Human Cadaveric Model Research Articles

Accuracy of MRI and X-Ray Measurement of Displacement Distance of Humeral Lateral Condyle Fractures.

ObjectiveTo investigate the accuracy of X‐ray and magnetic resonance imaging (MRI) measurements in evaluating the displacement of humeral lateral condyle fracture (HLCF) in different positions of the forearm based on human cadaveric HLCF models.MethodsThree human cadaveric elbow HLCF fracture models were successfully established. The wrist joint was fixed, and the forearm was rotated forward along the mid‐axis. The maximum distance between the two segments of the lateral fracture gap was defined as LFS (lateral fracture space) distance, and the maximum distance between the two segments of the fracture gap at the anterior and posterior margins of the fracture model was defined as PFS (posterior fracture space). The LFS and PFS distances of the human cadaveric elbow HLCF fracture models were measured during forearm rotation at 0º, 45º, 90º, and 135º rotation using a Capture Motion System (CMS), positive and lateral elbow X‐ray, coronal and sagittal MRI scans, respectively, and the CMS measurements were considered as the true fracture gap distances. The values obtained by CMS, X‐ray, and MRI measurements for both LPS and PFS distances in the HLCF fracture model at each position during rotation were recorded. The LFS and PFS distances were measured by two independent orthopaedic and joint imaging physicians. The data were measured three times by each physician, and the final values were the average of the two measurements. The outcomes were determined by whether a statistical difference exists in the LFS and PFS among the CMS, X‐ray, and MRI groups.ResultsThe interobserver agreement tests between the two observers showed good agreement in the measurements. A multiple sample ANOVA showed statistical differences in the LFS distances of HLCF measured at 0º, 45º, 90º, and 135º rotated by three radiographic measurements (P < 0.05). The LFS distances obtained by MRI and CMS measurements were greater than those obtained by X‐ray measurement in all positions using the LSD test (P < 0.05), and no statistical difference was found between the CMS and MRI methods in each position (P > 0.05). The same results were observed in terms of PFS values obtained by CMS, X‐ray, and MRI measurements at 0º, 45º, 90º, and 135º pronation. It was statistically different among the three groups as shown by multiple sample ANOVA (P < 0.05). The CMS and MRI measurements were greater than the X‐ray measurements (P < 0.05), while no statistical difference was observed between the CMS and MRI measurements (P > 0.05).ConclusionX‐rays often underestimate the degree of displacement of HLCF fractures; MRI measurements are closer to the true values compared with X‐ray.

Post-surgical wireless monitoring of arterial health progression

SummaryEarly detection of limb ischemia, strokes, and heart attacks may be enabled via long-term monitoring of arterial health. Early stenosis, decreased blood flow, and clots are common after surgical vascular bypass or plaque removal from a diseased vessel and can lead to the above diseases. Continuous arterial monitoring for the early diagnosis of such complications is possible by implanting a sensor during surgery that is wirelessly monitored by patients after surgery. Here, we report the design of a wireless capacitive sensor wrapped around the artery during surgery for continuous post-operative monitoring of arterial health. The sensor responds to diverse artery sizes and extents of occlusion in vitro to at least 20 cm upstream and downstream of the sensor. It demonstrated strong capability to monitor progression of arterial occlusion in human cadaver and small animal models. This technology is promising for wireless monitoring of arterial health for pre-symptomatic disease detection and prevention.

Determination of Face and Content Validity of Cadaveric Model for Holmium Anatomic Endoscopic Enucleation of the Prostate Training: An ESUT AEEP Group Study

