bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of the Greater Trochanter in Fracture Stability in Uni- or Biaxial Dynamisation with the Medoff Sliding Plate
Authors: Lunsjö K. , Ceder L. , Hauggaard A. , Stigsson L.
Published: March 2018

The greater trochanter and its role in stability in fixation of extracapsular hip fractures has been neglected in comparison with the lesser trochanter. In unstable fracture types, gradual medial translation of the femoral shaft occurs as a consequence of the use of sliding hip screws and, if excessive, may be associated with fixation failure. In a live bio-mechanical trial with the Medoff sliding plate (MSP), we wanted to evaluate how the fracture configurations of the lateral and the medial femoral cortices affected the reduction and the impaction of the fracture as well as the femoral medialisation.

The MSP is a modified hip screw-plate, which acts to prevent medialisation by allowing only vertical impaction of the fracture along the femoral shaft (uniaxial dynamisation). It also has an optional lag screw sliding along the neck of the femur, allowing biaxial dynamisation. Intertrochanteric fractures in 189 elderly patients were treated by either uni- or biaxial dynamisation and followed for one year with serial radiographs.

Fractures with a broken lateral cortical spike from the femoral shaft commonly had medial reduction as well as medialisation and also had a significant increase in both lag screw and plate slide compared with fractures with an intact lateral cortical spike. A medial cortical fracture with a major defect larger than the size of the lesser trochanter had less influence on sliding or on medialisation.

We conclude that involvement of the greater trochanter is an important factor in determining stability in complex intertrochanteric fractures
Contact Stresses in the Human Hip: Implications for Disease and Treatment
Authors: Brand R.A. , Iglič A. , Kralj-iglič V.
Published: March 2018

Contact stresses in the hip articular surfaces relate in some way to normal maintenance as well as destruction of joints. In vivo determinations of cartilage-on-cartilage contact pressure histories have never been reported, and current technology does not allow such measurements without the potential for artifact: all experimental methods require introducing some material between the surfaces, and all numerical methods have yet to be fully validated. Nonetheless, a variety of distinct experimental and numerical approaches lead to estimates of contact stresses and surprisingly, despite the choice of technique, values for peak contact stresses lie within a range of one order of magnitude (i.e. 0.5–5.0 MPa) and usually closer. Pathological conditions increase this to the range of over 5.0 MPa, while surgical procedures designed to reduce peak pressures theoretically can achieve reductions. Two critical unresolved issues are 1.) What aspect of the contact stress history (e.g. contact stress gradients over time) in fact cause the biological responses? 2.) What level of contact stress history is tolerated by the cartilage? Future research will need to address these critical issues.
Revision Hip Arthroplasty in the Octogenarian is it Worth It?
Authors: Talbot N.J. , Bannister G.C.
Published: March 2018

We retrospectively reviewed the clinical and patient perceived results of 76 revision hip arthroplasties performed in 68 octogenarians since 1990. 60% of patients gained a worthwhile reduction in pain. In contrast to previous studies, however, the functional level of the majority of patients did not improve. 29% of patients felt that they gained no benefit from their operation and, with the benefit of hindsight, 24% of patients would not have consented to surgery, from which they found recovery harder than their first operation. 47% of patients suffered complications which were multiple in over a quarter. There was a 17% dislocation rate which was usually recurrent and rarely salvageable. The indication for revision surgery in the octogenarian must be pain of sufficient severity to justify these risks.
Cortical Strut Allograft in Revision Total Hip Arthroplasty
Authors: Wong P.K.C. , King A. , Hutchison C.R. , Gross A.E.
Published: March 2018

Fifty-two patients with significant uncontained but non-circumferential femoral bone loss were reconstructed using cortical strut allografts. The allografts used were deep frozen and irradiated with 2.5 Mrads. The mean age was 65. The average follow-up was 4.8 (1.6–10.0) years. The following radiographic parameters were studied: location and the dimension of the allografts, resorption and incorporation of the allografts, and union between the cortical strut allografts and host bone.

Union between the allografts and host bone took an average of 10 months. There were 2 non-unions (union rate 96%) but no graft fractures. Severe graft resorption occurred in two cases. The overall radiographical failure rate was 8% (4/52). The process of incorporation could take over two years to complete.

The average length of the strut allografts immediately post-operatively was 154 mm (66–280 mm). The length of the strut allografts at final follow-up was 143 mm (54–258 mm). The percentage decrease in the length of the struts was 8% (0–48%).

The mean pre-operative and post-operative Harris hip score was 39.4 and 65.6 respectively. Six of the fifty-two patients had further femoral revision surgery (12%). None of these re-revisions was done for reasons directly related to the cortical struts.

Cortical strut allografts are useful to augment uncontained, non-circumferential femoral defects. They can remodel with time to enhance femoral bone stock. They unite consistently to host bone without significant resorption.
The Femoral Cement Mantle in JRI Furlong Total Hip Replacements
Authors: Mellor S.J. , Ripley L.G. , Ricketts D.M.
Published: March 2018

The creation of an adequate femoral cement mantle in cemented total hip replacement (THR) can reduce the incidence of cement fracture, focal osteolysis and subsequent aseptic loosening. Excavating a suitably sized cavity within the femoral canal with an appropriate broach is an essential step in this process.

