Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Hepatocellular carcinoma (HCC) is a highly invasive tumor with a strong tendency for metastasis. The most common sites of metastasis are the lungs, followed by lymph nodes, adrenal glands, and bones. However, metastasis of HCC to the small bowel is extremely rare. A 42-yearold female with HCC secondary to chronic hepatitis B and lung metastasis underwent a right hepatic lobectomy, followed by two wedge resections performed via video-assisted thoracic surgery, four sessions of transcatheter arterial chemoembolization, and stereotactic body radiation therapy. She was under regular follow-up for HCC, during which her alpha-fetoprotein level increased to 722.2 IU/ml. Abdominal computed tomography (CT) revealed segmental wall thickening and aneurysmal dilatation of the small bowel loops. An 18 F-fluorodeoxyglucose positron emission tomography/CT scan demonstrated a 3.3-cm hypermetabolic mass-like lesion (standardized uptake value: 11.3) in the small bowel. Surgical resection of the affected small bowel segment was performed. Histopathological examination of the specimen confirmed metastatic HCC, with immunohistochemical positivity for hepatocyte-specific antigen. The patient has remained cancer-free for 60 months post-operatively. Surgical intervention may offer favorable long-term outcomes in patients with small bowel metastasis from HCC.

Purpose: Hematopoietic stem cell transplantation (HSCT) has been an important method of treatment in the advance of pediatric acute lymphoblastic leukemia (ALL). The indications for HSCT are evolving and require updated establishment. In this study, we aimed to investigate the efficacy of HSCT on the treatment outcome of pediatric ALL, considering the indications for HSCT and subgroups. Materials and Methods: A retrospective analysis was conducted on ALL patients diagnosed and treated at a single center. Risk groups were categorized based on age at diagnosis, initial white blood cell count, disease lineage (B/T), and cytogenetic study results. Data on the patients’ disease status at HSCT and indications of HSCT were collected. Indications for HSCT were categorized as upfront HSCT at 1st complete remission, relapse, and refractory disease. Results: Among the 549 screened patients, a total of 418 patients were included in the study; B-cell ALL (n=379) and T-cell ALL (T-ALL) (n=39). HSCT was conducted on a total of 106 patients (25.4%), with a higher frequency as upfront HSCT in higher-risk groups and specific cytogenetics. The overall survival (OS) was significantly better when done upfront than in relapsed or refractory state in T-ALL patients (p=0.002). The KMT2A-rearranged ALL patients showed superior event-free survival (p=0.002) and OS (p=0.022) when HSCT was done as upfront treatment. Conclusion HSCT had a substantial positive effect in a specific subset of pediatric ALL. In particular, frontline HSCT for T-ALL and KMT2A-rearranged ALL offered a better prognosis than when HSCT was conducted in a relapsed or refractory setting.

Background/Aims: Proprotein-converting enzyme subtilisin-kexin type 9 (PCSK9) inhibitors act more promptly and efficiently than statins and reduce the risk of cardiovascular events in patients with acute coronary syndrome (ACS). This study aimed to assess the short-term effects of perioperative administration of a single-dose PCSK9 inhibitor in patients with ACS. Methods: This study included 789 consecutive patients undergoing percutaneous coronary intervention (PCI) for ACS. The primary clinical endpoint was the occurrence of major adverse cardiovascular events (MACEs) within one month, including cardiac death, non-fatal myocardial infarction, unanticipated revascularization, stroke, stent thrombosis, and rehospitalization for ischemic causes or heart failure. Results: PCSK9 inhibitors were administered to 201 of 789 patients. MACEs occurred in eight patients (4.0%) in the treated group and 60 patients (10.2%) in the non-treated group for one month (hazard ratio 0.38, 95% confidence interval 0.18 to 0.80, p = 0.010). The benefit of PCSK9 inhibitors in terms of MACEs was greater in the subgroup of patients treated more than 1 hour before PCI than in the subgroup treated less than 1 hour before PCI or treated after PCI and in the non-treated group. Conclusions In patients undergoing PCI for ACS, the risk of MACEs was lower in those treated with perioperative single-dose PCSK9 inhibitors than in those in the untreated group. This benefit was especially noticeable in the subgroups treated > 1 hour before PCI than in those treated less than 1 hour before PCI or after PCI, regardless of the clinical presentation of ACS.

