Effects of low-dose protocols in endovascular treatment of intracranial aneurysms: development of workflow task analysis during cerebral endovascular procedures.

OBJECTIVE: Reducing radiation exposure through the use of low-dose protocols during cerebral endovascular procedures is recommended, but evaluation of the impact on the procedure itself is difficult and subjective. A workflow task analysis could provide an objective comparison of two different radiation exposure protocols. SUBJECTS AND METHODS: Twenty endovascular aneurysm treatments were analyzed using a low-dose protocol (reducing radiation exposure by 20%) in 10 cases and a normal-dose protocol in the other 10 cases. The procedure was subdivided into five phases, each comprising a sequence of tasks. Each task was defined as a triplet, associating an action, an instrument, and an anatomic structure. A workflow editor was used to record tasks and phases with a tablet PC. The total duration of the entire procedure, the duration of each task, and the number of task repetitions were isolated and used as the metric. Moreover, the tasks involving x-ray use, essential for navigation and treatment phases, were separated and analyzed. RESULTS: For the microcatheter navigation and treatment phases, no statistically significant difference was found between the two radiation exposure protocols. For guide catheter navigation in cervical vessels, the total phase duration and total and mean time of tasks specifically involving x-ray use increased with age, but there was no difference between the two radiation protocols. CONCLUSION: Workflow task analysis of endovascular aneurysm treatment shows no difference between low-dose and normal-dose protocols in the guide catheter navigation, microcatheter navigation, or treatment phases.

Development of workflow task analysis during cerebral diagnostic angiographies: time-based comparison of junior and senior tasks.

OBJECTIVE: Assessing neuroradiologists' skills in the operating room (OR) is difficult and often subjective. This study used a workflow time-based task analysis approach while performing cerebral angiography. METHODS: Eight angiographies performed by a senior neuroradiologist and eight performed by a junior neuroradiologist were compared. Dedicated software with specific terminology was used to record the tasks. Procedures were subdivided into phases, each comprising multiple tasks. Each task was defined as a triplet, associating an action, an instrument and an anatomical structure. The duration of each task was the metric. Total duration of the procedure, task duration and the number of times a task was repeated were identified. The focus was on tasks using fluoroscopy and for moving the X-ray table/tube. RESULTS: The total duration of tasks to complete the entire procedure was longer for the junior operators than for the seniors (P=0.012). The mean duration per task during the navigation phase was 86s for the juniors and 43s for the seniors (P=0.002). The total and mean durations of tasks involving the use of fluoroscopy were also longer for the juniors (P=0.002 and P=0.033, respectively). For tasks involving the table/tube, the total and mean durations were again longer for the juniors (P=0.019 and P=0.082, respectively). CONCLUSION: This approach allows reliable skill assessment in the radiology OR and comparison of junior and senior competencies during cerebral diagnostic angiography. This new tool can improve the quality and safety of procedures, and facilitate the learning process for neuroradiologists.

Classification of surgical processes using dynamic time warping.

In the creation of new computer-assisted intervention systems, Surgical Process Models (SPMs) are an emerging concept used for analyzing and assessing surgical interventions. SPMs represent Surgical Processes (SPs) which are formalized as symbolic structured descriptions of surgical interventions using a pre-defined level of granularity and a dedicated terminology. In this context, one major challenge is the creation of new metrics for the comparison and the evaluation of SPs. Thus, correlations between these metrics and pre-operative data are used to classify surgeries and highlight specific information on the surgery itself and on the surgeon, such as his/her level of expertise. In this paper, we explore the automatic classification of a set of SPs based on the Dynamic Time Warping (DTW) algorithm. DTW is used to compute a similarity measure between two SPs that focuses on the different types of activities performed during surgery and their sequencing, by minimizing time differences. Indeed, it turns out to be a complementary approach to the classical methods that only focus on differences in the time and the number of activities. Experiments were carried out on 24 lumbar disk herniation surgeries to discriminate the surgeons level of expertise according to a prior classification of SPs. Supervised and unsupervised classification experiments have shown that this approach was able to automatically identify groups of surgeons according to their level of expertise (senior and junior), and opens many perspectives for the creation of new metrics for comparing and evaluating surgeries.

Recording of surgical processes: a study comparing senior and junior neurosurgeons during lumbar disc herniation surgery.

BACKGROUND: Evaluating surgical practice in the operating room is difficult, and its assessment is largely subjective. OBJECTIVE: Recording of standardized spine surgery processes was conducted to ascertain whether any significant differences in surgical practice could be observed between senior and junior neurosurgeons. METHODS: Twenty-four procedures of lumbar discectomies were consecutively recorded by a senior neurosurgeon. In 12 cases, surgery was entirely performed by a senior neurosurgeon with the aid of a resident, and in the 12 remaining cases, surgery was performed by a resident with the aid of a senior neurosurgeon. The data recorded were general parameters (operating time for the whole procedure and for each step), and general and specific parameters of the surgeon's activities (number of manual gestures, number and duration of actions performed, use of the instruments, and use of interventions on anatomic structures). The Mann-Whitney U test was used for comparison between the 2 groups of neurosurgeons. RESULTS: The operating time was statistically lower for the group of senior surgeons. The seniors statistically demonstrated greater economy in time and in gestures during the closure step, for sewing and for the use of scissors, needle holders, and forceps. The senior surgeons statistically worked for a shorter time on the skin and used fewer manual gestures on the thoracolumbalis fascia. The number of changes in microscope position was also statistically lower for this group. CONCLUSION: There is a relationship between surgical practice, as determined by a method of objective measurement using observation software, and surgical experience: gesture economy evolves with seniority.