Duran Ring Annuloplasty of the Tricuspid Valve

Transcription

1 Duran Rng Annuloplasty of the Trcuspd Valve Carlos M. G. Duran, MD, PhD T he trcuspd valve s often gnored by cardologsts and surgeons because of ts unque characterstcs: 1) t s rarely affected n solaton, and the promnent mpact of other dseased valves mnmzes ts mportance; 2) t s located at the entrance of the heart, so ts symptoms are prmarly extracardac and often slent; 3) ts behavor s closely related to rght ventrcular functon; 4) t follows the dctates of the mtral valve, so resoluton of the mtral problem s often followed by mprovement n the degree of trcuspd regurgtaton; and 5) t works n a low-pressure system, so evaluaton of ts preoperatve mportance s dffcult. Under general anesthesa, transesophageal echocardographc estmaton of the degree of regurgtaton s unrelable. These characterstcs explan why cardologsts and surgeons often gnore the trcuspd valve wth apparent mpunty. However, recent developments n dagnostc tools (two-dmensonal color Doppler echocardography n partcular) have ncreased awareness of ths valve, whch someone defned as the Cnderella of cardac valves. Tradtonally, trcuspd valve lesons have been classfed as organc or functonal accordng to whether the valve apparatus s macroscopcally dstorted or structurally normal but nsuffcent. Ths classfcaton has an mportant mpact on ts surgery and on the longterm clncal evoluton. Although organc lesons are more dffcult to repar, the mmedate and long-term results of surgery are superor to those after repar of functonal regurgtaton because n the frst case, the problem s valvular, whle n the second, t reflects an often rreversble rght ventrcular dysfuncton. 1 As n mtral repar, organc trcuspd dsease s treated wth commssurotomy, leaflet resecton or enlargement, chordal shortenng or replacement, and papllary plcaton or reposton. In the vast majorty of cases, annuloplasty must follow these maneuvers. Functonal cases are treated only wth annuloplasty. Early trcuspd annuloplastes conssted of plcaton of the annulus at the postero-septal level or Kay annuloplasty 2 or a double runnng suture along the base of the anteror and posteror leaflets as descrbed by Cabrol z and De Vega. 4' In 1968, the ntroducton of a prosthetc rng by Carpenter z dsplaced these technques, whch were shown to be unstable n the long run. The demonstraton by Tsakrs 6 of the contnuous changes n sze and shape of the normal trcuspd annulus stmulated our development of a completely flexble prosthetc rng that would follow and not nterfere wth these movements. 7 Operatve Teclnfques n Thoracc and Cardovascular Surgery, Vol 8, No 4 (November), 2003: pp

2 202 DURAN Left Trgone Des, Crc Left Anterc Anteror ",~ Leaflet / Septal ~> Leaflet ( Posteror Leaflet J Trcuspd Valve ~osteror Descendng Artery C s Osturn n,y,,t,,,~u,,= Posteror Descendng Ven ][ Anatomc relatonshps. Stuated at the base of the heart, the trcuspd valve s anchored to the rght fbrous trgone. Although the trcuspd valve has no anatomc fbrous annulus, surgcally, the lne of nserton of ts three leaflets on the ventrcular myocardum s tradtonally known as the trcuspd annulus. Although the base of the septal leaflet s anchored to the septum, the anteror and posteror leaflets are nserted nto the rght ventrcular free wall. Ths total lack of a fbrous annulus and close relatonshp wth the rght ventrcular myocardal basal band explans the nonhomogeneous pathologc dlaton of the annulus. In most cases of functonal regurgtaton, the base of the anteror and posteror leaflets enlarges more than the base of the septal leaflet. For ths reason, all avalable annuloplastes selectvely reduce ths area. The rght coronary artery runs parallel to the segment of the annulus correspondng to the rght ventrcular free wall. However, njury to the artery by the annuloplasty sutures s extremely rare. The area correspondng to the antero-septal commssure s very close to the noncoronary snus of the aortc valve. Ths has an mportant surgcal mplcaton because placement of the rng annuloplasty sutures at ths level can be dffcult f an aortc prosthetc valve s present. Because tears at ths level can be dffcult to repar, f a concomtant aortc valve surgery s planned, t s easer to place the trcuspd sutures before the aortc valve replacement. The coronary snus ostum s stuated above the postero-septal commssure. Because of ts consderable dstance from the conductng system (close to the rght trgone), t s safe to place purse-strng sutures around the snus orfce to hold a retrograde cardoplega caunnla.

