Management of cerebrospinal fluid pseudocysts in the laparoscopic age.

OBJECTIVE: Abdominal CSF pseudocysts are an uncommon but challenging complication of ventriculoperitoneal shunts. Pseudocysts consist of a loculated intraperitoneal compartment that inadequately absorbs CSF and may be infected or sterile at diagnosis. The treatment goal is to clear infection if present, reduce inflammation, and reestablish long-term function in an absorptive (intraperitoneal) space. This aim of this paper was to study the efficacy of primary laparoscopic repositioning of the distal shunt catheter for treatment of sterile abdominal CSF pseudocysts. METHODS: All patients treated for abdominal CSF pseudocysts at Dallas Children's Health from 1991 to 2021 were retrospectively reviewed. Patient history and pseudocyst characteristics were analyzed, with a primary outcome of pseudocyst recurrence at 1 year. RESULTS: Of 92 primary pseudocysts, 5 initial treatment strategies (groups) were used depending on culture status, clinical history, and surgeon preference: 1) shunt explant/external ventricular drain (EVD) placement (23/92), 2) distal tubing externalization (13/92), 3) laparoscopic repositioning (35/92), 4) open repositioning (4/92), and 5) other methods such as pseudocyst drainage or direct revision to another terminus (17/92). Seventy pseudocysts underwent shunt reimplantation in the peritoneal space. The 1-year peritoneal shunt survival for groups 1 and 2 combined was 90%, and 62% for group 3. In group 3, 1-year survival was better for those with normal systemic inflammatory markers (100%) than for those with high markers (47%) (p = 0.042). In a univariate Cox proportional hazards model, the risk of pseudocyst recurrence was increased if the most recent abdominal procedure was a nonshunt abdominal surgery (p = 0.012), and it approached statistical significance with male sex (p = 0.054) and elevated inflammatory markers (p = 0.056. Multivariate Cox analysis suggested increased recurrence risk with male sex (p = 0.05) and elevated inflammatory markers (p = 0.06), although the statistical significance threshold was not reached. The length of hospital stay was shorter for laparoscopic repositioning (6 days) than for explantation/EVD placement (21 days) (p < 0.0001). Ultimately, 62% of patients had a peritoneal terminus at the last follow-up, 33% (n = 30) had an extraperitoneal terminus (19 pleura, 8 right heart, and 3 gallbladder), and 5 patients were shunt free. CONCLUSIONS: Some sterile pseudocysts with normal systemic inflammatory markers can be effectively treated with laparoscopic repositioning, resulting in a significantly shorter hospitalization and modestly higher recurrence rate than shunt explantation.

Neurocritical care of the pregnant patient.

INTRODUCTION: An estimated 0.1%-0.8% of obstetric patients require admission to an intensive care unit (ICU) during pregnancy or the puerperium. When neurologic emergencies occur in pregnancy, collaboration between the neurointensivist, obstetric anesthesiologist, and obstetrician is key in minimizing morbidity and mortality. PRINCIPLES: Care of the critically ill pregnant patient mirrors that of the critically ill nonpregnant patient with some minor exceptions. Special care must be taken to consider the normal physiologic changes of pregnancy as well as possible fetal exposure to medical interventions. Timing and method of delivery must be carefully considered when caring for patients with neurologic emergencies. Common neurologic emergencies in pregnancy include hypertensive disorders of pregnancy, intracranial neoplasms, noneclamptic seizures, cerebrovascular disorders, and ventriculoperitoneal shunt malfunctions. CONCLUSION: While neurologic emergencies in pregnancy are overall rare, when they do occur, they can be devastating. As in the nonpregnant population, prompt recognition and rapid intervention are crucial in optimizing patient outcomes. When neurologic emergencies occur in pregnancy, maternal and fetal care is optimized through a multidisciplinary care team.

Diagnostic Accuracy of Non-Invasive Thermal Evaluation of Ventriculoperitoneal Shunt Flow in Shunt Malfunction: A Prospective, Multi-Site, Operator-Blinded Study.

BACKGROUND: Thermal flow evaluation (TFE) is a non-invasive method to assess ventriculoperitoneal shunt function. Flow detected by TFE is a negative predictor of the need for revision surgery. Further optimization of testing protocols, evaluation in multiple centers, and integration with clinical and imaging impressions prompted the current study. OBJECTIVE: To compare the diagnostic accuracy of 2 TFE protocols, with micropumper (TFE+MP) or without (TFE-only), to neuro-imaging in patients emergently presenting with symptoms concerning for shunt malfunction. METHODS: We performed a prospective multicenter operator-blinded trial of a consecutive series of patients who underwent evaluation for shunt malfunction. TFE was performed, and preimaging clinician impressions and imaging results were recorded. The primary outcome was shunt obstruction requiring neurosurgical revision within 7 d. Non-inferiority of the sensitivity of TFE vs neuro-imaging for detecting shunt obstruction was tested using a prospectively determined a priori margin of -2.5%. RESULTS: We enrolled 406 patients at 10 centers. Of these, 68/348 (20%) evaluated with TFE+MP and 30/215 (14%) with TFE-only had shunt obstruction. The sensitivity for detecting obstruction was 100% (95% CI: 88%-100%) for TFE-only, 90% (95% CI: 80%-96%) for TFE+MP, 76% (95% CI: 65%-86%) for imaging in TFE+MP cohort, and 77% (95% CI: 58%-90%) for imaging in the TFE-only cohort. Difference in sensitivities between TFE methods and imaging did not exceed the non-inferiority margin. CONCLUSION: TFE is non-inferior to imaging in ruling out shunt malfunction and may help avoid imaging and other steps. For this purpose, TFE only is favored over TFE+MP.

