Method for protecting brain during surgery for bilateral carotid artery lesions

Abstract

FIELD: medicine; cardiovascular surgery.SUBSTANCE: tolerance to cross-clamping is assessed in patients with bilateral carotid artery disease during carotid endarterectomy. In case of intolerance to compression, endovascular balloon occlusion of the subclavian artery (SCA) of the contralateral side distal to the orifice of the vertebral artery is performed with occlusion of the thyrocervical trunk and internal thoracic artery.EFFECT: method allows to increase the volumetric blood flow velocity through the intracranial arteries, which improves collateral blood supply to the brain on the ipsilateral and operated sides.1 cl, 3 dwg, 3 ex

Description

[0001] The proposed invention relates to vascular surgery and can be used to protect the brain during surgery for bilateral carotid artery lesions.

[0002] According to epidemiological studies, 3 to 15% of the world's population suffers from cerebrovascular insufficiency due to hemodynamically significant carotid artery disease, with the peak incidence occurring in those over 65 years of age. The 5-year risk of ischemic stroke in asymptomatic patients is 11% (the risk of transient ischemic attacks is 27%), while in symptomatic patients it is 16.2%. In Russia, 450,000 people develop stroke annually, 35% of whom die during the acute phase. The most complex and unresolved issue is the treatment of patients with bilateral carotid artery disease, which occurs in 13-20% of cases.

[0003] A method for performing carotid endarterectomy was selected as a prototype based on its closest technical essence. In the presented method, after clamping the common, external, and internal carotid arteries, performing an arteriotomy, removing the atherosclerotic plaque, and rinsing the arteries, the proximal end of a temporary intraluminal bypass graft is inserted into the lumen of the common carotid artery and the common carotid artery is secured with a tourniquet. Then, by antegrade blood flow from the common carotid artery into the proximal end of the temporary internal bypass graft and further through the temporary internal bypass system, air is released from the distal end of the bypass graft and the connection point of an empty syringe to remove blood from the temporary internal bypass system. Next, the clamp is removed from the internal carotid artery, and the distal end of the temporary internal bypass graft is inserted into it [Lysenko A.V., Belov Yu.V., Stonogin A.V. Temporary intraluminal bypass in reconstructive surgeries on the brachiocephalic arteries.Cardiology and cardiovascular surgery. 2015. Vol. 8. No. 4. P. 26-29].

[0004] The disadvantages of this method are: from the moment of installation of the proximal end of the temporary intraluminal shunt in the common carotid artery and the beginning of air release from the distal end of the shunt by antegrade blood flow from the common carotid artery until the installation of the distal end of the temporary intraluminal shunt in the internal carotid artery, it can take up to 3 minutes [A.V. Pokrovsky, “Classical” carotid endarterectomy, https: / / www.angiolsurgery.org / library / practical_medicine / publications / archive / carotid_endarterectomy / ].

[0005] Until the distal end of the temporary intraluminal shunt is immersed in the internal carotid artery and the white balloon is inflated, blood from the distal end of the temporary intraluminal shunt continues to flow into the wound. Considering that patients referred for carotid endarterectomy are most often elderly and suffer from arterial hypertension, the volumetric blood flow rate in the common carotid artery can reach 108.9 ± 7.6 ml per minute. Thus, in 3 minutes of ongoing bleeding from the distal end of the internal carotid artery, the volume of blood loss can amount to 326.7 ± 22.8 ml [Efremushkin G.G., Filippova T.V., Denisova E.A. Volumetric blood flow in the main arteries at different levels of blood pressure in elderly patients with arterial hypertension Russian Journal of Cardiology. 2011. T. 16. No. 3. P. 10-15].

[0006] Another drawback is that the authors first perform an endarterectomy from the common carotid artery and internal carotid artery, and then place a temporary intraluminal bypass graft. In this situation, since endarterectomy requires a time interval during which blood flow to the brain is blocked ipsilaterally, ischemic stroke may develop. The use of a temporary intraluminal bypass graft, in turn, contributes to distal air and material embolism and dissection of the internal carotid artery. Furthermore, embolism into intracranial vessels occurs from the aorta and proximal parts of the common carotid artery due to incomplete removal of the atherosclerotic substrate, leaving floating intimal areas. A temporary intraluminal bypass graft creates technical difficulties for the operator, which in turn increases the time required for carotid artery occlusion, increasing the risk of stroke during surgery.In addition, the use of a temporary bypass eliminates the need for eversion endarterectomy from the internal carotid artery.

[0007] Classical carotid endarterectomy (hereinafter referred to as CEA) is associated with the risk of cerebral ischemia during compression of the carotid artery.

[0008] The problem solved by the invention is a method for protecting the brain during surgery for bilateral lesions of the carotid arteries, reducing the risk of cerebral ischemia during compression of the carotid artery by maintaining adequate collateral blood flow.

[0009] The essence of the method: The method allows to improve collateral blood supply to the brain during surgery on the carotid arteries in patients who are intolerant to compression, which reduces the risk of ischemic complications during surgery.

