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Access-Related Complications in Endovascular Neurosurgery
S E C TI ON 2
Cranial Complications Endovascular Surgery
39
Access-Related Complications in Endovascular Neurosurgery MITHUN G. SATTUR, MATTHEW E. WELZ, BERNARD R. BENDOK
HIGHLIGHTS • Obtaining, maintaining, and exiting the vascular portal of entry in a safe and efficient manner are essential to achieve the goal of diagnosis and treatment of cranial, spinal, and head-neck neurovascular diseases. • Transfemoral/groin access represents the most common route for endovascular access in vascular neurosurgery. • Access-related complications are categorized as bleeding, pseudoaneurysm, infection, and other arterial abnormalities. • A standard regimental approach to complication avoidance is the secret to successful outcome.
2. Device navigation along vascular roadmap to the lesion a. Thoracoabdominal aortic b. Arch of aorta c. Carotid arteries d. Vertebral arteries e. Intracranial arteries and veins 3. Intracranial target lesion access a. Access to aneurysm b. Access to arteriovenous malformation/dural fistula c. Tumor access 4. Contrast-induced nephropathy
Introduction
Femoral Access
The field of vascular neurosurgery has been enriched by significant advances in endovascular technology and techniques. Despite rapid evolution, certain basic tenets remain sacrosanct. Chief among them is the art and science of safe vascular access. Obtaining, maintaining, and exiting the vascular portal of entry in a safe and efficient manner are essential to achieve the goal of diagnosis and treatment of cranial, spinal, and head-neck neurovascular diseases. Catastrophic complications can arise, and access-related complications should never be underestimated or viewed with hubris. The present chapter provides a concise overview of the nuances for safe access for each of the various endovascular access routes.
Transfemoral/groin access represents the most common route for endovascular access in vascular neurosurgery. The large size of the artery that allows placement of large devices in co-axial fashion for a stable construct, location over the femoral head that allows compressibility, situation away from the fluoroscopy arms, and a long history of operator familiarity are main factors for this preference. Most devices available for intervention are configured and optimized for femoral access. Spinal angiography and intervention are almost always carried out via the transfemoral route. Complications from femoral access have been documented to occur in 1.6% to 6.0% of patients in the literature but can be minimized with proper precautions. Complications are categorized as follows: 1. Bleeding Groin hematoma Retroperitoneal hematoma 2. Pseudoaneurysm (PA) 3. Other arterial abnormalities (arteriovenous fistula, acute thrombosis, dissection, distal embolism) 4. Infection
Access-Related Complications Access-related complications (ARC) should be considered if related to any of the following: 1. Injury at access site: a. Femoral b. Radial c. Brachial d. Carotid e. Vertebral f. Transorbital g. Transcranial access 224
Bleeding Minor hematomas at the puncture site are common and do not necessarily represent complications. Major hematomas may occur either in the groin or retroperitoneum and
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
represent difficulty with hemostasis. Risk factors for hematoma formation are: a. Obesity b. Puncture above inguinal ligament (high puncture) c. Advanced atherosclerotic disease d. Dual antiplatelet therapy (DAPT) e. Anticoagulation f. Uncontrolled hypertension g. Large sheath h. Rough catheterization of circumflex branch (and rupture) i. Backwall puncture j. Inability to deploy closure device k. Inadequate rest before ambulation A major hematoma manifests with increasing local pain, swelling, and bruising, along with declining hematocrit in the few hours post-procedure. However, a retroperitoneal hematoma is more treacherous because there is no external swelling. The only external sign sometimes is ipsilateral flank bruising. Typically with retroperitoneal hematoma, there is an initial transient episode of hypotension that improves with a fluid bolus; if left undiagnosed, it can lead to dangerous and rapid hemodynamic collapse.
Diagnosis A high index of suspicion is needed to diagnose a retroperitoneal hematoma. Close attention to clinical examination and prompt serial hematocrit estimations are important. Ultrasound is helpful with a thigh hematoma in ruling out expanding PA. Definitive diagnosis of retroperitoneal hematoma requires computed tomography (CT) imaging.
Management Many hematomas may not require surgical evacuation. Maintaining stable blood pressure and adequate circulatory status is paramount. Serial hematocrit estimation guides transfusion, and packed red cells should readily be available. It is prudent to obtain early vascular surgery consultation if a patient is being admitted for hematoma management. With active extravasation (which sometimes can be seen on contrast-enhanced CT) and impending cardiovascular collapse, vascular surgical intervention is indicated. Anticoagulated patients and those on DAPT pose a unique dilemma. Procedural anticoagulation usually reverses spontaneously in few hours. Reversal of chronic anticoagulation depends on the primary diagnosis for which this is indicated and should be undertaken on a case-by-case basis. DAPT patients tend to be more problematic due to difficulty in reversing platelet dysfunction and, more importantly, the fact that DAPT is indicated for recent intracranial or coronary (or other intravascular) stent. Placement of a covered stent across the site of leakage is an endovascular option in select cases.
Pseudoaneurysms A hematoma that occurs in the vessel wall and is in communication with the arterial lumen can become PA. Clinical presentation is with an enlarging firm mass that is pulsatile and may have a bruit on auscultation. Some degree of pain/discomfort may be seen. PA typically becomes evident after 48 hours. Some authors describe simple (one lobe) and complex (more than one lobe) PA.2 Whether use of a closure device in lieu of manual compression increases PA risk is debatable based on recent metaanalyses versus those from a decade ago.3,4 Other risk factors include high puncture, large sheath, and puncture below bifurcation in superficial femoral artery.
Diagnosis Duplex ultrasound (US) is the imaging modality of choice. PA neck, lobe(s), dimensions, and parent artery lumen communication are clearly visualized.
Management Small PAs frequently do not require treatment, but occasional lesions progressively enlarge. Treatment modalities are delineated in Table 39.1. The most common technique (including at our center) is thrombin injection because it is quick, highly effective, a bedside procedure, and largely safe.2 It may be prudent to repeat a US in 1 to 2 weeks to rule out recurrence.
Other Femoral Artery Complications Arterial thrombosis, dissection, and distal embolism are rare complications that present with pain, paresthesias, and diminished or absent pedal pulses. Thrombosis risk is strongly correlated with leaving the sheath in for prolonged duration post procedure. Risk factors include puncture below bifurcation of common femoral artery, large sheath placement, inadequate flush of heparinized saline, severe atherosclerosis, and rough technique. Arteriovenous fistula
TABLE 39.1 Various Treatment Modalities and Their
Advantages/Concerns
Treatment
Advantages
Concerns
Ultrasound-guided manual compression
Simple, bedside Inexpensive No risk to parent artery lumen
Patient discomfort Vasovagal symptoms
Ultrasound-guided thrombin injection
Excellent success rates (over 90%) Minimal patient discomfort
Parent artery reflux Distal embolism Systemic effects Recurrence
Covered stent
Endovascular option in larger neck Indicated for failure of ultrasound-guided techniques
Antiplatelet therapy Cost
Open surgical repair
Effective for large/ giant PA Indicated for rupture/ infection
Major surgical procedure
Prevention Though theoretically longer durations of bed rest might reduce bleeding, clinical studies have proven that a 2-hour bed rest period post sheath removal is adequate. One study used manual compression for hemostasis after use of 5 Fr sheaths in the majority of the 295 patients evaluated.1 Close attention to steps involved in femoral access is mandatory to prevent complications (see “Complication avoidance”).
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is recognized by characteristic thrill and bruit and usually presents in a delayed fashion. US guidance to avoid the femoral vein and tributaries during arterial puncture and avoiding a simultaneous femoral vein puncture (when required) on the same side may help avoid this complication. It is imperative to recognize these potentially limb-threatening complications early and involve vascular surgery expeditiously for open or endovascular intervention. The imaging modality of choice to document these complications is duplex US. Early recognition and management leads to good outcomes.
Complication Avoidance At our institution, all diagnostic angiography–related access is treated with a “nuclear launch code” protocol. Fluoroscopic confirmation of femoral head location is performed with a localizer (hemostat), and puncture occurs over this site (Fig. 39.1A–C). We use ultrasound to mark the bifurcation of the common femoral artery (into superficial femoral and profunda femoris artery), and we puncture above this point but still over the femoral head (Fig. 39.2D–G). Continuous heparinized saline flush is run through the sheath for the duration of the procedure. Invariably we endeavor to remove the femoral sheath on the table after the conclusion of the procedure. Femoral arteriography is performed before sheath removal. Particular attention is paid to puncture site vis-a-vis the bifurcation, location of puncture site (= sheath entry site) with respect to the femoral head, dissection, or thrombosis. Decision
regarding closure device deployment proceeds as described later, after ensuring that the puncture is above the bifurcation.
