Category: hydrocephalus

Posted on

Why does endoscopic aqueductoplasty fail so frequently?

J Neurosurg 117:141–149, 2012

The aim of this study was to evaluate and compare CSF flow after endoscopic third ventriculostomy (ETV) and endoscopic aqueductoplasty (EAP) in patients presenting with obstructive hydrocephalus caused by aqueductal stenosis.

Methods. In patients harboring aqueductal stenosis who underwent EAP (n = 8), ETV (n = 8), and both ETV and EAP (n = 6), CSF flow through the restored aqueduct and through the ventriculostomy was investigated using cine cardiac-gated phase-contrast MRI. For qualitative evaluation of CSF flow, an in-plane phase-contrast sequence in the midsagittal plane was used. The MR images were displayed in a closed-loop cine format. Quantitative through-plane measurements were performed in the axial plane perpendicular to the aqueduct and/or floor of the third ventricle.

Results. Evaluation revealed significantly higher CSF flow through the ventriculostomies compared with flow through the aqueducts. This was true both when comparing the ETV group with the EAP group and when comparing the flow of the ventriculostomy and aqueduct within the ETV and EAP group. There was no difference in aqueductal CSF flow between patients who underwent EAP alone and patients who underwent ETV and EAP. There was also no difference in ventriculostomy CSF flow between patients who underwent ETV alone and patients who underwent ETV and EAP. Fifty percent of the restored aqueducts became occluded at a mean of 46 months after surgery (range 18–126 months). In contrast, all ETVs remained patent in the mean follow-up period of 110 months after surgery, although 1 patient required shunt placement after 66 months.

Conclusions. Cerebrospinal fluid flow through ventriculostomies is significantly higher than aqueductal CSF flow after EAP. This could be one factor to explain why the reclosure rate of aqueducts after EAP is higher than the reclosure rate of the ventriculostoma after ETV.

 

Posted on

Hyponatremia following endoscopic third ventriculostomy

Neurosurg Pediatrics 10:39–43, 2012. http://thejns.org/doi/abs/10.3171/2012.4.PEDS1222

Electrolyte and endocrinological complications of endoscopic third ventriculostomy (ETV) are infrequent but serious events, likely due to transient hypothalamic-pituitary dysfunction. While the incidence of diabetes insipidus is relatively well known, hyponatremia is not often reported. The authors report on a series of 5 patients with post-ETV hyponatremia.

Methods. The records of patients undergoing ETV between 2008 and 2010 were reviewed. All ETVs were performed with a rigid neuroendoscope via a frontal bur hole, standard third ventricle floor blunt perforation, Fogarty catheter dilation, and intermittent normal saline irrigation. Postoperative MR images were evaluated for endoscope tract injury as well as the trajectory from the bur hole center to the fenestration site.

Results. Thirty-two patients (20 male and 12 female) underwent ETV. Their median age was 6 years (range 3 weeks–28 years). Hydrocephalus was most commonly due to nontumoral aqueductal stenosis (43%), nontectal tumor (25%), or tectal glioma (13%). Five patients (16%) had multicystic/loculated hydrocephalus. Five patients (16%) developed hyponatremia between 1 and 8 days following ETV, including 2 patients with seizures (1 of whom was still hospitalized at the time of the seizure and 1 of whom was readmitted as a result of the seizure) and 3 patients who were readmitted because of decline in their condition following routine discharge. No hypothalamic injuries were noted on imaging. Univariate risk factors consisted of age of 2 years or less (p = 0.02), presence of cystic lesions (p = 0.02), and ETV trajectory angle 10° or more from perpendicular (p = 0.001).

Conclusions. Endoscopic third ventriculostomy is a well-tolerated procedure but can result in serious complications. Hyponatremia is rare and may be more likely in younger patients or those with cystic loculations. Patients with altered craniometry may be at particular risk with a rigid endoscopic approach requiring greater manipulation of subforniceal or hypothalamic structures.

Posted on

Ventricular Catheter Location and the Clearance of Intraventricular Hemorrhage

Neurosurgery 70:1258–1264, 2012 DOI: 10.1227/NEU.0b013e31823f6571

There is no consensus regarding optimal position of an external ventricular drain (EVD) with regard to clearance of intraventricular hemorrhage (IVH).

OBJECTIVE: To assess the hypothesis that EVD laterality may influence the clearance of blood from the ventricular system with and without administration of thrombolytic agent.

