Handbook of Advanced Interventional Cardiology - part 9 pdf

524 Practical Handbook of Advanced Interventional Cardiology device that could be reused several times without any loss of performance after proper resterilization, thus decreasing the procedural cost. Other goals were to improve the effi cacy and tolerance of the technique resulting from the device’s me- chanical properties, which are aimed at acting principally on the mitral commissures. The technical aspects of the procedure and the results of an international multicenter registry including 1087 patients will be presented here. DESCRIPTION OF THE DEVICE The device (Medicorp Inc, Nancy, France) consists of a metallic dilator screwed on the distal end of a disposable catheter. The entire system consists of four components (Figs 25-1 and 25-2): • The stainless steel metallic dilator is a cylinder 5 cm long and 5 mm wide with a slightly tapered tip (Figure 25-1). Its distal half comprises 2 bars, 20 mm in length, that can be opened in parallel up to a maximum length of 40 mm using a lever arms system (Figure 25-2). An internal lumen allows the passage of a guidewire and the recording of the distal pressures. The metallic head is screwed on the distal end of the catheter and is detachable. • The catheter has a diameter of 13F (4.3 mm) and a length of 170 cm. Its proximal end has a connector for recording Figure 25-1: (A) Distal part of the 0.035" guidewire. Note the metallic bead soldered at the junction of the stiff proximal and fl exible and pigtail curved distal segments of the wire. (B) Dis- tal end of the catheter and metallic dilator before connection. (C) The dilator screwed at the extremity of the catheter. (D) The dilator in the opened (40 mm) position. Percutaneous Mechanical Mitral Commissurotomy 525 the distal pressures, and it enables the connection of the activating pliers. Its distal end enables the fastening of the dilator. • The metallic guidewire has a length of 270 cm and a diameter of 0.035". A metallic bead of 2 mm in diameter is soldered at the junction of the stiff core and the 10-cm- long fl oppy distal end (Figure 25-3). The wire is used as a guidewire to drive the catheter across the valve, and then as a traction system that enables the opening of the dilator. For that, the metallic bead is positioned in contact with the distal end of the dilator and the guidewire is locked into the commissurotome using a threaded fastener located on the activating pliers. Squeezing the arms of the pliers causes a backward traction of the guidewire and the metallic bead, which is transmitted to the distal end of the dilator, thus forc- ing the distal bars to spread apart. • The activating pliers are comprised of several elements: (1) A caliper used to program the degree of bars opening (30, 35, 37, or 40 mm). (2) A safety lock that prevents the complete closure of the dilator after the release of pressure exerted on the pliers (it holds the dilator open at 20 mm). To obtain a complete closure of the dilator after withdrawal from the mitral valve, the lock must be activated manually. This security system has been designed to avoid any acci- dental extraction of valvular tissue. (3) A threaded fastener that is designed to block the metallic guidewire into the commissurotome at the time of opening. Figure 25-2: Proximal end of the catheter and activating pliers. 526 Practical Handbook of Advanced Interventional Cardiology After dilatation, the metallic dilator is unscrewed from the catheter and sterilized by autoclave for reuse. The activating pliers and the guidewire can also be resterilized. TECHNIQUES OF MECHANICAL MITRAL COMMISSUROTOMY Transseptal catheterization: Transseptal catheteriza- tion constitutes an essential step because the transseptal puncture site greatly infl uences both the safety and the effec- tiveness of the procedure. The puncture site is ideally situated 1–2 cm below the spot usually recommended for the Inoue technique. The approach described here seems particularly recommended. This technique helps to prevent punctures that are too high, too low, or too posterior. In the anteroposterior view, the Mullins sheath with the Brockenbrough needle is pulled back from the superior vena cava until its distal tip is positioned midway between the tip of Figure 25-3: Upper left: position of the guidewire in the left ventricle. Upper right: 18F polyethylene dilator during the septum