Portomesenteric venous gas: is gas distribution linked to etiology and outcome?
OBJECTIVE
To investigate various anatomical locations of portomesenteric venous gas detected by computed tomography (CT) and their relationship with the underlying etiology and the outcome.


METHODS
The study group consisted of 47 cases with evidence of portomesenteric venous gas detected on abdominal CT examinations, 12 cases were identified through a retrospective PACS search, 35 were prospectively included. The presence of gas at specific anatomical locations in the portomesenteric venous vasculature was assessed according to a pre-defined classification: the arcade vessels close to the bowel segments followed by segmental vessels, the superior mesenteric vein, the extra- and intrahepatic portal vein. The etiology of portomesenteric venous gas and its prognosis were assessed by review of surgical reports, histopathology and medical records. Surgery was performed on 30 patients.


RESULTS
Overall 68.1% of cases were of ischemic etiology. Gas present in the arcade vessels was the best indicator for ischemia (sensitivity 93.8%; specificity 70.0%, positive predictive value 90.9%, negative predictive value 77.8%) compared to other locations and the mere presence of portomesenteric gas independent from the location. The overall mortality rate was 53.2%. Only gas in the arcade and segmental vessels were associated with considerably higher mortality rates (65.8% and 75.0%, respectively) and acceptable frequency (occurrence in 80.9% and 59.6%, respectively).


CONCLUSIONS
The study results indicate that the presence of gas at specific anatomical locations in the portomesenteric venous system, namely the arcade and segmental vessels, may serve as strong indicator for ischemic etiology and poor prognosis in the assessment of individual cases.
Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany. tobias.heye@web.de
Tobias
T
Heye
Michael
M
Bernhard
Arianeb
A
Mehrabi
Hans-Ulrich
HU
Kauczor
Waldemar
W
Hosch
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004618:Embolism, Air / Q000150:complications* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007422:Intestines / Q000098:blood supply* / Q000000981:diagnostic imaging; D007511:Ischemia / Q000000981:diagnostic imaging / Q000209:etiology*; D008297:Male; D008642:Mesenteric Veins / Q000000981:diagnostic imaging*; D008875:Middle Aged; D011169:Portal Vein / Q000000981:diagnostic imaging*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed