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Biomedical subjects

R G Grifka

Publications and source records attributed to R G Grifka.

At least 19 recordsLinked to original sources
PubMed2002

Natural history of growth of secundum atrial septal defects and implications for transcatheter closure.

OBJECTIVE: To investigate the natural history of secundum atrial septal defects (ASDs) over several years using serial echocardiographic studies. METHODS: All patients with isolated secundum ASDs who had serial transthoracic echocardiograms at Texas Children's Hospital, Houston, Texas, from January 1991 to December 1998 were identified. Patients with fenestrated or multiple ASDs, other congenital heart defects, or less than a six month interval between echocardiograms were excluded. There were 104 patients eligible for inclusion in the study. Studies were reviewed by two echocardiographers (blinded) and the maximal diameter was recorded. Defects were defined as small (> 3 mm to < 6 mm), moderate (> or = 6 mm to < 12 mm), or large (> or = 12 mm). ASDs that grew > or = 20 mm were defined as having outgrown transcatheter closure with the device available to the authors' institution. RESULTS: ASD diameter increased in 68 of 104 patients (65%), including 31 patients (30%) with a > 50% increase in diameter. Spontaneous closure occurred in four patients (4%). Thirteen defects (12%) increased to > or = 20 mm. One fifth of the patients studied had an insufficient atrial rim by transthoracic echocardiogram to hold an atrial septal occluder. The only factor associated with significant growth of ASDs was initial size of the defect. ASD growth was independent both of age at diagnosis and when indexed to body surface area. CONCLUSIONS: Two thirds of secundum ASDs may enlarge with time and there is the potential for secundum ASDs to outgrow transcatheter closure with specific devices. Further development in devices and general availability of devices capable of closing larger ASDs should circumvent this problem.

Adolescent↗
PubMed2001

Safety of magnetic resonance imaging immediately following Palmaz stent implant: a report of three cases.

Magnetic resonance imaging (MRI) can provide important information on patients with congenital heart defects. There is some reluctance to perform MRI acutely following intravascular stent implant, due to concerns of distortion or movement of the stent in the magnetic field. We report on three patients who underwent MRI evaluation less than 14 days following Palmaz stent implant in the pulmonary arteries and superior vena cava, with no acute adverse outcome or long-term problems.

Adult↗
PubMed2001

Reconstruction of stenotic or occluded iliofemoral veins and inferior vena cava using intravascular stents: re-establishing access for future cardiac catheterization and cardiac surgery.

OBJECTIVES: The study evaluated the safety and efficacy of stent reconstruction of stenotic/occluded iliofemoral veins (IFV) and inferior vena cava (IVC). BACKGROUND: Patients with congenital heart defects and stenotic or occluded IFV/IVC may encounter femoral venous access problems during future cardiac surgeries or catheterizations. METHODS: Twenty-four patients (median age 4.9 years) underwent implantation of 85 stents in 22 IFV and 6 IVC. Fifteen vessels were severely stenotic and 13 were completely occluded. Although guide wires were easily passed across the stenotic vessels, occluded vessels required puncture through the thrombosed sites using a stiff wire or transseptal needle. Once traversed, the occluded site was dilated serially prior to stent implantation. RESULTS: Following stent placement, the mean vessel diameter increased from 0.9 +/- 1.6 to 7.4 +/- 2.6 mm (p < 0.05). Twenty-one of 28 vessels had long segment stenosis/occlusion requiring two to seven overlapping stents. Repeat catheterizations were performed in seven patients (9 stented vessels) at mean follow-up of 1.6 years. Seven vessels remained patent with mean diameter of 6.4 +/- 2.0 mm. Two vessels were occluded, but they were easily recanalized and redilated. Echocardiographic follow-up in two patients with IVC stents demonstrated wide patency. In four additional patients, a stented vessel was utilized for vascular access during subsequent cardiac surgery (n = 3) and endomyocardial biopsy (n = 1). Therefore, 13 of 15 stented vessels (87%) remained patent at follow-up thus far. CONCLUSIONS: Stenotic/obstructed IFV and IVC may be reconstructed using stents to re-establish venous access to the heart for future cardiac catheterization and/or surgeries.

