Clinical presentation and short-term outcomes of dogs ≥15 kg with extrahepatic portosystemic shunts.

OBJECTIVE: To describe demographics, clinical presentation, shunt anatomy, clinical progression, and complications in large dogs ≥15 kg with single extrahepatic portosystemic shunts (EHPSS) treated with or without surgery. STUDY DESIGN: Multicenter retrospective (10 university hospitals, one private referral institution). ANIMALS: Dogs ≥15 kg (n = 63). METHODS: Medical records of dogs ≥15 kg diagnosed with EHPSS between January 01, 2005 and December 31, 2020 were reviewed. Dogs had a minimum follow-up of 90 days. Signalment, clinical signs, diagnostics, shunt anatomy, treatment interventions, and perioperative complications were assessed. RESULTS: Median age was 21.9 months (IQR: 9-36.8). The breed most represented was the Golden retriever (17/63 dogs). Portocaval (17/63) and splenocaval (15/63) shunt configurations were most common. Portal vein hypoplasia was noted in 18 imaging reports. Of the surgically treated dogs, 14/45 (35.6%) had short-term complications, and 3/45 (6.7%) had shunt-related deaths. Medical management was discontinued in 15/40 and reduced in 9/40 of surviving dogs who had surgical attenuation. All medically managed, nonattenuated dogs (18/18) were maintained on their original shunt-related medication regimens. CONCLUSIONS: Clinical presentation of dogs ≥15 kg with extrahepatic portosystemic shunts was similar to the more commonly reported small breed dogs. Surgical management of single EHPSS in large dogs ≥15 kg had similar clinical short-term outcomes as small breed dogs. CLINICAL SIGNIFICANCE: Clinicians should be aware that large breed dogs with EHPSS share similar characteristics and clinical outcomes to small breed dogs. The significance of the presence of a hypoplastic portal vein warrants further research. Surgical treatment is a viable option for large breed dogs with EHPSS.

Risk factors for intraoperative hemorrhage and perioperative complications and short- and long-term outcomes during surgical patent ductus arteriosus ligation in 417 dogs.

OBJECTIVE: To evaluate the short- and long-term outcomes of dogs undergoing surgical ligation for a left-to-right shunting patent ductus arteriosus (PDA), identify risk factors for intraoperative hemorrhage and intra- and postoperative complications, and report overall mortality rates. ANIMALS: 417 client-owned dogs undergoing surgical ligation for a left-to-right shunting PDA between January 2010 and January 2020. PROCEDURES: Data recorded included patient signalment, echocardiogram findings, intraoperative complications and mortality, postoperative complications, and short- and long-term outcomes. RESULTS: There was no association between age and risk of intraoperative hemorrhage (P = .7), weight and intraoperative hemorrhage (P = .96), or increasing left atrium-to-aortic (LA:Ao) ratio and intraoperative hemorrhage (P = .08). Intraoperative hemorrhage occurred in 10.8% of patients. Intraoperative mortality was 2%. Ninety-five percent of dogs experiencing intraoperative hemorrhage survived to discharge. Survival to discharge was 97%. One- and 5-year survival rates were 96.4% and 87%, respectively. CLINICAL RELEVANCE: Surgical ligation for a left-to-right shunting PDA is recommended due to the good long-term prognosis. Certain preoperative factors such as age, weight, and the presence and degree of mitral valve regurgitation had no detectable association with risks of intraoperative hemorrhage and, therefore, should not preclude surgical treatment for a left-to-right shunting PDA. Future studies are needed to further assess the association between increasing LA:Ao ratio and risk of intraoperative hemorrhage.

Staged mandibular lip flap for closure of a large palatal defect after maxillectomy in a dog.

OBJECTIVE: To report closure of an oronasal defect secondary to maxillectomy with a staged mandibular lip flap. STUDY DESIGN: Case report ANIMALS: One 9-year-old female spayed golden retriever. METHODS: A combined dorsolateral and intraoral approach was used to perform a central maxillectomy to excise a 2.4- × 2- × 2.7-cm oral osteosarcoma with 1-cm margins. A buccal mucosal flap was used to close the palatal defect but the site subsequently dehisced. A staged mandibular lip flap was performed to close the defect. An incision was made on the mandible at the intersection of the buccal mucosa and gingiva from the mandibular canine to the level of the commissure. A second incision was made 3 cm ventral to the lip margin. The flap pedicle was based at the commissure. The flap was rotated to cover the palatal defect from rostral to the canine tooth to the fourth premolar. A second procedure was performed 4 weeks after flap placement to desquamate the haired skin and transect the flap pedicle. RESULTS: Partial dehiscence at the caudal aspect of the flap occurred after the first revision. The defect was closed after pedicle transection on day 41, with acceptable cosmesis. The dog was eating canned food with no evidence of discomfort 159 days after the maxillectomy. Recurrence was noted on day 270 postoperatively. CONCLUSION: Closure of a large palatal defect with a staged mandibular lip flap led to good cosmesis and function.

