Caval chemodectoma in a cat.

Case summary: An 11-year-old male neutered domestic shorthair cat was presented with a 4-week history of an intermittent cough and dyspnoea. A pleural effusion was identified, which was confirmed as chyle. Echocardiography and CT revealed a 16 mm mass cranial to the heart, which was invading the cranial vena cava. Because of the location of the mass, it was assumed that chylothorax had developed as a result of direct disruption of the thoracic duct by the tumour or secondarily to central venous hypertension. An exploratory thoracotomy was performed, and the mass, which originated within the wall of the cranial vena cava, was excised with narrow gross margins. Histopathology and immunohistochemistry were consistent with a chemodectoma with residual tumour cells at the surgical margin. Given the residual microscopic disease, adjuvant treatment with toceranib phosphate was initiated. The cat remained well for the duration of treatment and was euthanased 31 months after diagnosis when CT identified recurrent pleural effusion, a heart base mass with cranial vena cava and azygos vein invasion. Relevance and novel information: Chemodectomas are rare in cats, with only 13 cases reported in the literature to date, and all were located in either the aortic or carotid body. The reported survival with partial resection and/or subtotal pericardiectomy was 13-19 months. Treatment of feline chemodectomas with toceranib phosphate has not been previously reported. To our knowledge, this is the first description of the surgical management of a feline vena cava chemodectoma, combined with adjuvant toceranib phosphate, resulting in a prolonged survival.

Sinonasal mycosis following transfrontal craniotomy in three dogs.

CASE DESCRIPTION: Three dogs were presented for investigation of chronic nasal discharge and epistaxis 141, 250, and 357 days after undergoing transfrontal craniotomy to treat an intracranial meningioma (2 dogs) or a meningoencephalocele (1 dog). CLINICAL FINDINGS: CT findings were consistent with destructive rhinitis and frontal sinusitis in all 3 dogs, with results of histologic examination and fungal culture of samples obtained during frontal sinusotomy confirming mycotic infection. Frontal sinusotomy revealed fungal plaques covering a combination of bone and residual surgical tissue adhesive at the site of the previous craniotomy in all 3 dogs. Aspergillus spp were identified in all 3 dogs, and Chrysosporium sp was also identified in 1 dog. TREATMENT AND OUTCOME: Surgical curettage was followed by antifungal treatment (topical clotrimazole in 2 dogs and oral itraconazole for 3 months in 1 dog). Nasal discharge improved in the short-term but recurred in all dogs 99, 118, and 110 days after frontal sinusotomy. One dog received no further treatment, 1 dog received an additional 8.5 months of oral itraconazole treatment, and 1 dog underwent 2 additional surgical debridement procedures. At last follow-up, 2 dogs were alive 311 and 481 days after frontal sinusotomy; the third dog was euthanized because of status epilepticus 223 days after frontal sinusotomy. CLINICAL RELEVANCE: Sinonasal mycosis should be considered as a potential complication in dogs developing persistent mucopurulent nasal discharge, intermittent epistaxis, and intermittent sneezing following transfrontal craniotomy. The pathophysiology may be multifactorial, and potential risk factors, including use of surgical tissue adhesive in the frontal sinus, require further investigation.

Canine intrahepatic portosystemic shunt insertion into the systemic circulation is commonly through primary hepatic veins as assessed with CT angiography.

