The gravity-assisted Paedi-Gav valve in the treatment of pediatric hydrocephalus

OBJECTIVE: A single-center, prospective, nonrandomized pilot study was performed to assess the Paedi-Gav gravity-assisted valve for the treatment of pediatric patients with hydrocephalus. METHODS: Participants were pediatric patients (age <16 years) who were candidates for a hydrocephalus shunt system that required a valve insertion at the time of enrollment. The primary outcome event was shunt malfunction; subclassified into shunt obstruction, shunt overdrainage, loculated ventricles, or infection. The shunt obstructions were further subclassified according to site. A total of 32 patients were enrolled onto the study, with 2 undergoing first shunt insertion after failed ventriculostomy and 30 undergoing shunt revisions. On average, the patients had had 3.3 shunt procedures prior to insertion of a Paedi-Gav valve. RESULTS: During a follow-up interval of minimum 52 weeks and a median of 24 months after the first implantation on-study, shunt revisions were required in 17 (53.1%) of the 32 patients. The 12-month shunt-survival rate without revision of any component was 53%, with a median shunt-survival time of 388 days. The most common reasons for shunt revision were shunt obstructions (12/17) and overdrainage (3/17). Shunt obstructions were caused by valve-related failures (9/12) and distal obstructions (3/12). CONCLUSION: Although the small number of patients enrolled in this study warrants cautious conclusions, the overall results are comparable to those reported for primary shunt insertions with conventional valves in pediatric patients with hydrocephalus. Although this study provides a rationale for examining the Paedi-Gav gravity-assisted shunt valve in a larger prospective randomized controlled trial, the shunt failure pattern, with a rather high frequency of valve-related failures, may indicate potential for further improvements in the valve design and/or manufacturing.     

The shunt design trial: variation in surgical experience did not influence shunt survival.

INTRODUCTION: An international multicenter randomized trial comparing standard pressure differential valves, Orbis Sigma valves and PS Medical Delta valves for children with newly diagnosed hydrocephalus failed to show a difference in the time to first shunt failure. Surgeons' prior experience with the three valves varied. This analysis was performed to assess whether lack of surgical experience with any of the valves could explain the overall negative result. METHODS: (1) Shunt survival was compared at high- and low-volume centers. (2) The 1-year shunt survival rates (+/-95% confidence interval) for patients entered in the first quarter and the last quarter of the 25-month accrual period were compared (for all patients, and for each shunt). RESULTS: Survival curves for high- and low-volume centers were similar. Ninety of the 344 randomized patients were accrued in the first quarter and 93 in the last quarter. The 1-year shunt survival for all patients entered in the first quarter was 72% (+/-11%) compared to 64% (+/-10%) for patients entered in the last quarter. The shunt-specific results were 66% (+/-20%) compared to 54% (+/-20%) for Delta valve patients, 75% (+/-20%) compared to 70% (+/-17%) for standard valve patients and 76% (+/-18%) compared to 66% (+/-16%) for Orbis Sigma patients. DISCUSSION: Shunt survival did not improve as surgeons accumulated experience over the course of the study. Although participating surgeons had varying levels of experience with the different shunts at the start of the trial, this does not appear to explain the overall negative trial result.     

The delta valve: how does its clinical performance compare with two other pressure differential valves without antisiphon control?