Retrospective multicentric study comparing durations of surgery and anesthesia and likelihoods of short- and long-term complications between cats positioned in sternal or dorsal recumbency for perineal urethrostomy.

OBJECTIVE: To compare the durations of surgery and anesthesia and the likelihoods of short- and long-term postoperative complications between cats positioned in sternal recumbency versus dorsal recumbency for perineal urethrostomy (PU). ANIMALS: 247 client-owned cats that underwent PU between January 2004 and December 2015 at 6 veterinary teaching hospitals and 1 private veterinary referral hospital. PROCEDURES: Medical records were reviewed, and signalment, presenting complaints, previous history of urethral obstruction or PU, diet fed, medications administered, indication for PU, durations of surgery and anesthesia for PU, suture type and size, suture pattern for skin closure, and short- and long-term postoperative complications were recorded. Univariable and multivariable analyses were performed to identify differences in durations of surgery and anesthesia and the likelihoods of short- and long-term complications between cats positioned in sternal recumbency and those positioned in dorsal recumbency. RESULTS: Patient position was not associated with durations of surgery and anesthesia for PU, even if a concurrent cystotomy was necessary or the patient required repositioning from sternal to dorsal recumbency. Likewise, patient position was not associated with the likelihood of short- and long-term complications. CONCLUSIONS AND CLINICAL RELEVANCE: The observed lack of differences in outcomes between sternal and dorsal recumbency suggested that logistic considerations and personal preference can continue to guide veterinarians when positioning cats for PU.

Treatment of idiopathic chylothorax in dogs and cats: A systematic review.

OBJECTIVE: To evaluate the evidence published on the treatment of idiopathic chylothorax (IC) in small animals. STUDY DESIGN: Systematic literature review. SAMPLE POPULATION: Dogs and cats with IC. METHODS: A literature search was performed in three bibliographic databases in July 2018 for publications on IC in dogs and cats. Articles meeting criteria for inclusion were evaluated for treatment, survival, outcome data, and level of evidence (LoE) with a modified Oxford Level of Evidence (mOLE) and GRADE (Grading of Recommendations, Assessment, Development and Evaluations) system. RESULTS: Eleven of 313 identified articles met the inclusion criteria. Only one study was identified in dogs as having higher LoE by using the mOLE system, whereas no study was identified as such in either species with the GRADE system. Surgery was the primary treatment in all dogs and in 93% (68/73) of cats. Medical therapy was the primary treatment in 7% (5/73) of cats. The most common surgical treatment combined thoracic duct ligation (TDL) and subtotal pericardiectomy (SP; 40%; 34/84) in dogs and TDL in cats (51% [37/73]). CONCLUSION: The body of literature for IC treatment in small animals was limited to one higher LoE study in dogs and none in cats. No strong conclusion could be drawn regarding the effectiveness of any one surgical method in dogs or cats, and no evidence was found to support medical therapy as a primary treatment. CLINICAL SIGNIFICANCE: The best available evidence regarding the treatment of IC is published in dogs and provides some support for surgical treatment with either TDL + cisterna chyli ablation or TDL + SP. Additional evidence is required to confirm this finding.

Feline Perineal Urethrostomy: A Review of Past and Present Literature.

Urethral obstruction is a potentially fatal condition and in cases of recurrent obstruction or an identified cause that is refractory to medical management, a urethrostomy may be performed for definitive treatment. Perineal urethrostomy is the surgical creation of a permanent stoma in the wider pelvic urethra via anastomosis to the perineal skin. Diagnosis of the underlying cause of obstruction, proper perioperative treatment, and an understanding of the anatomy and surgical technique, are imperative to the success of this procedure. This review intends to highlight these aspects, as well as the common complications and expected prognosis to aid decision making in the management of these cases.

Frequency of Dehiscence in Hand-Sutured and Stapled Intestinal Anastomoses in Dogs.

