Hollow Needles Research Articles

Faraldsfræði stunguóhappa á Landspítalanum á árunum 1986-2011. Lýsandi rannsókn

Needlesticks, bodyfluid exposure and bites (incident) put healthcare workers (HCWs) at risk of hepatitis B, C and HIV particularly if patients are infected (high risk incident). The risk of infection is greatest from bore-hollow needles. The aim of the study was to describe the epidemiology of reported incidents and evaluate underreporting by HCWs at Landspítali University Hospital (LUH). A retrospective descriptive study of reported incidents during 1986-2011. The ratio of incidents was calculated according to the HCWs age and profession and distribution by source and wards. The ratio of high risk incidents and vaccination status against HBV at time of incident was determined as well as underreporting during 01.01.2005-31.12.2011. At least 4089 incidents occured during the study period but 3587 were reported and blood samples taken from 2578 patients. Approximately a third of the incidents were associated with non-compliance with standard precaution and 54,7% of needlesticks were associated with bore-hollow needles. Few reports came from physicians and medical students (17,9%). During the study period 50,3% HCWs were vaccinated against HBV at time of incident. High risk incidents were 94 (2.6%), mostly related to hepatitis C (64,9%). Two HCWs became infected with HCV. During 2005-2011 underreporting was estimated to be 28,0%. Improved education of standard precaution when handling needles and sharps at LUH may reduce the number of incidents. Introduction of safety-needles and safety-devices may greatly reduce needlesticks as a large number of incidents were associated with hollow needles. Improved HBV vaccination among HCWs and reporting incidents should be encouraged.

Fabrication process for tall, sharp, hollow, high aspect ratio polymer microneedles on a platform

This paper reports on a new lithographic process for fabricating arrays of tall, high aspect ratio (defined as height/wall thickness), hollow, polymer microneedles on a platform. The microneedles feature a high sharpness (down to 3 µm tip radius) and aspect ratio (>65) which is a factor 2 and 4 better than the state of the art, respectively. The maximum achievable needle shaft length is over 1 mm. The improved performance was obtained by using an anisotropically patterned silicon substrate covered with an antireflective layer as mold for the needle tip and an optimized SU-8 lithographic process. Furthermore, a platform containing liquid feedthroughs holding an arbitrary number of needles out of plane can be manufactured with only one additional process step. The high aspect ratio microneedles undergo failure at the critical load of around 230 mN in the case of 1 mm long hollow needles with triangular cross section and a base of 175 µm. Penetration into human skin is demonstrated as well.

Verletzungsmuster des Operationsteams bei augenchirurgischen Eingriffen

Accidental sharp injuries among the health-care workers are frequent, especially in the surgical disciplines. Because there are only limited data available about accidental sharp injuries in small surgical disciplines, we investigated the occurrence of sharp injuries among ophthalmosurgeons in Switzerland. An anonymous questionnaire was sent to all 500 members of the Swiss Ophthalmological Association. We asked how often the surgeons or any member of the surgical team suffered injury during an ophthalmic surgery within the last 2 years and which instrument had caused the injury. Using linear regression we analysed the connection between the occurrence of injuries and various factors, e.g., the age or experience of the surgeon, whether any actions in the case of an injury were taken, whether the event was documented and whether actual guidelines were followed. In the 117 analysed questionnaires we counted 193 injuries. 42.7 % of the surgeons (n = 50, 95 % CI 33.7 % - 51.8 %) had injured themselves at least once during the past two years and 59.8 % of the surgeons (n = 70, 95 % CI 50.9 % - 68.7 %) reported injuries among the rest of the surgical team. On average, surgeons were injured 0.66 times in two years (range 0-4 injuries per person). Most injuries were caused by hollow needles [28.2 % of self injuries (95 % CI 18.2 % - 38.2 %)], 24.3 % of injuries of team members (95 % CI 16.5 % - 32.1 %). 53.0 % of the surgeons (n = 63, 95 % CI 44.0 % - 62.0 %) reported the case whereas 18.8 % (n = 22, 95 % CI 11.7 % - 25.9 %) never reported them. Some questionnaires did not contain the answers to those last questions. Using chi-square, we could observe more injuries in the middle-age section and in surgeons with 11-30 years of surgical experience (p < 0.05). The regression did not show any dependence on the rate of injuries on the surgeon's experience and the number of performed surgeries. We conclude that in ophthalmosurgery sharp injuries to surgeons or their surgical team happen frequently and only about 50 % of the cases are reported. This study shows that there is room for improvement concerning the documentation and the actions taken after an injury. Thereby potential sources of danger could be better monitored.

