CASE REPORT Perforated peptic ulcer imaged directly by computed tomography Abstract Perforation occu rs in 10% of patients with peptic ulcer. Computed tomography (CT) may show free intraperitoneal gas and/or extravasation of oral contrast. While the location of the free gas or contrast may suggest the site of perforation, the perforation itself is difficult to demonstrate. We present a case of perforated ulcer in which the perforation was imaged directly byCT. WK Loftus FRACR *,' LTC Chow FRCPA#; C Metreweli FRCR • * Dept. of Diagnostic Radiology and Organ Imaging, # Dept. of Pathology, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, N. T. Hong Kong 31 SA JOURNAL OF RADIOLOGY· June 1997 Introduction Perforation is said to occur in 5-10% of the overall population who have peptic ulcer (PU).I Recurrent ulcera- tion following surgery for PU is well recognized and in 95% is secondary to surgery for duodenal rather than gas- tric ulcer. Itis seen in about 3% of cases. Recurrent ulceration usually occurs following a gastrojejunal anastomosis but can develop even after vagotomy alone. Typically, however, th se ulcers develop at an anastomotic site and per- foration of these recurrent ulcers oc- curs in about 10%.2 While CT has no role in uncomplicated PU, it is useful in detecting perforation or penetration. The principal CT signs of perforation are extraluminal gas or, when adminis- tered, extravasated oral contrast. The location of a focal gas or contrast col- lection indicates a perforation in that area although the actual perforation itself is unlikely to be seen,' even when contrast is used.' The direct demonstra- tion of an actual perforation does not seem to have been previously reported. We present a case in which the perfo- ration was imaged by CT. Case report A 79 year old man presented with sudden onset of severe abdominal pain for 12 hours. Relevant past medical his- tory included a Billroth type II gastrec- tomy for PU more than 10 years be- fore. Clinically the patient had an acute abdomen. There was an elevated serum amylase and the clinical differential diagnosis was between pancreatitis and a perforated peptic ulcer. Plain films were unremarkable and did not reveal free gas. US showed free fluid in the abdomen consistent with either diag- nosis.The gallbladder was norma] with no gallstones but as the pancreas could topagB32 PerforZlled peptic ulcer irn<lged directly by oornpr.nc-d tOlllography frompage31 not be visualised, due to bowel gas,the patient was referred for CT. This dem- onstrated intraperitoneal free gas and fluid (Figure 1). There was a focal Figure 1: Axial CT image shows free intraperitoneal gas anteriorly and in the porta and extensive free fluid. Note the nasogastric tube in the stomach remnant. defect in the posterior wall of the gas- tric remnant consistent with a perfo- rated PU (Figures 2 and 3). The patient refused surgery and died within 24 hours. Post mortem confirmed the Figure 2: More caudal image directly imaging the perforation (arrow) and showing an adjacent gas bubble. Figure 3: Enlargement of Fig. 2 demonstrating the perforation more clearly. presence of a perforated peptic ulcer measuring 15 x 20 mm (mean 17.5 mm) on the posterior stomach wall at the site of the gastrojejunostomy (Fig- ure 4) as well as extensive peritonitis. Discussion There are several reports on the CT findings in perforated Pu. These find- ings are of extraluminal gas and/or extraluminal oral contrast. In a retro- spective study involving 35 patients with PU, two had perforation demon- strated on CT although the actual per- foration itself could not be identified.' Similarly, in a report of three cases of perforated PU, the site of perforation, i.e. gastric or duodenal, could be iden- tified by the location of extraluminal gas or oral contrast, but not the actual perforation itself" However, Fultz et al could identify a discontinuity of the bowel wall at the site of perforation in three of nine patients with perforation due to continuity of intra- and extraluminal oral contrast through the defect.' In our case the actual perfora- tion itself was clearly seen even with- out the use of oral contrast. It is not clear why, given the incidence of per- foration in PU, direct visualization of the defect does not appear to have been reported before. This perforation was no larger than normal; its size (17.5 mm) was the same as the mean diam- eter (17.6 mm) reported in a series of 80 cases of perforated pu.s Allowing for the role of non-op- erative management of a sealed-off perforated PU, the presence of free gas or extravasated oral contrast in the ap- propriate clinical setting indicates the need for operative intervention to re- pair the perforated viscus. Actual visu- alisation of the perforation itself as in this case, however, unequivocally con- firms the need for urgent surgery. In 32 SA JOURNAL OF RADIOLOGY· June 1997 Figure 4: Fixed, post mortem specimen of the opened gastrojejunostomy seen from the front. The large perforated anastamotic ulcer is clearly demonstrated. addition the knowledge of the exact site of the perforation will enable the sur- geon to locate and repair it as quickly as possible. We feel that this case also sug- gests that in patients with an acute ab- domen of uncertain cause, where perfo- rated PU is suspected, there may be a role for helical scanning with reconstruc- tions in the sagittal and coronal planes. This should increase the likelihood of di- rectly demonstrating these often sizeable defects. References I. Jacobs JM, Hill MC, Steinberg WM. Peptic Ulcer Disease: CT Evaluation. Radiology 1991; 178:7 45-748 2. Nyhus LM, Sheaff CM. Recurrent Ulcer. In: Wasteil C, ed. Surgery of the esophagus, stomach and small intestine 5th ed. Boston: Little Brown, 1995:531-540 3. Fultz PJ, Skucas J, Weiss SLo CT in Upper Gastrointestinal Tract Perforations Secondary to Peptic Ulcer Disease. Gastrointest Radiol 1992; 17:5- 8 4. Jeffrey RB, Federle MP, Wall S. Value of Computed Tomography in Detecting Occult Gastrointestinal Perforation. J ComputAssistTomog 1983; 7 (5): 825- 827. 5. Horowitz 1, Kukora IS, Ritchie WP. All Perforated Ulcers are not alike. 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