Successful Balloon Dilatation Research Articles

The results of the treatment of right ventricle myocardial infarction

To present the results and experience in diagnosing and treating of patients with acute right ventricle infarction, during the period of hospitalization of one month, with adjuvant analyses of the obtained results in the period of fifteen years. Acute right ventricle infarction porved clinicaly, enzymologicaly, by ECG, echochardiographically or scintigraphically we treated with thrombolitic therapy within first six hours after admittion, with salvaged PTA in case of the cardiogenic shock or AV block II degrees-III degrees despite of thrommbolitic therapy, or with postponed PTA within first month of intrahospital treatment. In the period from 1990 to 2004, 3 225 patients of both sexes were treated for acute myocardial infarction at the different localization in patients' at the mean age of 53.7 +/- 5.8. One-hundred-thirty-nine (43.9%) patients were treated with thrombolitic therapy according to the speed up protocole. Heparin was administered to 160 (50.7%) patients with water load, and 17 (5.4%) patients had the primary percutaneous transluminal coronary angioplasty (PPTCA), so that the mechanical blood flow could be established, by the implantation of a stent when necessary. In 316 patients with right ventricle infarction, 58 (18.3%) had postponed and salvaged percutaneous transluminal coronary angioplasty (PTCA). Twenty-two (15.8%) patients had thrombolitic therapy, whereas 36 (22.5%) patients were treated with heparin. We had a successful balloon dilatation in 21 (36.2%), whereas 32 (55.2%) patients had 1-3 intracoronary stents inplanted, depending upon the necessity, and 5 (8.6%) patients from this group were sent to surgical intervention. In the group of 214 (67.7%) patients treated with heparin or thrombolitic therapy combined therapy, with PTCA, 12 (5.7%) patients died, whereas in the group of 124 (39.3%) patients treated only with heparin 26 (16.2%) patients died, statistically significant difference (p < 0.001, chi2 = 18.423). Was noticed n the group of 1 204 patients with inferoposterior infarction, 122 (10.1%) patients died. In the group of 316 patients with right ventricle infarction, 38 (12%) died. In the group of 888 control patients with inferoposterior infarction, but without right ventricle infarction, 84 (9.4%) patients died. In the group of 2 021 patients (62.2%) with anterior infarction, 248 (12.3%) died. CONCLUSION. The obtained results showed that the patients with right ventricle infarction, due to the great expansion of necrosis and the involvement of the inferoposterior wall of the left ventricle, as well as the ischemia of sinus and AV nodes, were the patients of a high risk. That was why it was essential to do urgent widening of the artery to reestablish blood flow either by using drugs or by means of mechanical methods.

A case of successful enteroscopic balloon dilation for late anastomotic stricture of choledochojejunostomy after living donor liver transplantation

Biliary complications remain a major concern after living donor liver transplantation. We describe a pediatric case who underwent a successful endoscopic balloon dilatation of biliary-enteric stricture following living donor liver transplantation using a newly developed method of enteroscopy. The 7-year-old boy with late biliary stricture of choledochojejunostomy was admitted 6 years after transplantation. Since percutaneous transhepatic cholangiography was technically difficult in this case, endoscopic retrograde cholangiography was performed using a double-balloon enteroscope under general anesthesia. The enteroscope was advanced retrograde through the duodenum, jejunum, and the leg of Roux-Y by the double-balloon method, and anastomotic stricture of choledochojejunostomy was clearly confirmed by endoscopic retrograde cholangiography and endoscopic direct vision. Balloon dilatation was performed and the anastomosis was expanded. Restenosis was not noted as of 2 years after the treatment. In conclusion, endoscopic balloon dilation of biliary-enteric anastomotic stricture using a new enteroscopic method can be regarded as an alternative choice to percutaneous transhepatic management and surgical re-anatomists.

