Significance of atherosclerotic plaque location in recanalizing non-acute long-segment occlusion of the internal carotid artery.

To investigate the significance of atherosclerotic plaque location in hybrid surgery comprising both endovascular recanalization approaches and carotid endarterectomy for symptomatic atherosclerotic non-acute long-segment occlusion of the internal carotid artery (ICA), 162 patients were enrolled, including 120 (74.1%) patients in the proximal plaque group and 42 (25.9%) in the distal plaque group. Surgical recanalization was performed in all patients, with successful recanalization in 119 (99.2%) patients in the proximal and 39 (92.9%) in the distal plaque group. The total successful recanalization rate was 97.5% (158/162) with a failure rate of 2.5% (4/162). Periprocedural complications occurred in 5 (4.2% or 5/120) patients in the proximal plaque group, including neck infection in two (1.7%), recurrent nerve injury in 1 (0.8%), and laryngeal edema in 2 (1.7%), and 2 (4.8%) in the distal plaque group, including femoral puncture infection in 2 (4.8%). No severe complications occurred in either group. Univariate analysis showed plaque location was a significant (P = 0.018) risk factor for successful recanalization, and multivariate analysis indicated that the plaque location remained a significant independent risk factor for recanalization success (P = 0.017). In follow-up 6-48 months after the recanalization surgery, reocclusion occurred in two (2.8%) patients in the proximal plaque group and 4 (13.3%) in the distal plaque group. In conclusion, although hybrid surgery achieves similar outcomes in patients with ICA occlusion caused by either proximal or distal atherosclerotic plaques, plaque location may be a significant risk factor for successful recanalization of symptomatic non-acute long-segment ICA occlusion.

Transradial intra-aortic catheter looping in the angioplasty of severe intracranial symptomatic arteriosclerotic diseases.

Purpose: This study aims to investigate the effect and feasibility of intra-aortic catheter looping via transradial access in angioplasty for symptomatic intracranial severe (>70%) atherosclerotic stenosis or occlusion of large arteries (SISOLAs). Materials and methods: Patients with SISOLAs who underwent transradial endovascular angioplasty using the catheter looping technique in the ascending aorta were retrospectively enrolled. The clinical data and treatment outcomes were analyzed. Results: Fifteen patients aged 48-71 years were enrolled in this study. Left vertebrobasilar artery occlusion was present in 1 (6.7%) patient, severe left middle cerebral artery stenosis in 7 (46.7%) patients, severe left internal carotid artery (ICA) stenosis of the ophthalmic segment in 4 (26.7%) patients, severe left ICA stenosis of the cavernous segment in 2 (13.3%) patients, and severe right middle cerebral artery stenosis in 2 (13.3%) patients. The arterial stenosis ranged from 70 to 92% (mean 86%) before stenting. The looping of a guiding catheter in the ascending aorta via transradial access for angioplasty was successful in all patients (100%). The vertebral artery intracranial segment occlusion was successfully recanalized, while severe stenosis in the remaining 14 patients was successfully eliminated. After endovascular recanalization, the residual stenosis was reduced by 12-26% (median 18%). No puncture-related complications or surgical-related neurological complications occurred in these patients. In the follow-up angiography conducted on 10 (66.7%) patients after 6-25 months, no in-stent restenosis was detected. Conclusion: Intra-aortic guiding catheter looping via transradial access for endovascular angioplasty of SISOLAs is technically safe, feasible, and effective, especially when the transfemoral artery approach is difficult or impossible to undertake.

Recanalization of chronic long-segment occlusion of the internal carotid artery with endovascular and hybrid surgery.

