Computed tomography is one of the most evolving fields of modern radiology. The current CT applications permit among other things angiography, 3D image reconstructions, material decomposition and tissue characterization. CT is an important tool in the assessment of specific patient populations prior to an invasive or surgical procedure. The aim of this dissertation was to demonstrate the decisive role of CT with 3D-image reconstructions in haemodialysis patients scheduled to undergo fistulography, in patients undergoing surgical breast reconstructions with a perforator flap and in patients with complicated renal calculi scheduled to undergo percutaneous nephrolithotomy. CT Angiography with 3D image reconstructions was performed in 31 patients with failing arteriovenous fistulas and grafts, illustrating the vascular anatomy in a comprehensive manner in 93.5% of the evaluated segments and demonstrating a sensitivity of 95% compared to fistulography. In 59 mastectomy patients scheduled to undergo reconstructive breast surgery with a deep inferior epigastric perforator flap, the preoperative planning with CT Angiography with 3D image reconstructions of the anterior abdominal wall providing details of its vascular supply, reduced surgery time significantly (p< 0.001) and resulted in fewer complications. Dual Energy CT Urography with advanced image reconstructions in 31 patients with complicated renal calculi scheduled to undergo PNL, resulted in a new method of material characterisation (depicting renal calculi within excreted contrast) and in the possibility of reducing radiation dose by 28% by omitting the nonenhanced scanning phase. Detailed analysis of the changes renal calculi undergo when virtually reconstructed was performed and a comparison of renal calculi number, volume, height and attenuation between virtual nonenhanced and true nonenhanced images was undertaken. All parameters were significantly underestimated in the virtual nonenhanced images. CT with 3D-reconstructions is more than just “flashy images”. It is crucial in preoperative planning, optimizes various procedures and can reduce radiation dose.

Purpose Following the introduction of the Regulation (EU) 2017/745 by the European Parliament, any bioactive substance or surgical implant introduced into the human body must be documented. The regulation requires any implant to be traced back to the manufacturer. Lot numbers need to be available for every single medical implant. Also, the manufacturer is required by law to provide implants individually packaged and sterilized. Previously, model tray systems (MOS tray) were used for osteosynthesis in oral and maxillofacial surgery, in which the individual implants could not be registered separately. The new regulation made it impossible to use such processes during surgery anymore and a need for a change in the medical practice surged. We examined a possible solution for the new legislation. The aim of this prospective cohort study is to analyze the MOS tray systems to osteosynthesis materials prepackaged in sets. We record and evaluate parameters such as surgical time and documentation time. We perform a short cost analysis of our clinic. The primary aim is to determine how much time is gained or lost by the mandatory increased patient safety. The secondary aim is to describe change in costs. Methods Patients that underwent standard surgical procedures in the clinic of oral and maxillofacial surgery of the faculty hospital Carl Gustav Carus in Dresden were included. We chose open reduction and internal fixation (ORIF) of anterior mandibular corpus fractures as well as mandibular advancement by means of bilateral sagittal split osteotomies (BSSO) as standardized procedures. Both of these procedures require two osteosynthesis plates and at least four screws for each plate. MOS trays were compared to prepackaged sterilized sets. The sets include a drill bit, two plates, and eight 5-mm screws. A total number of 40 patients were examined. We allocated 20 patients to the ORIF group and the other 20 patients to the BSSO group. Each group was evenly subdivided into a MOS tray group and a prepackaged group. Parameters such as the incision-suture time (IST) as well as the documentation time (DT) by the operating room (OR) staff to complete documentation for the implants are the main focus of investigation. Results For open reduction, the incision-suture time was significantly different in favor of the MOS tray (p < 0.05). There was no difference in the BSSO groups. However, we observed a significantly different (p < 0.01) documentation time advantage for the prepackaged sets in both the ORIF and BSSO groups. On top of that, we find that by using the prepackaged kits, we are able to reduce sterilization costs by €11.53 per size-reduced container. Also, there is also a total cut of costs of €38.90 and €43.70, respectively, per standardized procedure for implant material. Conclusions By law, a change in the method of approaching surgery is necessary. For standardized procedures, the right choice of implants can lead to a reduction of documentation time and costs for implant material, sterilization, as well as utilizing less instruments. This in turn leads to lower costs for perioperative processing as well as provision of state-of-the-art implant quality implementing higher patient security.