Ventriculoauriculostomy-associated infection. A 12-year study

Ventriculoatrial Shunts in Adults, Incidence of Infection, and Significant Risk Factors: A Single-Center Experience

BACKGROUND

In recent years, the number of ventriculoatrial (VA) shunt insertions has decreased worldwide, the major cause being the risk of shunt infection. VA shunts remain as an alternative option to ventriculoperitoneal shunts. We describe our 10-year experience with VA shunts by analyzing the incidence of shunt infections and predisposing cofactors.

METHODS

During a median follow-up of 15.3 months, 259 shunt insertions, performed on 255 patients, were analyzed. The infection rate was calculated and the predisposing cofactors age, gender, cause of the hydrocephalus, previous external ventricle drainage, antibiotic-impregnated catheters, the number of revisions, the educational level of the surgeons, and the duration of the operations were analyzed. Two observation times were stratified.

RESULTS

We found overall infections in 18 patients (7.1%), 16 deep infections (6.3%) including 1 shunt nephritis (0.4%) and 2 superficial infections (0.8%). Wound dehiscence occurred in 17 patients (6. 6%). Analyzing follow-up time, the infection rate was 3.65% (95% confidence interval, 0.9%-5.9%) at survival time 1, 3.38% (95% confidence interval, 1.1%-6.2%) at survival time 2. In the first 6 months, 95% of patients were free of infection. Only the number of revision procedures was associated with the number of infections (P value < 0.0005).

CONCLUSIONS

In our patient cohort, the infection rate related to VA shunt insertion is low; the only statistically significant risk factor was the number of revisions. If the VA shunt is applied following a standardized protocol, the infection risk does not represent an argument for reluctance towards the VA draining concept.

Management of complicated shunt infections: a clinical report

OBJECTIVES

The authors present their experience with a protocol for the treatment of patients with complicated shunt infections.

METHODS

Complicated shunt infections are defined for the purpose of this protocol as multiple compartment hydrocephalus, multiple organism shunt infection, severe peritonitis, or infections in other sites of the body. The initial treatment protocol for these patients was 3 weeks of intravenous antibiotic therapy and 2 weeks of twice daily intraventricular/intrashunt antibiotic therapy. Cerebrospinal fluid (CSF) cultures were monitored during therapy and obtained again 48 hours after completion. The shunt was completely replaced. Additionally, follow-up cultures were obtained in all patients 3-6 months after therapy was completed.

RESULTS

A cure of the infection was achieved in all patients as defined by negative cultures obtained at completion of antibiotic therapy and in follow-up studies. The follow-up period was 2-11 years (mean 4.4 +/- 2.5 years). The treatment protocol was modified in the patients treated after 1991, and 18 patients were treated with this modified treatment regime. In these patients, intraventricular antibiotics were administered only once daily for 14 days, and the CSF was cultured 24 hours after antibiotic therapy had been stopped instead of after 48 hours. The results were similar to those obtained with the initial protocol.

CONCLUSIONS

Based on their prospective nonrandomized series, the authors believe that patients with complicated shunt infections can be successfully treated with 2 weeks of intraventricular antibiotic therapy administered once daily, concurrent with 3 weeks of intravenous antibiotic therapy. This protocol reduces length of treatment and hospital stay, and avoids recurrence of infection.

Aggressive management of shunt infection: combined intravenous and intraventricular antibiotic therapy for twelve or less days

OBJECTIVE

This report is limited to patients with a single cerebrospinal fluid (CSF) shunt infected by a single organism, and compares two treatment protocols.

METHODS

In the initial protocol (1975-1991), patients underwent removal of the shunt system and received intravenous and intraventricular antibiotics. Intraventricular antibiotics were administered twice daily to those with external ventricular drainage. When CSF was cultured 48 h off all antibiotics and found to be sterile at 24 h of incubation, a new shunt was inserted. Follow-up CSF cultures were obtained in all patients between 1-6 months following placement of the new shunt.