To investigate the effect of endovascular and/or hybrid surgical recanalization on chronic long-segment occlusion of the internal carotid artery (ICA) and the effect of occlusion location on the recanalization rate and prognosis, 87 patients with chronic ICA occlusion treated with endovascular approach only or hybrid surgery were retrospectively enrolled. The duration of ICA occlusion ranged from 21 to 360 days (median 30). Type I occlusion (from the neck to below the cavernous segment) consisted of 46 (52.8%) patients while type II (from the neck to above the clinoid segment) of 41 (47.1%). Hybrid surgery was performed in 44 (50.6%) patients while endovascular recanalization only was conducted in the other 43 (49.4%). In all patients, the success rate of recanalization was 93.0% (40/43) for the endovascular approach and 95.5% for the hybrid surgical approach. In patients with type I occlusion, endovascular recanalization only was performed in 22 (47.8%) patients and hybrid surgery in 24 (52.2%), resulting in successful recanalization in all patients (100%). In patients with type II occlusion, the success rate of recanalization was 85.7% (18/21) for the endovascular approach only but 90% (18/20) for the hybrid surgery. The total success rate of recanalization was 94.3% (82/87) for all patients, 100% for type I occlusion, and 87.8% for type II occlusion. No significant (P = 0.12) differences existed in the recanalization rate between groups I and II. Clinical follow-up was performed in 82 (94.3%) patients 6-39 months (mean 16) after the surgery. Re-occlusion occurred in 0 in group I but in four (9.8%) in group II. The mRS was good with 0-2 in 38 (82.6%) patients in group I and in 27 (75%) patients in group II, with no significant (P = 0.78) difference. In conclusion, chronic long-segment ICA occlusion can be safely and efficiently recanalized with the endovascular and hybrid surgery. The location of ICA occlusion may have a critical role in determining the recanalization rate, and careful evaluation of the occlusion location may be helpful in increasing the prognosis of recanalization.

Application of microcatheter shaping based on computational fluid dynamics simulation of cerebral blood flow in the intervention of posterior communicating aneurysm of the internal carotid artery.

Introduction: The present study aimed to investigate the application of the aneurysm embolization microcatheter plasticity method based on computational fluid dynamics (CFD) to simulate cerebral blood flow in the interventional treatment of posterior communicating aneurysms in the internal carotid artery and to evaluate its practicality and safety. Methods: A total of 20 patients with posterior internal carotid artery communicating aneurysms who used CFD to simulate cerebral flow lines from January 2020 to December 2022 in our hospital were analyzed. Microcatheter shaping and interventional embolization were performed according to the main cerebral flow lines, and the success rate, stability, and effect of the microcatheter being in place were analyzed. Results: Among the 20 patients, the microcatheters were all smoothly placed and the catheters were stable during the in vitro model test. In addition, the microcatheters were all smoothly placed during the operation, with a success rate of 100%. The catheter tips were stable and well-supported intraoperatively, and no catheter prolapse was registered. The aneurysm was completely embolized in 19 cases immediately after surgery, and a small amount of the aneurysm neck remained in one case. There were no intraoperative complications related to the embolization catheter operation. Conclusion: Microcatheter shaping based on CFD simulation of cerebral blood flow, with precise catheter shaping, leads to a high success rate in catheter placing, stability, and good support, and greatly reduces the difficulty of catheter shaping. This catheter-shaping method is worthy of further study and exploration.

Transradial access with intra-aortic catheter looping for the treatment of intracranial aneurysms.

Purpose: The study aimed to investigate the feasibility and effect of transradial access with intra-aortic catheter looping for the treatment of intracranial aneurysms. Materials and methods: This retrospective one-center study was performed on patients with intracranial aneurysms which were embolized through transradial access with intra-aortic catheter looping because of the difficulty of transfemoral access or transradial access without intra-aortic catheter looping. The imaging and clinical data were analyzed. Results: A total of 11 patients were enrolled, including seven (63.6%) male patients. Most patients were associated with one or two risk factors of atherosclerosis. There were nine aneurysms in the left internal carotid artery system and two aneurysms in the right internal carotid artery system. All 11 patients had complications with different anatomic variations or vascular diseases, which made endovascular operation via the transfemoral artery difficult or a failure. The right transradial artery approach was adopted in all patients, and the success rate of intra-aortic catheter looping was 100%. Embolization of intracranial aneurysms was successfully completed in all patients. No instability of the guide catheter was encountered. No puncture site complications or surgical-related neurological complications occurred. Conclusion: Transradial access with intra-aortic catheter looping for embolization of intracranial aneurysms is technically feasible, safe, and efficient as an important supplementary approach to the routine transfemoral access or transradial access without intra-aortic catheter looping.

Endovascular treatment of intracranial vertebral artery unruptured dissecting aneurysms: Comparison of flow diversion and stent-assisted coiling or stenting alone.

