Surgical Complications and Post-Operative Care

Routine postoperative care

• Horses are typically continued on flunixin meglumine at doses ranging from 0.25 mg/kg iv TID to 1.1 mg/kg iv BID. The  lower doses are anti-endotoxic but not anti-inflammatory.
• Antibiotics may be administered for 3-5 days if an enterotomy was performed or if the horse is being treated for a known infection.
• Horses are gradually reintroduced to feed using bran or green grass rather than hay to minimize intestinal blockage. Feeding does stimulate intestinal motility and and feeds the enterocytes. Horses are not usually fed grain but are put back on their hay ration over a 48+ hour period.
• IV fluids are given until the horse is able to drink sufficiently. It is important to remember that horses may not drink much while on iv fluids but should not be refluxing and should be normally hydrated.
• Horses are typically exercised when possible to further encourage motility
• Monitoring includes vital signs (temperature should be taken when flunixin is due to minimize the risk of masking fever), gut sounds, incisional status, appetite and attitude.

If horses did not have an enterotomy performed, the  recovery period can be relatively rapid and horses are ready to go home in 3-4 days. If the horse has complications, it can be 1-2 weeks before it is ready for discharge.

Postoperative colic complications

•  Postoperative ileus (reflux)
  • Risk Factors: Small intestinal lesions, torsions
  • Prevention: Early referral, minimize tissue handling during surgery, post-operative analgesics and anti-inflammatories such as Banamine and lidocaine CRI.
    • Lidocaine seems to work by resetting the motility patterns. Use it for a maximum of 24 hours and then discontinue.
  • Treatment: Iv lidocaine CRI (constant infusion) for 24 hours. Additional prokinetics such as metoclopramide, erythromycin and neostigmine have been used with variable efficacy across studies. Early feeding is considered beneficial but has to be balanced with trauma to any enterotomy incision.
•  Diarrhea
  • Risk Factors: Large colon lesions (volvulus, sand impactions, enteroliths), small colon lesions, Salmonellosis
    • Many horses carry Salmonella but do not show clinical signs or shed Salmonella unless stressed; colic surgery can be that stressor
    • We often are concerned about Salmonella if the horse is leukopenic, febrile and has diarrhea. Those can be seem postoperatively without Salmonellosis but it is safer to treat the horse as if it is Salmonella positive.
    • Antibiotic associated diarrhea may be present in some cases. GI microbiota changes with colic, colic surgery and with antibiotic administration
  • Prevention: One study showed administration of Biosponge for three days reduced the risk of post-op diarrhea in horses undergoing large colon colic surgeries
  • Treatment : Supportive care (fluids, laminitis support). Kaolin pectate or other antiendotoxic agent may be given.  Fecal cocktails may be given to replace flora if indicated.
• Endotoxemia / SIRS
  • Risk Factors: Strangulating lesions
  • These horses can often be very sick after surgery and require intensive care and management.
  • Clinical signs include tachycardia, elevated respiratory rates, toxic mucous membranes and/or fever. Laminitis is often a complication.
  • Prevention: Early referral, aggressive treatment with antibiotics, polymyxin B and plasma
  • Treatment: Polymyxin B (usually given intraoperative if risk is high). The treatment is not usually repeated due to the renal toxicity associated. Plasma infusions can help as can flunixin meglumine.
•  Laminitis
  • Risk Factors: Strangulating lesions, endotoxemia, SIRS
  • Prevention: Early referral, antimicrobial therapy, anti-endotoxin drugs (polymyxin-B, plasma), ice boots (variable evidence for the efficacy of ice boots), heparin.
    • Damage occurs well before you see signs of laminitis. Assume the worst.
  • Treatment – foot support, endotoxin binding, and careful (not overloaded fluids)
• Adhesions
  • Risk Factors: Being a horse, small intestinal surgeries, resection and anastomosis
  • Prolonged elevations of acute-phase proteins or fibrinogen levels may be identified
  • Prevention: Early surgery, careful intraoperative bowel handling and lavage
  • Treatment: Several techniques have been proposed with variable efficacy including: peritoneal lavage, 1% high molecular sodium carboxymethylcellulose (SCMC, belly jelly), hyaluronate/SCMC sprays or membranes
• Incisional infections
  • Risk Factors: Clean contaminated surgeries, environmental contamination
  • Prevention: Aseptic surgical techniques, adherence to appropriate antimicrobial therapy pre- and post-op, placement of a stent bandage over the incision during recovery
  • Watch for asymmetrical or worsening swelling near the incision, pain near the incision, drainage from the incision and fevers.
    • Differentiate from normal postoperative edema. Edema is cool, nonpainful and migrates forward. The lowest part is usually at the sternum. Too much edema can put stress on the incision line. Walking or belly wraps may help.
  • Treatment: Open the incision to allow drainage by removing a suture or part of the suture line. Antibiotics are not usually needed if drainage is obtained.
• Incisional dehiscence
  • the incision comes open and intestines may or may not come out too (eventration)
  • often fatal
  • can be associated with rough recoveries, distended intestines in recovery, low serum protein, incisional infections and relaparotomies
  • Treatment: repair under general anesthesia, typically with wire suture
• Incisional hernias
  • Risk Factors: Incisional infections, repeat laparotomy
  • Prevention: Belly bandage or hernia belt may be beneficial. Restrict “bouncing” for the first 60 days after surgery.
    • Sutures tend to last about 30 days and it takes the body wall 60 days to regain strength.
  • Treatment: Repair if indicated (most do not need it), once a good hernial ring is formed
• Postoperative peritonitis
  • Can be related to the colic cause or to contamination at surgery; drains used to flush the abdomen can also be a source of ascending infections
  • Treatment: Abdominal lavage and iv antibiotics
• Continued or recurrent pain
  • Signs of significant or severe pain is not common postoperatively. Usually severe pain indicates ongoing damage, adhesions, and/or ileus
  • Treatment : nasogastric intubation to relieve fluid, treatment for ileus; repeat laparotomy

