Recipient to donor conduction of atrial tachycardia following orthotopic heart transplantation

Postspinal headache is one of the most common complications of spinal anesthesia and has repeatedly led to controversy concerning needle size and configuration. In an in vitro investigation, we measured cerebrospinal fluid (CSF) leakage with Sprotte, Whitacre, Quincke, and Atraucan needles under physiological conditions in human dura. The puncture characteristics were examined under an electron microscope. The pencil-point needles show 2-3 times less leakage of CSF compared with the cutting Quincke needles of corresponding size. Between the Sprotte and the Whitacre needles, there were no significant differences. The least loss of CSF occurred with the 26-gauge Atraucan needle. Under the electron microscope, a sharply delineated, persistent perforation channel was shown with the Quincke needles, which may explain the high CSF loss. With pencil-point needles, which push the tissue apart bluntly, a large opening on the inside is found, with some tearing of the dura. However, in contrast to the cutting needles, a persistent perforation channel is not manifested. The 26-gauge Atraucan needle, which both cuts and pushes apart conically, shows a relatively discrete opening on the inside, with slight tears in the dura and arachnoidea but without a visible perforation channel. The results of our study show that larger needles (26-gauge Atraucan) that are easier to handle can lead to good and, in some cases even better, puncture results if they have characteristics of both the cutting and the pencil-point needles. IMPLICATIONS: We compared several brands of pencil-point and standard cutting spinal needles of varying sizes. All pencil-point needles had less cerebrospinal fluid leakage, the least loss occurring with 26-gauge Atraucan needles. Electron microscopic examination of the dura after puncture showed characteristic findings with each needle type. We conclude that the combined cutting and pencil-point characteristics seen in the Atraucan needle may have clinical advantages.     

CT-assisted needle biopsy in pulmonary and mediastinal space-occupying lesions. The effect of spiral CT and various biopsy needles on results

The efficacy of percutaneous CT-guided needle biopsies was investigated in 68 patients with pulmonary lesions and in 65 patients with mediastinal masses. In comparison with conventional multisectional CT, the time needed for the localization of the needle tip could be reduced by use of spiral CT. Comparing aspiration and cutting biopsy needle we achieved a higher accuracy of 94% in case of mediastinal masses and of 90% by using cutting needles. The rate of complications, such as pneumothoraces, is relatively low.     

Toxoplasma gondii: metabolism of intracellular tachyzoites is affected by host cell ATP production

PURPOSE: To evaluate different-caliber biopsy cutting needles in terms of the benefits and potential risk of bleeding in a swine model. MATERIALS AND METHODS: A total of 190 sequential liver biopsy specimens were obtained in 11 Yorkshire pigs (weight, 50-70 lb [22.5-31.5 kg]) by using 14-, 18-, and 20-gauge cutting needles. For each biopsy procedure, blood loss was determined by weighing sponges used to absorb bleeding, and sample-tissue DNA content was measured with spectrofluorometry. Analysis of variance was used to compare results. RESULTS: The larger the caliber of needle, the greater the absolute blood loss (for 14-gauge, 1.69 g; for 18-gauge, 0.74 g; for 20-gauge, 0.32 g) and DNA content per sample (for 14 gauge, 40.38 microg; for 18-gauge, 12.18 microg; for 20-gauge, 5.86 microg). The ratio of blood loss to amount of DNA recovered did not differ among the different-caliber needles. To obtain the same amount of diagnostic tissue, more passes were needed with the smaller-caliber needles. CONCLUSION: Use of larger-caliber needles is more efficient despite the greater amount of blood loss, because more tissue can be recovered and because fewer passes are necessary, which reduces the chances of complications.     