Balloon dilatation vs. balloon dilatation plus bile duct endoprostheses for treatment of anastomotic biliary strictures after liver transplantation

Biliary strictures after liver transplantation are a therapeutic challenge for endoscopy. Anastomotic strictures occur in 10% of patients after liver transplantation, leading untreated to mortality and ultimately to graft failure. Despite of successful reports, to date, there is no defined endoscopic therapy regimen for these cases. Therefore the aim of this study was to determine the most suitable concept for endoscopic treatment of post-liver transplant anastomotic strictures (PTAS). A total of 72 patients post-liver transplantation, who received endoscopic retrograde cholangiography (ERC) as a consequence of suspected biliary complications were retrospectively screened for the presence of PTAS. In all patients graft rejection or bile duct ischemia were excluded prior to ERC by liver biopsy or Doppler ultrasound respectively. We compared either balloon dilatation (BD) alone or dilatation plus placement of an increasing number of bile duct endoprostheses (BD + endoprostheses) in a retrospective analysis. A total of 25 of 75 patients showed PTAS. Overall, endoscopic therapy was successful in 22 of 25 patients (88%). BD was initially successful in 89% but showed recurrence in 62%. BD + endoprostheses was initially successful in 87%, and recurrence was observed only in 31%. All recurrences were successfully retreated by BD + endoprostheses. During 22 of 109 (20%) treatment sessions stone extraction was necessary. Complication rate was low with bacterial cholangitis in 8 of 109 (7.3%) sessions, mild pancreatitis in 10 of 109 (9%) sessions and minor bleeding in 2 of 25 (8%) sphincterotomies. Median follow-up after conclusion of endoscopic therapy is 6 months (range 1-43). In conclusion, our data confirm that endoscopic therapy of PTAS is highly effective and safe. As primarily successful BD shows a high rate of recurrence, we recommend a combination of BD followed by an increasing number and diameter of endoprostheses. Therapy sessions are effective at short intervals of every 2-3 months.

PORTAL VEIN OBSTRUCTION IN THE LONG-TERM COURSE AFTER PEDIATRIC LIVING DONOR LIVER TRANSPLANTATION.

O157 Aims: Portal vein stenosis or occlusion is the one of the major surgical problem in pediatric living donor liver transplantation (LDLT) with the left lobe grafts, which possibly lead to graft loss. The frequency, the time after operation, the outcome of portal vein stenosis or occlusion in the long-term course after pediatric LDLT is not clear in a large series. Methods: Between June 1990 and Septmber 2003, 527 pediatric patients received primary LDLT either with the left lobe graft, left lateral segment graft or monosegment graft. Their age ranged from 27 days to 17y9m (median; 1y10m) and their body weight at the operation ranged from 3.1 Kg to 62.4 Kg (median; 10.1 Kg). Original disease were biliary cirrhosis (n=416), metabolic diseases (n=39), fulminant liver failure (n=30), liver cirrhosis (n=17), tumors (n=15), and others (n=10). Portal vein anastomosis was performed with or without vein graft according to the size of the recipient portal vein and size mismatch between recipient and graft portal vein. Blood flow of the portal vein was checked with the doppler ultrasonography every day for the first one week and every other day for the first one month. After the patient was discharged, portal blood flow was checked in the outpatient clinic when indicated. Results: Forty-one patients (7%) showed portal vein stenosis (n=29) or occlusion (n=12). Their age ranged from 4m to 17y3m (median; 1y). and their body weight at the operation ranged from 3.8Kg to 44.8Kg (median; 8.5Kg). The portal vein stenosis or occlusion was detected in the first six months in 7 patients (17%), in the next six months in 12 patients (29%), in the second year in 7 patients (17%), between 2y and 5y in 12 patients and therafter in 2 patients. In 29 patients with portal vein stenosis, percutaneous transhepatic balloon dilatation of the portal vein was successful. Two patients received portal vein re-anastomosis at 55m and 51m after LDLT. Two patients received re-LDLT at 92m and 62m due to graft failure caused by portal vein occulusion. One patient died after re-LDLT due to infection and others are all alive between 10m and 12y3m. Decrease in the portal vein flow by the doppler ultrasonography and decrease in the platelet count were the indicative signs in the patients with portal vein stenosis or occlusion. Conclusions: Portal vein stenosis or occulusion occurred in 7% of the pediatric patients in LDLT using left lobe graft. Portal vein stenosis and occulusion can be detected with the use of Doppler ultrasonogrphy and platelet count was an indicative marker. Early detection of portal vein stenosis can lead successful balloon dilatation and can avoid graft loss.

