RU2828574C1 - Method for selecting a surgical approach to correcting atrial fibrillation in the presence of a formation in a left atrial appendage - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to cardiovascular surgery, and can be used for epicardial thoracoscopic diagnosis of thrombotic formations in the left atrial appendage (LAA) in atrial fibrillation ablation and choosing a surgical approach. Intraoperative analysis of LAA is performed by means of thoracoscopically introduced endoscopic ultrasonic sensor. In the absence of thrombotic formation (TF) in the LAA or in the presence of TF in the LAA with a volume of less than 2/3 of the LAA cavity, atrial fibrillation is surgically corrected using a minimally invasive technique. If observing a TF in the LAA with volume of 2/3 and more of the LAA cavity, a surgical intervention is performed through a sternotomy approach.

EFFECT: method enables minimizing intraoperative and postoperative complications due to minimally invasive intraoperative diagnosis of the nature of the formation in the LAA and selecting the optimal surgical intervention with due allowance for this.

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Description

Field of technology to which the invention relates

The invention relates to the field of medicine, namely to cardiovascular surgery, and can be used for epicardial thoracoscopic diagnostics of thrombotic formations in the left atrial appendage during atrial fibrillation ablation and selection of surgical intervention tactics.

State of the art

One of the most common arrhythmias with a grave prognosis, occurring in 60–70% of patients, is atrial fibrillation (AF) [Wilke T., Groth A., Mueller S., Pfannkuche M., Verheyen F., Linder R. et al. Incidence and prevalence of atrial fibrillation: an analysis based on 8.3 million patients. Europace. 2013; 15 (4):486–93. DOI: 10.1093/europace/eus333], the main complications of which are acute cerebrovascular accident and systemic thrombotic complications (5%) [Reddy V.Y., Möbius-Winkler S., Miller M.A., Neuzil P., Schuler G., Wiebe J. et al. Left atrial appendage closure with the Watchman device in patients with a contraindication for oral anticoagulation: the ASAP study (ASA Plavix Feasibility Study With Watchman Left Atrial Appendage Closure Technology). J. Am. Coll. Cardiol. 2013; 61 (25): 2551–6. OI:10.1016/j.jacc.2013.03.035]. In AF, conditions for thrombus formation are created in the left atrial appendage (LAA, LA) [Kirchhof P., Benussi S., Kotecha D., Ahlsson A., Atar D., Casadei B. et al. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur. J. Cardiothorac. Surg. 2016; 50 (5): e1–88. DOI:10.1093/ejcts/ezw313]. For surgical treatment and decision-making on the need and method of LAA isolation, accurate diagnosis of the thrombus localization or its absence is necessary [Cox J.L. Mechanical closure of the left atrial appendage: is it time to be more aggressive? J. Thorac. Cardiovasc. Surg. 2013; 146 (5): 1018–27e2. DOI: 10.1016/j.jtcvs.2013.07.011]. Existing methods are not perfect, which determines the need to search for new methods to determine the tactics of AF ablation.

A method of ultrasound diagnostics (US) is known in transthoracic echocardiography (Kornelyuk, I. V. Echocardiographic predictors of left atrial appendage thrombosis in patients with persistent atrial fibrillation / I. V. Kornelyuk, V. A. Rabtsevich, O. M. Kornelyuk // Annals of Arrhythmology. - 2014. - Vol. 11, No. 3. - Pp. 170-176. - DOI 10.15275/annaritmol.2014.3.5.). The disadvantages of the method are difficult visualization of the LAA, subjective assessment of the cavity condition and thrombus size, difficulty in characterizing the patient's tachycardia.

A diagnostic method is known using computed tomography of the heart with contrast (Guo T, Dong Y, Yu S. The Comparison of the Diagnostic Value of Left Atrial Pulmonary Vein Single-Phase and Dual-Phase Enhanced CT Scanning for Left Atrial Appendage Thrombosis and SEC in Patients with Atrial Fibrillation. Comput Math Methods Med. 2022 May 14;2022:8679511. doi: 10.1155/2022/8679511. Retraction in: Comput Math Methods Med. 2023 Jul 19;2023:9861583. PMID: 35607650; PMCID: PMC9124083.). The disadvantage of this method is that the quality of the resulting image depends on the patient’s heart rate – tachycardia does not allow obtaining a contrast image of the location and size of the LA thrombus.

A method known is transesophageal ultrasound echocardiography (TE ECHO). (Wang X, Xu X, Wang W, Huang H, Liu F, Wan C, Yao Q, Li H, Zhang Z, Song Z. Risk factors associated with left atrial appendage thrombosis in patients with non-valvular atrial fibrillation by transesophageal echocardiography. Int J Cardiovasc Imaging. 2023 Jul;39(7):1263-1273. doi: 10.1007/s10554-023-02841-x. Epub 2023 May 7. PMID: 37149503; PMCID: PMC10250506.) The disadvantages of the method are the difficulty of visualizing the LAA in case of anatomical abnormalities in the shape of the appendage, and, therefore, the high frequency of false positive or false negative results.

