Our study reports the experience of the cardiology department at CHU Mohammed VI of Marrakech in percutaneous pulmonary dilation in the presence of pulmonary stenosis. The dilation was successfully performed on three patients. The type of anesthesia varies among authors. For instance, Alsawah [5], Yucel [6], and Tabatabei [7] also performed general anesthesia, while Zeevi et al. [8], Gournay et al. [9], and Sullivan et al. [10] opted for local anesthesia in all patients in their series. Ladusan et al. [11], in a study involving a series of 15 patients, performed general anesthesia in eight cases and local anesthesia in seven cases.
Several approaches can be used during right heart catheterization. We used a right femoral vein approach in all our patients. Zeevi [8] and Gournay [12] used the same technique in their series. Alsawah [5] used the right femoral vein approach in 55% of his population and the umbilical route in 44% of cases. A heparin bolus was also administered to all our patients at a dose of 50 IU/kg. This heparin premedication has also been described by Kan [3] and Zeevi [8].
To cross the pulmonary valve, we used a right coronary catheter of the Right Judkins (JR) type. Gournay et al. [12] reported the same technique. The difficulty in crossing the stenotic valve orifice with the catheter tip during pulmonary dilation has been noted by some authors [8, 13, 15]. We encountered this problem in one patient in our series. Immediately after dilation, a decrease in ventricular pressure was observed in our patients. The right ventricular pressure decreased on average from 113 to 57 mmHg, a reduction of 46%. The right ventricular outflow tract (RVOT) gradient decreased on average from 99 mmHg to 30 mmHg, a reduction of 61%. This finding has been reported by several authors [12, 11, 9, 15, 17–18].
Several clinical, echocardiographic, and hemodynamic parameters have been studied to define immediate procedural success [1, 12]. According to the series reported in the literature, the success rate of percutaneous balloon valvuloplasty varied from 58 to 98% [1, 12, 9, 6–8, 16, 19]. The main causes of percutaneous valvuloplasty failure cited by different authors are failure to cross the pulmonary valve, failure of balloon progression, unfavorable valve anatomy (dysplasia, annular hypoplasia), right ventricular (RV) hypoplasia, and reduced RV compliance, which partly accounts for the persistence of cyanosis [12, 7, 17].
In our series, we had no valvuloplasty failures. The most important factor determining valvuloplasty success is RV compliance, which is partly determined by the size of the right ventricular cavity [17]. RV non-compliance plays a significant role in worsening hypoxemia even after pulmonary dilation. It is secondary to myocardial ischemia and fibrosis of the RV elastic fibers due to elevated right ventricular pressure [17].
Minor complications following valvuloplasty have been reported in the literature, such as transient bradycardia and hypotension during balloon inflation [9], variable atrioventricular block without hemodynamic consequences [5], right bundle branch block [8], and transient ventricular arrhythmias occurring during passage through the infundibular portion of the RV [9, 12, 5, 6, 16]. Local complications can also occur at the access site, such as intimal dissection of the right iliac vein during balloon passage attempts [8].
The mortality rate reported in the literature following percutaneous valvuloplasty ranges from 0 to 14% [12, 5, 7, 20, 14, 17]. These rates are lower than those for surgery, estimated at 20–25% [17]. Causes of mortality from valvuloplasty are generally due to infundibular perforation with hemopericardium and tamponade, or myocardial dissection occurring a few hours after the procedure [12, 5, 10, 16]. The follow-up mortality rate ranges from 0 to 25% in the literature [8, 10, 6, 7, 14, 20, 21]. The restenosis rate varies in the literature from 0.1–41% [7,0,17,18,22]. In case of post-valvuloplasty restenosis, a second valvuloplasty is indicated.
Study Limitations
This is a retrospective single-center study including a small sample size. Due to the small size of our population, an analytical study of predictive factors for reintervention was not conducted. Consequently, the response to this objective was limited to a description of the clinical and echocardiographic characteristics of patients who underwent reintervention.