Page 2611 - Hematology_ Basic Principles and Practice ( PDFDrive )

2324 Part XIII Consultative Hematology

predisposing to iron overload, such as thalassemia, the presence of that preserve or restore splenic function. Even large cysts that were
the spleen as a preferential site for the storage of harmful cellular indications for splenectomy until recently have been managed with
breakdown products may protect other organs from damage. Delay- spleen-conserving procedures, such as partial or total cyst removal,
23
ing splenectomy until a clear clinical indication is present will balance which can often be performed laparoscopically. Pancreatic surgery
risks and benefits to an optimal degree. The recently developed oral often requires sacrifice of the spleen; however, increasing numbers of
substrate inhibitor, eliglustat, has shown promising success in reduc- procedures are being performed with salvage of the spleen.
18
ing splenomegaly in patients with Gaucher disease. As this drug is Splenic transplantation is being used as a means of developing
studied further, it is possible that splenectomy may not be needed immune tolerance, as well as a means of reducing the risk for infec-
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as often. tion following organ transplantation. Allograft spleen has been
transplanted within multivisceral grafts with only minimal graft-
versus-host disease. To date there are more animal than human data,
Surgical Options and it is unclear how large an impact this approach will have on
25
visceral, especially small-bowel and pancreatic, allotransplantation.
When splenectomy is clearly indicated, acute complications are rarely If protection against infection is the main consideration, an intact
a consideration in the decision to perform surgery. Nevertheless, spleen is superior to a repaired or autotransplanted spleen, whereas
advances in surgical procedures have minimized the short-term risks accessory spleens and splenosis may be only marginally better than
of the procedure itself and of postoperative complications such as asplenia. 15
intestinal obstruction from adhesions. Subtotal splenectomy can be
performed when total splenectomy is not desirable, such as for the
removal of a cyst, a pseudocyst, or tumors, after trauma, or for Complications After Splenectomy
Gaucher disease. Wedge resection with mattress sutures and cyano-
acrylate adhesives and microfibrillar collagen omental packs have Acute complications in the perioperative period include rupture of
greatly improved partial splenectomy procedures in the past decade. the spleen, the development of a subphrenic abscess, and injury to
Laparotomy is required when extensive peritoneal adhesions are the pancreas during the operative procedure. In a healthy patient, the
present and for removal of massively enlarged spleens. A sufficiently immediate risk of splenectomy is limited. The degree of splenomegaly
large incision to permit full visualization and mobilization is essential greatly affects the risk for rupture and pancreatic injury. The technical
when the spleen is very large or when inspection is a major part of difficulty of performing a splenectomy is much greater when the
the surgical procedure. A retroperitoneal approach is useful when the spleen is massively enlarged than when the spleen is small. Once the
spleen is not massively enlarged but needs to be fully removed, such arterial supply is ligated, rupture of the spleen is rarely a problem.
as when cytopenias are the indication for the procedure. This The splenic hilum is retroperitoneal, so if the spleen is very large,
approach shortens the postoperative recovery time and avoids induc- mobilization to gain access to the splenic artery and vein can be
tion of peritoneal adhesions. difficult. After recovery from surgery, intestinal obstruction due to
Minimally invasive procedures have become standard for most formation of peritoneal adhesions is a complication that, if it is to
splenectomies. Laparoscopy is now the procedure of choice for occur at all, usually occurs within the first few months.
splenectomy. Although the operative time is significantly greater than Two late complications of splenectomy give the greatest
for laparotomy, the postoperative recovery time, risk for damage to concern: overwhelming postsplenectomy septicemia and atheroscle-
the pancreas, likelihood of developing a subphrenic abscess and rotic heart disease. Both of these complications may develop many
peritoneal adhesions postoperatively, and nutritional and metabolic years after the splenectomy (Fig. 160.9). The precise risk is not
challenges to the patient are considerably reduced. Laparoscopic known, and preventive interventions are probably underused because
splenectomy can be performed even in thrombocytopenic patients. patients may not be aware of the risks of splenectomy performed early
The outcome of laparoscopic splenectomy in ITP is affected by the in life.
experience and skill of the surgeon and by the patient’s obesity. Postsplenectomy septicemia is rare but may be rapidly lethal. In
Prolonged presurgical use of corticosteroids may induce obesity and the absence of protective levels of opsonic IgG antibodies produced
impair tissue healing, resulting in a higher risk for complications from in the spleen, hepatic and pulmonary macrophages are unable to
laparoscopic splenectomy than when splenectomy is performed effectively clear organisms from the bloodstream. Organisms that
before adverse drug effects develop. In the case of massive spleno-
megaly, splenic morcellation may be necessary prior to laparoscopic
retrieval.
Appreciation of the risk for postsplenectomy septicemia and
refinements in noninvasive, accurate radiologic monitoring tech-
niques have led to more conservative approaches to splenic injury. 80
Nonoperative management has increased over time and has an
acceptable mortality and complication rate in selected patients,
60
although early discharge may put patients at risk for the later com- Percent of total cases of PSS 100
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plications. Noninvasive imaging and minimally invasive surgical
procedures have greatly affected these trends. After traumatic 40
rupture, splenic tissue may regenerate as both micro- and macro-
scopic ectopic implants in the peritoneal cavity, a process termed
splenosis. Although splenosis appears to be partially protective 20
against overwhelming postsplenectomy infection in animals, its
protective value in humans is not known and may depend on the 0
adequacy of splenic tissue perfusion. If poorly vascularized, the 0 2 4 6 8 10 12 14 16 18 20
ectopic splenic tissue may not provide adequate contact between
macrophages and the antigens of the infecting organism. It is gener- Time (years)
ally valuable to attempt preservation of splenic function when pos- Fig. 160.9 THE INTERVAL FROM SPLENECTOMY TO POSTSPLE-
sible after traumatic rupture. Some surgeons attempt to induce NECTOMY SEPSIS. Of the total (n = 288), 3.1% occurred more than 20
splenosis when traumatic splenectomy is unavoidable, in the hope years after splenectomy. PSS, Postsplenectomy sepsis. (Used, with permission,
of minimizing late complications. from Lutwick LI: Infections in asplenic patients. In Mandell GL, Bennett JE, Dolin
As the late complications of splenectomy are better appreciated, R, editors: Principles and Practice of Infectious Diseases, ed 7, Philadelphia, 2009,
surgeons have become increasingly creative at performing procedures Churchill Livingstone.)