Braided Wire Research Articles

Polypectomy devices

Polypectomy devices

Distraction Forces on Repaired Bucket-Handle Lesions in the Medial Meniscus

Background Numerous studies have investigated the biomechanical properties of meniscal repair techniques. One of the most commonly discussed parameters is the failure load in the axis of insertion, although little is known about the distraction forces actually occurring at repaired bucket-handle lesions. Hypothesis There are clinically relevant distraction forces on repaired meniscus bucket-handle lesions. Study Design Controlled laboratory study. Methods Meniscus bucket-handle lesions were created and repaired in human cadaveric knees with a vertical suture made from a braided steel wire. A small-sized load sensor was connected to the wire at the periphery of the meniscus. The distraction forces acting on the lesion were measured at different knee joint angles (0°-120° of flexion) with internal and external rotation and with and without weight loading. Forces in excess of 10 N were considered to have clinical relevance. Results Mean forces on the meniscus repair ranged from 1.64 to 4.72 N. Irrespective of the modalities (ie, different flexion angles, weight load, direction of rotation), it was found that the forces were well below the cutoff value of 10 N (P <. 01). Increasing flexion angles generally did not cause an increase in distraction forces. Conclusion The data suggest that distraction forces are not the primary factor in the mechanical stability of meniscal repair. It must therefore be assumed that other factors such as shear forces are of greater significance. Clinical Relevance The results may help to validate the biomechanical properties of different meniscal repair techniques.

Deep Sternal Wire Infection Resulting in Severe Pulmonary Valve Endocarditis

Right-sided infective endocarditis is uncommon, comprising less than 5% of all cases of endocarditis. This is primarily seen in patients with drug abuse, long-term intravenous catheters, and congenital malformations, or a combination of these. Isolated pulmonary valve endocarditis is difficult to recognize due to its rarity, minimal cardiac manifestations, and predominance of pulmonary infections secondary to embolization of the vegetations. We describe an unusual case of chronic sternal wound infection and migration of an infected braided sternal wire causing right ventricular outflow tract and pulmonary valve endocarditis, which necessitated a complicated reoperation including pulmonary valve replacement with a homograft.

Elective Treatment of Saccular and Broad-necked Intracranial Aneurysms using a Closed-cell Nitinol Stent (Leo)

Endovascular coil embolization of saccular intracranial aneurysms is safe and effective, but long-term results are dissatisfying. Reconstructive treatments using stents improve occlusion rate and protect parent vessels. We present data on our experience with a new self-expanding stent manufactured with braided nitinol wires. Twenty-five saccular, complex, and broad-necked intracranial aneurysms in 21 patients were treated electively. They were located at the internal carotid artery (10), basilar trunk (5), cavernous carotid artery (4), basilar tip (2), anterior cerebral artery (2), anterior communicating artery (1), and middle cerebral artery (1). Eleven aneurysms exhibited recanalization after primary endovascular treatment without stent. Stent deployment was successful in 24 lesions, and additional coil embolization was performed in 23. No permanent neurological deficits were encountered consequent to endovascular procedure. Complete or partial occlusion immediately after stent deployment was achieved in 19 aneurysms, whereas no immediate coil embolization was chosen in 6 cases. There were two thromboembolic events related to the deployment of the Leo stent, one failure of stent deployment, difficulties in stent positioning in three cases, and one asymptomatic parent artery occlusion after 7 months. Follow-up (available in 18 patients and 21 aneurysms and obtained at 3-12 mo; average, 5 mo) revealed patent stents in the remaining cases. Angiographic recurrences arose in three lesions, which were retreated without complications. Primary and recurrence treatment of saccular and broad-necked intracranial aneurysms using the Leo stent is feasible and effective. No permanent neurological deficits were associated with stent placement. Short-term follow-up identified intact parent arteries and stable occlusion rates in the majority of cases.

