Extended trans-septal Our early experience

approach for mitral valve surgery:

Sundar Ramanathan, M.Ch., Shashi Kumar Varma, M.Ch., Kolli M a d h u s u d a n a Rao, M.Ch., Srinivasan Mural idharan, M.Ch. LRG Naidu Institute of Cardiology & Cardiothoracic Surgery, G Kuppuswamy Naidu Memorial Hospital, Coimbatore

Abstract

Background: Extended trans septal (ETS) approach for mitral valve surgery often divides the artery to the Sino-Atrial node. The clinical implication of this is contentious. We analyzed our early results with ETS approach.

Methods: Between June 1998 and September 2003 eleven patients underwent mitral valve surgery by ETS approach. Six were females. Age ranged from 19 years to 67 years (median 40 years). Six underwent mitral valve replacement (MVR). Four underwent aortic and mitral (double) valve replacement (DVR). One had mitral valve repair. Three had additional procedures (tricuspid valve repair =1, Coronary artery bypass=l, Aorto bifemoral graft =1). Cardiopulmonary bypass ranged from 64 minutes to 77 minutes (median 72 minutes) for MVR and 112 minutes to 178 minutes (median 140 minutes) for DVR. Aortic cross clamp times ranged from 39 minutes to 52 minutes (median 47 minutes) for MVR and 74 minutes to 120 minutes (median 95 minutes) for DVR.

Results: There was no mortality or morbidity attributed to the ETS approach. One early death in emergency DVR was due to heart failure. Three patients needed sequential pacing in the immediate post-operative period. Nine out of ten survivors were back to their preoperative rhythms on hospital discharge (6 sinus rhythm; 3 atrial fibrillation). One patient with preoperative trifascicular block who underwent reoperation to fix a paravalvular mitral leak needed a permanent pacemaker (VV1). The follow-up ranged from 1 month to 64 months (median 6 months) and is 100% complete. There was no late death or new arrhythmia.

Conclusions: Extended trans septal approach is safe. It gives excellent exposure of the mitral valve. Division of the sinus node artery is not deleterious in the short to intermediate term. (IndJ Thorac Cardiovasc Surg, 2004; 20: 164-167)

Key words: Valve replacement, Cardiopulmonary bypass, Arrhythmia

Introduction

Optimal surgical exposure is a pre requisite for successful mitral valve surgery. Surgical exposure of the mitral valve can be difficult in those with small left atrium, deep seated left atrium and in re operations. The very fact there are numerous surgical approaches described in the literature indicates there is no single

"ideal" approach. Extended trans septal (ETS) approach consistently gives excellent exposure of the mitral valve. The incision often divides the artery to the Sino atrial node (SA Node). The clinical implication of dividing the SA node artery is contentious. We have selectively used ETS approach since 1998. This is an analysis of our early experience with ETS approach.

Presented at the 50th Annual Meeting of IACTS, New Delhi, Feb. 2004.

Address for con'espondence: Dr. Sundar Ramanathan MCh FRCS Consultant Cardiothoracic Surgeon G Kuppuswamy Naidu Memorial Hospital Coimbatore 641037 Phone: (0422) 2211000, 2213501 Ext: 5530 Fax: (0422) 2213509 @IJTCVS 097091342041204/042

Received 23/02/04; Review Completed 13/07/04; Accepted 01/09/04.

Patients and Methods

Selection of patients Between June 1998 and September 2003 we

performed a total of 366 mitral valve replacements (MVR) and 116 aortic and mitral valve (double) valve replacements (DVR) in our Institution. Whenever we expected difficulty in visualizing the mitral valve because of small left atrium or deep seated left atrium and in a difficult reoperation, we have selectively used ETS approach. The decision to use ETS approach was

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IJTCVS Ramanthan et al 165 2004; 20:164 167 Trans septal approach

not premedi ta ted and was decided on the operat ing table . D u r i n g this t ime p e r i o d e l e v e n p a t i e n t s underwent mitral valve surgery by ETS approach. There were six females and five males. Age ranged from 19 years to 67 years median 40 years).

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Fig. 1. Surgical approach.

