The use of three-dimensional (3D) printed patient-specific anatomical models is nowadays a viable strategy for improving surgical outcome in medicine. In adult surgery, 3D printing technology is commonly studied, but its use in paediatric surgery is still under development. This work presents the implementation of 3D printing technology in Orthopaedic department of the paediatric hospital “Santobono-Pausilipon” in Naples by producing 3D printed anatomical models of paediatric patients. The 3D printed models produced were used for the training of the surgical team during the preoperative planning and for carrying out a surgical simulation. The anatomical models are designed in compliance with the current European Medical Devices regulation and following the already existing guidelines in literature. The impact of the 3D printed anatomical models used, a total of seven printed anatomical models based on four patients, is then evaluated throughout a questionnaire proposed to the surgical team, composed by eight paediatric orthopaedic surgeons. Surgeons answered to a total of ten questions, six scale-based questions and four free-text questions. Results obtained from the questionnaires highlighted how 3D printed anatomical models can lead to a better understating of the treated pathologies, carrying relevant improvements in both the surgical team training and the surgical outcome.

CG was a 80–years–old man with normal BMI, arterial hypertension and CAD family history.He suffered OSAS needs nocturnal cPAP, MGUS, colon diverticulosis and CKD in dialysis treatment since 2006 after right nephrectomy for adenocarcinoma and wrinkle left kidney for focal glomerulosclerosis since 1982.Note valvular heart disease with mitro–aortic insufficiency: in 6/2010 he performed aortic valve replacement with Carpentier Perimount 23 bioprosthesis, mitral annuloplasty with St Jude 28 ring and surgical revascularization with single graft on PDA coronary.During post–surgical period transients III degree AVB and AF were observed with subsequent restoration and stabilization in sinus rhythm.In 5/2011, thanks to Holter registration of stable sinus rhythm, VKA anticoagulation was stopped and only ASA continued.In 1/2013 well tolerated AF was found then VKA resumed.In 6/2016 during the follow up the echocardiogram showed hypertrophic and hypokinetic left ventricle, EF 45%, moderate biatrial dilatation, normofunctioning aortic bioprosthesis with mild aortic root and first ascending tract dilatation and successful mitral annuloplasty.In 3/2018 worsening exertional dyspnea with initial heart failure were documented and echocardiography showed aortic bioprosthesis degeneration with severe stenosis and mild intraprosthetic insufficiency, preserved EF, mild mitral steno–insufficiency, normal right sections with mild–moderate tricuspid insufficiency and mild pulmonary hypertension.In 6/2018 the subsequent coronary angiography evidenced venous graft occlusion and critical RCA stenosis treated by PTCA+DES Biofreedom in the middle segment: triple therapy with ASA, clopidogrel and VKA indicated for one month.One month later, in 7/2018 TAVI was performed on aortic bioprosthesis with Portico n.23 prosthesis: in the post–procedural phase mild anemia and positive FOB were found. The patient presented high both thrombotic and bleeding risk because of persistent AF, recently coronary reperfusion with DES and dialysis treatment so we decided to close left atrial appendage by Watchman system and keep on single antiplatelet therapy with ASA. Pre and post procedures dialysis treatments were performed without complications.Subsequent clinical and echocardiographic follow up without complications.The diagnostic–therapeutic iter sharing in Heart and multi–specialists team has favored the best timing of treatment and the success of procedures in a very high cardiovascular risk patient.