Closure Device Use Vascular closure devices are approved for femoral access closure and are currently available under various categories: i. Collagen plug–based (Angio-Seal, Terumo, Somerset, NJ) ii. Suture based (Perclose Abbott, Abbott Park, IL) iii. Clip based (StarClose Abbott, Abbott Park, IL) The advantages and disadvantages of using a closure device for femoral access are described in Table 39.2. Closure device deployment also follows a strict set of rules: i. Confirm location of puncture above common femoral artery bifurcation (Fig. 39.3) ii. Repeat prep and draping of groin site iii. Change of gloves by team iv. Prophylactic antibiotics before insertion v. Confirmation of intravascular placement vi. Avoidance of closure device deployment in certain situations: a. Puncture at/below bifurcation (higher risk of dissection) b. Severe calcified atherosclerotic disease c. Small artery size d. Immunocompromised patient (infection risk) e. Access through bypass graft
A
B
• Fig. 39.1
C
Anatomic (A) and fluoroscopic (B and C) landmarks for groin puncture (shown here on right side). A good approximation of the femoral pulse is a site 3 finger-breadths below a line joining the anterior superior iliac spine and the pubic symphysis (A). A localizer is placed at this site and X-ray is obtained to confirm position over the femoral head (B). This site in turn is marked (C). (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
A
227
B
D
C • Fig. 39.2
Strategic use of ultrasound for safe femoral puncture (A). Ultrasound is used to visualize the common femoral artery (B) and the bifurcation (C). The bifurcation is marked on the groin (D) and puncture is above this yet over the femoral head. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
TABLE 39.2 Advantages and Disadvantages of Using
Advantages
Disadvantages
Shortens bed rest
Potential vessel occlusion/ thrombosis
Infection of a closure device can be a severe complication and most commonly occurs in immunocompromised populations. It can potentially lead to vessel rupture in addition to bacteremia and sepsis. Treatment often involves open surgical resection and grafting and prolonged IV antibiotic therapy, but outcomes may not be satisfactory.
Less intense physician/nurse involvement
Dissection/PA risk may be greater
Transfemoral Venous Access
Cost benefit by reducing stay and personnel requirement
Infection
Potentially less incidence of hematoma formation
Cost
a Closure Device for Femoral Access
The principle of ensuring puncture over the femoral head is most important and probably more so than with arterial access, since typically closure devices cannot be deployed. Adequate manual compression is the key to achieving adequate hemostasis.
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Brachial Access The attraction of brachial access lies in the fact that atherosclerotic disease and tortuosity is rare at this location and that a device of somewhat larger size than at a radial access site (7 Fr sheath, for example) can be used. A unique scenario where we have used the brachial approach is documented in a patient with severe coarctation of aorta.13 Thrombosis and PA are potential complications. In a study of 214 patients who underwent transradial or transbrachial approach for carotid stenting, 4 had to be treated for acute thrombosis or PA of brachial artery (of 60 patients), and 6 had radial artery occlusion (of 154).14 Thrombosis usually requires surgical thrombectomy by a vascular surgeon. Occurrence of PA after brachial access is more frequent than femoral access and may be treated with US-guided manual compression or injection of fibrin, but eventually surgical intervention may be required. Hematoma at the access site has the potential to cause compartment syndrome if very large, but most cases do not require surgical evacuation. Cross-over to a femoral approach occurs in about 1% to 7%.
Transorbital Access • Fig. 39.3 Ideal puncture site (horizontal arrow) is over the femoral head (asterisk) and above the bifurcation (vertical arrow) for deployment of closure device. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
Radial Access Traditional transfemoral access may not be feasible in patients with severe aortoiliac or iliofemoral atherosclerosis. Severe obesity not only makes puncture challenging, but applying manual compression after sheath removal is also very difficult in situations where a closure device cannot be employed. In such cases, radial artery access is very attractive. The superficial location of radial artery, radial-ulnar collaterals to hand, and unrestricted ambulation have encouraged increasing use of radial access for vascular, both extracranial and intracranial vascular neurosurgery indications.5,6 For carotid stenting, radial artery access is attractive because of the ease of navigating a type III aortic arch and accessing a bovine carotid take-off.6,7 Radial access on the right side avoids aortic arch navigation; catheter manipulation in the aortic arch has been postulated as a mechanism of periprocedural stroke in patients who undergo carotid artery stenting.8 Based on success with cervical intervention, we have previously reported on the successful and effective application of the transradial approach for intracranial intervention9 (Fig. 39.4). The radial arteries, however, are prone to spasm easily and require administration of nitroglycerine and verapamil along with heparin in the form of a vasodilatory “cocktail.”5 Thrombosis is documented in about 5% of transradial interventions, but in general it is well tolerated due to collaterals from ulnar territory. An Allen’s test is performed before radial catheterization (Fig. 39.5). Immediate sheath removal and nonocclusive compression technique reduces the risk of occlusion Fig. 39.6). The size of the artery limits the size of devices that may be used for intervention, and usually it is difficult to insert devices larger than 6 Fr. Crossover to femoral approach was documented to occur in 4.9% of patients who underwent carotid stenting, according to one large Italian study.10–12
This specific access route is unique to management of cavernous sinus dural arteriovenous fistulas (CS-DAVF). In well-selected cases, transvenous embolization of DAVFs can be accomplished via direct transorbital puncture of the superior or inferior ophthalmic vein, which is frequently arterialized and prominent.15,16 Potential complications include orbital hematoma, infection, and puncture of the globe, vitreous leakage, and damage to the optic nerve and/ or ocular motor nerves. Prevention of complications starts with appropriate case selection. Clear visualization of the arterialized ophthalmic vein on angiography is necessary. Meticulous technique and optimal use of angiographic working views are paramount. Three-dimensional rotational angiography can be helpful in selecting appropriate working views.
Carotid Access Severe tortuosity of the aortic arch introduces a significant technical impediment in catheterizing arch vessels, especially the left common carotid artery. Transradial and transbrachial access is the next natural step in attempting access, but even these may prove unsuccessful. In such instances, direct carotid puncture remains an option.17,18 Sheaths from 4 Fr to 8 Fr may be inserted. Complications may be severe and include carotid dissection, embolism of plaque fragments and, most importantly, neck hematoma. The latter is important given that most situations are complicated with anticoagulation and antiplatelet therapy. Sheath removal is usually followed by manual compression, but closure devices have also been used.19 There has been recent resurgence in direct carotid access with the introduction of the ENROUTE transcarotid neuroprotection system (Silk Road Medical Inc., Sunnyvale, CA).20
Transcranial Access for Endovascular Therapy Rare instances may dictate direct microsurgical access to treat an intracranial vascular lesion. Examples have included access to arterialized and dilated middle cerebral vein or middle meningeal artery or the cavernous sinus.21 This situation is usually encountered with certain DAVFs where endovascular transarterial and/or transvenous access is not feasible and the only approach is via an arterialized vein accessible microsurgically. An apt example is
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
A
B
C
D
E • Fig. 39.4
Approach to basilar artery stenosis (A) via the radial approach because of severe tortuosity of the innominate artery (B) and left vertebral artery (D) for transfemoral access. The favorable angle of right vertebral artery off the right subclavian (C) enabled effective stent placement across the stenosis (E). (Adapted with permission Bendok BR, Przybylo JH, Parkinson R, Hu Y, Awad IA, Batjer HH. Neuroendovascular interventions for intracranial posterior circulation disease via the transradial approach: technical case report. Neurosurgery. 2005;56(3):E626)
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A
B
• Fig. 39.5
Allen’s test. Following simultaneous ulnar and radial artery compression till thumb oximeter saturation is no longer picked up, pressure over the ulnar artery is released. In the presence of adequate collateral circulation, the oxygen saturation rises to normal. (Adapted with permission Levy EI, Boulos AS, Fessler RD, et al. Transradial cerebral angiography: an alternative route. Neurosurgery. 2002;51(2): 335–340.)
