Clinical Applications of Mixed Reality and 3D Printing in Congenital Heart Disease

Understanding the anatomical features and generation of realistic three-dimensional (3D) visualization of congenital heart disease (CHD) is always challenging due to the complexity and wide spectrum of CHD. Emerging technologies, including 3D printing and mixed reality (MR), have the potential to overcome these limitations based on 2D and 3D reconstructions of the standard DICOM (Digital Imaging and Communications in Medicine) images. However, very little research has been conducted with regard to the clinical value of these two novel technologies in CHD. This study aims to investigate the usefulness and clinical value of MR and 3D printing in assisting diagnosis, medical education, pre-operative planning, and intraoperative guidance of CHD surgeries through evaluations from a group of cardiac specialists and physicians. Two cardiac computed tomography angiography scans that demonstrate CHD of different complexities (atrial septal defect and double outlet right ventricle) were selected and converted into 3D-printed heart models (3DPHM) and MR models. Thirty-four cardiac specialists and physicians were recruited. The results showed that the MR models were ranked as the best modality amongst the three, and were significantly better than DICOM images in demonstrating complex CHD lesions (mean difference (MD) = 0.76, p = 0.01), in enhancing depth perception (MD = 1.09, p = 0.00), in portraying spatial relationship between cardiac structures (MD = 1.15, p = 0.00), as a learning tool of the pathology (MD = 0.91, p = 0.00), and in facilitating pre-operative planning (MD = 0.87, p = 0.02). The 3DPHM were ranked as the best modality and significantly better than DICOM images in facilitating communication with patients (MD = 0.99, p = 0.00). In conclusion, both MR models and 3DPHM have their own strengths in different aspects, and they are superior to standard DICOM images in the visualization and management of CHD.

POS1217 ANTI-TNF THERAPY FOR IMMUNE MEDIATED INFLAMMATORY DISEASES MAY BE ASSOCIATED WITH LOWER ANTIBODY LEVELS AND VIRUS NEUTRALIZATION EFFICACY FOLLOWING SARS-CoV-2 mRNA VACCINATION

Background

The impact of immunosuppressants on COVID-19 vaccination response and durability in patients with immune-mediated inflammatory diseases (IMID) is yet to be fully characterized. Humoral response may be attenuated in these patients especially those on B cell depleting therapy and higher doses of corticosteroids, but data regarding other immunosuppressants are scarce.

Objectives

We aimed to investigate antibody and T cell responses and durability to SARS-CoV-2 mRNA vaccines (BNT162b and/or mRNA 1273) in IMID patients on immunomodulatory maintenance therapy other than B-cell depleting therapy and corticosteroids.

Methods

This prospective observational cohort study examined the immunogenicity of SARS-CoV-2 mRNA vaccines in adult patients with IMIDs (psoriatic arthritis, psoriasis, inflammatory bowel disease and rheumatoid arthritis) with or without maintenance immunosuppressive therapies (anti-TNF, methotrexate/azathioprine [MTX/AZA], anti-TNF + MTX/AZA, anti IL12/23, anti-IL-17, anti-IL23) compared to healthy controls. Automated ELISA for IgGs to spike trimer, spike receptor binding domain (RBD) and the nucleocapsid (NP) and T-cell release of 9 cytokines (IFNg, IL2, IL4, IL17A, TNF) and cytotoxic molecules (sFasL, GzmA, GzmB, Perforinin) in cell culture supernatants following stimulation with spike or NP peptide arrays were conducted at 4 time points: T1=pre vaccination, T2=median 26 days after dose 1, T3=median 16 days after dose 2 and T4=median 106 days after dose 2. Neutralization assays against four SARS-CoV-2 variants (wild type, delta, beta and gamma) were conducted at T3.

Results

We followed 150 subjects: 26 healthy controls and 124 IMID patients: 9 untreated, 44 on anti-TNF, 16 on anti-TNF with MTX/AZA, 10 on anti-IL23, 28 on anti-IL12/23, 9 on anti-IL17, 8 on MTX/AZA (Table 1). Most patients mounted antibody and T cell responses with increases from dose 1 to dose 2 (100% seroconversion at T3) and some decline by T4, with variability within groups. Antibody levels and neutralization efficacy was lower in anti-TNFgroups (anti-TNF, anti-TNF + MTX/AZA) compared to controls and waned by T4 (Figure 1). T cell responses were not consistently different between groups. Pooled data showed a higher antibody response to mRNA-1273 compared to BNT162b.