OBJECTIVE: To determine the frequency of dehiscence of hand-sutured and stapled intestinal anastomoses in the dog and compare the surgery duration for the methods of anastomosis. STUDY DESIGN: Historical cohort study. SAMPLE POPULATION: Two hundred fourteen client-owned dogs undergoing hand-sutured (n = 142) or stapled (n = 72) intestinal anastomoses. METHODS: Medical records from 5 referral institutions were searched for dogs undergoing intestinal resection and anastomosis between March 2006 and February 2014. Demographic data, presence of septic peritonitis before surgery, surgical technique (hand-sutured or stapled), surgery duration, surgeon (resident versus faculty member), indication for surgical intervention, anatomic location of resection and anastomosis, and if dehiscence was noted postoperatively were retrieved. Estimated frequencies were summarized and presented as proportions and 95% confidence intervals (CI) and continuous outcomes as mean (95% CI). Comparisons were made across methods of anastomosis. RESULTS: Overall, 29/205 dogs (0.14, 95% CI 0.10-00.19) had dehiscence, including 21/134 dogs (0.16, 0.11-0.23) undergoing hand-sutured anastomosis and 8/71 dogs (0.11, 0.06-0.21) undergoing stapled anastomosis. There was no significant difference in the frequency of dehiscence across anastomosis methods (χ(2), P = .389). The mean (95% CI) surgery duration of 140 minutes (132-147) for hand- sutured anastomoses and 108 minutes (99-119) for stapled anastomoses was significantly different (t-test, P < .001). CONCLUSION: No significant difference in frequency of dehiscence was noted between hand- sutured and stapled anastomoses in dogs but surgery duration is significantly reduced by the use of staples for intestinal closure.

The effect of uniaxial cyclic tensile load on gene expression in canine cranial cruciate ligamentocytes.

OBJECTIVE: To determine the effects of uniaxial cyclic tensile load amplitude and duration on gene expression in cranial cruciate ligamentocytes cultured in monolayer. STUDY DESIGN: In vitro experimental study. ANIMALS: Adult dogs (n=9) weighing 20-35 kg. METHODS: Cranial cruciate ligaments (CCL, n=18) were aseptically collected, diced, digested using clostridial collagenase, and primary monolayer cultures were established. CCL cells were seeded at a concentration of 3 x 10(5) cells/mL onto a specialized collagen membrane. After 24 hours to allow attachment, ligamentocytes were subjected to 0%, 4%, or 8% uniaxial strain for 24 or 48 hours using a sinusoidal strain profile at 0.5 Hz. At the end of each time point, the ligamentocytes were harvested and analyzed for collagen 1 (COL1), collagen 3 (COL3), and matrix metalloproteinase-3 (MMP-3) gene expression using reverse transcriptase real-time polymerase chain reaction. RESULTS: Approximately 33% of CCL processed for this study yielded viable cell cultures compared with 100% of the medial collateral ligaments processed. For CCL cells under uniaxial strain, gene expression for COL1 was variable, but higher strains and longer time in culture resulted in increased COL1 expression. There were no significant differences found for COL3 at any time point or between strain regimens. In general, MMP-3 gene expression was increased early in tissue culture and at higher strains. CONCLUSIONS: COL1 and MMP-3 gene expression can be influenced by amplitude and duration of strain on CCL cells in monolayer culture. CLINICAL RELEVANCE: These data have implications for modeling and understanding canine cruciate ligament pathophysiology. In particular, MMP-3 could serve as a potential preventative or therapeutic target in cruciate disease.

Clinical comparison of a novel extracapsular stabilization procedure and tibial plateau leveling osteotomy for treatment of cranial cruciate ligament deficiency in dogs.

OBJECTIVE: To develop and test a novel extracapsular technique, TightRope CCL technique (TR), and compare its 6-month clinical outcomes to tibial plateau leveling osteotomy (TPLO) in dogs with cranial cruciate ligament (CCL) deficiency. STUDY DESIGN: Prospective clinical cohort study. ANIMALS: Medium, large, and giant breed dogs (n=47) with CCL deficiency. METHODS: Before clinical use, TR was evaluated by mechanical testing and the surgical technique was developed and evaluated in canine cadavers. For the clinical study, dogs were assigned to either TR (n=24) or TPLO (n=23) groups and the assigned technique performed after arthroscopic assessment and treatment of joint pathology. Postoperative management was standardized for both groups. Outcome measures were performed immediately postoperatively and up to 6 months after surgery and included complication types and rate, subjective measurement of cranial drawer and tibial thrust, subjective assessment of radiographic progression of osteoarthritis (OA), and function using a validated client questionnaire (6 months only). RESULTS: TR with a fiber tape suture had superior mechanical properties for creep, stiffness, yield load, and load at failure. Duration of anesthesia, total surgical time, and stabilization procedure (TR versus TPLO) were all significantly (P<.001) shorter for TR compared with TPLO. Complications requiring further treatment occurred in 12.5% of TR cases and 17.4% of TPLO cases. No significant differences were noted between groups for cranial tibial thrust, but cranial drawer was significantly (P<.05) lower in TR stifles at all postoperative time points. No significant differences were noted between groups for radiographic OA scores. No statistically or clinically significant differences were noted between TR and TPLO for scores for each of the client questionnaire categories. CONCLUSIONS: TR resulted in 6-month outcomes that were not different than TPLO in terms of radiographic progression of OA and client-evaluated level of function. TR was associated with shorter anesthesia and surgery times as well as a lower complication rate. CLINICAL RELEVANCE: The TR technique is safe and effective and can be considered an appropriate surgical option as part of the overall treatment plan for CCL deficiency in dogs.

