Reduced Activity of von Willebrand Factor after Flow-Diverting Stent Implantation for Intracranial Aneurysms: A Link to Acquired von Willebrand Disease?

BACKGROUND AND PURPOSE: Vascular devices generating high shear stress can cause type 2A acquired von Willebrand disease, which is characterized by low von Willebrand factor activity accompanied by hemorrhagic complications. The braided mesh structure of flow-diverting stents with a relatively small strut size can create abnormally high shear stress while arterial blood flows through the stent struts into the aneurysm, and flow-diverting stent may be associated with reduced von Willebrand factor activity. MATERIALS AND METHODS: Aneurysmal morphologic parameters and patient data were examined retrospectively among patients who had an unruptured intracranial aneurysm treated with a flow-diverting stent. The RISTOtest (test for whole blood ristocetin-induced platelet aggregation) for von Willebrand factor activity, as well as tests for aspirin and clopidogrel/prasugrel effectiveness, were performed immediately before the endovascular procedure and 24 hours later by multiple electrode aggregometry. RESULTS: A total of 39 patients with 56 aneurysms were recruited, and statistical analyses were performed in 32 patents with 49 aneurysms. Compared with the baseline values, von Willebrand factor activity was reduced in 16 patients but increased in 23 patients. Aneurysmal variables (eg, neck area, volume, volume-to-neck area ratio, size ratio, and morphologic index) clearly distinguished patients with reduced von Willebrand factor activity from those with nonreduced von Willebrand factor activity. The receiver operating characteristic curve showed that the morphologic index and volume had the highest discriminative power, with an area under the curve of 0.99. CONCLUSIONS: In high-volume/large-neck aneurysms, flow-diverting stent implantation can cause reduced von Willebrand factor activity, which may be linked causally to acquired von Willebrand disease.

Endovascular Repair and Adjunctive Immunosuppressive Therapy of Aortic Involvement in Behçet's Disease.

OBJECTIVES: Aortic aneurysm is a serious problem in Behçet's disease, but open surgical therapy carries the risk of recurrent pseudoaneurysm. Here the outcomes of endovascular repair and adjunctive immunosuppressive therapy for aortic disease in Behçet's disease are presented. MATERIALS: This was a retrospective study. Between 2002 and 2012, nine patients with Behçet's disease (8 male, median age 41 years, range 33-60 years) were treated by endovascular stent grafting for abdominal or thoraco-abdominal aortic pseudoaneurysm. METHODS: Computed tomography angiography revealed infrarenal pseudoaneurysm in six (66.6%) patients and suprarenal pseudoaneurysm in three (33.3%). Patients received immunosuppressive therapy with oral prednisolone (60 mg/day) and cyclophosphamide (200 mg/day) for 2 weeks or more before the procedure, and intravenous hydrocortisone (200 mg/day) combined with cyclophosphamide (200 mg/day) for 3 days after the procedure. Thereafter, oral immunosuppressive therapy was continued for 2 years. RESULTS: A straight tube graft was implanted in seven patients and a bifurcated graft in two patients. Two stage procedures (debranching before endovascular therapy) were performed in three patients for thoraco-abdominal aortic pseudoaneurysms. Stent grafting was successful in all patients, without any peri-operative complications. However, two patients needed abdominal exploration later: one for seroma around the graft and the other for a fistula between the duodenum and the graft. No recurrence of aneurysm was observed during a mean follow up of 40 ± 16 months. One patient died in the 15th month from a non-vascular cause. CONCLUSIONS: Endovascular stent graft implantation and adjunctive immunosuppressive therapy seems to be safe and effective in the treatment of aortic involvement in Behçet's disease, but this approach needs further evaluation.

Endovascular Management of Vascular Injury during Transsphenoidal Surgery.

Vascular injury is an unusual and serious complication of transsphenoidal surgery. We aimed to define the role of angiography and endovascular treatment in patients with vascular injuries occurring during transsphenoidal surgery. During the last ten-year period, we retrospectively evaluated nine patients with vascular injury after transsphenoidal surgery. Eight patients were symptomatic due to vascular injury, while one had only suspicion of vascular injury during surgery. Four patients presented with epistaxis, two with subarachnoid hemorrhage, one with exophthalmos, and one with hemiparesia. Emergency angiography revealed a pseudoaneurysm in four patients, contrast extravasation in two, vessel dissection in one, vessel wall irregularity in one, and arteriovenous fistula in one. All patients but one were treated successfully with parent artery occlusion, with one covered stent implantation, one stent-assisted coiling method, while one patient was managed conservatively. One patient died due to complications related to the primary insult without rebleeding. Vascular injuries suspected intra or postoperatively must be investigated rapidly after transsphenoidal surgery. Endovascular treatment with parent artery occlusion is feasible with acceptable morbidity and mortality rates in the treatment of vascular injuries occurring in transsphenoidal surgery.

