New determinants for casual peripheral mechanism of neurogenic lung edema in subarachnoid hemorrhage due to ischemic degeneration of vagal nerve, kidney and lung circuitry. Experimental study1

Interaction between Neurogenic Pulmonary Edema and Thoracic 3 DRG Degeneration Following Spinal Subarachnoid Hemorrhage: First Experimental Study

BACKGROUND

 Neurogenic pulmonary edema (NPE) following subarachnoid hemorrhage (SAH) is still one of the most catastrophic complications with high morbidity and mortality rates. Systemic sympathetic hyperactivity has been considered in the pathogenesis, but it has not been clarified. In this study, we investigate the relationship between the degeneration of the T3 dorsal root ganglion (DRG) and the development of NPE following spinal SAH.

METHODS

 The study was conducted on 23 rabbits. Five rabbits were used as the control group, 5 as the sham group (n = 5), and 13 as the study group. The correlation between the degenerated neuronal densities of the T3 nerve axons and neurons in the DRG and NPE scores was analyzed statistically.

RESULTS

 A correlation between the neuronal degeneration of the T3 nerve, its DRG, and high NPE scores was found in the study group and the sham group. Massive NPE was detected in the study group along with neural degeneration of T3 axons and ganglia.

CONCLUSION

 The present study indicates that NPE and pulmonary artery vasospasm can be prevented by reducing T3 DRG degeneration.

Stellate ganglion ischemia on the prevention of pulmonary vasospasm during bilateral carotid artery ligation: The first experimental study

Fatal pulmonary edema and hemorrhage are significant complications of endovascular treatment in steno-occlusive carotid artery disease; a rational mechanism has not been adequately examined in the literature so far. We investigated if cervical sympathetic ganglia ischemia prevents pulmonary vasospasm on the prognosis of bilateral common carotid artery ligation (BCCAL). Twenty-three adult New Zealand rabbits (4.2 ± 0.3 kg) were randomly divided into three groups: the control group (G1, n = 5), the sham group (G2, n = 6), and the BCCAL group (G3, n = 12). Common carotid arteries were dissected bilaterally in G2/G3, and permanent BCCAL was applied to only in G3. All animals were followed for 3 weeks and decapitated under general anesthesia. Histopathological changes in stellate ganglia and severity of pulmonary vasospasm-related lung edema and hemorrhage were investigated. Results were analyzed by the Kruskal-Wallis test. Two animals of G3 dead within three weeks and the remainder were sacrificed three weeks later. Subpleural petechial foci and an endotracheal bloody fluid collection were grossly observed in the lungs. Histopathologically, pulmonary artery vasospasm, perivascular and subintimal edema, interalveolar hemorrhage, and alveolar wall destructions were observed with less ischemic-degenerated neuron density-determined stellate ganglia animals. Neurodegeneration of stellate ganglia may have a beneficial effect on the prevention of lung injury during steno-occlusive carotid artery disease.