Pericardial Sinus Research Articles

Morphology and Anatomical Classification of Pericardial Cavities: Oblique and Transverse Sinuses

The pericardial sinuses are an important anatomical feature of the pericardial cavity, however, their clinical anatomy has not been thoroughly studied. In this study, we aim to provide the first classification of the oblique and transverse sinuses. We analyzed 121 computer tomography scans (46.3% female, age of 66 ± 12 years) of the pericardial cavity. The oblique sinuses were classified into four types: 1 (shallow with narrow entrance), 2 (shallow with wide entrance), 3 (deep with narrow entrance), and 4 (deep with wide entrance). The transverse sinuses were classified into four types: Concave, Wine-type, Straight, and Convex. The most common oblique sinus type was Type 1. The median oblique sinus volume was 8.4 (5.3) mL, the median entrance length was 33.0 (13.2) mm, and the depth was 38.2 (11.8) mm. The most common transverse sinus type was Concave. The median transverse sinus volume was 14.8 (6.5) mL, and the median length was 52.8 (17.7) mm. Our study provides an anatomical classification of the pericardial sinuses. The individual variability of the sinuses’ morphology highlights the importance of understanding the clinical topography of the sinuses, particularly for minimally invasive thoracic ablation procedures.

A multiscale approach reveals elaborate circulatory system and intermittent heartbeat in velvet worms (Onychophora)

An antagonistic hemolymph-muscular system is essential for soft-bodied invertebrates. Many ecdysozoans (molting animals) possess neither a heart nor a vascular or circulatory system, whereas most arthropods exhibit a well-developed circulatory system. How did this system evolve and how was it subsequently modified in panarthropod lineages? As the closest relatives of arthropods and tardigrades, onychophorans (velvet worms) represent a key group for addressing this question. We therefore analyzed the entire circulatory system of the peripatopsid Euperipatoides rowelli and discovered a surprisingly elaborate organization. Our findings suggest that the last common ancestor of Onychophora and Arthropoda most likely possessed an open vascular system, a posteriorly closed heart with segmental ostia, a pericardial sinus filled with nephrocytes and an impermeable pericardial septum, whereas the evolutionary origin of plical and pericardial channels is unclear. Our study further revealed an intermittent heartbeat—regular breaks of rhythmic, peristaltic contractions of the heart—in velvet worms, which might stimulate similar investigations in arthropods.

The transverse pericardial sinus: an unpleasant third wheel.

The transverse pericardial sinus: an unpleasant third wheel.

The Intrusive nature of epicardial adipose tissue as revealed by cardiac magnetic resonance

The epicardial adipose tissue (EAT) refers to the deposition of adipose tissue fully enclosed by the pericardial sac. EAT has a complex mixture of adipocytes, nervous tissue, as well as inflammatory, stromal and immune cells secreting bioactive molecules. This heterogeneous composition reveals that it is not a simply fat storage depot, but rather a biologically active organ that appears playing a “dichotomous” role, either protective or proinflammatory and proatherogenic. The cardiac magnetic resonance (CMR) allows a clear visualization of EAT using a specific pulse sequence called steady-state free precession. When abundant, the EAT assumes a pervasive presence not only covering the entire epicardial surface but also invading spaces that usually are almost virtual and separating walls that usually are so close each other to resemble a single wall. To the best of our knowledge, this aspect of cardiac anatomy has never been described before. In this pictorial review, we therefore focus our attention on certain cardiac areas in which EAT, when abundant, is particularly intrusive. In particular, we describe the presence of EAT into: (a) the interatrial groove, the atrioventricular septum, and the inferior pyramidal space, (b) the left lateral ridge, (c) the atrioventricular grooves, and (d) the transverse pericardial sinus. To confirm the reliability in depicting the EAT distribution, we present CMR images side-by-side with corresponding anatomic specimens.

The transverse and oblique sinuses of the pericardium: Anatomic and echocardiographic insights.

A number of masses and pseudomasses may be encountered during the echocardiographic examination of the transverse and oblique sinuses with significant clinical implications. This review discusses the clinically relevant anatomy of the pericardial sinuses emphasizing diagnostic pitfalls that may be encountered during their echocardiographic examination.

