GRAY, H. H., MORGAN, J. M., PANETH, M. & MILLER, G. A.. H., 1988. Pulmonary embolectomy for acute massive pulmonary embolism: an analysis of 71 cases.
1989, The British Journal of Radiology, 62, 753-755 Case reports
massive, pulmonary embolism that the case for the urgent use of thrombolytic agents is powerful. We feel that in any hospital with two-dimensional echocardiography available, this should be carried out urgently prior to pulmonary angiography in suspected cases of major pulmonary embolism. This can speed the diagnosis and may eliminate the need for angiography. References ALDERSON, P. O. & MARTIN, E. C , 1987. Pulmonary embolism:
diagnosis with multiple imaging modalities. Radiology, 164, 297-312. FARFEL, Z., SHECHTER, M., VERED, Z., RATH, S., GOOR, D. &
right heart entrapment of pulmonary emboli-in-transit with emphasis on management. American Heart Journal, 113, 171-178. GRAY, H. H., MORGAN, J. M., PANETH, M. & MILLER, G. A.
H., 1988. Pulmonary embolectomy for acute massive pulmonary embolism: an analysis of 71 cases. British Heart Journal, 60, 196-200. KASPER, W., MEINERTZ, T., HENKEL, B., EISSNER, D., HAHN, K., HOFMANN, T., ZEIHER, A. & JUST, H., 1986.
Echocardiographic findings in patients with proved pulmonary embolism. American Heart Journal, 112, 1284— 1290. WINDEBANK, W. J., 1987. Diagnosing pulmonary thromboembolism. British Medical Journal, 294, 1369-1370.
GAFNI, J., 1987. Review of echocardiographically diagnosed
Aneurysm of the inferior pancreaticoduodenal artery diagnosed by real-time ultrasound and pulsed Doppler By *Paul Grech, BSc, MRCP, Peter Rowlands, BMedSci, MRCP and Mary Crofton, MRCP, FRCR Department of Radiology, St Mary's Hospital, Praed Street, London W2 1 NY {Received July 1988 and in revised form September 1988)
Aneurysms of the superior mesenteric artery are rare, being noted in only 1 of 12 000 autopsies (Lucke & Rae, 1921). Aneurysms of branch arteries are even less common. Presentation is most commonly at the time of rupture, which often results in catastrophic and usually fatal haemorrhage. The incidental finding of such aneurysms and their recognition thus assumes an importance out of proportion to their frequency. A case is presented in which an incidental finding of an asymptomatic aneurysm of the inferior pancreaticoduodenal artery was made by ultrasound and pulsed Doppler. The diagnosis and exact anatomy was confirmed by angiography. Case report A 50-year-old woman presented to a gynaecologist complaining of vaginal bleeding and was referred for ultrasound examination of the pelvis. The patient was a normotensive non-smoker and, on direct questioning, revealed no symptoms referable to the gastrointestinal tract or upper abdomen. The ultrasound examination revealed a 23 mm diameter sonolucent mass in the upper abdomen immediately anterior to the aorta (Fig. 1). The mass was pulsatile and lay posteromedial to the superior mesenteric artery but appeared to communicate with it. Pulsed Doppler revealed pulsatile but turbulent arterial flow within the mass and reliably excluded pancreatic or mesenteric cyst (Fig. 2). A saccular aneurysm of the superior mesenteric artery was diagnosed and angiography was performed. *Author for correspondence. Vol. 62, No. 740
Angiography revealed a previously unsuspected stenosis of the coeliac axis (Fig. 3). The vessel distal to the stenosis was of normal calibre. The superior mesenteric artery was normal but there was aneurysmal dilatation of its first branch, the inferior pancreaticoduodenal artery, which provided a collateral blood supply to the post-stenotic coeliac axis (Fig. 4).
Discussion
Visceral aneurysms are usually asymptomatic until rapid enlargement or rupture occurs (Ugolotti et al,
Figure 1. Longitudinal scan showing an echolucent mass lying between the abdominal aorta posteriorly and the superior mesenteric artery anteriorly.
753
Case reports
Figure 2. Transverse scan just below the origin of the superior mesenteric artery showing a mass communicating with the artery's lumen. The Doppler tracing below, taken from the site of the cursor, shows turbulent pulsatile flow.
1984). Up to 80% of reported cases presented at the time of rupture (West et al, 1968). In a review of cases of pancreaticoduodenal artery aneurysm, 13 of the 23 patients died at or soon after the onset of presenting
Figure 4. Selective superior mesenteric arteriogram showing an aneurysm arising just distal to the origin of the enlarged inferior pancreaticoduodenal artery. Contrast medium enters the common hepatic artery (arrowhead) and splenic artery (arrow) via the aneurysm.
