Ventriculoatrial shunt displacement by a central venous catheter in pediatrics: report of two atypical cases.

INTRODUCTION: The treatment of hydrocephalus accounts for 40% of all procedures in pediatric neurosurgery. Ventriculoperitoneal shunt placement is the treatment of choice for most patients. When contraindicated due to different abdominal complications, the use of a ventriculoatrial shunt is a safe second option. Nevertheless, this procedure is not without risk of complications. An extremely rare complication is the displacement of the distal catheter by a central venous catheter. CASE REPORT: We present two atypical cases of shunt dysfunction related to the placement of a central venous catheter. CONCLUSION: After an extensive review of the literature, we believe these are the first cases of this unusual complication in children. Awareness of this complication is essential for its prevention and to ensure safe medical care.

Noninvasive CSF shunt patency evaluation by superb microvascular imaging.

Occlusion of a ventriculoperitoneal shunt system is a potentially life-threatening complication in patients suffering from hydrocephalus. However, there is no imaging established as standard approach in this acute setting. In the present study, we evaluate the use of superb microvascular imaging for investigation of the patency of ventriculoperitoneal shunt systems. Simulation of low flow rates of cerebrospinal fluid through a small diameter CSF shunt system was performed in a dedicated phantom in order to proof the principle of superb microvascular imaging (SMI) being feasible for the measurement of slow CSF flow through the dedicated CSF shunt system. SMI is able to detect low flow rates in CSF shunt systems effectively and fast. Visualization of a Duplex ultrasound flow and Doppler wave pattern in the VP shunt system after the reservoir has been pressed confirms patency. SMI is an effective method for evaluating CSF shunt patency and diagnosing shunt obstruction. This bears the potential to facilitate evaluation of clinically symptomatic VP shunt patients in an acute setting. Further evaluation of ultrasound flow patterns is granted.

Retrospective single-center historical comparative study between proGAV and proGAV2.0 for surgical revision and implant duration.

OBJECTIVE: Cerebrospinal fluid (CSF) diversion shunt systems remain to be the most common treatment for pediatric hydrocephalus. Different valve systems are used to regulate CSF diversion. Preventing complications such as occlusions, ruptures, malpositioning, and over- or underdrainage are the focus for further developments. The proGAV and proGAV2.0 valve system are compared in this retrospective study for revision-free survival and isolated valve revision paradigms. METHODS: In the first part of the study, the shunt and valve revision-free survival rates were investigated in a retrospective historical comparison design for a period of 2 years in which each valve was used as standard valve (proGAV: July 2012-June 2014; proGAV2.0: January 2015-December 2016) with subsequent 30-month follow-up period, respectively. In the second part of the study, the implant duration was calculated by detecting isolated valve (valve-only) revisions together with another valve explantation during the entire period of the first study and its follow-up period. RESULTS: Two hundred sixty-two patients (145 male and 117 female, mean age 6.2 ± 6.1 years) were included in the cohort of revision-free survival. During the 30-month follow-up period, 41 shunt revisions, including 27 valve revisions (shunt survival rate: 72.1%, valve survival rate: 81.6%) were performed in the proGAV cohort and 37 shunt revisions, including 21 valve revisions (shunt survival rate: 74.8% and valve survival rate: 85.0%) were performed in the proGAV2.0 cohort without showing statistically significant differences. In the second part of the study, 38 cases (mean age 4.0 ± 3.9 years) met the inclusion criteria of receiving a valve-only-revision. In those patients, a total of 44 proGAV and 42 proGAV2.0 were implanted and explanted during the entire study time. In those, a significantly longer implant duration was observed for proGAV (mean valve duration 961.9 ± 650.8 days) compared to proGAV2.0 (mean length of implantation period 601.4 ± 487.8 days; p = 0.004). CONCLUSION: The shunt and valve revision-free survival rates were found to be similar among the groups during 30 month follow-up. In patients who received "valve only" revisions and a subsequent explanation, the implant duration was significantly longer in the proGAV. Although the amount of patients with valve-only-revisions are small compared to the entire cohort certain patients seem to be at higher risk for repeated valve revisions.

Permanent Visual Impairment due to Delayed Diagnosis of Shunt Malfunction in Case of Lack of Typical Features of Increased Intracranial Pressure and Unchanged Ventricular Size.

