bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dialock® Subcutaneous Port for Hemodialysis: A Twelve-Month Experience in a Single Center
Authors: Quarello F. , Forneris G. , Formica M. , Pozzato M. , Borca M. , Vallero A. , Cesano G. 
Published: January 2018

Background The arteriovenous fistula (AVF) is still considered the golden standard form of vascular access for hemodialysis. However, the increasing use of central venous catheters mirrors the growing difficulty in planning an AVF. A totally implantable new device, the Dialock® system (Biolink Corporation, Norwell, MA), allowed us to conduct the first Italian experience. Methods From February 1st 2000 to January 31st 2001, we implanted 21 devices in 12 males and 9 females, median age 66±12 years, with a dialysis duration ranging from 0 to 22 years. In 6 cases the Dialock® was first choice access, in 5 it replaced a malfunctioning tunneled central venous catheter, and in 10 cases it was the rescue access after previous AVF failures. Results On average, the device was accessed 3.5 days after implantation. Median duration of use was 142 days (range 29–365), for a global observation period of 118.2 pt-months. Nineteen devices are currently working without any problem. One port was removed after 60 days due to thrombosis, and another after 9 months of use due to sepsis. Another patient had a systemic infection with cardiac and vertebral involvement with complete remission after 4 months of antibiotic therapy and salvage of the device. The infection rate was 1.3 per 1000 catheter-days. Prescribed blood flow was achieved in 95.7% of the sessions. Conclusion Our short-term results confirm the efficacy and reliability of the new device. In order to assess the true indication for implanting Dialock®, a more prolonged observation period is needed.
The Effect of Age on Radiocephalic Fistula Patency
Authors: Burt C.G. , Little J.A. , Mosquera D.A. 
Published: January 2018

Background Inferior patency rates for radiocephalic fistulae in the elderly have been reported and may explain the increasing use of prosthetic grafts for vascular access. The aim of this study was to assess whether the patency rates of primary radiocephalic fistulae are affected by age. Methods A retrospective casenote review of 53 consecutive patients undergoing primary fistula formation between 1995 and 1998 under the care of a single consultant vascular surgeon. The setting was a specialist vascular surgical unit where the protocol is to offer all new patients a radiocephalic fistula. Fistula patency was defined as successful use for dialysis. Results Cumulative patency rates at 2 years were 60% in patients over 60 years (n=27), and 53% in patients under 60 years (n=26). The higher patency rates in the older age group were not significant on log rank testing (p=0.39). Conclusion Age over 60 years did not influence patency rates of primary radiocephalic fistulae, which should remain the haemodialysis access procedure of choice at all ages.
Early Failure Rates of Arterovenous Fistulas for Hemodialysis: Evaluation of Six-Year Activity
Authors: Ravani P. , Marcelli D. , Pecchini P. , Malberti F. 
Published: January 2018

Maintenance and complications of vascular access (VA) for hemodialysis (HD) represent the leading cause of morbidity and health care cost among end stage renal disease population. To define the reasons for the use of a particular VA at the beginning of replacement treatment, we prospectively evaluated the early failure rate and survival of arterovenous fistula (AVF) in 183 patients. These patients had high prevalence of cardiovascular risk factors and co-morbid conditions, and began HD in our renal unit from the 1st of January 1995. As a part of this study the present analysis focuses on potential predictors of early failure of the first AVF (within the first 7 days after the operation). Overall, 279 AVF were prepared: 193 at the wrist and 86 at the upper arm, including 11 prosthetic grafts; 150 patients (82%) were given a distal AVF in the first operation. Our conservative policy resulted in a relatively high prevalence of native AVF in use among our prevalent HD patients (84.3%). Early failure of the first VA was 10.4%. Multivariate analysis showed that this event was neither significantly associated with all traditional risk factors and co-morbids tested, nor with the operating surgeon. We conclude that in this prospectively studied cohort, the high rate of native AVF created in order to preserve the vascular bed, though associated with a high early failure rate unaffected by traditional cardiovascular risk factors, resulted in a low proportion of permanent catheters and arterovenous grafts in use among prevalent HD patients.
Central Venous Port Catheters: Evaluation of Patients' Satisfaction with Implantation under Local Anesthesia
Authors: Maurer M.H. , Beck A. , Hamm B. , Gebauer B. 
Published: January 2018

