Ureteral morphology and pathology during urolithiasis in cats

Cats exhibit high susceptibility to urinary organ-related diseases. We investigated the healthy ureter morphol-ogies and compared these with ureters that were surgically resected distal to a urolithiasis obstruction in cats. Healthy ureters (total length 9.88 +/- 0.38 cm) developed adventitia composed of collagen fibers (ADCF), con-taining a longitudinal muscular layer, toward the distal segment. The healthy ureter was the smallest in the middle segment (4.71-6.90 cm from the urinary bladder) with significantly decreased luminal and submucosal areas compared to those in the proximal segment. Diseased cats exhibited a high incidence of calcium oxalate urolithiasis with renal dysfunction, regardless of age, sex, and body size. Diseased ureters showed increased perimeters, inflammation, and decreased nerves in ADCF. Collagen fibers were increased in the submucosal area, intermuscular spaces, and ADCF, particularly near the obstructed lesion. The mean resected ureter length was 5.66 +/- 0.49 cm, suggesting a high obstruction risk in the middle segment. The middle segment also increased the cross-sectional area of the ureter and ADCF, regardless of the distance from the obstructed lesion. The ureters in several cases either lacked the transitional epithelium, or exhibited transitional epithelial hyperplasia, and some of these formed the mucosal folds. In conclusion, we demonstrated the following characteristics and histo-pathological features of cat ureters: decreases in the ureter size, lumen area, and submucosa area from proximal to middle segment in healthy; ADCF changes in urolithiasis, including increased connective tissues with inflammation and decreased nerves. These data are important to understand the pathogenesis of feline ureteral obstruction

An autopsy case of tako-tsubo cardiomyopathy presenting ventricular tachycardia after pacemaker implantation

AbstractWe herein report a rare autopsy case of tako-tsubo cardiomyopathy (TTC) presenting ventricular tachycardia after pacemaker implantation. A 69-year-old male received a dual-chamber pacemaker implantation for complete atrioventricular block. He had no chest symptoms after the operation. Three days later, he developed severe chest pain, followed by syncope. Electrocardiogram showed sustained monomorphic ventricular tachycardia. Despite the use of amiodarone and frequent electrical defibrillation, ventricular tachycardia and ventricular fibrillation were repeated incessantly. He died 24 h after the syncope. The autopsy revealed no hemopericardial effusion, or perforation of leads. There were also no obstructive lesions in the coronary arteries. Myocardial necrosis was observed in the entire circumference and the all layers of the left ventricle. Microscopically, myocardial necrosis was plurifocal and contraction band necrosis. We speculate that catecholamine cardiotoxicity caused ventricular tachycardia in this case. Further studies are needed to clarify the heterogeneity of this disease.<Learning objective: Tako-tsubo cardiomyopathy should be considered a potential complication of pacemaker implantation. Physicians should recognize that this disorder can occur unexpectedly during medical examination or treatment.