Efficacy of gloves in reducing blood volumes transferred during simulated needlestick injury

This study was designed to evaluate factors that affect blood volumes transferred to skin during simulated needlestick injuries in an in vitro paper prefilter model and an ex vivo porcine tissue model. The effect of needle type and size, penetration depth, and glove use on the volume of radiolabeled blood transferred was determined in each model. Blood volumes ranged from 0.47 +/- 0.26 microL (30-gauge needle, 0.5-cm depth, in vitro model) to 5.88 +/- 1.45 microL (18-gauge needle, 2.0-cm depth, in vitro model). Needle size and penetration depth were significantly associated with transfer volume. Glove material reduced the transferred blood volume by 46%-86% in both models. Transfer volumes were within the same order of magnitude for all conditions. Hence, virus titer in the source blood may be a better predictor of needlestick infectivity than is exposure volume. Regardless, gloves may exert some protective effect and should be worn whenever needles are handled.     

Electron microscopy of the lesions produced in the human dura mater by Quincke beveled and Whitacre needles

INTRODUCTION: Comparisons of Quincke needles and non traumatic "pencil point" needles in recent years have reported lower rates of post dural puncture headache using the later type. Our new understanding of the morphology of the human dura mater motivated us to study dural lesions caused by the Whitacre 25 G and Quincke 26 G needles, using scanning electron microscopy with the aim of determining whether there is an anatomic basis for the different outcomes. METHOD: The dura mater from three fresh cadavers of individuals aged 65, 70 and 72 years were punctured 40 times at an angle of 90 degrees each time. The Whitacre 25 G needle was used for 20 punctures and the Quincke 26 G needle was used for the other 20. Half the punctures were performed with the bevel in the parallel alignment and the other half with the bevel perpendicular to the spinal column. Fifteen min after causing the punctures, specimens were fixed in solutions of glutaraldehyde phosphate buffer and dehydrated in acetone. After critical point removal of the acetone, after the specimens were treated with carbon and metallized with gold. The lesions were examined externally and internally and expressed as the ratio of area of lesion to diameter of the needle that had caused them. RESULTS: Whitacre needle: each lesion consisted in the superimposition of multiple damaged layers that started to close individually. After 15 min the outermost layers were 90% closed and the innermost ones had closed entirely. Layers in the arachnoid surface of the dura mater had closed from 86 to 88%, while deeper layers in the thick part had closed 97 to 98%. Quincke needle: lesions were V-shaped or half-moon shaped, much like the opening formed by a can opener, on both the external and internal surfaces. Alignment of the bevel of the needle parallel to the spinal column did not lead to a different shape of puncture. After 15 min the lesions had closed 94 to 95% on the epidural surface and 95 to 96% on the arachnoid side, a difference attributable to the retraction of the arachnoid layers over the spinal column. CONCLUSION: Non traumatic beveled dural needles, termed "pencil point needles", only partially separate dural fibers, and lesions caused by these needles develop in a more complex way. The Quincke 26G needle produced a puncture that is morphologically different from that caused by the Whitacre 25G needle, although lesions produced by both types close more than 94% after 15 min. We believe the size of the lesion caused by these needles does not explain the difference in post dural puncture headache due to loss of spinal fluid.     

Atraucan: a new needle for spinal anesthesia

BACKGROUND AND OBJECTIVES: Atraucan 26-gauge spinal needles have a tip designed to make a small linear cut (as opposed to a V-shaped cut) in the dura mater. The cut is shorter than the outside diameter of the needle and is dilated as the needle passes through the dura. The needle is used with a 20-gauge introducer. In vitro, it causes less leakage of cerebrospinal fluid than Quincke 26-gauge or Sprotte 24-gauge needles. This study was designed to test the ease of use and any damage caused to the needle tip during lumbar dural puncture. METHODS: This was a multicenter trial (six centers in five countries) involving 362 patients undergoing spinal anesthesia. A detailed questionnaire was filled in for every patient by the anesthesiologist. All the needles were returned to the factory and examined microscopically for damage. RESULTS: Lumbar dural puncture was successful in all but one patient. Spinal anesthesia was satisfactory for the planned surgery in 97%. Microscopy of the needle tips showed only a minor degree (0.01-0.19 mm) of bending in 14%, and none of the tips had a "hook." Postdural puncture headache (PDPH) occurred in nine patients (2.5%), all but one of whom (a 15-year-old male) were females under 55 years of age. CONCLUSIONS: The Atraucan needle is easy to use and has a high success rate in identifying the subarachnoid space. Lumbar dural puncture causes minimal damage to the tip. The incidence of PDPH is low, but a larger comparative study needs to be performed.     

