Shunt revisions in children--can they be avoided? Experiences from a population-based study

Appendicitis and Peritonitis in Children with a Ventriculo-Peritoneal Shunt

The purpose of this study was to outline the management of patients with appendicitis and ventriculoperitoneal shunt (VPS) in the largest pediatric surgery department in Germany. Patients with VPS presenting with an acute abdomen between 2012 and 2022 at a tertiary-care pediatric facility were the subject of a retrospective descriptive analysis. Patients were divided into two groups based on their diagnoses: group A (appendicitis) and group B (primary peritonitis). Medical records were analyzed to look at the diagnostics, operative approach, complications, peritoneal and liquor culture, and antibiotic treatment. A total of seventeen patients were examined: seven patients in group A and ten individuals in group B. In the present study patients in group A typically presented younger, sicker, and with more neurological symptoms than those in group B. All patients with appendicitis had their VPS exteriorized, and a new shunt system into the peritoneum was reimplanted 20 days later. Surgery should be aggressively administered to patients who present with an acute abdomen and a VPS. Change of the whole shunt system is suggested. Shunt infection and dysfunction should be ruled out in patients with abdominal symptoms, and surgical care should be started with a low threshold.

Paediatric ventriculoperitoneal shunt infection caused by Actinomyces neuii

We present the first reported case of ventriculoperitoneal shunt infection secondary to Actinomyces neuii in a paediatric patient. Our patient was managed with temporary shunt removal, intrathecal antibiotics and a prolonged course of intravenous and then oral antibiotics. She went on to make a complete recovery. Subsequent cerebrospinal fluid analysis at 5 months post-treatment demonstrated no evidence of residual infection.

Incidence and risk factors of ventriculoperitoneal shunt infections in children: a study of 333 consecutive shunts in 6 years

The major aims of this study were to estimate the infection rate and recognize the risk factor for ventriculoperitoneal (VP) shunt infections in children. To analyze shunt infection rate and identify risk factors, a retrospective cohort analysis of 333 consecutive VP shunt series was performed at Seoul National University Children's Hospital in Korea between January 2005 and February 2011. Overall, 35 shunts (10.5%) were infected, which represented an infection rate of 0.075 infection cases per shunt per year. VP shunt infection occurred at a median of 1 month (range, 6 days to 8 months) after insertion. An independent risk factor for shunt infection was undergoing an operation before the first year of life (relative risk 2.31; 95% confidence interval, 1.19-4.48). The most common causative microorganism was coagulase-negative staphylococci in 16 (45.7%) followed by Staphylococcus aureus in 8 (22.9%). Methicillin resistance rate was 83.3% among coagulase-negative staphylococci and S. aureus. In this study, cerebrospinal fluid shunt infection rate was 10.5%. Infection was frequently caused by methicillin-resistant coagulase-negative staphylococci and S. aureus within two months after shunt surgery. Vancomycin may be considered as the preoperative prophylaxis for shunt surgery in a situation where methicillin resistance rate is very high.

More malfunctioning Medos Hakim programmable valves: cause for concern?

Object

In recent years, the authors have noticed a growing number of programmable valve defects at their institution. Therefore, they conducted this study to evaluate the increased incidence of malfunctioning valves.

Methods

They investigated all revisions that had been performed at their institution between 1994 and 2010 for dislodgement of the stator of a standard Medos Hakim programmable valve with a prechamber.

Results

Fifteen valves were removed because of dislodged stators. The valves had been implanted between May 16, 1993, and December 27, 2002, and were explanted between February 19, 2006, and January 22, 2010. Thus, the valves had been in place for a mean period of 11 years (median 11 years, range 7–14 years). The percentage of dislodged stators was almost 3% (15 of 546 valves). Particularly noteworthy is that all malfunctioning valves were found in children who had been younger than 1 year of age at the time of implantation.

Conclusions

Medos Hakim programmable valve malfunctions are rare events but should receive careful attention. When the pressure setting cannot be adjusted, a malfunction should always be suspected and radiographic imaging should be performed to assess the valve. Stator dislodgement is the most serious form of valve adjustment failure.

Congenital hydrocephalus and ventriculoperitoneal shunts: influence of etiology and programmable shunts on revisions

OBJECT

Hydrocephalus is a notorious neurosurgical disease that carries the adage "once a shunt always a shunt." This study was conducted to review the treatment results of pediatric hydrocephalus.