Purpose Evaluation of pain perception and patient satisfaction after implantation of a central venous port catheter system under local anesthesia. Methods A total of 100 consecutive patients (25 outpatients, 75 inpatients) who underwent successful implantation of a port catheter into the internal jugular vein from May through August 2007 were given an 8-item questionnaire. The extent of information about the implantation, the pain perception during implantation and the friendliness of the physician and nurse were evaluated. Furthermore, the patients were asked to assess their degree of anxiety and the pain they experienced during the intervention and to give an appraisal of whether local anesthesia was adequate. Each question was assessed on a 10–point scale (10 = very true to 1 = not at all true). In addition, the overall duration of the intervention (including patient preparation, implantation, patient aftercare, disinfection of the room) was documented. Results Patients felt highly satisfied with the way they were informed (mean score of 9.65) and considered the treating physician (9.89) and nurse (9.9) extremely friendly. Local anesthesia was rated as nearly completely adequate (9.56) and the degree of pain experienced was low (9.05; 10 = no pain). The average anxiety score was 8.56 (10 = not afraid at all). Overall satisfaction with the treatment was very high (9.62; outpatients: 9.72) and patients would recommend port catheter implantation at our department to others (9.77). The mean overall duration of the intervention was 76 min (range 40–120 min). Conclusion Positive patient reactions indicate that radiologic port catheter implantation under local anesthesia is a minimally invasive intervention with high patient satisfaction that can be performed on an outpatient basis and is a valid alternative to surgical implantation.
Dialysis Needle Hemodynamics in Arterio-Venous Fistulae: A Technical Report
Authors: Tuka Vladimir , Wijnen Edwin , van der Sande Frank M. , Hm Tordoir Jan 
Published: January 2018

Background Vascular access is the lifeline for end-stage renal disease patients needing hemodialysis treatment. For dialysis treatment two needles are placed into the vascular access. Few studies on needle hemodynamics have been published. Methods We investigated needle hemodynamics by means of Doppler ultrasonography, both in B-mode and in pulsed Doppler mode. Results Direct visualization of the needles, turbulence around the arterial needle and blood flow jet from the venous needle are presented. Conclusions Ultrasound investigation of the hemodynamics of the dialysis needles is feasible. The extreme blood flow jet through the arterial needle was directed in all patients to the anterior vessel wall.
Effects of the Arteriovenous Fistula on Pulmonary Artery Pressure and Cardiac Output in Patients with Chronic Renal Failure
Authors: Beigi Ali Akbar , Sadeghi Amir Mir Mohammad , Khosravi Ali Reza , Karami Mehdi , Masoudpour Hassan 
Published: January 2018

Introduction Access to the vascular system is necessary in patients with chronic renal failure planned to undergo dialysis. One of the complications of end-stage renal disease patients is pulmonary hypertension (PHT). Temporary arterio-venous access closure and successful kidney transplantation causes a significant fall in cardiac output and pulmonary artery pressure (PAP), indicating the possibility that excessive pulmonary blood flow is involved in the pathogenesis of the disease. We attempted to study the relationship of PHT with arteriovenous fistula (AVF) creation, as well as to assess the relationship between AVF flow and fistula characteristics. Methods Fifty patients were included in the study. Echocardiography was used to evaluate systolic PAP, cardiac output (CO), and ejection fraction (EF) before creating the AVF. After a follow-up interval of at least 6 months, a second echocardiographic assessment and a Doppler sonographic assessment of their fistula flow were carried out. Complete data were available for 34 patients. Results Study data were collected from 34 patients, 28 males and 6 females with a mean age of 52 yrs ranging from 15–78 yrs. The data showed a statistically significant positive correlation between fistula flow and PAP2 and PAP changes (p<0.05). Mean fistula flow was 1322 ml/min in patients without PHt and 2750 ml/min in patients with PHT. this difference (1428 ml/ min) was statistically significant (p=0.03). We found a significant negative correlation between PAP1 and EF1 and PAP2 and EF2 (p<0.05). In addition, the mean EF2 in patients without PHT was 57% in contrast to 46% in patients with PHT. Mean fistula flow in radial fistulae (mean=422 ml/min, range: 370–474 ml/min) was significantly less than brachial fistulae (mean=1463 ml, range: 270–3300 ml/min) (p=0.03). Mean systolic PAP2 of 14.8 mmHg in transplanted patients was 5.9 mmHg less than those who were not transplanted (20.7 mmHg). Diabetes was the most common cause of renal failure and diabetics had a significant reduction in their EF (15.5%) compared with non-diabetic patients (1% reduction) (p=0.016). Conclusion Fistula flow, PAP and EF of all patients should be checked at least 6 months after fistula creation. Patients with higher fistula flow rates and patients with diabetes mellitus need to be more closely observed. In addition, elderly patients with significant cardiac and other comorbidities may be more prone to develop symptoms after AVF creation
Aggressive Approach to Salvage Non-Maturing Arteriovenous Fistulae: A Retrospective Study with follow-up
Authors: Miller Gregg A. , Goel Naveen , Khariton Aleksandr , Friedman Alexander , Savransky Yevgeny , Trusov Ilya , Jotwani Kiran , Savransky Eric , Preddie Dean , Arnold William Perry 
Published: January 2018