BackgroundBench and virtual reality nonbiological simulator models for anatomic endoscopic enucleation of the prostate (AEEP) surgery have been reported in the literature. These models are acceptable but have limited practical applications. ObjectiveTo validate a fresh-frozen human cadaver model for holmium AEEP training and assess its content validity. Design, setting, and participantsHolmium AEEP operations on fresh-frozen cadavers performed by an experienced surgeon were recorded, and a video, including the main steps of the operation, was produced. Outcome measurements and statistical analysisThe video and an accompanying questionnaire were subsequently distributed electronically to ESUT AEEP study group experts and associates (N = 32) for assessment of the AEEP training model. A ten-point Likert global rating scale was used to measure the content validity. Results and limitationsA total of 26 answers were returned (81%). The experts agreed on the model’s suitability for AEEP training (mean Likert score: 8). According to the responses, “identifying anatomic structures and landmarks” was the most valuable aspect of the model in terms of AEEP training (median Likert score: 9). Conversely, the experts found the model’s ability, in terms of demonstrating laser and tissue reactions, to be weak (median Likert score: 6) ConclusionsBased on the content validity assessment, the fresh-frozen cadaver-training model for laser AEEP seems to be a promising model for demonstrating and learning the correct prostate enucleation technique. Patient summaryAn increasing number of researchers have proposed that anatomic endoscopic enucleation of the prostate (AEEP) should replace transurethral resection of the prostate surgery and become the gold standard for treatment of bladder outlet obstruction due to benign prostatic hyperplasia. AEEP requires anatomic familiarity for enucleation, technical knowledge, and a solid training program before starting with the first cases. This is the first cadaver study to assess the content validity of a fresh-frozen human cadaver model for AEEP training.

A multidirectional two-tube method for chemical pleurodesis could improve distribution of the sclerosing agent within the pleural cavity – A pilot study

IntroductionMalignant pleural effusion (MPE) affects approximately 200,000 people in the United States per annum. Chemical pleurodesis is a recommended first line treatment in the management of MPE, however, success rates as low as 43% has been reported. A bedside chemical pleurodesis can cost up to $11,224 and an estimated inpatient annual expenditure of more than $5 billion in the US alone. This study aims to assess the distribution of the talc slurry within the pleural space using human cadaveric models and to determine the force required to push the talc slurry though a 14 Fr chest tube. Materials and methodsThe force required to administer the talc slurry through a 14 Fr chest tube was tested using a Zwick/Roelle Z005 mechanical tester, using a porcine thoracic biomodel. Talc slurry distribution within the pleural cavity was assessed by direct visualisation following administration to the human cadaveric models using single and multidirectional two-tube methods. ResultsMaximum force required to push the talc slurry through a 14 Fr chest tube was 11.36 N ± 2.79 N. Distribution of the talc slurry within the pleural cavity was found to be poor with a single tube method. Multidirectional two-tube method of administration showed more even distribution. ConclusionThe experimental multidirectional two-tube method results in wider distribution of the talc slurry within the pleural cavity and could further improve success rate of the talc pleurodesis.

Reliability of mechanical ventilation during continuous chest compressions: a crossover study of transport ventilators in a human cadaver model of CPR

BackgroundPrevious studies have stated that hyperventilation often occurs in cardiopulmonary resuscitation (CPR) mainly due to excessive ventilation frequencies, especially when a manual valve bag is used. Transport ventilators may provide mandatory ventilation with predetermined tidal volumes and without the risk of hyperventilation. Nonetheless, interactions between chest compressions and ventilations are likely to occur. We investigated whether transport ventilators can provide adequate alveolar ventilation during continuous chest compression in adult CPR.MethodsA three-period crossover study with three common transport ventilators in a cadaver model of CPR was carried out. The three ventilators ‘MEDUMAT Standard²’, ‘Oxylog 3000 plus’, and ‘Monnal T60’ represent three different interventions, providing volume-controlled continuous mandatory ventilation (VC-CMV) via an endotracheal tube with a tidal volume of 6 mL/kg predicted body weight. Proximal airflow was measured, and the net tidal volume was derived for each respiratory cycle. The deviation from the predetermined tidal volume was calculated and analysed. Several mixed linear models were calculated with the cadaver as a random factor and ventilator, height, sex, crossover period and incremental number of each ventilation within the period as covariates to evaluate differences between ventilators.ResultsOverall median deviation of net tidal volume from predetermined tidal volume was − 21.2 % (IQR: 19.6, range: [− 87.9 %; 25.8 %]) corresponding to a tidal volume of 4.75 mL/kg predicted body weight (IQR: 1.2, range: [0.7; 7.6]). In a mixed linear model, the ventilator model, the crossover period, and the cadaver’s height were significant factors for decreased tidal volume. The estimated effects of tidal volume deviation for each ventilator were − 14.5 % [95 %-CI: −22.5; −6.5] (p = 0.0004) for ‘Monnal T60’, − 30.6 % [95 %-CI: −38.6; −22.6] (p < 0.0001) for ‘Oxylog 3000 plus’ and − 31.0 % [95 %-CI: −38.9; −23.0] (p < 0.0001) for ‘MEDUMAT Standard²’.ConclusionsAll investigated transport ventilators were able to provide alveolar ventilation even though chest compressions considerably decreased tidal volumes. Our results support the concept of using ventilators to avoid excessive ventilatory rates in CPR. This experimental study suggests that healthcare professionals should carefully monitor actual tidal volumes to recognise the occurrence of hypoventilation during continuous chest compressions.

