17 Endovascular Options to Treat Iatrogenic Vascular Injury and Tumor Involvement of the Skull Base


Jacob F. Baranoski, Colin J. Przybylowski, Bradley A. Gross, Felipe C. Albuquerque, and Andrew F. Ducruet


Internal carotid artery tumor encasement, concomitant aneurysms, and iatrogenic injury pose formidable surgical and clinical management challenges during skull base surgery. When encountering these scenarios, it is critical to understand the potential endovascular treatment and salvage options if an injury does occur. Better yet is understanding how preoperative endovascular techniques can help protect against intraoperative vascular injury and facilitate safe and efficacious tumor resection. This chapter describes the endovascular treatment options for acute and delayed vascular injury after skull base surgery, the utility and interpretation of balloon test occlusion (BTO), preoperative stenting for arterial protection during skull base tumor resection, and treatment strategies for concomitant internal carotid artery aneurysms and skull base tumors.

17 Endovascular Options to Treat Iatrogenic Vascular Injury and Tumor Involvement of the Skull Base

17.1 Key Learning Points

  • Although rare, iatrogenic internal carotid artery (ICA) injury is a potentially fatal complication of skull base surgery.

  • Preoperative evaluation of ICA anatomy, tumor involvement, and concomitant aneurysms is essential before skull base tumor resection surgery.

  • After recognition and attempted repair of an iatrogenic ICA injury, all patients should undergo an immediate angiogram to assess the extent of injury and the efficacy of the attempted repair.

  • Endovascular techniques can be used to treat the sequelae of iatrogenic ICA injury.

  • Depending on the endovascular repair performed and the severity of the injury, short-term follow-up angiograms may be warranted. Regardless of the technique used, 6-month follow-up vascular imaging is prudent.

  • Judicious use of preoperative endovascular techniques, including preoperative stenting, can help prevent ICA injury during skull base tumor surgery and can facilitate safe and efficacious tumor resection.

  • Treatment of ICA aneurysms before surgical or medical management of skull base tumors may prevent iatrogenic injury or subarachnoid hemorrhage.

17.2 Introduction

Surgical treatment of vascular injuries along the skull base is challenging because of the proximity of other critical structures, the complex surgical corridor, limited access, and technical limitations of endoscopic and even open instruments. Extreme care must be taken to avoid iatrogenic injury during skull base dissection and tumor resection while working in this critical region. If a vascular injury occurs during skull base surgery that cannot be repaired surgically at the time, it is critical to understand the potential endovascular salvage options. Further, judicious use of preoperative endovascular treatments to help protect against intraoperative vascular injury can be beneficial. In this chapter, we discuss the endovascular treatment options for acute and delayed vascular injury after skull base surgery, balloon test occlusion (BTO), preoperative stenting for arterial protection during skull base tumor resection, and treatment strategies for concomitant internal carotid artery (ICA) aneurysms and skull base tumors.

17.3 Endovascular Treatment for Iatrogenic Skull Base Vascular Injuries Sustained During Skull Base Surgery

Vascular injuries are rare but potentially fatal complications of both open microsurgical and endoscopic surgery for skull base tumors. Although ICA injury occurs in <2% of cases of pituitary adenomas, 1 ,​ 2 treatment of these vascular injuries is markedly challenging. Historically, ICA injuries that could not be primarily repaired required vessel sacrifice with or without attempted high-flow bypass, a treatment strategy that contributes to the morbidity associated with the injuries. 2 ,​ 3 ,​ 4 ,​ 5 ,​ 6 Vascular injuries may be immediately apparent intraoperatively or can present in a delayed fashion, days to even years after the index surgery. 1 ,​ 2 ,​ 6 ,​ 7 ,​ 8 ,​ 9

In general, the ideal strategy for managing ICA injury during skull base surgery is prevention. This requires a combination of anatomical knowledge, experience, and adherence to established surgical principles. Primary repair of vascular injuries, particularly during endonasal approaches, is very challenging because of the long working corridor, limited surgical freedom, and limitations in available instrumentation. Recently, dedicated teaching efforts using both live courses and simulator models have been designed to help prepare surgeons to manage endonasal ICA injuries intraoperatively. 10 ,​ 11 ,​ 12 ,​ 13 However, the combination of the challenging anatomy and technical limitations currently prevents definitive primary repair of ICA injuries in a majority of these cases.

