Glycoprotein IIb/IIIa inhibitors for the neurointerventionalist

Antiplatelet therapies are commonly used in neurointerventional procedures. However, specific guidelines for their use in these settings is lacking and it can often be difficult to balance the potential risks and benefits of these medications. Considering the continued growth and adoption of neurointerventional procedures, it is crucial to understand the properties of these agents in order to use them safely. Large-scale clinical trials are still needed to clarify many of these aspects for this emerging field. However, the existing literature already provides insight into which antiplatelet drugs are of benefit to the neurointerventionalist as well as their associated risks of ischemic and hemorrhagic complications. Hence, this review focuses on the applications of GPIIb/IIIA inhibitors to neurointerventional procedures.

Intensive therapies of delayed cerebral ischemia after subarachnoid hemorrhage: a propensity-matched comparison of different center-driven strategies

BACKGROUND

Intensive therapies of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH) have still controversial and unproven benefit. We aimed to compare the overall efficacy of two different center-driven strategies for the treatment of DCI respectively with and without vasospasm angioplasty.

METHODS

Two hundred consecutive patients with aSAH were enrolled in each of two northern European centers. In an interventional center, vasospasm angioplasty was indicated as first line rather than rescue treatment of DCI using distal percutaneous balloon angioplasty technique combined with intravenous milrinone. In non-interventional center, induced hypertension was the only intensive therapy of DCI. Radiological DCI (new cerebral infarcts not visible on immediate post-treatment imaging), death at 1 month, and favorable outcome at 6 months (modified Rankin scale score ≤ 2) were retrospectively analyzed by independent observers and compared between two centers before and after propensity score (PS) matching for baseline characteristics.

RESULTS

Baseline characteristics only differed between centers for age and rate of smokers and patients with chronic high blood pressure. In the interventional center, vasospasm angioplasty was performed in 38% of patients with median time from bleeding of 8 days (Q1 = 6.5;Q3 = 10). There was no significant difference of incidence of radiological DCI (9% vs.14%, P = 0.11), death (8% vs. 9%, P = 0.4), and favorable outcome 74% vs. 72% (P = 0.4) between interventional and non-interventional centers before and after PS matching.

CONCLUSIONS

Our results suggest either that there is no benefit, or might be minimal, of one between two different center-driven strategies for intensive treatment of DCI. Despite potential lack of power or unknown confounders in our study, these results question the use of such intensive therapies in daily practice without further optimization and validation.

The Silk Vista Baby - The UK experience

BACKGROUND

The Silk Vista Baby (SVB) flow diverter (FDS) is the only FDS deliverable via a 0.017 inch microcatheter and is specifically designed for the distal vasculature. We sought to evaluate the safety and efficacy of the SVB.

MATERIALS AND METHODS

We performed a retrospective review to identify SVB cases at 4 tertiary neurosurgical centres within the U.K. Clinical, procedural, angiographic and follow-up data were collected.

RESULTS

We identified 60 patients (35 female, 58%) of average age 54 ± 10.5 (range 30-72) with 61 aneurysms, 50 (81.9%) located in the anterior circulation. The majority of the aneurysms treated were unruptured (46, 75.4%) and saccular (46, 75.4%). Dome size was 6.2 ± 6.2 mm (range 1-36mm) and parent vessel diameter was 2.3 ± 0.4 mm (range 1.2-3.3 mm).An average number of 1.07 devices were implanted. Coils or other devices were implanted in 14 aneurysms (23.3%). At last angiographic follow-up (n = 55), 7.5 ± 4.2 months post-procedure, 32 aneurysms (57.1%) were graded as RRC I, 7 (12.5%) RRC II, and 17 RRC III (30.4%).Clinical complications, excluding death, were seen in 4 patients (6.8%) including 1 delayed aneurysm rupture and 3 symptomatic ischaemic events. Only one patient had permanent morbidity (mRS 1). 3 patients died during follow-up (5.1%); 2 deaths were related to the aneurysms (3.4%) - one ruptured dissecting MCA aneurysm, and one giant partially thrombosed posterior circulation aneurysm. 93% of patients were mRS ≤ 2 at last follow-up.

CONCLUSION

The SVB has high rates of technical success and an acceptable safety profile. Distal aneurysms may occlude slower due to relative oversizing of the devices.

P2Y12 inhibitors for the neurointerventionalist

The use of antiplatelets is widespread in clinical practice. However, for neurointerventional procedures, protocols for antiplatelet use are scarce and practice varies between individuals and institutions. This is further complicated by the quantity of antiplatelet agents which differ in route of administration, dosage, onset of action, efficacy and ischemic and hemorrhagic complications. Clarifying the individual characteristics for each antiplatelet agent, and their associated risks, will increasingly become relevant as the practice of mechanical thrombectomy, stenting, coiling and flow diversion procedures grows. The aim of this review is to summarize the existing literature for the use of P2Y12 inhibitors in neurointerventional procedures, examine the quality of the evidence, and highlight areas in need of further research.