Totally thoracoscopic surgical ablation of stand alone atrial fibrillation and concomitant left appendage exclusion

Minimally invasive surgical treatment of lone atrial fibrillation (AF) is indicated in patients at risk of recurrence after catheter ablation of AF. We evaluated our initial experience of surgical ablation of AF and left appendage exclusion by a bilateral thoracoscopic approach with a non-irrigated bipolar radiofrequency system (Atricure). Between January 2016 and March 2017, 8 patients underwent an off-pump, beating heart, lone AF surgical ablation with the Atricure system. Surgical technique starts with a right thoracic approach trough three ports. After dissection of transverse and oblique sinuses, a light dissector (Wolff Lumitip, Fig. 1 a) is used to guide a bipolar clamp around pulmonary veins (Sinergy Clamp, Fig. 1 b); a linear transmural lesion is created with bi-directional bipolar radiofrequency on the antrum of pulmonary veins. Two other lesions on the roof and on the floor of left atrium (LA) are created with a bipolar unidirectional catheter (CoolRail, Fig. 1 c). After creating the same pattern of lesions on left side, the left appendage is excluded with a clip (Atriclip Pro, Fig. 1 d). Preoperative characteristics are resumed in Table 1 . There were no postoperative major complications. Mean postoperative length of stay was 13 days (7–20), longest hospitalizations were due to persistent pleural effusions through thoracic drains in two patients and infection of thoracic ports in one patient. A patient died 10 months postoperatively of alcoholic cirrhosis. After a blanking period of 3 months, all patients were free from AF; 7 patients were under anticoagulant treatment; three of them were under VKA and 4 under NOACS. Only one patient was under anti-arrhythmic drugs. AF surgical ablation and left appendage exclusion seem to be safe and effective for patients at risk of recurrence after catheter ablation of AF. A longer follow-up is mandatory to confirm these results in the long term.

Transverse Pericardial Sinus Closure in Acute Type A Aortic Dissection Operation

In operations for acute type A aortic dissection with open technique in elderly patients and patients with long-term treatment of anticoagulation, the transverse pericardial sinus was routinely closed before the graft implantation. With the aid of both a bovine pericardial patch covering the pericardial recess between the superior caval vein and the pulmonary artery and an opening in the left inner side of the superior caval vein, this prophylactic transverse pericardial sinus closure could make autotransfusion of blood loss into the central venous system possible to deal with the diffuse oozing from the suture line.

Computerized tomography of the transverse pericardial sinus: Normal or pathologic?

The transverse pericardial sinus is a uniquely located structure subdivided into many parts. However, discrepancies still exist on the nomenclature and divisions. As noninvasive diagnostic technology such as CT and MR imaging improve, the transverse pericardial sinus and constituent recesses are visualized with more clarity, increasing the risk for misinterpretation. In this review, we will explore the anatomy of the transverse pericardial sinus and associated recesses with the goal of heightening awareness regarding the differential diagnosis between normal and pathological states as seen on CT. In addition, the inconsistencies of the right lateral superior aortic recess are also addressed. Last, we describe the clinical and surgical significance of the transverse pericardial sinus. Clin. Anat. 30:61-70, 2017. © 2016 Wiley Periodicals, Inc.

Anatomical study of the internal thoracic arteries; implications for use in coronary artery bypass graft surgery.

The feasibility of coronary artery bypass grafting using an internal thoracic artery (ITA) depends on the length of the graft with respect to the optimal route to reach the coronary target. The goal of this study was to assess the gain in length afforded by skeletonization and to evaluate the lengths of different pathways of the ITAs to the left coronary arteries. The left and right ITAs were dissected out from 20 specimens and measured before and after skeletonization. Distance between the origin of the right ITA and the base of the left atrial appendage, corresponding to the proximal circumflex artery, was measured for both the transverse pericardial sinus and preaortic routes. Skeletonization gave a significant gain of length for both ITAs. Analysis showed no significant correlation between the ITA length and the height, weight, and BMI of specimens. We found no association between the length of the sternum and the length of skeletonized RITA or LITA. The anterior route of the skeletonized right ITA was shorter than the transverse pericardial sinus route in 18 cases. The average length to the circumflex artery territory was 132.8±23.5mm in front of the aorta and 150.5±18.8 through the transverse pericardial sinus with a gain of length of 17.7mm (p<0.0001). Skeletonization gave significant gains in length of both ITAs. The preaortic route for the skeletonized right ITA toward the circumflex territory was shorter than the transverse pericardial sinus route in 90% of cases.

Interaction of the tracheal tubules of Scutigeracoleoptrata (Chilopoda, Notostigmophora) with glandular structures of the pericardial septum.