Occupational Exposure to Blood and Body Fluids among Healthcare Workers in a Teaching Hospital: an Experience from Northern Thailand

This retrospective study was conducted among healthcare workers (HCWs) in a tertiary care hospital to (i) determine the incidence of exposure to blood and/or body fluids, (ii) describe the characteristics of such exposures, and (iii) describe management after exposure. There were 1,611 episodes of occupational exposure between January 1, 2005 and December 31, 2010. Of those affected, 1,086 (67.4%) were women. The mean age was 27.6 ± 7.2 years. Nurses (483, 29.9%) were the HCWs most frequently exposed to blood and/or body fluids. The incidence was highest among physicians (11%/year). Percutaneous injury by hollow needles was the most common type of injury (576, 35.8%). Of the 1,611 episodes, 142 (8.8%) comprised HCWs being exposed to human immunodeficiency virus-positive sources. One hundred fifty-one HCWs (9.4%) were exposed to hepatitis B surface (HBs) antigen-positive sources. Sixty-one HCWs had indications for both hepatitis B virus (HBV) vaccine and hepatitis B immunoglobulin; 43 (70.5%) received both. Among the 266 HCWs who had no protective antibody against HBV and were exposed to HBs antigen-negative sources, only 1 (0.4%) received HBV vaccine. These findings suggest that guidelines for post-exposure management among HCWs exposed to HBs antigen-positive sources are not regularly followed. HBV immunization is necessary for all HCWs.

Pudendal nerve block in HDR-brachytherapy patients: do we really need general or regional anesthesia?

In male patients, the pudendal block was applied only in rare cases as a therapy of neuralgia of the pudendal nerve. We compared pudendal nerve block (NPB) and combined spinal-epidural anesthesia (CSE) in order to perform a pain-free high-dose-rate (HDR) brachytherapy in a former pilot study in 2010. Regarding this background, in the present study, we only performed the bilateral perineal infiltration of the pudendal nerve. In 25 patients (71.8±4.18years) suffering from a high-risk prostate carcinoma, we performed the HDR-brachytherapy with the NPB. The perioperative compatibility, the subjective feeling (German school marks principle 1-6), subjective pain (VAS 1-10) and the early postoperative course (mobility, complications) were examined. All patients preferred the NPB. There was no change of anesthesia form necessary. The expense time of NPB was 10.68±2.34min. The hollow needles (mean 24, range 13-27) for the HDR-brachytherapy remained on average 79.92±12.41min. During and postoperative, pain feeling was between 1.4±1.08 and 1.08±1.00. A transurethral 22 French Foley catheter was left in place for 6h. All patients felt the bladder catheter as annoying, but they considered postoperative mobility as more important as complete lack of pain. The subjective feeling was described as 2.28±0.74. Any side effects or complications did not appear. Bilateral NPB is a safe and effective analgesic option in HDR-brachytherapy and can replace CSE. It offers the advantage of almost no impaired mobility of the patient and can be performed by the urologist himself. Using transrectal ultrasound guidance, the method can be learned quickly.

Modeling cutting edge geometry for plane and curved needle tips

Hollow needles are commonly used in many areas of medicine, yet there has been limited research on needle tip geometry. A better understanding of needle tip geometry can lead to the creation of an optimized needle tip geometry design which would greatly benefit the procedure of biopsy, where a needle is used to cut and remove tissue from the body. The present research develops mathematical models to calculate the inclination and rake angle along the cutting edges of needle tips generated by curved surfaces. The parameters of needle insertion length and inner needle tip surface area are also examined. Needle insertion force is predicted based on needle geometry and calculated for curved and flat plane tip needles. A concave needle produced lower cutting forces than the convex and bias bevel needles. It is found that utilizing curved surface needle tip geometry, as opposed to flat plane geometry, allows for greater control in varying rake and inclination angles on the needle. This greater flexibility allows for more control in designing an optimized needle tip.

