Diagnosis and Imaging:
The most frequently relied upon modality for the diagnosis of SASS is angiography (8). It is defined as a subjective slow flow of blood in the hepatic artery relative to that in the splenic artery in the absence of significant artery abnormalities such as hepatic artery stenosis, thrombosis or kinks (15). Uflacker and coworkers diagnosed SASS when there is a visualization of hepatic artery during the portal-venous phase of angiogram (3). However, others have not relied on this definition or threshold (5). Other modalities for detection of SASS include regular doppler ultrasonography (US) (14). US is often performed daily within the first week after OLT. Emergency angiography is performed when a weakened or decreased signal is detected on US (14). US findings are nonspecific and are not often used to describe SASS cases since findings overlap with other conditions such as infection, transient graft edema, or rejection (16,17,18). The most described US findings include a high level of arterial resistive index (above 0.8) (19). Reversal of diastolic flow or low diastolic flow is also often observed (3,4). Furthermore, arterial velocities are rarely reported (17). Nevertheless, US findings are not often used for diagnosis of SASS (14). In fact, only 30 % percent (34 out of 113) of the SASS cases reported US findings. Other methods for the diagnosis of SASS include a splenic volume greater than 830 cm3, which has an almost 75% accuracy in diagnosing SASS (7,8). Splenic artery diameter of greater than 4.0 mm or splenic artery to hepatic artery ratio of greater than 1.5 are considered indicators of SASS (7,8). Some studies have also indicated a difference of at least 6mm between hepatic and splenic artery diameters as being predictive of SASS (6). However, no imaging modality truly solidifies the diagnosis, and the diagnosis is only confirmed upon seeing improved graft function and increased hepatic arterial perfusion after correcting splenic artery perfusion.