A Biomechanical Analysis of Suture Materials and Their Influence on a Four-Strand Flexor Tendon Repair

Flexor tendon repair strength depends on the suture technique and the suture material used. Configurations that incorporate locking loops prevent sutures from pulling through the tendon but typically fail because of suture breakage. The choice of suture material therefore influences repair strength. This study investigated the mechanical properties of 5 nonabsorbable 4-0 suture materials (monofilament nylon, monofilament polypropylene, braided polyester, braided stainless steel wire, and braided polyethylene) and evaluated their performance when used in a locking 4-strand flexor tendon repair configuration. Five samples of 2 strands of each suture type were tested mechanically to determine the material stiffness and ultimate load. In addition, 50 fresh porcine flexor tendons were divided and repaired with each of the 5 suture materials using a 4-strand single-cross technique. Gap force, ultimate strength, and stiffness were measured to compare biomechanical performance. All repairs failed by suture rupture at the locking loop. Fibrewire and stainless-steel sutures and repairs were significantly stronger and stiffer than the other suture types. The results for Prolene and Ethibond were similar in the tendon repair groups with respect to gap and ultimate forces although Ethibond provided significantly increased repair stiffness. Nylon sutures and repairs consistently produced the poorest mechanical performance in all outcome measures. Suture material strongly influences the biomechanical performance of multistrand tendon repairs and is an important consideration for the surgeon. Fibrewire and stainless steel are the most biomechanically suitable suture materials for flexor tendon repair whereas nylon is the least suitable. Further developments in suture materials are important for advancements in flexor tendon repair strength.

Failure of a braided stainless steel hose connector

Flexible water hoses are used as line connections from water supply plumbing to fixtures and appliances. The design configuration of these hoses varies; however, a common design involves an elastomeric liner surrounded by an outer reinforcement of braided stainless steel wire. These hoses are subject to rupture in service, traceable to the fracture of the braided wire reinforcement. The mechanism of failure involves localized corrosion of the stainless steel wire braid, a condition arising from the presence of water exterior to the hose. The following case of a ruptured water hose demonstrates this condition.

Novel System for Complete Removal of Secretions within the Endotracheal Tube

Novel System for Complete Removal of Secretions within the Endotracheal Tube

Deactivation force-deflection behavior of multistranded stainless steel wires

This investigation measured the deactivation (unloading) force-deflection behavior of selected multistranded stainless steel orthodontic wires. The guidelines from the revised American National Standards Institute/American Dental Association Specification No. 32 for orthodontic wires (type 2, nonlinear elasticity) were used to perform a 3-point bending test to obtain data for the deactivation force levels at 3, 2, 1, and 0.5 mm, and permanent deformation values. The study tested 20 wire designs: triple-stranded twisted wires, 5- and 6-stranded coaxial wires, and 8- and 9-stranded braided rectangular wires of selected cross-sections. Twenty specimens were tested for each wire design. The specification guidelines for testing provided a means for obtaining comparative unloading force delivery data for the deflections tested. Multistranded wires of significantly different cross-section, weave, and strand number fell within relatively narrow ranges of force delivery at the 0.5-mm (1.7-42.7 grams-force [gmf]) and 1-mm (31.1-134.2 gmf) deflections and wider ranges of force levels at the 2-mm (57.0-320.5 gmf) and 3-mm (72.5-451.8 gmf) deflections. All wires exhibited some permanent deformation, but none averaged greater than 0.66 mm. The testing also showed that multistranded wires of significantly different design exhibit similar force levels. The guidelines of the revised Specification No. 32 yielded deactivation data with regard to force delivery and provided comparisons of the wire designs tested.

Fracture force, deflection at fracture, and toughness of repaired denture resin subjected to microwave polymerization or reinforced with wire or glass fiber

Statement of Problem. The ultimate goal of denture repair is to restore the denture's original strength and avoid further fracture. The best materials and methods for repair have not been conclusively determined. Purpose. This study investigated the fracture force, deflection at fracture, and toughness of a heat-polymerized denture base material repaired with heat-polymerized resin, autopolymerized resin alone, or autopolymerized resin with glass fiber or wire reinforcement. Material and Methods. Eight groups were evaluated: 6 with autopolymerized resin repairs, 1 with heat-polymerized resin repairs, and a control group of intact specimens. The 6 autopolymerized resin groups included 1 group with no reinforcement, 1 treated with microwave irradiation after polymerization, 2 with monolayer or multilayer glass fiber reinforcement, and 2 with round or braided wire reinforcement. Each group consisted of 12 specimens. The experimental specimens were cut, and a 3-mm butt joint gap was repaired as indicated by the group assignment. A 3-point bending test was used to determine the fracture force, deflection at fracture, and toughness of the specimens. The data were analyzed with 1-way analysis of variance and the Tukey post-hoc test (α=.05). Results. The fracture force (28.4 to 73.4 N), deflection (1.6 to 3.8 mm), and toughness (0.02 to 0.13 J) values for all repaired groups were significantly lower than those for the control group (82.79 N, 4.4 mm, and 0.16 J, respectively), with one exception: the mean fracture force of specimens reinforced with round wire (102.9 N). Failure mode was always adhesive, meaning that fracture occurred between the denture base and repair resin. Conclusion. Among the repair treatments tested, the most effective was microwave-irradiated, autopolymerized resin reinforced with round wire or monolayer glass fiber ribbon. (J Prosthet Dent 2001;86:613-19.)