ETS a p p r o a c h has been d e s c r i b e d in de ta i l by G u i r a u d o n GM et al 1. Af te r m e d i a n s t e r n o t o m y , c a r d i o p u l m o n a r y bypass is es tabl ished wi th aorto bicaval cannulation and caval tapes. We've found direct Superior vena caval cannulation with metal t ipped right angled cannula very useful in this approach. After aortic cross clamp and cardioplegic arrest, the Right Atr ium (RA) is opened parallel to the atrioventricular groove. An alternative is to make the RA incision wi thout aortic clamp, but with both the caval tapes snared, and then cross clamp the aorta. The next step is to incise the Inter Atrial Septum (IAS) along the fossa ovalis vertically. Now the RA incision and the IAS incision are extended cephalad to meet each other at the Left Atrial (LA) roof between the Superior vena cava (SVC) and the aortic root. Care is taken to keep this incision away from the aortic valve. The incision is further extended along the roof of LA towards the base of the LA appendage. A couple of traction sutures placed at the junction of RA, IAS and LA on either side of the incision fixed to the drapes or the sternal retractor gives excellent exposure of the mitral valve. There is no need for any special

retractors. Often there is no need for any hand held retraction unlike the conventional LA incision parallel to the inter atrial groove. At the end of the mitral valve procedure, the LA and IAS are closed in two layers of 3 /0 mono filament suture (Polypropylene) and the RA is repaired with 4 /0 mono filament suture. If significant aort ic c lamp t ime has e lapsed, one can repa i r the tricuspid valve and close the RA with the aortic cross clamp released after adequately de airing the left heart. Retrograde cardioplegia if used can be unde r direct vision through the coronary sinus.

SuIgical procedures Six patients underwent MVR and four underwent

DVR. One underwent mitral valve repair. Three patients needed additional procedures (DeVega's tricuspid annuloplasty 1, coronary artery bypass graft 1, aorto bifemoral graft for chronic aorto iliac occlusion 1). For MVR the median Cardio Pulmonary Bypass (CPB) time was 72 minutes ( range 64 to 77 minutes) and the median Aortic Cross Clamp (ACC) time was 47 minutes ( range 39 to 52 minutes). For DVR the median CPB time was 140 minutes (range 112 to 178 minutes) and the med ian ACC time was 95 minutes (range 74 to 120 minutes).

R e s u l t s

There was one early death clue to cardiac failure following DVR in a patient who was on mechanical ventilator for pu lmonary edema preoperatively. This was unrelated to the ETS approach. The ten remaining patients all survived the operation and were discharged home between 8 to 16 days postoperat ively (median 10 days). On follow up ranging from 1 month to 64 months (median 6 months) there were no late deaths or new arrhythmia. The follow up is 100% complete.

A n h y t h m i a

Pre operatively seven patients were in Sinus rhythm, three in atrial fibrillation and one in trifascicular block. In the immediate post bypass period five remained in sinus rhythm. However four were in junctional rhythm and two in complete Atrio ventdcular (AV) dissociation. During this period, AV sequential pacing was needed in three patients and atrial pacing needed in one. At the t ime of discharge from the Hospital nine out of ten survivors were back to their pre operative rhythms (6 in Sinus rhy thm and 3 Atrial fibrillation). The lone patient with pre operative trifascicular block underwent re o p e r a t i o n to r ep a i r mi t r a l p a r a v a l v u l a r leak fo l lowing DVR. He had ex tens ive mi t ra l a n n u l a r

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166 Ramantban et al IJTCVS Trans septal approach 2004; 20:164 167

calc i f icat ion. He e v e n t u a l l y n e e d e d a p e r m a n e n t pacemaker (VV]) 2 weeks following surgery.

Bleeding and re exploration The m e d i a s t i n a l d r a inage in the first 24 h o u r s

following MVR was between 170 ml to 430 ml (median 190 ml). The drainage for DVR ranged from 540 ml to 1300 ml (median 700 ml). The only patient in this group who had re operation for mitral para valvular leak was re explored for excess mediastinal drainge. There was diffuse ooze with no obvious surgical bleeder.