OBJECTIVE: We present the clinical features, imaging, and management of 5 cases of visual impairment as the primary manifestation ventriculoperitoneal (V-P) shunt malfunction. METHODS: We retrospectively reviewed the medical records of 126 patients of V-P shunt malfunction in Shanghai Children's Medical Center between 2015 and 2020. Medical records including all hospital admissions were reviewed and follow-up data were collected. RESULTS: Five children (3.97%) had visual impairment as the primary manifestation of V-P shunt malfunction, with a mild or no headache. Four broken distal shunt catheters and one proximal catheter blockage were confirmed intraoperatively and cured by surgery. None of the patients had a definite improvement in ophthalmic examinations after 4-52 months of follow-up. CONCLUSION: Visual impairment as the primary manifestation of V-P shunt malfunction was uncommon and could be easily missed or misdiagnosed as the only problem for lack of typical features of increased intracranial pressure and unchanged ventricular size. Earlier definitive diagnosis and surgical intervention could prevent a further development of the visual loss caused by V-P shunt malfunction.

Determination of ventriculoperitoneal shunt dysfunction using optic nerve sheath diameter measurement on CT scan in pediatric patients with hydrocephalus.

PURPOSE: We aimed to evaluate whether optic nerve sheath diameter (ONSD) measurement by computed tomography (CT) can be a diagnostic criteria for the detection of ventriculoperitoneal shunt dysfunction among children whose fontanels are still open. METHODS: Patients with a ventriculoperitoneal shunt who were currently showing clinical and radiological signs of acute hydrocephalus depending on the shunt dysfunction were included in this study. The study was designed to compare the preoperative and postoperative ONSDs of three groups of patients divided according to their ages: group 1, patients aged < 4 months; group 2, patients aged 4-18 months; and group 3, patients aged > 18 months. RESULTS: We included 138 patients (mean age, 35.18 ± 51.01 months). Among the patients, 46.4% were females and 53.6% were males. ONSD measurements in the preoperative period were < 2.86 ± 0.59 in group 1, 3.93 ± 0.82 in group 2, and 5.40 ± 0.81 in group 3 and those in the postoperative period were 2.02 ± 0.38 in group 1, 2.72 ± 0.62 in group 2, and 3.64 ± 0.81 in group 3. Right, left, and mean ONSDs increased significantly in the three groups and were found to be statistically significant. CONCLUSION: ONSD measurement in CT has been evaluated as an appropriate finding that can be used especially in acute hydrocephalus, when clinical and radiological findings are not diagnostic.

Value of computerized shunt infusion study in assessment of pediatric hydrocephalus shunt function-a two center cross-sectional study.

BACKGROUND: Hydrocephalus shunt malfunction can-also in children-occur insidiously without clear symptoms of raised intracranial pressure (ICP) or changes in ventricular size, imposing a diagnostic challenge. Computerized shunt infusion studies enable quantitative shunt function assessment. We report on feasibility and results of this technique in children in a two center cross-sectional study. MATERIAL AND METHODS: Shunt infusion study (SIS) is performed with two needles inserted into a pre-chamber for ICP recording and CSF infusion. After baseline ICP recording, constant rate infusion is started until a new ICP plateau (ICPpl) is reached. Dedicated software containing the shunt's resistance characteristics calculates ICP and its amplitude outflow resistance and critical shunt pressure (CSP). Overall, 203 SIS were performed in 166 children. Shunts were defined as functional if ICPpl was 5 mmHg above CSP and borderline in between. RESULTS: Forty-one shunts (20.2%) were found obstructed, 26 (12.8%) had borderline characteristics, and 136 (67%) were functional. Baseline ICP in obstructed shunts was significantly above shunt operating pressure. CSF outflow resistance (Rout) and ∆ICP plateau were significantly elevated in obstructed shunts, with cut-off thresholds of 8.07 mmHg min/ml and 11.74 mmHg respectively. Subgroup analysis showed smaller ventricles in 69% of revised cases. CONCLUSION: SIS is a feasible, reliable, and radiation-free technique for quantitative shunt assessment to rule out or prove shunt malfunction. Dedicated software containing shunt hydrodynamic characteristics is necessary and small children may need short-term sedation. Due to the clinical and inherent economic advantages, SIS should be more frequently used in pediatric neurosurgery.

