End-hole Catheter Research Articles

Reopening acutely occluded cavopulmonary connections in infants and children☆

Little is known about the outcome of acute thrombotic occlusion of segments of the cavopulmonary connections (CPC) in infants and children with univentricular hearts. Early recognition and aggressive therapy may result in successful salvage of some of these patients. Five consecutive patients (age range 4-8 months) presenting with acute occlusion of a CPC segment underwent emergency cardiac catheterization. After angiographic confirmation, the occluded segment was crossed using an endhole catheter and guidewire combination. Serial balloon dilation and stent implantation (ten stents in total) were undertaken to recanalize the occlusion. The stents used were mounted on balloons ranging in diameter from 6 mm to 8 mm, depending on the size of the native vessel. The sites of occlusion were the left pulmonary artery (n=4), and the left-sided superior caval vein (n=3). All occlusions could be successfully recanalized. In three patients, early reocclusion necessitated either surgery or repeat catheterization and angioplasty. There were two early deaths, due to recurrent thrombotic obstruction confirmed either at autopsy or angiography. The remaining patients are alive and well; the majority of survivors have undergone completion of the Fontan operation. A high index of clinical suspicion combined with aggressive therapy can result in successful recanalization in some infants with acutely occluded CPC segments, with acceptable long-term outcome.

Inhaled Nitroglycerin Versus Inhaled Milrinone in Children with Congenital Heart Disease Suffering from Pulmonary Artery Hypertension

The aim of the present study was to compare the acute effects of inhaled milrinone and inhaled nitroglycerin on pulmonary and systemic hemodynamics in children with acyanotic congenital heart disease (left-to-right shunt) and pulmonary artery hypertension. Randomized clinical trial. Catheterization laboratory of a tertiary care hospital. Thirty-five children below the age of 12 years who were suffering from acyanotic congenital heart disease with left-to-right intracardiac shunt and pulmonary artery hypertension (mean PA pressure > 30 mmHg). Right-heart catheterization was done using an end-hole balloon wedge pressure catheter. Baseline pulmonary and systemic hemodynamic parameters were recorded for all patients while breathing room air. All patients then underwent pulmonary vasodilator testing with 100% oxygen. Following this, patients were randomized into two groups and received either inhaled milrinone (group M, n = 18) or inhaled nitroglycerin (group N, n = 17) in a 50% air-oxygen mixture. Oximetry data were used to calculate systemic and pulmonary cardiac output based on Fick's principle. Systolic, diastolic, and mean pulmonary artery pressures decreased significantly in both the groups after drug nebulization, while there were no significant changes in systemic pressures. The percentage decrease from baseline in systolic (5.2% v 8.6%, p = 0.43), diastolic (19.5% v 16.8%, p = 0.19) and mean (14.9% v14.5%, p = 0.29) pulmonary artery pressures were comparable in both groups. The pulmonary vascular resistance index (PVRI) decreased from 9.0 ± 3.9 to 2.9 ± 1.7 Wood Units (WU)/m(2) in group M (p < 0.001) and from 8.6 ± 3.8 to 3.2 ± 3.3 WU/m(2) in group N (p < 0.001). The fall in pulmonary artery pressures after drug nebulization in both groups was comparable to the fall seen with 100% oxygen. Both milrinone and nitroglycerin when given via the inhaled route significantly decrease systolic, diastolic and mean pulmonary artery pressures as well as PVRI without significant effects on systemic hemodynamics. Both the drugs given via inhaled route therefore can offer a good therapeutic choice and can help decrease the high inspired oxygen concentrations needed to treat pulmonary artery hypertensive episodes in perioperative settings.