Purpose: To investigate the effect and safety of flow diverters in the treatment of unruptured dissecting intracranial aneurysms of the vertebral artery in comparison with stent-assisted coiling or stenting alone. Materials and methods: Patients with unruptured dissecting intracranial aneurysms of the vertebral artery treated with the flow diverter, stent-assisted coiling, or stenting alone were retrospectively enrolled. The clinical data were analyzed and compared. Results: Twenty-five patients were enrolled in the flow diversion group and 42 patients in the stenting group. Twenty-six flow diverters were deployed in the flow diversion group. Immediate angiography revealed contrast agent retention within the aneurysm cavity in all patients. In the stenting group, 48 stents were deployed, and immediate angiographic outcome showed O'Kelly-Marotta (OKM) grade D in 18 (42.9%) aneurysms, grade C in 16 (38.1%), and grade B in 8 (19.0%). Periprocedural ischemic complications of thrombosis occurred in two (4.8%) patients and were treated with thrombolysis. In the flow diversion group, 19 (76%) patients underwent angiographic follow-up 3-46 (median 24) months after the procedure, with the OKM grade D in 11 (57.9%) patients, C in two (10.5%), and B in six (31.6%). The aneurysm recurrence rate was zero, and all diverters remained patent. Asymptomatic instent stenosis occurred in two (10.5%) patients. In seven of the ten patients with mild or moderate parent artery stenosis before the procedure who experienced angiographic follow-up, the stenosis was improved in five (71.4%) patients. In the stenting group, angiographic follow-up was carried out in 33 (78.6%) patients 6-58 months (median 34) after the procedure, with OKM grade D in 22 (66.7%) patients, grade C in five (15.2%), grade B in three (9.1%), and aneurysm recurrence (grade B, with increased contrast agent into the aneurysm cavity) in three (9.1%). Five (16.7%) patients experienced asymptomatic instent stenosis, and six of the 12 patients (50%) with parent artery stenosis were improved. Conclusion: Flow diverters with or without selective adjunctive coiling for the treatment of unruptured dissecting intracranial aneurysms of the vertebral artery may be safe and effective with good occlusion effects not inferior to those of stent-assisted coiling and stenting alone even though the long-term effect still warrants confirmation.

Transradial versus transfemoral approach for cerebral angiography: A prospective comparison.

OBJECTIVES: To evaluate the feasibility, efficiency, and safety of the transradial approach (TRA) for cerebral angiography versus the transfemoral approach (TFA) in patients. METHODS: In this trial, 2314 patients underwent cerebral angiography, with 1085 patients undergoing the procedure via radial access and 1229 via transfemoral access. The arterial puncture time, operation success rate, oppression time on puncture points, local vascular complication incidence (including bleeding, hematoma, and pseudoaneurysm), deep venous thrombosis of lower limbs (DVT), and bradycardia/hypotension were observed and compared between the two groups. RESULTS: Of the patients who underwent cerebral angiography via radial access, the procedure was successful in 1070 patients; compared with 1219 patients with transfemoral access, there was no significant difference (P > 0.05) in the success rate or the arterial puncture time. Radial access patients were less likely to present with oppression time on puncture points, local vascular complications, DVT, and bradycardia/hypotension compared with femoral access patients. CONCLUSIONS: For patients undergoing cerebral angiography, radial and femoral approaches are both safe and effective. However, the lower rate of local vascular complications may be a reason to use the radial approach.

Tiny Cerebral Aneurysms Can Be Treated Safely and Effectively with Low-Profile Visualized Intraluminal Support Stent-Assisted Coiling or Coiling Alone.

BACKGROUND: The effectiveness and safety of LVIS stent-coiling is currently not known for treating tiny intracranial aneurysms. OBJECTIVE: To investigate the effectiveness and safety of Low-profile visualized intraluminal support (LVIS) stent-assisted coiling and coiling alone in treating patients with mostly ruptured tiny aneurysms. METHODS: Seventy-five patients with tiny intracranial aneurysms, including 63 ruptured ones, were treated endovascularly and analyzed. RESULTS: In the coiling group, complete occlusion was achieved in 35 patients (83.6%)-nearly complete in 4 patients (9.5%) and noncomplete in 3 patients (7.1%). Intraprocedural rerupture occurred in 2 patients (4.8%), and coil protrusion occurred in 1 patient, with a complication rate of 7.1%. Clinical follow-up at 6-12 months revealed a modified Rankin Scale (mRS) score of 0-1 in 41 patients and 3 in 1 patient. In the stent-assisted group, occlusion was complete in 12 patients (36.4%), nearly complete in 15 patients (45.5%), and noncomplete in 6 patients (18.1%). Six stents (18.2%) did not have good adherence to the wall, with thrombus formation in 3 stents (9.1%). Follow-up angiography in 27 patients at 3-6 months showed no dislocation of the stents, complete occlusion in 24 patients (88.9%), and nearly complete occlusion in the other 3 patients. At 6 months, the mRS score was 0 in 30 patients and 2 in 3 patients. No significant (P > 0.05) differences existed between the 2 groups. CONCLUSION: Tiny cerebral aneurysms can be safely and effectively treated with appropriate endovascular approaches based on aneurysm specific morphology, especially neck size and neck-to-dome ratio.

