FR2714284A1 - Prosthesis for repairing heart wall defects - Google Patents

Abstract

The prosthesis consists of a circular component made from a supple material with a shape memory effect, able to occupy three different positions. In the first position (2) it is extended lengthwise to form a small cylinder which can be introduced through a catheter, with its proximal end closed by a valve (4). In a second position the two compartments (8,10) are inflated separately so that they are deployed on opposite sides of the ruptured wall, while in the third position the compartments are squeezed together to form a double patch on the wall. The prosthesis has a radio-opaque marker (6) between the two compartments which allows its progress through the patient's body to be monitored.

Description

i

  PROTRESS FOR CLOSING BREAKS

CARDIAC WALLS,

  IN PARTICULAR INTERVENTRICULAR SEPTAL BREAKS

  The present invention relates to techniques for percutaneously closing cardiac walls comprising a congenital opening or

acquired abnormal.

  More specifically, it applies to congenital interventricular and interauricular communications of the heart and, also to accidental ruptures of the septum, which while it normally separates the right and left ventricles, sometimes comes to rupture, following an infarction

myocardium.

  In the remainder of this text, reference will be made only to the latter case, both for reasons of simplicity of the description and because it is the most important field of application of the subject of the patent, but it must be understood that this does not imply any limitation of this field of application which, on the contrary, includes the percutaneous closure of any internal wall of the heart comprising an opening

congenital or acquired abnormal.

  The post-infartus myocardial septal rupture, without being very frequent (less than 1% of myocardial infarctions), is a formidable pathology by its spontaneous evolution and the heaviness of its medico-surgical management. She regularly places cardiologists and surgeons in front of difficult

therapeutic problems.

  A presentation of the state of the art - physiology and treatment - in this field will now be made with reference to the main known publications, cited at the end of this thesis

  description and referenced from 1 to 14.

  Interventricular septal ruptures secondary to myocardial infarction are burdened with a very unfavorable spontaneous course - 90 to 100% death in the absence of surgical treatment (1-3) -, and high post-operative mortality - 10% to 45% depending on the series, most often between 35 and 40%

(1-9) -.

  This increased mortality compared to "standard" myocardial infarction is largely linked to the acute left-right shunt, which, by communication - of the right heart and the left heart, causes low systemic flow and high blood pressure pulmonary with right heart failure. The temporary obturation (4 days) by a "classic" balloon mounted percutaneously, performed by a Japanese team clearly demonstrates the spectacular hemodynamic improvement thus obtained; in this case the surgery could have been carried out secondarily

in good conditions (10).

  The predictors of operative mortality most often found are: cardiogenic shock, a short delay between the formation of the septal defect and surgery, a right ventricular infarction, pluritronascular lesions,

  low average right pressures, diabetes (1-9).

  This pathology affects mono patients,

  * bi- and tritroncles in substantially equal proportion.

  The immediate mortality is not linked to the realization of aorto-coronary bypasses (3, 7); only one study shows that bypassing the right coronary artery would improve immediate survival (2). On the other hand, the bridges associated with the correction of the rupture

  septale would improve long-term survival (8).

  Finally, patients who survive the intervention have a good life expectancy and a functional status which is most often satisfactory.

(1, 3, 6, 7).

  Anatomically these septal ruptures are characterized by: - their macroscopic appearance: unlike congenital interventricular communications, well delimited within normal myocardial tissue, these post-infactus septal ruptures are clefts, tears located in a part of infarcted myocardium, soft and fragile. The opening is most often unique but sometimes there are several which are then all very close. The size of these septal ruptures is 1.8 + 0.8 cm with values

extremes ranging from 0.8 to 2.3 cm.

  - their situation: this is variable depending on the location of the infarction. Interventricular communication can be located on the basal, middle or apical septum and can be anterior, median or infero-posterior. They are in fact more rarely basal (10). Septal ruptures located too close to a valve device or sitting in the pulmonary or aortic flushing chamber (basal location) could be contraindications to

  the use of the method which is the subject of the patent.

  - The evolution of the myocardial tissue around the interventricular communication: if the patient survives, the myocardium concerned becomes fibrotic and becomes

  therefore firmer, like any infarcted heart wall.

  The surgeons prefer to intervene at this stage because the suture of the #patchs "of closing of communication

  interventricular is then easier.

  Current state of percutaneous closures of the intracardiac walls: To our knowledge, there has never been a final occlusion of post-infarction septal rupture having been the subject of publication. On the other hand there are materials used for the percutaneous closure of congenital interauricular and interventricular communications which are all in their experimental phase. It is mainly congenital inter-ear communications that

  were subject to percutaneous occlusions.

  These are systems developed by Doctor SIDERIS

  from the Athens Hospital and by the BARD Company.

