HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Emby, D. J. Articles by Aoun, G. Search for Related Content PubMed PubMed Citation Articles by Emby, D. J. Articles by Aoun, G. Social Bookmarking                      What's this?

CT Technique for Suspected Anterior Abdominal Wall Hernia

¹ Department of Radiology, Western Deep Levels Hospital, P. O. Box 8425, Western Levels 2501, South Africa.
² Department of Surgery, Western Deep Levels Hospital, Western Levels 2501, South Africa.

Received October 7, 2002; accepted after revision February 19, 2003.

 
Address correspondence to D. J. Emby.

Introduction

Top Introduction Method Results Discussion References

 
Anterior abdominal wall hernias often reduce spontaneously when the patient lies supine. In the clinical setting, patients with a suspected hernia are routinely examined in the erect position to facilitate hernia detection. Ideally, patients with suspected anterior abdominal wall hernias would also be imaged while erect. As a substitute for examination in the erect position, we perform CT examinations in the left or right lateral decubitus position, while increasing intraabdominal pressure, by having patients perform a Valsalva's maneuver. In our high-technology environment there is sometimes a tendency to overlook the more elementary approaches, and the value of this combination of maneuvers is perhaps not widely appreciated.

Method

Top Introduction Method Results Discussion References

 
A fast helical sequence from the diaphragm to the pubic symphysis is taken in full inspiration, during a single breath-hold, with the patient supine. All examinations are performed on a conventional single-detector helical scanner (Somatom Plus 4, Siemens Medical Systems, Erlangen, Germany) with a gantry rotation time of 0.75 sec. Eight-millimeter collimation and a pitch of 1.5 are adequate.

The symptomatic area is determined by a brief clinical examination of the abdomen before repositioning the patient. Herniation is most often confined to the upper abdomen, lower abdomen, or umbilical region. If a visible bulge is present, the upper and lower margins of the bulge are marked with small metallic skin markers. The patient is then turned to the lateral position, with the symptomatic side of the abdomen facing down. Either the left- or right-side-down position is suitable for suspected midline lesions. The patient is instructed in the Valsalva technique and allowed to practice. A fast helical sequence is then taken through the symptomatic area with the patient straining (performing maximum Valsalva's maneuver).

It is seldom necessary to rescan the entire abdomen. This sequence is taken with 5-mm collimation and with a pitch of 1.5.

Oral contrast material can be given to opacify the bowel before scanning, but good results have also been obtained without oral contrast material. IV contrast material is not routinely given but may be administered if other, unsuspected abnormalities are detected.

Results

Top Introduction Method Results Discussion References

 
Two representative patients show the results obtained with the technique. The first, a moderately obese 65-year-old woman, presented with left iliac fossa pain. No abnormality was found at abdominal palpation. The initial (conventional) abdominal helical sequence with the patient supine showed a lower anterior abdominal wall that was thin but with no clear visible defect (Fig. 1A). The patient was then turned onto her left side, and the lower abdomen was rescanned during a maximum Valsalva's maneuver. This sequence revealed extensive herniation of bowel through the anterior abdominal wall in the left iliac fossa region (Fig. 1B).

View larger version (149K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 1A. —65-year-old woman who presented with left iliac fossa pain. CT scan taken with patient supine shows thin anterior abdominal wall (arrows) but no clear defect.

View larger version (135K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 1B. —65-year-old woman who presented with left iliac fossa pain. CT scan taken during maximum Valsalva's maneuver with patient lying on left side shows extensive herniation of bowel through anterior abdominal wall (arrows) in left iliac fossa region.

The second patient, also moderately obese, was a 73-year-old man who presented with central abdominal pain. No abdominal hernia was clinically palpable. The conventional, supine abdominal helical sequence showed a small (approximately 12-mm) defect in the upper anterior abdominal wall, containing a small amount of intraperitoneal fat (not shown). Approximately 3 cm distal to this was a second apparent defect, approximately 5 cm wide (Fig. 2A). A repeated helical sequence was then taken through the mid and upper abdomen with the patient performing a maximum Valsalva's maneuver while lying on his left side. This scan showed herniation of a small loop of bowel into the small defect (Fig. 2B). The site of the initially suspected larger defect showed only thinning of the abdominal wall but no herniation.