Intrarenal Artery Delineation With Ultra High Resolution, Flat Panel Based, Volume Computerized Tomography: Outer Limits of Spatial Resolution

New methods of noninvasive high resolution imaging may improve the delineation of tumor microvessels and, thus, be of significant help in surgical planning and cost-effective monitoring of novel anti-angiogenic therapy. We determined the maximum delineation of intrarenal microvessels with a novel flat panel based volume computerized tomography system in an experimental setting. We prospectively evaluated 13 porcine renal specimens for intrarenal vessel delineation using a prototype gantry based, flat panel, cone beam computerized tomography system. The gantry incorporates an array of a 40 x 30 cm(2) CsI amorphous silicon flat panel detector consisting of a 2,048 x 1,536 matrix. After catheterizing the renal artery with a 5Fr end hole catheter a contrast enhanced scan was performed using BaS as contrast medium at a dilution of 200 mg/ml. The diameter of all definable arterial branches was determined using a software tool based on Medical Imaging and Interaction Toolkit, allowing semi-automatic segmentation of the vessel tree. In step 1 the vessel tree is segmented by a 3-dimensional region growing algorithm. Following its medial axis the vessel tree is extracted and converted to a representation, including the diameter of the vessels. In each kidney an average +/- SD of 47,454 +/- 22,382 arterial branches could be delineated. The diameter of the branches was 0.029 (mean 0.032 +/- 0.0025) to 3.444 mm (mean 1.813 +/- 0.6139) with a median of 0.263 mm. Of visible intrarenal arteries 2.7% had a vessel diameter of 0.029 mm. Flat panel based volume computerized tomography can visualize intrarenal microvessels down to a diameter of 0.03 mm. It may improve the assessment of renal microvessel architecture in healthy patients and in those with pathological conditions.

A randomized prospective study comparing two flexible epidural catheters for labour analgesia

Previous studies evaluating stiff epidural catheters found that the three-holed design provided superior labour analgesia compared with an end-holed design. This was believed due to improved medication distribution. Recently, flexible epidural catheters with both designs have been shown to be superior to the stiff epidural catheters. We investigated the success of labour analgesia comparing the flexible three-holed with the flexible end-holed epidural catheter. This was a prospective, single-blinded randomized study. We enrolled 500 parturients in active labour. The primary outcome was complete relief of labour pain assessed at 30 min. We also assessed the occurrence of paresthesias, intravascular and intrathecal placement, catheter replacement, and treatment of breakthrough pain during labour. Comparisons were made using Pearson's chi(2), with significance determined at the 0.05 level. Four hundred and ninety-three subjects completed the study. Initial analgesia was similar (complete labour analgesia: end-holed=85% vs 80% 95% CI of difference: 13% to -3%; P=NS). The incidence of paresthesia was similar (end-holed=3.6% vs 5.3%; P=NS). There was one intrathecal and three intravascular catheters in the three-holed group and two intravascular catheters in the end-holed group. The number of supplemental boluses and catheter replacements required during labour was similar between the groups. There were no differences in the initial analgesia success rate, complications, or labour analgesia between end-hole vs multi-hole flexible epidural catheters.

Can catheter-directed thrombolysis be applied to acute lower extremity artery embolism after recent cerebral embolism from atrial fibrillation?

To assess the feasibility and efficacy of catheter-directed thrombolysis with recombinant tissue plasminogen activator (rt-PA) for acute limb embolism in patients with recent cerebral embolism due to atrial fibrillation. Eight patients (six men, two women; mean age 63.5 years) with acute embolic occlusion of two left common iliac arteries, four femoral arteries (three left; one right), and two right popliteal arteries were treated. All patients had a history of recent cerebral embolism (mean 6 days, range 5-15 days) and all had a history of atrial fibrillation (duration 5-10 years). Catheter-directed thrombolysis started a few hours (mean 6.2h; range 3-10h) after the onset of arterial embolism. Two 5mg boluses of rt-PA were injected into the proximal clot through a 5 F end-hole catheter and, subsequently, two additional boluses of 5mg rt-PA were injected into the emboli. In patients with residual emboli, infusion with rt-PA (1mg/h) was continued. Percutaneous transluminal angioplasty was performed in three patients, and a stent was deployed in one patient. Technical success was achieved in all patients. Clinical success rate was 87.5% (7/8). The one clinical failure was secondary to chronic occlusion of outflow runoff vessels. The mean duration of continuous rt-PA infusion was 3.6h, the mean total dose of rt-PA administered was 23.6 mg (range 20-28 mg). There was no significant change in stroke scale scores during thrombolysis and no intracerebral haemorrhage was found at computed tomography (CT) after thrombolysis. Minor complications included haematomata at puncture sites (6/8), bleeding around the vascular sheath (2/8), and haematuria (1/8). During the follow-up period of 3-6 months, one patient suffered from recurrent cerebral embolism and died. Catheter-directed thrombolysis with rt-PA is an option for acute lower extremity arterial embolism in patients with recent cerebral embolism and a history of atrial fibrillation. Further studies should be undertaken to determine the risk of intracerebral haemorrhage caused by catheter-directed thrombolysis in individual stroke patients.