A
B • Fig. 39.6
Non-occlusive radial artery compression for hemostasis reduces risk of thrombosis. (Adapted with permission Levy EI, Boulos AS, Fessler RD, et al. Transradial cerebral angiography: an alternative route. Neurosurgery. 2002;51(2):335–340)
illustrated in the case of a challenging cavernous sinus DAVF that we treated via a strategic “hybrid” approach (Fig. 39.7i–v).21
Thromboembolic Complications From Intravascular Device Navigation in Large Vessels After diagnostic and interventional cerebral angiography, there is clear evidence that patients experience increased hyperintense signals
on diffusion-weighted magnetic resonance imaging (DWI) that represent microemboli.22-30 Ischemic thromboembolic events arise from following mechanisms: i. Dislodged atheromatous debris mainly in the region of the aortic arch and carotid bifurcation ii. Inherent thrombogenicity of an intravascular device iii. Exogenous air/debris in the catheter system The descending thoracic aorta and the distal aortic arch are the most common sites of atheromatous plaque in the aorta.31 Catheter navigation with increasing age carries increasing risk and requires smooth maneuvers while in the tortuous arch. Risk factors for thromboembolic complications can be divided as described in Table 39.3. The incidence of DWI “hits” ranges from about 11% to 22% in diagnostic angiography, to 20% to 60% in stent-assisted coiling of aneurysms, to as high as 86% with flow diverter placement. Most DWI signals interestingly spare deep perforator territories.25 On follow-up, most of the small (<2 mm) signals disappear.32 Not all signals correspond with clinical ischemic symptoms, but risk of neurologic adverse events can be as high as 3% with diagnostic cerebral angiography.33 Clinical stroke rate with flow diversion may be as high as 6% to 13%.22,34 The clinical stroke rate in carotid stenting ranges from 2% to 6.8% with far greater (>70%) new DWI lesions.28,35 Nearly 25% of those with diffusion abnormalities will have contralateral lesions also.
Complication Avoidance Table 39.4 outlines the steps that are rigorously followed at our institution to reduce the risk of thromboembolic events.
Extracranial Internal Carotid Artery/Vertebral Artery Spasm and Dissection Catheter manipulation inside of the internal carotid artery (ICA) or vertebral artery can lead to spasm and on occasion lead to dissection. In diagnostic angiography, this has been noted to occur in about 1.2% of cases, according to a single-center study that reviewed 597 angiograms in 494 patients.38 The vertebral artery tends to be more prone to dissection because of its smaller size
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
A
B
A
B
A
B
• Fig. 39.7
Illustration of transcranial microsurgical ‘hybrid’ access. Left posterior temporal hematoma (i) due to venous hypertension from a high grade left cavernous sinus DAVF (ii) with a prominent arterialized superficial middle cerebral vein (SMCV). Endovascular direct access was not feasible since venous outflow was exclusively through cortical veins. While the initial angiogram showed a small superior ophthalmic vein, this was noted to be spontaneously thrombosed during the subsequent angiogram after 72 hours of the initial study. Left frontotemporal craniotomy with zygomatic osteotomy for microsurgical exposure of the SCMV (iii A). Micropuncture (iii B) and insertion of sheath in middle fossa floor at entrance of SMCV into dura (iv A and B) for coil embolization of the arterialized cavernous sinus (v A). Complete elimination of fistula was successfully achieved (v B). (Adapted with permission Hurley MC, Rahme RJ, Fishman AJ, Batjer HH, Bendok BR. Combined surgical and endovascular access of the superficial middle cerebral vein to occlude a high-grade cavernous dural arteriovenous fistula: case report. Neurosurgery. 2011;69(2):E475–E482.)
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A
B
A
B • Fig. 39.7, cont’d
TABLE 39.3 Risk Factors for Thromboembolic Complications
Patient Factors
Pharmacology
Procedural Factors
Increased age and atherosclerosis Tortuous arch anatomy Hypercoagulable state Unstable carotid plaque Tight carotid stenosis Contralateral carotid stenosis >50% Large, wide-neck aneurysm Resistance to antiplatelet agents Fibromuscular dysplasia Connective tissue diseases
Inadequate heparinization Inadequate platelet inhibition
Increased fluoroscopy time Increased contrast use Operator inexperience Complex intervention Flow diversion Inconsistent use of heparin flush with/without in-line filters Failure to use distal protection device
and the rigid nature of transverse foramina in its V2 segment. Complex interventions and operator technique are main risk factors, in addition to vessel wall abnormalities as in fibro muscular dysplasia.
Management Spasm is usually relieved promptly with catheter withdrawal, time, and intraarterial verapamil or nitroglycerine. With ICA dissections the intimal flap is usually in the direction of flow (cranial), and
this carries the risk of progression. At the same time, small dissections tend to heal excellently with medium-term antiplatelet or anticoagulant therapy. Hence decision-making has to occur on a caseby-case basis. i. Subintimal dissection: this type carries the risk of stenosis and occlusion along with thromboembolic events. The initial therapy of choice is heparinization for 24 to 48 hours, followed by 1 to 3 months of Coumadin therapy. Milder degrees of stenosis may be alternatively treated with antiplatelet therapy such as aspirin for 3 to 6 months. Close follow-up with US is
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TABLE 39.4 Steps to Reduce Thrombotic Events Patient preparation
Anticipation of thromboembolic (TE) risk in elderly patients and atherosclerotic population Prophylactic aspirin for 5–7 days before planned diagnostic angiography30 Adequate dual antiplatelet inhibition for stent placement procedures MR for carotid plaque imaging to risk-stratify unstable plaque36 Noninvasive assessment (CTA or MRA) of arch and carotid/vertebral anatomy and atherosclerosis Radial or brachial access in case of prohibitive arch anatomy Consider microsurgical therapy
Pharmacology
Platelet inhibition testing
Technical steps
Meticulous “purging” of all flush lines of air, including line from power injector (Fig. 39.8) Keep field free of gauze fragments that may form embolizable debris during manipulation (Fig. 39.9) Heparin in flush lines and periodic check of pressure and content of bags to ensure continuous flush37 Include above technical points in pre/post briefing and timeout Administration of IV heparin after access sheath in place (in endovascular procedures: full dose 60–80 IU/kg body weight; in diagnostic angiograms: half dose) Separate bowl of heparinized saline for cleaning gloves of blood and contrast material Frequent activated clotting time (ACT) checks (every 30–60 minutes) and bolus heparin doses as needed Hermetic technique during contrast injection Smooth and efficient technique: ALWAYS lead by wire Spend minimum necessary time intravascularly
Postoperative period
Continue antiplatelet agents as indicated Consider avoiding active heparin reversal Minimize neck manipulation with carotid stent
• Fig. 39.8
Meticulous purging of flush lines of air at beginning of procedure and continual vigilance. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
sufficient. Alternately, CT angiogram (CTA) or MR angiogram (MRA) may be used. Recurrent thromboembolic (TE) events that do not respond to full anticoagulation and/or DAPT require stent placement. If the stenosis is severe and observed at the time of an interventional procedure in a patient who has been adequately anticoagulated (and on antiplatelets), a stent may be an expeditious measure but will require continuation of DAPT. ii. Subadventitial dissection: This type carries the risk of PA formation. Again, the first-line treatment is either anticoagulation or antiplatelet therapy to avoid thromboembolic events and to promote healing. An additional concern is periodic monitoring for PA enlargement, which can be accomplished with US or MRA or CTA. Progressive PA enlargement or recurrent TE events may require stent placement.
• Fig. 39.9 Avoidance of material (such as gauze, on right) that can produce embolizable debris and preferential use of material such as Telfa (American Surgical Company, Salem, MA). (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
Complications Related to Target Lesion Access These complications usually relate to microcatheter and microwire access and include: i. Rupture of arterial feeder during transarterial embolization ii. Aneurysm perforation and rupture iii. Arteriovenous malformation rupture iv. Rupture of draining vein during transvenous embolization Avoidance of the above complications requires compulsive attention to technique and constant review of the position of the guide catheter and distal access catheter, especially with tortuous anatomy. Forcing wires through vessels such as the middle meningeal artery
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is absolutely prohibited. In aneurysm coiling, adequate sizing of the initial (“framing”) coil and subsequent packing should be done carefully after a thorough assessment with rotational angiography.
Contrast Nephropathy Contrast-induced nephropathy is defined as the rise in serum creatinine concentration in the 24 to 48 hours after contrast administration. Typically it remains asymptomatic other than a laboratory abnormality, and oliguria is surprisingly rare. The pathology is acute tubular necrosis. The risk factors identified are: i. preexisting renal insufficiency, especially in combination with diabetes mellitus ii. hemodynamic instability and hypovolemia with reduced renal perfusion iii. arterial versus venous administration (such as CTA) iv. interventional versus diagnostic angiography (related to volume of contrast) v. use of nonionic hypo-osmolal agents such as iohexol or iopamidol.39
Complication Avoidance Avoidance of renal dysfunction or exacerbation post angiography requires proper identification of high-risk patients. Steps that are taken to mitigate contrast-induced nephropathy are: 1. Hydration: Pre-, intra- and postprocedure hydration with isotonic normal saline reduces risk of kidney damage. Typically we prefer administration of about 0.5 to 1.0 L for diagnostic angiography
and ensure ongoing hydration for more complex and lengthy interventions. Fluid overload should be avoided. 2. Acetylcysteine: Some evidence suggests benefit in the oral form given twice a day beginning the day before surgery and on the day of the procedure.40 3. Bicarbonate: Intravenous solution of bicarbonate has been compared with saline as a nephroprotectant with conflicting results, but most authorities consider it to be useful.40 Our preference is saline hydration. 4. Contrast agent selection: The nonionic iso-osmolal agent iodixanol (Visipaque) is our preferred choice in high-risk patients and when frequent repeated examinations are necessary, such as in vasospasm. The other safer agents are iopamidol (Isovue) and loversol (Optiray), both of which are nonionic hypo-osmolal. The high-osmolal nonionic agent iohexol (Omnipaque) should be avoided. 5. Dose of contrast agent: Whichever agent is selected, it is important to limit volume administered to the absolute essential. Intelligent use of angiographic equipment and deliberate thought about the steps involved are important. Diluted contrast may be used conveniently without sacrificing image quality. We have used 20% diluted contrast with excellent imaging results in very high risk patients.
