[Proposal of a human cadaveric model for bedside ultrasound-based pneumothorax detection.] / Humán kadávermodell a légmell ágy melletti ultrahang-diagnosztikájához.

INTRODUCTION: In the last decade, the use of bedside ultrasound examination has become one of the defining elements of emergency and intensive-anesthesia care. Among the everyday applications, lung ultrasound examination, which received a huge boost in connection with the coronavirus pandemic, stands out in a profession-specific manner. The first step of the most frequently used protocols is the immediate diagnosis of life-threatening conditions (e.g., pneumothorax) so that appropriate intervention can take place as soon as possible. In accordance with the above, the teaching of lung ultrasound examination has also been included in the domestic curriculum of emergency professions. OBJECTIVE: With our present cadaveric preliminary study, we want to improve the domestic practice of bedside lung ultrasound examination and thus increase patient safety in the everyday clinical workflow. METHOD: In our experimental set-up, we used 5 selected fresh, unpreserved human cadavers, on which we created artificial pneumothorax as detailed later. Based on emergency lung ultrasound protocol, we recorded 10-second loops with a bedside ultrasound device, which were later scored by two independent intensive experts based on a given scoring system. RESULTS: According to expert assessments, the image quality of the image database obtained with the help of our model, the clarity of lung profiles, and the semi-quantitative scoring all demonstrate a suitable level for further educational purposes, with a consensus ranging from moderate to excellent quality. DISCUSSION: In the future, we also plan to use preserved cadavers, which can be favourable from the point of view of cost-effectiveness and storability. CONCLUSION: According to our results, the cadaver model prepared in our way is sufficiently realistic, potentially suitable for clinical education, and also for creating an image data bank, which can also be used for digital education in the future. Orv Hetil. 2023; 164(46): 1824-1830.

Minimally invasive apical cannulation and cannula design for short-term mechanical circulatory support devices.

BACKGROUND: Refractory cardiogenic shock is still a major clinical challenge with high mortality rates, although several devices can be used to conquer this event. These devices have different advantages and disadvantages originating from their insertion or cannulation method, therefore many complications can occur during their use. The aim of our study was to develop and create prototypes of a novel minimal invasively insertable, transapical cannula for surgical ventricular assist devices, which uniquely incorporates the inflow and outflow routes for the blood of the patient in itself, therefore it enables the use for only one cannula for patients in cardiogenic shock. METHODS: To define the available space for the planned cannula in the left ventricle and ascending aorta, we analyzed computed tomography scans of 24 heart failure patients, who were indicated to left ventricular assist device therapy. Parallel to these measurements, hydrodynamical calculations were performed to determine the sizes of the cannulas, which were necessary to provide effective cardiac output. RESULTS: After the designing steps, we produced prototypes of double-lumened, tube-in-tube apically insertable devices for three different patient groups, which included a separated venous and an arterial part using 3D modelling and printing technology. All the created cannulas are able to provide 5 l/min circulatory support. CONCLUSION: As a result of our research we created a sizing method based on the specific analysis of computed tomography pictures of end stage heart failure patients and a cannula concept, which can provide effective antegrade flow for patients in cardiogenic shock. We believe the improved version of our tool could have a significant therapeutic role in the future after further development based on animal and in vivo tests.

Rare variation of hepatic blood supply with accessory right and left hepatic artery / A máj ritka vérellátási variációja járulékos arteria hepatica dextra és sinistra jelenlétével

In recent decades, multiple studies have examined the various manifestations of the hepatic blood supply using anatomical preparation and imaging procedures (angiography, CT). Based on these observations, several classifications have emerged to determine blood supply types and their incidence rates. Our aim is to present a rare variation of the arterial blood supply of the liver through an anatomical preparation. Postmortem native CT scans of the abdominal organs of the described cadaver were performed, followed by three-dimensional reconstruction. After imaging, the abdominal block was fixed with formalin, then the vessels were visualized by layered anatomical preparation. The liver is supplied not only from the bifurcated proper hepatic artery, but also receives accessory branches from the left gastric artery and the superior mesenteric artery. This variation represents the widely used Michels' classification type VII, found in 0.2­0.73% of the cases. Vascular variations are not only remarkable from an anatomical point of view, but their preoperative mapping also plays a significant role in performing surgical interventions without any complications.

Real 3D Visualization of the Circumflex Artery Surrounding the Mitral Annulus.