Various endovascular options have been used to treat iatrogenic ICA injuries after endonasal and open microsurgical skull base surgery. These options differ for injuries that are immediately evident and require emergent treatment 2 ,​ 3 ,​ 4 ,​ 6 ,​ 8 ,​ 14 –​ 20 and those that present in a delayed fashion after surgery, 2 ,​ 5 ,​ 7 ,​ 9 ,​ 21 –​ 27 radiosurgery, 26 ,​ 28 or medical management. 29

Acute injuries with active extravasation require immediate treatment. Traditionally, ICA hemorrhage control was accomplished via vessel sacrifice. However, this was often performed at the cost of ICA territory perfusion. This technique has also been used for injuries that present in a delayed fashion if the patient is determined to be tolerant of vessel occlusion after BTO.

As endovascular treatment technologies have evolved, so too have the treatment options and strategies for iatrogenic ICA injuries. In 2013, Gardner et al 3 reported on seven ICA injuries during endonasal cases that occurred over a 13-year period. They proposed an endovascular treatment algorithm that involved the use of covered stents or coil sacrifice of the ICA to treat pseudoaneurysms or lacerations with active hemorrhage, respectively. Additional studies have reported favorable outcomes treating acute injuries with covered stents to control bleeding and preserve vessel patency. 17 ,​ 18 ,​ 19 ,​ 20 With the advent of flow-diverting devices, potential treatment options have expanded further and cases of iatrogenic ICA injuries have been successfully treated with these devices. 14 ,​ 15 When using flow-diverting devices, covered stents, and stent-assisted coiling techniques, the need for antiplatelet therapy must be considered.

In 2016, Sylvester et al 2 reported on seven patients with an ICA injury after endonasal surgery who were treated with endovascular therapy, and these authors performed a comprehensive review of the literature. Combining their patients’ data with the available published data, they identified 105 total patients with ICA injuries after endonasal surgery who received endovascular treatment. Of these, 46 patients were treated with ICA sacrifice, 28 with focal embolization of the lesion with or without stent assistance, and 31 with parent vessel reconstruction via a covered stent or flow-diverter device. They found that ICA sacrifice provided durable hemorrhage control but carried a relatively high rate of persistent neurological complication (22%). Lesion coil embolization with or without stent assistance was likewise successfully accomplished but carried a high rate of technical complication (31 and 22%, respectively) and resulted in new or persistent neurologic deficits. Endoluminal reconstruction via a covered stent or flow-diverting device was successfully used for select cases. Although the cases for which this technique was used were carefully selected for this therapy, endoluminal reconstruction produced favorable results with a relatively low complication rate. Based on these data, the authors propose a treatment algorithm that takes into account numerous factors including vascular anatomy, injury characteristics, response to BTO, and relative risk of dual antiplatelet therapy (DAPT). Combining the treatment strategies discussed above with our own institutional experience, we propose a similar treatment algorithm (Fig. 17.1). If an iatrogenic injury occurs that cannot be readily repaired, the injury is packed off to limit bleeding. Regardless of whether the bleeding appears to be controlled by surgical packing, the patient is taken immediately to the angiography suite. The first critical decision-making branch point is to determine whether the patient is a candidate for DAPT. DAPT is required for any covered stent, stent-assisted coiling, or flow-diverter treatment. Of course, the use of DAPT puts patients at a higher risk for postoperative hematoma, and the use of these agents must be weighed against the benefits of the attempted endovascular repair. If the bleeding is controlled with packing and there is no angiographic evidence of active extravasation or large pseudoaneurysm, it may be reasonable to consider delaying treatment until DAPT can be initiated; however, proceeding with treatment urgently is favored, even with the risk of initiating DAPT earlier. Factors that may make patients poor candidates for DAPT are a large residual tumor volume that may predispose them to hematoma development from disrupted tumor vasculature or injuries resulting from trauma. 2 ,​ 30

Fig. 17.1 Treatment algorithm for addressing iatrogenic vascular injury during skull base surgery. DAPT, dual antiplatelet therapy; ICA, internal carotid artery. (Used with permission from Barrow Neurological Institute, Phoenix, Arizona.)

