ENdOvAScuLAR mANAGEmENT Of AORTIc ...

POLSKI PRZEGLĄD CHIRURGICZNY 2013, 85, 2, 90–95

10.2478/pjs-2013-0016

Endovascular management of aortic dissections involving the common carotid and subclavian arteries Mirosław Wąsiewicz1, Anna Kasielska-Trojan2, Dariusz Timler3, Mirosław Stelągowski1 Department of the Vascular, General and Oncologic Surgery, Memorial Copernicus Hospital in Łódź1 Ordynator: dr n. med. M. Stelągowski Plastic, Reconstructive and Aesthetic Surgery Clinic, Medical University in Łódź2 Kierownik: dr hab. B. Antoszewski Department of Emergency Medicine and Disaster Medicine, Medical University in Łódź3 Kierownik: dr hab. T. Gaszyński Aortic dissection is a life-threatening condition, in which rupture of the internal wall of the aorta is observed. The aim of the study was to present the techniques used in patients with type A Stanford aortic dissection treatment by means of carotid-carotid by-pass surgery and implantation of the aortic stent-graft with intentional occlusion of the left common carotid and subclavian arteries. Surgical methods were presented on the basis of three patients treated at the Department of Vascular, General and Oncological Surgery, Memorial Copernicus Hospital in Łódź. Different carotid- carotid bypass grafting techniques were also described. Our own clinical observations demonstrated that patients with retro-pharyngeal carotid-carotid bypass did not report dysphagia, and retropharyngeal grafting seems to be the optimal method considering patients in whom stent-grafts cause left carotid artery occlusion. Key words: aortic dissection, stent-graft, carotid-carotid by-pass

Aortic dissection is a life-threatening condition, where one may observe rupture of the internal wall of the aorta. Blood at high pressure is accumulated under the internal membrane, separating the medial layer from the vascular wall. The resulting hematoma spreads distally creating two canals: the real and pseudo-. In selected cases one may also observe retrograde aortic dissection towards the heart (1). The patient with suspicion of aortic dissection requires immediate diagnostics and implementation of appropriate treatment methods. Significant development considering both non-invasive and invasive techniques enables rapid diagnosis and treatment. Aortic dissection is not a frequent clinical diagnosis, the mortality rate (sudden death) being estimated at 3-5% in Europe and the United States (2). The division of aortic dissection is based on the anatomical location and duration of symptoms. DeBakey and Stan-

ford’s classification is most commonly used, dividing aortic dissection into two types: type A – involving the ascending aorta, and type B – involving the aorta, distally to the branching of the left subclavian artery. Aortic dissection is considered as acute when it occurs two weeks since the onset of symptoms, and chronic when the time difference is greater. Predisposing factors responsible for aortic dissection might be divided into congenital and acquired. Marfan’s syndrome, EhlersDanlos’s syndrome, familial aneurysmatic thoracic aorta, bicuspid aortic valve, aortic coarctation, Noonan’s syndrome, and Turner’s syndrome are the most common genetically conditioned disorders. Arterial hypertension, aortitis, pregnancy, and iatrogenic factors are considered as acquired (2). In case of 2/3 of patients with aortic dissection one may observe arterial hypertension, 1/3 are diagnosed with atherosclerosis, 25% mention previous

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Endovascular management of aortic dissections involving the common carotid and subclavian arteries

cardiosurgical or endovascular interventions, and 5% present with Marfan’s syndrome (3). The clinical picture of aortic dissection consists in localized severe thoracic pain (type A), and interscapular, lumbar and abdominal pain (type B). Additionally, one may observe the following symptoms: lower limb and visceral ischemic pain, renal dysfunction with anuria, as well as neurological complications, which occur in 15-20% of patients. Neurological complications include syncope as a consequence of cerebral hypoperfusion, ischemic stroke as a consequence of cervical and vertebral circulation insufficiency, and paraplegia (associated with anterior vertebral artery, Adamkiewicz artery, and intercostal thoracic arteries blood flow insufficiency). Type A dissection might be complicated by bleeding into the thoracic cavity, heart failure, and myocardial infarction. The following are more rarely observed: Horner’s syndrome, hoarseness, hemoptysis, hematemesis, small bowel and colon ischemic inflammation, and fever of unknown etiology (2). Diagnostics of aortic dissection include the physical examination (cervical, upper and lower extremity arteries) and imaging studies (chest X-ray, transesophageal echocardiography, CT angiography, endovascular ultrasonography, MRI, and classical contrast aortography). The above-mentioned examinations allow to precisely assess the aorta and localize the aortic dissection, which enables proper management. Indications for surgical intervention include all acute type A dissections, regardless of the location of the porta. Surgical treatment is aimed at preventing vascular rupture and ensuing blood extravasation, cardiac tamponade, and aortic insufficiency (4). In case of chronic type A dissections the following conditions are an indication for surgical intervention: the diameter of the aorta greater than 5 cm (Marfan’s syndrom – 4.5 cm), increase in the aortic transverse dimension greater than 1cm per year, and development of symptoms associated with the expansion or compression of surrounding structures. In case of acute type B dissections conservative management is recommended, consisting in the intravenous infusion of anti-hypertensive drugs stabilizing the blood pressure at a level of 90–100 mm Hg, and heart rate at a level of 50 – 60 beats per