OBJECTIVE: The Delta valve is a pressure differential valve with a siphon control device. The valve mechanism is normally closed, but is designed to open in response to positive ventricular pressure, thereby avoiding overdrainage of cerebrospinal fluid (CSF). As a result, the incidence of subdural fluid collections as well as postural symptoms is purportedly reduced. In addition, the valve might reduce the number of obstructions as there would be no negative pressure sucking tissue and debris into the shunt system. In order to assess whether use of the Delta valve reduced the number of shunt-related problems as compared with two other pressure differential valves without an antisiphon component, we performed a retrospective review of all children undergoing CSF diversion procedures at our institution. METHODS: We reviewed the charts of 1, 193 patients. Cases included 2,325 ventriculoperitoneal (V-P) shunt insertions or revisions from January 1, 1985, to December 31, 1994, performed at our institution. The Delta valve and two pressure differential valves without antisiphon function were exclusively inserted during the following time periods: Holter-Hausner (H-H): January 1, 1985, to August, 1987; Heyer-Schulte (H-S): August, 1987, to June, 1991, and Delta: June, 1991, to December 31, 1994. RESULTS: Of the cases reviewed, 475 patients underwent insertion of a V-P shunt at the Childrens Hospital of Los Angeles and had a total of 686 shunt operations. Median follow-up was 3 years and ranged up to 10 years. Kaplan-Meier analysis documented that 67% of H-H, 71% of H-S and 70% of the Delta valves were functioning at 1-year follow-up. At 2-year follow-up, 66% of H-H, 64% of H-S and 65% of the Delta valves were functioning. The difference was not statistically significant. The occurrence rate for symptomatic subdural fluid collections was 0.7% (1/130) for H-H, 2.2% (3/139) for H-S and 1.0% (2/206) for the Delta valve (p = 0.52). The combined breakage/obstruction rate for the series was 7.7% (10/130) for H-H, 2.9% (4/139) for H-S and 4.9% (10/206) for the Delta valve (p = 0.19). No Delta valves malfunctioned secondary to fibrous capsule affecting the antisiphon device. CONCLUSIONS: In conclusion, it appears that performance of the Delta valve was not significantly different from the H-H and H-S valves, two valves without an antisiphon device. There was no significant difference in the occurrence of symptomatic subdural fluid collections based upon valve type, or in the combined valve breakage/obstruction rates based upon valve type.     

Mechanical complications in shunts.

A retrospective study was conducted on 1,719 hydrocephalic patients, treated between 1974 and 1983 at the Hospital for Sick Children (Toronto) and l'H?pital des Enfants Malades (Paris), in order to better understand shunt failure. The statistical analysis demonstrates the following: (1) A probability of occurrence of shunt malfunction of 81% at 12 years of follow-up. (2) A high prevalence of shunt obstruction (56.1% of all malfunction) and fracture or disconnection of the tubings (13.6%). (3) A higher risk of proximal occlusion with flanged ventricular catheter. (4) Less malfunction with proximal-non-slit valves as compared to distal-slit valves. (5) The importance of pressure-flow characteristics of the shunt; because of an indirect relation between overdrainage and proximal occlusion. (6) A correlation between connectors and migration or fracture of the shunt. (7) Less distal obstructions when an open-ended distal-catheter was used. These complications were of some clinical, psychological and economical consequences. Their rate could be lowed.     

An assessment of observer bias in the shunt design trial.

INTRODUCTION: An international multicenter randomized trial comparing standard pressure differential valves, Orbis Sigma valves and PS Medical Delta valves, for children with newly diagnosed hydrocephalus failed to show a difference in the time to first shunt failure (power 80%). In order to avoid observer bias, the primary endpoint, shunt failure, was defined by detailed clinical and radiological criteria. Surgeons notified the data center when their patient reached endpoint. Their decision was blindly reviewed by a centralized adjudication process. The current analysis asks: (1) Did the surgeons and the blinded adjudication process agree on the presence of shunt failure? (2) Do the shunt survival curves change when the surgeons' assessment of outcome is used? METHODS: The two methods of outcome assessment (surgeons' decision and adjudication process) were compared with a kappa statistic for the presence of shunt failure and a log rank statistic for time to shunt failure. RESULTS: The surgeon and the adjudication process agreed on the presence of the primary outcome in 313/344 patients in the trial (kappa = 0.81). The 31 cases of disagreement were evenly distributed among the three shunts. The survival curves generated from the surgeons' decision were not significantly different from those generated by the adjudication process (log rank = 0.70, p = 0.37) and did not alter the study conclusions. DISCUSSION: Observer bias in the assessment of outcome is always a concern in an unblinded clinical trial such as this one. We did not detect an observer bias of sufficient magnitude to alter the study conclusions.     

