Abrupt vessel closure (AVC) is a complication of percutaneous coronary intervention (PCI) and is defined as the sudden cessation of forward coronary blood flow due to a variety of mechanisms. The incidence of AVC has markedly decreased from approximately 3.0% in the early era to about 0.3% today. Nevertheless, cardiovascular interventionists must remain prepared to manage AVC effectively, given its significant impact on clinical outcomes.AVC can arise from several mechanisms, including dissection, intramural hematoma, intracoronary thrombosis, air embolism, vasospasm, and no-reflow. The clinical impact of AVC varies depending on the extent of myocardium affected, ranging from asymptomatic events or transient ischemic chest pain to cardiogenic shock or cardiac arrest. Both a general approach for stabilizing hemodynamic consequences and an etiology-specific management strategy are essential. Hasty decision-making may worsen the situation, whereas a structured approach—focused on hemodynamic stabilization, logical diagnostic processes, and targeted interventions—can improve outcomes. In this narrative review, we describe the mechanisms underlying each etiology, outline mechanism-specific management strategies, and discuss general approaches to managing patients with AVC through logical diagnostic and treatment processes. We hope this review offers valuable insights into this uncommon but significant complication and enhances readers’ skills in managing AVC more effectively during PCI.

Background: Although patients with malignant melanoma in situ (MIS) have a high survival rate, a risk of recurrence or upstaging remains. Thus, a comprehensive understanding of its prognosis is essential for optimal patient management. Objective: To investigate the clinical characteristics and survival outcomes of Korean patients with MIS. Methods: We retrospectively analyzed the medical records and photographs of patients with MIS treated at a single tertiary center between 2008 and 2021. Clinical features, including diagnosis, treatment, recurrence, and mortality, were examined. Results: A total of 156 patients with MIS were included, with a mean age of 59.3 years. The most common subtype was acral lentiginous melanoma (80.8%). Delayed diagnosis was associated with subungual MIS (SUMis; p ＜0.05). Among the subtypes other than SUMis, 77.3% met three or more of the ABCD criteria for melanoma.Hutchinson’s sign was observed in 67.3% of cases of SUMis. Ulceration was present in only two cases (1.3%).Recurrence occurred in nine patients (5.8%), with four (2.6%) experiencing relapse after 5 years. Upstaging was observed in two patients (1.3%) due to intralymphatic or regional nodal metastasis occurring at 19 and 10 months post-treatment. The 5-year and 10-year melanoma-specific/overall survival rates were 100.0/96.9% and 100.0/89.0%, respectively. Conclusion Although the survival rates of patients with MIS are high, long-term and close follow-up after treatment is essential because of the possibility of late recurrence and rare instances of intralymphatic or regional nodal metastasis. Additionally, the presence of clinical ulceration is highly suggestive of invasive melanoma.

Diffuse alveolar hemorrhage (DAH) is a rare but life-threatening condition characterized by bleeding into the alveolar spaces because of damage to the pulmonary microvasculature. While it is commonly associated with autoimmune or coagulation disorders, post-ictal DAH following a generalized tonic-clonic seizure is extremely rare, especially in pediatric populations. We report the case of a previously healthy 13-year-old boy with allergic rhinitis and buckwheat allergy who presented with his first generalized tonicclonic seizure. Following admission, he developed dyspnea and tachypnea (respiratory rate of 38/min); on hospital day 2, oxygen desaturation (SaO 2 88%) accompanied by hemoptysis. Laboratory tests showed no evidence of coagulopathy or autoimmune disease. Chest radiography and computed tomography revealed bilateral pulmonary infiltrates consistent with alveolar hemorrhage.Intravenous methylprednisolone (1 mg/kg for 3 days) was administered, resulting in rapid improvement of respiratory symptoms and imaging findings. This case highlights the importance of early clinical suspicion and imaging-based diagnosis of post-ictal DAH, and the necessity of prompt supportive management to achieve favorable outcomes.

Background: The Act on Decisions on Life-Sustaining Treatment (LST) has been implemented in Korea since 2018, yet data on its application in neurocritical care units remain scarce. This study aimed to evaluate the clinical characteristics and outcomes of LST withdrawal or withholding in the neurocritical care unit. Methods: This study was a retrospective analysis conducted at a tertiary university hospital in Busan, South Korea. Among patients admitted to the neurocritical care unit between February 2018 and August 2023, those with documented decisions for LST withdrawal or withholding were enrolled. Demographic and clinical characteristics, underlying and combined conditions, reasons for LST decisions, measures taken, and time from LST withdrawal to death were extracted from medical records. Results: A total of 69 patients were included, with a median age of 67 years, and 38 (55%) were male. Cerebrovascular disease (62%) and traumatic brain injury (22%) were the most common underlying diagnoses. The primary reason for LST decisions was irreversible neurological damage (71%), followed by systemic complications (19%). Mechanical ventilation cessation (91%) and extubation (86%) were most frequently used measures for LST withdrawal. The median time from LST withdrawal to death was 22 minutes. Conclusions Our study demonstrates that LST decisions in the neurocritical care unit predominantly occur among patients with cerebrovascular disease or traumatic brain injury, mostly triggered by neurological deterioration. Most patients died shortly after withdrawal. These findings provide important insight into current LST withdrawal practices in neurocritical care and may assist clinical and ethical decision making in similar settings.

