myxomatous mitral valve repair loop ... - kb grup...

106 1522-2942/$-sehttp://dx.doi.or

☆Disclosure: Dr BorLifesciences and Sorinsciences and St Judedisclose.Division of Cardiac, Va

Hospital, ColumbiaAddress reprint reque

Cardiac, Vascular,Hospital, ColumbiFort Washingtoncumc.columbia.edu

Myxomatous Mitral Valve Repair: Loop NeochordTechnique$

Robert C. Neely, MD, and Michael A. Borger, MD, PhD

Surgical repair techniques for myxomatous mitral regurgitation have evolved over time, withmultiple different methods in current use. The loop neochord technique provides a versatileand reproducible method that can be used for anterior, posterior, or bileaflet prolapse, aswell as Barlow’s disease. Preoperative planning and careful intraoperative valvularassessment are used to determine the appropriate loop length. Prefabricated commercialloops are available, but loops can also be created at the time of operation withpolytetrafluroethylene 4-0 sutures and pledgets. We describe specific leaflet andsubvalvular landmarks and suture placement techniques to ensure an accurate and durablemitral valve repair. Although these principles can be applied via a full sternotomy, weillustrate our preferred approach using the loop technique via a right minithoracotomy andfemoral cardiopulmonary bypass.Operative Techniques in Thoracic and Cardiovasculary Surgery 20:106-123 r 2015Published by Elsevier Inc.

KEYWORDS Mitral regurgitation, Minimally invasive, Loop technique, Neochord

Introduction

Mitral valve (MV) repair remains the preferred treatmentof myxomatous mitral regurgitation.1-3 Although MV

repair techniques have evolved over the preceding decades,no particular method has emerged as the predominanttechnique in current day practice.4-6 To be a successful MVrepair surgeon, one should be comfortable performingseveral different repair techniques that can be tailored to a

e front matter r 2015 Published by Elsevier Inc.g/10.1053/j.optechstcvs.2015.10.003

ger reports receiving consulting fees from Edwardsand lecture fees from Medtronic, Edwards Life-

medical. Dr Neeley has no commercial interests to

scular, and Thoracic Surgery, New York-PresbyterianUniversity Medical Center, New York, NYsts to Michael A. Borger, MD, PhD. Division ofand Thoracic Surgery, New York-Presbyterian

a University Medical Center, Milstein 7GN-435 177Ave, New York, NY 10032. E-mail: mb3851@

patient’s individual valvular pathology. Nonetheless, weprefer using the loop neochord technique for most patientswith MV prolapse.7-9

A variety of approaches to expose the MV have beendescribed, including minimally invasive approaches with anarray of cannulation strategies for cardiopulmonarybypass.8,10-12 The advantages and disadvantages of mini-mally invasive cardiac surgery have been discussed at lengthin the literature.12-15 We describe our preferred method fortreating myxomatous mitral regurgitation using the loopneochord technique for MV repair. Although the approachdescribed herein is via a right minithoracotomy (ourpreferred approach for patients requiring MV surgery ortricuspid valve repair or both, closure of atrial septal defects,and atrial fibrillation ablation), the loop technique can beapplied also via a full sternotomy. We use a minimal invasivevalve XS system (Aesculap, Melsungen, Germany) andfemoral cannulation for minimally invasive MV surgeryFigs. 1-14.

dx.doi.org/10.1053/j.optechstcvs.2015.10.003



mailto:[email protected]

mailto:[email protected]

TEE probe Patient positioned & intubated

Figure 1 Set-up and patient positioning includes double-lumen endotracheal intubation, central line placement, and a Swan Ganz catheterinserted high in the neck to allow for supplemental internal jugular venous cannulation, if needed. A foley catheter is placed. The patient ispositioned supine with a roll under the right chest, and the right arm is tucked slightly posteriorly to expose the anterolateral chest wall.External defibrillator pads are placed and TEE is standard. TEE ¼ transesophageal echocardiography.

Myxomatous mitral valve repair by loop neochord technique 107

Site for thoracoscope with CO2 inflation Site for atrial retractor

5 - 8 cm mini-thoracotomyincision

Site for aortic cross clamp

Figure 2 A 5-8-cm curvilinear incision is made at the right inframammary crease (or just above) for women, or 1-2 cm below the nipple inmen. The CXR should be examined before opening the pleural space for guidance on which intercostal space is to be opened. The pleuralspace is entered 1-2 rib spaces above the skin incision for women, and at the incision or 1 rib space higher for men. The intercostal spaceopening is extended several centimeters medially and laterally using cautery along the superior aspect of the rib. A 5-mm incision is made justlateral to the sternum in the third or fourth intercostal space for the atrial retractor. An additional small incision is made a few centimeterscranial and posterior to the thoracotomy for introduction of the aortic cross-clamp. A final 5-mm incision is made directly cranial to theminithoracotomy for the thoracoscope port with CO2 inflation, which passes through the third intercostal space. CXR ¼ chest x-ray.

