Histological considerations of the cleavage plane for preservation of facial and cochlear nerve functions in vestibular schwannoma surgery

2009 ◽  
Vol 110 (4) ◽  
pp. 648-655 ◽  
Author(s):  
Tomio Sasaki ◽  
Tadahisa Shono ◽  
Kimiaki Hashiguchi ◽  
Fumiaki Yoshida ◽  
Satoshi O. Suzuki
Keyword(s):  
Connective Tissue ◽  
Basic Protein ◽  
Cleavage Plane ◽  
Nerve Fibers ◽  
Vestibular Nerve ◽  
Cochlear Nerve ◽  
Tissue Layer ◽  
Connective Tissue Layer ◽  
Tumor Capsule ◽  
Tumor Parenchyma

Object The authors analyzed the tumor capsule and the tumor–nerve interface in vestibular schwannomas (VSs) to define the ideal cleavage plane for maximal tumor removal with preservation of facial and cochlear nerve functions. Methods Surgical specimens from 21 unilateral VSs were studied using classical H & E, Masson trichrome, and immunohistochemical staining against myelin basic protein. Results The authors observed a continuous thin connective tissue layer enveloping the surfaces of the tumors. Some nerve fibers, which were immunopositive to myelin basic protein and considered to be remnants of vestibular nerve fibers, were also identified widely beneath the connective tissue layer. These findings indicated that the socalled “tumor capsule” in VSs is the residual vestibular nerve tissue itself, consisting of the perineurium and underlying nerve fibers. There was no structure bordering the tumor parenchyma and the vestibular nerve fibers. In specimens of tumors removed en bloc with the cochlear nerves, the authors found that the connective tissue layer, corresponding to the perineurium of the cochlear nerve, clearly bordered the nerve fibers and tumor tissue. Conclusions Based on these histological observations, complete tumor resection can be achieved by removal of both tumor parenchyma and tumor capsule when a clear border between the tumor capsule and facial or cochlear nerve fibers can be identified intraoperatively. Conversely, when a severe adhesion between the tumor and facial or cochlear nerve fibers is observed, dissection of the vestibular nerve–tumor interface (the subcapsular or subperineurial dissection) is recommended for preservation of the functions of these cranial nerves.

Histologic Findings in Two Very Small Intracanalicular Solitary Schwannomas of the Eighth Nerve

1986 ◽  
Vol 95 (5) ◽  
pp. 460-465 ◽  
Author(s):  
J. Gail Neely ◽  
Jack Hough
Keyword(s):  
Nerve Fiber ◽  
Longitudinal Direction ◽  
Nerve Fibers ◽  
Vestibular Nerve ◽  
Cochlear Nerve ◽  
The Other ◽  
En Bloc ◽  
Hearing Conservation ◽  
Eighth Nerve ◽  
Conservation Surgery

Two very small intracanalicular tumors, resected en bloc with the complete eighth nerve, were serially sectioned in order to study the relationship between the tumors and the nerves of origin. Both cases met the size criteria for hearing conservation surgery; however, the patient with the smaller tumor and the better hearing had no recognizable cochlear nerve fibers passing the tumor. The cochlear nerve in the patient with poorer hearing was completely free of tumor. The tumor with the infiltrated cochlear nerve seemed to originate from the inferior vestibular nerve. The other tumor seemed to arise from the superior vestibular nerve. Proximally, the tumors occupied a more central location in the involved nerves, but they abruptly became eccentric and exophytic as they proceeded laterally. Nerve fibers remaining about the tumors were displaced to the periphery. These nerve fiber aggregates became quite thin and attenuated, frequently separating into smaller aggregates which, ultimately, were incorporated into the tumors. As fibers came closer to the tumors, they tended to change from their longitudinal direction toward a more circumferential orientation about the surface of the tumors. The tumor-nerve fiber interfaces were quite variable throughout the course of the tumor, ranging from large aggregates of nerve fibers distinctly separate from the tumors to aggregates separate but tightly applied to the tumors without a tissue plane between, to aggregates partially incorporated within the periphery of the tumors, to aggregates completely incorporated into the periphery of the tumors. Frequently several types of interfaces were seen in the same section. These findings showed that in one case the cochlear nerve could have been surgically separated from the acoustic tumor; in the other specimen, it could not have been separated. It was impossible to predict between the two. In these two very small tumors, the gross specimen observation correlated reasonably well with the histology, thus suggesting that intraoperative observation may be a predictor in hearing conservation surgery; however, previous studies in slightly larger tumors make this an extremely guarded concept.