If a patient has been determined to be not a candidate for DAPT, but emergent intervention is required, BTO evaluation is recommended next. Because patients with iatrogenic ICA injuries remain intubated and under general anesthesia, the BTO must be completed and interpreted without neurological examination. In these scenarios, the determination of whether the patient can tolerate occlusion must be made on the basis of radiographical and electrophysiological data (discussed below). If the patient can tolerate occlusion, vessel sacrifice can be performed endovascularly using coils with or without liquid embolysates or microvascular plugs. If the patient cannot tolerate occlusion and active extravasation is noted at the injury site and if DAPT is contraindicated for the patient, a high-flow extracranial to intracranial bypass is needed to supplement blood flow before the ICA is sacrificed. In this situation, if a pseudoaneurysm is identified, it can be treated with primary coiling, if possible, or with high-flow bypass followed by vessel sacrifice.

If a patient is deemed an acceptable candidate for DAPT, the endovascular treatment selected is on the basis of angiographic findings. All patients are heparinized during the procedure. Because these patients were not treated with DAPT before stent placement, we use intraoperative intravenous and intra-arterial administration of abciximab, followed postoperatively by aspirin and clopidogrel. Our group recently showed that this strategy was not associated with an increased risk of perioperative thromboembolic complications. 31 We typically continue DAPT for 6 months to allow time for endothelialization of the stent and then repeat angiography. If no in-stent thrombosis is noted, we then consider discontinuing clopidogrel and maintaining the patient on an aspirin regimen. With regard to treatment selection for the ICA injury, if active extravasation is noted, the injury is treated by placing a covered stent across the site of injury. Traditional covered stents, such as those used to treat extracranial carotid injuries and pseudoaneurysms, can be difficult to place in the intracranial circulation. However, smaller covered stents, such as the Jostent (Abbott Vascular Devices, Abbott Medical, Abbott Park, IL), can be delivered through catheters capable of navigating through the cranial ICA and can be used to treat iatrogenic ICA injuries and cavernous carotid fistulas. 20 ,​ 32 ,​ 33 ,​ 34 If a pseudoaneurysm is noted, the endovascular treatment options include deployment of a covered stent, stent-assisted coiling, or deployment of a flow-diverter device. The specific treatment selected should be based on the patient’s individual injury and the operator’s discretion. In general, stent-assisted coiling or flow-diverter placement is favored, because of the technical nuances involved with the deployment of covered stents and because they are associated with an increased risk of thromboembolic complications. If these techniques are unsuccessful, BTO followed by ICA sacrifice is recommended either with or without high-flow bypass based on the results of the BTO, as discussed above. Depending on the type of endovascular repair performed and the severity of the injury, short-term follow-up angiograms may be warranted. These may be particularly necessary in the situations where a stent was placed across a pseudoaneurysm to ensure stabilization of the lesion. Regardless of technique used, 6-month follow-up vascular imaging is prudent.

As the technology and experience with flow-diverting devices continues to progress, endoluminal reconstruction techniques may continue to improve outcomes for these challenging cases. Additional techniques have also been reported. Cobb et al 35 reported an iatrogenic ICA injury that was repaired primarily after an endovascular balloon was inflated at the injury site during an intraoperative angiogram. 35

Regardless of the endovascular treatment strategy selected, timely recognition of the event and effective communication between the teams involved are essential. If an iatrogenic injury occurs, the surgical team should immediately alert the anesthesia team, so that they can prepare for blood pressure augmentation and necessary fluid resuscitation and transfusions. If primary control or repair of the injury cannot be achieved immediately, the surgical team should inform the endovascular team, conveying important details, including the side, site, mechanism, and likely extent of the injury, and ask them to have an angiography suite prepared. In cases that have a higher risk for a carotid artery injury (such as surgery for tumors encasing the carotid, revision surgeries, etc.), it is of paramount importance to discuss this elevated risk with all the teams involved and to have a plan in place before beginning surgery. We recommend that an endovascular team be available whenever central skull base surgery is to be performed. Furthermore, it is recommended that high-risk procedures be performed exclusively at institutions with immediately available endovascular services, such as comprehensive stroke centers.

