Per Undrén

Endovascular Treatment Using Predominantly Stent-Assisted Coil Embolization and Antiplatelet and Anticoagulation Management of Ruptured Blood Blister–Like Aneurysms

BACKGROUND AND PURPOSE: BBA is a rare type of intracranial aneurysm that is difficult to treat both surgically and endovascularly and is often associated with a high degree of morbidity/mortality. The aim of this study was to present clinical and angiographic results, as well as antiplatelet/anticoagulation regimens, of endovascular BBA treatment by using predominantly stent-assisted coil embolization. MATERIALS AND METHODS: Thirteen patients (men/women, 6/7; mean age, 49.3 years) with ruptured BBAs were included from 2 different institutions. Angiographic findings, treatment strategies, anticoagulation/antiplatelet protocols, and clinical (mRS) and angiographic outcome were retrospectively analyzed. RESULTS: Eleven BBAs were located in the supraclinoid ICA, and 2 on the basilar artery trunk. Nine of 13 were ≤3 mm in the largest diameter, and 8/13 showed early growth before treatment. Primary stent-assisted coiling was performed in 11/13 patients, double stents and PAO in 1 patient, each. Early complementary treatment was required in 3 patients, including PAO in 2. In stent-placement procedures, altered periprocedural antiplatelet (11/12) and postprocedural heparin (6/12) protocols were used without evidence of thromboembolic events. Two patients had early rehemorrhage, including 1 major fatal SAH. Twelve of 13 BBAs showed complete or progressive occlusion at late angiographic follow-up. Clinical midterm outcome was good (mRS scores, 0–2) in 12/13 patients. CONCLUSIONS: Stent-assisted coiling of ruptured BBAs is technically challenging but can be done with good midterm results. Reduced periprocedural and postprocedural antiplatelet/anticoagulation protocols may be used with a low reasonable risk of thromboembolic complications. However, regrowth/rerupture remains a problem underlining the importance of early angiographic follow-up and re-treatment, including PAO if necessary.

Nimodipine in aneurysmal subarachnoid hemorrhage: a randomized study of intravenous or peroral administration

OBJECT The calcium antagonist nimodipine has been shown to reduce the incidence of ischemic complications following aneurysmal subarachnoid hemorrhage (SAH). Although most randomized studies have been focused on the effect of the peroral administration of nimodipine, intravenous infusion is an alternative and the preferred mode of treatment in many centers. It is unknown whether the route of administration is of any importance for the clinical efficacy of the drug. METHODS One hundred six patients with acute aneurysmal SAH were randomized to receive either peroral or intravenous nimodipine treatment. The patients were monitored for at least 10 days after bleeding in terms of delayed ischemic neurological deficits (DINDs) and with daily measurements of blood flow velocities in the middle cerebral arteries by using transcranial Doppler ultrasonography. Three months after SAH, clinical outcome and new cerebral infarctions according to MR imaging studies were recorded. RESULTS Baseline characteristics (age, sex distribution, clinical status on admission, radiological findings, and aneurysm treatment) did not differ between the treatment groups. There was no significant difference in the incidence of DINDs (28 vs 30% in the peroral and intravenous groups, respectively) or middle cerebral artery blood flow velocities (> 120 cm/second, 50 vs 45%, respectively). Clinical outcome according to the Glasgow Outcome Scale was the same in both groups, and there was no difference in the number of patients with new infarctions on MR imaging. CONCLUSIONS The results suggest that there is no clinically relevant difference in efficacy between peroral and intravenous administration of nimodipine in preventing DINDs or cerebral vasospasm following SAH.

The Porcine Retinal Vasculature Accessed Using an Endovascular Approach: A New Experimental Model for Retinal Ischemia

PURPOSE The aim of this study was to examine whether the retinal circulation in the pig can be accessed using interventional neuroradiology and to explore the possibility of creating occlusions that result in experimental retinal ischemia. METHODS Six experiments were performed using 100-kg pigs. The external carotid system was catheterized using a fluoroscopy-monitored, transfemoral, endovascular approach. Transient and permanent vascular occlusions were performed using an angioplasty balloon catheter or a liquid embolic agent that was administered via an injection-catheter. RESULTS A technique for transfemoral catheterization of arteries supplying the retina was established. The ophthalmic artery was demonstrated to give rise to the main ciliary artery from which the retinal artery branched as a single artery or as several arteries. A balloon-catheter could be introduced into the ophthalmic artery but not into the main ciliary artery. An injection-catheter could, in all experiments, be introduced into the main ciliary artery and, in some experiments, into the retinal artery. Occlusion of the ophthalmic artery, over the branching of the main ciliary artery, caused incomplete ischemia, presumably because of collaterals feeding the distal parts of the vasculature. Multifocal ERG (mfERG) recordings showed decreased amplitudes and increased implicit times, indicating retinal ischemia. Occlusion of the ciliary and retinal arteries caused complete ischemia, as shown by complete flattening of the mfERG recordings and, by indirect ophthalmoscopy, blanching of the retinal arteries and a pale retina, CONCLUSIONS The authors show for the first time that the ophthalmic and retinal artery can be catheterized using a transfemoral endovascular approach. This technique may be useful to produce clear-cut experimental retinal ischemia.

Hybrid Iterative Reconstruction Algorithm Improves Image Quality in Craniocervical CT Angiography

OBJECTIVE The purpose of this study was to evaluate the potential of a hybrid iterative reconstruction algorithm for improving image quality in craniocervical CT angiography (CTA) and to assess observer performance. SUBJECTS AND METHODS Thirty patients (mean age, 58 years; range 16-80 years) underwent standard craniocervical CTA (volume CT dose index, 6.8 mGy, 2.8 mSv). Images were reconstructed using both filtered back projection (FBP) and a hybrid iterative reconstruction algorithm. Five neuroradiologists assessed general image quality and delineation of the vessel lumen in seven arterial segments using a 4-grade scale. Interobserver and intraobserver variability were determined. Mean attenuation and noise were measured and signal-to-noise and contrast-to-noise ratios calculated. Descriptive statistics are presented and data analyzed using linear mixed-effects models. RESULTS In pooled data, image quality in iterative reconstruction was graded superior to FBP regarding all five quality criteria (p < 0.0001), with the greatest improvement observed in the vertebral arteries. Iterative reconstruction resulted in elimination of arterial segments graded poor. Interobserver percentage agreement was significantly better (p = 0.024) for iterative reconstruction (69%) than for FBP (66%) but worse than intraobserver percentage agreement (mean, 79%). Noise levels, signal-to-noise ratio, and contrast-to-noise ratio were significantly (p < 0.001) improved in iterative reconstruction at all measured levels. CONCLUSION The iterative reconstruction algorithm significantly improves image quality in craniocervical CT, especially at the thoracic inlet. Despite careful study design, considerable interobserver and intraobserver variability was noted.

Endovascular Coiling of the Ophthalmic Artery in Pigs to Induce Retinal Ischemia

PURPOSE The authors recently showed that the retinal circulation can be accessed by transfemoral endovascular catheterization. The purpose of this study was to examine whether endovascular coiling can be used to induce different degrees of ischemic injury. The possibility of creating occlusions at different sites in the vasculature to cause retinal ischemia with different degrees of severity was investigated. METHODS The ophthalmic artery was catheterized through the external carotid system using a fluoroscopy-monitored, transfemoral, endovascular approach in 12 pigs (mean weight, 70 kg). The effects were evaluated using angiography and multifocal electroretinography. RESULTS Occlusion of arteries supplying the retina was established using endovascular coiling. Coiling in the proximal part of the ophthalmic artery caused no or little ischemia, presumably because of collateral blood supply. Coiling in the distal part of the ophthalmic artery, over the branching of the main ciliary artery, caused more severe retinal ischemia. Multifocal electroretinography recordings, which reflect retinal function in an area close to the visual streak, showed decreased amplitudes and increased implicit times after distal occlusion, but not after proximal occlusion of the ophthalmic artery. The responses were similar 1 hour and 72 hours after coiling, indicating that a permanent ischemic injury was established. CONCLUSIONS The porcine ophthalmic artery can be occluded using an endovascular coiling technique. This provides an experimental animal model of retinal ischemia in which occlusion at different sites of the vasculature produces different degrees of severity of the ischemic damage.

Endovascular treatment of vein of Galen aneurysmal malformation using rapid ventricular pacing: A case report

The treatment of choice of vein of Galen aneurysmal malformation (VGAM) involves endovascular procedures that can be difficult to perform in high-flow fistulas. We describe the use of rapid ventricular pacing (RVP), a well-known cardiologic technique, to safely treat a high-flow fistula in an infant with VGAM.

Angiography and Multifocal Electroretinography Show That Blood Supply to the Pig Retina May Be Both Ipsilateral and Contralateral

PURPOSE We recently presented a transfemoral endovascular coiling technique for inducing experimental retinal ischemia in pigs. Substantial variation was seen in the degree of ischemia. It was hypothesized that the blood supply to the retina may originate from both the ipsilateral and contralateral ophthalmic arteries and that there may be an interconnecting artery between the eyes. METHODS The external carotid system of 6 pigs was catheterized using a fluoroscopy-monitored, transfemoral, endovascular approach. Vascular occlusion was achieved in the ophthalmic artery using coils. The effect of occlusion was examined using angiography and multifocal electroretinography (mfERG). RESULTS During angiography of the ophthalmic artery on one side, contrast filling was seen in the retinas on both sides, suggesting that the ophthalmic artery on one side may supply both retinas. A blood vessel connecting the eyes was visualized. The mfERG recordings indicated that the use of coiling to occlude the ophthalmic artery had greater ischemic effects in eyes that may depend mainly on the ipsilateral ophthalmic artery for blood supply and had smaller ischemic effects in retinas that received blood from both the ipsilateral and contralateral ophthalmic arteries via the interconnecting vessel. CONCLUSIONS The blood supply to the retina may originate from both the ipsilateral and contralateral ophthalmic arteries in the pig. There is an interindividual variability in the ischemic effect of occlusion depending on the architecture of the vasculature. These findings may be important in the development of new animal models of experimental retinal ischemia because arterial occlusion in one eye may affect the blood supply to the contralateral eye.

Angiography and Multifocal Electroretinography Show That Blood Supply to the Pig Retina May Be Both Ipsilateral and ContralateralExperimental Retinal Ischemia

PURPOSE We recently presented a transfemoral endovascular coiling technique for inducing experimental retinal ischemia in pigs. Substantial variation was seen in the degree of ischemia. It was hypothesized that the blood supply to the retina may originate from both the ipsilateral and contralateral ophthalmic arteries and that there may be an interconnecting artery between the eyes. METHODS The external carotid system of 6 pigs was catheterized using a fluoroscopy-monitored, transfemoral, endovascular approach. Vascular occlusion was achieved in the ophthalmic artery using coils. The effect of occlusion was examined using angiography and multifocal electroretinography (mfERG). RESULTS During angiography of the ophthalmic artery on one side, contrast filling was seen in the retinas on both sides, suggesting that the ophthalmic artery on one side may supply both retinas. A blood vessel connecting the eyes was visualized. The mfERG recordings indicated that the use of coiling to occlude the ophthalmic artery had greater ischemic effects in eyes that may depend mainly on the ipsilateral ophthalmic artery for blood supply and had smaller ischemic effects in retinas that received blood from both the ipsilateral and contralateral ophthalmic arteries via the interconnecting vessel. CONCLUSIONS The blood supply to the retina may originate from both the ipsilateral and contralateral ophthalmic arteries in the pig. There is an interindividual variability in the ischemic effect of occlusion depending on the architecture of the vasculature. These findings may be important in the development of new animal models of experimental retinal ischemia because arterial occlusion in one eye may affect the blood supply to the contralateral eye.

Angiography and mfERG show that blood supply to the pig retina may be both ipsilateral and contralateral.

PURPOSE We recently presented a transfemoral endovascular coiling technique for inducing experimental retinal ischemia in pigs. Substantial variation was seen in the degree of ischemia. It was hypothesized that the blood supply to the retina may originate from both the ipsilateral and contralateral ophthalmic arteries and that there may be an interconnecting artery between the eyes. METHODS The external carotid system of 6 pigs was catheterized using a fluoroscopy-monitored, transfemoral, endovascular approach. Vascular occlusion was achieved in the ophthalmic artery using coils. The effect of occlusion was examined using angiography and multifocal electroretinography (mfERG). RESULTS During angiography of the ophthalmic artery on one side, contrast filling was seen in the retinas on both sides, suggesting that the ophthalmic artery on one side may supply both retinas. A blood vessel connecting the eyes was visualized. The mfERG recordings indicated that the use of coiling to occlude the ophthalmic artery had greater ischemic effects in eyes that may depend mainly on the ipsilateral ophthalmic artery for blood supply and had smaller ischemic effects in retinas that received blood from both the ipsilateral and contralateral ophthalmic arteries via the interconnecting vessel. CONCLUSIONS The blood supply to the retina may originate from both the ipsilateral and contralateral ophthalmic arteries in the pig. There is an interindividual variability in the ischemic effect of occlusion depending on the architecture of the vasculature. These findings may be important in the development of new animal models of experimental retinal ischemia because arterial occlusion in one eye may affect the blood supply to the contralateral eye.

Neck-bridge device for combined endovascular and surgical treatment of a giant anterior communicating artery aneurysm

We report the case of a 58-year-old man with a giant partially thrombosed anterior communicating artery aneurysm, which presented with mass effect. Our treatment strategy consisted of endovascular aneurysm circulatory exclusion prior to surgical resection. To do so, we first occluded both the two A1 segments and the aneurysm neck with a neck-bridge device to prevent further coil migration within the aneurysm sac. Five days later, the aneurysm was surgically removed.