A simple approach to a new technique for correction of posterior mitral leaflet prolapse
*Farouk M. Oueida, MD , ** Ibrahim M. Yassin, MD, ***Mustafa Al Refaei, MD, and * Khaled A. Eskander, MD
*SAUD AL-BABTIN CARDIAC CENTER(SBCC), CARDIAC SURGERY DEPARTMENT (AL-DAMMAM, KSA)
** CARDIO-THORACIC SURGERY DEPARTMENT ,TANTA UNIVERSITY HOSPITALS(EGYPT)
*** SAUD AL-BABTIN CARDIAC CENTER(SBCC), CARDIOLOGY DEPARTMENT (AL-DAMMAM, KSA)
Techniques that did not imply resection of any posterior leaflet (PL) scallop, or part of it during Mitral Valve Repair, were described by different authors for correction of PL prolapse [1-5].
In 2010, Calafiore et al.,  reported a comparison between resection and not resecting techniques, showing similar results in both groups. At this time, and for four years now, Calafiore  started one of his pioneer techniques in this field, The U-Technique via median sternotomy, with excellent mid-term results.
Some have expressed concern, however, that minimal invasive (MI) techniques may lead to inferior results for mitral valve (MV) surgery.
We present here the surgical technique with some modifications, our initial short and mid-term results and to examine the feasibility, safety and effectiveness of minimal invasive MV repair in patients with mitral regurgitation (MR) mainly due to PL prolapse.
From March 2012 to March 2015 in (SBCC), KSA, Fifteen patients with a main MV pathology of PL prolapse underwent (MI) (MV) repair via a 5-7 cm right antero-lateral thoracotomy with peripheral cannulation and external aortic clamping.
Candidates for minimally invasive Mitral Valve (MV) repair are:
Patients did not undergo minimal invasive MV surgery if they had a history of prior right-sided thoracotomy, if they required urgent surgery, Overweight of more than 130%, chronic obstructive lung disease and impaired renal function were further exclusion criteria. Patients with severe adhesions of the right pleura, small femoral vessels, or paralysis of the right diaphragm should be excluded from any minimally invasive surgical technique for the treatment of mitral valve disease. Patients who require concomitant coronary bypass or surgery on the aortic valve or ascending aorta are not candidates for a minimally invasive approach. Preoperative patient evaluation included trans-esophageal echocardiography and Doppler sonography in order to exclude major aortic valve incompetence and severe peripheral vascular disease.
Mean age, Female/Male, left ventricular ejection fraction and NYHA class were 28 ± 11 years, 2/1, 44 ± 7% and 3.1 ± 0.8. The mean preoperative MR grade was 2.9± 0.8. The primary cause of MR was myxomatous disease in the majority of patients. Concomitant procedures (Tricuspid valve repair in 6 cases (40%) and AF ablation in other 3 patients (20%).
Main finding of this technique is that PL prolapse (A) can be corrected only by annular over-reduction associated to scallop suturing between p1&p2 (C1-3)and between p2&p3(C4-5), and if necessary to longitudinal plication of the scallops to make uniform their height 9 cases (60%)(B). 3-D rings were implanted in all of the 15 cases (100%)(D).
In all patients studied, anaesthesia was induced with Fentanyl (5-10mcg/kg) propofol (2.0 to 2.5mg/Kg) and muscle relaxation with atracurium (0.5 mg/Kg). Ventilation was controlled with oxygen in air (50%). Anaesthesia was maintained with continuous infusion of propofol (1-2mg/Kg/h) and fentanyl (1-2mcg/kg/h) and atracurium (0.5mg/kg/h.) Then a double lumen tube was used in order to allow left sided single lung ventilation. A Swan-Ganz introduction sheath and catheter was placed into the right internal jugular vein for using it as usual at the beginning of the operation to assess the cardiac study and in addition here, the sheath been used to drain the superior vena cava during bypass time.
Using trans-esophageal echo-cardiography (TEE) is a routine as in all valve surgery. External defibrillation pads as a routine also in all mini-invasive procedures. In supine position the right shoulder and the right arm were elevated 30 degree.
The patient was draped with the right chest wall accessible as well as the sternum, in case the patient needed to be converted to median sternotomy. Both groins were prepared for surgical access. The femoral vessels were dissected for arterial and venous cannulation. Cardiopulmonary bypass (CPB) was instituted via femoral arterial and venous cannulation through a 3-4 cm transverse incision in the right groin.