Management As mentioned earlier, the incidence of oliguria is surprisingly low, and large studies have shown that the necessity of dialysis exists in less than 1%.41 The elevated creatinine levels tend to drop back to baseline toward the end of the week after angiography.
SURGICAL REWIND
My Worst Case Retroperitoneal Hematoma A 72-year-old lady underwent a second stage of stent-assisted coiling for a residual unruptured basilar apex aneurysm (Fig. 39.10). Approach was via the right transfemoral route. The previous treatment session was also via a right transfemoral approach about 3 months prior and was uneventful with regard to groin hemostasis and follow-up. Groin access for the index procedure was achieved with an 8 Fr sheath, and after the procedure, an 8 Fr Angio-Seal closure device was deployed uneventfully (Fig. 39.11). Complete heparinization had been achieved, and no reversal was undertaken (she was also on dual antiplatelet therapy). The next morning she developed acute severe groin pain and hypotension with tenderness over and around the puncture site. Hemoglobin dropped from 10.1 to 6.5 g/dL, and packed cells were transfused. Coagulation profile was normal. CT scan/CTA of the abdomen and pelvis revealed a massive retroperitoneal hematoma with a small site of contrast extravasation (Fig. 39.12A–C). Emergent pigtail aortogram (Fig. 39.13A) and right iliofemoral angiography (Fig. 39.13B) from left-sided femoral access did not show active site of leak or PA. One day later she developed atrial fibrillation with rapid ventricular response from the acute hemodynamic insult and discontinuation of metoprolol; this settled readily with rate control using diltiazem. She was managed with bed rest for 48 hours, close hemodynamic monitoring, and gradual mobilization and was discharged on day 7 in stable condition. Follow-up at 6 weeks was unremarkable, and hemoglobin was 13.1 g/dL.
• Fig. 39.10
Residual basilar apex aneurysm.
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
235
• Fig. 39.11
Groin puncture site towards uppermost aspect of femoral head. This would constitute a ‘high’ puncture though it appears to be over the femoral head. Strategic obliquity with the sheath pulled away can often demonstrate exact puncture site (not done in this case). (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
B
A • Fig. 39.12
Axial (A), coronal (B) and CT angiogram (C) images of abdomen and pelvis. A large retroperitoneal hematoma is evident (3A) that displaces the urinary bladder to the contralateral side and compresses it (3B, arrow). There is a site of contrast extravasation in the clot (3C, arrow). No pseudoaneurysm was evident. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
Continued
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C • Fig. 39.12, cont’d
A
B • Fig. 39.13
Pigtail aortogram (A) and right iliofemoral run (B) via left femoral approach does not show pseudoaneurysm or active dye extravasation. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
NEUROSURGICAL SELFIE MOMENT Access-related complications are not unusual in day-to-day endovascular neurosurgical practice. A standard regimental approach to complication avoidance is the secret to successful outcomes. Knowing your patient and patient-specific anatomy, identification of high-risk patients, brutal honesty about complications, minimizing procedural time, constant refinement of technique, and smooth techniques will help minimize the complications.
References 1. Wagenbach A, Saladino A, Daugherty WP, Cloft HJ, Kallmes DF, Lanzino G. Safety of early ambulation after diagnostic and therapeutic neuroendovascular procedures without use of closure devices. Neurosurgery. 2010;66(3):493–496, discussion 496–497. 2. Krueger K, Zaehringer M, Strohe D, Stuetzer H, Boecker J, Lackner K. Postcatheterization pseudoaneurysm: results of USguided percutaneous thrombin injection in 240 patients. Radiology. 2005;236(3):1104–1110. 3. Robertson L, Andras A, Colgan F, Jackson R. Vascular closure devices for femoral arterial puncture site haemostasis. Cochrane Database Syst Rev. 2016;(3):CD009541. 4. Koreny M, Riedmuller E, Nikfardjam M, Siostrzonek P, Mullner M. Arterial puncture closing devices compared with standard manual compression after cardiac catheterization: systematic review and meta-analysis. JAMA. 2004;291(3):350–357. 5. Levy EI, Boulos AS, Fessler RD, et al. Transradial cerebral angiography: an alternative route. Neurosurgery. 2002;51(2):335–340, discussion 340–332. 6. Levy EI, Kim SH, Bendok BR, Qureshi AI, Guterman LR, Hopkins LN. Transradial stenting of the cervical internal carotid artery: technical case report. Neurosurgery. 2003;53(2):448–451, discussion 451–442. 7. Kedev S, Mann T. Skin to skin: transradial carotid angiography and stenting. Intervent Cardiol Clin. 2014;3(1):21–35. 8. Hill MD, Brooks W, Mackey A, et al. Stroke after carotid stenting and endarterectomy in the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST). Circulation. 2012;126(25):3054–3061. 9. Bendok BR, Przybylo JH, Parkinson R, Hu Y, Awad IA, Batjer HH. Neuroendovascular interventions for intracranial posterior circulation disease via the transradial approach: technical case report. Neurosurgery. 2005;56(3):E626, discussion E626. 10. Mendiz OA, Fava C, Lev G, Caponi G, Valdivieso L. Transradial versus transfemoral carotid artery stenting: a 16-year single-center experience. J Interv Cardiol. 2016;29(6):588–593. 11. Faggioli G, Ferri M, Rapezzi C, Tonon C, Manzoli L, Stella A. Atherosclerotic aortic lesions increase the risk of cerebral embolism during carotid stenting in patients with complex aortic arch anatomy. J Vasc Surg. 2009;49(1):80–85. 12. Faggioli G, Ferri M, Gargiulo M, et al. Measurement and impact of proximal and distal tortuosity in carotid stenting procedures. J Vasc Surg. 2007;46(6):1119–1124. 13. Aoun SG, Bendok BR, Batjer HH. Acute management of ruptured arteriovenous malformations and dural arteriovenous fistulas. Neurosurg Clin N Am. 2012;23(1):87–103. 14. Montorsi P, Galli S, Ravagnani PM, et al. Carotid artery stenting with proximal embolic protection via a transradial or transbrachial approach: pushing the boundaries of the technique while maintaining safety and efficacy. J Endovasc Ther. 2016;23(4):549–560. 15. Dashti SR, Fiorella D, Spetzler RF, Albuquerque FC, McDougall CG. Transorbital endovascular embolization of dural carotid-cavernous fistula: access to cavernous sinus through direct puncture: case examples and technical report. Neurosurgery. 2011;68(1 Suppl Operative):75–83, discussion 83.