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minute by means of beta-blockers. Additionally, considering therapy of both types of dissection, pain control is necessary. Surgical treatment of type B dissection is recommended in case of unsuccessful conservative therapy and diameter of the aorta exceeding 6 cm, aneurysmal growth of more than 1 cm per year, as well as symptoms associated with the expansion and compression of the aneurysm, and Marfan’s syndrome (4). The aim of the study was to present the techniques associated with the treatment of type A (Stanford classification) aortic dissection, using carotid-carotid by-pass grafting and aortic stent-graft implantation covering the left common carotid and subclavian arteries. The study presented surgical methods used in case of three patients hospitalized at the Department of Vascular, General, and Oncological Surgery, Copernicus Hospital in Łódź. Case reports Case 1. A 53-year old patient was admitted to the department, due to acute type A aortic dissection. The angio-CT examination showed porta of the dissection at the level of the left common carotid artery, without retrograde delamination. The Doppler ultrasound of the carotid arteries showed no hemodynamically significant stenoses. The patient was qualified for two-staged surgery. During the first stage of the operation the patient was subject to grafting of the right common carotid artery and left common carotid artery using a PTFE 8 prosthesis. The prosthesis was introduced retropharyngeally and the proximal segment of the left common carotid artery was subject to ligation. Afterward, the left subclavian artery was anastomosed to the left common carotid artery, and due to the anatomical variant of the vertebral artery, the left vertebral artery was anastomosed to the side of the carotid artery. Lack of patient consent for further treatment was responsible for the abandonment of the second stage of the operation, initiating conservative treatment. Consent was obtained after two months and surgery was performed, consisting in the implantation of the stent-graft (Stentgraft Valiant Thoracic TE4040C200) to the thoracic aorta at the level of the brachiocephalic trunk. Control


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angiography showed an insignificant type Ia leak, which stopped spontaneously. The consecutive examination showed retrograde dissection and the patient was directed for a cardiosurgical consultation. Now, two years since the end of treatment the patient is symptomless (no pain or dysphagia), carotid artery blood flow is normal, as well as left upper limb circulation (fig. 1). Case 2. A 52-year old patient was admitted to the department, due to acute chest pain. The angio-CT showed signs of aortic dissection with porta at the level of the left common carotid artery, without retrograde delamination. The Doppler ultrasound of the carotid arteries showed no hemodynamically significant stenoses. The patient was qualified for emergency surgery, consisting in the implantation of the stent-graft (Valiant Thoracic TF3636c100x and TC4040C150X) to the thoracic aorta including the left subclavian artery and nearly complete closure of the left common carotid artery. Clinically, we observed no central nervous system blood circulation disorders, a trace of blood flow was visible through the left internal carotid artery. Simultaneously, we performed retropharyngeal carotid-carotid bypass grafting. In order to ensure intraoperative cerebral perfusion transient bypass grafting of the right subclavian artery and left common carotid artery was performed using the PTFE 8 prosthesis. Afterward, the reinforced PTFE 7 prosthesis was implanted into the right carotid artery, passing through the retropharyngeal space, and anastomosed to the left common carotid artery. The left subclavian artery was

