Therapeutic Internal Carotid Artery Occlusion Research Articles

Perioperative and long-term complications following therapeutic internal carotid artery occlusion.

Parent artery occlusion (PAO) is an effective treatment for hemorrhagic diseases associated with the internal carotid artery. There are several reports of long-term cerebral infarction or the formation of de novo cerebral aneurysms following PAO. We retrospectively reviewed these complications in 38 patients who underwent PAO for therapeutic treatment. We investigated perioperative cerebral infarctions, long-term cerebral infarctions, and de novo aneurysms. The mean age of the patients was 64.0 years, and 25 patients (65.8%) were female. The causative diseases were unruptured (n = 19; 50.0%) and ruptured (n = 8; 21.1%) aneurysms. PAO was performed after ischemic tolerance was assessed with balloon test occlusion (BTO), and BTO was performed in 34 patients, of whom 25 (73.5%) had ischemic tolerance. Twenty-six patients (68.4%) were treated with PAO alone, eight (23.5%) with low-flow bypass, and six (17.6%) with high-flow bypass. Perioperative complications occurred in five patients (13.2%): two of the 26 patients (7.7%) who underwent scheduled treatment and three of the 12 patients (25.0%) who underwent emergency treatment. One patient (2.6%) had long-term de novo aneurysm, and none developed cerebral infarction. These results showed that the assessment of ischemic tolerance by performing BTO and appropriate revascularization in scheduled treatments are important to reduce perioperative and long-term cerebral infarctions. PAO must be performed with greater caution in emergency treatment.

Balloon Test Occlusion of Internal Carotid Artery in Recurrent Nasopharyngeal Carcinoma Before Endoscopic Nasopharyngectomy: A Single Center Experience.

ObjectivesEndoscopic nasopharyngectomy (ENPG) is a promising way in treating recurrent nasopharyngeal carcinoma (rNPC), but sometimes may require therapeutic internal carotid artery (ICA) occlusion beforehand. Balloon test occlusion (BTO) is performed to evaluate cerebral ischemic tolerance for ICA sacrifice. However, absence of neurological deficits during BTO does not preclude occur of delayed cerebral ischemia after permanent ICA occlusion. In this study, we evaluate the utility of near-infrared spectroscopy (NIRS) regional cerebral oxygen saturation (rSO2) monitoring during ICA BTO to quantify cerebral ischemic tolerance and to identify the valid cut-off values for safe carotid artery occlusion. This study also aims to find out angiographic findings of cerebral collateral circulation to predict ICA BTO results simultaneously.Material and Methods87 BTO of ICA were performed from November 2018 to November 2020 at authors’ institution. 79 angiographies of collateral flow were performed in time during BTO and classified into several Subgroups and Types according to their anatomic and collateral flow configurations. 62 of 87 cases accepted monitoring of cerebral rSO2. Categorical variables were compared by using Fisher exact tests and Mann–Whitney U tests. Receiver operating characteristic curve analysis was used to determine the most suitable cut-off value.ResultsThe most suitable cut-off △rSO2 value for detecting BTO-positive group obtained through ROC curve analysis was 5% (sensitivity: 100%, specificity: 86%). NIRS rSO2 monitoring wasn’t able to detect BTO false‐negative results (p = 0.310). The anterior Circle was functionally much more important than the posterior Circle among the primary collateral pathways. The presence of secondary collateral pathways was considered as a sign of deteriorated cerebral hemodynamic condition during ICA BTO. In Types 5 and 6, reverse blood flow to the ICA during BTO protected patients from delayed cerebral ischemia after therapeutic ICA occlusion (p = 0.0357). In Subgroup IV, absence of the posterior Circle was significantly associated with BTO-positive results (p = 0.0426).ConclusionAngiography of cerebral collateral circulation during ICA BTO is significantly correlated with ICA BTO results. Angiographic ICA BTO can be performed in conjunction with NIRS cerebral oximeter for its advantage of being noninvasive, real-time, cost-effective, simple for operation and most importantly for its correct prediction of most rSO2 outcomes of ICA sacrifice. However, in order to ensure a safe carotid artery occlusion, more quantitative adjunctive blood flow measurements are recommended when angiography of cerebral collateral circulation doesn’t fully support rSO2 outcome among clinically ICA BTO-negative cases.

Extracranial vertebral artery to middle cerebral artery bypass in therapeutic internal carotid artery occlusion for epipharyngeal carcinoma: A technical case report.