Comparison of total versus partial revision of initial ventriculoperitoneal shunt failures

BACKGROUND: Optimal surgical management of patients presenting with shunt failure in the age of neuroendoscopy remains complex. The value of replacing the entire shunt system as opposed to a single shunt component has not been assessed. METHODS: We reviewed the records of all pediatric patients who underwent their first shunt revision between January 1992 and December 1998. Patients with primary shunt failure attributed solely to proximal catheter obstruction or distal catheter obstruction were included for analysis. Shunt revisions were classified as total (entire shunt replaced) or partial (only malfunctioning component replaced). Kaplan-Meier (shunt survival curves) and log rank analysis were used to compare failure rates between partially and totally revised shunts according to the underlying diagnosis and failed shunt part. Significant differences in univariate analysis were confirmed with a multivariate proportional hazards regression model. RESULTS: 301 pediatric patients underwent primary shunt revision (183 total, 118 partial revisions). All shunts utilized distal slit peritoneal catheters. In shunt failures attributed to proximal obstruction, reutilization of the distal catheter was associated with a 57% increased risk of subsequent shunt failure (hazard ratio 1.57, 95% confidence interval 1.19-3.49). In shunt failures attributed to distal obstruction, subsequent shunt survival was not affected by reutilization of the proximal catheter (p = 0.581). When stratified according to the etiology of hydrocephalus, only patients with intraventricular hemorrhage (IVH) failed to demonstrate greater survival of totally revised shunts. CONCLUSIONS: In this series, in the setting of proximal shunt catheter obstruction, reutilizing the functional distal catheter was associated with an increase in subsequent shunt failure rates compared to revising the entire shunt system. Total revision was not associated with improved shunt survival in patients with IVH.     

Screening for ventricular shunt function in children with hydrocephalus secondary to meningomyelocele.

OBJECTIVE: To evaluate the current method of using computerized tomographic (CT) scans to screen for ventricular shunt failure in children who have hydrocephalus. DESIGN: Retrospective review of 112 randomly selected charts. PATIENTS: Children diagnosed with infantile hydrocephalus secondary to meningomyelocele, who were treated at the Andrew J. Kirch Developmental Services Center since 1978. RESULTS: One hundred and twelve patients were monitored with CT scans for an average of 12.2 years. There was a total of 2,869 CT scans and an average of 2.1 CT scans per year. Shunt failure was diagnosed 76% of the time by symptoms, 15% by physical findings and 8% by routine CT scans. Sixteen patients had no shunt failure, whereas the remaining 96 had 255 shunt failures. Complications occurred during 30 of the 255 admissions. One child died due to complications directly related to shunt failure. No statistically significant correlations were found between the length of stay or complications and method of diagnosis. CONCLUSIONS: Although children in this study received frequent CT scans, 76% of the episodes of shunt failure were diagnosed because of symptoms. Children admitted to the hospital with symptomatic shunt failure did not have more complications or a longer stay than those diagnosed by routine CT scan. This study suggests that the use of routine CT scans to diagnose shunt failure while patients are asymptomatic does not lead to significantly better medical outcomes and is not cost-effective. However, before routine CT scans are eliminated, a prospective study needs to be conducted that examines outcomes such as cognitive and psychological functioning.     

What is the ideal initial valve pressure setting in neonates with ventriculoperitoneal shunts?

In order to determine the optimal valve pressure setting during the first weeks in neonates after implantation of programmable Hakim valves and to analyze the benefits and possible side effects of a new treatment protocol in this age group, we performed this prospective study. In 20 consecutive newborns less than 5 weeks of age with hydrocephalus due to various etiologies, a ventriculoperitoneal shunt with a programmable Hakim valve at an extremely low initial valve pressure setting of 30-40 mm H(2)O was implanted. This "overdrainage" was maintained, monitored by regular clinical examination and transcranial ultrasonographic imaging, until the wound healing was uneventfully completed and the permanent valve pressure setting of 100-120 mm H(2)O was chosen. In this age group, which is prone to specific noninfectious shunt complications like wound breakdown, cerebrospinal fluid (CSF) fistula and subcutaneous CSF collections, none of these complications were seen, nor were there any persisting overdrainage phenomena on transcranial ultrasonography. Initial, temporary "overdrainage" represents a simple, useful and risk-free therapy in neonates with programmable shunts which might lower the incidence of typical noninfectious complications in this age group.     