Figure 3. Lateral digital subtraction aortogram showing stenosis at the origin of the coeliac axis (arrow). The origin of the superior mesenteric artery is normal but a contrastmedium-filled aneurysm is seen overlying the artery more distally. 754
symptoms. Rupture is usually retroperitoneal or intraperitoneal rather than into the gastrointestinal tract (Verta et al, 1976). The prognosis of asymptomatic superior mesenteric branch aneurysms is unknown. Size does not appear to predict the risk of rupture and previous authors have suggested that elective resection should be undertaken (McNamara & Griska, 1980). The combination of arteriographic findings in our patient appears to be without precedent in the literature and a decision regarding future management is yet to be made. In general, aneurysms of branches of the superior mesenteric artery can be treated by resection without restoration of continuity. This is clearly not an option in this case as the majority of blood supply to the coeliac territory is derived from the superior mesenteric artery through the aneurysmal inferior pancreaticoduodenal artery. Resection of the aneurysm with restoration of continuity is possible but the consequences of surgical mishap would be severe in this asymptomatic patient. Surgical reconstruction of the coeliac stenosis with resection of the aneurysm is surgically more demanding but may reduce this risk. A possible option would be percutaneous balloon angioplasty of the coeliac stenosis The British Journal of Radiology, August 1989
1989, The British Journal of Radiology, 62, 755-758 Case reports
with resection of the aneurysm on a later occasion. Whether angioplasty of the stenosis alone would halt or cause regression of the aneurysm by reducing the flow through it is unknown. Mycotic aneurysms account for 60% of aneurysms of the visceral arteries. A further 25% are attributed to atherosclerosis. Trauma, polyarteritis nodosa, fibromuscular dysplasia, syphilis and pancreatitis account for the remainder (Ugolotti et al, 1984). In the case presented, there was no evidence of septic emboli or of arteriosclerotic disease elsewhere. The aneurysm may have arisen as a result of increased flow through the inferior pancreaticoduodenal artery caused by the coeliac axis stenosis. The cause of the stenosis is unclear. The patient has no risk factors for arteriosclerotic disease and there was no evidence of atheroma elsewhere on the arteriogram. There was no clinical evidence of arteritis. Encasement of vessels by tumour may result in a smooth constriction of similar appearance to this case but there is no evidence of local tumour in this patient. Chronic pancreatitis, too, may result in stricturing of adjacent vessels but again there was no evidence of such pathology. Fibromuscular hyperplasia has several histological variants with corresponding arteriographic appearances. An appearance similar to the case presented may occur in medial hyperplasia or the rarer intimal fibroplasia and periarterial fibroplasia (Abrams, 1983). Although there is no evidence of fibromuscular hyperplasia elsewhere, the authors consider this to be the most likely xause of the stenosis in this case. The ultrasonographic appearances of visceral artery aneurysm and its confirmation by pulsed Doppler should help to distinguish these masses from pancreatic or mesenteric cysts, which may initially appear similar. Confusion has arisen in the past when lack of visible
pulsation in a mass seen on real-time scanning has resulted in unnecessary delay of diagnosis or diagnostic puncture of a visceral artery aneurysm (Ugolotti et al, 1984; Mourad et al, 1987). It appears that the lack of visible pulsation does not reliably exclude an aneurysm in this situation. The diagnosis of visceral artery aneurysm should be considered on finding a nonpulsatile cystic mass on ultrasound and arterial blood flow excluded by Doppler if facilities are available. Acknowledgments We wish to thank Miss A. O. Mansfield, Consultant Surgeon, for permission to report this case. References ABRAMS, H. L., 1983. Renal arteriography in hypertension. In Abrams Angiography. Vascular and Interventional Radiology, 3rd edn, ed. by H. L. Abrams (Little, Brown and Company, Boston), pp. 1247-1297. LUCKE, B. & REA, M. H., 1921. Studies on aneurysm: general statistical data on aneurysm. Journal of the American Medical Association, 77, 935-940. MCNAMARA, M. F. & GRISKA, L. B., 1980. Superior mesenteric
branch aneurysms. Surgery, 88, 625-630. MOURAD, K., GUGGIANA, P. & MINASIAN, H., 1987. Superior
mesenteric artery aneurysm diagnosed by ultrasound. British Journal of Radiology, 60, 287-288. UGOLOTTI, U., MISELLI, A., MANDRIOLI, R., LARINI, P. & Ross,
A., 1984. Ultrasound diagnosis of superior mesenteric artery aneurysm: two case reports. Journal of Clinical Ultrasound, 12, 581-584. VERTA, M. J., DEAN, R. H., YAO, J. S. T., CONN, J., MEHN, W.
H. & BERGAN, J. J., 1977. Pancreaticoduodenal arterial aneurysms. Annals of Surgery, 186, 111-114. WEST,
J.
E.,
BERNHARDT,
H.
&
BOWERS,
R.
F.,
1968.
Aneurysms of the pancreaticoduodenal artery. American Journal of Surgery, 115, 835-839.
Atlanto-axial rotary fixation: diagnosis by functional computed tomography By J . G. Moss, FRCR, FRCS, R. J . Sellar, FRCR, MRCP and * B . Bradnock, FRCS Departments of Neuroradiology and *Paediatric Surgery, Western General Hospital, Crewe Road, Edinburgh EH4 2XU {Received January 1989)
The term atlanto-axial rotary fixation wasfirstcoined in 1968 (Wortzman & Dewar, 1968). It is an unusual condition, which refers to fixation of the atlas on the axis usually within the normal range of atlanto-axial rotation. The diagnosis can be difficult to make on plain radiography and many cases present late only to require open surgery (Fielding & Hawkins, 1977). Recently, Address correspondence to: J. G. Moss, Department of Radiology, Royal Infirmary, Lauriston Place, Edinburgh. Vol. 62, No. 740
functional computed tomography (CT) has been successfully used in a patient with atlanto-axial rotary fixation (Kowalski et al, 1987) and we discuss its value in our patient. Case report A 7-year-old girl presented with a painful torticollis of 3 weeks' duration following adenoidectomy and left myringotomy. She had a past history of neonatal Escherichia coli septicaemia and meningitis complicated by an intraventricular haemorrhage and subsequent arrested hydro-
755