Ventilatory Efficiency and Resting Hemodynamics in Hypertrophic Cardiomyopathy

In patients with systolic heart failure, the ability of cardiopulmonary exercise testing (CPX) variables to reflect pathophysiology is well established. The relationship between CPX and pathophysiology has, however, not been thoroughly investigated in patients with nonobstructive hypertrophic cardiomyopathy (NHCM). The objective of this study was to assess the ability of CPX variables to reflect resting hemodynamics in patients with nonobstructive hypertrophic cardiomyopathy NHCM. We performed CPX and right heart catheterization on 83 subjects with NHCM (51 male/32 female, mean age = 38 +/- 10 yr, NYHA I-III mean = 1.7). Peak oxygen consumption ( O2) and minute ventilation/carbon dioxide ratio (V E/VCO2) at peak exercise were compared to resting hemodynamics including pulmonary artery systolic, diastolic and mean pressures (PASP, PADP and MPAP), and pulmonary capillary wedge pressure (PCWP). Elevations in PCWP (> or = 15 mm Hg), PASP (> or =30 and > or = 40 mm Hg), PADP (> 15 mm Hg) and MPAP (> or = 20 mm Hg) were detected in 22, 33, 10, and 23% of subjects, respectively. Peak V E/VCO2 (positive correlation) and peak VO2 (negative correlation) correlated modestly with all pressure measurements (r = 0.33-0.51, P < 0.01 for all measurements). By receiver operating curve analysis, a V E/VCO2 >35.5 exhibited the best diagnostic accuracy with a curve areas of 0.81 for PAP > or = 30 mm Hg (sensitivity/specificity = 86%/67%), 0.87 for PAP > or = 40 mm Hg (77%/100%), 0.86 for MPAP > 20 mm Hg (83%/79%), and 0.84 for PCWP > or = 15 mm Hg (80%/76%). CPX can accurately identify abnormal resting hemodynamics in patients with NHCM. Further testing of this modality in other forms of diastolic dysfunction may be warranted.

Side-Hole Catheter Placement for Hepatic Arterial Infusion Chemotherapy in Patients with Liver Metastases from Colorectal Cancer: Long-Term Treatment and Survival Benefit

The objective of this study was to evaluate retrospectively correlations between catheter placement methods and treatment outcomes of patients treated with hepatic arterial infusion chemotherapy for unresectable liver metastases from colorectal cancer. This study involved 135 patients with liver metastases from colorectal cancer who underwent intrahepatic chemotherapy using catheter-port systems. Complications, treatment discontinuation, hepatic progression, and survival of patients treated with each method were evaluated retrospectively using the Kaplan-Meier method. Conventional 5-French end-hole catheter placement (n = 10) was compared with three side-hole catheter placement methods: 5-French side-hole catheter placement with a fixed catheter tip (original fixed catheter tip method, n = 77); long tapered side-hole catheter placement using a fixed catheter tip method (modified fixed catheter tip method, n = 24); and long tapered side-hole catheter inserted distally in the hepatic artery (long tapered catheter placement method, n = 24). The following treatment outcomes were significantly better for patients treated using the original or modified fixed catheter tip or long tapered catheter placement method than for those treated using the conventional method, respectively: hepatic arterial patency (1 year: 76.3%, 95.0%, and 94.4% vs 38.9%; p = 0.0014, 0.0007, and 0.0006), catheter stability (1 year: 96.7%, 95.5%, and 95.2% vs 42.9%; p < 0.0001, p = 0.0003, and p = 0.0009), time to treatment discontinuation (medians: 11.7, 14.4, and 12.4 vs 3.2 months; p < 0.0001, 0.0002, and 0.0019), time to hepatic progression (medians: 14.7, 15.7, and 15.8 vs 5.5 months; p = 0.0049, 0.0141, and 0.0004), and overall survival (medians: 21.1, 22.5, and 23.1 vs 13.1 months; p = 0.0146, 0.0036, and 0.0017). Compared with the conventional method, side-hole catheter placement methods allowed long-term intrahepatic chemotherapy and resulted in improved survival.

