OBJECTIVE: Our objective was to evaluate the role of Valsalvas maneuver during MDCT for the diagnosis and characterization of abdominal wall hernias.
SUBJECTS AND METHODS: From September 2002 to May 2003, 100 consecutive patients (37 men and 63 women; mean age, 53 years) with suspected anterior abdominal wall hernias underwent 4-, 8-, or 16-MDCT with and without Valsalvas maneuver. Patients received both oral and IV contrast material. On a workstation, three independent reviewers evaluated each scan obtained during rest and during Valsalvas maneuver for the following parameters: anteroposterior (AP) diameter of the abdomen; presence, location, and contents of the hernia; and transverse diameter of the fascial defect. The scans were compared to assess for changes in hernia size and contents and to determine whether the hernia would have been overlooked without Valsalvas maneuver. Fishers exact test, the McNemar test, and Cohens kappa coefficient were used to assess for significant differences.
RESULTS: The three reviewers identified a mean of 72 abdominal wall hernias (72%). The reviewers agreed (k = 0.723) with respect to the presence of a hernia. AP diameters increased an average of 1.33 cm during Valsalvas maneuver (p < 0.001). The transverse diameter of the fascial defect increased an average of 0.66 cm and the AP diameter of the hernia sac increased an average of 0.79 cm during Valsalvas maneuver (p < 0.001). Fifty percent of the hernias became more apparent with Valsalvas maneuver. Ten percent of the hernias could be detected only on the scan obtained during Valsalvas maneuver. Conversely, in no patients was the hernia detected only on the rest scan,
CONCLUSION: As opposed to scans obtained at rest, scans obtained during Valsalvas maneuver aid in the detection and characterization of suspected abdominal wall hernias. A single scan obtained during Valsalvas maneuver is sufficient to detect 100% of anterior abdominal wall hernias identified on CT.