BACKGROUND: The circumflex coronary artery is located close to the mitral annulus. Consequently, it is not immune to iatrogenic damage during mitral valve procedures. Our objective was to visualize the circumflex artery from a surgeon's point of view, emphasizing its proximity. Furthermore, comparing it to coronary angiograms might support preoperative planning. METHODS: Ten adult human hearts preserved in 4% formaldehyde solution were investigated (left coronary artery injected with contrast agent). After performing coronary angiographies from LAO (left anterior oblique) 40/cranial 20, RAO (right anterior oblique) 10/cranial 40, and true lateral projections, anatomical preparations were performed. Images were captured throughout the full course of the circumflex coronary artery from multiple angles. Finally, the mean distances were measured in every 5 mm between the investigated artery and the annulus of the mitral valve. RESULTS: Three-dimensional model of the circumflex coronary artery and its surroundings was successfully achieved from a left atrial surgical viewpoint. The main branches were identified on the coronary angiograms. The closest distance was measured under the region of the left auricle (2.02 ± 0.69 mm; 1-3.1 mm). Afterward, the circumflex artery was observed to make a loop away from the annular region. CONCLUSION: Our observations show correlation with previous anatomical studies and case reports addressing iatrogenic lesions on the circumflex coronary artery. Based on all these, we could determine a "danger zone" on the vessel. The simultaneous evaluation of the anatomical preparations and the angiograms might improve the acknowledgment of this vulnerable region serving to avoid any damage to the coronary artery.

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.

A different technique for sutureless coronary bypass grafting.

Introduction: Many coronary anastomotic devices have been designed to replace manual stitching in coronary surgery; however, interestingly, none of them became widespread. Our aim was to work out an easy and fast endoluminal vessel-to-vessel stent bridge distal anastomotic technique. Materials and methods: Ten coronary arteries of eight fresh human hearts were used in this study. The anastomosis was performed with the implantation of a graft vessel into the lumen of the coronary artery by performing stent fixation. The technique is described and photo documented in detail. The durability and the conductibility of the anastomosis were examined with intraluminal endoscopy, functional streaming test, and a coloring of the vessels. Results: The anastomosis had great results in all cases. Obstruction, dissection, or dislocation of the vessels was not observable. Conclusions: This study confirmed the ex-vivo feasibility of the described technique. This method can be an easy, fast, and reliable method applied in the endoscopic distal coronary artery anastomosis surgery. The development of stents adapted to this method and the in-vivo testing of this technique are necessary for the future.

Feasibility of the Far Lateral Suboccipital Approach to the Retroodontoid Region. How Much Bone Removal Is Truly Needed?

OBJECTIVE: The posterolateral extradural suboccipital approach can be used to reach the anterior epidural space and the retro-odontoid regions. The extent of necessary bone removal of the atlas vertebra (C1) has not yet been defined. We studied the changes in the size of the horizontal and vertical surgical windows using stepwise bone removal of C1. A representative case is shown. METHODS: The anatomical study was performed bilaterally on five Thiel-fixed human cadavers (mean age, 83.7 years). The surgical window (horizontal × vertical) required to access the retro-odontoid region via a posterolateral approach was measured for an intact C1 posterior arch, after a semicircular inferior partial resection of the C1 arch, after resection of the unilateral hemiarch of C1, and finally after drilling approximately 3 mm from the medial aspect of the lateral mass of C1. RESULTS: The intact C1 resulted in a very narrow surgical window of 6.3 mm × 9.7 mm (horizontal × vertical). The vertical window increased to a 13 mm after the semicircular inferior partial resection of the C1 arch and to 17.3 mm in the case of removal of the ipsilateral C1 posterior arch. The bone removal from the medial aspect of the C1 lateral mass resulted in a widening of the horizontal surgical window to 10.3 mm. The final size of the surgical window was 10.3 mm × 17.3 mm. The patient with severe kyphoscoliosis of the craniocervical spine was successfully operated on using odontoid and C1-2 facet osteotomies. CONCLUSION: If only the anterior epidural space or the base of the odontoid needs to be reached, the semicircular inferior partial resection of the C1 arch allows for an adequate surgical window. The tip of the odontoid could only be reached if the ipsilateral posterior arch is resected.

[New approach in the surgical treatment of mitral regurgitation: beating heart transapical neochord implantation]. / A mitralis elégtelenség sebészi kezelésének új megközelítése: transapicalis ínhúrpótlás dobogó szíven.

Severe mitral regurgitation due to prolapse of the valve demands early surgical intervention. Recently artificial chord implantation is the prefered solution, which requires cardioplegia and application of cardiopulmonary bypass using the left atrial approach. Transoesophageal echocardiography guided transapical neochord implantation is an emerging new technique for the treatment of mitral regurgitation. It enables the operation through left minithoracotomy on beating heart using a special instrument introduced into the left ventricle. Acute procedural success rates in different centres vary between 86 and 100%. According to reports, 92% of the patients do not require additional intervention at the 3-month follow-up. Continuous integration of data resulting improved outcomes supports the hope that this novel, less-invasive technique will be applied widely for the treatment of mitral regurgitation.

Minimally Invasive Cardiac Surgery Using a 3D High-Definition Endoscopic System.