Quantitative Ultrasound Imaging of Healthy and Reconstructed Cleft Lip: A Feasibility Study

2007 ◽  
Vol 44 (3) ◽  
pp. 261-268 ◽  
Author(s):  
Nancy J. M. van Hees ◽  
Johan M. Thijssen ◽  
Rinske W. Huyskens ◽  
Gert Weijers ◽  
Maartje M. Nillesen ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Cleft Lip ◽  
Scar Tissue ◽  
Noninvasive Evaluation ◽  
Central Position ◽  
Tissue Layer ◽  
Loose Connective Tissue ◽  
Connective Tissue Layer ◽  
Array Transducer ◽  
Orbicularis Oris Muscle

Objective: To investigate the feasibility of echographic imaging of healthy and reconstructed cleft lip and to estimate tissue dimensions and normalized echo level. Methods: Echographic images of the upper lip were made on three healthy subjects and two patients using a linear array transducer (7 to 11 MHz bandwidth) and a noncontact gel coupling. Tissue dimensions were measured using calipers. Echo levels were calibrated and were corrected for beam characteristics, gel path, and tissue attenuation using a tissue-mimicking phantom. Results: At the central position of the philtrum, mean thickness (SD) of lip loose connective tissue layer, orbicularis oris muscle, and dense connective layer was 4.0 (0.1) mm, 2.3 (0.7) mm, and 2.2 (0.7) mm, respectively, in healthy lip at rest; and 4.1 (0.9) mm, 3.8 (1.7) mm, and 2.6 (0.6) mm, respectively, in contracted lip. Mean (SD) echo level of muscle and dense connective tissue layer with respect to echo level of lip loose connective tissue layer was −19.3 (0.6) dB and −10.7 (4.0) dB, respectively, in relaxed condition and −20.7 (1.5) dB and −7.7 (2.3) dB, respectively, in contracted state. Color mode echo images were calculated, showing lip tissues in separate colors and highlighting details like discontinuity of the orbicularis oris muscle and presence of scar tissue. Conclusions: Quantitative assessment of thickness and echo level of various lip tissues is feasible after proper echographic equipment calibration. Diagnostic potentials of this method for noninvasive evaluation of cleft lip reconstruction outcome are promising.

A histological and histochemical study of the development of the amnioallantois in the chick, Gallus domesticus

1970 ◽  
Vol 48 (5) ◽  
pp. 1079-1086 ◽  
Author(s):  
T. P. Kenny ◽  
M. A. Gibson
Keyword(s):  
Connective Tissue ◽  
Incubation Period ◽  
Histochemical Study ◽  
Secretory Granules ◽  
Lymphatic Vessels ◽  
Muscle Layer ◽  
Peak Activity ◽  
Tissue Layer ◽  
Connective Tissue Layer ◽  
Period 2

The amnioallantoic membrane is composed of four layers. (1) An inner amnionic epithelium which is a stratified layer during most of the incubation period. This layer stains positively for glycogen, ribonucleic acid, and neutral and acidic lipids and appears to be most active during the 15 to 17 days of incubation period. (2) A muscle layer composed of dorsoventrally and anteroposteriorly directed bands. During the early incubation stages these bands are organized to form the muscle configurations known as "cross-figures." During the later incubation stages, the organization of these muscle layers is disrupted by invasions of connective tissue and fat. (3) A connective tissue layer which includes blood and lymphatic vessels. (4) An outer allantoic epithelium which is rich in secretory granules. These granules include a sulfated mucopolysaccharide component. The activity of the allantoic epithelium increases progressively during the incubation period and is at peak activity at the 17- to 19-day incubation stage. During the final stages of incubation all layers show signs of decreased activity and degeneration.