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16. White JB, Layton KF, Evans AJ, et al. Transorbital puncture for the treatment of cavernous sinus dural arteriovenous fistulas. AJNR Am J Neuroradiol. 2007;28(7):1415–1417. 17. Blanc R, Piotin M, Mounayer C, Spelle L, Moret J. Direct cervical arterial access for intracranial endovascular treatment. Neuroradiology. 2006;48(12):925–929. 18. Mokin M, Snyder KV, Levy EI, Hopkins LN, Siddiqui AH. Direct carotid artery puncture access for endovascular treatment of acute ischemic stroke: technical aspects, advantages, and limitations. J Neurointerv Surg. 2015;7(2):108–113. 19. Blanc R, Mounayer C, Piotin M, Sadik J-C, Spelle L, Moret J. Hemostatic closure device after carotid puncture for stent and coil placement in an intracranial aneurysm: technical note. AJNR Am J Neuroradiol. 2002;23(6):978–981. 20. Kwolek CJ, Jaff MR, Leal JI, et al. Results of the ROADSTER multicenter trial of transcarotid stenting with dynamic flow reversal. J Vasc Surg. 2015;62(5):1227–1234. 21. Hurley MC, Rahme RJ, Fishman AJ, Batjer HH, Bendok BR. Combined surgical and endovascular access of the superficial middle cerebral vein to occlude a high-grade cavernous dural arteriovenous fistula: case report. Neurosurgery. 2011;69(2):E475–E482. 22. Iosif C, Camilleri Y, Saleme S, et al. Diffusion-weighted imagingdetected ischemic lesions associated with flow-diverting stents in intracranial aneurysms: safety, potential mechanisms, clinical outcome, and concerns. J Neurosurg. 2015;122(3):627–636. 23. Heller RS, Dandamudi V, Calnan D, Malek AM. Neuroform intracranial stenting for aneurysms using simple and multi-stent technique is associated with low risk of magnetic resonance diffusion-weighted imaging lesions. Neurosurgery. 2013;73(4):582–590, discussion 590–591. 24. Park JC, Lee DH, Kim JK, et al. Microembolism after endovascular coiling of unruptured cerebral aneurysms: incidence and risk factors. J Neurosurg. 2016;124(3):777–783. 25. Park KY, Chung PW, Kim YB, Moon HS, Suh BC, Yoon WT. Post-interventional microembolism: cortical border zone is a preferential site for ischemia. Cerebrovasc Dis. 2011;32(3):269–275. 26. Biondi A, Oppenheim C, Vivas E, et al. Cerebral aneurysms treated by Guglielmi detachable coils: evaluation with diffusion-weighted MR imaging. AJNR Am J Neuroradiol. 2000;21(5):957–963. 27. Albayram S, Selcuk H, Kara B, et al. Thromboembolic events associated with balloon-assisted coil embolization: evaluation with diffusionweighted MR imaging. AJNR Am J Neuroradiol. 2004;25(10):1768–1777. 28. Bijuklic K, Wandler A, Varnakov Y, Tuebler T, Schofer J. Risk factors for cerebral embolization after carotid artery stenting with embolic protection: a diffusion-weighted magnetic resonance imaging study in 837 consecutive patients. Circ Cardiovasc Interv. 2013;6(3):311–316. 29. Bendszus M, Koltzenburg M, Burger R, Warmuth-Metz M, Hofmann E, Solymosi L. Silent embolism in diagnostic cerebral angiography and neurointerventional procedures: a prospective study. Lancet. 1999;354(9190):1594–1597. 30. Brockmann C, Hoefer T, Diepers M, et al. Abciximab does not prevent ischemic lesions related to cerebral angiography: a randomized placebo-controlled trial. Cerebrovasc Dis. 2011;31(4):353–357. 31. Meissner I, Whisnant JP, Khandheria BK, et al. Prevalence of potential risk factors for stroke assessed by transesophageal echocardiography and carotid ultrasonography: the SPARC study. Stroke Prevention: Assessment of Risk in a Community. Mayo Clin Proc. 1999;74(9):862–869. 32. Iosif C, Lecomte JC, Pedrolo-Silveira E, et al. Evaluation of ischemic lesion prevalence after endovascular treatment of intracranial aneurysms, as documented by 3-T diffusion-weighted imaging: a 2-year, single-center cohort study. J Neurosurg. 2018;128(4):982–991. 33. Dion JE, Gates PC, Fox AJ, Barnett HJ, Blom RJ. Clinical events following neuroangiography: a prospective study. Stroke. 1987;18(6):997–1004. 34. Brinjikji W, Kallmes DF, Cloft HJ, Lanzino G. Age-related outcomes following intracranial aneurysm treatment with the Pipeline Embolization Device: a subgroup analysis of the IntrePED registry. J Neurosurg. 2016;124(6):1726–1730.
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35. Brott TG, Hobson RWI, Howard G, et al. Stenting versus endarterectomy for treatment of carotid-artery stenosis. NEJM. 2010; 363(1):11–23. 36. Akutsu N, Hosoda K, Fujita A, Kohmura E. A preliminary prediction model with MR plaque imaging to estimate risk for new ischemic brain lesions on diffusion-weighted imaging after endarterectomy or stenting in patients with carotid stenosis. AJNR Am J Neuroradiol. 2012;33(8):1557–1564. 37. Bendszus M, Koltzenburg M, Bartsch AJ, et al. Heparin and air filters reduce embolic events caused by intra-arterial cerebral angiography: a prospective, randomized trial. Circulation. 2004;110(15):2210–2215. 38. Le Roux PD, Elliott JP, Eskridge JM, Cohen W, Winn HR. Risks and benefits of diagnostic angiography after aneurysm surgery: a retrospective
analysis of 597 studies. Neurosurgery. 1998;42(6):1248–1254, discussion 1254–1245. 39. Eng J, Wilson RF, Subramaniam RM, et al. Comparative effect of contrast media type on the incidence of contrast-induced nephropathy: a systematic review and meta-analysis. Ann Intern Med. 2016;164(6):417–424. 40. Gonzales DA, Norsworthy KJ, Kern SJ, et al. A meta-analysis of N-acetylcysteine in contrast-induced nephrotoxicity: unsupervised clustering to resolve heterogeneity. BMC Med. 2007; 5(1):32. 41. Rudnick MR, Goldfarb S, Wexler L, et al. Nephrotoxicity of ionic and nonionic contrast media in 1196 patients: a randomized trial. Kidney Int. 1995;47(1):254–261.
Cranial Complications Endovascular Surgery
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Access-Related Complications in Endovascular Neurosurgery MITHUN G. SATTUR, MATTHEW E. WELZ, BERNARD R. BENDOK
HIGHLIGHTS • Obtaining, maintaining, and exiting the vascular portal of entry in a safe and efficient manner are essential to achieve the goal of diagnosis and treatment of cranial, spinal, and head-neck neurovascular diseases. • Transfemoral/groin access represents the most common route for endovascular access in vascular neurosurgery. • Access-related complications are categorized as bleeding, pseudoaneurysm, infection, and other arterial abnormalities. • A standard regimental approach to complication avoidance is the secret to successful outcome.
2. Device navigation along vascular roadmap to the lesion a. Thoracoabdominal aortic b. Arch of aorta c. Carotid arteries d. Vertebral arteries e. Intracranial arteries and veins 3. Intracranial target lesion access a. Access to aneurysm b. Access to arteriovenous malformation/dural fistula c. Tumor access 4. Contrast-induced nephropathy
Introduction
Femoral Access
The field of vascular neurosurgery has been enriched by significant advances in endovascular technology and techniques. Despite rapid evolution, certain basic tenets remain sacrosanct. Chief among them is the art and science of safe vascular access. Obtaining, maintaining, and exiting the vascular portal of entry in a safe and efficient manner are essential to achieve the goal of diagnosis and treatment of cranial, spinal, and head-neck neurovascular diseases. Catastrophic complications can arise, and access-related complications should never be underestimated or viewed with hubris. The present chapter provides a concise overview of the nuances for safe access for each of the various endovascular access routes.
Transfemoral/groin access represents the most common route for endovascular access in vascular neurosurgery. The large size of the artery that allows placement of large devices in co-axial fashion for a stable construct, location over the femoral head that allows compressibility, situation away from the fluoroscopy arms, and a long history of operator familiarity are main factors for this preference. Most devices available for intervention are configured and optimized for femoral access. Spinal angiography and intervention are almost always carried out via the transfemoral route. Complications from femoral access have been documented to occur in 1.6% to 6.0% of patients in the literature but can be minimized with proper precautions. Complications are categorized as follows: 1. Bleeding Groin hematoma Retroperitoneal hematoma 2. Pseudoaneurysm (PA) 3. Other arterial abnormalities (arteriovenous fistula, acute thrombosis, dissection, distal embolism) 4. Infection
Access-Related Complications Access-related complications (ARC) should be considered if related to any of the following: 1. Injury at access site: a. Femoral b. Radial c. Brachial d. Carotid e. Vertebral f. Transorbital g. Transcranial access 224
Bleeding Minor hematomas at the puncture site are common and do not necessarily represent complications. Major hematomas may occur either in the groin or retroperitoneum and
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
represent difficulty with hemostasis. Risk factors for hematoma formation are: a. Obesity b. Puncture above inguinal ligament (high puncture) c. Advanced atherosclerotic disease d. Dual antiplatelet therapy (DAPT) e. Anticoagulation f. Uncontrolled hypertension g. Large sheath h. Rough catheterization of circumflex branch (and rupture) i. Backwall puncture j. Inability to deploy closure device k. Inadequate rest before ambulation A major hematoma manifests with increasing local pain, swelling, and bruising, along with declining hematocrit in the few hours post-procedure. However, a retroperitoneal hematoma is more treacherous because there is no external swelling. The only external sign sometimes is ipsilateral flank bruising. Typically with retroperitoneal hematoma, there is an initial transient episode of hypotension that improves with a fluid bolus; if left undiagnosed, it can lead to dangerous and rapid hemodynamic collapse.
Diagnosis A high index of suspicion is needed to diagnose a retroperitoneal hematoma. Close attention to clinical examination and prompt serial hematocrit estimations are important. Ultrasound is helpful with a thigh hematoma in ruling out expanding PA. Definitive diagnosis of retroperitoneal hematoma requires computed tomography (CT) imaging.