[Analysis of influencing factors of shunt dysfunction after transjugular intrahepatic portosystemic shunt in liver cirrhosis accompanied with portal vein thrombosis].

Objective: To investigate the efficacy of shunt after transjugular intrahepatic portosystemic shunt (TIPS) in liver cirrhosis accompanied with portal vein thrombosis (PVT). Methods: Forty-four cases with liver cirrhosis accompanied with PVT who underwent TIPS treatment from January 2015 to May 2018 were retrospectively analyzed. Clinical baseline data of the patients were collected. Portal vein pressure gradient (PVPG) before and after the surgery was recorded. Shunt patency was observed at 3, 6, 12, 18 and 24 months after the surgery. The influencing factors were determined by univariate and multivariate analysis. Results: Transjugular intrahepatic portosystemic shunt was successfully established in all 44 cases. The postoperative PVPG was lower than preoperative (P < 0.01). The shunt patency rate after TIPS in PVT was 18.2% (n = 8). The cumulative shunt patency rates at 3, 6, 12, 18, and 24 months after surgery were 95.5%, 90.7%, 90.7%, 86.8% and 74.4%, respectively. Univariate analysis showed that diabetes history, platelet level and prothrombin time-international normalized ratio were associated with postoperative shunt dysfunction. Multivariate analysis showed that diabetes history (P = 0.007, OR = 28.606) was an independent risk factor for postoperative shunt dysfunction. Conclusion: TIPS is a safe and feasible procedure, which can effectively reduce the portal pressure in liver cirrhosis accompanied with PVT. Diabetic patients have a higher risk of postoperative shunt dysfunction. Therefore, clinical intervention should be strengthened for high-risk patients.

Evaluation of Radiation Exposure on Physicians During Angioplasty for Hemodialysis Access Dysfunction.

BACKGROUND: Percutaneous interventions help patients with various cardiovascular diseases, however radiation exposure is a safety concern for both patients and health care providers. We previously reported that dose area product (DAP) is apparently different in central body and upper-limb areas during percutaneous transluminal angioplasty for arteriovenous shunt dysfunction. In this study, we investigated the precise radiation dose at the patients' back and at the non-targeted organs of the operators. METHODS: The radiation dose was measured with optically stimulated luminescent dosimeters and DAP on several sites including the backs of the patients, gonads, hands and lens of the operators. The studied populations were categorized into central, upper arm and forearm groups based on the lesion sites. RESULTS: The results indicated that there was a significantly higher radiation dose in the central lesion group than in the upper arm and forearm groups. Conversely, there were no specific differences in total procedure time and fluoroscopy time among groups. The radiation exposure doses in the operators showed that regardless of the site, including lens, hands and gonads of the operators, the radiation dose was significantly higher in the central lesion group. CONCLUSIONS: The closer the lesion site to the body center, the higher the radiation exposure in both the patients and operators.

Shunt age-related complications in adult patients with suspected shunt dysfunction. A recommended diagnostic workup.

BACKGROUND: Patients admitted for suspicion of shunt dysfunction (SD) often show unspecific symptoms and require time-consuming, expensive and even invasive diagnostics involving significant radiation exposure. The purpose of this retrospective study was to analyse the current diagnostic procedures and to propose a process optimisation. METHOD: As all patients admitted for suspicion of SD receive imaging studies, we searched for adult patients receiving neuroimaging in the period from January 2010 to July 2013, analysing referring diagnosis, clinical signs, products, diagnostic process and final diagnosis. Recursive partitioning was used to define time intervals for differentiating types of SD. RESULTS: A total of 148 patients, aged 18-89 (mean, 54) years, were studied. Forty-two percent were referred by a hospital or rehabilitation centre, 30% by general practitioners and 24% were self-referrals. The admission diagnosis was in the majority "shunt dysfunction" only. Further differentiations were rarely made. An SD was confirmed in 46% of the patients. In 17%, the symptoms were based on another cause and in 37% they could not be clearly attributed to any specific disorder. Abdominal dislocations (2%) and shunt infections (5%) were found within the first 6 months. Over- (3%) and under-drainage (14%) were the most frequent complications during the first 4 years. Disconnections (13%) occurred generally 4 years or more after implantation. Only shunt obstruction (9%) showed no temporal pattern. CONCLUSIONS: Symptoms of SD remain mostly unspecific. This study showed that the type of SD depends on the time interval from implantation. We propose a workup strategy for patients with SD based on the temporal profile.