Esophageal Intramural Pseudodiverticulosis Treated by Balloon Dilatation: Report of a Case

A 72-year-old man presented with a 17-year history of dysphagia, which had gradually become worse in recent months. A barium esophagogram showed stenosis of the upper thoracic esophagus with multiple tiny flask-shaped outpouchings along the region of stenosis. Based on this characteristic appearance, we diagnosed esophageal intramural pseudodiverticulosis. He underwent successful balloon dilatation of the stenosis and his dysphagia resolved. Dynamic esophagography showed improved passage through the esophagus. He has been well and not suffering from dysphagia for 4 years since the balloon dilatation.

Coarctation of the aorta in neonates and young infants: surgical experience.

A retrospective analysis of repair of aortic coarctation in young infants was conducted. Between April 1997 and December 2000, 21 patients under 4 months of age underwent repair of coarctation. Their mean age and weight were 41 42 days (range, 2 to 120 days) and 3.6 0.7 kg (range, 2.6 to 4.9 kg). The indications for surgery were congestive heart failure and/or shock. Diagnosis was made by 2-dimensional echocardiography with Doppler color flow imaging. Preoperative gradients ranged from 25 to 100 mm Hg. Aortic arch hypoplasia was present in 8 patients; 7 patients also had ventricular septal defect. Wide excision of the coarctation segment with extended end-to-end anastomosis was performed in 20 patients, while 1 required a Gore-Tex interposition graft between the left common carotid artery and the descending aorta. Subclavian angioplasty was performed to augment the anastomosis in 1 patient. There was no early mortality. One patient died 2 months after surgery. Follow-up examination revealed recoarctation in 5 patients (23.8%), all of whom underwent successful balloon dilatation. In conclusion, wider excision of the coarctation with extended end-to-end anastomosis reduces the chances of recoarctation. Percutaneous balloon angioplasty for treating recoarctation is effective in immediately reducing pressure gradients.

Postoperative Duodenal Stenosis as an Early Complication Following Laparoscopy-Assisted REsection of Transverse Colon Cancer: Report of Successful Endoscopic Balloon Dilatation

Postoperative Duodenal Stenosis as an Early Complication Following Laparoscopy-Assisted REsection of Transverse Colon Cancer: Report of Successful Endoscopic Balloon Dilatation

Postoperative duodenal stenosis as an early complication following laparoscopy-assisted resection of transverse colon cancer: report of successful endoscopic balloon dilatation

A 69-year-old man underwent laparoscopy-assisted resection for transverse colon cancer. He visited our department approxiately 1 month after operation suffering from nausea and epigastric discomfort. Endoscopy and X-ray examina-tion showed a severe stenosis in the second portion of the duodenum, which we believe was caused by the previous colectomy as indicated by no evidence of other causative event or factor found in his history or through thorough examination. He was then successfully treated by endoscopic balloon dilatation using of a controlled radial expansion wire-guided balloon dilatation catheter. We report a case of postoperative duodenal stenosis as an early complication following laparoscopy-assisted resection of transverse colon cancer. This case would be the first report documented in Japan that we are aware of. Furthermore, this experience suggested that endoscopic balloon dilatation for postoperative duodenal stenosis is effective.

High shear stress after successful balloon angioplasty is associated with restenosis and target lesion revascularization

