Object

Title: The results of percutaneous balloon valvuloplasty in the treatment of pulmonary valve stenosis in children

Abstract:

Isolated pulmonary valve stenosis (PVS) is encountered in approximately 0.33/1000 live births and accounts for approximately 6-9% of congenital heart defects. The mechanism underlying the abnormality may be commissural fusion or dysplasia of pulmonary valve leaflets (in 10 % of patients). Pulmonary valve stenosis is often found in Noonan’s, LEOPARD, or Allagil syndrome. The form of the stenosis may be a decisive factor in selecting surgical/intervention treatment. Since the first report on percutaneous balloon valvuloplasty (BVP) published by Kan et al. in 1982, this is the method of choice in the management of patients (pts) with pulmonary valve stenosis (PVS) of moderate to severe degree. In spite of the fact that BVP has been employed for the past 25 years, interest continues to focus on immediate and long-term results depending on the degree of PVS, age of patients and the employed technique. The subject of the present investigation – in addition to reduction of gradient across PVS – is normalization of hemodynamic disturbances, the incidence of recurrent stenosis and various complications, as well as monitoring the development of children subjected to therapy. Objective: to assess the results of BVP in subsequent patients with PVS (excluding newborns with critical PVS) treated in Department of Pediatric Cardiology, Collegium Medicum, Jagiellonian University, in the years ; 1988-2004, in relation to: 1. type of valvular lesions and degree of stenosis, 2. age of patients subjected to BVP and such technical aspects of the procedure as: a. balloon diameter and its ratio to the valve annulus, b. types of balloon catheters employed, c. the need for employing double balloon technique, 3. restrictions in employing the method resulting from the types of valvular morphological lesions, 4. immediate BVP results, including: a. reduction of pressure gradient across the pulmonary valve, b. development of valve insufficiency, c. development of other procedure-associated complications, 5. early and late results, including: a. recurrent stenosis, b. significant (>IIo ) pulmonary valve insufficiency, c. the need for re-intervention, d. assessment of physical development of patients and their physical efficiency (NYHA classification). Material: 137 (76 M+61 F) children, aged between 1 month and 16.3 years of life (x=5.3 ±4.8) with isolated PVS diagnosed by physical examination, ECG, chest X-ray, comprehensive echocardiography and detailed hemodynamic and angiocardiographic assessment. They were qualified to BPV between 28.03.1988-31.12.2004, based on echo studies (Doppler gradient > 25 mmHg). Newborns with critical PVS were excluded from the study. Three patients with PVS had been previously subjected to a surgical valvulotomy (when 1 month, ; 2 and 2.5 years old, respectively) and BPV was recommended due to recurrent stenosis (after 4 and 8 years postoperatively, respectively). One patient with coarctation of the aorta and PVS had undergone a Waldhausen operation when 2 weeks old, and was qualified to BPV when 14 months old. Methods: During BPV, the following parameters were analyzed: the type of PVS, the degree of stenosis and right ventricular load (assessment of systolic, end-diastolic right ventricular pressure, pulmonary systolic pressure, pressure gradient across PVS), the balloon diameter and its ratio to annulus diameter, the type of balloon catheter, and the need for double balloon technique employment. Immediately after BPV, the analysis included a decrease of gradient across PVS, a decrease of right ventricular end-diastolic pressure, changes of pulmonary systolic pressure, development/intensification of subventricular PVS, development of valve insufficiency and development of complications. A successful procedure was defined as one resulting in at least 50% decrease of pressure gradient across PVS. The patients were divided into three groups, depending on their right ventricular systolic pressure (RVSP) as compared to systemic pressure and assessed by hemodynamic studies: Group 1 (N=58) – mild to moderate PVS (RVSP ≤ 75 % of systemic pressure); Group 2 (N=41) – high degree PVS (RVSP = 