METHODS: The EVD location was assessed in 100 patients in 2 Clot Lysis Evaluating Accelerated Resolution of Intraventricular Hemorrhage (CLEAR IVH) phase II trials assessing the safety and dose optimization of thrombolysis through the EVD to accelerate the clearance of obstructive IVH. Laterality of catheter was correlated with clearance rates.

RESULTS: Clearance of IVH over the first 3 days was significantly greater when thrombolytic compared with placebo was administered regardless of catheter laterality (P , .005; 95% confidence interval, 214.0 to 24.14 for contralateral EVD and 224.7 to 25.44 for ipsilateral EVD). When thrombolytic was administered, there was a trend toward more rapid clearance of total IVH through an EVD placed on the side of dominant intraventricular blood compared with an EVD on the side with less blood (P = .09; 95% confidence interval, 29.62 to 0.69). This was not true when placebo was administered. Clearance of third and fourth ventricular blood was unrelated to EVD laterality.

CONCLUSION: It is possible that placement of EVD may be optimized to enhance the clearance of total IVH if lytic agents are used. Catheters on either side can clear the third and fourth ventricles with equal efficiency.

Posted on

Optimal trajectory of endoscopic third ventriculostomy

J Neurosurg 116:1153–1157, 2012. http://thejns.org/doi/abs/10.3171/2012.2.JNS111287

An optimal entry point for endoscopic third ventriculostomy (ETV) helps protect critical structures from undue manipulation. A commonly accepted ideal entry point is 3 cm from the midline and 1 cm anterior to the coronal suture. The authors of this study reexamine this ideal entry point.

Methods. Trajectory views from MR images or CT scans used for cranial image guidance in 53 patients (age range 3–85 years) who had undergone ETV were retrospectively evaluated. The trajectory from the tuber cinereum back through the center of the foramen of Monro was projected to the surface of the head. The relation of the entry point to the midline and the coronal suture was established.

Results. The mean perpendicular distance from the ideal entry point to the midline was 30.1 ± 7 mm (median 31.9 mm, range 12.5–42.2 mm). The mean perpendicular distance to the coronal suture was 8.9 ± 14.1 mm posterior (median 10.4 mm), ranging from 30.6 mm anterior to 35.8 mm posterior. The entry point tended to be located more posteriorly in women and adults: 5.8 ± 15.4 mm posterior in males versus 13.1 ± 13.2 mm posterior in females (p = 0.08) and 9.1 ± 14.8 mm posterior in adults versus 8.2 ± 11.7 mm posterior in children (p = 0.84).

Conclusions. While the entry point may need to be modified from the ideal trajectory for other anatomical reasons, such as a trajectory through the motor cortex, in general, the authors found that the optimal entry point for ETV was more posterior than previously published and highly variable. Using image guidance or a customized trajectory based on analysis of a patient’s own imaging is highly preferable to using an empirical ideal trajectory.

Posted on

Endoscopic Treatment of Isolated Fourth Ventricle: Clinical and Radiological Outcome

Neurosurgery 70:847–859, 2012 DOI: 10.1227/NEU.0b013e318236717f

Treatment of an isolated fourth ventricle should be considered when clinical symptoms or a significant mass effect occur.

OBJECTIVE: To report clinical and radiographic outcomes after endoscopic transaqueductal or transcisternal stent placement into the fourth ventricle. METHODS: In 19 patients (age, 34th week of gestation-20 years; median age, 17.5 months), 22 endoscopic procedures were performed. Either an aqueductoplasty or, in cases with a supratentorially extended fourth ventricular component, an interventricular fenestration was performed. In all patients, a stent connected to the cerebrospinal fluid–diverting shunt was placed through the fenestration. Surgical complications and radiological and clinical outcomes are reported.

RESULTS: All 19 patients had a mean follow-up of 26.9 ± 18.2 months. No persisting neurological complications were observed; 27.3% of patients experienced complete resolution of presenting symptoms, whereas 68.3% demonstrated partial resolution. Symptoms with short duration (< 4 weeks) resolved completely, whereas long-standing symptoms partially improved. Short-term shunt complications (n = 2; insufficient catheter placement and subdural hygroma) and a need for long-term stent revisions (n = 3; stent retraction and shunt revision for other causes) were observed. The mean fourth ventricular volume was reduced after surgery (44.2 ± 25.8 to 23.1 ± 21.9 mL; P < .01). Pontine diameter increased from 0.9 ± 0.3 to 1.2 ± 0.3 cm (P < .01) after surgery. Both effects were still demonstrated on later radiological follow-up of 24.4 ± 14.2 months (fourth ventricular size, 24.7 ± 28.1 mL; P < .01; pontine diameter, 1.3 ± 0.3 cm; P < .01).

