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Clincial Case of Successful Two-Stage Correction of type 1 Aortic Dissection Using Hybrid Surgical Approach
R.S. Akchurin1, T.E. Imaev, A.E. Komlev, M.R. Osmanov, T.N. Veselova, M.E. Nikonova,I.A. Pokidkin
Fedotenkov, A.S. Kolegaev
Department of Cardiovascular Surgery, Russian Cardiological Scientific and Production Complex of the Ministry of Healthcare and Social Development of the Russian Federation, Moscow, Russia.
Aortic dissection is an exclusively emergency situation with the incidence twofold higher than the incidence of abdominal aortic rupture, that is 10-20 cases per 1 mln. of population per year. About 20% of patients die before admission, 30% die in hospital and up to 20% — within the next 10 years.
Concomitant insufficiency of the aortic valve, ring and aortic root dilatation occurring in 50-60% of cases usually requires surgical replacement of the aortic valve, or aortic valve replacement with ascending aortic grafting following Bentall-De Bono technique, or some valve-preserving operations in David and Yacoub modifications.
Innovative hybrid surgical approach as a method of effective revascularization, combines the effectiveness of traditional open surgery and of percutaneous endovascular intervention with balloon valvuloplasty and endo-graft implantation. Due to its minimal invasiveness, the hybrid approach allows to minimize the complications and to decrease the mortality in high-risk patients.
The purpose of this paper is to present a case of successful use of hybrid approach for the correction of a chronic dissecting aortic aneurysm of type 1, extending from the level of Valsalva sinus and associated with aortic valve insufficiency.
The configuration of the thoracic aortic arch and the design of endografts often require more proximal zone for endograft fixation. Isolated endovascular intervention becomes risky because of eventual closure of aortic arch branches with the endograft. Hybrid surgical interventions possess all advantages of endovascular and traditional open surgery, thus allowing to avoid dangerous complications and minimize the duration of rehabilitation.
Keywords:: hybrid surgery, thoracic aortic aneurysms, open surgery, endovascular interventions, endograft.
Introduction
Aortic dissection is an exclusively emergency situation with the incidence twofold higher than the incidence of abdominal aortic rupture, that is 10-20 cases per 1 mln. of population per year. About 20% of patients die before admission, 30% die in hospital and up to 20% — within the next 10 years (1-4).
Aortic dissections can be classified by their location, length and presence of ischemic complications. According to one of the most often used Stanford classification, type A dissection involves the ascending, and type B — the descending aorta. De Bakey’s type I involves the whole aorta, type II — the ascending aorta, type III -the descending aorta.
Atherosclerotic degeneration of the aortic wall in hereditary diseases, eg. Marfan and Ehlers-Danlos syndromes, and in arterial hypertension, are facrots predisposing for dissection. The fenestrations in the intima permit the blood flow to enter into the aortic media, thus peeling the intima away from the aortic wall and forming two lumen — the true and the false
1 Address for correspondence:
Dr. Renat Akchurin,
Russia, 121552, Moscow,
3rd Cherepkovskaya ul, 15a
Tel. /Fax: 007 499 140-93-36, 007 499 149-17-08
Email: dddd99999@mail.ru
Manuscript received on June 06, 2011.
Accepted for publication on August 22, 2011.
ones. The exfoliation of the aortic wall can produce an obstruction, rupture or thrombosis of the aortic branches. The obstruction can be dynamical or static, leading to malperfusion. Repeated blood flow into the true lumen decrease dynamical load on the aortic wall, that causes spontaneous fenestrations. The formation of a false aortic lumen leads to a dangerous sequence of events, that constitute the indications for emergency intervention: rapid formation of aortic aneurysm, ongoing organs’ ischemia caused by the obstruction of the major aortic branches, unstable hemodynamics, cardiac tamponade, aortic rupture.
As a rule, the symptoms are very sharp, with marked chest pain irradiating into the neck or arms. Backache is usually related to type B dissection. Other symptoms depend on the degree of dissection and other organs’ involvement. Abdominal pain, renal failure, paraplegia, lower limb ischemia can be present.
Type A dissections are particularly dangerous and without treatment or in case of inappropriate diagnosis are associated with high mortality. Pharmacological therapy is not a basis for the management of type A dissections. Mortality rate at early stages is 1-2% per hour (5). Mortality can be as high as 40% per week, which is significant in comparison with about 10% mortality associated with open surgical interventions.
In type B dissections hypotensive therapy usually is applied. The purpose of treatment consists in the
Fig. 1. MHCT of patient Z
limitation of dissection, minimization of the impact on the aortic wall, prevention of dilatation and creation of conditions for false lumen thrombosis. Surgical mortality can be as high as 30% or even more (5).
Concomitant aortic valve insufficiency, ring and aortic root dilatation present in 50-60% of cases of aortic dissection usually require surgical aortic valve replacement, or aortic valve replacement with ascending aorta grafting using Bentall-De Bono technique, or valve-preserving surgery using David and Yacoub technique.
