Parasternal Approaches Research Articles

Construction of Soft Prep Cadaver Pericardiocentesis Training Model and Implementation Among Emergency Medicine Residents.

This procedure training model is designed for all levels of emergency medicine residents. Pericardiocentesis is a relatively uncommon but potentially life-saving procedure within the scope of Emergency Medicine practice. As such, the Accreditation Council for Graduate Medical Education (ACGME) designates its competency as a requirement within emergency medicine residency programs. Because of its relative rarity, simulation-based training is often utilized to fill the gaps in clinical experience during emergency medicine residency training. There have been several models of pericardiocentesis training, including gel-based models that can be purchased or constructed,1-3 non-gel models,4 and cadaveric models.5 In this paper, we describe the fabrication of a high-fidelity cadaveric model and report emergency medicine resident experience with this model. Training programs can use this model to increase trainee competence and confidence with this high-acuity, low-frequency procedure. By the end of this session, residents will gain increased procedural competence and confidence with pericardiocentesis. Residents will be able to identify necessary supplies for the procedure, identify relevant surface anatomy and ultrasound views, and successfully aspirate fluid from model effusion. We created a pericardial effusion in a soft prep cadaver by placing a catheter into the pericardial sac and then infusing normal saline via intravenous fluid tubing. Learners were then able to practice aspiration of pericardial fluid via landmark and ultrasound-guided approaches under observation by facilitators able to offer real-time feedback. Learners were asked to complete a survey assessing pre-intervention and post-intervention subjective confidence in their ability to perform pericardiocentesis and were asked for qualitative feedback on the experience of using the training model. All residents were able to successfully visualize the pericardial effusion and perform needle aspiration via parasternal and subxiphoid approaches under dynamic ultrasound guidance, allowing needle visualization. All residents reported a subjective increase in procedural confidence and competence after practicing with this training model. Overall, the primary benefit of this training model cited by emergency medicine residents was that it closely approximates reality. This model is re-usable, relatively durable, and reproducible. Emergency medicine residencies associated with academic medical centers that already utilize cadavers for education may relatively easily incorporate this training model into their procedure training curriculum. Pericardiocentesis, simulation, task trainer.

Pericardiocentesis Procedure: Anatomical Structures and Approaches

Knowledge of accurate surface anatomy is essential for safe clinical practice. Different views and opinions for clinically important surface markings exist between clinicians. Pericardiocentesis is performed as an emergency procedure in conditions aggravating cardiac tamponade. The approach of pericardiocentesis should be held by the hands of an experienced operator because of the surrounding relations. Nowadays, the introduction of imaging-guided procedures, especially echo-guided procedures, has significantly improved the safety and feasibility of pericardiocentesis and has provided the possibility of choosing the best anatomical approach among the apical, subcostal and parasternal approaches. This case report also emphasizes the importance of instillation of agitated saline as a supplementary technique while performing echo-guided pericardiocentesis in order to reduce the likelihood of cardiac chamber perforations.

Usefulness of the Right Parasternal Approach to Evaluate the Morphology of Atrial Septal Defect for Transcatheter Closure Using Two-Dimensional and Three-Dimensional Transthoracic Echocardiography

The aim of this study was to demonstrate the feasibility and usefulness of addition of the right parasternal approach to the conventional left parasternal and apical approaches using two-dimensional (2D) and three-dimensional (3D) transthoracic echocardiography (TTE) for morphologic evaluation in cases of transcatheter closure of atrial septal defects (ASDs). In 112 consecutive patients with ASDs, the morphology of the defects was evaluated for transcatheter closure in the right parasternal view in addition to the conventional left views using 2D and 3D TTE. Measurements of the maximal ASD diameter and detection of deficient rim obtained on 2D TTE were compared with those obtained by 2D transesophageal echocardiography. The shapes and locations of ASDs visualized by 3D TTE were compared with those visualized by 3D transesophageal echocardiography. In 88 patients (80.0%), optimal images from the right parasternal approach for morphologic evaluation of ASDs were obtained. Although there was a significant difference in maximal ASD diameter obtained only in the conventional left approach compared with transesophageal echocardiographic measurements (P < .05), when the right parasternal approach was applied, a significant difference was not found (P= .18), and the diagnostic concordance of the rim deficiency was improved from 85.2% to 90.9%. Three-dimensional TTE from the right parasternal approach improved visualization of the shape and location of ASDs from 65.5% to 74.5%. Additional use of the right parasternal approach enables detailed morphologic evaluation for transcatheter closure of ASDs. In patients with suboptimal images on 3D TTE in the left conventional approach, additional 3D TTE in the right parasternal approach can improve the feasibility of obtaining optimal 3D images to evaluate the shapes and locations of ASDs.

