Scanning electron micrographic study of vascular lesions caused by microvascular needles and suture

1980 ◽  
Vol 53 (1) ◽  
pp. 32-36 ◽  
Author(s):  
David M. Pagnanelli ◽  
T. Glenn Pait ◽  
Hugo V. Rizzoli ◽  
Arthur I. Kobrine
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Blood Vessels ◽  
Vascular Trauma ◽  
Vascular Lesions ◽  
Content Type ◽  
Fine Print ◽  
Scanning Electron

✓ The authors studied the damage to blood vessels 1 to 2 mm in diameter caused by the most commonly used types of microvascular needle. Excluding variables introduced by anastomosis, the study focused specifically on lesions attributable only to the needle and suture. Scanning electron microscopy revealed four distinct types of lesion. A theory is proposed to explain the mechanisms whereby these lesions were produced, and a needle design is recommended that may aid in minimizing vascular trauma.

Ovine pericardium as a new material for duraplasty

1996 ◽  
Vol 84 (3) ◽  
pp. 508-513 ◽  
Author(s):  
Jan Pařízek ◽  
Zdeněk Husěk ◽  
Pavel Měřička ◽  
Josef Téra ◽  
Stanislav Němeček ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Host Tissue ◽  
Γ Irradiation ◽  
Content Type ◽  
Dural Substitute ◽  
Freeze Dried ◽  
New Material ◽  
Fine Print ◽  
Scanning Electron

✓ The authors report on their 2 1/2-year clinical experience using a dural substitute, ovine pericardium, stabilized with 0.3% glutaraldehyde, flat freeze-dried, and sterilized with γ-irradiation. Packaging of the ovine pericardium in double-plastic transparent bags allows simple storage in operating rooms and the opportunity for the surgeon to choose an ideal graft according to its shape, size, and plasticity. The ovine pericardia were examined histologically and by transmission and scanning electron microscopy in their native, freeze-dried, and irradiated forms. The final product is composed solely of pericardium fibrosum interwoven with artificially formed extracellular microcavities that serve as natural pores for the ingrowth of host tissue. The surfaces of the grafts appear smooth on the inner and rough on the outer sides. Sixteen grafts were examined macroscopically at autopsy and four of these were also examined histologically to illustrate their successful healing with no adhesion to the underlying brain. As a new dural substitute, ovine pericardium proved to be superior to bovine and allogeneic pericardia because of its workability, flexibility, and reduced thickness. In a study of 120 grafts, all but one healed without complications.

An investigation of structural degradation of cerebrospinal fluid shunt valves performed using scanning electron microscopy and energy-dispersive x-ray microanalysis

2004 ◽  
Vol 100 (3) ◽  
pp. 534-540 ◽  
Author(s):  
Spyros Sgouros ◽  
Susan J. Dipple
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cerebrospinal Fluid ◽  
Energy Dispersive ◽  
Ventricular Catheter ◽  
Content Type ◽  
X Ray ◽  
Programmable Valve ◽  
Fine Print ◽  
Scanning Electron

Object. Surveys of cerebrospinal fluid (CSF) shunts that have been removed from patients have shown that even when the ventricular catheter is the cause of the obstruction, the valve may be obstructed or underperforming. The aim of this pilot study was to investigate the degradation of shunt valve structure over time due to the deposition of debris. The findings were compared with findings in unused valves. Methods. Scanning electron microscopy was used to visualize the structures of the valves. The items that were examined included two unused and nine explanted cylindrical medium pressure valves, one unused and six explanted Delta 1.5 valves (PS Medical, Goleta, CA), and one explanted Medos Programmable valve (Codman Johnson & Johnson, LeLocle, Switzerland). The valves were cut open, disassembled, and coated in gold. The areas that were analyzed included the main valve chamber, the diaphragm unit, and the antisiphon device. For areas with abnormal deposits, energy-dispersive x-ray microanalysis was performed to establish the chemical composition of the deposits. The reference unused valves had smooth surfaces with no deposits in any areas. All explanted valves had extensive deposits in all surveyed areas. The deposits varied from small clusters of crystals to large areas that displayed a cobblestone appearance. In diaphragm valves the deposits extensively affected the surface of the diaphragm and the gap between the diaphragm and the surrounding case, where normally CSF flows; in the Medos valve the deposits affected in the spring and “staircase” unit. Deposits were present as early as 2 weeks after implantation. On some valves there was a complete film covering the entire outlet of the valve, which formed a cast inside the valve stretching from wall to wall. The deposits consisted mostly of sodium and chloride, but occasionally contained calcium. In all infected and some noninfected valves there was a significant peak of carbon, indicating the presence of protein deposits. Conclusions. It appears that the continuous flow of CSF through shunt valves causes surface deposits of sodium chloride and other crystals on all aspects of the valve, including the outlet pathways. The formation of deposits may be encouraged by the adhesive properties of the materials that constitute the valve parts.