Treatment of recurrent ventriculoperitoneal shunt failure associated with persistent cerebrospinal fluid eosinophilia and latex allergy by use of an "extracted" shunt

Shunt failure is commonly associated with infection or mechanical obstruction of the shunt system. The presence of eosinophilia in the cerebrospinal fluid (CSF) has been associated with CSF shunt failure and may be related to both latex and shunt allergies. The authors describe the case of a child with a latex allergy who presented with 10 episodes of shunt failure over a period of 93 months. Cerebrospinal fluid sampling demonstrated persistent eosinophilia (3-36%) and negative cultures. Pathological examination of the ventricular catheter on 3 occasions demonstrated mechanical obstruction by inflammatory debris consisting largely of eosinophils and multinucleated giant cells. On the suspicion that the child might have some uncharacterized allergy to the shunt hardware, shunt replacement was performed using an "extracted" shunt system. The child has remained free of shunt malfunction for > 2 years since the last surgery. Immune responses to unpolymerized silicone are discussed.     

Experience with a new concept to lower non-infectious complications in infants with programmable shunts.

In neonates and infants less than 1 year of age who are treated with a ventriculo-peritoneal shunt, non-infectious complications are almost as frequent and dangerous as infectious complications. While the incidence of infections can be reduced, using perioperative antibiotics, special surgical techniques and postoperative care non-infectious complications such as wound break-down, cerebrospinal fluid (CSF) fistula and subcutaneous CSF collection are preventable, but seem difficult to manage, especially in the group of patients at a susceptible age. The authors present their experience with the programmable Hakim valve in 40 neonates and infants less than 1 year of age, who were treated with de novo implantation of a ventriculo-peritoneal shunt due to various pathologies. The uneventful wound healing during the first weeks after shunt implantation, avoiding the above mentioned non-infectious complications, was supported by initial, temporary overdrainage and readjustment of the programmable valve after completed wound healing. All patients tolerated this procedure well and showed no pathological signs or symptoms of overdrainage like premature closure of cranial sutures, clinical low-pressure syndrome, slit ventricle syndrome (SVS), subdural fluid collection or brain collapse during an average follow-up period of 2.6 years (2 - 65 months). Infectious and other mechanical, non-infectious complications were analysed as well during the follow-up period. These results suggest that an initial, temporary overdrainage in infants and neonates with shunted hydrocephalus may contribute to further lower the incidence of non-infectious complications like wound break-down, CSF-fistula or subcutaneous CSF accumulation, without negative side effects. This technique could be a valuable option in the regimen of shunt-treatment of this age group in order to optimise the overall success rate and lower the general complication rate.     

Image-guided cerebrospinal fluid shunting in children: catheter accuracy and shunt survival

Object Cerebrospinal fluid shunt placement has a high failure rate, especially in patients with small ventricles. Frameless stereotactic electromagnetic image guidance can assist ventricular catheter placement. The authors studied the effects of image guidance on catheter accuracy and shunt survival in children. Methods Pediatric patients who underwent placement or revision of a frontal ventricular CSF shunt were retrospectively evaluated. Catheters were placed using either anatomical landmarks or image guidance. Preoperative ventricular size and postoperative catheter accuracy were quantified. Outcomes of standard and image-guided groups were compared. Results Eighty-nine patients underwent 102 shunt surgeries (58 initial, 44 revision). Image guidance was used in the placement of 56 shunts and the standard technique in 46. Shunt failure rates were not significantly different between the standard (22%) and image-guided (25%) techniques (p = 0.21, log-rank test). Ventricular size was significantly smaller in patients in the image-guided group (p < 0.02, Student t-test) and in the surgery revision group (p < 0.01). Small ventricular size did not affect shunt failure rate, even when controlling for shunt insertion technique. Despite smaller average ventricular size, the accuracy of catheter placement was significantly improved with image guidance (p < 0.01). Shunt accuracy did not affect shunt survival. Conclusions The use of image guidance improved catheter tip accuracy compared with a standard technique, despite smaller ventricular size. Failure rates were not dependent on shunt insertion technique, but an observed selection bias toward using image guidance for more at-risk catheter placements showed failure rates similar to initial surgeries.     