Angioplasty, Balloon↗
PubMed2001

Redilation of endovascular stents in congenital heart disease: factors implicated in the development of restenosis and neointimal proliferation.

OBJECTIVES: We sought to determine the incidence of and risk factors for the development of restenosis and neointimal proliferation after endovascular stent implantation for congenital heart disease (CHD). BACKGROUND: Risk factors for the development of restenosis and neointimal proliferation are poorly understood. METHODS: This was a retrospective review of patients who underwent endovascular stent redilation between September 1989 and February 2000. RESULTS: Of 368 patients who had 752 stents implanted, 220 were recatheterized. Of those 220 patients, 103 underwent stent redilation. Patients were classified into three groups: 1) those with pulmonary artery stenosis (n = 94), tetralogy of Fallot/pulmonary atresia (n = 72), congenital branch pulmonary stenosis (n = 9), status post-Fontan operation (n = 6), status post-arterial switch operation (n = 7); 2) those with iliofemoral venous obstruction (n = 6); and 3) those with miscellaneous disorders (n = 3). The patients' median age was 9.9 years (range 0.5 to 39.8); their mean follow-up duration was 3.8 years (range 0.1 to 10). Indications for stent redilation included somatic growth (n = 67), serial dilation (n = 27) and development of neointimal proliferation or restenosis, or both (n = 9). There was a low incidence of neointimal proliferation (1.8%) and restenosis (2%). There were no deaths. Complications included pulmonary edema (n = 1), hemoptysis (n = 1) and contralateral stent compression (n = 2). CONCLUSIONS: Redilation or further dilation of endovascular stents for CHD is effective as late as 10 years. The risk of neointimal proliferation (1.8%) and restenosis (2%) is low and possibly avoidable. Awareness of specific risk factors and modification of the stent implantation technique, including avoidance of minimal stent overlap and sharp angulation of the stent to the vessel wall and avoidance of overdilation, have helped to reduce the incidence of restenosis.

Adolescent↗
PubMed2001

Coronary artery fistula. Management and intermediate-term outcome after transcatheter coil occlusion.

During the last 2 decades, transcatheter occlusion of coronary artery fistulae has developed into a safe and effective therapy for children. This procedure avoids the need for open surgical repair and the attendant complications of cardiopulmonary bypass and median sternotomy. The long-term outcome in patients after transcatheter occlusion remains unknown. We describe the intermediate-term progress of 4 such patients after coil occlusion of coronary artery fistulae. Persistent coronary artery dilatation was present in all patients reviewed, as late as 4 years after occlusion.

Arteriovenous Fistula↗
PubMed2001

Sizing of atrial septal defects to predict successful closure with transcatheter cardioSEAL device.

We conducted this retrospective study to compare methods for measuring atrial septal defects and to identify factors affecting echocardiographic measurement of such defects before transcatheter closure with the CardioSEAL'Septal Occluder. We reviewed the records of patients considered for device placement at our institution from January 1997 to April 1999. Atrial septal defect size was measured by transthoracic and transesophageal echocardiography; the stretched diameter was measured during catheterization by fluoroscopy and transesophageal echocardiography. The stretched-diameter fluoroscopic measurement was used for device size selection. Analysis of variance was used to calculate the effect of size, age, and size-by-age interaction. Thirty-one patients (3.3 to 72 years of age) underwent transthoracic and transesophageal echocardiography One patient was excluded from catheterization because of a 25-mm septal defect as indicated by transesophageal echocardiography (our maximum diameter, 15 mm). Thirty patients underwent transcatheter stretched-diameter sizing; 5 were excluded from device implantation because of defects >20 mm by stretched-diameter fluoroscopy (4) or septal length insufficient for device support (1). Implantation was successful in 23/25 patients; 2/23 had a residual shunt. In patients with available results (26/30), the stretched diameter was the same whether measured by stretched-diameter fluoroscopy or transesophageal echocardiography (P=0.007 R square=0.963). Compared with stretched-diameter fluoroscopy, precatheterization transthoracic and transesophageal echocardiography underestimated defect size by a mean of 22% and 13.2%, respectively. When data from those same tests were compared in defects of < or =0 mm and > 10 mm, transthoracic and transesophageal echocardiography were reliable predictors (P=0.003 and P=0.05, respectively) of stretched-diameter size in defects < or =0 mm.

