Use of Cerebral Oximetry to Monitor Brain Oxygenation Reserves for Skull Base Surgery

We used cerebral oximetry based on near-infrared re-emittance spectroscopy for noninvasive evaluation of the cerebral regional oxygen saturation (rSO₂) to preoperatively assess patients with skull base tumors and giant arterial aneurysms, for whom possible occlusion or partial resection of the internal carotid artery was considered. Monitoring cerebral oxygen saturation was performed during both endovascular (balloon) and open surgical test occlusions of the internal carotid artery. The presence (or absence) of changes in the cerebral oxygen saturation served as a criterion of the patient's tolerance to permanent occlusion of the internal carotid artery. In all cases the curves of saturation accurately corresponded to the clinical condition of the patients, primarily to the developing of neurological signs. Cerebral oximetry was an extremely informative and reliable technique for fast, easy, and noninvasive detection of changes in brain blood circulation. Generally, cerebral oximetry serves as a valuable adjunct in detection of brain tolerance to the occlusion of major arterial vessels and in monitoring the condition of the brain in regard to its oxygenation and perfusion.     

False aneurysms of the intracavernous carotid artery — Report of 7 cases

Summary We present 7 cases of false intracavernous carotid artery aneurysms. Four occurred after trauma and three were caused iatrogenically. Two of the latter occurred in patients with pituitary adenomas, one after transsphenoidal microsurgery and the other after yttrium [YI⁹⁰] seed implantation into the sella. The third iatrogenic aneurysm was seen shortly after transcavernous tumour surgery.In five of our seven patients massive, delayed, lifethreatening epistaxis was the leading symptom. All traumatic cases were associated with immediate unilateral blindness or blurred vision and with skull base fractures. One of these had a concomitant carotid cavernous fistula. Treatment of choice of our 5 recent cases was permanent balloon occlusion of the intracavernous carotid artery at the level of the lesion. Collateral circulation was evaluated prior to definitive carotid occlusion using a balloon test occlusion. During the balloon test adequate collateral circulation was defined as symmetric angiographic filling of both hemispheres. Awake patients were neurologically examined continuously. In unconscious patients transcranial Doppler sonography, electroencephalographic and somatosensory evoked potential monitoring was used in addition. Intra-operative heparin administration was not reversed with protamin. A postoperative continuous heparin infusion was not found necessary.In our two early cases this technique was not available: In the first case we accomplished aneurysm occlusion by a surgically introduced Fogarty balloon catheter. Our second patient needed surgical trapping of the involved carotid after early unsuccessful attempts of selective aneurysm occlusion, After treatment no further epistaxis occurred. Follow-up angiography showed persistent aneurysm occlusion. The results were excellent in 5 cases and good in 1 case. One patient with bilateral lesions suffered a stroke after occlusion of the second, remaining carotid artery, despite functioning bilateral extra-intracranial bypasses. Four years later there is a mild dysphasia still present in this patient. The mean follow-up time was 75.6 months.     

Treatment of 54 traumatic carotid-cavernous fistulas

A series of 54 traumatic carotid-cavernous fistulas has been treated with detachable balloon catheters. The balloon was introduced through one of three different approaches: the endarterial route; the venous route through the jugular vein, the inferior petrosal sinus, and the cavernous sinus; or surgical exposure of the cavernous sinus; with occlusion of the fistula by a detachable balloon directly positioned in the cavernous sinus. Full follow-up review demonstrated that the carotid blood flow was preserved in 59% of cases. The most frequent complication was a transient oculomotor nerve palsy, which occurred in 20% of cases. In three cases where both the fistula and the carotid artery were originally occluded by the balloon, the superior portion of the fistula was later found not to be completely occluded, and these patients had intracranial ligation of the supraclinoid portion of the carotid artery. Three patients had hemiparesis, transient in two cases and permanent in the other. The results show that the fistula was totally occluded in 53 cases; in the one exception the patient became asymptomatic but had a minimal angiographic leak.     