R.C. Neely and M.A. Borger108

Thoracoscopewith CO2 Atrial

retraction

Aorticcross clamp

Femoralcannulation

Figure 3 Femoral cannulation is performed through a 3-4-cm transverse incision over the right femoral pulse. Heparin is dosed to achieve anactivated clotting time4400 seconds. In the femoral vein and artery, 5-0 prolene overlapping purse-string sutures are placed at the cephalad-most aspect of exposure, to optimize the angle of cannulae insertion. We perform venous cannulation with a multistage Bio-Medicus(Medtronic, Minneapolis, MN) using the Seldinger technique. TEE is used to confirm that the guidewire crosses the IVC, RA, and SVC beforeadvancing the tip of the cannula to a few centimeters above the SVC-RA junction. In patients weighing more than 80 kg, a second smallvenous cannula can be inserted via the right internal jugular vein. We use a 16- or 18-mm FemFlex arterial cannula (Edwards Lifesciences,Irvine, CA) to cannulate the femoral artery. IVC ¼ inferior vena cava; RA ¼ right atrium; SVC ¼ superior vena cava; TEE ¼ transesophagealechocardiography. (Reprinted with permission from Elsevier, Seeburger et al.16)


Cardioplegia needlein ascending aorta

SVC

Left atrium

Right lung Right phrenic nerve& pericardium

Multistage venouscannula in right atrium

Waterston’s groove

IVC

Figure 4 Adequate venous drainage and a decompressed right atrium are ensured. Vacuum-assisted venous drainage (-25 to -40 mm Hg) isnearly always required. The pericardium is opened vertically 3-5-cm anterior to the phrenic nerve. Using blunt dissection, the ascending aortais carefully mobilized from the right pulmonary artery. A 4-0 prolene purse-string suture is placed on the anterior aspect of the ascendingaorta and an antegrade cardioplegia cannula is inserted. CPB is briefly stopped and the aortic cross-clamp (Chitwood Debakey Clamp,Scanlan; Saint Paul, MN) is applied. CPB is resumed and cardioplegia is administered. The oblique sinus is opened with blunt dissection, andthen the left atrium is opened along Waterston's groove with an 11 blade. After achieving adequate diastolic arrest, the atriotomy incision isextended superiorly and inferiorly and a left atrial retractor is used to expose the entire MV apparatus. A combination of direct andthoracoscopic visualization is used throughout the remaining procedure. CPB ¼ cardiopulmonary bypass; MV ¼ mitral valve.


Ruptured cord

Prolapsed P2-segmentFigure 5 The first step in the loop technique is a comprehensive assessment of MV pathology, which confirms the TEE findings. In this case,extensive prolapse of the P2 segment with a ruptured chordae tendinae is present. MV ¼ mitral valve; TEE ¼ transesophagealechocardiography.


Posteromedial papillary muscle

Anterolateral papillary muscleMidline of posterior leaflet

Figure 6 The prolapsing P2 segment is laid down into the ventricle to visualize location of the papillary muscles. The proximity of eachpapillary muscle to the prolapsed cusp determines where the loops are attached. Specifically, loops that are fixed to the posteromedialpapillary muscle should be attached to the medial half of the MV, and loops attached to the anterolateral papillary muscle should be attachedto the lateral half. Attaching a neochord from the posteromedial papillary muscle to the lateral aspect of the valve, for example, leads torestriction and must be avoided. Visualizing the midline of the valve aids this step and this so-called “do not cross the midline” rule preventssuch excessive tethering of the leaflet free edge. MV ¼ mitral valve.


Measuring for loop length betweenpapillary muscle & line of coaptation

Figure 7 The lengths of the loops are determined by measuring the distance between the papillary muscle and the envisioned line of leafletcoaptation with a caliper (ValveGate Suture Ruler, Geister; Tuttlingen, Germany). Remember that the level of leaflet coaptation is severalmillimeters below the annulus for the PML and nearly at the level of the annulus for the AML. In addition, AML sizing must be more preciseto prevent residual MR. The distal jaw is positioned 3-5 mm below the tip of the chosen papillary muscles, and the proximal jaw is placed atthe expected level of coaptation.Melnitchouk’s Rule can also be used before beginning the operation to determine loop sizing. The distance between the mitral annulus and theleft ventricular (LV) apex is measured using the 2-chamber long-axis view in transesophageal echocardiography.For PML neochords: mitral annulus distance to LV apex (cm) � 2 ¼ # mm loop length.For AML neochords: (mitral annulus distance to LV apex (cm) � 2) þ 10 ¼ # mm loop length.In general, loop sizes fall within the following ranges in most patients: PML 10-16 mm; AML 20-26 mm; and commissures 16-20 mm.AML ¼ anterior mitral leaflet; MR ¼ mitral regurgitation; PML ¼ posterior mitral leaflet


Loops for neochordae

Figure 8 Commercially available nonabsorbable ePTFE loops (Implant Chordae Loop, Santech Medical; Grosswallstadt, Germany [pictured] orChord-X suture, On-X Life Technologies; Austin, TX) simplify the procedure, although loops can be handmade using Gore-Tex 4-0 CVsutures (W.L. Gore and Associates; Flagstaff, AZ), 2 pledgets, and the loop sizing caliper. ePTFE ¼ expanded polytetrafluoroethylene.(Modified from Seeburger et al.16).


