Rectum: trauma - management and repair in Horses (Equis) | Vetlexicon
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Rectum: trauma – management and repair

ISSN 2398-2977


Synonym(s): Rectal liner

Introduction

Initial management

  • First aid and prompt referral/treatment is of paramount importance to prognosis.
  • Early assessment of degree and extent of damage is indicated.
  • Epidural anesthesia Anesthesia: epidural may be necessary to reduce peristalsis and tenesmus. This can be achieved using lidocaine Lidocaine, but xylazine Xylazine may be preferred as it causes less ataxia and weakness.
  • Alternatively oral propantheline bromide can be used to reduce straining, or 25-50 ml lidocaine can be administered with an equal volume of saline or lubricant as an enema.
  • Gentle removal of any feces from rectum is advised.
  • Packing from cranial to the damaged area to the anus with cotton wool helps prevent further contamination of peritoneum/retroperitoneal space.
  • Broad spectrum antibiotics should be promptly instituted Therapeutics: antimicrobials.
  • A non-steroidal anti-inflammatory drug with anti-endotoxin activity such as flunixin meglumine Flunixin meglumine or ketoprofen/vedaprofen Ketoprofen is also useful.
  • Fasting of food should be instituted.
  • Medical therapy +/- laxatives usually adequate for Grade 1 tears.
  • No treatment required for Grade 2 tears.
  • Surgical repair of >Grade 2 rectal tears Rectum: tear.
  • Four surgical techniques:
    • Suturing the defect.
    • Temporary rectal liner.
    • Loop colostomy.
    • End colostomy.
  • Selection of technique dependent upon location, severity and age of injury and presence/absence of peritonitis Abdomen: peritonitis.
  • Medical/conservative therapy of Grade 3 tears possible.
  • Grade 4 tears carry a grave prognosis.

Uses

  • Surgical treatment of >Grade 2 rectal tears Rectum: tear.
  • Non-visual direct suturing is a useful treatment alone for tears involving 50% or less of the circumference of the rectal lumen, and tears that have very small perforations of the serosa.
  • Non-visual direct suturing is an adjunct only for extensive Grade 3 and 4 tears.

Advantages

Suturing
  • Simple, inexpensive standing procedure.
  • Non-visual technique requires minimal equipment.
  • Can prevent progression of a rectal tear → higher grade → fecal contamination of abdomen → peritonitis Abdomen: peritonitis.
Laparoscopic closure
  • Minimally invasive method for direct closure.
Temporary indwelling rectal liner
  • Prevents fecal contamination during healing process.
Loop colostomy and end colostomy
  • Diverts feces away from tear during healing process.

Disadvantages

Suturing
  • Access is difficult: often sutures have to be placed 'blind' using feel per rectum.
  • Special long-handled instruments may be required.
  • Laparotomy Abdomen: laparotomy may be required.
  • A diverting procedure, eg temporary indwelling rectal liner or colostomy Colostomy, should follow suturing to reduce fecal passage over damaged tissues during healing.

Technical problems

Suturing

  • Experience necessary.
  • Temporary indwelling rectal liners:
  • Laparoscopic closure:
    • Require experience and technical skills.
    • Requires laparoscopic equipment.
    • Exposure may be limited based on location of the tear.
  • Loop colostomy requires:
    • General anesthesia and laparotomy.
    • Two surgical procedures.
  • End colostomy requires:
    • General anesthesia and laparotomy.
    • Two surgical procedures.

Alternative techniques

  • Medical treatment of Grade 3 and 4 rectal tears:
    • Repeated manual evacuation of feces from tear.
    • Repeated epidural anesthesia.
    • Laxative diet.
    • Broad spectrum bactericidal antibiotics.

Time required

Preparation

  • Epidural anesthesia: 15-20 min.
  • General anesthesia induction and maintenance: 20 min.
  • Aseptic preparation: 10 min.

Procedure

  • Suturing: dependent on accessibility and size of tear: about 60 min.
  • Temporary rectal liner: at least 1 h.

Decision taking

Criteria for choosing test

  • Size, position and age of injury and whether peritonitis present: see alternatives.

Risk assessment

Requirements

Personnel

Veterinarian expertise

  • All potential methods of closure are difficult and advanced expertise is necessary for success.

Anesthetist expertise

  • For any procedure performed under general anesthesia Anesthesia: general - overview, an anesthetist with experience with horses that have the potential for hypotension and shock secondary to peritonitis is recommended.

Nursing expertise

  • Nursing expertise with the instrumentation and procedures used is quite helpful, as these procedures are not routine.

