Obstructive Thebesian valve: anatomical study and implications for invasive cardiologic procedures

[Coronary sinus reducer : Technical aspects, prevention and management of potential complications]

Coronary sinus reducer implantation is a percutaneous technique creating a narrowing in the coronary sinus through the implantation of an hourglass-shaped endoprosthesis. It is proposed to reduce symptoms in patients suffering from refractory angina pectoris. This innovative treatment is experiencing a major craze among interventional cardiologists. It is associated with very high procedural success rates. Complications are rare and include coronary sinus dissection or perforation and migration of the device. This review exposes the device implantation technique, the potential anatomical difficulties, the tips and tricks to overcome challenging situations. It also focuses on the prevention and management of potential complications.

Clinical anatomy of the coronary venous system and relevance to retrograde cardioplegia and cardiac electrophysiological interventions

Anomalies of coronary venous system, the valve of the coronary sinus (Thebesian valve) and other cardiac malformations may make interventions through the coronary sinus difficult. These variants may pose a challenge in cannulating the coronary sinus for retrograde cardioplegia and for interventions performed through the coronary sinus by cardiac electrophysiologist/interventional cardiologist. Retrograde cardioplegia is an established method of myocardial protection with advantages, indications, and complications. A good knowledge of the anatomy of the coronary sinus and its variants is important in understanding the difficulties encountered while cannulating the coronary sinus for the delivery of retrograde cardioplegia, cardiac resynchronization therapy, treatment of arrhythmias, and percutaneous mitral valve annuloplasty.

Morphological Study of the Thebesian Valve in Fresh Autopsied Adult Human Hearts

Background The coronary sinus (CS) and its tributaries have been used to perform various electrophysiological and cardiac interventional procedures which require cannulation. The Thebesian valve (TV) guarding the coronary sinus orifice (CSO) exhibits morphological variations which might make cannulation unsuccessful leading to the failure of invasive cardiac procedures. This study aimed to analyze in detail the morphological features of the TV in fresh autopsied human hearts which were representative of the adult population of this region owing to its practical implications in invasive cardiac procedures. Methodology This was a cross-sectional, descriptive study conducted in the Department of Anatomy in collaboration with the Department of Forensic Medicine and Toxicology at Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry. A total of 104 fresh adult heart specimens were collected during the autopsy. The CSO was located, and the characteristic shape, composition, position, and extent of coverage of the CSO by the TV were observed and analyzed. Results The TV was present in 65% of heart specimens. The most common shape was remnant (33%), and the most common site of origin was inferior (63%). The valve composition was thin and membranous in 63% of heart specimens. In 7% of heart specimens, the TV covered more than 75% of the CSO diameter, of which in 4% of heart specimens, the CSO was completely closed and found to be obstructive. Conclusions This study highlights the variability in the morphological structure of the TV in adult human hearts and its potential implications in unsuccessful CS cannulation and failure of invasive cardiac procedures. Thus, prior imaging of the TV should be an integral part of CS cannulation procedures to avoid unsuccessful cannulation and complications related to repeated forceful cannulation.

Raymond de Vieussens (1641-1715): connoisseur of cardiologic anatomy and pathological forms thereof

Raymond de Vieussens was an exemplary anatomist who made seminal contributions in the field of cardiology. During initial part of his academic career, he adopted human dissection based experiments as medium of his research. This was in accordance with prevailing trend among anatomists during 17th century. He discovered the presence of tiny venous tributaries communicating between cardiac veins and chambers of heart (ducti carnosi/venae cordis minimae). He reported the existence of a collateral circulatory pathway between right and left coronary arterial systems (Vieussens arterial ring). He was the first to note the valve at the junction of great cardiac vein and coronary sinus (valve of Vieussens) and the prominent oval margin of the fossa ovalis (Vieussens Annulus). All his findings were associated with considerable clinical significance as evidenced in literature that followed. Vieussens accurately demonstrated the three-layered orientation of myocardium and gave a precise description of coronary arteries and their branches. At the onset of 18th century, buoyed by royal patronage from King Louis XIV of France, the second half of Vieussens illustrious career was defined by pathologic anatomy (autopsy based) and anatomo clinical correlations. This was a new trend initiated by Vieussens in anatomical research and was later adopted as a signature method by anatomists of 18th century. As a true connoisseur of cardiologic anatomy, Vieussens accurately charted the anatomo clinical correlations of cardiac tamponade, mitral stenosis and aortic regurgitation. His contributions were pivotal elements in metamorphosis of cardiology as a robust discipline of medicine in modern times.

