PubMed Health⌕ Search

Biomedical subjects

J Viladoms

Publications and source records attributed to J Viladoms.

9 recordsLinked to original sources
PubMed2006

[Prevalence and functional profile of unsuspected radial artery stenosis in native radiocephalic fistula dysfunction. Diagnosis by vascular access flow monitoring using Delta-H method].

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.

Adult↗
PubMed2006

[Tesio twin catheter system for hemodialysis tunnelized using an echo-guided technique. Retrospective analysis of 210 catheters].

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.

Aged↗
PubMed2005

[Study of vascular access (VA) by color Doppler ultrasonography (CDU). Comparison between delta-H and CDU methods in measuring VA blood flow rate].

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.

Adult↗
PubMed2003

[Non-invasive monitoring of a humeral arteriovenous fistula with hemodynamic repercussions].

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.

Aged↗
PubMedDate not supplied

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.

Adult↗