bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-Target Versus Low-Target Blood Pressure Management During Cardiopulmonary Bypass to Prevent Cerebral Injury in Cardiac Surgery Patients
Authors: Vedel Anne G. , Holmgaard Frederik , Rasmussen Lars S. , Langkilde Annika , Paulson Olaf B. , Lange Theis , Thomsen Carsten , Olsen Peter Skov , Ravn Hanne Berg , Nilsson Jens C. 
Published: January 2018

Background:
Cerebral injury is an important complication after cardiac surgery with the use of cardiopulmonary bypass. The rate of overt stroke after cardiac surgery is 1% to 2%, whereas silent strokes, detected by diffusion-weighted magnetic resonance imaging, are found in up to 50% of patients. It is unclear whether a higher versus a lower blood pressure during cardiopulmonary bypass reduces cerebral infarction in these patients.

Methods:

In a patient- and assessor-blinded randomized trial, we allocated patients to a higher (70–80 mm Hg) or lower (40–50 mm Hg) target for mean arterial pressure by the titration of norepinephrine during cardiopulmonary bypass. Pump flow was fixed at 2.4 L·min
−1
·m
−2
. The primary outcome was the total volume of new ischemic cerebral lesions (summed in millimeters cubed), expressed as the difference between diffusion-weighted imaging conducted preoperatively and again postoperatively between days 3 and 6. Secondary outcomes included diffusion-weighted imaging–evaluated total number of new ischemic lesions.

Results:

Among the 197 enrolled patients, mean (SD) age was 65.0 (10.7) years in the low-target group (n=99) and 69.4 (8.9) years in the high-target group (n=98). Procedural risk scores were comparable between groups. Overall, diffusion-weighted imaging revealed new cerebral lesions in 52.8% of patients in the low-target group versus 55.7% in the high-target group (
P
=0.76). The primary outcome of volume of new cerebral lesions was comparable between groups, 25 mm
3
(interquartile range, 0–118 mm
3
; range, 0–25 261 mm
3
) in the low-target group versus 29 mm
3
(interquartile range, 0–143 mm
3
; range, 0–22 116 mm
3
) in the high-target group (median difference estimate, 0; 95% confidence interval, −25 to 0.028;
P
=0.99), as was the secondary outcome of number of new lesions (1 [interquartile range, 0–2; range, 0–24] versus 1 [interquartile range, 0–2; range, 0–29] respectively; median difference estimate, 0; 95% confidence interval, 0–0;
P
=0.71). No significant difference was observed in frequency of severe adverse events.

Conclusions:
Among patients undergoing on-pump cardiac surgery, targeting a higher versus a lower mean arterial pressure during cardiopulmonary bypass did not seem to affect the volume or number of new cerebral infarcts.

Clinical Trial Registration:

URL:
https://www.clinicaltrials.gov
. Unique identifier: NCT02185885.
Vascular Screening Prior to Placement of Tunnelled and Cuffed Hemodialysis Catheters
Authors: Falk A. , Lookstein R. , Uribarri J. , Shen C. , Teodorescu V. , Vassalotti J.A. 
Published: January 2018

Purpose To demonstrate the importance of venous vascular screening before the placement of tunneled and cuffed hemodialysis catheters in patients requiring hemodialysis prior to placement and/or maturation of an arteriovenous fistula (AVF) or graft (AVG). Methods Between October 1998 and March 2000, all patients requiring hemodialysis access placement were prospectively evaluated with duplex ultrasound for status of upper extremity vessels and central veins prior to selection of a permanent access site. When interim tunneled and cuffed hemodialysis catheters were required, they were placed on the side contralateral to proposed AVF/AVG placement. No catheters were placed without initial vascular screening. The study group was compared to historical controls during a similar period (April 1997 through September 1998) when no vascular screening was performed. Results During the study period, 234 screening duplex ultrasound examinations were performed in 244 patients. Ten patients required no screening prior to access site placement. Overall, 353 catheters were placed, 243 (69%) on the right side and 110 (31%) on the left side. During the control period, 394 catheters were placed in 255 patients, 306 (78%) right-sided and 88 (22%) left-sided. The increase in left-sided catheters with ultrasound screening and careful planning for future access sites was significant (p<0.01). Conclusion Vascular-screening-directed catheter placement significantly alters the side of catheter placement when compared to a management protocol without prior screening. Such screening helps identify the side of permanent access placement, while directing interim catheters to the contralateral side such that central veins may be preserved for permanent access.
Steal Syndrome after Brachiocephalic Fistula for Vascular Access: Correction with a New Simple Surgical Technique
Authors: Henriksson A.E. , Bergqvist D. 
Published: January 2018