Fig. 1. Control angio-CT after retropharyngeal carotidcarotid bypass grafting, vessel transposition, and stent-graft implantation

anastomosed to the left common carotid and left vertebral arteries. After another month we peripherally implanted a stent-graft at the Th10-11 level, due to pseudocanal leakage (type 1b). We also observed leakage at the proximal site of the stent-graft fixation (type 1a) and the patient was referred to the Department of Cardiosurgery, being subject to surgical intervention. The ascending aorta was replaced by a graft, its distal end anastomosed to the previously implanted stent-graft. Currently, the patient does not report dysphagia. Control angio-CT showed proper vascular anastomoses, and Color Doppler showed normal blood flow through the carotid and left subclavian arteries (fig. 2). Case 3. A 75-year old patient was admitted to the department, due to chronic chest pain. The angio-CT showed signs of type A aortic dissection with porta at the level of the left common carotid artery, without retrograde delamination. The Doppler ultrasound of the carotid arteries showed no hemodynamically significant stenoses. The patient was qualified for two-staged surgery. The first stage of surgery consisted in the grafting between the right common carotid and left common carotid arteries. The PTFE 8 prosthesis was implanted

Fig. 2. Control angio-CT after retropharyngeal carotidcarotid by-pass grafting, vessel transposition, stentgraft implantation, and replacement of the ascending aorta with a graft



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subcutaneously on the chest after removal of the thyroid gland. The second stage of the operation consisted in the unsuccessful attempt of internal aortic membrane fenestration at the level of the visceral trunk. The patient was subject to stent-graft implantation to the ascending aorta and arch (Valiant Thoracic TF4444C200AX). Control angiography showed no signs of leakage, and subsequent examinations revealed distal false canal filling. The patient remained under observation for a period of one year, being currently qualified for endovascular treatment, due to asymptomatic dilatation of the descending aorta – 61 mm (fig. 3). Discussion Endovascular treatment of an aortic dissecting aneurysm requires careful procedure planning. The proximal fixation site of the stent-graft and its dimensions are calculated on the basis of the CT or MRI examinations. The beginning of the dissection located at the level of the branching of the left subclavian artery sometimes requires coverage and transposition or extra-anatomical reconstruction (carotid – subclavian) (2). A similar image is observed in case of dissection porta located between the left carotid artery and left subclavian artery or below the brachiocephalic trunk. The study presented different surgical techniques and difficulties associated with the management of type A aortic dissection in case of patients requiring stent-graft implantation to the thoracic aorta, additionally covering the left subclavian artery and/or left common carotid artery. According to some studies routine treatment of ascending aorta dissection consists in the relocation of the aortic arch or extended relocation, regardless the location of the dissection porta (5-8). One must pay attention to the high risk associated with the need to perform extensive extracorporeal circulation surgery, especially in case of type A dissections (9, 10). However, Crawford et al. recommended such aggressive treatment only in case of dissection of the entire aortic arch and risk of pseudo canal rupture (11). Endovascular techniques are an alternative to the classical method of treating aortic dissections, being characterized by high efficiency, even in case

Fig. 3. Control angio-CT after subcutaneous carotidcarotid by-pass grafting, vessel transposition, and stent-graft implantation, visible descending aorta dilatation

of elderly patients or those burdened with concomitant diseases (12). Kato et al. described the hybrid surgical technique, considering management of type A aortic dissections. The ascending aorta and aortic arch are replaced by a graft comprising four branches, while a normal stent-graft is implanted to the descending aorta (13, 14). Further studies demonstrated that endovascular stent-graft implantation to the aortic arch is an effective method of managing aortic dissections, leading towards closure of the porta and thrombus development, and thus, contraction of the false aortic lumen (15). Similarly, the authors showed that stent-graft implantation to the descending aortic dissections might reduce the number of surgical complications (16, 17). Despite the lack of prospective, multicenter studies comparing the classical and endovascular methods, their exist many publications concerning the high efficacy of the abovementioned, and lower mortality rate in case of endovascular methods used during acute aortic dissections (18, 19). In order to facilitate the primary repair of the thoracic aorta a technique was elaborated, which used the stent-graft with


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three branches, located in the proximal part of the descending aorta, aortic arch, and three large arch vessels with simultaneous graft replacement of the ascending aorta (20). In clinical practice of type A dissection management one may observe difficulties associated with the necessity to cover the subclavian and common carotid arteries. When preparing for such treatment one needs to perform transposition of large vessels or their extra-anatomical reconstruction. Additionally, stent-graft implantation in such cases requires left carotid artery revascularization procedures. The surgical approach to the arteries of the aortic arch is possible after sternum incision. In case of patients when sternotomy is burdened with a high risk of complications extra-anatomical procedures are performed, such as carotid-carotid bypass grafting with the implantation of a PTFE prosthesis (21). The prosthesis should be introduced subcutaneously in front of the trachea or in the retropharyngeal space. Riesenman et al. showed that the stent-graft introduced into the left subclavian artery is well tolerated by the patients and in most cases may be performed as the initial stage of treatment (22). Rehders et al. demonstrated that the occlusion of the left subclavian artery by the stent-graft is well tolerated and does not lead towards functional disturbances. What is more, in the absence of vertebral and cervical artery vasoconstriction, and confirmed lack of vertebralbasilar system abnormalities, prophylactic transposition of the subclavian artery is not recommended before planned stent-graft implantation (23). Literature data show, that although in some cases of aortic dissection treatment by means of stent-graft implantation, there is the need to implement invasive surgical procedures. It appears that the minimization of aggressive therapy by avoiding transverse clamping of the aorta and/or extracorporeal circulation surgery reduces the mortality rate (24).

