THROMBOCYTOPENIA AFTER HEPATIC CRYOTHERAPY FOR COLORECTAL METASTASES - CORRELATES WITH HEPATOCELLULAR INJURY

Postoperative thrombocytopenia following hepatic cryotherapy has been well documented and shown to be significantly greater than in control patients who had an identical incision or major laparotomy. Serum aspa rtate transaminase (AST) levels have been used as a reliable indicator of hepatocellular destruction. This study reviews 65 consecutive hepa tic cryotherapy operations. We have excluded all patients who had repe at cryotherapy to lesions (n = 6), all who had a colonic or hepatic re section procedure (n = 7), all who had tumors other than colorectal me tastases (n = 5), patients with inadequate data (n = 9), and those who were asplenic (n = 2). Of the remaining 36 patients, 14 were treated with a single freeze/thaw cycle, 12 were treated with a double freeze/ thaw cycle, and 10 were treated with mixed single and double freezes. The most common platelet nadir was day 3 (n = 21) followed by day 2 (n = 11), with the remaining platelet nadirs being day 1 or 4 (n = 4). T he percentage fall in platelet count was found to correlate with the r ise in day 1 AST level (r(2) = 0.74, least squares linear regression). The double freeze/thaw cycle patients had a significantly greater fal l in platelet count (p = 0.01, Mann-Whitney two sample test). Another institution has reported three deaths due to multiple problems, includ ing coagulopathy in patients treated with double freeze/thaw cycle cry otherapy. The conclusions of this study are that a high AST level on d ay 1 is a good predictor of impending thrombocytopenia, and that doubl e freeze/thaw cycle cryotherapy results in marked thrombocytopenia, wh ich may be responsible for the coagulopathy seen in some of these pati ents.