Materials required

Minimum equipment

Suturing

  • Per rectum:
    • Long-handled instruments.
    • Standard surgical kit.
    • Synthetic absorbable suture material.
  • Via laparoscopy:
    • Standard laparoscopic instrumentation and equipment.
    • Barbed suture may be of use.
  • Via laparotomy Abdomen: laparotomy:
Temporary indwelling rectal liner
  • Standard surgical kit.

Ideal equipment

Suturing
  • Per rectum:
    • Long-handled instruments with pistol grips.
    • 60 cm long expandable rectal speculum or 'cage'.

Minimum consumables

Suturing
  • Partial repair: antiseptic-soaked gauze sponges.
  • Non-visual repair: No. 5 Dacron, with a 6-8 cm half circle cutting or trocar point needle.
Temporary indwelling rectal liner
  • Rectal liner made from a 5 cm diameter plastic ring with No. 5 Dacron suture laced through holes in a central groove to form a circumferential anchor suture and a plastic rectal sleeve glued with Superglue and a rubber band to the other end of the central groove.
  • 2/0 absorbable suture material.
  • Same as Colostomy Colostomy.

Preparation

Pre-medication

Dietary preparation

Site preparation

Approach

Preparation

  • Suturing:
    • Per rectum: empty rectum of feces, taking care not to increase contamination of the wound.
    • Via laparotomy: same as ventral midline laparotomy Abdomen: laparotomy.
  • Temporary indwelling rectal liner: same as midline or flank laparotomy Abdomen: laparotomy.

Other preparation

Restraint

Suturing

Temporary indwelling rectal liner

Technique

Approach

  • Suturing - three alternatives:
    • Per rectum: insert hand through rectum to level of tear.
    • Via midline laparotomy: perform a ventral midline laparotomy Abdomen: laparotomy, close to brim of pelvis, to access damaged rectum.
      Access to tear may still be difficult if enclosed within mesorectum.
    • Prolapsing colon per rectum: perform a ventral midline laparotomy Abdomen: surgical approaches, close to brim of pelvis; pass hand through rectum and grasp a sponge (placed by an assistant via the laparotomy) through the colon wall; carefully apply traction on sponge to prolapse rectum through anus until the rectal tear is exposed (involves minimum tension on mesenteric vessels).
      This exposure is more readily achieved in thin horses
  • Temporary indwelling rectal liner: perform flank or midline laparotomy to expose rectal tear Abdomen: surgical approaches.

Core procedure

Step 1 - Repair the defect

  • Suturing: suture rectal tear using an inverting suture pattern and synthetic absorbable suture material.
  • Non-visual direct suturing technique:
    • Remove fecal material from the rectum and distal colon.
    • Wipe lumen of bowel with a dampened 4x4 cm gauze as far forward as possible.
    • Carefully clean defect by wiping; if defect is not complete use gently lavage using gravity flow.
    • If defect is potentially a Grade 4, assess degree of abdominal contamination, by palpation and/or endoscopy and clean area before deciding to continue.
      Suture tears on the left side with the right hand and tears on the right side with the left hand, however, this can be guided by surgeon's preference and expertise.
    • Dilate rectum with air (tie tail in vertical position).
    • Place needle halfway along a 100-150 cm length of suture material and hold both ends outside while the guarded needle is passed up the rectum.
    • First bite: hold the needle between the thumb and first two fingers and pass the needle about 1.5 cm from the edge at the center of the caudal border of the tear, guiding the needle through the subserosa with the second or third fingers.
    • Pull needle through only enough to enable placement in the proximal edge of the wound, aiming to exit 1.5 cm from the edge.
      Use the third finger of the suturing hand to push the tissue of the proximal edge onto the needle.
    • Withdraw the needle in the guarded hand from the rectum and pull one side of the double strand through the wound. Clamp the distal end of the suture with a hemostat (pass it to an assistant), leaving the proximal end attached to the needle.
    • Slide the needle along the suture strand and into the rectum. Place traction on the suture to bring the edges of the defect together.
    • Pass needle through both caudal and cranial edges in one movement. Pull needle through the tissues and bring it outside the rectum.
    • Release hemostat and pull up the two suture ends - this creates a cruciate suture.
    • Form the knots outside the rectum and push down tight with one hand inside the rectum. 4-6 throws are necessary.
      Use this first suture to stabilize the defect during placement of subsequent sutures.
    • If defect has not formed a transverse plane, suture from the cranial extent of the defect caudally.
    • Once all sutures are placed (usually 3-5 in total), cut them to different lengths to enable later identification.
      Leave suture ends long and protruding outside the rectum if horse's diet will keep the feces soft and unformed; cut them short near the knot if normally formed fecal balls are anticipated.
  • Temporary indwelling rectal liner: get an assistant to gently pass ring of liner through anus.
  • Surgeon should position the ring via the laparotomy incision, proximal to tear but distal enough for liner to extend beyond rectum.