Referrals for suspected ventriculo-peritoneal shunt dysfunction and necessity for further imaging.

Shunt series (SS) X-rays are often performed as additional routine initial investigations for suspected ventriculo-peritoneal shunt dysfunction, despite low diagnostic utility and radiological implications. We reviewed such referrals at our neurosurgical unit and found an 8.3% sensitivity rate for SS; consistent with current evidence. SS should not be performed routinely.

VP-shunt dysfunction caused by malaria CNS infection.

INTRODUCTION: Malaria is a widespread mosquito-borne infectious disease with over 300 million cases and roughly 900 thousand deaths in 2013. Cerebral involvement of malaria causes 50 % of all infection-associated deaths, especially in children below the age of 5 years. Hydrocephalus is a medical condition with abnormal accumulation of cerebrospinal fluid in physiological cavities and ventricles. Standard treatment is the implantation of a cerebrospinal fluid shunt device. A common problem associated with shunt treatment especially in pediatric patients is infection and consecutive shunt dysfunction caused by bacteriae or high protein levels clogging the valve. In these cases, Staphylococcus aureus and Staphylococcus epidermidis are predominantly found in CSF cultures. CASE PRESENTATION: We present a case of a 2-year old boy from Saudi Arabia with a ventriculoperitoneal (VP)-shunt-dependent congenital hydrocephalus who suffered from cerebral malaria and developed consecutive shunt failure. CONCLUSION: To the best of our knowledge, shunt failure caused by malaria CNS infection with Plasmodium falciparum has not yet been reported in the literature and should be considered as a rare cause of VP-shunt failure in patients with atypical VP-shunt infections living in or traveling from endemic areas.

Comparison of specialized stent versus generic stent and bare stent combination for transjugular intrahepatic portosystemic shunt creation.

Transjugular intrahepatic portosystemic shunt (TIPS) creation using the Viatorr stent remains relatively uncommon in underdeveloped and high-burden disease regions in Asia-Pacific, and there is a lack of comparative studies regarding its prognostic effects compared with the generic stent-graft/bare stent combination. The purpose of this retrospective study is to compare the prognostic endpoints of these two treatments in patients who underwent TIPS creation. Clinical data from 145 patients were collected, including 82 in the combination group and 63 in the Viatorr group. Differences in prognostic endpoints (shunt dysfunction, death, overt hepatic encephalopathy [OHE], rebleeding) between the two groups were analyzed using Kaplan-Meier curves. The Cox proportional hazards model was used to identify independent risk factors for post-TIPS shunt dysfunction. The TIPS procedure was successful in all patients. After TIPS creation, both groups showed a significant decrease in porto-caval pressure gradient compared to that before TIPS creation. The stent patency rates at 6, 12, and 18 months were high in both the combination and Viatorr groups (93.7%, 88.5%, and 88.5% vs. 96.7%, 93.4%, and 93.4%, respectively). The stent patency rates was higher in the combination group than in the Viatorr group, although not statistically significant (HR = 2.105, 95% CI 0.640-6.922, Log-rank P = 0.259). There were no significant differences in other prognostic endpoints (death, OHE, rebleeding) between the two groups. The Cox model identified portal vein diameter (HR = 0.807, 95% CI 0.658-0.990, P = 0.040) and portal vein thrombosis (HR = 13.617, 95% CI 1.475-125.678, P = 0.021) as independent risk factors for post-TIPS shunt dysfunction. The shunt patency rates between the Viatorr stent and the generic stent-graft/bare stent combination showed no significant difference and the generic stent-graft/bare stent combination may be a viable alternative in areas where the Viatorr stent is not yet available.

Effect of cranial entry site on the rate of proximal catheter misplacement in ventriculoperitoneal shunt insertion.