Crystalline coats or hollow crystals as tools for product design in pharmaceutical industry

The coating of pharmaceutical compounds is a field of high interest. As most of the coating materials form an amorphous layer around the material, the studies on crystalline coatings are rare. In this work the progress in this domain should be summarized and innovative results concerning crystalline hollow needles as coating material are presented. Since the first reports on needles formed via a solvent-mediated phase transition from solvates to hydrates, the field could be widened to hydrate-to-anhydrate and anhydrate-to-hydrate transformations. Novel investigations on hollow theophylline monohydrate and carbamazepine dihydrate needles are presented. It is shown that the inclusion of substances into the hollow needle crystals is feasible by simple means, which enable an application in industry as coating for sensitive materials.

Development of a minimally invasive laser needle system: effects on cortical bone of osteoporotic mice

Many studies have shown the positive effects of low-level laser therapy in the treatment of bone disease. However, laser radiation is scattered in the skin surface which reduces the initial photon density for tissue penetration and consequently the therapeutic efficacy. We developed a minimally invasive laser needle system (MILNS) to avoid laser scattering in tissue and investigated its stimulatory effects in the cortical bone of osteoporotic mice. The MILNS was designed to stimulate cortical bone directly by employing fine hollow needles to guide 100μm optical fibers. The study animals comprised 12 mice which were subjected to sciatic denervation of the right hind limb and were randomly divided into two groups, a sham group and a laser group which were treated using the MILNS for 2weeks without and with laser irradiation, respectively. In vivo micro-CT images were taken to analyze the structural parameters and bone mineral density. After 2weeks of treatment with the MILNS, the relative changes in mean polar moment inertia, cross-section thickness, and periosteal perimeter were significantly higher in the laser group than in the sham group. Moreover, the distribution of bone mineral density index was higher in the laser group. The MILNS was developed as a minimally invasive treatment modality for bone disease and resulted in positive therapeutic efficacy in the cortical bone of osteoporotic mice.

A Self-Defined Hollow Needle Formation on Silicon Membranes with the Aids of Carbon Nanotubes

A self-defined method for the formation of hollow needles and micro-cylindrical structures on silicon substrates is reported which uses the combination of high aspect ratio vertical etching of silicon with a small angle vacuum deposition technique. These structures can be used as the media to transfer gas and liquid through their tiny holes. The fabrication is further continued with the growth of carbon nanotubes on the already created silicon-based features to form a cage-like cylindrical structure. In addition, the growth of vertical carbon nanotubes just inside the cup-like structures has been demonstrated without a need for an extra lithography step.

Iatrogenic Spinal Epidermoid Cyst After Lumbar Puncture Using Needles with Stylet

Iatrogenic spinal epidermoid tumors are extremely rare and may be caused by implanted skin fragments in the spinal canal, most commonly due to lumbar punctures using hollow needles without a stylet. The authors report for the first time an iatrogenic spinal epidermoid tumor that developed 26 months after several lumbar punctures, performed using disposable spinal needles with stylet, in an 8-year-old boy with persistent lower back pain. The authors hypothesize that an ill-fitting stylet compounded by multiple therapeutic lumbar punctures and young age as possible risk factors for the development of the tumor in the present case. A total excision of the tumor with laminectomy yielded good symptomatic recovery.

