Mediastinal Anatomy Research Articles

Don't judge a book by its cover: Unusual presentations of pericardial disease.

The presentation of pericardial disease can be unusual, and what is assumed to be pericardial disease may not be. Knowing pericardial and mediastinal anatomy is vital for understanding these unusual presentations. This review focuses on the history, physical examination, and fundamental diagnostic testing, integrated with pericardial and mediastinal anatomy and pathophysiology.

The cervical branch-first technique in complex resternotomy

BackgroundBranch-first total aortic arch repair is a paradigm shift in the technical approach for uninterrupted neuroprotection during open aortic surgery. This technique is further modified to instigate hazardous sternal reentry in patients with hostile mediastinal anatomy at risk of aortic injury. MethodsIntraoperative preparation and the illustrated operative technique of the cervical branch-first technique are described. The accompanying case series narrates the experiences and outcomes of 4 patients who underwent successful complex reoperative aortic surgery utilizing this technique. ResultsThe indications for resternotomy included a sixth reoperation for recurrent mycotic aortic pseudoaneurysm, a third reoperation for extensive infective endocarditis, a reoperation for complete Bentall graft dehiscence with contained aortic rupture, and a third reoperation for residual type A dissection. All patients survived their proposed surgery. Two patients were operated on in an emergency setting. Two patients separated from cardiopulmonary bypass with extracorporeal support. None experienced permanent neurological sequelae, gut ischemia, peripheral arterial complications, or in-hospital mortality. One mortality due to decompensated heart failure was reported at 6 months postoperatively. ConclusionsThe cervical branch-first technique offers unparalleled advantage in neuroprotection from an early stage of complex reoperative aortic surgery. It provides an independent circuit for complete antegrade cerebral perfusion, irrespective of suspension to circulatory flows to the rest of the body during complex reentry into hostile chests. Our experience to date has demonstrated promising outcomes and further refinements will guide patient selection best suited for this technique.

Step-by-Step Dissection of the Mediastinum: A Training Protocol

The understanding of mediastinal anatomy represents a real challenge because of the vital structures inside it and due to its complex relationships with surrounding anatomical regions. Human anatomical specimens are always used both for the teaching of anatomy and the training of young surgeons, thus providing a deep understanding of the most complex anatomical regions and allowing less experienced surgeons to become familiar with surgical instruments and their use on actual human tissues. Despite the spread of these learning practices, there are no principles of dissection to follow for a young physician interested in the anatomy of the mediastinum. Therefore, the main objective of this study is to define a reliable and reproducible protocol for the dissection of the mediastinum. A stratigraphic anatomical dissection on three embalmed human specimens was performed. All steps were documented by high-quality photographs, taken with a professional digital reflex camera, and subsequently edited. A step-by-step anatomical dissection guide was created, detailing every phase, guiding the dissection of the mediastinal anatomy, and leading to the correct identification of its main anatomical structures. We present a step-by-step dissection guide to the mediastinal anatomy with point-by-point explanations and dedicated images, providing an additional tool for the comprehension of this complex anatomical area.

A deep learning-based system for mediastinum station localization in linear EUS (with video).

EUS is a crucial diagnostic and therapeutic method for many anatomical regions, especially in the evaluation of mediastinal diseases and related pathologies. Rapidly finding the standard stations is the key to achieving efficient and complete mediastinal EUS imaging. However, it requires substantial technical skills and extensive knowledge of mediastinal anatomy. We constructed a system, named EUS-MPS (EUS-mediastinal position system), for real-time mediastinal EUS station recognition. The standard scanning of mediastinum EUS was divided into 7 stations. There were 33 010 images in mediastinum EUS examination collected to construct a station classification model. Then, we used 151 videos clips for video validation and used 1212 EUS images from 2 other hospitals for external validation. An independent data set containing 230 EUS images was applied for the man-machine contest. We conducted a crossover study to evaluate the effectiveness of this system in reducing the difficulty of mediastinal ultrasound image interpretation. For station classification, the model achieved an accuracy of 90.49% in image validation and 83.80% in video validation. At external validation, the models achieved 89.85% accuracy. In the man-machine contest, the model achieved an accuracy of 84.78%, which was comparable to that of expert (83.91%). The accuracy of the trainees' station recognition was significantly improved in the crossover study, with an increase of 13.26% (95% confidence interval, 11.04%-15.48%; P < 0.05). This deep learning-based system shows great performance in mediastinum station localization, having the potential to play an important role in shortening the learning curve and establishing standard mediastinal scanning in the future.