View larger version (151K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2A. —73-year-old man who presented with central abdominal pain. CT scan with patient supine shows possible defect approximately 5 cm wide (arrows) in upper anterior abdominal wall. Approximately 3 cm proximal to this, smaller definite defect containing intraperitoneal fat was also found (not shown).

View larger version (157K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2B. —73-year-old man who presented with central abdominal pain. CT scan taken during maximum Valsalva's maneuver with patient lying on left side shows herniation of small loop of bowel into smaller, more proximal defect (arrow) in upper anterior abdominal wall. No herniation was found at site of suspected larger defect seen in A.

Discussion

Top Introduction Method Results Discussion References

 
A number of excellent articles have reviewed cross-sectional imaging of abdominal wall hernias [1–4]. Although some authors have stressed the importance of performing a Valsalva's maneuver during the examination [5], others give this only a cursory mention, and at least two of the reviews do not mention it at all.

The technique of peritoneography has been found to be of value for detecting occult inguinal hernias [6] but is more invasive and more time-consuming than helical CT.

Abdominal wall defects may not be visible on supine CT scans. Stressing the anterior abdominal wall in the manner described, however, can not only facilitate the visualization of occult defects but can also confirm herniation through the defect. In addition, herniation through suspicious areas of abdominal wall thinning that are not true defects can be excluded.

The technique is of particular value in obese patients in whom clinical assessment is difficult, and in patients with atypical or unexplained abdominal pain in whom other investigations have had negative findings. It can also be performed as the first component of a more detailed CT examination of the abdomen; the decision to proceed to more detailed sequences can be made if the assessment for anterior abdominal wall hernia has negative findings.

Using this technique, we have identified a number of symptomatic but clinically occult abdominal wall hernias that might otherwise have been missed.

References

Top Introduction Method Results Discussion References

 

1. Toms AP, Dixon AK, Murphy JMP, Jamieson NV. Illustrated review of new imaging techniques in the diagnosis of abdominal wall hernias. Br J Surg 1999;86:1243 –1250[Medline]
2. Zarvan NP, Lee FT Jr, Yandow Dr, Unger JS. Abdominal hernias: CT findings. AJR1995; 164:1391 –1395[Abstract/Free Full Text]
3. Wechsler RJ, Kurtz AB, Needleman L, et al. Cross-sectional imaging of abdominal wall hernias. AJR1989; 153:517 –521[Free Full Text]
4. Donnelly LF, Frush DP. Cross-sectional imaging of abnormalities of the abdominal wall in pediatric patients. AJR2001; 176:1233 –1239[Free Full Text]
5. Hojer A-M, Rygaard H, Jess P. CT in the diagnosis of abdominal wall hernias: a preliminary study. Eur Radiol1997; 7:1416 –1418[Medline]
6. Heise CP, Sproat IA, Starling JR. Peritoneography (herniography) for detecting occult inguinal hernia in patients with inguinodynia. Ann Surg 2002;235 : 140–144[Medline]

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				S Upponi and H Bungay Imaging of abdominal wall hernias Imaging, December 1, 2006; 18(4): 268 - 277. [Abstract] [Full Text] [PDF]

				D. A. Aguirre, A. C. Santosa, G. Casola, and C. B. Sirlin Abdominal Wall Hernias: Imaging Features, Complications, and Diagnostic Pitfalls at Multi-Detector Row CT RadioGraphics, November 1, 2005; 25(6): 1501 - 1520. [Abstract] [Full Text] [PDF]

				D. J. Emby, G. Aoun, and T. Jaffe Valsalva's Maneuver in Abdominal Wall Hernia Imaging Am. J. Roentgenol., October 1, 2005; 185(4): 1081 - 1082. [Full Text] [PDF]

				T. A. Jaffe, M. J. O'Connell, J. P. Harris, E. K. Paulson, and D. M. DeLong MDCT of Abdominal Wall Hernias: Is There a Role for Valsalva's Maneuver? Am. J. Roentgenol., March 1, 2005; 184(3): 847 - 851. [Abstract] [Full Text] [PDF]

				D. A. Aguirre, G. Casola, and C. Sirlin Abdominal Wall Hernias: MDCT Findings Am. J. Roentgenol., September 1, 2004; 183(3): 681 - 690. [Full Text] [PDF]

This Article Figures Only Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Emby, D. J. Articles by Aoun, G. Search for Related Content PubMed PubMed Citation Articles by Emby, D. J. Articles by Aoun, G. Social Bookmarking                      What's this?