dilatation phase. Lower left: the commissurotome in position across the mitral valve before opening; the metallic bead of the guidewire has been placed against the tip of the dilator, and the pigtail catheter faces the proximal third of the dilator. Lower right: the dilator in the opened (40 mm) position during the commissurotomy phase. Percutaneous Mechanical Mitral Commissurotomy 527 the pigtail (lying just above the aortic valve in the ascending aorta) and the top of the right hemidiaphragm (Figure 25-4 A). At this stage, it is not necessary to get a contact of the needle with the septum. While carefully maintaining the position of the assembly, the image intensifi er is moved to the 90° lateral position. The needle is then rotated in such a way that the distal tip of the dilator points upward (in as straight a vertical line as possible) and makes contact with the septum. Ideally, the contact will be made at a point two-thirds of the way down from the pigtail to the posterior border of the heart (Figure 25-4 B). The needle is deployed and the transseptal puncture performed. Left atrial pressure should now be seen through the needle. In no case should the septum be punctured high and anterior (Figure 25- 4 C) or low and posterior (Figure 25-4 D). Crossing the mitral valve: In the 30° RAO position, the Mullins catheter is advanced into the left atrium gently and the needle is withdrawn from inside the catheter. When the sheath is situated inside the left atrium, the dilator is withdrawn. The Mullins sheath should now appear with its distal curvature di- rected toward the mitral orifi ce, lying in a plane close to horizon- tal, and entirely below the pigtail catheter (Figure 25-4 E). If the two catheters appear on the screen to cross over each other, then t he septal puncture is too high and will render subsequent crossing of the mitral valve with the commissurotome diffi cult if not impo ssible ( Figure 25 - 4 F) . In this setting, it is reco mme nd- ed that the transseptal puncture be repeated at a slightly lower site. At this point, 2000 IU of heparin is given intravenously. Using the Mullins sheath in the left atrium and the pigtail catheter advanced into the left ventricle, the transmitral pres- sure gradient is recorded. The mitral valve area can also be evaluated using the Gorlin formula. 9 The pigtail catheter is then withdrawn into the ascending aorta to a point just in con- tact with the aortic valve; this position is important because it serves as a marker for the subsequent positioning of the commissurotome. Through the Mullins sheath, a 7F Critikon-type balloon catheter is advanced, the balloon is infl ated, and the valve is crossed. As far as possible, the balloon is advanced all the way to the apex (Figure 25-5 A). The Mullins sheath is then advanced until it contacts the tip of the balloon (Figure 25-5 B), the balloon is defl ated, and the catheter is withdrawn. The Mul- li ns sheath is left fre e in the lef t ventricle (Fig ure 25 -5 C ). The commissurotomy guidewire is advanced through the Mullins sheath into the left ventricle. Its fl exible distal tip is left in place in the apex of the left ventricle. The Mullins sheath is pulled back when its tip reaches the tip of the guidewire (Fig- ure 25-5 D). Ideally, the bead on the guidewire is maintained in the center of the ventricular cavity. During the dilatation maneuvers, the bead should never move all the way to the apex to avoid the risk of laceration of the wall of the heart by 528 Practical Handbook of Advanced Interventional Cardiology Figure 25-4(A–F): See text for details. Percutaneous Mechanical Mitral Commissurotomy 529 the rigid portion of the guidewire. The Mullins sheath is with- drawn, and the guidewire is maintained in the same position (Figure 25-5 E). Figure 25-5(A–E): See text for details. 