Print Email Facebook Twitter Defining parameters for objective assessment of technical skills in a transanal purse string suture Title Defining parameters for objective assessment of technical skills in a transanal purse string suture Author van Kasteren, Rhea (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Biomechanical Engineering) Contributor Horeman, T. (mentor) Dankelman, J. (graduation committee) de Winter, J.C.F. (graduation committee) Degree granting institution Delft University of Technology Date 2018-04-13 Abstract Total Mesorectal Excision is the recommended curative surgical treatment for most cases of rectal cancer that exceed multiple layers of the bowel. For some cases a laparoscopic approach is difficult to perform. In cases of highly obese patients, or a specifically distal laying tumor. The tumor is then difficult to reach because of the funneling shape of the pelvis. This creates difficulties for the surgeon resulting for higher risk of damaging nerves and surrounding organs. For these cases a transanal approach is introduced: Transanal Total Mesorectal Excision (TaTME). A key step in TaTME is the purse string suture which is used to close the distal stump of the rectum before starting full thickness incision. Currently training of the procedure is done through proctoring and a two-day introductory course with OR-observation and cadaver training. Literature study showes that no box trainers that allow objective assessment of skills are currently available for this specific task. This goal of this thesis is to find parameters that might contain construct validity for expertise for a transanal purse string suture. Several force-based parameters are selected for analysis. To obtain the goal a novel measurement system is designed according to a set of requirements. The system measures forces exerted on the entrance port for the instruments as well as tissue interaction forces. A pilot study is done after which improvements in the device and test protocol are implemented. Last a construct validity study is performed at VU medical center in Amsterdam. Two groups participated in the study: novice (n=7) and experts (n=3). Promising results are found for tissue interaction forces. Novices apply higher and longer peaks of force. This correlates to observed difficulties in positioning the needle correctly before incision. Experts create a smooth motion by interchanging the needle between instruments. Interesting results are obtained for portal forces along the long axis of the port, in other words box in- and outward. It is seen that the resultant force shifts from a mostly pulling force for novice to a pushing force for experts. This can be a sign of incorrect instruments handling and must be researched further for its function as a parameter for objective skill assessment. Furthermore, internal moments about x-axis and y-axis show interesting results. Where the moment about the y follows a clear sinusoid for both novices and experts, this is not the case for the moment about the x-axis. It is very likely that this is due to the interference of the scope. Significant differences are found for Mx.min, Mx.mean, and Mx.pos. It is suggested that the moment about the x-axis can also be a good indicator for instrument handling skillsThe novel measurement system designed for this study can be used to give insight in instrument handling behavior when performing a transanal purse string suture. It has the unique feature to assess internal moments in a single-port setting, which is not applied in skill assessment in laparoscopy yet. Subject TaTMEtotal mesorectal excisionskills assessmentobjectiveparameterspurse string suture To reference this document use: http://resolver.tudelft.nl/uuid:944e17f3-1d58-4e45-874e-76ab24596b63 Part of collection Student theses Document type master thesis Rights © 2018 Rhea van Kasteren Files PDF Kasteren_Rhea_van_Thesis_paper.pdf 1.02 MB PDF Kasteren_Rhea_van_Thesis_report.pdf 5.1 MB Close viewer /islandora/object/uuid:944e17f3-1d58-4e45-874e-76ab24596b63/datastream/OBJ1/view