RESULTS

There were 25 patients (ages 1 month to 16 years; mean +/- SD: 23 +/- 4.0 months). CSF obtained from the shunt yielded the following: Staphylococcus epidermidis (19), Staphylococcus aureus (2), Streptococcus species (2), Serratia marcescens (1), and Propionebacterium species (1). The duration of intravenous antibiotics was 7-12 days (mean +/- SD: 9.7 +/- 1.3 days), and intraventricular antibiotic therapy was 6.2 +/- 1.7 days. Total hospital stay was 15.2 +/- 2.3 days. The follow-up period was 7.7 +/- 3.6 years. Following the initial protocol in another 15 patients (1992-2004), the treatment regime was modified in that intraventricular antibiotics were administered once daily in patients with external ventricular drainage, and the CSF was cultured at 24 h off antibiotics, instead of 48 h. Results were similar to the initial protocol with respect to days of antibiotic therapy and hospital stay.

CONCLUSION

Based on our retrospective nonrandomized series, we believe patients with a single shunt and noncompartmentalized hydrocephalus can be successfully treated without a prolonged antibiotic course and lengthy hospital stay.

Cerebral ventricular shunts

Cerebral ventricular shunts are siphoning devices used to treat hydrocephalus. They are placed within cerebral ventricles and peripheral cavities such as the ventricular atrium or peritoneal cavity. Complications include obstruction of cerebral spinal fluid (malfunction) and infection. Morbidity and mortality rates are high when shunt malfunction and infection are not treated emergently. This report summarizes the physical examination of patients with ventricular shunts, reviews the type of shunts commonly used, discusses shunt malfunctions (causing overshunting or undershunting of cerebrospinal fluid) and infections, and makes recommendations concerning empiric antibiotic therapy for shunt infection. The technique of tapping a shunt is presented for management of patients with elevated intracranial pressure that does not respond to non-invasive maneuvers to lower the pressure.

Shunt malfunction in relation to shunt infection

Ventriculo-peritoneal shunt malfunction may be caused by shunt infection which may not be clinically apparent as the cause of the malfunction by standard diagnostic criteria. This suggests that the real incidence of infected shunts might be higher than previously suspected. In order to study the relationship between infection and shunt malfunction, we followed a protocol over five years (54 V-P shunts) consisting of (1) removal of the malfunctioning shunt and replacement in the same surgical procedure with a new one or institution of an external ventricular drainage for 8 days (if there were clear signs of infection), (2) culturing of CSF and every part of the removed shunt, and (3) intravenous antibiotic treatment (Vancomycin 1g./12h + Ceftriaxone 1g./12h) for five days after the new V-P shunt had been inserted. In those cases in which an external ventricular drainage had been placed, its tip and a portion of the new V-P shunt were also cultured. The results showed that although CSF cultures were negative in 49/54 cases (90.7%), cultures of the removed shunts were positive in 32/54 (59.2%), most of them (21/32, 65.6%) for Staphylococcus coagulase negative organisms. The CSF samples obtained by puncturing the reservoir on admission to Hospital were positive only in 5 out of 54 cases (9.2%), only in those showing clinical features of infection. In the remaining cases, 27 out of 54 (50%) the CSF cultures were negative but the shunt cultures proved positive and required further treatment. For the newly inserted shunts (173) CSF was collected through the shunt during the surgical procedure, and a small piece of the extra-tube from the ventricular and from the peritoneal catheter were obtained and cultured. All the six shunts (6/173, 3.4%) that showed positive cultures after insertion had to be replaced within a period of three to four weeks due to malfunction (range 26 +/- 7 days), indicating that the systematic culture of CSF and tubing helps to predict which shunts will soon need to be replaced due to infection. We conclude that CSF culture alone does not rule out infection in cases of shunt malfunction. The percutaneous CSF obtained from the shunt reservoir admission is particularly prone to show negative cultures even when the shunt is colonized by bacteria.

Long-term follow-up in 233 patients with congenital hydrocephalus

Data on 233 children with congenital hydrocephalus who were operated on in our department from 1964 to 1984 were analyzed. The study was started in January 1990 and was based on questionnaire followed by a psychological examination. Thirty-two patients (13.7%) died during the follow-up period. The average number of operations during the observation period was 2.7; in 166 patients (= 71.2%) the shunt had to be revised at least once. The reason for revision was a mechanical problem in 79.4% and infection in 15.5%. The psychological evaluation in 115 patients showed a normal performance in 62.8%, while 29.8% had mild retardation, evident in speech impairment and/or impaired speech development, in memory and concentration, in poor intellectual performance and decreased performance in school. Severe retardation was seen in 7.4% of cases. Our results showed that the best outcome can be achieved with early shunt implantation. We did not, however, find any correlation between shunt revision rate and psychological results.