Background: Vertebral artery (VA) to middle cerebral artery (MCA) bypass is a rarely selected technique because a complex expanded dissection is required, and often, a better donor artery than VA exists. A good indication for VA-MCA bypass is the treatment of head-and-neck malignancies with the sacrifice of the internal carotid artery (ICA) or for carotid artery rupture.Methods: A 23-year-old man with epipharyngeal carcinoma, treated by ligating the carotid artery with a VAMCA bypass before chemoradiotherapy, was reported. Radiographic findings showed that the bone of the carotid canal was dissolved, and the right ICA was engulfed by the tumor. As epipharyngeal carcinoma is hypersensitive to radiation, in cases where the tumor rapidly disappears, ICA may dangle in the pharynx and rupture may occur. In addition, to irradiate sufficiently, the ICA may become an obstacle. Hence, we decided to perform carotid ligation with a VA-MCA bypass before radiation and chemotherapy for the primary lesion. We selected the V3 portion of the VA as the donor on the ipsilateral side, as it can supply high-flow cerebral blood flow, which is not influenced by carcinoma and less influenced by irradiation for the epipharynx.Results: The VA-MCA bypass was completed without complications followed by endovascular occlusion of the ICA. Induction chemotherapy was initiated for the patient 2 weeks after surgery. The patient achieved a complete response following chemoradiotherapy.Conclusion: ICA ligation with VA-MCA high-flow bypass earlier than chemoradiotherapy is useful for epipharyngeal carcinoma as it prevents carotid artery rupture and allows radical intervention.

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.

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.

Therapeutic Internal Carotid Artery Occlusion for Large and Giant Aneurysms: A Single Center Cohort of 146 Patients

At our institution, patients with large or giant ICA aneurysms are preferably treated with endovascular ICA balloon occlusion. Alternative treatment or conservative treatment is offered only for patients who cannot tolerate permanent ICA occlusion. In this observational study, we report the clinical and imaging results of ICA occlusion for aneurysms in a large single-center patient cohort. Between January 1995 and January 2015, occlusion of the ICA was considered in 146 patients with large or giant ICA aneurysms. Ninety-six patients (66%) passed the angiographic test occlusion, and, in 88 of these 96 patients (92%), the ICA was permanently occluded. In 11 of 88 patients with angiographic tolerance, ICA occlusion was performed with the patient under general anesthesia without clinical testing. There was 1 hypoperfusion infarction after hypovolemic shock from a large retroperitoneal hematoma (complication rate 1.1% [95% CI, 1%-6.8%]). The mean imaging and clinical follow-up was 35 months (median 18 months; range, 3-180 months). On the latest MR imaging, 87 of 88 aneurysms (99%) were completely occluded and 61 of 80 aneurysms (76%) were decreased in size or completely obliterated. Of 62 patients who presented with cranial nerve dysfunction by mass effect of the aneurysm, 30 (48%) were cured, 25 (40%) improved, 6 (10%) were unchanged, and 1 patient (2%) was hemiplegic after a complication. ICA occlusion for large and giant aneurysms after angiographic test occlusion was safe and effective. Two-thirds of eligible patients passed the angiographic test. Most aneurysms shrunk, and most cranial nerve dysfunctions were cured or improved.

Bilateral Cavernous Carotid Aneurysms: The Growth Potential of a Contralateral Aneurysm after Therapeutic Unilateral Internal Carotid Artery Occlusion

Although the introduction of flow-diverter stents has been recognized as a major revolution in the treatment of cavernous carotid aneurysms (CCAs), therapeutic internal carotid artery occlusion (TICAO) remains a reliable procedure for alleviating symptoms caused by CCAs. However, TICAO has the potential risk of the enlargement of coexisting aneurysms that are frequently detected in CCA patients. The purpose of this study is to assess the occurrence of the enlargement of aneurysms coexisting with CCAs after TICAO. We reviewed medical charts of CCA patients who were managed using unilateral TICAO. Coexisting aneurysms were identified using angiograms obtained before TICAO, and imaging data in long follow-up periods were retrospectively examined to determine the extent of the enlargement after TICAO. Of 12 patients with CCAs, 10 had 12 coexisting aneurysms; 5 of the coexisting aneurysms (41.7%) showed enlargement during a mean follow-up period of 8.1 years, and all enlarged aneurysms were smaller of the bilateral CCAs; the larger CCA had been managed by TICAO. Five of 6 (83.3%) patients with bilateral CCAs showed enlargement of the contralateral aneurysm after TICAO. Two contralateral CCAs showed marked enlargement after TICAO and were subsequently treated with stent-assisted coil embolization. Contralateral, smaller aneurysms frequently enlarge after unilateral TICAO in patients with bilateral CCAs. The findings emphasize the importance of long-term observation after TICAO and appropriate interventions against enlarging contralateral aneurysms.

