Biopsy

In Encyclopedia by Lorraine Dupre Views: 12

A biopsy is a sample of body tissues to achieve microscopic examination in General. However it may be sometimes biochemical, immunological, genetic, or even bacteriological.

Description

A biopsy described the procedure which is used to obtain a very small piece of target tissue. The levy can be either all of the targeted region or part. The latter can be done in three different ways, according to the sample:

• a surface sampling of the fabric;
• a sample with a needle;
• a sampling by aspiration with a needle syringe.

For certain fabrics, such as oral mucosa, the clinician may have to make several types of levies to the level of the oral mucosa:

• Biopsy by incision
• Biopsy excision,
• Extemporaneous biopsy,
• Smears,
• Dipping-needle biopsy.

Other samples are collected using forceps that are placed at the end of an optical device called endoscope. The doctor can view the surface of tissue (such as the wall of the large intestine) with this instrument and use pliers to remove the tissues of the desired region.

In other cases, the tissue sample can be collected with a large hypodermic needle (examples: samples of liver or kidneys). Samples of muscles and nerves can also be obtained by taking a fraction of the target after incision to the scalpel to achieve the latter.

When a biopsy is obtained with a needle, sampling depends on design of the needle and the energy of its insertion into the fabric. The used needle is a tube with some able to perforate the tissues. As the needle is sinking into the fabric, it will accumulate in the tube. When the needle is removed from the fabric, the sample remains in the tube and needle can be retrieved for analysis.

Interest diagnostic

Various reviews provide vital information to the laying of diagnosis by the doctor. In diseases such as cancer, the knowledge of the latter type is essential to this diagnosis and the establishment of a treatment.

Muscle biopsy is the only examination for diagnosing some way the myofasciite macrophages, consecutive to the injection of a vaccine containing aluminum hydroxide, to provided that the injection is not too old and know the specific location.

In other cases, may be interested in the calculation of the activity of enzymes in a fabric, used as a marker of disease. For such approaches, a parseable tissue laboratory sample is necessary.

Similarly, for some diseases that cause of anomalies of the nerves, the ability to directly consider the latter may be advantageous in the diagnosis and treatment. For example, the microscopic examination of a sample of nerve can reveal if the protective myelin sheath surrounding nerve, is intact or degrading. Muscle biopsies may have the same objective, as the diseases that affect the structure and/or the functioning of the nerves, affect the muscles in which passes nerve. The loss of muscle function may be the direct consequence of damage to the nervous system.

Of many biopsy samples are examined using a microscope to find abnormalities in tissues of cells. This review may combine sample staining, in particular for detecting target molecules. In addition, samples can be used for various biochemical tests, particularly to test the presence and the activity of certain genes.

Examples of applications

Brain biopsy

A brain biopsy is done after the circular opening of the skull, by which the needle is introduced. An MRI or a scanner is performed before the procedure to identify the area where the biopsy will be performed. Mid-1990s, the patient’s head is more immobilized during the procedure by an external frame. However, the precise location given by a computer system, prevents damage to other parts of the brain. Unlike a skin biopsy, where the only risk, assign a few nerves is a biopsy of the brain is a delicate procedure that could have serious risks.

For the realization of Stereotactic devices biopsies the surgeon may be assisted by a robotic assist device to Neurosurgery as ROSA. The use of this system allows it to secure and protect the surgical Act.

Muscle biopsy

A muscle biopsy may be a piece of tissue obtained with a needle or after an incision again. This biopsy is performed for various reasons: to make the distinction between nerve and muscle disorders, identify muscle disorders such as muscular dystrophy, diagnose the myofasciitis, probe the metabolic activity of the muscle, or yet to detect infections such as toxoplasmosis and trichinosis. Biopsy of a muscle necessarily implies the collection of nerve, because the sample is highly innervated. This is of no practical consequence of the small amount of muscle which is extracted.

Nerve biopsy

A nerve biopsy is performed to find the cause of a severe or disabling neuropathy for which other explorations (electromyography in particular) have not made the diagnosis. It can double-edged leprosy, a Necrotizing Vasculitis, an inflammation of the nerve, or property damage or loss of the myelin sheath. The sural nerve at the level of the ankle and the superficial radial nerve in the wrist are most often the scene of biopsy.

During the biopsy, local anesthesia is used. Then, a small incision is made and a small piece of the nerve is collected. Usually, adjacent muscle biopsy is done at the same time. The procedure involves a minimum of risk, including allergic reactions to anesthesia, infection, engourdissement… However a persistent numbness is possible because a part of nerve was removed.

