William Senhouse Kirkes was a British physician and contributed significantly to the knowledge of bacterial endocarditis. In his work, Kirkes described several cases of infective endocarditis with peripheral embolization.
He initially referred to Laennec's description of vegetations and defined them:
"...the forms of fibrinous concretions to which my observations chiefly apply, are, first, the masses usually decribed as Laennec's globular excrescences; and secondly, the granular or warty growths adhering to the valves and presenting innumerable variables from mere granules to large irregular fungous or cauliflower excrescences projecting into the cavities of the heart."
He then continued with the potential risk of embolization of these "fibrinuos concretions" or "outgrowths":
"If of large size and only lossely-adherent, as they often are, one or more masses of even considerable magnitude may at any time be detached from the valves and conveyed with the circulating blood until arrested within some arterial canal which may be completely plugged up by it, and thus the supply of blood to an important part be suddenly cut off, and serious, even fatal results ensue. Or, the deposits on the valves may be detached in smaller masses, and pass on into arteries of much less size, or even into the capillaries, where, being arrested, they may cause congestion, followed by stagnation and coagulation of the blood..."
Finally, he emphasized on the general symptoms and systemic manifestations of the disease that he was describing, namely infective endocarditis:
"...the masses of fibrine may soften, break up, and discharge the finely granular material resulting from their disintegration; and this, mingling and circulating with the blood, may give rise to various disturbances indicative of a contaminated state of this fluid [poisoned blood], producing symptoms very similar to those observed in phlebitis, typhus, and other analogous blood-diseases."
In his writing, Kirkes mentioned that the presentation of the symptoms would depend on the location of these vegetations on the left-sided or right-sided valves. Consequently, his articles is divided into two parts.
The part one is entitled, "On the effects which may result from the separation of fibrinous deposits from the valves or interior of the left side of the heart, and their circulation with the systemic blood."
In this section, Kirkes described four cases of endocarditis affecting the left-sided valves. The mitral valve was involved in all these patients. In his description, he noted that these patients presented with fever, profuse sweating, stroke, skin lesions (spots of a pinkish color or petechial spots on the body) and a systolic murmur. Three of these patients died from massive stroke due to cerebral embolism. At autopsy, multiple vegetations were note on the leaflets of the mitral valve in all four patients. Occasionally he observed the extension of the lesions toward the left atrium.
There were also multiple embolizations involving several large arteries including right middle cerebral artery. Multiple emboli were also observed in the kidneys and spleen. Here is the description of case one.
The part two of his work focused on the right side of the heart and is entitled, "On the effects which may result from the detachment of fibrinous deposits from the right valves of the heart." In this section, he discussed the cases of right-sided valve endocarditis with the risk of embolization into the lungs.
In the conclusion of his article, Kirkes wrote:
"... In conclusion, let me briefly recapitulate the principal points I have endeavoured to establish to the satisfaction of the Society. They are, 1st, the general fact that fibrinous concretions on the valves or the interior of the heart admit of being readily detached during life, and mingled with the circulating blood; 2dly, that if detached and transmitted in large masses, they may suddenly block up a large artery, and so cut off the supply of blood to an important part; if in smaller masses, they may be arrested in vessels of much less size, and give rise to various morbid appearances in internal organs; while, under other circumstances, the particles mingled with the blood may be extremely minute, possibly the debris of softened fibrine, yet in sufficient quantity and with sufficient power to produce a poisoned state of the circulating fluid, as manifested in the production of typhoid or phlebitic symptoms: 3dly, that the effects produced and the organs affected will be in great measure determined by the side of the heart from which the fibrinous masses have been detached; for, if the right valves have furnished the source of the fibrine, the lungs will bear the brunt of the secondary mischief, displaying it in coagula in the pulmonary arteries, and various forms of deposit in the pulmonary tissue: but if, as is far more commonly the case, the left valves are affected, the mischief is more widely spread, and may fall on any systemic part, but especially on those organs which, such as the brain, spleen, and kidneys, are largely and directly supplied with blood from the left side of the heart."
Kirkes work was extremely influential and was quoted by several authors during the second half of the 19th century. Sir William Osler wrote in 1885 "we date our accurate knowledge of the affection" from Kirkes' publication.