Background Vascular wall shear stress (WSS) has been implied in the pathogenesis of atherosclerosis and vascular remodeling. Our aim was to calculate WSS after balloon angioplasty and evaluate its predictive value for long-term outcome. Methods WSS was calculated proximal to, in, and distal to the lesion after angiographically successful balloon dilatation and at follow-up with the Hagen-Poiseuille formula (WSS = 4μQ/πR3) in 202 patients. Volumetric blood flow (Q) and lumen radius (R) were derived from Doppler scanning velocities and videodensitometric cross-sectional areas. Results Postprocedural proximal and in-lesion values were higher in vessels that developed restenosis (n = 72; 1.22 ± 0.61 N/m2 and 3.61 ± 2.38 N/m2, respectively) than in those without restenosis (n = 130, 1.05 ± 0.51 N/m2 and 2.46 ± 1.39 N/m2, respectively; P <.05). In-lesion WSS was revealed to be predictive of restenosis by means of logistic regression analysis (odds ratio [OR] = 1.42, P <.05), whereas WSS of the proximal segment was associated with an increased rate of target lesion revascularization (OR = 2.33, P <.005). In the multivariate regression model, WSS of the proximal segment was the only independent predictor when entered with known predictors such as diameter stenosis and coronary flow reserve (OR = 2.15, P <.05). Conclusions WSS in the lesion after balloon angioplasty is predictive of angiographic restenosis. Moreover, the proximal value is an independent predictor of target lesion revascularization. This study opens perspectives for the on-line use of WSS as a combined parameter of anatomy and physiology to assess the necessity of adjunctive therapy after successful balloon dilatation. (Am Heart J 2002;144:136-43.)

Balloon dilation and stent implant through the side of a previously placed intravascular stent: a new option for the interventionalist.

Intravascular stent placement for relief of vascular stenoses often requires that a stent be positioned across the origin of side-branch vessels. Most currently available peripheral vascular stents have a closed-cell design that will not allow catheter manipulation, dilation, or stenting through the stent cells. Therefore, if a side branch arising off a previously stented vessel is stenotic or if its origin has been compromised, transcatheter dilation of the branch vessel has not been possible. We report a series of successful balloon dilation and stent placement through the sides (cells) of previously placed IntraStent DoubleStrut LD stents in the aortic arch and abdominal aorta of pigs.

Heme oxygenase-1 gene promoter microsatellite polymorphism is associated with restenosis after percutaneous transluminal angioplasty.

To determine if an association exists between postdilation restenosis and heme oxygenase-1 (HO-1), which is induced by balloon injury and inhibits neointimal formation through the action of endogenous carbon monoxide. A dinucleotide repeat in the promoter region of the HO-1 gene shows a length polymorphism that modulates the level of gene transcription. This cohort study included 96 consecutive patients (64 men; median age 69 years, interquartile range 60-75) who underwent successful balloon dilation in the femoropopliteal segment. Six-month patency was evaluated using oscillography, ankle-brachial index, and duplex sonography. The association of patency and the length of (GT) repeats in the HO-1 gene promoter was assessed in univariate and multivariate analyses. Restenosis was found in 23 (24%) patients within the first 6 months. Patients with short (<25 GT) dinucleotide repeats in the HO-1 gene promoter on either allele had restenosis significantly less often than patients with longer (> or = 25 GT) dinucleotide repeats (p = 0.01). Multivariate analysis revealed a significantly reduced risk for restenosis in these patients compared to patients without the short allele (odds ratio 0.2, 95% Cl 0.06 to 0.70, p = 0.007). Genetic risk factors for restenosis after percutaneous transluminal angioplasty have not been investigated. In this patient population, short repeat alleles of the heme oxygenase-1 gene promoter polymorphism were associated with reduced postdilation restenosis at 6 months. Upregulation of HO-1 may be an important protective factor after balloon angioplasty by inhibition of vascular smooth muscle cell proliferation.

Pulmonary artery trauma due to balloon dilation: recognition, avoidance and management

