No description available.

Image-guided interventions using intraoperative three-dimensional (3D) imaging can be less cumbersome than systems dependent on preoperative images, especially by needing neither image-to-patient registration nor a lengthy process of segmenting and generating a 3D model. In this dissertation, a method for computer-assisted surgery using direct navigation on intraoperative images is presented. In this system the registration step of a navigated procedure was divided into two stages: preoperative calibration of images to a ceiling-mounted optical tracking system, and intraoperative tracking during acquisition of the 3D image. The preoperative stage used a custom-made multi-modal calibrator that could be optically tracked and also contained fiducial spheres for radiological detection; a robust registration algorithm was used to compensate for the high false-detection rate that arose from the optical light-emitting diodes. Intraoperatively, a tracking device was at- tached to bone models that were also instrumented with radio-opaque spheres; a calibrated pointer was used to contact the latter spheres as a validation. The fiducial registration error of the calibration stage was approximately 0.1 mm with the Innova 3D X-ray fluoroscope and 0.7 mm with the mobile-gantry CT scanner. The target registration error in the valida- tion stage was approximately 1.2 mm with the Innova 3D X-ray fluoroscope and 1.8 mm with the mobile-gantry CT scanner. These findings suggest that direct registration can be a highly accurate means of performing image-guided interventions in a fast, simple manner. / Thesis (Master, Computing) -- Queen's University, 2009-08-17 11:14:03.275

Background: The most common investigations used in the pre-operative diagnosis of choledocholithiasis are ultrasound and liver function tests (LFTs). These modalities have a low sensitivity for detecting common bile duct stones amongst the intermediate-risk groups. Aim: Identify pre-operative findings which predict choledocholithiasis in intermediate-risk groups. Describe the implications of a positive intra-operative cholangiogram (IOC). Method: A retrospective study of all consecutive laparoscopic cholecystectomies with IOC performed. Data were collected over two years between 1st January 2015 and 31st December 2016. Standard demographic variables, preoperative symptoms, LFTs, IOC findings, abdomen ultrasound, and postoperative symptoms were included. Results: 23 cases were planned for IOC. The median age was 41 years. Seventeen cases were females. Indications were 12 biliary colic, eight gallstone pancreatitis, two cases of acute cholecystitis, and one case was for ascending cholangitis. Four cases had a positive IOC, and in this group, the median age was 44.5 years with one male. The mean common bile duct diameter was 6.5 mm. Two patients had biliary colic, one patient gallstone pancreatitis and one acute cholecystitis. One patient had a history of jaundice, and all four cases had elevated GGT above 40 mmol/l, three cases had ALP above 98 mmol/l. Post-operative, out of 23 cases, five cases had an ERCP, repeated ultrasound in three cases, persistence symptoms in four cases. Conclusions: GGT was the strongest predictor of choledocholithiasis. A normal GGT seems to be quite good at ruling out CBD stones. ALP was less accurate. Gallstone pancreatitis is not a good predictor, but it is importance to exclude choledocholithiasis before/during cholecystectomy. There is no relation between the IOC and persistent symptoms.

In image-guided surgical navigation, instruments tools are tracked by a position sensor and their locations rendered along with the patient's anatomy. Conventional methods require an invasive, time-consuming and potentially uncertain process of intra-operative registration of the images to the patient. In a direct navigation system, such an intra-operative registration is replaced with pre-operative patient-independent calibration in a process that determines the relationship between the coordinate frame of imaging equipment and the coordinate frame of the position sensor. This dissertation presents a method for pre-operatively calibrating a direct navigation system that used an optical position sensor and a mobile gantry CT scanner. A custom bi-local calibration device was designed and manufactured, after which existing navigation software was augmented with components that used the pre-operatively determined transformation to provide image-guided surgical navigation. The resulting system was tested in an image-guided operating suite using plastic bone models. In the validation stage, the inherent error was less than 0.4 mm and the target registration error was approximately 1.6 mm for a ceiling-mounted position sensor and 0.7 mm for a portable position sensor. This accuracy is consistent with the best intra-operative registrations reported in the literature and this calibration method may be useful in future surgical systems. / Thesis (Master, Computing) -- Queen's University, 2013-09-05 12:53:08.994

Zugl.: München, Techn. Universiẗat, Diss., 2007.

