Correlation of postoperative and two-year follow-up angiography with neurological function in 99 carotid endarterectomies in 86 consecutive patients.

Eighty-six consecutive patients in 1982 underwent 99 endarterectomies and routine postoperative digital subtraction angiography. Ten vessels were closed primarily and 89 with a patch graft. Minor morbidity was 2%, major morbidity 0%, and mortality 1%, but these varied according to the patient's preoperative medical and neurological function and angiographic findings. Postoperative patency for the common carotid artery (CCA) and internal carotid artery (ICA) was 100% and for the external carotid artery (ECA) 97%. Seventy-nine vessels were evaluated by a DSA 2 years after surgery. There was one asymptomatic occlusion in follow-up and one symptomatic re-stenosis in a patient with a proven heparin induced hypercoagulability state. The three postoperative ECA occlusions were associated with a lethal postoperative stroke, the only ICA occlusion in follow-up, and a 50% stenosis of the CCA in follow-up at the site of ECA occlusion. Vein patch grafting protected the ICA but not the CCA from recurrent stenosis. The carotid slim sign on preoperative angiograms is judged to indicate a patient at high risk of stroke morbidity.     

Impact of external carotid artery occlusion at declamping of the external and common carotid arteries during carotid endarterectomy on development of new postoperative ischemic cerebral lesions

Objective

The external carotid artery (ECA) is inadvertently occluded during carotid endarterectomy (CEA). The importance of ECA occlusion has been emphasized as a loss of extracranial to intracranial collaterals, a source of chronic embolization, or a site for extended thrombosis during wound closure. This study aimed to determine whether ECA occlusion that inadvertently developed during endarterectomy and that was eventually detected using blood flow measurement of the ECA after declamping of all carotid arteries is a risk factor for development of new postoperative ischemic lesions at declamping of the ECA and common carotid artery (CCA) while clamping the internal carotid artery (ICA). This study also aimed to determine whether intraoperative transcranial Doppler (TCD) monitoring predicts the risk for development of such lesions.

Hemodynamic conditions at the carotid bifurcation during protective common carotid occlusion.

OBJECTIVES: Carotid angioplasty and stenting procedures are associated with an obligatory release of particulate debris into the distal cerebral circulation. Although most of the emboli are small and do not result in symptomatic neurologic deficits, some may be large enough to cause stroke. For this reason, a variety of filters and balloon occlusion devices have been employed as adjuvants to decrease the risk of distal embolization during carotid stenting. Some of these devices rely on the arrest of antegrade blood flow with the use of inflow arrest. The present study was undertaken to investigate the hemodynamic conditions that exist at the carotid bifurcation during common carotid artery (CCA) occlusion. METHODS: Internal carotid artery (ICA) and external carotid artery (ECA) stump pressures were measured in 29 patients undergoing carotid endarterectomy. Duplex ultrasound scanning was used to measure the direction and velocity of blood flow in the ICA and ECA with the CCA cross-clamped but the ICA and ECA open, a clinical scenario analogous to CCA balloon occlusion at the time of carotid angioplasty and stenting. The direction and magnitude of ICA and ECA flow were compared with the stump pressures to determine whether a correlation existed between these variables. RESULTS: The mean stump pressure in the ICA and ECA averaged 56 +/- 16 and 53 +/- 12 mm Hg, respectively. The ICA systolic stump pressure was lower than the ECA systolic stump pressure in six patients (21%), and all of these patients had persistent antegrade systolic duplex blood flow by duplex interrogation during CCA occlusion. The ICA systolic stump pressure exceeded the ECA systolic stump pressure in 19 patients (66%), and all of these patients had retrograde ICA flow during systole. Diastolic flow was also well correlated with the magnitude of the ICA/ECA stump pressure differential, with antegrade diastolic ICA blood flow in all nine patients with an ICA diastolic stump pressure less than the ECA diastolic stump pressure. None of the 10 patients with ICA diastolic stump pressure greater than ICA diastolic stump pressure maintained antegrade ICA diastolic flow, but four of these patients had flow to zero in diastole. Overall, 13 of 29 patients (45%) could be surmised to be at risk for distal embolization to the brain based on the persistence of some element of either systolic or diastolic antegrade ICA flow during common carotid occlusion. CONCLUSIONS: Common carotid occlusion alone appears insufficient to protect against distal embolization during manipulations of the carotid bifurcation. Persistent systolic or diastolic antegrade blood flow occurs in a high proportion of patients, lending credence to the use of additional protective strategies to ameliorate the risk of embolic complications.     