Purpose To establish a standardized approach for the maturation of non-maturing arteriovenous fistulae. Methods consecutive patients (n=122) with non-maturing fistulae presented to our outpatient vascular access center for percutaneous interventions to assist in maturation. The techniques used included flow rerouting, competing branch vein elimination, staged balloon angioplasty, and limited controlled extravasation. Results Successful fistula maturations were achieved in 118/122 patients. Fistulae were divided into two classes according to initial vessel size: class 1 (6.0–8.0 mm diameter, >6 mm deep) and class 2 (2.0–5.0 mm diameter) fistulae were evaluated for differences in technical procedures and clinically successful fistula maturation. Class 1 and class 2 fistulae were evaluated for mean number of procedures to maturation (1.6 and 2.6, respectively), and time to maturation (5 and 7 weeks, respectively). Follow-up for 109 of the initial 118 patients was achieved (mean=24 months, range=0.25–60 months). Class 1 and class 2 fistulae had primary patencies of 17 and 39% at 6 months; and secondary patencies of 72 and 77% at 12 months, 53 and 61% at 24 months, and 42 and 32% at 36 months, respectively. Primary and secondary patencies (Mann-Whitney test, p=0.44 and p=0.38, respectively) of class 1 and class 2 fistulae did not differ significantly, and secondary patencies were comparable to other fistula salvage studies. Conclusion Fistula salvage attempts should not be limited by factors such as a diffusely small diameter or an inaccessibly deep position.
Vascular access Localization Determines Regional Changes in Arterial Stiffness
Authors: Fischer Edmundo I. Cabrera , Bia Daniel , Valtuille Rodolfo , Graf Sebastián , Galli Cintia , Armentano Ricardo L. 
Published: January 2018

Background Vascular access (VA) dysfunction is a common cause of hospitalization in chronically hemodialyzed patients (CHP) limiting the improvement in health and has been largely studied in order to decrease the morbidity events that involves both the artery and the vein used in the construction of the fistula. In parallel, patients in end-stage renal failure show an increase in arterial stiffness. Aim The aims of this work were: (a) to evaluate arterial stiffness through pulse wave velocity (PWV) measurements in the carotid-brachial pathway where the arteriovenous fistulae (AVF) was constructed, and (b) to determine possible differences in arterial stiffness between the carotid-brachial pathway with and without VA. Methods PWV, clinical and biochemical parameters were measured in 38 CHP. PWV was obtained in the carotid-femoral, and in the left and right carotid-brachial pathway. Results Carotid-brachial PWV determination in upper limbs with AVF (10.07 ± 2.43 m/s) showed significantly lower values than those observed in the contra-lateral arm without VA (11.55 ± 2.27 m/s). Curiously, the PWV value observed in arms with an AVF was significantly lower in diabetic than in non-diabetic hemodialyzed patients (NDHP) (8.00 ± 2.86 m/s and 10.38 ± 2.33 m/s; respectively). Measurements of PWV in the carotid-femoral pathway in CHP showed a mean value of 14.09 ± 3.12 m/s. Carotid-femoral PWV in NDHP (14.06 ± 2.44 m/s) was significantly lower than that observed in the diabetic patients (16.87 ± 3.42 m/s). Conclusions Carotid-brachial PWV values obtained in the upper limbs, in which VAs were constructed, were significantly lower than that measured in intact arteries in the contra-lateral pathway in CHP.
Should Fistulas Really be First in the Elderly Patient?
Authors: Richardson Albert I. , Leake Andrew , Schmieder Gregory C. , Biuckians Andre , Stokes Gordon K. , Panneton Jean M. , Glickman Marc H. 
Published: January 2018

