One of the most insightful articles regarding the vessels_of_Wearn, is that of Muir, CS. Muir's sections are arguably among the best because the heart has been sectioned and displayed in a manner that permits viewing the length of the lumen of the pathologically altered vessel_of_Wearn.
The clinically "fistulous," vessel of Wearn's lumen is visible in a single plane. Most cases the sections of the heart are not near-parallel with the long-axis of the fistula's lumen, and therefore only part of the "vessels of Wearn," is appreciable without three-dimensional reconstruction,which can be facilitated by serial histologic sections.
Muir, CS from Singapore at the University of Malaya, published in the British Jou
Cardioplegia, one liter of crystalloid solution injected over three minutes at a pressure of of 60-to-80 mmHg through the right atrium results in effluent obtained in the aortic root. Presumably this occurs through the vessels of wearn.1
Right atrium -> vessels of wearn -> coronary arteries -> aortic root
Rigth atrium -> right ventricle -> vessels of wearn -> coronary arteries -> aortic root
1. Fabiani JN, Deloche A, Swanson J, Carpentier A. Retrograde cardioplegia through the right atrium. The Annals of thoracic surgery 1986;41:101-2.
Brett Snodgrass | Jan 07 2014 22:45 EST
These diffuse (minute, aka fine) connections may be consistent with the vessels of Wearn. Since we cannot definitively exclude an arteriosinusoidal vessel, using the term "vessels of Wearn" is appropriate.
It is also possible that some of the connections enter the capillary bed before entering the heart chamber. If that is the case, then it is possible that some of the connections are Thebesian connections.
For serial histologic sections, Wearn studied the arteriosinusoidal and arterioluminal vessels utilizing cold celloidin that was too thick to enter the capillaries. Wearn did note that when India ink was injected into the coronary arteries it would enter the heart chambers through numerous minute connections. Since, the ink would not permit serial histologic sections with 3D reconstruction as was used for the arteriosinusoidal and arterioluminal vessels, we may not have sufficient information to specify whether the connections are Arterio-capillary-cameral, or Arterio-capillary-venule-cameral (The venule-cameral connection would be a Thebesian vein).
Thus, when the diffuse connections are identified, we do not have sufficient data to determine whether they are arteriosinusoidal only, or whether some are arteriosinusoidal and some enter the capillary bed before entering the heart chamber. In addition, if some of the connections were arterioluminal vessels, then we would have an even more difficult time naming the radiographic finding. Thus, the term vessel of Wearn has been proposed. For additional commentary, please see. https://twitter.com/BrettSnodgrass1/status/404825015771619328 and https://twitter.com/BrettSnodgrass1/status/413860163033247744
Comments, disagreements, and suggestions are welcome.
Thank you kindly.
Always be cautious in reading an article, after corresponding with one of the authors on this excellent study, what I found out is that they did not identify the "vessels of Wearn," with great frequency. However, they did identify the #vessels_of_Wearn in the right ventricular outflow tract in this study.
This is further corroborating data that these "fistula," are often normal.
An unusual anomaly of the coronary vessels in the malformed heart of a child
Heart, 13 (1926), pp. 273–284
Here is a tangential section of myocardial sinusoid. The pediatric Cardiologist identified flow between the heart chamber and the coronary arteries. Furthermore, the report didn't call them thebesian veins. Perhaps a sign that we had a great team to write up this case. It really should be simple, but the number of very confused publications is large. With the internet, and all of the literature now uploaded, it would be prudent for us to collaborate and make that which is simple, both simple and accurate.