Skull base vascular injuries are not limited only to the ICA. Cases of posterior cerebral artery injury following endonasal and open surgery have also been reported. 36 ,​ 37 ,​ 38

17.3.1 Case Example

One example is a case of a hemorrhagic posterior communicating artery (PComA) pseudoaneurysm after endoscopic endonasal surgery. A 41-year-old man was diagnosed with a midline intracranial dermoid cyst and underwent endoscopic endonasal resection (Fig. 17.2a). No vascular injury was noted during surgery. On postoperative day 9, the patient experienced a sudden-onset severe headache and neurologic decline from a subarachnoid hemorrhage. An angiogram demonstrated a right PComA pseudoaneurysm (Fig. 17.2b). Vertebral artery injection demonstrated robust filling of bilateral posterior cerebral arteries (Fig. 17.2c), and the pseudoaneurysm was treated with coil embolization with focal sacrifice of the distal PComA (Fig. 17.2d). The patient did not experience any neurologic complication associated with this treatment.

Fig. 17.2 (a) Sagittal magnetic resonance imaging (MRI) demonstrating a midline intracranial dermoid cyst. (b) Lateral projection angiogram of a right internal carotid artery (ICA) injection demonstrating a pseudoaneurysm of the right posterior communicating artery. (c) Townes projection angiogram of a right vertebral artery injection demonstrating robust filling of bilateral posterior cerebral arteries, suggesting that the right posterior communicating artery could be safely sacrificed. (d) Posttreatment lateral projection angiogram of a right ICA injection demonstrating successful treatment of the pseudoaneurysm and sacrifice of the distal posterior communicating artery. (Used with permission from Dr. Bradley Gross of the University of Pittsburgh.)

Similar treatment strategies and techniques can be applied to skull base vascular injuries secondary to other etiologies, including trauma or sinus surgery. 14 Patients with an ICA injury and pseudoaneurysm development have also presented in a delayed fashion after radiosurgery for tumors, and these injuries necessitated endovascular therapy. 26 ,​ 28 ,​ 39

17.4 Preoperative Evaluation, Endovascular Stenting or Vessel Sacrifice Prior to Resection of Skull Base Tumors

Skull base tumors that abut or encase the carotid artery represent a technically challenging surgical problem. Aside from tumor resection, the primary goal of surgery and often one of the most difficult aspects of management involves preservation of the ICA. As surgical skull base techniques continue to evolve, surgeons are able to attempt resection of tumors formerly considered inoperable. Nevertheless, attempted resection of tumors that encase the ICA is associated with a significant risk of morbidity stemming from carotid artery rupture, dissection, and stroke. 40 Though carotid artery reconstruction has been attempted in patients with these lesions, this treatment itself is technically difficult and carries a high rate of morbidity. Subtotal lesion resection is also an option; however, this predisposes the patient to a high likelihood of recurrence with these often-aggressive tumors. As we continue to push the boundary of skull base surgery, endovascular techniques have also evolved to aid in the treatment of these challenging lesions.

These endovascular techniques include preoperative permanent occlusion of the ICA, external carotid artery to ICA bypass followed by vessel sacrifice, and ICA reinforcement with carotid stents. All of these techniques carry associated risks and limitations and must be used cautiously and judiciously. Application of any of these techniques requires thorough preoperative evaluation, and technique selection must be tailored on the basis of patient-specific characteristics, including the degree of ICA involvement, overall patient prognosis and clinical presentation, and the anatomic integrity of collaterals and the circle of Willis. A BTO can also assist in the decision-making process by helping to determine whether a patient can tolerate vessel sacrifice without risking ischemic injury. To assist in planning salvage options if an ICA injury occurs, BTO is recommended for all patients with tumors where the risk of carotid artery injury is elevated (e.g., circumferential involvement, revisions, postradiation) and when preoperative endovascular manipulation of the ICA (either permanent occlusion or stenting) procedures are being planned or en bloc ICA resection considered.