METHODS

Pediatric patients who underwent ventriculoperitoneal shunt surgery over the past 14 years were reviewed for shunt revisions. Variables studied included age at shunt placement, revision, or replacement; programmable shunts; infection; obstruction; and diagnosis (congenital, posthemorrhagic, craniospinal dysraphism, and others including trauma, tumors, and infection). Multiple regression analysis methods were used to determine independent risk factors for shunt failure and the number of shunt revisions. The Kaplan-Meier method of survival analysis was used to compare etiologies on the 5-year survival (revision-free) rate and the median 5-year survival time.

RESULTS

A total of 253 patients were studied with an almost equal sex distribution. There were 92 patients with congenital hydrocephalus, 69 with posthemorrhagic hydrocephalus, 48 with craniospinal dysraphism, and 44 with other causes. Programmable shunts were used in 73 patients (other types of shunts were used in 180 patients). A total of 197 patients (78%) underwent revision surgeries due to shunt failures. The mortality rate was 1.6%. Age at first revision, the 5-year survival rate, and the median 5-year survival time were significantly less for both posthemorrhagic and craniospinal dysraphism than for either the congenital or "other" group (p < 0.05). The failure rate and number of revisions were not significantly reduced with programmable shunts compared with either pressure-controlled or no-valve shunts (p > 0.5).

CONCLUSIONS

Posthemorrhagic hydrocephalus and craniospinal dysraphism hydrocephalus had significantly earlier revisions than congenital and other etiologies. Programmable systems did not reduce the failure rate or the average number of shunts revisions.

A multi-institutional, 5-year analysis of initial and multiple ventricular shunt revisions in children

OBJECTIVE

To evaluate risk factors and predictors of cerebrospinal ventricular shunt revisions in children.

METHODS

A retrospective, longitudinal cohort of 1307 children ages 0 to 18 years undergoing initial ventricular shunt placement in the year 2000, with follow-up through 2005, from 32 freestanding children's hospitals within the Pediatric Health Information Systems database was studied. Rates of ventricular shunt revision were compared with patient demographic, clinical, and hospital characteristics with use of bivariate and multivariate regression accounting for hospital clustering.

RESULTS

Thirty-seven percent of children required at least one shunt revision within 5 years of initial shunt placement; 20% of children required two or more revisions. Institutional rates of first shunt revision ranged from 20 to 70% of initial shunts placed among the 32 hospitals in the cohort. Hospitals where one to 20 initial shunt placements per year experienced the highest initial shunt revision rate (42%). Hospitals performing over 83 initial shunt placements per year experienced the lowest revision rate (22%). We found that children undergoing shunt placement in the Midwest were more likely to experience multiple shunt revisions (odds ratio, 1.25; 95% confidence interval, 1.06-1.47) after controlling for hospital volume, shunt type, age, and diagnosis associated with initial shunt placement.

CONCLUSION

Higher hospital volume of initial shunt placement was associated with lower revision rates. Substantial hospital variation in the rates of ventricular shunt revision exists among children's hospitals. Future prospective studies are needed to examine the reasons for the variability in shunt revision rates among hospitals, including differences in specific processes of care.

The Hakim programmable valve: reasons for reprogramming failures

Object

In patients with hydrocephalus, the pressure settings of a Medos Hakim programmable valve may require adjustments even months after implantation. In some cases, however, adjustment proves to be impossible. The object of this study was to illuminate the reasons for reprogramming failures.

Methods

Data pertaining to the authors' experience with programmable valves at their clinic were obtained through retrospective review of patient records from 1992 to 1998 and prospectively collected from 1998 to 2006. Between 1992 and 2006, 585 Medos Hakim programmable valves were implanted at the authors' center, and reprogramming failure was observed in 12 of these 585 cases. The authors investigated and recorded the reasons for reprogramming failure. In cases in which the valves had to be explanted, the valves were returned to the manufacturer for further investigation and the results were recorded.

Results

In three of the 12 cases of reprogramming failure, the pressure settings could eventually be adjusted by placing the transmitter upside down against the flow direction. In the remaining nine cases, the valve had to be removed, yielding a rate of valve explantation of approximately 1.5% in this series. In two of these nine cases, the valve was found to be rotated longitudinally along its axis. In two cases the ratchet wheel had become loose and in one the radiopaque marker had become dislodged from the baseplate. Extensive deposits were identified macroscopically and microscopically within four explanted valves.

Conclusions

The reasons for failed reprogramming of Codman Medos Hakim valves as described in this article have not been mentioned in the literature so far. Failure of adjusting the pressure setting is a very rare event in a Medos Hakim programmable valve. The programming and adjustment mechanism appears to be very reliable. Valve replacement was required due to failed reprogramming in only a few cases.