Background: Three-dimensional (3D) printing technology has rapidly emerged as a transformative tool in medicine, enabling the conversion of two-dimensional scans into highly accurate 3D models. This technology, especially when combined with artificial intelligence (AI) and advanced materials, offers numerous applications in surgical planning, simulation-based training, and patient-specific care. Methods: This review examines current literature and case studies on the use of 3D printing technology in various fields of medicine, especially in surgical specialties. Key applications include surgical planning, mock surgeries, biopsy guide creation, and customized implant fabrication across various surgical fields. Results: 3D printing is transforming surgery by enabling precise visualization of tumors and critical structures, significantly enhancing preoperative planning for conditions such as bone, soft tissue (e.g., neuroblastomas), renal, and maxillofacial tumors. In reconstruction surgeries, patient-specific 3D-printed implants ensure better anatomical compatibility, particularly in maxillofacial, neurosurgical, and vascular applications. Puncture guides improve procedural accuracy in interventions like percutaneous nephrolithotripsy. Detailed anatomical models aid in simulation-based training, increasing preparedness for complex procedures. Additionally, patient-specific implants and AI-integrated decision support systems are paving the way for more personalized and efficient surgical care. Conclusions: 3D printing technology, especially when combined with AI, is reshaping modern surgery by improving both accuracy, safety, and personalized healthcare. Its applications extend across multiple specialties, offering new possibilities in surgical planning, training, and patient-specific treatments. As AI and bioprinting continue to evolve, the potential for real-time applications, such as live-printed tissue implants and enhanced decision support, could drive the next phase of innovation in various fields.

Background: Vascular anomalies are rare congenital disorders associated with significant morbidity. Local therapies may be insufficient for complex lesions. Sirolimus, an mTOR inhibitor, is a promising systemic treatment option. Methods: We retrospectively analyzed pediatric patients with vascular anomalies treated with sirolimus between October 2020 and June 2025. Of 29 patients who initiated treatment, 23 completed at least 12 months of therapy and had evaluable 12-month outcomes; these patients constituted the primary 12-month efficacy cohort. Treatment discontinuations were analyzed separately, and an all-treated sensitivity analysis was performed. Results: The cohort included 10 patients (43%) with lymphatic malformations (LMs), 9 (39%) with venous malformations (VMs), 2 (9%) with combined malformations, and 2 (9%) with other vascular anomalies. At 12 months, magnetic resonance imaging (MRI) demonstrated lesion size reduction in 17/23 patients (74%), stabilization in 5/23 (22%), and progression in 1/23 patients (4%). In a conservative sensitivity analysis including all 29 treated patients and classifying patients without an evaluable 12-month outcome, documented reduction or stabilization was observed in 22/29 patients (76%). Additional treatment was less frequent during treatment (30% vs. 65%, p = 0.043), although observation periods differed. Pain decreased (p = 0.021), and physical activity increased (p = 0.034). No severe adverse events led to permanent treatment discontinuation. The most common adverse events were laboratory abnormalities (47%) and aphthous stomatitis (32%). Exploratory Multiple Factor Analysis (MFA) demonstrated substantial multidimensional heterogeneity but did not identify stable radiological response phenotypes. Conclusions: Sirolimus was associated with radiological improvement or stabilization, symptom relief, and fewer additional interventions in pediatric vascular anomalies, with generally favorable tolerability.