Transcatheter recanalization of acutely occluded modified systemic to pulmonary artery shunts in infancy

There are few data on successful recanalization of acutely occluded modified aortopulmonary shunts in infants in whom the major component of pulmonary flow is shunt-dependent. Seven infants (age range 6 days to 7 months) with modified (polytetrafluoroethylene) aortopulmonary shunts (central shunt n = 6, modified Blalock-Taussig shunt n = 1), in whom acute shunt occlusion was documented following surgery (interval from shunt surgery 2-6 days) underwent emergency cardiac catheterization with a view to reopening the shunt. Anterograde right ventricle to pulmonary artery flow was present in three patient; two other had additional aortopulmonary collateral vessels, and intravenous prostaglandin E (PGE1) infusion was restarted in three infants to achieve or maintain ductal patency. All occluded shunts could be crossed with a 4F endhole catheter and various guidewire combinations. Balloon dilation was performed using a balloon with the same nominal diameter as the shunt (5 or 6 mm). All shunts were successfully recanalized. Two infants with recurrent cyanotic episodes underwent stent implantation in the right ventricular outflow tract (RVOT) during the same procedure. One infant required shunt revision 24 h following balloon angioplasty, during which a small clot was evacuated from the distal end of the shunt. An immediate improvement in oxygen saturation could be documented in all patients. In the remaining six infants, shunt patency was confirmed at follow-up, until further definitive repair. One infant died of non-cardiac causes, while awaiting definitive repair. This small series demonstrates that acutely occluded shunts can be successfully recanalized, and that patency can be maintained until further definitive surgery in the majority of infants.

Neonatal Patent Ductus Arteriosus Recanalization and Stenting in Critical Ebstein’s Anomaly

A critically ill 3-day-old neonate with severe tricuspid valve Ebstein's anomaly, functional pulmonary atresia, and closed ductus arteriosus, unresponsive to prostaglandin infusion, underwent percutaneous ductal recanalization and stenting as an alternative to a surgical shunt. After local prostaglandin infusion through an end-hole catheter, the ductus was passed using a hydrophilic, high-support coronary guidewire. It was then stabilized by coronary stent implantation, after which the arterial oxygen saturation showed a sudden rise. In conclusion, ductus arteriosus recanalization and stenting can be successfully achieved within a few days after spontaneous closure as a cost-effective alternative to a surgical shunt for critical neonatal, duct-dependent Ebstein's anomaly.

Convective delivery of glial cell line–derived neurotrophic factor in the human putamen

The authors conducted an analysis of the distribution of glial cell line-derived neurotrophic factor in the human striatum following convection-enhanced delivery. Computational examinations of the effects of differing catheters, infusion rates, infusate concentrations, and target placement on distribution were completed based on the protocols of three recent clinical trials. Similar drug distributions around on-target end-hole catheters were predicted in two of the trials (AmgenUT study and Bristol study), although there was slightly deeper penetration for one of the trials (Bristol) due to a higher infusate concentration. However, when positioning uncertainly located catheter tips close to gray-white matter interfaces, backflow could diminish delivery, shunting infusate across the interfaces. For delivery via a multiport catheter at a constant base infusion rate plus a periodic bolus inflow rate (Kentucky study), base inflow alone generated a somewhat smaller distribution volume relative to those in the other trials, was positioned more anteriorly in the putamen, and was somewhat elongated axially; the bolus component extended this putaminal distribution to a larger relative volume but may have been reduced by backflow loss. Results of these computations indicated that for catheters placed exactly on the intended target, ideal drug distributions were similar for two of the trials (AmgenUT and Bristol) and different in terms of location and extent in the third study (Kentucky); yet the pattern of trial outcomes did not reflect these same groupings. This finding suggests that other factors are at play, widely varying statistical power and the possible effects of not excluding data from patients who experienced large drug losses across gray tissue boundaries due to variation in catheter placement.