A right lateral mini-thoracotomy, 5-7 cm in length, was performed in the 4th intercostal space Fig1. A small thoracic and soft tissue retractor was utilized. The pericardium was opened longitudinally anterior to the phrenic nerve and stay sutures were put thus gaining access to the heart. After systemic heparinization femoral vessels were cannulated for institution of the cardiopulmonary bypass. In those patients requiring concomitant additional venous canula when insufficient venous drainage to the CPB, It can be inserted through the mini-thoracotomy without interruption of the field. When adequate venous drainage is achieved, both superior and inferior venae cavae are snared and aorta is cross clamped. A trans-thoracic aortic cross-clamp was inserted through a 5 mm incision in the 3rd intercostal .
In all patients, Custadiol cardioplegia was applied via the aortic root immediately after aortic cross-clamping. Trans-septal approach is our routine access to the mitral valve, the mitral valve was inspected and repaired using the U-Technique strategy. 
This goal was achieved through: (1) making the height of the scallops uniform by modification of posterior leaflet height with longitudinal plication if needed. Once the height is similar, (2) all scallops are sutured together (4-0 Prolene) to change the PL from a multi-scalloped to a single scalloped leaflet aiming to prevent excess leaflet motion at the level where chordal elongation is more pronounced and to limit total PL movement to the portion with a lower degree of chordal elongation . If the prolapse involves all scallops, suturing allows us to consider the PL as a whole and not composed of different segments, independently of any prolapse grade. Scallops are identified by the indentations, which sometimes can be less evident, because they can be of different length. In patients with chordal rupture, the donor scallop (i.e. the scallop with normal or elongated chordae close to the one with ruptured chordae) is positioned below the receiving scallop (the scallop with ruptured chordae) to support it. The rim of the receiving scallop is then sutured to the body of the donor scallop. It is worth noting that the portion of a scallop without chordae will not cause leaflet prolapse, and thus MR, if it is 10 mm or less, Lastly, and essentially in all cases (3) annular over-reduction, the MV annulus is reshaped using Medtronic 3D® Ring annuloplasty which preserves its physiologic "Saddle" shape. The PL then remains fixed in the vertical position and becomes a buttress for the anterior leaflet (AL). Anatomic systolic anterior motion (SAM) of the AL cannot occur because the 2 leaflets meet at the extremity of the mitral area. 
Anterior leaflet prolapse or rupture: In patients with associated AL prolapse, 2 or more artificial chordae are used. Any deviant cusp, if present, is sutured with the main body of the leaflet. Chordal re-implantation was carried out for anterior leaflet prolapse or rupture in 6 cases (40%).
Tricuspid regurgitation: Correction of moderate or greater tricuspid regurgitation was performed in all patients using the Sorin Band caliber 50mm for ring annuloplasty, if present, whereas correction of mild tricuspid regurge was performed only in patients with annular enlargement. It was successfully done in 6 cases (40%).
Atrial fibrillation (AF): Radiofrequency ablation was done for patients with chronic, paroxysmal AF in the usual manner using the radiofrequency system from Medtronic (Cardioblate® Gemini® Surgical Ablation Device) it was successfully done in 3 cases (20%).
The septum and the right atrium was closed with a continuous 4/0 Prolene suture. Ante-grade de-airing was made by active suction through the aortic vent, and trans-mitral LV vent through the right superior pulmonary vein was also used for de-airing. Intra-operative valvular function was monitored by TEE in all cases. After re-warming the patients were weaned from cardiopulmonary bypass, arterial and venous canula were removed and heparin was antagonized with Protamin. After hem-stasis both lungs were ventilated. Two chest tubes were placed Temporary pace maker wires were placed and both incisions were closed in layers. The valve function was monitored postoperatively by TEE in all cases during the first 3 months follow-up and then by TTE.
All procedures were successfully completely done, no any major complication like aortic dissection or major bleeding necessitating conversion to median sternotomy
All cases performed with highly accepted echo-cardio graphic results, no/mild residual mitral regurgitation (MR), Mean pressure gradient (MPG) = 2.3 ± 1.1 intra-operatively. No systolic anterior motion (SAM). Fig2
Mean aortic cross-clamp and cardiopulmonary bypass times were 108 ± 23 and 141 ± 31 min. respectively.
Hospital mortality was (0%), Only one case was re-explored for bleeding.
At a mean follow-up of 6±8.2 months. All patients are alive with preserved left ventricular function (LVEF) (47 ± 6% postoperatively vs. 44 ± 7% preoperatively) and a freedom from ≥2+ degree of MR of 100% at the latest echo-cardio graphic evaluation. Follow up was 100% complete.
Acknowledgments: Many thanks to prof. Calafiore for his continuous advices and possible reproducibility of his novel technique
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