Image-Guided Cryoablation of the Spine in a Swine Model: Clinical, Radiological, and Pathological Findings with Light and Electron Microscopy

This study was designed to present the feasibility of an in vivo image-guided percutaneous cryoablation of the porcine vertebral body. Methods The institutional animal care committee approved this study. Cone-beam computed tomography (CBCT)-guided vertebral cryoablations (n = 22) were performed in eight pigs with short, 2-min, single or double-freezing protocols. Protective measures to nerves included dioxide carbon (CO2) epidural injections and spinal canal temperature monitoring. Clinical, radiological, and pathological data with light (n = 20) or transmission electron (n = 2) microscopic analyses were evaluated after 6 days of clinical follow-up and euthanasia. Results CBCT/fluoroscopic-guided transpedicular vertebral body cryoprobe positioning and CO2 epidural injection were successful in all procedures. No major complications were observed in seven animals (87.5 %, n = 8). A minor complication was observed in one pig (12.5 %, n = 1). Logistic regression model analysis showed the cryoprobe-spinal canal (Cp-Sc) distance as the most efficient parameter to categorize spinal canal temperatures lower than 19 °C (p<0.004), with a significant Pearson’s correlation test (p < 0.041) between the Cp-Sc distance and the lowest spinal canal temperatures. Ablation zones encompassed pedicles and the posterior wall of the vertebral bodies with an inflammatory rim, although no inflammatory infiltrate was depicted in the surrounding neural structures at light microscopy. Ultrastructural analyses evidenced myelin sheath disruption in some large nerve fibers, although neurological deficits were not observed. Conclusions CBCT-guided vertebral cryoablation of the porcine spine is feasible under a combination of a short freezing protocol and protective measures to the surrounding nerves. Ultrastructural analyses may be helpful assess the early modifications of the nerve fibers.

Manifestação incomum de paralisia de membros pélvicos em felino com hidronefrose decorrente de ovariectomia - Relato de caso

This study describes the occurrence of iatrogenic hydronephrosis in left kidney with compression of the abdominal aorta in persian cat and paralysis of hind limbs. The animal had slight dehydration, pale mucous membranes, cold extremities and cyanotic, absence of bilateral femoral artery pulse, and absence of superficial and deep pain, and presence of a mass of firm consistency with six centimeters in diameter, on abdominal palpation. Performed exploratory celiotomy, there was increased left kidney compressing the abdominal aorta and dilation of the cranial left ureter attached to the uterine horn by means of ligation with nonabsorbable. After nephrectomy, it was observed the restoration of local circulation. The animal died after eight hours.

Avaliação do efeito do pré e pós-condicionamento em modelo de isquemia renal transitória: estudo comparativo experimental em ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estresse, depressão e suporte familiar em pacientes em diálise peritoneal e hemodiálise

Pós-graduação em Psicologia do Desenvolvimento e Aprendizagem - FC