The role of external carotid revascularization in the treatment of ocular ischemia

During the past 13 years, 16 patients with visual disturbances, ipsilateral internal carotid artery (ICA) occlusion, and external carotid artery (ECA) stenosis have had ECA reconstruction. Indications for operation included amaurosis fugax (AF) in five patients, AF and transient ischemic attacks in four patients, ischemic optic neuropathy in two patients, retinal artery occlusion in one patient, and blurry vision and scotomata in four patients. In 12 cases (75%), there were hemodynamically significant contralateral ICA lesions, including four contralateral ICA occlusions. EC endarterectomies were performed in 15 patients, whereas one patient was treated with a bypass graft. One transient neurologic event occurred in the perioperative period (6%). There were no deaths nor permanent neurologic deficits. Patients were followed up for periods of 1 to 60 months (mean 18.4 months). Two patients had AF postoperatively; in one instance, AF was associated with ECA thrombosis 53 months after operation. One patient had a transient ischemic attack when the ECA thrombosed 24 months after operation. This study demonstrates that visual symptoms can occur despite ipsilateral ICA occlusion. ECA revascularization is effective and can be performed with acceptable morbidity and mortality.     

Computational analysis of effects of external carotid artery flow and occlusion on adverse carotid bifurcation hemodynamics

OBJECTIVE: This is a computational analysis of the effects of external carotid artery (ECA) flow, waveform, and occlusion geometry on two hemodynamic wall parameters associated with intimal hyperplasia and atherosclerosis.Study design Transient three-dimensional fluid mechanics analysis was applied to a standard carotid artery bifurcation. Mean internal carotid artery (ICA) flow was maintained at 236 mL/min with a normal waveform. ECA flow was increased from zero to 151 mL/min (64% of ICA flow) with both a normal biphasic waveform and a damped waveform. Geometry of five ECA occlusions was studied: distal, proximal stump, smooth, smooth without carotid sinus, and optimal reconstruction.Primary outcome measures Two time-averaged and area-averaged hemodynamic wall parameters were computed from the velocity and wall shear stress (WSS) solutions, ie, wall shear stress angle gradient (WSSAG) and oscillatory shear index (OSI). Both local and area-averaged hemodynamic wall parameters were computed for the distal common carotid artery (CCA) and the proximal ICA. RESULTS: When ECA flow with a normal waveform is increased from zero to 151 mL/min, area-averaged WSS values increase in the CCA, from 3.0 to 4.4 dynes/cm(2) (46%), and in the ICA, from 16.5 to 17.1 dynes/cm(2) (4%); minimum local WSS values in the carotid sinus remain less than 1 dyne/cm(2); maximum local values of WSSAG and OSI are observed in the carotid sinus and increase from 3.5 to 9.1 radian/cm (160%) and 0.23 to 0.46 (100%), respectively; CCA plus ICA area-averaged WSSAG increases by 52%, and OSI increases by 144%; and damping of the ECA waveform has little effect on local or area-averaged WSSAG but reduces OSI to 68%. When the ECA is occluded, the minimum local WSS in the carotid sinus is less than 1 dyne/cm(2). However, if the carotid sinus is removed or the CCA-ICA geometry hemodynamically optimized, the minimum WSS is approximately 4 dynes/cm(2). Similarly, eliminating the carotid sinus markedly reduces local maximum WSSAG, from 3.0-3.5 radian/cm to 0.3 radian/cm, and reduces local maximum OSI from 0.22-0.49 to 0.04. Area-averaged WSSAG and OSI over the CCA and ICA are reduced by approximately 50% with elimination of the carotid sinus. CONCLUSIONS: The degree of adverse carotid bifurcation hemodynamics as measured with WSSAG and OSI is directly proportional to ECA flow. The marked difference in normal ICA and ECA flow waveforms does not contribute to adverse wall hemodynamics. Location of an ECA occlusion (distal, proximal, stump, smooth) does not affect adverse carotid hemodynamics; however, marked improvement is obtained with elimination of the carotid sinus.     