530 Practical Handbook of Advanced Interventional Cardiology Dilatation of the interatrial septum: A 14F polyethylene dilator is pushed over the guidewire, advanced 2–3 cm across the interatrial septum, and left in place for approximately 30 sec (Figure 25-6 A). The same procedure is performed using an 18F dilator. This dilator should be left in place across the septum for approximately 60 sec (Figure 25-6 B). Before completely withdrawing the 18F dilator, it should be passed back and forth through the femoral venous punc- ture site several times. This step is very important because it greatly facilitates the introduction of the metal commissuro- tome into the femoral vein. At this point, additional intravenous heparin (50 IU/kg) should be administered. Mechanical mitral commissurotomy: The commissur- otome should have been assembled and fl ushed and the de- gree of opening selected with the aid of the calibration device. The tightening screw is relaxed in order to permit the advance of the catheter over the guidewire. A pressure line is connect- ed to the proximal port of the catheter and an active fl ushing of heparinized saline should be maintained throughout the procedure. The safety latch is confi rmed to be raised into the locked position. Technical tips during the different steps of the procedure, also shown in Figure 25-3, are as follows. TECHNICAL TIPS **Introduction and advancement of the guidewire: During introduction into the distal tip of the commissuro- tome and advancement to the site of the femoral puncture, Figure 25-6(A, B): See text for details. Percutaneous Mechanical Mitral Commissurotomy 531 the second operator must maintain traction on the device handle and the guidewire and maintain a straight line along the shaft of the catheter. **Introduction of the metal head: In order to introduce the metal head into the femoral vein at an approximately 45° angle, it is recommended that the catheter be held at the point where the metallic head is attached to the rest of the catheter, and that any rotational motion once it is intro- duced be avoided. The position of the guidewire in the left ventricle is monitored by fl uoroscopy during this maneuver as well as during the advancement of the device up to the mitral valve. **Advancement of the catheter: During advancement of the catheter to the interatrial septum and across the septum, the traction on the guidewire may be exerted by the second operator, or better yet by the principal operator himself, in order to optimally coordinate the pushing of the catheter and the traction on the wire in such a way as to maintain the metallic ball at the center of the left ventricular cavity. **Crossing of the mitral orifi ce: The same maneuver is used to pass the metal head through the mitral orifi ce. The metal head is advanced across the mitral orifi ce until its proximal third is situated roughly along a vertical line from the pigtail that was left in place above the aortic valve (Figure 25-7 A). It is inadvisable to push the device further forward into the left ventricle because the bars opening will then be at the level of the subvalvular apparatus. **Positioning of the ball: I n t h i s p o s i t i on , tr a c t i o n i s p l ac e d on the guidewire and the ball is brought into fi rm contact with the distal extremity of the metal head (Figure 25-7 B). The screw at the back end of the device must now be tight- ened around the guidewire to lock the ball in place. **Opening of the commissurotome and valvular dilata- tion: Opening of the commissurotome must be performed slowly and in two phases. The commissurotome is opened partially to allow for the metal struts to position themselves along the lines of least resistance, which in the majority of cases is along the commissural lines. One can observe on the fl uoroscopy screen that the struts separate along a slightly oblique line. The dilator is then totally opened and maintained open during a 3- to 5-sec period (Figure 25-7 C), and then closed. In reality, the relaxation of pressure on the handle leads to a partial closure of the metal struts, maintaining a half-open position thanks to the position of the security latch (Figure 25-7 D). 532 Practical Handbook of Advanced Interventional Cardiology Figure 25-7(A–E): See text for details. Percutaneous Mechanical Mitral Commissurotomy 533 Three or four additional openings of the valvulotome are then performed in sequential fashion, separated each time by pulling back the head of the device approximately 5 mm (Figure 25-7 E). It is important to never push the com- missurotome forward in a semi-open position (Figure 25-7 F). If additional dilation is required with the head placed more distally, the metal head must be retracted into the left atrium, closed completely, and then readvanced to the cho- sen position. The operator should feel progressive diminu- tion in the resistance to opening of the commissurotome after repeated dilatations; this confi rms the success of the commissurotomy. The