Iatrogenic iliac artery rupture

Clinical History

Catastrophic arterial rupture during angioplasty is not uncommon , usually requiring immediate surgical intervention. We describe three cases of iliac artery rupture one during routine angioplasty and two during iliac artery stenting. Two were successfully treated with a covered stent obviating surgery and one resulted in death as a covered stent was not available despite rapid transfer of the patient to the operating theatre. We recommend all interventionist carrying out routine iliac angioplasty and or stenting should have access to covered stents for such emergencies.

Imaging Findings

Case 1 A 72 year old male smoker with type II diabetes presented with a history of right calf claudication at 50 yards and a small ulcer on the right great toe. He was on long term warfarin therapy following a heart valve replacement. Anticoagulation was converted to heparin in preparation for angiography and the patient's clotting indices were within therapeutic range at the time of the procedure. Examination revealed a weak right femoral pulse and a normal left femoral arterial pulse. All other leg pulses were absent. Angiography demonstrated a short, eccentric stenosis in the right external iliac artery(Fig 1). The vessel measured 7mm just proximal to the site of stenosis. This was dilated with a 7mm x 4cm angioplasty balloon (Schneider, UK). The patient complained of severe pain; the balloon was immediately deflated. A check angiogram demonstrated considerable extravasation of contrast at the site of the angioplasty (Fig. 2). The balloon was re-inflated across the rupture to tamponade the leak. However this failed and the patient became hypotensive and despite intravenous colloid resuscitation the patient's blood pressure dropped from 160/90 to 80/60. A 10mm x 4cm covered stent (Passager, Boston Scientific, UK) was consequently deployed across the site of rupture. Further check angiography showed a smooth vessel lumen and no leakage of contrast (Fig. 3). The blood pressure returned to normal with continued resuscitation. At 16 month out patient follow-up the claudication had improved, the right femoral pulse was normal and the toe ulcer had healed. Case 2 A 63 year old female ex-smoker presented with a history of right leg claudication at 25 yards. Examination revealed a poor right femoral arterial pulse. All pulses on the left were satisfactory. Angiography with access from the left revealed a long (11cm) external iliac artery occlusion on the right( Fig 4). The occlusion was crossed using a cobra catheter ( Cordis UK) and curved terumo wire (Radiofocus, Terumo Corporation) from an ipsilateral approach . The common iliac artery was sized to 7.5mm using a ruler. Two overlapping (9mm x 7cm and 8mm x 5cm) stents (Memotherm, Angiomed, Bard, UK) were deployed across the occlusion thorugh a 7F arrow sheath( Arrow international ). The stent was dilated at low pressure with a 7mm x 4cm balloon (Schneider, UK). Subsequent check angiography demonstrated localised extravasation of contrast at the point of overlap of the two Memotherm stents (Fig. 5). An attempt to tamponade the rupture with the balloon (over 15 minutes) was unsuccessful. A 10mm x 4cm covered stent (Passager, Boston Scientific, UK), the smallest size available in the department at that time, was consequently deployed across the rupture. The patient remained asymptomatic and normotensive throughout. Repeat angiography demonstrated satisfactory positioning of all three stents and no evidence of contrast extravasation (Fig. 6). At 11 month out patient follow-up the patient was asymptomatic with good pulses on the right. Case 3 A 68 year old hypertensive lady presented with short distance right leg claudication at 20yards. Examination revealed an absent right femoral pulse and angiography from the contralateral side confirmed a 9cm occlusion of the external iliac artery(Fig 7). The right common femoral artery was punctured and the occlusion crossed antegradely using a cobra catheter ( Cordis ,UK) and curved terumo ( Radiofocus, Terumo corporation) wire. The contralateral external iliac artery was sized to 6.5mm using a ruler . 3000 units of intra-arterial heparin was administered and a 12cm long 8mm diameter Memotherm iliac stent ( Angiomed, Bard UK) was placed through a 7 F arrow sheath (Arrow international) across the occlusion. The stent was dilated using a 4cm x 7mm angioplasty balloon ( Boston Scientific ,UK) during which the patient complained of pain which persisted after the balloon was deflated. The patients blood pressure dropped to 48/28 and the patient was resuscitated with 500mls of normal saline and 1.5 litres of colloid.. Angiography confirmed rupture of the iliac artery ( Fig 8 ) and the balloon was re-inflated across the site of rupture. The patients condition did not improve and she was taken to the operating room within 40 minutes of the arterial rupture. The patient subsequently died during surgery.

Discussion

Iliac artery rupture, carrying the risk of life-threatening retroperitoneal haemorrhage, is a recognised complication of angioplasty (1, 2) but has not been previously described in association with the deployment of an iliac stent. Initial reports of percutaneous treatment for such ruptures advocated balloon tamponade of the leaking vessel either as a prelude to surgical treatment (3) or as a definitive curative procedure (2). However as demonstrated by our third case, the slightest delay in sealing the leak can be catastrophic. In our first patient rupture occurred during angioplasty, as has been described previously with rapid drop in blood pressure, requiring immediate resuscitation . In the second patient vessel rupture occurred more slowly with a jet at the point of overlap of two Memotherm stents during low pressure balloon dilatation. In both cases a special larger 10 french sheath was required which although undesirable during the period of high stress only took 1-2 minutes during which time the stentgrafts were being flushed with ice cold saline.Newer devices such as the Wallgrafts (Boston Scientific) do not require cold saline for deployment. Although a case of delayed external iliac artery rupture following stent placement using a palmaz stent has been described ,it is uncommon. A characteristic of the memotherm stent are it's sharp edges . These are seen particularly when the stent is bent over the convex surface. We surmise that one of these led to the development of a focal vessel wall rupture in both the second and third cases and subsequently prevented closure of the rupture with balloon tamponade. As is often the case iliac artery rupture was unexpected .In all three cases simple balloon tamponade of the site of rupture failed to control the leakage. In the first case this was presumably a consequence of the size of the rupture but in the second two cases this may have been due to mechanical factors related to the design of the stents. Placement of covered stents proved to be a quick and effective therapeutic manoeuvre resulting in immediate haemostasis. Only two other cases have been previously described where iliac artery rupture was successfully treated by the deployment of a uncovered(4) and covered stent(5) across the site of leakage. An effective percutaneous treatment is clearly preferable to surgery in such cases. We suggest that radiologists performing percutaneous therapeutic procedures should have ready access to covered stents in case of accidental vessel rupture. Covered stents are expensive but the cost is clearly offset by the savings achieved, and the benefits to the patient, if surgery can be avoided.To reduce cost we only stock three sizes currently, 12mmx4cm, 10mmx4cm and 8mmx4cm wall stent grafts to cover most standard vessel sizes in the iliacs. A pragmatic and cost effective approach for the treatment of iatrogenic iliac artery rupture would be to attempt simple balloon tamponade of smaller leaks and resort to stenting only when this is unsuccessful or in those cases where it is clear that the leak is large. This should eliminate the need for surgery in virtually all cases.

Differential Diagnosis List

Final Diagnosis

Iliac artery rupture treated with covered stent

URL:	https://www.eurorad.org/case/635
DOI:	10.1594/EURORAD/CASE.635
ISSN:	1563-4086