OBJECTIVESWe reviewed the management and outcome of patients experiencing pulmonary artery (PA) trauma during balloon dilation (BD).BACKGROUNDBalloon dilation of the PA is important in the management of peripheral pulmonary stenosis. Successful BD requires a controlled tear of the PA; excessive tearing can produce complications ranging from pseudoaneurysms to rupture and death. The incidence and optimum management for such complications are unreported.METHODSAll records of patients who underwent branch PA dilation between June 1984 and October 1997 were reviewed; those with a significant complication were analyzed.RESULTSOf 1,286 catheterizations in 782 patients, PA trauma (excluding isolated pulmonary edema and PA aneurysms) was identified in 29 catheterizations in 26 patients. Tears occurred distal to the area of stenosis in most cases (62%). Intensive medical management, with and without catheter directed therapy, was employed. The damaged PA was successfully coil embolized in five patients, four of whom survived; temporary balloon occlusion did not prevent death in two patients. There were six deaths from pulmonary hemorrhage. A case control analysis demonstrated that PA trauma was significantly associated with pulmonary hypertension.CONCLUSIONSPulmonary artery trauma associated with BD occurs mostly distal to the site of narrowing, is associated with underlying pulmonary hypertension and is frequently (5/12 or 42%) fatal in those with unconfined tears. Intensive management strategies as well as attention to distal balloon position may reduce incidence and mortality. Coil occlusion of the damaged PA appears to be a valuable strategy to prevent fatal hemorrhage.

Management of unsuspected common bile duct stones found during laparoscopic cholecystectomy by means of transcystic catheter placement and papillary dilation

Background: The optimal treatment strategy for treatment of bile duct stones first diagnosed during laparoscopic cholecystectomy has not been established. We prospectively treated unsuspected bile duct stones by means of intraoperative placement of a transcystic catheter followed by postoperative pharmacologic papillary dilation or endoscopic papillary balloon dilation. Methods: In 17 patients with bile duct stones first found at laparoscopic cholecystectomy, a catheter was introduced via the cystic duct into the bile duct. If postoperative cholangiography via a transcystic catheter showed stones 5 mm or less in diameter, glyceryl trinitrate was infused via the catheter into the bile duct. Patients in whom medical dilation was unsuccessful or who had larger stones underwent endoscopic papillary balloon dilation. Results: Stone diameter measured 3 to 11 mm (mean 6.4 mm). Postoperative cholangiography revealed spontaneous passage in four patients. After pharmacologic papillary dilation, two of five patients with stones 5 mm or less in diameter had stone clearance. The remaining 11 patients underwent successful endoscopic papillary balloon dilation with stone clearance. In two patients, a guidewire introduced via a transcystic catheter through the papilla facilitated selective biliary cannulation. One early minor complication occurred. All patients remained without symptoms for a mean follow-up of 13 months. Conclusion: For unsuspected bile duct stones (usually small ones), this strategy is a simple and effective alternative to laparoscopic bile duct exploration and postoperative sphincterotomy and may minimize early and late complications. Transcystic catheterization ensures access to the bile duct, thereby avoiding endoscopic treatment failures.

Balloon Dilation of Posterior Urethral Stricture Secondary to Radiation and Cryotherapy in a Patient with a Functional Artificial Urethral Sphincter

Severe urethral stricture disease as an isolated entity can be a management dilemma. In the patient described here, this problem was associated with prior external-beam radiation and cryosurgical ablation of the prostate, and a functional artificial urethral sphincter (AUS) had been placed. An attempt to relieve partial urinary obstruction while preserving AUS function led to successful balloon dilation proximal to the sphincter cuff.

Morphological Effects on In-Stent Restenosis Assessed by Intravascular Ultrasound Imaging.

The purpose of this study was to evaluate the rupture and dissection of the vessel wall immediately after balloon dilatation by intravascular ultrasound (IVUS) imaging and to predict restenosis in patients who underwent subsequent coronary stent implantation. Stent implantation improves the long-term results of coronary angioplasty by reducing lesion elastic recoil and arterial remodeling. However, several studies have suggested that neointimal hyperplasia is the cause of instant restenosis. We recruited 60 patients in whom IVUS studies were performed immediately after successful balloon dilatation and just before stent implantation. We compared IVUS parameters with 6-month follow-up quantitative coronary angiography. This was performed in 51 lesions of 51 patients (85%). Qualitative analysis included assessment of plaque composition, plaque eccentricity, plaque fracture and the presence of dissection. In addition, minimal luminal diameter, percent diameter stenosis, percent area stenosis and plaque burden were quantitatively analyzed. Two morphological patterns after balloon dilatation were classified by IVUS. Type I was defined as absence or partial tear of the plaque without disclosure of the media to lumen (22 lesions). Type II was defined as a split in the plaque or dissection of the vessel wall with disclosure of the media to the lumen (29 lesions). At 6 months follow-up, angiographic restenosis occurred in 17 of the 51 lesions (33%). Restenosis was significantly (p < 0.05) more likely to occur in type II (13/29: 45% incidence) than in type I (4/22: 18% incidence). The assessment of plaque morphology immediately after balloon dilatation and before stent implantation provides important therapeutic and prognostic implications.

