RU218832U1 - Apical-aortic cannula for minimally invasive mechanical circulatory support - Google Patents

Abstract

The utility model relates to medicine, namely to cardiovascular surgery, and can be used for minimally invasive connection of the patient's cardiovascular system and devices for mechanical circulatory support or an extracorporeal membrane oxygenation circuit. The proposed solution is designed to implement the apical-aortic scheme for connecting mechanical circulatory support devices. The apical-aortic cannula for minimally invasive mechanical circulatory support is a double-lumen solid-cast tube. The outer (ventricular) branch pipe has a slanted inner end with a radiopaque band, which allows visualizing the position of the cannula in the heart cavity with additional circular inlets, as well as the extracorporeal part of the bifurcation type. The internal (aortic) branch pipe also has a slanted implantable end with additional round outlets and is located in the corresponding separate (aortic) canal of the external (ventricular) branch pipe. In this case, the length of the free end of the aortic branch pipe can change due to free sliding along the longitudinal axis. The fixing mechanism of the aortic branch pipe includes a silicone sealing plug, located flush, and a union nut, fastened together by a threaded connection. Fixing the position of the aortic branch pipe is carried out by compressive radial forces after tightening the union nut using a threaded connection. The supply branch of the extracorporeal part of the external (ventricular) branch pipe ends with a connecting adapter and a silicone plug. The resistance of the body of the outer (ventricular) branch pipe to kinks is ensured by spiral intra-wall reinforcement. In order to safely install the apical-aortic cannula, the lumen of the aortic branch pipe has a peak-shaped introducer with a dilating tip and a guidewire channel. The introducer is fixed to the aortic tube using a crimped silicone cap. The body of the apical-aortic cannula is fixed to the heart by means of a crimping rim with a felt fixing cuff. The technical result is reduced to the creation of a device that allows for minimally invasive apical-aortic connection of circulatory assist devices.

Description

The utility model relates to medicine, namely to cardiovascular surgery, and can be used for assisted circulatory support (ACS) or extracorporeal membrane oxygenation (ECMO). The proposed solution is designed for a minimally invasive connection of the patient's cardiovascular system and mechanical circulatory support devices (MCSD) or an ECMO circuit.

Technological progress in surgery and intensive care has led to a significant improvement in the survival of patients with congenital heart defects, which has led to an increase in the number of children requiring mechanical circulatory support. To date, VPK in children is possible either through ECMO as a short-term measure, or implantation of UMPC in order to provide long-term circulatory support as a "bridge to transplantation".

Ventricular assist devices consist of inflow and outflow cannulas, a pumping system, a power supply, and a system controller. The inflow cannula can be attached to the left atrium or left ventricular apex, then blood enters the pump and is pumped by the device into the outflow cannula, which is sutured to the ascending aorta. Peripheral cannulation is preferred through the neck in infants and young children and through the femoral vessels in older children. In the case of auxiliary support of the right ventricle, the inflow cannula is attached to the right atrium, the outflow cannula to the pulmonary artery trunk. Unlike ECMO, UMPC implantation requires central cannulation through a sternotomy under cardiopulmonary bypass.

Miniaturization of devices and connection schemes is one of the main problems that significantly complicate the use of assisted circulation methods in children, especially newborns. The small size of the holes and cannulas causes high shear stress, which is responsible for the development of hemolysis. Despite the developed small-sized models of UMPC devices (Jarvik VAD, PediPump and PediaFlow), their implantation is hampered by the lack of intrathoracic space in the body of newborns and the high risk of compression of both device lines and heart chambers when the chest is closed (Wei X. et al. Pre-clinical evaluation of the infant Jarvik 2000 heart in a neonate piglet model Tamez D. et al. of the transapical approach for the HeartWare MVAD ventricular assist system // ASAIO journal (American Society for Artificial Internal Organs: 1992). - 2014. - V. 60 - No. 2 - P. 170).

