Correlation of splenic volume with hematological parameters, splenic vein diameter, portal pressure and grade of varices in extrahepatic portal vein obstruction in children.

Purpose: To study the correlation between the volume of the spleen and hematological parameters, splenic vein diameter, portal pressure before shunt, portal pressure after shunt, reduction of portal pressure and grade of esophageal varices in patients with extrahepatic portal vein obstruction (EHPVO).

Methods: Twenty-four patients with EHPVO who underwent splenectomy with leino-renal shunt during a period of 2 years were prospectively analyzed. Splenic volumes were measured from CT scans using appropriate volumetry software. In order to standardize the difference in the size of the patients, the splenic volume was expressed as a ratio, the splenic volume index, between the actual volume as measured on the CT scan and the surface area of the body. The splenic vein diameter was measured on the CT portogram and confirmed during surgery using a caliper. The grade of esophageal varices was determined during esophageal endoscopy using the Japanese Research Society for Portal Hypertension classification. The portal pressure was measured by cannulating a venous tributary of the gastro-epiploic arcade and using a pressure transducer.

Results: The splenic volume, expressed as splenic volume index, ranged from 362.15 to 1,849.51 ml/m² (mean 929.23 ± 409.02). Larger splenic volumes were associated with lower hemoglobin and platelet counts and significantly lower total leukocyte counts (p = 0.0003). The portal pressures reduced remarkably following the splenectomy and leino-renal shunt; mean post-shunt pressure 20 ± 6.63 mmHg from mean pre-shunt pressure of 34.33 ± 6.21 mmHg (mean percentage reduction 43.37 ± 16.02%). There was no statistically significant correlation between splenic volume and any of the hemodynamic parameters except a weak correlation with splenic vein diameter. There was no correlation between the splenic vein diameter and the pre-shunt portal pressure; however, there was a statistically significant correlation between the splenic vein diameter and the percentage of post-shunt portal pressure reduction (p = 0.0494).

Conclusion: Splenic volume has a weak correlation with splenic vein diameter, but does not correlate with portal pressure or the grade of varix. Splenic vein diameter has a statistically significant correlation with the percentage of portal pressure reduction following a leino-renal shunt. There is a statistically significant negative correlation between the splenic volume and the total leukocyte count.