We measured the size and volume of the femoral broaches and stems supplied with the JRI Furlong THR system. Least Significant Difference Multiple Comparison revealed that the volume of all 4 broaches was significantly less than the equivalent stems (p<0.001). Using an in vitro method, we created cement mantles that could be directly measured. We found the cement mantles created by these broaches were of inadequate thickness, with numerous cement defects (mean thickness = 0.89 mm, cement defects at 23% of measurement sites).

JRI have developed a new set of broaches to be used with the original femoral stems. Assessment of these broaches showed that all four sizes were significantly larger (CI 14.20 – 26.96) than the original design (CI 10.45 – 13.21, p = 0.011). Volumetric analysis confirmed this significant difference (p<0.001). The cement mantles created by these broaches were significantly thicker and more uniform, with fewer cement defects (mean thickness = 1.99 mm, p<0.05, cement defects at 3% of sites).

We conclude that, in vivo, the original broaches would fail to excavate an appropriate cavity and may not prevent direct bone-stem contact. The newer broaches are significantly larger, and may have an unpredictable effect on subsequent stem longevity when used in vivo.
Analysis of the Catastrophic Failure of a THR: The Role of the Acetabular Component
Authors: Maccauro G. , Piconi C. , Proietti L. , Timpanaro M. , De Santis V. , Magliocchetti G. , De Santis E.
Published: March 2018

This paper investigates the failure of a total hip prosthesis due to the disruption of the PE inlay and the Ti-alloy metal back of the acetabular component. The PE inlay was coupled with an alumina ball head. The case analysis showed that the initiator of the failure was the size selection of the prosthesis, followed by the positioning of the acetabular component. The deformation of the PE inlay leads to rupture of the inlay itself, followed by the direct contact between the alumina ball head and the titanium alloy cup, causing the disruption of the Ti-alloy metal back, with massive release of wear debris in the surrounding tissues.
In Situ Failure of Screw Fixation for Slipped Capital Femoral Epiphysis: A Case Report
Authors: Chell J. , Hunter J.B.
Published: March 2018

In situ fixation with a single screw is the treatment of choice for mild to moderate slipped capital femoral epiphysis and has been reported as relatively complication-free. The complications that do occur tend to be related to screw insertion, with joint penetration, and on screw removal, when fracture of the screw may occur. The authors report a unique case of in situ failure of the single cannulated screw leading to progression of the slip. This may have been related to screw design, and the treatment options and complications of screw fixation in slipped capital femoral epiphysis are discussed.
Biomechanical Aspects of Modular Inlay Fixation
Authors: Blömer W.
Published: March 2018

Based on positive clinical experience with the taper lock of ceramic heads in total hip replacement, conical fixation was also chosen for modular cup inlays made of alumina ceramic and polyethylene. For a comparative assessment of inlay fixation, new ceramic and polyethylene inlays with a taper lock were biomechanically tested and compared with clinically proven system with a snap lock mechanism. With regard to the prevention of dislocation and relative movements the same level of safety was found. Measurements of the damping characteristic of the acetabulum replacement showed that there is no considerable shock-absorption for a metal backed polyethylene inlay and there are no differences in this respect between ceramic and polyethylene inlays.
Displacement of Femoral Stem during Closed Reduction of Total Hip Arthroplasty
Authors: Cordes J. , Sperling K. , Kramhøft M.
Published: March 2018

In the literature, only one case of displacement of a cemented femoral stem from its cement bed during closed reduction of a dislocation has been reported. In that case, it was suggested that the stem design may in part be the explanation for the displacement.

Another case with a cemented Müller straight stem is now presented, emphasizing the use of image intensification if reduction proves difficult.
Leg Length Discrepancy after Total Hip Replacement
Authors: Sarangi P. P. , Bannister G.C.
Published: March 2018

Leg length differential in 110 patients with unilateral hip arthritis was measured on supine AP radiographs before and after hip arthroplasty, and compared with subjective sensation of leg length discrepancy at that time. Eight percent of limbs were of equal length, 60% were within 0.5 cm. and 9% demonstrated a discrepancy greater than 1 cm. Shortening was tolerated better than lengthening. No patient with true shortening of less than 6 mm or lengthening of less than 4 mm perceived discrepancy. Shortening of over 10 mm and lengthening of over 6 mm was perceived universally. Shortening of between 6 mm and 10 mm was perceived by 55% of patients, and lengthening between 4 mm and 6 mm by 26%.
The Steps in the Evaluation of a New Implant -From the Inventor to the Orthopaedic Community
Authors: Lunsjö K.
Published: March 2018

New implants are constantly being introduced to the orthopaedic community. Their steps from invention to general clinical use vary. Some devices have not been evaluated scientifically, others have undergone assessment in case series, and a few have been critically reviewed in randomized controlled trials. The reasons for these variations are discussed and a practical example is presented.
Finite Element Analysis Applied to Bone Remodelling in Revision Arthroplasty of the Femur using Morselized Allograft and Cement
Authors: Simon J.P. , Sloten J. Vander , Van Audekercke R. , Van Der Perre G. , Ling R.S.M. , Gie G.A. , Fabry G.
Published: March 2018