Effects of growth factors on equine synovial fibroblasts seeded on synthetic scaffolds for avascular meniscal tissue engineering.

Across species, the avascular portion of the knee meniscus cannot heal spontaneously if severely injured. The most common treatment is meniscectomy which results in osteoarthritis. The objective of this study was to assess the fibrochondrogenic potential of equine fibroblast-like synoviocytes (FLS) seeded on scaffolds under the influence of growth factors in vitro to determine the potential of developing a novel cell-based repair strategy. Cultured FLS were seeded onto synthetic scaffolds in a rotating bioreactor under the influence of three growth factor regimens: none, basic fibroblast growth factor (bFGF) alone, and bFGF plus transforming growth factor (TGF-beta(1)) and insulin-like growth factor (IGF-1). Constructs were analyzed for mRNA expression and production of fibrochondroid extracellular matrix constituents. Type II collagen and aggrecan mRNA were significantly higher in growth factor-treated groups (p<0.05). Despite sub-optimal extracellular matrix production, FLS can exhibit fibrochondral characteristics and may have potential for cell-based tissue engineering for avascular meniscal regeneration.

Clinical anatomy and surgical repair of prepubic hernia in dogs and cats.

Prepubic hernia is a traumatic hernia in small animals, most often associated with severe trauma to the caudal abdomen. Common causes include vehicular trauma, dog fights, and kicks by large animals. Rupture of the prepubic tendon in dogs and of its equivalent in cats results in a ventral abdominal hernia. Due to the traumatic nature of the injury, concurrent injuries are frequently seen. Clinical signs of herniation are often nonspecific, and the resultant hernia may not be readily apparent during routine physical examination. This being so, diagnosis is often based on a thorough physical examination in conjunction with abdominal radiography and, possibly, abdominal ultrasonography. Multiple methods of repair of prepubic hernia have been reported, and survival rates are quite good if concurrent injuries are not severe.

Meniscal release in cruciate ligament intact stifles causes lameness and medial compartment cartilage pathology in dogs 12 weeks postoperatively.

OBJECTIVE: To evaluate after 12 weeks the effects of caudal medial meniscal release (MR) in the cranial cruciate ligament-intact canine stifle. STUDY DESIGN: Blinded, prospective in vivo study. ANIMALS: Purpose-bred hound dogs (n=10). METHODS: Either MR (n=5) or a sham (SH) surgery (n=5) was performed via arthroscopy. Orthopedic examination and subjective lameness evaluation were performed in each dog preoperatively and at 4, 8, and 12 weeks after surgery. Twelve weeks postoperatively, ultrasonographic, radiographic, and arthroscopic examinations were performed on the operated stifles. Gross pathology of the articular cartilage, cruciate ligaments, and menisci was assessed. India ink staining of the femoral and tibial articular surfaces was performed to determine the percent area of articular cartilage damage. RESULTS: At 8 and 12 weeks after surgery, MR dogs were lamer than SH dogs. At 12 weeks, the degree of radiographic OA was significantly higher in MR stifles than in SH stifles. Gross and sonographic meniscal pathology was more severe in MR stifles compared with SH stifles. MR stifles had significantly more severe articular cartilage pathology compared with SH stifles 12 weeks after surgery; pathology was most severe in the medial compartment. CONCLUSIONS: MR alone is associated with articular cartilage loss, further meniscal pathology, degenerative joint disease, and lameness. CLINICAL RELEVANCE: Subsequent osteoarthritis and dysfunction of the stifle joint should be considered when making clinical decisions regarding MR in dogs.

An in vitro model to assess mechanisms and efficacy of a cellular conduit for treatment of avascular meniscal injuries.

Tears in the avascular portion of the knee meniscus are commonplace and are frequently incapable of healing spontaneously. Delivery of synovial cells from the meniscal periphery to avascular injuries can result in an effective healing response but is difficult to accomplish surgically. This report describes the development of a novel in vitro model comprised of three-dimensionally cultured cells in agarose used to assess the proof of concept that a cellular conduit device could be used to facilitate the delivery of synovial fibroblasts from a cell source to a remote acellular recipient site. The results indicate that synovial fibroblasts are capable of migrating through a cellular conduit more optimally than a created trephined channel over a clinically relevant distance in response to a chemotactic gradient. This model proved to be a reliable way to assess fibroblast-like synoviocyte migration in a clinically relevant fashion for application to avascular meniscal tear healing methodologies, and provided mechanistic information regarding the successful in vivo testing of this specific biomedical device.