Dai, Yuqian

ABSTRACT This study aims to identify and characterize fenestrations in the aortic and pulmonary valves using an endoscopic approach and compare their prevalence and morphology in adult and fetal hearts. The research explores whether these fenestrations are congenital or acquired and their potential clinical implications. We analyzed 41 adult human hearts (mean age: 74.25 years; range: 62–92) and 97 fetal human hearts (mean gestational age: 26 weeks; range: 12–40). Specimens were preserved in alcohol‐phenol‐formaldehyde and examined using a Stryker 5 mm 0 degree endoscope to visualize valve structures in situ, followed by post‐endoscopic dissection. Two independent investigators assessed the specimens for fenestration prevalence, distribution, and morphology, categorized into ovoid, filamentous, and fenestrated types. Fenestrations were absent in all fetal hearts. Fenestrations were identified in 75.61% of adult hearts (31/41), with 74 fenestrations observed in total. Of these, 41 were in the pulmonary valve and 33 in the aortic valve. Ovoid fenestrations predominated in both valves (aortic: 76.3%, pulmonary: 85%), with significant distribution along leaflet edges, particularly in the left coronary and semilunar leaflets. No correlation with age or sex was found. The findings from this study suggest that valve fenestrations are more likely to be acquired postnatally, rather than representing congenital anomalies. The complete absence of fenestrations in all fetal heart specimens, contrasted with their high prevalence in adult hearts, supports this hypothesis. While our results do not directly prove a causal relationship, they align with prior literature proposing that biomechanical factors, such as cumulative leaflet stress, turbulent flow, and repeated coaptation, may contribute to the formation of fenestrations over time. These insights into the prevalence, morphology and leaflet distribution of fenestrations provide a valuable foundation for future research investigating their etiology, clinical significance, and potential role in valve dysfunction.

ABSTRACT Femoral nerve block is an essential regional anesthetic technique for surgery and analgesia of the anterior thigh, hip, and knee. Its effectiveness depends on understanding the femoral nerve's origin, branching pattern, fascial relationships, and common anatomical variations. This review summarizes current anatomical, cadaveric, and imaging studies to clarify the course of the femoral nerve and highlight variations such as high divisions, accessory branches, and vascular overlap that may influence block success. Approaches including landmark, nerve stimulator, and ultrasound‐guided techniques are reviewed with emphasis on procedural anatomy. Ultrasound features of the femoral nerve and fascia iliaca are correlated with cadaveric findings to outline optimal needle placement and spread of injectate. Continuous catheter methods, anesthetic selection, and volume considerations are also described. Comparative evidence indicates that ultrasound guidance improves accuracy, reduces vascular puncture, and decreases local anesthetic requirements compared with blind or stimulator‐based approaches. Clinical applications across orthopedic surgery, trauma care, and multimodal perioperative pathways are discussed, along with potential complications such as nerve injury, hematoma, systemic toxicity, and quadriceps weakness. Specifically, detailed knowledge of the femoral nerve's course beneath the fascia iliaca, its shifting proximity to the femoral vessels, and its variable early branching is the key to accurate needle placement, dependable block success, and fewer procedure‐related complications.

ABSTRACT Anatomical descriptions of left‐sided oblique coronary branches remain inconsistent, hindering imaging interpretation and surgical planning. To quantify the prevalence, branching patterns and morphometry of the ramus intermedius (RI) and diagonal branches, and propose a unified nomenclature. Following PRISMA guidelines, a PubMed search up to 12 June 2025 yielded 623 records. Forty‐six studies involving 25,602 hearts were included, and random‐effects meta‐analysis was applied to pool prevalence and continuous outcomes. Overall, an additional left‐main branch (RI) was present in 25.2% (95% CI: 8.7–54.5). Trifurcation dominated (22.7%), whereas quadrifurcation and pentafurcation occurred in 3.7% and 1.3% respectively. The pooled RI/diagonal diameter averaged 2.21 mm (95% CI 2.02–2.39), and mean branch length was 49.1 mm (95% CI 37.8–60.5). Methodological heterogeneity was high but consistent patterns emerged across cadaveric and imaging modalities. An oblique “diagonal artery”, whether arising from the left main (RI) or anterior interventricular artery, is present in roughly 25% of hearts, averages 2.2 mm in caliber and extends to 49 mm. Recognizing this vessel family and standardizing the term “diagonal arteries” will improve coronary imaging reporting and guide revascularization strategies.