CONCLUSION: The clinical and radiological outcomes after endoscopic aqueductoplasty and interventriculostomy in children with an isolated fourth ventricle indicate that this procedure is feasible, effective, and safe.

Posted on

Traumatic subdural effusion with concomitant hydrocephalus

J Neurosurg 116:558–565, 2012. DOI: 10.3171/2011.10.JNS11711

Traumatic subdural effusion (TSE) is a common sequela of traumatic brain injury. Surgical intervention is suggested only when TSE exerts mass effect. The authors have found that many patients with TSE exerting mass effect have concomitant hydrocephalus. Patient experiencing this occurrence were studied, and the pathogenesis of this phenomenon was discussed in the context of recent advances in the understanding of CSF circulation.

Methods. During a 2-year period, the authors’ institution treated 14 patients with TSE who developed hydrocephalus, after 1 of the patients suffered subdural drainage and other 13 received subdural peritoneal shunt (SPSs). Thirteen of those who had SPSs received programmable ventriculoperitoneal shunts (VPSs) for the hydrocephalus. The clinical characteristics as well as the imaging and operative findings of these patients were reviewed.

Results. All patients with symptomatic TSE exerting mass effect received SPSs. All of these patients had a modified Frontal Horn Index of more than 0.33 at presentation, and high opening pressure on durotomy. Following a brief period (4–7 days) of clinical improvement, the condition of all patients deteriorated due to hydrocephalus. Programmable VPSs were inserted with the initial pressure set at approximately 8–10 cm H2O according to opening pressure at ventriculostomy. Shunt valve pressure was gradually decreased to 5–7 cm H2O, according to clinical and radiological follow-up.

Conclusions. Elevated modified Frontal Horn Index in patients with TSE is suggestive of concomitant hydrocephalus. The authors propose that tearing of the dura-arachnoid plane following trauma contributes to TSE and may also impede CSF circulation, causing hydrocephalus. Shunt pressure was adjusted to relative low pressure, indicating the old age of the patients and poor reexpansion of brain parenchyma after the mass effect. Subdural peritoneal shunts and VPSs are indicated in those patients with TSE exerting mass effect with concomitant hydrocephalus.

Posted on

New Telemetric Intracranial Pressure-Monitoring System

Neurosurgery 70[ONS Suppl 1]:ons44–ons49, 2012 DOI: 10.1227/NEU.0b013e31822dda12 

The knowledge of intracranial pressure (ICP) is the basis of an appropriate neurosurgical treatment. Because clinical, fundoscopic, or radiological data alone are often elusive, a pre- or postoperative long-term monitoring of the ICP itself is desirable.

OBJECTIVE: We describe the first clinical experiences with a new telemetric ICPmonitoring device.

METHODS: The transducer of this telemetric intraparenchymal pressure probe is placed under the galea over the calvaria. ICP can be monitored via a special telemetric reader, placed over the intact skin, and the ICP values are stored in a small portable computer. The system does not require an intensive care environment and can be used in any ward or even at home. The system was successfully applied in 10 patients (age, 3- 56 years) in whom raised ICP due to hydrocephalus, shunt dysfunction, endoscopic third ventriculostomy failure, craniostenosis, or pseudotumor cerebri was suspected.

RESULTS: Continuous telemetric monitoring of ICP was performed for 2 to 24 weeks. In 7 patients, increased ICP values could be excluded, and further surgical maneuvers were avoided. In 3 patients, repeated plateaus or continuously raised ICP indicated surgery resulting in a normalization of ICP.

CONCLUSION: This new telemetric system was safe and effective for ICP measurement over a long period, including home monitoring. For the patients, it was easy to handle, and reliable data could be recorded over many weeks. Based on this preliminary experience, the authors consider the new system extremely advantageous in surgical decision making in particularly difficult cases of suspected abnormalities of ICP.

Posted on

Alteration of brain viscoelasticity after shunt treatment in normal pressure hydrocephalus

Neuroradiology (2012) 54:189–196. DOI 10.1007/s00234-011-0871-1

Normal pressure hydrocephalus (NPH) represents a chronic neurological disorder with increasing incidence. The symptoms of NPH may be relieved by surgically implanting a ventriculoperitoneal shunt to drain excess cerebrospinal fluid. However, the pathogenesis of NPH is not yet fully elucidated, and the clinical response of shunt treatment is hard to predict. According to current theories of NPH, altered mechanical properties of brain tissue seem to play an important role. Magnetic resonance elastography (MRE) is a unique method for measuring in vivo brain mechanics.