[0010] The proposed method is aimed at maintaining adequate blood flow in the brain by redirecting blood through collateral pathways. Occlusion of the subclavian artery (hereinafter referred to as SCA) distal to the orifice of the vertebral artery (hereinafter referred to as VA) on the contralateral side creates conditions under which blood is directed around the occlusion using the following collateral pathways: vertebrobasilar system - blood from the contralateral SCA through the vertebral artery (hereinafter referred to as VA) enters the basilar artery, and then into the posterior cerebral arteries, which supply the posterior regions of the brain. Anterior communicating artery (hereinafter referred to as ACA) - in the presence of a functional ACA, blood from the contralateral internal carotid artery (ICA) can flow into the ipsilateral ICA, compensating for the decrease in blood flow during clamping. Posterior communicating artery (hereinafter referred to as PCA) - similar to the ACA, the PCA can provide collateral blood flow from the vertebrobasilar system to the middle cerebral artery (hereinafter referred to as MCA).Muscular collaterals—small arteries connecting the VA and ICA basins—can also play a role in compensating blood flow. Improved collateral blood supply to the operated side is determined by two indicators: an increase in retrograde pressure in the internal carotid artery and linear blood flow velocity in the middle cerebral artery.

[0011] Preoperative preparation: A thorough assessment of the patient's condition, including neurological status and the presence of comorbidities. Duplex scanning of the carotid and vertebral arteries, as well as CT angiography or MR angiography to assess the vascular anatomy and the presence of collateral pathways. (Fig. 1) Mandatory assessment of the patency and diameter of the ASA and PSA. Discussion with the patient of the risks and benefits of the proposed technique. Preparation for possible conversion to classical CEE in case of ineffectiveness or complications.

[0012] Anesthesia: General anesthesia with EEG and / or SSEP (somatosensory evoked potential) monitoring to detect signs of cerebral ischemia.

[0013] Surgical approach: Standard incision along the anterior edge of the sternocleidomastoid muscle on the affected side. Isolation and control of the common carotid artery (CCA), external carotid artery (ECA), and ICA. Heparinization (100 U / kg).

[0014] Occlusion of the contralateral subclavian artery: Access is obtained through puncture of the brachial artery. Insertion of a balloon catheter into the subclavian artery distal to the vertebral artery orifice under radiographic control. Inflation of the balloon to occlude the subclavian artery. (Fig. 2)

[0015] Accurate balloon placement is critical. Occlusion of the SCA should be performed immediately after the origin of the vertebral artery, blocking the shunt into the thyrocervical trunk and internal thoracic artery. This allows for the redirection of all blood flow from the SCA to the vertebral artery. Clamping of the carotid artery after confirming adequate collateral blood flow is performed, followed by sequential clamping of the CCA, ECA, and ICA on the affected side.

[0016] Cerebral blood flow monitoring: Transcranial Doppler (TCD): Continuous monitoring of the linear blood flow velocity (LBFV) in the MCA on the ipsilateral side. An increase in LBFV indicates adequate collateral blood flow.

[0017] EEG / SSEP: Monitoring the electrical activity of the brain to detect signs of ischemia.

[0018] Retrograde pressure of the ICA: Measurement of retrograde pressure in the ICA after compression. Pressure above 40 mmHg is considered acceptable.

[0019] Enarterectomy: Performing standard CEE.

[0020] Reperfusion: Removal of thrombus and re-endothelialization of the internal carotid artery, removal of clamps from the CCA, ECA and ICA.

[0021] Restoration of blood flow: Deflation of the balloon in the PA and removal of the catheter, Control of hemostasis., Prescription of anticoagulant therapy.

[0022] Prevention of ischemia: The main benefit is to reduce the risk of cerebral ischemia during carotid artery clamping by increasing collateral blood flow.

[0023] Increased retrograde pressure in the ICA: Occlusion of the SCA contributes to an increase in retrograde pressure in the ICA, which indicates improved blood supply to the brain.

[0024] Increased MCA LBFV: TCD shows an increase in MCA LBFV, confirming adequate collateral blood flow.

[0025] Individualized approach: Evaluation of the vascular anatomy and collateral pathways (ASA, PSA) using CT or MR angiography allows for an individualized approach to each patient. In patients with well-developed collateral pathways, the effect of VA occlusion may be more pronounced.

[0026] Clinical Case 1

[0027] Patient P., 67 years old, was admitted with complaints of episodes of loss of consciousness and dizziness. There is no history of stroke and TIA. According to the ultrasound of the BCA and MSCT-AG, there are signs of stenosis of the ICA on the left up to 77%, the orifice of the RCA on the right up to 88%, the ICA on the right up to 70%, hypoplasia of the vertebral artery on the right; the circle of Willis is of the "classic" type. A decision was made to perform a hybrid surgery. In the first stage, under ETN, access to the carotid arteries on the left was achieved. The second stage was endovascular stage (balloon angioplasty of the RCA) through a puncture of the brachial artery on the right. During the clamping test, retrograde pressure in the ICA was measured by puncture, which amounted to 43 mmHg. with a systemic pressure of 160 / 100 mmHg. The linear blood flow velocity in the left MCA during TCD was 60 cm / sec. The patient was deemed intolerant to clamping, and the clamps were removed. Next, balloon occlusion of the right SCA distal to the vertebral artery orifice was performed, with occlusion of the thyrocervical trunk and internal thoracic artery.The clamps were reapplied, and retrograde pressure in the ICA was measured at 65 mmHg, while the systemic pressure was 160 / 100 mmHg. Accordingly, an increase in linear blood flow velocity in the left MCA to 85 cm / sec was noted. The third stage was carotid endarterectomy. After removing the clamps from the carotid arteries, balloon angioplasty of the right RCA was performed. The postoperative period was uneventful. The patient was transferred to the surgical department on the first day and discharged on the sixth day for outpatient treatment.

