Manual Shunt Connector Tool to Aid in No-Touch Technique.

BACKGROUND: Given the morbidity and cost associated with cerebrospinal fluid shunt infections, many neurosurgical protocols implement "no-touch" technique to minimize infection. However, current surgical tools are not designed specifically for this task and surgeons often resort to using their hands to connect the shunt catheter to the valve. OBJECTIVE: To develop an efficient and effective shunt assembly tool. METHODS: Prototypes were designed using computer assisted software and machined in stainless steel. The amount of time and number of attempts it took volunteers to connect a Bacticel shunt catheter to a Delta valve were recorded using the new tool and standard shodded mosquitos. Scanning electron microscopy (SEM) was done on manipulated catheters to assess potential damage. Practicing neurosurgeons provided feedback. RESULTS: Nonsurgeon (n = 13) volunteers and neurosurgeons (n = 6) both completed the task faster and with fewer attempts with the new tool (mean 7.18 vs 15.72 s and 2.00 vs 6.36 attempts, P < .0001; mean 2.93 vs 5.96 s and 1.06 vs 2.94 attempts, P < .001, respectively). SEM of 24 manipulated catheters showed no microscopic damage. 100% of neurosurgeons surveyed (n = 10) would adapt the tool in their practice, 90% preferred use of the new tool compared to their existing method, and 100% rated it easier to use compared to existing instruments. CONCLUSION: The new tool shortened the time and number of attempts to connect a shunt catheter to a valve. Neurosurgeons preferred the new tool to existing instruments. There was no evidence of catheter damage with the use of this tool.

Development of a dynamic Chest Wall and operating table simulator to enhance congenital heart surgery simulation.

BACKGROUND: The Hands-On Surgical Training in Congenital Heart Surgery (HOST-CHS) program using 3D printed heart models has received positive feedback from attendees. However, improvements were necessary in the simulator set up to replicate the ergonomics experienced in the operating room. This paper illustrates the development of a dynamic chest wall and operating table simulator to enhance the simulation experience. METHODS: The simulator was designed to address the limitations with the existing set up. This included a suboptimal operating position, unrealistic surgical exposure and limitations in illuminating the operative field and recording procedures. A combination of computer-aided design and various 3D-printing techniques were used to build the components. The simulator's usefulness was evaluated by surgeons who attended the 5th annual HOST course via a questionnaire. RESULTS: The simulator consists of three components; an operating table simulator which allows height adjustment and pitch-and-roll motion; a suture retraction disc, which holds sutures under tension to improve exposure; and a pediatric chest wall cavity to replicate a surgeon's access experience during surgery. Nineteen surgeons completed the questionnaire. All surgeons agreed that the addition of the simulator was acceptable for surgical simulation and that it helped replicate the ergonomics experienced in the operating room. CONCLUSIONS: The inclusion of the HOST-CHS simulator adds value to simulation in congenital heart surgery (CHS) as it replicates the view and exposure a surgeon experiences. Improvements like these will help develop high-fidelity simulation programs in CHS, which could be utilized to train surgeons globally.

Simulation of semilunar valve function: computer-aided design, 3D printing and flow assessment with MR.

BACKGROUND: The structure of the valve leaflets and sinuses are crucial in supporting the proper function of the semilunar valve and ensuring leaflet durability. Therefore, an enhanced understanding of the structural characteristics of the semilunar valves is fundamental to the evaluation and staging of semilunar valve pathology, as well as the development of prosthetic or bioprosthetic valves. This paper illustrates the process of combining computer-aided design (CAD), 3D printing and flow assessment with 4-dimensional flow magnetic resonance imaging (MRI) to provide detailed assessment of the structural and hemodynamic characteristics of the normal semilunar valve. METHODS: Previously published geometric data on the aortic valve was used to model the 'normal' tricuspid aortic valve with a CAD software package and 3D printed. An MRI compatible flow pump with the capacity to mimic physiological flows was connected to the phantom. A peak flow rate of 100 mL/s and heart rate of 60 beats per minute were used. MRI measurements included cine imaging, 2D and 4D phase-contrast imaging to assess valve motion, flow velocity and complex flow patterns. RESULTS: Cine MRI data showed normal valve function and competency throughout the cardiac cycle in the 3D-printed phantom. Quantitative analysis of 4D Flow data showed net flow through 2D planes proximal and distal to the valve were very consistent (26.03 mL/s and 26.09 mL/s, respectively). Measurements of net flow value agreed closely with the flow waveform provided to the pump (27.74 mL/s), confirming 4D flow acquisition in relation to the pump output. Peak flow values proximal and distal to the valve were 78.4 mL/s and 63.3 mL/s, respectively. Particle traces of flow from 4D-phase contrast MRI data demonstrated flow through the valve into the ascending aorta and vortices within the aortic sinuses, which are expected during ventricular diastole. CONCLUSION: In this proof of concept study, we have demonstrated the ability to generate physiological 3D-printed aortic valve phantoms and evaluate their function with cine- and 4D Flow MRI. This technology can work synergistically with promising tissue engineering research to develop optimal aortic valve replacements, which closely reproduces the complex function of the normal aortic valve.