Congenital intrahepatic portosystemic shunts (IHPSS) in dogs are traditionally classified as right, left, or central divisional. There are few descriptive studies regarding the variation of IHPSS within these categories. This multicenter, analytical, cross-sectional study aimed to describe a large series of dogs with CT angiography (CTA) of IHPSS, hypothesizing that there would be variation to the existing classification. Ninety CTA studies were assessed for IHPSS type, insertion, and the relationship of the insertion to the primary hepatic veins. Ninety-two percent of IHPSS inserted into a primary hepatic vein (HV) or phrenic vein, 8% inserted directly into the ventral aspect of the intrahepatic caudal vena cava. The most common IHPSS type was a single right divisional (44%), including those inserting via the right lateral HV or the caudate HV. Left divisional IHPSS (33%) inserted into the left HV or left phrenic vein. Central divisional IHPSS (13%) inserted into the quadrate HV, central HV, dorsal right medial HV, or directly into the ventral aspect of the intrahepatic caudal vena cava. Multiple sites of insertion were seen in 9% of dogs. Within left, central, and right divisional types, further subclassifications can therefore commonly be defined based on the hepatic veins with which the shunting vessel communicates. Relating IHPSS morphology to the receiving primary HV could make IHPSS categorization more consistent and may influence the type and method of IHPSS attenuation recommended.

Variations in surgical technique for adrenalectomy with caudal vena cava venotomy in 19 dogs.

OBJECTIVE: To describe surgical techniques, caval occlusion times, and short-term outcomes in dogs undergoing adrenalectomy with caval venotomy. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs undergoing adrenalectomy with caval venotomy between October 1, 2010 and May 31, 2018. METHODS: Medical records of dogs undergoing adrenalectomy with caval venotomy were reviewed for signalment, perioperative management, surgical details, perioperative complications, mortality, and histopathology. Computed tomography images were reviewed to describe tumor morphology and signs of thrombus extension. RESULTS: Nineteen dogs had adrenal tumor thrombi extending into the prehepatic (14 dogs, 74%), hepatic (3 dogs, 16%), and posthepatic (2 dogs, 11%) caudal vena cava. Tumors occurred in left (11) and right (8) adrenal glands. Median caval occlusion was 6.5 minutes (range, 2-25). Two to six vascular tourniquets were used. Venotomy closure was performed under full caval occlusion in 11 dogs and by using a partial occlusion clamp in 8 dogs. Left ureteronephrectomy was performed in 5 dogs. Perioperative mortality rate was 21% (4 dogs). CONCLUSION: Extension of caval tumor thrombus beyond the hepatic hilus did not preclude a good outcome. Longer caval occlusion than has been previously reported was tolerated in some cases. Number of vascular tourniquets used reflected the location of phrenicoabdominal vein insertion on the cava and length of the caval tumor thrombus. Venotomy closure under full occlusion was often required for right adrenal tumors. When required, ureteronephrectomy was left sided. CLINICAL SIGNIFICANCE: Dogs with adrenal tumors extending beyond the hepatic hilus and those requiring a long caval occlusion time can survive adrenalectomy.

Association between hepatic histopathologic lesions and clinical findings in dogs undergoing surgical attenuation of a congenital portosystemic shunt: 38 cases (2000-2004).

OBJECTIVE: To review hepatic histopathologic lesions in dogs undergoing surgical attenuation of a congenital portosystemic shunt (CPSS) in relation to clinical findings and tolerance of complete surgical attenuation. DESIGN: Retrospective case series. ANIMALS: 38 dogs that underwent surgical attenuation of a CPSS. PROCEDURES: Hepatic histologic examination findings and medical records of dogs undergoing surgical attenuation of a single CPSS between August 2000 and July 2004 were reviewed. Liver biopsy specimens were obtained from 38 dogs during surgery prior to complete (n = 16) or partial (22) attenuation of a CPSS and from 13 of the same dogs a median of 3 months following surgical attenuation. RESULTS: Portal tracts were inadequate for interpretation in 2 liver biopsy specimens. Liver biopsy specimens obtained prior to surgical attenuation of a CPSS had a lack of identifiable portal veins (13/36 dogs), hepatic arteriolar proliferation (25/36), ductular reaction (5/36), steatosis (16/38), and iron accumulation (32/38). Lack of identifiable portal veins on histologic examination was associated with increased hepatic arteriolar proliferation, decreased tolerance to complete surgical CPSS attenuation, and decreased opacification of intrahepatic portal vessels on portovenography. Ductular reaction was always associated with failure to tolerate complete surgical attenuation of a CPSS. Surgical CPSS attenuation resulted in significant clinical, serum biochemical, and portovenographic changes indicative of improved liver function, but only subtle changes in hepatic histologic examination findings. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs without identifiable intrahepatic portal veins that had a ductular reaction on hepatic histologic examination were less likely to tolerate complete attenuation of a CPSS.