Finite element models have extensively been developed and reported for primary cemented and uncemented total hip replacement, but not for revision arthroplasty of the hip. A two-dimensional equivalent thickness model was developed of the proximal femur with bone grafts, a thin but uniform cement layer and a standard femoral component. This model represents the reconstructed femoral revision setting described by Gie et al (1). The effects of surface texture, cement-stem friction, cement creep and stem malplacement were evaluated. Within the range of coefficients of friction which was investigated in this study (0.03, 0.136 and 0.3) it was observed that the influence of the value of the coefficient upon the stresses in the bone-implant structure are less than 5%. Also static cement creep and certain stem malalignments which were simulated showed a relatively small influence upon the stress distribution within this structure. An agreement between trabecular orientations in the remodeled bone allograft and the principal stress orientations in this structure was observed in the calcar region. It was concluded that the remodelling which occurs in the bone allografts follows Wolff's law of optimal material use in the trabecular structure.
Simultaneous Bilateral Central Acetabular Fracture-Dislocations following an Epileptic Seizure in a Patient with Chronic Renal Failure
Authors: Papanikolaou A.G. , Aktipis D.D. , Giota A.G. , Antoniou N.C.
Published: March 2018

We report on a rare injury in a 60-year old diabetic lady suffering from chronic renal insufficiency. She sustained bilateral central acetabular fracture-dislocations following an epileptic seizure.
The Wagner Uncemented Long-Stemmed Revision Prosthesis: Medium-Term Results for Proximal Femoral Osteolysis
Authors: Karnezis I.A. , Dretakis K.E. , Chesser T.J.S. , Lee M.B. , Learmonth I.D.
Published: March 2018

This paper presents a clinical and radiological review of nineteen hips that were revised using the uncemented long stem Wagner prosthesis. All the hips were symptomatic and demonstrated proximal femoral osteolysis. The mean follow-up was 61 months: there were four hips with a follow-up of more than 4 years, eight hips with a follow-up of more than 5 years, three hips with a follow-up of over 6 years, while there were two hips with a follow-up of above 7 years. Only two hips had a follow-up of less than 4 years. The clinical results were satisfactory. 95% of patients had mild, occasional or no pain, and 90% minimal or no limitations of mobility. Radiographically, significant restoration of the proximal femoral bone stock (Pak and Paprosky classification) occurred in 42% of cases. No stems were radiographically loose. 89% of stems showed subsidence of less than 4mm. There were no re-revisions at the time of follow-up. These medium-term results support the use of the Wagner uncemented distal load bearing femoral prosthesis for difficult revision cases in the presence of symptomatic proximal femoral bone resorption. Significant stem subsidence was not encountered.
The MRL Stem: A Decade of Follow-Up of 100 Primary Implants
Authors: Ravaglia L. , Zucchi M.
Published: March 2018

The Authors report the results with the MRL prosthesis in 100 hips, reviewed on the basis of specific chronological parameters, with a mean follow-up of 11 years and 6 months, range 10–14 years. Results were excellent or good in 97%.

A valgus cervicodiaphyseal angle of the stem constitutes a relative contraindication in some cases of coxa vara. We recommend widening the range to include stems with greater lateralizing effect and a physiological cervicodiaphyseal angle.
The Repeatability of EBRA in Migration and Wear Analysis
Authors: Ilchmann T.
Published: March 2018

The new computerized EBRA method should be tested for its usefulness in multicentre studies. One patient was followed with roentgen-stereophotogrammetry for three years after THA. Ten clinical pelvic radiographs were taken over a period of nine years and analysed with EBRA at four different centres independently. The maximum difference in repeated measurements after nine years was 2,2 mm for migration and 0,7 mm for wear. The error of measurement (two standard deviations) was 0,36 mm for horizontal and 0.62 mm for vertical migration. For wear it was 0,06 mm and 0,16 mm respectively. The results with EBRA were similar to the corresponding roentgen-stereophotogrammetric results. EBRA proved to be useful for multicentre studies, reducing the error of measurement. It might detect prosthetic failure at a more early stage.
The Effect of a Lateral Flare Feature on Uncemented Hip Stems
Authors: Walker P.S. , Culligan S.G. , Hua J. , Muirhead-Allwood S.K. , Bentley G.
Published: March 2018

Ideal goals for a primary uncemented femoral stem prosthesis are to transmit the loads to the femur proximally, and to minimise the interface migration. It has been proposed that the addition of a lateral flare which loads the lower region of the greater trochanter will contribute positively to these goals. Analytical and radiographic studies were used to study the load transfer between the stem and the bone, and the migration. A comparison was made between a straight stem, and a straight stem with the addition of a lateral flare. The finite element study showed that the straight stem migrated down the canal approximately four millimeters before stabilisation was reached. The forces were transmitted on to the proximal-medial femur and around the lower half of the stem. When the lateral flare was added, there was only one millimeter of migration to reach stability. The loads were transferred by a wedging effect between the proximal-medial femur and the around the lateral flare, with little force transfer from the stem. In a radiographic follow-up of an HA-coated lateral flare stem, trabeculae could be seen attaching to the lateral flare. The axial migration was significantly less for this stem design compared with that from a series of previously reported cemented stems. This study suggested that the lateral flare contributed positively to the goals of uncemented stem design, and that the stems could be made shorter than designs not incorporating the lateral flare feature.
The Effect of Legislation on Discharge from Hospital of Patients with Proximal Femoral Fractures 1990–1997
Authors: Crowther M.A.A. , Bannister G.C. , Dixon J.H.
Published: March 2018

