Current status of transcatheter intervention for complex right ventricular outflow tract abnormalities.

Various transcatheter interventions for the right ventricular outflow tract (RVOT) have been introduced and developed in recent decades. Transcatheter pulmonary valve perforation was first introduced in the 1990s. Radiofrequency wire perforation has been the approach of choice for membranous pulmonary atresia in newborns, with high success rates, although complication rates remain relatively common. Stenting of the RVOT is a novel palliative treatment that may improve hemodynamics in neonatal patients with reduced pulmonary blood flow and RVOT obstruction. Whether this option is superior to other surgical palliative strategies or early primary repair of tetralogy of Fallot remains unclear. Transcatheter pulmonary valve replacement has been one of the biggest innovations in the last two decades. With the success of the Melody and SAPIEN valves, this technique has evolved into the gold standard therapy for RVOT abnormalities with excellent procedural safety and efficacy. Challenges remain in managing the wide heterogeneity of postoperative lesions seen in RVOT, and various technical modifications, such as pre-stenting, valve ring modification, or development of self-expanding systems, have been made. Recent large studies have revealed outcomes comparable to those of surgery, with less morbidity. Further experience and multicenter studies and registries to compare the outcomes of various strategies are necessary, with the ultimate goal of a single-step, minimally invasive approach offering the best longer-term anatomical and physiological results.

Ongoing vascular inflammation evaluated by 18F-fluorodeoxyglucose positron emission tomography in patients long after Kawasaki disease.

BACKGROUND: This study aimed to determine whether ongoing vascular inflammation presents in patients who had coronary artery aneurysms (CAAs) caused by Kawasaki disease (KD). METHODS: Subjects were 26 patients with a history of KD; 15 had giant CAA (gCAA) ≥ 8.0 mm and 11 had smaller CAA (smCAA) < 8 mm in the acute phase. They underwent X-ray computed tomography and 18F-fluorodeoxyglucose positron emission tomography. We determined the maximum coronary target-to-background ratio (CaTBR) and the mean thoracic aorta TBR (TaTBR) in each patient. They were compared between groups, and their correlation with various variables was determined. RESULTS: CaTBR and TaTBR were significantly higher in gCAA than in smCAA (P < .005 for both values) and were significantly higher even in patients without any metabolic risk factor (P < .05 for both values). The CAA size in acute phase significantly positively correlated with CaTBR (R2 = 0.32) as well as TaTBR (R2 = 0.28). Also, TaTBR significantly positively correlated with CaTBR (R2 = 0.32) as well as cumulative number of metabolic risk factors (trend, P = .03). CONCLUSIONS: Ongoing vascular inflammation may present long after KD, especially in patients with severe inflammation expressed as gCAA in the acute phase.

Intracardiac Echocardiography as a Guide for Transcatheter Closure of Patent Ductus Arteriosus.

BACKGROUND: Transcatheter closure of patent ductus arteriosus (TC-PDA), conventionally guided by aortography, has become the standard treatment of this disease. The purposes of this study were to evaluate whether intracardiac echocardiography (ICE) may be used for measuring PDA size and be used as a guide for TC-PDA. METHODS: This study had 2 phases. In phase 1, we compared the measurements of PDA size: pulmonary artery side diameter (PA-D), length, and aortic side diameter (Ao-D) of PDA, as measured by ICE with those measured by aortography or cardiac computed tomography (AoG/CCT) in 23 patients who underwent TC-PDA. In phase 2, we compared the demographics, fluoroscopic time, contrast volume, and complications of the TC-PDAs between 10 adult patients with ICE guidance and 16 without it. RESULTS: In phase 1, we found great correlation and agreement between ICE and AoG/CCT in PA-D (r = 0.985, bias -0.077 to 0.224), but moderate to poor correlation and agreement in length (r = 0.653, bias -0.491 to 3.065) and Ao-D (r = 0.704, bias 0.738 to 4.732), respectively. Nevertheless, all patients underwent successful TC-PDA with ICE guidance that allowed us to continuously monitor the whole process. In phase 2, TC-PDA required a significantly lower contrast volume with ICE guidance than without it, and there was no significant difference in the remaining variables between the 2 groups. CONCLUSION: ICE is comparable to AoG/CCT in providing accurate PA-D of the PDA and may be a safe alternative to guide TC-PDA as compared to conventional aortography.