The described cases present a significant problem of endovascular treatment in case of aortic arch dissections. The awareness of the need to cover the common carotid artery is important considering surgical management, indicating the need to perform carotid-carotid bypass grafting. There are various options to perform the bypass, such as subcutaneously on the thorax. Such a location might pose problems in the future, when further operations are required (thyroidectomy, tracheotomy or surgery requiring sternotomy) (25). It should be noted that the implantation of the bypass in the retropharyngeal space enables to avoid such a risk, and therefore appears to be a safer method for the patient. Despite the lack of the need to perform vascular transposition operations in the above-mentioned cases, our own experience shows that in case of patients subject to endovascular treatment of aortic dissections, future stent-graft implantation to the distal abdominal aorta might be required. Such management might result in spinal cord vascularization disturbances. Patients might require coronary bypass surgery, thus, a preserved internal thoracic artery. Considering the above-mentioned the transposition of the vertebral and internal thoracic arteries appears to be especially importnat when preparing for endovascular treatment. In conclusion, the study presented type A aortic dissection treatment techniques in case of patients requiring carotid-carotid bypass grafting and thoracic aorta stent-graft implantation, additionally supplying the left common carotid and subclavian arteries. The study also presented various techniques associated with carotid-carotid by-pass grafting. Our own clinical observations demonstrated that patients subject to retropharyngeal space grafting did not report dysphagia, and the abovementioned technique appears to be the optimal solution for these patients. The described surgical techniques might also be applied when treating aortic injuries.

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16. Uchida N, Ishihara H, Shibamura H et al.: Midterm results of extensive primary repair of the thoracic aorta by means of total arch replacement with open stent graft placement for an acute type A aortic dissection. J Thorac Cardiovasc Surg 2006; 131: 862-67. 17. Svensson LG, Kouchoukos NT, Miller DC et al.: Society of Thoracic Surgeons Endovascular Surgery Task Force. Expert consensus document on the treatment of descending thoracic aortic disease using endovascular stent-grafts. Ann Thorac Surg 2008; 85(1, Suppl): S1-S41 18. DiMusto PD, Williams DM, Patel HJ et al.: Endovascular management of type B aortic dissections. J Vasc Surg 2010; 52(4, Suppl): 26S-36S 19. Janczak D, Skóra J, Garcarek J i wsp.: Własne doświadczenia w leczeniu zespołu ostrego rozwarstwienia aorty typu B. Pol Przegl Chir 2012; 84: 38-50. 20. Chen LW, Dai XF, Lu L et al.: Extensive primary repair of the thoracic aorta in acute type A aortic dissection by means of ascending aorta replacement combined with open placement of triple-branched stent graft: early results. Circulation 2010; 122: 1373-78. 21. Bortone AS, Schena S, Mannatrizio G et al.: Endovascular stent-graft treatment for diseases of the descending thoracic aorta. Eur J Cardiothorac Surg 2001; 20: 514-19. 22. Riesenman PJ, Farber MA, Mendes RR et al.: Coverage of the left subclavian artery during thoracic endovascular aortic repair. J Vasc Surg 2007; 45: 90-95. 23. Rehders TC, Petzsch M, Ince H et al.: Nienaber CA Intentional occlusion of the left subclavian artery during stent-graft implantation in the thoracic aorta: risk and relevance. J Endovasc Ther 2004; 11: 659-66. 24. Riesenman PJ, Tamaddon HS, Farber MA: Surgical by-pass procedures to facilitate endovascular repair of aortic arch pathology. J Cardiovasc Surg (Torino) 2008; 49: 461-69. 25. Tracci MC, Cherry KJ: Leczenie chirurgiczne chorych z niedrożnością tętnic odchodzących od łuku aorty. Chirurgia po dyplomie 2010; 4: 4455.

Received: 19.05.2012 r. Adress correspondence: 93-513 Łódź, ul. Pabianicka 62
