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Case report: the ultrasound diagnosis of enterocutaneous fistula
ClinicalRadiology (1992) 45, 349 350
Case Report: The Ultrasound Diagnosis of Enterocutaneous Fistula C. S. T W E E D and R. J. P E C K
Department of Radiology, Royal Hallamshire Hospital, Sheffield The sonographic diagnosis of post-operative enterocutaneous fistula is presented. This has not previously been reported in the English literature. Tweed, C.S. & Peck, R.J. (1992). Clinical
Radiology 45, 349-350. Case Report: T h e U l t r a s o u n d Diagnosis of E n t e r o c u t a n e o u s F i s t u l a
Investigation o f fistulae n o r m a l l y requires the injection of contrast via catheters i n t r o d u c e d into the leakage site. This is frequently a t i m e - c o n s u m i n g , a w k w a r d a n d occasionally 'messy' procedure. We report the case o f an e n t e r o c u t a n e o u s fistula which was diagnosed by ultrasound (US), a n d discuss the merits of s o n o g r a p h y in the investigation of a b d o m i n a l sepsis.
CASE R E P O R T A 48-year-old woman was referred for an abdominal US scan because of abnormal liver function tests and a suspected simple wound abscess. Six months previously she had had surgery to fashion an ileoanal pouch before closingan ileostomy,which had been made after total colectomy for ulcerative colitis. Her post-operative course was rather stormy, with the development of two wound abscesses. She eventually settled and was sent home. On review in out-patients she was found to have slightly abnormal liver function tests and a discharge had developed from the anterior abdominal wound. US was carried out, first of the liver and upper abdomen, where no abnormality was seen, and then using a 7.5 MHz transducer of the area of the wound abnormality. The latter showed a hypoechoic track from the site of the discharge, through the anterior abdominal wall, to a loop of small bowel closely abutting the track (Fig. 1). A presumptive diagnosis of enterocutaneous fistula was made, which was subsequently confirmed by a fistulogram (Fig. 2).
(a)
DISCUSSION E n t e r o c u t a n e o u s fistulae usually occur as a complication of complex a l i m e n t a r y tract surgery, b u t m a y also arise s p o n t a n e o u s l y in patients with i n f l a m m a t o r y bowel disease, after t r a u m a or r a d i a t i o n therapy ( M c L e a n et al., 1982). The diagnosis of a fistula is i m p o r t a n t as it m a y clarify the origin of a recurrent abscess, a p r o b l e m frequently e n c o u n t e r e d in s i n o g r a p h y being that o f the i n t e r m i t t e n t healing abscess which has usually closed over w h e n the p a t i e n t presents to the X - r a y D e p a r t m e n t . Disadvantages of s i n o g r a p h y include the r e q u i r e m e n t for large a m o u n t s of c o n t r a s t when d e m o n s t r a t i n g enteric fistulae, a n d a high r a d i a t i o n dose to the p a t i e n t a n d the examiner's fingers, particularly with repeated examinations. M a n y patients with fistulae secondary to inflamm a t o r y bowel disease are y o u n g a n d attempts to reduce the r a d i a t i o n dose are i m p o r t a n t considerations. O n s o n o g r a p h y a fistula can be hypoechoic if entirely fluid filled, as in this case, or it m a y be echogenic due to a high c o n t r a s t of tiny gas b u b b l e s a n d therefore difficult to differentiate from adjacent g a s - c o n t a i n i n g bowel. CornCorrespondence to: Dr C. S. Tweed, Department of Radiology, Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF.
(b) Fig. 1 - (a) Transverse ultrasound scan and (b) longitudinal ultrasound scan, both showing the fistula as a hypoechoic tract (open arrow) leading from the skin (arrowhead) through the muscles of the anterior abdominal wall (m) to connect with the bowel (arrow) which was seen to peristalse on the real-time scan.