Post evar endovascular revision of late onset stent graft collapse due to type 1 endoleak in a complicated case with left limb occlusion and solitary kidney.

Type 1 endoleak is one of the most frequent complication usually seen at the initial phase of EVAR procedure. Balloon dilatation is mostly used to oversize the proximal or the distal part of the orifice to stabilize the attachment of the graft stent to the aortic wall. Late onset of type 1 endoleak with graft stents may cause severe lumen compression of the stent and aneurysm enlargement which might cause a serious problem especially in a patient whose graft stents left iliac branch is thrombosed and the left leg is supplied by the bypass graft from right CFA. Although operation was advised by the endovascular specialists the procedure was done in our hospital as the patient preferred the endovascular method instead of open surgery.

Stent implantation in chronic mesenteric ischemia.

BACKGROUND: Chronic mesenteric ischemia (CMI) is a life-threatening disorder, which is usually associated with stenosis or occlusion of celiac or mesenteric arteries. PURPOSE: To review our experience and to assess short-term results of stent placement in stenotic mesenteric arteries. MATERIAL AND METHODS: Primary stent placement was performed in 15 patients who had nausea, vomiting, postprandial pain, and weight loss due to steno-occlusive diseases of mesenteric arteries. After stenting, the patients were followed clinically and with Doppler ultrasound at 1, 6, and 12 months. Symptomatic patients with restenosis were examined with digital subtraction angiography and were referred for retreatment with balloon dilatation. RESULTS: Twenty-three stenoses and 11 occlusions were detected in 15 patients, and 18 stenoses were treated with primary stenting. Single-vessel endovascular treatment was performed in 12 patients. In three patients, two arteries were stented in the same session. Technical success rate was 18/18 (100%). Clinical success was achieved in 13/15 (86.6%) patients. First-month mortality was 13%. During the mean 16.1-month follow-up period, restenoses developed in three patients. One of them was successfully treated with balloon angioplasty. Primary patency was 9/11 (81%) and primary assisted patency was 81% at 12 months. The complication rate was 1/15 patients (0.06%). CONCLUSION: Our experience suggests that stent placement has a potential role in chronic mesenteric ischemia with low incidence of complications and high technical and clinical success rates.

Acute hepatic vein thrombosis after liver transplantation in a child with biliary atresia and absent inferior vena cava.

Stenosis of the hepatic venous outflow anastomosis is rare after liver transplantation. Hepatic venous outflow obstruction affects 5.1% to 7% of transplanted patients. Clinical findings among children include massive ascites and abdominal pain and laboratory findings demonstrate altered liver function tests and coagulopathy. In this article, we report a case of hepatic venous thrombosis occurring 22 days after living-related liver transplantation. The patient was treated with hepatic venoplasty and stent implantation.

Sinistral portal hypertension; imaging findings and endovascular therapy.

Sinistral portal hypertension, a rare and localized form of portal hypertension, is the result of splenic vein thrombosis or obstruction and may cause gastrointestinal hemorrhages from the esophageal and gastric varices. This report presents two cases (69- and 10-year-old females) of bleeding gastric varices. The patients were diagnosed as having sinistral portal hypertension. Splenic artery embolization was performed in both patients to overcome intractable bleeding, and the clinical outcome was good.

Embolisation of both fistulae through the same carotid artery tear in a patient with bilateral traumatic caroticocavernous fistulae.

Endovascular treatment of traumatic caroticocavernous fistulae (CCF) may present technical difficulties with specific angiographic dilemmas. We report endovascular techniques used in a patient with bilateral post-traumatic CCF, high-flow on one side, and slow-flow on the other. Complete closure of both was achieved through the same carotid artery tear. To our knowledge, transarterial venous coil embolisation of a low-flow fistula through a contralateral carotid artery tear, with transarterial detachable balloon embolisation of the ipsilateral high-flow fistula has not been described previously.

Posttraumatic intradural internal carotid artery-cavernous sinus fistula associated with ipsilateral carotid dissection. Transarterial embolization with detachable coils.

SUMMARY: We describe a relatively unusual case of traumatic direct carotid-cavernous fistula in association with a giant intradural venous pouch and ipsilateral carotid dissection, related to carotid artery fistula located in the supraclinoid segment just below the origin of posterior communicating artery. Endovascular therapy could be accomplished by use of detachable coils transarterially. Awareness of an unusual intradural origin of a carotid-cavernous sinus fistula and the possibility of an embolization should be kept in mind.

Embolization of visceral pseudoaneurysms with platinum coils and N-butyl cyanoacrylate.

