Hypoplastic left heart syndrome: surgical therapy

Pabst von Ohain, Jelena (2021): Hypoplastic left heart syndrome: surgical therapy. Dissertation, LMU München: Medizinische Fakultät

Abstract

Unloading of right ventricle by bidirectional superior cavopulmonary anastomosis in hypoplastic left heart syndrome patients promotes remodeling of systemic right ventricle but does not improve tricuspid regurgitation Jelena Kasnar-Samprec*, Andreas Kühn*, Jürgen Hörer, Manfred Vogt, Julie Cleuziou, Rüdiger Lange, Christian Schreiber J Thorac Cardiovasc Surg. 2012 Nov;144(5):1102-8. * Equally contributing authors Objective: Our study aimed to evaluate the effect of bidirectional superior cavopulmonary anastomosis (BSCPA) and consequent reduction in volume load on the systemic right ventricle and the systemic tricuspid valve in patients with hypoplastic left heart syndrome (HLHS). Patients and methods: Ninety consecutive patients with HLHS, who were early-survivors after BSCPA were included in the study. Two ultrasound examinations from each patient were re-evaluated by an experienced paediatric cardiologist: one prior to BSCPA and the second prior to completing the Fontan circulation. The degree of tricuspid regurgitation, the morphology of the systemic tricuspid valve, the diameter of the tricuspid annulus, tricuspid annular plane systolic excursion (TAPSE), and the right ventricular function were noted. Results: In the echocardiograms performed in median five days before BSCPA, tricuspid regurgitation was absent in 11 patients, trivial in 37 patients, mild in 24 patients, and moderate in 11 patients. In the echocardiograms performed in age of median 17 months, tricuspid regurgitation was absent in 14 patients, trivial in 37 patients, mild in 21 patients, moderate in 6 patients, and severe in 5 patients. The change in grade of tricuspid regurgitation before and after BSCPA was not statistically significant. Most of the patients with a moderate and severe tricuspid regurgitation had a structurally abnormal tricuspid valve, most commonly a prolapse of the anterior leaflet and/or a restriction of the posterior leaflet. The diameter of the tricuspid valve annulus stayed the same after BSCPA in patients with moderate and severe tricuspid regurgitation; in the remaining patients, it decreased. Prior to BSCPA, the TAPSE/age ratio was similar in all patients. After BSCPA, the TAPSE/age ratio was larger in patients with postoperative moderate or severe tricuspid regurgitation, than in the remaining patients. The function of the systemic right ventricle was normal in 95% of the patients before BSCPA and 87% of the patients after BSCPA. The postoperative function of the right ventricle was not dependent on the diameter of the tricuspid annulus. Comment: In our study, the grade of the tricuspid valve regurgitation did not change after the BSCPA. The diameter of the tricuspid annulus decreased, most likely due to a reduction of the volume load. In patients with moderate or severe tricuspid regurgitation, the annulus did not change and was larger than in the remaining patients. The leaflets of the systemic tricuspid valve were only rarely described as normal in patients with moderate or severe regurgitation. TAPSE was significantly reduced after BSCPA only in patients without moderate or severe tricuspid regurgitation. In our cohort, more patients had a reduced function of the systemic RV after BSCPA than before the operation. A partial explanation is that a morphologically right ventricle must sustain the systemic blood flow in patients with HLHS. Additional investigation of the morphology and function of the systemic right ventricle and its interaction with the hypoplastic left ventricle are necessary to explain this result. Conclusion: Our study suggests that the reduction in volume load reduces the size of the systemic tricuspid annulus, without necessarily influencing the valve regurgitation. It can be assumed that the degree of tricuspid regurgitation won’t change after the BSCPA without valve surgery. Therefore, tricuspid valve repair should be carefully discussed prior to performing BSCPA. Recoarctation after the Norwood I procedure for hypoplastic left heart syndrome: incidence, risk factors, and treatment options Julie Cleuziou, Jelena Kasnar-Samprec, Jürgen Hörer, Andreas Eicken, Rüdiger Lange, Christian Schreiber. Ann Thorac Surg. 2013 Mar;95(3):935-40. Objective: Our study aimed to determine the incidence, evaluate risk factors, and analyse therapy options of re-coarctation after Norwood operation in patients with hypoplastic left heart syndrome (HLHS). Patients and methods: One hundred twenty-four consecutive patients with HLHS who underwent the Norwood operation were included in the study. The following factors were included in the risk analysis: age, weight, gender, the diameter of the native ascending aorta, the surgical technique and the patch material. The difference in the pressure in the ascending and the descending aorta, as well as the need for dilatation of a re-coarctation, was noted on the angiography before bidirectional superior cavopulmonary anastomosis (BSCPA). Results: Re-coarctation was diagnosed in 13% of the patients at a mean time of 6.4±5 months following the Norwood operation. Freedom from re-coarctation was 89.5% at six months, 88.2% at 12 months and 84.9% at ten years. In the univariate analysis, none of the examined morphologic or surgical factors influenced the development of a re-coarctation. The mean pressure difference in patients with a re-coarctation was 24±16 mmHg, and significantly higher than in patients without a re-coarctation. One patient demised before the re-coarctation could be treated. In the remaining 12 patients, balloon angioplasty was performed in 10 patients while two required surgical relief of the obstruction. After the interventional or surgical procedure, the difference in pressures significantly decreased to 6.3±4 mmHg. Comment: In our cohort, the incidence of re-coarctation after the Norwood operation in HLHS patients was low, with 13%. Although the patch material is one of the implicated risk factors for developing a re-coarctation after a Norwood operation in the HLHS patients, our study could not confirm this. All of the examined patient characteristics and surgical factors did not significantly influence the recurrence of an aortic arch obstruction. Treatment options for re-coarctation include interventional (balloon angioplasty, stent implantation) and surgical procedures. No complications occurred after balloon angioplasty. However, several patients had to undergo a re-dilatation prior to total cavopulmonary connection. No complications occurred after the surgical relief of the re-coarctation Conclusion: A low frequency of re-coarctation following the Norwood procedure in HLHS patients can be accomplished using a standardised surgical technique which includes complete resection of the arterial duct and a careful broadening of the anastomosis at the distal end of the descending aorta. A re-coarctation can be treated successfully by balloon angioplasty at the time of the diagnosis. Surgical treatment of the re-coarctation is rarely required.

Abstract

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Keywords: hypoplastic left heart syndrome, bidirectional superior cavopulmonary anastomosis, congenital heart surgery
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften ; 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• Fakultäten: Medizinische Fakultät
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 8. September 2021
• 1. Bericht­erstatter:in: Hörer, Jürgen