Anatomy of mediastinal veins and nerves.

The mediastinum is the central compartment in the thoracic cavity that lies between the lungs. It extends from the thoracic inlet superiorly to the diaphragm inferiorly and sternum anteriorly to the vertebral column posteriorly. It is commonly divided into four compartments-superior, anterior, middle and posterior mediastinum. However, some have started to classify it into the more recent three compartments-anterior (prevascular), middle (visceral) and posterior (paravertebral). The mediastinum is of clinical significance because many vital structures, such as the heart, great vessels, esophagus, lymphatics, and trachea, lie within these compartments. Disease presentation can greatly vary depending on the structures involved, and the differential diagnosis can range widely. Therefore, knowledge of the anatomy and subdivisions of the mediastinum is vital for thoracic surgeons. Herein, we have provided a brief review of the mediastinal anatomy. Utilizing the four-compartment model, we detail the contents of each compartment of the mediastinum with special attention to its veins and nerves. There are also several venous junctions that are important for mediastinal surgery, such as the internal jugular-subclavian venous junction and the left-right brachiocephalic venous junction. We describe useful superficial landmarks, such as the sternocleidomastoid and manubrium, and how they relate to some of the key venous junctions.

Impact of obesity on double-lumen endobronchial tube displacement after lateral decubitus positioning.

Double-lumen endobronchial tube (DLT) displacement, defined as migration of the DLT > 15 mm from optimal position, may threaten patient safety. Lateral decubitus positioning (LDP) of the patient can induce DLT displacement; however, little is known regarding the predictors for DLT displacement after this maneuver. Obesity may further aggravate DLT displacement by distorting mediastinal anatomy, but no comprehensive data exist concerning the impact of obesity on DLT displacement after LDP. Therefore, we evaluated the predictive value of preoperative risk factors, including obesity, for DLT displacement after LDP in patients who underwent pulmonary resection. Data of patients who underwent pulmonary resection between July 2020 and July 2021 were retrospectively reviewed. Age, sex, height, weight, body mass index, left main bronchus diameter, DLT size, lateral decubitus direction, DLT depth, patient height divided by the DLT depths in supine and lateral decubitus positions (H/Dsupine and H/Dlateral, respectively), and extent of DLT dislocation were assessed. Logistic regression analysis identified risk factors, and the optimal cutoff values for continuous variables were determined using receiver operating characteristic curve analysis. Data from 428 patients were analyzed. DLT displacement was observed in 52 patients (12.1%). Obesity and H/Dsupine were independent predictors for DLT displacement after LDP (odds ratio [OR]: 5.69, 95% CI [2.89, 11.23], P < 0.001 and OR: 8.28, 95% CI [2.92, 23.48], P < 0.001, respectively). Obesity was significantly associated with DLT displacement after LDP. Pre-emptively advancing the DLT from its optimal position before LDP may be advantageous in patients with obesity.

Pneumomediastinum and pneumorrhachis following sinoscopy in an adult horse

AbstractA horse presented to the referral hospital for pyrexia and unilateral nasal discharge. Computed tomographic examination demonstrated changes consistent with unilateral primary sinusitis. Frontal and rostral maxillary trephination facilitated sinoscopy and lavage of the paranasal sinuses. Postoperatively, subcutaneous emphysema of the head and neck developed and upon further investigation pneumomediastinum and pneumorrhachis were diagnosed on radiographic examination. The trephine portals were the likely entry point of the subcutaneous emphysema; gas then dissected through the fascial planes of the neck into the mediastinum. It is hypothesised that gas also extended along cervical fascial planes and through intervertebral foramina to enter the spinal canal causing pneumorrhachis. This is accordant with cases in human medicine and current understanding of mediastinal anatomy. The horse recovered with conservative management; however, it is noteworthy that pneumomediastinum and pneumorrhachis are potential complications of sinoscopy. Pneumothorax can subsequently develop, which could be life threatening.