Adolescent↗
PubMed2000

Premature closure of the foramen ovale associated with aortic stenosis, left ventricular dilation with thrombus, and early mortality.

Premature foramen ovale (FO) closure has been postulated as a cause of hypoplastic left heart syndrome. We suggest that premature FO closure is also associated with left ventricular (LV) dilation and LV thrombus formation, and that FO closure in patients with aortic stenosis and LV dilation is a secondary event that occurs later in gestation than that seen with the hypoplastic left heart.

Aortic Valve Stenosis↗
PubMed2000

Transcatheter closure of surgical shunts in patients with congenital heart disease.

The aim of this study was to review contemporary techniques, devices, and results of transcatheter occlusion of surgical shunts in 2 pediatric cardiac programs. Closure of superfluous surgical shunts may reduce cardiac work and risk of endocarditis. Previous studies have shown that transcatheter closure of shunts is feasible, but have not demonstrated acceptable efficacy or safety. In addition, the performance of new techniques and devices has not been reviewed. Between 1993 and 1998, 18 patients with congenital heart disease underwent transcatheter closure of 19 Blalock-Taussig shunts. Detachable and standard Gianturco coils and Gianturco-Grifka vascular occlusion devices were employed. All 19 shunts had complete closure. Eight shunts had initial placement of detachable coils. Five shunts had stents placed that bridged the pulmonary end of the shunts. These 5 and 4 additional shunts had closure by standard coils. Two shunts were closed with Gianturco-Grifka devices. There were no complications, no embolizations, and no requirement for surgery precipitated by the procedures. This review of contemporary techniques, devices, and results suggests that transcatheter occlusion of surgical shunts is effective and safe.

Blood Vessel Prosthesis Implantation↗
PubMed2000

A technique to prevent newly implanted stent displacement during subsequent catheter and sheath manipulation.

We describe a novel technique to prevent the displacement or migration of a newly implanted stent as a consequence of any subsequent catheter and sheath manipulation during the same catheterization procedure. The technique involves reinflation of the dilation balloon within the stent immediately after implant followed by advancing the long delivery sheath carefully over the balloon as the balloon is slowly deflated within the stent. The technique was used successfully in 78 stents in 30 patients without stent dislodgment or migration.

Adolescent↗
PubMed2000

18-year experience with transseptal procedures through baffles, conduits, and other intra-atrial patches.

The presence of an intra-atrial patch (IAP) has been considered a relative contraindication to transseptal puncture (TSP). The purpose of this study is to determine the efficacy and safety of the TSP through baffles, conduits, pericardial patches and other prosthetic materials in the intra-atrial septum. We reviewed the records of all pediatric patients with IAP who underwent TSP at Texas Children's Hospital from November 1979 through February 1998. The review included the cardiac diagnoses, indications for TSP, technical difficulties and follow up echocardiograms specifically addressing residual atrial shunts A total of 1958 TSP were performed. Thirty-nine patients had IAP. Cardiac diagnoses in those 39 patients included D-transposition of the great arteries after Mustard (10) or Senning procedure (6), single ventricle variant post-Fontan operation (4), total anomalous venous return repair (4), atrioventricular canal repair (9) and atrial septal defect with patch repair (6). Patients' age ranged from 1-31 years (median 7 years). The duration from the time of surgical repair to TSP ranged from 0.1-21 years (median 5 years). Indications for TSP included diagnostic and therapeutic intervention for pulmonary venous obstruction (12), creation of a baffle fenestration (2), prosthetic mitral valve evaluation (1), left ventricular outflow tract evaluation (1), access the left heart for hemodynamic evaluation (23). The IAP was traversed in 38/39 patients (97.5%), followed by diagnostic or therapeutic prograde left-heart catheterization. No complications were encountered. Follow up echocardiography in 30/38 PTS demonstrated no residual shunting across the atrial septum except for two cases in which the atrial baffle had been intentionally fenestrated. Transseptal puncture through an intra-atrial patch is a safe procedure. This technique is effective in permitting diagnostic and therapeutic left heart catheterization and does not result in residual shunting through the patch.

