Indications and Results of Repair of the Rhumatismal Valve in Children in Senegal concerning 63 Cases

In Africa, acute rheumatic fever is endemic. Cardiac involvement is one of the most common complications in the form of valvular heart disease representing all damages to the heart valves. It is in this perspective that we realized this study whose general objective was to evaluate the results of mitral repair surgery in children in Senegal and the specific objective was to state the indications for mitral repair surgery and assess the results in terms of morbidity and mortality. This is a retrospective and analytical monocentric study, in the thoracic and cardiovascular surgery department of FANN National University Hospital Center in Dakar. It took place over a period of 30 months. All the patients who underwent mitral surgery, aged less than 18 years were included. The total number of patients was 63, including 39 girls and 24 boys, a sex ratio of 0.62. The average age at the time of the surgery was 12 years old [5 -17]. The functional symptomatology was dominated by the dyspnea found in all the patients. Cardiac ultrasound was diagnosed with mitral regurgitation in all patients. For all surgical procedures, the approach was a vertical midline sternotomy. The mitral valve was approached by left atriotomy in 40 patients (63.5%) and by transseptal way in 23 patients. All double mitral and an aortic valve replacement associated with a tricuspid repair and in 4 cases a perfection of their mitral repair. Early and late surgical mortality was zero. The average follow-up time for our patients was 9 months [1 - 26]. During their follow-up, the evolution was favorable in 89% of patients who no longer had any functional symptoms.


Introduction
In Africa, acute rheumatic fever is endemic. Cardiac involvement is one of the most common complications in the form of valvular heart disease representing all damages to the heart valves [1]. In Senegal, rheumatic heart disease represents the second nosological group of cardiovascular pathology in a hospital setting immediately after high blood pressure [2]. The mitral valve is the most frequently affected [3]. Damage to the mitral valve can result in mitral stenosis, mitral insufficiency or a combination of bothleading to mitral disease [4]. Conservative valve surgery, among others, retains precise indications and has significant advantages especially in children. Valve repair techniques have seen major advances in the last few decades [1]. They require a perfect knowledge of valve damage mechanism.

Objectives
The main objective was to assess the results of mitral repair in children in Senegal. The specific objective was to clarify the indications for mitral repair surgery and assess the results in terms of morbidity and mortality.

Materials and Methods
We report a retrospective and analytical monocentric study, in the thoracic and cardiovascular surgery service of FANN National University Hospital Center in Dakar. It covers a period of 30 months or 2 and a half years. All patients who underwent mitral valve repair, aged less than 18 and whose records were complete, were included in the study.

Procedure
The

Results
The study included 63 patients who underwent mitral valve repair surgery over a period of two and a half years. It includes 39 girls and 24 boys, a sex ratio of 0.62. The average age at the time of the intervention was 12 years old [5]- [17]. The functional symptomatology was dominated by the dyspnea found in all patients. Only one patient (1.6%) had NYHA stage 1 dyspnea; 23 patients (36.5%) had stage 2 dyspnea; 35 patients (55.6%) stage 3 and 4 patients or (6.3%) dyspnea stage 4. Thirty-two patients or 51% had a history of recurrent angina, 29 patients or 46% had polyarthralgia and 39 patients or 62% had at least one episode of cardiac decompensation. The physical examination showed a murmur of mitral valve insufficiency in all patients (Table 1). On the chest X-ray, 54 patients (86%) had cardiomegaly. Signs of pulmonary hypertension were found in 60 patients (95%). A complete arrhythmia by atrial fibrillation was found in 13 patients (21%). Atrioventricular block was found in 2 patients (3%). Cardiac ultrasound was diagnosed with mitral regurgitation in all patients with a breakdown by mitral insufficiency grade as follows: Grade 1:1 patient (1.6%); Grade 2:3 patients (4.7%); Grade 3:20 patients (31.7%); Grade 4:39 patients (62%). Mitral valve prolapse was present in 57 patients (90%); restriction of the posterior valve in 58 patients (92%). The fusion of commissures was found in 6 patients (9.5%). The subvalvular apparatus was affected in 54 patients (86%). The mitral ring was dilated in 53 patients (84%). In 50 of our patients there was a tricuspid insufficiency (79%) and in 26 patients (41%) an aortic insufficiency ( Table 2).