Fluid perfused urethral pressure profilometry and Valsalva leak point pressure: a comparative study in a biophysical model of the urethra

In patient studies the correlation between maximum urethral closure pressure (MUCP) and Valsalva leak point pressure (LPP) is meagre at best (r = 0.22-0.50). We therefore studied the relation between MUCP and LPP in a flexible and extensible model urethra. We applied differently sized pressure zones and different degrees of resistance to a biophysical model urethra by stepwise inflating three types of blood pressure cuff placed around the model. At each degree of resistance we measured detrusor LPP, an in vitro equivalent of Valsalva LPP. Subsequently, we recorded the Urethral Pressure Profile using a water-perfused 5F end-hole catheter at four withdrawal rates and five perfusion rates and calculated MUCP. We tested the dependence of LPP on pressure zone length and MUCP on perfusion rate, withdrawal rate and pressure zone length using analysis of variance. We tested the correlation between LPP and MUCP using Pearson's correlation coefficient and Linear Regression. LPP did not significantly depend on the pressure zone length (P = 0.80) and increased linearly with increasing cuff pressure. MUCP also increased with increasing cuff pressure, however, MUCP significantly depended (P < 0.01) on perfusion rate, withdrawal rate and pressure zone length. MUCP increased with increasing perfusion rate, and decreased with increasing withdrawal rate. In our model urethra MUCP only accurately reflected urethral resistance for a very limited number of combinations of perfusion rate and withdrawal rate. LPP reflected urethral resistance independent of the type of pressure zone.

The coiling length of thoracic epidural catheters: the influence of epidural approach angle

Thoracic epidural catheters are used for anaesthesia and postoperative analgesia. Usually, epidural catheters are placed without confirmation of their position despite frequent reports of complications as a result of malposition. In this study, we evaluated the threading length of thoracic epidural catheters without coiling and assessed the influence of two different epidural approach angles on the threading length without coiling. Eighty-three patients scheduled for thoracotomy were enrolled and randomly allocated into the acute angle group and the obtuse angle group. In both groups, skin insertion was performed at the T8-9 intervertebra level. Epidural access was performed under fluoroscopy using a paramedian approach at the T7-8 level in the acute angle group and at the T6-7 level in the obtuse angle group, and an end-hole 19-gauge epidural catheter was inserted. Coiling length, defined as the length of the catheter within the epidural space when any part of the catheter just begins to head caudally, was measured in both groups. The coiling length was 7.4(4.4) cm (95% CI 6.0-8.7 cm) in the obtuse angle group compared with 4.9(3.3) cm (95% CI 3.8-6.0 cm) in the acute angle group (P = 0.005). Approaching the thoracic epidural space with an obtuse approach angle provides longer coiling length. We recommend that an obtuse approach angle should be used to maximize the chance of the catheter reaching the intended level with minimum risk of coiling.

A novel technique in selective venous sampling in the localization of parathyroid tumours utilizing a micro-wire and standardized catheter

Selective venous sampling (SVS) is a useful technique to localize a number of hormone-producing tumours, such as parathyroid tumours, when other imaging techniques are inconclusive. Typically, a 5 French selective single end-hole catheter and standard hydrophilic wire are utilized to access the required vessels and an attempt made to withdraw blood. However, most interventional radiologists are familiar with the difficulty and limited success in withdrawing venous blood through an end-hole catheter. We describe a simple, cheap and novel technique utilizing a micro-wire that we have developed in our interventional suite to overcome this common problem. Having reached the target site with the selective end-hole catheter, a Tuohy Borst adapter is attached to the catheter end. A 0.018-inch micro-wire is then inserted through the selective end-hole catheter such that the distal wire tip exits the distal catheter tip. The purpose of the micro-wire exiting the catheter is to both straighten the catheter tip to a position parallel to the vessel, allowing easier aspiration as well as physically preventing blockage of the catheter by the vein intimal wall collapse on suction. The 5-ml sample required for PTH assay is then successfully obtained via the Tuohy Borst adapter.