Intraoperative duplex ultrasonography as an adjunct to technical excellence in 100 consecutive carotid endarterectomies

PURPOSE: To evaluate the relationship of intraoperative duplex ultrasonography (duplex) results to neurologic outcomes and restenosis among patients undergoing carotid endarterectomy (CEA). METHODS: One hundred consecutive CEAs were performed at a military medical center over 28 months. Prospectively acquired demographics, duplex results, revisions, and surgical outcomes were reviewed. RESULTS: Thirty-four percent (34 of 100) of sites were abnormal by completion duplex. Of these, 70% (24 of 34) were B-mode flap type defects located in the common carotid artery (CCA), internal carotid artery (ICA), or external carotid artery (ECA). Twenty-one percent of the defects (7 of 34) were technically unacceptable and immediately revised. Subsequently, 3 perioperative neurologic events occurred, 2 strokes and 1 transient ischemic attack (TIA), all among patients with an identified but unrepaired defect involving the ICA or CCA. This association of unrepaired defect with early stroke or TIA was significant (P = 0.02). No significant association (P >0.05) between unrepaired defects and late ipsilateral stroke or TIA or restenosis was identified. CONCLUSIONS: Intraoperative duplex scanning is a useful adjunct to CEA that can identify correctable mechanical problems. Residual elevated velocities or B-mode flaps 2 mm or greater in the ICA warrant consideration for immediate repair. Findings not requiring revision include flaps <2 mm, as well as isolated ECA defects. Prospectively validated duplex criteria are needed to further define which defects require immediate repair.     

颈内动脉闭塞术的初步临床应用

目的探讨颈内动脉闭塞术治疗颈内动脉血管性病变的价值。方法共5例患者,1例鼻咽癌行放疗后清创术,并发难以制止的鼻咽部大出血,双侧后鼻孔填塞无效;1例巨大颈内动脉眼段动脉瘤,无法手术夹闭;3例外伤后颈内动脉海绵窦瘘,单纯闭塞瘘口失败。采用Seldinger技术经股动脉穿刺置管行全脑血管造影,经球囊闭塞试验或病变侧压颈试验,病人耐受良好后方行闭塞术。闭塞材料为3例应用可脱弹簧圈,2例应用可脱球囊,闭塞位置为病变近端及瘘口。结果所有病例闭塞颈内动脉后,即行对侧颈动脉造影复查,可见前交通动脉和/或后交通动脉代偿良好,患者无明显并发症发生,病变未见显影。临床症状消失、无合并症发生,病变未见复发。结论颈内动脉闭塞术作为一种治疗颈动脉血管性疾病的方法,可以在不危及病人生命、加重病人病情的情况下,取得良好的治疗效果。     

Combined carotid endarterectomy with transluminal angioplasty and primary stenting of the supra-aortic vessels

BACKGROUND: Carotid endarterectomy (CEA) is the standard of care for patients with high-grade carotid artery stenosis who are acceptable surgical candidates. Focal occlusive lesions of the origin of aortic arch vessels can be effectively and safely treated with balloon angioplasty and primary stenting. The purpose of this study was to retrospectively review results of carotid endarterectomy for high-grade carotid bifurcation stenosis combined with intraoperative retrograde transluminal angioplasty and primary stenting of a hemodynamically significant stenosis at the origin of a proximal ipsilateral aortic arch vessel. METHODS: Between October 1994 and August 1998, 592 patients underwent CEA. Six patients were found to have hemodynamically significant tandem lesions affecting one of the aortic arch vessels and the ipsilateral ICA for an overall incidence of 1%. Age ranged from 63 to 78 years (mean 74.7). Four of 6 (67%) patients had asymptomatic lesions, and 2 of 6 (33%) had symptoms of cerebral ischemia. Five patients had tandem lesions affecting the proximal left common carotid artery and the left ICA. One patient had a tandem lesion affecting the innominate artery and the right ICA. Carotid duplex imaging and arch and cerebral arteriography was performed in all six patients. Arteriography confirmed high-grade stenoses in both the ICA and ipsilateral proximal aortic arch vessel. The range of stenoses in the ICA was 70 to 95% (mean 80.8%) measured arteriographically. The range of stenoses at the origin of the aortic arch vessels was 75-90% (mean 79.2%). All six patients underwent combined retrograde transluminal balloon angioplasty and primary stenting of the ipsilateral CCA or innominate artery with temporary occlusion of the ICA for cerebral protection. The endovascular procedure was then followed with standard surgical endarterectomy using an inline shunt. RESULTS: All six procedures were successfully completed. There were no periprocedural strokes or other morbidities. Follow-up ranged from 6 to 43 months (mean 23.6) and showed no evidence of recurrent stenosis by carotid duplex imaging. No TIAs or strokes related to the surgically corrected lesions were noted during the follow-up period. One patient suffered a right hemispheric stroke secondary to a high-grade right carotid stenosis which occurred two months after her procedure surgically correcting tandem lesions on the opposite side. CONCLUSIONS: Carotid endarterectomy with balloon angioplasty and primary stenting of an ipsilateral hemodynamically significant aortic arch trunk vessel stenosis can be safely and successfully accomplished and avoids the need for an intra/extrathoracic bypass procedure.     

