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Radiology
Pseudoaneurysm
of the left external iliac artery complicating Shirodkar's sling surgery and
its successful endovascular management.
A 25-year-old lady presented with complaints of a painful limp which had developed gradually over a period of a month. She had undergone Shirodkar's sling surgery for uterine prolapse, four months prior to presentation.
On examination, a tender lump in the left iliac fossa was palpable. On per vaginal examination bogginess was felt in the cul-de-sac, more on the left side. B-mode USG showed an anechoic lesion (2.1 x 1.3 cm) with thick irregular walls in close proximity to the left external iliac artery. An echogenic linear band was seen attached to the posterior surface of the cervix and an irregular echogenic collection was seen in the cul-de-sac.(fig 1&2)
Color doppler demonstrated that the lesion had a channel of communication with the lumen of the left external iliac artery. It also showed the 'yin -yang' sign diagnostic of a pseudoaneurysm. High velocities with aliasing were seen at the neck of the pseudoaneurym with reversal of flow in diastole. (Fig 3).
For further characterization a CT angiogram with 3D and MIP (maximum intensity projection) reconstructions was done which revealed the extraluminal extent of the pathology; the thrombosed part of the pseudoaneurysm. The lamellated clot in different stages of evolution was seen to exert a mass effect on the parent artery proximal to the lesion in the form of a smooth tapered narrowing. (Figs 4 & 5).
An intra-arterial DSA was performed, which revealed a smooth tapered narrowing approximately 3cm long in the left external iliac artery proximal to the site of the pseudoaneurysm arising from the lateral surface of the external iliac artery. It confirmed the narrow neck of the pseudoaneurysm, arising from the lateral surface of the external iliac artery. (figure 6)
A self-expandable stent-graft (6cm x 4mm) was deployed across the pseudoaneurysm after crossing the lesion with an exchange glide wire (0.035inch ,260cm) (Terumo) through the right transfemoral route. This was followed by stent plasty using a 6mm , 4cm balloon angioplasty catheter( Meditech, Boston scientific) in order to correct residual stenosis in the stent graft.
A post-stent angiogram showed complete exclusion of the pseudoaneurysm with no residual stenosis. (figure 7 & 8 )
The patient was heparinised with low dose heparin 5000 units s.c 8 hourly for next 24 hrs after the procedure.She was discharged after 2 days. A follow-up color doppler study 4 months after the stent placement was performed which showed a normal triphasic waveform within the stent graft.
Discussion :
Iliac artery aneurysms and pseudoaneurysms most commonly affect the common iliac and internal iliac arteries. External iliac artery involvement is infrequent. The common causes includes atherosclerosis, trauma, infection and dissection. Anastomotic iliac aneurysm of distal suture line of previously implanted aortoiliac graft is comman cause of pseudoaneurysm. Rare causes are Marfan syndrome, Kawasaki disease, Ehler- Danlos syndrome and cystic medial necrosis.
Untreated Iliac aneurysms as small as 3 cms have been known to rupture, commonly into retroperitoneum, peritoneal cavity or rarely colon.
Although open surgical repair of iliac aneurysm has excellent long-term result, the operative procedure causes high morbidity and perioperative motality. There are technical problems associated with gaining proximal control and avoiding damage to the ureter and iliac veins. The operation usually requires an intraperitoneal approach, which may result in bowel obstruction or paralytic ileus. The percutaneous placement of stent graft offers advantage of immediate isolation of the aneurysm from the circulation without need of general anesthesia with reduced likelihood of clinically significant blood loss and prolonged hospital stay, particularly so in high risk surgical candidates because of other co-morbid conditions.
Pre-treatment imaging for endovascular repair of the aneurysm includes Helical CT and angiography for determination of the maximum diameter and length of the aneurysmal segment and assessment of the length and diameter of normal artery proximal and distal to aneurysm is required to select the most appropriate endovascular device. For isolated iliac aneurysm, a proximal segment of relatively normal iliac artery is required for implantation and attachment of the proximal part of the graft; this proximal implant area or attachment zone should be at least 10mm in length and free of mural thrombus. Severe angulation or tortuosity of the iliac segment and firm calcification of the arterial wall are negative factors that may lead to failure of the procedure.
Embolisation of the ipsilateral internal iliac artery often is required as an adjuvant procedure to prevent persistent retrograde blood flow into aneurysmal sac if aneurysm involves or closely approximates its origin . Before this embolisation, it is necessary to know whether the opposite internal iliac artery is patent otherwise debilitating buttock claudication may develop. Unless contraindicated, low dose aspirin is required to be given 48 hrs prior to procedure and continue for life to prevent graft thrombosis. Imaging follow up should be done with CT after 3 & 6 months and yearly there after. Complications described are misplacement result in failure to exclude the aneurysm, graft thrombosis and late endoleaks. Persistent endoleaks puts the aneurysm at risk of rupture, if endovascular treatment is not possible, surgical repair is mandatory.
Case 13 : Contributed
by Dr. Shreyas Masrani
Other Cases
A 25-year-old lady presented with complaints of a painful limp which had developed gradually over a period of a month. She had undergone Shirodkar's sling surgery for uterine prolapse, four months prior to presentation.
