Complex Internal Carotid Artery Aneurysms Research Articles

Viabahn-assisted sutureless anastomosis (VASA) repair of a complex internal carotid artery aneurysm.

Extracranial carotid artery aneurysms (CAAs) are extremely rare and often require surgical intervention to avoid complications such as local compression symptoms and thrombo-embolization. We present the case of a 63-year-old man with a history of hypertension, meningioma, and an incidental finding of a right saccular internal carotid artery aneurysm at the base of the skull. He underwent open surgical repair; nonetheless, end-to-end anastomosis was not feasible. As bailout, the internal carotid artery was successfully reconstructed with a novel Viabahn-assisted sutureless anastomosis technique (GORE, Viabahn). Postoperative clinical assessment revealed no complications, postoperative computed tomography angiography revealed a patent reconstruction, and the patient was discharged home uneventfully with 1-year clinical and computed tomography angiography follow-up without remarks. Hybrid procedure is a viable option for technically challenging carotid anastomoses near the skull base.

Combined standard bypass and parent artery occlusion for management of giant and complex internal carotid artery aneurysms

BackgroundComplex aneurysms do not have a standard protocol for treatment. In this study, we investigate the safety and efficacy of microsurgical revascularization combined with parent artery occlusion (PAO) in giant...

Bypass Surgery for Complex Internal Carotid Artery Aneurysms: 39 Consecutive Patients

Bypass surgery is a special technique used to treat complex internal carotid artery (ICA) aneurysms. The aim of this retrospective study is to provide a comprehensive description of treatment and outcome of complex ICA aneurysms at different ICA segments (cavernous, supraclinoid, ICA bifurcation) treated with bypass procedures. We identified 39 consecutive patients with 41 complex ICA aneurysms that were treated with 44 bypass procedures between 1998 and 2016. We divided the aneurysms into 3 anatomic subgroups to review our treatment strategy. All the imaging studies and medical records were reviewed for relevant information. The aneurysm occlusion (n= 34, 83%) or flow modification (n= 5, 12%) was achieved in 39 aneurysms (95%). The long-term bypass patency rate was 68% (n= 30). Minor postoperative ischemia or hemorrhage was commonly seen (n= 20, 51%), but large-scale strokes were rare (n= 1, 3%). Preoperative dysfunction of extraocular muscles (cranial nerves III, IV, and VI) showed low-to-moderate improvement rates (20%-50%). Preoperative vision disturbance (cranial nerve II) improved seldom (22%). At the latest follow-up (mean; 51 months) 29 patients (74%) were independent (modified Rankin Scale ≤2). Bypass surgery for complex ICA aneurysms is a feasible treatment method with an acceptable risk profile. Patients should be informed of the uncertainty related to improvement of pretreatment cranial nerve dysfunctions.

Management of recurrent intracranial aneurysms after coil embolization: a novel classification scheme based on angiography.

Recurrent aneurysms after coil embolization remain a challenging issue. The goal of the present study was to report the authors' experience with recurrent aneurysms after coil embolization and to discuss the radiographic classification scheme and recommended management strategy. Aneurysm treatments from a single institution over a 6-year period were retrospectively reviewed. Ninety-seven aneurysms that recurred after initial coiling were managed during the study period. Recurrent aneurysms were classified into the following 5 types based on their angiographic characteristics: I, pure recanalization inside the aneurysm sac; II, pure coil compaction without aneurysm growth; III, new aneurysm neck formed without coil compaction; IV, new aneurysm neck formed with coil compaction; and V, newly formed aneurysm neck and sac. Aneurysm recurrences resulted in rehemorrhages in 6 cases (6.2%) of type III-V aneurysms, but in none of type I-II aneurysms. There was a significantly higher proportion of ophthalmic artery aneurysms and complex internal carotid artery aneurysms presenting as types I and II than presented as the other 3 types (63.3% vs 16.4%, p < 0.001). In contrast, for posterior communicating artery aneurysms and anterior communicating artery aneurysms, a higher proportion of type III-V aneurysms was observed than for the other 2 types, but without a significant difference in the multivariate model (56.7% vs 23.3%). In addition, giant (> 25 mm) aneurysms were more common among type I and II lesions than among type III and IV aneurysms (36.7% vs 9.0%, p = 0.001), which exhibited a higher proportion of small (< 10 mm) lesions (65.7% vs 13.3%, p < 0.001). A single reembolization procedure was sufficient to occlude 80.0% of type I recurrences and 83.3% of type II recurrences from coil compaction but only 65.6% of type III-V recurrences from aneurysm regrowth. Aneurysm size and location represent the determining factors of the angiographic recurrence types. Type I and II recurrences were safely treated by reembolization, whereas type III-V recurrences may be best managed surgically when technically feasible.