Growth differentiation factor 15 as a useful biomarker of heart failure in young patients with unrepaired congenital heart disease of left to right shunt.

BACKGROUND: Growth differentiation factor 15 (GDF 15) is a member of the transforming growth factor-beta superfamily and is considered to be a useful biomarker for severity of heart failure (HF) in repaired congenital heart disease (CHD). The aim of this study was to determine the clinical implication of GDF 15 in children with unrepaired CHD. METHODS: Subjects included 69 patients (≤14 years old) who had unrepaired CHD with left to right shunt and underwent cardiac catheterization. Demographic and hemodynamic data, including oxygen demand-supply relationship, were collected from medical records. Severity of HF was evaluated using modified Ross score. Serum GDF 15 levels were determined using enzyme-linked immunosorbent assay and correlated with patients' demographics, hemodynamic data, and blood chemistry data. RESULTS: Subjects had median age of 71 (range 1-173) months and simple acyanotic CHDs with mean pulmonary to systemic flow ratio of 2.0 (1.0-5.6), median N-terminal pro type Brain natriuretic peptide (NT-pro-BNP) of 162.8 (17.1-8789) pg/mL, and median GDF 15 of 242.1 (13.6-1116.7) pg/mL. GDF 15 significantly positively correlated with the modified Ross score, mean pulmonary artery pressure, oxygen extraction rate (OER), and Ln NT-pro-BNP, but negatively correlated with age, oxygen delivery and its components, and estimated glomerular filtration rate (eGFR). Multiple linear regression analysis revealed significant correlation of GDF 15 levels with the modified Ross score, OER, and eGFR. CONCLUSIONS: GDF 15 mainly reflects oxygen demand-supply relationship and can be used as a diagnostic marker of HF in unrepaired CHD with left to right shunt for a wide range of age and diagnoses.

Successful combined intravenous and subcutaneous immunoglobulin treatment for intractable protein-losing enteropathy in a patient long after Fontan-type operation.

A 20-year-old patient, who had double outlet right ventricle, mitral atresia, pulmonary atresia, and bilateral superior vena cava and underwent successful lateral tunnel total cavo-pulmonary connection at 6 years old, presented with frequent watery diarrhea, general malaise, and tetany. He was known to have intractable protein-losing enteropathy (PLE) from 7 years of age that was resistant to various treatments. To keep hemodynamics stable, he required intravenous albumin infusion every day. Fontan fenestration partially improved his condition and allowed to stop albumin infusion, however still he showed muddy stool and cachexia with low serum albumin <20 g/L and immunoglobulin <3 g/L. Because of serious risk of infection, we placed him on regular subcutaneous immunoglobulin supplementation with rescue intravenous immunoglobulin that improved his PLE within a month and allowed him to be discharged. This case illustrates that immunoglobulin supplementation can be one of the choices of treatment for intractable PLE. .

CT-based automated planning of acetabular cup for total hip arthroplasty (THA) based on hybrid use of two statistical atlases.