Relationship between the presence of side-holes in bone marrow aspiration needle and the number of harvested bone marrow mononuclear cells

The aim of this study was to evaluate the yield of nucleated cells in bone marrow harvested by means of Downs' Islam aspiration needles with or without side-holes. Twenty marrow donors for HLA identical sibling transplants were studied. Bone marrow nucleated cells were harvested 50 ml in the right iliac bone with a Downs' Islam aspiration needle with or without side-holes and 50 ml in the left with another kind of needle by means of 5 ml aspirations in each donor. There were no significant difference between the number of nucleated cells by means of Downs' Islam aspiration needles with and without side-holes by cross-over analysis. All nucleated cell counts were 33.06 +/- 12.93 x 10(3)/microliter (mean +/- standard deviation) by means of the needle with side-holes and 32.90 +/- 15.25 x 10(3)/microliter by means of the needle without side-holes. The Downs' Islam aspiration needle without side-holes seems to be better in bone marrow harvest from normal volunteers than that with side-holes, because the former may be stronger than the latter.     

Interactive MR imaging-guided biopsy and aspiration with a modified clinical C-arm system

OBJECTIVE: This investigation was performed to test the hypotheses that interactive guidance of MR image acquisition during needle-directed procedures using a clinical 0.2-T C-arm open MR imaging system integrated with a frameless optically linked stereotaxy system is feasible, and that procedure times can be sufficiently short to be well tolerated by the patient. SUBJECTS AND METHODS: One hundred six MR-guided procedures were performed in 86 patients (ranging in age from 5 months to 88 years) using a clinical C-arm imaging system supplemented with an in-room RF-shielded liquid crystal display monitor, a frameless stereotaxy system, rapid gradient-echo sequences for needle guidance, and MR-compatible monitoring and surgical lighting equipment. We performed 50 biopsies and aspirations of the head and neck in 37 patients, 23 biopsies of musculoskeletal lesions in 22 patients, 16 biopsies of abdominal sites in 10 patients, six biopsies of the thoracolumbar spine or sacrum in six patients, and 11 shoulder joint injections for MR arthrography in 11 patients, in addition to 38 MR arthrographic injections on the same imaging system described in a previous report. Tissue sampling included fine-needle aspiration (n = 90) and cutting needle core biopsy (n = 41). Thirty-five patients underwent both procedures. Procedures were evaluated for success of needle placement, procedure time, and complications. RESULTS: Needle placement was successful in all cases, and no complications occurred. Tissue was sufficient for pathologic diagnosis for all but eight patients. Passes per patient averaged 2.1. For fine-needle aspiration, instrument time averaged 7 min 42 sec per pass, cutting needle core biopsy averaged 6 min 24 sec, and shoulder injection averaged 8 min. CONCLUSION: MR imaging guidance for needle procedures on a clinical 0.2-T C-arm system with supplemental interventional accessories is feasible, with relatively rapid needle placement.     

The effect of arterial pressure on the ocular pressure-volume relationship in the rabbit