Graft Occlusion and Graft Size Changes in Complex Internal Carotid Artery Aneurysm Treated by Extracranial to Intracranial Bypass Using High-Flow Grafts with Therapeutic Internal Carotid Artery Occlusion.

Although the extracranial-to-intracranial high-flow bypass (EC-IC HFB) continues to be indispensable for complex aneurysms, the risk factors for the graft occlusion and whether the graft size changes after the bypass have not been well established. To evaluate the risk factors for the graft occlusion and to confirm whether graft diameters changed over time. The data of 75 patients who suffered from complex internal carotid artery (ICA) aneurysms and were treated by EC-IC HFB using radial artery graft (RAG) or saphenous vein graft (SVG) with therapeutic ICA occlusion were evaluated. Clinical and radiological characteristics were compared in patients with and without the graft occlusion by the log-rank test. Graft diameters measured preoperatively, postoperatively, at 6 months, and at 1 year were compared by paired t-test. During a follow-up period (median 26.2 months), graft occlusions were seen in 4 patients (5.3%), and these were the SVGs. Only SVG was related to graft occlusion (P < .001). There was a significant increase with time in RAG diameters (preoperative, 3.1 ± 0.41 mm; postoperative, 3.6 ± 0.65 mm; 6 months, 4.3 ± 1.0 mm; 1 year, 4.4 ± 1.0 mm), while there were no significant diameter changes in SVGs. The present study showed that the SVG was related to the graft occlusion and RAGs gradually enlarged. Unless Allen test is negative, RAG may be better to be used as a graft in EC-IC HFB if therapeutic ICA occlusion is needed.

Rationale for graft selection in patients with complex internal carotid artery aneurysms treated with extracranial to intracranial high-flow bypass and therapeutic internal carotid artery occlusion.

OBJECTIVE After internal carotid artery (ICA) sacrifice without revascularization for complex aneurysms, ischemic complications can occur. In addition, hemodynamic alterations in the circle of Willis create conditions conducive to the formation of de novo aneurysms or the enlargement of existing untreated aneurysms. Therefore, the revascularization technique remains indispensable. Because vessel sizes and the development of collateral circulation are different in each patient, the ideal graft size to prevent low flow-related ischemic complications (LRICs) in external carotid artery (ECA)-middle cerebral artery (MCA) bypass with therapeutic ICA occlusion (ICAO) has not been well established. Authors of this study hypothesized that the adequate graft size could be calculated from the size of the sacrificed ICA and the values of MCA pressure (MCAP) and undertook an investigation in patients with complex ICA aneurysms treated with ECA-graft-MCA bypass and therapeutic ICAO. METHODS In the period between July 2006 and January 2016, 80 patients with complex ICA aneurysms were treated with ECA-MCA bypass and therapeutic ICAO. Preoperative balloon test occlusion (BTO) was performed, and the BTO pressure ratio was defined as the mean stump pressure/mean preocclusion pressure. Low flow-related ischemic complications were defined as new postoperative neurological deficits and ipsilateral cerebral blood flow reduction. Initial MCAP (iMCAP), MCAP after clamping the ICA (cMCAP), and MCAP after releasing the graft (gMCAP) were intraoperatively monitored. The MCAP ratio was defined as gMCAP/iMCAP. Based on the Hagen-Poiseuille law, the expected MCAP ratio ([expected gMCAP]/iMCAP) was hypothesized as follows: (1 - cMCAP/iMCAP)(graft radius/ICA radius)2 + (cMCAP/iMCAP). Correlations between the BTO pressure ratio and cMCAP/iMCAP, and between the actual and expected MCAP ratios, were evaluated. Risk factors for LRICs were also evaluated. RESULTS The mean BTO pressure ratio was significantly correlated with the mean cMCAP/iMCAP (r = 0.68, p < 0.0001). The actual MCAP ratio correlated with the expected MCAP ratio (r = 0.43, p < 0.0001). If the expected MCAP ratio was set up using the BTO pressure ratio instead of cMCAP/iMCAP (BTO-expected MCAP ratio), the mean BTO-expected MCAP ratio significantly correlated with the expected MCAP ratio (r = 0.95, p < 0.0001). During a median follow-up period of 26.1 months, LRICs were observed in 9 patients (11%). An actual MCAP ratio < 0.80 (p = 0.003), expected MCAP ratio < 0.80 (p = 0.001), and (M2 radius/graft radius)2 < 0.49 (p = 0.002) were related to LRICs according to the Cox proportional-hazards model. CONCLUSIONS Data in the present study indicated that it was important to use an adequate graft to achieve a sufficient MCAP ratio in order to avoid LRICs and that the adequate graft size could be evaluated based on a formula in patients with complex ICA aneurysms treated with ICAO.