Unruptured Large and Giant Carotid Artery Aneurysms Presenting with Cranial Nerve Palsy: Comparison of Clinical Recovery after Selective Aneurysm Coiling and Therapeutic Carotid Artery Occlusion

Internal carotid artery (ICA) aneurysms may present with cranial nerve dysfunction. Therapeutic ICA occlusion, when tolerated, is an effective treatment resulting in improvement or cure of symptoms in most patients. When ICA occlusion is not tolerated, selective endovascular aneurysm occlusion can be considered. We compare recovery of cranial nerve dysfunction in patients treated with selective coil occlusion and with therapeutic ICA occlusion. In 16 patients with 17 large or giant (11-45 mm) unruptured ICA aneurysms presenting with dysfunction of cranial nerves (CN) II, III, IV, or VI, selective coil occlusion was performed. From a cohort of 39 patients with ICA aneurysms treated with ICA occlusion and long-term follow-up, we selected 31 patients with aneurysms presenting with cranial nerve dysfunction. Clinical recovery at follow-up from oculomotor dysfunction and visual symptoms was compared for both treatment modalities. Of 17 aneurysms treated with selective coiling, symptoms of cranial nerve dysfunction resolved in 3, improved in 10, and remained unchanged in 4. In 9 of 17 patients, additional coiling during follow-up was required. Of 31 aneurysms treated with carotid artery occlusion, cranial nerve dysfunction resolved in 19, improved in 9, and remained unchanged in 3. These differences were not significant. There were no complications of treatment. Recovery of ICA aneurysm-induced cranial nerve dysfunction occurs in most patients, both after ICA occlusion and after selective coiling. In patients who cannot tolerate ICA occlusion, selective aneurysmal occlusion with coils is a valuable alternative.

Long-Term Clinical Follow-Up of Therapeutic Internal Carotid Artery Occlusion

I read with interest and congratulations the results of “Long-Term 3T MR Angiography Follow-Up after Therapeutic Occlusion of the Internal Carotid Artery to Detect Possible de Novo Aneurysm Formation,”[1][1] as well as the opinion regarding management of internal carotid artery (ICA) aneurysms

Pathogenesis of subcortical hyperintense lesions on magnetic resonance imaging of the brain. Observations in patients undergoing controlled therapeutic internal carotid artery occlusion.

Factors associated with the pathogenesis of subcortical hyperintense lesions on magnetic resonance imaging of the brain are not known. We describe four cases of de novo genesis of subcortical hyperintense lesions in patients undergoing controlled therapeutic internal carotid artery occlusion, and we speculate on associated pathophysiological mechanisms. Twelve consecutive patients underwent controlled therapeutic internal carotid artery occlusion for symptomatic giant cerebral aneurysm using the detachable balloon technique under full anticoagulation. Preocclusion (within 2 weeks) and postocclusion (within 6 weeks) magnetic resonance imaging of the brain was performed in eight cases and evaluated for preexisting and new appearance of subcortical hyperintense lesions. There were four instances of de novo genesis of subcortical hyperintense lesions after carotid occlusion. New subcortical hyperintense lesions were ipsilateral to carotid occlusion in every instance and in two cases were associated with ipsilateral hemispheric ischemic symptoms despite anticoagulant therapy. In one instance, there were transient hemispheric symptoms without the appearance of new subcortical hyperintense lesions. Age, vascular risk factors, and preexisting subcortical hyperintense lesions did not appear to predispose patients to de novo genesis of new hyperintensities. This is the first documentation of de novo genesis of subcortical hyperintense lesions in a controlled setting of hemodynamic ischemic insult. Symptomatic and asymptomatic lesions can be detected in this setting. Anticoagulation does not appear to provide protection from this phenomenon. Careful prospective studies are required to further evaluate risk factors and possible clinical consequences associated with the genesis of new subcortical hyperintense lesions.

Superficial temporal artery to proximal middle cerebral artery anastomosis: clinical and angiographic long term results.

Anastomosis of the superficial temporal artery (STA) with a proximal segment of the middle cerebral artery (MCA) has been proposed as a new cerebral revascularization technique alternative to the conventional bypass on the cortical surface. We introduced this procedure in our surgical practice in 1982 for patients with internal carotid artery (ICA) aneurysms not suitable for direct repair in whom occlusion of the ICA is considered necessary. One patient died because a conventional STA-MCA bypass did not prevent a major stroke caused by a therapeutic ICA occlusion. We are reporting our surgical technique and the immediate and long term clinical and angiographic results in five cases operated on during the period June 19, 1982, through January 19, 1983. The early and late patency rates were good. No neurological complications were observed after the bypass procedure or during a 3-year follow-up period. In our opinion, the use of proximal segments of the MCA as recipient arteries for supratentorial revascularization is a good alternative to the use of cortical surface arteries and, in selected cases, could be the first choice technique.