350
CLINICAL RADIOLOGY
pression of bowel may also squeeze air bubbles or faeces through the fistula tract, improving visualization (Chen et al., 1990). US is well recognized in the investigation of abdominopelvic abscesses (Gooding et al., 1989). Joseph and MacVicar (1990) recommend US as the primary radiological investigation when an abdominal abscess is suspected, suggesting a sensitivity in excess of 90%. US also has a well established role in investigating bowel disease (Sonnenburg et al., 1983; Price and Metreweli, 1988; Gholkar and Khan, 1989). Jenss et al. (1980)
describe the ultrasound demonstration of enteroenteric fistulae, two enteroenteric, one enterocutaneous, in three women with Crohn's disease with appearances similar to these described here. An advantage of US as the primary investigation in enterocutaneous fistulae is the ability to image underlying bowel abnormalities and detect any associated abscesses. Sonography is, however, 'operator dependent' and the importance of a careful examination with removal of dressings is discussed by Joseph and MacVicar (1990). The sonographic detection of fistulae has been difficult until recently but has improved due to high resolution equipment and real time scanning that allow one to identify the layers of the abdominal wall and visualize peristalsis. US has a major contribution to play in the evaluation of abdominal abscesses and bowel disease. We suggest it can also be useful in the investigation of enteric fistulae.
REFERENCES
Fig. 2 - Fistulogram confirming that the fistula communicated with the small bowel.
Chen, SS, Chou, YH, Tiu, CM & Chang, T (1990). Sonographic features of colovesical fistula. Journal of Clinical Ultrasound, 18, 589 591. Gholkar, J & Khan, AN (1989). Sonography of adult bowel disorders. Radiology Now, 6, 53 55. Gooding, GAW, Filly, RA & Laing, FC (1989). Ultrasonography of the alimentary tube. In Alimentary Tract Radiology, 4th edn. Eds. Margulis, AR & Burhenne, HJ. p. 203. CV Mosby Co., St Louis. Jenss, H, Klott, KJ & Malchow, H (1980). Sonografie: Darstellung von Fisteln und Abszessen beim Morbus Crohn. Lieber Magen Darm, 10, 317-320. Joseph, AEA & MacVicar, D (1990). Ultrasound in the diagnosis of abdominal abscesses. Clinical Radiology, 42, 154-156. McLean, GK, Mackie, JA, Freiman, DB & Ring, EJ (1982). Enterocutaneous fistulae: interventional radiologic management. American Journal of Roentgenology, 138, 615 619. Price, J & Metreweli, C (1988). Ultrasonographic diagnosis of clinically non-palpable primary colonic neoplasms. British Journal of Radiology, 61, 190 195. Sonnenburg, A, Erdenbrecht, J, Petter, P & Niederau, C (1983). Detection of Crohn's disease by ultrasound. Gastroenterology, 83, 434-440.
Case Report: The Ultrasound Diagnosis of Enterocutaneous Fistula C. S. T W E E D and R. J. P E C K
Department of Radiology, Royal Hallamshire Hospital, Sheffield The sonographic diagnosis of post-operative enterocutaneous fistula is presented. This has not previously been reported in the English literature. Tweed, C.S. & Peck, R.J. (1992). Clinical
Radiology 45, 349-350. Case Report: T h e U l t r a s o u n d Diagnosis of E n t e r o c u t a n e o u s F i s t u l a
Investigation o f fistulae n o r m a l l y requires the injection of contrast via catheters i n t r o d u c e d into the leakage site. This is frequently a t i m e - c o n s u m i n g , a w k w a r d a n d occasionally 'messy' procedure. We report the case o f an e n t e r o c u t a n e o u s fistula which was diagnosed by ultrasound (US), a n d discuss the merits of s o n o g r a p h y in the investigation of a b d o m i n a l sepsis.
CASE R E P O R T A 48-year-old woman was referred for an abdominal US scan because of abnormal liver function tests and a suspected simple wound abscess. Six months previously she had had surgery to fashion an ileoanal pouch before closingan ileostomy,which had been made after total colectomy for ulcerative colitis. Her post-operative course was rather stormy, with the development of two wound abscesses. She eventually settled and was sent home. On review in out-patients she was found to have slightly abnormal liver function tests and a discharge had developed from the anterior abdominal wound. US was carried out, first of the liver and upper abdomen, where no abnormality was seen, and then using a 7.5 MHz transducer of the area of the wound abnormality. The latter showed a hypoechoic track from the site of the discharge, through the anterior abdominal wall, to a loop of small bowel closely abutting the track (Fig. 1). A presumptive diagnosis of enterocutaneous fistula was made, which was subsequently confirmed by a fistulogram (Fig. 2).