Willis covered stent for complex internal carotid aneurysms

Objective To investigate the safety and efficacy of the Willis covered stent system for the treatment of complex internal carotid aneurysms. Methods Eight patients with complex internal carotid aneurysm treated with Willis covered stent system at the Department of Neurosurgery, Nanfang Hospital, Southern Medical University from November 2013 to May 2015 were analyzed retrospectively. Among them, 3 patients had internal carotid artery blood blister like aneurysms, 2 had paraclinoid segment aneurysms, and 3 had cavernous segment aneurysms (1 traumatic pseudoaneurysm, 1 iatrogenic pseudoaneurysm, and 1 giant aneurysm). According to the intraoperative condition of the paren artery, the guiding catheters were placed as high as possible (near the cavernous segment) to provide adequate support. After the covered stents were implanted.the balloon were inflated to release the stent and the aneurysm were eliminated at the same time. Results Eight patients with complex internal carotid aneurysm (8 aneurysms) were implanted 8 covered stents, 7 of them were successfully released in the parent arteries. Angiography immediately after stenting in 5 patients showed that the lesions disappeared completely and the parent arteries were patent; After 1 stent was implanted, 1 patient with recurrent giant aneurysm at the cavernous segment after stent-assisted embolization, a small amount of contrast agent leaked into the aneurysm (endoleak). The stent system in place was difficult in 1 patent with blood blister like aneurysm because of his internal carotid artery tortuosity. Iatrogenic internal carotid cavernous fistula occurred during the operation. Bypass and occlusion of the parent artery was performed after balloon embolization. Other cases did not have operation-related complications. The 8 patients were followed up clinically at 2 to 12 months after procedure. They did not have any neurological deficits. The modified Rankin scale (mRS) scores were 0 in 5 cases, 1 in 2 cases, and 2 in 1 case. Three patients got DSA followed-up again at 6 month after procedure. No recurrence of aneurysms was observed, and their parent arteries were patent without stenosis. Conclusion Willis covered stents were safe and effective for the treatment of some complex internal carotid artery aneurysms. Key words: Intracranial aneurysm; Carotid artery, internal; Willis covered stents

クリッピング困難な内頚動脈瘤に対するバイパス併用手術

The treatment of complex internal carotid artery (ICA) aneurysms is still a controversial issue. This study aimed to evaluate the safety and efficacy of a surgical strategy using the bypass procedure in such patients. We retrospectively reviewed the clinical and radiological records of 50 consecutive patients with 52 complex ICA aneurysms who underwent bypass surgery. In this study, we divided the ICA into 3 segments based on the origin of the ophthalmic artery (OpthA) and posterior communicating artery (PComA). All patients with an aneurysm located in the portion proximal to the OpthA (segment 1) were treated with bypass and proximal ICA occlusion, and only 1 patient (5.2%) experienced an ischemic complication. Among patients with an aneurysm located between the OpthA and PComA (segment 2), 14 were treated with bypass and trapping, and 10 were treated with clipping under bypass. Among these, 3 (12.5%) had an ischemic complication and 1 (4.2%) had a hemorrhagic complication. Among patients with an aneurysm located distal to the PComA (segment 3), clipping under temporary bypass was performed in 2, clipping with bypass and proximal occlusion in 4, trapping in 2, and bypass and proximal occlusion in 1. However, 4 of 9 (44.4%) patients had an ischemic complication. Finally, 41 of 50 (82.0%) patients showed a favorable outcome (modified Rankin scale 0-2) in this series. In conclusion, the results of our surgical strategy using a bypass procedure were acceptable; however, ischemic complications were a persistent problem in aneurysms located distal to the PComA.