OBJECTIVE: The insertion of a ventriculoperitoneal shunt (VPS) is a common neurosurgical procedure, but the optimal entry site of the ventricular catheter is still under debate. In this study, the authors compare the parietal (Keen's) and frontal (Kocher's) entry sites in terms of the rate of revision surgery due to ventricular catheter misplacement, VPS dysfunction, and VPS infection. METHODS: The authors retrospectively analyzed the data on consecutive adults (age ≥ 18 years) who had undergone primary VPS insertion between 2010 and 2020 at two neurosurgical centers. One center regularly inserts the ventricular catheter frontally (frontal group); the other center, parietally (parietal group). The primary outcome of interest was the rate of ventricular catheter misplacement necessitating revision surgery. Secondary outcomes were functional outcome as measured by the modified Rankin Scale (mRS), rate of revision surgery for VPS dysfunction and infection, as well as early (≤ 30 days) and late (> 30 days) mortality rates. Propensity score matching was performed based on baseline variables, such as normal pressure hydrocephalus, postinfectious hydrocephalus, and idiopathic intracranial hypertension, which were identified as predictors of ventricular catheter misplacement using logistic regression analysis. RESULTS: Among 539 consecutive patients, 301 (55.8%) were in the frontal group and 238 (44.2%) in the parietal group. Postoperative rates of revision surgery due to misplacement were comparable in the two catheter entry site groups (frontal 14 [4.7%] vs parietal 11 [4.6%], p = 0.987). Rates of revision surgery for VPS dysfunction (14 [4.7%] vs 10 [4.2%], respectively, p = 0.802) and infection (22 [7.3%] vs 10 [4.2%], p = 0.13) exhibited no significant differences. Favorable functional outcomes (mRS score ≤ 2; 164 [76.3%] vs 174 [79.5%], respectively, p = 0.058) and early mortality rates (5 [1.7%] vs 6 [2.5%], p = 0.483) were similar between the groups. After propensity score matching, the primary and secondary outcome measures remained comparable between the groups. CONCLUSIONS: The entry site of the ventricular catheter in VPS surgery does not seem to affect proximal revision rates. Further, revision rates due to VPS dysfunction, VPS infection, and morbidity were comparable as well.

Shunt dysfunction and mortality after transjugular intrahepatic portosystemic shunt (TIPS) in patients with portal hypertension.

OBJECTIVES: Transjugular intrahepatic portosystemic shunt (TIPS) is a catheter-based, minimally invasive procedure to reduce portal hypertension. The aim of the study was to investigate dysfunction and mortality after TIPS and to identify factors associated with these events. METHODS: A retrospective analysis of 834 patients undergoing TIPS implantation in a single center from 1993-2018 was performed. Cumulative incidence curves were estimated, and frailty models were used to assess associations between potentially influential variables and time to dysfunction or death. RESULTS: 1-, 2-, and 5-year mortality rates were 20.9% (confidence interval (CI) 17.7-24.1), 22.5% (CI 19.1-25.8), and 25.0% (CI: 21.1-28.8), 1-year, 2-year, and 5-year dysfunction rates were 28.4% (CI 24.6-32.3), 38.9% (CI 34.5-43.3), and 52.4% (CI 47.2-57.6). The use of covered stents is a protective factor regarding TIPS dysfunction (hazard ratio (HR) 0.47, CI 0.33-0.68) but does not play a major role in survival (HR 0.95, CI 0.58-1.56). Risk factors for mortality are rather TIPS in an emergency setting (HR 2.78, CI 1.19-6.50), a previous TIPS dysfunction (HR 2.43, CI 1.28-4.62), and an increased Freiburg score (HR 1.45, CI 0.93-2.28). CONCLUSION: The use of covered stents is an important protective factor regarding TIPS dysfunction. Whereas previous TIPS dysfunction, emergency TIPS implantation, and an elevated Freiburg score are associated with increased mortality. Awareness of risk factors could contribute to a better selection of patients who may benefit from a TIPS procedure and improve clinical follow-up with regard to early detection of thrombosis/stenosis. CRITICAL RELEVANCE STATEMENT: The use of covered stents reduces the risk of dysfunction after transjugular intrahepatic portosystemic shunt (TIPS). TIPS dysfunction, emergency TIPS placement, and a high Freiburg score are linked to higher mortality rates in TIPS patients. KEY POINTS: The risk of dysfunction is higher for uncovered stents compared to covered stents. Transjugular intrahepatic portosystemic shunt dysfunction increases the risk of instantaneous death after the intervention. A higher Freiburg score increases the rate of death after the intervention. Transjugular intrahepatic portosystemic shunt implantations in emergency settings reduce survival rates.