  For the first it is a patch of fabric retained by a staple and in the second case a double patch of Dacron deployed by metal arms placed on either side of the orifice to be closed. This last system called Nclams-shell "in English terminology has also been used in the closure of congenital interventricular commumnications in the context of complex cardiac malformations most often before palliative or corrective surgery, but also after this type of surgery to occlude residual interventricular communications (12, 13) Finally, a very small series of six patients was occluded by perimembranous interventricular communications by the Rashkind umbrella system usually used to close the arterial canals (14) These different prostheses have serious drawbacks which have not allowed their widespread development until now and have led them to stay rather at the experimental stage. staples or metal arms deployed, is not without requiring problematic mechanical stresses on the necessarily fragile walls of the rupture, without however constantly guaranteeing their good behavior. Furthermore, the quality of the seal they provide

is partly random.

  Early occlusion (as soon as the diagnosis is made, before any hemodynamic degradation) by a non-surgical method, with little trauma to the septal rupture, should allow a notable reduction in the deaths observed in this pathology. This is why the present invention relates to an implantable prosthesis percutaneously for the closure of these interventricular septal ruptures which makes it possible to overcome most of the drawbacks mentioned.

previously of the prior art.

  This prosthesis for the percutaneous occlusion of the heart wall openings is characterized in that it comprises a piece of flexible material, having an axis of symmetry of revolution, made of a material endowed with a shape memory, capable of to take three different positions, namely: - a first position stretched in length along the axis, in which the piece of flexible material takes the form of a small closed cylinder, hollow and elongated, accommodable in an insertion guide catheter , the proximal end of this small cylinder being closed by a communication valve between the interior of the preceding cylinder and the exterior; - a second position, recorded in the shape memory of the material, obtained by inflating the interior of the preceding cylinder through the valve and consisting of a double balloon, the two compartments of which deploy in the manner of a% yoyo "in a direction perpendicular to the axis of symmetry, each of the compartments being intended to be applied against one of the faces of the opening to be sealed; - a third position obtained by placing the interior of the double balloon under vacuum, in which the two compartments of the balloon contract by enclosing the walls of the opening which they seal

  like a double patch.

  According to an additional characteristic, certain areas of the prosthesis, including the middle part, located between the two compartments of the balloon, are provided with radio-opaque markers which make it possible to follow the evolution of the prosthesis and its exit from the

  catheter when implanted in the human body.

  The three previously defined positions of the prosthesis each correspond to a phase of the placement thereof by percutaneous route. Indeed: - the first position or "stretched" position is used to introduce and slide the ball into

  the percutaneous introduction guide catheter.

  The stretched position in this catheter is maintained by a 0.3 mm stiffening wire, the end of which is foam; - the second position or inflated position allows the positioning of the ball. The distal compartment is first removed from the sheath, introduced through the orifice to be closed, then inflated and placed against the distal face of this orifice. The proximal compartment is then inflated and placed against the proximal face of the orifice, the walls of the orifice being thus inserted between the two compartments of the balloon. The stiffener is gradually removed as the balloon is put in place, before the inflation of each compartment. During these various operations, the location of the balloon in its guide catheter and relative to the wall to be closed is followed by observation of the location of the markers opaque to X-rays; - the third position or position in depression is obtained by putting the two compartments of the balloon in depression through the valve, which causes the plating of the two compartments against the wall to be closed, in the manner of a double patch and gives the prosthesis stability by tightening one against the other of the two half-patches constituted by each

balloon compartment.

  During the two preceding phases, the inflation of the balloon and its depression are carried out by injection and withdrawal inside the balloon of an liquid opaque to X-rays, to the exclusion of any gaseous compound whose contribution in blood in the event of an accidental balloon leak would

catastrophic for the patient.

  Once the balloon is thus placed in depression, it occupies its final position and, after a monitoring period of a few hours, during which a security system possibly allows its

  emergency recovery, it can be left in place.

  The prosthesis object of the invention perfectly meets the constraints set for a device of this kind which must: 1. Before its installation: have a maximum diameter of 3 mm in the folded position so that it can be slid into a sheath of diameter 12 French, see 11 French (1 French = 0.33 mm), - ability to slide in the sheath,

- be sterile.

  2. When placing: - be able to unfold in a predictable and constant manner in a pre-established form, - be applied and placed in the right place, - do not cause traction on the septum (soft myocardial tissue and fragile), - be dropped with a security system if possible, the objective of which is to be able to recover the patch during the first 24 hours if necessary, and also to avoid possible early migration of this patch. 3. After installation:

- be stable,

  - be immediately continent in order to immediately obtain the hemodynamic benefit, - if possible be non-thrombogenic (if this condition cannot be fulfilled, anticoagulation, just as for mechanical valves,

can be performed).