Technical note: rectangular femoral tunnel for anterior cruciate ligament reconstruction using a new ultrasonic device: a feasibility study

PurposeThe goal of this preliminary report was to show the use of novel Ultrasound (US) technology for anterior cruciate ligament (ACL) reconstruction surgery and evaluate its feasibility for the creation of a rectangular femoral bone tunnel during an arthroscopic procedure in a human cadaver model.MethodsTwo fresh frozen human cadaver knees were prepared for arthroscopic rectangular femoral tunnel completion using a prototype US device (OLYMPUS EUROPA SE & CO. KG). The desired rectangular femoral tunnel was intended to be located in the femoral anatomical ACL footprint. Its tunnel aperture was planned at 10 × 5 mm and a depth of 20 mm should be achieved. For one knee, the rectangular femoral tunnel was realized without a specific cutting guide and for the other with a 10 × 5 mm guide. One experienced orthopedic surgeon performed the two procedures consecutively. The time for femoral tunnel completion was evaluated. CT scans with subsequent three-dimensional image reconstructions were performed in order to evaluate tunnel placement and configuration.ResultsIn the two human cadaver models the two 10 × 5x20mm rectangular femoral tunnels were successfully completed and located in the femoral anatomical ACL footprint without adverse events. The time for femoral tunnel completion was 14 min 35 s for the procedure without the guide and 4 min 20 s with the guide.ConclusionUS technology can be used for the creation of a rectangular femoral bone tunnel during an arthroscopic ACL reconstruction procedure. The use of a specific cutting guide can reduce the time for femoral tunnel completion. Additional experience will further reduce the time of the procedure.

Development and implementation of an ultralow-dose CT protocol for the assessment of cerebrospinal shunts in adult hydrocephalus

BackgroundCerebrospinal fluid shunts in the treatment of hydrocephalus, although associated with clinical benefit, have a high failure rate with repeat computed tomography (CT) imaging resulting in a substantial cumulative radiation dose. Therefore, we sought to develop a whole-body ultralow-dose (ULD) CT protocol for the investigation of shunt malfunction and compare it with the reference standard, plain radiographic shunt series (PRSS).MethodsFollowing ethical approval, using an anthropomorphic phantom and a human cadaveric ventriculoperitoneal shunt model, a whole-body ULD-CT protocol incorporating two iterative reconstruction (IR) algorithms, pure IR and hybrid IR, including 60% filtered back projection and 40% IR was evaluated in 18 adult patients post new shunt implantation or where shunt malfunction was suspected. Effective dose (ED) and image quality were analysed.ResultsULD-CT permitted a 36% radiation dose reduction (median ED 0.16 mSv, range 0.07–0.17, versus 0.25 mSv (0.06–1.69 mSv) for PRSS (p = 0.002). Shunt visualisation in the thoracoabdominal cavities was improved with ULD-CT with pure IR (p = 0.004 and p = 0.031, respectively) and, in contrast to PRSS, permitted visualisation of the entire shunt course (p < 0.001), the distal shunt entry point and location of the shunt tip in all cases. For shunt complications, ULD-CT had a perfect specificity. False positives (3/22, 13.6%) were observed with PRSS.ConclusionsAt a significantly reduced radiation dose, whole body ULD-CT with pure IR demonstrated diagnostic superiority over PRSS in the evaluation of cerebrospinal fluid shunt malfunction.

Role of the Cadaver Lab in Lymphatic Microsurgery Education: Validation of a New Training Model