To perform a BTO, the awake patient is taken to the angiography suite. After femoral access is obtained, the patient is systemically heparinized to a goal activated clotting time of 250 to 300 seconds. A balloon is then inflated in the ipsilateral cervical or petrous ICA. A dual-lumen, compliant microcatheter balloon is preferred as it allows the flow of heparinized saline distal to the balloon occlusion, which can help limit stagnation and subsequent thrombus formation. Complete occlusion of the ICA is confirmed with ipsilateral contrast injection demonstrating complete angiographic block. With the balloon inflated, a clinical neurological examination is performed every 2 to 5 minutes. The development of any neurologic deficit or a decreased level of consciousness indicates that the patient is intolerant of occlusion, and the balloon should be deflated immediately. Additional assessments include angiographic visualization of collateral flow via injection of the contralateral ICA or vertebral arteries or use of somatosensory evoked potential (SSEP) and electroencephalogram (EEG) recordings. The ICA must be completely occluded for at least 30 minutes with no development of neurologic dysfunction before the BTO is considered to have been successful. Adjunctive testing that includes a hypotensive challenge component of the BTO is also recommended, in which the patient’s systolic blood pressure is decreased by 25 to 30% and neurologic testing is done for an additional 10 to 20 minutes. This technique increases the sensitivity of the BTO by further diminishing collateral reserves. Another technique uses single-photon emission computed tomography (SPECT) to extrapolate cerebral blood flow. To perform this technique, a baseline SPECT study of the patient is obtained before the BTO is performed. During the BTO, the patient is injected intravenously with a radioisotope. After the BTO is completed, repeat SPECT imaging is performed. The assessment is considered to be unsuccessful if a >10% change occurs between the pre- and post-BTO SPECT imaging.

The aforementioned assessment of collaterals from the contralateral ICA and vertebral arteries is also valuable. With the balloon inflated in the ipsilateral ICA, if the distal ipsilateral ICA branch arteries and hemispheres fill adequately during contralateral ICA or vertebral artery injections via the circle of Willis, the patient is deemed to be able to tolerate occlusion. If the ipsilateral ICA branches and hemisphere do not adequately fill, the patient may not tolerate occlusion. If the BTO and supplemental testing are successful, they are deemed acceptably low risk for ischemic complication secondary to ICA occlusion and are considered for permanent ICA sacrifice. If patients fail any portion of the BTO, they should be considered at higher risk of permanent occlusion, and an alternative technique (e.g., stenting, bypass, subtotal resection) should be considered instead. As discussed above, in emergent situations following iatrogenic ICA injury, the determination of whether a patient passed the BTO and will be able to tolerate ICA sacrifice must be based solely on radiographical and electrophysiological data.

17.4.1 Case Example

A 47-year-old man with a history of aggressive retinoblastoma who had undergone previous surgical resection with bilateral enucleations followed by radiation developed a radiation-induced leiomyosarcoma involving the nasal septum and anterior skull base. This lesion was resected but recurred (Fig. 17.3a). Given that the lesion circumferentially encased the right ICA, carotid artery sacrifice was considered prior to attempting re-resection (Fig. 17.3b). Angiography revealed robust collaterals with widely patent posterior and anterior communicating arteries (Fig. 17.3c, d). The patient tolerated a BTO of his right ICA based on clinical and nuclear medicine radiographic assessment. Given these results, we proceeded with endovascular sacrifice of the right ICA using a combination of coils and liquid embolysate (Fig. 17.3e). This procedure resulted in complete occlusion of the right ICA (Fig. 17.3f). Injection of the left ICA and vertebral arteries demonstrated robust opacification of the right middle cerebral artery and anterior cerebral artery territories (Fig. 17.3g). The patient then successfully underwent gross total resection of his tumor without vascular complication.