Intraoperative angiography and temporary balloon occlusion facilitating surgical obliteration of a traumatic carotid cavernous fistula: a case report

A patient with a traumatic carotid cavernous fistula was successfully treated by a direct surgical approach after failed endovascular balloon occlusion. Surgical identification of the fistula and confirmation of its obliteration were achieved with intraoperative angiography. Dissection, control of bleeding, and carotid blood flow were facilitated by temporary balloon occlusion of the cavernous carotid artery. The combination of surgery, intraoperative angiography, and interventional radiologic techniques may improve the management of intracavernous vascular lesions.     

Detection of cerebral ischemia in neurovascular surgery using quantitative frequency-domain near-infrared spectroscopy

OBJECT: There is great value in monitoring for signs of ischemia during neurovascular procedures. Current intraoperative monitoring techniques provide real-time feedback with limited accuracy. Quantitative frequency-domain near-infrared spectroscopy (Q-NIRS) allows measurement of tissue oxyhemoglobin (HbO2), deoxyhemoglobin (HHb), and total hemoglobin (tHb) concentrations and brain tissue oxygen saturation (SO2), which could be useful when monitoring for evidence of intraoperative ischemia. METHODS: Using Q-NIRS, the authors monitored 25 neurovascular procedures including aneurysm clip placement, arteriovenous malformation resection, carotid endarterectomy, superficial temporal artery-middle cerebral artery (MCA) bypass surgery, external carotid artery-MCA bypass surgery, encephaloduromyosynangiosis, and balloon occlusion testing. The Q-NIRS technology provides measurable cerebral oxygenation values independent from those of the scalp tissue. Thus, alterations in the variables measured with Q-NIRS quantitatively reflect cerebral tissue perfusion. Bilateral monitoring was performed in all cases. Five of the patients exhibited evidence of clinical ischemic events during the procedures. One patient suffered blood loss with systemic hypotension and developed diffuse brain edema intraoperatively, one patient suffered an ischemic event intraoperatively and developed an occipital stroke postoperatively, and one patient showed slowing on electroencephalography intraoperatively during carotid clamping; in two patients balloon occlusion testing failed. In all cases of ischemic events occurring during the procedure, Q-NIRS monitoring showed a decrease in HbO2, tHb, and SO2, and an increase in HHb. CONCLUSIONS:. Quantitative frequency-domain near-infrared spectroscopy provides quantifiable and continuous real-time information about brain oxygenation and hemodynamics in a noninvasive manner. This continuous intraoperative oxygenation monitoring is a promising method for detecting ischemic events during neurovascular procedures.     

A safe technique for the precise localization of carotid-cavernous fistula during balloon obliteration. Technical note

The authors report a technique to precisely localize a fistulous opening in the carotid artery. The patient is heparinized and a Prolo catheter is introduced into the internal carotid artery and inflated distal to the approximate site of the fistula. Heparinization allows the balloon to be inflated long enough to obtain and analyze high-quality angiography film without fear of thromboembolism generated by the temporary balloon occlusion. Contrast material injected through the Prolo catheter proximal to the balloon reveals a small segment of cavernous carotid artery between the inflated balloon distally and the fistula proximally. The venous structures are now only faintly opacified and cannot obscure the morbid anatomy of the exact fistulous tear in the carotid artery. If the balloon is placed exactly opposite to the site of the fistula, a standing, stagnant column of dye forms a cast of the cavernous, petrous, and cervical carotid artery. Once the fistula is localized with this method, it may be obliterated by any therapeutic means preferred. If the Prolo catheter is used for intraluminal occlusion, then a transfemoral contralateral carotid angiogram is done before the heparin is reversed to confirm that the balloon has not been placed proxial to the fistula.     