Characteristics and Endovascular Management of the Posterior Cerebral Artery Anterior Temporal Branch Aneurysms.

PURPOSE: To investigate characteristics of the posterior cerebral artery anterior temporal branch aneurysm and the safety and efficacy of endovascular management. MATERIALS AND METHODS: A total of 6 patients with anterior temporal branch aneurysms were enrolled. All 6 patients had concurrent occlusion of the ipsilateral anterior circulating arteries. The aneurysms ranged from 2.5 to 5.0 mm. All patients were treated and followed up. RESULTS: Four unruptured aneurysms were treated with coil embolization of the aneurysm sac only, with the parent artery maintained in 2 patients, slow flow in the parent artery in one and thrombosis at the aneurysm neck leading to parent artery occlusion in the last one. One patient with subarachnoid hemorrhage was treated with coil embolization of both the aneurysm and the parent artery, and the last patient with subarachnoid hemorrhage was treated with the Glubran 2 glue to embolize both the aneurysm and the parent artery. One patient with subarachnoid hemorrhage died of lung complication after embolization. Followed up for 3 months to 1 year, the 4 patients with unruptured aneurysms had no symptoms, including 1 patient with slow flow in the anterior temporal artery and 1 patient with thrombosis and parent artery occlusion. The remaining patient with parent artery occlusion had a good recovery. CONCLUSIONS: The anterior temporal artery aneurysm is a special subtype of aneurysm and can be readily misdiagnosed as on the posterior cerebral artery trunk or the superior cerebellar artery. Endovascular management has a greater success rate, good effect, and fewer complications but with greater difficulties.

Transradial Stenting for Carotid Stenosis in Patients with Bovine Type and Type III Aortic Arch: Experience in 28 Patients.

BACKGROUND: The effects and safety of transradial access for stenting of carotid artery stenosis in patients with bovine-type and type III aortic arch are currently unknown and are the purpose of this study. METHODS: Patients who were treated with stenting via transradial (n = 28) compared with transfemoral (n = 30) access of carotid artery stenosis complicated with bovine-type and type III aortic arch were enrolled. The clinical data were studied for comparison. RESULTS: The success rate of transradial access for carotid artery stenting was 100%. During the transradial access procedure, 3 patients experienced a temporary blood pressure drop and bradycardia that was resolved with atropine injection. No radial artery occlusion or severe cardiac or cerebral events occurred. The success rate of transfemoral access for carotid artery stenting was 90% with failure in 3 patients. No complications occurred during or after the stenting procedure. The irradiation duration was significantly (P = 0.001) smaller in transradial than in transfemoral access stenting (8.6 ± 0.87 vs. 11.4 ± 1.25 minutes). The arterial stenosis ranged 71.25%-96.50% (mean, 86.50% ± 10.15%) for transradial and 78%-97.75% (85.1% ± 10.42%) for transfemoral access groups before treatment, and the residual stenosis following treatment was significantly smaller in either the transradial (2.4%-17.75%; mean, 11.2% ± 6.03%) or transfemoral (4%-18.6%; mean, 12.4% ± 6.3%) groups compared with before treatment, respectively. CONCLUSIONS: The transradial access for stenting of patients with type III aortic arch plus left carotid artery stenosis or in the bovine-type aortic arch combined with right carotid artery stenosis can decrease the stenting difficulty, risks of embolization, and radiation time and increase the success rate.

Stent treatment for basilar artery dissection: A single-center experience of 21 patients.

