title: Intraoperative lung edema monitoring by microwave reflectometry.
abstract: Microwave reflectometry might be a suitable tool for the thoracic surgeon to monitor edema formation of the lung during lung surgery. A new setup of microwave reflectometry for lung water measurements was developed and tested for clinical application. Three lung models were used for the microwave reflectometry tests: 1) the model of an ex vivo isolated perfused rat lung to investigate lung edema formation during ischemia-reperfusion (n=6), 2) the in situ lung of a human patient to demonstrate the feasibility of lung water monitoring during a surgical operation, 3) the model of an ex vivo isolated perfused human lung to investigate edema formation during postischemic reperfusion and to investigate the changes in water content in the region of a tumor. During human lung operation, significant changes in water content occurred in different lung areas. During isolated perfusion, a significant increase in lung water was measured in models 1) and 3) (P=0.03). Water content of tumor tissue was higher than in the surrounding healthy lung tissue. Microwave reflectometry offers a non-invasive approach to monitor lung edema formation in experimental models and during thoracic surgery.
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Mannheim University Medical Center, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68135 Mannheim, Germany. kai.nowak@umm.de
authors.forename: Kai
authors.initials: K
authors.lastname: Nowak
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Gross
authors.forename: Kathrin
authors.initials: K
authors.lastname: Nicksch
authors.forename: Christine
authors.initials: C
authors.lastname: Hanusch
authors.forename: Marko
authors.initials: M
authors.lastname: Helbig
authors.forename: Peter
authors.initials: P
authors.lastname: Hohenberger
authors.forename: Martha M
authors.initials: MM
authors.lastname: Gebhard
authors.forename: Michael
authors.initials: M
authors.lastname: Schaefer
mesh_terms: D000818:Animals; D001834:Body Water / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000601:surgery*; D005240:Feasibility Studies; D005583:Fourier Analysis; D006801:Humans; D066298:In Vitro Techniques; D008168:Lung / Q000378:metabolism / Q000601:surgery*; D008175:Lung Neoplasms / Q000378:metabolism / Q000601:surgery*; D008872:Microwaves; D016343:Monitoring, Intraoperative / Q000379:methods*; D010477:Perfusion; D011237:Predictive Value of Tests; D011654:Pulmonary Edema / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D019616:Thoracic Surgical Procedures / Q000009:adverse effects*; D013997:Time Factors