PURPOSE: This study describes the use of CT images in atlas-based automated planning methods for acetabular cup implants in total hip arthroplasty (THA). The objective of this study is to develop an automated cup planning method considering the statistical distribution of the residual thickness. METHODS: From a number of past THA planning datasets, we construct two statistical atlases that represent the surgeon's expertise. The first atlas is a pelvis-cup merged statistical shape model (PC-SSM), which encodes global spatial relationships between the patient anatomy and implant. The other is a statistical residual thickness map (SRTM) of the implant surface, which encodes local spatial constraints of the anatomy and implant. In addition to PC-SSM and SRTM, we utilized the minimum thickness as a threshold constraint to prevent penetration. RESULTS: The proposed method was applied to the pelvis shapes segmented from CT images of 37 datasets of osteoarthritis patients. Automated planning results with manual segmentation were compared to the plans prepared by an experienced surgeon. There was no significant difference in the average cup size error between the two methods (1.1 and 1.2 mm, respectively). The average positional error obtained by the proposed method, which integrates the two atlases, was significantly smaller (3.2 mm) than the previous method, which uses single atlas (3.9 mm). In the proposed method with automated segmentation, the size error of the proposed method for automated segmentation was comparable (1.1 mm) to that for manual segmentation (1.1 mm). The average positional error was significantly worse (4.2 mm) than that using manual segmentation (3.2 mm). If we only consider mildly diseased cases, however, there was no significance between them (3.2 mm in automated and 2.6 mm in manual segmentation). CONCLUSION: We infer that integrating PC-SSM and SRTM is a useful approach for modeling experienced surgeon's preference during cup planning.

Automated preoperative planning of femoral stem in total hip arthroplasty from 3D CT data: atlas-based approach and comparative study.

Atlas-based methods for automated preoperative planning of the femoral stem implant in total hip arthroplasty are described. Statistical atlases are constructed from a number of past preoperative plans prepared by experienced surgeons in order to represent the surgeon's expertise of the planning. Two types of atlases are considered. One is a statistical distance map atlas, which represents surgeon's preference of the contact pattern between the femoral canal (host bone) and stem (implant) surfaces. The other is an optimal reference plan, which is selected as the best representative plan expected to minimize the deviation from the surgeon's preferred contact pattern. These atlases are fitted to the patient data to automatically generate the preoperative plan of the femoral stem. In this paper, we formulate a general framework of atlas-based implant planning, and then describe the methods for construction and utilization of the two proposed atlases. In the experiments, we used 40 cases to evaluate the proposed methods and compare them with previous methods by defining the errors as differences between automated and surgeon's plans. By using the proposed methods, the positional and orientation errors were significantly reduced compared with the previous methods and the size error was superior to inter-surgeon variability in size selection using 2D templates on an X-ray image reported in previous work.

Expertise modeling for automated planning of acetabular cup in total hip arthroplasty using combined bone and implant statistical atlases.

Intraoperative robotic and computer-guided assistances are now commonly used in total hip arthroplasty (THA) for accurate execution of the preoperative plan. Although the preoperative plan to be accurately executed is critical, it is still interactively prepared in a time-consuming and subjective manner. In this paper, atlas-based approach to automated surgical planning of the acetabular cup in THA is described to stabilize its quality as well as reduce its time-consuming nature. Surgeon's expertise is embedded in two types of statistical atlases, which are constructed from training datasets of CT-based 3D plans prepared by experienced surgeons. One is a statistical shape model which encodes global spatial relationships between the patient anatomy and implant. The other is the statistical map of residual bone thickness on the implant surface, which encodes local spatial constraints of the anatomy and implant. Given the 3D pelvis shape of the patient, we formulate a procedure to determine the best size and position of the acetabular cup which satisfy the constraints derived from the two statistical atlases. We validated the proposed planning method by retrospective study using the datasets which were actually used in the THA surgery.

Construction of a statistical surgical plan atlas for automated 3D planning of femoral component in total hip arthroplasty.

The problem of automating preoperative planning of the femoral component (stem) for total hip arthroplasty (THA) is addressed. In our previous method, time-consuming trial-and-error processes were involved in parameter tuning of the objective function. This problem prevents application in different stem systems. To overcome this problem, a statistical surgical plan atlas (SSPA) is constructed from training datasets of stem planning. The SSPA represents the average and variance of the distance distribution on the stem surface to the femoral canal surface. That is, it encodes the distribution of the degree of contact preferred by the surgeon. Automated planning is performed by minimizing the squared difference between distributions of the SSPA and planning solution. The proposed method involves no parameter tuning to define the objective function that evaluates differences from the planning the surgeon prefers. Experimental evaluations showed that the proposed method renders parameter tuning unnecessary while it still provides comparable accuracy to the previous method.