A portacaval anastomosis or portocaval anastomosis is a specific type of circulatory anastomosis that occurs between the veins of the portal circulation and the vena cava, thus forming one of the principal types of portasystemic anastomosis or portosystemic anastomosis, as it connects the portal circulation to the systemic circulation, providing an alternative pathway for the blood. When there is a blockage of the portal system, portocaval anastomosis enables the blood to still reach the systemic venous circulation. The inferior end of the esophagus and the superior part of the rectum are potential sites of a harmful portocaval anastomosis.[1]
In portal hypertension, as in the case of cirrhosis of the liver, the anastomoses become congested and form venous dilatations. Such dilatation can lead to esophageal varices and anorectal varices. Caput medusae can also result.[2]
A portacaval shunt is analogous in that it diverts circulation; as with shunts and anastomoses generally, the terms are often used to refer to either the naturally occurring forms or the surgically created forms.
Presentation
Clinical presentations of portal hypertension include:
| Region | Name of clinical condition | Portal circulation | Systemic circulation |
|---|---|---|---|
| Esophageal | Esophageal varices | Esophageal branch of left gastric vein | Esophageal branches of azygos vein |
| Rectal | Rectal varices | Superior rectal vein | Middle rectal veins and inferior rectal veins |
| Paraumbilical | Caput medusae | Paraumbilical veins | Superficial epigastric vein |
| Retroperitoneal | Splenorenal shunt[3] | Splenic vein | Nierenvene , Nebennierenvene , paravertebrale Vene und Gonadenvene |
| (keine klinische Bezeichnung) [ 4 ] | Rechte Kolonvene , mittlere Kolonvene , linke Kolonvene | Retroperitoneale Venen von Retzius | |
| Intrahepatisch | Leberpseudoläsionen [ 5 ] | Perihepatische Venen von Sappey | Obere epigastrische Vene |
| Offener Ductus venosus | Linker Ast der Pfortader | Untere Hohlvene |
Eine erweiterte untere Mesenterialvene kann, muss aber nicht, mit einer portalen Hypertension zusammenhängen. Weitere Anastomosenstellen sind die Leberarterie (Area nuda) an der Verbindung zum Zwerchfell , der hintere Abschnitt des Gastrointestinaltrakts an der hinteren Bauchwand und der untere Teil der Speiseröhre.
Referenzen
- ^ Sato, Takahiro; Akaike, Jun; Toyota, Jouji; Karino, Yoshiyasu; Ohmura, Takumi (2011). „Klinisch- pathologische Merkmale und Behandlung ektopischer Varizen mit portaler Hypertension“ . International Journal of Hepatology . 2011 960720. doi : 10.4061/2011/960720 . PMC 3170857. PMID 21994879 .
- ^ Gray’s Anatomy for Students Gray H, Drake R, Vogl W, Mitchell A, Tibbitts R, Richardson P. Philadelphia: Elsevier/Churchill Livingstone; 2010. S. 226
- ^ D'Souza, Donna. „Portal-systemische Kollateralwege | Radiologie-Referenzartikel | Radiopaedia.org“ . radiopaedia.org . Abgerufen am 12.08.2016 .
- ^ „Surgicomania: Portale Hypertension“ . surgicomania.blogspot.co.uk . 23.11.2009 . Abgerufen am 12.08.2016 .
- ^ Khader.O.Thabet, Mohammed Al (24. Dezember 2014). „Hepatische Pseudoläsion in der Nähe des Ligamentum falciforme | Radiologisches Referenzprodukt | Radiopaedia.org“ . radiopaedia.org . Abgerufen am 12. August 2016 .