Value of sonography for follow‐up of mediastinal lymphadenopathy in children with tuberculosis

To assess the clinical value of sonography for the follow-up of mediastinal lymphadenopathy in children diagnosed with pulmonary tuberculosis (TB). We conducted a retrospective review of the medical records of 21 children (9 boys, 12 girls) with a mean age of 6 years (range, 7.4 months to 18 years) who had a positive intradermal tuberculin skin test. All patients underwent thorough history-taking, physical examination, frontal and lateral chest radiographs, and sonographic study of the mediastinum. The mediastinum was accessed through the suprasternal and left parasternal approaches. The presence of 1 or more masses with an ovoid or round shape and hypoechoic appearance in the anterior or middle mediastinum was recorded. A comparison was made between the results of the sonographic examination of the mediastinum before administration of anti-TB agents and after 3 months of treatment. Pulmonary radiographic findings were suggestive of TB in 17 patients and were uncertain in 4 patients. Sonographic examination, however, detected mediastinal lymphadenopathy in all patients. A comparison of pretreatment mediastinal sonograms with those obtained after 3 months of anti-TB treatment showed a marked reduction of lymph node involvement in 17 patients (80.9%). In the remaining 4 patients, mediastinal lymphadenopathy was still present. Mediastinal sonography appears to be a valuable tool for the diagnosis of TB and in the monitoring of response to treatment in children.

Diagnosis of the Double Aortic Arch and Its Differentiation from the Conotruncal Malformations

PurposeThe clinical and radiological characteristics of the double aortic arch (DAA) and its differentiation from conotruncal malformations (CTM) were reported in order to familiarize pediatric practitioners with these congenital heart diseases.Materials and MethodsFrom July 1994 to December 2006, a total of 6 patients (4 male and 2 female, aged 16 days to 6.5 years) with DAA were enrolled in this retrospective study. The study modalities included chart recordings, plain chest radiographs, barium esophagograms, echocardiograms, cardiac catheterization, cardiac angiograms, surgery, magnetic resonance imaging, and chromosome analysis. Patients with incomplete vascular rings or with right aortic arches and left ligamentum were excluded. In addition, the clinical and radiological profiles of 38 patients with CTM, including dextro-transposition of the great arteries (d-TGA) (n = 28), hemitruncus arteriosus (HTA) (n = 3), type I truncus arteriosus (TA) (n = 4), and the aortopulmonary window (APW) (n = 3), were comparatively reviewed.ResultsAll 6 patients with DAA presented with postprandial choking and respiratory distress that prompted their initial visit to the hospital. One of the 6 patients presented with congestive heart failure, and none with cyanosis. Esophagograms showed indentations in 5 patients with DAA. All patients with d-TGA presented with cyanosis and heart failure, while patients with HTA, type I TA, and APW manifested overt heart failure. Suprasternal and subcostal approaches of the echocardiography may offer diagnositic windows for DAA. As for CTM, parasternal and subcostal approaches could always determine the causality. Cardiac catheterization with angiography comprehensively delineated the pathology.ConclusionIn case of postprandial choking and respiratory distress in neonates and infants, barium esophagograms can indicate the presence of DAA. Diagnosis of DAA and its differentiation from the CTM can be achieved by echocardiography, angiography, or magnetic resonance imaging.

Imaging-guided Percutaneous Biopsy of Mediastinal Lesions: Different Approaches and Anatomic Considerations

Percutaneous needle biopsy with imaging guidance allows access to lesions in virtually all mediastinal locations. A direct mediastinal approach, which enables extrapleural needle placement, is the preferred method to avoid the risk of pneumothorax. Techniques that allow extrapleural access include the parasternal, paravertebral, transsternal, and suprasternal approaches, which are performed with computed tomographic or ultrasonographic guidance. The parasternal approach is used for biopsy of anterior or middle mediastinal lesions when the lesion or intervening mediastinal fat extends to the anterior chest wall, lateral to the sternum; injury to the internal mammary vessels is a potential complication. The paravertebral approach is used for biopsy of subcarinal and other posterior mediastinal lesions; saline solution is often injected to widen the mediastinum. The transsternal approach, which involves needle placement through the sternum, is used for biopsy of anterior or middle mediastinal lesions that are not accessible with the parasternal approach. Biopsy of superior mediastinal lesions can be performed with a suprasternal approach. An alternative to these direct mediastinal approaches involves advancing the needle through a pleural space created by an existing pleural effusion or iatrogenic pneumothorax. Another alternative is the transpulmonary approach, which involves transgression of the lung and visceral pleura by the needle and is associated with a substantial risk of pneumothorax.

