RESUMEN
Background: The cause for the association between increased cardiovascular mortality rates and lower blood pressure (BP) after aortic valve replacement (AVR) is unclear. This study aims to assess how the epicardial coronary flow (ECF) after AVR varies as BP levels are changed in the presence of a right coronary lesion. Methods: The hemodynamics of a 3D printed aortic root model with a SAPIEN 3 26 deployed were evaluated in an in vitro left heart simulator under a range of varying systolic blood pressure (SBP) and diastolic blood pressure (DBP). ECF and the flow ratio index were calculated. Flow index value <0.8 was considered a threshold for ischemia. Results: As SBP decreased, the average ECF decreased below the physiological coronary minimum at 120 mmHg. As DBP decreased, the average ECF was still maintained above the physiological minimum. The flow ratio index was >0.9 for SBP ≥130 mmHg. However, at an SBP of 120 mmHg, the flow ratio was 0.63 (p ≤ 0.0055). With decreasing DBP, no BP condition yielded a flow ratio index that was less than 0.91. Conclusions: Reducing BP to the current recommended levels assigned for the general population after AVR in the presence of coronary artery disease may require reconsideration of levels and treatment priority. Additional studies are needed to fully understand the changes in ECF dynamics after AVR in the presence and absence of coronary artery disease.
RESUMEN
Purpose: Three-dimensional (3D) printing has had a significant impact on patient care. However, there is a lack of standardization in quality assurance (QA) to ensure printing accuracy and precision given multiple printing technologies, variability across vendors, and inter-printer reliability issues. We investigated printing accuracy on a diverse selection of 3D printers commonly used in the medical field. Approach: A specially designed 3D printing QA phantom was periodically printed on 16 printers used in our practice, covering five distinct printing technologies and eight different vendors. Longitudinal data were acquired over six months by printing the QA phantom monthly on each printer. Qualitative assessment and quantitative measurements were obtained for each printed phantom. Accuracy and precision were assessed by comparing quantitative measurements with reference values of the phantom. Data were then compared among printer models, vendors, and printing technologies; longitudinal trends were also analyzed. Results: Differences in 3D printing accuracy across printers were observed. Material jetting and vat photopolymerization printers were found to be the most accurate. Printers using the same 3D printing technology but from different vendors also showed differences in accuracy, most notably between vat photopolymerization printers from two different vendors. Furthermore, differences in accuracy were found between printers from the same vendor using the same printing technology, but different models/generations. Conclusions: These results show how factors such as printing technology, vendor, and printer model can impact 3D printing accuracy, which should be appropriately considered in practice to avoid potential medical or surgical errors.
RESUMEN
BACKGROUND: Surgical vaginoplasty is a highly successful treatment for congenital absence of the vagina. One key to long-term success is the use of an appropriate vaginal mold in the immediate postoperative period. We present the use of a three-dimensional (3D)-printed vaginal mold, customizable to the anatomy of individual patients. TECHNIQUE: Vaginal molds were designed using a 3D modeling software program. The design included narrowing around the urethra, holes for egress of secretions, and a knob for insertion and removal. Dental resin was 3D-printed into various-sized vaginal molds, and postprocessing was performed. EXPERIENCE: We present the use of the 3D-printed mold for a patient with a history of cloacal exstrophy and a unique pelvic shape. Two prior neovagina surgeries in this patient had been unsuccessful due to ineffective handheld dilator use; the patient experienced success with the 3D-printed intravaginal mold. CONCLUSION: The use of the 3D-printed vaginal mold is an alternative to the limited commercially available models today and allows for customization to user anatomy. With 3D printers becoming more widely accessible, we believe this method could become universally accepted, with hopes of contributing to increased patient satisfaction and decreased complications.