It is known to perform epicardial ultrasound of the LA, when the ultrasound sensor is inserted through a sternotomy approach (Gianfagna P, Ciani R, Morocutti G, Porreca L, Frassani R, Puricelli C, Feruglio GA. Transesophageal and epicardial echocardiography in the evaluation of conservative surgery of the mitral valve. Complementary methods?]. Minerva Cardioangiol. 1995 Mar; 43 (3): 69-79. Italian. PMID: 7609891.) The disadvantages of this method are the traumatic nature of the surgical approach with a high risk of bleeding, postoperative wound complications, which excludes the use of minimally invasive methods of AF ablation and removal of the appendage.

The technical problem being solved is to minimize the risk of bleeding and postoperative wound complications by accurately determining the nature of the formation in the LAA.

Disclosure of the essence of the invention

The technical result achieved is the minimization of intraoperative and postoperative complications due to minimally invasive intraoperative diagnostics of the nature of the formation in the LAA and the selection of the optimal surgical intervention taking this into account.

The accuracy of diagnostics of the nature of thrombotic formations in the LAA is critically important for the choice of surgical treatment for AF, as it allows choosing the optimal intervention route. If a thrombus is not visualized, or the diagnosed thrombus does not exceed 2/3 of the LAA volume, minimally invasive treatment may be performed, for example, by thoracic ablation and minimally invasive amputation of the LAA. Otherwise, a safer tactic is sternotomy and open surgery (for example, Labyrinth 5 and thrombectomy from the LA).

The authors of the present invention have found that the nature of the LAA formation can be determined most accurately by an intraoperatively introduced endoscopic sensor inserted into the chest through a thoracoscopic port. Due to the fact that the distance between the sensor surface and the LAA is no more than 1-2 mm, it becomes possible to determine with maximum accuracy the presence or absence of thrombotic formations in the LAA, their prevalence, and to differentiate thrombotic masses from muscular trabeculae in the auricle and with the slow-low/stasis phenomenon with high accuracy.

This access can be used later during the surgical intervention for minimally invasive AF ablation. This, accordingly, helps to reduce intra- and postoperative complications.

An epicardial ultrasound sensor, installed on the left atrium by a thoracoscopic method, allows one to determine with maximum accuracy whether the formation in the LAA is a thrombotic mass or other ultrasound artifacts (trabeculae or other phenomena).

Diagnosis of a thrombus occupying 2/3 or more of the LAA volume determines the choice of open treatment via sternotomy; when diagnosing a thrombus of smaller volumes, minimally invasive thoracoscopic ablation is possible. Filling the LAA with a thrombus by 2/3 or more of the LAA volume excludes the possibility of safe positioning of the stapler at the base of the LAA and its amputation.

Thus, the set of essential features that influence the achievement of the above technical result is:

- intraoperatively, using a thoracoscopically inserted endoscopic ultrasound sensor, the LAA is examined,

- in the absence of a thrombotic formation (TF) in the LAA or the presence of a TF in the LAA with a volume of less than 2/3 of the LAA cavity, surgical correction of atrial fibrillation is performed using minimally invasive technology,

- if there is a lesion in the LAA with a volume of 2/3 or more of the LAA cavity, surgical intervention is performed through a sternotomy approach.

Implementation of the invention

Thoracoscopic ports are installed. Endovideosurgical optics are inserted through a 5-mm port in the 4th intercostal space, which allows visualization of the left pleural cavity, pericardium, and surrounding structures. Endoscopic tweezers and scissors with an electrocoagulation function are inserted through 12-mm ports. The root of the left lung is visualized under the left pulmonary veins. The pericardial cavity is opened with a semicircular incision from the left pulmonary artery to the oblique sinus. The left atrial appendage is visualized. A sterile endoscopic probe with an ultrasound attachment at the end is inserted through the 12-mm port instead of scissors. The sensor is successively applied to different areas of the LAA, and the structure is analyzed in the normal (gray) diagnostic and tissue modes.

If the presence of a thrombus in the LAA with a volume of 2/3 or more of the LAA cavity is confirmed, a sternotomy is performed and, for example, the classical “labyrinth” operation is performed with surgical occlusion of the auricle and thrombectomy.

In the absence of thrombus formation in the LAA or the presence of TO in the LAA with a volume of less than 2/3 of the LAA cavity, without changing the points of thoracoscopic access, a minimally invasive operation is performed, for example, amputation of the LAA and ablation of the AF.

The end of the operation depends on the chosen method of treatment of AF.

Clinical example 1.

