safety and acceptable catheter performance and outcomes for effective hemodialysis.

[Study of vascular access (VA) by color Doppler ultrasonography (CDU). Comparison between delta-H and CDU methods in measuring VA blood flow rate]. / Estudio del acceso vascular (AV) mediante ecografía Doppler color (EDC). Comparación entre los métodos EDC y delta-H aplicados para la determinación del flujo sangúineo del AV.

INTRODUCTION: The color Doppler ultrasonography (CDU) is a noninvasive vascular access (VA) monitoring technique that provides both structural and hemodynamic information from VA. On the other hand, the delta-H (AH) method is another noninvasive technique that measures the VA blood flow rate during hemodialysis (HD). OBJECTIVE: 1) To analyze some anatomic and functional parameters of VA by CDU. 2) To compare AH and CDU methods in measuring VA blood flow rate. PATIENTS AND METHODS: We explored the VA (radial arteriovenous fistula AVF 60.6%, brachial AVF 24.2%, femoral graft 15.2%; mean VA duration 33.5 +/- 31.5 months) of 33 stable ESRD (mean age 61.7 +/- 13.3 yr, sex M: 48.5%; F: 51.5%; mean time on hemodialysis HD 39.3 +/- 33.3 months; 9.1% diabetes) patients (pts) by CDU over 3 months period. All CDU examinations were performed off HD by the same radiologist using a 5-10 MHz linear transducer. The arterial and venous blood flow rates were calculated by CDU using the equation: flow (ml/min) = time average velocity (mean of three cardiac cycles) (m/s) x cross-sectional area (mm2) x 60. No VA explored had any sign of dysfunction prior to CDU evaluation. All pts with significant VA stenosis by CDU (> or = 50% reduction in the luminal diameter) were referred for angiography (AG). All functional parameters were measured in duplicate and the values were averaged. In addition, QA was also calculated in the same week by the deltaH method during HD using the Crit Line III Monitor. RESULTS: Feeding artery (FA) results. Mean FA diameter (FAd): 0.7 +/- 0.2 cm. Mean peak systolic velocity: 161.8 +/- 44.5 m/s. Mean FA blood flow rate (FA flow) (n = 27): 2,030.8 +/-987.1 ml/min. We found a positive correlation between mean FA flow and mean FAd (R2 = 0.39, p < 0.001). Arterialized vein (AV) results. Mean AV diameter (AVd): 0.7 +/- 0.2 cm. Mean AV blood flow rate (AVflow): 1,783.8 +/- 1,009.7 ml/min (range, 398-5,843 ml/min). Mean coefficient of variation for duplicate AV flow measurements: 9.2%. We found a positive correlation between mean AV flow and: mean FAd (R2 = 0.22, p = 0.005), mean FAflow (R2 = 0. 19, p = 0.022) and mean AVd (R2 = 0.14, p = 0.034). Three pts (9.1%) showed significant VA stenosis by CDU and in, all cases, the location and degree of stenoses were confirmed by AG. The mean AVflow was lower in VA with significant stenosis (511.0 +/- 179.1 ml/min) compared to VA without stenosis (1,911.1 +/- 968.7 ml/min) (p = 0.006). The calculated values of VA blood flow rate obtained by the CDU technique (AV flow) were highly correlated with those determined by the AH method (QA) when considering all comparison values (n = 33, ICC = 0.74, p < 0.0001), for AV flow < 2,000 ml/min (n = 23, ICC = 0.82, p < 0.0001) and for AV flow < 1,500 ml/min (n = 14, ICC = 0.73, p = 0.001). No significant difference was found when QA (1,593.8 +/- 645.7 ml/min, range 559-2,778 ml/min) and AV flow were compared (p = 0.082). CONCLUSIONS: 1) The CDU technique is a valuable and reproducible method for AV flow measurement and for early diagnosis of significant VA stenosis. 2) The AV flow is related to FA parameters. 3) Both methods, CDU and AH, correlated highly with each other when were applied on VA blood flow rate measurement.

[Non-invasive monitoring of a humeral arteriovenous fistula with hemodynamic repercussions]. / Monitorización no invasiva de fístula arteriovenosa (FAVI) humeral con repercusión hemodinámica.

A 70-year-old woman, who undergoing hemodialysis due to chronic pyelonephritis, is reported. She suffered from dyspnea due to pulmonary artery hypertension secondary to volume overload as a complication of high-flow brachial AVF. The combined estimation of vascular access blood flow rate (QA) and systolic pulmonary artery pressure by noninvasive methods (ultrafiltration and Doppler echocardiography, respectively) allowed us the diagnosis, make a surgical indication and post-surgical follow-up of AVF with hemodynamic repercussion.

Monitorización no invasiva de fístula arteriovenosa (FAVI) humeral con repercusión hemodinámica / Noninvasive monitoring of arteriovenous fistula (avf) with hemodynamic repercussion

Presentamos el caso de una enferma de 70 años, en programa de hemodiálisis periódica por pielonefritis crónica, que presentó disnea en relación a hipertensión arterial pulmonar moderada secundaria a la sobrecarga volumétrica de FAVI humeral hiperdinámica. La estimación del flujo sanguíneo (QA) del acceso vascular y de la presión arterial pulmonar sistólica (PAPs) de forma conjunta por métodos no invasivos (ultrafiltración y ecocardiograma doppler, respectivamente) nos permitió diagnosticar, sentar la indicación quirúrgica y efectuar el seguimiento postoperatorio de la FAVI con repercusión hemodinámica

A 70-year-old woman, who undergoing hemodialysis due to chronic pyelonephritis, is reported. She suffered from dyspnea due to pulmonary artery hypertension secondary to volume overload as a complication of high-flow brachial AVF. The combined estimation of vascular access blood flow rate (QA) and systolic pulmonary artery pressure by noninvasive methods (ultrafiltration and doppler echocardiography, respectively) allowed us the diagnosis, make a surgical indication and post-surgical follw-up of AVF with hemodynamic repercussion