Kidney Autotransplantation in the Management of Residual Retroperitoneal Mass in a Germ Cell Tumor.

The main indication for kidney autotransplantation is ureteric disease, although it is also performed to treat renovascular diseases or neoplasms, such as complex intrasinusal kidney tumors or in patients with a solitary kidney. Only a few cases of kidney autotransplantation in the context of resection of complex retroperitoneal masses have been reported in the literature. CASE PRESENTATION: We report the case of a 26-year-old man with history of nonseminomatous germ cell tumor who had undergone a left radical orchiectomy 3 months earlier. Follow-up computed tomography revealed a residual retroperitoneal postchemotherapy mass involving the renal hilum. It was surgically removed via en bloc resection and bench ex vivo nephron-sparing surgery, and subsequently autotransplantation, thereby avoiding the necessity of nephrectomy and the resulting risk of chronic kidney disease. The pathology of the excised specimen demonstrated mixed germ cell tumor, composed of immature teratoma and yolk sac tumor, and confirmed tumor-free margins. CONCLUSIONS: This technique should be taken into account in selected patients as an alternative to radical nephrectomy when a retroperitoneal tumor is unresectable using standard surgical techniques or when a radical nephrectomy is considered, especially in patients with chronic kidney disease or solitary kidney, or in young patients who will potentially need nephrotoxic chemotherapy.

Donor-recipient matching in hand transplantation: a comparison of anthropometric measurements, 3-dimensional virtual models and printed epitheses.

Donor-recipient matching in hand transplantation remains challenging. The usefulness of three-dimensional (3-D) virtual models and printed epitheses were compared with measurements on cadaveric extremities to evaluate the most accurate method of donor-recipient matching for allograft procurement. Ten anthropometric measurements were recorded from 12 human cadaveric upper extremities and matched to printed epitheses and 3-D virtual models. Five circumferential and two longitudinal measurements obtained an intra-class correlation of >0.75 with all three methods, with the Kaplan (0.973) and wrist circumferences (0.942) achieving the highest concordance. Measurement on cadaveric specimens was the most reliable method. Using different combinations of donor hand and recipient forearms, a series of 72 virtual transplantations were then created, and their compatibility rated by ten transplant surgeons. The results confirmed that anthropometric measurements, obtained directly from potential human donor limbs and based on wrist circumference as the primary parameter, provide the best and most clinically relevant donor-recipient match.

Affordable Three-Dimensional Printed Heart Models.

This is a 7-years single institution study on low-cost cardiac three-dimensional (3D) printing based on the use of free open-source programs and affordable printers and materials. The process of 3D printing is based on several steps (image acquisition, segmentation, mesh optimization, slicing, and three-dimensional printing). The necessary technology and the processes to set up an affordable three-dimensional printing laboratory are hereby described in detail. Their impact on surgical and interventional planning, medical training, communication with patients and relatives, patients' perception on care, and new cardiac device development was analyzed. A total of 138 low-cost heart models were designed and printed from 2013 to 2020. All of them were from different congenital heart disease patients. The average time for segmentation and design of the hearts was 136 min; the average time for printing and cleaning the models was 13.5 h. The average production cost of the models was €85.7 per model. This is the most extensive series of 3D printed cardiac models published to date. In this study, the possibility of manufacturing three-dimensional printed heart models in a low-cost facility fulfilling the highest requirements from a technical and clinical point of view is demonstrated.

How to obtain a 3D printed model of renal cell carcinoma (RCC) with venous tumor thrombus extension (VTE) for surgical simulation (phase I NCT03738488).

This is the phase 1 of a multicenter clinical trial (NCT03738488), which aims to assess the efficacy and efficiency of surgery planning with 3D models of renal cell carcinoma (RCC) with venous tumor thrombus extension (VTE) compared to the standard images (CT). The objective of this phase is to obtain a 3D printed model of RCC with VTE that is feasible, accurate, reproducible, suitable for surgical simulation, and affordable. A specific protocol was developed to obtain the computed tomography (CT) image: early arterial and nephrogenic phase. ITK-snap® and VirSSPA Software® were used to segment the areas of interest. The resulting 3D mesh was processed with MeshMixer® and Cura®. Ten models from seven different cases were segmented and printed using different 3D printers and materials. We evaluated the material, scale, wall thickness, anatomy printed, 3D conformation, accuracy compared to the CT, suitability to perform the surgery, material, cost, and time (segmentation + design + fabrication + finishing). The four selected models were printed with a BQ Witbox FDM printer in polyurethane filament with a 0.8 mm wall thickness and 100% scale. All the relevant anatomical structures could be correctly identified, the 3D conformation was maintained with good accuracy compared to the CT and the surgery could be performed on them. Mean design time, model cost and printing time were 8.3 h, 33.4 €, and 38.5 h respectively. Various feasible 3D models of RCC with VTE were obtained after a few attempts. The final models were proved to be reproducible, accurate compared to the CT, and suitable for surgery simulation. The printing process was standardized making it possible to manufacture affordable 3D printed models.