Live Three‐Dimensional Transthoracic Echocardiographic Assessment of Thrombus in the Innominate Veins and Superior Vena Cava Utilizing Right Parasternal and Supraclavicular Approaches

We report the usefulness of right parasternal and supraclavicular live three-dimensional transthoracic echocardiography in the delineation and follow-up of a thrombus involving a catheter placed in superior vena cava for dialysis in an adult patient with chronic renal disease.

Live Three‐Dimensional Right Parasternal and Supraclavicular Transthoracic Echocardiographic Examination*

In the present study, we describe the usefulness of the recently developed technique of live three-dimensional transthoracic echocardiography in the assessment of normal cardiac structures and adjacent vessels using the right parasternal and supraclavicular approaches. Examples of some abnormalities diagnosed from these approaches are also illustrated.

CT-guided pericardiocentesis.

Pericardial effusion in patients who have recently undergone cardiac surgery is often trapped in compartments. CT of the pericardium provides good information about the distribution of pericardial fluid in the postoperative period after cardiac surgery. Contrary to echocardiography, CT imaging is not affected by postoperative mediastinal emphysema and pain from the wound. A method for CT-guided pericardiocentesis was developed. CT-guided pericardiocentesis was carried out with a stereotactic device in 10 patients. The pericardium was punctured with a 0.9-mm needle and a 0.46-mm guide wire was introduced through the needle. An indwelling catheter was introduced over the guide wire and was left in the pericardium. Both the subxiphoid and parasternal approaches were used. CT guidance facilitated placement of an indwelling catheter into the pericardial space in positions difficult to reach in patients with postoperative pericardial compartments, i.e. near the right atrium and adjacent to the cardiac apex/left ventricle. CT-guided pericardiocentesis offers a new possibility in patients where fluoroscopically or echocardiographically guided pericardiocentesis is difficult.

Accuracy and reproducibility of left ventricular mass measurement by subcostal M-mode echocardiography in hypertensive patients and professional bicyclists

In some patients, left ventricular (LV) mass cannot be evaluated by M-mode echocardiography because the parastemal long-axis view is not available. The aim of this study was to determine whether the subcostal view obtained by M-mode echocardiography under 2-dimensional guidance allows accurate and reproducible LV mass determination. Using the cube formula, LV mass was calculated, from parasternal and subcostal views in 96 subjects: 73 hypertensives and 23 professional bicyclists, covering a wide range of LV dimensions. M-mode tracings were read by 2 experienced echocardiographers and the interobserver variability was evaluated. With use of the subcostal view, the interobserver reproducibility, expressed as observer 1-observer 2, was excellent: −0.3 ± 1.3 mm for LV diastolic diameter, −0.1 ± 1.0 mm for ventricular diastolic septal thickness, 0.2 ± 0.6 mm for diastolic free wall thickness and 0.03 ± 16.7 g for LV mass. In 96% of cases, the difference in LV mass between the 2 observers did not exceed 30 g. With use of the parasternal and subcostal approaches, LV mass was not statistically different (202.6 ± 2.2 g and 206.5 ± 2.0 g, respectively) and the difference was <52 g (clinically significant threshold) in 91 of 96 cases. It is concluded that, using the cube formula, LV mass calculation based on the subcostal view was accurate and not statistically different from that provided by the usual parastemal approach.

Real-time sonography of the mediastinum in adults: a study in 100 healthy volunteers

Real-time sonography has proved to be a valuable tool in the evaluation of the mediastinum in children. In the literature there is a paucity of information on ultrasound examination of the mediastinum in adults. Using a 3.5-MHz sector scanner, we evaluated a new method for the examination of mediastinal organs in adults, which is practicable in routine as well as emergency diagnosis. The endpoints of this study were the visibility of mediastinal organs and the discomfort of the patient. In 100 healthy volunteers aged 20-40 years, the normal anatomy of the anterior and middle mediastinum was investigated. Neither the height nor the weight of the volunteers limited the examination. We found that this method causes no discomfort to the subject. Via the supra-, infra- and left parasternal approaches, anatomical structures of the mediastinum are visible in a high percentage of cases. To date, this method has proved its practicability in more than 250 patients suffering from blunt thoracic trauma, primary and metastatic tumours, and infections of the mediastinum.