Methods In this study cerebral MRE was applied to test the viscoelastic properties of the brain in 20 patients with primary (N=14) and secondary (N=6) NPH prior and after (91±16 days) shunt placement. Viscoelastic parameters were derived from the complex modulus according to the rheological springpot model. This model provided two independent parameters μ and α, related to the inherent rigidity and topology of the mechanical network of brain tissue.

Results The viscoelastic parameters μ and α were found to be decreased with −25% and −10%, respectively, compared to age-matched controls (P<0.001). Interestingly, α increased after shunt placement (P<0.001) to almost normal values whereas μ remained symptomatically low.

Conclusion The results indicate the fundamental role of altered viscoelastic properties of brain tissue during disease progression and tissue repair in NPH. Clinical improvement in NPH is associated with an increasing complexity of the mechanical network whose inherent strength, however, remains degraded.

Posted on

Different Patterns of Fornix Damage in Idiopathic Normal Pressure Hydrocephalus and Alzheimer Disease

Am J Neuroradiol 33:274 –79  Feb 2012

The fornix contains efferent fibers of the hippocampus and is in close contact with the corpus callosum. Part of the fornix is directly attached to the corpus callosum, and another part is suspended from the corpus callosum via the septum pellucidum. DTI can be used to evaluate the morphology and microstructural integrity of the fornix. We examined the pattern of fornix damage in patients with iNPH or AD.
MATERIALS AND METHODS: We enrolled 22 patients with iNPH, 20 with AD, and 20 healthy controls. DTI data were obtained. The morphology (volume, length, and mean cross-sectional area) and FA values of the fornix were evaluated by using tract-specific analysis and compared among groups.
RESULTS: The volume, cross-sectional area, and FA value of the fornix were significantly smaller in patients with iNPH than in controls, whereas the length was significantly greater. In patients with AD, the volume, mean cross-sectional area, and FA value of the fornix were significantly smaller than those in controls, whereas the length was not altered. The fornix was significantly longer in patients with iNPH than in patients with AD, whereas the volume and cross-sectional areas were significantly smaller.
CONCLUSIONS: Our results suggest that the different pathogeneses of these diseases lead to fornix damage through different mechanisms: through mechanical stretching due to lateral ventricular enlargement and corpus callosum deformation in patients with iNPH, and through degeneration secondary to hippocampal atrophy in patients with AD.

Posted on

Ventriculoperitoneal Shunt Surgery Outcome in Adult Transition Patients With Pediatric-Onset Hydrocephalus

Neurosurgery 70:380–389, 2012 DOI: 10.1227/NEU.0b013e318231d551

Ventriculoperitoneal shunting remains the most widely used neurosurgical procedure for the management of hydrocephalus, albeit with many complications.

OBJECTIVE: To review and assess the long-term clinical outcome of ventriculoperitoneal shunt surgery in adult transition patients with pediatric-onset hydrocephalus.

METHODS: Patients 17 years or older who underwent ventriculoperitoneal shunt placement for hydrocephalus during their pediatric years (younger than 17 years) were included. Medical charts, operative reports, imaging studies, and clinical follow- up evaluations were reviewed and analyzed retrospectively.

RESULTS: A total of 105 adult patients with pediatric-onset hydrocephalus were included. The median age of the patients was 25.9 years. The median age at the time of the initial ventriculoperitoneal shunt placement was 1.0 year. The median follow-up time for all patients was 17.7 years. The incidence of shunt failure at 6 months was 15.2%, and the overall incidence of shunt failure was 82.9%. Single shunt revision occurred in 26.7% of the patients, and 56.2% had multiple shunt revisions. The cause of hydrocephalus was significantly associated with shunt survival for patients who had shunt failure before the age of 17 years. Being pediatric at first shunt revision, infection, proximal shunt complication, and other causes were independently associated with multiple shunt failures.

CONCLUSION: The findings of this retrospective study show that the long-term ventriculoperitoneal shunt survival remains low in adult transition patients with pediatric-onset hydrocephalus.

Posted on

The economic impact of ventriculoperitoneal shunt failure

J Neurosurg Pediatrics 8:539–599, 2011.DOI: 10.3171/2011.9.PEDS11192

Detailed costs to individuals with hydrocephalus and their families as well as to third-party payers have not been previously described. The purpose of this study was to determine the primary caregiver out-of-pocket expenses and the third-party payer reimbursement rate associated with a shunt failure episode.