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.     

Reassessment of usefulness of porcine heterografts in mitral position in children

Summary The use of porcine heterograft valves in children is restricted because of valve calcification and dysfunction at follo-up. Because of inability to monitor the anticoagulant status or of desire of some teenage girls to get married and get pregnant, several pediatric patients received porcine heterografts. The purpose of this paper is to examine the issue of heterografts in children, based on our experience with children and adolescents aged 1 to 20 years, who underwent left heart valve replacement during a 7-year period ending April 1985. Ninety-four percent of the lesions were rheumatic in origin, 4% congenital, and 2% infectious. Of 168 mitral valves replaced, 54 (32%) were porcine heterografts and 114 (68%) were mechanical valves. These were divided into four groups, based on type of valve implanted and age at implantation: mechanical (M), age >15 years (M>15), 49 cases; heterografts (H) age >15 years (H>15), 34 cases; mechanical, age <-15 years (M<-15), 65 cases; and heterografts, age <-15 years (H<-15), 20 cases. None of the patients with heterografts received anticoagulation. Five-year actuarial valve survival was 86% for M>15, 96% for H>15, 82% for M<-15, and 60% for H<-15. The respective 9-year valve survival was 86%, 72%, 75%, and 18%. The valve survival data indicate that heterograft valves in patients older than 15 years are comparable (p=0.97) to mechanical valves, while heterografts in children less 15 years do poorly (p=0.015). Based on 8- to 10-year follow-up data, heterografts should not be inserted into children <-15 years of age. Heterografts may be used in children over 15 years of age with the expectation of valve survival comparable to that of mechanical valves and with little or no threat of thromboembolic complications.     

Clinical course of isolated ventricular septal defect: An Indian experience

To define the clinical course of ventricular septal defect, 410 consecutive patients with isolated ventricular septal defect were evaluated over a period of 13 years. Their age ranged from 12 days to 24 years at the time of first visit to the hospital. Patients with less than 2 years follow-up period were excluded. One hundred and fifty seven patients were one year of age or less. The left to right shunt size remained the same in 52.4% of cases. In 34.4% the shunt size decreased, with complete closure of ventricular septal defect in 8.8%. Closure of ventricular septal defect was observed even in patients who had initially presented with large left to right flow, and congestive heart failure in infancy. Right ventricular outflow tract obstruction developed in 8.5% of patients usually between 2 and 10 years of age. Murmur of aortic regurgitation appeared in 8.9% on follow-up. Infective endocarditis developed in 6 cases. The unfortunate complication of Eisemenger's complex was seen in 3 patients; they had not returned for follow up for a long period of time. Hence, our data show that the left to right shunt across the ventricular septal defect decreases in about one-third of patients. However, a regular follow up is essential to prevent development of Eisenmenger's complex and for early detection of other complications like aortic regurgitation and right ventricular outflow tract obstruction.     

The effects of protein,red blood cells and whole blood on PS valve function

We tested the performance of low- and medium-pressure PS flow control valves as they were perfused with (1) solutions with varying concentrations of protein, (2) solutions with varying numbers of red blood cells (RBC) or (3) solutions with varying concentrations of whole blood. Perfusion was performed with a peristaltic pump at a constant rate and each trial lasted 2 weeks or until valve failure. Mean valve pressures were measured and recorded electronically, and opening and closing pressures were obtained at baseline and at the end of the perfusion period or upon valve failure. Any buildup of material within the valve was noted and recorded. Our findings were as follows: (1) protein levels have little practical effect on valve function; (2) moderate numbers of RBC cause increased variability in valve function while large numbers of RBC uniformly lead to valve failure; (3) prolonged perfusion with solutions of dilute whole blood is poorly tolerated, and (4) valve failure is preceded by a period of increased variability in perfusion pressure.     

