RU2511246C2 - Method for heart mobilisation accompanying surgical management of hypertrophic obstructive cardiomyopathy from transaortal approach - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, particularly cardiac surgery. A transaortal approach is ensured by a partial heart separation. An ascending aorta and a superior vena cava is transected in the presence of cardiopulmonary bypass. A left ventricular wall is incised between right pulmonary veins and an interatrial sulcus from the level of an inferior vena cava parallel with the interatrial sulcus with the incision extending onto a cupula of the left atrium to a left ventricular appendage. Thereafter, the heart is brought upwards and to the left. An interventricular septum is changed from a horizontal into vertical position.

EFFECT: method enables visualising the interventricular septum well through an aortic valve cusp for performing a septal myectomy, providing higher effectiveness of the operation ensured by reducing a risk of an injury of subvalvular structures of the mitral valve, as well as performing the septal myectomy in an adequate volume on the first try that enables shortening aortic compression and related myocardial injury.

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Description

The invention relates to medicine, in particular to cardiac surgery, and can be used to mobilize the heart during septal myectomy from transaortic access.

Hypertrophic cardiomyopathy is characterized by a significant thickening of the interventricular septum. This leads to a narrowing of the exit tract of the left ventricle. An increase in the load on the myocardium occurs due to the need to overcome hydrodynamic resistance in the narrowing zone. In the exit tract of the left ventricle, the flow rate of blood increases, which causes a shift in the systole of the anterior mitral valve leaflet towards the cavity of the left ventricle (Venturi effect) and the development of mitral insufficiency. Thus, with the progression of hypertrophic obstructive cardiomyopathy, narrowing of the left ventricular outlet tract and mitral valve insufficiency develop, which cause the development of chronic heart failure. Hypertrophic obstructive cardiomyopathy is a genetically determined disease and is not treatable by medications. Surgical treatment allows in some cases to radically eliminate the obstruction of the exit tract of the left ventricle and mitral insufficiency associated with SAM-syndrome (SAM - systolic anterior motion). However, surgical treatment is associated with significant technical difficulties. For this reason, despite the prevalence of pathology, operations for hypertrophic obstructive cardiomyopathy are performed in single large centers in the Russian Federation and abroad. So, in 2010 in Russia, only 42 septal myectomy operations were performed in 14 centers [Bokeria L.A., Gudkova R.G. Cardiovascular Surgery 2010. Diseases and congenital malformations of the circulatory system. - M .: NTSSSH them. A.N. Bakuleva RAMS, 2011. - P.45].

According to the literature, excision of the myocardium of the hypertrophic part of the interventricular septum is recommended, in some cases mobilization or excision of hypertrophied papillary muscles, mitral valve prosthetics with low-profile prostheses are required. In this case, the majority of authors noted the technical complexity of providing visualization of the interventricular septum [Bokeria L.A., Borisov K.V., Sinev A.F., Zlochevskaya E.V. Surgical treatment of hypertrophic obstructive cardiomyopathy in children. // Children's diseases of the heart and blood vessels. - 2005. - No. 1. - S.23-28. Maron B.J. Surgery for hypertrophic obstructive cardiomyopathy // Circulation. - 2005 .-- Vol. 111. - C.2016-2018].

Known methods of mobilizing the heart are dissecting the pericardium in places of transitional folds, a number of unconventional accesses to the mitral valve (combined right lateral and superior access with the intersection of the superior vena cava), methods of complete and partial autologous heart transplantation. With the help of complex devices and installations, surgical instruments, the work of which is based on various physical principles, the tissues fixing the heart are cut or the heart is completely or partially cut off with or without removal from the chest cavity and its subsequent reimplantation.

There is a method of dissection of the pericardium in places of transitional folds (dissection of extracardiac tissue) [McCarthy J.F., Delos M. Cosgrove, III. Optimizing mitral valve exposure with conventional left atriotomy. // Ann. Thorac. Surg. - 1998 .-- Vol.65. - P.1161-1162. Cox J.L., Schuessler R. B., D'Agostino H. J., Stone C. M., Chang B. C., Cain M. E., Corr P. B., Boineau J. P. The surgical treatment of atrial fibrillation. III. Development of a definitive surgical procedure. // J. Thorac. Cardiovasc. Surg. - 1991. - Vol. 101. - P.569-583], in which, depending on the task facing the surgeon, the pericardium is dissected in the area of its transition to the aortic wall, pulmonary trunk, vena cava and pulmonary veins, the left atrium, or the pericardium is dissected in the places of its transition from the diaphragm to the mediastinal pleura . The known method of dissecting the pericardium in places of transitional folds allows to some extent increase the mobility of the heart for the convenience of performing the main stage of the operation and to provide better visualization of its various departments. However, in some cases, mobilization of the heart only due to dissection of the pericardium is insufficient.