Adolescent↗
PubMed2000

Steerable control of the eustachian valve during transcatheter closure of secundum atrial septal defects.

Over the past decade there has been increased use of transcatheter devices for closure of secundum atrial septal defects. The presence of a large eustachian valve complicating transcatheter closure has not been described. We describe four patients with prominent eustachian valves, in three of whom we employed a simple technique to obtain control of the eustachian valve during device placement using transesophageal echo guidance.

Cardiac Catheterization↗
PubMed2000

Vascular endothelial growth factor and basic fibroblast growth factor in children with cyanotic congenital heart disease.

OBJECTIVE: Vascular endothelial growth factor and basic fibroblast growth factor are potent stimulators of angiogenesis. Children with cyanotic congenital heart disease often experience the development of widespread formation of collateral blood vessels, which may represent a form of abnormal angiogenesis. We undertook the present study to determine whether children with cyanotic congenital heart disease have elevated serum levels of vascular endothelial growth factor and basic fibroblast growth factor. METHODS: Serum was obtained from 22 children with cyanotic congenital heart disease and 19 children with acyanotic heart disease during cardiac catheterization. Samples were taken from the superior vena cava, inferior vena cava, and a systemic artery. Vascular endothelial growth factor and basic fibroblast growth factor levels were measured in the serum from each of these sites by enzyme-linked immunosorbent assay. RESULTS: Vascular endothelial growth factor was significantly elevated in the superior vena cava (P =.04) and systemic artery (P =.02) but not in the inferior vena cava (P =.2) of children with cyanotic congenital heart disease compared to children with acyanotic heart disease. The mean vascular endothelial growth factor level, determined by averaging the means of all 3 sites, was also significantly elevated (P =.03). Basic fibroblast growth factor was only significantly elevated in the systemic artery (P =.02). CONCLUSION: Children with cyanotic congenital heart disease have elevated systemic levels of vascular endothelial growth factor. These findings suggest that the widespread formation of collateral vessels in these children may be mediated by vascular endothelial growth factor.

Child↗
PubMed1999

Right aortic arch with isolation of the left subclavian artery, moderate patent ductus arteriosus, and subclavian steal syndrome: A rare aortic arch anomaly treated with the Gianturco-Grifka vascular occlusion device.

We present the first described use of the Gianturco-Grifka Vascular Occlusion Device to close a moderate patent ductus arteriosus associated with the rare congenital condition of right aortic arch with isolation of the left subclavian artery. Left vertebral artery "steal" through the moderate patent ductus arteriosus was eliminated by this transcatheter technique. Cathet. Cardiovasc. Intervent. 47:320-322, 1999.

Aorta, Thoracic↗
PubMed1999

Cyanotic congenital heart disease with increased pulmonary blood flow.

Pediatricians daily encounter children with systemic cyanosis. The numerous reasons for cyanosis in neonates and infants include pulmonary, hematologic, toxic, and cardiac causes. Congenital heart defects may cause cyanosis. Often, an obvious cardiac reason for cyanosis is decreased PBF; however, several congenital heart defects cause systemic cyanosis with increased PBF, such as TGA, truncus arteriosus, and TAPVR. Because neonates are discharged from the hospital soon after birth, this magnifies the importance of each physical examination. Pediatricians need to remain alert for children who have symptoms of increased PBF with or without cyanosis. With advances in the diagnosis and treatment of patients with CHD, corrective procedures can be performed at many ages.