In 1993, legislation (The Community Care Act) was passed requiring that patients be assessed by social workers before discharge from hospital back to the community. The effect of the Care in the Community Act on the discharges from Weston General Hospital of patients, with fractures of the femoral neck, was studied comparing prospective data from 1990 three years before implementation of the Act, and data from February 1996–1997. Length of hospital stay and distribution of placement after admission from home were compared. There was a 13% rise in bed occupancy caused by a significant increase in time to discharge for patients newly placed in nursing homes as well as a rise in average inpatient stay for patients discharged home.
Detection of Asymptomatic Venous Thrombosis following Hip Replacement Surgery
Authors: De Thomasson E. , Strauss C. , Girard P. , Caux I. , Guingaud O. , Mazel C.
Published: March 2018

This study evaluates a pragmatic approach using duplex ultrasonography (US) for detecting venous thromhosis (VT) after total hip arthroplasty (THA).

Venous B-mode and colour duplex US examination of both legs including a systematic evaluation of calf veins was performed twice during hospitalisation in 286 consecutive patients. VT was diagnosed in 31 patients (12%). Thrombosis was asymptomatic in 28 patients (90%), and was bilateral or concerned the non-operated leg in 6 patients (19,4%). No clinical pulmonary embolism occurred during hospitalisation. Prior phlebitis and age over 70 were identified as statistically significant risk-factors (p<0,02 and p<0.04 respectively). All patients were seen at three months. Four patients (1.6%) developed VT between hospital discharge and the 3-month follow-up visit.

Venous US performed twice after THA detected VT in 31 patients, 90% of these were asymptomatic. This approach might explain the absence of pulmonary embolism (PE) in our series, and support a systematic evaluation of the vein of the lower limb with ultrasonography after THA.
Progressive Osteolysis after Porous-Coated Anatomic (PCA) Uncemented Total Hip Arthroplasty Ten-Year Results in 32 Consecutive Cases
Authors: Revald P. , Kjaersgaard-Andersen P. , Lucht U.
Published: March 2018

Thirty-two primary non-cemented first generation Porous-Coated Anatomic (PCA) total hip prostheses in 31 patients were followed prospectively. The average follow-up period was 10.3 years. The median age at surgery was 53 years (range 21–65). All operations were performed by one surgeon.

Preoperatively, all cases had a poor Harris Hip Score. Ten years after surgery, 95% were rated good or excellent.

Progressive roentgenographical changes were observed. In particular there was severe femoral osteolysis in zones 1, 2 and 7, and extensive wear of the polyethylene liner at the two latest follow-up examinations. Wear of the polyethylene liner, up to 0.4 mm/year, was significantly correlated with osteolysis after seven years (p=0.003). Aseptic cup loosening was the reason for six of the eight failures. At 10.3 years after surgery the survival with revision as end-point was 72%.

We stopped using the 1st generation PCA prosthesis after five years due to worrying roentgenographic changes. The seven and ten years results have confirmed that this prosthesis cannot be recommended for implantation.
Superficialization of Basilic Vein: Last Chance for a Native Arteriovenous Fistula in Hemodialysis Patients
Authors: Onaran M. , Erer D. , Şen I. , Elnur E.E. , Iriz E. , Sert Ş.
Published: March 2018

Background

Although the best type of vascular access for chronic hemodialysis patients is a native arteriovenous fistula, in an increasing number of patients all the superficial veins have been used and only the placement of vascular grafts or permanent catheters is left. Superficialization of the basilic vein is a possible alternative.

Materials and Methods

In 49 chronic hemodialysis patients who had no possibilities to have a native arteriovenous fistula created, we performed a basilic vein- brachial artery fistula in the arm. During the same operation the basilic vein was then superficialized for easier access for hemodialysis.

Results

Mean follow-up was 22.36±15.56 months. Forty-eight patients are still undergoing hemodialysis with their superficialized basilic vein native A-V fistula without any complications. Only one fistula was thrombosed just after the procedure because of poor vessel quality.

Conclusion

For hemodialysis patients who have no suitable superficial veins at the wrist or elbow, performing a basilic vein - brachial artery fistula and superficializing the vein to the subcutaneous tissue is an acceptable choice before deciding to use more complicated procedures like vascular grafts.
Evaluation of Gore-Tex Graft Patency in Hemodialysis Access
Authors: Kawecka A. , DȨbska-Ślizien A. , Korejwo G. , Prajs J. , Król E. , Rutkowski B. , Lasek J. , Gwoździewicz J.
Published: March 2018

Aim

The purpose of this retrospective study was to analyze the patency and complications of Gore-Tex grafts used in hemodialysis (HD) access.

Methods

In the last 16 years, 1649 surgical procedures were performed on 655 patients to ensure and maintain permanent HD access. The study group consisted of 64 HD patients on whom 81 vascular synthetic PTFE Goretex grafts were performed. There were 28 males and 36 females, 3 of them were children (4.7%). Mean age was 54.2 years (range 15–77). Two types of Gore-Tex prosthesis were used: Diastat and Stretch. All grafts were implanted in the upper extremities. Kaplan-Meier survival curves were calculated to determine primary and secondary patency. Log-rank analysis was used to determine differences between curves.