Methods. A retrospective study of children born between 2000 and 2005 who underwent initial ventriculoperitoneal (VP) shunt placement and who subsequently experienced a shunt failure requiring surgical intervention within 2 years of their initial shunt placement was conducted. Institutional reimbursement and demographic data from Children’s Hospital of Alabama (CHA) were augmented with a caregiver survey of any out-of pocket expenses encountered during the shunt failure episode. Institutional reimbursements and caregiver out-of-pocket expenses were then combined to provide the cost for a shunt failure episode at CHA.

Results. For shunt failures, the median reimbursement total was $5008 (interquartile range [IQR] $2068– $17,984), the median caregiver out-of-pocket expenses was $419 (IQR $251–$1112), and the median total cost was $5411 (IQR $2428–$18,582). Private insurance reimbursed at a median rate of $5074 (IQR $2170–$14,852) compared with public insurance, which reimbursed at a median rate of $4800 (IQR $1876–$19,395). Caregivers with private insurance reported a median $963 (IQR $322–$1741) for out-of-pocket expenses, whereas caregivers with public insurance reported a median $391 (IQR $241–$554) for out-of-pocket expenses (p = 0.017).

Conclusions. This study confirmed that private insurance reimbursed at a higher rate, and that although patients had a shorter length of stay as compared with those with public insurance, their out-of-pocket expenses associated with a shunt failure episode were greater. However, it could not be determined if the significant difference in outof- pocket expenses between those with private and those with public insurance was due directly to the cost of shunt failure. This model does not take into consideration community resources and services available to those with public insurance. These resources and services could offset the out-of-pocket burden, and therefore should be considered in future cost models.

Posted on

More malfunctioning Medos Hakim programmable valves: cause for concern?

J Neurosurg 115:1047–1052, 2011. DOI: 10.3171/2011.5.JNS101396

In recent years, the authors have noticed a growing number of programmable valve defects at their institution. Therefore, they conducted this study to evaluate the increased incidence of malfunctioning valves.

Methods. They investigated all revisions that had been performed at their institution between 1994 and 2010 for dislodgement of the stator of a standard Medos Hakim programmable valve with a prechamber.

Results. Fifteen valves were removed because of dislodged stators. The valves had been implanted between May 16, 1993, and December 27, 2002, and were explanted between February 19, 2006, and January 22, 2010. Thus, the valves had been in place for a mean period of 11 years (median 11 years, range 7–14 years). The percentage of dislodged stators was almost 3% (15 of 546 valves). Particularly noteworthy is that all malfunctioning valves were found in children who had been younger than 1 year of age at the time of implantation.

Conclusions. Medos Hakim programmable valve malfunctions are rare events but should receive careful attention. When the pressure setting cannot be adjusted, a malfunction should always be suspected and radiographic imaging should be performed to assess the valve. Stator dislodgement is the most serious form of valve adjustment failure.

Posted on

Management of Adult Hydrocephalus With Ventriculoperitoneal Shunts: Long-term Single- Institution Experience

Neurosurgery 69:774–781, 2011 DOI: 10.1227/NEU.0b013e31821ffa9e

Ventriculoperitoneal shunting is the most widely used neurosurgical procedure for the management of hydrocephalus.

OBJECTIVE: To evaluate our long-term single-institution experience in the management of adult hydrocephalus patients with ventriculoperitoneal shunts.

METHODS: Adult patients who underwent ventriculoperitoneal shunt placement for hydrocephalus from October 1990 to October 2009 were included. Medical charts, operative reports, imaging studies, and clinical follow-up evaluations were reviewed and analyzed retrospectively for clinical outcome in adult hydrocephalus patients.

RESULTS: A total of 683 adult patients were included in the study. The most common etiologies of hydrocephalus include idiopathic (29%), tumors and cysts (20%), postcraniotomy (13%), and subarachnoid hemorrhage (13%). The overall shunt failure rate was 32%, and the majority (74%) of shunt revisions occurred within the first 6 months. The median time to first shunt revision was 9.31 months. Etiology of hydrocephalus showed a significant impact on the incidence of shunt revision/failure and on the median time to shunt revision. Similarly, the type of hydrocephalus had a significant effect on the incidence of shunt failure and the median time to shunt revision.

CONCLUSION: A large proportion of patients (32%) experience shunt failure after shunt placement for hydrocephalus. Although the overall incidence of shunt revision was comparable to previously reported studies, the fact that a large proportion of adult populations with shunt placement experience shunt failure is a concern.