The disadvantage of this method is the possibility of damage to the phrenic nerves, large vessels and the left atrium.

A well-known combined method of right lateral and superior access to the mitral valve with the intersection of the superior vena cava [Selle J.A. Temporary division of the superior vena cava for exceptional mitral valve exposure. // J. Thorac. Cardiovasc. Surg. - 1984. - Vol. 88. - P.302. Bamer H.B. Combined superior and right lateral left atriotomy with division of the superior vena cava for exposure of the mitral valve. // Ann. Thorac. Surg. - 1992. - Vol. 54. - No. 9. - P.594] is one of the alternative mitral valve exposures. In conditions of cardiopulmonary bypass according to the scheme "aorta - vena cava - left ventricle" and cardioplegia, the superior vena cava intersects, the left atrium opens along the atrial groove with the passage to the dome of the left atrium.

This method provides a good exposure of the mitral valve, but increases the morbidity of access and the risk of bleeding.

A surgical method is known for complete autologous heart transplantation, which involves complete heart explantation, performing the main stage of an operation on an isolated heart and its subsequent reimplantation [Reardon M.J., Malaisrie C.S., Walkes J.-Cecil, Vaporciyan A.A., Rice D.C., Smythe W.R., DeFelice C.A., Wojjc. Cardiac autotransplantation for primary cardiac tumors. // Ann. Thorac. Surg. - 2006 .-- Vol.82. - P.645-650; Troise G., Cirillo M., Brunelli F., Tasca G., Amaducci A., Mhagna Z., Tomba M.D., Quaini E. Mid-term results of cardiac autotransplantation as method to treat permanent atrial fibrillation and mitral disease. // Eur. J. Cardiothorac. Surg. - 2004 .-- Vol.25 (6). - P.1025-1031]. There are two main methods of complete autotransplantation - biatrial and bicaval. According to the biatrial autotransplantation method, under conditions of cardiopulmonary bypass and cardioplegia, the right and left atria with the mouths of the vena cava and pulmonary veins and part of the atrial septum are separated from the rest of the heart in a single block, the heart is removed from the pericardial cavity and placed in a special container. During bicaval autotransplantation of the heart under cardiopulmonary bypass and cardioplegia, the vena cava, the aorta and the pulmonary artery are sequentially crossed, the left atrium with the mouths of the pulmonary veins are separated from the rest of the heart, the heart is removed from the pericardial cavity, and placed in a container. On the explanted heart, the main stage of the operation is performed - correction of valvular defects, removal of tumors, reduction of atrial cavities. Next, the heart is reimplanted in the reverse order.

Both of these methods provide a good exposure of different parts of the heart, as well as the possibility of a significant reduction in the atrial cavity, however, they are technically difficult, feasible only with a significant increase in the atrial cavity, are highly traumatic with complete separation of the sinus and atrioventricular nodes in the biatrial method, which leads to the development persistent rhythm and conduction disturbances.

There is also a method of partial autotransplantation of the heart [Lessana A., Scorsin M., Scheuble C., Raffoul R., Rescigno G. Effective reduction of a giant left atrium by partial autotransplantation. // Ann. Thorac. Surg. - 1999 .-- Vol.67 (4). - P.1164-1165], which provides for a partial cut-off of the heart with the aim of mobilizing it, performing the main stage of the operation and the subsequent restoration of the anatomical integrity of the damaged structures. According to the known method, in the conditions of cardiopulmonary bypass and cardioplegia, the superior vena cava, aorta and pulmonary trunk are crossed, and the completely left atrium with the mouths of the pulmonary veins is cut off. At the main stage, the cavity of the left atrium is reduced, the mitral valve defect is corrected. After the completion of the main stage of the operation, reimplantation of the heart is performed in the reverse order.

In a similar method for partial heart autotransplantation [Garcia-Villareal O.A., Gonzalez R. Avoiding potential complications in left atrial reduction: partial heart autotransplantation. // J. Cardiovasc. Surg. (Torino). - 2004 .-- Vol. 45 (1). - P.39-42], in conditions of cardiopulmonary bypass and cardioplegia they cross the superior vena cava and the left atrium with the mouth of the pulmonary veins is separated from the rest of the heart. At the main stage, the left atrial cavity is reduced and the mitral valve defect is corrected. At the end of the main stage, the integrity of the left atrium and superior vena cava is restored.

The basis for all options for partial autologous heart transplantation is the principle of maintaining the integrity of the inferior vena cava due to significant difficulties in creating its reanastomosis. Both methods of partial autotransplantation differ in the degree of cut-off of the heart.