Incorporation of virtual reality in the clinical training of medical students studying esophageal and mediastinal anatomy and surgery.

To analyze the effectiveness of incorporating virtual reality (VR) in lectures on esophageal and mediastinal anatomy and surgical procedures for medical students at Gifu University during clinical training. We divided medical students participating in clinical training, randomly, into two groups of 30 students each: those who received a lecture using 3D images (3D group) and those who received a lecture using VR images (VR group). Four days after the lecture, the students completed a written test to allow us to evaluate their comprehension, and a questionnaire on their opinion of the lectures. Based on the results of the written test, the VR group achieved better understanding of computed tomography (CT) images (p = 0.0001) and better interpretation of surgical images (p = 0.0163). However, there was no difference in the scores for spatial recognition and general problems. The questionnaire revealed that the VR group became more interested in mediastinal anatomy (p = 0.0165) and surgery (p = 0.0135). Our findings suggest that VR enhances the learning process. The lecture incorporating the VR experience was more effective than the traditional lecture for promoting an understanding of CT images and interpretation of surgical images; thus, it enhances the learning experience for medical students studying surgery.

Outcomes in LVAD Implantation via Lateral Thoracotomy with Outflow Cannula Anastomosis to the Descending Aorta

<h3>Purpose</h3> LVAD implantation via left lateral thoracotomy with outflow cannula anastomosis to the descending aorta is an alternative technique that uses a single incision and avoids anterior mediastinal planes in cases with hostile mediastinal anatomy. However, the long-term outcomes of outflow cannula to descending aorta anastomosis using contemporary LVADs are unknown and are evaluated in this study. <h3>Methods</h3> Adult patients implanted with a continuous flow centrifugal LVAD (HeartWare HVAD) in an academic center were included to the study. Hospital stay following implantation, short & long-term survival and readmission patterns were compared between ascending and descending aorta anastomosis groups. Readmission analysis only included patients that survived >30 days following the index hospitalization. <h3>Results</h3> 338 patients (Asc Ao: 280, Desc Ao:58) were included to the study. Readmission analysis included 277 patients (Asc Ao: 231, Desc Ao: 46) and a total of 1043 readmissions during 667 years of follow-up were analyzed (Table 1). There was no significant difference in hospital-stay following implantation or 90-day, 1-year, 3-year and 5-year mortality between the two groups. Readmission-free survival, 30-day readmission, number of admissions per year and hospital length of stay per year were similar. Number of admissions for specific causes were not significantly different (Table 2). <h3>Conclusion</h3> LVAD implantation via lateral thoracotomy with outflow cannula anastomosis to the descending aorta has a comparable survival and readmission profile with standard ascending aorta anastomosis in long-term follow-up.

Practical approach to linear EUS examination of the mediastinum.

EUS has become a substantial diagnostic and therapeutic modality for many anatomical regions. The extent of endosonographic assessment is wide, and among others, allows for the evaluation of the mediastinal anatomy and related pathologies such as mediastinal lymphadenopathy and staging of central malignant lung lesions. Moreover, EUS assessment has proved more accurate in detecting small lesions missed by standard imaging examinations such as computed tomography or magnetic resonance. Endosonographically, various mediastinal anatomical landmarks and stations can be visualized by transesophageal scanning, thus providing arranged systematic examination of the mediastinum. In addition, the correct position during the examination is crucial for EUS-guided procedures such as tissue sampling and drainage of mediastinal abscesses. The evolution of EUS-guided diagnostic and interventional procedures has contributed to the increasing importance of understanding the mediastinal anatomy during the EUS examination.