The terminal vascular bed in the superficial cortex of the rat

1986 ◽  
Vol 65 (6) ◽  
pp. 834-846 ◽  
Author(s):  
Enrico D. F. Motti ◽  
Hans-Georg Imhof ◽  
M. Gazi Yaşargil
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Casts ◽  
Content Type ◽  
Vascular Bed ◽  
Arteriovenous Shunts ◽  
Network Pattern ◽  
Fine Print ◽  
Scanning Electron ◽  
Terminal Vascular Bed

✓ The capillaries in the vascular bed of the rat brain have been investigated by means of scanning electron microscopy of corrosion casts. A technique is described that allowed the finer ramifications to be observed. A series of representative sites from the arteriovenous terminal pathway are described in detail. Contrary to previous reports, the dichotomic pattern of vessel distribution is shown to prevail over the network pattern. Arteriovenous shunts of discrete size were not seen.“Thoroughfare channels” could be recognized. The findings are considered in light of current physiological knowledge, and their significance for microcerebrovascular flow is indicated.

Ultrastructural changes in feline arterial endothelium following subarachnoid hemorrhage

1978 ◽  
Vol 48 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Marc R. Mayberg ◽  
O. Wayne Houser ◽  
Thoralf M. Sundt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Subarachnoid Hemorrhage ◽  
Ultrastructural Changes ◽  
Content Type ◽  
Physiological Pressure ◽  
Arterial Endothelium ◽  
Elastic Lamina ◽  
Fine Print ◽  
Scanning Electron

✓ Scanning electron microscopy of feline basilar arterial endothelium 4 hours and 1, 3, 5, and 7 days after subarachnoid hemorrhage (SAH) showed longitudinal furrows that correlated with angiographically demonstrated vasospasm. These ridges persisted after fixation at physiological pressure, and probably reflected medial contraction with undulation of the underlying elastic lamina. No change in endothelial cell morphology or thrombogenesis was observed as long as 7 days after SAH. There is no evidence from this study to suggest that ischemia from vasospasm is a product of thromboembolism from damaged endothelial surfaces.

Long-term reendothelialization of excimer laser—assisted nonocclusive anastomoses compared with conventionally sutured anastomoses in pigs

2005 ◽  
Vol 103 (2) ◽  
pp. 328-336 ◽  
Author(s):  
Henk Johan N. Streefkerk ◽  
Sanne Kleinveld ◽  
Ester L. G. E. Koedam ◽  
Marcel M. M. Bulder ◽  
Hans D. Meeldijk ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Excimer Laser ◽  
Flow Characteristics ◽  
Electron Microscopic ◽  
Content Type ◽  
Microscopic Evaluation ◽  
Fine Print ◽  
Scanning Electron

Object. In contrast to conventional anastomosis methods, the excimer laser—assisted nonocclusive anastomosis (ELANA) technique involves a platinum ring and intima—adventitia apposition with a rim of medial and adventitial layers exposed to the bloodstream. The authors assessed the reendothelialization of porcine carotid arteries through ELANA compared with conventional anastomosis by using scanning electron microscopy. Methods. In 28 pigs a bypass with one ELANA and one conventional anastomosis was made on the left common carotid artery. All patent anastomoses were evaluated intraoperatively with the aid of an ultrasonographic flowmeter and postoperatively by using scanning electron microscopy at 2 weeks, 2 months, 3 months, and 6 months thereafter. Twenty-four of 28 bypasses (48 of 56 end-to-side anastomoses) were fully patent at the time of evaluation. On scanning electron microscopic evaluation of the bypasses, all 48 patent anastomoses showed complete reendothelialization, including all 24 ELANAs in which the endothelium covered the rim and the laser-ablated edge completely. No endothelial difference was observed between conventional anastomoses and ELANAs, aside from the obvious anatomical differences like the platinum ring, which had been completely covered with endothelium. At 6 months postsurgery, remodeling of the ELANA was observed, leaving the ring covered with a layer of endothelium as the most narrow part of the anastomosis. Conclusions. In long-term experiments, ELANA allows reendothelialization comparable to that achieved with conventional anastomosis. Considering its nonocclusive and high-flow characteristics, the ELANA technique is preferable in cerebral revascularization procedures.

