Intra-abdominal complications following intestinal anastomoses by suture and staple techniques in dogs.

OBJECTIVE To compare the incidence of intra-abdominal complications in dogs following resection and functional end-to-end stapled anastomosis (FEESA) versus anastomosis with an end-to-end sutured technique for treatment of enteric lesions. DESIGN Multicenter, retrospective descriptive cohort study. ANIMALS 180 dogs. PROCEDURES Medical records of dogs undergoing intestinal resection and anastomosis at 3 nonaffiliated private practice specialty centers were retrospectively reviewed. Preoperative clinical variables, indication for surgery, surgical technique (sutured end-to-end anastomosis vs FEESA), and evidence of postoperative anastomosis site leakage (dehiscence) were recorded. Variables of interest were analyzed for associations with dehiscence. RESULTS Dehiscence rates of sutured and stapled anastomoses were 12 of 93 (13%) and 4 of 87 (5%), respectively; odds of postoperative dehiscence were significantly lower for dogs with FEESAs than for dogs with sutured anastomoses (OR, 0.28; 95% confidence interval, 0.09 to 0.94). Among dogs that underwent surgery for treatment of intestinal dehiscence after surgery at another facility, subsequent dehiscence developed in 3 of 5 with sutured anastomoses and 0 of 11 with stapled anastomoses. Dehiscence rates varied significantly among clinics. No other variable was associated with risk of dehiscence. Eleven of 16 dogs with dehiscence were euthanized without additional surgery. Impaction at the anastomosis site was identified months or years after surgery in 3 dogs (4 anastomosis sites) that had FEESAs. CONCLUSIONS AND CLINICAL RELEVANCE Odds for dehiscence were significantly greater for sutured end-to-end anastomoses than FEESAs, and dogs undergoing surgery for previous dehiscence were significantly more likely to experience a subsequent dehiscence with a sutured anastomosis. However, variability of procedure types and dehiscence rates among clinics suggested further research is needed to confirm these findings. Obstruction at the anastomosis site was identified as a potential long-term complication of FEESA.

Wear testing of a canine hip resurfacing implant that uses highly cross-linked polyethylene.

Hip resurfacing offers advantages for young, active patients afflicted with hip osteoarthritis and may also be a beneficial treatment for adult canines. Conventional hip resurfacing uses metal-on-metal bearings to preserve bone stock, but it may be feasible to use metal-on-polyethylene bearings to reduce metal wear debris while still preserving bone. This study characterized the short-term wear behavior of a novel hip resurfacing implant for canines that uses a 1.5 mm thick liner of highly cross-linked polyethylene in the acetabular component. This implant was tested in an orbital bearing machine that simulated canine gait for 1.1 million cycles. Wear of the liner was evaluated using gravimetric analysis and by measuring wear depth with an optical scanner. The liners had a steady-state mass wear rate of 0.99 ± 0.17 mg per million cycles and an average wear depth in the central liner region of 0.028 mm. No liners, shells, or femoral heads had any catastrophic failure due to yielding or fracture. These results suggest that the thin liners will not prematurely crack after implantation in canines. This is the first hip resurfacing device developed for canines, and this study is the first to characterize the in vitro wear of highly cross-linked polyethylene liners in a hip resurfacing implant. The canine implant developed in this study may be an attractive treatment option for canines afflicted with hip osteoarthritis, and since canines are the preferred animal model for human hip replacement, this implant can support the development of metal-on-polyethylene hip resurfacing technology for human patients. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1196-1205, 2018.

Fracture repair using a polyaxial locking plate system (PAX).

OBJECTIVES: To report outcomes and complications of dog and cat fractures treated with the polyaxial locking plate system (PAX). STUDY DESIGN: Case series. ANIMALS: Dogs (n = 60) and 2 cats. METHODS: Medical records (December 2009-March 2011) of dogs and cats with fractures treated with the PAX system were reviewed. Cases with adequate follow-up to document a functional union, had surgery performed by an author, had no prior treatment of the fracture(s), and with complete operative records were included. Signalment, body weight, bone(s) fractured, area of bone fractured, fracture classification, concurrent orthopedic injuries, complications, time to functional union, if minimally invasive plate osteosynthesis (MIPO) techniques were used, plate size, number of plates, bone graft use, and ancillary methods of fixation were recorded. Additionally, fracture segment: plate length, screw, number of plate holes, number of empty screw holes overlying/adjacent to the fractures, number of cortices engaged above/below the fracture was evaluated. Variables were evaluated statistically for effect on complications and functional union. RESULTS: Sixty-two animals were included. Mean time to functional union was 7.1 weeks. Complications occurred in 12 animals (19%) and plate failure occurred in 3 (5%). Statistically significant factors that affected time to functional union were the presence of multiple injuries and age. Those associated with complications were double plates and number of cortices engaged above and below fractures. CONCLUSIONS: The PAX system allows for multidirectional screw insertion with an overall complication rate and time to functional union similar to other fracture repair implant systems.