3 DURAN ANNULOPLASTY OF THE TRICUSPID VALVE 203 Membranous septum Anteroseptal commssure Anteroposteror Posteroseptal ~ / commssure commssure \! /: IA I 9 I [~! _-'~~"--'-~X'~, ' Septa, ', d'! Anteror,, t~,~! ~)111 Posteror ~ " ~ leaflet _ ~1,., ~n~e ~ ; W[~;I ' 1/f//~ Septal Fan ~ X \ ~ I~,[ /ly band chordae N~\\, Free wall Free wall 2 Anatomy of the trcuspd valve. It s generally accepted that the trcuspd valve conssts of three very thn leaflets known as septal, anteror, and posteror, and these are separated by three clefts wth small commssural leaflets. These clefts do not extend to the so-called trcuspd annulus. Ths s an mportant surgcal pont n cases wth fused commssures: ther ncson should not extend all the way to the annulus because ths would destroy the commssural leaflets. The leaflets and commssural areas nsert nto the base of the septum and rght ventrcular free wall. Note that as n the mtral valve, the lne of leaflet nserton s not n a sngle plane. In fact, t s saddle-shaped, wth ts horn correspondng to the area of the antero-septal commssure. Ths anatomc fact advocates for the use of a flexble rng, whch adapts better to ths nonplanar annulus. The contactng system runs near the antero-septal commssure, close to the rght trgone. Ths s a danger area when performng annuloplasty because placement of deep sutures at ths level can result n an atroventrcular block. The septal leaflet s nserted nto the curved uppermost edge of the nterventrcular septum. Its anteror half s close to the membranous septum and, therefore, to the conducton system. The anteror leaflet s the largest and s separated from the septal leaflet by the antero-septal commssure. The free margns of the three leaflets are held by mostly- frst-order or margnal chords. At the level of the commssures, the margnal chords are very thn and fan out to the edge of the small commssural leaflets. These "fan" chords are crtcal from the surgeon's pont of vew because ncorrect sectonng when performng a commssurotomy can lead to nsuffcency. Chords nserted nto the ventrcular aspect of the leaflets (known as basal or second-order chords) are very thn and dffcult to dentfy through an atral approach. Although consderable attenton has been recently gven to the mtral basal chords, the possble functon of the trcuspd basal chords s stll unknown. Tertary chords (arsng from the ventrcular wall) are frequent. The chords orgnate from a varable number of papllary heads. Most often, a large septal band s present below the antero-septal commssure. Two or more free wall papllary muscles can be detected, whch hold the chords of the antero-posteror and postero-septal commssures and ther correspondng parts of the leaflets.

4 204 DURAN A Tour~~~ "~ Tape ' '. \,/1 l~ j 7,~ ' Rght atrotomy Cannulae Tape L \ L.,,a.e,/,." / Membranous ~/~"" \ B septum / Fossa ovals AV node quet Coronary retrograde snus cannula 3 Standard approach to the trcuspd valve. The trcuspd valve s usually approached through a medan sternotomy wth a vertcal ncson of the percardum medal to the rght phrenc nerve. Standard placement of aortc and bcaval cannulatons are used to establsh cardopulmonary bypass. The superor caval cannula s nserted through the rght appendage, and the nferor cannula s nserted through the lateral wall of the rght atrum close to the entrance of the nferor vena cava. Both cavae are snared wth tournquets, and the rght atrum s ncsed startng close to the appendage and drected toward the posteror aspect of the atrum between the rght nferor pulmonary ven and the nferor vena cava (A). Ths ncson mnmzes the problem when an accdental tear of the lower extremty of the ncson occurs by over-retracton. The tear wll extend nto the posteror wall of the atrum nstead of runnng toward the nferor vena cava. Ths standard approach can easly be performed through a rght thoracotomy. Because the standard atrotomy leaves a large rm of anteror rght atral wall, a retractor s needed to expose the valve. Although trcuspd annuloplasty can be easly performed n the beatng heart, most surgeons prefer an arrested heart. If retrograde cardoplega s to be used, the coronary snus s located above the postero-septal commssure and cannulated (B). To ensure maxmum dstrbuton of cardoplega to the whole heart, place a 4/0 polypropylene purse strng around the coronary ostum. After the retrograde cannula s n place, the purse strng s tghtened wth a tournquet, the balloon s nflated, and the catheter s pulled outwardly untl arrested by the purse strng.