Fig. 17.3 (a) Axial contrast-enhanced magnetic resonance imaging (MRI) demonstrating a recurrent radiation-induced leiomyosarcoma involving the nasal septum and anterior skull base. (b) Coronal MRI demonstrating that this lesion has circumferentially encased the right internal carotid artery (ICA). (c) Townes projection angiogram of a left ICA injection demonstrating robust filling of right anterior circulation via a widely patent anterior communicating artery. (d) Townes projection angiogram of a left vertebral artery injection demonstrating robust filling of bilateral posterior cerebral arteries. (e) Lateral projection angiogram demonstrating the coil mass deployed into the right ICA resulting in complete occlusion of the vessel (f). (g) Post-treatment Townes projection angiogram of a left ICA injection demonstrating robust filling of bilateral anterior and middle cerebral artery territories with the contralateral side filling via a widely patent anterior communicating artery. (Used with permission from Dr. Bradley Gross of the University of Pittsburgh.)

A number of endovascular techniques can be used to sacrifice the ICA, including placement of coils with or without liquid embolysates, detachable balloons, or microvascular plugs. In general, we recommend performing all of these procedures in the angiography suite with the patient under general anesthesia, although some surgeons may opt to perform the vessel sacrifice with the patient awake immediately following the BTO. Transarterial access is achieved, and the patient is systemically heparinized. When coils, with or without liquid embolysates, are used—as in this case—a balloon is inflated in the ICA proximal to the site of the desired occlusion. If a single-lumen balloon catheter is used, a coil delivery catheter must be positioned distal to the balloon catheter before the balloon is inflated. The use of a dual-lumen balloon catheter can obviate the need for an additional catheter system. With the balloon inflated, coiling can be performed, and the balloon can then be deflated and removed. The advent and refinement of vascular plug devices provide endovascular surgeons with additional options for achieving permanent ICA occlusion. The location of ICA sacrifice should take into account the origins of the ICA branches and the relative location of the tumor. In general, we tend to perform ICA occlusion in the distal petrous segment.

Sanna et al 41 reported their series of tympanojugular paragangliomas that were resected with preoperative endovascular ICA augmentation. Complex tympanojugular paragangliomas can infiltrate the ICA; this infiltration represents a significant risk of surgical morbidity and limits the ability to achieve a gross total resection. For patients with tympanojugular paragangliomas, the ICA is classically involved along the posterolateral surface of the vertical segment near the jugular bulb. Although carotid artery manipulation at this location can often be accomplished safely, tympanojugular paragangliomas that have invaded the ICA preclude manipulation of the ICA and can result in incomplete tumor resection or ICA injury. To address this, endovascular techniques have been used to protect the ICA and promote gross total resection of the tumor while minimizing the potential surgical morbidity.

In the study reported by Sanna and colleagues, 41 20 patients with tympanojugular paragangliomas planned for gross total resection were evaluated for preoperative ICA intervention. Ten patients underwent a preoperative permanent balloon occlusion for carotid sacrifice after a BTO indicated they were tolerant of vessel occlusion. Two of these patients had an external carotid artery to ICA bypass before balloon occlusion. Out of these 10 patients, 8 patients underwent subsequent surgery that resulted in gross total resection in 7 cases and subtotal resection in 1 case. There were no endovascular or intraoperative complications in these 8 patients. Two patients died before surgical resection could be performed because of intracranial hypertension, which may or may not be directly related to the endovascular treatment. 41

The other 10 patients who were deemed intolerant of vessel occlusion after evaluation by a BTO underwent preoperative ICA stenting using one of three types of self-expanding nitinol stents: Xpert Stent System (Abbott Laboratories Vascular Enterprises, Dublin, Ireland), Neuroform 3 (Boston Scientific, Fremont, CA), and LEO (Balt Extrusion, Montmorency, France). In this series, patients who underwent stenting were started on antiplatelet therapy 1 week before stent placement that consisted of either a combination of ticlopidine (250 mg twice daily) and aspirin (100 mg daily) or clopidogrel (75 mg daily) and aspirin (100 mg daily). Patients were continued on a dual antiplatelet regimen for a minimum of 30 days after stenting and were then transitioned to an aspirin-only regimen. The interval between stenting and surgery varied from 1 to 3 months. In this series, antiplatelet therapy was suspended 1 week before surgery and resumed 1 week afterward. During the interim, patients were maintained on a heparin regimen. 41