Aneurysms of the communicating segment of the internal carotid artery with posterior communicating artery agenesis are associated with perforator infarction after embolization

BACKGROUND

While anatomic features associated with the risk of posterior communicating artery (PcoA) occlusion after embolization of aneurysms of the PcoA segment of the internal carotid artery (ICA) are well known, the link between perforator origin and perforator infarction has only been reported following neurosurgical clipping. The aim of this study was to determine the origin of anterior thalamic perforators and correlate it with risk of perforator infarction after embolization of PcoA segment aneurysms.

METHODS

One-hundred-and-ninety consecutive patients treated for PcoA segment aneurysms between 2017 and 2019 were included. PcoA and anterior thalamic perforator origin anatomy was assessed with computed tomography (CT) angiography, digital subtracted angiography, and high-resolution three-dimensional rotational cone-beam CT angiography (CBCT-A) by two independent interventional neuroradiologists. The presence of perforator infarction after embolization was ascertained from the patient's notes and follow-up imaging.

RESULTS

CBCT-A was superior in demonstrating the origin of perforators (P<0.001). The prevalence of perforator origin was estimated at 86% (95% CI 81%-92%) for PcoA, 8% (95% CI 4%-13%) for aneurysm wall, and 5% (95% CI 2%-9%) for ICA. The aneurysm wall origin was exclusively associated with PcoA agenesis, as well as higher risk of perforator infarction after aneurysm coiling compared with other variants (OR=14, 95% CI 2-88, P=0.006).

CONCLUSIONS

Our study suggests that anterior thalamic perforators may arise from aneurysm wall when there is no PcoA. Anatomic association between PcoA agenesis and perforator arising from ICA could underlie such findings, and careful consideration is essential before aneurysm repair to anticipate the risk of thalamic infarction in such cases.

Preoperative T and N staging of colorectal cancer: accuracy of contrast-enhanced multi-detector row CT colonography--initial experience

PURPOSE

To evaluate the accuracy of contrast material-enhanced multi-detector row computed tomographic (CT) colonography for preoperative staging of colorectal cancer.

MATERIALS AND METHODS

Forty-one patients with colorectal carcinoma underwent preoperative contrast-enhanced multi-detector row CT colonography. Images were obtained in the arterial (start delay of 35 seconds) and portal venous (start delay of 70 seconds) phases. The arterial phase was focused on the suspected region of neoplasm, whereas the venous phase included the whole abdomen and pelvis. Two radiologists independently evaluated the depth of tumor invasion into the colorectal wall (T) and regional lymph node involvement (N) on transverse CT images alone and in combination with multiplanar reformations (MPRs). Disagreements were resolved by means of consensus. CT findings were compared with pathologic results, which served as the reference standard. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were assessed. Differences in accuracy for T and N staging were assessed by using the McNemar test.

RESULTS

In T staging, overall accuracy was 73% when transverse images were evaluated alone and 83% when they were evaluated in combination with MPRs. This difference was not significant. N staging was associated with an overall accuracy of 59% with transverse images alone and 80% with combined transverse and MPR images (P <.01).

CONCLUSION

Contrast-enhanced multi-detector row CT colonography is an accurate technique for preoperative local staging of colorectal tumors.

Clinical impact of MR cholangiopancreatography in patients with biliary disease

PURPOSE

To evaluate the role of MR Cholangiopan-creatography (MRCP) as a first imaging modality in patients with suspected biliary tree pathology and indications to endoscopic retrograde cholangiopancreatography (ERCP).

MATERIAL AND METHODS

Eighty-eight patients, with clinical signs of biliary tree pathology underwent MRCP, performed with a 1.5 T unit and a phased-array coil. Surgery, intraoperative cholangiography, percutaneous transhepatic cholangiography (PTC) or ERCP were regarded as the gold standard in patients with obstruction; the remaining patients underwent follow-up MRCP examinations at 6-9 months. The MR examination was performed with baseline T1w 2D FLASH and T2w TSE sequences, followed by the MRCP study (single-slab breath-hold RARE and multislice breath-hold HASTE sequences). The MR images were independently evaluated by two radiologists.

RESULTS

MRCP showed normal findings in 20 patients; 68 patients had biliary duct dilatation. In 11 out of 68 patients MRCP did not identify any obstruction (9/11 were true negative cases). A diagnosis of benign obstruction was expressed in 36/59 patients (4 chronic pancreatitis, 29 choledocolithiasis, 4 inflammatory obstruction, 2 primary sclerosing cholangitis), with 1 false positive and 5 false negatives (sensitivity, specificity and diagnostic accuracy of 86%, 95% and 90%, respectively). MRCP identified 23 neoplastic stenoses (20/23 were true positives): the sensitivity, specificity and diagnostic accuracy values were 100%, 87% and 95%, respectively. MRCP correctly identified the level of obstruction in 100% of cases.

CONCLUSIONS

MRCP may be considered as a first-step imaging method in patients with clinical signs of biliary disease. The workload of ERCP in the diagnostic stage could therefore be reduced and its use be reserved for therapeutic indications.