Minimally invasive coronary artery bypass grafting via a lower ministernotomy for left anterior descending artery myocardial bridging: mid-term results.

OBJECTIVES: Coronary artery bypass grafting or supra-arterial myotomy is now suggested as a better therapeutic option in myocardial bridging (MB) when medical treatment fails to control symptoms. For left anterior descending (LAD) MB, minimally invasive coronary artery bypass via a lower ministernotomy can be offered. METHODS: Forty-four consecutive patients who underwent elective minimally invasive coronary artery bypass surgery from 2005 to 2014 via an inferior sternotomy using the left internal mammary artery as a bypass graft for LAD MB were evaluated retrospectively. RESULTS: The mean age was 59.1 ± 13.1 years with 26 (59%) men and 18 (41%) women. The mean body mass index was 27.2 ± 3.9 and the mean EuroSCORE II was 1.6 ± 1.8. Routine coronary multislice computed tomography angiography on the 6th postoperative day revealed 97.7% graft patency. During the initial hospital stay, 1 patient (2.3%) underwent a reoperation for early graft failure. Forty patients (91%) could be followed up for a mean period of 64.4 ± 24.5 months after the procedure, during which 2 patients (4.5%) died of non-cardiac causes and 9 patients (20.5%) underwent postoperative coronary angiography with confirmed graft occlusion in only 1 case (2.3%). The improvement in the distribution of patients in the Canadian Cardiovascular Society class 0 was from 4 patients (9%) preoperatively to 37 patients (84%) at the end of the follow-up period (P-value 0.001). CONCLUSIONS: Minimally invasive coronary artery bypass surgery via a lower ministernotomy may be safe and efficient for treating LAD artery MB with acceptable complication rates, cosmetic benefits and patency rates.

Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy.

As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original STL file using dedicated 3D engineering software. The mean wall thickness for the large-scale aortic models was 2.11 µm (+5%), and 1.26 µm (+0.8%) for the coronary models, resulting in an overall mean wall thickness of +5% for all 35 3D models when compared to the original STL file. The mean surface deviation was found to be +120 µm for all models, with +100 µm for the aortic and +180 µm for the coronary 3D models, respectively. Both printing technologies were found to conform with the currently set standards of accuracy (<1 mm), demonstrating that accurate 3D models of large and small vessel anatomy can be generated by both FDM and PolyJet printing technology using rigid and flexible polymers.

Development and evaluation of 3-dimensional printed models of the human tracheobronchial system for training in flexible bronchoscopy.

OBJECTIVES: Training and assessment of proper skills in flexible bronchoscopy are major educational goals for cardiothoracic residents. Therefore, we developed 3-dimensional (3D) printed models of the human tracheobronchial system for training and assessment of cardiothoracic residents in flexible bronchoscopy. METHODS: Three models of normal (size/shape) human tracheobronchial anatomy were generated using a commercially available 3D printer. Ten residents (inexperienced: Group 1; experienced: Group 2) participated in this study with an experimental setting of initial assessment (Model 1), training (15 min, Model 2) and post-training assessment (Model 3). The time needed for flexible bronchoscopy assessment of randomly assigned ostia was recorded before and after training. Additionally, the time for retrieval of a foreign body from the tracheobronchial system was measured before and after training. RESULTS: The average time for intubation of a given ostium (Model 1) at initial assessment was 88 s for Group 1 and 38 s for Group 2 (P < 0.0001). Following training, there was a significant reduction in time for intubation of a given ostium (Model 3) in both groups (P < 0.0001). However, the initial difference between experienced and inexperienced residents was no longer present following training. Additionally, the time for retrieval of a foreign body (cotton wool plug) from the tracheobronchial system was significantly reduced following training in both groups. CONCLUSIONS: Accurate models of the human tracheobronchial system can be generated from representative patient images using 3D engineering software and 3D printing technology. With these models, residents can be effectively trained in flexible bronchoscopy with significant improvement in their proficiency and handling capability.

Use and durability of femoral vein for autologous reconstruction with infection of the aortoiliofemoral axis.

OBJECTIVE: To analyze early and late mortality, venous morbidity, reinfection, and freedom from reintervention after using the femoral vein (FV) for vascular reconstruction with infection of the aortoiliofemoral axis. METHODS: By reviewing our database, 86 patients could be identified with implantation of FV grafts in infected fields between November 1995 and July 2012. The patient records were retrospectively analyzed and follow-up information obtained from patients or their general physician. Seventy-one patients presented with prosthetic graft infection and 15 with an infected aneurysm. For data analysis, patients were divided into an aortoiliac (n = 67) and a femoral group (n = 19). Study end points assessed were early and late mortality, incidence of deep vein thrombosis of the FV donor limb, graft patency, limb salvage, reinfection, and freedom from reintervention. RESULTS: Sixty-seven aortoiliac reconstructions were performed using 84 FV grafts with an operative mortality of 9%. After a mean follow-up of 45 months, survival, patency, limb salvage, and freedom from reintervention were 45%, 97%, 94%, and 91%, respectively, at 5 years. Twenty FV grafts were employed for 19 femoral reconstructions with an operative mortality of 10.5%. Here, mean follow-up was 35 months and survival, patency, limb salvage, and freedom from reintervention were 29%, 87%, 93%, and 81%, respectively, at 5 years. Specimen culture confirmed Staphylococcus (epidermidis and aureus) as the predominant microorganism. Venous morbidity after FV harvest showed an incidence of deep venous thrombosis of 13.7% for popliteal and 10.6% for tibial level at a follow-up of 24 months with only mild clinical symptoms (21% limb swelling). CONCLUSIONS: Vascular reconstruction using autologous FV in arterial and graft infection of the aortoiliofemoral axis provides durable long-term results with acceptable mortality and morbidity.