Management Many hematomas may not require surgical evacuation. Maintaining stable blood pressure and adequate circulatory status is paramount. Serial hematocrit estimation guides transfusion, and packed red cells should readily be available. It is prudent to obtain early vascular surgery consultation if a patient is being admitted for hematoma management. With active extravasation (which sometimes can be seen on contrast-enhanced CT) and impending cardiovascular collapse, vascular surgical intervention is indicated. Anticoagulated patients and those on DAPT pose a unique dilemma. Procedural anticoagulation usually reverses spontaneously in few hours. Reversal of chronic anticoagulation depends on the primary diagnosis for which this is indicated and should be undertaken on a case-by-case basis. DAPT patients tend to be more problematic due to difficulty in reversing platelet dysfunction and, more importantly, the fact that DAPT is indicated for recent intracranial or coronary (or other intravascular) stent. Placement of a covered stent across the site of leakage is an endovascular option in select cases.
Pseudoaneurysms A hematoma that occurs in the vessel wall and is in communication with the arterial lumen can become PA. Clinical presentation is with an enlarging firm mass that is pulsatile and may have a bruit on auscultation. Some degree of pain/discomfort may be seen. PA typically becomes evident after 48 hours. Some authors describe simple (one lobe) and complex (more than one lobe) PA.2 Whether use of a closure device in lieu of manual compression increases PA risk is debatable based on recent metaanalyses versus those from a decade ago.3,4 Other risk factors include high puncture, large sheath, and puncture below bifurcation in superficial femoral artery.
Diagnosis Duplex ultrasound (US) is the imaging modality of choice. PA neck, lobe(s), dimensions, and parent artery lumen communication are clearly visualized.
Management Small PAs frequently do not require treatment, but occasional lesions progressively enlarge. Treatment modalities are delineated in Table 39.1. The most common technique (including at our center) is thrombin injection because it is quick, highly effective, a bedside procedure, and largely safe.2 It may be prudent to repeat a US in 1 to 2 weeks to rule out recurrence.
Other Femoral Artery Complications Arterial thrombosis, dissection, and distal embolism are rare complications that present with pain, paresthesias, and diminished or absent pedal pulses. Thrombosis risk is strongly correlated with leaving the sheath in for prolonged duration post procedure. Risk factors include puncture below bifurcation of common femoral artery, large sheath placement, inadequate flush of heparinized saline, severe atherosclerosis, and rough technique. Arteriovenous fistula
TABLE 39.1 Various Treatment Modalities and Their
Advantages/Concerns
Treatment
Advantages
Concerns
Ultrasound-guided manual compression
Simple, bedside Inexpensive No risk to parent artery lumen
Patient discomfort Vasovagal symptoms
Ultrasound-guided thrombin injection
Excellent success rates (over 90%) Minimal patient discomfort
Parent artery reflux Distal embolism Systemic effects Recurrence
Covered stent
Endovascular option in larger neck Indicated for failure of ultrasound-guided techniques
Antiplatelet therapy Cost
Open surgical repair
Effective for large/ giant PA Indicated for rupture/ infection
Major surgical procedure
Prevention Though theoretically longer durations of bed rest might reduce bleeding, clinical studies have proven that a 2-hour bed rest period post sheath removal is adequate. One study used manual compression for hemostasis after use of 5 Fr sheaths in the majority of the 295 patients evaluated.1 Close attention to steps involved in femoral access is mandatory to prevent complications (see “Complication avoidance”).
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is recognized by characteristic thrill and bruit and usually presents in a delayed fashion. US guidance to avoid the femoral vein and tributaries during arterial puncture and avoiding a simultaneous femoral vein puncture (when required) on the same side may help avoid this complication. It is imperative to recognize these potentially limb-threatening complications early and involve vascular surgery expeditiously for open or endovascular intervention. The imaging modality of choice to document these complications is duplex US. Early recognition and management leads to good outcomes.
Complication Avoidance At our institution, all diagnostic angiography–related access is treated with a “nuclear launch code” protocol. Fluoroscopic confirmation of femoral head location is performed with a localizer (hemostat), and puncture occurs over this site (Fig. 39.1A–C). We use ultrasound to mark the bifurcation of the common femoral artery (into superficial femoral and profunda femoris artery), and we puncture above this point but still over the femoral head (Fig. 39.2D–G). Continuous heparinized saline flush is run through the sheath for the duration of the procedure. Invariably we endeavor to remove the femoral sheath on the table after the conclusion of the procedure. Femoral arteriography is performed before sheath removal. Particular attention is paid to puncture site vis-a-vis the bifurcation, location of puncture site (= sheath entry site) with respect to the femoral head, dissection, or thrombosis. Decision
regarding closure device deployment proceeds as described later, after ensuring that the puncture is above the bifurcation.
Closure Device Use Vascular closure devices are approved for femoral access closure and are currently available under various categories: i. Collagen plug–based (Angio-Seal, Terumo, Somerset, NJ) ii. Suture based (Perclose Abbott, Abbott Park, IL) iii. Clip based (StarClose Abbott, Abbott Park, IL) The advantages and disadvantages of using a closure device for femoral access are described in Table 39.2. Closure device deployment also follows a strict set of rules: i. Confirm location of puncture above common femoral artery bifurcation (Fig. 39.3) ii. Repeat prep and draping of groin site iii. Change of gloves by team iv. Prophylactic antibiotics before insertion v. Confirmation of intravascular placement vi. Avoidance of closure device deployment in certain situations: a. Puncture at/below bifurcation (higher risk of dissection) b. Severe calcified atherosclerotic disease c. Small artery size d. Immunocompromised patient (infection risk) e. Access through bypass graft
A
B
• Fig. 39.1
C
Anatomic (A) and fluoroscopic (B and C) landmarks for groin puncture (shown here on right side). A good approximation of the femoral pulse is a site 3 finger-breadths below a line joining the anterior superior iliac spine and the pubic symphysis (A). A localizer is placed at this site and X-ray is obtained to confirm position over the femoral head (B). This site in turn is marked (C). (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
A
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B
D
C • Fig. 39.2
Strategic use of ultrasound for safe femoral puncture (A). Ultrasound is used to visualize the common femoral artery (B) and the bifurcation (C). The bifurcation is marked on the groin (D) and puncture is above this yet over the femoral head. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
TABLE 39.2 Advantages and Disadvantages of Using
Advantages
Disadvantages
Shortens bed rest
Potential vessel occlusion/ thrombosis
Infection of a closure device can be a severe complication and most commonly occurs in immunocompromised populations. It can potentially lead to vessel rupture in addition to bacteremia and sepsis. Treatment often involves open surgical resection and grafting and prolonged IV antibiotic therapy, but outcomes may not be satisfactory.
Less intense physician/nurse involvement
Dissection/PA risk may be greater
Transfemoral Venous Access
Cost benefit by reducing stay and personnel requirement
Infection
Potentially less incidence of hematoma formation
Cost
a Closure Device for Femoral Access
The principle of ensuring puncture over the femoral head is most important and probably more so than with arterial access, since typically closure devices cannot be deployed. Adequate manual compression is the key to achieving adequate hemostasis.
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Brachial Access The attraction of brachial access lies in the fact that atherosclerotic disease and tortuosity is rare at this location and that a device of somewhat larger size than at a radial access site (7 Fr sheath, for example) can be used. A unique scenario where we have used the brachial approach is documented in a patient with severe coarctation of aorta.13 Thrombosis and PA are potential complications. In a study of 214 patients who underwent transradial or transbrachial approach for carotid stenting, 4 had to be treated for acute thrombosis or PA of brachial artery (of 60 patients), and 6 had radial artery occlusion (of 154).14 Thrombosis usually requires surgical thrombectomy by a vascular surgeon. Occurrence of PA after brachial access is more frequent than femoral access and may be treated with US-guided manual compression or injection of fibrin, but eventually surgical intervention may be required. Hematoma at the access site has the potential to cause compartment syndrome if very large, but most cases do not require surgical evacuation. Cross-over to a femoral approach occurs in about 1% to 7%.