Clinical outcome following pneumonectomy for management of chronic pyothorax in four cats.

Pneumonectomy is the resection of all lung lobes from one side of the thorax. The clinical findings, treatment and outcome of four cases of feline chronic pyothorax managed with exploratory thoracotomy and pneumonectomy are reported. All cases were initially medically managed with thoracic drain placement and antibiosis. However, resolution was not achieved with medical therapy and diagnostic imaging findings consistent with an area of abscessation or marked lung lobe consolidation were identified, supporting a decision for surgical management. Surgical exploration was performed via median sternotomy and, on the basis of gross inspection, non-functional lung was removed. A left-sided pneumonectomy was performed in three cats and a right-sided pneumonectomy in one. All cases survived to discharge and an excellent quality of life was reported on long-term follow-up. Pneumonectomy appears to be well tolerated in the cat.

Vaginourethroplasty as a salvage procedure for management of traumatic urethral rupture in a cat.

This report describes a cat that suffered pelvic urethral rupture associated with multiple pelvic fractures. A vaginourethroplasty was performed as a salvage procedure, via intrapelvic anastomosis of the proximal urethra to the caudal vagina, following failure of a primary urethral anastomosis. Urinary diversion was achieved via tube cystostomy and a vagino-urethral catheter was maintained for 3 days postoperatively. Anterograde cystourethrography was performed at 7 days and 14 days postoperatively. Absence of contrast leakage from the vagino-urethral anastomosis was documented at 14 days postoperatively and the tube cystostomy was removed. An Escherichia coli urinary tract infection was treated following removal of the tube cystostomy and subsequent urine culture revealed no evidence of urinary tract infection. The cat retained normal urinary continence and elimination behaviour during the 7-month follow-up period. Vaginourethroplasty could be considered as a salvage option for management of traumatic pelvic urethral rupture in the neutered female cat.

Uterine rupture and septic peritonitis following dystocia and assisted delivery in a Great Dane bitch.

A Great Dane bitch was treated for presumed primary uterine inertia with repeated doses of oxytocin and manually assisted whelping. She was diagnosed with uterine rupture and septic peritonitis the following day. The uterine rupture is hypothesized to have occurred as a result of the management strategy used to treat dystocia. The dog underwent ovariohysterectomy, and the septic peritonitis was managed with open peritoneal drainage. The dog recovered well and was discharged 5 days later. No previous reports of canine uterine rupture associated with manual intervention appear to have been published. This report highlights the potential dangers involved in such an approach.

Partial right ventriculectomy using the incised patch technique to treat double chambered right ventricle and chylothorax in a cat.

OBJECTIVE: To report successful surgical treatment of double chambered right ventricle (DCRV) in a cat. STUDY DESIGN: Clinical report. ANIMALS: Cat with DCRV. METHODS: DCRV was diagnosed in a 5-month-old male Maine Coon cat using echocardiography and angiocardiography. At 2 years, despite medical therapy, chylothorax developed. A section of the right ventricular free wall that spanned the fibromuscular obstruction was excised under total venous inflow occlusion (TVIO) using the incised pericardial patch technique. RESULTS: Short-term recovery was complicated by return of chylothorax but this resolved after thoracocentesis and diuretic therapy. Three years after surgery, the cat is free of clinical signs and no longer on any medical therapy. CONCLUSIONS: Partial right ventriculectomy can be performed under TVIO through an incised pericardial patch. CLINICAL RELEVANCE: DCRV in cat can be successfully treated by partial right ventriculectomy performed under TVIO through an incised pericardial patch.

Separation of the auricular and annular ear cartilages: surgical repair technique and clinical use in dogs and cats.