Cerebrospinal fluid shunt survival and etiology of failures: a seven-year institutional experience

BACKGROUND: Innovations in shunt technology and neuroendoscopy have been increasingly applied to shunt management. However, the relative life span of shunts and the etiology of shunt failure have not been characterized recently. METHODS: We reviewed the records of all shunting procedures at our institution between January 1992 and December 1998. Independent predictors of shunt failure were analyzed via multivariate Cox regression analysis in 836 shunting procedures. Independent predictors of the etiology of failure (infection, proximal obstruction, distal malfunction) were analyzed via multivariate logistic regression analysis in the 383 shunts which failed. RESULTS: A total of 353 pediatric patients underwent 308 shunt placements and 528 revisions. The risk (hazard ratio; HR) of shunt failure decreased as a function of time in both primary placements and revised shunts. In failed shunts, the odds of infection decreased 4-fold per year of shunt function, while the odds of distal malfunction increased 1.45-fold per year. Increasing number of shunt revisions (HR 1.31, p < 0.05), decreasing patient age in years (HR 1.04, p < 0.001), gestational age <40 weeks (HR 2.15, p < 0.001) but not the etiology of hydrocephalus were associated with an increased risk of shunt failure. Revisions versus primary placements, Dandy-Walker cysts and gestational age <40 weeks were independently associated with proximal, distal and infectious causes of failure, respectively. CONCLUSIONS: The long-term shunt revision rates observed here are similar to those reported over the past 2 decades. Shunt life span remains poorer in shunt revisions and in younger patients. Patient characteristics may suggest a specific risk and mechanism of failure, aiding in the long-term management of shunted hydrocephalus.     

Fate of Ventricular and Valve Performance Following Early Bidirectional Glenn Procedure After Norwood Operation Controlled for Hypoplastic Left Heart Syndome Anatomic Subtype

The Norwood operation (NO) with a right ventricle (RV)-to-pulmonary artery (PA) shunt (NRVPA) is reportedly associated with early hemodynamic advantage. Shunt strategy has been implicated in ventricular function. Outcomes after NRVPA compared with classic procedure as part of a strategy involving early bidirectional Glenn (BDG) procedure were analyzed with reference to RV, tricuspid, and neoaortic valve performance. Between January 2005 and December 2010, 128 neonates with hypoplastic left heart syndrome (HLHS) underwent NO. Controlled for aortic/mitral stenosis (AS–MS) subtype, 28 patients underwent NRVPA (group A), and 26 patients had classic procedure (group B). The patients with a non-HLHS single-ventricle anatomy and those who had undergone a hybrid approach for HLHS were excluded from the study. The mean age at NO was 6.8 ± 3.5 days in group A and 6.9 ± 3.6 days in group B. Transthoracic echocardiographic evaluation (TTE) after NO (TTE-1) at the midinterval between NO and BDG (TTE-2), before BDG (TTE-3), before Fontan (TTE-4), and at the last follow-up evaluation (TTE-5) was undertaken. Cardiac catheterization was used to assess hemodynamic parameters before the Glenn and Fontan procedures. The operative, interstage, and pre-Fontan survival rates for AS–MS after NO were respectively 88.1 % (90.3 % in group A vs. 84.7 % in group B; p = 0.08), 82.5 % (82.7 % in group A vs. 81.8 % in group B; p = 0.9), and 80.7 % (79.5 % in group A vs. 81.8 % in group B; p = 0.9). The median follow-up period was 39.6 months (interquartile range 2.7–4.9 months). The RV global function, mid- and longitudinal indexed dimensions, fractionated area change before BDG (TTE-1, TTE-2, TTE-3) and after BDG (TTE-4, TTE-5), and right ventricular end-diastolic pressure did not differ statistically between the groups (p > 0.05). No statistically significant difference in tricuspid or neoaortic intervention was found between the groups (p > 0.05). Controlled for the AS–MS HLHS subtype, shunt strategy showed no midterm survival or hemodynamic (ventricular or valve) impact. At midterm, the follow-up need for neoaortic or tricuspid valve surgical intervention was not affected by shunt selection. The structural ventricular adaptation after reversal of shunt physiology was irrespective of shunt strategy.     

