Catheter Valve Research Articles

Outcome Analysis of Initial Neonatal Shunts: Does the Valve Make a Difference?

Objective: Ventriculoperitoneal shunts have one of the highest complication rates of all neurosurgical procedures. The purpose of this study was to identify factors associated with malfunction of shunts placed in infants with neonatal hydrocephalus, with the goal of maximizing long-term shunt survival. Methods: We performed a retrospective chart review of 200 consecutive patients less than 1 year old who underwent primary intracranial shunt placement for hydrocephalus by one of two experienced pediatric neurosurgeons at a single institution. A multivariate analysis was conducted to identify variables that were statistically independent predictors of a shunt malfunction or problem. Results: Adequate data were available for 158 patients, with a mean follow-up of 39.8 months (range 6–99 months). Variables tested for independent prediction of shunt revision included the etiology of the hydrocephalus, gestation period, age at shunt placement, surgeon, ventricular catheter entry site and valve opening pressure. Frontal versus occipital catheter entry site was not associated with a different revision rate. The only significant controllable factor associated with shunt malfunction was the valve opening pressure. The revision rate per year of follow-up was 4 times higher for patients with no valve or a low-pressure valve than for patients with a medium- or high-pressure valve. Conclusions: This retrospective review demonstrated that the valve opening pressure is an important component of the shunt complication rate. A prospective multicenter randomized trial is warranted to further evaluate the conclusions of this study.

Peripherally Inserted Central Catheters with Distal versus Proximal Valves: Prospective Randomized Trial

To evaluate whether peripherally inserted central catheters (PICCs) with a proximal valve have any advantage compared to those with a distal valve in regard to the incidence of occlusion, infection, or malfunction. One hundred patients (mean age, 46 y) were randomized to receive either a distal-valved Bard Groshong catheter (n = 48) or a proximal-valved Catheter Innovations Pressure Activated Safety Valve catheter (n = 52). All catheters were 4-F, single-lumen PICCs. Catheters were placed under fluoroscopic (n = 82) or sonographic (n = 18) guidance. Most (91%) were placed for the administration of antibiotics. The placement procedure, maintenance, and weekly follow-up were the same for both catheters. Percutaneous placement with the catheter tip in the central veins was successful in all patients. Mean dwell time was 36 days. There were 12 (25%) occlusive or infectious complications in the distal valve catheter group and six (11.5%) in the proximal valve group (P = .08). There were 25 fractures in 17 distal valve catheters (35.4%) and three (5.8%) proximal valve catheter fractures (P < .01). There was a marked difference in durability between the valved catheters, in favor of the catheter with a proximal valve. There was also a trend for fewer occlusive and infectious complications with the proximal valve catheter.

Catheter valves: a special focus on the Bard Flip-Flo catheter.

This article examines catheter valves with a special focus on the Bard Flip-Flo. Catheter valves were first introduced into the UK in 1986. Ten years later, seven catheter valves were available of which three, including Flip-Flo, were available on prescription. Catheter valves are suitable for both males and females and both short- and long-term urethral or suprapubic catheters. Catheter valves can combine with urinary drainage bags to form link systems. The benefits of catheter valve usage, many of which are perceived but not well researched, include reduced urinary tract infection and maintenance of bladder tone and capacity. Current opinion indicates that patients with detrusor instability, impaired bladder sensation or confusion may find catheter valves unsuitable. Catheter care, including health education and monitoring, are required for catheter valve patients as well as conventional leg bag users. The Bard Flip-Flo catheter valve offers many benefits and is an established product within the UK.

The Sims Portex Catheter Valve: an alternative to the leg bag

Any patients who would normally use a catheter and leg bag could benefit from exchanging their leg bag for a catheter valve, as long as they have the manual dexterity to open their valve at regular intervals and remember to do so. The Sims Portex Catheter Valve is a lightweight and compact catheter valve that is discrete and offers more comfort than a leg bag system, especially to the more mobile patient. This article examines this type of catheter valve and assesses its relevance for use in both the community and the acute sector.