Use of the 4F Rösch Inferior Mesenteric Catheter in Embolization Procedures in the Pelvis: A Review of 300 Cases

The aim of this study is to evaluate the use of a 4F Rösch inferior mesenteric (RIM) catheter for pelvic embolization procedures. Between October 2000 and January 2006, 364 patients (357 female, 7 male; age: 23-67 years) underwent embolization of various pathologies [uterine fibroids (n = 324), pure adenomyosis of the uterus (n = 19), postpartum hemorrhage (n =1), traumatic or postoperative hemorrhage (n = 9), bleeding related to cervical cancer (n =7), AV malformation of the uterus (n = 2) and high-flow priapism (n = 2)] at a single institution. In all cases, bilateral catheterization was primarily attempted with the use of a 4F hook-shaped braided endhole catheter (Rösch-Inferior-Mesenteric, RIM-Catheter, Cordis, Miami, FL). Frequency of initial failure to catheterize the vascular territory of interest and carry out the embolization were recorded and the types of difficulty encountered were noted. Catheterization of the main stem of the vessel territory of interest with the use of a unilateral femoral approach and the 4F RIM catheter was successful in 334/364 (91.8%) the embolization cases. Bilateral catheterization of the internal iliac arteries using a single common femoral artery access and the 4F RIM catheter was achieved in 322/364 (88.5%) patients. In 12/364 (3.3%) patients, a contralateral puncture was performed and the same 4F catheter was used. In 28/364 (7.7%) cases the 4F RIM catheter was exchanged for a catheter with a cobra-shaped or sidewinder configuration. The 4F RIM catheter is a simple and valuable alternative to catheters and techniques commonly employed for pelvic artery embolization.

Catheter-Directed Thrombolysis for the Management of Postpartum Deep Venous Thrombosis

Women are at their highest risk of developing venous thromboembolism, still the most important cause of maternal mortality in developed countries, during the postpartum period. Acute deep venous thrombosis (DVT) causes significant morbidity, chiefly as a result of postthrombotic syndrome. Heparin anticoagulation can prevent pulmonary embolism but leads to thrombolysis in fewer than 15% of patients with DVT and does not protect against postthrombotic syndrome. Catheter-directed thrombolysis, combined with angioplasty and stent placement when indicated, removes thrombus and restores venous patency. This treatment has, however, been avoided during and after pregnancy because of an increased risk of placental abruption and bleeding complications as well as fetal exposure to radiation. The investigators performed this procedure in 5 women having acute postpartum DVT within 6 weeks of delivery and for less than 3 weeks. The diagnosis was confirmed by color Doppler ultrasound and/or venography. Patients received low-molecular-weight heparin when diagnosed as having DVT. With the patient prone on an angiography table, the ipsilateral popliteal vein was entered with a 6-F microaccess set under ultrasound guidance using a 21-G needle and a guidewire 0.46 mm in diameter. Ascending venography was performed and, using a sidearm sheath and 5-F angled endhole catheter, a 0.89-mm hydrophilic guidewire was passed into the inferior vena cava. The endhole catheter than was replaced with a 5-F multisideholed catheter that was embedded in the thrombus. A recombinant human tissue plasminogen activator, alteplase, was infused for up to 24 hours. Unfractionated heparin also was infused. Doses were adjusted to maintain a fibrinogen level above 1 g/L and cephotest of 50s to 70s. Venography was repeated after 20–24 hours of thrombolytic treatment. If stenosis was found, angioplasty was carried out with or without a stent. Lysis was considered complete if the remaining luminal-area narrowing was less than 5%. Catheter-directed thrombolysis was carried out in 4 women with iliofemoral DVT and 1 with renal and ovarian vein thrombus. Two women had a positive thrombophilia screen for protein S deficiency, but none had recognized risk factors during or after pregnancy. One woman received low-molecular-weight heparin postoperatively after cesarean delivery. Two patients had a stent placed. Thrombolysis succeeded in all 4 patients with iliofemoral DVT. Partial lysis was achieved in the patient with renal and ovarian vein thrombosis, but kidney function was absent a month later. Symptoms resolved completely in all 5 patients. In women with acute postpartum DVT, early endovascular catheter-directed thrombolytic therapy—combined with thrombectomy, angioplasty, and/or stenting when indicated—may preserve function of the venous vales and prevent later venous occlusive disease. Evidence of safety remains insufficient. The authors recommend the use of graded compression stockings after thrombolysis to lessen the risk of postthrombotic syndrome.