Repeated shunt dysfunction due to Barium allergy that was difficult to differentiate from shunt infection.

We encountered a case of repeated shunt dysfunction caused by barium allergy. The patient was a 60-year-old male who underwent ventricular peritoneal shunting for hydrocephalus following subarachnoid hemorrhage due to a ruptured aneurysm;however, it malfunctioned many times. A patch test performed after the third reconstruction was positive for barium. To the best of our knowledge, this is the first case report of shunt malfunction due to barium allergy. The patch test is useful in cases of suspected allergy-related dysfunction. We recommend the introduction of barium into antigen testing using the patch test. J. Med. Invest. 70 : 521-523, August, 2023.

Predicting endoscopic third ventriculostomy success in pediatric shunt dysfunction: a monocentric retrospective case series of 70 consecutive children, systematic review, and meta-analysis.

OBJECTIVE: The outcome of endoscopic third ventriculostomy (ETV) in children who had previously received shunts and who were experiencing shunt dysfunction is still discussed in terms of efficacy (success rate from 40% to 80%) and safety (0%-32.5% of complications). Reported predictive factors of secondary ETV failure are age, early onset of hydrocephalus, and prematurity. The best surgical strategy in the different subgroups of patients with shunt dysfunction is still debated. Therefore, the authors aimed to identify subgroups of patients in whom shunt treatment was associated with favorable outcome of ETV, to define the role of ETV in patients with global rostral midbrain dysfunction syndrome. METHODS: This study was a monocentric retrospective case series and a meta-analysis of children who had previously received shunts and who underwent secondary ETV for shunt dysfunction between 2012 and 2022. Clinical and MRI features were examined, along with surgical outcome, etiology of hydrocephalus, and preoperative ETV Success Score. Univariate and multivariate analyses were performed to find predictors of outcome of secondary ETV. Youden's J index was calculated on age distribution to find an optimal age cutoff. Systematic review of the literature and a meta-analysis were performed according to the PRISMA statement. RESULTS: Seventy consecutive patients were included. The overall success rate of secondary ETV was 63%. Primary obstructive hydrocephalus, age ≥ 36 months, and the presence of aqueductal obstruction were predictors of ETV success. Multivariate analysis found that age < 36 months, primary inflammatory hydrocephalus, and presence of fourth ventricular obstruction were associated with ETV failure. All patients with global rostral midbrain dysfunction syndrome experienced clinical and radiological improvement after ETV. The meta-analysis showed that postinflammatory etiology and age < 36 months were predictors of ETV failure. CONCLUSIONS: ETV is safe and effective for children with obstructive hydrocephalus experiencing shunt dysfunction, notably in cases of primary obstructive hydrocephalus with aqueductal stenosis, and among children whose age was ≥ 36 months who had postinflammatory hydrocephalus.

Factor VII Deficiency in an End-Stage Renal Disease Patient With Recurrent Thrombosis: A Case Report.

Congenital factor VII deficiency is a rare bleeding disorder with variable presentations. Thromboembolism is a well-established complication of this heterogeneous disease. As it is a rare disease, there is no information regarding its treatment when it is present with other comorbidities such as end-stage renal disease. This study describes a 47-year-old male with multiple comorbidities who was recently diagnosed with end-stage renal disease. He had recurrent admissions to the hospital due to thrombotic arteriovenous access failure as well as acute coronary syndrome, despite a high international normalized ratio that was resistant to replacement therapy. Eventually, apixaban became his main treatment regimen. This case needs to be reported because it is rare in terms of including a factor VII deficiency patient with end-stage renal disease, as well as to emphasize the unclear recommendations available for patients with factor VII deficiency and end-stage renal disease. International collaboration may be the best course of action to study enough patients and come up with effective recommendations.

Ventriculoperitoneal shunt survey in pediatric patients in an emergency setting: a comparison between ultra-low-dose CT using a tin filter and plain radiography.

