Outcome and prognostic indicators in 20 cats with surgically treated primary lung tumors.

The purpose of this retrospective study of 20 client-owned cats was to describe the clinical signs, surgical interventions, histological features, stage and treatments of primary lung tumors removed by surgical excision, and to determine which factors significantly influence survival. Any cat that underwent surgical resection of a primary lung tumor between 2000 and 2007 was included in the study. Patient records were reviewed and signalment, clinical signs, preoperative diagnostics, surgical findings and histopathological results recorded. Histological reports were reviewed and scored using World Health Organization criteria. The Kaplan-Meier test was used to evaluate each potential prognostic factor with survival. Twenty cats met the inclusion criteria. The presence of clinical signs (such as dyspnea) at the time of diagnosis (P = 0.032), pleural effusion (P = 0.046), stage M1 (P = 0.015), and moderately and poorly differentiated tumors on histopathology (P = 0.011) were factors that were significantly correlated with reduced survival times. The median survival time of the 20 cats was 11 days. Cats presenting with no clinical signs had a median survival time of 578 days post-surgery vs 4 days post-surgery when presented with clinical signs. Cats staged T1N0M0 lived longer than cats at other stages (P = 0.044). Of the cats that survived to the time of suture removal, median survival time was 64 days. The results indicate that the presence of clinical signs, pleural effusion, moderately and poorly differentiated tumors on histopathology, evidence of metastasis and any stage beyond T1N0M0 are negative prognostic indicators for cats with primary lung tumors. The findings demonstrate that cats that presented with clinical signs, pleural effusion, any stage other than T1N0M0, or moderately and poorly differentiated tumors on histopathology had a poor prognosis. Therefore, extensive preoperative diagnostics, including computed tomography scans, should be performed before considering surgical intervention in these cats. These findings may be used to guide therapeutic decision-making in cats diagnosed with primary lung tumors.

Elective and emergency surgical management of adrenal gland tumors: 60 cases (1999-2006).

Sixty-one adrenal gland tumors were surgically removed from 60 dogs. Fifty-two dogs underwent elective adrenalectomy and 8 dogs underwent emergency adrenalectomy for acute adrenal hemorrhage. Size of adrenal tumors ranged from 10 mm to 80 mm. Histopathology confirmed a diagnosis of adrenocortical tumor in 47 dogs, 26 of which were malignant. Pheochromocytoma was diagnosed in 11 dogs. Six dogs had tumor invasion of the caudal vena cava. Of the seven dogs that did not survive the perioperative period, four underwent emergency adrenalectomy. No dogs with tumor invasion of the caudal vena cava died perioperatively. Perioperative morality rates were 5.7% for dogs that underwent elective adrenalectomy and 50% for dogs that underwent emergency adrenalectomy for acute adrenal hemorrhage. Median survival time was 492 days for the 53 dogs that survived the perioperative period. Of the factors analyzed, only adrenal tumor size and the presence of acute adrenal hemorrhage had predictive values for perioperative mortality. Those dogs that survived the perioperative period had extended survival times of up to 1,590 days. The mortality rate associated with elective adrenalectomy in dogs may be lower than previously reported. Dogs with very large tumors or acute adrenal hemorrhage may have a more guarded prognosis.

The effect of cancellous autograft and novel plate design on radiographic healing and postoperative complications in tibial tuberosity advancement for cranial cruciate-deficient canine stifles.

OBJECTIVE: To assess the effect of autogenous cancellous bone graft (autograft) and novel plate use on radiographic healing and complications in tibial tuberosity advancement (TTA) for treatment of cranial cruciate ligament (CrCL)-deficient stifles in dogs. STUDY DESIGN: Prospective clinical study. ANIMALS: Consecutive dogs (n=125) with unilateral CrCL-deficient stifles. METHODS: Four treatment groups: CPG, conventional plate with autograft; CPNG, conventional plate without autograft; NPG, novel plate with autograft; NPNG, novel plate without autograft were studied. Radiographs from 60 dogs were scored for healing at 6 and 10 weeks postoperatively; all 125 dogs were assessed for radiographic complications. Variables evaluated for relationship with healing scores and radiographic complications were age, weight, sex, cage and plate size, implant type, and graft use. RESULTS: Dogs with autograft had overall higher healing scores at 6 and 10 weeks. Radiographic complications occurred in 13 dogs (12 minor, 1 major), and were not influenced by graft or novel plate use. CONCLUSION: Autograft increases healing scores, but was not found to have a significant impact on the rate of complications in TTA. The novel plate was not found to have healing scores or radiographic complication rates significantly different from the conventional plate design.

A retrospective study of factors influencing survival following surgery for gastric dilatation-volvulus syndrome in 306 dogs.

Gastric dilatation-volvulus (GDV) is a life-threatening condition in dogs that has been associated with high mortality rates in previous studies. Factors were evaluated in this study for their influence on overall and postoperative mortality in 306 confirmed cases of GDV between 2000 and 2004. The overall mortality rate was 10%, and the postoperative mortality rate was 6.1%. The factor that was associated with a significant increase in overall mortality was the presence of preoperative cardiac arrhythmias. Factors that were associated with a significant increase in postoperative mortality were postoperative cardiac arrhythmias, splenectomy, or splenectomy with partial gastric resection. The factor that was associated with a significant decrease in the overall mortality rate was time from presentation to surgery. This study documents that certain factors continue to affect the overall and postoperative mortality rates associated with GDV, but these mortality rates have decreased compared to previously reported rates.

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.