Background Microsurgical transplantation of vascularized lymph nodes (VLNT) or lymphatic vessels (VLVT) alongside derivative lymphaticovenous procedures are promising approaches for treatment of lymphedema. However, clinically relevant training models for mastering these techniques are still lacking. Here we describe a new training model in human cadaver and validate its use as training tool for microsurgical lymphatic reconstruction. Methods 10 surgeons with previous exposure to microsurgery were trained in a controlled environment. Lymphatic vessel mapping and dissection in 4 relevant body regions, harvesting of five different VLNTs and one VLVT were performed in 5 fresh-frozen cadavers. The number of lymphatic vessels and lymph nodes for each VLNT were recorded. Finally, the efficacy of this model as training tool was validated using the Dundee Ready Education Environment Measure (DREEM). Results The average cumulative DREEM score over each category was 30,75 (max = 40) while individual scoring for each relevant category revealed highly positive ratings from the perspective of teaching (39,3), training 40,5 (max = 48) and self perception of the training 30,5 (max = 32) from all participants. The groin revealed the highest number of lymphatic vessels (3.2 ± 0.29) as all other regions on the upper extremity, while the gastroepiploic VLNT had the highest number of lymph nodes (4.2 ± 0.37). Conclusions This human cadaver model represents a new, reproducible “all-in-one” tool for effective training in lymphatic microsurgery. Its unique diligence in accurately reproducing human lymphatic anatomy, should make this model worth considering for each microsurgeon willing to approach lymphatic reconstruction.

P0898 - A novel vacuum-based tissue holding device for laparoscopic and robotic partial nephrectomy: The development process and in vitro evaluation in human cadaveric and porcine models

P0898 - A novel vacuum-based tissue holding device for laparoscopic and robotic partial nephrectomy: The development process and in vitro evaluation in human cadaveric and porcine models

Human Cadaveric Artificial Lung Tumor-Mimic Training Model.

Introduction: An important phase in surgical training is gaining experience in real human anatomical situations. When a cadaver is available it may complement the various artificial practice models. However, it is often necessary to supplement the characteristics of the cadavers with a simulation of a tumor. Our objective was to develop an easy-to-create, realistic artificial tumor-mimic model for peripheral lung tumor resection practice. Methods: In our work we injected barium sulphate enriched silicone suspension into 10 isolated, non-fixed lungs of human cadavers, through the puncture of the visceral pleura. Four lesions–apical, hilar and two peripheral–were created in each of ten specimens. After fixation CT scans were obtained and analyzed. The implanted tumor-mimics were examined after anatomical preparation and slicing. Also performed CT-guided percutaneous puncture was also performed to create the lesions in situ in two lungs of human cadavers. Results: Analyzing the CT data of 10 isolated lungs, out of 40 lesions, 34 were nodular (85.0%) and in the nodular group five were spiculated (12.5%). Satellite lesions were formed in two cases (5.0%). Relevant outflow into vessels or airway occurred in five lesions (12.5%). Reaching the surface of the lung occured in 11 lesions (27.5%). The tumor-mimics were elastic and adhered well to the surrounding tissue. The two lesions, implanted via percutaneous puncture, both were nodular and one also showed lobulated features. Conclusion: Our artificial tumor-mimics were easy to create, varied in shape and size, and with percutaneous implantation the lesions provide a model for teaching every step of a surgical procedure.

Accuracy and efficiency of guided root-end resection using a dynamic navigation system: a human cadaver study.

To determine and compare the accuracy and efficiency of a dynamic navigation system (DNS) with a freehand (FH) technique when conducting root-end resection in a human cadaver model. Forty roots in cadaver heads were included and divided into two groups: DNS (n=20) and FH (n=20). Cone beam computed tomography (CBCT) scans of all teeth were taken. The drilling path and depth were planned virtually to using the X-guide software (X-Nav Technologies, Lansdale, PA, USA). Osteotomy and root-end resection were done under navigation in the DNS group, and freehand under the dental operating microscope in the FH group. Post-operative CBCTs were taken. Linear deviations, angular deflection, time of operation and number of mishaps were compared with determine the accuracy and efficiency. Shapiro-Wilk, one-way ANOVA and Fisher exact tests were used (P<0.05). Linear deviations, angular deflection and operation time were significantly less in the DNS group (P<0.05). The number of mishaps was not different between the two groups (P>0.05). Subgroup analyses revealed that the distance of >5mm from buccal cortical plate was significantly associated with lower accuracy, increased operation time and greater incidence of mishaps in the FH group (P<0.05), but not in the DNS group. The dynamic navigation system was more accurate and more efficient in root-end resection in a cadaver model than the freehand technique. The distance of the roots from the buccal cortical plate had a significant negative impact on the accuracy and efficacy of the root-end resection procedure when using the freehand technique. The dynamic navigation system has the potential to be a safe and reliable technological addition to endodontic microsurgery.