Long-term results of endoscopic balloon dilatation for gastric outlet obstruction.

Endoscopic balloon dilatation has been used for more than 10 years for the treatment of peptic gastric outlet obstruction. Long-term outcomes in series from tertiary centers have shown a high rate of failure in several studies. We reviewed a series of patients treated with balloon dilatation in a community hospital to evaluate the effectiveness in this procedure and factors that would affect success rate. Forty consecutive patients who had successful initial balloon dilatation for benign gastric outlet obstruction were followed for at least two years or until death or surgical therapy occurred. Data were obtained from the gastrointestinal laboratory log book, hospital, and office records. Patients were also interviewed by telephone. Twelve patients had relief of obstruction by initial dilatation. The remaining 28 patients developed recurrent symptoms and 12 in this group eventually required surgery. Factors predicting referral for surgery included younger age, need for multiple procedures, technical failure of dilatation in four patients, and long duration of treatment course. Eradication of Helicobacter pylori was associated with successful relief of obstruction without surgery, whereas continued use of nonsteroidal antiinflammatory drugs was associated with recurrent obstruction. In the community hospital, endoscopic treatment is safe and is usually successful in relieving benign gastric outlet obstruction. Repeat dilation is often needed and long-term success will be improved by elimination of H. pylori infection and nonsteroidal antiinflammatory use.

Repair of coarctation with resection and extended end-to-end anastomosis

Background. Our surgical strategy for infant coarctation changed from subclavian flap aortoplasty to resection with extended end-to-end anastomosis in 1991. The purpose of this review was to evaluate the results of that strategy. Methods. From 1991 through 1997, 55 infants underwent repair of coarctation of the aorta using resection with extended end-to-end anastomosis. Isolated coarctation of the aorta was present in 26 patients, 20 patients had a ventricular septal defect, and 9 patients had other associated intracardiac lesions. Mean age at surgery was 0.20 ± 0.24 years (median, 21 days). In 34 patients (62%), arch reconstruction was performed through a left thoracotomy. Twenty patients (36%) had median sternotomy with simultaneous repair of coarctation of the aorta and intracardiac repair of associated lesions. One patient had recoarctation repair through a median sternotomy. All coarctation and ductal tissue was resected and the anastomosis was constructed starting opposite the left carotid artery with running polypropylene suture. Results. There was one early death 26 days after coarctation of the aorta and ventricular septal defect repair in a child on extracorporeal membrane oxygenation for meconium aspiration and 2 late deaths owing to pneumonia and pulmonary hypertension (1) and interventricular hemorrhage (1). There were no instances of paraplegia. Follow-up in survivors ranges from 10 to 76 months (mean, 39.8 ± 17.2 months). Recoarctation has developed in 2 patients, who have had successful balloon dilation 6 and 14 months after the operation. This yields a low recoarctation rate of 3.6%. Conclusions. Resection with extended end-to-end anastomosis yields a low mortality and particularly a low recoarctation rate and is our procedure of choice for infants with coarctation of the aorta.

Anomalous origin of one pulmonary artery from the ascending aorta: 36 years' experience from one centre.

