EQUINE VETERINARY EDUCATION / AE / MARCH 2012 109 Case Report Extraperitoneal incisional abscess formation after colic surgery in 3 horses L. M. Rubio Martínez*, N. C. Cribb and J. B. Koenig Department of Clinical Studies, Ontario Veterinary College, University of Guelph, N1G 2W1 Guelph, Ontario, Canada. Keywords: horse; colic; surgery; incision; infection; abscess Summary et al. 2010). Horses with wound infections typically present with gross drainage of purulent material from the wound In this article we report 3 horses that developed an associated with swelling, heat and pain around the skin extraperitoneal abscess after colic surgery at the incision incision (Mair and Smith 2005; Coomer et al. 2007). site. All 3 horses presented with nonspecific clinical signs Removal of the skin and subcutaneous sutures is usually and extraperitoneal abscess was diagnosed from performed to provide adequate drainage since the ultrasound evaluations and cytological examination of infection appears to be localised within the superficial abscess aspirates. One horse developed dehiscence of layers (Dukti and White 2008). In this study 3 cases that the incision after drainage of the abscess through the developed incisional infections in the form of an incision. In 2 cases a small standing paramedian incision extraperitoneal abscess after colic surgery are reported. was performed through which the abscess was drained Extraperitoneal abscess formation is a previously and lavaged; complete resolution of the abscess and unreported incisional complication after colic surgery in healing of the incision was achieved in both cases. horses. Extraperitoneal abscess is a previously unreported incisional complication after colic surgery in horses. Early Case 1 and careful ultrasonographic examination of the abdominal incision is required for diagnosis in cases with A 3-year-old Thoroughbred stallion with a 2 day history of a nonspecific clinical signs. A paramedian incision through complete, displaced, lateral condylar fracture of the right the rectus abdominis muscle into the abscess cavity third metacarpal bone was placed under general permitted adequate drainage and debridement of the anaesthesia and underwent surgical repair using abscess in 2 cases. arthroscopic and fluoroscopic guidance at the Ontario Veterinary College Teaching Hospital (OVCTH). The horse Introduction showed mild colic signs the day following surgical repair and rectal examination revealed a severely distended Surgical wound infection following exploratory laparotomy caecum occupying the right caudal half of the abdomen is a well recognised cause of post operative morbidity in and extending into the left side. The ventral caecal band equine colic surgery. Consequences of wound infection was extremely taut and food material and gas were include pain to the horse, further cost to the client and palpated inside the caecum. A severe caecal impaction increased risk of herniation (Gibson et al. 1989; Ingle-Fehr was diagnosed. An exploratory laparotomy was et al. 1997; French et al. 2002). Several studies have performed and caecal contents evacuated via a previously investigated the prevalence and risk factors typhlotomy. The abdomen was clipped under general predisposing horses to wound complications including anaesthesia and chlorhexidine soap used to scrub the incisional infections (Phillips and Walmsley 1993; Freeman ventral abdomen for 5 min or more until it was visibly et al. 2000; Mair and Smith 2005; Coomer et al. 2007; Torfs spotless on a clean white laparotomy sponge. This was followed by cleaning of the abdomen with ethanol, *Corresponding author email: [email protected]. Present followed by one preparation with ethanol-based address: Department of Companion Animal Studies, University of chlorhexidine gluconate followed by ethanol. Once the Pretoria. Private Bag X04 Onderstepoort 0110, Republic of South Africa. This work was presented as a poster at the 2010 European College of horse was moved into the operating theatre another Veterinary Surgeons Meeting in Helsinki, July 2010. preparation of the abdomen with ethanol-based © 2011 EVJ Ltd 110 EQUINE VETERINARY EDUCATION / AE / MARCH 2012 chlorhexidine gluconate followed by ethanol was performed. The ventral abdomen was draped following routine 4 corner double draping with an iodophor impregnated incise drape (Ioban)1 applied over the BW surgical field inbetween both draping layers. A ventral midline approach to the abdomen was performed; a No. 22 scalpel blade was used to incise the skin and subcutaneous tissue and after haemostasis was applied by coaptive electrocoagulation, the linea alba was carefully entered at the umbilical scar with a fresh No. 10 scalpel blade. The abdominal incision was extended cranially along the midline using a scalpel blade after digital Absc LC dissection of the extraperitoneal fat located dorsal to the linea alba. A sterile plastic drape was placed over the