Table 1.

Baseline characteristics of study participants

Controluntreated IMIDAnti- TNFAnti- TNF +MTX/AZAAnti-IL-23Anti -IL-12/23Anti -IL-17MTX/AZAn=26n=9n=44n=16n=10n=28n=9n=8p-valueIMID*N/A IBD9301002704 Psoriasis1318122 PA0732172 AS0830010 RA1100011Age median years [IQR]36 [26-46]33 [27-41]38 [30-51]53 [44-59]48 [45-61]34 [28-47]49 [46-61]42 [31-55]<0.001^Sex male (%)16 (62)5 (56)18 (41)8 (50)5 (50)13 (46)6 (67)4 (50)0.772~BMImedian kg/m2 [IQR]25 [23-28]26 [22-27]22 [24-26]26 [24-28]27 [24-35]22 [21-24]32 [26-34]26[25-33]0.001^Vaccine interval median days [IQR]74 [35-84]54 [31-64]60 [45-69]64 [50-72]74 [35-84]62 [49-69]65 [52-75]58 [21-97]0.372^

*multiple IMIDs per patient possible

Figure 1.

Antibody responses (A) Anti spike and anti RBD IgG levels at indicated time points. Blue line represents median ratio in convalescent patients. The red line is the seropositivity threshold: the median antibody level of those that pass both a 1% false positive rate and show ≥3SD from the log means of the negative controls. (B) Relative ratio of RBD, spike and NP across time. Black and gray lines indicate median and mean values, respectively. *p≤0.05, **p≤0.01, ***p≤0.001, ****p≤0.0001

Conclusion

Following 2 doses of mRNA vaccination there is 100% seroconversion in IMID patients on maintenance therapy. Antibody levels and neutralization efficacy in anti-TNF group are lower than controls, and wane substantially by 3 months after dose 2. These findings highlight the need for third dose in patients undergoing treatment with anti-TNF therapy and continued monitoring of immunity in these patient groups, taking into consideration newer variants and additional vaccine doses.

Acknowledgements

This work was funded by a donation from Juan and Stefania Speck and by grants VR-1 172711, VS1-175545, FDN-143250, GA1- 177703 and GA2- 177716, from Canadian Institutes of Health Research and COVID Immunity task force and by Sinai Health Foundation

Disclosure of Interests

Naomi Finkelstein: None declared, Roya M. Dayam: None declared, Jaclyn Law: None declared, Rogier Goetgebuer: None declared, Gary Chao: None declared, Kento T. Abe: None declared, Mitchell Sutton: None declared, Joanne M. Stempak: None declared, Daniel Pereira: None declared, David Croitoru: None declared, Lily Acheampong: None declared, Saima Rizwan: None declared, Klaudia Rymaszewski: None declared, Raquel Milgrom: None declared, Darshini Ganatra: None declared, Nathalia V. Batista: None declared, Melanie Girard: None declared, Irene Lau: None declared, Ryan Law: None declared, Michelle Cheung: None declared, Bhavisha Rathod: None declared, Julia Kitaygorodsky: None declared, Reuben Samson: None declared, Queenie Hu: None declared, Nigil Haroon: None declared, Robert Inman Consultant of: AbbVie, Janssen, Lilly, Novartis., Grant/research support from: AbbVie, Novartis, Vincent Piguet Consultant of: AbbVie, Almirall, Celgene, Janssen, Kyowa Kirin Co. Ltd, LEO Pharma,

Novartis, Pfizer, Sanofi, UCB, and Union Therapeutic, Grant/research support from: Unrestricted educational grants from AbbVie, Bausch Health, Celgene, Janssen, LEO Pharma, Lilly, L’Oréal, NAOS, Novartis, Pfizer, Pierre-Fabre, Sandoz, and Sanofi, Mark Silverberg Speakers bureau: AbbVie, Janssen, Takeda, Pfizer, Gilead and Amgen, Consultant of: AbbVie, Janssen, Takeda, Pfizer, Gilead and Amgen, Grant/research support from: AbbVie, Janssen, Takeda, Pfizer, Gilead and Amgen, Anne-Claude Grigras: None declared, Tania H. Watts: None declared, Vinod Chandran Consultant of: AbbVie, Amgen, BMS, Eli Lilly, Janssen, Novartis, Pfizer and UCB, Grant/research support from: AbbVie, Amgen, Eli-Lilly.