Loops stitched to papillary muscle

Figure 9 Loops of the appropriate length are sutured to the papillary muscle head approximately 3-5 mm below its tip. The needles are thenpassed through a free pledget and the Gore-Tex sutures are knotted several times to avoid slippage. (Modified from Seeburger et al.16).


One anchoring suture is passed through each loop, thenthrough the free edge of the prolapsing segment

Figure 10 The loops should protrude away from the papillary muscles and into the ventricular cavity without entrapment of any of thesurrounding chordae. Each loop is then attached to the free edge of the prolapsing segment with a separate, nonpledgeted anchoring suture(Gore-Tex 4-0) passed through the loop. The anchoring suture can be placed through more than 1 loop if the prolapsing segment is narrow,but no less than 2 anchoring sutures should be used.


Loops sutured toprolapsing segment of leaflet

A

Figure 11 (A) An end of the anchoring suture is passed through the prolapsing segment of the leaflet, approximately 5-8 mm from its free edge,and the 2 ends are tied over the free edge of the leaflet. The distance between anchoring sutures on the leaflet free edge is also 5-8 mm.


B

Figure 11 Continued (B) The distance from the free edge of the prolapsing leaflet progressively decreases as the anchoring sutures advancetoward the middle of the valve to compensate for the fact that the distance to the papillary muscle progressively increases. Note the “do notcross the midline rule.”


Water-sealing test with filling of left ventricle using irrigatorA

Figure 12 A water-sealing test is performed using a laparoscopic suction irrigator such as StrykFlow 2 (Stryker, Kalamazoo, MI). (A) before ringannuloplasty.


Final assessment ofprolapse correction, prior

to tying annuloplasty sutures

B

Figure 12 Continued (B) After lowering of the ring annuloplasty into place (but before tying sutures). Any required adjustments to the loops areeasier to perform before fixing the annuloplasty ring in place. Note the Gore-Tex suture knots shift below the level of coaptation when theventricle is full.


Annuloplasty ring affixed after assuring proper adjustment of loops

Figure 13 The annular sutures are tied with a knot pusher and a final water-sealing test is performed. Automatic tying devices may reduce themyocardial ischemic time.


Epicardial ventricular wire

Chest tubes

Figure 14 The left atrium is closed with a Prolene 3-0 suture, being sure to inject the cavity with saline before tying the suture. Suction isplaced on the aortic vent, CPB flow is reduced, and the aortic cross-clamp is removed. A single epicardial ventricular wire is placed along theinferior RV wall before filling the heart. A second wire can be placed at the skin for grounding. The presence of significant air emboli is ruledout by TEE before removing the aortic root vent. CPB flow should be reduced again during tying of the aortic root vent suture. Thepericardium is closed, leaving a small window for a mediastinal drain. The patient is weaned from CPB and decannulated. Protamine is givenand the thoracoscope is used to look for residual chest wall bleeding before closing. A pleural chest tube and mediastinal drainage tube (via asmall opening in the inferior pericardium) are placed. The thoracotomy is closed in standard fashion. For anesthetic rib blockade, 0.25%Marcaine is injected. CPB ¼ cardiopulmonary bypass; RV ¼ right ventricular; TEE ¼ transesophageal echocardiography.



ConclusionsThe loop neochord technique is a reproducible operationand can be used routinely for a variety of valvularpathologies. Applying the tenents of “respect rather thanresect,” this technique allows the operator to correct nearlyall different forms of MV prolapse while achieving maximalleaflet coaptation. Determining the correct loop length,however, can be challenging. In the only randomizedcontrolled trial to date, loop neochords resulted in similarclinical and echocardiographic outcomes, but greater line ofcoaptation, compared with classic leaflet resection techni-ques.6

Our preferred approach to the MV is via a rightminithoracotomy. In addition to improved cosmesis, thebenefits of a minimally invasive approach include less bloodloss, fewer transfusions, shorter length of stay, and quickerreturn to normal activity levels without compromisingpatient safety or durability of MV repair.8,12,13 Moreover,femoral cannulation for cardiopulmonary bypass is safe andsimplifies the operative field.17 Although the routineadoption of a minimally invasive technique can be achievedwith very low rates of conversion to full sternotomy,18,19

a definite learning curve exists for this procedure.20 The looptechnique may facilitate the learning curve for minimallyinvasive MV surgery. Indeed, one may want to employ theloop technique first via a full sternotomy before proceedingto the minimally invasive approach. Once mastered, weconsider the loop technique via a right minithoracotomy thestandard of care for patients with myxomatous MV disease.

