Ventriculo-atrial shunt. Comparison of an ultrasound-guided peel-away technique versus conventional technique in the management of normal pressure hydrocephalus: A retrospective cohort

Background: Normal pressure hydrocephalus (NPH) is a common neurodegenerative syndrome among the elderly characterized by ventriculomegaly and the classic triad of symmetric gait disturbance, cognitive decline and urinary incontinence. To date, the only effective treatment is a cerebrospinal fluid shunting procedure that can either be ventriculo-atrial, ventriculo-peritoneal, or lumbo-peritoneal shunt. The conventional ventriculo-atrial shunt uses venodissection, whereas the peel-away is a percutaneous ultrasound (US)-guided technique that shows some advantages over conventional technique. We sought to compare perioperative complication rates, mean operating time and clinical outcomes for both techniques in NPH patients at our institution. Methods: A retrospective cohort-type analytical study was conducted, using clinical record data of patients diagnosed with NPH and treated at our center from January 2009 to September 2019. Parameters to be compared include: Perioperative complication rates, intraoperative bleeding, mortality, and mean operating time. Perioperative complication rates are those device-related such as shunt infection, dysfunction, and those associated with the procedure. Complications are further classified in immediate (occurring during the first inpatient stay), early (within the first 30 days of surgery), and late (after day 30 of surgery). Results: A total of 123 patients underwent ventriculo-atrial shunt. Eighty-two patients (67%) underwent conventional venodissection technique and 41 patients (33%) underwent a peel-away technique. Immediate complications were 3 (3.6%) and 0 for conventional and peel-away groups, respectively. Early complications were 0 and 1 (2.4%) for conventional and peel-away groups, respectively. Late complications were 5 (6.1%) and 2 (4.9%) for conventional and peel-away groups, respectively. Mean operating time was lower in the peel-away group (P = 0.0000) and mortality was 0 for both groups. Conclusion: Ventriculo-atrial shunt is an effective procedure for patients with NPH. When comparing the conventional venodissection technique with a percutaneous US-guided peel-away technique, the latter offers advantages such as shorter operating time and lower perioperative complication rates.

Thrombosis associated with ventriculoatrial shunts

Ventriculoatrial shunts are the most common second-line procedure for cases in which ventriculoperitoneal shunts are unsuitable. Shunting-associated thrombosis is a potentially life-threatening complication after ventriculoatrial shunt insertion. The overall prevalence of this complication is still controversial because of substantial differences in the numbers found in studies using clinical data and in those analyzing postmortem findings. The etiology of thrombosis may be multifactorial, including shunt catheter itself, contents of cerebrospinal fluid, shunt infection, and genetic disorder. The clinical presentation can vary widely, ranging from asymptomatic to a life-threatening condition. Timely recognition of thromboembolic lesions is critical for treatment. However, early diagnosis and management is still challenging because of a relatively long asymptomatic latency and lack of clear guideline recommendations. The purpose of this review is to provide an overview of ventriculoatrial shunt thrombosis, especially to focus on its etiopathogenesis, diagnosis, treatment, and prevention.

Stenotrophomonas maltophilia as a rare cause of meningitis and ventriculoperitoneal shunt infection

Stenotrophomonas maltophilia is an extremely rare pathogen responsible for ventriculoperitoneal shunt infection and meningitis. This young female patient with history of multiple shunt revisions in the past, came to us with shunt dysfunction and exposure of the ventriculoperitoneal shunt tube in the neck. The abdominal end of the shunt tube was seen migrating into the bowel during shunt revision. The cerebrospinal fluid analysis showed evidence of Stenotrophomonas maltophilia growth. This is the first reported case of Stenotrophomonas maltophilia meningitis associated with ventriculoperitoneal shunt migration into the bowel.

Factors associated with early shunt revision within 30 days: analyses from the National Surgical Quality Improvement Program