OBJECTIVE: To report a surgical technique for primary repair of separation of the annular and auricular cartilages of the ear and long-term outcome. STUDY DESIGN: Case series. ANIMALS: Cats (3) and dogs (2) with ear canal separation. METHODS: Medical records (1998-2007) of dogs and cats with ear canal separation were reviewed. Long-term outcome was obtained by telephone interview of owners or referring veterinarians. RESULTS: Three cats and 1 dog had ear canal separation after being hit by a car; there was no history of trauma in 1 dog. Successful repair was achieved by a caudal approach to the ear canal, identifying and debriding separated cartilage edges and using primary repair. A patent ear canal was confirmed in all animals by otoscopy 4-12 weeks later and by ear canalography in 3 animals. Long-term outcome was excellent with no reported complications 10-90 months later (median 24 months). CONCLUSIONS: Both acute and chronic separation between the annular and auricular cartilages, in the absence of middle ear disease, can be successfully treated using primary repair via a caudal approach to the ear canal, with excellent long-term outcome. CLINICAL RELEVANCE: Primary repair should be considered in animals with separation of the annular and auricular cartilages.

Association of mesenteric portovenographic findings with outcome in cats receiving surgical treatment for single congenital portosystemic shunts.

OBJECTIVE: To determine whether hepatic portal vascularity assessed via intraoperative mesenteric portovenography (IMP) is related to outcome in cats undergoing surgical attenuation of a congenital portosystemic shunt (CPSS). DESIGN: Retrospective case series. ANIMALS: 25 cats, each with 1 CPSS, in which IMP was performed before and after temporary complete occlusion of the shunting vessel to provide complete (n=9) or partial (16) shunt attenuation. PROCEDURES: Medical records were reviewed for signalment, clinical history, postoperative complications, clinical outcome, and results of bile acids stimulation testing. Portovenograms obtained before and after shunt occlusion were graded to determine whether degree of intrahepatic portal branching was correlated with degree of shunt attenuation, clinical or biochemical factors, postoperative complications, or outcome. In 12 of the 16 cats that had partial CPSS attenuation, procedures were later repeated to achieve complete (n=9) and additional partial (1) CPSS attenuation. RESULTS: Degree of opacification of the intrahepatic portal vessels increased significantly (higher portovenogram grade) after CPSS attenuation. The median portovenogram grade assigned after temporary shunt occlusion at the first surgery was significantly higher in cats that did not have postattenuation neurologic complications or neurologic signs at follow-up than in cats that did. It was also higher in cats that had a better clinical response to surgery versus those that had a poor response and in cats with reduced preprandial and postprandial serum bile acids concentrations at follow-up versus those that did not. CONCLUSIONS AND CLINICAL RELEVANCE: IMP may be used to help predict complications and outcome following surgical treatment of CPSS in cats.

Long-term palliation of tetralogy of Fallot in dogs by use of a modified Blalock-Taussig shunt.

OBJECTIVE: To describe a modified Blalock-Taussig shunt (mBT) procedure and assess its use in dogs with clinical signs associated with tetralogy of Fallot (TOF). DESIGN: Descriptive report. ANIMALS: 6 dogs with severe TOF-associated clinical signs. PROCEDURES: Each dog had TOF (confirmed echocardiographically or angiographically) and underwent an mBT shunt procedure for surgical palliation of signs. The surgery was performed through a left fourth rib resection or a left fifth intercostal thoracotomy. The left subclavian artery was dissected free from surrounding mediastinal tissue. The main pulmonary artery trunk was exposed through an incision in the overlying pericardium. A shunt comprised of a 6-mm-diameter tube of expanded polytetrafluoroethylene (5 dogs) or a segment of carotid artery (1 dog) was sutured end to side between the left subclavian artery and pulmonary artery trunk. RESULTS: 5 of the 6 dogs survived the immediate postoperative period. The dog that died shortly after surgery was the smallest of the dogs (weight, 2.9 kg [6.38 lb]) and had received the carotid artery autograft. Three dogs survived long term and 2 dogs died of unknown causes 6 years after undergoing the mBT shunt procedure. In all dogs that survived the mBT procedure, shunt patency was confirmed and quality of life appeared improved. CONCLUSIONS AND CLINICAL RELEVANCE: These findings have suggested that the mBT shunt procedure safely provides long-term palliation of TOF-associated clinical signs in dogs. In addition, it may offer an effective low-risk and lower-cost alternative to open heart repair of TOF.

