38) Congenital Abnormalities of Anus скачать в хорошем качестве

38) Congenital Abnormalities of Anus

Congenital Abnormalities - Imperforate Anus -this is a not uncommon congetial abnormality. There is imperfect fusion between the post allanatioc gut ( hind gut) and proctoderm. (which forms lower part of the anal canal below the dentate line. ) Classified in to 2groups low anomaly & high anomaly - depending of weather the termination of the bowel is below or above the pelvic floor respectivel . Low anomally – -this minor developmental errors & spincter mechanism of the anus is almost normal. these are 4 varieties - a)Membraniuos stenosis (Imperforate anal membrane) – -in this condition anal canal is narrowed anal covered with a thin membrane. Rx- A cruciate incision on the membrane & regular anal dilatation. b)Covered anus – -the anus is covered by the skin, so that the opening is not situated in its normal position. Rx- To open the track with scissors up to the normal position of the anus, followed by regular dilatation of the anus. c)Stenosed anus – (anal stenosis ) – -more or less the whole anal canal is slightly narrowed and the anus is microscopic with a minute openings. Rx- Regular dilatation of anus. d)Ectopic anus – -the anus is is not situated in its normal position but is placed more anteriorly in the perineum of the boys or near the vulve in case of girls. -Anal canal is normally developed but a thick skin covers the normal anal opening. Rx- Plastic cut back operation. e)Anal agenesis – is comparatively rare. High anomalies - -Rectum ends above the pelvic floor and ther is often a fistulous connection between the blind rectal stump & the bladder. a)Rectal atresia – -Anal canal is normal but ends proximally just below the level of the pelvic floor .The rectum ends below blindly above the pelvic floor. Rx- Mobilization of the rectum, an opening is made through the pelvic floor end to end anastomosis is performed with the anal canal . b)Anoretctal agencies – commoner malformation, the rectum ends above the pelvic floor & usually connected with the bladder or with the posterior fornix of the vagina through fistulous communication. the anal canal is not developped. c)Cloaca - very rare type, only seen in female. -the hind gut, urinary bladder & genital track all open into a common wide cavity. Clinical features – Failure of passage of meconium X – ray exam - -To know whether the anomaly is of high or low variety. metal coin strapped at the site of the anus or a metal bougie inserted in to the blind anal canal. -After 3-4 min. radiographs are taken in inverted position, -by that time, gas will reach the end of the rectum & one can see the distance between the end of the gas shadow and the metal indicator. If distance between, these two is more than 2.5 the abnormality is high. -one has to wait till nthe rectal gas appears, sometimes it takes a day or more for rectal gas appear. Rx – High anomalies – Common anorectal agenesis with fistula formation- If the intestinal obstruction a preliminary transverve colostomy. -If fistula, it should be divided after both ends are closed. -If anorectal agenesis – the Rx is preliminary transverve colostomy followed by abdomino – perineal pull through operation at the age of 6-12 months. Sacro Coccygeal Teratoma - -It is a teratoma at the sacrococcygeal region. -The most common tumour seen in a neonatal baby. -The tumour is actually situated between the rectum and the sacrum. -It is firmly attached to the coccyx and occasionally to the last piece of the sacrum. -It usually presents as a big swelling & may certain rudimentary limbs, such as hands or feet. It may become malignant. -This site is ‘primitive knot’, a group of totipotent cells, which possesses potentiality to form various types of cells and that is the reason why tatatoma is seen at sacroccoccygeal region. Rx- Exicision of tumour - as soon as the diagnosis is made. Post anal Dermoid Dermoid cyst is situated behind the anal canal and rectum and infront of the coccyx & sacrum - soft and cysic swelling - presented in adult life. Rx- Excision of the cyst alongwith the sinus.