Trans-anal protrusion of ventriculo-peritoneal shunt catheter with silent bowel perforation: report of ten cases in children

Ventriculo-peritoneal (VP) shunting used in the treatment for hydrocephalus is associated with several complications. Mechanical failure of shunt is the commonest complication of all. Visceral/bowel perforation is an unusual but serious complication of VP shunting. This article reports our experience in the management of ten children who had VP Shunt catheter protrusion from anus. This is a retrospective study of ten patients who had VP shunt catheter protrusion from anus, admitted in the department of paediatric surgery between Jan 1996 and Dec 2005. The records of above ten cases were reviewed for their clinical presentation and management, etc. We had performed 398 VP shunt operations in the last 10 years. Two hundred and seventy one (68.09%) VP Shunts were done for congenital hydrocephalus of which 164 were done in infancy/neonatal period and 107 VP shunts were done in the age group of >1–12 years. One hundred and twenty-seven (31.90%) VP shunt operations were done for patients who had hydrocephalus as a complication following tubercular meningitis (TBM). Out of 398 VP shunts, ten patients (2.51%) had protrusion of the distal end of peritoneal catheter from anus without causing/leading to peritonitis. We observed a 08.29% mortality of all VP shunt operations. Protrusion of VP shunt catheter per rectum can occur without producing peritonitis. Formal exploration and localization of entry of VP shunt catheter in bowel is not mandatory. Mini laparotomy and revision of peritoneal part of shunt can be done if there is no shunt infection.     

Percutaneous pulmonary valve replacement

Each year in the United States more than 4000 newborns are diagnosed with complex congenital heart disease involving right ventricular outflow tract obstruction. Despite advances in surgical techniques with right ventricle to pulmonary artery conduits, progressive conduit failure often occurs within 4–12 years. Consequently, the majority of these patients, prior to becoming adults, require 2–4 operations for the right ventricle outflow tract to reverse the adverse ventricular effects of a volume or pressure load. Fortunately, over the past decade, percutaneous pulmonary valve replacement has emerged as a nonsurgical intervention for right ventricle to pulmonary artery conduit failure.Currently, there are two percutaneous pulmonary valves available in the United States with the Edwards SAPIEN? valve actively enrolling in a Phase II FDA approved clinical trial, and the Medtronic Melody® valve now FDA approved through a Humanitarian Device Exception pathway. In this article, we review indications, technique and outcomes for percutaneous pulmonary valve replacement and compare and contrast the available percutaneous stent valves.     

The programmable adult Codman Hakim valve is useful even in very small children with hydrocephalus. A 7-year retrospective study with special focus on cost/benefit analysis.

INTRODUCTION: Ventriculo-peritoneal shunting is the most commonly used method for the treatment of paediatric hydrocephalus. The programmable valve with the ability to adjust the opening pressure non-invasively has made it easier to find exactly the right opening pressure for each child and reduce the risk of over- or under-drainage. The aim of this investigation was to study our clinical experience with the adult Codman Hakim programmable valve in children, with reference to complications and economic impact. METHODS: A seven-year retrospective study of 122 hydrocephalic children (aged from children born prematurely to 15 years old) shunted with the adult Codman Hakim programmable valve was performed. RESULTS: The programmable valve was the first shunt in 76 children and in 14 after prior ventricular drainage. The remaining 46 had different non-programmable systems as their first shunt. The most common reason for changing to a programmable valve was over-drainage. With the programmable valve, catheter-related complications, e.g. proximal (36%) or distal obstructions (30%), were the main reasons for surgical revision. Non-invasive pressure adjustment was performed in 73% of the children. Among the children with the programmable valve as their first shunt, 57 (75%) were adjusted, 12 (21%) had severe symptoms of over-drainage and would have required urgent surgical change of the valve if it had not been adjustable. A resetting of the opening pressure after MRI was found in 38% and accidental resetting occurred in 4%. Programmable valves are about twice as expensive as non-programmable valves. We estimated the increased cost of the valve and compared it with the savings from a reduction in the number of re-operations. The total cost for the programmable valve (as the primary shunt) in our study was less than that for expected re-operations due to over- or under-drainage when using non-programmable valves. CONCLUSION: The programmable valve was easy to handle; only one size was required and the adjustment made it possible to achieve an optimal intraventricular pressure with a lower total cost, reduced hospital stay as well as an increased quality of life for the children.