Human Dura Mater Research Articles

Catecholaminergic innervation of the human dura mater involved in headache.

The catecholaminergic innervation of cranial dura mater in humans was studied by examining several dural zones (vascular, perivascular, intervascular) in different regions (basal, calvarial, occipital, frontal, tentorial, parietal, temporal). The results demonstrate that catecholaminergic nerve fibers are present in human cranial dura mater and that these fibers, after exposure to formaldehyde vapors, show the specific fluorescence of catecholamines. There are more dural catecholaminergic nerve fibers in the basal region than in the calvarial region. Moreover, these nerve fibers are more abundant in the perivascular dural zone than in the intervascular zone. We hypothesize that these catecholaminergic nerve fibers may be involved in headache.

Quantification of the collagen fibre architecture of human cranial dura mater.

The purpose of this study was to quantify and map the gross fibre architecture of the cranial dura mater (CDM) using small angle light scattering (SALS). In SALS, HeNe laser light is passed through the tissue, and the resultant scattering pattern is analysed to determine the preferred fibre direction and degree of orientation. The dura mater was found to be a complex structure with fibre orientations ranging from highly aligned to nearly random. In the temporal region, 80% of the samples (n = 20) were found to have regions composed of highly oriented fibres with a mean fibre direction of 6.3 degrees +/- 0.8 degree with respect to the sagittal plane (i.e. almost parallel to the superior sagittal sinus). These highly aligned regions were found in symmetric anatomical locations about the median sagittal sinus and had similar fibre orientations over both hemispheres. Although our sample size was small, we found that the size of the symmetric regions, which covered 14.4 +/- 1.6% of the total CDM area, was not influenced by subject's age or sex. The presence of these highly oriented fibre regions in CDM may be due to mechanical forces exerted on dura mater during its development. These forces may have induced realignment of the collagen fibres in the direction of tensile pull, although the exact basis for the unique gross fibre architecture of CDM remains unknown.

Bladder autoaugmentation in the rabbit using de-epithelialized segments of small intestine, stomach and lyophilized human dura mater.

To develop an animal model of partial detrusorectomy (autoaugmentation) and thus avoid the consequences of the direct contact of intestinal mucosa with the urinary tract in bladder augmentation. A diverticular urothelial bulge was created and patched with demucosalized segments of small bowel (group A), stomach (group B) and with lyophilized human dura mater (group C). The surgery was performed on 50 New Zealand rabbits which were compared with 10 control animals and killed at 2, 4 and 6 weeks after surgery. Urodynamic studies and cystography were performed before operation and at death, and the augmented bladders examined histologically. Six weeks after the procedure, the mean (SD) bladder compliance was 22.7 (5.7) in group A (intestinal patch. n = 6). 2.3 (0.5) in group B (stomach patch, n = 3). 3.1 (1.9) in group C (lyophilized human dura, n = 3) and 9.4 (0.4) in the control group (n = 4). Histological studies showed residual enteric and gastric mucosa but an intact urothelium under the intestinal patch. The results of this experimental study suggest that a demucosalized segment of small bowel is the best material to increase bladder compliance in detrusorectomy (autoaugmentation) as applied in this animal model.