Purpose Steal syndrome is the condition of arterial insufficiency distal to a permanent haemodialysis fistula. Three treatment options have been recommended: ligation of the fistula, banding of the fistula, and distal revascularization. We report an alternative simple surgical technique for correction of steal syndrome. Methods Two patients were treated for steal syndrome after brachiocephalic fistula operation. The treatment of the steal syndrome was done by interponating an ePTFE graft loop tunnelated subcutaneously in the upper arm. Results At follow-up one year later both fistula were patent without any reoperation and with normal flow at haemodialysis. There were no symptoms of steal. Conclusion This new method for correction of steal syndrome seems to be an attractive alternative.
ProCol® Vascular Bioprosthesis for Vascular Access: Midterm Results
Authors: Hatzibaloglou A. , Velissaris I. , Kaitzis D. , Grekas D. , Avdelidou A. , Kiskinis D. 
Published: January 2018

Background/Aims This study aimed to evaluate the safety and efficacy of the ProCol, vascular bioprostheses as vascular access (VA) material, especially in patients with a history of prior failed access. Methods During a 20-month period, 25 arteriovenous (AV) bovine vein grafts were placed in 24 hemodialysis (HD) patients for VA. All patients presented with failed autologous access sites. Results Graft placement was successful in all patients with no procedure-related complications. Follow-up from 6–26 months gave primary 6-month, 12-month and 24-month patency rates of, respectively, 90%, 80% and 70%. Graft characteristics in cannulation and hemostasis were very satisfying. Conclusion Our midterm results demonstrated that the ProCol, vascular bioprosthesis was a promising material for VA with good patency and low complication rates.
New Graft for Low Friction Tunneling in Vascular Access Surgery
Authors: Schild A.F. , Baltodano N.M. , Alfieri K. , Livingstone J. , Raines J.K. 
Published: January 2018

Purpose Prosthetic accesses of the upper extremity have been in use for more than 25 years. Many different conduits have been employed; investigators have continually searched for a graft with superior properties. Methods We describe a prospective randomized study comparing the new Slider Graft (Atrium) with the Hybrid PTFE Graft (Atrium); the latter has been used for a number of years. The Slider Graft is also made of PTFE. For this study, both grafts were 6 mm in diameter and 40 cm in length. The Slider Graft has a low friction polyethylene sheath over its entire length. This sheath expedites the passage of the graft through the tunnel. At one end, the graft and the polyethylene sheath are attached to a metal tip. This tip has male threads, which may be inserted firmly into a Kelly Wyck, Atrium, or any standard non-sheath tunneling system. This alleviates graft separation, turning, and slipping during tunneling. The primary objective of this trial was to determine the safety and efficacy of the Slider Graft as compared to the Hybrid Graft in vascular access surgery. The secondary objective was to evaluate how tunneling effects graft performance. We randomized 60 subjects for this study with two equal arms. During surgery we measured various parameters including ease of tunneling, tunnel bleeding, anastomotic bleeding, graft sweating, and immediate patency. To assess arm edema we measured circumference 7.5 cm and 20 cm above the wrist, prior to surgery and in follow-up visits at 1 week, 1 month, and 3 months. Primary patency was also assessed at these visits and at 6, 9, and 12 months. Results Our results show tunneling with the Slider Graft is easier to accomplish (p = 0.0001) with reduced tunnel bleeding (p = 0.0047) and anastomotic bleeding (p = 0.042). Further, the Slider Graft virtually eliminated the complication of graft sweating and seroma development (p = 0.0005). This may be due to reduced stretching and graft wetting during insertion. At 180 days the Slider Graft demonstrated improved primary patency, which was statistically significant (p = 0.047). At 360 and 720 days the Slider Graft continued to demonstrate a trend toward improved primary patency (p = 0.160). Conclusions This study suggests the Slider Graft has significant advantages when compared to the Hybrid Graft and highlights the importance of tunneling in creating prosthetic accesses.
Salvage Insertion of Tunneled Central Venous Catheters in the Internal Jugular Vein after Accidental Catheter Removal
Authors: Bellasi A. , Brancaccio D. , Maggioni M. , Chiarelli G. , Gallieni M. 
Published: January 2018