Enhancing myocardial plasmid expression by retrograde coronary venous delivery

Myocardial delivery of genes holds great promise for treating many heart diseases; however, the optimal delivery technique, which maximizes safety and efficacy, has not been established. Two delivery techniques were evaluated in swine; percutaneous retrograde coronary venous delivery (RCVD) and direct intramyocardial injection (IM). RCVD was performed in the anterior interventricular vein (AIV) with an end-hole occlusion balloon catheter. The plasmid gWiz, encoding beta-galactosidase (10 ml; 1 mg/ml), was injected using either manual high pressure (HP-RCVD; n = 5) or pressure wire-guided low pressure (LP-RCVD; n = 4). For the IM group (n = 4), beta-Gal plasmid (5 mg/ml) was injected at 10 sites (200 microl/site) in the anterior left ventricular wall. Animals were euthanized after 5 days. The percentage of beta-Gal expressing cells in the delivered region was higher in the HP-RCVD (0.26% +/- 0.05%) than the LP-RCVD (0.05% +/- 0.03%; P = 0.07) and IM groups (0.02% +/- 0.01%; P = 0.01). Myocardium from the HP-RCVD group contained 7- and 17-fold higher levels of beta-Gal activity than either LP-RCVD and IM groups, respectively (P = 0.05 for both). The results of this study confirm the safety and efficacy of RCVD for myocardial gene delivery.

Short-term ureteral catheter stenting after uncomplicated transurethral uretero-lithotomy

Short-term (1 or 2 post-operative days) ureteral catheter stenting after transurethral uretero-lithotomy (TUL) to avoid flank pain due to transient ureteral edema is described. Patients who underwent TUL for middle or distal ureteral stones with a rigid ureteroscope without complications during the procedures were the candidates for short-term ureteral stenting. An end-hole ureteral catheter, used to insert a guide wire during TUL, were used for stenting. The tip of the catheter was located near the renal pelvis and the other end was introduced outside through the urethra with a 14 F urethral catheter. The stent and catheter were removed on post-operative day 1 or 2. For the 18 patients treated using this method, the time of analgesic use after stent removal was 0.6+/-0.8, indicating a sufficient duration of stenting. Short-term ureteral catheter stenting is a cheap and easy way for post-operative management for uncomplicated TUL.

Kinks of the Transplant Renal Artery Without Accompanying Intraarterial Pressure Gradient Do Not Require Correction: Five-Year Outcome Study

Significant transplant renal artery stenosis (TRAS) results in an intraarterial pressure gradient and increasing graft dysfunction correctable by endovascular therapy. Kinks of the transplant artery cause velocity gradients on Doppler ultrasound, but some will have no intraarterial pressure gradient across the kink. It is not known whether these nonflow limiting kinks progress further to threaten graft function and should undergo endovascular correction. This is a longitudinal study of conservatively managed arterial kinks to define their natural history. Fourteen patients who had undergone angiography over a 5-year period for suspected TRAS had kinks of the renal artery. True intraarterial pressures were measured in all cases by slow withdrawal of an end-hole catheter after intraarterial injection of a vasodilator. Those with a significant pressure change (> or =10% change in peak systolic pressure across the area of suspicion) underwent endovascular treatment. The rest were managed conservatively, with maximal antihypertensive therapy. Outcome of all 14 cases was determined by follow-up of creatinine levels, blood pressure (BP) control and graft outcome over a 3-5-year period (median 4 years). Of the 14 patients with kinks, 10 were male and 4 female; age range 23-67 years (mean 47 years). Eleven had received cadaveric transplants and 3 were allografts; 12 had end-to-side and 2 end-to-end anastomosis, 11/14 cases had an intraarterial pressure ratio of <10% and at median 4 years follow-up on conservative treatment, the serum creatinine of these 11 patients did not differ significantly from those who underwent successful endovascular treatment (mean 118 micromol/l versus 149 micromol/l; p = 0.30, Mann Whitney test). Mean blood pressure was 137/82 mmHg, with a range of 124-155/56-95 mmHg. Only one patient has required an unexplainable increase in antihypertensive medication. Grafts (2/11) were lost and both had chronic rejection on histology. There were no unexplained graft failures. Kinks of the renal transplant artery with normal intraarterial pressures do not appear to progress and threaten renal graft function. Satisfactory graft outcome was seen on 5-year follow-up with conservative therapy alone.

Transcatheter thrombolysis with high-dose bolus tissue plasminogen activator in iatrogenic arterial occlusion after femoral arterial catheterization.