Long-term results after ventriculo-atrial shunting in children

A consecutive series of 120 patients with infantile hydrocephalus who were submitted to ventriculo-atrial shunting was studied. The average follow-up was 11 years. There was no operative mortality; 7 patients died during the follow-up period, but only in 1 case was the cause of death a consequence of the shunt procedure. The incidence rates of infection and slit ventricle syndrome were 4.2% and 1.8%, respectively. Shunt revision was performed on 253 occasions yielding a revision rate of 2.2 per patient. Of these 253 revisions 167 (66%) took the form of elective lengthening of the atrial catheter. The number of reoperations to adjust the length of the atrial catheter or to revise the distal end of the shunting system is a major disadvantage, which actually favors ventriculo-peritoneal shunting as the primary procedure for the treatment of pediatric hydrocephalus.

Long-term results after ventriculoatrial shunting in children

A consecutive series of 120 patients with infantile hydrocephalus who were subjected to ventriculoatrial shunting was studied. The average length of follow-up was 11 years. Operative mortality was zero. Seven patients died during the follow-up period; in all cases but one of these the cause of death was not a consequence of a shunt-related procedure. The incidences of infection and slit ventricle syndrome were 4.2% and 1.8% respectively. Two hundred and fifty-three shunt revisions were performed, yielding a revision rate of 2.2 per patient. Of these 253 revisions 167 (66%) were elective lengthening of the atrial catheter. The number of reoperations for adjusting the length of the atrial catheter of for revision of the distal end of the shunting system is a major disadvantage of ventriculoatrial shunting which actually speaks in favor of ventriculoperitoneal shunting as the primary procedure for the treatment of pediatric hydrocephalus.

Shunt nephritis. Case report

The incidence of shunt nephritis has decreased over the past several years due to the increased use of ventriculoperitoneal (VP) shunts rather than the ventriculovascular systems for which this complication was originally reported in 1965. Despite this trend, the syndrome has been reported in cases of VP shunting and, for this reason, merit a renewed look. Shunt nephritis is thought to be secondary to immune complex formation and deposition in the kidney in response to Staphylococcus epidermidis. The diagnostic workup and management of this disease is discussed.

Vancomycin pharmacokinetics in hydrocephalic shunt prophylaxis and relationship to ventricular volume

Vancomycin pharmacokinetics were determined in 25 patients receiving ventriculoperitoneal shunts for hydrocephalus. Computed tomography scan-derived ventricular-brain ratio as an expression of hydrocephalus varied between 9.3% and 15.4% (12.9% +/- 1.7%). One hour prior to surgery each patient received 1 g of vancomycin infused intravenously over 60 minutes. Samples of cerebrospinal fluid and venous blood were obtained 1 hour later and vancomycin levels assayed by fluorescence polarization immunoassay. There were 11 females and 14 males, with a mean age of 44.5 +/- 10.3 years and a mean weight of 72.0 +/- 11.4 kg. All had normal renal function. Levels of vancomycin in the cerebrospinal fluid at 1 hour ranged from 0.1 to 1.5 micrograms/mL (0.9 +/- 0.3). Weight did not affect these values (p greater than 0.1). Simultaneous blood vancomycin levels varied between 9.1 and 38.7 micrograms/mL (22.3 +/- 8.3). Ventricular volume, expressed as the ventricular-brain ratio, did not correlate with cerebrospinal fluid vancomycin levels (p greater than 0.5). There was no significant increase in concentrations of vancomycin in CSF as cerebrospinal fluid protein concentration increased, nor when blood vancomycin concentration was greater than 20 mg/dL (therapeutic range) (p greater than 0.1). No patient had evidence of infection at 6 months follow up. These results indicate minimal cerebrospinal fluid penetrance of vancomycin when administered systemically 1 hour prior to shunt surgery. In addition concentrations of vancomycin in cerebrospinal fluid bear no relationship to weight, ventricular volume, meningeal inflammation, or blood levels in the therapeutic range. The minimum inhibitory concentration of vancomycin for staphylococci is 1.5 to 3.1, and as bactericidal levels of 5 to 8 minimum inhibitory concentration are needed to kill organisms, a combination of both systemic and intraventricular vancomycin may be needed to ensure adequate cerebrospinal fluid and tissue concentration of antibiotic during shunt prophylaxis.