Surgical revision for hypotonia after glaucoma operation with mitomycin C

Persistent hypotony with maculopathy is a severe complication of mitomycin C when used during filtration surgery. We wanted to know whether this complication can be controlled by a surgical reintervention yielding tight closure of the initial sclerostomy. In our clinic, 52 eyes underwent filtering surgery with intraoperative application of mitomycin C. Seven of them required a reoperation owing to persistent hypotony with maculopathy. During this reoperation, the scleral flap was tightly sutured (5x) or, if necessary, was closed with dehydrated human dura mater (2x). In all cases the intraocular pressure increased immediately (i.e., within less than 24 h) after reoperation. This intraocular pressure increase was accompanied by a simultaneous regression of the maculopathy. Further details: mean intraocular pressure (mmHg): before initial operation with mitomycin C: 38.5 +/- 2.9; after initial operation: 3.7 +/- 0.6; before reoperation (= 8 months after initial operation): 3.3 +/- 0.7; 24 h after reoperation: 22.0 +/- 2.9; 9 months after reoperation: 16.7 +/- 1.7. Mean visual acuity: before initial operation with mitomycin C: 0.72 +/- 0.1; after initial operation: 0.34 +/- 0.1; before reoperation (= 8 months after initial operation): 0.17 +/- 0.05; 24 h after reoperation: 0.28 +/- 0.05; 9 months after reoperation: 0.55 +/- 0.1. (1) Since the interval between reoperation and intraocular pressure increase was very short in all cases, overfiltration is at least one major reason for hypotony, not only ciliary body failure; (2) in cases of persistent hypotony after filtering surgery with mitomycin C, surgical reintervation can be recommended. During this reoperation, the initial sclerostomy should be closed tightly.

Human Dura Mater as a Wrapping Material for Hydroxyapatite Implantation in the Anophthalmic Socket

Homologous sclera and autologous fascia lata have been accepted as common wrapping materials for hydroxyapatite implantation; however, various problems have been observed, such as the risk of transmittable diseases such as AIDS or hepatitis. This report details the use of cadaver dura mater to wrap hydroxyapatite implants. For 73 eyes of 73 patients with hydroxyapatite implantation, cadaver dura mater was used to wrap the hydroxyapatite after enucleation or secondary implantation. Of the 73 patients, 20 had conjunctival erosion; however, all of the patients but 1 healed spontaneously within an average of 22 days. Only 1 of the 73 patients progressed to implant exposure requiring a dermis graft. The authors suggest that cadaver dura mater is a suitable wrapping material for hydroxyapatite implantation.

New perspectives in the microscopic structure of human dura mater in the dorsolumbar region

The object of this study was to describe the three-dimensional structure of the dura mater by use of scanning electron microscopy. Microscopic dissection of the dura mater from four fresh cadavers (aged 70, 75, 76, and 80 years) 8-12 hours after death were investigated in three different planes (longitudinal, tangential, and transverse). The external surface of the dura mater, facing the epidural space, consisted of a network of randomly oriented fine collagen fibers. The thicker elastic fibers (2 microns in diameter) were observed on the surface of the dura. In the inner part of the dura mater, there were very fine lamellae of collagen fibers, which were bundled into thicker (4-5 microns) layers. The dura mater consisted of 78-82 layers, each layer including 8-12 very fine lamellae. The fibers of the dura mater do not run in a longitudinal direction and are not arranged in a parallel fashion. Cytoarchitecturally the dura mater is a laminated structure built up from well-defined layers oriented concentrically around the medulla spinalis.

New Perspectives in the Microscopic Structure of Human Dura Mater in the Dorsolumbar Region

Background and ObjectivesThe object of this study was to describe the three-dimensional structure of the dura mater by use of scanning electron microscopy.MethodsMicroscopic dissection of the dura mater from four fresh cadavers (aged 70, 75, 76, and 80 years) 8-12 hours after death were investigated in three different planes (longitudinal, tangential, and transverse).ResultsThe external surface of the dura mater, facing the epidural space, consisted of a network of randomly oriented fine collagen fibers. The thicker elastic fibers (2 μm in diameter) were observed on the surface of the dura. In the inner part of the dura mater, there were very fine lamellae of collagen fibers, which were bundled into thicker (4-5 μm) layers. The dura mater consisted of 78-82 layers, each layer including 8-12 very fine lamellae.ConclusionsThe fibers of the dura mater do not run in a longitudinal direction and are not arranged in a parallel fashion. Cytoarchitecturally the dura mater is a laminated structure built up from well-defined layers oriented concentrically around the medulla spinalis.

Mechanical properties of the human lumbar dura mater.