BACKGROUND: We evaluated the efficacy of transcatheter embolization in visceral artery pseudoaneurysms with platinum coils and N-butyl-cyano-acrylate (NBCA). METHODS: Over the past 7 years, 20 patients were treated by transcatheter embolization in the same sitting with diagnostic angiography. Four right hepatic, one cystic, two gastroduodenal, one cavernosal artery, three superior mesenteric artery branch, and 11 renal artery branch pseudoaneurysms were included in the study. RESULTS: Surgery was completely avoided in 19 patients. In the remaining patient with a superior mesenteric artery branch pseudoaneurysm, endovascular embolization was unsuccessful. Eighteen pseudoaneurysms were thrombosed with coil embolization alone. The remaining three pseudoaneurysms needed NBCA embolization. Two patients died from sepsis within 5 weeks after embolization. CONCLUSION: Emergent diagnosis and treatment are essential in visceral artery pseudoaneurysms because of the high rate of death. Transcatheter embolization with platinum coils is an efficient, safe treatment of choice. NBCA may be used to avoid proximal embolization of the visceral arteries that could not be catheterized selectively because of tortuosity, vessel size, or anatomic location.

Mesenteric artery aneurysms in intestinal tuberculosis as a cause of lower gastrointestinal bleeding.

A 41-year-old woman with intestinal tuberculosis developed massive lower gastrointestinal hemorrhage. Angiographic examinations showed two aneurysms arising from the proximal branches of the superior mesenteric artery, one of which was resected and the other one was successfully embolized with microcoils. Understanding the angiographic features of the disease with gastrointestinal hemorrhage helps in making an appropriate clinical decision for the treatment strategy.

Intradural Aneurysm Caused by Arterial Injury during Surgery: Treatment with Coil Embolization.

SUMMARY: We described a patient with subarachnoid hemorrhage due to a ruptured intradural aneurysm caused by arterial injury during surgery and severe symptomatic vasospasm. The iatrogenic posttraumatic aneurysm was occluded by using GDC with preservation of parent artery followed by intraarterial infusion of papaverine to treat vasospasm as an one-stage procedure. This resulted in significant angiographic resolution of the vasospasm and the patient's clinical outcome was excellent. Endovascular approach to posttraumatic intracranial aneurysms and endosaccular GDC embolization of aneurysm with concomitant intraarterial papaverine infusion to treat vasospasm are discussed.

Mucinous (colloid) breast cancer: mammographic and US features with histologic correlation.

OBJECTIVE: Mucinous carcinoma of the breast presents with different survival rates in pure and mixed types. The purpose of this study was to correlate the mammographic and ultrasonographic findings of mucinous carcinoma with histologic features in different types and mucin rates. MATERIAL AND METHODS: Thirty-four patients (2.3%) had mucinous cancer after retrospective review of the 1439 breast cancers diagnosed between 1990 and 1996. Twenty-seven patients, 19 pure and eight mixed type of mucinous carcinomas of the breast, were included in this study to evaluate the imaging findings. In 22 of these, the microscopic slides were available and re-evaluated to estimate the volume of extracellular mucin. The volume of the extracellular mucin was classified histologically as: (+), less than 50% of mucin; (++), 50-80% of mucin; and ( ), more than 80% of mucin. Mammographic features with emphasis on margin characteristics and sonographic echo pattern of tumors were correlated with histologic findings. RESULTS: Ten cases (53%) of pure mucinous type carcinomas had a circumscribed mass lesion on the mammograms. The well-defined, lobulated margins of the masses were well correlated with pure histologic type (P<0.01; chi(2) analysis) Two-thirds of these tumors had high volume extracellular mucin. All mixed type mucinous carcinomas demonstrated poorly defined or spiculated margins with no relation to the mucin rates (P<0.01). The sonographic appearances of the tumors showed correlation with histologic types. Most of the pure type carcinomas (53%) were seen with isoechogenic echo texture relative to that of subcutaneous fat, while all of the mixed type carcinomas were hypoechogenic (P<0.01). CONCLUSION: The mammographic and sonographic features of mucinous breast carcinoma show differences in pure and mixed types of the tumor. The most common mammographic appearance of pure mucinous carcinomas with high percentages of mucin is a mass lesion having well-defined margins, which is isoechogenic relative to fat on the sonographic examination. Pure type of carcinomas with small percentages of mucin and mixed type carcinomas have more aggressive imaging characteristics.

Catheter and MR angiography of persistent trigeminal artery associated with occipital arteriovenous malformation.

We present a patient with an occipital arteriovenous malformation fed by the posterior cerebral artery coexisting with an ipsilateral persistent trigeminal artery. These anomalies were well demonstrated by MR angiography and confirmed by catheter angiography.

Crutch-Induced Axillobrachial Artery Stenosis: Management With Vascular Stent.

This paper describes a patient with clinical and angiographic evidence of axillobrachial artery stenosis, secondary to the misuse of axillary crutch. Although crutch-induced axillobrachial artery injuries have long been described, percutaneous transluminal angioplasty in such cases has recently been introduced into the literature, and vascular stent treatment as in our patient has not previously been reported.