Background The Kidney Disease Outcomes and Quality Initiative (K/DOQI) has developed guidelines from available data suggesting that arteriovenous fistulas (AVF) be performed in the majority of patients. Patient demographics were not included nor suggested in their recommendations. The purpose of this study is to analyze the outcomes of elderly patients, age greater than 70, undergoing first-time permanent access surgery. Methods A retrospective review of consecutive patients undergoing new, first time access procedures from January 2005 through December 2005 was performed. Patients with previous attempts at permanent Arteriovenous (AV) access were removed from analysis. Standard statistical methods were used and patency was determined with Kaplan-Meier curves. Results One hundred and sixty eight patients underwent first time AVF, 48 of whom were older than 70 years of age. Comparing elderly patients to younger ones, the 12 month primary assisted patency was 35% and 67%, respectively (p=0.002) and secondary patency was 36% and 67%, respectively (p=0.004). Of the 48 elderly patients, 48% had died in the subsequent follow up period as compared to just 20% of the 120 patients younger than 70. The 18-month survival for the elderly group was 50% versus 74% for the younger patients (p=0.004). Of the elderly group who died, the average time to death was 13.1 months and only 8 AVF were able to be accessed. Similar intervention rates per year were seen in both groups. Discussion With an aging population, more patients older than 70 are being evaluated for permanent vascular access. This group poses a difficult dilemma for surgeons attempting to adhere to K/DOQI guidelines. In light of the increased mortality and decreased patency of AVF, this data questions which form of permanent access should be first-line treatment in this subgroup of patients. Conclusion This data suggest in the elderly patients, autogenous fistulas may not be the best option for this set of patients.
Serum Chromogranin-A Immunoradiometric Assay in the Diagnosis of Pheochromocytoma
Authors: Giovanella L. , Ceriani L. 
Published: January 2018

Background The diagnosis of pheochromocytoma is based on laboratory tests that demonstrate an increase in urinary excretion of catecholamines or their metabolites. Chromogranin A (CgA) is a member of the granin family and is widely distributed in neuroendocrine cells and particularly in chromaffin adrenal cells. Consequently, serum CgA increases in patients affected by pheochromocytoma and other diseases of the chromaffin system. Aim This study investigated the performance of serum CgA assay in the diagnosis of pheochromocytoma and compared serum CgA with 24-hour urinary epinephrine (E), norepinephrine (NE), vanillylmandelic acid (VMA) and metanephrines (MNs). Methods We enrolled 15 patients with histologically proven pheochromocytoma; 100 healthy blood donors and 148 patients with essential hypertension were enrolled as controls. Serum CgA was assayed by a specific immunoradiometric method (IRMA). Urinary tests were done with high performance liquid chromatography (HPLC). Results Circulating CgA showed a higher sensitivity (1.00), specificity (0.96) and accuracy (0.96) than all other tests. Serum levels of CgA clearly increased from blood donors and patients with essential hypertension to patients with pheochromocytoma (p<0.0001). Furthermore, a strong relationship between serum CgA and tumor mass was found (p<0.0001). In conclusion, our data suggest that the CgA assay might be used as a single test for the diagnosis of pheochromocytoma.
The Impact of Intraoperative Manipulation of the Prostate on Total and Free Prostate-Specific Antigen
Authors: Oberpenning F. , Schmid H.-P. , Fuchs-Surdel W. , Hertle L. , Semjonow A. 
Published: January 2018