Clinical Value of Virtual Reality versus 3D Printing in Congenital Heart Disease

Both three-dimensional (3D) printing and virtual reality (VR) are reported as being superior to the current visualization techniques in conveying more comprehensive visualization of congenital heart disease (CHD). However, little is known in terms of their clinical value in diagnostic assessment, medical education, and preoperative planning of CHD. This cross-sectional study aims to address these by involving 35 medical practitioners to subjectively evaluate VR visualization of four selected CHD cases in comparison with the corresponding 3D printed heart models (3DPHM). Six questionnaires were excluded due to incomplete sections, hence a total of 29 records were included for the analysis. The results showed both VR and 3D printed heart models were comparable in terms of the degree of realism. VR was perceived as more useful in medical education and preoperative planning compared to 3D printed heart models, although there was no significant difference in the ratings (p = 0.54 and 0.35, respectively). Twenty-one participants (72%) indicated both the VR and 3DPHM provided additional benefits compared to the conventional medical imaging visualizations. This study concludes the similar clinical value of both VR and 3DPHM in CHD, although further research is needed to involve more cardiac specialists for their views on the usefulness of these tools.

Quantitative and qualitative comparison of low- and high-cost 3D-printed heart models

Current visualization techniques of complex congenital heart disease (CHD) are unable to provide comprehensive visualization of the anomalous cardiac anatomy as the medical datasets can essentially only be viewed from a flat, two-dimensional (2D) screen. Three-dimensional (3D) printing has therefore been used to replicate patient-specific hearts in 3D views based on medical imaging datasets. This technique has been shown to have a positive impact on the preoperative planning of corrective surgery, patient-doctor communication, and the learning experience of medical students. However, 3D printing is often costly, and this impedes the routine application of this technology in clinical practice. This technical note aims to investigate whether reducing 3D printing costs can have any impact on the clinical value of the 3D-printed heart models. Low-cost and a high-cost 3D-printed models based on a selected case of CHD were generated with materials of differing cost. Quantitative assessment of dimensional accuracy of the cardiac anatomy and pathology was compared between the 3D-printed models and the original cardiac computed tomography (CT) images with excellent correlation (r=0.99). Qualitative evaluation of model usefulness showed no difference between the two models in medical applications.

Three-dimensional printing in congenital heart disease: A systematic review

Three-dimensional (3D) printing has shown great promise in medicine with increasing reports in congenital heart disease (CHD). This systematic review aims to analyse the main clinical applications and accuracy of 3D printing in CHD, as well as to provide an overview of the software tools, time and costs associated with the generation of 3D printed heart models. A search of different databases was conducted to identify studies investigating the application of 3D printing in CHD. Studies based on patient's medical imaging datasets were included for analysis, while reports on in vitro phantom or review articles were excluded from the analysis. A total of 28 studies met selection criteria for inclusion in the review. More than half of the studies were based on isolated case reports with inclusion of 1-12 cases (61%), while 10 studies (36%) focused on the survey of opinion on the usefulness of 3D printing by healthcare professionals, patients, parents of patients and medical students, and the remaining one involved a multicentre study about the clinical value of 3D printed models in surgical planning of CHD. The analysis shows that patient-specific 3D printed models accurately replicate complex cardiac anatomy, improve understanding and knowledge about congenital heart diseases and demonstrate value in preoperative planning and simulation of cardiac or interventional procedures, assist surgical decision-making and intra-operative orientation, and improve patient-doctor communication and medical education. The cost of 3D printing ranges from USD 55 to USD 810. This systematic review shows the usefulness of 3D printed models in congenital heart disease with applications ranging from accurate replication of complex cardiac anatomy and pathology to medical education, preoperative planning and simulation. The additional cost and time required to manufacture the 3D printed models represent the limitations which need to be addressed in future studies.

Microcalcifications in stone-obstructed human submandibular gland are associated with apoptosis and cell proliferation

OBJECTIVE

Human submandibular gland (SMG) stones are associated with inflammation, fibrosis and microcalcifications in the surrounding tissues. However, there is little information about the accompanying cell injury-repair process, apoptosis, and cell proliferation. The purpose of this study was to investigate such an association and its clinical significance.

