Surgical treatment and outcome of intrahepatic shunts in 12 cats.

CASE SERIES SUMMARY: The objective of this case series was to describe the presentation, surgical treatment and outcome of a congenital intrahepatic portosystemic shunt (IHPSS) in 12 cats. A retrospective case series of cats undergoing surgical treatment for an IHPSS was undertaken. Signalment, clinical signs, imaging, surgical treatment, complications and short-term outcome (<30 days) were obtained using medical records. Long-term outcome (>1 year after first surgery) was obtained, where possible, using a health-related quality of life owner questionnaire. Seven cats were diagnosed with a left divisional shunt, three with a central divisional shunt and two with a right divisional shunt using intraoperative mesenteric portovenography. Three cats tolerated complete acute suture attenuation, eight cats underwent partial suture attenuation, four of which received complete suture ligation at a second surgery, and one cat underwent partial attenuation with a thin film band. Six cats (50%) developed post-attenuation neurological signs (PANS) after first surgery and two cats (17%) died or were euthanased due to severe PANS. Long-term outcome was available for eight cats (67%), with a median follow-up time of 1743 days (range 364-2228), and was described as excellent in five cats (63%), fair in two cats (25%) and poor in one cat (12%). RELEVANCE AND NOVEL INFORMATION: Few papers exist that describe the presentation, intraoperative imaging, treatment and outcome of IHPSSs in cats. This is the first to describe surgical attenuation with a thin film band in a cat with an IHPSS. This case series reports excellent long-term outcomes in a majority of surgically treated cats with IHPSS.

Haematology and coagulation profiles in cats with congenital portosystemic shunts.

Objectives The objectives of this study were, first, to report the haematological parameters and coagulation times for cats with a congenital portosystemic shunt (CPSS) and the influence of surgical shunt attenuation on these parameters; and, second, to identify any association between prolongation in coagulation profiles and incidence of perioperative haemorrhage. Methods This was a retrospective clinical study using client-owned cats with a CPSS. Signalment, shunt type (extra- or intrahepatic), degree of shunt attenuation (complete or partial), haematological parameters, prothrombin time (PT) and activated partial thromboplastin time (aPTT) test results, and occurrence of any perioperative clinical bleeding complications were recorded for cats undergoing surgical treatment of a CPSS at the Royal Veterinary College, UK, between 1994 and 2011. Results Forty-two cats were included. Thirty-six (85.7%) had an extrahepatic CPSS and six (14.3%) had an intrahepatic CPSS. Preoperatively, mean cell volume (MCV) and mean cell haemoglobin (MCH) were below the reference interval (RI) in 32 (76.2%) and 31 (73.8%) cats, respectively. Red blood cell count and mean cell haemoglobin concentration (MCHC) were above the RI in 10 (23.8%) and eight (19.1%) cats, respectively. Postoperatively, there were significant increases in haematocrit ( P = 0.044), MCV ( P = 0.008) and MCH ( P = 0.002). Despite the significant increase in MCV postoperatively, the median MCV postoperatively was below the RI, indicating persistence of microcytosis. Preoperatively, PT was above the upper RI in 14 cats (87.5%), and aPTT was above the upper RI in 11 cats (68.8%). No cat demonstrated a perioperative clinical bleeding complication. Conclusions and relevance Cats with a CPSS are likely to present with a microcytosis, but rarely present with anaemia, leukocytosis or thrombocytopenia. Surgical attenuation of the CPSS results in a significant increase in the HCT and MCV. Coagulation profiles in cats with a CPSS are likely to be prolonged, irrespective of shunt type, but do not appear to be associated with an increased risk of clinical bleeding.

Serum anti-Müllerian hormone concentrations before and after treatment of an ovarian granulosa cell tumour in a cat.

CASE SUMMARY: A 15-year-old female cat was presented for investigation of progressive behavioural changes, polyuria, polydipsia and periuria. An ovarian granulosa cell tumour was identified and the cat underwent therapeutic ovariohysterectomy (OHE). The cat's clinical signs resolved, but 6 months later it was diagnosed as having an anaplastic astrocytoma and was euthanased. Serum anti-Müllerian hormone (AMH) concentration prior to OHE was increased vs a control group of entire and neutered female cats. Following OHE, serum AMH concentration decreased to <1% of the original value. RELEVANCE AND NOVEL INFORMATION: Serum AMH measurement may represent a novel diagnostic and monitoring tool for functional ovarian neoplasms in cats.