Valvular infections in patients with hydrocephalus: preventive aspects

Shunt infections in children have become a serious problem. In order to solve this, we have been using antibiotic therapy with Rifampicin (Rifampin) for the last 2 years; the dosage is 20 mg/kg per day 1 h before surgery and then for 48 h after the surgical procedure. We have had experience with 203 children operated on between January 1987 and December 1988. The result was a significant decrease in the number of children with shunt infections. In 1980 we reported an incidence of 10%, while by 1988 the rate had gone down to 1%.

Use of an in vitro model for studying the eradication of catheter colonisation by Staphylococcus epidermidis

Silicone rubber catheters were experimentally colonised with three different strains of Staphylococcus epidermidis sensu stricto. The catheters were then perfused with brain-heart infusion broth by means of an in vitro apparatus which simulates the pharmacokinetics of intraventricular administration of antimicrobial agents. When colonisation was established, vancomycin was administered to the dosing chamber three times daily so as to give peak concentrations of 16, 32, 64 and 128 mg/l. Each experiment was performed in triplicate. Samples of fluid taken from each catheter were cultured before treatment and at intervals thereafter during perfusion for 4 weeks or until recolonisation became apparent. Those catheters not showing evidence of recolonisation were examined by scanning electron microscopy for the presence of organisms. Colonisation was eradicated (as judged by cultural examination) in 37% catheters but eradication did not bear any clear relationship to drug concentrations. Electron microscopical examination of all catheters showing eradication by cultural means revealed the presence of organisms.

Cerebrospinal fluid shunt infections in children. A study on the relationship between the etiology of hydrocephalus, age at the time of shunt placement, and infection rate

A total of 431 patients who underwent their first cerebrospinal fluid shunt insertion at Children's Memorial Hospital over a 10-year period were retrospectively studied with regard to the relationship between the etiology of the hydrocephalus, age at the time of shunt placement, and infection rate. Forty percent of the patients had constrictive hydrocephalus and meningomyelocele, 33% congenital communicating or obstructive hydrocephalus, and 18% tumors. Intraventricular hemorrhage and meningitis accounted for the remaining 8%. Eighty-three percent of the patients were less than 1 year old at the time of surgery; 18% were 1 week old or younger. A total of 1,485 procedures were performed with an average of 3 procedures per patient. Ninety-six patients had infections, resulting in a 22% infection rate per patient and a 6% infection rate per procedure. No significant correlation was evident between etiology of the hydrocephalus and infection rate (P greater than 0.05), even though meningomyelocele patients seemed to be more prone to infection than congenital hydrocephalus patients (P = 0.06). Age at the time of shunt placement was related to infection rate, with younger patients having more infections than older ones (P less than 0.01). More in-depth analysis of the relationship between age and infection rate was possible in the meningomyelocele and congenital hydrocephalus groups, owing to the significant number of these patients that fell into each one of the subdivisions chosen with respect to age at the time of shunt placement. Meningomyelocele patients shunted in the first week of life have a higher infection rate than those shunted at 2 weeks of age or older (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

An analysis of cerebrospinal fluid shunt infections in adults. A clinical experience of twelve years

The authors analyze a group of 451 shunt operations where 317 patients had hydrocephalus and 23 cases were reported positive after cerebrospinal fluid (CSF) cultures. Staphylococcus was the most frequent bacterial organism found (57%). This retrospective study of 23 patients in whom infection developed following placement of an extrathecal shunt, although not a complete biometric evaluation, shows an incidence of infection of 5%. The authors also indicate the limitations in antibiotic treatment when three significant aspects of therapy are not considered fully: 1. sensitivity of the identified organism, 2. CSF levels of the drug that can be attained, and 3. the pharmacokinetic action of the drug in the CSF.

Sedimentation cytomorphology of the CSF in ventriculitis

The cytological technique of cytocentrifugation and millipore filter collection of cells allows accurate identification of cells in the CSF. This study reports the changing CSF cell-populations during 26 episodes of ventriculitis in children with shunts to control hjydrocephalus. There was a significant discordance between lymphocytes and macrophages in the CSF. Neurosurgery led to a 20 per cent increase in neutrophils on the first postoperative day, with a progressive decline to a mean of 10 cells on the fourth postoperative day. There was a small decrease in lymphocytes on the first postoperative day, followed by an increase on the second day. Macrophages were reduced by 12 per cent on the first postoperative day and then steadily increased from the second to the fourth day. A mean number of two peaks (of all cells) occurred during the treatment for ventriculitis: there was a greater number of of neutrophils in the first peak, with less lymphocytes and macrophages than in the second peak. This study supports the advantages of this technique in the diagnosis and management of ventriculitis.