Results

Primary and secondary patency at 12 months was 52.5% and 67.5%, and at 18 months respectively 41.5% and 58.2%. The Diastat graft had a lower primary and secondary patency compared with the Stretch graft (respectively p = 0.02 and p = 0.008). Factors such as gender, coexisting diabetes and hypertension did not determine graft patency. Thrombosis was one of the most frequent complications. The remaining complications included stenosis, pseudoaneurysms, infection, steal syndrome and seroma.

Conclusion

On the basis of our experience Stretch grafts appear a better option for creating vascular access for HD than Diastat grafts.
Insertion of Short Introducer Sheaths into a Polyurethane Vascular Access Graft for Immediate Hemodialysis Access
Authors: Ross John R.
Published: March 2018

While native AV fistulae are considered the “gold standard” for hemodialysis patients in need of long-term access, synthetic grafts are the best option for patients who are not candidates for an AV fistula. While AV fistulae should be allowed to mature for 3 – 4 months prior to cannulation, PTFE grafts may be cannulated 14 days after placement. Despite the benefit of earlier cannulation in PTFE graft recipients compared to AV fistulae patients, one critical limitation is that immediate post-operative cannulation is not possible. The self-sealing nature of the polyurethane Vectra® Graft overcomes the time restriction until first cannulation, allowing much earlier vascular access than conventional PTFE grafts. We describe here a procedure for insertion of 5-French DialEase™ Introducer Sheaths into the Vectra Graft for immediate, post-operative hemodialysis access. This procedure eliminates time restrictions until first cannulation of the Vectra Graft; the sheath's large diameter side-port ensures high flow for efficient hemodialysis. Moreover, insertion of the sheath into a new or existing Vectra Graft provides vascular access for inspection of the graft anastomoses, angiography, angioplasty, venography, and declotting procedures. The post-operative introduction of DialEase Sheaths into a Vectra Graft for immediate hemodialysis was successfully performed in 35 patients. All patients then immediately received high-flow hemodialysis (400 – 500 ml) with venous pressures ≤ 125 mmHg and negative arterial pressure ∼100 mmHg. To date, there have been no infections, immediate graft thrombosis or other complications associated with this procedure, and all patients have remained free of anastomotic problems.
Fluidodynamic Evaluation of Arteriovenous Fistulae for Hemodialysis
Authors: Liepsch D. , Pallotti G. , Pettazzoni P. , Colì L. , Donati G. , Rossi C. , Losinno F. , Freyrie A. , Stefoni S.
Published: March 2018

Arteriovenous fistulae (AVF) are commonly used in dialysis treatment of uremic patients. However, many AVF create problems and have to be re-examined. Problems arise in the cannulation site and must be treated with antibiotics, and stenosis, both in the arterial and in the venous side of the AVF. In the worst case, the AVF must be replaced for treatment to continue. However, this can only be repeated once before the AVF site is no longer viable. This increases the discomfort, the morbidity and the mortality of the dialysis patient. Several kinds of AVF were studied to determine whether flow disturbances give rise to these complications. Many studies have already demonstrated the importance of hemodynamic factors in vascular disease pathogenesis. These factors include: the pulsatility of flow, the elasticity of the vessel, the non-Newtonian blood, flow behavior and, very importantly for AVF, the vessel geometry. In model studies, intimal changes have been observed in bends and bifurcations, regions of vessel construction and vessel stenosis. In these regions, blood flow changes abruptly and this contributes to arterial disease. We prepared several one-to-one, true-to-scale elastic silicon rubber models of different AVF. The AVF models were based on angiographic studies of chronic dialysis patients and on AVF from the arms of cadavers. The models had a similar compliance to that of the human blood vessel. Flow was visualized using photoelasticity apparatus and a birefringent blood-like fluid. This method is suitable to analyze the spatial configuration of flow profiles, to differentiate laminar flow from disturbed flow, and to visualize flow separation, vortex formation and secondary flow. It was found that AVF create disturbances that are not found under normal physiological flow conditions. The X-formed AVF was very unsatisfactory, creating significant flow disturbances. The AVF had high velocity fluctuations. These could lead, for example, to aneurysm formation. A better configuration would be an end-to-end AVF. However, this formation creates other complications. For example, there is not enough blood to the hand and parts of the hand lose feeling. The recommended AVF would be an end-to-side anastomosis. In this case, attention is needed for placement geometry, to minimize additional flow disturbances. Several models as well as patient angiographic studies are discussed.
Endoscopic Saphenous Vein Harvesting for Hemodialysis Vascular Access Creation in the Forearm: A New Approach for Arteriovenous Bridge Graft
Authors: Oto T.
Published: March 2018

When superficial arm veins are not suitable to create a native arteriovenous (AV) fistula, an arteriovenous bridge graft by native and/or prosthetic graft is the next best alternative. However, harvesting a native vein, such as the saphenous vein (SV), is invasive and requires a large incision. We report an endoscopic saphenous vein harvesting (ESVH) technique combined with forearm bridge grafting as a new approach for vascular access (VA).