The purpose of this study was to quantify the effect of mean arterial pressure (MAP) on the ocular pressure-volume relationship. The experiments were performed in pentobarbital anesthetized rabbits instrumented with occluders on the thoracic aorta and inferior vena cava to control MAP which was measured via a cannula in the central ear artery. To vary the ocular volume and measure the intraocular pressure (IOP), two 23 gauge needles were inserted through the pars plana into the vitreous: one needle was connected to a saline-filled syringe and the other needle was connected to a pressure transducer. In one group of animals (n = 5), pressure-volume curves were determined at MAPs of 100, 80, 60, 40 and 20 mmHg and post mortem by cumulative saline injections (2 microliters) every 1-1.5 sec. In a second group (n = 7), pressure-volume curves were obtained at MAPs of 80, 60 and 40 mmHg and post mortem by saline infusion at 0.5 microliter sec-1 until the IOP reached 100 mmHg. The infusion protocol was repeated in a third group (n = 11) where the choroidal flux and the concentration of moving blood cells (CMBC) were measured by a laser Doppler flowmeter as indices of choroidal blood flow and the blood volume, respectively. MAP had three primary effects on the ocular pressure-volume relationship: (1) the baseline IOP varied exponentially with MAP, (2) the steepness of the initial portion of the pressure-volume curves was MAP-dependent and (3) the curves exhibited a 'plateau' as the IOP approached the prevailing MAP at MAPs > or = 40 mmHg. All of the curves in the living eye intersected and became indistinguishable from the post mortem curve when the IOP exceeded the prevailing MAP. The flux and CMBC measurements indicated that the MAP-dependence of the initial portion of the curves was due to failure of choroidal autoregulation and diminished increases in choroidal blood volume at the lower MAPs, and that the plateau portion of the curves was due to expulsion of blood from the eye. It is concluded that MAP has a significant effect on the ocular pressure-volume relationship.     

Evaluating the effectiveness of gloves in reducing the hazards of hand-transmitted vibration

OBJECTIVES: A method of evaluating the effectiveness of gloves in reducing the hazards of hand-transmitted vibration is proposed. METHOD: The glove isolation effectiveness was calculated from: (a) the measured transmissibility of a glove, (b) the vibration spectrum on the handle of a specific tool (or class of tools), and (c) the frequency weighting indicating the degree to which different frequencies of vibration cause injury. With previously reported tool vibration spectra and glove transmissibilities (from 10-1000 Hz), the method was used to test 10 gloves with 20 different powered tools. RESULTS: The frequency weighting for hand-transmitted vibration advocated in British standard 6842 (1987) and international standard 5349 (1986) greatly influences the apparent isolation effectiveness of gloves. With the frequency weighting, the gloves had little effect on the transmission of vibration to the hand from most of the tools. Only for two or three tools (those dominated by high frequency vibration) did any glove provide useful attenuation. Without the frequency weighting, some gloves showed useful attenuation of the vibration on most powered tools. CONCLUSIONS: In view of the uncertain effect of the vibration frequency in the causation of disorders from hand-transmitted vibration, it is provisionally suggested that the wearing of a glove by the user of a particular vibratory tool could be encouraged if the glove reduces the transmission of vibration when it is evaluated without the frequency weighting and does not increase the vibration when it is evaluated with the frequency weighting. A current international standard for the measurement and evaluation of the vibration transmitted by gloves can classify a glove as an antivibration glove when it provides no useful attenuation of vibration, whereas a glove providing useful attenuation of vibration on a specific tool can fail the test.     

A hereditary chiasmal optic neuropathy

The purpose of this study was to examine hand sensibility of surgeons wearing single and double latex gloves. Evaluation of hand sensibility, including cutaneous pressure thresholds, moving two-point discrimination, and static two-point discrimination, was performed on 25 surgeons (mean age 45 years). The dominant hand index finger was assessed with no glove, single glove, and double glove. The majority of surgeons had a moving and static two-point discrimination of 2 or 3 mm. The lowest cutaneous pressure thresholds were found when measured with no gloves and increased with single and double gloves. Statistically significant differences in cutaneous pressure thresholds using Semmes-Weinstein monofilaments were found for gloves versus no gloves (p < 0.0003) and single versus double gloves (p = 0.0003). Statistically significant differences in moving two-point discrimination were found for no gloves versus double gloves (p = 0.05) and single versus double gloves (p = 0.02). In conclusion, we found significant differences in hand sensation when measured with single and double gloves.     