Use of a latissimus dorsi myocutaneous flap for one-stage reconstruction of the thoracic wall after en bloc resection of primary rib chondrosarcoma in five dogs.

OBJECTIVE: To describe a thoracic wall reconstructive technique using a latissimus dorsi myocutaneous flap after en bloc resection of primary rib chondrosarcoma and report outcome in 5 dogs. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=5) with primary rib chondrosarcoma. METHODS: Medical records (2003-2005) were reviewed for signalment, staging investigations, surgical findings, complications, and outcomes. Owners and veterinary surgeons were contacted for outcome information. RESULTS: A latissimus dorsi myocutaneous flap provided an air-tight thoracic wall closure after chondrosarcoma resection. Paradoxical respiratory movement of the flap occurred; however, from physical examination and blood gas analysis (2 dogs), ventilation was adequate. All flaps survived, 1 had superficial skin necrosis distally and 2 had minor wound dehiscence. One dog without tumor-free margins died of tumor-related disease 56 days after surgery. Tumor recurrence did not occur in 4 dogs with tumor-free margins. One dog was euthanatized 10 months after surgery for unrelated disease; 3 dogs were alive at writing (median follow-up: 20 months; range, 18-27 months) and all had a satisfactory functional and cosmetic outcome. CONCLUSIONS: Reconstruction of ventral thoracic wall defects using a latissimus dorsi myocutaneous flap yields a functional, cosmetic outcome. CLINICAL RELEVANCE: A latissimus dorsi myocutaneous flap can be used as a successful 1-stage reconstructive technique for ventral thoracic wall defects.

Tricuspid valve stenosis caused by fibrous adhesions to an endocardial pacemaker lead in a dog.

Acquired tricuspid valve stenosis (TVS) is a rare complication of endocardial lead placement in humans that has not been described in the veterinary literature. We describe a 6.5-year-old Border terrier that was presented with right-sided congestive heart failure 5.5 years after placement of a transvenous pacemaker. Severe TVS was confirmed by cardiac ultrasonography and appeared to be secondary to excessive endocardial pacemaker lead within the right atrium. Repositioning of the lead proved impossible and subsequent postmortem examination demonstrated fusion of the tricuspid valve (TV) leaflets around the endocardial lead with associated narrowing of the tricuspid valve orifice. In addition, the loop of the endocardial lead was anchored by thick fibrous tissue to the right atrial wall. This case report suggests that if sufficient endocardial lead is left inside the heart, in dogs undergoing transvenous pacemaker therapy, the redundant lead can become adherent to the tricuspid valve apparatus and cause valvular stenosis.

Association of portovenographic findings with outcome in dogs receiving surgical treatment for single congenital portosystemic shunts: 45 cases (2000-2004).

OBJECTIVE: To determine whether hepatic portal vascularity, as assessed by intraoperative mesenteric portovenography (IMP), is related to outcome in dogs undergoing attenuation of single congenital portosystemic shunts (CPSSs). DESIGN: Retrospective case series. ANIMALS: 45 dogs, each with a single CPSS, in which IMP was performed before and after temporary complete occlusion of the shunting vessel and that underwent complete (17 dogs) or partial (28 dogs) CPSS attenuation (surgery 1). PROCEDURES: Medical records were reviewed for signalment, clinical history, and bile acids stimulation test results. Intrahepatic portal vessel (IPV) opacification in pre- and postocclusion portovenograms was graded to determine whether the degree of opacification was correlated with the degree of shunt attenuation, clinical or biochemical factors, or long-term clinical outcome. In 17 of 28 dogs that had partial CPSS attenuation, these procedures were subsequently repeated (surgery 2) to achieve complete (14 dogs) or further partial (3 dogs) CPSS attenuation. RESULTS: Compared with preattenuation findings, IPV opacification increased significantly after partial or complete CPSS attenuation. The degree of IPV opacification before and after CPSS occlusion (surgery 1) was greater in dogs that tolerated complete versus partial CPSS attenuation and was correlated positively with age. The degree of IPV opacification following CPSS occlusion (surgery 1) was maximal in all dogs without encephalopathy and was correlated negatively with follow-up preprandial serum bile acids concentrations and positively with clinical improvement. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that IMP can be used to assess changes in IPV blood flow and help predict outcome following attenuation of single CPSSs in dogs.