We describe a minimally invasive heart surgery application of the EinsteinVision 2.0 3D high-definition endoscopic system (Aesculap AG, Tuttlingen, Germany) in an 81-year-old man with severe tricuspid valve insufficiency. Fourteen years ago, he underwent a Ross procedure followed by a DDD pacemaker implantation 4 years later for tachy-brady-syndrome. His biventricular function was normal. We recommended minimally invasive tricuspid valve repair. The application of the aformentioned endoscopic system was simple, and the impressive 3D depth view offered an easy and precise manipulation through a minimal thoracotomy incision, avoiding the need for a rib spreading retractor.

Endoscopic Resection of a Giant Left Atrial Appendage.

A 23-year-old woman with a history of arterial hypertension presented to our institution complaining of dyspnea and chest pain. Her workup including echocardiography and magnetic resonance imaging revealed an aneurysm of the left atrial appendage. No thrombus was identified in the aneurysm or left atrial appendage, and the patient was in sinus rhythm. She was started on prophylactic anticoagulation, and surgical resection of the aneurysm was recommended as a definitive treatment of this lesion. The surgery was performed using a minimally invasive left-sided thoracoscopy approach. The entire left atrial appendage including the aneurysm was removed at its base using an articulating endoscopic stapler device. On postoperative echocardiography, no residual left atrial appendage tissue was evident. The patient could be taken off oral anticoagulation and left the hospital in good condition.

Experimental transapical endoscopic ventricular visualization and mitral repair.

BACKGROUND: An increasing number of experimental beating heart animal studies describe simple transapical mitral valve repairs based on the direct endoscopic visualization of the left ventricle. The aim of our human cadaveric study was to develop a method for more complex transapical endoscopic procedures by on-pump heart operations. MATERIALS AND METHODS: After preparation of 20 human fresh cadavers, a standard left anterolateral minithoracotomy was performed in the fifth intercostal space and the pericardium was entered. A rigid 0 degree endoscope and the instruments were introduced through a silicon apical port. To restore the natural form of the left heart, CO2 was insufflated. To test the mitral valve competence, the left ventricle was pressure-injected with saline after each step. After transecting the chords of the A2 segment of the anterior mitral leaflet before the experimental mitral valve repair, the tendinous chord was replaced using an especially designed clip chord. The second part of the experiment consisted of a segmental excision of the P2 segment of the posterior mitral leaflet followed by a standard valvuloplasty and suture annuloplasty. RESULTS: With the help of the described transapical endoscopic mitral valve repair technique, we gained direct visual information of the coaptation line of the mitral leaflets as well as the anatomy and function of the subvalvular apparatus. Using intracardiac imaging, we could perform successful transapical complex mitral repair in each case. CONCLUSION: The minimally invasive transapical endoscopic method has the potential to offer advantages for on-pump mitral valve repair procedures even in complex mitral valve repair cases.

Comparative endoscopic anatomic description of the mitral valvular complex: a cadaveric study.

BACKGROUND: We compared the aortic, left atrial, and apical approaches to visualize the mitral valve with the goal to investigate the endoscopic anatomy and give exact step-by-step descriptions of these views. MATERIALS AND METHODS: The mitral valvular complex of human cadaveric fresh hearts was investigated from three approaches using 0, 30, and 70 degrees rigid endoscopic optics. In 30 cases after the removal of the hearts, the endoscopes were introduced directly into the aortic root through an aortotomy, left atrium through a standard atriotomy, and apex of the heart through a transmural incision. In 10 cases, the in situ visualization was performed using standard surgical approaches, such as partial upper ministernotomy, right and left minithoracotomy. The investigation was performed first with the mitral valve open, then the left ventricle was filled with saline, and the valve was closed by clamping the aorta. RESULTS: For the visualization of ventricular surfaces of the mitral leaflets and the subvalvular apparatus, the apical approach was most optimal. The aortic approach had limitations at the posterior leaflet. Using the atrial approach, we did not obtain any direct visual information about the subvalvular apparatus with the valve closed. The atrial surfaces of the leaflets were best visible using both the atrial and apical approaches with the mitral valve open. In the case of a closed valve, the apical approach did not allow for an investigation of the atrial surfaces. The aortic approach was useful to visualize the atrial surface of the posterior leaflet with an opened valve. CONCLUSION: In mitral valve repairs through the left atrium, an additional aortic or apical view could be useful to obtain functional information about the subvalvular apparatus by the sealing probe.

Safeguards and pitfalls in minimally invasive mitral valve surgery.

Minimally invasive mitral valve surgery has been established in many institutions worldwide. Appropriate indications and patient selection for this procedure must be based on a thorough understanding of its limitations and specific pitfalls. Particular risks can be minimized with careful attention to detail when planning and performing the surgery. The following chapter offers a stepwise description of the procedure; we point out particular advantages, discuss our rationale for certain steps, as well as focus on potential dangers of minimally invasive mitral valve surgery. Several graphics have also been provided to illustrate our approach and demonstrate important structural and anatomical concepts of the mitral valve apparatus.