Diagnostic accuracy of D-dimer for splanchnic vein thrombosis : a systematic review and meta- analysis

Abstract

Background : D- dimer is included in the diagnostic algorithm for deep vein thrombosis of the lower limbs and pulmonary embolism. However, its role for the diagnosis of splanchnic vein thrombosis (SVT) is still debated, especially considering that several conditions predisposing to SVT are associated with increased D- dimer (malignancy, abdominal surgery, liver cirrhosis).

Aims : To evaluate the accuracy of D- dimer in the diagnosis of SVT by performing a systematic review of the literature and meta- analysis

Methods : The protocol of this systematic review was registered a priori in PROSPERO (CRD42020184300). We performed a bibliographic search within the electronic databases MEDLINE, EMBASE, and CENTRAL up to July 2020, in order to identify all studies which evaluated D- dimer accuracy in patients with suspected SVT. The index test was any D- dimer assay. The reference standard was radiological imaging (abdominal ultrasound, computed tomography, magnetic resonance, angiography) or abdominal surgery. The QUADAS- 2 checklist was used for the risk of bias assessment. We calculated pooled weighted mean specificity/sensitivity and positive/ negative likelihood ratios.

Results : Among the 11 included studies, 9 enrolled only cirrhotic patients (5 of them post- surgery). Risk of bias was high in 9 studies. Only 4 studies tested D- dimer within 24 hours from the reference standard, while 3 studies did not use the D- dimer manufacturers’ cut- off. Overall, mean prevalence of SVT was 34.6% (95% CI, 23.0– 47.2%, I 2 = 95.1%). D- dimer sensitivity was 95.3% (95% CI, 70.0– 99.4%), specificity was 41.6% (95% CI, 15.4– 73.6%). Positive likelihood ratio was 1.63 (95% CI, 0.99– 2.68), negative likelihood ratio was 0.11 (95% CI, 0.02– 0.54). The area under the ROC curve was 0.81 (95% CI, 0.78– 0.84).

Conclusions : This systematic review showed high risk of bias and high heterogeneity in the published literature on this topic. Although D- dimer seems to have high sensitivity also for the diagnosis of SVT, there is strong need for more robust evidence.