OBJECTIVE: The aim of this study was to investigate the diagnostic performance, effective radiation dose, and examination time of ventriculoperitoneal shunt evaluation using full-body ultra-low-dose CT (ULD CT) with a tin filter compared with digital plain radiography in a pediatric population. METHODS: A retrospective cross-sectional study was conducted in an emergency setting. Data from 143 children were collected. Sixty were examined with ULD CT with a tin filter and 83 with digital plain radiography methods. Effective doses and times were compared between the two methods. Two observers in pediatric radiology evaluated the patient images. Clinical findings and results from shunt revision, if it was performed, were used to evaluate the diagnostic performance between modalities. An examination-room simulation was performed of the two methods to estimate representative examination times. RESULTS: The mean effective radiation dose for ULD CT with the tin filter was estimated to be 0.29 ± 0.16 mSv compared with 0.16 ± 0.19 mSv for digital plain radiography, with both examinations associated with a very low lifetime attributable risk (< 0.01%). The shunt tip could be more reliably located with ULD CT. ULD CT also allowed assessment of additional findings to explain patient symptoms, such as a cyst at the tip of the shunt catheter and the presence of an obstructing rubber nipple in the duodenum that could not have been observed on a plain radiograph. The examination time with ULD CT of the shunt was estimated to be 20 minutes. The examination time of the shunt with digital plain radiography, including the examination itself time and transfer of the patient between rooms, was estimated to be 60 minutes. CONCLUSIONS: ULD CT using a tin filter allows good visualization of the position or disruption of the shunt catheter that is comparable or superior to plain radiography, at a higher dose, while providing additional findings and reduced patient discomfort.

Predictive power of portal pressure gradient remeasured shortly after transjugular intrahepatic portosystemic shunt.

BACKGROUND AND AIMS: The portal pressure gradient (PPG) measured at the time of transjugular intrahepatic portosystemic shunt (TIPS) completion (immediate PPG) is easily disturbed by many factors. This study aimed to assess the diagnostic value of PPG remeasured 2-4 days after TIPS (delayed PPG) by comparison with immediate PPG. METHODS: We retrospectively analyzed cirrhotic patients aged 18-75 years who received TIPS for preventing variceal rebleeding and pressure measurements at different time points. RESULTS: Of 154 eligible patients, 60 (39.0%), 62 (40.3%), and 32 (20.8%) were categorized into group LL (both immediate and delayed PPG < 12 mmHg), LH (immediate PPG < but delayed PPG ≥ 12 mmHg) and HH (both immediate and delayed PPG ≥ 12 mmHg), respectively. Mean immediate and delayed PPG were 9.2 mmHg and 12.8 mmHg (p < 0.001). During a median follow-up of 22 months, the 1-year probability of variceal rebleeding was significantly lower in group LL (1.7%) compared to LH (9.8%, absolute risk difference [ARD]: - 8.2%, p = 0.028) and HH (12.6%, ARD: - 11.1%, p = 0.014), but was not significantly different between groups LH and HH (ARD: - 2.9%, p = 0.671). Delayed PPG (p < 0.001) was identified as an independent predictor of variceal rebleeding in multivariable Cox regression analysis. The area under curves of delayed and immediate PPG in predicting variceal rebleeding were 0.837 and 0.693 for all patients (p = 0.031), and 0.936 and 0.694 for patients without shunt dysfunction (p < 0.001). CONCLUSIONS: In cirrhotic patients with variceal bleeding, delayed PPG has higher predictive power for variceal rebleeding than immediate PPG.

Ventriculoperitoneal shunt failure due to raised intra-abdominal pressure: A case report and review of the literature.

Background: Ventriculoperitoneal (VP) shunt implantation is the standard neurosurgical procedure to treat hydrocephalus for various reasons. Its function depends on the differential pressure between the ventricular space and the peritoneal cavity. Correct functioning of cerebrospinal fluid (CSF) valves requires a gradient of pressure between the ventricular and the abdominal cavity. Any reason that disrupts this balance can result in dysfunction of the system. Increased intra-abdominal pressure (IAP) may be a reason to induce shunt failure by decreasing CSF drainage from the ventricular system to the peritoneal cavity. Case Description: We report a case of repeated VP shunt failure because of constipation and successful conservative management by lowering IAP without surgical revision of the VP shunt system and reviewed the relevant literature. Conclusion: Increased IAP for a variety of reason should always be considered as a possible reason for shunt failure that can often be treated conservatively and therefore can reduce unnecessary shunt revision surgery.