Anomalous origin of one pulmonary artery from the ascending aorta is an uncommon lesion with an uncertain outcome. We reviewed 16 consecutive children (9 males) presenting with this lesion over a 36 year period at a single institution. Median age at presentation was 2 days (range, birth to 3.2 years). The anomalous pulmonary was the right in 12 and the left in 4, all originating from the proximal ascending aorta, with no patient having stenosis at the origin of the anomalous pulmonary artery. Associated cardiac anomalies were noted in 9 patients. No intervention was attempted in 2 patients: one was deemed inoperable due to complex associated lesions and pulmonary vascular obstructive disease, while the other one died before repair. Surgical intervention was attempted in 14 patients, with 3 intraoperative deaths (21%). Of 11 operative survivors, 8 developed pulmonary arterial stenosis graded severe in 2, moderate in 1 and mild in 5. Patients with severe stenosis required surgical angioplasty, 1 after unsuccessful dilation combined with placement of an endovascular stent. One patient with moderate, and one with mild, stenosis underwent successful transcatheter balloon dilation. The remaining 4 patients with mild stenosis remain unchanged during follow-up. One patient had biopsy evidence of pulmonary vascular obstructive disease at 3.3 years of age. There were no late deaths, giving a total mortality of 25% (4/16). While early diagnosis and repair of anomalous origin of one pulmonary artery from the ascending aorta is necessary, restenosis of the site of repair is common.

Intravascular ultrasound assessment of regional aortic wall stiffness, distensibility, and compliance in patients with coarctation of the aorta

Background: Impaired aortic pulsatility has been demonstrated by angiography in children and in studies of experimental animals with coarctation of the aorta. Objectives: The purpose of this study was to assess regional aortic stiffness, distensibility, and compliance before and after balloon dilation in patients with coarctation of the aorta. Methods and Results: Intravascular ultrasound examination was performed in 13 pediatric patients with the diagnosis of coarctation of the aorta to yield aortic diameter. Area transverse sections at both systolic and diastolic period were measured at three aortic levels: the proximal, distal, and coarctation segments. Balloon dilation was also performed in eight of 13 patients. By using pressures measured in the same areas, an aortic stiffness index (β) was calculated as ln(Ps/Pd)/(Ds-Dd), where ln is natural logarithm, Ps is systolic pressure, Pd is diastolic pressure, Ds is systolic diameter, and Dd is diastolic diameter. Aortic distensibility and an estimation of aortic compliance were also calculated. The β stiffness index of the coarctation and the proximal segments of the aorta were significantly greater than that of the distal segment of the aorta ( p < 0.01). The aortic wall stiffness β index did not acutely change after successful balloon dilation, but the distensibility and compliance of distal aorta were nonetheless significantly decreased after balloon dilation ( p < 0.01, p < 0.05) as a function of changes of pulsatility of flow. Conclusions: Abnormal proximal aortic stiffness may be a strong contributing factor that promotes the genesis of hypertension in patients with coarctation even after successful repair or balloon angioplasty. (Am Heart J 1997;134:93-98.)

Efficacy of low-molecular-weight heparin delivery with the Dispatch catheter following balloon angioplasty in the rabbit iliac artery.

Local drug delivery can be achieved with active injection systems or passive contact of a compound with the arterial wall. The Dispatch catheter allows for passive diffusion of drugs from drug compartments while preserving blood flow through the central conduit. The aim of this study was to investigate whether a reduction in neointima formation can be achieved by local delivery of a limited amount of a highly concentrated solution of the low-molecular-weight heparin Reviparin. In 16 New Zealand white rabbits, successful balloon dilatation was performed in both iliac arteries, followed by local delivery of 4 ml Reviparin (1,000 IU/ml). The arteries were harvested at 7, 28, or 56 d following the procedure. The intimal cell layers increased substantially between 7 and 28 d following balloon dilatation with or without local drug delivery. The medial cell layers showed only a little increase. Proliferation of smooth muscle cells reached an early peak after 7 d, with a significantly higher proliferation index following local delivery. The maximum amount of macrophages in the intima and media was detected after 28 d. The lumen area decreased with time and was 0.6 +/- 0.7 mm2 in the local delivery group at 56 d compared with 0.5 +/- 0.5 mm2 in the control group. In conclusion, local delivery of Reviparin with the Dispatch catheter is safe and feasible. However, the infusion of highly concentrated low-molecular-weight heparin over a short period of time did not result in a reduction of neointima formation and restenosis following balloon dilatation in the rabbit iliac artery.