On examination, a tender lump in the left iliac fossa was palpable. On per vaginal examination bogginess was felt in the cul-de-sac, more on the left side. B-mode USG showed an anechoic lesion (2.1 x 1.3 cm) with thick irregular walls in close proximity to the left external iliac artery. An echogenic linear band was seen attached to the posterior surface of the cervix and an irregular echogenic collection was seen in the cul-de-sac.(fig 1&2)
 |
 |
|
Fig.1
|
Fig.2
|
Color doppler demonstrated that the lesion had a channel of communication with the lumen of the left external iliac artery. It also showed the 'yin -yang' sign diagnostic of a pseudoaneurysm. High velocities with aliasing were seen at the neck of the pseudoaneurym with reversal of flow in diastole. (Fig 3).
 |
|
Fig.
3
|
For further characterization a CT angiogram with 3D and MIP (maximum intensity projection) reconstructions was done which revealed the extraluminal extent of the pathology; the thrombosed part of the pseudoaneurysm. The lamellated clot in different stages of evolution was seen to exert a mass effect on the parent artery proximal to the lesion in the form of a smooth tapered narrowing. (Figs 4 & 5).
 |
 |
|
Fig.
4
|
Fig.
5
|
An intra-arterial DSA was performed, which revealed a smooth tapered narrowing approximately 3cm long in the left external iliac artery proximal to the site of the pseudoaneurysm arising from the lateral surface of the external iliac artery. It confirmed the narrow neck of the pseudoaneurysm, arising from the lateral surface of the external iliac artery. (figure 6)
 |
|
Fig.
6
|
A self-expandable stent-graft (6cm x 4mm) was deployed across the pseudoaneurysm after crossing the lesion with an exchange glide wire (0.035inch ,260cm) (Terumo) through the right transfemoral route. This was followed by stent plasty using a 6mm , 4cm balloon angioplasty catheter( Meditech, Boston scientific) in order to correct residual stenosis in the stent graft.
A post-stent angiogram showed complete exclusion of the pseudoaneurysm with no residual stenosis. (figure 7 & 8 )
 |
 |
|
Fig.
7
|
Fig.
8
|
The patient was heparinised with low dose heparin 5000 units s.c 8 hourly for next 24 hrs after the procedure.She was discharged after 2 days. A follow-up color doppler study 4 months after the stent placement was performed which showed a normal triphasic waveform within the stent graft.
Iliac artery aneurysms and pseudoaneurysms most commonly affect the common iliac and internal iliac arteries. External iliac artery involvement is infrequent. The common causes includes atherosclerosis, trauma, infection and dissection. Anastomotic iliac aneurysm of distal suture line of previously implanted aortoiliac graft is comman cause of pseudoaneurysm. Rare causes are Marfan syndrome, Kawasaki disease, Ehler- Danlos syndrome and cystic medial necrosis.
Shirodkar, devised an ingenious technique for conservative surgical treatment of partial uterine prolapse in women desirous of preserving the uterus using a loop of mersilene tape to suspend the back of the cervix from the front of the sacral promontory. The left limb of this loop was passed through a separate loop of tape attached to the left psoas major muscle. This separate loop on the psoas was needed only on the left side to prevent the compression of the sigmoid colon by the main suspending loop of tape, thus explaining the side of arterial trauma in the patient (left external iliac artery which is in close vicinity of this loop).
Pseudoaneurysm of external iliac artery has never been described in literature as a complication of Shirodkar's sling surgery. The present case report describes an extremely unusual cause of pseudoaneurysm of the left external iliac artery as a result of a complication during Shirodkar's sling surgery and highlights it's endovascular management.Untreated Iliac aneurysms as small as 3 cms have been known to rupture, commonly into retroperitoneum, peritoneal cavity or rarely colon.
Although open surgical repair of iliac aneurysm has excellent long-term result, the operative procedure causes high morbidity and perioperative motality. There are technical problems associated with gaining proximal control and avoiding damage to the ureter and iliac veins. The operation usually requires an intraperitoneal approach, which may result in bowel obstruction or paralytic ileus. The percutaneous placement of stent graft offers advantage of immediate isolation of the aneurysm from the circulation without need of general anesthesia with reduced likelihood of clinically significant blood loss and prolonged hospital stay, particularly so in high risk surgical candidates because of other co-morbid conditions.
Pre-treatment imaging for endovascular repair of the aneurysm includes Helical CT and angiography for determination of the maximum diameter and length of the aneurysmal segment and assessment of the length and diameter of normal artery proximal and distal to aneurysm is required to select the most appropriate endovascular device. For isolated iliac aneurysm, a proximal segment of relatively normal iliac artery is required for implantation and attachment of the proximal part of the graft; this proximal implant area or attachment zone should be at least 10mm in length and free of mural thrombus. Severe angulation or tortuosity of the iliac segment and firm calcification of the arterial wall are negative factors that may lead to failure of the procedure.
Embolisation of the ipsilateral internal iliac artery often is required as an adjuvant procedure to prevent persistent retrograde blood flow into aneurysmal sac if aneurysm involves or closely approximates its origin . Before this embolisation, it is necessary to know whether the opposite internal iliac artery is patent otherwise debilitating buttock claudication may develop. Unless contraindicated, low dose aspirin is required to be given 48 hrs prior to procedure and continue for life to prevent graft thrombosis. Imaging follow up should be done with CT after 3 & 6 months and yearly there after. Complications described are misplacement result in failure to exclude the aneurysm, graft thrombosis and late endoleaks. Persistent endoleaks puts the aneurysm at risk of rupture, if endovascular treatment is not possible, surgical repair is mandatory.