Past, Present, and Future of Non-vascular IVR Tetsuya Yoshioka, M.D., 1) Hiroshi Anai, M.D., 2) and Hiroshi Sakaguchi, M.D. 2) 1) Department of Radiology, Nara Prefectural Nara Hospital 2) Department of Radiology, Nara Medical University NICHIDOKU-IHO Vol. 50 No. 1 84 97 (2005) Summary The 1980s appeared to be the dawn of a new era of non-vascular interventional radiology (IVR) in Japan. The procedures conducted during this time included cyst ablation, abscess drainage, urinary and biliary drainage, external-internal drainage, endoprosthesis, bougie or balloon dilatation for luminal stenosis, lithotomy, biopsy, and percutaneous gastrostomy. The aim of these strategies was primarily radical cure in benign diseases or palliative treatment in malignant diseases to improve the quality of life (QOL) of patients. These procedures or treatment approaches are still popular today, but the non-vascular IVR of that era covered only narrow areas as compared with vascular IVR, and the target diseases were limited. In the 1990s, however, the advent of metallic stents brought dynamic change to the field of non-vascular IVR, not only in Japan, but also throughout the world. New areas were introduced, and many new treatment approaches were developed, including percutaneous ethanol injection therapy (PEIT), a treatment developed in Japan for hepatic tumors, as well as procedures for the reproductive organs such as prostatic urethral balloon dilatation and fallopian tube recanalization. The era could be represented not only by the advent of new devices such as metallic stents implantable in the body but also by progress in mechanization, such as the rotablator used in gallbladder lithotomy, ushering in an era of progress in which immense strides were made. In the 2000s, the techniques advanced into the orthopedic field, an area largely uncultivated until then. The representative treatment procedures included percutaneous injection of acrylic bone cement, as well as percutaneous laser disk decompression. In addition, as a replacement for PEIT, percutaneous microwave coagulation therapy and radiofrequency ablation appeared as topical heat therapies, in addition to the opposite technique of cryotherapy, or topical freezing. Also attracting attention are anastomoses formed by magnetic compression, with surgical anastomosis completed with IVR for the first time in the world. The era after 2000 can be considered an era of evolution. As described above, progress in non-vascular IVR has been remarkable since the 1990s. Through the efforts of many experts, including those in Japan, many new devices, procedures, and treatment approaches were developed and established, and their indications continue to be extended. The low invasiveness of IVR was emphasized in the 1990s. In the future, narrower devices will be developed, and, although current common procedures generally involve puncture, future treatment will advance so as not to require puncture, as with the focused ultrasound therapy used in tumor ablation. Further, the trend toward uniform, standardized procedures that offer more precise results and are not dependent on the operator s skill have led to the development of medical robots, some of which are already in practical use in the surgical field and are expected to be introduced into the field of IVR as well. In recent years, radiation exposure to patients and medical personnel has drawn attention, especially with use of CT-guided IVR. To reduce radiation
exposure to both patients and personnel, medical robots will be useful, and the development of MRI-guided IVR should be further promoted since MRI, like ultrasound, involves no radiation exposure. In the area of patients QOL, the purpose of non-vascular IVR in the treatment of malignant lesions has been changed dramatically by the advent of PEIT. Before PEIT, the majority of procedures were aimed at palliative treatment, but now the goal has been shifted to radical cure and a firm position has been established. In the dynamic areas of immunogenetic therapy and regenerative medicine, this non-vascular IVR is expected to play a significant role. However, the finances of the national health care system and comprehensive medicine need to be considered. Thus, in the future, it is inevitable that the duration of hospitalization will be shortened, and outpatient-based treatment will be enhanced to improve the QOL of patients. Non-vascular IVR is strongly expected to continue its progress, and new procedures and treatment approaches are expected to be developed one after another.
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