Alcohol embolization of carotid-cavernous indirect fistulae

OBJECTIVE: Carotid-cavernous fistulae (CCFs) are abnormal communications between the carotid artery and cavernous sinus that may present with rapid visual deterioration and extraocular paresis as a result of increasing intraocular pressure requiring emergent treatment to preserve vision. We present a technique of balloon-assisted ethanol embolization of the cavernous carotid artery supply to indirect CCFs providing immediate reduction in intraocular pressure with symptomatic improvement. METHODS: We reviewed clinical and angiographic data and present a retrospective case series illustrating six patients who underwent endovascular embolization because of worsening visual acuity and extraocular motility disorder caused by CCFs. Cerebral angiography revealed significant blood supply from the cavernous carotid artery to these CCFs. We performed ethanol embolization of these branches with distal balloon protection. RESULTS: Five of the six patients experienced immediate and sustained (mean follow-up, 21 mo) decreases in intraocular pressure, with significant symptom improvement. One patient experienced cavernous sinus thrombosis after conclusion of embolization, which caused a temporary worsening of symptoms that improved gradually over time. CONCLUSION: Many surgical and endovascular options are available to treat indirect CCFs. Absolute ethanol is a liquid agent that causes immediate vessel sclerosis and occlusion, which makes it a dangerous but potent liquid embolic agent. With distal temporary balloon protection to prevent migration of ethanol, we achieved excellent clinical and angiographic results using absolute ethanol to embolize the cavernous carotid supply to indirect CCFs. This represents a safe and effective method of endovascular management of this complex vascular anomaly.     

A successful treatment of spontaneous carotid cavernous fistula causing hemorrhagic infarction treated by detachable balloon

A rare case of hemorrhagic infarction associated with carotid-cavernous fistula is reported. The patient was a 74-year-old female. CT scan showed hemorrhagic infarction of the left superior temporal gyrus, irregular vascular enhancement of the bilateral front-temporal lobe, and dilatation of the cavernous sinus. Left carotid angiogram revealed a high-flow left-sided CCF, cross filling to the right cavernous sinus, and intracavernous aneurysm. Bilateral front-temporal cortical veins were visualized early in the arterial phase. In this case, there was a direct shunt between the internal carotid artery and the cavernous sinus, and venous hypertension. Therefore urgent treatment using detachable balloon catheters was performed. Postoperative digital subtraction angiography revealed the disappearance of CCF. In conclusion, in CCF with cortical venous drainage there is a high possibility of developing hemorrhagic infarction. Only immediate detachable balloon occlusion can improve the outcome in elderly patients.     

Comparison of cerebral oximeter and evoked potential monitoring in carotid endarterectomy

Purpose

To assess the cerebral oximeter, which measures regional oxygen saturation (rSO₂) continuously and noninvasively, as a cerebral monitor during carotid endarterectomy (CEA). The rSO₂ was compared with Somatosensory Evoked Potentials (SSEPs) as an indicator for shunting and as a predictor of postoperative neurological deficits.

Methods

Seventy-two consenting patients undergoing CEA with general anaesthesia were studied. Normocarbia, normothermia and normotension were maintained. Cerebral monitoring consisted of bilateral median nerve SSEPs and the INVOS 3100 cerebral oximeter with the sensor pad placed on the ipsilateral forehead. Decreases in SSEP amplitude of 50% and in rSO₂ of 10% were considered clinically significant. Neurological assessment was performed at emergence from anaesthesia, 24 hr postoperatively and at discharge. The rSO₂ changes were compared with SSEP changes and with neurological deficits. Statistical analysis was with chi square and analysis of variance. P < 0.05 was considered significant.

Results

During carotid artery clamping, rSO₂ decreased from 72 ±8% to 68 ±9% and mean arterial blood pressure increased from 92 ±14 mmHg to 98 ±14 mmHg. In four patients, the carotid artery was shunted because of SSEP changes after cross-clamping. Five patients had ≥10% decreases in rSO₂ following clamp application. Changes in both SSEP and rSO₂ occurred in two patients. Three of the four shunted patients had transient postoperative neurological deficits. One patient had a transient deficit without changes in either monitor. There were no persistent postoperative deficits. Compared with SSEPs, rSO₂ had a sensitivity of 50% and a specificity of 96%.

Conclusion

Clinical experience with this evolving technology is ongoing. Its role in neurovascular procedures has yet to be established.     

Use of cerebral oximetry to monitor brain oxygenation reserves for skull base surgery

We used cerebral oximetry based on near-infrared re-emittance spectroscopy for noninvasive evaluation of the cerebral regional oxygen saturation (rSO(2)) to preoperatively assess patients with skull base tumors and giant arterial aneurysms, for whom possible occlusion or partial resection of the internal carotid artery was considered. Monitoring cerebral oxygen saturation was performed during both endovascular (balloon) and open surgical test occlusions of the internal carotid artery. The presence (or absence) of changes in the cerebral oxygen saturation served as a criterion of the patient's tolerance to permanent occlusion of the internal carotid artery. In all cases the curves of saturation accurately corresponded to the clinical condition of the patients, primarily to the developing of neurological signs. Cerebral oximetry was an extremely informative and reliable technique for fast, easy, and noninvasive detection of changes in brain blood circulation. Generally, cerebral oximetry serves as a valuable adjunct in detection of brain tolerance to the occlusion of major arterial vessels and in monitoring the condition of the brain in regard to its oxygenation and perfusion.     

