Non-invasive laser technology for the treatment of malignant tumours
The Department of Thoracic Surgery at Constance Hospital, which was established in November 2008, has since March 2009 been using an innovative laser scalpel for removing metastases of malignant tumours from the lung. Dr. Thomas Kiefer, the department’s chief physician, envisages that this will open up numerous new possibilities, which at the moment are unfortunately not fully exploited at all hospitals due to lack of knowledge.
Dr. Thomas Kiefer is the chief physician in the Department of Thoracic Surgery at Constance University Hospital
© private
In about 30 percent of all cancer patients treated, metastases usually appear in the lung after a few years. Lung metastases usually occur in large quantities and tend to recur after treatment. It is of key importance to save as much healthy lung tissue as possible so that 30 or 40 metastases can be operated on three, four or even more times. Unlike in the past, the diagnosis of metastases is no longer a death sentence, as innovative laser technology can now remove malignant tumours in a non-invasive way. The Department of Thoracic Surgery at the Constance Hospital uses just such a method, which was first used to treat patients on 5th March 2009. The Nd:YAG laser (Neodym: yttrium-aluminium-garnet-laser) was developed by the Tuttlingen-based medical device company Gebrüder Martin.
Parallel cutting and sealing
A single irradiation crater in the lung obtained with a wavelength of 1318 nm and 20 Watt/1s. The enlarged photo shows the three zones in the treated area: a vaporisation crater in the centre, surrounded by a wide and light coagulation zone that is enclosed by a hyperaemic seam.
© Coswig Hospital
Dr. Thomas Kiefer, chief physician in the Department of Thoracic Surgery, explained that this innovative method enables the treatment of patients who were previously considered inoperable, thereby considerably increasing their life expectancy and assuring a virtually unaltered quality of life. "The advantage for patients is that the lung tissue can be made air- and fluid-tight as very precise cuts are made," said the physician who came to Constance from the Ortenau Hospital in Offenburg where, for nine years, he coordinated the establishment of an interdisciplinary tumour centre. The new laser method means that sutures, which frequently gather the tissue, are no longer necessary. "In the past, sutures and braces needed to be placed in healthy tissue, thereby reducing the tissue surface that was available for breathing," explains Dr. Thomas Kiefer.
Healthy tissue is saved
The ND:YAG MY40 laser enables the removal of metastases up to the size of a tennis ball
© Gebrüder Martin GmbH & Co. KG
Modern lasers use a wavelength of 1318 nm and are specifically designed to take into account the biophysical properties of the lung. They enable the removal of a large number of metastases (more than 150) of the size of a grain of rice or a tennis ball, both from the central parenchyma or the hilus region structures without having to remove much or any lung lobe tissue or parenchyma. Deeper metastases and tumours can also be removed and the lung segments or lobes to a large degree saved. Due to resection areas that are free of blood and have a high density of fistulas, and due to the repeatability of laser treatments in the case of recurrence, there are flexible but mechanically robust coagulation zones, which enables the Pleura visceralis fissure to be used for double safety.
"The function and effect of this specific laser has been tested by our clinical partner over a period of ten years," said Uwe Ott, product manager at Gebrüder Martin GmbH & Co. KG, the company that developed the laser. As is the case with all medical applications, the method was initially tested and analysed in animal experiments before it was authorised as an alternative method to partial lung resection. According to Uwe Ott, the new laser is currently being used in approximately 60 hospitals in Germany.
Long surgery for the removal of multiple metastases
The new method with a laser scalpel involves the chest being opened with a lateral cut. The lung is then thoroughly palpated with the fingers in order to detect the conspicuous areas that will subsequently have to be removed. On average, 7.3 metastases (from solitary metastases up to 84 metastases) are removed during one laser intervention. “Removing just a small seam (only a few millimetres) of healthy tissue around the metastasis is sufficient,” said Dr. Thomas Kiefer explaining that a tube is inserted into the lung as drainage after the operation and the chest is closed again.
Depending on the number and size of the metastases that have to be removed, an intervention takes between 60 and 240 minutes. It is quite challenging, both for the surgery team and for the technology. “We have to use protective goggles for one to three hours, and an enormous amount of noise is generated after 45 minutes by the laser’s cooling system. This, along with the need to concentrate very hard on the work, makes the intervention a real challenge,” said Kiefer.
Biophysical data of the ND:YAG MY40 laser. The figure shows important laser parameters and tissue determinants. Of key importance is the low lung density of 0.15 g/ccm, 80% water content and strong shrinking capacity as a result of the air contained in the alveoles.
© Gebrüder Martin GmbH & Co. KG
Need for more information
At the Offenburg Hospital and now also in Constance, Dr. Thomas Kiefer has already treated over 100 patients and has more than 15 years experience in thoracic surgery. In addition, he has long been acquainted with the use of laser technology. He is well prepared for using the new laser through his participation in trials and he has also been assisted by a colleague at another clinic who already had an excellent knowledge of the new laser. Kiefer had one patient who had over 30 metastases per lung lobe, all of which he managed to remove.
Kiefer is sure that the continued development of new technologies for the treatment of lung metastases and metastases in general is what makes his work possible. But he is also sure that all the opportunities are not yet being fully exploited as many of his colleagues lack specific knowledge in the use of the new technologies in clinical applications. “The German Society for Thoracic Surgery estimates that in our field of treatment in Germany about 10,000 operations, not exclusively relating to the removal of metastases, are not carried out although there is a clear indication of disease.” Many patients are not operated on because they do not have access to a specialist. “In addition, many laypeople and physicians unfortunately assume that the diagnosis of lung metastases or metastases in general is a catastrophe,” said Kiefer who is sure that it would be possible to help many patients, even older ones, if their doctors were better informed about the progress made in thoracic surgery. “We often see a kind of therapeutic nihilism, even though this is not at all justifiable,” said Kiefer.
In future, Dr. Kiefer hopes that further technical improvements will improve the removal of metastases with lasers. “The lasers have to become even more effective so that the preparation time can be reduced. In addition, it is of equal importance to make it clear to the public and in particular also to physicians that we are able to help patients with metastases,” said the thoracic surgery specialist.
Further information:
Dr. med. Thomas Kiefer
Department of Thoracic Surgery
Constance Hospital
Luisenstrasse 7
78464 Konstanz
Tel: +49 (0)7531 / 801 - 1901
E-mail: lungenzentrum(at)klinikum- konstanz.de