HSC Section 3 - Trauma, Critical Care and Sleep Medicine

All stents and particularly covered stents, however, are thrombogenic, and patients require antiplatelet med- ication prior to the procedure if it is performed electively (i.e., threatened CBS) or during the procedure if it is performed emergently, after ensuring the success of the covered stent in controlling the hemorrhage. Systemic heparinization may also be used in nonemergent proce- dures and selectively in emergent cases. Furthermore, patients need to be maintained on dual antiplatelet ther- apy for several months to ensure covered stent patency. Covered stents can also be used for the treatment of pseudoaneurysms of the carotid artery associated with head and neck cancer. If injury is localized to the ECA trunk or its branches, a BOT is not necessary, because the risk of brain injury during embolization is negligible. PVA particles, pushable fibered platinum coils, detachable coils, or a combination of these materials are used for ECA hemorrhage, which is commonly due to tumoral oozing. There are, however, a number of potentially dangerous ECA-ICA connections that the interventionalist should be aware of when using PVA particles in the external carotid circulation to avoid embolic intracranial complications. 14 CONCLUSION This study highlights the successful triage and management of CBS using a modern stepwise approach. In patients with impending or acute hemorrhage, utili- zation of endovascular covered stenting serves to achieve rapid hemostasis while protecting cerebral blood flow. The long-term efficacy of endovascular covered stents largely depends on patient factors such as tissue necro- sis or disease recurrence. In most cases, the covered stents should be viewed as a temporizing measure until definitive reconstruction or ablative procedure can be performed. The above case scenarios represents the full spectrum of contemporary, multidisciplinary triage of acute CBS, in which multiple therapeutic interventions were necessary to save the life and limit morbidity. BIBLIOGRAPHY 1. Chen YJ, Wang CP, Wang CC, Jiang RS, Lin JC, Liu SA. Carotid blowout in patients with head and neck cancer: associated factors and treatment outcomes. Head Neck 2015;37:265–272. 2. Cohen J, Rad I. Contemporary management of carotid blowout. Curr Opin Otolaryngol Head Neck Surg 2004;12:110–115. 3. McDonald MW, Moore MG, Johnstone PA. Risk of carotid blowout after reirradiation of the head and neck: a systematic review. Int J Radiat Oncol Biol Phys 2012;82:1083–1089. 4. Brinjikji W, Cloft HJ. Outcomes of endovascular occlusion and stenting in the treatment of carotid blowout. Interv Neuroradiol 2015;21:543–547. 5. Gaba RC, West DL, Bui JT, Owens CA, Marden FA. Covered stent treatment of carotid blowout syndrome. Semin Intervent Radiol 2007;24:47–52. 6. Shah H, Gemmete JJ, Chaudhary N, Pandey AS, Ansari SA. Acute life- threatening hemorrhage in patients with head and neck cancer present- ing with carotid blowout syndrome: follow-up results after initial hemo- stasis with covered-stent placement. AJNR Am J Neuroradiol 2011;32: 743–747. 7. Powitzky R, Vasan N, Krempl G, Medina J. Carotid blowout in patients with head and neck cancer. Ann Otol Rhinol Laryngol 2010;119:476–484. 8. Chang FC, Lirng JF, Luo CB, et al. Patients with head and neck cancers and associated postirradiated carotid blowout syndrome: endovascular therapeutic methods and outcomes. J Vasc Surg 2008;47:936–945. 9. Lu HJ, Chen KW, Chen MH, et al. Predisposing factors, management, and prognostic evaluation of acute carotid blowout syndrome. J Vasc Surg 2013;58:1226–1235.

CTA can be employed in hemodynamic stable patients to ascertain the likely site of the bleeding and the assess- ment of patency of the circle of Willis. If the patient survives this acute hemodynamic change, then utilization of endovascular techniques either in a constructive (covered stent) or a destructive (endovascular sacrifice) manner should be employed based on hemodynamic status, contralateral anatomy, and overall goals, keeping in view the long-term progno- sis of individual patients. 12 In the present scenarios, both approaches utilized were successful in achieving immediate control. Reviews have indicated a 95% effi- cacy rate for endovascular covered stents in controlling acute hemorrhage if the patient can be stabilized long enough to make it to the interventional radiology suite. 5,6 Although these endovascular techniques may be efficacious for acute hemostasis, their role is often only a temporizing measure. A review of 10 patients with acute CBS, in which endovascular covered stents were placed, showed a 30% rate of recurrent bleeding. 6 Our experi- ence supports the need for definitive treatment after cov- ered stent placement, particularly if the etiology of the tissue breakdown has not been addressed and is not the result of unresectable cancer. This should be achieved with aggressive wound management and nutritional optimization before rebleeding or stent exposure ensues. In two out of three cases in our series, a covered stent became exposed after a mean duration of 19.5 days. In addition, covered stent deployment in an infected field raises the chances of septic emboli and may serve as a source for potential problems including cerebral abscess. 13 Definitive management of CBS is dependent upon collateral arterial flow. Case 3 exemplifies this important determinant that guides selection of proper endovascular approach. Initial CTA showed a high-grade contralateral carotid stenosis, indicating that sacrifice of the patient’s vulnerable carotid artery would carry increased risk of neurological morbidity, and thus an attempt at recon- struction or bypass must be employed. In this case, the necrotic portion of the CCA and ICA after initial man- agement were resected and reconstructed with a SFV graft. The reconstructed vessels were then covered with healthy, nonradiated tissue from the contralateral supra- clavicular region for added protection with no resultant neurological morbidity. In case of threatened CBS, the imaging and the anatomy should be discussed with the interventional radiologist, and BOT should be done to ascertain collat- eral circulation. In case 2, we employed an approach of initial covered stenting of the carotid artery followed by nutritional and overall optimization. However, the stent eroded through the arterial wall in the fistula site. Endovascular sacrifice was then employed after the patient passed the BOT successfully. Because of the exposed neck wound, however, the patient had eventual resection of the carotid artery, and the wound was closed with vascularized tissue. This serves to illustrate the critical importance of follow-up, as any exposure of cov- ered stent or coils in the exposed field would require sur- gical intervention and wound closure.

Laryngoscope 127: February 2017

Manzoor et al.: Endovascular Techniques for Management of CBS

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