Partial Splenectomy Helps Some Hereditary Blood Disorders

Removing just part of the spleen, rather than the entire organ, is beneficial to children with certain inherited blood disorders because it appears to maintain the normal functions of the spleen. This is the primary finding of a study conducted by researchers from the Medical College of Wisconsin and Duke University Medical Center.

Hereditary blood disorders are serious illnesses that lead to the destruction of red blood cells, causing fatigue, anemia, jaundice and enlargement of the spleen. The spleen, located on the left side of the upper abdomen, normally filters the blood and breaks down old or damaged red blood cells. This natural breakdown process can be accelerated in certain hereditary anemias.

While they are relatively rare, one of the more common types of hereditary anemias is hereditary spherocytosis (HS), which often shows up in infancy or early childhood. In HS, the red blood cells are rounder and more fragile than normal red cells, tending to become trapped in the spleen, where they may break up. This break-up gives rise to an excess of the bile pigment bilirubin, which can cause jaundice and the formation of gallstones, even in childhood.

"The historic treatment of hereditary spherocytosis is to remove the child's spleen. After splenectomy (removal of the spleen), the red cell defect persists, but the destruction of the red cells is substantially diminished, minimizing the disease," according to Keith T. Oldham, MD, Professor and Chief of Pediatric Surgery at the Medical College of Wisconsin. Dr. Oldham is one of the physicians who took part in the study. Partial splenectomies have become more common in Europe in the past decade, but still are a relatively controversial procedure in the United States.

Assessing the Risks
Removal of the spleen is not without risks. While removal helps limit these inherited blood disorders, it poses potential health problems, especially in young children. "The unique risk of total removal of the spleen is late infection," Dr. Oldham said. The spleen produces immune cells that protect the body from infection and it also clears unwanted materials from the blood. Young children without a spleen are at increased risk for overwhelming sepsis, an infection of the blood that can cause severe problems and even death in rare instances. The risk of post-splenectomy sepsis is reduced by use of immunizations to streptococcus pneumoniae, meningococcus, and others, as well as postoperative antibiotics, but it is never completely eliminated.

A partial splenectomy was proposed as an alternative to total splenectomy, with the goal of removing enough spleen to gain the desired effect on the disease while preserving the spleen's immune function. In the study, 25 children with hereditary anemia had a portion of their spleen removed, preserving 10% to 20% percent of the tissue. Researchers followed the children for as long as six years post-surgery and concluded that the partial splenectomy was successful in all 25 children.

Partial removal of the spleen carries some risks as well, noted Dr. Oldham. One possible risk is that the spleen could regenerate and that could mean re-operating on the patient. To date, that has not happened with any of the children who participated in the study. "As we have learned more about regeneration, it has become apparent that some patients have remarkable regeneration and some not very much.

Offering Options
When a child comes to them with a diagnosis of HS, Dr. Oldham and his colleagues now are able to offer parents three options: total splenectomy, partial splenectomy or no splenectomy. "We make our recommendation based on what is known about the individual patient and our experience. Partial splenectomy is a reasonably good option. It is a demonstrably safe surgery and we explain the plusses and minuses."

The study is significant because it was the largest one of its kind done in North America. "Sixteen of the 25 children had hereditary spherocytosis and nine had other disorders," Dr. Oldham explained. Follow-up done over successive years showed that children with HS had improved hemoglobin values, decreased bilirubin levels and preserved function of the spleen.

Overall, the study has shown that a partial splenectomy appears to control hemolysis (breakup of the red blood cells) while retaining the function of the spleen. "The conclusions from our studies have held up very well. They show that you can safely convert someone from severe or moderate disease to mild disease. We are continuing our study," said Dr. Oldham.

JoAnn Petaschnick
HealthLink Contributing Writer

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.