Removing Portion of Spleen Effective in Treating Inherited Childhood Anemias
DURHAM, N.C. -- Researchers from Duke University Medical
Center and the Medical College of Wisconsin have shown that
removing a portion, instead of all, of the spleen, can
successfully treat children with a variety of congenital
anemias while preserving important splenic immune function.
In the largest study of its kind in the U.S., the
researchers performed the surgery, known as a partial
splenectomy, on 25 children with congenital forms of anemia
caused by abnormal red blood cells. Typically, these children
suffer from fatigue, jaundice and extreme vulnerability to
infections that can require repeated hospital or physician
visits. Many also need repeated blood transfusions.
The results of the team's research were published today
(Jan. 31, 2003) in the Annals of Surgery.
The spleen has two main functions: it produces immune system
cells that protect the body from infection, and it also serves
to clear unwanted materials -- including defective blood cells
-- from the bloodstream. The majority of the children in the
current study had hereditary spherocytosis, a condition marked
by misshapen and rigid red blood cells. Because of their shape
and rigidity, the red blood cells become trapped and destroyed
in the spleen, resulting in an enlarged spleen and a reduction
in the number of oxygen-carrying red blood cells.
"Many children with these disorders do fine with little or
no intervention, but for those who have repeated infections and
medical crises, their quality of life can be very poor," said
Duke pediatric surgeon Henry Rice, M.D., principal investigator
for the study. "Some of these patients receive total
splenectomies, which can relieve many of the symptoms, but can
leave patients at risk of fatal infections."
"There has been a resurgence in doing partial splenectomies
in Europe for the past 10 years, but it still remains a very
controversial procedure in the U.S.," Rice continued. "The goal
is to take away enough of the spleen to help relieve the anemia
and its symptoms, while leaving enough to maintain a viable
immune function. Until now, there have been no large and
conclusive studies showing the procedure can be performed
safely with good outcomes."
Partial splenectomies have been slow to catch on in the U.S.
for a number of reasons, according to Rice. First, the
operation itself is technically difficult to perform. Secondly,
somewhat like the liver, the spleen can regenerate itself, so
physicians have worried that even if they perform a successful
procedure, the spleen will eventually return to its original
size and function.
"In our group of patients, some of which have been followed
as long as six years, we have seen some regrowth of spleen
tissue, but it has not been associated with the return of
symptoms," Rice said. "The regrowth appears to vary widely from
patient to patient, and it is not certain whether the new
tissue acts exactly like the original tissue."
To date, none of the 25 children who have received the
operation have needed another procedure, and none have
succumbed to serious infections, Rice said.
While the procedure shows promise in improving the quality
of life for these patients, Rice points out that it does not
address the cause of these disorders, which have a genetic
"However, these tend to be very sick children with a poor
quality of life," Rice said. "We hope that this study will
provide the necessary scientific basis to convince other
surgeons that despite the difficulty of the procedure, it can
benefit this group of children."
The surgeons removed between 80 to 90 percent of the spleen
in the children followed in the study. According to Rice, a
total splenectomy takes about one hour to perform, while a
partial splenectomy takes about two hours. In both procedures,
patients receive appropriate immunizations and antibiotics
prior to surgery to reduce the risks of infections.
Of the 25 children who received partial splenectomies, 16
had hereditary spherocytosis, while nine had other red blood
cell disorders, including pyruvate kinase deficiency and
thalassemia. The children ranged in age from 1 to 14 years of
age. As humans age, Rice said, the spleen becomes less
important to maintaining overall good health.
While the results of current experience of the Duke and
Wisconsin surgical teams appear promising, Rice believes that a
prospective, long-term trial is needed to further refine the
role of partial splenectomies in hereditary anemias, as well as
possibly expanding the number of patients who could benefit to
include those with similar rare disorders, including some forms
of sickle cell disease.
The study was supported by the surgery departments at Duke
and the Medical College of Wisconsin.
Other members of the research team included, from Duke,
Russell Ware, M.D., and Michael Skinner, M.D. Other members
were Keith Oldham, M.D., and Cheryl Hillery, M.D., Children's
Hospital of Wisconsin, and Sara O'Hara, M.D., Children's
Medical Center of Cincinnati.