Most cases of portal vein thrombosis (PVT) remain without apparent explanation (JPGN 2012; 55: 599-604).
In this study from Brazil, 32 children with portal vein clots (1990-2011) were reviewed in this cross-sectional study. The median age at diagnosis was 2.4 years. Hereditary or acquired thrombophilia was detected in 34% and 9 of these patients had identified risk factors.
The most common thrombophilia factor was the presence of heterozygous state for methylenetetrahydrofolate reductase (MTHFR) C677T which was present in 11 patients. 2 of these patients had a cofactor, including G20210A prothrombin gene, and factor V Leiden.
Risk factors included umbilical catheterization in 13 patients (40.6%).
18 (56%) had no risk factors.
Related blog entry:
VTE with IBD | gutsandgrowth
Additional references:
- -Hepatology 2009; 39: 1729. AASLD practice guidelines on vascular disorders. Recs mesoRex shunt for PVT.
- -JPGN 2008; 47: 630. n=108. Infrequent thrombophilia d/o with PVT. Banding/sclero -effective.
- -J Pediatr 2006; 148: 735. PVT more common than previously thought; umbilical vein catheter, esp if misplaced, is risk factor.
- -NEJM 2011; 365: 147. Review. In cirrhosis pts, platelet count as low as 60K usually sufficient to preserve thrombin generation equivalent to lower limit of normal range in healthy subjects. PVT occurs in 8-25% of pts listed for OLTs. Thus, many procoagulant factors as well as potential propensity for bleeding.
- -J Pediatr 2003; 142: 197. Rex procedure corrects clotting abnormalities.
- -J Pediatr 2005; 146: 568. Portal vein -cavernous transformation –associated with cholestasis.
- -J Pediatr 2000; 136: 805. 49% of children with PV clot had bleeding by 16 yrs & 76% by 24 yrs. (n=44).
- -Gastroenterol 2001; 120: A-49, #256. Attention span deficits can be corrected c REX.
- -Hepatology 2000; 31: 345-348 & 587-591. Hyperhomocysteine mutation frequent when PVT assoc c cirrhosis. Etiologic factors. 87% c thrombophilic d/o.
- -Gastroenterol 2001; 120: 490-497 & 579. Anticoagulation helpful.
- -J Peds 2006; 149: 275. Reference values.
- -NEJM 2005; 352: 1791. Thrombosis of cerebral veins & sinuses (review); includes assoc c IBD. Specific thrombophilia disorders: Antithrombin deficiency, protein S and C deficiencies,Factor V Leiden mutation, (the A for G 20210) prothrombin gene mutation, lupus anticoagulant, antiphospholipid antibodies, factor XI, and MTHFR-hyperhomocysteinemia (thermolabile variant of methylenetetrahydrofolate reductase- C677T MTHFR-). The later was paricularly interesting in view of the recent report of hyperhomocysteinemia in patients with inflammatory bowel disease (Thromb Haemost 1998,80;542-5)