Development of the braided wire damper for exhaust radiation noise reduction

Single pipes used in a conventional vehicle exhaust system are not enough to reduce exhaust noise to a satisfactory level, especially at high frequencies. Double pipes are effective for reducing noise, but still not enough, and they are heavy. The new method, `Braided Wire Damper’, is an exhaust pipe partly wrapped with braided wire net. Proposed here is the use of `Braided Wire Damper’ and it is found to be very effective for reducing not only the noise but also the weight of the exhaust system.

A 13.56 MHz multicusp ion source for high intensity Ar beam

A 13.56 MHz radio frequency (rf) inductively coupled multicusp ion source has been developed for producing an intense argon beam with current density in excess of 30 mA cm−2. The source chamber is a 10 cm diam aluminum cylinder surrounded by 20 rows of 3.5 kG Sm–Co5 magnets which form a longitudinal line-cusp field configuration. The rf antenna coil, placed inside the source chamber, is made of a braided wire threaded through a two turn pyrex tube 6 cm in diameter to prevent electrical leakage and ion sputtering. A 10:1 turns-ratio matching transformer is used to match the 50 Ω output impedance of the rf generator to the impedance of the plasma load. Preliminary measurements were carried out with a single- and four-hole aperture extracting system using argon gas. For single-hole extraction with pressure at 5 mTorr and rf power at 500 W, the ion current density was 27 mA cm−2. Under the same operating condition, a four-hole extracting system could achieve almost the same amount of current density of 25 mA cm−2.

An analysis of normal‐mode noise caused by braided shield current flowing on coaxial cable attached by a ferrite core

Since coaxial cables have excellent electromagnetic shielding characteristics, they are widely used as interconnecting cables for digital information equipment. However, since braided lines are used in the shield layer of most coaxial cables, if an RF current flows, a noise voltage (normal mode noise) is induced between the core wire and the braided wire by electromagnetic coupling. Electromagnetic noise is also radiated from the common mode current of the braided shield. It has been considered that ferrite core loading is effective for reduction of the electromagnetic noise, and such loading is frequently used. In this article, in order to study whether ferrite core loading is effective in reducing normal mode noise, the normal mode noise generated by the braided shield current is analyzed with respect to the core loading location. Next, a formula for the noise-reduction effect due to ferrite core loading is derived and its validity is demonstrated experimentally. © 1998 Scripta Technica, Electron Comm Jpn Pt 1, 82(2): 1–10, 1999

An analysis of normal-mode noise caused by braided shield current flowing on coaxial cable attached by a ferrite core

Since coaxial cables have excellent electromagnetic shielding characteristics, they are widely used as interconnecting cables for digital information equipment. However, since braided lines are used in the shield layer of most coaxial cables, if an RF current flows, a noise voltage (normal mode noise) is induced between the core wire and the braided wire by electromagnetic coupling. Electromagnetic noise is also radiated from the common mode current of the braided shield. It has been considered that ferrite core loading is effective for reduction of the electromagnetic noise, and such loading is frequently used. In this article, in order to study whether ferrite core loading is effective in reducing normal mode noise, the normal mode noise generated by the braided shield current is analyzed with respect to the core loading location. Next, a formula for the noise-reduction effect due to ferrite core loading is derived and its validity is demonstrated experimentally. © 1998 Scripta Technica, Electron Comm Jpn Pt 1, 82(2): 1–10, 1999

A process for the manufacture of cold, clean, dry air at temperatures down to 173 K and its application in the forced cooling of high-pressure rubber hose prior to wire braiding

This paper describes a new technique for freezing braided wire rubber hose with cold air produced by refrigeration using an air turbine. This work details the whole refrigeration system and the procedure, highlights the characteristics of the refrigeration cycle and the design of the freezing chamber and also discusses the present situation of the technique in a wide range of applications. It has been proved in the production practice of the rubber hose that this new technique is a pioneering and effective achievement with low production costs.