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.

Background: Current guidelines recommend factor IIa- or Xa-specific inhibitors over warfarin analogs for preventing thromboembolic stroke in patients with atrial fibrillation (AF).However, their plasma concentrations in Korean patients are not well understood. Methods: We conducted a single-center laboratory study to determine the distribution ranges of peak and trough concentrations of three factor Xa inhibitors (apixaban, edoxaban, and rivaroxaban) prescribed for preventing strokes in patients with AF. Patients receiving one of these drugs and undergoing blood specimen collection for laboratory tests were screened. Blood specimens were obtained from patients who had adhered to the prescribed drug regimen consistently for at least 1 week. Drug plasma concentrations were measured using heparin liquid-reagent technology-based anti-Xa chromogenic assays. Results: We selected 459 patients who were taking standard or on-label-reduced doses of apixaban (N = 252), edoxaban (N = 182), or rivaroxaban (N = 25). The 5th–95th percentile ranges of the peak concentrations were 84–414 ng/mL (apixaban), 72–424 ng/mL (edoxaban), and 97–517 ng/mL (rivaroxaban). The respective 5th–95th percentile ranges of the trough concentrations were 44–237 ng/mL, 23–93 ng/mL, and 13–219 ng/mL. Approximately 19.6% (apixaban), 33.3% (edoxaban), and 64.0% (rivaroxaban) of patients in each group had peak concentrations out of the predicted distribution ranges based on pharmacokinetic data. Approximately 7.3%, 52.8%, and 8.3% of patients had trough concentrations out of the predicted distribution ranges. Conclusions A considerable proportion of Korean patients with AF taking factor Xa inhibitors may require population-specific reference ranges to guide therapeutic monitoring.

Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Popliteal artery entrapment syndrome (PAES) can mimic ankle pathology in young athletes and may lead to irreversible ischemia if a diagnosis is delayed. A 13-year-old Taekwondo athlete had exertional ankle pain unresponsive to synovectomy. Computed tomography angiography revealed a 5-cm popliteal artery occlusion. The patient underwent decompression surgery, but the arterial occlusion persisted, and bypass surgery was planned. This case highlights the importance of considering PAES as part of a differential diagnosis in young athletes presenting with persistent ankle pain, particularly when symptoms persist despite appropriate orthopedic treatment.

This study aimed to describe the technical feasibility and clinical outcome of unilateral biportal endoscopy (UBE)-assisted posterior C1–2 fusion for irreducible traumatic atlantoaxial rotatory dislocation (AARD) with facet fracture and locking. A 67-year-old man presented with severe neck pain following a motor vehicle accident. Computed tomography revealed C1–2 rotatory dislocation with a right C2 facet fracture and locking, while magnetic resonance imaging demonstrated left vertebral artery hypoplasia without cord compression. Traction for 3 days failed to achieve reduction. Surgery was subsequently performed using UBE under continuous saline irrigation. Following muscle-splitting exposure, facet release and reduction were achieved with a curette. Because the bulky right C2 nerve root obstructed access, it was transected proximal to the dorsal root ganglion. Facet distraction was then performed, the articular cartilage removed, and the subchondral bone prepared. Bilateral screws were inserted, and a polyether ether ketone cage filled with demineralized bone matrix was placed for fusion. The procedure was completed successfully without complications. Blood loss was minimal. The patient’s visual analogue scale score improved from 8 preoperatively to 2 on postoperative day 1. He was discharged uneventfully on postoperative day 7. At the 3-month follow-up, he remained pain-free with stable fixation and no loss of reduction on imaging. UBE-assisted posterior C1–2 fusion enables precise facet release, safe instrumentation, and minimal tissue trauma in irreducible AARD with facet fracture and locking. This minimally invasive approach may yield favorable short-term outcomes and represents a viable alternative to conventional open posterior fusion techniques.

This study aimed to describe the technical feasibility and clinical outcome of endoscope-assisted anterior odontoid lag screw fixation in a patient with ankylosing spondylitis, in whom the conventional open anterior approach was limited due to cervical rigidity. A 56-year-old man with longstanding ankylosing spondylitis presented with severe neck pain and right-sided tingling sensations following trauma. Imaging revealed a type III odontoid fracture. Because of rigid cervical alignment, adequate neck extension required for the conventional open anterior approach was not achievable. Endoscope-assisted anterior odontoid screw fixation was performed using a biplane C-arm. The procedure involved endoscopic dissection of the prevertebral corridor and insertion of the cannulated lag screw under fluoroscopic guidance. The screw was successfully placed across the fracture site without intraoperative complications. Postoperative imaging confirmed appropriate screw trajectory and fracture reduction. The patient’s pain improved immediately, allowing early ambulation. He was discharged uneventfully, and follow-up examinations demonstrated stable fixation. Endoscope-assisted anterior odontoid lag screw fixation appears to be a safe and effective alternative for treating odontoid fractures in patients with ankylosing spondylitis. This technique minimizes soft-tissue injury and facilitates optimal screw trajectory in cases where rigid cervical alignment precludes the conventional open approach.