The effect of azygos vein preservation on postoperative complications after esophageal atresia repair: Results from the Turkish Esophageal Atresia Registry

AimPreservation of the azygos vein (AV) maintains normal venous drainage of the mediastinum and decreases postoperative congestion. The modification of esophageal atresia (EA) repair by preserving AV may prevent postoperative complications and may lead to better outcomes. The data from the Turkish Esophageal Atresia Registry (TEAR) were evaluated to define the effect of AV preservation on postoperative complications of patients with EA. MethodsData from TEAR for a period of five years were evaluated. Patients were enrolled into two groups according to the preservation of AV. Patients with divided (DAV) and preserved AV (PAV) were evaluated for demographic and operative features and postoperative complications for the first year of life. The DAV and PAV groups were compared according to the postoperative complications, such as fistula recanalization, symptomatic strictures, anastomotic leaks, total number of esophageal dilatations, and anti-reflux surgery. In addition, respiratory problems, which required treatment, were compared between groups. ResultsAmong 502 registered patients; the data from 315 patients with the information of AV ligation were included. The male female ratio of DAV (n = 271) and PAV (n = 44) groups were 150:121 and 21:23, respectively (p > 0.05). The mean body weight, height, gestational age, and associated anomalies were similar in both groups (p > 0.05). The esophageal repair with thoracotomy was significantly higher in DAV group, when compared to the PAV group (p < 0.05). The rates of primary anastomosis and tensioned anastomosis were similar in both groups (p > 0.05). There was no difference between DAV and PAV groups for anastomotic leaks, symptomatic anastomotic strictures, fistula recanalization, and the requirement for anti-reflux surgery (p > 0.05). The rate of respiratory problems, which required treatment, was significantly higher in the DAV group (p < 0.05) ConclusionThe data in the TEAR demonstrated that preserving the AV during EA repair led to no significant advantage on postoperative complications, with exception of respiratory problems. AV should be preserved as much as possible to maintain a normal mediastinal anatomy and to avoid respiratory complications.

Radiation dose for thymic tumours.

Thymomas and thymic carcinomas are rare epithelial cell tumours arising from the thymus. Definitive surgical resection continues to be the primary approach for the management of thymomas and thymic carcinomas. However, complete resection is not always achievable due to the complexity of the mediastinal anatomy and in rare cases local recurrences may occur which are often incurable. Therefore, the use of Post-Operative Radiotherapy (PORT) may be considered with the intent of improving local control while being judicious of toxicity in the setting of prolonged clinical trajectories and proximity to critical structures. There continues to be a paucity of literature surrounding the use of PORT for thymomas and thymic carcinomas and the optimal dose has not yet been established. This review aims to summarize the current literature regarding radiotherapy indications and to explore issues surrounding radiotherapy dose-response-relationships for thymomas and thymic carcinoma. Long-term prospective studies using contemporary surgical and radiotherapy techniques are needed to further elucidate the optimal radiation approach in the management of thymic tumours.