Background and Objectives: Among various emerging catheter-based treatments for severe tricuspid regurgitation (TR), the spacer device can reduce the regurgitation orifice without manipulating the valve leaflet. However, its clinical application has been hampered by traumatic anchoring to the myocardium and the coaxial alignment of the balloon resulting in insufficient TR reduction. This study aimed to evaluate the early-stage safety, technical feasibility, and preliminary efficacy of the novel atraumatic vertical spacer in patients with isolated severe TR. Methods: All procedures were guided by fluoroscopy and transthoracic echocardiography.The maximum device placement time with an inflated balloon was 24 hours. Changes in the amount of TR, right ventricular function, and patient hemodynamics were measured during balloon deployment. Results: A total of 7 patients (median age 74), underwent successful device implantation without procedure-related complications. During balloon inflation (median 25 minutes), there were no symptoms or signs indicative of TR intolerance. TR was reduced by 1 grade or greater in all patients, with 2 patients exhibiting a reduction of 3 grades, from torrential TR to a moderate degree. Mild TR after balloon inflation was achieved in 3 patients with baseline severe TR. The TR reduction observed during initial balloon deployment was sustained during the subsequent balloon maintenance period. Conclusions The Pivot-balloon procedure was safe, technically feasible, and effective in reducing TR in patients with severe TR. No periprocedural complications or adverse cardiovascular events were reported during device placement with TR reduction observed in all patients. However, longer-term follow-up is needed to confirm safety and treatment effect.

The use of miniscrew-assisted rapid palatal expansion (MARPE) has yielded successful outcomes in late adolescence and early adulthood, particularly in correcting transverse maxillary discrepancies and enhancing airway expansion. This report presents three cases of children at different dentition stages treated with MARPE. In one patient with severe crowding, MARPE enabled dental alignment without the need for premolar extractions. Additionally, MARPE combined with facemask therapy improved the patient’s facial profile, resulting in high patient and guardian satisfaction. These cases highlight MARPE’s potential as an effective treatment for maxillary discrepancies and severe arch length discrepancies in children.

Objectives: Many three-dimensionally-evaluated difficulty indices for impacted third molars have been suggested; however, their radiological and clinical validation according to the inferior alveolar nerve (IAN) remains unknown. This study aimed to evaluate the association of the difficulty index with IAN proximity and injury risk. Materials and Methods: We retrospectively enrolled patients with cone-beam computed tomography (CBCT) for a fully impacted mandibular third molar from January to December 2020. We evaluated the third molar according to the difficulty index based on panoramic x-ray and the nerve index based on CBCT and analyzed postoperative nerve complications. The relationships among nerve proximity, difficulty indices, and nerve complications were evaluated. Data were analyzed using the Pearson’s chi-square test and the Cochran–Armitage test for trends. Results: We included 367 subjects (177 males, 28.9±9.8 years) with follow-up of at least 1 month. Twenty-two subjects had nerve complications.Radiologic evaluation showed that third molars with a high nerve index had an increased difficulty index (P=0.001). Nerve complication risk showed a statistically significant correlation with both nerve and difficulty indices. Conclusion In conclusion, the difficulty index of an impacted third molar was valid in terms of its spatial relationship with the IAN and in predicting nerve complications.

Background: With growing elderly populations, management of patients with acute stroke is increasingly important. In South Korea, the Acute Stroke Quality Assessment Program (ASQAP) has contributed to improving the quality of stroke care and practice behavior in healthcare institutions. While the mortality of hemorrhagic stroke remains high, there are only a few assessment indices associated with hemorrhagic stroke. Considering the need to develop assessment indices to improve the actual quality of care in the field of acute stroke treatment, this study aims to investigate the current status of human resources and practices related to the treatment of patients with acute stroke through a nationwide survey. Methods: For the healthcare institutions included in the Ninth ASQAP of the Health Insurance Review and Assessment Service (HIRA), data from January 2022 to December 2022 were collected through a survey on the current status and practice of healthcare providers related to the treatment of patients with acute stroke. The questionnaire consisted of 19 items, including six items on healthcare providers involved in stroke care and 10 items on the care of patients with acute stroke. Results: In the treatment of patients with hemorrhagic stroke among patients with acute stroke, neurosurgeons were the most common providers. The contribution of neurosurgeons in the treatment of ischemic stroke has also been found to be equivalent to that of neurologists. However, a number of institutions were found to be devoid of healthcare providers who perform definitive treatments, such as intra-arterial thrombectomy for patients with ischemic stroke or cerebral aneurysm clipping for subarachnoid hemorrhage. The intensity of the workload of healthcare providers involved in the care of patients with acute stroke, especially those involved in definitive treatment, was also found to be quite high. Conclusion Currently, there are almost no assessment indices specific to hemorrhagic stroke in the ASQAP for acute stroke. Furthermore, it does not reflect the reality of the healthcare providers and practices that provide definitive treatment for acute stroke. The findings of this study suggest the need for the development of appropriate assessment indices that reflect the realities of acute stroke care.

Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.