Comparing antibiotic, silver, and standard ventriculoperitoneal shunts
Authors: Ann Marie Flannery
Journal: The Lancet (2019)

Hydrocephalus, a build-up of cerebrospinal fluid within the ventricles of the brain, is the most common paediatric neurosurgical diagnosis, and is among the most common conditions in all age groups treated by neurosurgeons.1Dewan MC Rattani A Mekary R et al.Global hydrocephalus epidemiology and incidence: systematic review and meta-analysis.J Neurosurg. 2019; 130: 1065-1079Crossref Scopus (61) Google Scholar Surgical treatment is usually either a mechanical diversion with a ventriculoperitoneal shunt or creation of an internal drainage pathway (third ventriculostomy). Shunts have been used for more than six decades to treat hydrocephalus, meaning that the advantages and risks of the procedure are well known. Conor Mallucci and colleagues2Mallucci CL Jenkinson MD Conroy EJ et al.Antibiotic or silver versus standard ventriculoperitoneal shunts (BASICS): a multicentre, single-blinded, randomised trial and economic evaluation.Lancet. 2019; (published online Sept 12.)http://dx.doi.org/10.1016/S0140-6736(19)31603-4Summary Full Text Full Text PDF PubMed Scopus (47) Google Scholar report in The Lancet a multicentre, single-blind, randomised trial and economic evaluation (BASICS) of the clinical effectiveness and cost-effectiveness of antibiotic-impregnated (rifampicin and clindamycin) or silver-impregnated shunts compared with standard shunts at reducing infection. 1605 UK patients (49% women, 31% aged 65 years or older) with hydrocephalus of any aetiology who were undergoing insertion of their first ventriculoperitoneal shunt were evaluated. The primary outcome was time to shunt failure caused by infection and was analysed with Fine and Gray survival regression models for competing risk. 32 (6%) of 533 evaluable patients in the standard shunt group had a shunt revision for infection compared with 12 (2%) of 535 evaluable patients in the antibiotic shunt group (cause-specific hazard ratio 0·38, 97·5% CI 0·18–0·80; p=0·0038) and 31 (6%) of 526 patients in the silver shunt group (0·99, 0·56–1·74; p=0·96). Adverse events, most of which were related to valve or catheter malfunction, occurred in 135 (25%) patients in the standard shunt group, 127 (23%) in the antibiotic shunt group, and 134 (36%) in the silver shunt group. The authors report that in the UK's National Health Service health-care system, the use of antibiotic shunts saves £135 753 per infection avoided. This trial advances the current evidence base on hydrocephalus surgery. Few neurosurgical randomised controlled trials of good quality exist since the complexity of neurosurgical problems, their relative scarcity in the population, and the diversity of their pathology make them poor candidates for such trials. Hydrocephalus is one of the few diagnoses that is amenable to the randomised controlled trial design because of its frequency, which allows the recruitment of an adequate population size, and the small number of treatment alternatives, of which ventriculoperitoneal shunt insertion is the most frequent. Evidence for ventriculoperitoneal shunt insertion before the BASICS trial was restricted to meta-analyses of relatively small, mostly non-controlled studies.3Klimo P Thompson CJ Ragel BT Boop FA Antibiotic-impregnated shunt systems versus standard shunt systems: a meta- and cost-savings analysis.J Neurosurg Pediatr. 2011; 8: 600-612Crossref PubMed Scopus (35) Google Scholar, 4Klimo Jr, P Thompson CJ Baird LC Flannery AM Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 7: antibiotic-impregnated shunt systems versus conventional shunts in children: a systematic review and meta-analysis.J Neurosurg Pediatr. 2014; 14: 53-59Crossref PubMed Scopus (47) Google Scholar Our systematic review and evidence-based guidelines on paediatric hydrocephalus4Klimo Jr, P Thompson CJ Baird LC Flannery AM Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 7: antibiotic-impregnated shunt systems versus conventional shunts in children: a systematic review and meta-analysis.J Neurosurg Pediatr. 2014; 14: 53-59Crossref PubMed Scopus (47) Google Scholar showed that only a few studies had been done until 2012 and all had class 2 evidence at best; moreover, few studies have been reported since these guidelines.3Klimo P Thompson CJ Ragel BT Boop FA Antibiotic-impregnated shunt systems versus standard shunt systems: a meta- and cost-savings analysis.J Neurosurg Pediatr. 