OCCUPATIONAL SHARP INJURIES IN HEALTH CARE WORKERS; RESULTS FROM EL-MINIA UNIVERSITY HOSPITALS AND EL-MINIA GENERAL HOSPITAL

Objective: One of the potential occupational hazards for health care workers (HCWs)is sharps injuries especially needle stick injuries (NSIs). These hazards are influenced by numerous factors including setting, environmental factors, staffing levels, type of procedures, devices and equipment.Aim of work:To determine the frequency, characteristics and determinants of occupational sharp injuries in HCWs.Subjects and Methods:This study is a cross-sectional study; involved 160 HCWs employed in jobs with potential exposure to sharps injuries. Data were collected by questionnaire that included demographics, occupation categories; shift work,knowledge of prevention measures and details of sharp injuries.Results: The results showed that 40% of HCWs were > 30ys old; (57.5%) females;(70%) married; and (77.5%) academic workers. Occupational categories showed (45%)nurses; (26.3%) physicians (surgeons and others), (17.5%) technicians, (11.2%) cleaners and (51.9%) working a shift work day and night (rotating shifts). The majority (40.6%)have < 10 years in service and (71.3%) not trained about precautions. Surveyed HCWs,admitted sharp injuries in (42.5%) with reporting percent of 11.8 as they don’t know(18%) or lack of direction (57%). Injuries caused by hollow bored needles (29.2%),stabs, scalpel (30.8%) and others (40%).Conclusion:The frequency of sharp injuries among HCWs is high and reporting is low and awareness of protection is very low. The data showed that continued training effort, need to be directed toward new HCWs ; this research, also points to the need for better safety devices products and work practices to reduce suture related injuries.

An Instrument for Controlled, Automated Production of Micrometer Scale Fused Silica Pipettes

Micropipettes are hollow glass needles with tip openings ranging from less than 1 μm up to 75 μm. Based on the size of the inner diameter of the micropipettes, they can be used for applications such as patch clamping, microinjection, and cell transfer. In the state-of-the-art fabrication of micropipettes, a skilled individual is able to produce about 2 − 4 micropipettes per minute. Many labs, which utilize hundreds of pipettes on a weekly basis, would benefit from the increased speed, accuracy, and repeatability of an automated fabrication apparatus. We have designed, built, and tested a working prototype of a fully automated fused silica micropipette puller. Our device pulls pipettes from a continuous spool of capillary glass, which leads to minimized setup time for the operator and the ability to produce 6 micropipettes per minute. Micropipettes were pulled with average lengths ranging from 6–20 mm and average tip diameters ranging from 18–175 μm. Standard deviations for length and diameter were calculated to range from 0.24-2.9 mm and 3.5–12 μm, respectively. Through measurements of the pulled pipettes, a trend has been determined which shows higher pulling velocity increases tip length and decreases tip diameter. A new model for heat transfer and geometrical analysis for the heating and cooling of the pipettes has been developed and matches closely to this experimental data. This can be used to predict pipette geometry.