External carotid artery revascularization: indications, operative techniques and results.

The external carotid artery (ECA) is an important collateral pathway in patients with ipsilateral internal carotid artery (ICA) occlusion and recurrent symptoms. An ipsilateral ECA revascularization can improve cerebral perfusion or eliminate an embolic source. In the past 11 years 11 patients underwent operation, 6 times for amaurosis fugax and 5 times for transient ischaemic attacks. Eight times ECA endarterectomy was performed for stenosis and/or ulceration. Eight times closure or separation of the ICA stump with thrombus was carried out. There were no perioperative neurological deficits or deaths, with the exception of 3 patients who already had a long-standing deficit due to the ICA occlusion. All patients were relieved of their ocular or hemispheric symptoms in a follow-up period of 8 years. Two late strokes occurred after 1 1/4 and 4 years. Ipsilateral ECA revascularization is an effective and safe operation and has good long-term results.     

The Influence of Routine Completion Arteriography on Outcome following Carotid Endarterectomy

n = 69) normal; Group B (n= 29), abnormal, severe defects; Group C (n= 56), abnormal, mild–moderate defect. RCA detected 32 defects in Group B: 10 internal carotid (ICA), seven endpoint flaps, two kinks, one dissection; 16 external carotid (ECA), 10 severe endpoint defects and six total occlusion; six common carotid (CCA), five irregular proximal shelfs, one web. Thirty of 32 defects were successfully repaired as confirmed by normal repeat RCA studies; one ECA defect was not repaired and the ICA dissection was irreparable. In Group C, 67 mild–moderate defects were identified, but not corrected. These included <30% stenosis in the ICA (12), ECA (18), CCA (24), and vein patch corrugation or irregularity (13). For the entire series the postoperative ICA occlusion rate was 2% (3/154), stroke rate 2.6% (4/154), and a subsequent >50% restenosis rate of 7% (11/154). The yield from routine carotid completion arteriograms was significant, with 19% of studies identifying a severe defect that required repair. Although the difference in stroke rates and restenosis between the different groups did not reach statistical significance, patients with normal intraoperative arteriograms initially or after correction of a significant RCA defect had no early carotid occlusion (p= 0.05, Fisher's exact test) compared to patients with residual RCA defects. All early carotid occlusions occurred in patients with unrepaired defects. We conclude that RCA is an important method of quality control after CEA and exerts a subtle, but real, reduction in postoperative complications.     

The clinical importance of the inferolateral trunk of the internal carotid artery

The inferolateral trunk (ILT) of the internal carotid artery (ICA) is a branch that arises inferiorly from the C4 segment of the cavernous ICA. It provides blood supply to the 3rd, 4th, and 6th cranial nerves, as well as to the gasserian ganglion. The ILT anastomoses to branches of the internal maxillary artery, providing collateral circulation between the external carotid artery and the ICA systems. Retinal and cerebral emboli can arise from the external carotid artery system and travel via the ILT to the ICA. Cranial nerve palsies may result after occlusion of the ILT. We present the cases of four patients who had iatrogenic neurological dysfunction subsequent to intravascular procedures that involved the ILT. These cases provide further clinical confirmation of the importance of this blood vessel. A 5th case involving iatrogenic occlusion of the ILT and no neurological deficit is also presented, demonstrating that the ILT is not the sole blood supply of the cranial nerves in the cavernous sinus.     

