[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.

[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.

[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.

[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.

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.

[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.

[Vascular access surveillance with blood flow monitoring: a prospective study with 65 patients]. / Monitorización del acceso vascular mediante la determinación del flujo sanguíneo durante la hemodiálisis por el método de ultrafiltración. estudio prospectivo de 65 pacientes.

BACKGROUND: Periodic intra-access blood flow rate (QA) monitoring is the preferred method for vascular access (VA) surveillance (NKF-K/DOQI, update 2000). OBJECTIVES: 1) To determine the ultrafiltration (UF) method accuracy for early detection of VA stenosis. 2) To evaluate the hemodynamic effect of elective VA intervention (angioplasty or surgery). 3) To define the impact of periodic QA monitoring using the UF method combined by elective VA intervention on VA thrombosis. PATIENTS AND METHODS: We prospectively monitored QA during hemodialysis (HD) in 65 ESRD (mean age 64.9 +/- 11.4 years, 20% diabetes) patients over 1 year period. All patients undergoing HD in the Hospital de Mollet by arteriovenous fistula (89.2%) or graft 10.8%. QA was measured at least every 4 months by the UF method using the Crit Line III Monitor. Fifty (77%) patients were included at the beginning of the study period and the remaining 15 (23%) were added later when they started HD. All patients with absolute QA <700 ml/min or decreased >20% from baseline met criteria of positive evaluation (PE) and were referred for angiography (AG) plus subsequent preventive intervention (angioplasty or surgery) if VA stenosis >50%. We also studied 94 not QA monitored patients since the beginning of the study period (mean age 64.6 +/- 13.7 years; 12.8% diabetes) that undergoing HD simultaneous in the Institut Nefrològic Granollers. RESULTS: We performed 200 QA measurements in 509 months of follow-up. The overall mean QA was 1176.7 +/- 491.8 ml/min (range, 380.5-2904.0 ml/min). Three patients (4.6%) thrombosed VA. Nineteen (29.2%) patients had PE; none of them clotted VA. The AG was performed in 84.2% (16/19) patients with PE and all of them (16/16) showed VA stenosis > or =50%; 31.2% (5/16) were lost to follow-up (3 death, 2 transplantation); of the remaining explored patients (11/16), 72.7% (8/11) underwent intervention (3 angioplasty, 5 surgery). The mean QA increased from 577.2 +/- 108.2 ml/min to 878.1 +/- 264.4 ml/min postintervention (p=0.005). The positive predictive value, negative predictive value, sensitivity and specificity of UF method for VA stenosis were 84.2%, 93.5%, 84.2% and 93.5%, respectively. VA thrombosis rate in our 50 beginners QA monitored patients (mean age 64.5 +/- 1 1.4 years; 20% diabetes) was lower (2/50, 4%) compared to 94 not QA monitored patients (16/94, 17%) (p=0.024). CONCLUSIONS: 1) QA monitoring using the UF method allows an early diagnosis of VA stenosis. 2) Serial QA measurement by UF method can be used in assessing the functional response to corrective VA intervention. 3) Periodic VA surveillance by QA measurements using the UF method combined with elective intervention results in reduced VA thrombosis.

[Cutaneous trophic disorders secondary to arteriovenous fistula for hemodialysis]. / Trastornos tróficos cutáneos secundarios a fístula arteriovenosa para hemodiálisis.

The arteriovenous fistula is the vascular access of choice for hemodialysis treatment in patients with chronic renal failure. Clinical occurrence of local circulatory troubles caused by the fistula in addition to arterial robbery or venous hypertension are infrequent but may provoke serious consequences. Two patients with arteriovenous fistula with cutaneous trophic disorders secondary to the venous hypertension syndrome (case 1) and to the arterial robbery syndrome (case 2) are present. Prevalence, pathogenic factors, physiopathology, clinical aspects, and diagnosis and treatment of both syndromes are reviewed. Finally, the difficulty and morbidity of the creation of an efficient arteriovenous fistula in the diabetic patient is underlined.

[Familial microepidemics of tuberculosis]. / Microepidemia familiar de tuberculosis.

We report a microepidemic of tuberculosis (TBC) in a family of 12 members, 4 of which were parenteral drug abusers and 3 had anti-human immunodeficiency virus (HIV) antibodies. Four new cases were simultaneously diagnosed in the investigation of the contacts of a patient with extrapulmonary tuberculosis and acquired immunodeficiency syndrome. We review the requirements for the development of these epidemic outbreaks, both in noninfected communities and in the family contacts, where positive anti-HIV antibodies may increase the risk. We emphasize the importance of a systematic study of contacts in these families and the indication of chemoprophylaxis in all those sharing the same household, without age limit.

Guía clínica española del acceso vascular para hemodiálisis / Spanish clinical guidelines on vascular access for haemodialysis

El acceso vascular para hemodiálisis es esencial para el enfermo renal tanto por su morbimortalidad asociada como por su repercusión en la calidad de vida. El proceso que va desde la creación y mantenimiento del acceso vascular hasta el tratamiento de sus complicaciones constituye un reto para la toma de decisiones debido a la complejidad de la patología existente y a la diversidad de especialidades involucradas. Con el fin de conseguir un abordaje consensuado, el Grupo Español Multidisciplinar del Acceso Vascular (GEMAV), que incluye expertos de las cinco sociedades científicas implicadas (nefrología [S.E.N.], cirugía vascular [SEACV], radiología vascular e intervencionista [SERAM-SERVEI], enfermedades infecciosas [SEIMC] y enfermería nefrológica [SEDEN]), con el soporte metodológico del Centro Cochrane Iberoamericano, ha realizado una actualización de la Guía del Acceso Vascular para Hemodiálisis publicada en 2005. Esta guía mantiene una estructura similar, revisando la evidencia sin renunciar a la vertiente docente, pero se aportan como novedades, por un lado, la metodología en su elaboración, siguiendo las directrices del sistema GRADE con el objetivo de traducir esta revisión sistemática de la evidencia en recomendaciones que faciliten la toma de decisiones en la práctica clínica habitual y, por otro, el establecimiento de indicadores de calidad que permitan monitorizar la calidad asistencial.

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support.

El acceso vascular para hemodiálisis: la asignatura pendiente / No disponible

No disponible

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)