V371 INTRAOPERATIVE URODYNAMIC CONSIDERATIONS IN BULBOURETHRAL SLING SURGERY FOR POST PROSTATECTOMY INCONTINENCE

You have accessJournal of UrologyMale Voiding Dysfunction (BPH & Incontinence), Oncology & Prostate Cancer1 Apr 2011V371 INTRAOPERATIVE URODYNAMIC CONSIDERATIONS IN BULBOURETHRAL SLING SURGERY FOR POST PROSTATECTOMY INCONTINENCE Marcus Horstmann, Christian Padevit, Christoph Schwab, Christian Vollmer, Isabelle Rauter, Kevin Horton, and Hubert John Marcus HorstmannMarcus Horstmann Winterthur, Switzerland More articles by this author , Christian PadevitChristian Padevit Winterthur, Switzerland More articles by this author , Christoph SchwabChristoph Schwab Winterthur, Switzerland More articles by this author , Christian VollmerChristian Vollmer Winterthur, Switzerland More articles by this author , Isabelle RauterIsabelle Rauter Winterthur, Switzerland More articles by this author , Kevin HortonKevin Horton Winterthur, Switzerland More articles by this author , and Hubert JohnHubert John Winterthur, Switzerland More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.458AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Incontinence after prostatectomy remains a frustrating problem with a significant negative impact on quality of life. One possible option for moderate to severe incontinence is the implantation of a retropubic implant system, the bulbourethral suspension (J. Urology 171: 1866-70, 2004 and UROLOGY 71: 1191-5, 2008). This video demonstrates the improved technique with focus on intraoperative urodynamic measurements for optimal sling tension adjustment. METHODS The patient is first placed in a modified lithotomy position. A vertical perineal midline incision is performed to expose the bulbar urethra in a lithotomy position. The implant is positioned around the bulbar urethra and both ends of the sling are brought up strictly retropubically, lateral to the bladder neck to suprapubic skin incisions through two curved hollow needles. Bladder perforation is further excluded by 70° cystoscopy. Under general anaesthesia without relaxation sling tension is stepwise increased until an antegrade opening pressure of 60–65 cmH20 is reached. These measurements are repeated at least three times. Once a stable antegrade urethral opening pressure measurement is reached the polypropylene ends are tied off. Finally urethral pressure profile is repeatedly measured before and after sling implantation for further evaluation. The perineal and suprapubic incision lines are closed by interrupted sutures. A Foley bladder catheter is placed for 3 days. Antibiotics are stopped after bladder catheter removal. RESULTS With the use of intraoperative urodynamics the antegrade opening pressure was successfully increased to 65 cmH20. The urethral pressure profile revealed an increased functional length without an increase of the maximal urethral pressure. CONCLUSIONS The use of intraoperative urodynamics allows us to precisely determine the antegrade opening pressure and consequently reach urinary continence in most patients. Postoperative manipulations to adjust the sling tension can be avoided. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e151 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Marcus Horstmann Winterthur, Switzerland More articles by this author Christian Padevit Winterthur, Switzerland More articles by this author Christoph Schwab Winterthur, Switzerland More articles by this author Christian Vollmer Winterthur, Switzerland More articles by this author Isabelle Rauter Winterthur, Switzerland More articles by this author Kevin Horton Winterthur, Switzerland More articles by this author Hubert John Winterthur, Switzerland More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Generation of Crystalline Hollow Needles: New Approach by Liquid‐Liquid Phase Transformation

AbstractThe formation of hollow crystalline needles by means of a solvent‐mediated phase transformation takes place during the dehydration of hydrate crystals in methanol into hollow needle‐shaped anhydrate crystals. Here, a special way of achieving needle growth is presented. When a saturated aqueous solution of sodium‐2‐ketogulonate is dropped into methanol, a simultaneous nucleation of monohydrate crystals and anhydrate needles takes place in the alcohol. It was proven by scanning electron microscope images that these needles are hollow. By means of the variation of the production method, it is for the first time possible to observe the needle growth in a more detailed manner, and to show that the nucleation can take place at impurities and surface roughnesses. The method helped to discuss and to deepen the understanding of the growth mechanism of the hollow crystalline needles.

Prosper: Image and robot-guided prostate brachytherapy

Brachytherapy for localized prostate cancer consists in destroying cancer by introducing iodine radioactive seeds into the gland through hollow needles. The planning of the position of the seeds and their introduction into the prostate is based on intraoperative ultrasound (US) imaging. We propose to optimize the global quality of the procedure by: i) using 3D US; ii) enhancing US data with MRI registration; iii) using a specially designed needle-insertion robot, connected to the imaging data. The imaging methods have been successfully tested on patient data while the robot accuracy has been evaluated on a realistic deformable phantom.

Hollow needle tissue insertion force model

In this study, a mechanistic approach using elementary cutting tool (ECT) edges of varying inclination and normal rake angles is demonstrated to be capable to predict hollow needle insertion force. A needle force model is developed and validated for the specific case of 11 gauge two-plane symmetric needles. Blades of varying inclination and rake angles are inserted into bovine liver to determine the specific force of initial tissue cutting for the given edge geometry; this information is applied to the ECT force model which is validated against experimental force results of hollow needles inserted into bovine liver.