Evolution of the fabric of cardiovascular science: Saga of an enduring process of refinement

BACKGROUND

The core elements of cardiovascular science have been established by scholarly pursuits of numerous scientists across centuries. In this article, we have tried to trace the evolutionary journey of cardiovascular science from a rudimentary form in ancient period to a robust scientific discipline in modern times.

METHODS

A literature search of relevant, peer-reviewed, published articles was undertaken from indexed databases (Medline & Pubmed, Scopus, Embase, CINAHL Plus, Web of Science and Google Scholar).

RESULTS

Cardiovascular science has its roots in antiquity, when Greek scholars mostly relied on philosophical thoughts and ancient texts. This was followed by addition of few structural details to the theory of circulation by Galen based on animal dissection. Arab scholar Ibn al-Nafis provided new insights regarding circulation pathway in humans. Nevertheless, an erroneous concept prevailed into the onset of European Renaissance. Even with legalization of human dissection, little headway could be made till sixteenth century due to persistent reliance of anatomists on ancient Galenic principles. During seventeenth century, the circulatory pathway (as we know it today) was established due to significant contributions from scholars like Harvey and Malpighi. Their efforts were based on findings from experiments and logical conclusions. Eighteenth century witnessed the emergence of autopsy based methods which led to valuable contributions from Vieussens, Thebesius, Morgagni and Hunter regarding normal and pathologic anatomy of cardiovascular system. With structural details mostly established, researchers during nineteenth century focussed on innovations in diagnostic methods based on human experiments. Further development of advanced human experiment models during twentieth century led to emergence of contemporary treatment methods for various cardiac conditions. In the twenty-first century, cardiovascular science is undergoing comprehensive progress at an exponential rate due to technological advances.

CONCLUSION

The evolutionary journey of cardiovascular science as a discipline across centuries has been intriguing and eventful.

Peculiarities in coronary sinus anatomy: implications for successful cannulation from an autoptic study

Aims

The number of cardiovascular procedures using the coronary sinus (CS) as a gateway is constantly increasing. The present study aimed to define specific structures within CS, which could potentially complicate CS cannulation and to develop a new Thebesian valve (TV) classification system.

Methods and results

The study was performed on 560 consecutive unfixed cadaveric hearts during routine autopsy examination (1–3 days post-mortem). Basic CS dimensions were measured and the presence and dimensions of the TV and the Vieussens valve (VV) were assessed. Thebesian valves were classified according to their morphology into six main types: remnant fold, semilunar, fenestrated, chord, fused strands, and mixed shaped. The median age of hearts was 48 years (range 16–95 years), and 38.9% were female. Thebesian valve was present in 79.5%. The most common TV type was semilunar (54%) followed by fenestrated (8.2%), remnant fold (5.5%), fused strands (4.8%), chord (4.0%), and mixed shaped (3.0%). In 1.1% of hearts, TV totally covered the coronary sinus ostium (CSO). The VV was detected in 67.9%. Potentially occlusive VV was found in 1.1% hearts and in all of which it coexisted with obstructive TV. The median CSO area was 87.9 mm² [interquartile range (IQR): 56.5–127.1 mm²] and median CS length was 38 mm (IQR: 29.5–45 mm). The CSO area and CS length correlated with each other and with the right atrium’s dimensions.

Conclusion

We identified six types of TVs, among which only 1.1% TVs caused total occlusion of CSO. The obstructive TV co-existed with potentially occlusive VV what might hinder CS cannulation.

Reliability of Percutaneous Pulmonary Vent and Coronary Sinus Cardioplegia in the Setting of Minimally Invasive Aortic Valve Replacement: A Single-Center Experience

OBJECTIVES

Evaluating the efficacy of 2 new percutaneous devices specifically designed to be placed through the right internal jugular vein, therefore named "necklines," for achieving retrograde cardioplegia and pulmonary venting in the setting of minimally invasive aortic valve replacement (MIAVR).

