The Two-point Fluoroscopy Technique for Ureteroscopy
There is a raising concern regarding patient exposure to ionizing radiation and efforts are directed to minimize it, especially in the younger group. Fluoroscopy is being used as a guide in various invasive procedures, ureteroscopy being one of the best-known indications. Different measures, such as collimation and pulsed fluoroscopy, have been implemented to lower unnecessary x-ray exposure during invasive procedures. In this study we propose a new technique of fluoroscopic guidance for ureteroscopy based on 2 pre-determined anatomic points, which covers all the areas of interest in one hand while limiting the continuous use of fluoroscopy during repositioning of the c-arm in the other.
To achieve the aforementioned goal, we have developed a technique in which the c-arm is moved in caudal to cephalad direction and vice-versa by the intrinsic articulation of the fluoroscope (instead of moving the whole machine) and 2 predetermined anatomic limits ("points") are fixed, making 2 marks on the degree's rule at the c-arm's collar. These points were called point 1 (caudal) and point 2 (cephalad), being the caudal limit of point 1 the lower limit of the symphysis pubis and the caudal limit of point 2 the upper limit of point 1. This way, in normal anatomic conditions the whole area from the ureteral orifice to the upper pole of each kidney is covered. During the procedure, the surgeon indicates the x-ray technician which point should be shown in each step and this way, the amount of radiation is limited to only the minimum required for the specific indication. Using this innovative technique, we have recorded the radiation dose and time required in different procedures and the results were compared to matched groups in which this technique was not implemented.
Data has been recorded from 29 procedures, 41.37% implementing the "Two-Point Technique" (TPT) and 58.6% using a Conventional Fluoroscopic Technique (CFT). The x-ray dose delivered ranged from 1.83 to 35.4 mGy in the TPT group and from 2.87 to 102 mGy in the CFT group, while the fluoroscopy time ranged from 24 to 138 seconds in the TPT group and from 27 to 296.1 seconds in the CFT group.
According to this initial data, he Two-Point Fluoroscopy Technique has shown to potentially reduce the radiation dose and time required during ureteroscopy, minimizing the exposure of the patient and staff to excessive and unnecessary ionizing radiation.