Posted on

Effect of Antibiotic-Impregnated Shunts on Infection Rate in Adult Hydrocephalus: A Single Institution’s Experience

Neurosurgery 69:625–629, 2011 DOI: 10.1227/NEU.0b013e31821bc435

Cerebrospinal fluid (CSF) shunt infection remains a major cause of morbidity and mortality in the treatment of hydrocephalus. Studies have demonstrated the efficacy of antibiotic-impregnated shunt (AIS) systems in reducing CSF shunt infections in pediatric patients. Fewer studies evaluate the efficacy of AIS systems in adult hydrocephalus.

OBJECTIVE: To determine whether categorical conversion to AIS shunt systems reduced the incidence of shunt infection in adults.

METHODS: All adult patients undergoing CSF shunt insertion over a 7-year period were retrospectively reviewed (2004-2009). In 2006, a categorical switch to AIS catheters was made. Before 2006, standard nonimpregnated shunt catheters were used. We retrospectively reviewed the first 250 cases of AIS catheter implantation and compared them with the immediately preceding 250 non-AIS cases to assess 1-year incidence of CSF shunt infection.

RESULTS: Five hundred shunt surgeries were performed for normal-pressure hydrocephalus in 378 patients (76%), pseudotumor cerebri in 83 patients (17%), and various obstructive/communicating hydrocephalus etiologies in 40 patients (8%). All patients were followed for 12 months. The mean age was 60 6 18 years. Baseline characteristics were similar between AIS (n = 250) and non-AIS (n = 250) cohorts. Overall, 13 patients (2.6%) experienced CSF shunt infection, occurring a mean of 2 6 2 months postoperatively. Shunt infection incidence was decreased in AIS (1.2%) vs non-AIS (4.0%) cohorts (P = .0492). Staphylococcus epidermidis was the most common pathogen in AIS and non-AIS cohorts. Oxacillin resistance was not increased in the AIS cohort.

CONCLUSION: Categorical conversion to AIS catheters was associated with a reduced incidence of shunt infection. AIS catheters may be a reliable instrument for decreasing perioperative shunt colonization and subsequent infection in adults with hydrocephalus.

Posted on

Laparoscopic versus open insertion of the peritoneal catheter in ventriculoperitoneal shunt placement: review of 810 consecutive cases

J Neurosurg 115:151–158, 2011. DOI: 10.3171/2011.1.JNS101492

Traditional ventriculoperitoneal (VP) shunt surgery involves insertion of the distal catheter by minilaparotomy. However, minilaparotomy may be a significant source of morbidity during shunt surgery. Laparoscopic insertion of the distal catheter is an alternative technique that may simplify and improve the safety of shunt surgery.

Methods. The authors performed a retrospective review of hospital records of all patients undergoing new VP shunt insertion at a tertiary care center between 2004 and 2009. Patient characteristics and outcomes were compared between patients undergoing open or laparoscopic insertion of the distal catheter. Independent variables in the analysis included age, sex, race, body mass index, surgical technique, previous VP shunt placement, previous abdominal procedures, American Society of Anesthesiology (ASA) score, and indication for shunt placement. Dependent variables included the occurrence of shunt failure, cause of shunt failure, complications, length of stay (LOS), LOS after shunt placement, estimated blood loss, and operative time.

Results. The authors identified 810 patients who met the inclusion criteria; open or laparoscopic distal catheter insertion was performed in 335 and 475 patients, respectively. There were no significant differences between the groups regarding age, race, ASA score, or indication for shunt placement. The most common indication was hydrocephalus due to subarachnoid hemorrhage, followed by tumor-associated hydrocephalus, normal pressure hydrocephalus (NPH), and hydrocephalus due to trauma. The incidence of shunt failure was not statistically different between cohorts, occurring in 20.0% of laparoscopic and 20.9% of open catheter placement cases (p = 0.791). With analysis of causes of shunt failure, shunt obstruction occurred significantly more often in the open surgery cohort (p = 0.012). In patients with a known cause shunt obstruction, distal obstruction occurred in 35.7% of the open cohort obstructions and 4.8% of the laparoscopic cohort obstructions (p = 0.014). The relative risk of distal obstruction in open cases compared with laparoscopic cases was 7.50. Infections occurred in 8.2% of laparoscopic cases compared with 6.6% of open cases (p = 0.419). Within the NPH subgroup, the laparoscopically treated patients had significantly more overdrainage (p = 0.040), whereas those in the open cohort experienced significantly more shunt obstructions (p = 0.034). Laparoscopically treated patients had shorter operative times (p < 0.0005), inpatient LOS (p < 0.001), and inpatient LOS after VP shunt placement (p = 0.01) as well as less blood loss (p = 0.058).

