西澤 春紀

Cytogenetic information about the product of conception (POC) is important to determine the presence of recurrent chromosomal abnormalities that are an indication for preimplantation genetic testing for aneuploidy or structural rearrangements. Although microscopic examination by G-staining has long been used for such an evaluation, detection failures are relatively common with this method, due to cell-culture-related issues. The utility of low-coverage whole-genome sequencing (lcWGS) using short-read next-generation sequencing (NGS) has been highlighted recently as an alternative cytogenomic approach for POC analysis. We, here, performed comparative analysis of two NGS-based protocols for this purpose based on different short-read sequencers (the Illumina VeriSeq system using a MiSeq sequencer and the Thermo Fisher ReproSeq system using an Ion S5 sequencer). The cytogenomic diagnosis obtained with each NGS method was equivalent in each of 20 POC samples analyzed. Notably, X chromosome sequence reads were reduced in some female samples with both systems. The possibility of low-level mosaicism for monosomy X as an explanation for this was excluded by FISH analysis. Additional data from samples with various degrees of X chromosome aneuploidy suggested that it was a technical artifact related to X chromosome inactivation. Indeed, subsequent nanopore sequencing indicated that the DNA in the samples showing the artifact was predominantly unmethylated. Our current findings indicate that although X chromosome data must be interpreted with caution, both the systems we tested for NGS-based lcWGS are useful alternatives for the karyotyping of POC samples.

INTRODUCTION: The da Vinci SP surgical system is a surgical platform capable of implementing robotic-assisted surgery through a single port and was first introduced in Japan at our hospital. In this paper, we describe our experience of the initial introduction of the da Vinci SP surgical system and its surgical outcomes. This is the first report on the surgical outcomes of using da Vinci SP, and its comparison with the conventional system in Japan. METHODS: After developing an application for a highly difficult new medical technology in-house, we compared the surgical outcomes (median values) of 15 patients who had undergone total hysterectomy at our hospital using the da Vinci SP (1-port) system (SP group) for uterine myoma after March 2023 and of 154 patients who underwent total hysterectomy using the conventional da Vinci Xi (four ports) system (Xi group) for uteri weighing <500 g. RESULTS: The results of the comparison of the characteristics between 15 patients in the SP group and 154 patients in the Xi group were as follows: uterus weight (g): 230 (90-500) versus 222 (55-496) (p = .35); surgical time (minutes): 199 (171-251) versus 198 (88-387) (p = .63); intraoperative blood loss (mL): 13 (5-82) versus 20 (2-384) (p = .17); and rate of surgical complication (%): 0.0 versus 1.3 (p = .66). The data indicated a comparable weight of the resected uterus, surgical time, intraoperative blood loss, and rate of surgical complications between the two groups. CONCLUSION: Robotic-assisted total hysterectomy using the da Vinci SP surgical system allowed clinicians to safely perform surgeries according to the conventional systems.