The Valveless Saphenous Vein Graft Technique for EC-IC High-Flow Bypass: Technical Note

Extracranial to intracranial (EC-IC) high-flow bypass using radial artery or saphenous vein (SV) graft has remained vital for complex aneurysms. If an Allen test is positive, the radial artery cannot be harvested because of poor palmer collateral circulation. The valves are thought to be one of causes of SV graft failure. Herein we illustrate the "valveless SV graft technique" as bypass conduits. Between August 2014 and December 2014 at the Department of Neurosurgery at Teishinkai Hospital, 4 patients whose Allen test was positive underwent EC-IC bypass with the valveless SV graft for complex internal carotid artery (ICA) aneurysm. After SV harvesting, we identified the SV valve, cut it, and performed an end-to-end anastomosis using the fish mouth trimming technique. Graft patency was confirmed by computed tomography angiography. We have not encountered any problems related to graft failure, and all valveless SV grafts were patent during the follow-up period (median, 210 days; interquartile range, 93-287 days). The valveless SV graft technique is a useful technique in patients with complex ICA aneurysms who undergo EC-IC high-flow bypass with therapeutic ICA occlusion and whose Allen tests are positive.

Risk factors for neurological worsening and symptomatic watershed infarction in internal carotid artery aneurysm treated by extracranial-intracranial bypass using radial artery graft.

OBJECT The revascularization technique, including bypass created using the external carotid artery (ECA), radial artery (RA), and M2 portion of middle cerebral artery (MCA), has remained indispensable for treatment of complex aneurysms. To date, it remains unknown whether diameters of the RA, superficial temporal artery (STA), and C2 portion of the internal carotid artery (ICA) and intraoperative MCA blood pressure have influences on the outcome and the symptomatic watershed infarction (WI). The aim of the present study was to evaluate the factors for the symptomatic WI and neurological worsening in patients treated by ECA-RA-M2 bypass for complex ICA aneurysm with therapeutic ICA occlusion. METHODS The authors measured the sizes of vessels (RA, C2, M2, and STA) and intraoperative MCA blood pressure (initial, after ICA occlusion, and after releasing the RA graft bypass) in 37 patients. Symptomatic WI was defined as presence of the following: postoperative new neurological deficits, WI on postoperative diffusion-weighted imaging, and ipsilateral cerebral blood flow reduction on SPECT. Neurological worsening was defined as the increase in 1 or more modified Rankin Scale scores. First, the authors performed receiver operating characteristic curve analysis for continuous variables and the binary end point of the symptomatic WI. The clinical, radiological, and physiological characteristics of patients with and without the symptomatic WI were compared using the log-rank test. Then, the authors compared the variables between patients with and without neurological worsening at discharge and at the 12-month follow-up examination or last hospital visit. RESULTS Symptomatic WI was observed in 2 (5.4%) patients. The mean MCA pressure after releasing the RA graft (< 55 mm Hg; p = 0.017), mean (MCA pressure after releasing the RA graft)/(initial MCA pressure) (< 0.70 mm Hg; p = 0.032), and mean cross-sectional area ratio ([RA/C2 diameter](2) < 0.40 mm [p < 0.0001] and [STA/C2 diameter](2) < 0.044 mm [p < 0.0001]) were related to the symptomatic WI. All preoperatively independent patients remained independent (modified Rankin Scale score < 3). After adjusting for age and sex, left operative side (p = 0.0090 and 0.038) and perforating artery ischemia (p = 0.0050 and 0.022) were related to neurological worsening at discharge (11 [29%] patients) and at the 12-month follow-up or last hospital visit (8 [22%] patients). CONCLUSIONS Results of the present study showed that the vessel diameter and intraoperative MCA pressure had impacts on the symptomatic WI and that operative side and perforating artery ischemia were related to neurological worsening in patients with complex ICA aneurysms treated by ECA-RA-M2 bypass.