Acknowledgments

We would like to thank Rob Gordon for his hard work inpreparing the expert illustrations presented in this article.

References1. Carpentier A: Cardiac valve surgery—the “French correction”. J Thorac

Cardiovasc Surg 86:323–337, 19832. Galloway AC, Colvin SB, Baumann FG, et al: Long-term results of mitral

valve reconstruction with carpentier techniques in 148 patients withmitral insufficiency. Circulation 78:97–105, 1988

3. Carabello BA: The current therapy for mitral regurgitation. J Am CollCardiol 52:319–326, 2008

4. David TE: Replacement of chordae tendinae with expanded polytetra-fluroethylene sutures. J Card Surg 4:286–290, 1989

5. Perer P, Hohenberger W, Lakew F, et al: Toward a new paradigm for thereconstruction of posterior leaflet prolapse: Midterm results of the“respect rather than resect” approach. Ann Thorac Surg 86:718–725,2008

6. Falk V, Seeburger J, Czesla M, et al: How does the use ofpolytetrafluroethylene neochordae for poster mitral valve prolapse(loop technique) compare with leaflet resection? A prospectiverandomized trial. J Thorac Cardiovasc Surg 136:1206, 2008

7. Borger MA, Mohr FW: Repair of bileaflet prolapse in barlow syndrome.Semin Thorac Cardiovasc Surg 22:174–178, 2010

8. Seeburger J, Borger MA, Doll N, et al: Comparison of outcomes ofminimally invasive mitral valve surgery for posterior, anterior andbileaflet prolapse. Eur J Cardiothorac Surg 36:532–538, 2009

9. Kuntze T, Borger MA, Falk V, et al: Early and mid-term results of mitralrepair using premeasured gore-tex loops (“loop technique”’). Eur JCardiothorac Surg 33:566–572, 2008

10. Von Oppell UO, Mohr FW: Chordal replacement for both minimallyinvasive and conventional mitral valve surgery using premeasured gore-tex loops. Ann Thorac Surg 70:2166–2168, 2000

11. Holzhey DM, Shi W, Borger MA, et al: Minimally invasive versussternotomy approach for mitral valve surgery in patients greater than 70years old: A propensity-matched comparison. Ann Thorac Surg91:401–405, 2011

12. McClure RS, Athanasopoulos LV, McGurk S, et al: One thousandminimally invasive mitral valve operations: Early outcomes, lateoutcomes, and echocardiographic follow-up. J Thorac Cardiovasc Surg145:1199–1206, 2013

13. Ward AF, Grossi EA, Galloway AC: Minimally invasive mitral surgerythrough right mini-thoracotomy under direct vision. J Thorac Dis 5(6):S673–S679 (suppl), 2013

14. Goldstone AB, Atluri P, Szeto WY, et al: Minimally invasive approachprovides at least equivalent results for surgical correction of mitralregurgitation: A propensitymatched comparison. J Thorac CardiovascSurg 145:748–756, 2013

15. Algarni KD, Suri RM, Schaff H: Minimally invasive mitral valve surgery:Does it make a difference? Trends Cardiovasc Surg 25(5):456–465,2015

16. Seeburger J, Borger MA, Falk V, et al: Gore-tex loop implantation formitral valve prolapse: The Leipzig loop technique. Op Tech ThoracCardiovasc Surg 13:83–90, 2008

17. Saadat S, Schultheis M, Azzolini A, et al: Femoral cannulation:A safe vascular access option for cardiopulmonary bypass in minimallyinvasive cardiac surgery. Perfusion. 2015 [Epub ahead of print].

18. Vollroth M, Seeburger J, Barbade J, et al: Minimally invasive mitralvalve surgery is a very safe procedure with very low rates ofconversion to full sternotomy. Eur J Cardiothoracic Surg 42(1):e13–e15, 2012

19. Panos A, Vlad S, Milas F, et al: Is minimally invasive mitral valve repairwith artificial chords reproducible and applicable in routine surgery?.Interact CardioVasc Thorac Surg 20(6):707–711, 2015

20. Holzhey DM, Seeburger J, Misfeld M, et al: Learning minimally invasivemitral valve surgery: A cumulative sum sequential probability analysis of3895 operations from a single high-volume center. Circulation 128(5):483–491, 2013

http://refhub.elsevier.com/S1522-2942(15)00132-4/sbref1































































myxomatous mitral valve repair loop ... - kb grup...

Documents