Salivary gland biopsy

Accessory salivary gland biopsy has become a systematic review in the aetiology of syndrome research dry or in the diagnostic assessment of sarcoidosis or other autoimmune disease. It’s a simple gesture which involves an incision of a few millimetres of the lower lip. Before the examination, the mouth must be clean. The patient is lying on the back, the head slightly elevated. Anesthesia is practised by a local injection with a very fine needle under skin. The help of an incision of 1.5 to 2 cm in length of the lower lip mucosa. Isolated and it takes at least 5-6 accessory salivary glands. The wound is then stitched. After the review, avoid the shackling of food on a suture thread, to rinse the mouth after each meal. The spicy dishes or acids are to be avoided for a few days. This review is often used in practice due to its safety (little painful, few secondary incidents) and accessibility of the glands. Some have advocated the study of Palatine salivary glands or that of the sublingual gland, which allows for a greater amount of salivary parenchyma. These main salivary gland biopsy is strongly discouraged, because neurological risks (breach of the facial nerve in Parotid gland enlargement).

Risk/benefit balance

Secondary salivary gland biopsy is a common practice in the diagnosis of Amyloidosis. Indeed this biopsy is little painful, salivary glands are easy to access and biopsy is very of little side effects (hematoma of the lip or regressive local anaesthesia) more, the results are very satisfactory. On the other hand if one wishes to obtain a greater amount of salivary parenchyma, can perform a biopsy of the major salivary glands but this present operations of neurological risks: facial nerve in Parotid gland enlargement. In addition, as all the biopsy, there are a number of risks that contre-indiquent the realization of a levy:

• Risk of malignant degeneration: this risk is caused as a result of the trauma represented by the Act itself. Ex: Neurofibromatosis, Von Recklinghaussen, lichen-plan.
• Risk of swarming and extension in healthy tissue. Ex: Salivary mixed tumor.
• Risk of aggravation of an evolutionary malignant process. Some tumors, such as vascular tumors, are likely after trauma biopsy to see their evolutionary potential exacerbated, because during the biopsy, it will cause a vascular break and therefore a risk of dissemination.
• Haemorrhagic risk seriously.

As any surgical biopsy may be contraindicated if infectious or hemorrhagic. These contraindications, in relation to the General State of the patient, are only relative, because anything can be achieved as soon as the Protocol of the patient support is established in collaboration with the doctor treating and taking the necessary precautions before any patient at risk. The biopsy may also be contraindicated when the concept of continuity is compromised. Indeed consider biopsy as one of the elements of the set of therapeutic measures for which a degree of continuity must be respected. However the biopsy may lead to changes in shape or volume or tissue disruption of inflammatory nature likely to confuse or hinder the assessment of therapy by the practitioner to the patient will be assigned. When the lesion is frankly malignant, or when its nature, size or location (e.g. part posterior language) problem, then it is preferable to send the patient to more specialized practitioners. The biopsy is contraindicated for reasons of feasibility or jurisdiction.

Bone biopsy

Need this biopsy to determine whether a tumor is malignant, it also allows to follow its evolution and its potential spread. Biopsy is a diagnostic examination that is done under local anaesthesia, it can be done as well in an operating room than in a medical specialist. Bone biopsy occurs mainly in patients with (for example):

• Of ostéopénie(diminution_de_la_masse_osseuse_pour_un_patient_comparé_à_un_sujet_témoin_de_même_âge,_même_sexe_et_même_origine_ethnique) biopsy is performed to quantify via histology.
• Bone tumor (whether they are malignant or bégnines)
• Osteoporosis
• Osteomyelitis
• Glass bone disease

Biopsy occurs most often after reviews easier to achieve as x-rays or blood tests. The examination cannot be done without the free and informed consent of the patient. The biopsy should be carried out on a near bone of the surface of the skin and preferably from the organs and blood vessels. This bone biopsy is done most often on iliac crests.

The Act is to insert a needle (called a trocar) which is composed of a metal rod of cylindrical shape and completed by a very cutting triangular tip, supplemented by a tool for creating a rotation of it (called Chuck). This needle to collect a piece of bone as a drill and retrieve it quickly to a point of compression very quickly after the extraction to avoid any bleeding. The levy is then placed in a liquid of fixation to send it to the lab.

Bone biopsy is part therapeutic approach and cannot be considered as exploratory surgery, why this review is often complemented by a surgical treatment (for tumors bégnines for example). During the surgical Act practitioners are often assisted by various tools such as scanners to well locate the area where the practitioner wants to levy.

Biopsy is not something innocuous a major risk of this Act is the fragmentation of the bone that can lead fracture it. On the other hand during the intervention the doctors are particularly attentive to the risks of bleeding. After examination it is recommended to stay at least 24 hours, lengthened to prevent bleeding where the biopsy was performed.