Risk Factors for Low-Flow Related Ischemic Complications and Neurologic Worsening in Patients with Complex Internal Carotid Artery Aneurysm Treated by Extracranial to Intracranial High-Flow Bypass

The revascularization technique has remained indispensable for complex aneurysms. However, risk factors for low-flow related ischemic complications (LRICs) and neurologic worsening (NW) have been less well documented. We evaluated the risk factors for LRICs and NW in 67 patients treated with extracranial to intracranial bypass graft using radial artery or saphenous vein graft for complex internal carotid artery (ICA) aneurysm with ICA occlusion. Intraoperative middle cerebral artery pressure (MCAP) by backup superficial temporal artery to middle cerebral artery bypass was measured. The MCAP ratio was the ratio of the MCAP after release of the graft bypass to the initial MCAP. LRICs were defined as new neurologic deficits and ipsilateral cerebral blood flow reduction in single-photon emission computed tomography. Early and late NW were defined as an increase in 1 or more modified Rankin Scale at discharge and at the 12-month follow-up examination. During a median follow-up period of 13.3 months, LRICs were observed in 7 patients (10%). The Cox proportional hazards model showed that an MCAP ratio ≤0.80 was significantly related to LRICs. Multivariate logistic regression analysis revealed that perforating artery ischemia was significantly associated with early NW (n = 13, 19%) and late NW (n = 7, 13%). It also showed that LRICs were also significantly related to late NW. The present study showed that regardless of the graft type, the MCAP ratio was associated with LRICs, which were related to late NW in patients with complex ICA aneurysms treated by extracranial to intracranial high-flow bypass graft.

Endovascular treatment of ophthalmic artery aneurysms: ophthalmic artery patency following flow diversion versus coil embolization

Background and purposeThe Pipeline Embolization Device (PED) has been shown to effectively treat complex internal carotid artery aneurysms while maintaining patency of covered side branches. The purpose of this retrospective...

Extracranial–intracranial bypass in the treatment of complex or giant internal carotid artery aneurysms

ObjectivesDirect microsurgical clipping or endovascular coiling for complex and giant internal carotid artery (ICA) aneurysms is usually risky and leads to inadequate occlusion of the aneurysm. Extracranial–intracranial (EC-IC) bypass may help eliminate neurological complications. Materials and methodsWe retrospectively reviewed patients with intracranial aneurysms who were treated with the assistance of EC-IC bypass from July 2002 to February 2014. Six patients with complex ICA aneurysms were identified, and their clinical characteristics were analyzed. There were two men and four women ranging in age from 40 to 76 years. Three of these patients presented with hemorrhage, and two with compression with visual impairment. One aneurysm was an incidental finding during a physical examination. ResultsThree of the six ICA complex aneurysms were large or giant sized, one was an ICA blood blister-like aneurysm, one was a dissecting aneurysm, and one was a pseudoaneurysm due to tumor invasion. Bypass was performed with superficial temporal artery–middle cerebral artery anastomosis. The follow-up period ranged from 2 to 103 months (mean 36.67 months). The postoperative bypass patency rate was 100%. One patient had cerebellar intracerebral hemorrhage and one had temporary ptosis. There was no bypass surgery-related morbidity. The modified Rankin scale showed good outcomes in four of the six patients. ConclusionsCerebral revascularization plays an important role in the treatment of complex ICA aneurysms that have a significant mass effect on the optic nerve or require occlusion of the parent ICA as a salvage procedure.

E-112 endovascular coil embolization versus stent-assisted coil embolization of complex internal carotid artery aneurysms: long-term follow-up of treatment effectiveness

Introduction/purpose Compare the outcomes of coil embolization alone (CA) versus stent-assisted coil embolization (SAC) in aneurysms of internal carotid artery (ICA) with unfavorable anatomic characteristics. Materials and methods Institutional Review Board approval was obtained for this study. Retrospective review of the patient registry containing 767 patients with 1,170 aneurysms was performed. Inclusion criteria: 1. Previously untreated aneurysm internal carotid artery aneurysm 2. Complex morphology: Neck size of ≥4mm or a dome to neck ratio Results Patients characteristics and number of aneurysms treated did not differ significantly between the two groups. Aneurysm baseline characteristics in the two groups are similar except for significantly wide neck size in SAC group (CA: 4.4 ± 1.7 versus SAC: 5.5 ± 1.8, P = 0.003). No significant change between the study groups demonstrated for safety end-point (p = 0.99). In spite of similar effectiveness in both the CA and SAC groups at immediate post treatment phase (n = 18 (45%) vs. n = 18 (41.9%) respectively, P = 0.827) and at 6-months follow-up (n = 17 (58.6%) vs. n = 24 (70.6%) respectively, P = 0.428), patients in the SAC group shows significantly higher effectiveness (n = 13 (43.3%) vs. n = 26 (68.4%), P = 0.038, in the CA vs. SAC groups respectively) beyond 6 months. Conclusion Stent-assisted coil embolization in unruptured complex internal carotid artery aneurysms with an unfavorable anatomy offers a more effective long-term treatment option while having a similar safety profile to coil embolization alone. Disclosures S. Boddu: None. A. Banihashemi: None. P. Gobin: None. J. Knopman: None. A. Patsalides: None.

