INTRODUCTIONThe study seeks to investigate how the duration of storage of cryopreserved human cadaveric iliac arteries impacts their mechanical, structural and microbiological properties as compared to their fresh sample.

MATERIALS AND METHODSIliac arteries were harvested from 12 human cadavers and divided into 2 groups. One group underwent mechanical stress-strain assessment immediately and another was cryopreserved for a pre-determined time-period (range, 29 to 364 days). Mechanical functionality was assessed with a customised clamping mechanism. The arteries' microbiological properties were studied pre- and post-cryopreservation. The post-thawed arteries were also assessed histologically for structural integrity.

RESULTSOf the 12 pairs, only 7 (58, 119, 150, 252, 300, 332 and 364 days) iliac arteries were included in the final analysis. The other 5 pairs (29, 90, 188, 205 and 270 days) had abundant local calcification and their stress-strain curves could not be characterised. From the curves, pre- and post-cryopreserved arteries had the most similar mechanical properties when stored for 119 days. A trend of increasing relative stiffness with increased duration of storage was noted. The post-thawed arteries demonstrated minimal fragmentation except in atherosclerotic areas. Majority of the arteries were not contaminated by bacterial or fungal infection pre- and post-cryopreservation. Also, 2 arteries (364 and 332 days) which had initial bacterial colonisation showed no bacterial growth on their post-thawed sample.

CONCLUSIONMechanically, non-atherosclerotic cryopreserved arteries can be a good substitute to their corresponding fresh arterial graft. However, the length of cryopreservation has an effect on the relative stiffness of the pre- and post-cryopreserved arteries. Histological and microbiological findings suggest that cryopreservation have little impact on an artery structural integrity and may possibly have a role in maintaining sterility and sterilising the arteries.

Aged ; Biomechanical Phenomena ; Cadaver ; Cryopreservation ; Humans ; Iliac Artery ; anatomy & histology ; microbiology ; physiology ; Middle Aged

Radiofrequecy ablation is the most widely used local ablative therapy for both primary and metastatic liver tumours. However, it has limited application in the treatment of large tumours (tumours >3cm) and multicentric tumours. In recent years, many strategies have been developed to extend the application of radiofrequency ablation to large tumours. A promising approach is to take advantage of the rapid advancement in imaging and robotic technologies to construct an integrated surgical navigation and medical robotic system. This paper presents a review of existing surgical navigation methods and medical robots. We also introduce our current developed model - Transcutaneous Robot-assisted Ablation-device Insertion Navigation System (TRAINS). The clinical viability of this prototyped integrated navigation and robotic system for large and multicentric tumors is demonstrated using animal experiments.
Catheter Ablation ; instrumentation ; methods ; Humans ; Imaging, Three-Dimensional ; Liver ; Liver Neoplasms ; pathology ; surgery ; therapy ; Robotics ; Surgery, Computer-Assisted ; instrumentation ; methods ; Surgical Procedures, Operative ; methods

INTRODUCTION: In Europe and North America, the majority of children with high-risk neuroblastoma survive the disease. Elsewhere, the treatment outcomes are poor. METHODS: A retrospective review of children treated for high-risk neuroblastoma in a single institution in Singapore from 2007 to 2019 was carried out. Treatment consisted of intensive chemotherapy, surgery aimed at gross total resection of residual disease after chemotherapy, consolidation with high-dose therapy followed by autologous stem cell rescue, and radiotherapy to the primary and metastatic sites followed by maintenance treatment with either cis-retinoic acid or anti-disialoganglioside monoclonal antibody therapy. Survival data were examined on certain clinical and laboratory factors. RESULTS: There were 57 children (32 male) treated for high-risk neuroblastoma. Their mean age was 3.9 (range 0.7-14.9) years. The median follow-up time was 5.5 (range 1.8-13.0) years for the surviving patients. There were 31 survivors, with 27 patients surviving in first remission, and the five-year overall survival and event-free survival rates were 52.5% and 47.4%, respectively. On log-rank testing, only the group of 17 patients who were exclusively treated at our centre had a survival advantage. Their five-year overall survival rate compared to patients whose initial chemotherapy was done elsewhere was 81.6% versus 41.1% (P = 0.011), and that of event-free survival was 69.7% versus 36.1% (P = 0.032). Published treatment results were obtained from four countries in Southeast Asia with five-year overall survival rates from 13.5% to 28.2%. CONCLUSION Intensified medical and surgical treatment for high-risk neuroblastoma proved to be effective, with superior survival rates compared to previous data from Southeast Asia.
Child ; Humans ; Male ; Infant ; Child, Preschool ; Adolescent ; Disease-Free Survival ; Neuroblastoma/pathology* ; Hematopoietic Stem Cell Transplantation/methods* ; Treatment Outcome ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Asia, Southeastern/epidemiology* ; Combined Modality Therapy