Carotid angioplasty with internal carotid artery flow reversal is well tolerated in the awake patient

OBJECTIVE: The purpose of this study was to evaluate the neurologic tolerance and changes in ipsilateral hemispheric oxygen saturation during transcervical carotid artery stenting with internal carotid artery (ICA) flow reversal for embolic protection. PATIENTS AND METHODS: This was a prospective study of 10 patients (mean age 68 years) undergoing transcervical carotid angioplasty and stenting. All ICA stenoses were greater that 70%. Seven patients had an ipsilateral hemispheric stroke (3) or transient ischemic attack (4), two patients had a contralateral stroke, and one patient was asymptomatic. Nine procedures were done under local anesthesia. Cerebral protection was established through a cervical common carotid (CCA) cutdown to create an external fistula between the ICA and the internal jugular vein with temporally CCA occlusion. Venous oxygen saturation (SVO(2)) was continuously monitored through a catheter placed in the distal internal jugular vein. Mental status and motor-sensory changes were categorized and assessed throughout and after the procedure. RESULTS: All procedures were technically successful without significant residual stenosis. Mean ICA flow reversal time was 22 minutes (range, 15 to 32). Common carotid artery (CCA) occlusion produced a slight (SVO(2) = 72.6%+/-9.4) but significant decrease (P =.012) in SVO(2), compared with baseline (SVO(2) = 77% +/-10.5). During ICA flow reversal (SVO(2) = 72.4% +/-10.1) cerebral oxygen saturation did not change compared with CCA occlusion alone (P =.85). Transient balloon occlusion during angioplasty of the ICA (SVO(2) = 64.6%+/-12.9) produced a significant decrease in cerebral SVO(2) compared with CCA occlusion (P =.015) and compared with CCA occlusion with ICA flow reversal (P =.018). No mental status changes or ipsilateral hemispheric focal symptoms occurred during CCA occlusion with ICA flow reversal. One patient with contralateral ICA occlusion sustained brief upper extremity weakness related to the contralateral hemisphere. Five patients sustained a vasovagal response during balloon dilatation, four did not require treatment, and one had asystole requiring atropine injection. Mean SVO(2) saturation was not different in these five patients compared with the five who did not sustain a vasovagal response. No deaths or neurologic deficits occurred within 30 days after the procedure. CONCLUSIONS: Our data suggest that transcervical carotid angioplasty and stenting with ICA flow reversal is well tolerated in the awake patient, even in the presence of symptomatic carotid artery disease. Cerebral oxygenation during ICA flow reversal is comparable to that during CCA occlusion. ICA angioplasty balloon inflation produces a decrease in cerebral SVO(2) significantly greater than that occurring during ICA flow reversal.     

Angiographic classification for the selection of treatment of spontaneous carotid-cavernous sinus fistula

Sixteen cases of spontaneous carotid-cavernous sinus fistula treated in our clinic were angiographically classified into four types, based on the report by Barrow et al; Type A: direct shunts between the internal carotid artery (ICA) and the cavernous sinus (CS), Type B: dural shunts between meningeal branches of the ICA and the CS, Type C: dural shunts between meningeal branches of the external carotid artery (ECA) and the CS, type D: dural shunts between meningeal branches of both the ICA and ECA and the CS. Our fundamental modality of treatment for each type was described as follows; detachable balloon occlusion of fistula was performed for Type A immediately after the diagnosis was confirmed. On the other hand, conservative treatment was selected at first routinely for Type B, C and D with administration of hemostatic agents, control of the blood pressure and Matas test for a certain period. This selection was made because the latter three types sometimes showed a high rate of spontaneous regression of symptoms. Only when no improvement was obtained by conservative therapy with Type B, C and D, the following treatments were adopted respectively; Type B: irradiation----detachable balloon occlusion of fistula, Type C: embolization through ECA, Type D: embolization through ECA----irradiation.     