Sa2009 DEVELOPMENT OF A PER ORAL TRANSESOPHAGEAL ENDOSCOPIC CRUROPLASTY (POTEC) IN AN ACUTE PORCINE MODEL

Transluminal and intramural endoscopic procedures continue to increase in type and variety. Notably, POEM and ESD are now performed regularly in many centers. These procedures have led to additional diagnostic and therapeutic procedures in the extraluminal space via submucosal tunneling. Using an acute porcine model, our goal was to develop a procedure to approach the diaphragmatic hiatus and perform a cruroplasty via an esophageal tunnel. The specific aims were to determine the ideal location for access, ease of display of anatomy, feasibility of the cruroplasty, and to define the key steps of the procedure. An acute study with IACUC approval and veterinary staff assistance using 4 Yorkshire pigs was completed by a single endoscopist. Submucosal tunnels were made at different locations (10 and 20 cm above GEJ) in two animals, one prone and the other supine, and suturing of crura attempted. Lessons from these cases informed the latter two procedures. A 5cm submucosal tunnel was created posteriorly. The mediastinum was entered 2cm into the tunnel via myotomy and trans-mural incision sizable enough to accommodate the suturing device. From within the mediastinum, the esophagus was followed to the hiatus requiring dissection of connective tissue to allow for identification of both vagus nerves and crura on either side of the hiatus. One suture was placed after taking two bites from each crura. Immediate euthanasia and necropsy followed. Safe trans-esophageal access, display of anatomy, and cruroplasty was reliably achieved in all animals. Trans-esophageal access was best performed dorsally about 10-12cm above the GEJ, with the animal in the prone position. One animal was attempted in the supine position and had to be repositioned during the procedure as this position altered ability to navigate the hiatus. An anterior approach to mediastinal access was attempted in one animal and also interfered with ease of identification of structures. Tunnels that were made 10cm proximal to the GEJ allowed for easier access and identification of structures than those made 20cm from the GEJ (directly assessed in the first two animals). Myotomy and mediastinal access was done from the end of a 5 cm tunnel. Attempts to stay in the mediastinum caused micropuncture and tension pneumothorax in the first animal, resolved by making a larger access point. Immediate necropsy showed successful cruroplasty without iatrogenic injury. POTEC procedure is feasible. The procedural steps are defined and mediastinal anatomy can be safely identified and avoided during suturing. The cruroplasty was shown to be successfully placed without iatrogenic injury on necropsy. A survival study will confirm the potential for clinical application, particularly in the treatment of GERD.Figure 2Photo of necropsy showing successful endosuturing of the crura from the superior view of the diaphragm.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Aortic inflation with agar injection is a useful method of cadaveric preparation which creates a mediastinal anatomy that better mimics the living body for surgical training.

In cadavers, even Thiel-embalmed cadavers, the arteries (especially the thoracic aorta) are extremely collapsed. This is in marked contrast to the state of the arteries in a living body. Aortic inflation is necessary to improve this unfavorable situation for anatomical observation or dissection. To inflate the aorta, we injected 500ml of hot liquid agar into the aorta using a 18-Fr catheter inserted into the common femoral artery and subclavian artery. The injected agar then rapidly cools to room temperature and solidifies. As a result, the thoracic aorta remains sufficiently and constantly inflated in the mediastinum. This method is not only easy and inexpensive, but also useful and effective for achieving a life-like anatomy in cadavers used in surgical training for operations involving mediastinal organs, with the exception of the heart and great vessels.

Esophagectomy for end-stage achalasia

Approximately 5% of patients will require esophageal replacement for end-stage achalasia. This progressive, chronic, and incurable disease is often marked by persistent obstructive symptoms despite treatment, or the development of a dilated, tortuous megaesophagus. The surgical management of patients with end-stage achalasia is challenging given their altered esophageal and mediastinal anatomy, as well as marginal preoperative pulmonary and nutritional reserve. In this brief review, we further describe the indications, preoperative considerations, operative techniques, and outcomes of patients undergoing esophagectomy for end-stage achalasia.

PS01.230: THE THREE-DIMENSIONAL ANIMATION ILLUSTRATING THE UPPER MEDIASTINAL ANATOMY FOR VIDEO-ASSISTED TRANSCERVICAL APPROACH IN ESOPHAGEAL CANCER SURGERY

Abstract Description Video-assisted transcervical approach may be promising for the upper mediastinal lymphadenectomy in patients with esophageal cancer. However, it is difficult to recognize positioning of landmark organs, such as the bronchus, recurrent nerves, and major vessels, since the operating field is unfamiliar for most surgeons and any anatomical charts have failed to show. Using a technique of the computer graphics, we have created three-dimensional animation illustrating the upper mediastinal anatomy which includes stepwise positional change of such landmark organs depending on progress of the dissection of the esophagus. This animation clip will become a useful tool for education for surgeons who introduce transcervical approach in upper mediastinal lymphadenectomy in video-assisted esophageal cancer surgery. Disclosure All authors have declared no conflicts of interest.

Magnetic resonance imaging of the pediatric mediastinum.