The Sims Portex Catheter Valve: an alternative to the leg bag.

Any patients who would normally use a catheter and leg bag could benefit from exchanging their leg bag for a catheter valve, as long as they have the manual dexterity to open their valve at regular intervals and remember to do so. The Sims Portex Catheter Valve is a lightweight and compact catheter valve that is discrete and offers more comfort than a leg bag system, especially to the more mobile patient. This article examines this type of catheter valve and assesses its relevance for use in both the community and the acute sector.

Catheter valve

Catheter valve

Failure Properties of Leaf Valve Inflatable Saline Breast Implants

From 1992 to 1996, 189 saline breast implants were inserted into patients (54 for breast augmentation and 135 for replacement of explanted silicone gel implants). Nine implants (4.8%) underwent spontaneous deflation at a mean of 2.8 months postoperation (range, 0.5 to nine months). Six deflations were partial (10% to 50% of implant volume), and three were complete. All failed implants were from the same manufacturer and had the same leaf valves. None of the failed implants demonstrated any visible defects in their walls or valve mechanisms when examined in the operating room. However, subsequent analyses indicated that all failed implants demonstrated a slow leak through the leaf valve mechanism – as slow as two to three drops per 12 h. This rate increased significantly when pressure was applied to the implant. In the three implants with delayed leakage (six to 10 months), fibrous tissue was observed in the leaf valve mechanism of the implants. It is postulated that failure of all nine implants resulted because of defects in their valves and that fibrous tissue ingrowth into the leaf catheter valve mechanism may have played a role in at least three. The tissue may have provided a ‘wick’ to stimulate fluid leakage. The use of these leaf valve implants was discontinued one year ago. Since then, no failures have been observed in any of the 68 diaphragm valve implants that have been inserted during the past year.

A multicentre comparative evaluation of catheter valves

Catheter valves are an alternative to leg bags for urine drainage, but no studies have yet been published which have compared the performance of different valves. This study was undertaken to evaluate the performance of the seven catheter valves available on the UK market in April 1996. The study was carried out by the Continence Products Evaluation (CPE) Network funded by the Medical Devices Agency (Department of Health). Each valve type was tested for 1 week by 19-36 cognitively unimpaired and manually dextrous subjects recruited from 11 test centres. At the end of each week, subjects completed an evaluation form (based on a three-point rating scale) to record product performance. The same catheter valves were also tested for ease of opening/closing by 33 subjects (mostly catheter users) who had some manual impairment. Performance scores varied widely between products. It was found that, to be successful, a valve needs to be easy to manipulate, leak-free, comfortable and inconspicuous. Prescribers need to be aware of the strengths and limitations of different valves for appropriate product selection.

The Sonographic Diagnosis of Infravesical Obstruction in Children: Evaluation of Bladder Wall Thickness Indexed to Bladder Filling

The pathophysiological changes that result from posterior urethral valves depend primarily on the degree and duration of infravesical obstruction. Delayed diagnosis may result in progressive bladder dysfunction, renal parenchymal loss or sepsis. Specific radiographic and clinical criteria predictive of a diagnosis of infravesical obstruction are available in the form of voiding cystourethrography and cystoscopy. However, these modalities share the disadvantage of being invasive in nature. Although noninvasive, sonographic evaluation of bladder thickness has a high degree of variability and it markedly depends on the degree of bladder filling. Bladder wall thickness and bladder diameter were assessed in 15 children with posterior urethral valves, and 10 age and sex matched children with no bladder dysfunction. Ultrasound was performed before intervention (that is catheter placement or valve ablation). A positive predictive value of 93% was achieved between the 2 groups when bladder wall thickness was indexed to inner wall diameter in the anteroposterior or transverse dimension. Mean bladder wall thickness divided by mean inner bladder diameter plus or minus standard deviation was 0.402 +/- 0.25 in the obstructed population and 0.094 +/- 0.025 in controls (p = 0.0004). The bladder thickness index is a sensitive sonographic predictor of infravesical obstruction. Application of this index as a noninvasive screening tool for the patient with persistent voiding dysfunction may prove beneficial for identifying infravesical pathology.