Noninvasive Thermal Evaluation of Ventriculoperitoneal Shunt Patency and Cerebrospinal Fluid Flow Using a Flow Enhancing Device.

BACKGROUND: While a noninvasive flow determination would be desirable in the diagnosis of cerebrospinal fluid shunt malfunction, existing studies have not yet defined a role for thermal flow detection. OBJECTIVE: To evaluate a revised test protocol using a micropumper designed to transiently enhance flow during thermal testing to determine whether thermal detection of flow is associated with progression to shunt revision surgery. METHODS: Eighty-two unique tests were performed in 71 shunts. The primary outcome, need for revision within 7 d of testing, was compared with results of micropumper-augmented thermal flow detection. Statistical analysis was based on blind interpretation of test results and raw temperature data recorded during testing. RESULTS: The test was sensitive (73%) and specific (68%) in predicting need for revision, with 5.6-fold higher probability of revision when flow was not detected. Negative predictive value in our sample was 94.2%. The probability of not requiring revision increased with increasing total temperature drop. Analysis of various possible thresholds showed that the optimal temperature cutoff may be lower than suggested by the manufacturer (0.125°C vs 0.2°C). CONCLUSION: This is the first study to report a strong association between thermal flow evaluation and a clinical impression that a shunt is not malfunctioning. The current recommended threshold may increase the false positive rate unnecessarily, and as clinicians gain experience with the method, they may find value in examining the temperature curves themselves. Multicenter studies are suggested to further define a role for this diagnostic test.

Bone Overgrowth Causing Proximal Ventriculoperitoneal Shunt Malfunction.

BACKGROUND: Hydrocephalus is an international disease process that is commonly treated surgically with a ventriculoperitoneal shunt. This device may be prone to malfunction, most commonly from obstruction, disconnection, or infection. CASE DESCRIPTION: A 35-year-old female with hydrocephalus and a ventriculoperitoneal shunt presented with altered mental status and imaging concerning for a shunt malfunction. Intraoperatively, she was found to have bone growing over and compressing the proximal occluder of the shunt valve, causing a mechanical obstruction. Removal of the bone allowed for egress of cerebrospinal fluid and return of proper shunt function. The patient did well postoperatively. CONCLUSION: Hydrocephalus, ventriculoperitoneal shunts, and shunt revisions represent a significant health burden and cost. Here we present an unusual cause of a shunt malfunction caused by bony overgrowth.

High Intra-Abdominal Pressure Secondary to Obesity as a Determining Factor for Ventriculoperitoneal Shunt Malfunction

The ventriculoperitoneal shunt (VPS) is an established treatment for hydrocephalus. The functioning of the system requires a pressure difference between the cranial and abdominal cavities. The VPS can be particularly problematic in patients with increased intra-abdominal pressure (IAP). We report the case of a 16-year-old girl with VPS since she was 2 months old due to hydrocephalus secondary to myelomeningocele. The patient had been asymptomatic ever since, but she sought the emergency service with intermittent headache and vomiting. A non-enhanced brain tomography, a shunt trajectory X-ray and an abdominal ultrasound revealed no cause of system malfunction. In view of the persistent clinical picture, a revision of the shunt was performed, which revealed adequate intraoperative functioning. She returned with the same symptoms two weeks after surgery. The patient was obese (body mass index [BMI]: 48). We hypothesized intermittent valve malfunction due to increased intra-abdominal pressure. She underwent a ventriculoatrial shunt, without intercurrences. In the postoperative period, the patient presented transient tachycardia and was asymptomatic at the 6-month follow-up. Obesity should be considered an important variable for the inadequate functioning of the VPS due to increased IAP and catheter dystocia to the extraperitoneal cavity. Studies have already correlated the IAP with the BMI, which reaches between 8 mm Hg and 12 mm Hg in obese individuals. Therefore, the BMI can be considered during the selection of valve pressure in systems with non-adjustable valves to prevent insufficient drainage. The recognition of obesity as a cause of VPS malfunction is fundamental to avoid unnecessary surgeries and intermittent malfunction of the system.