Methods

We used the Clearglide, Endoscopic Vessel Harvesting System (Eticon, Inc.) for a less invasive SV harvesting technique. Five patients had a SV graft implant and 10 patients had a polytetrafluoroethylene (PTFE) graft implant in the forearm.

Results

The SV was harvested easily in all patients in 46 ± 2 min. There were no wound complications. All SV and PTFE grafts provided satisfactory access within 1 month; however, two declotting procedures in the SV group and five in the PTFE group were required. The PTFE group had two graft infections.

Conclusions

It is possible that a combination of ESVH and SV forearm grafting will be one of the new approaches for hemodialysis (HD) access.
Magnetic Resonance Techniques in Hemodialysis access Management
Authors: Bakker C.J.G. , Peeters J.M. , Bartels L.W. , Elgersma O.E.H. , Zijlstra J.J. , Blankestijn P.J. , Mali W.P.T.M.
Published: March 2018

In this review we describe current applications and future perspectives of MR angiography, MR flow quantification, and interventional MRI in hemodialysis access management. Each section starts with a brief overview of the main techniques that are currently available or under development. This is followed by a survey of the pertinent literature. Each section concludes with a discussion of the reported findings and an indication of research opportunities.
Vascular access for Chronic Dialysis using the Superficial Femoral Vein
Authors: Kapala A. , SzczȨsny W. , Stankiewicz W. , Hryncewicz W.
Published: March 2018

Purpose

We report our experience in using the superficial femoral vein to create hemodialysis (HD) arteriovenous (AV) fistulas. Surgery was performed on six patients (four female, two male). Indications for surgery included previous fistula loss, graft infection and exhaustion of typical shunt sites.

Methods

The femoral vein was evaluated preoperatively, by Doppler ultrasound, harvested by one long incision on the anteromedial surface of the thigh, followed by suction drainage. In four patients, harvested veins were transplanted in the arm between the brachial artery and axillar vein, followed by an end-to-side anastomosis. In two patients, the venous graft remained on the anterior surface of the thigh. In those patients, they were extended with either a piece of polytetrafluoroethylene (PTFE) graft or the saphenous vein.

Results

Follow-up ranged between 14 months and 2 yrs, ensuring proper dialysis. Two patients presented with complications, including lower leg swelling and axillary lymphorrhea, which subsided spontaneously.

Conclusions

We recommend this type of AV fistula, especially in difficult cases, where all other classical vascular approaches have been used. However, the procedure is time consuming and requires experience in vascular surgery.
Unusual Clot Formation following Insertion of Central Double Lumen Catheter for Hemodialysis
Authors: Soubassi L. , Chaniotis D. , Zerefos S. , Soubassi S. , Lambropoulou A. , Saridakis N. , Toumanidis S. , Soubassis P. , Zerefos N.
Published: March 2018

Background

We report a case of a patient with chronic renal failure (CRF) due to fibrillary glomerulonephritis, who was admitted to our Hospital with fever accompanied by chills, of two days duration. Due to aggravation of his CRF, accompanied by severe metabolic acidosis, an internal jugular double lumen central vein catheter was inserted, through which he was hemodialyzed.

Methods

Blood cultures were negative. The catheter was removed and the tip was cultured; it revealed colonization with hemolytic Staphylococcus sensitive to vancomycin and metilmycin. They were both given to the patient with excellent results. Trans-thoracic and trans-esophageal echocardiography revealed a clot in the right atrium with an abnormal circumference, connected to the tip of the second catheter. Anticoagulants were administered (calsium nadroparin, converted seven days later to acenocoumarol) and the size of the clot was significantly reduced.

Results

The case is presented in order to prove the significant contribution of trans-esophageal echocardiography as a non-invasive imaging technique for the detection of a clot in the right atrium and the impressive influence of appropriate therapeutic management in saving the patient's life and reducing the clot size.

Conclusions

The trans-esophageal echocardiogram provides invaluable information concerning the evolution, development and regression of right atrium clots formed at the tip of jugular catheters.
Increased use of Catheters as Vascular Access: Is it Justified by Patients' Clinical Conditions?
Authors: Di Benedetto A. , Basci A. , Cesare S. , Marcelli D. , Ponce P. , Richards N.
Published: March 2018

Background

Over the last years many technical improvements have been made in hemodialysis treatment. Vascular access (VA) still remains an important problem. Although the use of indwelling vascular catheters is discouraged, in Europe there is an increasing use of them. The K/DOQI Guidelines recommend a native arteriovenous fistula (AVF) as VA of choice. As reported by DOPPS, there is considerable geographic variation in the distribution of type of VA used amongst hemodialysis patients. The aim of this study was to evaluate the time patients in four European countries have to wait before undergoing their first surgery for VA (AVF or graft).

Methods

All incident patients admitted to HD clinics located in Turkey, Italy, the UK and Portugal of the European FME clinics network between October 1, 2002 and September 30, 2004 were considered. Data were gained from the Clinical Database EuCliD®.

Results

2,152 patients (males 55.9%, mean age 62.5±15.7 years, diabetics 27%) were selected. Italy and Portugal had a higher proportion of elderly patients. At time of admission, the proportion of patients starting dialysis with AVF ranged between 23% and 60% from Turkey to Italy respectively. Patients with an indwelling catheter at admission are expected to undergo VA surgery as soon as possible. After 3 months of follow-up, about 75% of all patients had undergone surgery, however in the UK less than 50% of the patients had had a VA procedure. Overall, males have significantly higher probability of undergoing surgery, whilst elderly patients have a lower probability (27% and 14% respectively).