Scanning electron microscopy of the floor of the fourth ventricle in rats subjected to graded impact injury to the sensorimotor cortex

1999 ◽  
Vol 90 (4) ◽  
pp. 734-742 ◽  
Author(s):  
Theodore G. Sarphie ◽  
Michael E. Carey ◽  
June F. Davidson ◽  
Joseph S. Soblosky
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Head Injury ◽  
Sensorimotor Cortex ◽  
Fourth Ventricle ◽  
Structural Integrity ◽  
Area Postrema ◽  
Content Type ◽  
Fine Print ◽  
Scanning Electron

Object. Respiratory dysfunction including apnea frequently follows head injury in humans. The purpose of this study was to identify any structural alterations in the region of brainstem respiratory nuclei that might account for immediate postinjury respiratory abnormalities in anesthetized experimental animals.Methods. Using scanning electron microscopy, the authors examined the floor of the fourth ventricle in injured rats after a piston strike to the sensorimotor cortex that depressed the dura 1, 2, or 4 mm. The rats were killed within minutes of injury. Cortical impact depths measuring either 1 or 2 mm (eight rats) produced no respiratory abnormalities, and the structural integrity of the ependymal lining of the ventricular floor in these animals was not compromised. Thirteen rats were subjected to impact to a 4-mm depth and 10 of these exhibited immediate temporary or permanent apnea. The medullae of nine of these rats were studied using scanning electron microscopy, and the fourth ventricular floors of all nine rats showed tears. Four rats that exhibited immediate, permanent apnea had tears in the caudal fourth ventricle floor near the obex, whereas five rats with no or only transient apnea had tears located more anteriorly, near the aqueduct or laterally. Changes in cerebrospinal fluid flow or pressure dynamics may have caused these tears. Light microscopy, focused near the area postrema, revealed a shearing defect through the ependyma of the fourth ventricular floor into the subjacent neuropil with a disruption of axonal pathways.Conclusions. Respiratory neuronal network components lying within 2 mm of the area postrema may well have been disrupted by the caudal tears producing permanent apnea. A similar phenomenon could account for the transient or permanent postinjury apnea seen in humans with severe head injury.

scholarly journals Three-dimensional relationships between tumor cells and microcirculation with double cyanine immunolabeling, laser scanning confocal microscopy, and computer-assisted reconstruction: an alternative to cast corrosion preparations.

1994 ◽  
Vol 42 (5) ◽  
pp. 681-686 ◽  
Author(s):  
V Rummelt ◽  
L M Gardner ◽  
R Folberg ◽  
S Beck ◽  
B Knosp ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Blood Vessels ◽  
Tumor Cells ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Melanoma Cells ◽  
Tumor Blood Vessels ◽  
The Relationship ◽  
Scanning Electron

The morphology of the microcirculation of uveal melanomas is a reliable market of tumor progression. Scanning electron microscopy of cast corrosion preparations can generate three-dimensional views of these vascular patterns, but this technique sacrifices the tumor parenchyma. Formalin-fixed wet tissue sections 100-150 microns thick from uveal melanomas were stained with the lectin Ulex europaeus agglutinin I (UEAI) and proliferating cell nuclear antigen (PCNA) to demonstrate simultaneously the tumor blood vessels and proliferating tumor cells. Indocarbocyanine (Cy3) was used as a fluorophore for UEAI and indodicarbocyanine (Cy5) was used for PCNA. Double labeled sections were examined with a laser scanning confocal microscope. Images of both stains were digitized at the same 5-microns intervals and each of the two images per interval was combined digitally to form one image. These combined images were visualized through voxel processing to study the relationship between melanoma cells expressing PCNA and various microcirculatory patterns. This technique produces images comparable to scanning electron microscopy of cast corrosion preparations while permitting simultaneous localization of melanoma cells expressing PCNA. The microcirculatory tree can be viewed from any perspective and the relationship between tumor cells and the tumor blood vessels can be studied concurrently in three dimensions. This technique is an alternative to cast corrosion preparations.