To date, the only UMPC model approved for use in infants and young children is the Berlin Heart EXCOR Pediatric VAD device (Berlin Heart A.G., Berlin, Germany) (Hetzer R. et al. Single-center experience with treatment of cardiogenic shock in Kirklin J. K. et al Mechanical circulatory support: strategies and outcomes in pediatric congenital heart disease children by pediatric ventricular assist devices The Journal of thoracic and cardiovascular surgery 2011 //Seminars in Thoracic and Cardiovascular Surgery: Pediatric Cardiac Surgery Annual - WB Saunders, 2014. - V. 17 - No. 1 - P. 62-68). The Berlin Heart EXCOR Pediatric VAD device is a pneumatically actuated paracorporeal pulsatile flow system with five pump chamber sizes (10-60 ml) and is capable of providing both left ventricular and biventricular circulatory support. However, the use of the developed devices often requires the management of patients with an open chest, which is associated with a high risk of bleeding (44%), thromboembolic (21%) and infectious (46%) complications, requires additional sedation, making it impossible to activate and breastfeed the child ( Almond C. S. et al. Berlin Heart EXCOR pediatric ventricular assist device for bridge to heart transplantation in US children // Circulation. - 2013. - V. 127. - No. 16 - S. 1702-1711). In addition, UMPC implantation in neonates requires sternotomy and cardiopulmonary bypass. A minimally invasive connection of the UMPC system will allow avoiding traumatic access, the use of cardiopulmonary bypass and prolonged mechanical ventilation, therefore, the development of new models of cannulas and methods for their implantation is an urgent problem in the surgical treatment of heart failure in children.

Several models of minimally invasive cannulas are known from the existing level of technology for mechanical support of blood circulation in both the right and left parts of the heart. At the same time, all these cannulas are double-lumen hollow products, suggesting both central and peripheral cannulation and allowing multidirectional blood flow. Patent application US 8,834,344 B2 (Sep. 16, 2014) describes a model of a double-lumen cannula with which it is possible to perform parallel cardiopulmonary bypass using the patient's own lungs as an oxygenator. The inlets of the external branch pipe are located at the level of the right atrium. The inner tube is located inside the outer one. The free end of the internal cannula is installed transseptally in the cavity of the left atrium or ventricle. The cannulation system also includes a pumping unit connected to the internal and external cannulas for performing the VPK, which provides blood flow from the right atrium to the pulmonary trunk in case of right heart bypass, or from the left atrium or ventricle to the aorta in case of mechanical support of the left heart.

Structurally similar inlet models are described in patent applications US 2022/0054730 A1 (Feb. 24, 2022) and US 2005/0085761A1 (Apr. 21, 2005). In this case, the products are a coaxial double-lumen reinforced cannula for peripheral implantation and mechanical support of blood circulation in the right heart. In this case, multiple inlets of a larger diameter tube are placed in the projection of the right atrium, and the inner longer branch pipe is placed in the lumen of the pulmonary artery trunk. To prevent kinking and flow disruption at the level of the inlets, the outer cannula wall has a circular reinforced component.

The double lumen cannula model described in patent application US 2021/0121659 A1 (Apr. 29, 2021) has a special self-expanding stent element that provides translumenal fixation of the cannula. This cannula allows for circulatory support of both the right and left parts of the heart. Another model proposed for the purpose of mechanical support of the circulation of the left ventricle is described in patent application US 7,524,277 B1 (Apr. 28, 2009). In this case, the device is a single lumen inflow cannula with an integrated intraventricular pump that can be implanted through the left ventricular apex of the heart and pump blood from the left ventricle through the aortic valve into the ascending aorta.

The closest to the claimed technical solution is the model described in the patent application WO 2019/210043 A1 (October 31, 2019). In this case, the cannula is a double-lumen tube without reinforcement and allows for support of both the left and right ventricles, as well as placement of the cannula in the cavity of the heart and great vessels by central implantation through the apex of the left ventricle or the ascending aorta.

However, the device models described above do not have the ability to adjust the dimensional characteristics, namely the length of the nozzles, change the position of the cannula parts in the heart cavities, and also, in the case of support for the left heart, require open access to the heart, which complicates postoperative rehabilitation of patients.

The technical result of the proposed device is the creation of an apical-aortic cannula for minimally invasive mechanical circulatory support. The technical result of the proposed device is achieved through the use of a double-lumen thin-walled solid tube with the ability to change the position and length of the inner (aortic) branch pipe.

The essence of the invention is illustrated by drawings, which show:

Fig. 1 - cross section of the apical-aortic cannula in the middle third;

Fig. 2 - the main components of the apical-aortic cannula, isometric view;

Fig. 3 - the main components of the fixing mechanism of the aortic branch pipe;

Fig. 4 is a general view of the implanted cannula.