Reparación percutánea de comunicación interauricular tipo seno venoso superior y drenaje venoso pulmonar anómalo parcial con técnica de doble stent en chimenea / Transcatheter repair of superior sinus venosus atrial septal defect with partial anomalous pulmonary venous drainage with the chimney double stent technique

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Pediatric extremity bone sarcoma reconstruction with the vascularized fibula flap: Observational study assessing long-term functional outcomes, complications, and survival.

BACKGROUND: Limb salvage is important in pediatric patients with bone sarcomas. The vascularized fibula flap is a versatile option, combined or not with a bone allograft. The authors evaluated the functional long-term outcomes, complications, and survival of using this technique in pediatric patients. METHODS: A retrospective review of 27 pediatric patients reconstructed between 2011 and 2018 with the fibula flap after bone sarcoma resection was conducted. Long-term functional outcomes, complications, and survival were assessed. Variables analyzed were age, sex, Capanna technique, follow-up, complications, additional surgeries, time to weight bearing, length discrepancy, and sport practice. RESULTS: Twenty-seven patients with a mean age of 9.3 years were included. The mean follow-up was 44.33 months. The Capanna technique was performed in 15 patients. All extremities but one were salvaged. The overall complication rate was 74.07%. Fibula fracture and nonunion rates were 34.04% and 11.11%, respectively. Partial weight bearing was resumed at a mean of 9.07 months. About 79.17% of patients with a 12-month follow-up achieved full weight bearing. An age below 8 years was significantly associated with a lower major complication rate and a shorter time to weight bearing and full weight bearing. Major complications and additional surgeries were significantly associated with longer periods until weight bearing and full weight bearing. CONCLUSIONS: The fibula flap allows the majority of extremities to be reconstructed. However, a high rate of complications and additional surgeries should be anticipated. Full weight bearing is usually achieved within the first year, with modest functional increase afterward. Less complications and a faster functional recovery are expected in patients below the age of 8 years.

Apical Muscular Ventricular Septal Defects: Surgical Strategy Using Three-Dimensional Printed Model.

To evaluate the utility of a three-dimensional printed model (3D-model) for surgical decision planning in a complex case of multiple ventricular septal defect (VSD) (so-called Swiss-cheese septum). A 3 month-old-girl with diagnosis of multiple apical VSDs in the trabecular septum, perimembranous VSD, and atrial septal defect that resulted in congestive heart failure was referred for surgical intervention. Due to inconclusive understanding of the total number, openings and locations of the apical VSDs, there were concerns regarding the best surgical approach. Using computed tomography images, a 3D-model was fabricated by fused deposition modeling of polyurethane filament. The 3D model helped identifying the total number of VSD, their origins and exits as well as the minimum number of septal bands to resect, the optimal patch size and morphology to completely close all VSDs without reducing significantly the RV cavity. The procedure was successfully replicated in the patient by right atrial approach, resulting in good RV cavity size, function and no residual VSDs evaluated by transesophageal echocardiography. Direct evaluation of the 3D printed replica anatomy and surgical simulation may help optimizing surgical approach, patch size and location and therefore it might reduce complications and residual defects.

Comparison of different constitutive models to characterize the viscoelastic properties of human abdominal adipose tissue. A pilot study.

Knowing the mechanical properties of human adipose tissue is key to simulate surgeries such as liposuction, mammoplasty and many plastic surgeries in which the subcutaneous fat is present. One of the most important surgeries, for its incidence, is the breast reconstruction surgery that follows a mastectomy. In this case, achieving a deformed shape similar to the healthy breast is crucial. The reconstruction is most commonly made using autologous tissue, taken from the patient's abdomen. The amount of autologous tissue and its mechanical properties have a strong influence on the shape of the reconstructed breast. In this work, the viscoelastic mechanical properties of the human adipose tissue have been studied. Uniaxial compression stress relaxation tests were performed in adipose tissue specimens extracted from the human abdomen. Two different viscoelastic models were used to fit to the experimental tests: a quasi-linear viscoelastic (QLV) model and an internal variables viscoelastic (IVV) model; each one with four different hyperelastic strain energy density functions to characterise the elastic response: a 5-terms polynomial function, a first order Ogden function, an isotropic Gasser-Ogden-Holzapfel function and a combination of a neoHookean and an exponential function. The IVV model with the Ogden function was the best combination to fit the experimental tests. The viscoelastic properties are not important in the simulation of the static deformed shape of the breast, but they are needed in a relaxation test performed under finite strain rate, particularly, to derive the long-term behaviour (as time tends to infinity), needed to estimate the static deformed shape of the breast. The so obtained stiffness was compared with previous results given in the literature for adipose tissue of different regions, which exhibited a wide dispersion.