Notostigmophora (Scutigeromorpha) exhibit a special tracheal system compared to other Chilopoda. The unpaired spiracles are localized medially on the long tergites and open into a wide atrium from which hundreds of tracheal tubules originate and extend into the pericardial sinus. Previous investigators reported that the tracheal tubules float freely in the hemolymph. However, here we show for the first time that the tracheal tubules are anchored to a part of the pericardial septum. Another novel finding is this part of the pericardial septum is structured as an aggregated gland on the basis of its specialized epithelium being formed by hundreds of oligocellular glands. It remains unclear whether the pericardial septum has a differently structure in areas that lack a connection with tracheal tubules. The tracheal tubules come into direct contact with the canal cells of the glands that presumably secrete mucous substances covering the entire luminal cuticle of the tracheal tubules. Connections between tracheae and glands have not been observed in any other arthropods.

Coronary CT findings of coronary to bronchial arterial communication in chronic pulmonary disease.

To describe the coronary CT findings of coronary-to-bronchial artery communication (CBAC) in chronic pulmonary disease. Coronary CT was performed in 15 patients with chronic pulmonary disease using 64-channel or greater multidetector CT. Among those patients, one or two CBACs were identified. A retrospective analysis of the CT findings was done to determine the originating artery, arterial course of the communications and other associated results. The main underlying pulmonary disease was bronchiectasis (n = 12). The origin of the CBAC was from the left atrial (n = 7) or sinoatrial (SA) nodal (n = 3) branch of the left circumflex artery in nine patients and the SA nodal branch of the right coronary artery in six patients. The CBAC was connected to the left bronchial artery in 11 patients and the right bronchial artery in five patients. The course of the CBAC passed through the interpulmonary venous bare area between reflections of the serous pericardium of the transverse and oblique sinuses in 13 patients. In three patients, it passed through the perivascular space around the left upper or lower pulmonary vein. In one patient, there were two communications-one through the interpulmonary venous bare area and the other through the perivascular space around the left lower pulmonary vein. There was no significant coronary arterial stenosis except in two patients. Bronchial arterial hypertrophy was found in all 15 patients. Detailed analysis of coronary CT can be a helpful guide for hemodynamic significance and clinical management including embolotherapy for CBAC in patients of chronic pulmonary disease with hemoptysis.

Pitfalls in Oncologic Imaging: Pericardial Recesses Mimicking Adenopathy

Introduction The pericardium is a thin, avascular sac that envelops the heart. It is made up of an outer fibrosa (the fibrous pericardium) and a double-layered inner serosa (the serous pericardium). The serosa forms a complete sac (the pericardial cavity) which is filled with up to 50 mL of plasmatic ultrafiltrate and is separated from the heart by loose epicardial connective tissue and a single layer of mesothelial cells. The pericardial cavity contains 2major pericardial sinuses, the transverse and oblique sinuses, which, in turn, are composed of different recesses (Fig. 1). Advances in multidetector computed tomography (MDCT) technology have improved detection of pericardial recesses. Ozmen et al have shown that visualization rates of pericardial recesses are higher with 4-, 16-, and 64-slice MDCT than with 2-slice MDCT. Additionally, thin-section computed tomography (CT) has improved the detection of pericardial recesses and sinuses. Kodama et al assessed the prevalence of pericardial sinuses and recesses on thin section (2.5 or 3 mm) and thick section (5 or 7 mm) CT scans. Thinsection CT improved the depiction rate of every pericardial sinus and recess: 44.7% comparedwith 30.4% for the superior aortic recess, 16.7% comparedwith 3.4% for the inferior aortic recess, 36.8% compared with 12.5% for the left pulmonic recess, 29.7% compared with 7.9% for the right pulmonic recess, 28.7% compared with 7.7% for the oblique sinus, 16.8% compared with 2.7% for the postcaval recess, 19.8% comparedwith 2.5% for the left pulmonary venous recess, and 10.8% compared with 4.7% for the right pulmonary venous recess. Similarly, Basile et al identified the high-riding

HISTOLOGICAL AND STATISTICAL STUDIES ON THE OVARIAN CYCLE OF THE CARAMOTE PRAWN MELICERTUS KERATHURUS (FORSKÅL, 1775) (CRUSTACEA – DECAPODA)

