From antiquity, the spleen was viewed as an organ of mystery. Innumerable properties were ascribed to its humors. Hippocrates' humoral theory of pathology attributed melancholy or morose feelings to a heavy mixture of splenic black bile with the other humors. Apparently, Shakespeare believed that a light mixture could produce mirth and happiness. To this day the spleen is a perplexing, computerized structure.
Christopher Wren, of 17th-century architectural fame, probably performed a great disservice when he showed experimentally that the dog could survive without a spleen. The ancient reverence for this unfathomed organ gradually disappeared in spite of, or because of, a lack of understanding of the spleen's total role. The many activities of the spleen in health and disease are still being studied and imperfectly understood.
For at least the past 50 years, splenectomy has been a popular operation not only for many medical indications but also following trauma, whether severe or trivial. Splenectomy for total disintegration of the organ is obviously understandable. However, even for less severe injuries, too often iatrogenic, extirpation has been tacitly considered advisable to avoid delayed rupture, presumably with exsanguinating hemorrhage, or splenosis, with its many reputed complications.
Unfortunately, two mutually supportive concepts have become popular. First, the spleen is considered to be important in combating infection only during infancy or, at most, for the first two years of life. Second, once it is traumatized, removal has been accepted as the safest procedure for all concerned. The increased incidence of overwhelming sepsis in infants without spleens was recognized as a threat to life over a quarter of a century ago. For many years, pediatricians have been pleading for conservation of injured spleens. The uncontrollable sepsis and excessive mortality in older children without spleens are only now receiving the attention they deserve. As interest in this problem heightens, evidence accumulates to support the need for increased regard for the spleen and to magnify our concern as physicians and surgeons over the removal of such a protective agent.
It would be presumptuous to do more than allude to the role played by the spleen in combating infection. The bacterial agents in question are many. Three of the four most often incriminated are polysaccharideencapsulated organisms with rapid doubling times (pneumococcus, meningococcus, and, less rapidly. Hemophilus influenzae).
In response to infection, the spleen is known to enlarge as a result of vascular engorgement as increased phagocytic activity of the splenic macrophage becomes evident. If the infection is blood-borne, the spleen plays a major role in the mechanical clearing of the microorganisms from the bloodstream, particularly those that have a polysaccharide capsule. This is of special importance, since the spleen can accomplish this function without the presence of antibodies specific for the invading organisms, and some of these organisms, particularly pneumococcus and meningococcus, have a doubling time as short as 20 minutes.
Splenic antibody production against these organisms is also of great importance, especially when the antigen is particulate (such as bacteria) and is circulating in the bloodstream. The splenic macrophages, by removing bacteria from circulation, put them in very close contact with the lymphoid follicles of the spleen, where antibody formation takes place.
Once the specific antibodies are formed, the circulating phagocyte becomes very effective in the ultimate clearing of invading bacteria. These crucial phagocytic and antibody-producing functions are lost when the spleen is removed, since no antibodies will be formed in the splenectomized person in the face of blood-borne infection, and the initial clearing of bacteria by the reticuloendothelial system is accomplished primarily by the spleen.
Following splenectomy, there is a reduction in IgM. During the initial antigenic stimulus of an infection, the immune response is primarily with macroglobulin antibodies (IgM), and only more slowly does the patient respond with IgA and IgG. It would appear likely that this deficiency of IgM in the patient without a spleen is at least partly responsible for the overwhelming nature of the infection.
In the past, when performing splenectomy for trauma, many of us have on occasion been comforted by the knowledge that an accessory spleen was left behind. Possibly, it was assumed that these tissues would hypertrophy and mature should the need arise and time permit. Recent reports indicate that accessory spleens do not take over the protective role hoped for. Seedings of splenic tissue following trauma and splenectomy have not shown evidence of assuming a primary splenic role. Studies suggest that the amount of splenic tissue necessary to confer protection must be equal to about one-quarter of the original spleen and must be nourished by an adequate circulation. Splenic remnants that have become walled off with fibrous capsules and are relatively avascular appear unable to function.
As evidence accumulates, it seems obvious that sepsis of a precipitous nature, with unusually high mortality, is to be feared in any person without a spleen. The age of the patient is becoming less important, and the period "at risk" is lengthening with each report. The intervals have varied from 13 days to over 14 years after splenectomy. It has been suggested that the younger the patient, the shorter the period is likely to be.
In view of this increasingly recognized hazard, it behooves surgeons to reassess their views on damaged spleens. In one large series recently reported, iatrogenic trauma associated with upper abdominal operations was the leading indication for splenectomy. At least one lawsuit, based specifically on this concern for loss of the protective spleen, has been filed by an apprehensive parent against an automobile driver. Presumably, the spleen could not be salvaged. An informed public, with knowledgeable legal advice, will eventually extend this reasoning to implicate the attending surgeon in cases of incidental surgical injury.
Except in the patient who is in profound shock with a completely shattered, avascular organ, the surgical management of such trauma cases must be rethought. Children rarely approach exsanguination from even complete avulsion of a spleen. Routine abdominal exploration in a stable patient, performed just because peritoneal lavage returned some bloody fluid, is open to serious question. In many cases, careful observation will avoid the need for surgery.
When an operation is deemed necessary, hemostasis by electrocoagulation of lacerated surfaces and Gelfoam packs will take care of a great many damaged spleens. Through-and-through absorbable sutures tied over Telfa sponge will even salvage many extensively traumatized organs. Partial splenectomy is definitely feasible. Even a "second look" operation or a subsequent arteriogram in questionable situations now seems preferable to routine, arbitrary splenectomy.
It may take a great deal of evangelism and a few legal procedures, but I predict that splenectomy will become much more infrequent and the documentation of the necessity for the procedure will become of paramount importance to every surgeon. When repair or partial salvage is not possible, the patient and reliable relatives must be informed that he is now "at risk" and share the responsibility for the early detection and institution of strenuous treatment of any infection.
For the present, keep in mind the incalculable value of the spleen while determining the risks of operating or not operating, and let this knowledge also guide decision making at the operating table. Please treat each case as a very special problem - which it is.