Pullout strength of pedicle screws using cadaveric vertebrae with or without artificial demineralization

OBJECTIVESTo evaluate the differences in the pullout strength and displacement of pedicle screws in cadaveric thoracolumbar vertebrae with or without artificial demineralization. METHODSFive human lumbar and five thoracic vertebrae from one cadaver were divided into two hemivertebrae. The left-side specimens were included in the simulated osteopenic model group and the right-side bones in a control group. In the model group, we immersed each specimen in HCl (1 N) solution for 40 minutes. We measured bone mineral density (BMD) using dual-energy X-ray absorptiometry and quantitative computerized tomography. We inserted polyaxial pedicle screws into the 20 pedicles of the cadaveric lumbar and thoracic spine after measuring the BMD of the 2 hemivertebrae of each specimen. We measured the pullout strength and displacement of the screws before failure in each specimen using an Instron system. RESULTSThe average pullout strength of the simulated osteopenic model group was 76% that of the control group. In the control and model groups, the pullout strength was 1678.87±358.96 N and 1283.83±341.97 N, respectively, and the displacement was 2.07±0.34 mm and 2.65±0.50 mm, respectively (p<.05). We detected positive correlations between pullout strength and BMD in the control group and observed a negative correlation between displacement and BMD in the model group. CONCLUSIONSBy providing an anatomically symmetric counterpart, the human cadaveric model with or without demineralization can be used as a test bed for pullout tests of the spine. In the simulated osteopenic model group, pullout strength was significantly decreased compared with the untreated control group. CLINICAL SIGNIFICANCEDecreased bone mineral density may significantly reduce the pullout strength of a pedicle screw, even though the range is osteopenic rather than osoteoporotic.

Deep infiltrating endometriosis with sacral plexus involvement: Improving knowledge through human cadaver dissection

IntroductionThe aim of this study was to assess a human cadaver model of sacral plexus dissection for learning about deep innervation in the female pelvis, and the latter's relationship with deep infiltrating endometriosis. MethodsThis was a prospective, observational study. Eight residents in obstetrics and gynecology were tested before and after a lecture on innervation of the female pelvis and a cadaver dissection class. Standardized cadaver dissection was used to identify the sacral nerve roots S2 to S4, superior and inferior hypogastric plexuses, hypogastric nerve, and splanchnic nerves. ResultsThe residents’ level of knowledge improved significantly after a one-hour lecture (p = 0.9.10−5) and after a cadaver dissection class (p = 0.6.10−6). The improvement was significantly greater for the dissection class (p = 0.0003). All the pelvic nerve structures were identified in all but one of the cadavers and had similar measurements. A vascular anatomical variant was observed in one case. ConclusionA human cadaver model is of value for learning about deep pelvic innervation and the latter's relationship with deep infiltrating endometriosis. The reproducibility and safety of cadaver dissection might improve surgical skills.

MRI-Compatible and Conformal Electrocorticography Grids for Translational Research.

Intraoperative electrocorticography (ECoG) captures neural information from the surface of the cerebral cortex during surgeries such as resections for intractable epilepsy and tumors. Current clinical ECoG grids come in evenly spaced, millimeter‐sized electrodes embedded in silicone rubber. Their mechanical rigidity and fixed electrode spatial resolution are common shortcomings reported by the surgical teams. Here, advances in soft neurotechnology are leveraged to manufacture conformable subdural, thin‐film ECoG grids, and evaluate their suitability for translational research. Soft grids with 0.2 to 10 mm electrode pitch and diameter are embedded in 150 µm silicone membranes. The soft grids are compatible with surgical handling and can be folded to safely interface hidden cerebral surface such as the Sylvian fold in human cadaveric models. It is found that the thin‐film conductor grids do not generate diagnostic‐impeding imaging artefacts (<1 mm) nor adverse local heating within a standard 3T clinical magnetic resonance imaging scanner. Next, the ability of the soft grids to record subdural neural activity in minipigs acutely and two weeks postimplantation is validated. Taken together, these results suggest a promising future alternative to current stiff electrodes and may enable the future adoption of soft ECoG grids in translational research and ultimately in clinical settings.

Anatomical relationships of the transmuscular portal to its surrounding structures in arthroscopic treatment of superior labrum anterior posterior lesions: A cadaveric study and preliminary report.