Objectives It is well documented that mechanical manipulation of the prostate can elevate total PSA (t-PSA) levels in serum. However, less is known about its effects on free PSA (f-PSA) and the free-to-total PSA ratio (f/t-PSA). We therefore examined the impact of prostate manipulation on t-PSA and f-PSA during surgical procedures involving the prostate. Methods Intraoperative blood samples for t-PSA and f-PSA measurement (Hybritech) were collected every 15 min during 14 radical retropubic prostatectomies (RRP) and 10 radical cystoprostatectomies (RCP). Results Prostatic manipulation induced significant elevations in t-PSA and f-PSA during RRP and RCP. Postmanipulatory peaks were markedly higher for f-PSA than for t-PSA. The mean maximum f-PSA levels showed a 4.3- (RRP) and 7.9-fold (RCP) increase, followed by a rapid decline after prostate removal. t-PSA increased 1.2- (RRP) and 1.3-fold (RCP), and declined more slowly. Postmanipulatory f/t-PSA ratios also increased significantly, reaching mean elevations of +0.29 and +0.28 over preoperative ratios during RRP and RCP, respectively. Conclusions Prostate manipulation can induce transient increases in t-PSA, f-PSA and f/t-PSA in benign and malignant prostates. The extent of these alterations and their course over time must be taken into account when postmanipulatory changes in PSA forms are investigated. Timing of postmanipulatory venipunctures and the molar response ratio of t-PSA assays used (equimolar versus nonequimolar) seem to have substantial impact on the results of such studies.
Prostate-Specific Antigen Levels among Cirrhotic Patients
Authors: Akdogan M. , Hassoun B.S. , Gurakar A. , El-Sahwi K. , Jazzar A. , Wright H. , Sebastian A. , Nour B. 
Published: January 2018

Purpose The aim of this study was to determine serum prostate-specific antigen (PSA) levels in patients with liver cirrhosis. Patients and methods Between January 1995 and August 2001, 216 men with cirrhosis were evaluated. The extent of their liver disease was classified according to the Child-Pugh classification. Serum PSA levels were measured with the Hybritech Tandem-R RIA method and matched with age-related reference PSA levels. Digital rectal examination (DRE) was performed in all patients. Patients with elevated PSA levels and/or abnormal DRE were recommended to undergo further assessment including transrectal ultrasonography (TRUS) and biopsy performed by an urologist. Results Two hundred and sixteen men (mean age 54.09±9.09 years, range 25–76) with cirrhosis were examined. Their mean PSA value was 0.57±0.84 ng/mL and tended to be lower than in the normal population. The degree of PSA decrease was found to parallel the severity of the liver disease (p=0.002). The mean serum PSA level increased with each age decade in a statistically significant manner (p<0.001). Four patients (three with elevated PSA values) underwent prostate biopsy. Three biopsies were positive for prostate cancer, the other showed evidence of benign prostatic hyperplasia (BPH). Conclusion Serum PSA is influenced by the severity of liver disease and its levels tend to be lower in cirrhotic patients than in the normal population. However, serum PSA can still be considered a reliable marker in the clinical management of prostatic disease in patients with cirrhosis.
Quantitative Assessment of HER-2/Neu Protein Concentration in Breast Cancer by Enzyme-Linked Immunosorbent Assay
Authors: Müller V. , Thomssen C. , Karakas C. , Eustermann I. , Porras J. Ramirez , Coith C. , Berger J. , Löning T. , Jänicke F. , Pantel K. 
Published: January 2018

Purpose The HER-2/neu protein (p185) has become a promising target for antibody therapy in breast cancer. We tested the feasibility of a quantitative approach for HER-2/neu testing based on the analysis of tumor tissue extracts by an enzyme-linked immunosorbent assay (ELISA). Experimental design Tumor tissue extracts of primary human breast cancers (n=124) were prepared using a triton-based buffer. HER-2/neu concentration was quantified by ELISA. Paraffin-embedded tissue sections of the same tumors were analyzed by immunohistochemical staining applying the monoclonal HER-2/neu antibody TAB 250 (n=124) and by chromogenic in situ hybridization (CISH) (n=73). Results Concentrations of p185 in tissue extracts determined by ELISA varied from 1 to 927 ng per mg protein with a median of 25 ng/mg protein, whereas normal breast tissue showed values from 0.4 to 5.5 ng/mg with a median of 2.2 ng/mg (p<0.0001, Mann-Whitney U test). A significant correlation between p185 concentration and immunohistochemical staining was observed (p<0.0001, Kruskal-Wallis test). In addition, p185 concentration measured by ELISA was correlated with the degree of HER-2/neu gene amplification determined by CISH. HER-2/neu-amplified tumors had significantly higher p185 concentrations (median value 181 ng/mg protein) than non-amplified tumors (median value 20 ng/mg; p<0.0001, Mann-Whitney U test). Conclusions ELISA-based measurement of HER-2/neu protein concentration in breast cancer tissue extracts is feasible and provides quantitative results for p185 protein concentrations that correlate closely with HER-2/neu immunoscore and gene amplification.