To assess the efficacy of percutaneous local thrombolysis with high-dose bolus recombinant tissue plasminogen activator (rt-PA) in patients with acute limb ischemia due to arterial thrombosis after cardiac catheterization. We treated eight patients (7 men; mean age 56 years) with thrombotic occlusion of both the common femoral artery (CFA) and external iliac artery (EIA) in six patients and of the CFA only in two patients. Two 5 mg boluses of rt-PA were injected into the proximal clot through a 5 Fr end-hole catheter and subsequently two additional boluses of 5 mg rt-PA were given through a catheter with multiple side-holes. In case of a significant amount of residual thrombus, a continuous infusion of 2.5 mg/hr of rt-PA was started. Successful lysis was achieved in all patients. The mean duration of lysis was 2 hr 41 min. The mean total amount of rt-PA delivered was 23.16 mg. In four patients unmasked flow-limited dissections confined to the CFA were managed by prolonged balloon dilatation, while in the remaining four patients with extension of the dissection to the external iliac artery one or two Easy Wallstents were implanted. There was prompt relief of lower limb ischemic symptoms and signs in all patients. Two groin hematomas were conservatively treated. Clinical and color Doppler flow imaging follow-up with a mean duration of 15 months, showed no reappearance of ischemic symptoms or development of restenosis in any of the patients. One patient died 6 months after thrombolysis. Transcatheter thrombolysis with high-dose bolus rt-PA is a safe and effective treatment in patients with iatrogenic arterial occlusion after femoral catheterization. Underlying dissections should be treated by prolonged balloon dilatation but stent implantation is often required.

Factors influencing late course of residual valvular and infundibular gradients following pulmonary valve balloon dilatation

Background: Though acute and follow-up benefits of pulmonary valve balloon dilatation (PVBD) for pulmonic valve stenosis are well known, the late course of residual gradients at individual valvular and infundibular levels is not well described. Furthermore, the factors influencing this late course have not been studied. Materials and methods: We assessed the transpulmonary gradients by echo-Doppler in 96 patients (61 male, mean age 10.7 years) at a mean follow-up interval of 58.8±32.1 months (minimum 2 years) following PVBD. The patients were divided into three groups based on the residual gradients at valvular and infundibular levels immediately following PVBD as assessed by pull-back of an end-hole catheter across the right ventricular outflow tract: Group A with minor pressure gradients at both valvular and infundibular levels of less than 30 mmHg ( n=60, 62.5%), Group B with predominantly infundibular gradients of more than 30 mmHg with a valvular gradient of less than 30 mmHg ( n=27, 28.1%), and Group C with a residual valvular gradient of greater than 30 mmHg irrespective of the infundibular gradient ( n=9, 9.4%). Demographic characteristics, hemodynamic parameters and procedural variables were correlated with the change in gradient at follow-up (late fall) and with long-term results. Results: The mean follow-up trans-pulmonary gradient was 20±14 mmHg which was significantly lower than that immediately post-PVBD (43±32 mmHg), P<0.001. The late fall (mean 24±29, range −55 to 110 mmHg) varied widely depending upon the acute result group: patients in Groups A and B showed significant late fall of 9±12 mmHg ( P<0.05 for follow-up gradient compared to that following PVBD) and 58±31 mmHg ( P<0.0001), respectively, while patients in Group C showed an insignificant late fall of 14±37 mmHg ( P=0.21). In particular, each one of the patients in Group B showed decrease in trans-pulmonary gradients. On multivariate analysis, the extent of infundibular gradient emerged as the most important predictor of late fall (coefficient of determination 75%, P<0.0001). Patients who underwent PVBD at less than 2 years of age had a significantly greater late fall (41±33 mmHg) as compared to older patients (22±25 mmHg), P<0.05. A sub-optimal long-term result (transpulmonary gradient >25 mmHg, n=24) was significantly related to older age ( P<0.001), dysplastic valve morphology ( P=0.002), greater baseline trans-pulmonary gradients ( P<0.001) and higher post-PVBD gradients ( P=0.04). Conclusions: The long-term course of patients following PVBD depends upon the site and magnitude of the residual gradients. Even high residual infundibular gradients show marked reduction at follow-up, especially in infancy.