Light and Scanning Electron Microscopy of Human Spinal Ligaments

1985 ◽  
Vol 55 ◽  
Author(s):  
L.-H. Yahia ◽  
G. Drouin ◽  
C.-H. Rivard
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Connective Tissue ◽  
Idiopathic Scoliosis ◽  
Blood Vessels ◽  
Structural Changes ◽  
Loose Connective Tissue ◽  
Morphological Studies ◽  
Spinal Ligaments ◽  
Scanning Electron

ABSTRACTSpinal ligaments were obtained from normal and scoliotic individuals. Detailed morphological studies were carried out on the yellow, interspinous and supraspinous ligaments by light and scanning electron microscopy. Normal yellow ligaments are mostly constituted of dense elastin fibers with only a few collagen fibers and sparse blood vessels, while in normal interspinous and supraspinous ligaments, the presence of collagen is highly dominant. In the latter structures, the collagen fascicles are characterized by a regular waviness morphology. The fibrils constituting the fascicles appear either parallel or helical with respect to the fascicle axis. Structural changes are observed in the spinal ligaments of patients with congenital as well as idiopathic scoliosis. For yellow ligaments, only slight differences are found between normal and scoliotic specimens. However, alterations in collagen waviness and architecture are observed mainly in the supraspinous ligaments and to a lesser extent in the interspinous ligaments. In addition, increases in the cellularity, loose connective tissue and vessels are found in both forgoing ligaments. These results indicate that the more pronounced scoliosis-related changes occur in ligaments having the farthest distance from the axis of flexion-rotation.

Lower extremity peripheral vascular disease. Part 1: Scanning electron microscopy

1989 ◽  
Vol 79 (11) ◽  
pp. 527-535
Author(s):  
DJ McCarthy ◽  
N Abell ◽  
T Reed
Keyword(s):  
Electron Microscopy ◽  
At Risk ◽  
Scanning Electron Microscopy ◽  
Lower Extremity ◽  
Vascular Disease ◽  
Blood Vessels ◽  
Peripheral Vascular Disease ◽  
Peripheral Vascular ◽  
Tissue Alterations ◽  
Scanning Electron

The surgical loss of the foot or leg is vigorously resisted by podiatrists who are committed to the conservation of limbs at risk because of peripheral vascular disease. Pathologic changes in blood vessels may, however, progress to a point where no other option is available to the patient. This study assesses amputation of the extremities and investigates tissue alterations that can be identified in diseased blood vessels implicated in these circumstances. Gross pathology and scanning electron microscopy are examined in this, the first of a two-part study.

scholarly journals Indirect Immunodetection of Fungal Fragments by Field Emission Scanning Electron Microscopy

2015 ◽  
Vol 81 (17) ◽  
pp. 5794-5803 ◽  
Author(s):  
Komlavi Anani Afanou ◽  
Anne Straumfors ◽  
Asbjørn Skogstad ◽  
Ajay P. Nayak ◽  
Ida Skaar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Emission ◽  
Polyclonal Antibodies ◽  
Detection Methods ◽  
Indoor Environments ◽  
Content Type ◽  
Freeze Dried ◽  
Scanning Electron

ABSTRACTSubmicronic fungal fragments have been observed inin vitroaerosolization experiments. The occurrence of these particles has therefore been suggested to contribute to respiratory health problems observed in mold-contaminated indoor environments. However, the role of submicronic fragments in exacerbating adverse health effects has remained unclear due to limitations associated with detection methods. In the present study, we report the development of an indirect immunodetection assay that utilizes chicken polyclonal antibodies developed against spores fromAspergillus versicolorand high-resolution field emission scanning electron microscopy (FESEM). Immunolabeling was performed withA. versicolorfragments immobilized and fixed onto poly-l-lysine-coated polycarbonate filters. Ninety percent of submicronic fragments and 1- to 2-μm fragments, compared to 100% of >2-μm fragments generated from pure freeze-dried mycelial fragments ofA. versicolor, were positively labeled. In proof-of-concept experiments, air samples collected from moldy indoor environments were evaluated using the immunolabeling technique. Our results indicated that 13% of the total collected particles were derived from fungi. This fraction comprises 79% of the fragments that were detected by immunolabeling and 21% of the spore particles that were morphologically identified. The methods reported in this study enable the enumeration of fungal particles, including submicronic fragments, in a complex heterogeneous environmental sample.

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