Iatrogenic carotid-cavernous fistulas, complications of carotid thrombectomy

The authors report four cases of carotid cavernous fistula at the C5 segment of the internal carotid artery following embolectomy by a 3F Fogarty Catheter. All patients were operated on a carotid bifurcation stenosis (pre-occlusive) and a thrombectomy with a 3F Fogarty Catheter was carried out in the same time in 3 patients and during re-operation in 1 patient who had post operative thrombosis. The carotid-cavernous fistula occurred the day after surgery in 2 cases, 1 week after in 1 case, and 2 months later in 1 case. Spontaneous recovery occurred in two patients (1 occlusion--1 re-stenosis), 1 patient died from controlateral carotid occlusion, and 1 patient was lost for investigation. There were no relationship between the number of "repeated passages" of the Fogarty Catheter and the interval time where the fistula occurred. However the location of fistula was constant. Overtension on the internal wall of the artery by the balloon could be advocated rather than a collateral torn of the intra cavernous internal carotid. Endoluminal treatment of various vascular lesion is increasingly used and iatrogenic problems as reported here should be kept in mind. Age and atheromatous lesion of carotid siphon appear to be the main risk factors.     

Intracranial stent placement for the treatment of a carotid-cavernous fistula associated with intracranial angioplasty. Case report

The authors report a case of an iatrogenic carotid-cavernous fistula (CCF) associated with intracranial angioplasty. Angioplasty was performed using a 3 x 10-mm Open Sail coronary balloon in a patient with high-grade stenosis of the left cavernous internal carotid artery (ICA). After angioplasty, a perforation developed in the cavernous ICA, resulting in a CCF. A 3.5 x 9-mm S670 coronary stent was used to treat the fistula. To the authors' knowledge, this is the first reported case in which a CCF developed after angioplasty was performed using a coronary balloon. Long-term angiographic and clinical evaluation is needed to test the suitability and durability of intracranial angioplasty and stent placement in the treatment of symptomatic intracranial stenosis.     

Submandibular puncture of the facial vein: An original route for endovascular therapy of cavernous sinus dural fistulas

Introduction

Carotid cavernous sinus fistulas are a potentially severe pathology. Their basic standard treatment is an occlusion of the CCF performed by retrograde venous catheterization via the inferior petrous sinus. When the inferior petrous sinuses are occluded, other alternative venous routes are possible with various subsequent difficulties and risks. We report an original and safe method for endovascular treatment using submandibular puncture of the facial vein.

Clinical cases

We report 4 cases of patients with severe unilateral carotid cavernous sinus fistula associated with the occlusion of both inferior petrous sinuses. A submandibular surgical puncture of the ipsilateral inferior facial vein permitted the catheterization of the fistula. Complete occlusion of carotid cavernous sinus fistula was obtained by using a combination of microcoils and Onyx™.

Discussion

When inferior petrous sinuses are occluded, endovascular treatment of carotid cavernous sinus fistulas is more difficult. After reviewing the other treatment options reported in the literature and their respective advantages and adverse effects, we describe an original technique based on the surgical puncture of the ipsilateral facial vein. The occlusion of the fistula is then obtained by using a combination of microcoils and Onyx™.

Conclusion

When the inferior petrous sinuses are occluded, an endovascular treatment for a carotid cavernous sinus fistula can be performed using an original and secure method. This method relies on a simple surgical puncture of the facial vein in the submandibular region, which then permits a retrograde catheterization of the carotid cavernous sinus fistula with no significant risk.     

