20 Food Animal Intestinal/Anorectal Surgery Part 2

• Rectal Prolapse

Causes of Rectal Prolapse

• Parasites can be a cause
• Inflammation can contribute to rectal prolapse
• Colitis, trauma (rectovaginal), and urinary disease are specific inflammatory conditions
• Heritability may play a role
• Innervation issues can be a cause
• Spinal trauma and short tail docks can affect innervation

Anatomy

• Rectal prolapse involves the mucosa, submucosa, and serosa, doubled over

Reduction

• Exposed mucosa in a prolapse is often friable and edematous
• Two serosal layers adhering may complicate reduction
• Reduction requires patience and massage

Retention

• Retention with irritant is a method used in small ruminants
• Peri-rectal injections of irritant (sclerotherapy) are used
• Sclerotherapy facilitates intrapelvic adhesion formation
• Umbilical tape can be used as a broad suture
• The purse string suture should be placed outside the anal sphincter
• The broad suture such as umbilical tape prevents/minimizes tearing of the perirectal tissues
• The purse string suture should be tightened only until it is snug around your thumb
• Tie the suture in a bow so it can be loosened and re-tied if necessary
• The suture must be maintained for 5-7 days to allow adhesion of the terminal rectum to pelvic structures

Rectal Prolapse Amputation

• Amputation is a choice for prolapse with extensive mucosal damage
• Amputation is considered if the prolapse is non-reducible or recurrent
• Amputation can be done with a commercial prolapse ring (small ruminants) or other sufficient tube (cattle)
• Surgical amputation is a method of treatment

Colonic and Anal Atresia

• Atresia ani refers to an imperforate anus

Atresia Ani Prognosis

• Prognosis and treatment options depend on the length of the terminal rectum
• It is important to determine how far the terminal rectum has to stretch to the new anal opening

Holstein Example

• A 3-day-old Holstein calf was born without problems
• The calf had good milk intake for the first couple days
• The calf stopped eating on the third day
• The calf developed progressive abdominal distention
• Digital rectal exam shows clear-transparent mucous and no meconium color

Atresia Coli

• Atresia coli is a failure of a portion of the colon to develop in utero
• In atresia coli, a calf is born with a normal small intestine, rectum, and anus
• There is no connection between any of these structures

Clinical Syndrome

• Atresia coli is most common in dairy calves
• A history often includes failure to pass feces (though mucous may be seen)
• Calves are initially vigorous with eager nursing
• Calves become progressively bloated and depressed by 3 to 5 days

Physical Examination

• Abdominal palpation reveals distended intestinal loops on the right paralumbar fossa (PLF)
• Digital rectal exam reveals a "clean" rectum
• There will be no feces or meconium discoloration
• The rectum contains only clear mucous
• T, P, and R (temperature, pulse, respiration) readings are variable

Diagnostics

• Ultrasound can be utilized
• Radiographs can be utilized

Exploratory Laparotomy

• Exploratory laparotomy can be utilized

Atresia Coli Cause

• The cause of atresia coli is genetics or embryo/fetal manipulation
• Case reports may indicate genetics
• In regards to embryo/fetal manipulation, a controlled prospective study of > 5000 cows
• Risk factor identified: Rectal palpation < 42 days gestation
• Specifically, the colonic artery may be particularly fragile

Anastomosis

• Anastomosis may be used to perform a side to side colon to rectum repair
• Anastomosis is difficult due to rectal wall thickness
• 3-0 monofilament suture is utilized
• Suture patterns may be interrupted or containous

Prognosis Factors for Atresia Coli

• Age is a critical prognosis factor
• Older calves are more likely to have a devitalized colon
• Septicemia and peritonitis are other factors that can cause a poorer prognosis
• Presence of feces in the terminal colon is a positive prognostic factor
• If surgery is done before 5 days (especially < 3 days), expect ~60% survival for surgery
• Expect ~40% survival to productivity
• If surgery is done after > 5 days, expect < 10% survival