Improved hair restoration method for burns

Background Extracted partial longitudinal follicular units can be used as complete follicular units to regenerate completely differentiated hair growth. The partial follicular units that remained in the dermis in the donor area can survive and produce hairs. This technique enables us to multiply hair follicles in vivo, while preserving the donor area and therefore is suitable in persons, who have a relative small donor area compared to the recipient area, as in scalp burns. Objectives With this study, we try to determine if partial longitudinal follicular unit transplantation (PL-FUT) can be used for facial and/or scalp burns. Materials and methods Four burn victims (age 22–39 years, mean 27.75 years) were treated in the face (eyebrows, and beard) and/or on the scalp with PL-FUT. The grafts were harvested with hollow wave-tipped needles with an inner diameter of 0.6 mm from the occipital area of the scalp. The suitable longitudinal partial follicular units were impregnated with a preservative medium, and implanted into the recipient area. Hair growth in the donor area as well as the recipient area was observed before treatment, and at intervals of 1 week, 3 months and 1 year after the treatment. Results After evaluation of the donor area, sometimes a few little white spots were visible, but almost all hair follicles in the donor site re-produce hairs after 2 years. All treated patients had satisfactory or very satisfactory cosmetic results in the treated area. Conclusions Longitudinal partial follicular unit transplantation (LP-FUT) may represent the first reliable patient-friendly method to generate two hair follicles from one hair follicle with consistent results and preservation of the donor area. Therefore, this method is very suitable for people with facial and/or scalp burns.

Modeling of the Plane Needle Cutting Edge Rake and Inclination Angles for Biopsy

Hollow needles are one of the most common medical devices, yet little study has focused on the needle tip cutting geometry for biopsy, which is a tissue cutting process. This research develops mathematical models to calculate the inclination and rake angles along cutting edges on needle tips generated by planes. Three types of plane needle tips, the one-plane bias bevel, multi-plane symmetrical, and two-plane nonsymmetric needles, are investigated. The models show that the leading tip of a bias bevel needle has an inclination angle of 0 deg, the worst configuration for cutting. Symmetric multiplane needles on the other hand have very high inclination angles, 60, 56.3, and 50.8 deg, given a needle formed by two-, three-, and four-plane, respectively, for a bevel angle of 30 deg and can assist more effective needle biopsy. The rake angle is at its greatest value (the best configuration for cutting), which equals the 90 deg minus the bevel angle, at the initial cutting point for the bias bevel needle. Experiments are performed using three 11 gauge two-plane symmetric needles with 20, 25, and 30 deg bevel angles on bovine liver and demonstrate that the needle tip geometry affects biopsy performance, where longer biopsy samples are collected with needles of higher rake and inclination angle.

High–dose rate brachytherapy in the treatment of penile carcinoma—First experience

Purpose Interstitial low–dose rate brachytherapy (BRT) allows a conservative treatment of T1–T2 penile carcinoma. High–dose rate (HDR) BRT is often considered as a dangerous method for interstitial implants because of higher risk of complications. However, numerous reports suggest that results of HDR-BRT may be comparable to low–dose rate BRT. There are no data available in the literature regarding HDR interstitial BRT for carcinoma of the penis. Methods and Materials Ten patients with early penile carcinoma were treated by interstitial hyperfractionated HDR-BRT at the dose of 18 times 3 Gy twice daily between years 2002 and 2009. Breast interstitial BRT template was used for fixation and precise geometry reconstruction of stainless hollow needles. Results Median followup was 20 months. Our BRT technique and fractionation schedule was well tolerated by all patients. Acute reaction consisted predominantly of penis edema and Grade 2 radiation mucositis that dissolved during 8 weeks after the treatment. We neither observed any postradiation necrosis nor urethral stenosis. The worst late side effects recorded were mild telanagiectasias in the treatment region. At the last followup, all patients were alive without evidence of the tumor and with fully functional organ. Conclusions Hyperfractionated interstitial HDR-BRT with 18 times 3 Gy per fraction twice daily is a promising method in selected patients of penile carcinoma and deserves further evaluation in a larger prospective study.

Ultrafine hollow needle formation on silicon

A method for the formation of ultrafine hollow needles, microcylindrical and nano-wall structures on silicon substrates is reported. The fabrication of these ultrafine structures is possible through a combination of high-precision high aspect ratio vertical etching of silicon with a small angle vacuum deposition technique where nanometric walls are feasible. These structures can be used as the media to transfer gas and liquid through their tiny holes. In addition, the structure has been used to realize cavity-based capacitance inclination sensor suitable for small angle detection. A capacitance variation of 0.6 pF/degree of inclination has been obtained.