Multiple acquired portosystemic shunts in a cat secondary to chronic diaphragmatic rupture.

CASE SUMMARY: A cat with a chronic diaphragmatic rupture presented with neurological signs, including twitching and focal seizures. Blood ammonia level was markedly elevated and therefore neurological signs were thought to be related to hepatic encephalopathy. Exploratory laparotomy revealed that the left lateral and medial liver lobes were herniated into the thorax and multiple acquired portosystemic shunts (MAPSS) were present. The hernia was reduced and the diaphragm repaired. Neurological signs gradually resolved following surgery and 1 year postoperatively the cat was clinically normal, was not on any medication and had no evidence of hepatic dysfunction. RELEVANCE AND NOVEL INFORMATION: This is the first report of a chronic diaphragmatic rupture leading to MAPSS in a cat.

Hyperammonemia and systemic inflammatory response syndrome predicts presence of hepatic encephalopathy in dogs with congenital portosystemic shunts.

Hepatic encephalopathy (HE) is an important cause of morbidity and mortality in patients with liver disease. The pathogenesis of he is incompletely understood although ammonia and inflammatory cytokines have been implicated as key mediators. To facilitate further mechanistic understanding of the pathogenesis of HE, a large number of animal models have been developed which often involve the surgical creation of an anastomosis between the hepatic portal vein and the caudal vena cava. One of the most common congenital abnormalities in dogs is a congenital portosystemic shunt (cpss), which closely mimics these surgical experimental models of HE. Dogs with a cPSS often have clinical signs which mimic clinical signs observed in humans with HE. Our hypothesis is that the pathogenesis of HE in dogs with a cPSS is similar to humans with HE. The aim of the study was to measure a range of clinical, haematological and biochemical parameters, which have been linked to the development of HE in humans, in dogs with a cPSS and a known HE grade. One hundred and twenty dogs with a cPSS were included in the study and multiple regression analysis of clinical, haematological and biochemical variables revealed that plasma ammonia concentrations and systemic inflammatory response syndrome scores predicted the presence of HE. Our findings further support the notion that the pathogenesis of canine and human HE share many similarities and indicate that dogs with cPSS may be an informative spontaneous model of human HE. Further investigations on dogs with cPSS may allow studies on HE to be undertaken without creating surgical models of HE thereby allowing the number of large animals used in animal experimentation to be reduced.

Use of vacuum-assisted closure to maintain viability of a skin flap in a dog.

CASE DESCRIPTION: A 4-year-old sexually intact male Labrador Retriever-Poodle mix was admitted to the hospital for treatment of a wound in the left thoracic region. The wound had been debrided and primary closure had been performed by the referring veterinarian 4 days previously. CLINICAL FINDINGS: The dog had a 20-cm-long wound covered by a large flap of skin that extended caudally from the scapula over the left side of the thorax. A 3-cm defect was evident at the cranioventral aspect of the wound, from which purulent material was being discharged. The skin flap was necrotic, and the skin surrounding the flap was bruised. Signs of pain were elicited when the wound and surrounding region were palpated. Other findings, including those of thoracic radiography, were unremarkable. TREATMENT AND OUTCOME: The wound was debrided, and vacuum-assisted closure (VAC) was initiated for 3 days until a healthy bed of granulation tissue developed. A reconstructive procedure was performed with a rotation flap 3 days after VAC dressing removal. The VAC process was reinitiated 2 days following reconstruction because of an apparent failing of the skin flap viability. After 5 days of VAC, the flap had markedly improved in color and consistency and VAC was discontinued. Successful healing of the flap occurred without the need for debridement or additional intervention. CLINICAL RELEVANCE: Use of VAC led to a good overall outcome for the dog, with complete healing achieved. Additional evaluation of this technique for salvaging failing skin flaps is warranted in dogs, particularly considering that no reliable method for flap salvage in veterinary species has been reported to date.