Results of trimethoprim-sulfamethoxazole prophylaxis in ventriculostomy and shunting procedures. A double-blind randomized trial

The author reports the results of a study to assess the effectiveness of a trimethoprim-sulfamethoxazole combination as prophylaxis in ventriculostomy or shunting operations. Between 1980 and 1983, 122 patients undergoing shunting procedures were randomly assigned to receive trimethoprim-sulfamethoxazole (Group 1, 62 cases) or a placebo (Group 2, 60 cases). The same regimen was followed at each operation, and the patients were followed for a minimum of 6 months. There was a higher infection rate in the placebo group (14 of 60 patients compared with 4 of 62 patients in the antibiotic group, p less than 0.01). The antibiotic protected against early infections (nine of the 60 patients in Group 2 against none of the patients in Group 1), but not against late infections (four of the 62 in Group 1 compared with five of the 60 in Group 2). During the same period, 52 patients undergoing ventriculostomy only were also randomly assigned to receive trimethoprim-sulfamethoxazole (Group 3) or placebo (Group 4). There were no differences in the infection rates between these groups (one of 25 in Group 3 as against one of 27 in Group 4).

Factors causing acute shunt infection. Computer analysis of 1174 operations

A series of 1174 operations performed on 802 hydrocephalic children was analyzed in an effort to find the factors causing acute postoperative infection. Culture of the cerebrospinal fluid (CSF) samples during the operation was positive in 33 cases. These cases were excluded from the series. Ninety infections were observed in the remaining 1141 operations, an overall rate of 7.9%. Most of these infections were meningitis (56 cases). Staphylococcus epidermidis was the bacterium most frequent identified (44%). Statistically significant relationships were found between shunt infection and the following factors: 1) age: infection was 2.6 times as frequent before 6 months than after 1 year of age (p = 0.03); 2) poor condition of the skin; 3) presence of intercurrent seats of infection at the time of surgery; 4) type of operation: the rate of infection was 8.4% in primary shunt insertions, 5% in shunt revisions, and 17.5% in reinsertions following shunt removal for infection (p = 0.0001); 5) end of the shunt requiring revision: an infection rate of 7.7% followed revision of the ventricular catheter alone, and 2.6% followed revision of the other end alone (p = 0.012); and 6) postoperative wound dehiscence or scalp necrosis. The surgical team involved was poorly correlated with the rate of infection (p = 0.12). No statistically significant relationships have been found between infection and 1) etiology of hydrocephalus: 2) sex; 3) recent neurosurgical operation before the shunt procedure; 4) preoperative presence of an external drainage tube or CSF fistula; 5) lumbar or ventricular taps, or ventriculography; 6) number of previous operations performed on the shunt; 7) time (month and year) of operation; or 8) sugar level and cell count in the CSF.

Extrinsic factors that put patients at risk of acquiring central nervous system infections

Although many host defenses, including physical barriers, phagocytic cells, and humoral elements, normally protect the central nervous system from microbial pathogens, a variety of extrinsic factors may compromise these defenses and put patients at risk of acquiring central nervous system infection. These risk factors include: (1) communication of the cerebrospinal fluid space with integumentary surfaces; (2) communication of the cerebrospinal fluid space with other body spaces through shunts; (3) suppurative foci contiguous to the central nervous system; (4) hematogenous spread of infectious agents; (5) new acquisition of infectious agents with a propensity for causing central nervous system infection; and (6) administration of certain antimicrobial or immunosuppressive drugs. Recognition that these factors are present and therefore that the patient is at risk allows monitoring for and prompt response to signs and symptoms of central nervous system infection.

Cerebrospinal fluid shunt infection. Influences on initial management and subsequent outcome

A retrospective study of the management of patients with infected cerebrospinal fluid (CSF) shunts was undertaken, covering the 20 years from 1960 to 1979, inclusive, and involving 222 patients with 267 infections. The data were analyzed with emphasis on influences surrounding treatment choice and subsequent outcome. Treatment was classified into three major categories: medical management (antibiotics alone), surgical management (antibiotics plus operative removal of the infected shunt), and no treatment (ranging from admission and observation only to shunt revision), the diagnosis of shunt infection having been missed. Results showed surgical treatment to be more efficacious than medical or no treatment, with a higher rate of initial cure, and lower morbidity and mortality rates. Also examined were the relationships among clinical presentation, infection rate, and results of specimens sent for culture, and initial treatment. The definitive nature of initial treatment was revealed to be directly proportional to the aggressiveness of microbiological investigation. This latter aspect was related to clinical presentation, with shunt malfunction being the least recognized symptom of shunt infection. Patients presenting with blocked shunts were less likely to receive therapy appropriate for infection than any other group, leading to the conclusion that shunt malfunction may be more specific to infection than heretofore believed.