The two ovaries of the caramote prawn Melicertus kerathurus lie above the hepatopancreas and below the pericardial sinus and the heart. Both ovaries were reduced in general size with white compact and sickle-shaped contents during January- March. Their contents attain gradually a pale green colour in April - June. This stage is an early maturing in which the ovary increased in size and the anterior and middle lobes are developing. When the ovary is immature the surface is relatively smooth and homogenous, but as the organ grows the surface acquires an increasingly irregular ppearance. They contain oocytes and small spherical ova with light-stained cytoplasm free from granules and a conspicuous nucleus. During July -September, mature stage in which the ovary is in a maximal size and filled with vitellogeneic and ripe oocytes. They were dark green. During October- December, the gonad reverted gradually to the immature condition i. e., the ovary undergoes a spent-recovering and was with varying degrees of yellow colour. For each season three ovaries were studied carefully through serial histological preparations. The length and width for each histological section was measured using slide micrometer (4 cm & 3 cm) respectively.The different stages of oocyte developmental stages were counted and analyzed in each season through One Way Analysis of Variance (ANOVA) with p<0.05 and Tukey's Multiple Comparison Test. This calibrations clarified that the oogonia predominate the ovary during winter season, the previtellogenic oocytes predominate the ovary during spring season, the vitellogenic oocytes predominate the ovary during summer season. The majority of autolyzed oocyte were observed during winter season.

Isolated pericardial echinococcosis: Perioperative transesophageal echocardiographic evaluation

Hydatid cyst (HC) is a human parasitic disease caused by the larval stage of Echinococcus granulosus. Cardiac involvement is rare and occurs in 0.5%–2% of patients with hydatid cyst, but isolated pericardial hydatid cyst is rarer still. We present two cases of isolated pericardial hydatid cyst who presented with precordial chest pain and dyspnea. In both the cases, HC were diagnosed by transthoracic echo (TTE), Computed Tomography/Magnetic Resonance and positive hydatid serology. Intraoperatively transesophageal echo (TEE) revealed unilocular transitional cystic lesion the transverse pericardial sinus in one case and multilobulated active cystic lesion in another. The report highlights the role of TEE in diagnosis and evaluation of cardiac HC. Both the cases underwent surgical resection followed by albendazole therapy to prevent recurrence.

Box lesion in the open left atrium for surgical ablation of atrial fibrillation

Cut-and-sew maze with a box lesion around the pulmonary veins is currently the criterion standard procedure for surgical ablation of atrial fibrillation. Recently, we changed our technique from standard bilateral epicardial pulmonary vein isolation with interconnecting lesions to a box lesion procedure with a bipolar radiofrequency ablation device. Our study describes this technique. Between March 2009 and June 2012, we performed 90 ablations by the box technique with a bipolar radiofrequency device. Fifty-five patients (61%) had persistent atrial fibrillation, and 21 (23%) had long-standing persistent atrial fibrillation. The left atriotomy was performed along the interatrial septum and the left atrial appendage amputated. The box was made by connecting the left atriotomy to the base of the amputated appendage with lines along the transverse and oblique sinuses by epicardial and endocardial application of a bipolar radiofrequency ablation device. The left atrial isthmus was ablated by cryoprobe. There were no ablation-related complications. The box was easy to perform, with no dissection around the pulmonary veins. At 6-month, 1-year, and 2-year follow-ups, 80 (94%), 69 (93%), and 47 (91%) patients, respectively, were in sinus rhythm. Freedoms from antiarrhythmic medications in patients in sinus rhythm at 6months, 1 year, and 2 years were 78%, 88%, and 85%, respectively. The box lesion provided excellent freedom from atrial fibrillation and may improve transmurality through ablation of 1 rather than 2 layers of atrial wall, as in epicardial pulmonary vein isolation. With the box lesion, dissection around the pulmonary veins is unnecessary.

The hemolymph vascular system in Cupiennius salei (Araneae: Ctenidae)

In terms of physiology and behavior, Cupiennius salei is one of the best-investigated spider species. However, parts of its anatomy have only been described superficially to date. In the course of a comparative survey of the hemolymph vascular system in Araneae we therefore investigated C. salei using several injection methods in combination with semi-thin sections and micro computer tomography (MicroCT). Like all other Arthropoda, C. salei possesses an open circulatory system. A tubular heart is suspended dorsally in the opisthosoma via a number of ligaments. It is equipped with three pairs of ostia, and three pairs of cardiac arteries. The heart is surrounded by a pericardial sinus in which we were able for the first time to describe an intra-pericardial membrane. Anteriorly, the heart is extended by an anterior aorta which runs through the pedicel and divides into two branches within the prosoma. Arteries emanating from the branches of the aorta supply the prosomal appendages and the central nervous system. The subesophageal ganglion is supplied by numerous fine vessels which emanate from the transganglionic arteries and form tight loops. A network of capillaries, i.e. interconnections between afferent and efferent vessels, is here demonstrated for the first time to exist in the central nervous system of chelicerates. Data are compared with existing literature on the morphology of the circulatory system in Araneae and discussed with regard to the extension of the respiratory system and the varying lifestyles of different spiders.

