What is Atresia Coli

1. Pathogenesis and indication

Operation of an atresia ani

the essentials in brief
As atresia ani This is a term for an inhibition malformation in which the affected animals have a partial or complete absence of the anus. The procedure tries to create an artificial outlet (stoma) below the base of the tail.

Inhibition malformation of unknown origin. It can be associated with rectovaginal or vesical fistula formation. An indication to create a stoma is when no or too little faeces can be deposited.

Affected animals show curvature of the back, press on faeces, and the waist circumference increases. The droppings are missing (complete atresia ani) or feces can only be pressed out in small quantities (partial atresia ani). From the outside it is difficult to assess whether the rectum is also missing or whether it ends as a blind sac under the skin (the latter can be indicated as a protrusion of the skin below the base of the tail with abdominal compression).

Before an operation, animal owners must be informed that in some cases it is not possible to find the blind sack, that after a successful operation only passive excrement will take place and the perianal area will therefore be heavily soiled with feces (no sphincter muscle present) and that the animal will not should be used for breeding (suspected heredity).

The calf is placed on its back and the hind legs are stretched and tied cranially.
Preparation of the surgical field in the area of ​​the perineum.

Injection, inhalation or high epidural anesthesia

6.1 Description of the implementation of the surgery

Ventral to the base of the tail (at the normal anatomical position of the anus) a circular piece of skin is excised, diameter approx. 2.5 - 3.0 cm. After cutting through the underlying fascia, an attempt is made to locate and mobilize the blind sac by blunt dissection. If the end of the intestine is pulled far enough caudally, an attempt can be made to sew the perirectal tissue to the subcutaneous tissue. The blind sack is then opened and the edge of the intestinal wall is sutured to the skin in a continuous, circular manner with absorbable suture material (e.g. braided polyglycolic acid thread, HRT37s, 70 cm, metric 4).

6.2 Pictures of the operation


Calf with atresia ani. The slight curvature of the back and the holding back of the tail while pressing are typical



Female calf restrained in the supine position. A significant protrusion of the skin is visible at the dorsal commissure.

In the present case, there is another malformation in the form of a protrusion of the skin dorso-lateral to the vulva



Hardly any resistance can be seen when pressure is applied to the protrusion (skin deformity is pulled out of the surgical field by a thread).



A circular piece of skin (diameter approx. 2.5-3.0 cm) was excised.



Divide the fascia exactly in the median.



The blunt dissection is carried out with the aid of a clamp that is spread apart.



The caudal end of the blind bag was grasped and mobilized by blunt dissection of the area. However, it cannot be pulled far enough caudally. In this case, the perirectal tissue is not sutured to the subcutis.



When the blind sack is opened, the edge is immediately gripped with several clamps. This makes the subsequent sewing of the intestinal wall to the skin easier, because meconium constantly oozes out during the sewing process and obstructs the view.



Finished circular suture (braided polyglycolic acid thread, HRT37s, 70 cm, metric 4). Meconium oozes out of the stoma.


Photos: M. Metzner

Cover the periphery with an ointment or a spray bandage, administer an anti-infective agent for at least 5 days, continue the anti-inflammatory process as required.

The threads should not be removed.

Wound infection.

Overall, the healing prospects are very good. However, the animals should only be used for fattening. Since the spinner function is absent, feces well up in an uncontrolled manner, and the anal area of ​​the animals is constantly contaminated with feces.