This study aimed to evaluate the transverse and longitudinal distensibility of the posterior human lumbar dura mater. Results are compared with previous literature on biomechanical property studies. Possible clinical implications were also examined. Samples of human dural sac were obtained from autopsy studies in three adult male cadavers. Dural sac samples were sectioned longitudinally to measure transverse and longitudinal distensibility, thickness and circumference. It was recorded that the posterior lumbar dura mater was easily distensible only in the transverse direction. The longitudinal force required to distend and rupture the posterior lumbar dura mater samples is 3.5 to 6.7 times greater than the force to produce a transversal rupture. Depending on the local cerebrospinal fluid pressure, the documented easier transverse distensibility of the posterior lumbar dura mater may allow greater contact of the lumbar dural sac with the wall of the lumbar vertebral canal. This fact may affect the diffusion of solutions introduced into epidural space.

Scanning electron microscopy of human cerebral meningeal stomata

The human dura mater and pia mater were studied by using a scanning electron microscope and a computer image processing system (C.I.P.). The human cerebral meningeal stomata are located between the mesothelial cells of the cerebral meninges. They are round or oval in shape with diameters of 0.33-2.98 microns. The cerebral meningeal stomata are stable structures, scattered or clustered together. Their density in the dura mater is greater than in the pia mater (P < 0.01), and they are regularly distributed. The statistical analysis showed that the stomata diameter and distribution density in the dura mater are 1.34 microns and 381.55/0.1 mm2; while in the pia mater they are 0.88 micron and 195.06/0.1 mm2 respectively. The cerebral meningeal stomata are probably part of the cerebral prelymphatic capillary system, which undertakes the cerebral lymph drainage because there are no lymphatic vessels in the brain although yet there is lymph drainage. Thus, we believe that the cerebral meningeal stomata are involved in maintaining the physiological function of the brain as part of the cerebrospinal fluid (CSF) which absorbs the cerebral interstitial fluid.

頚部廓清術後に生じたＦｒｅｙ症候群に対してヒト溶媒乾燥硬膜挿入法を応用した１例

Gustatory sweating (Frey's syndrome) presents as localized flushing and sweating of the skin in the anterior region of the ear lobe and the temporal region after a certain period of time after surgery or trauma to the region of the parotid gland or the angle of the mandible over the site of the parotid bed. It is an intractable disease, and effective therapy has not been established yet.We report a case of gustatory sweating that occurred after radical neck dissection. A 65-year-old woman underwent radical neck dissection for cervical metastasis of maxillary cancer. The post operative course was uneventful, and there was after no local recurrence or distant metastasis in the year after operation.However, the patient complained of gustatory sweating near the operative region, and Minor's starch iodine test was positive.We attemped to treat gustatory sweating by subcutaneously implanting solventdehydrated human dura mater in regions of the skin where sweating and flushing were observed.There was no evidence of a foreign body reaction, infection, or other adverse reactions as of 1 year after dura implantation.Therefore, this method is useful in the treatment of Frey's syndrome.

Dehydrated Human Dura Mater Patch Repair for Closure of Duodenal Defects

The suitability of dehydrated human dura mater patch on the repair of full thickness duodenal wall tissue loss is investigated, the healing process is followed. In 28 Spraque Dawley rats, approximately 3 mm in diameter defects were made laterally to the second duodenal portion by excision. These defects were repaired using a dehydrated human dura mater patch. The rats were sacrificed at the 3rd, 7th, 14th and 21 st days and wound healing was evaluated histopathologically. Three rats died post-operatively. Two two of them died after 24 hours with possible acute panceratitis. The other rat which died later on had duodenal obstruction at the patched area. 0n the 21st day, the defects were covered by duodenal mucosa macroscopically. According to histopathological evaluation, no surface epithelium nor mucosal regenanation existed at the 3rd and 7th days. 0n the 14th day, surface epithelium regeneration was partial, yet no mucosal restoration was observed. More than 25% of the dural patches were replaced by newly formed collagen fibers at the 7th and 14th days. 0n the 21st day, surface epethelial regeneration was complete and the mucosal reconstruction was partial. Cryptic restoration was nearly complete, villous formation had started, and the newly formed collagen leaflets hat almost completely replaced the dura patch.