The accumulation of ferric iron in the guts of some spatangoid echinoderms

1980 ◽  
Vol 60 (3) ◽  
pp. 631-640 ◽  
Author(s):  
J. B. Buchanan ◽  
B. E. Brown ◽  
T. L. Coombs ◽  
B. J. S. Pirie ◽  
J. A. Allen
Keyword(s):  
Connective Tissue ◽  
Ferric Iron ◽  
Dry Weight ◽  
Iron Deposit ◽  
Tissue Layer ◽  
Intestinal Tissue ◽  
Connective Tissue Layer ◽  
Ferrous Salt ◽  
Ferric Phosphate ◽  
Reducing Conditions

The connective tissue layer of the large intestines of Brissopsis and Echinocardium spp. is shown to contain a massive quantity of ferric iron in the form of ferric phosphate. The ferric phosphate is present as a granular extracellular deposit. In large mature specimens of Brissopsis, the weight of iron present may account for almost 30% of the dry weight of large intestinal tissue. The iron deposit appears to be cumulative with age. It is speculated that the deposit is derived from oxidative deposition of a soluble ferrous salt ingested in reducing conditions.

Surgical Pathology of Spinal Schwannomas: A Light and Electron Microscopic Analysis of Tumor Capsules

Neurosurgery ◽  
2001 ◽  
Vol 49 (6) ◽  
pp. 1388-1393 ◽  
Author(s):  
Mitsuhiro Hasegawa ◽  
Hironori Fujisawa ◽  
Yutaka Hayashi ◽  
Osamu Tachibana ◽  
Shinya Kida ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Light And Electron Microscopy ◽  
Nerve Fibers ◽  
Nerve Tissue ◽  
Electron Microscopic Level ◽  
Fibrous Layer ◽  
Neoplastic Tissue ◽  
Electron Microscopic ◽  
Tissue Layer ◽  
Tumor Capsule

ABSTRACT OBJECTIVE Although spinal schwannomas are often encountered, the pathology of the tumor capsule has not been reported. In this study, we describe the ultrastructural pathology of the tumor capsule of spinal schwannomas. METHODS In 18 patients who underwent total removal of spinal schwannomas (C2–conus), the tumor capsule was collected and examined by light and electron microscopy. RESULTS The thickness of the tumor capsule ranged from 15 to 800 μm (mostly 30–100 μm) and was composed of three layers from the surface to the center: 1) a thinly stretched nerve tissue layer; 2) a fibrous layer of fibrocytes, abundant collagen fibers, and tumor vessels; and 3) a thin transitional layer intermingled with fibrous components and tumor cells. The thickness of each layer varied in different regions of the surface. There was no clear separation between the tumor capsule and the neoplastic tissue, even on the electron microscopic level. A number of nerve fibers ran through the fibrous layer and beneath the capsule as well as in the nerve tissue layer. CONCLUSION Compared with vestibular schwannomas, which have been reported to be covered by an extremely thin layer (3–5 μm) of connective tissue, spinal schwannomas were well encapsulated. The capsule was composed of three distinct components; however, the cleavage between thin capsule and tumor cells was indistinct, and the thickness of the axon-containing capsule varied from site to site. Therefore, resection of the nerve of tumor origin, rather than enucleation, would be justified to avoid tumor recurrence. Surgeons should be aware of this pathology when performing the procedure.

Cholinergic Motor Control of Sea Urchin Tube Feet: Evidence for Chemical Transmission without Synapses

1980 ◽  
Vol 88 (1) ◽  
pp. 281-292
Author(s):  
E. FLOREY ◽  
M. A. CAHILL
Keyword(s):  
Electrical Stimulation ◽  
Connective Tissue ◽  
Outer Surface ◽  
Muscle Fibres ◽  
Nerve Terminals ◽  
Tissue Layer ◽  
Connective Tissue Layer ◽  
Electrical Stimuli ◽  
Tube Feet ◽  
Chemical Transmission