A derivação ventriculoperitoneal (DVP) é um tratamento estabelecido para a hidrocefalia; contudo, algumas variáveis podem influenciar na eficácia desta modalidade. O funcionamento do sistema requer uma diferença de pressão entre as cavidades craniana e abdominal. A DVP pode ser particularmente problemática em pacientes com aumento da pressão intra-abdominal (PIA). Neste artigo, relatamos o caso de uma paciente do sexo feminino, de 16 anos, portadora de DVP desde os 2 meses de idade por hidrocefalia secundária a mielomeningocele. Desde então assintomática, procurou o pronto-socorro com queixa de cefaleia e vômitos intermitentes. Uma tomografia de crânio sem contraste, um raio X (RX) do trajeto do cateter distal, e uma ultrassonografia (USG) abdominal não evidenciaram a causa do mau funcionamento do sistema. Diante do quadro persistente, realizou-se uma revisão da derivação, que mostrou funcionamento adequado no período intraoperatório. A paciente retornou com os mesmos sintomas duas semanas após a cirurgia. A paciente era obesa (índice de massa corporal [IMC]: 48). Aventou-se possível funcionamento intermitente da válvula pelo aumento da PIA. A paciente foi submetida a uma derivação ventrículo-atrial, que foi realizada sem intercorrências. No pós-operatório, ela apresentou quadro transitório de taquicardia, e não apresentou sintomas no acompanhamento feito depois de 6 meses. A obesidade deve ser considerada uma variável importante para o funcionamento inadequado da DVP, pelo aumento da PIA e pela associação com distocia do cateter para a cavidade extraperitoneal. Estudos já correlacionaram a PIA com o IMC, que pode atingir entre8 mm Hg e 12 mm Hg em obesos. Logo, o IMC pode ser considerado na seleção da pressão da válvula em sistemas com válvulas não ajustáveis, para prevenir a drenagem insuficiente. O reconhecimento da obesidade de risco para o mau funcionamento da DVP é fundamental para evitar cirurgias desnecessárias e o mau funcionamento intermitente do sistema.

Ventriculoperitoneal shunt malfunction caused by proximal catheter fat obstruction.

Ventriculoperitoneal (VP) shunt placement is the mainstay of treatment for hydrocephalus, yet shunts remain vulnerable to a variety of complications. Although fat droplet migration into the subarachnoid space and cerebrospinal fluid pathways following craniotomy has been observed, a VP shunt obstruction with fat droplets has never been reported to our knowledge. We present the first reported case of VP shunt catheter obstruction by migratory fat droplets in a 55-year-old woman who underwent suboccipital craniotomy for removal of a metastatic tumor of the left medullocerebellar region, without fat harvesting. A VP shunt was inserted 1month later due to communicating hydrocephalus. The patient presented with gait disturbance, intermittent confusion, and pseudomeningocele 21days after shunt insertion. MRI revealed retrograde fat deposition in the ventricular system and VP shunt catheter, apparently following migration of fat droplets from the fatty soft tissue of the craniotomy site. Spinal tap revealed signs of aseptic meningitis. Steroid treatment for aseptic "lipoid" meningitis provided symptom relief. MRI 2months later revealed partial fat resorption and resolution of the pseudomeningocele. VP shunt malfunction caused by fat obstruction of the ventricular catheter should be acknowledged as a possible complication in VP shunts after craniotomy, even in the absence of fat harvesting.

Acute Shunt Malfunction Caused by Percutaneous Endoscopic Gastrostomy without Shunt Infection.

Percutaneous endoscopic gastrostomy tube placement is often performed in patients with a ventriculoperitoneal shunt and it has been accepted as a safe procedure. The authors report a case of a 50-year-old male who developed acute exacerbation of the hydrocephalus immediately after the percutaneous endoscopic gastrostomy tube placement without any signs of shunt infection, which has not been reported until now. After revision of the intraperitoneal shunt catheter, the sizes of the intracranial ventricles were normalized.

Shunt malfunction presenting with symptomatic syringomyelia: Demonstrated on contrast ventriculogram.

Ventriculoperitoneal (VP) shunt malfunction commonly presents as raised intracranial pressure. Rarely, when the central canal of the spinal cord communicates with the 4(th) ventricle, shunt malfunction can present as an expanding syrinx. The diagnosis is often delayed, resulting in severe morbidity. Some of these patients undergo repeated syrinx surgeries without much benefits. We report a case of chronic tuberculous meningitis with shunt malfunction presenting as an expanding spinal canal syrinx and quadriparesis. Fourth ventricular communication with syrinx was demonstrated with the help of a contrast ventriculogram. After shunt revision, syrinx resolved completely and the patient made significant improvement in his neurological deficits. The present case illustrates that a historical and rarely used investigation like contrast ventriculogram aids in the diagnosis and management even in the current neurosurgical practice. All patients with late onset syrinx and a previous VP shunt need to be investigated for shunt malfunction before considering syrinx surgery. A simple shunt revision resolves the syrinx in such conditions and avoids more complex procedures like Foramen magnum decompression. Relevant literature has been reviewed; pathophysiology and management options have been discussed.

Acute Shunt Malfunction Caused by Percutaneous Endoscopic Gastrostomy without Shunt Infection

Percutaneous endoscopic gastrostomy tube placement is often performed in patients with a ventriculoperitoneal shunt and it has been accepted as a safe procedure. The authors report a case of a 50-year-old male who developed acute exacerbation of the hydrocephalus immediately after the percutaneous endoscopic gastrostomy tube placement without any signs of shunt infection, which has not been reported until now. After revision of the intraperitoneal shunt catheter, the sizes of the intracranial ventricles were normalized.