Demonstration of living anatomy clarifies the morphology of interatrial communications

Multimodality imaging in delineation of complex sinus venosus defects and treatment outcomes over the last decade

BACKGROUND

Diagnosis of sinus venosus defects, not infrequently associated with complex anomalous pulmonary venous drainage, may be delayed requiring multimodality imaging.

METHODS

Retrospective review of all patients from February 2008 to January 2019.

RESULTS

Thirty-seven children were diagnosed at a median age of 4.2 years (range 0.5-15.5 years). In 32 of 37 (86%) patients, diagnosis was achieved on transthoracic echocardiography, but five patients (14%) had complex variants (four had high insertion of anomalous vein into the superior caval vein and three had multiple anomalous veins draining to different sites, two of whom had drainage of one vein into the high superior caval vein). In these five patients, the final diagnosis was achieved by multimodality imaging and intra-operative findings. The median age at surgery was 5.2 years (range 1.6-15.8 years). Thirty-one patients underwent double patch repair, four patients a Warden repair, and two patients a single-patch repair. Of the four Warden repairs, two patients had a high insertion of right-sided anomalous pulmonary vein into the superior caval vein, one patient had bilateral superior caval veins, and one patient had right lower pulmonary vein insertion into the right atrium/superior caval vein junction. There was no post-operative mortality, reoperation, residual shunt or pulmonary venous obstruction. One patient developed superior caval vein obstruction and one patient developed atrial flutter.

CONCLUSION

Complementary cardiac imaging modalities improve diagnosis of complex sinus venosus defects associated with a wide variation in the pattern of anomalous pulmonary venous connection. Nonetheless, surgical treatment is associated with excellent outcomes.

The evolution of epistemological methodologies in anatomy: From antiquity to modern times

Present day scenario regarding epistemological methods in anatomy is in sharp contrast to the situation during ancient period. This study aimed to explore the evolution of epistemological methodologies in anatomy across centuries. In ancient times Egyptian embalmers acquired anatomical knowledge from handling human bodies and likewise anatomical studies in India involved human dissection. Ancient Greeks used theological principles-based methods, animal dissection and human dissection in practice of anatomy. Human dissection was also practiced in ancient China for gaining anatomical knowledge. Prohibition of human dissection led to use of animal dissection in ancient Rome and the trend continued in Europe through Middle Ages. Epistemological methods used by Muslim scholars during Middle Ages are not clearly chronicled. Human dissection returned as primary epistemological method in Renaissance Europe and empirical methods were reinstated after ancient period in human dissection during 16th century. The situation further improved with introduction of pragmatic experiment based approach during 17th century and autopsy-based methods during 18th century. Advances in anatomical knowledge continued with advent of microscope-based methods and emergence of anatomical sections in practice of human dissection in 19th century. Introduction of human observational studies, medical imaging, and molecular methods presented more options in terms of epistemological methods for investigating the human body during 20th century. Onset of 21st century has witnessed dominance of technology-based methods in anatomy. Limited emphasis on ethics in epistemological methodologies since antiquity is a dark aspect of otherwise an eventful evolutionary journey but recent developments are in positive direction.

Clarifying the anatomy of the superior sinus venosus defect

OBJECTIVES

We sought to clarify the variations in the anatomy of the superior cavoatrial junction and anomalously connected pulmonary veins in patients with superior sinus venosus defects using computed tomographic (CT) angiography.

METHODS

CT angiograms of 96 consecutive patients known to have superior sinus venosus defects were analysed.

RESULTS

The median age of the patients was 34.5 years. In seven (7%) patients, the defect showed significant caudal extension, having a supero-inferior dimension greater than 25 mm. All patients had anomalous connection of the right superior pulmonary vein. The right middle and right inferior pulmonary vein were also connected anomalously in 88 (92%) and 17 (18%) patients, respectively. Anomalous connection of the right inferior pulmonary vein was more common in those with significant caudal extension of the defect (57% vs 15%, p=0.005). Among anomalously connected pulmonary veins, the right superior, middle, and inferior pulmonary veins were committed to the left atrium in 6, 17, and 11 patients, respectively. The superior caval vein over-rode the interatrial septum in 67 (70%) patients, with greater than 50% over-ride in 3 patients.

CONCLUSION

Anomalous connection of the right-sided pulmonary veins is universal, but is not limited to the right upper lobe. Not all individuals have over-riding of superior caval vein. In a minority of patients, the defect has significant caudal extension, and anomalously connected pulmonary veins are committed to the left atrium. These findings have significant clinical and therapeutic implications.

Pacemaker and conduction disturbances in patients with atrial septal defect

OBJECTIVE

To determine the prevalence of pacemaker and conduction disturbances in patients with atrial septal defects.

DESIGN

All patients with an atrial septal defect born before 1994 were identified in the Danish National Patient Registry, and 297 patients were analysed for atrioventricular block, bradycardia, right bundle branch block, left anterior fascicular block, left posterior fascicular block, pacemaker, and mortality. Our results were compared with pre-existing data from a healthy background population. Further, outcomes were compared between patients with open atrial septal defects and atrial septal defects closed by surgery or transcatheter.

RESULTS

Most frequent findings were incomplete right bundle branch block (40.1%), left anterior fascicular block (3.7%), atrioventricular block (3.7%), and pacemaker (3.7%). Average age at pacemaker implantation was 32 years. Patients with defects closed surgically or by transcatheter had an increased prevalence of atrioventricular block (p < 0.01), incomplete right bundle branch block (p < 0.01), and left anterior fascicular block (p = 0.02) when compared to patients with unclosed atrial septal defects. At age above 25 years, there was a considerably higher prevalence of atrioventricular block (9.4% versus 0.1%) and complete right bundle branch block (1.9% versus 0.4%) when compared to the background cohorts.

CONCLUSIONS

Patients with atrial septal defects have a considerably higher prevalence of conduction abnormalities when compared to the background population. Patients with surgically or transcatheter closed atrial septal defects demonstrated a higher demand for pacemaker and a higher prevalence of atrioventricular block, incomplete right bundle branch block, and left anterior fascicular block when compared to patients with unclosed atrial septal defects.

What is the real cardiac anatomy?

The heart is a remarkably complex organ. Teaching its details to medical students and clinical trainees can be very difficult. Despite the complexity, accurate recognition of these details is a pre‐requisite for the subsequent understanding of clinical cardiologists and cardiac surgeons. A recent publication promoted the benefits of virtual reconstructions in facilitating the initial understanding achieved by medical students. If such teaching is to achieve its greatest value, the datasets used to provide the virtual images should themselves be anatomically accurate. They should also take note of a basic rule of human anatomy, namely that components of all organs should be described as they are normally situated within the body. It is almost universal at present for textbooks of anatomy to illustrate the heart as if removed from the body and positioned on its apex, the so‐called Valentine situation. In the years prior to the emergence of interventional techniques to treat cardiac diseases, this approach was of limited significance. Nowadays, therapeutic interventions are commonplace worldwide. Advances in three‐dimensional imaging technology, furthermore, now mean that the separate components of the heart can readily be segmented, and then shown in attitudinally appropriate fashion. In this review, we demonstrate how such virtual dissection of computed tomographic datasets in attitudinally appropriate fashion reveals the true details of cardiac anatomy. The virtual approach to teaching the arrangement of the cardiac components has much to commend it. If it is to be used, nonetheless, the anatomical details on which the reconstructions are based must be accurate. Clin. Anat. 32:288–309, 2019. © 2019 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.