For these 10 patients, the selected stents deployed spanned the petrous and cervical carotid artery. This was achieved without difficulty in eight of these patients. One patient developed vasospasm that was successfully treated with intra-arterial vasodilators without clinical consequence and another patient required permanent occlusion of the ICA after stent placement. No other thromboembolic or periprocedural complications were encountered during endovascular treatment or surgical resection. Of the nine patients who underwent surgical resection after preoperative stent placement, eight patients were able to have a surgical plane established, which resulted in a gross total resection in six cases and near-total resection in two patients. In one patient with a recurrent tumor who underwent preoperative stenting, it was not possible to establish a cleavage plane between the recurrent tumor and the ICA, which resulted in a subtotal resection. On the basis of these results, these authors conclude that preoperative stenting can be advantageous in the surgical management of complex tympanojugular paragangliomas. 41

Similarly, Markiewicz et al 40 describe a series of five patients with squamous cell carcinoma of the head and neck who underwent preoperative stenting of the ICA before surgical resection. In this study, patients underwent placement of a heparin-bonded Viabahn covered stent(s) (W.L. Gore and Associates, Inc., Flagstaff, AZ) spanning the portion of the ICA that was encased in tumor with an additional 1 cm of proximal and distal coverage. All patients were initiated on a dual-antiplatelet regimen of clopidogrel (75 mg daily) and aspirin (325 mg daily) that was continued for at least 6 months. After stent placement, all five patients underwent surgical resection. The interval from stent placement to surgery was 1 to 22 days. The short interval was due to the aggressive nature of the patients’ tumors that required immediate surgical intervention upon presentation. In all five patients, a gross total resection was achieved, including resection of the carotid artery adventitia from the stent. No intraoperative complications were reported. One stent-related complication occurred in one patient that was caused by in-stent thrombosis, which resulted in decreased visual acuity. No spontaneous hemorrhage or pseudoaneurysm formation was noted in any patient at the site of carotid artery adventitia resection. Based on these results, these authors conclude that preoperative covered stent placement can facilitate safe and efficacious resection of tumors encasing the ICA with minimal associated morbidity. 40

Carotid body tumors represent another technically challenging lesion due to their vascularity and proximity to the carotid artery. McDougall et al 42 reported on two patients on whom preoperative deployment of a covered stent was used during resection of carotid body tumors. Two patients with carotid body tumors were selected for preoperative covered stent deployment, the first because of bilateral tumors and the second because evaluation by BTO determined the patient was intolerant of vessel occlusion. The stents used were either a Wallgraft covered stent (Boston Scientific, Marlborough, MA) or a Fluency covered stent (Bard Peripheral Vascular Inc, Tempe, AZ). Both patients were maintained on dual antiplatelet regimen of clopidogrel and aspirin for 6 weeks after stent placement followed by an aspirin-only regimen that was then held 1 week prior to surgery. Patients were admitted 3 days preoperatively and started on an intravenous heparin drip that was then held 6 hours preoperatively. Aspirin was restarted postoperatively. Gross total resection of the tumor was able to be achieved with preserved patency of the ICA in both cases. 42

Overall, preoperative stenting for tumors that abut or involve the carotid artery may provide significant benefit in the management of these difficult lesions. The primary goal of stenting should be carotid artery preservation with potential secondary benefits of tumor devascularization and assisting with achievement of a gross total resection. The stent may provide a physical and hemodynamic barrier that protects the artery, promotes laminar arterial flow, devascularizes the tumor, and allows for tactile feedback facilitating subadventitial dissection and complete tumor removal. This technique may allow surgeons to perform a more aggressive anatomical dissection of the artery while decreasing overall risk. This may be particularly useful in cases where the ICA sacrifice cannot be tolerated. However, it is important to note that carotid stenting, particularly using a covered stent, carries its own risk and potential morbidity. The risks of thromboembolic complications, vessel rupture or dissection, in-stent stenosis, and the lifelong requirement for antiplatelet medication must be considered. Therefore, careful consideration on a case-by-case basis and judicious use of these techniques is of paramount importance in making treatment decisions.

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Apr 30, 2022 | Posted by in OTOLARYNGOLOGY | Comments Off on 17 Endovascular Options to Treat Iatrogenic Vascular Injury and Tumor Involvement of the Skull Base

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