abdomen and the peritoneum opened with blunt finger dissection. After completion of the surgery, a 30 Fr abdominal drain (Mushroom drain)2 was placed Spleen approximately 10 cm lateral to the incision on the right side at the most ventral point of the abdomen. This drain was placed for post operative lavage of the abdominal cavity Fig 1: Transverse ultrasonographic image at the cranial aspect of the ventral midline incision from Case 1 (right to right). Note the as a standard procedure after typhlotomy by the large mixed heterogenic structure located dorsal to the linea alba operating surgeon. The abdominal incision was closed in a (BW: body wall; Absc: abscess; LC: large colon; Arrow: midline). simple continuous suture pattern using No. 2 polyglactin 910 (coated Vicryl)3, the subcutaneous tissue was closed in a simple continuous pattern using No. 2/0 glycomer 631 unremarkable and the horse was ambulating (Biosyn)4 and skin closed with No. 2/0 polypropylene in a comfortably on the affected limb. No swelling was simple continuous suture pattern (Surgipro)3. For recovery, evident at the ventral abdominal incision which was not sterile gauze and a fresh iodophor impregnated incise painful to the touch; however, a small amount of drape (Ioban)1 were applied over the incision. After the serosanguineous discharge was noted at the cranial horse recovered uneventfully from anaesthesia the incise aspect of the abdominal incision. An abdominal drape was removed and an abdominal bandage ultrasound examination was performed on the 8th post consisting of sterile towels over the incision held in place operative day and revealed the presence of an with roll gauze and adhesive bandage material applied. approximately 10 ¥ 10 cm large mixed heterogenic Treatment with sodium penicillin (22,000 iu/kg bwt i.v. q. structure located dorsal to the linea alba at the cranial 6 h), gentamicin (6.6 mg/kg bwt i.v. q. 24 h) and aspect of the abdominal incision (Fig 1); this was located phenylbutazone (4.4 mg/kg bwt, i.v. q. 12 h) had been cranial to the abdominal drain site. Several small started before fracture repair. This treatment was hypoechoic areas were also found just dorsal to the linea continued after colic surgery but anti-inflammatory alba at the middle part of the incision. No free fluid was therapy was substituted with flunixin meglumine (1.1 mg/kg noted within the abdomen and the intestines had normal bwt i.v., q. 12 h). After colic surgery, the stallion was also wall thickness and adequate motility. The abnormal administered heparin (40 iu/kg bwt s.c., q. 8 h), findings seemed to be separate from the abdominal metronidazole (15 mg/kg bwt, q. 6 h per rectum) and a cavity even though a distinct wall was not evident at the constant rate infusion of metoclopramide (0.04 mg/kg dorsal limits of the mass. No purulent drainage was bwt/h, i.v.). Abdominal lavages were performed with 15 l observed upon removal of part of the skin sutures. A of lactated Ringers’ solution through the abdominal drain complete blood cell count showed mild leucocytosis every 12 h during the first 24 h after surgery; after that time (11.1 ¥ 109 cells/l; ref: 5.1–11.0 ¥ 109 cells/l) with mild the drain was removed. Heparin was also discontinued mature neutrophilia (8.99 ¥ 109 cells/l; ref: 2.8–7.7 ¥ 109 after 24 h. Food was gradually reintroduced over the cells/l). No other remarkable findings were noted on following days after surgery without complications. physical examination. Findings were consistent with the formation of an abscess or organising haematoma in the Case progression extraperitoneal space. An aspirate sample was collected from the mass and cytological examination revealed the No abnormal findings were observed in the horse’s presence of mixed rods and cocci as well as a large clinical examination and demeanour during the post number of toxic neutrophils. Abdominocentesis was not operative period until the 7th post operative day when performed due to the lack of abnormal findings and free the horse developed pyrexia (40.2°C) and was quieter fluid within the rest of the abdomen. A final diagnosis of than normal. The surgical area at the fracture site was an extraperitoneal abscess was made. © 2011 EVJ Ltd EQUINE VETERINARY EDUCATION / AE / MARCH 2012 111 the linea alba; a mushroom drain was not used in this case. Recovery from anaesthesia was uneventful and an BW abdominal bandage was not used in this case. BW Preoperatively, the horse was placed on sodium penicillin (22,000 iu/kg bwt i.v. q. 6 h), gentamicin (6.6 mg/kg bwt i.v. q. 24 h) and flunixin meglumine (1.1 mg/kg bwt i.v. q. 12 h) which were administered for 5, 6 and 4 days in total, respectively. Case progression Initially, good clinical progression was seen and the horse was sent home 6 days following surgery. Twelve days following surgery the horse was re-examined at the OVCTH 3.18 cm for mild colic signs of unknown aetiology which resolved without treatment.