Catheter valves.

Catheter valves.

Absorption Through the Peritoneum of the Macromolecular Profibrinolytic Drug Defibrotide in the Rabbit

Defibrotide is the sodium salt of a polydeoxyribonucleotide extracted from mammalian lungs by controlled depolymerization. This macromolecular compound (mean molecular weight 20,000 d) has profibrinolytic activity. It also is antithrombotic after both intravenous and oral administration. The purpose of this study was to see whether defibrotide could activate the fibrinolytic system after intraperitoneal administration, because it has been observed that in ascitic patients treated intraperitoneally with defibrotide, no occlusion of the peritoneal-jugular catheter valve draining the ascitic fluid (according to LeVeen et al.) occurred. The profibrinolytic activity of defibrotide and its plasma levels were dose dependent, with a statistically significant correlation between the fibrinolytic activities and the AUC of the plasma levels of defibrotide. No rebound effect was observed during the duration of the experiments (24 hours). We hypothesize that the fibrinolytic activity elicited by defibrotide prevented the deposition of fibrin in the catheter valve, enabling normal drainage of the ascitic fluid. The lack of rebound makes defibrotide a safe drug. The mechanism by which this macromolecular compound is absorbed is still unknown.

A new complication of left atrial catheters

Left atrial catheters are commonly used to guide the intraoperative and postoperative care of patients with congenital heart disease. Complications associated with these catheters include air embolism to the systemic circulation, thrombosis at the catheter tip, bleeding after removal, retention of the catheter, and aortic or mitral prosthetic valve entrapment. A previously unreported complication of left atrial (LA) catheter placement is presented

Cephalhydrohematocele due to catheter valve disconnection following ventriculoperitoneal shunting

A 5-year-old boy with a right-sided ventriculoperitoneal shunt presented with a 3-month history of progressively enlarging subperiosteal fluid collection in the scalp, which started in the right parietal region and had spread and extended across the midline to occupy both parietal regions. There were no changes in symptoms or signs from those observed 3 months previously. A CT scan confirmed the collection of fluid under the scalp over both parietal regions. The peritoneal catheter was found to be disconnected from the distal end of the functioning valve, which drained cerebrospinal fluid into the subperiosteal space. Distention of the parietal subperiosteal space led to stretching and tearing of the emissary veins. This resulted in the formation of a hydrohematocele. The spread of fluid to the opposite parietal region may be due to a disorganized and loose attachment of the periosteum to the widely separated sagittal suture.

Perihepatitis and Hepatitis as Complications of Experimental Endocarditis Due to Neisseria gonorrhoeae in the Rabbit

Seven strains of Neisseria gonorrhoeae (colony type 1 or 2) were tested for their ability to produce endocarditis in rabbits with transaortic valve catheters. The gonococci exhibited three auxotype patterns and a broad range of susceptibility to penicillin and to complement-mediated serum bactericidal activity. Only four strains produced endocarditis; infectivity appeared to be related to serum resistance. Neither arthritis nor skin lesions were observed in infected animals, but 40% had hepatitis, often with fibrinous perihepatitis. Hepatic lesions could be induced by the continuous infusion of gonococci without a transvalvular catheter. Suppurative hepatitis in the rabbit endocarditis model is of particular interest in light of the unusual hepatic involvement reported in association with gonococcal endocarditis in humans. Since perihepatitis also occurs as a complication of experimental gonococcal bacteremia, perhaps the Fitz-Hugh-Curtis (gonococcal perihepatitis) syndrome appearing in women occurs more often as a function of undiagnosed bacteremia than has heretofore been suspected.