Isolated tube feet of Strongylocentrotus franciscanus contract briefly when the outer epithelium is touched. Similar twitch-like contractions can be induced by electrical stimulation of the outer surface of the tube foot. These responses appear to be chemically mediated. The following evidence indicates that the transmitter substance may be acetylcholine (ACh): ACh causes muscle contraction. This effect and that of electrical stimuli is potentiated by anticholinesterase agents and is antagonized by cholinergic blocking agents. Anaesthesia with chloralhydrate or chloretone abolishes responsiveness to mechanical or electrical stimulation but not to ACh. Desensitization with carbachol prevents responses to ACh and to mechanical or electrical stimulation. There are no neuromuscular synapses and no axons can be detected which cross the connective tissue layer which separates the muscle fibres from the subepithelial nerve plexus. The latter is known to contain conspicuous amounts of ACh; nerve terminals containing clear vesicles invest the outer surface of the connective tissue layer. All evidence indicates that chemical transmission involves diffusion of ACh (released from activated nerve terminals) across this connective tissue layer which is around 5 μm thick in fully extended tube feet but may have a thickness of 20 or even 25 μm in less extended ones. Calculations based on equations describing transmitter diffusion prove the feasibility of such a mechanism. Note:

The Unrecognized Rotation of the Vestibular and Cochlear Nerves from the Labyrinth to the Brain Stem: Its Implications to Surgery of the Eighth Cranial Nerve

1986 ◽  
Vol 95 (5) ◽  
pp. 543-549 ◽  
Author(s):  
Herbert Silverstein ◽  
Horace Norrell ◽  
Thomas Haberkamp ◽  
Alan B. Mcdaniel
Keyword(s):  
Brain Stem ◽  
Cleavage Plane ◽  
Internal Auditory Canal ◽  
Vestibular Nerve ◽  
Cochlear Nerve ◽  
Eighth Cranial Nerve ◽  
Vestibular Neurectomy ◽  
Intimate Association ◽  
Inferior Vestibular Nerve ◽  
The Brain

The cochlear and vestibular nerves rotate 90 degrees from the inner ear to the brain stem. Most of the rotation occurs within the internal auditory canal (IAC); only minimal rotation occurs in the cerebellopontine (CP) angle. At the labyrinthine end of the IAC, the cochlear nerve—which at first lies anterior to the inferior vestibular nerve (saccular nerve)—rapidly fuses with the inferior vestibular nerve. It then rotates to become inferior as the nerves leave the porus acousticus. The cochleovestibular (C-V) cleavage plane lies in a superior-inferior direction in the lateral IAC and rotates to become anterior-posterior in the CP angle. In 25% of patients in whom no C-V cleavage plane can be seen, it is not possible to completely transect all vestibular fibers. The surgical implications are that (1) the most complete vestibular neurectomy can be done only in the lateral IAC, (2) the cochlear and inferior vestibular nerves, because of their intimate association, should not be separated in the mid-IAC, in order to prevent damage to the cochlear nerve, and (3) to create a complete denervation of the vestibular labyrinth, only the posterior ampullary nerve along with the superior vestibular nerve should be transected.

scholarly journals Effects of age on growth and development of vagina in ISA Brown chickens

2012 ◽  
Vol 28 (2) ◽  
pp. 75-79
Author(s):  
K. A. Ferdous ◽  
M. N. H. Parvez ◽  
M. T. Rahman
Keyword(s):  
Smooth Muscle ◽  
Connective Tissue ◽  
Growth And Development ◽  
Structural Changes ◽  
Columnar Epithelium ◽  
Muscle Fibres ◽  
Adult Bird ◽  
Tissue Layer ◽  
Connective Tissue Layer ◽  
Mucosal Folds

Structure and postnatal development of vagina in 21 ISA brown chickens was studied at three, 23 and 46 weeks of age. At 3 weeks of age the vagina was narrower and thicker then the uterus. The undifferentiated wall of vagina consisted of low primary mucosal folds lined by simple columnar epithelium to a pseudostratified ciliated columnar epithelium and a connective tissue layer underneath. At three weeks of age, scattered smooth muscle fibres were in the subepithelial connective tissue layer. Rapid structural changes occurred at 23 weeks of age in the adult bird, mucosal folds were narrowed and tongue-shaped. Lamina propia was devoid of glands and contained lymphocytes. Tunica muscularis was well developed at 23 and 46 weeks.DOI: http://dx.doi.org/10.3329/bvet.v28i2.10676Bangl. vet. 2011. Vol. 28, No. 2, 75 – 79

Sign in / Sign up

Export Citation Format

Share Document