  The two main advantages of this patch are: - the absence of traction on the interventricular septum to apply it; - its maintenance by the phenomenon of aspiration, without stitches on the septum, which is in order

general very brittle.

  In any case, the invention will be better understood

  with reference to the following description of an example

  of realization and implementation of the prosthesis

  subject of the invention, description which will be given in

  referring to Figures 1 to 7 attached given for description and not limitation, on which we see: - in Figure 1, the prosthesis in its stretched position, - in Figure 2, the inflated prosthesis, with its balloon two compartments, - in Figure 3, the prosthesis in depression, - in Figure 4, the establishment of a sheath containing the prosthesis before a septal rupture of a human heart, - in Figure 5, the place of the distal compartment of the prosthesis after inflation, - in Figure 6, the establishment of the proximal compartment of the prosthesis also inflated, in Figure 7, the deflation of the balloon. In Figure 1, we see the prosthesis 2 in the stretched form, consisting of a small cylinder of flexible material endowed with shape memory, here in this case that of a double balloon with two compartments (Figure 2). In an exemplary embodiment, given without limitation, the length a of the stretched balloon is 92 mm and its outside diameter is c = 3 mm. According to the invention, it is terminated on its proximal face by a valve 4, of a type known per se, therefore the length b = 3 mm. In the center of the prosthesis is one of the markers 6, opaque to X-rays. In FIG. 2, the prosthesis 2 is seen in the inflated position, composed of its balloon with two compartments 8 and 10, intended to be placed, as will be seen below, for the proximal compartment 8 in the right ventricle and for the distal compartment 10, in the left ventricle of a heart which one seeks to close an interventricular communication present in the septum. The inflated balloon 2 has the general shape of a Uyoyol, the compartments of which have a radius of around 23 mm. The

  central area of the yoyon has a diameter close to 5 mm.

  FIG. 3 shows the same balloon, provided with the same elements, but in the retracted position after placing under vacuum through the valve 4. It is the final position of the double patch which allows the occlusion of the interventricular septal rupture and the stability of the patch, enclosing the septal wall between the two half-patches, each consisting of a

  balloon compartment flattened by depression.

  Referring to Figures 4 to 7, we will describe below the different stages of the establishment of the prosthesis, object of the invention. In these schematic figures, an open human heart is seen and seen from the front, on which one recognizes the myocardium 12, the right and left atria 14 and 16 and the right ventricles 18 and left 20, separated by the septum 22, which comprises precisely an opening 24 consecutive to a heart attack and which one wishes to close using the prosthesis object of the invention. The upper 26 and lower 28 vena cava were also shown. a) Preliminary phase In a preliminary phase, an arterial puncture with a diameter of 6 French is first carried out to place the end of a "pigtail" probe in the left ventricle 20 and perform a double incidence ventriculography in order to to locate the location of the interventricular communication 24. Depending on this location, a right or femoral jugular puncture then allows the introduction of an introducer of 11 French diameter and the rise of a sheath 30 of 11 French whose l the end 32 is placed in front of the interventricular communication 24. The end 32 is shaped with steam on the operating table according to the location of

  interventricular communication.

  b) Mounting and placement of the patch: A 3F diameter probe is introduced into valve 4 of the prosthesis. A 0.30 mm stiffening wire with a foam end is slipped into the 3F diameter probe and then into the balloon in order to put it in "position

stretched. "

  The prosthesis thus mounted is introduced and then pushed into the guide probe to its end by a pusher catheter of diameter 9F (in the same way as for a cellar filter). The patch is extended over half its length to the area of the isthmus between the two compartments 8 and 10. The 0.30 mm stiffener is then removed from the distal part of the patch which is inflated by a radio solution -opaque (mixture of

  physiological saline and iodized contrast liquid).

  Initially (Figure 5), only the distal part 10, released from the guide takes its shape, on the left ventricular side of the septum in the manner of a button through a buttonhole. While gradually withdrawing the 0.30 mm guide, the sheath of diameter 11F is withdrawn on the pusher (the latter being at a fixed point) which releases the proximal part 8 of the balloon. During this maneuver, the swelling of the patch is continued until it takes its "inflated position" form. It then has a form of "yoyo"

  enclosing the interventricular septum (Figure 6).

  Then it is deflated and applied on both sides

  septum (Figure 7) by simple depression.

  c) Patch release: Keeping the pusher in a fixed point, the

  3F probe is taken from the valve which closes.