5 DURAN ANN ULOPLASTY OF THE TRICUSPID VALVE 205 AortcCannu[a ~1 \\\ ~ Cardloplagla C~nnut~ B t 4[ Extended transatral approach. Trcuspd pathology often accompanes mtral dsease. In these cases, most surgeons approach both valves through separate ncsons. An alternatve s the use of the extended transatral septal ncson descrbed by Guraudon. a To facltate ths ncson, the caval cannulatons should be dfferent. Rght angle metallc cannulae are used. The superor s nserted nto the superor vena cava, and the nferor s nserted laterally and close to the entrance of the nferor vena cava nto the rght atrum. Both cannulae are dsplaced toward the surgeon. The rght appendage s pulled laterally, and a suture s placed on ts tp and ted to the percardal sac. The rght atral ncson s performed parallel to and as close as possble to the atroventrcular groove to avod damage to the snus node. In practce, a dstance of about 1 cm from the fat that hdes the atroventrcular juncton s safe (A). The ncson s contnued medal to the rght appendage to avod danmge to the snus node and stopped at the juncton of the rght and left atra. The coronary snus s cannulated, and the edges of the rght atrotomy are held medally wth pledgeted sutures. The fossa ovals s dentfed and ncsed vertcally. Its lower end termnates at the lower extremty of the fossa. Accdental prolongaton of the ncson at ths level s not dangerous because t opens nto the oblque snus of the percardal sac. Its upper extremty s contnued untl t jons the rght atrotomy and s prolonged along the roof the left atrum. Care must be taken to stay away from the aortc root, leavng approxmately 1 cm of atral tssue (B). Two pledgeted retractng sutures are placed: one n the fbrous tssue of the fossa and the other at the thck tssue of the juncton of both atra. Because of ts proxmty to the aorta, no retractng sutures should be placed on tle thn medal rm of the left atral roof. Practcally, no retractors are needed to expose both the mtral and trcuspd valves (C). Closure of the ncson s easy because of the excellent vew afforded by ths ncson. Although a hgher ncdence of junctonal rhythms occurs n the mmedate postoperatve perod, no rhythm dfferences have been found several months later. 9,1~

6 206 DURAN A Anteroseptal commssure ~ Septal ' ~ leaflet Anteror leaflet ~', l!~ Posteror leaflet 2 ~)}~E~ 7' Posteroseptal -., ~ commlssure Corona snus Fused, -.:~- ~ Fused commsure,,, z' <.,~ commsures B AVnode~ J Dlated annulus. ~>--.-..:: ~ I ~~'~'~'9>~\\ Outlne of the normal C Av node ~ / ~ szed annulus 5 Surgcal vew of the normal and pathologc trcuspd valve. A, The components of the normal trcuspd valve are shown. Note the locaton of the coronary snus, the AV node, and the area to avod when performng trcuspd surgery (danger zone). B, A stenotc trcuspd valve, whch s most often due to rheumatc dsease. Even small degrees of commssural fuson should be ncsed to ncrease leaflet moblty. Severe fusons should also be treated conservatvely followed by a sgnfcant annulus reducton wth a smaller rng. Although mperfect competence s to be expected, the results are superor to valve replacement. C, Functonal trcuspd regurgtaton. In most cases, the orfce dlaton s practcally lmted to the part of the annulus correspondng to the free wall of the rght ventrcle. Rng or open band trcuspd annuloplasty returns the dlated porton of the annulus to ts correct dmenson wthout reducng the septal area. However, n cases of dlated cardomyopathes, a rng s preferred to a band and s placed n both the mtral and the trcuspd valves to provde a constranng effect on the heart's base. Even very moderate degrees of trcuspd regurgtaton are treated n these cases.

7 DURAN ANNULOPLASTY OF THE TRICUSPID VALVE 207 ~ "t@ ~ ~ ~Cardoplaga Cannula / AV node "Danger" area 6 Placement of septal sutures. Septal sutures are passed frst, usng 2/0 double-armed, nonpledgeted, multflament sutures. Forceps are used to pull the leaflet forward toward the trcuspd orfce. Ths maneuver clearly exposes the lmt between leaflet tssue and the septal myocardum. It s easer to hold the needle backhand. The needle s passed through the base of the leaflet nto the ventrcle and out agan through the leaflet. The tp of the needle can be seen n the ventrcle through the very thn leaflet tssue. Ths maneuver completely avods damage to the AV node. The sutures are approxmately 3 to 4 mm wde and parallel to the base of the leaflet. Usually, three to four septal sutures are suffcent. A larger (+ 5 mm) suture s placed at each of the septal commssures. ~V Fosa ovals 7 Rng szng. All septal sutures (ncludng the two adjacent commssural sutures) are held together wth a mosquto. A Duran obturator must be used. The obturator s lowered onto the valve so that the less curved porton of the obturator s n contact wth the septal sutures and the engraved "T" faces the surgeon. The obturator s moved down the sutures. The two notches of the obturator should concde wth the two septal commssural sutures. In organc lesons where leaflet retracton predomnates over annulus dlaton, the area of the obturator should be smlar to the surface area of the anteror leaflet. The obturator that has a surface area most nearly matchng that of the anteror leaflet and notch spacng most nearly matchng the ntercommssural septal dstance ndcates the approprate rng sze. In general, f the mtral valve has been rnged or replaced, the sze of the trcuspd rng should always be larger than that of the mtral valve. et