Caliceal Fistula Formation Following Renal Transplantation

Six patients in this series of 543 renal transplants (1.10%) suffered a post-transplant renal segmental infarct of the donor kidney because of occlusion of an accessory renal artery. Five grafted kidneys had multiple renal arteries. Patients presented with symptoms of a caliceal fistula and were treated by partial (25 to 40%) transplant nephrectomy, followed by closure and tissue coverage with either parietal peritoneum (4 patients) or lyophilized human dura mater sealed with fibrin (2). In 2 cases the renal ischemia and necrosis involved the ureter, and a pyelo-pyelostomy was performed. One patient died of cardiorespiratory complications immediately postoperatively. Five years postoperatively all kidneys functioned well without recurrence of fistula and 5 patients returned to a normal life-style. The combination of radical excision and tissue closure, plus ureteral substitution when needed was an effective treatment that prevented loss of the graft.

Artificial Dura Film for Femoral Vessel Coverage after Inguinofemoral Lymphadenectomy

Eleven patients undergoing inguinofemoral lymphadenectomy for carcinoma of the vulva had the femoral vessels covered with Dura Film (Codman, Randolph, MA); a total of 21 groins were explored. The Dura Film was sutured to the inguinal ligament, sartorius muscle fascia, and adductor longus fascia. Nine of the 21 groins became infected with 3 of these breaking down; each of these 3 required removal of the Dura Film to achieve satisfactory healing. One patient developed a unilateral inflammatory groin mass requiring surgical removal of the Dura Film. One patient developed a chronic draining sinus that required surgical intervention. Seven groins developed lymphocysts. The morbidity was high with 9 of the 11 patients experiencing complications. Coverage of the femoral vessels with Dura Film after inguinofemoral lymphadenectomy is not an effective alternative to human dura mater or sartorius muscle transplant.

Biomechanical aspects on rehydrated freeze‐dried human allograft dura mater tissues

AbstractBiomechanical properties of rehydrated freeze‐dried human dura mater tissues were studied. Scanning electron and polarized light analysis indicated a multilayered distribution of collagen fibers in the dura mater tissue. Uniaxial tensile testing of 95 test strips permitted determination of average values for failure stress (6.65 ± 0.14 MPa), failure strain (0.15 ± 0.003), tangent modulus (69.50 ± 1.29 MPa), elongation (0.56 ± 0.01), and tangent stiffness (12.53 ± 0.24 kN/m) of the dura mater tissue. © 1994 John Wiley &amp; Sons, Inc.

Quantification of the edge effect in calcified bioprosthetic tissues.

In bioprosthetic tissue samples that had been implanted in the subcutaneous space of rats, and recurring pattern of calcification was observed. In this pattern, which we call the edge effect, the interior of the tissue is calcified and is surrounded and separated from the subcutaneous fluid by a zone that is free from calcification. The edge effect has been qualitatively described in the literature for subcutaneous implants and for valve leaflets, and it may be related to the mechanism of calcification for these materials. The thickness of the calcification free outer layer was quantified for glutaraldehyde treated bovine pericardium, glycerol treated bovine pericardium, glutaraldehyde treated human dura mater, and glycerol treated human dura mater. The edge effect values were found to be unique and consistent for each material type, and they were inversely related to the shrinkage temperatures and the calcium contents of the materials. It was determined that the chemical treatment was more important than the tissue type in determining the edge effect value.

Anatomic and biomechanical properties of human lumbar dura mater.

