“Denervation” of autonomous nervous system in idiopathic pulmonary arterial hypertension by low-dose radiation: a case report with an unexpected outcome

Abstract

Wolfgang Hohenforst-Schmidt,1 Paul Zarogoulidis,2 Filiz Oezkan,3 Christian Mahnkopf,4 Gerhard Grabenbauer,5 Alfons Kreczy,6 Rolf Bartunek,7 Kaid Darwiche,3 Lutz Freitag,3 Qiang Li,8 Haidong Huang,8 Thomas Vogl,9 Patrick LePilvert,10 Theodora Tsiouda,11 Kosmas Tsakiridis,12 Konstantinos Zarogoulidis,2 Johannes Brachmann11II Medical Clinic, Coburg Clinic, University of Würzburg, Coburg, Germany; 2Pulmonary Department-Oncology Unit, G Papanikolaou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece; 3Department of Interventional Pneumology, Ruhrlandklinik, West German Lung Center, University Hospital, University of Duisburg-Essen, Essen, Germany; 4II Medizinische Klinik, Klinik für Kardiologie, Angiologie, Pneumologie, Klinikum Coburg, 5Department of Radiotherapy, 6Department of Pathology, Cytology and Molecular Diagnostics, 7Institute of Diagnostic and Interventional Radiology, Coburg Clinic, University of Wüerzburg, Coburg, Germany; 8Department of Respiratory Diseases, Changhai Hospital/First Affiliated Hospital of the Second Military Medical University, Shanghai, People’s Republic of China; 9Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Frankfurt, Germany; 10Interventional Drug Delivery Systems and Strategies (ID2S2), Medical Cryogenics, Lakeland Court Jupiter, FL, USA; 11Internal Medicine Unit, Theagenio Cancer Hospital, Thessaloniki, 12Cardiothoracic Surgery Department, Saint Luke Private Hospital, Thessaloniki, GreeceAbstract: Vasointestinal peptide metabolism plays a key physiological role in multimodular levels of vasodilatory, smooth muscle cell proliferative, parenchymal, and inflammatory lung reactions. In animal studies, vasointestinal peptide relaxes isolated pulmonary arterial segments from several mammalian species in vitro and neutralizes the pulmonary vasoconstrictor effect of endothelin. In some animal models, it reduces pulmonary vascular resistance in vivo and in monocrotaline-induced pulmonary hypertension. A 58-year-old woman presented with dyspnea and mild edema of the lower extremities. A bronchoscopy was performed without any suspicious findings suggesting a central tumor or other infiltrative disease. Endobronchial ultrasound revealed enlarged pulmonary arteries containing thrombi, a few enlarged lymph nodes, and enlarged mediastinal tissue anatomy with suspicion for mediastinal infiltration of a malignant process. We estimated that less than 10% of the peripheral vascular bed of the lung was involved in direct consolidated fibrosis as demonstrated in the left upper lobe apex. Further, direct involvement of fibrosis around the main stems of the pulmonary arteries was assumed to be low from positron emission tomography and magnetic resonance imaging scans. Assuming a positive influence of low-dose radiation, it was not expected that this could have reduced pulmonary vascular resistance by over two thirds of the initial result. However; it was noted that this patient had idiopathic pulmonary arterial hypertension mixed with “acute” (mediastinal) fibrosis which could have contributed to the unexpected success of reduction of pulmonary vascular resistance. To the best of our knowledge, this is the first report of successful treatment of idiopathic pulmonary arterial hypertension, probably as a result of low-dose radiation to the pulmonary arterial main stems. The patient continues to have no specific complaints concerning her idiopathic pulmonary arterial hypertension.Keywords: radiation, pulmonary hypertension, denervatio