The mediastinum, the central anatomical space of the thorax, is divided by anatomical landmarks but not by physical boundaries. The mediastinum is a conduit, a space through which cranial nerves, important nerve branches, the sympathetic chain, vascular structures, and visceral structures, the trachea and esophagus pass. This arrangement allows contiguous extension or communication of disease along facial planes and through potential spaces to and from the head and neck or cervical spine, to and from the superior mediastinum, between superior and inferior mediastinal levels, and between inferior mediastinal spaces into the intra- and retroperitoneal spaces. Magnetic resonance imaging (MRI) of the mediastinum in children poses technical challenges, in particular cardiac and respiratory motion, and diagnostic challenges, including a broad range of tissue types and possible diagnoses. In this paper we review mediastinal anatomy, MRI sequences and protocol choices and include a short discussion of features and MRI findings of some of the congenital and acquired pathologies that are most often encountered in the pediatric mediastinum.

Mediastinal Parathyroid Adenoma Resection Through Robotic Video-Assisted Thoracoscopy Utilizing Firefly Fluorescence

Introduction: Parathyroid adenomas are ectopic in up to 20% of patients with 1%–2% located in the mediastinum and inaccessible through cervical incisions.1 Primary hyperparathyroidism (PHP) from such adenomas presents unique diagnostic and surgical challenges. In addition to the routine comprehensive biochemical evaluation to confirm PHP, preoperative imaging is key. Mediastinal parathyroid adenomas (MPAs) have most effectively been identified by Sestamibi-Tc99m scan and computed tomography of the chest, including recent advances using 4DCT protocols.2–4 Despite improved preoperative localization, intraoperative observation of a small parathyroid in the mass of mediastinal thymic tissue is exceptionally difficult. Indocyanine green (ICG) fluorescence has been used with diverse surgical applications to illuminate tissues of interest, including parathyroids.5 The da Vinci Si surgical robots (Intuitive Surgical, Sunnyvale, CA) have built-in Firefly™ technology (Novadaq Technologies, Mississauga, Canada) that detects ICG fluorescence in real time. This video illustrates an innovative strategy for removal of MPAs by using robotic video-assisted thoracoscopy (VATS) with Firefly. Case: A 66-year-old woman with incidental hypercalcemia was found to have PHP based on elevated serum calcium 10.8 mg/dL (nl 8.6–10.6) and ionized calcium 5.7 mg/dL (nl 4.5–5.3), elevated parathyroid hormone 89 pg/mL (PTH, nl 15–65), and normal levels of vitamin D25, albumin, creatinine, and 24-hour urine calcium. She had fatigue, memory changes, arthralgias, and osteoporosis. Sestamibi-Tc99m imaging localized a parathyroid adenoma to the mid-anterior mediastinum. A subsequent neck ultrasonography showed a normal thyroid gland without identifying parathyroid disease. 4DCT was thus used to delineate the precise anatomic relationship between mediastinal structures and guide operative planning. Because the adenoma was inferior to the innominate vein, we elected a surgical approach through the left thoracic cavity. The patient received Sestamibi-Tc99m injection 1 hour before surgery to allow ex vivo radiotracer detection in the excised specimen. Patient positioning was typical for VATS (supine, three ports in lateral left chest). The video illustrates optimal timing of ICG injection and technical steps to expose anterior mediastinal anatomy and perform the thymectomy. ICG uptake into the MPA was best seen only after skeletonizing the innominate vein as the adenoma was located deeper and more medial than expected. The thymectomy specimen was externalized and then examined to confirm that the MPA was resected in its entirety: the gamma probe detected greatest radioactivity within a grossly intact 10 × 9 × 7 mm nodule, which was hypercellular parathyroid tissue by histology. Intraoperative PTH decreased appropriately from 198 to 19 pg/mL after MPA removal. The patient had an uncomplicated postoperative course and was discharged home 2 days later. Six-month follow-up revealed calcium 9.6 mg/dL, PTH 45 pg/mL, mid-normal range vitamin D 25 (41 ng/mL), and symptom resolution. Conclusion: To our knowledge, this is the first reported case of robotic VATS, facilitated by Firefly, for removal of a mediastinal ectopic parathyroid adenoma. We highlight key steps in the management of MPAs: the need for precise preoperative localization with dual imaging, benefits of novel minimally invasive robotic surgery, and innovative use of fluorescence for in vivo visualization, radiotracer for ex vivo detection, and intraoperative PTH for biochemical confirmation of cure. No competing financial interests exist. Runtime of video: 6 mins 55 secs