Placement accuracy of percutaneous transthoracic pacemakers

Experience has shown that the frequency of electrical capture of the heart with percutaneous transthoracic pacemakers is disappointingly low. The authors sought to determine whether the accuracy of vertricular placement could help to explain this observation. Six approaches were used in each of twenty adult patients who were examined at autopsy. Three parasternal approaches used the fifth intercostal space (5ICS). One pacing wire was inserted immediately to the left of the sternum along the parasternal line (5ICS-PS), one wire was inserted 4.0 cm to the left of the midsternal line (5ICS-4), and the third wire was inserted 6.0 cm to the left of the midsternal line (5ICS-6). All parasternal needle insertions were directed medially, dorsally, and cephalad toward the second right costrochondral junction at an angle of 30° to the skin. Three subxiphoid approaches were performed through the left xyphocostal notch at an angle of 30° to the skin. One pacing wire was directed toward the right shoulder (SXRS), one toward the sternal notch (SXSN) and one toward the left shoulder (SXLS). Accuracy of ventricular placement was assessed at autopsy. The success rates for the three parasternal approaches were as follows: 5ICS-PS = 0.85; 5ICS-4 = 0.80; 5ICS-6 = 0.90. For the three subxiphoid approaches success rates were as follows: SXRS = 0.25; SXSN = 0.50; SXLS = 0.65. All three parasternal approaches had higher success rates than the SXRS approach ( P < 0.05). In addition, the 5ICS-PS and 5ICS-6 approaches were more successful than the SXSN approach ( P < 0.05). There was no significant difference in success rates between each of the three parasternal approaches and the SXLS approach ( P > 0.10). Based on these data, the most accurate routes for the percutaneous placement of a transthoracic pacemaker are the 5ICS-PS, 5ICS-6, and SXLS approaches. This may explain in part the low rate of successful electrical capture reported in previous studies in which the SXRS and SXSN approaches were employed. Further studies are needed to address the potential for injuries associated with these approaches.

Injuries associated with percutaneous placement of transthoracic pacemakers

Injuries associated with the percutaneous placement of transthoracic pacemakers are poorly documented. We prospectively sought to determine any injuries associated with various placement routes. Six different approaches were used in each of 20 adult patients examined at autopsy. Three parasternal approaches utilized the fifth intercostal space (5ICS). One pacing wire was inserted immediately to the left of the sternum along the parasternal line (5ICS-PS), one pacing wire was inserted 4 cm to the left of the midsternal line (5ICS-4), and the third wire was inserted 6 cm from the midsternal line (5ICS-6). All parasternal needle insertions were directed medially, dorsally, and cephalad toward the right second costochondral junction at an angle of 30 degrees to the skin. Three subxiphoid approaches were inserted through the left xyphocostal notch at an angle of 30 degrees to the skin. One pacing wire was directed toward the right shoulder, one toward the sternal notch, and one toward the left shoulder (SXLS). Injuries were assessed by autopsy, postmortem coronary angiography, and stereoscopic radiography. The 5ICS-PS approach resulted in fewer injuries when compared to all other approaches. Because previous work has demonstrated that the 5ICS-PS, 5ICS-6, and SXLS approaches are more accurate than the other approaches for transthoracic pacemaker insertion, the 5ICS-PS represents an approach that combines reasonable accuracy with the least likelihood for injury in the placement of percutaneous transthoracic pacing wires.

Comparison of M-mode echocardiographic measurement of right ventricular wall thickness obtained by the subcostal and parasternal approach in children

Right ventricular (RV) wall thickness was measured from M-mode echocardiograms at end-diastole from both the parasternal and subcostal approaches in 50 children of various body surface areas (0.24 to 1.68 m2). The measurements were obtained from M-mode recordings generated from sector scans to ensure precise location and position. Twenty-three children had normal hearts, and 27 had various congenital heart defects that may be associated with RV hypertrophy. Corresponding measurements of the RV wall thickness at end-diastole from the 2 approaches were similar. Subcostal echocardiographic measurement of RV wall thickness was found to be a reliable alternative to parasternal measurement in children with normal hearts and in those with congenital heart disease and RV hypertrophy.

Echocardiographic evaluation of left ventricular size, shape and function--advantages and limitations of this method.

Both M-mode and two-dimensional echocardiographies are now available in most institutions and hospitals. Correct understanding of the characteristics of M-mode and two-dimensional echocardiography, such as time resolution, will lead us to a successful application of each of these two displays. Detection of changes in ventricular wall and visualization of segmental wall motion are the most unique abilities in echocardiography. These characteristics permit echocardiographic evaluation of left ventricular function. Left ventricular size, shape and function are not independent parameters, but are interrelated. Various parameters on left ventricular function are calculated from the dimensions of the left ventricle. However, these estimations are valid only when the dimensional determination is optimized and all the assumptions on the model of the left ventricle are satisfied. The simultaneous display system of M-mode and two dimensional echocardiograms on the same frame has been shown particularly useful for an optimization of the measurements. For ischemic heart disease, a knowledge of regional function of the left ventricle and the analysis of segment wall motion are indispensable. One of the major problems in evaluating the left ventricle using echocardiography is a limited acoustic window. A combination of standard parasternal approaches and other approaches is commonly required for obtaining an entire image of the left ventricle.