76-100 % of s ; ystemic pressure), Group 3 (N=38) – severe PVS (with suprasystemic right ventricular pressure - RVSP > 100 % of systemic pressure). In each group, the analysis included age at BPV, results of clinical assessment and basic tests (ECG and chest X-ray), comprehensive echocardiographic evaluation and intervention management. Results: The follow-up period was between 1 year and 10 years, x = 6.1 years (SD – 3.4 years). The age of pts at BPV was as follows: Group 1 – x = 6.0 ±4.9 years, Group 2 – x = 4.1 ±3.8 years, Group 3 – x = 5.6 ±5.6 years. In each group, BPV was most commonly performed in patients aged 2-6 years. At the same time, the percentage of infants increased (8.6 %, 24.4 % and 28.9 %, respectively). In Group 1, the sex ratio was equal. A predominance of males was noted with an increasing degree of stenosis (Group 2 – 56.1 %, Group 3 – 63.2 %). As it follows from the analysis of clinical signs, with the increase of PVS, cardiac murmur was louder and split 2nd sound in the pulmonary artery area was more common, along with right ventricular impulse. The results of physical examination showed the highest degree of discrimination between Groups 1 and 2 and 1 and 3, being the most similar in Groups 2 and 3. ECG showed right ventricular hypertrophy in the majority of children from Group 1 and 2 and in all Group 3 patients. ECG recording was normal in 24.1% of Group 1 a ; nd 12.2% of Group 2 patients. Chest X-ray showed that an increasing degree of PVS was accompanied by an increasing cardiothoracic ratio (↑CTR) and lobulated contour of the main pulmonary artery (↑LCMPA) – Group 1: ↑CTR – 17.2% and ↑LCMPA – 13.8%, Group 2 - ↑CTR – 31.7% and ↑LCMPA – 46.3%, Group 3 - ↑CTR – 57.9% and ↑LCMPA – 63.2%, As it followed from the analysis of echocardiographic results, the majority of patients (92.4%) demonstrated a typical form of PVS, while the dysplastic form was observed in 10 children only (7.3%) (4/41 Group 2 and 6/38 Group 3 patients, with the highest degree of stenosis). The most common finding (67.7%) was a three-leaflet form of PV, but in approximately 20% of pts the structure of the defect could not have been determined. Pulmonary valve insufficiency (PVI) >IIo and subvalvular pulmonary stenosis (SVPS) were seen infrequently (3/137 and 7/137, respectively). The incidence of SVPS slightly increased with an increasing PVS degree. No statistical significance was noted in SVPS (P = 0.07) and PVI (P = 0.07) incidence in particular groups. However, tricuspid valve insufficiency was found to occur significantly more commonly in Group 3 (9/38) as compared to Group 1 (0/58) and Group 2 (3/41) (P<0.002). The analysis of selected parameters as assessed by echocardiography vs. angiocardiography showed (all values represented as mean): - the respective ; diameter of pulmonary valve annulus in Group 1 was 15.0 mm vs. 15.7 mm, in Group 2 – 13.1 mm vs. 13.9 mm, in Group 3 – 11.8 mm vs. 13.9 mm. No statistical differences were noted between the results of both examinations (Group 1-3: P = 0.08, P = 0.09 and P = 0.1, respectively). - the respective mean values of systolic pressure gradient were as follows: Group 1 – 56.8 mmHg vs. 49.3 mmHg, Group 2 – 73.5 mmHg vs. 75.6 mmHg and Group 3 – 99.1 mmHg vs. 115.6 mmHg. Significant differences were observed between the results obtained using the two methods in Group 1 children, where echocardiography significantly overestimated the gradient, and in Group 3, where the said examination significantly underestimated its value (P<0.001). In Group 2 children, however, the two results did not differ significantly (P = 0.09). As it follows from the comparison of both methods, echocardiography underestimated the size of pulmonary valve annulus, but the results of the examination did not significantly differ from the results obtained in angiography. On the other hand, in Doppler assessment of the gradient in milder forms of PVS, the result was overestimated, while in more advanced stages, it was underestimated as compared to hemodynamic evaluation. The ratio of the balloon catheter diameters and PVS annuli were extremely similar in the groups, equaling 1.3±0.1, 1.29±0.1 and 1.28±0.1, respectiv ; ely. After BPV, in all but one patient, a significant (P<0.001) reduction of RVSP, RVEDP (right ventricular end-diastolic pressure), SPG (systolic pressure gradient), as well as an increase of PASP (pulmonary artery systolic pressure) were observed in Group 3. Double balloon procedures were required by a total of eight patients, including six from Group 1 and two from Group 2. The method was successful in all the children. In patients with dysplastic pulmonary valves, the ratio of balloon diameter to valve annulus was significantly higher (P<0.002) (Group 1 – 1.4±0.3, Group 3 – 1.43±0.13). In one Group 2 child, the immediate effect PBVP was good, but 5 years later, restenosis requiring a repeated intervention was diagnosed. In another patient from this group, the procedure was unsuccessful and surgery was necessary. The immediate PBVP result was good in all Group 3 patients. However, 7/38 children (18.4%) were re-catheterized in late follow-up due to recurrent stenosis diagnosed by echocardiography. In four of these children, a repeated BVP was successfully performed; two – with dysplastic form of the defect - were referred to surgical correction and one was disqualified (pulmonary systolic pressure gradient = 20 mmHg). Five patients (3.6%) developed various complications, including one with a serious complication of a split balloon (Balt BDC) being lodged in the iliac ; vein, requiring surgical removal. Three children needed blood transfusions, and one – supraventricular arrhythmia treatment (adenosine). In late follow-up, one patient subjected to a repeated BPV due to restenosis most likely developed detachment of the pulmonary trunk intima (?), what was diagnosed elsewhere. In late follow-up (x = 6.1 years after BPV), loud systolic murmur (>3/6) was demonstrated by a similar percentage of patients from each group (12.1 %, 14.6 % and 13.2%, respectively), similarly as persistent signs of right ventricular hypertrophy in ECG (10.3 %, 9.8 % and 13.2%, respectively). Echocardiography performed 1, 2 and 5 years after the procedure demonstrated a gradual decrease of pulmonary systolic pressure gradient in all groups; at the end of the follow-up, its value was 13.4±6.9 mmHg, 16.9±12.1 mmHg and 17.1±12.2 mmHg, respectively. The percentage of subvalvular pulmonary stenosis was decreased, dropping from 8.6% to 0 in Group 1, 12.2 % to 2.4 % in Group 2 and 28.9 % to 10.5% in Group 3. Tricuspid valve insufficiency >IIo was non-significantly (P = 0.07) more common in Group 3 children (Group 1 – 5.2 %, Group 2 – 4.8 %, Group 3 – 13.2 %). On the other hand, a significant PVI rate (P = 0.007) was noted more frequently in Group 3 children (Group 1 – 17.2 %, Group 2 – 24.2 %, Group 3 – 39.5 %). The majority of children developed normally. Body mass d ; eficit as compared to standards for height and age was similar in all three groups, amounting to 8.6 % (Group 1), 7.4 % (Group 2) and 10.5 % (Group 3). Conclusions: 1) While qualifying patients to BPV, in addition to a thorough physical examination and basic supplementary studies, a decisive role is played by comprehensive echocardiographic diagnostic management, despite its limitations. 2) Late follow-up confirms the validity and effectiveness of PBVP in the management of PVS, even in cases of valvular dysplasia. 3) Restenosis is rare and may be effectively treated in a repeated procedure. Subvalvar pulmonary stenosis, observed in most severe forms of PVS, may regress after a successful BPV. 4) Significant, gradually increasing with age pulmonary valve insufficiency may develop after BPV in late follow-up in patients with most severe form of PVS, what requires careful monitoring of this group of children. 5) The risk of complication development is low providing the principles of the procedure are carefully followed. 6) Further development of children with PVS subjected to BPV is normal.

Place of publishing:

Kraków

Level of degree:

2 - studia doktoranckie

Degree discipline:

choroby układu krążenia ; pediatria

Degree grantor:

Wydział Lekarski

Promoter:

Rudziński, Andrzej

Date issued:

2007

Identifier:

oai:dl.cm-uj.krakow.pl:1023

Call number:

ZB-107981

Language:

pol

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nieograniczony

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Jun 26, 2023

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