OBJECTIVE CSF shunt insertion is the most commonly performed neurosurgical procedure for pediatric patients with hydrocephalus, and complications including infections and catheter obstruction are common. The rate of readmission in the first 30 days after surgery has been used across surgical disciplines to determine healthcare quality. In the current study, the authors sought to assess factors associated with early shunt revision within 30 days using real-world data. METHODS Targeted shunt data set participant user files of the National Surgical Quality Improvement Program (NSQIP) from 2016 to 2019 were queried for patients undergoing a shunt procedure. A multivariable logistic regression model was performed to assess the impact of demographics, etiologies, comorbidities, congenital malformations, and shunt adjuncts on shunt revision within 30 days, as well as shunt revision due to infection within 30 days. RESULTS A total of 3919 primary pediatric shunt insertions were identified in the NSQIP database, with a mean (± SD) patient age of 26.3 ± 51.6 months. There were a total of 285 (7.3%) unplanned shunt revisions within 30 days, with a mean duration of 14.9 ± 8.5 days to first intervention. The most common reason for intervention was mechanical shunt failure (32.6% of revision, 2.4% overall, n = 93), followed by infection (31.2% of all interventions, 2.3% overall, n = 89) and wound disruption or CSF leak (22.1% of all interventions, 1.6% overall, n = 63). Patients younger than 6 months of age had the highest overall unplanned 30-day revision rate (8.5%, 203/2402) as well as the highest 30-day shunt infection rate (3%, 72/2402). Patients who required a revision were also more likely to have a cardiac risk factor (34.7%, n = 99, vs 29.2%, n = 1061; p = 0.048). Multivariable logistic regression revealed that compared to patients 9–18 years old, those aged 2–9 years had significantly lower odds of repeat shunt intervention (p = 0.047), while certain etiologies including congenital hydrocephalus (p = 0.0127), intraventricular hemorrhage (IVH) of prematurity (p = 0.0173), neoplasm (p = 0.0005), infection (p = 0.0004), and syndromic etiology (p = 0.0136), as well as presence of ostomy (p = 0.0095), were associated with higher odds of repeat intervention. For shunt infection, IVH of prematurity was found to be associated with significantly higher odds (p = 0.0427) of shunt infection within 30 days, while use of intraventricular antibiotics was associated with significantly lower odds (p = 0.0085). CONCLUSIONS In this study of outcomes after pediatric shunt placement using a nationally derived cohort, early shunt failure and infection within 30 days were found to remain as considerable risks. The analysis of this national surgical quality registry confirms that, in accordance with other multicenter studies, hydrocephalus etiology, age, and presence of ostomy are important predictors of the need for early shunt revision. IVH of prematurity is associated with early infections while intraventricular antibiotics may be protective. These findings could be used for benchmarking in hospital efforts to improve quality of care for pediatric patients with hydrocephalus.

Ventriculopleural shunts in a pediatric population: a review of 170 consecutive patients

OBJECTIVE The authors sought to determine the outcome of using the pleural space as the terminus for ventricular CSF-diverting shunts in a pediatric population. METHODS All ventriculopleural (VPl) shunt insertions or revisions done between 1978 and 2018 in patients at Children’s Hospital Los Angeles were identified. Data recorded for analysis were age, sex, weight, etiology of hydrocephalus, previous shunt history, reason for VPl shunt insertion or conversion from a ventriculoperitoneal (VP) or ventriculoatrial (VA) shunt, valve type, nature of malfunction, presence of shunt infection or pleural effusion, and conversion to a different distal site. RESULTS A total of 170 patients (mean age 14 ± 4 years) with a VPl shunt who were followed up for a mean of 57 ± 53 months were identified. The reasons for conversion to a VPl shunt for 167 patients were previous shunt infection in 57 (34%), multiple abdominal procedures in 44 (26%), inadequate absorption of CSF in 34 (20%), abdominal pseudocyst in 25 (15%), and obesity in 7 (4%). No VPl revisions were required in 97 (57%) patients. Of the 73 (43%) patients who did require revision, the most common reason was proximal obstruction in 32 (44%). The next most frequent complication was pleural effusion in 22 (30%) and included 3 patients with shunt infection. All 22 patients with a clinically significant pleural effusion required changing the distal end of the shunt from the pleural space. Pleural effusion was more likely to occur in VPl shunts without an antisiphon valve. Of the 29 children < 10 years old, 7 (24%) developed a pleural effusion requiring a revision of the distal catheter to outside the pleural space compared with 15 (11%) who were older (p = 0.049). There were 14 shunt infections with a rate of 4.2% per procedure and 8.2% per patient. CONCLUSIONS VPl shunts in children younger than 10 years of age have a significantly higher rate of symptomatic pleural effusion, requiring revision of the shunt’s terminus to a different location. VPl shunt complication rates are similar to those of VP shunts. The technical difficulty of inserting a VPl shunt is comparable to that of a VP shunt. In a patient older than 10 years, all else being equal, the authors recommend that the distal end of a shunt be placed into the pleural space rather than the right atrium if the peritoneal cavity is not suitable.