8 208 DURAN Posteror and Anteror Leaflet Sutures Wde Septal Commssural Suture al "al Rng Sutul g Sutures AV N, 8 Placement of the septal sutures through the selected rng. The selected rng holder s brought to tle operatve feld. The holder s orented so that "T" for Trcuspd carl be read. The handle can be bent to the desred angle. Both arms of all septal sutures are passed equdstantly through the rng. Each arm of the sutures correspondng to the anteroseptal and postero-septal commssures should pass on ether sde of the two markers n the rng. An alternatve s to pass all the annulus sutures before brngng the rng nto the operatve feld. The septal sutures are then passed through the rng frst followed by the anteror and posteror annulus sutures. 9 Placement of the anteror and posteror annulus sutures through the rng. Whle pullng the correspondng leaflet toward the valve orfce wth forceps, the remanng 2/0 double-armed sutures are passed. The sutures are passed along the annulus wth large and farly deep btes approxmately 4 mm n wdth. Approxmately sx sutures are suffcent. M1 sutures along the annulus are passed equdstantly through the rng approxmately 2 mm n wdth. In ths fashon, the annulus s "gathered up," resultng n a reduced annulus confguraton. The rm of the rng holder has an nverted "L" shape. Ths forces the surgeon to pass the sutures oblquely from the mdpont of the lower aspect of the rng toward ts lateral aspect so that once ted, the knots lay away from the valve orfce. The thrd rng marker should correspond to the mdpont of all sutures (e, ths rng marker should not correspond to the antero-septal commssure).

9 DURAN ANNULOPLASTY OF THE TRICUSPID VALVE 209 I ~o (~Trm f/ / :ut Cut b [ 0 Duran flexble rng system. The Duran flexble rng system s desgned to 1) smplfy the passng of the annulus sutures through the rng; and 2) make the rng temporarly rgd whle the sutures are ted and the valve competence s tested. It conssts of the totally flexble rng anchored to a rgd rng holder held by a removable handle. The system s brought to the operatve feld, and the handle s bent to the desred angle to facltate the passng of the annulus sutures through the flexble rng (A). The system s then brought down to the trcuspd valve, and the handle s separated from the holder by cuttng ts retanng suture wth a scalpel (B, no. 1) and pulled away (B, no. 2). The rng holder s kept n place whle all sutures are ted (C, no. 1) and trmmed (C, no. 2). Because of the holder, the flexble rng s temporarly rgd durng ts mplantaton, whch avods ts plcaton when the sutures have been placed too far apart. Also, the test for valve competence should be done wth the holder n place to avod false regurgtatons due to dstorton of the annulus secondary to over-retracton on the atral wall. Contrary to mtral repar where full competence s requred, small resdual trcuspd jets can be accepted because a small trcuspd regurgtaton s far better than prosthetc replacement. The rng holder s then renmved by cuttng wth scalpel the four retanng sutures (D, nos. 1-4). Alter the Jholder s removed, the rng s completely flexble (E). In other words, durng the maneuvers of mplantaton and checkng for competence, the rng s rgd; after the holder s removed, the flexble rng s free to adapt to the contnuous changes n sze and shape of the trcuspd annulus.

10 210 DURAN ru~,a uv~.~.-..:onary Snus ][ ][ Duran rng n place. The Duran rng s held by approxmately 12 to 14 sutures. Three to four sutures hold the rng to the base of the septal leaflet. Both septal commssural sutures lay across the two rng markers. The thrd rng marker s not located at the level of the antero-posteror commssure but toward the base of the larger anteror leaflet.

11 DURAN ANNULOPLASTYOF THE TRICUSPID VALVE 21 ] ][ 2 Long-term flexblty of the Duran rng. The total flexblty of the Duran rng before mplantaton (A) s mantaned 10 years after mplantaton n the mtral poston (B). A recent echocardographc study of patents wth the Duran flexble rng mplanted for a mnmum of 6 years showed that t mantaned ts flexblty. 11 Dastolc and systolc three-dmensonal echo mages of the annulus clearly show ts changng nonplanar confguraton (C). D shows valve orfce area changes durng the cardac cycle 6 years after rng mplantaton.