Treatment of CSF shunt infections with intrashunt plus oral antibiotic therapy

Infections of 12 cerebrospinal fluid (CSF) shunts in 11 children were treated with oral systemic antibiotic therapy plus daily intrashunt injections of antibiotics. Eight patients were infected with Staphylococcus epidermidis (four patients) or Staphylococcus aureus (four patients), and were treated with intrashunt vancomycin, plus oral trimethoprim/sulfamethoxazole (T/S), plus oral rifampin. One of these eight patients was later changed to a course of intrashunt cephapirin and oral cephalexin plus oral rifampin. One patient with Micrococcus varians infection was treated with oral T/S and rifampin, without intrashunt therapy, another patient with Pseudomonas cepacia infection was treated with intrashunt kanamycin plus oral T/S, and a third with Corynebacterium sp. infection was treated with intrashunt vancomycin plus oral T/S. Eight of the 11 patients required some form of shunt surgery, the most common being temporary externalization of the peritoneal end of the catheter. Only two shunts were completely replaced (both were ventriculojugular shunts which were changed to ventriculoperitoneal shunts). Nine of 10 evaluable cases were considered cured of their infections. The patient treated with cephalosporins had an uncorrected shunt malfunction and relapsed 1 month after completing therapy. The authors have shown that CSF shunts infected with Staphylococci can be effectively cleared with daily intrashunt vancomycin plus systemic therapy with oral T/S and rifampin. Less common infections may also be amenable to this form of therapy. Revision surgery, if necessary, should be carried out during the antibiotic therapy.

Cerebrospinal fluid shunt infections. A review of 35 infections in 32 patients

The authors have reviewed the clinical manifestations and therapy of hydrocephalus shunt infections in 32 patients with a total of 35 shunt infections. These 35 infections accounted for 43 hospital admissions. First infections usually developed within 2 months following surgery. At the time of diagnosis, 89% of patients were febrile. Fever and cough as a symptom complex characterized the initial clinical presentation in six of 19 episodes of infection complicating ventriculoatrial (VA) shunts, as compared with none of 21 episodes in which infection complicated ventriculoperitoneal (VP) shunts. Seven of 21 infectious episodes occurring in patients with VP shunts in situ were associated with significant abdominal pain and tenderness. These patients usually had no other clinical features to suggest shunt infection. Both of these symptom complexes often led to delays in diagnosis and treatment. Causative organisms included Staphylococcus epidermidis in 21, Staphylococcus aureus in seven, Gram-negative aerobic bacilli in seven, diphtheroids in five, Streptococcus species in four, and anaerobes in three. Five infections were polymicrobial in nature. Positive blood cultures were seen in 13 of 17 infectious episodes complicating VA shunts, as compared with only three of 13 other infections. When the shunt was completely removed, with or without replacement, all 13 patients were cured. When intravenous antibiotics were administered in conjunction with incomplete shunt removal, only eight of 15 courses resulted in cure. Intraventricular antibiotics were administered in four patients and all were cured. Therapy of shunt infections with parenteral antibiotics and incomplete shunt removal is associated with an unacceptably high failure rate.

Ventriculo-atrial shunt nephritis

A case of immune complex glomerulonephritis with reversible renal insufficiency following ventriculoatrial shunting is described and the English language literature is reviewed. The importance of recognizing this reversible glomerulonephritic lesion is emphasized.

Systemic Hemophilus influenzae infection. A study of risk factors

In Omaha, from 1974 to 79, 30 (12.5%) of 240 patients with Haemophilus influenzae bacteremia or meningitis had a wide variety of conditions known to be associated with increased susceptibility to bacterial infection. Neonates and adults accounted for 47 per cent of the infections. Non-type b and non-typable strains caused 41 per cent of the episodes. Forty-one per cent of patients had bacteremia with no detectable focus of infection. The incidence of meningitis was low. Mortality was 28 per cent, considerably higher than in patients who were previously healthy. A review of the medical literature indicated that low-birth weight infants and patients with leukemia and other malignancies undergoing chemotherapy, splenectomy, congenital asplenia, sickle cell anemia, immunoglobulin deficiency diseases, cerebrospinal fluid shunts, and skull defects are at greater risk for systemic H. influenzae disease than the general population.

