Thrombocytopenia after isolated limb or hepatic perfusions with melphalan: the risk of heparin-induced thrombocytopenia.
BACKGROUND
Three cases of heparin-induced thrombocytopenia (HIT) were observed in patients undergoing isolated limb perfusion (ILP) with melphalan. This occurrence prompted the discontinuation of prophylactic postoperative heparin in ILP patients and its avoidance in patients undergoing isolated hepatic perfusion (IHP). The need to reassess these decisions led to a review of thrombocytopenia in both patient populations.


METHODS
Records of all patients treated with ILP or IHP at our institution from July 1992 through November 1996, were reviewed. Nine IHP patients were tested prospectively for heparin-related antibodies using serum samples obtained perioperatively and during the second postoperative week.


RESULTS
Thrombocytopenia (< 100,000 platelets/microL) developed postoperatively in 30% of 131 ILP patients and in 77% of 56 IHP patients. No cases of HIT were identified other than the three who had been previously diagnosed. The prevalence of HIT in heparinized ILP patients was 2.8% (3/108). All nine IHP patients developed heparin-related antibodies postoperatively.


CONCLUSIONS
Because the prevalence of HIT following ILP is in the range observed in other clinical settings, postoperative heparin prophylaxis is an option. However, it probably should be limited to the first week, and daily platelet counts should be reviewed for a pattern of thrombocytopenia consistent with HIT. The prevalence of heparin-related antibodies after IHP is so high that prophylactic heparin should be avoided in this setting.
Masucci
I P
IP
Pharmacy Department of the Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892, USA.
Calis
K A
KA
Bartlett
D L
DL
Alexander
H R
HR
Horne
M K
MK
D000328:Adult; D000906:Antibodies / Q000097:blood; D000925:Anticoagulants / Q000009:adverse effects* / Q000276:immunology; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage*; D010478:Chemotherapy, Cancer, Regional Perfusion; D004797:Enzyme-Linked Immunosorbent Assay; D006493:Heparin / Q000009:adverse effects* / Q000276:immunology; D006801:Humans; D008499:Medical Records; D008558:Melphalan / Q000008:administration & dosage*; D011183:Postoperative Complications / Q000139:chemically induced; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D013921:Thrombocytopenia / Q000139:chemically induced*
D000906:Antibodies; D000925:Anticoagulants; D018906:Antineoplastic Agents, Alkylating; D006493:Heparin; D008558:Melphalan