The fenestrations in the aortic arch occur in 30% of dissection cases. In case of fenestrations in the aortic arch, distal anastomosis between the graft and the aorta is performed to bypass a part of aortic arch, not involved in dissection. In any case, if prolonged multiple fenestrations extend beyond the site of aortic arch passage into the descending part of the aorta, it is necessary to perform subtotal or total arch replacement with rebranching of several or all aortic branches into the graft. This is performed in the settings of hypothermic circulatory arrest and antegrade cerebral perfusion. If the dissection involves also the descending aorta, the “elephant trunk” aortic arch reconstruction is indicated.
Most patients with aortic dissection are severely ill and unlikely to survive traditional open surgical intervention with deep circulatory arrest, aortic arch reconstruction, etc. Such high-risk patients, as well as the complications occurring during open heart surgery and pharmacological therapy, have stimulated the search of new technologies for the treatment of aortic dissections — minimally invasive endovascular interventions.
In general endovascular treatment is being used for both types of aortic dissection — A and B, — both in acute and in chronic forms. Recent results of meta-analyses have shown technical feasibility of endovascular intervention in 98% of cases, as well as encouraging immediate and mid-term results (1-2 years) (6, 7). The advantages of endovascular interventions and hybrid surgery for aortic dissections in comparison with traditional open surgery are evident. In particular, endovascular approach allows to avoid thoracotomy with subsequent formation of pleural adhesions (8-11). Usually the procedure is performed through the femoral approach. Unlike open operation, primary or repeated endovascular intervention can be performed under spinal or even local anesthesia. It is evident that in high-risk patients endovascular interventions have significant advantages over surgical treatment and offer hope for recovery for patients with contraindications for open surgery. These advantages comprise the decreased
rate of mortality and complications, the minimization of time spent in the ICU and in hospital, as well as of postoperative rehabilitation.
Innovative hybrid surgical approach as a method of effective revascularization, combines the effectiveness of traditional open surgery and of percutaneous endovascular intervention with balloon valvuloplasty and endograft implantation. Due to its minimal invasiveness, the hybrid approach allows to minimize the complications and to decrease the mortality in high-risk patients. In case of lower limb ischemia this approach is preferable for legs perfusion using extra-corporeal circulation.
Clinical case
The purpose of our paper is to present a clinical case of successful two-stage correction of type I aortic dissection using hybrid surgical approach.
A 52-years-old woman was admitted to the Department of Cardiovascular Surgery on September 10, 2009 with complaints of restrictive retrosternal pain associated with minimal physical load, palpitations and pulsation of the neck vessels. History analysis revealed that the patient had poorly controlled arterial hypertension for over 20 years (max. BP 190/110 mm Hg). She has considered herself sick from May 20, 2009, when in the night she suddenly felt an intensive retrosternal pain irradiating into the neck and the mandible. After 40 minutes the pain has been stopped with Nitroglycerin. In-hospital examination excluded myocardial infarction, EchoCG revealed severe aortic valve insufficiency. Within 2 weeks after the pain attack her body temperature remained high — 380C. Her condition at admission was severe, with respiration rate at rest — 25/ min. and visible pulsation of the cervical vessels. A loud diastolic murmur heard over the whole heart, radiating to the carotid arteries, interscapular space, as well as a systolic murmur with maximal
(№ 26, 2011)
Fig. 2. First stage - surgery. Replacement of the ascending aorta, reimplantation of aortic arch branches
Fig 3.
Fig. 4. Duration of extracorporeal circulation — 184 min.; of aortic cross-clamping — 125 min.; of circulatory arrest — 31 min.
loudness in the 2nd right intercostal space were revealed. HR —
50 b/min.. BP in the right arm —
180/70 mm Hg, in the left arm —
160/65 mm Hg.
ECG: sinus bradycardia with HR 50b/min., transient I degree AV block (PQ 180-480 msec.), signs of LV overload and hypertrophy.
EchoCG: the diameter of ascending aorta is enlarged up to 6.0 cm, the aortic root — 5.0 cm. Left atrium — 3.5 cm, LVEDS — 6.5 cm,
LVESS — 3.9 cm, LV EF — 55%. 1st degree mitral and tricuspid regurgitation. 3rd degree aortic regurgitation. The exfoliation of the aortic intima is seen immediately after the aortic valve cusps and extends up to the brachiocephalic trunk. The false lumen is significantly larger than the true one, without signs of thrombosis.
Coronary angiography, aortography: the left main coronary artery, the LAD and the CxB with irregular contours. The angiographically intact RCA arises from the false channel. At the level of the right coronary sinus there is a large communication between the aorta and the false channel, with its lumen extending in the ascending aorta up to the brachiocephalic trunk ostium.
MHCT of the aorta (Fig. 1): dissecting aneurysm of the ascending aorta starting at the root, with multiple intimal fenestrations at the root level.
Maximal dilatation of the aorta at the level of the right coronary sinus — 6.0 cm, the diameter of the ascending aorta — 4.0 cm, of the aortic arch —
2.7 cm, of the descending segment —
2.2 cm. The false lumen starts from the right sinus of Valsalva, and has a helix-like course, the RCA arises from the false lumen. A proximal fenestration is located near the isthmus, aortic dissection extends to the level of the common iliac artery on the left and to the external iliac artery on the right.