Basilar artery dissection is a rare disease with high morbidity and mortality. No well-established management strategy exists for this lesion. Endovascular reconstructive therapy using stents (with or without coiling) may be the optimum strategy.We describe our center's experience for this treatment strategy in 21 patients with basilar artery dissection from January 2009 to July 2014 (17 men, four women; age range, 18-70 years; median age, 56 years). We divided patients into two groups: Group 1 patients received stent-assisted coiling treatment, and Group 2 patients received stent-only treatment. Pre-treatment, peri-operation and follow-up evaluation were investigated for complications, clinical outcome and angiographic results. The median follow-up time was 20 months (range, 3-67 months).All patients were treated endovascularly by stent-assisted coiling (14 patients) or stent only (seven patients). Immediate angiography showed: in Group 1, five of 14 lesions were completely occluded, five were partially occluded, four revealed retention of contrast media; in Group 2, all patients (seven of seven) had contrast retention. At the follow-up visit (median seven months, 3-29 months), the aneurysms were angiographically improved in five of 13 patients in Group 1 compared with immediately post-operation, while six of sevenimproved in Group 2. Five patients (all in Group 1) had ischemic or hemorrhage peri-operation complications. Long-term good clinical outcomes (modified Rankin Scale score (mRS) ≤ 2) were achieved in all patients except three death cases (two in Group1, one in Group 2).In our experience, endovascular reconstructive therapy using stents (with or without coiling) for basilar artery dissection is effective and safe. Stent-only treatment seems have a better safety profile during the peri-operation period.

Crystal networks in silk fibrous materials: from hierarchical structure to ultra performance.

This review provides a comprehensive survey of the structural characteristics of crystal networks of silk soft fibrous materials in correlation with the macroscopic properties/performance and the network formation mechanisms. The correlation between the hierarchical mesoscopic structures and the mechanical properties of silk soft fibrous materials including silk fibroin hydrogels and naturally spun silk fibers are addressed based on the hierarchical crystal network models. Namely, two types of hierarchical networks are identified: the weak nanofibril-nanofibril interaction case (i.e., silk fibroin hydrogels), and the strong nanofibril-nanofibril interaction case (i.e., silk fibers). The macroscopic properties, i.e., the rheological/mechanical properties, can be controlled in terms of tuning different levels of hierarchical network structures by ultrasonication-induced gelation, introducing the initial nucleation centers, etc. Such controls take effect by different mesoscale assembly pathways, which are found to occur via different routes of the nucleation and growth processes. Furthermore, the hierarchical network model of soft fibrous materials can be applied to explain the superior mechanical properties and the unique strain-hardening behaviors of spider silk fibers within the framework of hierarchical breaking mechanism. Obviously, a knowledge of crystal networks will allow the prediction of the performance and engineering strategy of silk fibrous materials in generals.

What makes spider silk fibers so strong? From molecular-crystallite network to hierarchical network structures.

A Hierarchical Network (HN) model of soft matter was put forward to explain the mechanical properties of animal silk fibers. At the nano-micro level, the silk fibers consist of a bundle of twisted nano-fibrils with strong friction among them. At the nano-fibril level, ß-crystallites together with silk molecular chains constitute the molecular networks. According to the model, the influences of different structural parameters, i.e. the ordering, and the density of ß-nanocrystallites, on the breaking stress of silk fibers were analyzed quantitatively. It turns out that a better alignment of ß-crystallites, a larger number of ß-crystallites within the cross-section of a nano-fibril and a smaller effective loading area of a peptide chain will correlatively lead to stronger silk fibers. This is in excellent agreement with our observations for both spider dragline and silkworm silk fibers, and explains the fact that the spider dragline silk fibers having a lower crystallinity are much stronger than silkworm silk fibers. Furthermore, it was found that at the nanofibril scale, the interlock among the adjacent nanofibrils in the nanofibril bundle serves as a crack-stopper, which restricts the propagation of cracks. Such a structure reinforces the silk fibers significantly. The knowledge obtained will shed light on how to obtain ultra-strong fibrous materials from the structural point of view.

Interventional therapy for the treatment of severe hemobilia after percutaneous transhepatic cholangial drainage: a case series.

From May 2003 to May 2010, a total of 9 patients with severe hemobilia after percutaneous transhepatic cholangial drainage (PTCD) were diagnosed using superselective angiography and cholangiography, and then were treated with interventional procedures. Two patients with hepatic arterio-biliary fistula underwent proximal and distal arterial embolization of the responsible vessel. Six patients with pseudoaneurysm had pseudoaneurysm occlusion with proximal and distal embolization. Another patient with biliary-portal vein fistula received a biliary fully covered stent placement. The effects in these patients were evaluated using superselective angiography immediately after the intervention and at 3- and 6-month follow-up. In all patients, hemobilia was stopped right after the treatment and no sign of recurrence was noted at 3- and 6-month follow-up after the interventional therapy. Our findings demonstrate that interventional therapy is a simple, minimally invasive, and safe approach for treating severe hemobilia in patients receiving PTCD.