Hand in Hand

Publications        Pictures of the Future Fall 2001

Doctors, technicians, engineers and computer scientists at the Klinikum rechts der Isar—one of Munich's largest hospitals—are working with Siemens to develop the operating room (OR) of the future. The main focus of their efforts is the improvement of minimally invasive procedures and treatments.

Siemens has succeeded in combining CT and PET data in a single image—a decisive step forward in the diagnosis and treatment of tumors

Minimally invasive surgery, also known as keyhole surgery, is less traumatic for patients than conventional surgery and continues to grow in importance. For engineers, the challenge is to develop new medical instruments and techniques that take all the intricacies of human anatomy into account. It goes without saying that methods and tools that function perfectly in high-precision tests on a rigid plastic model are not necessarily suitable for the human body, which is constantly in motion. The MITI working group at the Klinikum recht der Isar in Munich is testing new technologies and procedures in conditions that are as realistic as possible. Siemens Medical Solutions is one of the partners involved in this interdisciplinary group, which was established in early 1999.

The Minimally Invasive Interdisciplinary Therapeutic Intervention (MITI) working group was established at the Klinikum rechts der Isar—a clinic belonging to the Technical University of Munich—in early 1999. MITI is a research association comprising the following members: the Surgical Clinic (Professor Siewert); the Second Medical Clinic (Professor Classen); the Institute for Diagnostic Radiology (Professor Rummeny); the industrial companies Ethicon, Hamburg, Olympus Optical, Hamburg, and Siemens Medical Solutions, Erlangen; the German Aerospace Center (DLR, Professor Hirzinger), Oberpfaffenhofen; the Institute for Medical Physics (IMP, Professor Kalender); and the University of Erlangen-Nuremberg. MITI also receives support for its interdisciplinary gastroenterological surgical workplace project from the Bavarian Research Foundation.

"MITI's main goal is to develop and implement the concept of the 'operating room of the future'," says Professor Hubertus Feussner, a surgeon at the Klinikum rechts der Isar and member of the MITI working group. "Our latest project is the interdisciplinary gastroenterological surgical workplace. With this project, we want to optimize minimally invasive procedures and treatments. In particular, we hope to make the surgical treatment of diseases of the abdominal and thoracic cavities less traumatic and more efficient than is the case at present." The magic word "teamwork" is certainly not a meaningless motto here. Not only do independent disciplines such as surgery, gastroenterology (the branch of medicine that deals with the esophagus and gastrointestinal tract) and radiology work closely together within MITI; the group has also established close relationships with companies such as Siemens. Both sides are benefiting from this cooperation. For example, the MITI working group has developed new imaging techniques and navigation systems for guiding instruments, as well as image processing methods such as those for the fusion of different image data. While a computer tomography (CT) examination provides sectional views of human anatomy, positron emission tomography (PET) provides information on the metabolic activities of tissue—for example, the tissue in tumors and metastases. However, PET does not allow for exact anatomical location. Siemens has succeeded in combining the two imaging procedures to provide doctors with reliable indications of any suspicious changes in tissue. As a result, doctors can now more reliably diagnose whether the metastases have spread to the liver or whether the growth in question is benign. "CT-PET image fusion is a decisive step forward as far as the identification and treatment of tumors is concerned," says Feussner. "Using a patient-based coordinate system and our navigation system, we can now accurately locate tissue areas identified by PET and then take an appropriate tissue sample."

Metastases that have been identified in the patient's liver can be surgically removed. Every step of such an operation must be monitored with the help of imaging procedures. "It is important that we use simple and gentle methods in the operating room," says Feussner. "Computer tomographs cannot be used in every situation because of ionizing radiation, and magnetic resonance imaging (MRI) scanners are associated with high equipment costs. This is why we are making increasing use of ultrasound techniques." Together with the MITI group, Siemens has developed the world's first navigational ultrasound laparoscope probe. The device, which has been in use for the last 12 months, can be used for high-resolution examinations of the organs in the abdomen during an operation.

Although experts agree that the number of minimally invasive operations will continue to increase, it is still difficult to arrive at an accurate prognosis. That's because the healthcare market is regulated by the government, and political influences are constantly changing. Another problem is that because the areas of application for microtherapy are so varied, serious forecasts can only be made for individual disciplines. Professor Ernst Eypasch of St. Hildegardis hospital in Cologne, estimates that some 70,000 to 80,000 intestinal cancer operations are carried out in Germany every year. About 15 % of such operations are now conducted in a minimally invasive manner. This figure could reach 60 to 70 % by 2010. Such procedures result in much shorter hospital stays and faster recuperation, all of which reduces the cost of treatment. Whether this will apply to all operations is not clear, as the Association of Employees' Health Insurance Companies has noted that an increasing number of operations conducted are not medically essential.

Several treatments can be used to remove growths from the gastrointestinal tract, including new combination surgery. With the so-called rendezvous technique, which is currently being refined at the Klinikum rechts der Isar, two or more instruments (flexible endoscopes and rigid laparoscopes) are used simultaneously. The tips of the instruments must be brought together carefully in the area which is being operated upon—a very difficult feat, since the surgeons cannot see the instruments. The endoscope, for example, is inside the intestines while the laparoscope is outside. This "blind date" is relatively difficult to bring about because the wall of the intestines blocks the surgeon's view.

Rendezvous in the intestines: Great precision is required when bringing the tips of an endoscope and a laparoscope together

"But an interdisciplinary workplace also requires measures that actively include medical disciplines situated at different locations in both the diagnostic and treatment processes," says Wessels. "For such a workplace to function properly, identical image information and therapy planning data must be available in different parts of the clinic." This vision has become reality at Munich's Klinikum, thanks to a combination of modern network technology and Siemens "syngo" workstations. Says Wessels: "Doctors can exchange, discuss and alter their therapy planning data using these terminals. The workstations store all the information, process it and display it on monitors. The same data is available simultaneously to the team in the operating room and the clinical institutes involved. This allows them to conduct professional discussions via the internal clinic network. Alternatively, if someone draws something on a screen, others can follow what is happening via their monitors." Syngo workstations also allow doctors to call up CT data sets both as a series of layer images and in a 3D depiction. They can also move around inside these images virtually and determine the best path of access for an instrument. Should an unforeseen situation arise during the course of an operation, doctors will also soon be able to use the clinic network to confer with specialists from other disciplines before deciding what to do.