2011; 8: 600-612Crossref PubMed Scopus (35) Google Scholar, 4Klimo Jr, P Thompson CJ Baird LC Flannery AM Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 7: antibiotic-impregnated shunt systems versus conventional shunts in children: a systematic review and meta-analysis.J Neurosurg Pediatr. 2014; 14: 53-59Crossref PubMed Scopus (47) Google Scholar Importantly, Mallucci and colleagues included children in their study. Clinical trials in paediatric patients can have greater administrative challenges than trials in adults, but hydrocephalus is more common in children (estimated at one in 500 births globally), which makes this study format necessary to assess treatment for the condition.1Dewan MC Rattani A Mekary R et al.Global hydrocephalus epidemiology and incidence: systematic review and meta-analysis.J Neurosurg. 2019; 130: 1065-1079Crossref Scopus (61) Google Scholar Surgical randomised controlled trials are disadvantaged by the difficulty in concealing the intervention outcome. The authors were careful to ensure that the assessment investigators did not know which shunt had been inserted.2Mallucci CL Jenkinson MD Conroy EJ et al.Antibiotic or silver versus standard ventriculoperitoneal shunts (BASICS): a multicentre, single-blinded, randomised trial and economic evaluation.Lancet. 2019; (published online Sept 12.)http://dx.doi.org/10.1016/S0140-6736(19)31603-4Summary Full Text Full Text PDF PubMed Scopus (47) Google Scholar The trial design also included an adequate number of patients, unlike previous studies.3Klimo P Thompson CJ Ragel BT Boop FA Antibiotic-impregnated shunt systems versus standard shunt systems: a meta- and cost-savings analysis.J Neurosurg Pediatr. 2011; 8: 600-612Crossref PubMed Scopus (35) Google Scholar, 4Klimo Jr, P Thompson CJ Baird LC Flannery AM Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 7: antibiotic-impregnated shunt systems versus conventional shunts in children: a systematic review and meta-analysis.J Neurosurg Pediatr. 2014; 14: 53-59Crossref PubMed Scopus (47) Google Scholar The principle limitation of the study by Mallucci and colleagues is the inability to mask the treating physician to the intervention as the three shunts had different colours. The authors also noted that some of the malfunctions classed as not due to infection in the antibiotic shunt group might have been low-grade infection concealed by the presence of antibiotics.2Mallucci CL Jenkinson MD Conroy EJ et al.Antibiotic or silver versus standard ventriculoperitoneal shunts (BASICS): a multicentre, single-blinded, randomised trial and economic evaluation.Lancet. 2019; (published online Sept 12.)http://dx.doi.org/10.1016/S0140-6736(19)31603-4Summary Full Text Full Text PDF PubMed Scopus (47) Google Scholar The work by Mallucci and colleagues provides important evidence for the cost-effectiveness of antibiotic shunts. Physicians can no longer afford to apply new techniques or technologies that do not show substantial benefit. The prevention of infection in individuals treated for hydrocephalus can lead to better overall outcomes.5Vinchon M Dhellemmes P Cerebrospinal fluid shunt infection: risk factors and long-term follow-up.Childs Nerv Syst. 2006; 22: 692-697Crossref PubMed Scopus (137) Google Scholar Although the number of non-infection revisions was slightly higher in the antibiotic shunt group (22%) than in the standard (18%) and silver (20%) shunt groups, the antibiotic shunt was still cost-effective because revision for infection expends more hospital time and treatment costs than revision for other causes.2Mallucci CL Jenkinson MD Conroy EJ et al.Antibiotic or silver versus standard ventriculoperitoneal shunts (BASICS): a multicentre, single-blinded, randomised trial and economic evaluation.Lancet. 2019; (published online Sept 12.)http://dx.doi.org/10.1016/S0140-6736(19)31603-4Summary Full Text Full Text PDF PubMed Scopus (47) Google Scholar This evidence offers substantial support to both the treatment and economic benefits of antibiotic shunts. I declare no competing interests. Antibiotic or silver versus standard ventriculoperitoneal shunts (BASICS): a multicentre, single-blinded, randomised trial and economic evaluationThe BASICS trial provides evidence to support the adoption of antibiotic shunts in UK patients who are having their first ventriculoperitoneal shunt insertion. This practice will benefit patients of all ages by reducing the risk and harm of shunt infection. Full-Text PDF Open Access