12 2 12 DURAN A B 1! I Rng Sze: 33 Permeter: 99ram Band Sze: 33 Permeter: 99ram C~ Band Sze: 33 Incorrect Placement Permeter: >> 99ram D ~ Band Sze: 33 Progressve Permeter: Dlataton >> 99ram 13 Flexble rng vs. flexble band. Both the flexble rng (A) and the flexble band (B) ensure the desred annulus support and selectve reducton. The advantage of the band s that the surgeon can avod placng sutures along the base of the septal leaflet and, consequently, allevate the danger of nducng an AV block. However, care must be taken when mplantng a band to ensure that ts extremtes are correctly placed. For nstance, f a 33-mm rng or band s used, the fnal permeter of the orfce wll necessarly be 99 mm (A and B). If a band of the same sze (33 mm) s placed away from the septal commssures, the fnal permeter of the orfce wll be much larger (C). In cases of severe left and rght ventrcular dlaton, the nonprotected septal area wll also enlarge (D). A complete rng s safer. COMMENTS The ncdence of trcuspd dsease s closely related to that of rheumatc fever and s therefore prevalent n the developng world. In a 5-year perod n Saud Araba, 306 of 1298 valvular patents (23.6%) requred nterventon on the natve trcuspd valve. Ths rate rose to 27.7% among those wth rheumatc dsease, and to 31.8% f only the rheumatc mtral patents were consdered. The trcuspd dsease was "organc" n half of the patents, although 45% of them had a concomtant annulus dlaton. These data should alert the sur- geon when dealng wth rheumatc mtral patents. Also, awareness of the hgh ncdence of organc dsease should enhance the search for ts presence. Today, most trcuspd regurgtatons are secondary to schemc or dlated cardomyopathes. Ahhough mtral rng annuloplasty s regularly performed on these patents, the trcuspd s most often gnored. A preoperatve transthoracc echocardographc study that specfcally searches for trcuspd regurgtaton s mandatory. In these cases, a complete flexble rng should be used not only because the septal annulus s enlarged but also because of the constranng effect of a double annuloplasty on the base of the heart. A very smple trcuspd rng annuloplasty wll mprove the mmedate postoperatve course and the long-term well-beng of the patent. Acknowledgments I would lke to thank Peter Dolan for hs excellent llustratons and for patently sufferng the many changes mposed by my naccurate drafts. REFERENCES l. Prabhakar G, Kumar N, Gometza B, et al: Surgery for organc rheumatc dsease of the trcuspd valve. J Heart Valve Ds 2: , Kay JH, Masell-Campagna G, Tsuj IlK: Surgcal treatment of trcuspd nsuffcency. Ann Surg 162:53-58, Cabrol C: Annuloplaste valvulare: Un nouveau procede. Nouv Press Med I: , De Vega NG: La annuloplasta selectve, regulable y permanente. Rev Esp Cardol 25: , Carpenter A, Deloche A, Dauptan J, et al: A new reconstructve operaton for correcton of uftral and trcuspd valve dsease. J Thorae Cardovasc Surg 61:1-13, Tsakrs AG, Mar DD, Sek S, et al: Moton of the trcuspd valve annulus n anesthetzed ntact dogs. Crculaton Res 36:43-48, Duran CG, Ubago JL: Clncal and hemodynamc performance of a totally flexble prosthetc rng for atroventrcular valve reconstructon. Ann Thorac Surg 22: , Guraudou GM, Ofesh AG, Kaushk R: Extended vertcal transatral septal approach to the mtral valve. Ann Thorac Surg 52: , Kulnar N, Saad E, Prabakhar G, et al: Extended transeptal versus conventonal atrotomy: Early postoperatve study. Ann Thorac Surg 60: , Smth CREffcacy and safety of the superor-septal approach to the mtral valve [Edtoral]. Ann Thorac Surg 55: , Okada Y, Nasu M, Kawa J, et al: Flexblty of the mtral annulus wth the Duran rng at 6 years post-mplantaton. J Heart Valve Ds 11:32-38, 2002 From the Internatonal Heart Insttute of Montana at Sant Patrck Hosptal, Mssoula, Montana and The Unversty of Montana, Mssoula, Montana. Address reprnt requests to Carlos M. G. Duran, MD, PhD, The Internatonal Heart Insttute of Montana, 554 West Broadway, Mssoula, MT 59802; e-mal: duran@santpatrck.org Elsever Inc. All rghts reserved /03/ /0 do: /s (03)