Determinants of dural defects subsequent to deliberate or accidental dural puncture include the equipment, techniques, and the inherent anatomic and biomechanical properties of dura mater. These properties were studied in specimens of human and canine lumbar dura mater in an attempt to delineate the structure of the tissue and to characterize its behavior in biomechanical terms. Human dura had a longitudinal orientation on gross appearance, and was confirmed microscopically to be composed of longitudinal lamella of collagen and elastin fibers. Longitudinal tensile strength and stiffness were greater than transverse tensile strength and stiffness, which is consistent with the dura's apparent anatomic structure and functional requirements. Additional biomechanical testing of the dura demonstrated the property of relaxation which is a characteristic of a viscoelastic material. Significant differences were observed between human and canine dural properties, suggesting limited value of this animal model. Integration of these observed anatomic and biomechanical properties of the lumbar dura provides a greater understanding of dural puncture and may explain previous and often confusing clinical and experimental findings.

In vitro determination of human dura mater permeability to opioids and local anaesthetics.

The permeability of human thoracic and lumbar dura mater to various compounds in clinical use was determined in vitro. Sections of dura mater, 3 to 4 cm in diameter, obtained at post-mortem were placed between the ports (area = 3 cm2) of two glass chambers (A and B) which fitted tightly together to form a two-chamber apparatus for measuring permeability through the dura. Each chamber contained 5 ml of artificial cerebrospinal fluid. A sample of test drug solution was introduced into one chamber (A) and 50 microliters aliquots were withdrawn from the other chamber (B) at predetermined intervals. Permeability was determined by calculating the rate of diffusion (slope) from the plot of mean drug concentration (chamber B) versus time. Dura mater permeability was shown to be a simple diffusion process and to be independent of lipid-solubility and molecular weight. Permeability appeared to increase with age and may have a linear relationship to the initial concentration.

Dura Mater for Soft-Tissue Augmentation: Evaluation in a Rabbit Model

Irradiated human dura mater, a commercially available preparation of dura mater (Tutoplast), and irradiated rabbit dura mater were implanted in subcutaneous pockets in the pinna and forehead of New Zealand white rabbits and evaluated for their usefulness in soft-tissue augmentation at 3 months and 6 months. Postoperatively, no evidence of erythema, purulence, hematoma or seroma formation, wound dehiscence, graft extrusion, or flap necrosis was noted. Irradiated human dura mater was well tolerated by the host and elicited a mild cellular inflammatory response. The graft was well preserved, infiltrated by fibrous connective tissue, and fixed in place in the pinna sites. Forehead grafts were surrounded by a capsule of host tissue and were intact. Dura mater seems to be useful for soft-tissue augmentation. Tutoplast may give good results clinically. Because this represents a short-term evaluation, long-term clinical results are needed to define the potential of dura mater grafts.

The biology and molecular biology of scrapie-like diseases.

The transmissible spongiform encephalopathies (TSE's) are degenerative diseases of the central nervous system which naturally affect man (Creutzfeldt-Jakob disease [CJD], Gerstmann-Sträussler syndrome [GSS], kuru), sheep and goats (scrapie), cattle (bovine spongiform encephalopathy [BSE]), mink (transmissible mink encephalopathy), mule deer, elk and antelope (chronic wasting disease). Spongiform encephalopathies have also been diagnosed in captive species of zoo antelope and in domestic cats. Much has been written about these maladies in the wake of the BSE outbreak, the tragic cases of CJD in recipients of cadaver-derived human growth hormone, sex hormones or dura mater and this has stimulated a continuing public health debate about the transmissibility, prevalence and clinical variability of scrapie, CJD and related ("prion") diseases. Prions (Weissmann, Liautard, this volume) and the human (Kretzschmar, this volume) and cattle (Wilesmith, Marsh, this volume) diseases are described in more detail elsewhere. This article presents a brief overview of the biology and molecular cell biology of scrapie and rodent models of these diseases.

溶媒乾燥硬膜挿入によるＦｒｅｙ症候群の予防法

We attempted to prevent Frey's syndrome by using solvent dehydrated human dura mater in the closing procedure after parotidectomy. The area was covered by the dura and sutured. The presence or absence of symptome was noted subjectively and by Minor's method. One out of 17 patients reported a positive symptom during the observation period of 6 to 35 months.Neither foreign body reaction, infection nor other adverse reaction occured after the dura implantation. This method is useful in prevention of Frey's syndrome.