Partial autotransplantation methods for the heart have such advantages as a significant reduction in the size of the left atrium; providing an excellent exposure of the mitral valve and the possibility of interrupting the impulse circulation loop around the mouth of the pulmonary veins.

However, these methods also have serious disadvantages, which include damage during surgery of the initially intact anatomical structures, such as the ascending aorta, pulmonary trunk, superior vena cava, and the possibility of developing cerebral edema [Apostolakis E., Shuhaiber J. The surgical management of giant left atrium. Eur. J. Cardiothoracic Surg. - 2008 .-- Vol.33. - P. 182-190. Erdogan H., Kirali K., Omeroglu S.N., Goksedef D., Isik O., Yakut C. Partial cardiac autotransplantation for reduction of the left atrium. // Asian Cardiovasc. Thorac. Ann. - 2004 .-- Vol.12. - P.111-114].

The described methods of heart autotransplantation were originally developed to reduce the atrial cavity and to remove heart tumors (options for complete autotransplantation). Their implementation is significantly complicated in the absence of dilatation of the left atrium.

Of the known analogues as a prototype of the claimed method, the method of partial autologous heart transplantation was selected [Lessana A., Scorsin M., Scheuble C., Raffoul R., Rescigno G. Effective reduction of a giant left atrium by partial autotransplantation. // Ann. Thorac. Surg. - 1999 .-- Vol.67 (4). - P.1164-1165].

The objective of the present invention is to improve the visualization of the interventricular septum through the aortic valve during septal myectomy and increase the effectiveness of the operation, which consists in reducing the risk of damage to the subvalvular structures of the mitral valve, as well as performing a sufficient volume of septal myectomy.

The achievement of this task is achieved by the fact that in the method of mobilizing the heart during surgical treatment of hypertrophic obstructive cardiomyopathy with transaortic access by partial cutoff of the heart, which consists in the fact that in conditions of extracorporeal circulation according to the scheme "aorta - vena cava - left ventricle" and cardioplegia cross the ascending aorta and superior vena cava, after which an incision is made of the wall of the left atrium between the right pulmonary veins and the atrial groove from the level of the lower pulmonary veins parallel to the atrial sulcus with the passage of the incision to the dome of the left atrium to the level of the ear of the left atrium, the heart is taken up and to the left, while the interventricular septum moves from horizontal to vertical.

Due to the anatomical features, the interventricular septum is often poorly visible through the aortic valve. This leads to the fact that in some cases it is not possible to excise a sufficient volume of the myocardium of the interventricular septum, which causes the preservation of a high pressure gradient in the output section of the left ventricle and the preservation of SAM syndrome. The operation is ineffective or ineffective; repeated interventions are required to achieve the desired result. Poor visualization leads to an increased risk of damage to the subvalvular structures of the mitral valve when performing myoectomy. In this case, there is a need for mitral valve replacement. The proposed method of mobilization of the heart allows for optimal visualization of the interventricular septum through the aortic valve. This, in turn, allows you to perform a sufficient volume myectomy the first time. Good visualization also reduces the risk of damage to the subvalvular structures of the mitral valve. The method is as follows:

The patient is injected into anesthesia according to a standard technique. An incision is made in the skin, subcutaneous fat. In parallel, a transesophageal echocardiographic study is performed, the thickness of the interventricular septum, its anatomical features, the presence of SAM syndrome and mitral insufficiency are assessed. Access to the heart is carried out using a complete longitudinal sternotomy. Carry out hemostasis and establish a retractor. The "T" -shaped incision reveals the pericardium. At the same time, heparin is administered at a dose of 300 U / kg. The edges of the pericardium are fixed with ligatures - holders. Dissect the pericardium around the mouth of the vena cava, the right pulmonary veins and adjacent sections of the left atrium around the ascending aorta. The pericardiotomy incision is extended to the left, along the diaphragm, to the left phrenic nerve. Next, purse string sutures are applied to the ascending aorta near the mouth of the brachiocephalic trunk, to the superior vena cava, as distally as possible, to the wall of the right atrium near the mouth of the inferior vena cava. The aorta is opened in the center of the pouch, the aortic cannula of the cardiopulmonary bypass is installed, filled and connected to the trunk. In a similar manner, venous cannulas are inserted into the superior and inferior vena cava. Around the upper and lower vena cava conduct rubber tight. A purse string suture is applied to the wall of the right atrium between the inferior vena cava and the ear of the right atrium. They begin cardiopulmonary bypass. The atrium is opened in the center of the pouch, a retrograde cardioplegic cannula is placed in the coronary sinus. A pouch is placed on the ascending aorta and an antegrade cardioplegic cannula is inserted through it. Put the last pouch on the right upper pulmonary vein. Atrial furrow is cleared of adipose tissue. The aorta is pinched. Install the left drainage through a pouch on the right upper pulmonary vein. Left drainage heart emptied. An anti-retrograde blood isothermal cardioplegia is performed. Tighten the skin on vena cava. Cross the ascending aorta just above the synotubular junction (about 1 cm above the mouth of the right coronary artery). Perform visual and palpation revision of the interventricular septum through the aortic valve. The left atrium is opened from the level of the right lower pulmonary vein parallel to the atrial sulcus. The superior vena cava is crossed 1 cm proximal to the cannula of the heart-lung machine. The section of the left atrium is continued under the crossed superior vena cava to the dome of the left atrium behind the dissected aorta above the mouths of the superior pulmonary veins and further to the left atrial ear. The right coronary valve of the aortic valve is pressed against the aortic wall with an aortic hook and at the same time traction is performed on the aortic wall. Thus, the heart is taken up and to the left, after which the anterior mitral valve leaflet with its chordal apparatus is removed with forceps from the interventricular septum. In this case, the interventricular septum becomes clearly visible through the aortic valve. Perform myoectomy in the required volume. After its completion, traction of the aortic wall is stopped. Under the influence of gravity, the heart falls to its original horizontal position. Next, suturing of the left atrial incision is performed with two threads sequentially towards each other, starting from the ends of the incision. The integrity of the superior vena cava and aorta is restored by continuous upholstery. Remove the skin from the vena cava. Reperfusion is carried out until cardiac activity is restored and the prevention of air embolism begins. Remove the clamp from the aorta. Prevention of air embolism continues. The heart-lung machine is stopped and transesophageal echocardiography is performed. The presence of SAM-syndrome, the thickness of the interventricular septum, the pressure gradient in the exit tract of the left ventricle, the presence of mitral regurgitation, and blood discharge through the interventricular septum are assessed. Further, with sufficient effectiveness of myoectomy, a typical completion of the operation follows. A specific example of the proposed method.

Example

20 experimental studies on the mobilization of the heart to perform myoectomy and interventricular septum were performed on posthumous hearts. Access to the heart was carried out through complete longitudinal sternotomy and pericardotomy. The purse string sutures were applied to the ascending aorta and superior vena cava. Through them, as in a real operation, aortic and "T" -shaped venous cannulas of the cardiopulmonary bypass were installed, respectively. Rubber tightening was performed around the superior vena cava. The right part of the atrial groove was released from fatty tissue. The pericardium was dissected along the perimeter of the superior and inferior vena cava in the area of transitional folds. A transverse intersection of the ascending aorta was made just above the sinotubular articulation. Through the aortic lumen, visual and palpation revisions of the aortic valve, supravalvular aortic space, exit tract of the left ventricle, and accessible part of the interventricular septum were performed. The left atrium was opened parallel to the atrial groove from the level of the right lower pulmonary vein to the superior vena cava. Further, the superior vena cava intersected transversely 1 cm distal to the venous cannula of the heart-lung machine. The atrial incision was further extended in the cranial direction under the intersected superior vena cava with the passage to the dome of the left atrium behind the intersected aorta above the mouths of the superior pulmonary veins and further to its ear. The right coronary valve of the aortic valve was pressed against the aortic wall by an aortic hook, and traction on the aortic wall was carried out simultaneously. The heart was diverted up and to the left. In this case, the interventricular septum from a vertical plane turned into a horizontal one and most of it became accessible for viewing through the aortic valve target. The chordal apparatus of the mitral valve was retracted with forceps. An interventricular septal muscle was excised from the level of the fibrous ring of the aortic valve to the level of the bases of the papillary muscles under visual and tactile control. The left atrial incision was closed by continuous continuous single-row suture. The integrity of the superior vena cava and aorta was restored by a similar suture.

Using the proposed method allows to provide good visualization of the interventricular septum through the aortic valve to perform septal myectomy, to increase the effectiveness of the operation, which is to reduce the risk of damage to the subvalvular structures of the mitral valve, and also to perform septal myectomy in an adequate amount from the first time, which reduces the duration of aortic compression and related myocardial damage.

Claims (1)

A method of mobilizing the heart in the surgical treatment of hypertrophic obstructive cardiomyopathy with transaortic access by partial cut-off of the heart, which consists in the fact that in conditions of extracorporeal circulation according to the scheme "aorta - vena cava - left ventricle" and cardioplegia intersect the ascending aorta and superior vena cava, characterized in that after the intersection of the ascending aorta and the superior vena cava, an incision is made of the wall of the left atrium between the right pulmonary veins and the atrial groove from the level of the lower of the pulmonary vein parallel to the atrial sulcus with the transition of the incision to the dome of the left atrium to the level of the left atrial ear, the heart is taken up and to the left, while the interventricular septum moves from horizontal to vertical.