This study aims to investigate the anatomical relationships of the transmuscular portal to its surrounding structures in arthroscopic treatment of superior labrum anterior posterior (SLAP) lesions in a human cadaveric model. In this anatomic study, bilateral shoulder girdles of 12 adult formalin embalmed cadavers were used. All cadavers were male, and the mean age was 63.4±7.3 years. The portal entry point was determined as midway between the anterior and posterior borders of the acromion, approximately 1 cm lateral from the edge of the acromion. After a guidewire was placed in the glenoid cavity at the 12 o'clock position where the SLAP lesion typically occurs, a switching stick was inserted there. Each glenoid was then drilled with a 2.4 mm drill through an arthroscopic cannula. Subsequently, anatomical dissection was executed to assess the relationship of the transmuscular portal with the suprascapular nerve, axillary nerve, supraspinatus tendon, acromion, and biceps tendon. Lastly, the shortest distance between the aforementioned structures with the drill was measured by a sensitive caliper to determine whether there was a penetration of the structures. Differences between the right and left sides were analyzed. The mean distance between the portal and the axillary nerve was 55.5 mm±6.0 mm, and the mean length of the suprascapular nerve was 61.2 mm±7.0 mm. The mean distance between the portal and the supraspinatus tendon was 2.8 mm±1.5 mm. No penetration of the axillary nerve, suprascapular nerve, and supraspinatus tendon was observed in any cadaver. No differences were detected for measured anatomical parameters between the right and left sides (p>0.05). Findings from this cadaveric study revealed that the transmuscular portal may allow for a reliable anchor placement without any nerve or tendon penetration during arthroscopic SLAP repair. Level V.

Bone cement augmentation of femoral nail head elements increases their cut-out resistance in poor bone quality– A biomechanical study

The aim of this study was to analyze biomechanically the impact of bone cement augmentation on the fixation strength and cut-out resistance of Proximal Femoral Nail Antirotation (PFNA) and Trochanteric Fixation Nail Advanced (TFNA) head elements within the femoral head in a human cadaveric model with poor bone quality. Methodology: Fifteen pairs of fresh-frozen human cadaveric femoral heads were randomized to three sets of five pairs each for center-center implantation of either TFNA blade, TFNA screw, or PFNA blade. By splitting the specimens of each pair for treatment with or without bone cement augmentation, six study groups were created. All specimens were biomechanically tested under progressively increasing cyclic loading featuring a physiologic loading trajectory in a setup simulating a reduced intertrochanteric fracture with lack of posteromedial support. Number of cycles to 5° varus collapse was evaluated together with the corresponding load at failure. Results: Compared to the non-augmented state, all types of implants demonstrated significantly higher numbers of cycles to failure and load at failure following augmentation, p ≤ 0.03. Augmented TFNA blades resulted in highest numbers of cycles to failure and loads at failure (30492; 4049 N) followed by augmented PFNA blades (30033; 4003 N) and augmented TFNA screws (19307; 2930 N), p = 0.11. Augmented TFNA screws showed similar numbers of cycles to failure and loads at failure compared to both non-augmented TFNA and PFNA blades, P = 0.98.From a biomechanical perspective, bone cement augmentation significantly increases the cut-out resistance of instrumented TFNA and PFNA head elements and is a valid supplementary treatment option to these nailing procedures in poor bone quality.

Taking the frozen elephant trunk technique to the next level by a stented side branch for a left subclavian artery connection: a feasibility study.

OBJECTIVESOur goal was to develop a modified frozen elephant trunk (FET) prosthesis with a stented left subclavian artery (LSA) side branch for LSA connection and to perform preclinical testing in a human cadaver model. METHODSWe measured aortic diameters, distance between and diameters of supra-aortic vessels and the distance from the LSA offspring to the level of the left vertebral artery offspring in 70 patients. Based on these measurements, a novel FET prosthesis was developed (Cryolife/Jotec, Hechingen, Germany) featuring a stented side branch for an intrathoracic LSA connection. The feasibility and ease of implantation were tested in 2 human cadaver models at the Anatomical Institute of the Medical University Graz. A covered stent graft (Advanta V12™ by Atrium Medical Corp., Hudson, NH, USA) was used for an LSA extension.RESULTSAccurate deployment of the novel FET prosthesis with anatomical orientation of the stented side branch towards the LSA ostium followed by consecutive stent graft deployment was feasible in both cases. Proximalizing the distal anastomosis level from zone 3 to zone 1 not only diminished the complexity of the procedure but substantially facilitated the completion of the distal anastomosis. A 2.5-cm long extension stent graft was sufficient to seal to the LSA and to maintain left vertebral artery patency in both cases.CONCLUSIONSThis initial study in human anatomical bodies could demonstrate the feasibility of implanting a newly designed FET prosthesis. This evolution of the FET technique has the potential to substantially ease total aortic arch replacement by proximalization of the distal anastomosis into zone 1 and by shortening spinal and lower body hypothermic circulatory arrest times via a stented side branch to the LSA. This direct connection enables early restoration of systemic perfusion.