Transorbital Access • Fig. 39.3 Ideal puncture site (horizontal arrow) is over the femoral head (asterisk) and above the bifurcation (vertical arrow) for deployment of closure device. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
Radial Access Traditional transfemoral access may not be feasible in patients with severe aortoiliac or iliofemoral atherosclerosis. Severe obesity not only makes puncture challenging, but applying manual compression after sheath removal is also very difficult in situations where a closure device cannot be employed. In such cases, radial artery access is very attractive. The superficial location of radial artery, radial-ulnar collaterals to hand, and unrestricted ambulation have encouraged increasing use of radial access for vascular, both extracranial and intracranial vascular neurosurgery indications.5,6 For carotid stenting, radial artery access is attractive because of the ease of navigating a type III aortic arch and accessing a bovine carotid take-off.6,7 Radial access on the right side avoids aortic arch navigation; catheter manipulation in the aortic arch has been postulated as a mechanism of periprocedural stroke in patients who undergo carotid artery stenting.8 Based on success with cervical intervention, we have previously reported on the successful and effective application of the transradial approach for intracranial intervention9 (Fig. 39.4). The radial arteries, however, are prone to spasm easily and require administration of nitroglycerine and verapamil along with heparin in the form of a vasodilatory “cocktail.”5 Thrombosis is documented in about 5% of transradial interventions, but in general it is well tolerated due to collaterals from ulnar territory. An Allen’s test is performed before radial catheterization (Fig. 39.5). Immediate sheath removal and nonocclusive compression technique reduces the risk of occlusion Fig. 39.6). The size of the artery limits the size of devices that may be used for intervention, and usually it is difficult to insert devices larger than 6 Fr. Crossover to femoral approach was documented to occur in 4.9% of patients who underwent carotid stenting, according to one large Italian study.10–12
This specific access route is unique to management of cavernous sinus dural arteriovenous fistulas (CS-DAVF). In well-selected cases, transvenous embolization of DAVFs can be accomplished via direct transorbital puncture of the superior or inferior ophthalmic vein, which is frequently arterialized and prominent.15,16 Potential complications include orbital hematoma, infection, and puncture of the globe, vitreous leakage, and damage to the optic nerve and/ or ocular motor nerves. Prevention of complications starts with appropriate case selection. Clear visualization of the arterialized ophthalmic vein on angiography is necessary. Meticulous technique and optimal use of angiographic working views are paramount. Three-dimensional rotational angiography can be helpful in selecting appropriate working views.
Carotid Access Severe tortuosity of the aortic arch introduces a significant technical impediment in catheterizing arch vessels, especially the left common carotid artery. Transradial and transbrachial access is the next natural step in attempting access, but even these may prove unsuccessful. In such instances, direct carotid puncture remains an option.17,18 Sheaths from 4 Fr to 8 Fr may be inserted. Complications may be severe and include carotid dissection, embolism of plaque fragments and, most importantly, neck hematoma. The latter is important given that most situations are complicated with anticoagulation and antiplatelet therapy. Sheath removal is usually followed by manual compression, but closure devices have also been used.19 There has been recent resurgence in direct carotid access with the introduction of the ENROUTE transcarotid neuroprotection system (Silk Road Medical Inc., Sunnyvale, CA).20
Transcranial Access for Endovascular Therapy Rare instances may dictate direct microsurgical access to treat an intracranial vascular lesion. Examples have included access to arterialized and dilated middle cerebral vein or middle meningeal artery or the cavernous sinus.21 This situation is usually encountered with certain DAVFs where endovascular transarterial and/or transvenous access is not feasible and the only approach is via an arterialized vein accessible microsurgically. An apt example is
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
A
B
C
D
E • Fig. 39.4
Approach to basilar artery stenosis (A) via the radial approach because of severe tortuosity of the innominate artery (B) and left vertebral artery (D) for transfemoral access. The favorable angle of right vertebral artery off the right subclavian (C) enabled effective stent placement across the stenosis (E). (Adapted with permission Bendok BR, Przybylo JH, Parkinson R, Hu Y, Awad IA, Batjer HH. Neuroendovascular interventions for intracranial posterior circulation disease via the transradial approach: technical case report. Neurosurgery. 2005;56(3):E626)
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A
B
• Fig. 39.5
Allen’s test. Following simultaneous ulnar and radial artery compression till thumb oximeter saturation is no longer picked up, pressure over the ulnar artery is released. In the presence of adequate collateral circulation, the oxygen saturation rises to normal. (Adapted with permission Levy EI, Boulos AS, Fessler RD, et al. Transradial cerebral angiography: an alternative route. Neurosurgery. 2002;51(2): 335–340.)
A
B • Fig. 39.6
Non-occlusive radial artery compression for hemostasis reduces risk of thrombosis. (Adapted with permission Levy EI, Boulos AS, Fessler RD, et al. Transradial cerebral angiography: an alternative route. Neurosurgery. 2002;51(2):335–340)
illustrated in the case of a challenging cavernous sinus DAVF that we treated via a strategic “hybrid” approach (Fig. 39.7i–v).21
Thromboembolic Complications From Intravascular Device Navigation in Large Vessels After diagnostic and interventional cerebral angiography, there is clear evidence that patients experience increased hyperintense signals
on diffusion-weighted magnetic resonance imaging (DWI) that represent microemboli.22-30 Ischemic thromboembolic events arise from following mechanisms: i. Dislodged atheromatous debris mainly in the region of the aortic arch and carotid bifurcation ii. Inherent thrombogenicity of an intravascular device iii. Exogenous air/debris in the catheter system The descending thoracic aorta and the distal aortic arch are the most common sites of atheromatous plaque in the aorta.31 Catheter navigation with increasing age carries increasing risk and requires smooth maneuvers while in the tortuous arch. Risk factors for thromboembolic complications can be divided as described in Table 39.3. The incidence of DWI “hits” ranges from about 11% to 22% in diagnostic angiography, to 20% to 60% in stent-assisted coiling of aneurysms, to as high as 86% with flow diverter placement. Most DWI signals interestingly spare deep perforator territories.25 On follow-up, most of the small (<2 mm) signals disappear.32 Not all signals correspond with clinical ischemic symptoms, but risk of neurologic adverse events can be as high as 3% with diagnostic cerebral angiography.33 Clinical stroke rate with flow diversion may be as high as 6% to 13%.22,34 The clinical stroke rate in carotid stenting ranges from 2% to 6.8% with far greater (>70%) new DWI lesions.28,35 Nearly 25% of those with diffusion abnormalities will have contralateral lesions also.
Complication Avoidance Table 39.4 outlines the steps that are rigorously followed at our institution to reduce the risk of thromboembolic events.
Extracranial Internal Carotid Artery/Vertebral Artery Spasm and Dissection Catheter manipulation inside of the internal carotid artery (ICA) or vertebral artery can lead to spasm and on occasion lead to dissection. In diagnostic angiography, this has been noted to occur in about 1.2% of cases, according to a single-center study that reviewed 597 angiograms in 494 patients.38 The vertebral artery tends to be more prone to dissection because of its smaller size
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
A
B
A
B
A
B
• Fig. 39.7
Illustration of transcranial microsurgical ‘hybrid’ access. Left posterior temporal hematoma (i) due to venous hypertension from a high grade left cavernous sinus DAVF (ii) with a prominent arterialized superficial middle cerebral vein (SMCV). Endovascular direct access was not feasible since venous outflow was exclusively through cortical veins. While the initial angiogram showed a small superior ophthalmic vein, this was noted to be spontaneously thrombosed during the subsequent angiogram after 72 hours of the initial study. Left frontotemporal craniotomy with zygomatic osteotomy for microsurgical exposure of the SCMV (iii A). Micropuncture (iii B) and insertion of sheath in middle fossa floor at entrance of SMCV into dura (iv A and B) for coil embolization of the arterialized cavernous sinus (v A). Complete elimination of fistula was successfully achieved (v B). (Adapted with permission Hurley MC, Rahme RJ, Fishman AJ, Batjer HH, Bendok BR. Combined surgical and endovascular access of the superficial middle cerebral vein to occlude a high-grade cavernous dural arteriovenous fistula: case report. Neurosurgery. 2011;69(2):E475–E482.)
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A
B
A
B • Fig. 39.7, cont’d
TABLE 39.3 Risk Factors for Thromboembolic Complications
Patient Factors
Pharmacology
Procedural Factors
Increased age and atherosclerosis Tortuous arch anatomy Hypercoagulable state Unstable carotid plaque Tight carotid stenosis Contralateral carotid stenosis >50% Large, wide-neck aneurysm Resistance to antiplatelet agents Fibromuscular dysplasia Connective tissue diseases
Inadequate heparinization Inadequate platelet inhibition
Increased fluoroscopy time Increased contrast use Operator inexperience Complex intervention Flow diversion Inconsistent use of heparin flush with/without in-line filters Failure to use distal protection device
and the rigid nature of transverse foramina in its V2 segment. Complex interventions and operator technique are main risk factors, in addition to vessel wall abnormalities as in fibro muscular dysplasia.