Monitored gradual occlusion of the internal carotid artery followed by ligation for giant internal carotid artery aneurysms

To demonstrate a technique of gradual monitored occlusion of the internal carotid artery (ICA) followed by ligation for giant aneurysms as an option for balloon test occlusion followed by permanent ligation of ICA. Authors retrospectively analyzed 27 patients with giant and complex ICA aneurysms who underwent carotid artery ligation between January 2001 and December 2010. Clinical presentation included headache, vision loss and diplopia. There were 19 patients with cavernous aneurysm, 5 supraclinoid, 1 ophthalmic, 1 petrous segment and 1 cervical segment aneurysm located extracranially. All demonstrated good cross-circulation. Selverstone clamp was used for gradual occlusion of the ICA over 72 h under closed observation in the intensive care unit. Six patients developed hemiparesis in the postoperative period. Improvement occurred in one patient over two to three weeks while the remaining five patients had residual hemiparesis. One patient developed malignant MCA infarct for which decompressive craniectomy had to be done. There was no mortality in the present series. Gradual monitored occlusion and ICA ligation may be a simple, safe alternative procedure to clipping in surgically inaccessible and complex aneurysms, especially for surgeons with limited experience. Cross circulation study is an absolute requisite for carotid ligation.

Treatment of Complex Internal Carotid Artery Aneurysms

Treatment of Complex Internal Carotid Artery Aneurysms

Ｒａｄｉａｌ ａｒｔｅｒｙ ｇｒａｆｔを用いて治療した内頚動脈病変の長期成績

Complex internal carotid artery disease presents a surgical challenge because limitations and difficulty are encountered with either clipping or endovascular treatment. Our review of previous reports suggests that no current vascular assessment can accurately predict occurrence of ischemic complications after internal carotid artery ligation. The present study concerns long-term clinical outcome of radial artery grafting followed by parent artery trapping or proximal occlusion for management of these difficult lesions. Between September 1997 and October 2007, we performed radial artery grafting followed immediately by parent artery occlusion in 20 sides of 19 patients with complex internal carotid arteries disease with follow-up for more than 36 months (5 men, 14 women; mean follow-up duration, 62 months). All patients underwent postoperative MRI and MRA every year to assess graft patency, ischemic complications, and de novo aneurysm. Another 20 carotid aneurysms with visual disturbance were assessed concerning outcome. Among 13 patients with cranial nerve (III & VI) disturbances, all dysfunctions were improved in cases treated within 8 months of onset to operation. On the other hand, patients with second cranial nerve disturbances were not improved in cases treated after 4 months of onset. No long-term complications were discovered with MRI and MRA. With appropriate attention to surgical technique, radial artery grafting followed by acute parent artery occlusion is a safe treatment for complex internal carotid artery aneurysms. Long-term safety is satisfactory, with no delayed complications such as graft stenosis, ischemic complications or de novo aneurysm formations in follow-up periods of more than 3 years. Good clinical outcome of cranial nerve palsy was achieved in patients treated within 8 months of onset for CN III and VI, and 4 of CN II palsy.

Acute ischemic complications after therapeutic parent artery occlusion with revascularization for complex internal carotid artery aneurysms

Background Parent artery occlusion (PAO) is an alternative surgical strategy for complex internal carotid artery (ICA) aneurysms, which are unclippable because of their anatomical structures, including a broad neck, fragile dome, critical branch, and cavernous sinus location. Despite revascularization, ischemic complications occur after the PAO because of several factors, such as hypoperfusion, embolism, and perforator impairment. Methods Acute ischemic complications and their mechanisms were analyzed in a consecutive series of 32 patients presenting with complex ICA aneurysms treated by PAO. Results Fourteen ruptured and 18 unruptured aneurysms were located in the cavernous sinus (n = 16) and paraclinoid portion (n = 16). Preoperative balloon test occlusion was performed to investigate ischemic tolerance and to select the bypass method in 24 cases. An extracranial-intracranial bypass was constructed using the superficial temporal artery in 17, and a saphenous vein graft was done in 12 cases. Although postoperative hypoperfusion was prevented by revascularization based on the balloon test occlusion, acute ischemic complications due to perforator occlusion and thromboembolism were observed in 10 cases after the surgery. Five cases presented with impairment of perforating branches adjacent to the occluded parent artery, resulting in prolonged neurologic deterioration. Conclusion The distal location of ICA aneurysms is a risk factor for the perforator impairment, when treated by PAO, and PAO by clip placement is preferred to endovascular coiling to prevent of perforator impairment.