Discussion
In the series, we note a female predominance with a sex ratio of 0.62 as in the literature [5] [6] [7]. The relatively young average age of the patients is related to the prevalence of rheumatic disease in developing countries but also to the youth of African population. Most of the series from underdeveloped countries report a similar age, namely a more frequent attack of subjects of school age [3] [5] [7]. Among the 20 million rheumatic heart diseases listed worldwide and the 500,000 deaths attributed to them, 95% occurs in underdeveloped or developing countries. Sub-Saharan Africa is believed to be responsible for half of the cases on the continent [8]. Thus, valve disease occurs in a relatively young population, unlike the series in developed countries where the elderly predominates. In our study population, the etiology is infectious. Our region is a rheumatic endemic area. Before their admission, the majority of patients (55.6%) had stage 3 dyspnea as in most studies [5] [9] and 62% of them had at least one episode of cardiac decompensation. This confirms a fairly advanced course of the disease before diagnosis and/or management. Cardiac ultrasound is the examination we chose to confirm the diagnosis of mitral valve disease and establish a therapeutic strategy. It assesses the severity of the lesions, the mechanism of leak, the valve surfaces, the state of the subvalvular apparatus, the impact on the heart chambers, pulmonary pressures and cardiac function. In rheumatic disorders, the valve morphology is generally typical with a pseudoprolapse of the anterior leaflet in its different segments A1, A2, or A3; annular dilation, restriction of the posterior valve and shortening and fusion of the valvular apparatus are frequently found as a mechanism for mitral regurgitation [8]. Involvement of the subvalvular apparatus is manifested by fusion of chordae, shortening and/or thickening of the pillars and chordaes [10]. We found these typical lesions in our patients, at various stages. All had a rheumatic valve morphology. The dilation of the left cavities is frequent (84%). We have a high frequency of pulmonary arterial hypertension. The mitral valve is exposed by left atriotomy in 63.5% of cases and by transseptal way in 36.5% in cases where the left atrium was not very dilated. After careful examinations of the lesions, we found in most cases a mitral insufficiency by prolapse of the A2 segment of the large valve (92%) and a restriction of the posterior valve. These proportions are often found in rheumatic disorders [11] [12] [13]. This prolapse of the anterior valve is due to a rupture or elongation of chordae. During the repair of the mitral valve, we proceed to an enlargement of the posterior valve in the majority of cases (47%) according to the technique of Carpentier [4]. Surgical techniques also included the insertion of a mitral ring (54%) which makes it possible to reduce the size of the native ring and thus participates in the prevention of secondary dilation [10], the transfer of chordae (38%), the insertion of neochorade (15.2%), the closure of indentations (25.3%). These corrections are completed by a commissurotomy in the event of a commissure fusion. Similar proportions are found in the literature [14]. We report a higher frequency of aortic valve repair (14.2%) than aortic valve replacement (4.8%). There has been renewed interest in aortic plastic techniques for some time. This is linked to the fact that the morbidity linked to valvular prostheses is not negligible [15] and that the aortic plasty avoids the disadvantages of the implantation of prosthetic material in the young population (risk of early degeneration of bioprostheses, complications of anticoagulants oral, endocarditis) whose expectation and quality of life must be considered in the choice of therapeutic modalities [16]. Tricuspid valve surgery is performed as soon as tricuspid insufficiency is rated as average. Tricuspid insufficiencies have been demonstrated as a factor of poor prognosis with high morbidity and mortality in patients operated for valvulopathy of the left heart [17]. Valvular involvement is more functional than organic. The purpose of the repair is to preserve the right ventricular function. Among the 31 patients who underwent tricuspid plasty, the majority of plasties were performed using the DeVega technique (9 patients) and Carpentier (9 patients). The plasty technique according to De Vega has advantages related to the absence of foreign material, therefore a very low economic cost and a shortened operating time. Conversely, Carpentier ring annuloplasty requires the installation of a ring. The results of the two techniques are satisfactory and can be superposed in the short and medium term, however the plasty with Carpentier ring presents better long-term results [17]. Post-surgery complications are hemodynamic, pulmonary, infectious. There are also rhythm and conduction disturbances. We observe hemodynamic complications in 23.8% of cases. Patients with ventricular dysfunction received inotropic and tonicardiac support. In the event of a pulmonary arterial hypertension crisis, we combine milrinone continuously with a relay with sildenafil. The evolution is generally favorable. Conduction disorders after cardiac surgery are quite frequent with an incidence between 1.2% and 7% depending on the series [9] [16] [18]. In this series, they are 6.3% and are transient. Respiratory complications including pneumonitis and pleural effusions had a rate of 14.3% supported by the results of the series of Bakkali [9] and Talwar [18] however other series such as that of Gos [19] and Duran [16] found a much lower rate. The 8 repeat operations concern the mitral valve with 4 replacements of the mitral valve by a mechanical valve and 4 corrections of the mitral plasty. Surgery mortality in our series is zero as in most series where this mortality is low [5] [9] [16] [18] [20]. However, there are differences in terms of medium-term results; this is strongly linked to the experience of the surgical team in mitral repair [15]. The best immediate results are reported by Gos [19] in 200 patients. That said, the results obtained in our series are very promising.