Management Spasm is usually relieved promptly with catheter withdrawal, time, and intraarterial verapamil or nitroglycerine. With ICA dissections the intimal flap is usually in the direction of flow (cranial), and
this carries the risk of progression. At the same time, small dissections tend to heal excellently with medium-term antiplatelet or anticoagulant therapy. Hence decision-making has to occur on a caseby-case basis. i. Subintimal dissection: this type carries the risk of stenosis and occlusion along with thromboembolic events. The initial therapy of choice is heparinization for 24 to 48 hours, followed by 1 to 3 months of Coumadin therapy. Milder degrees of stenosis may be alternatively treated with antiplatelet therapy such as aspirin for 3 to 6 months. Close follow-up with US is
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TABLE 39.4 Steps to Reduce Thrombotic Events Patient preparation
Anticipation of thromboembolic (TE) risk in elderly patients and atherosclerotic population Prophylactic aspirin for 5–7 days before planned diagnostic angiography30 Adequate dual antiplatelet inhibition for stent placement procedures MR for carotid plaque imaging to risk-stratify unstable plaque36 Noninvasive assessment (CTA or MRA) of arch and carotid/vertebral anatomy and atherosclerosis Radial or brachial access in case of prohibitive arch anatomy Consider microsurgical therapy
Pharmacology
Platelet inhibition testing
Technical steps
Meticulous “purging” of all flush lines of air, including line from power injector (Fig. 39.8) Keep field free of gauze fragments that may form embolizable debris during manipulation (Fig. 39.9) Heparin in flush lines and periodic check of pressure and content of bags to ensure continuous flush37 Include above technical points in pre/post briefing and timeout Administration of IV heparin after access sheath in place (in endovascular procedures: full dose 60–80 IU/kg body weight; in diagnostic angiograms: half dose) Separate bowl of heparinized saline for cleaning gloves of blood and contrast material Frequent activated clotting time (ACT) checks (every 30–60 minutes) and bolus heparin doses as needed Hermetic technique during contrast injection Smooth and efficient technique: ALWAYS lead by wire Spend minimum necessary time intravascularly
Postoperative period
Continue antiplatelet agents as indicated Consider avoiding active heparin reversal Minimize neck manipulation with carotid stent
• Fig. 39.8
Meticulous purging of flush lines of air at beginning of procedure and continual vigilance. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
sufficient. Alternately, CT angiogram (CTA) or MR angiogram (MRA) may be used. Recurrent thromboembolic (TE) events that do not respond to full anticoagulation and/or DAPT require stent placement. If the stenosis is severe and observed at the time of an interventional procedure in a patient who has been adequately anticoagulated (and on antiplatelets), a stent may be an expeditious measure but will require continuation of DAPT. ii. Subadventitial dissection: This type carries the risk of PA formation. Again, the first-line treatment is either anticoagulation or antiplatelet therapy to avoid thromboembolic events and to promote healing. An additional concern is periodic monitoring for PA enlargement, which can be accomplished with US or MRA or CTA. Progressive PA enlargement or recurrent TE events may require stent placement.
• Fig. 39.9 Avoidance of material (such as gauze, on right) that can produce embolizable debris and preferential use of material such as Telfa (American Surgical Company, Salem, MA). (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
Complications Related to Target Lesion Access These complications usually relate to microcatheter and microwire access and include: i. Rupture of arterial feeder during transarterial embolization ii. Aneurysm perforation and rupture iii. Arteriovenous malformation rupture iv. Rupture of draining vein during transvenous embolization Avoidance of the above complications requires compulsive attention to technique and constant review of the position of the guide catheter and distal access catheter, especially with tortuous anatomy. Forcing wires through vessels such as the middle meningeal artery
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is absolutely prohibited. In aneurysm coiling, adequate sizing of the initial (“framing”) coil and subsequent packing should be done carefully after a thorough assessment with rotational angiography.
Contrast Nephropathy Contrast-induced nephropathy is defined as the rise in serum creatinine concentration in the 24 to 48 hours after contrast administration. Typically it remains asymptomatic other than a laboratory abnormality, and oliguria is surprisingly rare. The pathology is acute tubular necrosis. The risk factors identified are: i. preexisting renal insufficiency, especially in combination with diabetes mellitus ii. hemodynamic instability and hypovolemia with reduced renal perfusion iii. arterial versus venous administration (such as CTA) iv. interventional versus diagnostic angiography (related to volume of contrast) v. use of nonionic hypo-osmolal agents such as iohexol or iopamidol.39
Complication Avoidance Avoidance of renal dysfunction or exacerbation post angiography requires proper identification of high-risk patients. Steps that are taken to mitigate contrast-induced nephropathy are: 1. Hydration: Pre-, intra- and postprocedure hydration with isotonic normal saline reduces risk of kidney damage. Typically we prefer administration of about 0.5 to 1.0 L for diagnostic angiography
and ensure ongoing hydration for more complex and lengthy interventions. Fluid overload should be avoided. 2. Acetylcysteine: Some evidence suggests benefit in the oral form given twice a day beginning the day before surgery and on the day of the procedure.40 3. Bicarbonate: Intravenous solution of bicarbonate has been compared with saline as a nephroprotectant with conflicting results, but most authorities consider it to be useful.40 Our preference is saline hydration. 4. Contrast agent selection: The nonionic iso-osmolal agent iodixanol (Visipaque) is our preferred choice in high-risk patients and when frequent repeated examinations are necessary, such as in vasospasm. The other safer agents are iopamidol (Isovue) and loversol (Optiray), both of which are nonionic hypo-osmolal. The high-osmolal nonionic agent iohexol (Omnipaque) should be avoided. 5. Dose of contrast agent: Whichever agent is selected, it is important to limit volume administered to the absolute essential. Intelligent use of angiographic equipment and deliberate thought about the steps involved are important. Diluted contrast may be used conveniently without sacrificing image quality. We have used 20% diluted contrast with excellent imaging results in very high risk patients.
Management As mentioned earlier, the incidence of oliguria is surprisingly low, and large studies have shown that the necessity of dialysis exists in less than 1%.41 The elevated creatinine levels tend to drop back to baseline toward the end of the week after angiography.
SURGICAL REWIND
My Worst Case Retroperitoneal Hematoma A 72-year-old lady underwent a second stage of stent-assisted coiling for a residual unruptured basilar apex aneurysm (Fig. 39.10). Approach was via the right transfemoral route. The previous treatment session was also via a right transfemoral approach about 3 months prior and was uneventful with regard to groin hemostasis and follow-up. Groin access for the index procedure was achieved with an 8 Fr sheath, and after the procedure, an 8 Fr Angio-Seal closure device was deployed uneventfully (Fig. 39.11). Complete heparinization had been achieved, and no reversal was undertaken (she was also on dual antiplatelet therapy). The next morning she developed acute severe groin pain and hypotension with tenderness over and around the puncture site. Hemoglobin dropped from 10.1 to 6.5 g/dL, and packed cells were transfused. Coagulation profile was normal. CT scan/CTA of the abdomen and pelvis revealed a massive retroperitoneal hematoma with a small site of contrast extravasation (Fig. 39.12A–C). Emergent pigtail aortogram (Fig. 39.13A) and right iliofemoral angiography (Fig. 39.13B) from left-sided femoral access did not show active site of leak or PA. One day later she developed atrial fibrillation with rapid ventricular response from the acute hemodynamic insult and discontinuation of metoprolol; this settled readily with rate control using diltiazem. She was managed with bed rest for 48 hours, close hemodynamic monitoring, and gradual mobilization and was discharged on day 7 in stable condition. Follow-up at 6 weeks was unremarkable, and hemoglobin was 13.1 g/dL.
• Fig. 39.10
Residual basilar apex aneurysm.
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• Fig. 39.11
Groin puncture site towards uppermost aspect of femoral head. This would constitute a ‘high’ puncture though it appears to be over the femoral head. Strategic obliquity with the sheath pulled away can often demonstrate exact puncture site (not done in this case). (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
B
A • Fig. 39.12
Axial (A), coronal (B) and CT angiogram (C) images of abdomen and pelvis. A large retroperitoneal hematoma is evident (3A) that displaces the urinary bladder to the contralateral side and compresses it (3B, arrow). There is a site of contrast extravasation in the clot (3C, arrow). No pseudoaneurysm was evident. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
Continued
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C • Fig. 39.12, cont’d
A
B • Fig. 39.13
Pigtail aortogram (A) and right iliofemoral run (B) via left femoral approach does not show pseudoaneurysm or active dye extravasation. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)
CHAPTER 39 Access-Related Complications in Endovascular Neurosurgery
NEUROSURGICAL SELFIE MOMENT Access-related complications are not unusual in day-to-day endovascular neurosurgical practice. A standard regimental approach to complication avoidance is the secret to successful outcomes. Knowing your patient and patient-specific anatomy, identification of high-risk patients, brutal honesty about complications, minimizing procedural time, constant refinement of technique, and smooth techniques will help minimize the complications.
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