DESIGN OF STUDY

Mid-gland paraffin sections of human SMGs ("stone glands") and normal SMGs ("non-stone glands") were subjected to stains for general histology (hematoxylin and eosin), fibrosis (Masson's trichrome), and calcification (alizarin red) and to immunohistochemistry for proliferative activity (Ki-67), and apoptosis (Caspase-3). Tissues were assessed for areas of inflammation, calcium deposition, and fibrosis, and for cycling and apoptotic cells.

RESULTS

Acini were atrophic and proportionately fewer in lobules with fibrosis in stone glands. Additionally, stone glands had intraluminal calcifications (microliths) in scattered excretory and striated ducts and blood vessel walls. Areas of inflammation and fibrosis were small and uncommon, and calcifications were not seen in non-stone glands. Proliferating and apoptotic cells were common in the main duct of stone glands where ciliated and mucous cell hyperplasia and stratified squamous metaplasia had occurred, uncommon in the main duct of non-stone glands, and uncommon in all other parenchymal elements of both stone and non-stone glands.

CONCLUSION

Stone obstruction in the main excretory ducts of SMG resulted in progressive depletion of acini from proximal to distal lobules via calcification, inflammation, fibrosis, and parenchymal cell atrophy, apoptosis and proliferation. Interlobular duct microliths contributed to this depletion by further provoking intralobular inflammation, fibrosis, and acinar atrophy.

High-altitude paragangliomas diagnostic and therapeutic considerations

Forty-one cervical paragangliomas that occurred in 40 patients born and living in Mexico City, Mexico, were studied. Tumors were most common in women (38/40); were unilateral (39/40), without a side preference; were of the nonhereditary type; and were not malignant. Tumor imaging with radionucleaide angiographic scanning was noninvasive, innocuous, and reliable for screening, whereas selective carotid angiography allowed for definitive diagnosis and clinical stratification of patients. Surgical resection was performed in 29 patients; in 23 cases, en bloc resection was accomplished without a vascular compromise, whereas in 4 patients, a portion of the external carotid artery had to be ligated and resected. Two other patients required a vascular graft to restore blood flow to the internal carotid. Seven patients had postoperative transient cranial nerve palsies, and one had an incomplete hemiplegia. Permanent nerve damage occurred in seven patients. It was concluded that high-altitude paragangliomas are hyperplastic growths that result from adaptation to hypoxia. They are rarely true neoplasm and, in general, are not associated with functional loss. In view of this and of the high morbidity rate associated with surgical removal, it was recommended that these patients be referred to research centers where efforts toward the elucidation of the etiology and pathophysiology of these tumors can be carried out. Surgery should be reserved for symptomatic cases or cases in which the diagnosis remains in doubt. The decision to operate must weigh the following factors: The tumor's benign nature, its slow growth rate, the technical difficulties associated with its resection, the high postoperative morbidity rate, and the general condition of the patient.

Prevention of cadmium-induced sterility by zinc in the male rat

The potential of zinc (Zn) to antagonize the adverse effects of cadmium (Cd) on the male reproductive processes was studied. A significant reduction in the weights of the testis and epididymis, the testicular sperm population and oligospermia to azoospermia in the epididymis was recorded in rats treated once s.c. with 2 mg/kg Cd and sacrificed 20 days later. This was accompanied by a significantly reduced serum T and a loss of fertility. Administration of a single s.c. injection of Zn (80 mg/kg) did not alter significantly any of the reproductive parameters studied. On the other hand, Zn given 1/2 to 2 h after Cd resulted in partial recovery. Organ weights and sperm population in these groups were maintained and the fertility rate was 67% and 50% at 5 and 20 days as compared to 67% and 0% at corresponding period in Cd-exposed males. The protective effect diminished when Zn was given more than 2 h after Cd exposure. The most effective regimen of Zn therapy was an administration of a total dose of 80 mg/kg Zn given in 3 injections (15 mg/kg before, 50 mg/kg at the time and 15 mg/kg 2 h after Cd). The results provide evidence that Zn, if given before or within 2 h of Cd exposure, is capable of at least partially reversing its deleterious effects on spermatogenesis, steroidogenesis and fertility of the male rat.