Platelet-dense granule deficiency causes postoperative hemorrhage in patients receiving enoxaparin: a novel observation with dramatic clinical implications

Mark D. Kligman, Nicholas J. Zyromski, Daniel G. McCullough, William T. Gunning

Research output: Contribution to journalArticle

1 Scopus citations


Background: Inherent hemorrhage risk has impeded the universal adoption of low-molecular-weight heparin (LMWH) for venous thromboembolic prophylaxis in surgical patients. Coagulation pathway parameters and platelet numbers routinely are evaluated preoperatively; scant attention has been directed toward evaluation of platelet function. We hypothesized that administration of LMWH may unmask latent platelet dysfunction and result in postoperative hemorrhage. Methods: Postoperative hemorrhage occurred in 15 (3.5%) of 423 consecutive patients undergoing laparoscopic gastric bypass. All patients received LMWH (enoxaparin, 40 mg) preoperatively. Hematologic evaluation included measurement of von Willebrand's factor level and activity, factor VIII level, and electron microscopic enumeration of platelet-dense granules. Results: All patients had normal preoperative platelet counts and coagulation profiles. Ten patients underwent hematologic evaluation: coagulation pathway parameters were normal in all; however, all patients had a markedly decreased number of platelet-dense granules. Conclusions: Platelet-dense granule deficiency may cause postoperative hemorrhage in patients receiving LMWH.

Original languageEnglish (US)
Pages (from-to)365-370
Number of pages6
JournalAmerican Journal of Surgery
Issue number3
StatePublished - Mar 1 2009



  • Bariatric surgery
  • Dense granule deficiency
  • Low-molecular-weight heparin
  • Platelets
  • Postoperative bleeding

ASJC Scopus subject areas

  • Surgery

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