Towards reducing the trauma of direct intracompartmental pressure measurement for children: an in vitro assessment of small-diameter needles

Direct intracompartmental pressure (ICP) measurement in children is an important investigation, the use of which may be inhibited by the invasive nature of the procedure and the large 18-gauge (G) needles that have hitherto been recommended. These large needles contribute to patient, parental, and physician anxiety. This study compares ICP measurements using needles of different lengths and port configuration, ranging from 18 to 25 G, against the "gold standard" 18 G, long, double-ported needle. All except the 18 G long, single-ported needle had limits of agreement within 3 mm Hg of the gold-standard needle. The results indicate that needle manometry can confidently be performed using small needles, and that the addition of a side-port is unnecessary in needles of small volume.     

Temperatures measured by a deep body thermometer (Coretemp) compared with tissue temperatures measured at various depths using needles placed into the sole of the foot

Continuous monitoring of body temperature during anaesthesia is a widely accepted clinical practice for which a variety of techniques are used. In this study, the accuracy of the deep body thermometer (Coretemp) was compared with temperatures measured by needle thermocouples. With IRB approval and informed consent, seven ASA physical status I and II patients undergoing otolaryngeal surgery were studied. General anaesthesia and neuromuscular blockade were induced with thiamylal and vecuronium. Anaesthesia was maintained with isoflurane at an end-tidal concentration of 1.0-2.0% and 66% nitrous oxide in oxygen. After induction of general anaesthesia, subcutaneous temperature was measured at the sole of the left foot using a Coretemp. Additionally 8-, 18-, and 38-mm-long needle thermocouples were inserted into the the sole of the left foot close to Coretemp and skin-surface temperature was also recorded adjacent to the needles. The Coretemp measurement (Tc) correlated best with 18-mm-deep needle temperature (r2 = 0.87). There was also a good correlation between Tc and 38-mm-deep needle temperature (r2 = 0.83). Skin and 8-mm-deep needle temperatures correlated poorly or only moderately with Tc (r2 = 0.67, 0.75, respectively). These results indicate that temperatures measured by Coretemp well reflect the temperatures at a depth of 18 mm or more from the skin into the foot.     

Biomechanical performance of cutting edge surgical needles

The purpose of this study was to compare the biomechanical performance of cutting edge needles made of S45500 stainless steel alloy to Surgalloy stainless steel. The new high-nickel stainless steel alloy, Surgalloy, has superior performance characteristics over that of the other high-nickel stainless steel alloy, S45500. The Surgalloy needle is produced from a stronger stainless steel alloy than the S45500 needle. The Surgalloy needle has considerably greater resistance to bending than the needle produced from S45500 alloy. In addition, Surgalloy stainless steel has almost a twofold greater resistance to fracture than the S45500 stainless steel alloy.     

Chromosomes of Damaliscus (Artiodactyla, Bovidae): simple and complex centric fusion rearrangements

G- and C-banded karyotypes of Damaliscus hunteri, D. lunatus and D. pygargus were compared using the standard karyotype of Bos taurus. Chromosomal complements were 2n = 36 in D. lunatus jimela, 2n = 38 in D. pygargus phillipsi and D. p. pygargus, and 2n = 44 in D. hunteri. The fundamental number in all karyotypes was 60. Among the three species of Damaliscus, seven autosomal pairs and the X chromosomes were conserved. Y-chromosome differences were attributed to heterochromatic additions or deletions. Banded karyotypes of the two subspecies of D. pygargus exhibited complete homology. Chromosomal complements of D. pygargus and D. lunatus differed by a simple centric fusion. However, karyotypes of D. pygargus and D. lunatus differed from D. hunteri by numerous centric fusions, several of which were related by monobrachial chain complexes. Between the karyotypes of D. hunteri and D. pygargus or D. lunatus, there were two chain complexes, one involving five chromosomes (chain V) and the other involving 12 in pygargus (chain XII) or 13 in lunatus (chain XIII). There were also two simple centric fusions between D. hunteri and D. lunatus/D. pygargus; acrocentric chromosomes 13, 15, 20 and 22 in D hunteri were fused as 13;15 and 20;22 in D. lunatus and D. pygargus.     