The apical-aortic cannula for minimally invasive mechanical circulatory support consists of a double-lumen thin-walled solid tube made of polyurethane. The transverse section of the apical-aortic cannula has a round shape, allowing you to adjust the position after implantation in the heart cavity (Fig. 1). The outer (ventricular) branch pipe 1 has a slanted inner end 2 implanted into the heart cavity with a radiopaque strip 3 and additional circularly located oval inlets 4, as well as an extracorporeal part of the bifurcation type 5. The internal (aortic) branch pipe 6 has a slanted implanted end with additional round-shaped outlets 7 and is located in the corresponding separate (aortic) canal 8 of the ventricular tube 1 (Fig. 1, 2). In this case, the length of the implanted end of the aortic branch pipe 6 can be changed due to free sliding along the longitudinal axis in the case of the untwisted union nut 9 of the fixing mechanism of the aortic branch pipe (Fig. 2, 3). The fixing mechanism of the aortic branch pipe 6 includes a silicone sealing plug 10, which is located flush due to the stepped cut 11 of the inner part of the wall of the ventricular branch pipe 1. The fixation of the position of the aortic branch pipe 6 is carried out due to compressive radial forces after tightening the union nut 9 using a threaded connection 12 (Fig. .3). The supply branch 13 of the bifurcation part 5 of the ventricular tube 1 ends with a connecting adapter 14 and a silicone plug 15 (Fig. 2). The inner surface of the outer (ventricular) and inner (aortic) pipes is covered with a hemocompatible film. The resistance of the external (ventricular) branch pipe to kinks is ensured by spiral intra-wall reinforcement 16. For the safe installation of the apical-aortic cannula, the lumen of the aortic branch pipe 6 has a peak-shaped introducer 17 with a dilating tip and a channel 18 for the conductor 19. The introducer is fixed to the aortic branch pipe using crimp silicone cap 20 (Fig. 2, 4). The body of the apical-aortic cannula is fixed to the heart by means of a crimping rim 21 and a felt fixing cuff 22, connected by gluing (Fig. 1-4).

Implantation of the apical-aortic cannula for minimally invasive mechanical circulatory support is carried out in an X-ray operating room through a left-sided anterolateral minithoracotomy. After opening the pericardium, a felt fixing cuff 22 is attached to the avascular zone of the apex of the left ventricle using adhesive or suture techniques. Then, under the control of transesophageal echocardiography in the center of the crimping rim 21, a puncture of the cavity of the left ventricle of the heart 23 is performed, a conductor 19 is installed in the lumen of the aorta 24, with which the apical-aortic cannula is implanted. After visualization of the aortic branch pipe 6 in the lumen of the aorta 24 1-1.5 cm above the level of the aortic valve 25, the conductor 19 and the introducer 17 are removed (Fig. 4). Then the supply branch 13 of the bifurcation part 5 of the ventricular tube 1 and the inner (aortic) tube 6 are connected to the corresponding lines of the circulation circuit. After the initiation of circulatory support under the control of transesophageal echocardiography, the final positioning of the apical-aortic cannula is performed.

The developed model of the apical-aortic cannula for minimally invasive mechanical circulatory support will allow: 1) to avoid the formation of bulky extracardiac tracts, preventing compression of the heart structures; 2) to avoid compression of the inflow and outflow tracts of the UMPC device; 3) place the inflow and outflow lines inside the cavity of the heart, without occupying the intrathoracic space with the possibility of primary closure of the latter; 4) wean the child from sedation and artificial ventilation of the lungs; 5) provide early natural breastfeeding.

Claims (1)

Apical-aortic cannula for minimally invasive mechanical circulatory support, including an external (ventricular) branch pipe, which is a double-lumen solid-cast tube containing a spiral intramural reinforcement and having an oblique truncated inner end, with a radiopaque band and additional circularly located oval inlets, and an extracorporeal part bifurcation type, and an internal (aortic) branch pipe having a slanted implantable end with additional round outlets, while the internal (aortic) branch pipe is located in the corresponding separate (aortic) canal of the external (ventricular) branch pipe and is connected to the external (ventricular) branch pipe at using the fixing mechanism of the aortic branch pipe, including a silicone sealing plug and a union nut, fastened together by a threaded connection, the lumen of the aortic branch pipe contains a peak-shaped introducer with a dilating tip and a channel for the conductor, fixed to the aortic branch pipe with a crimped silicone cap, and the outer (ventricular) branch pipe is made with the possibility of positioning in a crimping rim connected by gluing to a felt fixing cuff, the inflow branch of the extracorporeal part of the outer (ventricular) branch pipe contains a connected adapter with a silicone plug, and the inner surface of the outer (ventricular) and internal (aortic) branch pipes is covered with a hemocompatible film.

Images