(a)
DISCUSSION E n t e r o c u t a n e o u s fistulae usually occur as a complication of complex a l i m e n t a r y tract surgery, b u t m a y also arise s p o n t a n e o u s l y in patients with i n f l a m m a t o r y bowel disease, after t r a u m a or r a d i a t i o n therapy ( M c L e a n et al., 1982). The diagnosis of a fistula is i m p o r t a n t as it m a y clarify the origin of a recurrent abscess, a p r o b l e m frequently e n c o u n t e r e d in s i n o g r a p h y being that o f the i n t e r m i t t e n t healing abscess which has usually closed over w h e n the p a t i e n t presents to the X - r a y D e p a r t m e n t . Disadvantages of s i n o g r a p h y include the r e q u i r e m e n t for large a m o u n t s of c o n t r a s t when d e m o n s t r a t i n g enteric fistulae, a n d a high r a d i a t i o n dose to the p a t i e n t a n d the examiner's fingers, particularly with repeated examinations. M a n y patients with fistulae secondary to inflamm a t o r y bowel disease are y o u n g a n d attempts to reduce the r a d i a t i o n dose are i m p o r t a n t considerations. O n s o n o g r a p h y a fistula can be hypoechoic if entirely fluid filled, as in this case, or it m a y be echogenic due to a high c o n t r a s t of tiny gas b u b b l e s a n d therefore difficult to differentiate from adjacent g a s - c o n t a i n i n g bowel. CornCorrespondence to: Dr C. S. Tweed, Department of Radiology, Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF.
(b) Fig. 1 - (a) Transverse ultrasound scan and (b) longitudinal ultrasound scan, both showing the fistula as a hypoechoic tract (open arrow) leading from the skin (arrowhead) through the muscles of the anterior abdominal wall (m) to connect with the bowel (arrow) which was seen to peristalse on the real-time scan.
350
CLINICAL RADIOLOGY
pression of bowel may also squeeze air bubbles or faeces through the fistula tract, improving visualization (Chen et al., 1990). US is well recognized in the investigation of abdominopelvic abscesses (Gooding et al., 1989). Joseph and MacVicar (1990) recommend US as the primary radiological investigation when an abdominal abscess is suspected, suggesting a sensitivity in excess of 90%. US also has a well established role in investigating bowel disease (Sonnenburg et al., 1983; Price and Metreweli, 1988; Gholkar and Khan, 1989). Jenss et al. (1980)
describe the ultrasound demonstration of enteroenteric fistulae, two enteroenteric, one enterocutaneous, in three women with Crohn's disease with appearances similar to these described here. An advantage of US as the primary investigation in enterocutaneous fistulae is the ability to image underlying bowel abnormalities and detect any associated abscesses. Sonography is, however, 'operator dependent' and the importance of a careful examination with removal of dressings is discussed by Joseph and MacVicar (1990). The sonographic detection of fistulae has been difficult until recently but has improved due to high resolution equipment and real time scanning that allow one to identify the layers of the abdominal wall and visualize peristalsis. US has a major contribution to play in the evaluation of abdominal abscesses and bowel disease. We suggest it can also be useful in the investigation of enteric fistulae.
REFERENCES
Fig. 2 - Fistulogram confirming that the fistula communicated with the small bowel.
Chen, SS, Chou, YH, Tiu, CM & Chang, T (1990). Sonographic features of colovesical fistula. Journal of Clinical Ultrasound, 18, 589 591. Gholkar, J & Khan, AN (1989). Sonography of adult bowel disorders. Radiology Now, 6, 53 55. Gooding, GAW, Filly, RA & Laing, FC (1989). Ultrasonography of the alimentary tube. In Alimentary Tract Radiology, 4th edn. Eds. Margulis, AR & Burhenne, HJ. p. 203. CV Mosby Co., St Louis. Jenss, H, Klott, KJ & Malchow, H (1980). Sonografie: Darstellung von Fisteln und Abszessen beim Morbus Crohn. Lieber Magen Darm, 10, 317-320. Joseph, AEA & MacVicar, D (1990). Ultrasound in the diagnosis of abdominal abscesses. Clinical Radiology, 42, 154-156. McLean, GK, Mackie, JA, Freiman, DB & Ring, EJ (1982). Enterocutaneous fistulae: interventional radiologic management. American Journal of Roentgenology, 138, 615 619. Price, J & Metreweli, C (1988). Ultrasonographic diagnosis of clinically non-palpable primary colonic neoplasms. British Journal of Radiology, 61, 190 195. Sonnenburg, A, Erdenbrecht, J, Petter, P & Niederau, C (1983). Detection of Crohn's disease by ultrasound. Gastroenterology, 83, 434-440.