Step 2 - Tie suture around rectal liner

  • Temporary indwelling rectal liner: pass absorbable suture material around the colon and tie tightly into groove on ring to constrict the serosal surface.

Step 3 - Place retention sutures for liner

  • Temporary indwelling rectal liner: place 4 equidistant, interrupted retention sutures through the colon wall to include this circumferential suture and the Dacron anchor suture in the ring.
  • Suture the colon wall over these sutures with 2/0 absorbable suture material in a Lembert pattern (the ring and circumferential suture will slough at 9-12 days leaving this anastomosis).

Exit

Step 1 - Close sutures and empty bowel 

  • Suturing: partial closure: antiseptic-soaked gauze should be used to pack the rectum up to 10 cm cranial to the remaining defect and held in place by closing the anus with a purse-string suture or towel clamps/forceps.
  • In Grade 3 or 4 tears or partial closure (or where wound is left to heal by secondary intention): a diverting procedure, eg rectal liner or colostomy should be performed after suturing to allow healing.
  • Temporary indwelling rectal liner: evacuate the large colon via a pelvic flexure enterotomy.

Step 2 - Flush small colon

  • Temporary indwelling rectal liner: pass a stomach tube retrograde up the sleeve and flush small colon with water.
  • Instill 4 liters of mineral oil (liquid paraffin Liquid paraffin) into the right dorsal colon.

Aftercare

Immediate Aftercare

Monitoring

  • ​Monitor closely for signs of shock (tachycardia, tachypnea, cool extremities, change in mentation, change in gum color, increased capillary refill time).
  • Monitor for signs of laminitis Foot: laminitis.

Fluid requirements

General Care

Analgesia

Antimicrobial therapy

Other medication

  • Feed low-bulk, laxative diet, eg complete pelleted ration, grass or water-soaked grass pellets.
  • Administer laxatives via nasogastric tube as required to prevent straining and fecal impaction.
  • Assess suture line 24-48 h later for looseness and replace any as necessary.
Temporary indwelling rectal liner
  • Maintain horse in a standing position until rectal tear heals, eg cross-tie: liner may retract into rectum if horse lies down.

Potential complications

  • Abscess formation at wound site: break down manually; flush abscess cavity daily with dilute antiseptic solution; pack with antiseptic-soaked gauze.

Long term Aftercare

Follow up

  • Healing takes 4-6 weeks.

Outcomes

Complications

  • Fecal contamination in mesorectum/retroperitoneal space can → cellulitis Cellulitis → infection of peritoneal cavity (peritonitis Abdomen: peritonitis, abdominal abscesses) and tissue necrosis.
  • Cellulitis Cellulitis/abscess formation can extend to medial aspect of thigh and testicles → toxemia → death.
  • Abnormal healing can → :
    • Rectal stricture.
    • Mucosal/submucosal hernia → fecal impaction (Grade 3 or 4 tears).
    • Rectoperitoneal fistula (Grade 4 tear).
  • Laminitis Foot: laminitis.
  • Adhesions → recurrent intestinal obstruction.

Reasons for treatment failure

Temporary indwelling rectal liner

  • Fecal contamination of tear before liner inserted.
  • Tearing of liner.
  • Liner retracting into rectum exposing tear.

Prognosis

  • Guarded: depends upon site, age and severity of tear and promptness of medical and surgical treatment.
  • Poor: Grade 4 tears can be rapidly fatal.
  • Increased survival with rectal suturing.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Stewart S G, Johnston J K & Parente E J (2014) Hand-assisted laparoscopic repair of a grade IV rectal tear in a postparturient mare. JAVMA 245 (7), 816-820 PubMed.
  • Claes A, Ball B A, Brown J A & Kass P H (2008) Evaluation of risk factors, management, and outcome associated with rectal tears in horses: 99 cases (1985-2006). JAVMA 233 (10), 1605-1609 PubMed.
  • Kay A T, Spirito M A, Rodgerson D H & Brown S E II (2008) Surgical technique to repair grade IV rectal tears in post-parturient mares. Vet Surg 37 (4), 345-349 PubMed.
  • Eastman T G et al (2000) Treatment of grade 3 rectal tears in horses by direct suturing per rectumEquine Vet Educ 12 (1), 32-34 VetMedResource.