Conclusion

Significant differences exist between countries in the time interval from referral to creation of VA. Health care system related problems seem to be the major reason to explain such differences. Patients in the UK have longer waiting times than the other countries studied.
A Patient Centered Decision Making Dialysis Access Algorithm
Authors: Davidson I. , Gallieni M. , Saxena R. , Dolmatch B.
Published: March 2018

Much controversy surrounds the establishment of proper planning, placement and management (the best practice pattern) of dialysis access. These include the dialysis type and modality selection, timing of access placement and who places the access. The lack of and the difficulty of performing randomized studies with multiple confounding factors, in an extremely heterogeneous and rapidly changing ESRD population demographics, only partly explains the dialysis access conundrum. Add to this the rapidly developing and competing technologies, the wide spectrum of the professional experience, bias and socio-economic forces to make the ESRD problems as multivariate and complex as life itself.

This overview describes a dialysis access algorithm approach to the patient needing renal replacement therapy, considering long-term improved patient outcome as the ultimate objective.
Color Doppler Ultrasonography Percutaneous Transluminal Angioplasty of Vascular Access Grafts
Authors: Bacchini G. , La Milia V. , Andrulli S. , Locatelli F.
Published: March 2018

Percutaneous transluminal angioplasty (PTA) is a possible treatment for stenosis. This study aimed to verify the impact of a vascular access (VA) surveillance protocol, based on the detection of functional changes and their correction by a new PTA method for VA performed under color Doppler ultrasonography (CDU) guidance. We divided the patients into two groups: group A, before May 1999 (retrospective study) without the surveillance protocol, and group B, from 1 May 1999 to January 2001 (prospective study) with the surveillance protocol. Access blood flow (Qa) was assessed every 4 weeks by ultrasound velocity dilution. In cases of a reduction of ≥35% from the baseline value, VA was examined using CDU: if a stenosis >50% was detected, angioplasty was performed. In cases of Qa reduction <35% we continued monitoring. By Cox's multivariate analyses, only the use of PTA with or without stenting reduced the relative risk of thrombosis by 64% during the follow-up (p=0.017 confidence intervals 88%-15%) in group B patients. Secondary patency was 80% for VA in which we performed PTA with or without stenting at 18 months, and 58% at 18 months in which we did not perform PTA. Our data show how PTA under CDU is useful to maintain and to improve graft patency. This PTA under CDU guidance allows patients to avoid surgical intervention, hospitalization, and adverse reactions to contrast media and exposure to ionizing radiation, with reduced cost and with better graft survival.
Percutaneous Placement of a Constrained Stent for the Treatment of Dialysis Associated Arteriovenous Graft Steal Syndrome
Authors: Zangan S.M. , Van Ha T.G.
Published: March 2018

Though rare, dialysis associated steal syndrome (DASS) can cause debilitating symptoms. Surgical revision of the dialysis access is typically required. We describe a percutaneous technique to alleviate steal syndrome utilizing a constrained stent within an arteriovenous graft. A brief review of the incidence, pathophysiology, and standard treatment of DASS is also provided.
Survival of Arteriovenous Fistula for Dialysis at Different Centers in the North of England
Authors: Shrestha P.C. , Asher J. , Shrestha S.M. , Jenner S. , Wilson C. , Taylor C. , Rewcastle T. , Handerson D. , Wilson M. , Rix D. , Talbot D.
Published: March 2018

Background

Renal failure patients rely on their vascular access for hemodialysis. Surgery for construction of arteriovenous fistulae is provided by a range of specialists. The aim of this review was to assess the survival of arteriovenous fistulae for hemodialysis patients in different centers of Northern England.

Methods

Data was collected on 473 hemodialysis patients in the North of England. Risk factors for failure were determined for each patient (age, sex, diabetes), together with their current mode of dialysis and history of surgical access procedures. This was expressed against their duration of dialysis. The dialysis units were then compared for fistula survival using the Kaplan Meier method.

Results

68.3% (323) patients were dialysed through via arteriovenous fistulae and 31.7% (150) via neck line. Overall fistula survival rates were 85.1% at 1 year, 82.5% at 2 years and 72.7% at 3 years. The best 1 year survival was 91.6% and worst 76.1%. These were 74.4% and 53.1% at 5 years and 74.4% and 29.5% at 10 years; these differences were highly statistically significant (p=0.0033).

Conclusion

Though graft survival is affected by many things, surgical training in access surgery is not mandatory and a review of surgical practice is urgently needed.
Effect of Ethanol/Trisodium Citrate Lock on Microorganisms Causing Hemodialysis Catheter-Related Infections
Authors: Takla T.A. , Zelenitsky S.A. , Vercaigne L.M.
Published: March 2018

Purpose

This in vitro study tested the effectiveness of a novel 30% ethanol/4% trisodium citrate (TSC) lock solution against the most common pathogens causing hemodialysis catheter-related infections.

