Educational Lecture 2-4 (EL 2-4) : Various biopsy methods and suturing technique = Educational Lecture 2-4 (EL 2-4) : Various biopsy methods and suturing technique

다국어 초록 (Multilingual Abstract)

Skin biopsy is essential to establish a diagnosis of skin disorders and in planning of therapy. The type of skin biopsy depends on the kind of lesion to investigate. First, punch biopsy is performed with a pre-made circular cutting punch and range in size from 2mm to 6mm. This may be the most commonly used technique. The technique is as follows: After anesthesia, the skin is drawn taut with the non-dominant hand and the punch is applied gently and firmly against the skin surface perpendicularly. Next, a downward pressure using a twirling motion is applied, The cylindrical specimen should be lifted smoothly with the tip of the needle or by gentle handling with the forceps. Then the base of specimen can be cut and ensuring a good amount of fatis very important. Second, save biopsy can remove the elevated portion of surrounding skin which is caused by the protruding lesion itself or the manner of injection of local anesthetic. The depth of shave biopsy is limited to the epidermis and the deep papillary dermis. It is useful tool to remove seborrheic keratoses, warts, pyogenic granuloma and so on. The technique is as follows : The lesion is elevated from the surrounding skin by injecting local anesthesia to facilitate the procedure. With pinching the skin between the thumb and index finger, a razor blade or surgical blade should be moved under the lesion horizontally to the skin surface. The operator can control the depth of the biopsy by the angle of the blade. Third, the excisional and incisional biopsy could be needed to remove larger lesion or when deep specimen including subcutis must be taken. Above biopsy requires much time, more skill and advance preparation of instruments. The elliptical biopsy in which the length is three or four times larger than width making 30 angle at the poles is widely used. It is necessary when the specimen for microscopic examination must include either a continuum from uninvolved normal skin through the edge of a lesion into the thickest or most representative area of the lesion. The defect after skin biopsy usually closed by suturing. The simple interrupted suture is the most and widely used. It is important that the path of a simple interrupted stitches enters the skin at an angle 90, and the suture loop at the base is broader than the skin surface. In a simple running stitch, the individual stitches need not knot except the first and the last suture and the time is much shorter comparing with interrupted stitches. Buried subcutaneous sutures is helpful in spreading wound closure tension, closing dead space and apposing wound edges. Proper placement is critical for good result. So the entering point and the exit point in the dermis should be same level to prevent a step-off deformity.