DESIGN

Case series.

SETTING

University-affiliated private hospital.

PARTICIPANTS

Patients undergoing MIAVR.

INTERVENTIONS

Necklines were placed by the anesthesiologist using transesophageal electrocardiography, with pressure guidance before the surgical procedure was initiated.

MEASUREMENTS AND MAIN RESULTS

The records of 51 consecutive patients who underwent MIAVR with necklines placement were reviewed retrospectively. The access for MIAVR was through either a J-hemisternotomy or a right anterior thoracotomy. The efficacy of the 2 catheters, successful placement rate, time needed to deploy catheters, and perioperative complications were recorded. Necklines were placed successfully in all patients in 23±13 minutes. A total of 110 doses of retrograde cardioplegia were delivered at a mean flow rate of 173±35 mL/min and a mean pressure of 41±6 mmHg. The pulmonary catheter ensured venting of the heart that was graded by surgeons as "excellent" in 33 patients, "sufficient" in 12 patients, and "not adequate" in 2 patients. There were no major adverse events or deaths.

CONCLUSIONS

Necklines ensure effective retrograde cardioplegia and venting of the heart, provide optimal surgical vision and access during MIAVR, and allow surgeons to operate in an unobstructed surgical field. Nevertheless, additional studies are required to determine whether the use of necklines is associated with better outcomes than those with conventional methods.

Anatomical barriers in the right atrium to the coronary sinus cannulation

Background. The coronary venous system is an increasingly frequent target of minimally invasive cardiac procedures. The purpose of this paper is to assess the anatomical barriers in the right atrium to coronary sinus cannulation.

Methods. We examined the anatomy of the right atrium, coronary sinus ostium, inferior and superior vena cava ostia in 110 randomly selected autopsied human hearts of both sexes (27% females; mean age 49.2 ± 17.5 years).

Results. The Eustachian valve was present in 79 cases (71.8%) with mean height =4.9 ± 2.6 mm. The valve was perforated in 11 cases (13.9%). It is typically too small to hinder the coronary sinus catheterization, but in some cases (about 2%) a significantly protruding valve may be an obstacle. Chiari’s network (4.6%) is not a barrier to catheter entry into the right atrium but may significantly impede further catheter manipulations inside the heart venous system. A typical Thebesian valve leaves enough space for the passage of the standard catheter to the coronary sinus.

Discussion. Detailed anatomy of various anatomical structures within the right atrium that could play a potential role in coronary sinus cannulation is discussed.

The Thebesian valve height/coronary sinus ostium diameter ratio (H/D-Ratio) as a new indicator for specifying the morphological shape of the valve itself in multisliced computed tomography

BACKGROUND

The coronary sinus ostium (CSO) is covered by the Thebesian valve (ThebV), which has a variable shape when assessed subjectively. The ThebV is an anatomical barrier during CS cannulation, which may be complicated due to the valves' size. The types of valves are: cord, remnant, semilunar, fold, and mesh/fenestrated. The ThebV can be visible using multisliced computed tomography (MSCT), however, this method cannot show the ThebV's morphological shape, only its size.

METHODS

301 randomly selected autopsied human hearts were examined. The shape of the valve was subjectively assessed, whereas the ThebV height (H) and the CSO diameter (D) were measured. The H/D-Ratio was computed as the ThebV height divided by the CSO diameter, afterwards k-means cluster analysis was performed to estimate H/D-Ratio's range of values between valves. MSCT scans from 114 patients that underwent CSO cannulation were objectively evaluated based on similar measured parameters in accordance with received H/D-Ratio values.

RESULTS

Boundaries of ratio evaluations between remnant and semilunar, and semilunar and fold types were 0.35 and 0.65 respectively. In MSCT scans, the ThebV was recorded in 61 cases (remnant=5.3%, semilunar=24.6%, fold=16.7%, cord=0.0%, mesh/fenestrated=7.9%). Except for the remnant and cord types, the other types appear similarly as in the cadaveric and MSCT studies. There were no differences between ThebV height and the CSO diameter in cadavers and MSCT studies.

CONCLUSION

The H/D-Ratio can be useful in assessing ThebV shape as visualized in MSCT. We give threshold values for the H/D-Ratio which easily allow the ThebV shape to be determined.