Rupture of a presumed hydatid cyst of the interventricular septum diagnosed by transoesophageal echocardiography

In a sample of 34 study subjects, Cook and Jamshidi intraosseous (IO) needles were compared for ease of insertion into turkey bones. The averaged lapsed time of insertion was significantly shorter using the Jamshidi needle (25.5 v 56.2 seconds, P < .0001). The mean difficulty of insertion score was lower using the Jamshidi needle (3.0 v 7.1 on a 10-cm visual analog scale, P < .0001). The less costly Jamshidi needle is easier to use in IO insertion in this turkey bone model.     

Surface coverage of vascular grafts with cultured human endothelial cells from subcutaneous fat tissue obtained with a biopsy needle

Surface coverage with autogeneous endothelial cells is effective in reducing thrombogenicity of an artificial vascular graft, but procedure for obtaining the cells is invasive for patients. The purpose of this study was to establish cultures of human endothelial cells separated from a small piece of subcutaneous fat tissue. A piece of tissue weighing about 10 mg was obtained from subcutaneous fat using a biopsy needle, and treated with collagenase and dispase. Microvascular endothelial cells were selected and other types of cells contaminating the cultures were eliminated by scraping with a needle under a microscope. The yield of the cells was 8362 +/- 4264/10 mg of subcutaneous fat (n = 7). The cultures reached confluence in about 2 weeks. The cells were positive for von Willebrand factor, P-selectin, and uptake of acetylated low density lipoprotein. The cells produced 15.9 +/- 3.3 ng/mg cell protein/h of 6-ketoprostaglandin F1 alpha (n = 5) when stimulated with thrombin. Thrombin also stimulated the production of platelet-activating factor: 7653 +/- 4297 dpm/10(6) cells (n = 5). Endothelin-1 accumulation in the medium of unstimulated endothelial cells was 0.54 +/- 0.16 ng/mg cell protein/10 h (n = 8). As a preliminary experiment for graft seeding, the cells were also cultured on pieces of a gelatin-coated Dacron graft, and scanning electron microscopy revealed the surface coverage of the graft. We herein described about successful culture of human microvascular endothelial cells from subcutaneous fat tissue obtained using a biopsy needle. The cultured cells may be applicable to a seeded vascular graft.     

Measurement of intracompartmental pressure: a comparison of the slit catheter, side-ported needle, and simple needle

An experimental model of acute compartment syndrome involving the anterolateral compartment of the hindlimb in dogs was used to compare three methods of measurement of intracompartmental pressure: the simple-needle technique, use of the slit catheter, and use of the side-ported needle. No statistical difference was found between the values obtained with the slit catheter and those obtained with the side-ported needle; the mean difference was 1.4 millimeters of mercury throughout the range of compartment pressures that were measured. The side-ported needle appeared to be as accurate as the slit catheter for the measurement of compartment pressures (p = 0.355, 1-beta = 0.9). The values obtained with use of the simple needle were consistently higher than those obtained with the other two methods (p < 0.001): an average of 18.3 millimeters of mercury higher than the values measured with the slit catheter and 19.3 millimeters of mercury higher than those measured with the side-ported needle. Clinically, the side-ported needle or the slit catheter can be used to obtain accurate measurements of compartment pressure. Use of the simple 18-gauge needle is not recommended for this purpose.     

The protective effect of a cut-resistant glove liner. A prospective, randomised trial

We performed a prospective, randomised study comparing the rates of glove perforation using double latex gloving with or without a disposable protective glove liner (Paraderm) on 118 patients undergoing primary or revision arthroplasty of the hip or knee by one surgeon (FRH). The patients were randomly allocated into two groups: in group 1 an inner and outer pair of latex gloves were worn as double gloves and in group 2 the glove liner was worn between the two latex gloves. There was glove perforation in at least one outer glove in 99 operations (84%). The operating surgeon was aware of the perforation in 21 of these. There were 22 perforations of the inner glove. Group 1 had a significantly higher perforation rate per operation (p < 0.05) than group 2. Our findings show that protective glove liners significantly reduce the rate of perforation of the inner glove during hip and knee arthroplasty.