Purpose Tunneled catheters are widely used for intermediate to long-term hemodialysis (HD) access, but are prone to several complications that can require catheter replacement. Replacing malfunctioning catheters with a new line, placed in a different access site, can lead to problems with multiple vein occlusions. This has led many nephrologists to continue using the same vein as long as possible by guidewire catheter exchanges, to preserve other veins for future use. We describe a guidewire exchange technique for the Ash-Split catheter in the internal jugular vein. Methods In three patients, the exchange was performed because of partial catheter removal, as evidenced by the outward dislocation of the Dacron cuff. In these patients, the guidewire was inserted through the catheter. In two additional patients, the catheter had been completely removed by accident: the replacement of the dislodged tunneled venous catheters was attempted 5 hr and 1 day after accidental removal. In these patients, the guidewire was inserted through the previous tunnel. After guidewire placement, a skin incision was made in the supraclavicular region. The metal guidewire was easily located inside the fibrous structure that had previously surrounded the catheter. The guidewire was then extracted from the subcutaneous tunnel and used to insert a new catheter safely and easily after creating a new tunnel. Patients were routinely given antibiotic prophylaxis (1 g of cefazolin) immediately before the procedure. A strict aseptic technique was used, including several sterile glove changes. Results No infections developed following this procedure, which has the potential for bacterial contamination. All procedures were successful. Only in one patient did we have to convert to a different catheter: it was not possible to replace the old Ash-Split catheter with the same dual-lumen catheter because of difficulties in inserting the peel away introducer-catheter complex. In this patient, rather than forcing it with larger dilators or trying to disrupt the fibrin sheath with balloon dilatation, a single lumen Tesio catheter was successfully placed. In both patients who completely lost the previous catheter, the guidewire was readily reinserted through the subcutaneous tunnel into the vein. Catheter function was excellent in all patients, with a test blood flow rate on the 1st catheter use >350 ml/min. Conclusions We described a new method for catheter exchange, which allows the easy insertion of a new catheter and the creation of a new and safer subcutaneous tunnel. In addition, we demonstrated that in cases of complete catheter removal, it is possible to reinsert a catheter in the same vein through a guidewire, even when reinsertion was attempted up to 1 day later.
In vitro and in vivo hemocompatibility evaluation of graphite coated polyester vascular grafts
Authors: Arabi H. , Mirzadeh H. , Ahmadi S.H. , Amanpour S. , Rabbani S. , Abdi A. 
Published: January 2018

Attempts have been made in this study to prepare a homogeneous and stable coating of graphite on polyester vascular grafts (GPVG) using an electrophoresis method to evaluate thromboresistant and blood compatibility of GPVG in comparison to non-coated PVG and InterGard (collagen sealed PVG) as control. Lactate dehydrogenase (LDH) activity measurement was carried out on all PVG types to evaluate platelet adhesion. To examine tissue reaction GPVG and non-coated sheets of knitted polyester fabric were implanted simultaneously in the dorsal flank of rats subcutaneously. The GPVG, non-coated and control were implanted in descending aorta as end-to-end or end-to-side implantation substitution in 25 sheep for 4–60 weeks. Results showed that the graphite coating on polyester vascular grafts reduced the number of adherent platelets and prevent platelet activation and spreading on the surface in comparison with non-coated and control. Pathological investigation showed inflammatory reactions were totally resolved after 12 weeks and there was no difference in the tissue reaction between graphite coated, non-coated and control patches. All grafts remained patent and there was no significant difference in patency rate between these three types of PVG. We found that GPVG has no need for pre-clotting and it showed lower platelet aggregation, thinner capsule formation and lower calcification after 15 months. However, suturing of GPVG was more difficult in comparison with the other types.
Right Atrial Thrombi Complicating use of Central venous Catheters in Hemodialysis
Authors: Shah A. , Murray M. , Nzerue C. 
Published: January 2018