Cerebral protection during retrograde carotid artery stenting for proximal carotid artery stenosis: technical note

Carotid artery stenting for carotid bifurcation stenosis usually uses the transfemoral approach. However, in patients with proximal common carotid artery (CCA) stenosis, the guiding catheter is difficult to introduce into the narrow origin of the CCA without risking cerebral embolization before activation of the protection device. A technique of cerebral protection by internal carotid artery (ICA) clamping with or without simultaneous external carotid artery (ECA) clamping was used to treat patients with proximal CCA stenosis by the retrograde direct carotid approach. The carotid bifurcation was surgically exposed and retrograde catheterization was performed to approach the stenosis. The ICA was clamped during angioplasty and stenting to avoid cerebral embolization. The ECA was clamped simultaneously if any extracranial-intracranial anastomosis was present. None of five patients treated with this technique experienced ischemic complications attributable to this technique.     

Thyrocervical trunk-external carotid artery bypass for positional cerebral ischemia due to common carotid artery occlusion. Technical note

Medically refractory positional cerebral ischemia (PCI) and concomitant orthostatic hypotension associated with chronic common carotid artery (CCA) occlusion are rare. In this technical report, the authors describe an extracranial bypass in which the thyrocervical trunk was used as a donor vessel to treat three cases of CCA occlusion with PCI. Postoperatively, although orthostatic hypotension remained, ischemia-related symptoms resolved in all three patients and long-term graft patency was demonstrated. It is possible to treat cerebral ischemia due to CCA occlusion with extracranial bypass surgery. In these patients, the thyrocervical trunk proved to be a suitable donor vessel for the reconstitution of blood flow within the external carotid artery.     

Protection of anastomotic pathways to the vertebral artery during stenting of external carotid artery stenosis

A 61-year-old man presented with a severe external carotid artery (ECA) stenosis with concomitant ipsilateral internal carotid artery (ICA) occlusion manifesting as amaurosis fugax. The left ophthalmic artery was supplied from the left ECA. The left intracranial ICA was supplied by the collateral flow from the contralateral ICA and ipsilateral ECA through the ophthalmic artery. The left vertebral artery also participated in the latter collateral pathway through the left occipital artery and ascending pharyngeal artery. Percutaneous revascularization of the ECA was performed using a nitinol self-expanding stent. To prevent embolic complications through the ophthalmic or vertebral arteries, distal protection was performed using a balloon. During a 22-month follow-up period, the patient was completely free from any ocular or neurological symptoms. The present case of severe ECA stenosis with ipsilateral ICA occlusion showed that percutaneous balloon angioplasty with stenting is feasible and effective. This intervention requires cautious evaluation of the anastomotic pathways connecting the ECA to the cerebral circulation to avoid embolic complications.     

External carotid endarterectomy: indications, technique, and late results

In the past 14 years, 22 patients (25 operated sides), with occlusion of the internal carotid artery (ICA), underwent ipsilateral external carotid artery (ECA) endarterectomy at our institution. Operative indications were amaurosis fugax in 13 sides and nonlateralizing transient ischemic attacks in the remaining 12. There were no operative deaths. One patient suffered a minor stroke after operation. Follow-up ranged from 6 to 110 months (median 36 months). In 16 cases, simple endarterectomy with or without vein patch closure was performed (type I). In two cases the ostium of the ICA was occluded with interrupted sutures after endarterectomy (type II). In the remaining seven cases the ICA was transposed as a patch over the endarterectomized ECA after endarterectomy (type III). All but six patients (six sides) underwent duplex scanning or angiography during follow-up. Four of nine patients with previous nonlateralizing symptoms had persistent symptoms after operation, whereas none of those with previous amaurosis fugax did. Recurrent occlusive disease was more common in type I reconstructions (p less than 0.05). Proper ECA reconstruction results in long-term patency. In the patient with ipsilateral ICA occlusion, transposition of the ICA as a patch over the endarterectomized ECA offers a valid hemodynamic solution. Objective parameters are needed to identify patients with nonlateralizing symptoms who will benefit from operation.     