Conclusions. To our knowledge this is the largest reported comparison of distal VP shunt catheter insertion techniques. Compared with minilaparotomy, the laparoscopic approach was associated with decreased time in the operating room and a decreased LOS. Moreover, laparoscopy was associated with fewer distal shunt obstructions. Laparoscopic shunt surgery is a viable alternative to traditional shunt surgery.

Posted on

A standardized protocol to reduce cerebrospinal fluid shunt infection: The Hydrocephalus Clinical Research Network Quality Improvement Initiative

J Neurosurg Pediatrics 8:22–29, 2011. DOI: 10.3171/2011.4.PEDS10551

Quality improvement techniques are being implemented in many areas of medicine. In an effort to reduce the ventriculoperitoneal shunt infection rate, a standardized protocol was developed and implemented at 4 centers of the Hydrocephalus Clinical Research Network (HCRN).

Methods. The protocol was developed sequentially by HCRN members using the current literature and prior institutional experience until consensus was obtained. The protocol was prospectively applied at each HCRN center to all children undergoing a shunt insertion or revision procedure. Infections were defined on the basis of CSF, wound, or pseudocyst cultures; wound breakdown; abdominal pseudocyst; or positive blood cultures in the presence of a ventriculoatrial shunt. Procedures and infections were measured before and after protocol implementation.

Results. Twenty-one surgeons at 4 centers performed 1571 procedures between June 1, 2007, and February 28, 2009. The minimum follow-up was 6 months. The Network infection rate decreased from 8.8% prior to the protocol to 5.7% while using the protocol (p = 0.0028, absolute risk reduction 3.15%, relative risk reduction 36%). Three of 4 centers lowered their infection rate. Shunt surgery after external ventricular drainage (with or without prior infection) had the highest infection rate. Overall protocol compliance was 74.5% and improved over the course of the observation period. Based on logistic regression analysis, the use of BioGlide catheters (odds ratio [OR] 1.91, 95% CI 1.19–3.05; p = 0.007) and the use of antiseptic cream by any members of the surgical team (instead of a formal surgical scrub by all members of the surgical team; OR 4.53, 95% CI 1.43–14.41; p = 0.01) were associated with an increased risk of infection.

Conclusions. The standardized protocol for shunt surgery significantly reduced shunt infection across the HCRN. Overall protocol compliance was good. The protocol has established a common baseline within the Network, which will facilitate assessment of new treatments. Identification of factors associated with infection will allow further protocol refinement in the future.

Posted on

Laparoscopy-assisted ventriculoperitoneal shunt surgery: personal experience and review of the literature

Neurosurg Rev (2011) 34:363–371. DOI 10.1007/s10143-011-0309-6

Ventriculoperitoneal shunting is a widely accepted technique for the treatment of hydrocephalus. The standard procedure to insert the peritoneal catheter requires an abdominal incision, muscle dissection, and opening of the peritoneum. A number of complications related to the abdominal surgical phase have been reported. Laparoscopy-assisted ventriculoperitoneal shunting is a valid alternative procedure that reduces surgical trauma.

We describe our experience and review the literature. A total of 30 laparoscopically guided ventriculoperitoneal shunting procedures were performed between January 2007 and June 2008, in collaboration with a general surgeon experienced in laparoscopy. Of these procedures, 25 were new shunt placements and 5 were revisions. Data about operative time, outcome, and complications were registered and compared with a group of 30 patients treated by means of standard laparotomy in the period 2005–2007. Laparoscopic shunt placement was successful in all patients. Operative duration, complications, and postoperative pain were all lower in patients treated by laparoscopy as compared to the laparotomy. In the laparoscopic group, an earlier peristalsis, quicker mobilization, and better cosmetic results were also noted.

Laparoscopy in both ventriculoperitoneal shunt placement and revision is a safe, effective, and minimally invasive technique. It ensures proper abdominal placement of the distal catheter under direct vision allowing confirmation of its patency.