Background There has been an increase in the use of central venous catheters for temporary hemodialysis access. In this report, we describe a case series of 12 patients on hemodialysis who developed intracardiac clots associated with the use of central venous catheters, their outcomes and review the literature on this syndrome. Methods Retrospective, single-center case series of 12 patients with right atrial thrombi associated with central venous catheter use for dialysis vascular access. These patients were treated between June 1, 2001 and June 30th 2002 at the three University of Rochester affiliated dialysis clinics. The medical records of these patients were reviewed to obtain information concerning demographics, dialysis history, dates of catheter insertion, catheter complications, identification and dimensions of intracardiac thrombi, echocardiographic data, and outcome of anticoagulant therapy. Results Right heart thrombi were identified in 12 patients in our hemodialysis population over the study interval. Anticoagulation for 6 months led to clot resolution in more than 50% of our patients. Bacteremia recurred in 6 patients (50%), in spite of catheter replacement. There was zero mortality related to presence of clots in the short term. One patient with non-bacteremic right atrial thrombus suffered sudden cardiac arrest, but was successfully resuscitated. Conclusion Right atrial thrombi may occur in hemodialysis patients who use central venous catheters for dialysis access. These clots are frequently found in the right atrium or right atrial-superior vena caval junction. Ten of 12 patients (83%), had catheter-associated bacteremia, but the precise relationship between bacteremia and intracardiac clots is unclear. Chronic anticoagulation for 6 months lead to resolution of these clots in more than 50% of patients in our series.
Continuous low volume delivery of intravenous treprostinil via a central venous catheter with a miniature pump in a conscious dog model
Authors: Laliberte K. , Jerat S. , Tenneson K. , Wade M. , Zaccardelli D. 
Published: January 2018

Purpose Two animal studies were conducted to determine the feasibility of infusing treprostinil via a central venous catheter at an infusion rate of 0.1 mL/hour. Currently treprostinil is administered intravenously at infusion rates of approximately 1.0 to 2.0 mL/hour to patients with pulmonary arterial hypertension, which reflects standard clinical practice to ensure line patency with continuous intravenous administration via a central venous catheter. Methods In a pilot study three male beagle dogs were administered 50 ng/kg/min of treprostinil continuously at an infusion rate of 0.1 mL/hr via the MiniMed 407C infusion pump for 21 days. In a definitive study, six male beagle dogs were administered 50 ng/kg/min of treprostinil continuously at an infusion rate of 0.1 mL/hr via the MiniMed 407C infusion pump for 60 days. In both studies “no delivery” pump alarms were documented throughout the study in addition to pharmacokinetic data at specified time points. Results There were no documented occlusions in the 21-day pilot study. In the 60-day study one animal had a documented catheter occlusion after 16 days of therapy. Following re-implantation with a new catheter this animal did not have any additional occlusions for 40 days. No other animals in this study had any significant problems. In both studies, pharmacokinetic data were similar to that observed in previous animal studies evaluating treprostinil administration at the same dose and at higher infusion rates. Conclusion These animal data support the evaluation of administering treprostinil at a low infusion rate via the MiniMed 407C infusion pump in patients with pulmonary arterial hypertension.
Ultrasound Guided Brachial Arterial Angioplasty during the Creation of a Radio-Cephalic Arteriovenous Fistula: A Case Report
Authors: Napoli M. , Montinaro A. , Russo F. , Valletta A. , De Pascalis A. , Proia S. , Aprile M. , Alfonso L. , Patruno P. , Buongiorno E. 
Published: January 2018