The brachiocephalic trunk and the left common carotid artery arise at the border of the false and true lumens, the dissection does not spread into the proximal segments of brachiocephalic arteries.
The diagnosis comprised: chronic large dissecting type I aortic aneurysm, starting at the level of the sinuses of Valsalva, severe aortic valve insufficiency, arrhythmia (transient 1st degree AV block), 3rd de-
gree arterial hypertension. The patient was in NYHA class III.
The first stage of correction consisted in hybrid operation for aortic valve replacement with valved conduit (Figs. 2,3,4), during the second stage leftsided carotid-subclavian bypass and partial aortic
Fig. 5. Second stage — left-sided carotid-subclavian bypass grafting, endovascular grafting of the aortic arch and the descending aorta
Fig. 6. Postoperative MHCT of patient A
Fig. 7. MHCT-aortography of patient Z. after the 2nd stage of intervention
arch replacement with an endograft were performed (Fig. 5).
The first stage (October 4, 2010): the heart was approached through median sternotomy. A T-shaped aortotomy was performed above the sinoaortic area. The revision showed the dissection starting from the level of aortic valve’s commissures, spreads into the anterior, lateral and posterior aortic walls involving the right coronary artery ostium, and then spreads into the aortic arch in the shape of a two-barreled gun. The button-like isolation of the coronary ostia was performed for subsequent implantation. The valve’s cusps were sectioned. The aortic valve and the ascending aorta were replaced by a valved conduit Carbomedics Inc. (aortic valve prosthesis 25, graft diameter 28). The right and the left coronary arteries were reimplanted onto the conduit. The revision of the aortic arch revealed that the dissection spreading in the upper wall of the aorta, ends by a fenestration at the level of brachiocephalic trunk; the dissection involving the posterior and the lateral walls spreads into the arch and ends in the area of the left subclavian artery ostium. The aortic arch branches arise from the true lumen. The aortic arch was sectioned in oblique way, with the preservation of the upper wall and a part of lateral walls. The false lumen was eliminated and the distal anastomosis line was reinforced with internal and external padded sutures (the “layered cake”). The distal anastomosis between the conduit and the aorta was performed using the open technique.
The second stage (October 7, 2010): the procedure was performed under endotracheal an-esthesis. The approach to the left common carotid artery and the left subclavian artery was achieved through the supraclavicular incision. An “end-to-side” anastomosis was performed between the subclavian artery and the common carotid artery. Simultaneously an introducer was inserted into the left common femoral artery; on the right the introducer was inserted percutaneously. The diagnostic catheters were advanced by
(№ 26, 2011)
the guidewires inserted through the introducers into the thoracic aorta. The position of diagnostic catheters in the true aortic lumen was confirmed. A super-stiff guidewire was inserted through the left diagnostic catheter and positioned in the thoracic aorta, and a Gore Tag 34x20 endograft was advanced by this guidewire. The endograft was implanted from the ostium of the left common carotid artery up to the diaphragm. Neither leakage nor false lumen filling were seen.
Results of study
The patient’s rehabilitation was achieved within the shortest term. The patient was discharged at day
5. Postoperative course was uneventful. The patient has been followed in the long-term (1 month — 1 year), no complications were revealed. Control MHCT-aortography (Fig. 6) revealed Gore endograft positioned from the level of the left common carotid artery to the celiac trunk. The segment of false aortic lumen, with an entry fenestration, immediately under the ostium of the left subclavian artery, is filled by partially thrombotic masses, there is no blood flow in this segment.
Discussion
Traditional open surgical treatment of type I aortic dissection can leave uncorrected the false lumen of the arch and the descending thoracic aorta, thus causing aneurysm progressing up to its rupture, or distal malperfusion, which is accompanied by high morbidity and mortality.
The configuration of the thoracic aortic arch and the design of endografts often require more proximal zone for endograft fixation. Isolated endovascular intervention becomes risky due to the danger of eventual covering of the aortic arch branches with endograft.
The replacement of the ascending aorta and the aortic arch with a conduit with supraaortic vessels’ debranching is a safe and effective method for the treatment of acute as well as of chronic aortic pathology, provides the creation of an optimal and safe zone for endograft fixation during endovascular stage of arch and descending aorta replacement, allows for partial solution of the problem of “oversized” endografts; optimizes the technique of surgery, significantly decreases the duration of circulatory arrest and extracorporeal circulation, allows to avoid deep hypothermia, prevents potential development of proximal en-doleak, thus contributing to low rate of morbidity and mortality.
Hybrid surgical interventions possess all advantages of endovascular and traditional open surgery, thus allowing to avoid severe complications and minimizing the duration of rehabilitation period. This technique deserves to be included into the basic arsenal of surgical options used for revascularization.
In our opinion, hybrid surgery is a transition stage to the eventual primacy of endovascular in-tervetions. In the future, the use of fenestrated and multi-branch endografts could allow to completely exclude traditional open interventions on the aorta and its branches.
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