[0028] Clinical Case 2

[0029] Patient K., 73, was admitted with complaints of headaches, dizziness, and frequent episodes of loss of consciousness. The patient has a history of ischemic stroke (2023) in the right hemisphere with the development of right-sided hemiparesis. She was treated in the neurology department, and the signs of hemiparesis partially resolved. According to ultrasound dopplerography of the brachiocephalic arteries and MSCT angiography, the patient has occlusion of the right internal carotid artery, stenosis of the left internal carotid artery up to 97%, and a "classic" circle of Willis. The patient underwent surgical treatment according to the developed scheme.

[0030] At the first stage, access to the carotid arteries on the left was performed under ETN. Next, an endovascular balloon was advanced to the right subclavian artery distal to the origin of the right vertebral artery through a puncture of the brachial artery on the right. (Fig. 3) During the clamping test, retrograde pressure in the left ICA was measured by puncture and amounted to 37 mmHg, while the systemic pressure was 180 / 100 mmHg. And the linear blood flow velocity in the left MCA during TCD was 50 cm / sec. The patient was deemed intolerant to clamping, and the clamps were removed. Next, balloon occlusion of the SCA was performed on the right distal to the orifice of the right vertebral artery with occlusion of the thyrocervical trunk and internal thoracic artery. The clamps were reapplied, and the retrograde pressure in the ICA was measured at 55 mmHg, while the systemic pressure was 180 / 100 mmHg. An increase in the linear blood flow velocity in the left MCA to 70 cm / sec was also noted. A classic carotid endarterectomy was then performed.After starting blood flow through the left ICA, the balloon was removed from the right subclavian artery.

[0031] The postoperative period was uneventful. The patient was transferred to the surgical department on the second day and discharged on the seventh day for outpatient treatment. The patient noted positive changes, including a regression of headaches and dizziness. There were no episodes of loss of consciousness during the postoperative observation period.

[0032] Clinical Case 3

[0033] Patient B, 60 years old. Admitted to the department with complaints of dizziness, unsteadiness of gait, and attacks of weakness in the right limbs. History includes two episodes of TIA. These were treated in the neurology department.

[0034] According to ultrasound and CT-AG data, the patient's brachiocephalic arteries showed 75% ICA patency on the right and 70% on the left. Hemodynamically significant S-shaped tortuosity of the ICA was present on both sides. The patient underwent surgical treatment according to the developed protocol.

[0035] After accessing the right ICA, a balloon was inserted through the brachial artery into the left subclavian artery distal to the origin of the left vertebral artery. A clamping test was performed: retrograde pressure in the right ICA was 63 mmHg, while the systemic pressure was 170 / 100 mmHg. The linear blood flow velocity in the left MCA during TCD was 65 cm / sec. Temporary balloon occlusion of the left subclavian artery distal to the origin of the left vertebral artery was performed, overlapping the thyrocervical trunk and internal thoracic artery. A repeat clamping test was performed: retrograde pressure in the right ICA was 80 mmHg, while the systemic pressure was 170 / 100 mmHg, and the linear blood flow velocity in the left MCA during TCD was 85 cm / sec. Next, a carotid endarterectomy with redressal of the right internal carotid artery was performed. The postoperative period was uneventful. There was positive progress, including complete resolution of headaches and dizziness. The patient was discharged on the seventh day.

[0036] The technical result of the proposed invention—improving CEA with balloon occlusion of the contralateral SCA—is an effective method for reducing the risk of cerebral ischemia during surgery for bilateral carotid artery lesions. This method can be used in patients with a high risk of ischemia, poor collateral circulation, or a high risk of developing ischemia during CEA. The proposed method enables both classical endarterectomy and ICA redressal. Furthermore, this method allows for the operation to be performed without the use of a temporary intraluminal shunt, thus eliminating the potential complications associated with it.

Claims

A method of endovascular-assisted carotid endarterectomy for bilateral carotid artery disease, including endotracheal anesthesia, access to the carotid arteries, and performing carotid endarterectomy in patients intolerant of carotid artery clamping, characterized in that endovascular balloon occlusion of the subclavian artery is performed distal to the orifice of the contralateral vertebral artery with occlusion of the thyrocervical trunk and internal thoracic artery through a puncture of the brachial artery, followed by redirection of all blood flow from the subclavian to the vertebral artery.

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