14 Epiduroscopic, Histopathologic, and Microbiological Findings In pain medicine literature, the histologic (fine tissue) analysis of neuraxial tissue samples, taken from the vicinity of the spinal cord with the help of spinal endoscopy, are not at the heart of pain diagnostics currently, but that may change. Different methods are available to investigate and evaluate tissue from the epidural space histologically. Cytologic and histologic lightmicroscopic laboratory investigations of tissue samples are the basis of routine diagnostics. The analysis of removed cerebrospinal fluid (CSF) and epidural irrigation fluid is also part of cytologic diagnostics. Infectious inflammatory diseases are a cause, but not the most important, of neuraxial pain in patients. Depending on the age of the patient, the course of the disease, the route of the inflammation and the affected region, conclusions can often be drawn on the causative agent of the infection. But in many cases of infection (including our own), a clear differential diagnosis of the clinical investigation findings only becomes possible through an endoscopically supported biopsy with subsequent histologic investigation. Biopsies also serve for control of the course of therapy and evaluation of the results of therapy. The strategy for the patient’s pain therapy can also be optimized utilizing the endoscopic survey findings and the histologic investigation results. Also, in invasive–interventional pain medicine, every operatively removed piece of tissue must undergo histologic analysis. A new endoscopic technique, endomicroscopy, is ever more prominently taking center stage in general endoscopic and histologic diagnostics. During endoscopy, endomicroscopy generates histologic-type images of the endoscopically visualized tissue available in real time, making a histologic evaluation possible.2,3 This cellular-level in vivo diagnostics, or optical biopsy, may play a role in the future as a supplement or alternative to established epidural biopsy. On the Internet, countless depictions of histologic preparations of the highest quality are available, retrievable at all times, digitized, and also editable with Photoshop (Adobe Systems, San Jose, California), CorelDRAW (Corel Corp., Ottawa, Ontario, Canada), and PowerPoint (Microsoft Corp., Redmond, Washington). These depictions are available for use in comparing with research findings or in creating patient reports and showing comparative images. In diagnostic pain management, the method of obtaining and preparing tissue samples for histologic and cytologic evaluation is significant. These preanalytics include the extraction, workup, storage, and transport of the patient’s specimen material. The conditions to which the specimen material is subjected until it enters the laboratory also have a decisive influence on the reliability of histologic and microbiological laboratory findings. During spinal endoscopy, neuraxial tissue specimens for biopsy can be extracted through the working channel of the endoscope with the help of a grasping forceps. The tissue specimens secured from the epidural space are first fixed in the operating room (OR) in a 4% formalin solution and sent to the laboratory in special packaging. In the laboratory, the workup of the tissue specimen for microscopic investigation takes place. For most histologic investigations, the light microscope (with a resolution of 200 nm) is used.4,5 For histologic investigation, the small tissue specimens from the neuraxial space are embedded in paraffin from which 1.0-to 3.0-μm translucent slices will be prepared. To do this, water is removed from the tissue specimens in the tissue processor. Then the tissue specimens are saturated with paraffin and poured into paraffin blocks. After cooling of the paraffin, the tissue specimens can be found on the upper surface of a paraffin block on the back surface of an embedding cassette. On a microtome cutter, up to 3-μm thin slice preparations can now be made. In a water bath, the tissue specimens are afterward raised on a glass slide. The remaining thin, now translucent tissue slice on the slide can now be automatically or manually stained for visualization of cell nuclei, cell boundaries, and certain tissue structures.4 Histopathologic Indications: Stains The standard staining of histologic preparations is carried out with hematoxylin/eosin (HE). The stained structures such as the cell nucleus, bacteria, or calcium carbonate are stained blue. Cytoplasm and connective tissue are stained red. Further staining methods include, for example, Congo red, Ziehl-Neelsen, Prussian blue [Berlin blue], Giemsa, Elastica van Gieson, and silver staining.4 With special questions, additional diagnostic methods such as enzymo- and immunohistology as well as molecular biological investigation methods (polymerase chain reaction [PCR] and microarray investigations) come into use.5 For the isolation, differentiation, and cultivation of aerobic and anaerobic bacteria, the necessary test glassware with culture media and incubation systems are available from the industry.5 Some 2 to 3 cm of the catheter tip is cut off with sterile scissors and placed in a sterile test tube. Liquid transport media or blood culture bottles are to be avoided, because a semiquantitative determination is otherwise impossible. The catheter sample should immediately be sent to the laboratory. Storage should be avoided as much as possible. If necessary, the catheter tip can be stored up to 24 hours at 4°C. Before a sample of cerebrospinal fluid (CSF) or epidural irrigation fluid is sent, the laboratory should be contacted to record its upcoming arrival. A strictly aseptic removal of CSF or fluid should be observed. Inoculate a sterile test tube with at least 2 mL of CSF or fluid, depending on the scope of the investigation. For CSF antigen detection, blood cultures should be obtained simultaneously witth the CSF sample. CSF diagnostics as the occasion arises are needed