Applications of a Novel Microangioscope for Neuroendovascular Intervention.

Visualization in neuroendovascular intervention currently relies on biplanar fluoroscopy and contrast administration. With the advent of endoscopy, direct visualization of the intracranial intravascular space has become possible with microangioscopes. We analyzed the efficacy of our novel microangioscope to enable direct observation and inspection of the cerebrovasculature, complementary to a standard fluoroscopic technique. Iterations of microangioscopes were systematically evaluated for use in neurodiagnostics and neurointerventions in both live animal and human cadaveric models. Imaging quality, trackability, and navigability were assessed. Diagnostic procedures assessed included clot identification and differentiation, plaque identification, inspection for vessel wall injury, and assessment of stent apposition. Interventions performed included angioscope-assisted stent-retriever thrombectomy, clot aspiration, and coil embolization. The microangioscope was found helpful in both diagnosis and interventions by independent evaluators. Mean ratings of the imaging quality on a 5-point scale ranged from 3.0 (clot identification) to 4.7 (Pipeline follow-up). Mean ratings for clinical utility ranged from 3.0 (aspiration thrombectomy) to 4.7 (aneurysm treatment by coil embolization and WEB device). This fiber optic microangioscope can safely navigate and visualize the intravascular space in human cadaveric and in vivo animal models with satisfactory resolution. It has potential value in diagnostic and neurointerventional applications.

Feasibility of fresh frozen human cadavers as a research and training model for endovascular image guided interventions.

To describe the feasibility of a fresh frozen human cadaver model for research and training of endovascular image guided procedures in the aorta and lower extremity. The cadaver model was constructed in fresh frozen human cadaver torsos and lower extremities. Endovascular access was acquired by inserting a sheath in the femoral artery. The arterial segment of the specimen was restricted by ligation of collateral arteries and, in the torsos, clamping of the contralateral femoral artery and balloon occlusion of the supratruncal aorta. Tap water was administered through the sheath to create sufficient intraluminal pressure to manipulate devices and acquire digital subtraction angiography (DSA). Endovascular cannulation tasks of the visceral arteries (torso) or the peripheral arteries (lower extremities) were performed to assess the vascular patency of the model. Feasibility of this model is based on our institute's experiences throughout the use of six fresh frozen human cadaver torsos and 22 lower extremities. Endovascular simulation in the aortic and peripheral vasculature was achieved using this human cadaver model. Acquisition of DSA images was feasible in both the torsos and the lower extremities. Approximately 84 of the 90 target vessels (93.3%) were patent, the remaining six vessels showed signs of calcified steno-occlusive disease. Fresh frozen human cadavers provide a feasible simulation model for aortic and peripheral endovascular interventions, and can potentially reduce the need for animal experimentation. This model is suitable for the evaluation of new endovascular devices and techniques or to master endovascular skills.

Design, prototype development and pre-clinical validation of a novel instrument with a compliant steerable tip to facilitate endoscopic ear surgery

This work presents the design of a novel compliant steerable tip (CST) instrument to facilitate transcanal (or totally) endoscopic ear surgery (TEES). The evolution of the instrument’s design is shown, where prototypes were evaluated by surgeons and their feedback was used to inform the design changes for the next prototype iteration. The final prototype enables the surgeon to articulate the compliant tip to achieve the desired bending curvature while automatically locking in place and providing dissection and suction capabilities. Pre-clinical validation testing was performed in goat and human cadaver models by two surgeons who successfully removed an allograft from the middle ear. Time and the number of blockages while suctioning saline in both cadaver models were measured and compared with current instruments used during TEES. The CST took significantly less time to suction saline within a flooded middle ear compared to the Panetti suction dissector (PSD) for atticus and underwent less blockages than the PSD for atticus, ear drum and sinus tympani instruments, Wilcoxon Method p < .05. Our study demonstrates the development and successful clinical evaluation of a minimally invasive surgical instrument designed to facilitate endoscopic approaches to the ear.