内頸動脈瘤に対するＲＡグラフトの合併症‐その原因と予後‐

Complex giant or large internal carotid artery aneurysms present a surgical challenge because limitations and difficulty are encountered with either clipping or endovascular treatment. Our review of previous reports suggests that no current vascular assessment can accurately predict the occurrence of ischemic complications after internal carotid artery ligation. The present study concerns surgical technique, complications, and clinical outcome of radial artery grafting followed by parent artery trapping or proximal occlusion for management of these difficult lesions. Between September 1997 and October 2005, we performed radial artery grafting followed immediately by parent artery occlusion in 17 patients with giant or large complex intracranial carotid aneurysms (3 men, 14 women; mean follow-up duration, 62 months). All patients underwent postoperative digital subtraction angiography to assess graft patency and aneurysm obliteration. All 17 aneurysms were excluded from the cerebral circulation, with all radial artery grafts patent. Among 4 patients with cranial nerve disturbances, dysfunction was temporary in 5; in the others, oculomotor nerve paresis persisted. No perioperative cerebral infarction occurred. Sensory aphasia reflecting cerebral contusions caused by temporal lobe retraction resolved within 2 months, as did hemiparesis from a postoperative epidural hematoma. With appropriate attention to surgical technique, radial artery grafting followed by acute parent artery occlusion is a safe treatment for complex internal carotid artery aneurysms. Graft patency and aneurysm thrombosis were achieved in all patients. Cranial nerve dysfunction (III, VI) caused by altered blood flow from the internal carotid artery after occlusion was the most common complication and typically was temporary. In our experience with these difficult aneurysms, not only clipping but also reconstruction of the internal carotid artery was required, especially for wide-necked symptomatic cavernous internal carotid artery aneurysms. Radial artery grafting was a reliable way to bypass the parent segment just prior to its occlusion.

血行再建術を用いた脳動脈瘤治療におけるＢａｌｌｏｏｎ ｔｅｓｔ ｏｃｃｌｕｓｉｏｎの有用性と問題点

For the treatment of patients with complex internal carotid artery (ICA) aneurysms, it may be necessary to occlude the parent artery following a bypass surgery. The bypass surgery may be low or high flow bypass, but selection criteria have not been established. We retrospectively analyzed our method using preoperative balloon test occlusion (BTO). Thirty-five patients with ICA aneurysms, 15 ruptured and 20 unruptured, were treated with parent artery occlusion with bypass surgery. Preoperative BTO was performed in 27 cases (all unruptured and 7 ruptured, chronic stage cases). When ischemic symptoms occurred during BTO, high flow bypass was performed followed by parent artery occlusion. Otherwise, single-photon emission computed tomographic findings during BTO were used for the bypass selection. If ipsilateral residual blood flow was 70-75% or less of the contralateral hemisphere, high flow bypass was chosen and if between 70-75% and 90%, superficial temporal artery-middle cerebral artery (STA-MCA) bypass was employed. In the acute stage of 8 ruptured cases, BTO was not performed and bypass selection was made according to angiographic findings only. After completion of the bypass, ipsilateral ICA occlusion (ICO) was performed either by direct or intravascular technique. The site of ICO was determined to completely block the blood flow into the aneurysm considering both conventional angiography and BTO findings. A total of 15 STA-MCA and 20 high flow bypasses were performed followed by ICO. There was no mortality or morbidity in unruptured cases. In ruptured cases, there were 3 complications related to surgical procedure such as perforator injury, but no patients showed insufficient ipsilateral cerebral blood flow postoperatively. One asymptomatic cerebral infarction developed due to BTO. In 5 cases, petrous portion collateral flow from external to internal carotid artery was seen, and the ICO was performed above the collateral using intravascular embolization. In patients with complex ICA aneurysms to be treated with bypass surgery and ICO, BTO may provide a reliable tool to determine the bypass method and the site of ICO.