Human Left Ventricular Endocardial Activation Mapping Using a Novel Noncontact Catheter

The patient was a 39-year-old male who had recurrent sustained monomorphic ventricular tachycardia, satisfying the electrocardiographic criteria for fascicular tachycardia, in a structurally normal heart. These isopotential maps were acquired from the patient’s left ventricle during an otherwise routine electrophysiology study by deploying a catheter-mounted multielectrode array consisting of a wire braid on the surface of an 8-mL balloon (Endocardial Solutions Inc). Without endocardial contact, this system uses inverse solution mathematics (boundary-element method) to reconstruct 3360 “virtual” electrograms onto a shell model of the endocardium. A manually selected line of virtual electrograms shows a …

A self-expanding bifurcated endovascular graft for abdominal aortic aneurysm repair. An initial study in a canine model.

Approximately 50,000 abdominal aortic aneurysms (AAAs) are surgically repaired annually in the United States. Endovascular grafts (EVGs) combine a stent and a vascular graft offering great potential for reduced morbidity, mortality, and hospital stay because of minimally invasive endoluminal placement through catheters. Because most AAAs extend into one or both iliac arteries, a bifurcated EVG (bEVG) was developed, consisting of a proximal aortic trunk divided into two distinct lumens or sockets to receive two smaller diameter leg (iliac) components. All components were composed of Didcott self-expanding braided wire stents integrally attached to porous spun polycarbonate urethane liners. Successful placement of the bEVGs (trunks 10-12 mm and legs 5-6 mm diameter) by a 10 Fr introducer through the femoral arteries into the infrarenal aorta and external iliac arteries of 9 of 11 dogs was achieved. Subsequently, 11 of 12 bEVGs were successfully placed to exclude a saccular aneurysm exceeding three aortic diameters created by a fascia lata pouch extending from the aorta into the left external iliac artery, of which 7 were patent at 1 to 4 months. These findings establish design feasibility of the bEVG as well as the utility of the canine experimental model.

The ultimate strength of suture anchors

Suture anchors of various designs are gaining acceptance for open and arthroscopic procedures. The rapid proliferation of these devices challenges those using them to apply objective criteria for device selection. Comparative data on implant security in different settings, modes of failure, and ultimate failure strengths is lacking. This study was undertaken to independently develop such data for an objective comparison of the suture anchors currently available. Using a fresh never-frozen porcine femur model, 10 samples of each of the 14 different anchors tested were inserted int each of the three different test areas: diaphyseal cortex (usually 3- to 4-mm thick), metaphyseal cortex (usually 1- to 2-mm thick), and a cancellous bone “trough”. The suture anchors were threaded with 0.018-inch stainless steel wire or, for anchors requiring a more flexible suture, 0.018-inch stainless steel 1 × 7 wire braid. Tensile stress parallel to the axis of insertion was applied at a rate of 12.5 mm/second by an Instron 1321 (Instron Corp.,City, State) until failure. Average failure strength was calculated for each anchor at each test area. The anchors tested were the Mitek G2, Mitek G3, Mitek G4 (Mitek Surgical Products, Norwood, MA), Linvatec Revo screw (Linvatec, Largo, FL), Acufex TAG Wedge, Acufex TAG Rod 2 (Acufex Microsurgical Mansfield, MA), Statak models 1.5, 2.5, 3.5, 5.0, and 5.2 (Zimmer, Warsaw, IN), Arthrex ESP (Arthrex Inc, Naples, FL), Arthrotek Harpoon, and Arthrotek LactoSorb (Arthrotek, Warsaw, IN). The average failure strength of each of these anchors in the diaphyscal cortex, metaphyseal cortex, and cancellous bone is reported. Using Duncan's multiple range test, the Statak 5.0, 5.2, Revo screw, and Mitek G4 showed the highest mean failure strengths in cortical bone. The Statak 5.0, 5.2, Revo screw, and Mitek G2 had the highest mean failure strengths in cancellous bone. The Revo screw was the most consistent of these anchors in all locations showing very little variation in failure strength despite variations in location or bone density. Mode of failure (anchor pullout, suture cutout of the anchor, or wire breakage) was generally consistent for each anchor type, although some variations occurred in different test areas. The size of the insertion hole is clinically important and each anchor's performance was evaluated as a function of its minor diameter or drill hole. All screw anchors were compared and the larger the screw anchor, the higher the mean failure strengths in all three test environments. In contrast, larger drill holes for non-screw anchors resulted in lower mean failure strengths in cancellous bone. Those anchors suitable for a bioabsorbable construct (ESP, Mitek G3, LactoSorb, Acutex TAG Rod 2, and Acufex TAG Wedge) were evaluated together. In this group, for diaphyseal cortex, larger drill holes resulted in higher mean failure strengths. Considering the metallic anchors in cancellous bone, larger drill holes lead to lower mean pullout strengths.