Surgical management of acute complications and critical restenosis following carotid artery stenting

Carotid artery angioplasty with stenting (CAS) is being increasingly used in the treatment of extracranial carotid artery stenosis. As in other catheter-based approaches to the treatment of arterial disease, surgical intervention may be required because of either acute complications or correct critical restenosis. We have reviewed our experience managing early complications and critical in-stent restenoses after CAS in a tertiary care university hospital and a Veterans Affairs Medical Center. During the last 5 years, 22 carotid arteries (21 patients) underwent CAS. One patient developed thrombosis and rupture of the carotid artery during stenting. Two other patients (3 arteries) developed critical restenosis within 12 months. Subsequent surgical reconstructions included an internal carotid artery (ICA)–to–external carotid artery (ECA) transposition and a common carotid artery (CCA)–to–ICA bypass with reversed saphenous vein (RSV). The patient who underwent CCA–to–ICA bypass later required subclavian–to–ICA bypass because of rapidly progressive intimal hyperplasia and subsequent occlusion of the CCA. The other patient has not had surgical repair because of his deteriorating condition and significant co-morbidities. During the same time period, two additional patients were referred from outside institutions specifically for surgical intervention after carotid stenting. One had delayed rupture of the carotid artery 1 day after stenting and underwent urgent surgical repair. Another patient had early, critical restenosis within the stent and underwent placement of a CCA–to–ICA interposition graft using RSV. Acute treatment failures after CAS can be successfully managed using standard surgical techniques. Patients who develop critical in-stent restenosis requiring surgical repair may need more challenging surgical reconstructions to maintain cerebral perfusion.     

Management of internal carotid artery occlusion

Although attempts to restore patency of occluded internal carotid arteries are now rarely made, endarterectomy in the contralateral artery, external carotid endarterectomy and until recently EC/IC bypass have remained surgical options in the management of such patients. Over a four-year period at this institution 104 patients underwent carotid endarterectomy for stenosis. In this group the contralateral carotid was patent (Group A). Fifty-four patients with unilateral carotid artery occlusion underwent contralateral endarterectomy (Group B), 8 underwent ECA/ICA bypass (Group C) and 4 an ECA endarterectomy (Group D). No statistically significant difference was noted in perioperative stroke and death rates for Groups A and B were (1% and 1%) and (3.7% and 1.9%) respectively. One Group C patient died from perioperative stroke (12.5%). For late events the life table adjusted annual rates for stroke and mortality were similar, Group A (stroke 2.1% and death 5%), and Group B (stroke 1.6% and death 5%). In Group C stroke rate was 10% and death 3%. All four patients undergoing ECA endarterectomy were relieved of their symptoms. It is concluded that in patients with internal carotid artery occlusion TEA may be performed with perioperative morbidity and mortality rates comparable to those when the opposite carotid artery is patent. The late outcome for stroke compares favorably with the reported natural history of the disease and outcome for such patients treated medically in the Joint Study of Extracranial Occlusion and EC-IC Bypass Study. External carotid artery endarterectomy appears useful in the treatment of embolic events on the occluded side. ECA/ICA bypass does not appear to confer benefit.     

Proximal intracranial internal carotid artery branches: prevalence and importance for balloon occlusion test

OBJECT: The aim of this study was to determine the prevalence of angiographically identifiable skull base arterial branches that potentially serve as collateral conduits during a balloon occlusion test (BOT) of the internal carotid artery (ICA). The authors posited that neurological deficits in patients who had previously tolerated the occlusion test may be attributable to an unrecognized collateral support through these channels (operant during proximal ICA BOT) when permanent ICA occlusion was performed more distally. METHODS: In 481 cases (962 ICAs), cerebral angiograms obtained during routine Wada testing were retrospectively reviewed. Two hundred sixty-one patients had at least one angiographically identifiable ICA branch; 109 patients had two or more branches. A meningohypophyseal branch of the cavernous ICA was identified on the right side in 108 patients and on the left in 122. A vidian artery originated from the petrous portion of the ICA on the right side in 58 patients and on the left in 85. The inferolateral trunk revealed itself as a branch of the cavernous ICA on the right side in 17 patients and on the left in 33. A caroticotympanic artery arose from a left cavernous ICA. A persistent trigeminal artery was situated on the right side in two patients and on the left in three. More than half of the patients had angiographically identifiable and perhaps hemodynamically significant skull base branches of the ICA, and approximately one quarter had more than one identifiable branch. CONCLUSIONS: The authors recommend that patients be screened during angiography studies performed prior to BOT in branches of the proximal intracranial ICA and that the site of BOT be moved distally if such branches are identified.