The management of cerebrospinal fluid shunt infections: a clinical experience

Fifty patients with infected cerebrospinal fluid shunts were treated by one of three forms of treatment: a) Twenty-two patients had shunt removal, systemic antibiotic treatment, and either external ventricular drainage or intermittent ventricular taps for decompression and antibiotic administration. b) Seventeen patients had removal and immediate replacement of the shunt with intrashunt and systemic antibiotics. c) Eleven patients received intrashunt and systemic antibiotics without shunt removal. In the first group, antibiotics were given for a period of one week; in the second and third groups, intravenous antibiotics were administered for a minimum period of three weeks, and intraventricular antibiotics twice daily for two weeks. In all patients ventricular CSF was obtained and cultured 48 hours after cessation of antibiotic therapy, and cultures were repeated within four months after completion of therapy. Twenty-one of 22 patients in the first group as well as 11 of 13 of the second group, were successfully treated. In the third group only four of the 11 patients responded to treatment.

Haemophilus influenzae infections of cerebrospinal fluid shunts. Report of two cases

Two (1%) of 165 episodes of Haemophilus influenzae infection of the central nervous system occurred in patients with cerebrospinal fluid shunts. Both cases were caused by strains that could not yet be typed. The clinical presentation was similar to that of other forms of shunt infection, yet the pathogenesis may be similar to that of H. influenzae meningitis in children without shunts. Systemic antibiotic therapy, without shunt replacement or intraventricular antibiotic administration, may be more successful in shunt infections caused by H. influenzae than in those caused by other organisms.

Diphtheroid infections of cerebrospinal fluid shunts. The changing pattern of shunt infection in Cleveland

In the process of trying to decrease infection rates, gentamicin has been used to irrigate shunt systems at the time of surgery. The infection rate did not change, but the epidemiology of infecting organisms changed from Staphylococcus epidermidis to diphtheroids. These indolent and sometimes asymptomatic infections can progress to cause systemic disease with nephritis, peritonitis, or blocked shunts, and are difficult to detect. Laboratory values of cerebrospinal fluid and blood may not be helpful, but prolonged culture incubation on anaerobic media will subsequently yield the organism. Systemic and intraventricular antibiotics may rid the system of diphtheroids and avoid morbidity of shunt revision if the infection is found before systemic disease occurs.

Cerebrospinal fluid antibiotic levels during treatment of shunt infections

Twenty patients with documented cerebrospinal fluid shunt infections were treated with daily intraventricular injections of methicillin, cephalothin, or gentamicin without removal of the shunt or external ventricular drainage. Periodic determinations of intraventricular antibiotic concentration revealed significant levels in relation to the established minimum inhibitory concentration in all cases.

Cerebral cyst infection with Micrococcus sedentarius. Case report

A 7-year-old boy with congenital hydrocephalus and a left septate cerebral cyst presented with a shunt infection due to Micrococcus sedentarius, resistant to all penicillins. The shunt infection was persistent despite several courses of parenteral, intraventricular, and intracyst antibiotics. Evaluation of the ventricular fluid revealed adequate "killing power" against the patient's microorganism. No extracranial focus of infection could be found. Computerized tomographic scanning, along with air ventriculography, identified a noncommunicating area of the cerebral cyst. Only when communication between this location and the rest of the cyst was established were the antibiotics efficacious. Undercirculated areas of cerebrospinal fluid should be sought when shunt infections and ventriculitis persist in spite of adequate parenteral and local therapy in patients with brain cysts.

Shunt catheter impacted in the vena cava. Case report

A shunt-dependent patient had an atrial catheter firmly adherent in the superior vena cava. Thoracotomy was required for its removal.