Discussion

There are numerous surgical approaches to the mitral valve described in literature 2. Guiraudon ~ first described the ETS approach in 1991. Based on morphologic s tudy of coronary artery supply to the Sino atrial node, it has been predicted ETS approach will divide the SA node artery in 54% of patients 3. Following ETS the incidence of t rans ien t junc t iona l r h y t h m is 10% for those in preoperat ive atrial fibrillation and 32% in those with preoperat ive sinus rhythm 4. Though the incidence of transient junctional rhythm may be as high as to 38 % in some series 5 the need for permanent pacemaker is ve ry r a r e Post opera t ive e lec t rocard iographic and e l e c t r o p h y s i o l o g i c s t u d i e s have c o n f i r m e d we l l mainta ined Sinus node function after ETS approach more than one year after operat ion 6. Comparis ion of three different approaches to the mitral valve viz, trans septal, extended trans septal and left atrial approaches has not shown any significant difference between these three groups in maintenance of Sinus rhythm in the mid term follow up 7. Hence when one anticipates a difficult exposure of the mitral valve, it is useful to be familiar w i t h ETS a p p r o a c h . H o w e v e r the p o s s i b i l i t y of postoperative junctional rhythm, even though transient in mos t ins tances , w a r r a n t s rou t ine p l a c e m e n t of epicardial temporary pacing wires. The additional time

n e e d e d to repai r the LA roof and IAS incisions is compensated by the time saved in mitral valve surgery, due to the excellent exposure afforded by ETS approach.

Conclusions

Extended Trans septal approach is safe. It gives excellent exposure of the mitral valve. Division of Sinus node artery may necessitate temporary epicardial pacing in the immediate post bypass period. However there are no deleterious effects in the medium term. Majority of patients regain their preoperative rhythm by the time of discharge fi'om the Hospital. Long term effects of the division of Sinus node artery await further studies.

Acknowledgements

We wish to a c k n o w l e d g e wi th thanks the he lp rendered by the Medical records depar tment of GKNM Hospital for retrieving the case records and Mr Sriram for the illustration of the surgical approach.

References

1. Guiraudon MG, Ofiesh JG, Kaushik R. Extended vertical transatrial septal approach to the mitral valve. Ann Thor Stag 1991; 52:1058 62.

2. Balasundaram SG, Duran C. Surgical approaches to the mitral valve. ] Cardiac Surg 1990; 5:163 69.

3. Bredajs D, Patonay L, Turina MI. The clinical anatomy of the sinus node artery. Ann Tborac Stag 2003; 76:732 35.

4. Masielo P, Triumbari F, Leone R, Itri F, DelNegro G, Di Benedetto G. Extended vertical transseptal approach versus conventional left atriotomy for mitral valve surgery. ] Heart Valve Dis 1999; 8: 440 44.

5. Kumar N, Saad E, Prabakhar G, De Vol E, Dinan CMG. Extended transseptal versus conventional left atriotomy: Early postoperative study. Ann Thor Surg 1995; 60:426 30.

6. Takeshita M, Furuse A, Kotsuka Y, Kubota H. Sinus node function after mitral valve surgery via the transseptal superior approach. EurJ Cardiothorac Surg 1997; 12:341 44.

7. Tenpaku H, Wariishi S, Kanemitsu N Okabe M, Nakamura T. ]pn ] Tborac Cardiovasc Surg 2000; 48:688 92.

Editor's Note:

The old adage "Hundred ways to skin a cat" is aptly applicable to approaches for" the mitral valve. It can be approached through a (1) s tandard incision behind the right AV groove (2) via the interatrial septum (3) via the roof of the LA (4) via an incision that divides the IA s e p t u m in the h o r i z o n t a l p lane (5) the G u i r a d o n approach (6) through the aorta (7) through the roof after transection of aorta (8) through the left atrial appendage (9) t h r o u g h the left v e n t r i c l e and by (10) au to

t ransplanta t ion (bench surgery) of the heart. Every surgeon must choose the one most appropriate for the patient and for the surgery. However an approach that is potentially time consuming, hazardous or associated with complications is best avoided. Nature has provided the SA nodal artery with a purpose. If it was redundant it would not be there. Guiradon's original article in 1991 used this technique in a smalll number of patients with a high early mortality and morbidity 1'2. The above article

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