Oelsner D H, Caldwell S H, Coles M, Driscoll C J
The University of Virginia, Department of Internal Medicine, Charlottesville, USA.
Gastrointest Endosc. 1998 May;47(5):388-90. doi: 10.1016/s0016-5107(98)70224-x.
Large volume paracentesis is a common treatment of ascites. Injury to abdominal wall collateral veins during this procedure can lead to hemoperitoneum. Because of this concern, the midline below the umbilicus is often recommended as a site for paracentesis because of its presumed avascularity.
We examined the subumbilical peritoneal surface in 20 consecutive patients with liver disease undergoing diagnostic laparoscopy. This area was visualized by table tilting and confirmed by external finger compression. Nineteen patients had cirrhosis of various etiologies, and one had advanced fibrosis with evidence of portal hypertension.
In these 20 patients, only 7 had avascular midlines below the umbilicus. Seven had small but definite veins running along the path of the urachus (median umbilical fold), and 6 had more prominent veins in this region. The internal landmarks in this region (median and medial folds) were frequently asymmetric with regard to the external appearance of the midline.
The subumbilical midline in patients with portal hypertension is commonly vascular. When using this site for paracentesis, care should be exercised to identify venous structures with the narrow-gauge needle used to inject local anesthetic agent before placement of larger paracentesis needles.