Risk factors for unchanged ventricles during pediatric shunt malfunction

OBJECTIVE Children whose ventricles do not change during shunt malfunction present a diagnostic dilemma. This study was performed to identify risk factors for unchanged ventricular size at shunt malfunction. METHODS This retrospective 1:1 age-matched case-control study identified children with shunted hydrocephalus who underwent shunt revision with intraoperative evidence of malfunction at one of the three participating institutions from 1997 to 2019. Cases were defined as patients with a change of < 0.05 in the frontal–occipital horn ratio (FOR) between malfunction and baseline, and controls included patients with FOR changes ≥ 0.05. The presence of infection, abdominal pseudocyst, pseudomeningocele, or wound drainage and lack of baseline cranial imaging at the time of malfunction warranted exclusion. RESULTS Of 450 included patients, 60% were male, 73% were Caucasian, and 67% had an occipital shunt. The median age was 4.3 (IQR 0.97–9.21) years at malfunction. On univariable analysis, unchanged ventricles at malfunction were associated with a frontal shunt (41% vs 28%, p < 0.001), programmable valve (17% vs 9%, p = 0.011), nonsiphoning shunt (85% vs 66%, p < 0.001), larger baseline FOR (0.44 ± 0.12 vs 0.38 ± 0.11, p < 0.001), no prior shunt infection (87% vs 76%, p = 0.003), and no prior shunt revisions (68% vs 52%, p < 0.001). On multivariable analysis with collinear variables removed, patients with a frontal shunt (OR 1.67, 95% CI 1.08–2.70, p = 0.037), programmable valve (OR 2.63, 95% CI 1.32–5.26, p = 0.007), nonsiphoning shunt at malfunction (OR 2.76, 95% CI 1.63–4.67, p < 0.001), larger baseline FOR (OR 3.13, 95% CI 2.21–4.43, p < 0.001), and no prior shunt infection (OR 2.34, 95% CI 1.27–4.30, p = 0.007) were more likely to have unchanged ventricles at malfunction. CONCLUSIONS In a multicenter cohort of children with shunt malfunction, those with a frontal shunt, programmable valve, nonsiphoning shunt, baseline large ventricles, and no prior shunt infection were more likely than others to have unchanged ventricles at shunt failure.

Reducing the risks of proximal and distal shunt failure in adult hydrocephalus: a shunt outcomes quality improvement study

OBJECTIVE Patient outcomes of ventriculoperitoneal (VP) shunt surgery, the mainstay treatment for hydrocephalus in adults, are poor because of high shunt failure rates. The use of neuronavigation or laparoscopy can reduce the risks of proximal or distal shunt catheter failure, respectively, but has less independent effect on overall shunt failures. No adult studies to date have combined both approaches in the setting of a shunt infection prevention protocol to reduce shunt failure. The goal of this study was to determine whether combining neuronavigation and laparoscopy with a shunt infection prevention strategy would reduce the incidence of shunt failures in adult hydrocephalic patients. METHODS Adult patients (age ≥ 18 years) undergoing VP shunt surgery at a tertiary care institution prior to (pre–Shunt Outcomes [ShOut]) and after (post-ShOut) the start of a prospective continuous quality improvement (QI) study were compared. Pre-ShOut patients had their proximal and distal catheters placed under conventional freehand approaches. Post-ShOut patients had their shunts inserted with neuronavigational and laparoscopy assistance in placing the distal catheter in the perihepatic space (falciform technique). A shunt infection reduction protocol had been instituted 1.5 years prior to the start of the QI initiative. The primary outcome of interest was the incidence of shunt failure (including infection) confirmed by standardized criteria indicating shunt revision surgery. RESULTS There were 244 (115 pre-ShOut and 129 post-ShOut) patients observed over 7 years. With a background of shunt infection prophylaxis, combined neuronavigation and laparoscopy was associated with a reduction in overall shunt failure rates from 37% to 14%, 45% to 22%, and 51% to 29% at 1, 2, and 3 years, respectively (HR 0.44, p < 0.001). Shunt infection rates decreased from 8% in the pre-ShOut group to 0% in the post-ShOut group. There were no proximal catheter failures in the post-ShOut group. The 2-year rates of distal catheter failure were 42% versus 20% in the pre- and post-ShOut groups, respectively (p < 0.001). CONCLUSIONS Introducing a shunt infection prevention protocol, placing the proximal catheter under neuronavigation, and placing the peritoneal catheter in the perihepatic space by using the falciform technique led to decreased rates of infection, distal shunt failure, and overall shunt failure.