  The 11F pusher catheter and sheath are

  removed and the security system is left in place.

  d) The security system: It is a simple looped wire, the middle part of which is passed through the patch, and the other end is kept outside the patient, through the introducer. Just cut the wire outside and then pull it to remove it. Thread

  must be thin, tensile resistant and slippery.

  e) Verification: After 24 hours, it is possible to perform a verification, either by echocardiography or

  by a new left ventricular clouding.

  If the patch is continent, the safety system is removed (the wire is cut outside the patient, and simply pulled) and the venous introducer is removed. On the other hand if the patch is not effective or is no longer in place, or even causes a side effect it can be removed by traction and recovered at the level of the venous introducer (if necessary by ironing a stiffener of 0.30 mm to stretch it and

  slide it through the introducer).

REFERENCES:

  I. Cummings RG, Califf R. Jones RN, et al. Correlates of survival in patients with postinfarcion ventricular septal defect. Ann Thorac Surg 1989,47: 824-30 2. Anderson DR, Adams S. Bhat A, Pepper JR. Postinfarction ventricular septal defect: the importance of site of infarction and cardiogenic shock on outcome. Eur J Cardio-thorac Surg

1989; 3: 554-557

  3. Radford MJ, Johnson RA, Dagget WM, et al. Ventricular septal rupture: a review of clinical and physiologic features and an analysis of survival. Circulation 64,1981,3: 545-553 1 0 4. Komeda M, Fremncs SE, David TE, et al. Surgical repair of posinfarction ventricular septal defect Cuculation 1990; 82 (suppl IV): IV-243-IV-247 5. Deville C, Fontan F. Chevalier IM, et al. Surgery of post-infarction ventricular septal defect: risk factors for hospital death and long-term resuts. Eur J Cardio-thorac Surg (1991) 5: 167-175 6. Blanche C, Khan SS, Matloff IM, et al. Results of early repair of ventricular septal defect after an acute myocardial infarction. I Thorae Cardiovasc Surg 1992; 104.961- S 7. Skillingon PD, Davies RH, Luff Al, and aL Surgical treaunent for infarct-related ventricular septal defects. J Thorac Cardiovasc Surg 1990.99: 798-808 8. Muchreke DD, Dagget WN. Buckley MJ, et al. Postinfaret ventricular septal defect repair: effect of coronary artery bypass grafting. Ann Thorac Surg 1992; 54: 876-83 9. Loisance DY, Lordez JM, Deleuze PH, et al. Acute posinfarction septal rupture: long-term results. Ann Thorac Surg 1991; 52: 474-8 10. Mitsuhiro Hachida, Hideaki Nakano, Masayuki Hirai, et al. Percutaneous transaortic closure of postinfaconal ventricular sepual rupture. Ann Thoec Surg 1991; 51: 655-7 11. Helmncke F, Edward F. Mahan III EF, Nanda NC. and have. Two-dimensional echocardiography and doppler color flow mrnapping in the diagnosis and prognosis of ventricular septal ruptur Circulation

1990.81: 1775-1783

  12. Lock JE, Block PC, McKay RG, Bairm DS, Keane IF. Transcatheter closure of ventricular septal defects. Circulation 1988; 78: 361-368 13. Bridges ND, PeTy SP, Keane JF, et al. Preoperative transcatheter closure of congenital muscular ventricular scptal defects. New Engl J Mcd 1991; 324: 1312-1317 14. Rigby M, Redington A. Primay transcatheter closure of perimembranous ventricular septal defects. C = adiology in thec young 1993; 3 (suppl 1): 38 BAIG CORIG lL

Claims (2)

  1. Prosthesis for closing ruptures (24) of the cardiac walls, in particular interventricular septal ruptures consecutive to a heart attack, characterized in that it comprises a piece of flexible material, having an axis of symmetry of revolution, made of a material endowed with a shape memory, capable of taking three different positions, namely: - a first position (2) stretched in length along the axis, in which the piece of flexible material takes the form of a small closed cylinder, hollow and elongated, accommodable in an insertion guide catheter, the proximal end of this small cylinder being closed by a valve (4) for communication between the interior of the preceding cylinder and the exterior; - a second position, registered in the shape memory of the material, obtained by inflation of the interior of the preceding cylinder through the valve (4) and consisting of a double balloon, the two compartments of which (8, 10) are deployed in the manner of a "yoyo" in a direction perpendicular to the axis of symmetry, each of the compartments being intended to be applied against one of the faces of the opening (24) to be sealed; - a third position obtained by depressurizing the interior of the double balloon, in which the two compartments of the balloon contract by enclosing the walls of the opening which they clog   like a double "patch".   2. Prosthesis according to claim 1, characterized in that it is provided, at various places and in particular in the axial zone between the two compartments of the balloon, with markers (6) opaque to X-rays making it possible to follow its progress, outside of the introducer sheath, inside the human body.