Long-term analysis of cerebrospinal fluid shunt infections. A 25-year experience

The authors have retrospectively analyzed 840 cerebrospinal fluid shunting procedures over a 25-year period to determine the relationships between infection rates and several possible influences on infection. Two-thirds of all shunt infections occurred within 1 month of surgery. The very young and very old had higher infection rates. Infections became less prevalent over the period of the study, and mortality from infection decreased from 35% to 6%. Successive shunts (revisions) were found to have progressively higher infection rates. Ventriculoatrial and ventriculoperitoneal silicone plastic shunts had similar infection rates (11.4% and 12.0%). The uncontrolled use of prophylactic antibiotics had no effect on shunt infections. Staphylococcus epidermidis became gradually more prevalent over the period of the study, and eventually caused one-half of all infections. Where infection occurred in the presence of prophylaxis, the infectious organism was usually sensitive to the antibiotic being used. The surgeon was found to be the largest single factor in the incidence of shunt infections. A 25-fold variance in infection rates among surgeons could be related to individual experience and technique.

Extracranial CSF shunting for infantile non tumoral hydrocephalus--a retrospective analysis of 360 cases

A series of 360 consecutive extracranial CSF shunts performed between June 1960 and June 1976 for infantile non tumoral hydrocephalus is reviewed. The surgical methods used, the reasons for re-operation, the time distribution of post-operative complications, the causes of death and the long term results are analysed and discussed for each of the four groups: tetraventricular communicating hydrocephalus, triventricular hydrocephalus, obstructive hydrocephalus with a ventriculo-cisternal block and post-meningocele or post-myelomeningocele hydrocephalus.

Non-pneumococcal Gram-positive coccal meningitis related to neurosurgery

Thirty-eight of 154 cases (25%) of bacterial meningitis seen by the authors during a 7-year period were due to non-pneumococcal Gram-positive cocci. Thirty cases (80%) resulted from neurosurgical manipulation; half of these were shunt infections and half were early postoperative complications. Only three cases (8%) occurred de novo in patients with presumably normal host defenses. Signs, symptoms, and laboratory data related more to predisposing factors than to infecting microorganisms. Fever, peripheral leukocytosis, abnormal cerebrospinal fluid (CSF), and positive Gram stain were the most reliable indicators of infection. Prognosis was good with antibiotic therapy and removal of CSF shunt equipment when present.

Ventriculolymphatic shunt

The authors report the cases of 16 adult patients who underwent ventriculolymphatic shunt procedures with apparent good results. The follow-up period is from 2 to 12 years. The anatomy of the terminal portion of the thoracic duct studied in 51 patients undergoing sympathectomy of the lower cervical-upper thoracic ganglionic chain is reported. The operative technique of the ventriculothoracic duct shunting procedure is described, and a general review of the function of the shunt as compared with that of ventriculoatrial shunts is presented.

Propionibacterium acnes: pathogen in central nervous system shunt infection. Report of three cases including immune complex glomerulonephritis

Propionibacterium acnes is a pleomorphic gram-positive anaerobic rod usually isolated as a contaminant from skin. We report three cases of P. acnes infection of central nervous system shunts for hydrocephalus. The organism was seen repeatedly on gram stain in a specimen of shunt fluid in all three cases; initially, it was regarded as a contaminant. In addition, two of the patients had precipitins to extracts of their organism. Serum from normal control subjects had no such precipitins. One of the patients had an immune-complex glomerulonephritis--an entity not previously associated with anaerobic organisms. All three patients recovered after removal of the shunt and treatment with antibiotics. P. acnes is a significant pathogen in patients with central nervous system shunts.

Control of shunt infection. Report of 150 consecutive cases

The author analyzes 150 consecutive ventriculovenous, ventriculoperitoneal, and lumboperitoneal shunt procedures with particular attention to shunt colonization by Staphylococcus epidermidis. There was one primary infection with Staphylococcus epidermidis early in the series, and in two other cases, the organism was felt to be a secondary invader. In those procedures involving either primary placement or revision of a ventriculovenous shunt, there was not a single infection. The operative protocol that has virtually eliminated Staphylococcus epidermidis is outlined.

Follow-up comparison of hydrocephalus with and without myelomeningocele

A series of 454 hydrocephalic patients with and without myelomeningocele and with and without treatment is reviewed. The survival rates for hydrocephalus alone and for hydrocephalus with myelodysplasia are comparable. The authors reach the conclusion that treatment of the hycrocephalic process and its complications is the most critical therapeutic consideration. Mental retardation is the major unalterable cause for failure to develop independence; some lesser emotional causes can be modified by encouragement. Repeated reassessment of the patient's condition and adjustment are important. Before treatment is started parents or guardians should be fully informed of the child's future potential for independent life and mental development.