Brain Oxygen Supply in Older Adults During Coronary Artery Bypass Grafting

ObjectivesTo evaluate the dynamics of the cerebral oxygen supply in patients aged ≥65 years, during coronary artery bypass grafting (CABG), and to test the hypothesis that lower intraoperative brain oxygen saturation is associated with postoperative neurological complications.DesignProspective cohort study.SettingThe E. Meshalkin National Medical Research Center of the Ministry of Health of the Russian Federation, Novosibirsk, Russia.ParticipantsThe study comprised 200 elderly patients who underwent CABG between April, 2018 and November, 2019.InterventionsNone.Measurements and Main ResultsThe regional hemoglobin oxygen saturation (rSO₂, %) of the right and left brain hemispheres were assessed during the intraoperative period using bilateral near-infrared spectroscopy. Furthermore, neurological complications during hospitalization were evaluated. At the anesthesia induction stage, the average levels of rSO₂ for the right and left hemispheres were within 65% and did not differ significantly at any stage of CABG (p>0.05). The risk of neurological complications was associated with rSO₂ decrease during cardiopulmonary bypass (CPB). An increased risk was associated with rSO₂ decrease by 20% or more during CPB, relative to the stage of anesthesia induction, which was observed in 19% of patients.ConclusionsIn elderly patients, the decrease in rSO₂ during CPB is associated with an increased risk of neurological complications during hospitalization. This risk increases with a decrease in rSO₂ by 20% or more during CPB relative to the stage of anesthesia induction, by a 5-fold and 7-fold for the left and right hemispheres, respectively.     

Transvenous balloon occlusion of the cavernous sinus: an alternative therapeutic choice for recurrent traumatic carotid-cavernous fistulas

We report a case of traumatic carotid-cavernous fistula (CCF) that recurred some 9 years after carotid trapping. The recurrent CCF was accompanied by a huge aneurysmal dilatation of the cavernous sinus. Transarterial balloon occlusion of the proximal internal carotid artery failed to occlude the fistula completely because of collateral flow to the fistula. the fistula was completely occluded by a transvenous approach via the jugular vein and inferior petrosal sinus using detachable balloons. The transjugular-inferior petrosal approach to the cavernous sinus can be an alternative for the treatment of traumatic CCF when the transarterial approach has failed to occlude the cavernous sinus.     

Venous rupture during transvenous approach to a carotid-cavernous fistula. Case report

An attempt at transfemoral transarterial balloon occlusion of a high-flow spontaneous carotid-cavernous fistula was unsuccessful because the carotid artery rent was too small for this approach. During a subsequent transvenous approach to the cavernous sinus through the jugular vein, the inferior petrosal sinus was perforated. A minor subarachnoid hemorrhage occurred before the tear could be sealed by the deposition of three Gianturco coils in the vein. The patient was taken to the operating room for emergency obliteration of the fistula and petrosal sinus in order to remove the risk of further hemorrhage. Under the guidance of intraoperative digital subtraction angiography, isobutyl-2-cyanoacrylate was injected directly into the surgically exposed cavernous sinus. Successful obliteration of the fistula was achieved with preservation of the carotid artery, and the angiography catheter was removed safely from the petrosal sinus. Although initially after surgery the patient had nearly complete ophthalmoplegia, at her 1-year follow-up examination she had normal ocular motility and visual acuity. The transvenous approach to the cavernous sinus and alternative methods of treatment of carotid-cavernous fistulas are discussed.     

Multimodal endovascular treatment for traumatic carotid- cavernous fistula

bjective：To present our experience in treating traumatic carotid-cavernous fistula （TCCF） by multimodal endovascular treatment.Methods：The management of 28 patients with TCCF between January 2004 and October 2012 in our hospital was retrospectively analyzed.According to imaging charateristics,24 cases were categorized into Type Ⅰ,3 Type Ⅱ and 1 Type Ⅲ.Totally 30 endovascular treatments were performed：Type Ⅰ TCCFs were obliterated via transvenous approach （7/25）,or transarterial approach （18/25） including 6 by detachable balloon occlusion,6 by microcoil embolization,3 by Hyperglide balloon-assisted coil embolization and 3 by a combination of detachable balloon and coil embolization.Two patients were treated with closure of internal carotid artery （ICA）.Type Ⅱ TCCFs were treated with transvenous embolotherapy （2/3） or carotid artery compression therapy （1/3）.The Type Ⅲ patient underwent detachable balloon embolization.Results：Immediate postoperative angiography showed recovery in 26 cases.One recurrent TCCF was found 2 weeks after detachable balloon embolization,and then reobliterated by transarterial coils.Reexamination found balloon deflation and fistula recanalization in 1 patient one month after combination of detachable balloons and coil embolization,which was cured by a second treatment via transvenous approach.The immediate angiography revealed residual blood flow in 4 patients.Among them,2 patients with delayed symptoms at follow-up needed a second treatment,1 patient recovered after carotid artery compression therapy,and the remaining patient＇s symptoms disappeared on digital subtraction angiography at five-month follow-up.CT angiography revealed anterior communicating artery aneurysm in the patient who was treated with closure ofICA 4 years later.Conclusion：According to results of images,characteristics of the fistula and type of drainage,proper treatment approach and embolic material can maximally heal pathological changes,retain the ipsilateral ICA patency and reduce long-term complications.     