The Operating Room (OR) is a clinical context in which interprofessional teams surgically intervene with the intention of improving the health of the patients they care for. Despite this, surgery is high risk, invasive and often volatile. The reality is that some patients die in the OR, an outcome which violates the care intention of the clinicians who work there. Using the narrative paradigm, this study explores the stories interprofessional team members shared about caring for patients who died intraoperatively. To appreciate the cultural climate in which these stories were rooted, a literature review of OR culture and theoretical analysis of master narratives was conducted. Using individual interviews, six perioperative clinicians were invited to share their stories: two Registered Nurses, one Registered Practical Nurse, two Surgeons and one Anesthetist. Two analytic approaches were used to authentically capture participant narratives: a narrative thematic approach and structural analysis. The structural analysis revealed the types of stories told—tragedies, romances, comedies and satires—while the thematic perspective elucidated participants’ experiences of intraoperative death and their interpretation of the impact of these experiences. These findings illustrated unique perspectives of intraoperative death, illuminating features which enhanced or deteriorated the experiences for clinicians and their teams. Examining results in tandem with master narratives highlighted prevalent cultural discourses which are held in tension by the clinicians who perpetuate them. Exploring these intersecting elements provides insight into implications for nursing practice, research, education and policy, with particular attention to interprofessional dynamics, staff support, and promoting a culture of resilience.

Red blood cells are commonly administered during the perioperative period, however our understanding of available guidance informing transfusion decisions as well as appropriateness of current practice is not well understood. Blood transfusions are associated with post-operative morbidity and possibly worse long-term outcomes. Furthermore, they are a costly and limited resource. They should therefore be used sparingly. The objective of this thesis was to further our understanding of guidance available for administration of intraoperative red blood blood cell transfusion, as well as conduct an audit of the appropriateness of transfusions administered during the perioperative period. This thesis is composed of both a systematic review as well as a retrospective review of a prospectively maintained database. The systematic review of identified 10 guidelines published between 1992-2018 that included indications for intraoperative transfusions. Six provided objective clearly defined criteria for transfusion based on hemoglobin triggers (range 60-100g/L) or hematocrit (<30%); one stated a specific clinical situation for which transfusion would be appropriate (ST changes). The evidence supporting intraoperative recommendations was extrapolated primarily from the non-operative setting. Retrospective review of a single centre revealed 19% of patients underging liver resection were transfused a mean of 2.6 units during the perioperative period. A total of 22% to 63% of transfusions administered during the intraoperative period were considered inappropriate based on the application of three different instruments. In contrast, 38% to 67% of transfusions administered during the postoperative period were considered inappropriate. Patients considered to have been inappropriately transfused during the intraoperative period were at increased risk of developing a major postoperative adverse event (Clavien-Dindograde 3) compared to those who did not receive a transfusion (OR 4.2; 95% CI 1.1-15.6). In conclusion, this thesis demonstrates evidence-based, practitioner oriented, intraoperative transfusion guidance for clinicians is lacking. Furthermore, a significant proportion of patients continue to be exposed to unnecessary transfusion. Further work in this area is warranted to clarify indications for intraoperative transfusion and subsequently minimize the administration of unnecessary transfusion.

In dieser Arbeit wird die intraoperative Boost-Bestrahlung mit 9 oder 20 Gy bei Mammakarzinompatientinnen evaluiert. Es werden das onkologische Ergebnis, die bestrahlungsassoziierte Toxizität, das kosmetische Therapieergebnis und die Lebensqualität ausgewertet. Die Analyse bezieht sich auf 124 Fälle im frühen Brustkrebsstadium. / This paper evaluates the use of intraoperative boost irradiation with 9 or 20 Gy in breast cancer patients. The study assesses the oncological outcome, radiation-associated toxicity, cosmetic therapeutic outcome and quality of life. The analysis refers to 124 cases of early-stage breast cancer.

No description available.

This thesis begins with a brief review about the role and importance of the small molecules containing fluorine atoms in medicine and imaging. Then, the first part of the thesis will discuss the synthesis, purification and characterization of pentamethine cyanine dyes. The structure identification of the final dyes is done by using 1H NMR, 13C NMR, 19F NMR, and mass spectrometry. The studies performed after full characterization were the determination of optical and physicochemical properties. After these properties were performed, the fluorophores were evaluated to be good candidates for in vivo testing.