**4. Conclusion**

Lesurtel et al. proposed a new criterion in evaluating the extent and impact of thrombocytopenia they called the 60-5 criterion. In their study, they demonstrated a strong correlation

A rare cause of low platelet count in this stage is heparin-induced thrombocytopenia, heparin therapy being the standard of care in many centers post LT. Bachmann et al. in a single center study looking at 205 LT found in 1.95% of patients, a suspicious clinical platelet course with

Chang et al. looked at the role platelets have in antimicrobial host defense. They analyzed 50 LT recipients and looked at the impact of thrombocytopenia as a related variable to infectious complications in the posttransplant period. They found a significant correlation between low

correlation was very strong for fungal and bacterial infections but not for viral ones. Infection can determine thrombocytopenia but the authors stated that the lowest platelet count pre-

Generally, platelet transfusion is not needed during the postoperative period and one can wait for the spontaneous resolution. Resolution starts after the first week due to increasing levels of thrombopoietin. It will reach normal values on time due to the regression of spleno-

After liver transplantation, the blood level of TPO increases but it will take several days for

The **beneficial role** of platelets is due to platelet-derived serotonin that is involved in liver regeneration. This phenomenon is of great importance in living-related LT, small-for-size syndrome, and also plays a role in hepatic repair after ischemia/reperfusion injury. Serotonin accumulates in thrombocytes and is released in areas of tissue injury stimulating mitogenesis [3]. All the mechanisms promoting liver regeneration and involving platelets are not yet very well understood but they certainly play an important role through the release of various mediators like serotonin, hepatocyte growth factor, insulin growth factor, and vascular endothelial growth factor. The last one supports liver regeneration by stimulating neoangiogenesis [22].

Blood loss is a major concern during liver transplantation due to the precarious hemostatic condition of these patients combined to a surgical procedure at high risk for bleeding. Since the beginnings of LT, surgical techniques and anesthetic patient management have improved and the blood loss and transfusion needs have decreased. Despite life-saving benefits, transfusion has also related complications and platelet transfusion has been identified as an independent risk factor for postoperative complications. Risks related to platelet concentrate administration are allergic reactions, alloimmunization, bacterial sepsis, and transfusion-related acute lung injury (TRALI), and nowadays to a lesser extent viral transmission [23]. Therapeutic

on postoperative day 5 and the incidence of severe

) and infections in the first month following transplantation. The

between a platelet count of <60,000/mm<sup>3</sup>

elevated antibody levels [18].

90 Thrombocytopenia

platelet count (<30,000/mm<sup>3</sup>

complications and a twofold increase in mortality at 90 days [17].

ceded the infection with a median time of 7 days [19].

megaly once portal hypertension has been resolved [20].

the rise of platelet number to happen [21].

**3. Treating thrombocytopenia**

In conclusion, thrombocytopenia is a common figure of chronic liver disease and liver transplant with multifactorial etiologies. Platelet count exclusively is not a good marker to anticipate risk for bleeding in cirrhotic patients because compensatory mechanisms increasing production of von Willebrand factor will interfere. Splenectomy is not indicated anymore as a therapeutic measure for regulating thrombocytopenia in the pretransplant period. It still may have some indications if done concomitantly with the transplant procedure especially in living-related LT or when small-for-size complication is anticipated.

Thrombocytopenia will be aggravated during the surgical procedure due to bleeding and entrapment in the graft secondary to reperfusion. The decrease in platelet number will continue in the initial postoperative phase but a spontaneous resolution will take place if no complication.

[7] Massoud OI, Zein NN. The effect of Transjugular intrahepatic Portosystemic shunt on platelet counts in patients with liver cirrhosis. Gastroenterology & Hepatology. 2017;**13**:

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[8] Gangireddy V, Kanneganti P, Sridhar S, Talla S, Coleman T. Management of thrombocytopenia in advanced liver disease. Canadian Journal of Gastroenterology & Hepatology.

[9] Tripodi A, Primignani M, Chantarangkul V, Clerici M, Dell'Era A, Fabris F, et al. Thrombin generation in patients with cirrhosis: The role of platelets. Hepatology. 2006;**44**:

[10] Saner FH, Gieseler RK, Akiz H, Canbay A, Gorlinger K. Delicate balance of bleeding and thrombosis in end-stage liver disease and liver transplantation. Digestion. 2013;**88**:

[11] Ohira M, Ishifuro M, Ide K, Irei T, Tashiro H, Itamoto T, Ito K, Chayama K, Asahara T, Ohdan H. Significant correlation between spleen volume and thrombocytopenia in liver transplant patients: A concept for predicting persistent thrombocytopenia. Liver

[12] Morimoto H, Ishiyama K, Ishifuro M, Ohira M, Ide K, Tanaka Y, Tahara H, Teraoka Y, Yamashita M, Abe T, Hashimoto S, Hirata F, Tanimine N, Saeki Y, Shimizu S, Sakai H, Yano T, Tashiro H, Ohdan H. Clinical efficacy of simultaneous Splenectomy in liver transplant recipients with hepatitis C virus. Transplantation Proceedings. 2014;**46**:770-773

[13] Chu HC, Hsieh CB, Hsu KF, Fan HL, Hsieh T, Chen T. Simultaneous splenectomy during liver transplantation augments antiviral therapy in patients infected with hepatitis C

[14] Ito K, Akamatsu N, Ichida A, Ito D, Kaneko J, Arita J, Sakamoto Y, Hasegawa K, Kokudo N. Splenectomy is not indicated in living donor liver transplantation. Liver

[15] Juttner B, Brock J, Weissig A, Becker T, Studzinski A, Asthaus WA, Bornscheuer A, Scheinichen D. Dependence of platelet function on underlying liver disease in ortho-

[16] Droc G, Popescu M, Filipescu D, Bubenek S, Popescu I. Defining risk factors for post liver transplant thrombocytopenia. Archives of the Balkan Medical Union. 2015;**50**:309-313

[17] Lesurtel M, Raptis DA, Melloul E, Schlegel A, Oberkoffer C, El-Badry AM, Weber A, Mueller N, Dutkowski P, Clavien PA. Low platelet counts after liver transplantation predict early posttransplant survival: The 60-5 criterion. Liver Transplantation. 2014;**20**:

[18] Bachmann R, Bachmann J, Lange J, Nadalin S, Konigsrainer A, Ladurner R. Incidence of heparin-induced thrombocytopenia type II and postoperative recovery of platelet count

in liver graft recipients. Journal of Surgical Research. 2014;**186**:429-435

virus. The American Journal of Surgery. 2015;**209**:180-186

topic liver transplantation. Thrombosis Research. 2009;**124**:433-438

286-291

440-445

135-144

147-155

Transplantation. 2009;**15**:208-215

Transplantation. 2016;**22**:1526-1535

2014;**28**:558-564

Administration of platelets is not indicated if there is no bleeding or immediate bleeding risk. New emerging therapies like thrombopoietin-receptor agonist will furthermore limit the administration of blood products.