To prevent arteriovenous fistula (AVF) early failure, due to radial or brachial artery stenosis, ultrasound guided angioplasty performed while surgically creating the AVF could be an effective procedure. Case report A 76-year-old diabetic male patient, on hemodialysis (HD) for 15 months, presented extensive thrombosis of the radio-cephalic AVF at the right arm, which had lasted for about 10 days. Ultrasound examination showed a 40% brachial artery stenosis with eccentric calcified plaque. The stenosis was localized about 1.5 cm before the artery bifurcation. The brachial artery diameter was 0.45 cm before and 0.26 cm at the level of the stenosis, the latter being 0.45 cm long. At the left wrist, under local anesthesia, the radial artery and the cephalic vein were exposed; the radial artery was then longitudinally incised for 7–8 mm in the area selected to create the AVF. A 6 Fr introducer, a metallic guide wire and a catheter for angioplasty were inserted one after the other in the radial artery. When the correct position of the angioplasty catheter in the stenotic area was established by ultrasound examination, the balloon was blown up to 13 atm for 35 sec, reducing the stenosis from 40–20%. Finally, a side-to-side radio-cephalic fistula was created, legating the distal vein. The AVF was used for HD after 3 weeks. The follow-up at 6 months demonstrated fair access performance and it was used without problems. Our satisfactory experience suggests that ultrasound guided angioplasty of brachial artery stenosis, performed simultaneously with surgical AVF creation, is possibly a successful procedure. This technique reduces the risk of early AVF failure and also allows, when required, stent implantation.
Comparison of access blood flow and venous pressure measurements as predictors of arteriovenous graft thrombosis
Authors: Singh N. , Ahmad S. , Wienckowski J.R. , Murray B.M. 
Published: January 2018

Purpose The purpose of the present study was to prospectively compare the predictive accuracy of static venous pressure (SVP); dynamic venous pressure (DVP) and access blood flow (ABF) in determining subsequent graft thrombosis and/or failure. Methods This study included 43 patients with functional arteriovenous grafts (AVG's) who underwent monthly serial measurements of SVP, DVP and ABF for 3 consecutive months. Patients were then followed for an additional 6 months. The primary end point was graft thrombosis. Results Six patients were excluded from the final analysis. Of the 37 patients completing the study, 7 episodes of graft thrombosis occurred within 6 months of follow up. Neither SVP nor DVP exhibited satisfactory sensitivity or specificity for graft thrombosis. Ten patients either began with or developed an ABF < 600 during the 3 months of measurements, but only 5 clotted. Δ ABF of >20% provided the best combination of sensitivity (86%) and specificity (90%) for graft thrombosis. In AVG's that have an ABF<600, it is those grafts with falling ABF that appear most likely to clot in the short term. Conclusion The study supports the concept that it is a falling level of access flow rather than the absolute level that is the most potent predictor of graft thrombosis.
The brachio-brachial arteriovenous fistula: a new method in patients without a superficial venous system in the upper limb
Authors: Dorobantu L.F. , Stiru O. , Iliescu V.A. , Novelli E. 
Published: January 2018

Purpose This study aimed to report our experience in the creation of brachio-brachial arteriovenous fistulas (AVFs) in patients without adequate superficial venous circulation at the upper limb. Methods A retrospective study of 33 patients, operated on between 2004–2005, in whom we created a brachio-brachial fistula between the brachial artery and the brachial vein. After dissection and adequate mobilization, the brachial vein was anastomized to the brachial artery in an end-to-side fashion. After the maturation period (1 month) the brachial vein was transposed into the subcutaneous tissue. Results Thirty-three patients underwent 33 brachio-brachial fistula constructions. Primary patency was achieved in all patients. After 1 month, 27 fistulas (81.8%) were functional. Six patients developed fistula occlusion. The 27 remaining patients had subsequently good fistulas for hemodialysis (HD) afterwards. Discrete edema of the forearm was noted in 12 patients (36%); in one of these patients the edema was extended to the entire arm. No other complications were noted. A follow-up study, extended from 3–26 months (mean 14 ± 6.6 months), was performed. The overall patency rate of the brachio-brachial fistula at the end of the follow-up was 85.2%. Conclusions The brachio-brachial fistula can represent a viable choice in patients with an inadequate superficial venous system in the upper limb.