Vertical Ligated Gastroplasty by Clamp, Cut and Suture: A Series of 504 Cases Dating Back to 1977.

A restrictive operation for obesity makes a small pouch above a reinforced stoma. This series of 504 patients of one surgeon dating back to February 1977 has developed the same end result as the vertical banded gastroplasty, but does not involve stapling. The stomach is divided from the angle of His downwards for 11 or 12 cm, and the right channel is ligated with two ligatures made of Teflon-coated braided stainless steel wire. The pouch is made snug on a 30-French (9.5 mm) bougie, and the stoma is accurately gauged to 43 mm circumference, by matching marks made on the ligature. Making the pouch actually starts from the middle of the stomach and progresses upwards by clamp, cut and suture. The sutured anastomosis would appear to be more reliable than a stapled one. Weight loss is similar to other restrictive procedures, and two series of 30 consecutive cases each are presented with a 100% follow-up: 80% lost at least 60% of their excess weight, and 60% lost more than 60% of their excess weight. There has been no mortality for the primary gastroplasty operation.

Pacing thresholds of temporary epicardial electrodes: Variation with electrode type, time, and epicardial position

We compared the variation in pacing thresholds of two widely used temporary pacing electrodes at different epicardial sites in 67 patients after coronary artery operations performed with either cardioplegia or ventricular fibrillation. In 33 patients, a bare, braided pacing wire (DW) was placed on the right ventricle and a Medtronic localized epicardial electrode (MED), on each ventricle. In the other 34 patients, the DW wire was placed on the right atritum and a MED electrode, on each atrium. Pacing thresholds were measured at the time of placement; at 1 hour, 6 hours, and 12 hours postoperatively; and daily for 4 days. The pacing thresholds (mean ± standard error of the mean) at implantation were as follows: DW wire = 0.93 ± 0.08 V and MED electrode = 0.63 ± 0.1 V in the ventricles and DW = 1.28 ± 0.18 V and MED = 0.65 ± 0.09 V in the atria. On the fourth postoperative day, the pacing thresholds were DW = 2.08 ± 0.21 V and MED = 1.19 ± 0.22 V in the ventricles and DW = 2.33 ± 0.29 V and MED = 1.04 ± 0.09 V in the atria. The pacing thresholds of both types of wire increased significantly over time, but this deterioration was more pronounced with the braided wire both on the ventricle and on the atrium. The pacing threshold patterns were not affected by chamber side or mode of myocardial preservation. The braided ventricular wire failed to capture after 24 hours in 9 of 30 patients, whereas the localized epicardial electrode captured in all instances ( p < 0.001). There was no significant difference in failure rate between the two wires in the atrial position. Localized epicardial electrodes have consistently lower pacing thresholds than braided wires in both the ventricles and the atria and are less prone to failure in the ventricular position.

PROPHYLACTIC CERCLAGE: A METHOD OF PREVENTING FEMUR FRACTURE IN UNCEMENTED TOTAL HIP ARTHROPLASTY

The incidence of femur fracture in non-cemented hip arthroplasty has been reported to be between 4.1% and 27.8%. To quantitate the hoop stress generated during insertion of a femoral broach in total hip arthroplasty and determine the effect of cerclage with both braided cable and wire, we harvested 14 pairs of embalmed cadaver femurs. These were reamed and broached to duplicate the surgical technique of inserting a straight non-cemented femoral component. Group one consisted of eight matched cadaver femurs which were tested using a single 2.0 mm chrome-cobalt cable placed around the calcar of one femur, with the other serving as a control. Group two consisted of five matched cadaver femurs which were tested using a single 18 gauge cerclage wire in the same manner. In group one, the femurs serving as controls were found to have a mean microstrain of (1425.00 +/- 1180.19). The eight femurs tested with a 2 mm cable were determined to have a mean microstrain of (4179 +/- 2853.89). In group two, the femurs serving as controls were found to have a mean microstrain of (962.60 +/- 956.78). The five femurs in group two tested with a cerclage wire were determined to have a mean microstrain of (1112.00 +/- 975.66). Using a paired t-test, statistical significance was achieved with a confidence level of P less than or equal to .01 in group one. Prophylactic wiring of the proximal femur with 2 mm cable increases the hoop stress resistance and, therefore, should decrease the incidence of intraoperative femur fractures in uncemented total hip arthroplasty.