Surgical Rectification of Atresia Ani et Recti and Patent Urachus in a Male Cattle Calf

The calf was sedated with a concomitant use of injecting XylazingHCL @ 0.3mg/kg Intra-Muscular and lignocaine 2% 5 ml High epidural at the lumbosacral space. After sedation, a caudal ventral midline laparotomy was performed and the intestine palpated till its terminal portion, which was found as a blind pouch, located at the dorsal pelvic wall, 10cm away from the site of anal atresia (Supplementary Fig. 1B). The terminal end was detached manually, incised to evacuate the meconium (Supplementary Fig. 1E) and lavaged with lukewarm normal saline. It was then replaced into the pelvic canal. After surgical reconstruction of the anal orifice (Supplementary Fig. 1E), using the cruciate flap technique, a sterile non-crushing forceps were introduced through the artificially-made anal opening, and the terminal end of the intestine was grasped and pulled outvia traction at the anal orifice, where it was sutured with the skin in a circular fashion (Supplementary Fig. 1D). Finally, colopexy was performed to further stabilize the intestinal loop.

For rectification of the patent urachus, the urachal duct was identified at the cranial vertex of the urinary bladder, whereby itwas found to be communicating with the external abdominal wall through the umbilicus. After sharp dissections of adhesions, the urachus was isolated, ligated very close to the urinary bladder and excised.

The abdominal cavity was lavaged with lukewarm normal saline solution, and the laparotomy incision was closed in three layers as routine. Post-operatively, the calf was monitored through a 7-day course of broad-spectrum antibiotics and antipyretics. After one week, the calf recovered completely and on follow-up, no complication was reported, either.

Ano-rectal anomalies can be satisfactorily diagnosed on the basis of clinical findings without necessitating the need of radiographic examination for disease confirmation. Based on the degree of severity, anal atresia can be divided into four types. In Type 1, there is no anal opening; in Type 2, the rectum ends as a blind pocket cranial to the imperforated anus; in Type 3, the terminal portion of the rectum lies at a greater distance from the imperforate anus and is synonymously called as atresia aniet recti, which was the case presentation; Type 4, on the other hand, is characterized by multiple intestinal atresias. Differentiation among these four types can be made using advanced imaging techniques of contrast radiography (Rahal et al., 2007).

Patent urachusis a condition in which the urachal duct fails to degenerate after parturition. During prenatal life, the urachus forms the communication between the bladder and the allantoic cavity for urine excretion (Rao et al., 2000). Failure of the duct to close at birth leads to this anomaly which is commonly found in calves; it may be associated with imperforate urethra and may additionally predispose the calf to omphalitis and ascending infection of the umbilical remnants (Hunt and Allen, 1989; Ha et al., 2018).

Both conditions, however, were successfully treated surgically with good survival rates. Surgical management of atresia anirequires incision at the expected anal orifice and subsequent permanent reconstruction of the anal opening. This is done by giving a cruciate skin incision and removing a circular piece of skin, which is then sutured with the terminal excised rectal loop (Azizi et al., 2010). Atresia aniet recti can be treated by incising through the anal area, or, in case of Type 3 atresias, approaching through a caudal ventral midline laparotomy [as was done in this case], identifying the terminal blind intestinal pouch, incising and trimming it so as to create a permanent opening and reconstructing a rectal orifice with an anal orifice by suturing it with the skin at the anal aperture induced surgically. Euthanasia is indicated if the intestinal atresia is more extensive, since the survival rate of calves with atresia aniet recti or atresia coli is reportedly low as compared to Type 1 anal atresia (Durmus, 2008). Patent urachus, likewise, requires surgical management in which the urachal duct is identified, separated and excised after ligating the duct at the apex of the bladder (Laverty and Salisbury, 2002).

Congenital anomalies in ruminants (Simon et al., 2011), usually occur in association with various other malformations, such as rectovaginal fistula (Bademkiran et al., 2009; Shakoor et al., 2012), absence of the penis, urethra and the scrotal raphe in the male (Abd-Almaseeh, 2012), vaginal agenesis in the female, and urinary bladder agenesis (Sutharetal., 2010).

The present case, diagnosed as atresia aniet recti (Type-3), was associated with a patent urachus, which was further confirmed at surgery. The history and clinical signs were similar as documented earlier (Chauhan et al., 2011; Suthar et al., 2010). Contrary to reports of unfavorable prognosis for Type 3 atresias, this case was successfully treated surgically by reconstructing the anal opening, identifying and isolating the terminal end of the intestine through a caudal ventral midline laparotomy, replacing it into the pelvic canal, and subsequent suturing of the terminal part of the intestine subcutaneously with the aperture on the skin of the artificially-made anus; and the calf completely recovered, when examined at a follow-up of 07 days.

There is supplementary material associated with this article. Access the material online at: https://dx.doi.org/10.17582/journal.pjz/20180424050426

The authors declare that there is no conflict of interest.