Three-dimensional printed models for surgical planning of complex congenital heart defects: an international multicentre study.

OBJECTIVES: To evaluate the impact of 3D printed models (3D models) on surgical planning in complex congenital heart disease (CHD). METHODS: A prospective case-crossover study involving 10 international centres and 40 patients with complex CHD (median age 3 years, range 1 month-34 years) was conducted. Magnetic resonance imaging and computed tomography were used to acquire and segment the 3D cardiovascular anatomy. Models were fabricated by fused deposition modelling of polyurethane filament, and dimensions were compared with medical images. Decisions after the evaluation of routine clinical images were compared with those after inspection of the 3D model and intraoperative findings. Subjective satisfaction questionnaire was provided. RESULTS: 3D models accurately replicate anatomy with a mean bias of -0.27 ± 0.73 mm. Ninety-six percent of the surgeons agree or strongly agree that 3D models provided better understanding of CHD morphology and improved surgical planning. 3D models changed the surgical decision in 19 of the 40 cases. Consideration of a 3D model refined the planned biventricular repair, achieving an improved surgical correction in 8 cases. In 4 cases initially considered for conservative management or univentricular palliation, inspection of the 3D model enabled successful biventricular repair. CONCLUSIONS: 3D models are accurate replicas of the cardiovascular anatomy and improve the understanding of complex CHD. 3D models did not change the surgical decision in most of the cases (21 of 40 cases, 52.5% cases). However, in 19 of the 40 selected complex cases, 3D model helped redefining the surgical approach.

3D printed models in patients with coronary artery fistulae: anatomical assessment and interventional planning.

AIMS: Coronary artery fistulae represent one of the most challenging anatomical defects to define accurately. We aimed to investigate the additional benefit conferred by volume rendering of tomographic images and 3D printing for diagnosis and interventional planning. METHODS AND RESULTS: Four cases of coronary fistulae were considered for transcatheter closure. Multidetector computed tomography (three cases) or cardiac magnetic resonance (one case) images were acquired and segmented using Mimics software. Each case was reviewed after incremental consideration of diagnostic resources: two cardiologists reported source and volume-rendered images; device closure was discussed by the interventional cardiology team. All diagnoses and planned management were reviewed after inspection of a 3D model. Using source images alone, both cardiologists correctly described the course and drainage in two out of four cases. Aided by volume rendering, this improved to three out of four cases. Inspection of the 3D printed model prompted the planned interventional approach and device sizing to be altered in two out of four cases. In one out of four cases, the intervention was abandoned after inspection of the 3D printed model. CONCLUSIONS: Diagnosis and management of patients with coronary artery fistulae rely on detailed image analyses. 3D models add value when determining the feasibility of, and the approach to intervention in these cases.

New technologies applied to surgical processes: Virtual Reality and rapid prototyping.

AYRA is software of virtual reality for training, planning and optimizing surgical procedures. AYRA was developed under a research, development and innovation project financed by the Andalusian Ministry of Health, called VirSSPA. Nowadays AYRA has been successfully used in more than 1160 real cases and after proving its efficiency it has been introduced in the clinical practice at the Virgen del Rocío University Hospital . Furthermore, AYRA allows generating physical 3D biomodels using rapid prototyping technology. They are used for surgical planning support, intraoperative reference or defect reconstruction. In this paper, some of these tools and some real cases are presented.

Virtual reality AYRA software for preoperative planning in facial allotransplantation.

PURPOSE: The purpose of this study was to validate a virtual reality software for the recording of anthropometric measurements as a first step towards matching donors with recipients in the preoperative planning process which precedes the harvest of a facial allograft. METHODS: Anthropometric measurements of both soft and bone tissue were recorded in 5 cryopreserved human heads to compare conventional analogue measurements with digital measurements obtained from 3-dimensional (3D) reconstructions produced using AYRA software. To test the degree of correlation between both measuring methods, intraclass correlation coefficient (ICC) was applied to each pair of measurements. RESULTS: ICCs calculated were greater than 0.6 (substantial or almost perfect correlation) for all of the pairs of variables, with the exception of 2 of the measurements studied in bone tissue. CONCLUSIONS: In facial transplantation, preoperative planning is crucial to select an allograft whose anatomical compatibility with the recipient defect is as close as possible. The dimensions of the potential face donor must be congruent to ensure the procedure's feasibility and the adequate insertion of the allograft into the defect. The recording of anthropometric measurements with the virtual reality software displayed an equivalent correlation to those produced using a conventional analogue method. The 3D reconstructions obtained by using a virtual reality software can play a useful role to facilitate the characterization of the donor face.