Posted on

Benign external hydrocephalus: a review, with emphasis on management

Neurosurg Rev. DOI 10.1007/s10143-011-0327-4

Benign external hydrocephalus in infants, characterized by macrocephaly and typical neuroimaging findings, is considered as a self-limiting condition and is therefore rarely treated. This review concerns all aspects of this condition: etiology, neuroimaging, symptoms and clinical findings, treatment, and outcome, with emphasis on management. The review is based on a systematic search in the Pubmed and Web of Science databases. The search covered various forms of hydrocephalus, extracerebral fluid, and macrocephaly. Studies reporting small children with idiopathic external hydrocephalus were included, mostly focusing on the studies reporting a long-term outcome.

A total of 147 studies are included, the majority however with a limited methodological quality. Several theories regarding pathophysiology and various symptoms, signs, and clinical findings underscore the heterogeneity of the condition. Neuroimaging is important in the differentiation between external hydrocephalus and similar conditions. A transient delay of psychomotor development is commonly seen during childhood. A long-term outcome is scarcely reported, and the results are varying.

Although most children with external hydrocephalus seem to do well both initially and in the long term, a substantial number of patients show temporary or permanent psychomotor delay. To verify that this truly is a benign condition, we suggest that future research on external hydrocephalus should focus on the long-term effects of surgical treatment as opposed to conservative management.

Posted on

Diffusion Tensor Imaging Reveals Supplementary Lesions to Frontal White Matter in Idiopathic Normal Pressure Hydrocephalus

Neurosurgery 68:1586–1593, 2011 DOI: 10.1227/NEU.0b013e31820f3401

Idiopathic normal-pressure hydrocephalus (INPH) is associated with white matter lesions, but the extent and severity of the lesions do not cohere with symptoms or improvement after shunting, implying the presence of further, yet undisclosed, injuries to white matter in INPH.

OBJECTIVE: To apply diffusion tensor imaging (DTI) to explore white matter lesions in patients with INPH before and after drainage of cerebrospinal fluid (CSF).

METHODS: Eighteen patients and 10 controls were included. DTI was performed in a 1.5T MRI scanner before and after 3-day drainage of 400 mL of CSF. Regions of interest included corpus callosum, capsula interna, frontal and lateral periventricular white matter, and centrum semiovale. White matter integrity was quantified by assessing fractional anisotropies (FA) and apparent diffusion coefficients (ADC), comparing them between patients and controls and between patients before and after drainage. The significance level corresponded to .05 (Bonferroni corrected).

RESULTS: Decreased FA in patients was found in 3 regions (P < .002, P < .001, and P < .001) in anterior frontal white matter, whereas elevated ADC was found in genu corpus callosum (P < .001) and areas of centrum semiovale associated with the precentral gyri (P < .002). Diffusion patterns in these areas did not change after drainage.

CONCLUSION: DTI reveals subtle injuries—interpreted as axonal loss and gliosis—to anterior frontal white matter where high-order motor systems between frontal cortex and basal ganglia travel, further supporting the notion that motor symptoms in INPH are caused by a chronic ischemia to the neuronal systems involved in the planning processes of movements.

Posted on

Use of the proGAV Shunt Valve in Normal-Pressure Hydrocephalus

Neurosurgery 68[ONS Suppl 2]:ons245–ons249, 2011 DOI: 10.1227/NEU.0b013e318214a809

Overdrainage is a common complication associated with shunt insertion in normal-pressure hydrocephalus (NPH) patients. Using adjustable valves with antigravity devices has been shown to reduce its incidence. The optimal starting setting of an adjustable shunt valve in NPH is debatable.

OBJECTIVE: To audit our single-center practice of setting adjustable valves.

METHODS: We performed a retrospective review of clinical records of all NPH patients treated in our unit between 2006 and 2009 by the insertion of shunts with a proGAV valve, recording demographic and clinical data, shunt complications, and revision rates. Radiological reports of postoperative follow-up computed tomography scans of the brain were reviewed for detected subdural hematomas.

RESULTS: A proGAV adjustable valve was inserted in 50 probable NPH patients between July 2006 and November 2009. Mean 6 SD age was 76 6 7 years. Mean follow-up was 15 months. The initial shunt setting was 6 6 3 cmH2O, and the final setting was 4.9 6 1.9 cm H2O. Nineteen patients required 24 readjustment procedures (readjustment rate, 38%; readjustment number, 0.48 times per patient). One patient (2%) developed delayed bilateral subdural hematoma after readjustment of his shunt valve setting as an outpatient.

CONCLUSION: Starting with a low opening pressure setting on a proGAV adjustable shunt valve does not increase the chances of overdrainage complications and reduces the need for repeated readjustments.

Proudly powered by WordPress