Cyanosis↗
PubMed1998

Intravascular stents in congenital heart disease: short- and long-term results from a large single-center experience.

OBJECTIVES: This report describes the results of the Food and Drug Administration's phase 1 and 2 clinical trials of intravascular stents at Texas Children's Hospital. BACKGROUND: Since the late 1980s, intravascular stent implantation for the treatment of arterial and venous stenoses in congenital heart disease has been highly successful. METHODS: Stents were placed in postoperative pulmonary artery (PA) stenoses, congenital PA stenoses or stenoses of systemic veins/venous anastomoses. Prospective collection of data according to protocol was done before intervention, after stent implantation and at follow-up catheterization. RESULTS: At stent implantation, pressure gradients decreased significantly in all three groups (mean +/- SD): from 46 +/- 25 to 10 +/- 13 mm Hg in postoperative PA stenoses (p < 0.001); from 71 +/- 45 to 15 +/- 21 mm Hg in congenital PA stenoses (p < 0.001); and from 7 +/- 6 to 1 +/- 2 mm Hg in stenoses of systemic veins/venous anastomoses stenoses (p < 0.001). Vessel diameters markedly increased: from 6 +/- 3 to 12 +/- 3 mm in postoperative PA stenoses (p < 0.001); from 3 + 1 to 9 + 1 mm in congenital PA stenoses (p < 0.001); and from 3 +/- 4 to 12 +/- 4 mm in stenoses of systemic veins/venous anastomoses (p < 0.001). In the postoperative and congenital PA stenoses groups, right ventricular pressure decreased (right ventricular pressure indexed to femoral artery pressure ratio): from 0.63 +/- 0.2 to 0.41 +/- 0.02 (p < 0.001) and from 0.71 +/- 0.3 to 0.55 +/- 0.35 (p = 0.04), respectively. Perfusion to a single affected lung increased from 31 +/- 17% to 46 +/- 14% (p < 0.001). On recatheterization (mean 14 months), results varied minimally. Repeat angioplasty of residual stent stenoses was safe and effective. Complications included four early patients with stent migration, three with stent thrombosis and two deaths. There were no late complications. Significant restenosis occurred in only three patients. CONCLUSIONS: Intravascular stents for the treatment of vascular stenoses in congenital heart disease provide excellent immediate and long-term results.

Adolescent↗
PubMed1998

Stent dilation of superior vena cava and innominate vein obstructions permits transvenous pacing lead implantation.

The purpose of this study was to assess the feasibility of stent dilation of venous obstructions/occlusions to permit transvenous pacing lead implantation. Innominate vein or superior vena cava (SVG) obstruction may preclude the implantation of transvenous pacing leads. Patients with d-transposition of the great arteries, after a Mustard or Senning procedure, and children with previously placed transvenous pacing leads are at higher risk for this vascular complication. From May 1993 to January 1996, eight pediatric patients who underwent transvenous pacing lead implantation or replacement were found to have significant innominate vein or SVC obstruction or occlusion. Utilizing intravascular stents, a combined interventional and electrophysiological approach was used to relieve the venous obstruction and to permit implantation of a new transvenous pacing lead. Two patients had complete SVC occlusion requiring puncture through the obstruction with a transseptal needle. Vessel recanalization was achieved with balloon dilation and stent implantation. The remaining six patients had severe venous obstruction with a mean minimum diameter of 3.1 +/- 3.3 mm. The mean pressure gradient across the obstructed veins was 8.6 +/- 7.3 mmHg. Following implantation of 15 Palmaz P308 stents in eight vessels, the mean diameter increased to 14.2 +/- 1.9 mm and the mean pressure gradient across the stented vessels decreased to 1.0 +/- 2.0 mmHg. A transvenous pacing lead was implanted successfully through the stent(s) immediately or 6-8 weeks later. Innominate vein and SVC obstruction can be safely and effectively relieved with intravascular stents and permit immediate or subsequent transvenous pacing lead implantation.

Adolescent↗