Successful replacement of an obstructed ureter with an ileal graft in a cat.

CASE DESCRIPTION: A 10-year-old spayed female domestic shorthair cat with a 1-week history of vomiting, lethargy, and anorexia was examined. CLINICAL FINDINGS: Abdominal radiography and ultrasonography revealed that calculi and a nonpatent stricture obstructed the right ureter, which resulted in secondary dilatation of the ureter proximal to the obstruction and severe hydronephrosis. The left kidney was small and suspected to be failing. Concentrations of BUN and creatinine were elevated. Despite administration of fluids, azotemia persisted. TREATMENT AND OUTCOME: Surgery was performed. The obstructed right ureter was replaced with a vascularized segment of ileum. Azotemia resolved, and the cat improved with regard to clinical signs. The cat was clinically normal for > 36 months after the surgery. CLINICAL RELEVANCE: An ileal graft can successfully be used as a surgical option for ureteral obstruction in cats.

Radiographic and clinical changes of the tibial tuberosity after tibial plateau leveling osteotomy.

OBJECTIVE: To investigate radiographic changes of the tibial tuberosity after tibial plateau leveling osteotomy (TPLO) surgery and identify clinical findings and risk factors associated with such changes. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Hundred and eighty-six client-owned dogs (219 stifles) that had TPLO surgery. METHODS: Patient data retrieved included radiographic changes of the tibial tuberosity during re-examination, age, body weight, whether unilateral or single-session bilateral surgery had been performed, location of the anti-rotational pin, approximate tibial tuberosity area, and approximate average tibial tuberosity width. RESULTS: Fracture with resulting caudal displacement of the proximal tibial tuberosity (1.4%; 3 of 219) occurred less frequently than non-displaced tibial tuberosity fractures (7.3%; 16 of 219). Age, weight, average tibial tuberosity width, location of the anti-rotational pin, and single session bilateral surgery were identified as risks factors for non-displaced fracture. Weight divided by the square of the average tibial tuberosity width may be a stronger risk factor than either weight or average tibial tuberosity width alone. CONCLUSIONS: Dogs undergoing single session bilateral TPLO surgery are at greater risk for developing non-displaced tibial tuberosity fractures. The non-displaced tibial tuberosity fracture does not appear to adversely affect outcome or lead to tibial tuberosity avulsion. Significant risk factors for fracture of the proximal tibial tuberosity with caudal displacement were not identified. CLINICAL RELEVANCE: Factors including age, weight, tibial tuberosity thickness, and conditions that may enhance strain on the tibial tuberosity, such as single-session bilateral procedures, may increase risk of fracture.

Cardiopulmonary bypass in the cat.

OBJECTIVE: To assess the physiologic response to, and acute survival of, cats undergoing cardiopulmonary bypass (CPB) and to evaluate the efficacy of a commercial human pediatric oxygenator system on cats weighing less than 6 kg. STUDY DESIGN: Experimental study. ANIMALS: Six intact male cats METHODS: Cats were placed on cardiopulmonary bypass by cannulating the cranial and caudal vena cavae and the carotid artery. The pediatric CPB circuit was primed with 150 mL of a balanced crystalloid solution. Venous drainage was enhanced by a controlled, vacuum-assist system. A cross-clamp was placed on the ascending aorta and cardiac arrest was induced by antegrade infusion of a cold cardioplegia solution. After 45 minutes of arrest time, the cross-clamp was removed and the cats were weaned off bypass and decannulated. No blood products were administered. Heart rate, mean arterial pressure (MAP), central venous pressure, arterial blood gas, hematocrit (HCT), total plasma protein concentration (TP), serum electrolyte concentrations, and activated clotting time (ACT) were measured at baseline period (BL), during CPB, 60 minutes after CPB (CPB 60) and 90 minutes after CPB (CPB 90). A complete blood count (CBC), blood chemistry profile, and urinalysis were performed at BL, during CPB, and CPB 90. Cats were euthanatized after CPB 90. RESULTS: Cardiopulmonary bypass resulted in a significant (P <.05) decrease in mean HCT (18.0%) and TP (2.3 gm/dL) at CPB 90 when compared to BL (30.5% and 6.0 gm/dL, respectively). The MAP at CPB 90 (54 mm Hg) was decreased from BL (94 mm Hg). The ACT increased from a mean of 124 seconds to > 400 seconds with heparinization and was reversed to 300 seconds with protamine. Mean platelet counts decreased from BL (369,000 /microL) to CPB 90 (94,500 /microL). Mean white blood cell counts decreased from 13,200 /microL at BL to 2,200 /microL at CPB 90. Upon reperfusion, 1 cat fibrillated but was successfully defibrillated. CONCLUSIONS: Cardiopulmonary bypass was performed successfully in 6 cats weighing less than 6 kg. Acute survival to 90 minutes after CPB was achieved in all 6 cats CLINICAL RELEVANCE: The ability to perform CPB in the cat may allow intracardiac repair of various heart defects in this species.