Organ Care System: MHH doctors treat diseased lungs outside the body

Due to the increased occurrence of antibiotic resistance, more and more often there is no alternative treatment option for severe pneumonia. Doctors at Hannover Medical School (MHH) have for the first time successfully used the Organ Care System (OCS) to treat pneumonia caused by antibiotic-resistant bacteria outside the body. The advantage: if the lung is explanted for treatment, the physicians can use very high-dose antibiotics. These dosages would be toxic to the body because of side effects. The scientists published their findings in the journal "PLoS One".

In the pilot study, the team headed by Professor Axel Haverich, Director of the Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), investigated the treatment of pigs suffering from severe pneumonia with high-dose antibiotics in an Organ Care System (OCS) as a new therayp for otherwise incurable antibiotic-resistant lung infections. The physicians treated on the one hand diseased animals with the body-compatible dose of the antibiotic colistin and on the other hand the explanted diseased lung in the OCS with the hundredfold dose of the antibiotic. "Such a dose would be incompatible with the patient. It would lead to kidney failure and damage to the central nervous system, "explains Dr. Norman Zinne, Medical Specialist in the Department of Cardiothoracic, Transplantation and Vascular Surgery.
To treat the lung infection in the OCS, the doctors first explanted the affected lung and implanted it in an OCS. The OCS is a mobile device for ex vivo lung perfusion. In the device, the organ is transported body warm, flowed through with donor blood and supplied with nutrients - or just with antibiotics. The lung is ventilated in the OCS during the treatment and can thus provide itself with oxygen.
After two hours of treatment, the doctors implanted the lung back into the animal. "While in the untreated control group and the conventionally treated group, only one third of the pigs survived the pneumonia, two-thirds of the animals whose lungs we treated outside the body recovered from the disease," says Dr. Zinne. Also, the clinical symptoms of the infection were less severe in the OCS group than in the other groups. "The results show that treating multidrug-resistant pneumonia with very high-dose off-the-field antibiotics is a new therapeutic strategy for severe infections that otherwise lack alternative therapies," says Professor Haverich. "Before we can apply the method to humans, we will continue to study the animal model for patient safety," he says. "It is quite possible to transfer the method to other organs such as the heart or other therapeutic options such as chemo- or cell therapies."

The antibiotic colistin
Colistin is an antibiotic that has been known since the 1950s, but has been rarely used because of its toxic properties to the body. Due to the emergence of antibiotic-resistant bacteria, colistin has also been increasingly used as a reserve antibiotic for the treatment of pneumonia caused by the antibiotic-resistant bacterium Pseudomonas aeruginosa.
The project was supported by the German Center for Lung Research BREATH (Biomedical Research in Endstage and Obstructive Lung Disease), funded by the Federal Ministry of Education and Research, and by the Cluster of Excellence REBIRTH (from Regenerative Biology to Reconstructive Therapy), funded by the German Research Foundation.

For further information, please contact Professor Dr. Axel Haverich, phone (0511) 532-6581.

Picture: MHH / Kaiser

Dr. Norman Zinne and Professor Dr. Axel Haverich with an Organ Care System (OCS).