Left Atrial Anatomy Revisited

Recent decades have seen rapid developments in arrhythmia treatment, especially the use of catheter ablation. Although the substrates of atrial fibrillation, its initiation and maintenance, remain to be fully elucidated, catheter ablation in the left atrium has become a therapeutic option for patients with this arrhythmia. With ablation techniques, various isolation lines and focal targets are deployed; the majority of these are anatomic approaches. It has been over a decade since we published our first article on the anatomy of the left atrium relevant to interventional electrophysiologists.1 Our aim then, as now, was to increase awareness of anatomic structures inside the left atrium. In this review of anatomy, we revisit the left atrium, inside as well as outside, for a better understanding of the atrial component parts and the spatial relationships of specific structures. ### Location and Atrial Walls Viewed from the frontal aspect of the chest, the left atrium is the most posteriorly situated of the cardiac chambers. Owing to the obliquity of the plane of the atrial septum and the different levels of the orifices of the mitral and tricuspid valves, the left atrial chamber is more posteriorly and superiorly situated relative to the right atrial chamber. The pulmonary veins enter the posterior part of the left atrium with the left veins located more superior than the right veins. The transverse pericardial sinus lies anterior to the left atrium, and in front of the sinus is the root of the aorta. The tracheal bifurcation, the esophagus, and descending thoracic aorta are immediately behind the pericardium overlying the posterior wall of the left atrium. Further behind is the vertebral column. Following the direction of blood flow, the atrial chamber begins at the pulmonary veno-atrial junctions and terminates at the fibro-fatty tissue plane that marks the atrioventricular junction at the mitral orifice. The walls …

Technical tips for concomitant off-pump epicardial pulmonary vein isolation

Combination of off-pump coronary artery bypass grafting and epicardial pulmonary vein (PV) isolation is a less-invasive option to treat atrial fibrillation and coronary artery disease simultaneously. However, the exposure and clamping of the left PV on a beating heart are technically challenging. We here demonstrate technical tips to perform off-pump concomitant epicardial PV isolation easily using a tape through the transverse pericardial sinus.

A case of anomalous bronchial artery ramified from coronary artery

There have been no anatomical reports on the origin of the bronchial artery derived from the coronary artery. In a 2006 cadaveric dissection course, an anomalous bronchial artery that reached the middle lobe of the right lung from the left coronary artery was observed in an 88-year-old Japanese man. In this specimen, the circumflex branch of the left coronary artery passed under the left auricle in the coronary sulcus and bifurcated to three branches (left marginal branch, posterior left ventricular branch, atrial branch), which were 3.2-3.4mm in diameter. The atrial branch intersected on the surface of the great cardiac vein, ran along the oblique vein of the left atrium, and reached the atrial side of the transverse pericardial sinus, and then divided into two branches. One of them led to the right atrium. The other branch passed between two right superior pulmonary veins, which derived from superior and middle lobes of the right lung, respectively, through the hilum of the lung along the right superior pulmonary vein derived from the middle lobe, and finally became the bronchial artery in the middle lobe of the right lung. In the middle lobe, the bronchial artery divided into a thin branch along the pulmonary vein for the lateral segment, ran along the surface of the right middle bronchus, and then reached the medial segment, being wedged between the segmental bronchus and vein.

Cabrol Composite Graft for Aortic Root Replacement: Echocardiographic Imaging

A 55-yr-old woman with history of Marfan syndrome presented with an enlarging aortic arch aneurysm. Fifteen years ago, she had undergone repair of an aortic root aneurysm. A preoperative transthoracic echocardiogram (TTE) revealed normal biventricular function, 3+ tricuspid regurgitation, a small nonobstructive mechanical aortic prosthesis, and an aortic root graft. The distal ascending aorta and aortic arch were dilated, measuring 5 cm in diameter. Left heart catheterization showed normal coronary arteries originating from the aortic root graft, with the left adjacent to the right. The patient was scheduled for aortic arch reconstruction and tricuspid valve repair.