with cytology in suspected cases of polyradiculitis or neuroborreliosis. The CSF investigation specimen should be processed in the laboratory within 2 hours of collection without cooling. Blood samples are needed for basic laboratory evaluations: erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) value, blood count, platelet count, liver and kidney values, and creatine kinase value. An extended blood serology is helpful when there is reasonable suspicion of borreliosis (Lyme disease) or herpes zoster. The blood specimens for a blood culture should be obtained as much as possible in the early phase of the temperature rise, before the beginning of antibiotic therapy or, with current antibiotic therapy, before the next antibiotic dose. The blood draw is to be carried out after skin disinfection with alcohol and drying, using single-use gloves and a blood culture special set (8–10 mL per bottle). The prepared blood cultures are not to be cooled but incubated at 35 to 37°C if an immediate transport to the laboratory is not possible. The endoscopically, microsurgically obtained neuraxial tissue specimen is to be put into a sterile test tube, stored at room temperature, and promptly transported to the laboratory. When necessary and for storage under 2 hours, the tissue specimen is to be placed in a transport medium such as a 4% formalin solution at room temperature, to be stored and transported. The integration of a miniaturized confocal microscope in the distal end of a conventional endoscope makes possible a new endoscopic imaging method, endomicroscopy. Endomicroscopy provides a microscopic view of the mucous membrane and mucosal surface during endoscopy in higher resolution by means of laser-supported, confocal fluorescence technology. Cellular, vascular, and connective tissue structures can be differentiated and immediately evaluated during endoscopy via endomicroscopy. By shifting the color spectrum (visualization tool), even the finest tissue structures can be identified endoscopically. Deepred parts of the visible spectrum are filtered out and the remaining portions of the color spectrum are expanded. Through this technology, such as the Storz Professional Image Enhancement System (SPIES; Karl Storz, Tuttlingen, Germany), the ability to differentiate between tissue types can be facilitated directly on the monitor ( A histologic evaluation of the anatomical structures in real time during endoscopy becomes possible through the enlargement of the endoscopically visualized tissue. Endomicroscopy therefore makes possible cellular level in vivo diagnostics (optical biopsy).2,6 On technological grounds, endomicroscopy is not yet ready for clinical use in spinal endoscopy for evaluating cell and tissue. Intravascular ultrasound (IVUS) technology offers detailed sonographic information on the composition of anatomical structures of the patient. An ultrasound catheter, placed through the working channel of the epiduroscope, produces sonographic images. The images of virtual histology are processed with the help of the Volcano imaging console and the Eagle Eye Gold IVUS catheter (Volcano Corp., Rancho Cordova, CA, USA) ( Along with the endoscopic imaging, the color presentation of the virtual histology simultaneously delineates four types of tissue components: fibrous, fibrous/fatty, dense calcium, and those with necrotic nuclei. Fig. 14.2 Intravascular sonographic image of the epidural space, in cross section, of a patient with. failed back surgery syndrome (FBSS). This virtual epidural histologic image shows, along with echo-poor and echo-dense areas, the four principally occurring tissue components in intravascular ultrasound in this color-coded spectrum analysis virtual epidural histology: epidural fibrosis (green), adhesions with epidural fat (yellow), necrotic tissue (red), and calcium-containing tissue (white). Histopathologic Indications: Virtual Histology In sonographic virtual histology, four types of tissue components—fibrous, fibrous/fatty, dense calcium, and those with necrotic nuclei—are differentiated by color. Structurally and functionally, the cell is the smallest independent unit of life. Associations of cells of similar structure and function are designated as tissues. Along with epithelial tissue, connective and supporting tissue and nervous tissue are of particular significance in the neuraxial space. With the help of endoscopic investigative techniques, diagnostic clues as to the basis of neuraxial pathomorphological processes such as adhesions, fibroses, inflammatory changes (arachnoiditis, epiduritis, radiculitis), sequestrations, ischemias, edemas, cysts, or tumors can be obtained. The neuraxial space is sensitive to circulatory, inflammatory, traumatic, metabolictoxic, and degenerative damage. The cells and tissues of neuraxial structures are distinctive for their ability to adapt to altered environmental conditions, including: • Increased or decreased loading requirements. • Presence and effects of toxic substances. • Replacement (regeneration) of dead tissue. The following are the adaptative reactions to altered environmental conditions of cells and tissues in the neuraxial region4: • Atrophy, diminution of and reduction of function of the cells or tissue. • Dysplasia, pathologic change to a tissue. • Hyperplasia, increase of the functional cells of a tissue with a raised functional demand and capacity. • Hypertrophy, increase of cell volume with an accompanying enlargement of tissue and a raised functional capacity. • Metaplasia, change in cell differentiation. • Regeneration, complete replacement of lost tissue by a functionally and structurally equivalent tissue (restitutio ad integrum). • Repair (reparatio), replacement of structurally and functionally lost or damaged tissue, as in scar formation. Cell and tissue damage due to pathologic processes in the neuraxial space is commonly seen in epithelial tissue (squamous epithelium, endothelium), connective and supporting tissues