A 65-year-old patient with persistent atrial fibrillation, tachystolic form. EHRA IIa. CHA2DS2-VASc 4 points. HAS-BLED 2 points. In the preoperative period, multispiral computed tomography (MSCT) of the left atrium, pulmonary veins and left atrial appendage (LA) was performed. According to MSCT, there is no convincing evidence of LA appendage thrombosis. Transesophageal echocardiography was performed intraoperatively, according to which the effect of spontaneous echo contrast is noted, but the thrombus was not visualized.

Thoracoscopic ports were installed in the 3rd, 4th, and 5th intercostal spaces on the left, and the left pleural cavity was visualized. Longitudinal pericardiotomy was performed below the phrenic nerve. A sterile endoscopic probe with an ultrasound attachment at the end was inserted through the 12-mm port. During epicardial ultrasound of the left atrium, a parietal thrombus was detected extending from the apex to the base of the LA appendage, and its volume did not allow for safe positioning of the stapler, since with an appendage volume of 22 ml, the calculated volume of thrombotic masses was 18 ml and the proximal edge of these masses was 3 mm from the LAA orifice (i.e., the thrombus volume is "2/3 or more" of the LAA cavity).

A decision was made to perform sternotomy in order to minimize the risk of developing intraoperative cardioembolic stroke. Sternotomy was performed. CPB was connected according to the ascending aorta - superior and inferior vena cava scheme, the aorta was clamped and antegrade cardioplegia was performed with Custodiol solution. A revision was performed, a red lining thrombus was found, loosely adjacent to the wall of the left atrial appendage. The thrombus was removed, the LA appendage was sutured from the inside with a blanket suture. Then the Labyrinth IV operation was performed. The aortic clamping time was 35 min, CPB time was 76 min. Blood loss was 500 ml.

The patient was extubated 6 hours after the end of the operation and on the third day was transferred to a specialized department.

No focal neurological symptoms were observed in the postoperative period. Cardiotonic support with dopamine (3-5 mcg/kg/min) was administered during the first day. No paroxysms of AF were observed during the entire observation period in the hospital.

The patient was discharged on the 9th day. After 3 months, the paroxysms did not recur, according to Holter monitoring - sinus rhythm, heart rate 72 beats/min, no rhythm or conduction disturbances were noted.

Clinical example 2. A 54-year-old patient with persistent atrial fibrillation, tachystolic form. EHRA IIa. CHA2DS2-VASc 3 points. HAS-BLED 2 points. In the preoperative period, multispiral computed tomography (MSCT) of the left atrium, pulmonary veins and left atrial appendage (LA) was performed. According to the MSCT data, a left atrial appendage thrombus in the apex region cannot be excluded; increased trabecularity and a chicken wing-shaped appendage are noted. Transesophageal echocardiography was performed intraoperatively, according to which the effect of spontaneous echo contrast and a left atrial appendage thrombus are noted.

Thoracoscopic ports were installed in the 3rd, 4th, and 5th intercostal spaces on the left, the left pleural cavity was visualized. Longitudinal pericardiotomy was performed below the phrenic nerve. A sterile endoscopic probe with an ultrasound attachment at the end was inserted through the 12-mm port. During epicardial ultrasound of the left atrium, pronounced trabecularity of the LA appendage was visualized, there were no thrombi. A decision was made to perform thoracoscopic treatment of AF and amputation of the LA appendage. 10 plications were performed with a bipolar RFA electrode until transmurality was achieved on the left, then the upper and lower BOX lines were formed, additional linear ablations along the posterior wall of the LA. Drainage of the right pleural cavity was performed.

10 plications of the pulmonary vein orifices on the left were performed until transmurality was achieved. Additional ablation lines were made with a monopolar electrode. The upper and lower BOX lines were formed. Additional ablation lines were made along the posterior wall of the left atrium.

Next, amputation of the left atrium appendage was performed using an EndoGia 60 mm endostapler, once. Restoration of sinus rhythm. High-frequency stimulation 15 mA 100-300 ms, rhythm disruption in AF with independent restoration of sinus rhythm, additional ablations were performed using a monopolar electrode. Suturing of the pericardium. Drainage of the left pleural cavity.

At the end of the operation, the monitor recorded a sinus rhythm with a heart rate of 66 beats per minute. The patient was extubated 2 hours after the operation and on the second day was transferred to the cardiac surgery department.

Discharged from the hospital on the 5th day. No paroxysms of AF were observed for 6 months after the operation; according to Holter ECG, the rhythm was sinus with a heart rate of 64 beats/min.

Claims (3)

A method for selecting surgical tactics for correcting atrial fibrillation in the presence of a formation in the left atrial appendage (LAA), characterized in that the LAA is examined intraoperatively using a thoracoscopically inserted endoscopic ultrasound sensor, in the absence of a thrombotic formation (TF) in the LAA or the presence of a TF in the LAA with a volume of less than 2/3 of the LAA cavity, surgical correction of atrial fibrillation is performed using minimally invasive technology, in the presence of TO in the LAA with a volume of 2/3 or more of the LAA cavity, surgical intervention is performed through a sternotomy approach.