Is renal tissue oxygen desaturation during severe hypoxia underestimated? An observational study in term newborn piglets

The kidney is an organ highly susceptible to injury by regional tissue oxygen desaturation during hypoxic episodes. Transcutaneous monitoring of renal tissue oxygen saturation is therefore of increasing interest. The aim of the present study was to compare renal tissue oxygen saturation measured by near‐infrared spectroscopy (NIRS) during acute hypoxia in neonates directly on the kidney and transcutaneously. We hypothesized that transcutaneous renal tissue oxygen saturation measurements would be influenced by superficial tissue. Five term newborn piglets were anesthetized, instrumented and exposed to normocapnic hypoxia at an inspired oxygen concentration of 0.14. Regional tissue oxygen saturation (rSO₂) was simultaneously measured for comparison with the sensor of NIRS (Invos 5100, Somanetics Corp., Troy, MI, USA) applied directly on the left kidney (_renaldirectrSO₂) and on the skin of right flank above the right kidney (_renalskinrSO₂). Cerebral regional tissue oxygenation (_cerebralskinrSO₂), arterial oxygen saturation, heart rate (HR) and mean arterial pressure (MAP) were also monitored. NIRS parameters were analyzed in 5 s intervals during first 2 min of hypoxia. Hypoxia was achieved with an arterial oxygen desaturation from median (range) 95.3% (86.8–98.0) to 23.5% (13.0–41.0) after 2 min. HR and MAP did not change significantly during hypoxia. There were pronounced and lower _renaldirectrSO₂ readings when compared with those of _renalskinrSO₂ with significant differences from 25 to 55 s after initiation of hypoxia. Changes of _cerebralskinrSO₂ and _renalskinrSO₂ were similar. Transcutaneous monitoring of renal tissue oxygen saturation may underestimate acute oxygen desaturation of the kidney during hypoxia in neonates.     

Transvascular treatment of giant aneurysms of the cavernous carotid and vertebral arteries: Functional investigation and embolization

Functional angiographic investigation and percutaneous embolization using detachable balloons in nine carotid cavernous aneurysms, three petrous aneurysms, one vertebral artery aneurysm, and one posterior inferior cerebellar aneurysm are reported. A double-lumen balloon catheter is used to evaluate acute tolerance to occlusion of the carotid or vertebral arteries. Occlusion is tested under systemic heparinization. Local perfusion of heparinized saline, proximal as well as distal, to the balloon occlusion is used. The procedure was successful in all but one cavernous aneurysm. The arterial lumen was sacrificed in all cases. Clinical improvement occurred in all successful cases. Retroorbital pain was relieved in all. Ocular cranial nerve palsies improved or resolved in most. One delayed ophthalmic episode that improved represents the only complication. No such embolic problems occurred in any case in which the cavernous carotid artery was occluded by balloon trapping. The delayed embolic complications after carotid artery occlusion are related to the collateral vessels to the C-4 and C-5 segments of the artery. Balloon trapping decreases the length of the thrombosed segment and prevents retrograde filling of the aneurysm.     

Carotid cavernous fistula following Fogarty catheter thrombectomy

A patient had carotid cavernous fistula following Fogarty catheter thrombectomy. The patient was successfully treated by percutaneous detachable balloon closure of the fistula. Intraoperative angiography may be helpful in detecting unsuspected injuries of the intracranial carotid artery following thrombectomy.