withdrawal of the metal head into the left atrium will appear on the screen as a vertical rocking motion (Figure 25-7 G). At this stage, if the maximal de- gree of opening calibrated on the handle has already been achieved (40 mm), the dilatation procedure is fi nished. **Withdrawal of the commissurotome: The metal head in its semi-opened position in the left atrium is closed totally by repositioning the security latch (the lever is pulled back- ward). The metallic head is pulled back to the edge of the septum and the guidewire is withdrawn from the left ven- tricle and maintained in position in the left atrium. Left atrial pressure can be recorded through the line attached to the proximal portion of the catheter. At this stage, a fi rst evalua- tion of the transmitral pressure gradient may be obtained by simultaneously recording the left atrial pressure and the left ventricular pressure, the latter using the catheter that was Figure 25-7(F, G): See text for details. [...]... balloon valvotomy Circulation 199 5; 91 : 671–6 7 Cribier A, Rath PC, Letac B Percutaneous mitral valvotomy with a metal dilator Lancet 199 7; 3 49: 1667–8 8 Cribier A, Eltchaninoff H, Koning R et al Percutaneous mechanical mitral commissurotomy with a newly designed metallic valvulotome: Immediate results of the initial experience in 153 patients Circulation 199 9; 99 : 793 9 9 Wilkins GT, Weyman AE, Abascal... splitting of the commissures was noted in 86% of Figure 2 5-8 : Decrease in gradient and increase in mitral valve area after PMMC in the overall population 536 Practical Handbook of Advanced Interventional Cardiology Figure 2 5 -9 : Post-PMMC valve areas according to the echo score the patients According to the echocardiographic score, the mean post-PMMC mitral valve area was 2.18 ± 0.4, 2. 09 ± 0.3, and 1 .91 ... a prosthetic valve *Basic; * *Advanced; ***Rare, exotic, or investigational From: Nguyen T, Hu D, Saito S, Grines C, Palacios I (eds), Practical Handbook of Advanced Interventional Cardiology, 2nd edn © 2003 Futura, an imprint of Blackwell Publishing 551 552 Practical Handbook of Advanced Interventional Cardiology consisting of a porcine bioprosthesis attached in a wire-based stent frame could be successfully... fully inflated at the level of the calcific native valve using a 20 mL hand-held syringe with 1 :9 mixture of contrast media and saline, then deflated and removed A Figure 2 7-4 : (A) The 260-cm, 0.035", stiff wire is advanced through the Swan-Ganz catheter and placed beyond the renal arteries (Continued) 556 Practical Handbook of Advanced Interventional Cardiology B C Figure 2 7-4 : (B) This wire is snared... wire through (A) the femoral vein, (B) the trans-atrial septum, (C) the left ventricle and (D) positioned at the midpart of the native aortic valve (Continued) 558 Practical Handbook of Advanced Interventional Cardiology B C Figure 2 7-5 B,C (Continued) Percutaneous Implantation of Aortic Valve Prosthesis 5 59 D Figure 2 7-5 D 1 measurement of the trans-PHV gradient (using the pigtail in the left ventricle... Khalilullah M Immediate and long-term results of balloon and surgical closed 538 Practical Handbook of Advanced Interventional Cardiology mitral valvotomy: A randomized comparative study Am Heart J 199 3; 125: 1 091 –4 3 Reyes VP, Raju BS, Wynne J et al Percutaneous balloon valvuloplasty compared with open surgical commissurotomy for mitral stenosis N Engl J Med 199 4; 331: 96 1–7 4 Iung B, Cormier B, Ducimetiere... REFERENCES 1 ACC/AHA guidelines for the management of patients with valvular heart disease A report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients with Valvular Heart Disease) J Am Coll Cardiol 199 8; 32 : 1486–588 550 Practical Handbook of Advanced Interventional Cardiology 2 Levinson JR, Akins CW, Buckley MJ et... patients with a score . initial experi- ence in 153 patients. Circulation 199 9; 99 : 793 9. 9. Wilkins GT, Weyman AE, Abascal VM, Block PC, Palacios IF. Percutaneous mitral valvotomy: An analysis of echocardio- graphic. cost- effectiveness of the procedure. A French prospective study started in January 199 8 with the goal of assessing the immedi- ate as well as the long-term results of the technique; these re- sults. long-term results of balloon and surgical closed 538 Practical Handbook of Advanced Interventional Cardiology mitral valvotomy: A randomized comparative study. Am Heart J 199 3; 125 : 1 091 –4. 3. Reyes