Comparison of two surgical techniques for management of intramural ureteral ectopia in dogs: 36 cases (1994-2004).

OBJECTIVE: To determine outcome associated with intramural ureteral ectopia treated with 1 of 2 surgical techniques (neoureterostomy with ligation of the distal ureteral segment vs neoureterostomy with resection of the distal ureteral segment) and compare results of these 2 techniques in dogs. DESIGN: Multicenter retrospective case series. ANIMALS: 36 dogs (15 treated with the ligation technique and 21 treated with the resection technique). PROCEDURES: Information was obtained from medical records. Long-term follow-up information was obtained by owner questionnaire. RESULTS: 15 of 21 (71%) dogs in the resection group and 7 of 14 (50%) dogs in the ligation group still had urinary incontinence after surgery. Three of 20 (15%) dogs in the resection group and 4 of 14 (29%) dogs in the ligation group reportedly had multiple episodes of urinary tract infection following surgery. The outcome of surgery was judged to be excellent by the owners of 10 of 18 (56%) dogs in the resection group and 9 of 14 (64%) dogs in the ligation group. No significant differences were found between surgery treatment groups. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the present study suggest that although most owners of dogs that undergo surgery for treatment of intramural ureteral ectopia consider the outcome of surgery to be excellent, substantial proportions of dogs will continue to have urinary incontinence and recurrent urinary tract infections after surgery. Findings do not provide any support to the hypothesis that the resection technique is superior to the ligation technique for management of dogs with intramural ureteral ectopia.

Early postinfarction ventricular restraint improves borderzone wall thickening dynamics during remodeling.

BACKGROUND: Early infarct expansion impairs function of normally perfused borderzone myocardium (BZM), initiates adverse remodeling, and portends a poor long-term outcome. Early ventricular restraint has been demonstrated to improve global remodeling but its effect on BZM function has not been assessed. Using an ovine model of infarct induced remodeling and MRI, we tested the hypothesis that ventricular restraint early after MI preserves BZM function and reduces remodeling. METHODS: Six sheep had a large anterior infarction after ligation of all diagonal branches. One week after infarction 3 sheep had placement of a cardiac support device (CSD) to restrain infarct expansion. Global remodeling and borderzone wall thickening strain were assessed using tagged MRI before and 8 weeks after infarction. RESULTS: Global remodeling was greatly reduced in the CSD group compared with control. The BZM systolic wall thickening was similar in both groups at baseline (13.5% +/- 2.0%, control; 12.8% +/- 2.0%, CSD, p = 0.8). After 8 weeks of infarction-induced remodeling, systolic wall thickening strain decreased significantly to 4.9% +/- 0.7% in the control group (p = 0.03). In contrast, systolic wall thickening was preserved in the CSD group at 8 weeks (11.0% +/- 1.6%, p = 0.3). In the control group all thickening occurred during isovolemic contraction, plateauing during ejection. The CSD improved late systolic borderzone wall thickening, although dynamics remained perturbed. CONCLUSIONS: Ventricular restraint early after MI improves both contractile function of the BZM and global ventricular remodeling. The dynamics of BZM wall thickening are impaired during remodeling. The CSD significantly improves but does not completely maintain baseline BZM wall thickening dynamics.