Prognosis

This is highly dependent on the type of colic, severity of disease, and post-operative complications.  Most studies have combined large and small intestinal lesions together when estimating prognosis and survival rates.

For horses allowed to recover from anesthesia, short term survival rate for small intestinal surgeries has been reported to by 68% to 100%.

Long term prognosis is approximately 85% for all surgical colics combined. Almost all horses discharged from the hospital return to training  and 65-84% achieved the same or better performance.

Age is not associated with an increased risk of post-operative complications.  Horses with concurrent diseases such as PPID may have an increased risk of infection or delayed healing. Older horses with strangulating lesions do not live as long as younger horses or older horses with simple displacements.

Horses with Salmonella had a higher rate of surgical wound infections, weight loss and death while in hospital.

Post-Operative Care

In non-complicated colic surgeries (often large colon displacements or impactions), horses will be maintained on intravenous antibiotics perioperatively and analgesics for 72 hours.  During this time, if there is no signs of post-operative colic or reflux, they will be slowly re-fed and monitored for colic signs.

Average regimen after discharge

• First 30 days: Stall rest with hand walking the first 30 days after surgery. Hand walking, 10 minutes per walk, and hand grazing if grass is available, is recommended 3 to 4 times daily.
• 30 to 60 days: Round pen or small paddock self-exercise is permissible from day 30 to day 60 after surgery if the incision is healing well. If a round pen or small paddock is not available, increase the time hand walking.
  • Malone keeps them stall rested for 60 days. We typically close with Vicryl which loses strength about day 28. Since the body wall takes 60 days to regain strength, she worries that they will over-exercise if turned out.
• 60 to 90 days: Gradually return to normal activity from day 60 to day 90 after surgery. If postoperative complications occurred, especially in the incision, additional rest is recommended.

Resources

Critical care of the colic patient, Vet Clin Equine 39 (2023) 287–305

Basic Postoperative Care of the Equine Colic Patient, Vet Clin Equine 39 (2023) 263–286

Long-term outcome after colic surgery, Front. Vet. Sci., 04 October 2023 Sec. Veterinary Surgery Volume 10 – 2023 |

Fifty Years of Colic Surgery; Equine Veterinary Journal 50 (2018) 423–435

Influence of Salmonella status on the long-term outcome of horses after colic surgery. Veterinary Surgery. 2017;46:780–788.

Prognostic Value and Development of a Scoring System in Horses With Systemic Inflammatory Response Syndrome. J Vet Intern Med 2017;31:582–592

Factors associated with survival of horses following relaparotomy. Equine Veterinary Journal 2016; 49 (2017) 448–453

Prevention of post operative complications following surgical treatment of equine colic: Current evidence. Equine Veterinary Journal 48 (2016) 143–151