Left-sided video-assisted thoracic surgery thymectomy

Thymectomy is widely used as integrated treatment of patients with non-thymomatous myasthenia gravis (MG) and in the case of early thymomas. However, the best approach to thymus is still under debate. For decades, median sternotomy was the only option offered. This access provides a massive exposure of the anterior mediastinum allowing an extended thymectomy with the exenteration of the whole mediastinal fat, which are the two mainstays for the therapeutic success of the procedure. Unfortunately, median sternotomy produces a quite significant tissue trauma, with a certain morbidity rate and relevant postoperative pain, thus leading to longer hospital stay. Furthermore, it implies the creation of an unpleasant scar thus meeting a very low acceptance rate in patient’s population manly represented by young women. Over the years, video-assisted thoracic surgery (VATS) thymectomy has progressively replaced transsternal accesses. This approach proved safe and as extended as an open one. The procedure is better accepted by both patients and neurologists given the less postoperative pain, the insignificant cosmetic side-effects and the faster return to normal living and occupational activities. VATS thymectomy requires a perfect preparation and stabilization of the patient by a multidisciplinary group, perfect patient lying on operatory table, correct positioning of trocars, excellent knowledge of mediastinal anatomy gained through a certain number of previous sternotomies, rehearsed surgical team including an anesthesiologist experienced in myasthenic disease. Surgical steps follow grossly a precise sequence, which entails dissection of lower horns, dissection of the veins and dissection of the upper horns. Major complications are represented by innominate vein injury, which often requires rapid conversion to median sternotomy. The procedure can be feasible from either side of the thorax. Since the beginning we preferred the left-sided approach for a number of reasons such as best visualization of the left pericardio-phrenic angle, innominate vein and aorto-pulmonary window, which are most frequently sites of ectopic thymic tissue. However, each side presents different advantages and limits. Long-term results appear similarly effective in the majority of the available series. The choice of the side is prevalently based on the surgeon’s preference and experience, but one should also consider the prevalent location of the thymus or thymoma, and other local conditions predicted by imaging. In conclusion, whatever the side VATS can provide safe, effective and extended thymectomy.

Avoiding oesophageal injury during cardiac ablation: insights gained from mediastinal anatomy.

This study investigates the lateral displacement of the oesophagus at the level of the left atrium (LA) in 11 cadavers. The study was conducted using human cadavers. An endotracheal stylet probe was inserted into the eosphagus. The pericardium overlying the posterior LA was fixed in place. The lateral movement of the oesophagus from side to side was recorded. The initial study method had the stylet probe extending to the gastroesophageal (GE) junction. A revised protocol had the distal end of the endotracheal stylet probe ∼4 cm cranial to the GE junction. In six cadavers using the initial study method, the oesophagus was displaced a mean of 1.8 ± 0.35 cm to the right and 2 ± 0.48 cm to the left. In five cadavers, using the revised method, the oesophagus was displaced by a mean of 2.26 ± 0.27 cm to the right and 2.3 ± 0.66 cm to the left. Mediastinal anatomy, specifically the presence of a loose connective tissue that attaches the oesophagus to the parietal pericardium overlying the posterior LA wall will allow for a lateral displacement of the oesophagus. This should decrease or eliminate the likelihood of thermal injury of the oesophagus. Using an endotracheal stylet, we investigated the lateral displacement of the oesophagus in 11 human cadavers. In six with the stylet extending to the GE junction, the oesophagus was displaced a mean of 3.8 cm. In five, with stylet 4 cm cranial to the junction, the displacement was 4.56 cm.