Methods

Clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) (n=4), methicillin-sensitive S. aureus (MSSA) (n=8), methicillin-resistant Staphylococcus epidermidis (MRSE) (n=8), Pseudomonas aeruginosa (n=4) and Escherichia coli (n=4) were tested in duplicate. Bacterial suspensions of each isolate were made in a control solution of normal saline and Mueller-Hinton broth (MHB), and in a lock solution of ethanol 30%, TSC 4% and MHB. Suspensions were incubated at 37 °C for 48 h. Colony counts were determined from samples collected at t=0 h (before exposure to the ethanol/TSC lock), t=1 h (one hour after exposure to the ethanol/TSC lock), t=24 h and t=48 h. To confirm the absence of viable organisms in the lock solution, the remaining volume at 48 h was filtered through a 0.45 μm filter. The filter was rinsed with 15 mL sterile water and plated on tryptic soy agar (TSA).

Results

All controls demonstrated significant growth over 48 h. In the lock solutions, initial inocula were reduced to 0 viable colonies by t=1 h (6-log kill), and there was no growth at t=24 and 48 h. Filtering of lock solutions also showed no growth. These results were consistent among duplicates of all isolates.

Conclusions

The 30% ethanol/4% TSC lock solution consistently eradicated MRSA, MSSA, MRSE, P. aeruginosa and E. coli within 1 h of exposure. Experiments are currently underway to test this novel lock solution on preventing biofilm production by these pathogens.
Risk Factors for the Development of Cephalic Arch Stenosis
Authors: Jaberi A. , Schwartz D. , Marticorena R. , Dacouris N. , Prabhudesai V. , Mcfarlane P. , Donnelly S.
Published: March 2018

Purpose

The creation of a vascular access is necessary in hemodialysis patients, including those with marginal vessels. Upper arm fistulae are attractive due to the ease of creation and of achieving high access flow rates. Cephalic arch stenosis (CAS) can lead to failure of upper arm fistulae and is increasingly identified. We hypothesized that CAS is promoted by high blood flow rates, brachiocephalic fistulae, and an angle of cephalic vein insertion approaching 90 degrees.

Methods

All patients requiring a fistulogram between January 2004 and May 2006 had surveillance fluoroscopy of the central veins. Demographic, clinical and laboratory parameters were collected and the angle of the cephalic vein insertion measured by 3 blinded independent observers.

Results

Fifty-eight patients had fistulograms and CAS was detected in 18 subjects. Significant differences between the CAS and non-CAS groups were brachiocephalic fistula site (p=0.046), access flow (mL/min) (p=0.012), and absence of diabetes (p=0.03). Univariate predictors of CAS include access flow (per 100 mL/min) (p=0.042), platelet count (p=0.031) and calcium-phosphate product (p=0.026). The relationship of brachiocephalic site and CAS was confounded by access flow [(per 100 mL/min)*brachiocephalic fistula site (p=0.016)] and fistula age [brachiocephalic fistula site*fistula age (p=0.017)]. In multivariate analysis, renovascular disease, calcium-phosphate product, platelet count and access flow (per 100 mL/min)*brachiocephalic fistula predicted CAS (p<0.001, Negelkerke's R-Square= 0.55). The angle of insertion of the cephalic vein was not predictive for CAS.

Conclusions

CAS may be a long-term consequence of high blood flow rates. The interaction of access flow and brachiocephalic fistula supports the hypothesis that high flow through a brachiocephalic fistula promotes CAS. The multiple factors influencing cephalic arch remodeling require further research.
A Novel Catheter System for Totally Implantable Intravenous Drug Therapy: Assessment of Catheter Function and Patency with Trepostinil Therapy
Authors: Morris M. , Phares K. , Zaccardelli D. , Ujhelyi M.R.
Published: March 2018

Background

Catheter failure, either due to dislodgment, occlusion or infection is the leading complication of chronic intravenous drug therapy. Better drug delivery techniques are required to advance life saving therapies that require this delivery method. This study evaluated the chronic performance of a fully implantable drug delivery system that incorporates a novel intravenous catheter. The system was designed to reduce complications associated with intravascular drug delivery including catheter occlusion, breakage, migration, and infection.

Methods

Twelve canines were implanted with a novel central venous catheter (Model 10642; Medtronic, Minneapolis, MN) connected to a totally implanted programmable drug pump (Model 8637 SynchroMed II®, Medtronic). The drug delivery systems infused saline (n=6) or treprostinil (n=6) (Remodulin®; United Therapeutics, Research Triangle Park, NC) for either 12 or 26 weeks at a continuous flow rate of 540 μL/day. Catheter performance was assessed at 0 (implant), 2, 4, 8, 12, 16, 20, and 24 weeks by quantifying delivery pressure, delivery volume and steady state Treprostinil concentrations.

Results

All catheters remained patent and free of complications for the duration of the study. Analysis of pressure waveforms during bolus delivery showed low and unchanged catheter resistance throughout the study. Measurement of pump delivery volume accuracy showed that the delivered volume was statistically similar to the calculated delivery (product of flow rate and elapsed time). Measurement of plasma treprostinil levels showed stable concentrations over the study period. There were no catheter dislodgments or breakage. Pathology showed all catheters free from fibrosis and thrombus and minimal changes to the vascular endothelium.

Conclusions

The Model 10642 vascular catheter along with the SynchroMed II implantable drug delivery system showed promising performance in a chronic animal model.