with the cells, fibrocytes, histiocytes, mast cells, and plasma cells. The fibers of epidural connective tissue, such as collagen fibers, elastic fibers, lattice fibers, and the amorphous gel-like substanc, can be massively impaired by pathologic changes such as adhesions, fibroses, or sequestrations. Connective tissues composed of parallel fibers, important building blocks of the ligamentum flavum and posterior longitudinal ligament, have a very high proportion of elastic fibers and so are easily recognized macroscopically by their yellow color. Under the light microscope, they form nets or organize themselves into fenestrated lamellae. The special connective tissue structures are stained, for example, with aldehyde fuchsin, orcein, resorcinfuchsin, and elastin stains according to Weigert or to Van Gieson.4 Epidural fatty tissue, which often presents endoscopically as adiffuse, symmetric, massive, or doughy fatty tissue structure often cannot be delimited from a lipomatosis, as there is no capsule. Microscopically, lipomas cannot be delimited from normal fatty tissue. They appear as diffuse, nonseptate proliferations of mature single-vacuole lipocytes with tongue-shaped streamers into adjacent structures.4,8,9 The nervous tissue found in the neuraxial region, composed of nerve cells, nerve fibers, ganglia, and neuroglia, stands in particular pathologic anatomical focus, as for example in neuropathy, arachnoiditis, and radiculitis.10,11 Insufficient oxygen and/or exposure to chemical, physical, and biologic toxins can lead to morphological damage of neuraxial cells and tissues. Along with reversible structural changes, necroses are also found as a result of irreversible tissue destruction. Programmed cell death, a special form of cell destruction, also occurs and even without the effect of a toxin. Histopathologic Indications: Necrosis Necrotic cells are often recognized by their strongly eosinophilic cytoplasm and their damaged or absent cell nucleus. Neoplasias present as autonomously proliferating tissue masses that are able to be delimited from normal tissue, and whose cells are uncoupled from normal physiologic mechanisms of regulation. These tumors are characterized, using the TNM system (where T stands for extent of primary t umor, N stands for extent of lymph n ode involvement, and M stands for extent of m etastasis) of the Union of International Cancer Control (UICC) and the International Classification of Diseases (ICD) for oncology. Histopathologic Indications: Benign Tumors In microscopic investigations of benign tumors, no changes or only slight changes to cell structure are demonstrable. Histopathologic Indications: Malignant Tumors In malignant tumors, numerous mitoses, and even atypical mitoses, are a distinctive histopathologic mark of the high proliferative activity of the cells. Also characteristic of these tumors is an aggressive–destructive or invasive–infiltrative growth pattern. Enlarged cell nuclei, polymorphy and polychromatophilia of cell nuclei, and numerous enlarged nucleoli are also characteristic of malignant tumor cells. The primary task of all reactions of the nonspecific immune system is to defend the organism against invading microorganisms or various biologic or nonbiologic agents harmful to the organism. Monocytes, macrophages, neutrophil granulocytes, natural killer cells, and neutrophil granulocytes are the cellular factors of the nonspecific immune system. The cellular factors of the specific immune system, which holds specialized immunity for particular pathogens, are the T lymphocytes and B lymphocytes. In addition, the immune system must tolerate the body’s own tissues, that is, it must be self-tolerant. B-lymphocytes are responsible for the humoral immune response and the T cells for the cell-mediated immune response. The specific immune system of the B- and T-lymphocytes can overreact in special situations. These processes are referred to as hypersensitivity reactions or hypersensitivity. In the course of the increased immunological reaction, inflammatory reactions can occur, which in turn have disease value. In addition, the immune system must tolerate the body’s own tissues, that is, it must be self-tolerant. Acquired immune deficiencies are essentially more frequent than congenital immune deficiencies. The most important acquired immune deficiency is human immunodeficiency virus (HIV) infection (leading to acquired immunodeficiency syndrome, AIDS) and the changes to the immune system due to malignant diseases. Histopathologic Indications: Immune Deficiency Syndrome Congenital and acquired immune deficiencies as a rule accompany histologic changes in the lymphatic organs.
14.1 Introduction
14.2 Preanalytics for Histologic and Cytologic Investigation
14.2.1 Extraction, Workup, Storage, and Transport of Specimen Material
14.2.2 Removal, Storage, and Transport for Bacteriologic Investigations
Spinal Epidural Catheters
Removal, storage, and transport
Cerebrospinal Fluid and Epidural Irrigation Fluid
Removal, storage, and transport
Native cerebrospinal fluid for serology
Venous Blood
Removal, storage, and transport
Neuraxial Tissue Material
Removal, storage, and transport
14.3 Virtual Histology
14.3.1 Optical Biopsy via Endomicroscopy
Fig. 14.1).
14.3.2 Sonographically Supported Virtual Histology
Fig. 14.2) and are then displayed in real time, so that the pain therapist carrying out the intervention can evaluate them while the patient is still lying on the operating table.7 This technology offers an automatic measurement tool to simplify the interpretation of the images and uses a predefined color key to show the composition of a specified neuraxial region, such as the spinal dura mater or within the epidural cavity.
14.4 Neuraxial Pathomorphological Changes
14.4.1 Adaptive Reactions of Cells and Tissues in the Neuraxial Region
14.4.2 Cell and Tissue Damage
Neoplasias
Immunopathology
Immune deficiency syndromes
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
