Article Text
Abstract
Background Long term failure rates after venous sinus stenting (VSS) for idiopathic intracranial hypertension (IIH) are poorly understood.
Methods Retrospective analysis was performed on a prospectively-maintained single center database to identify patients with medically refractory IIH who underwent VSS. Patients with persistent or severe recurrent symptoms after VSS undergo lumbar puncture (LP), therefore LP serves as a marker for treatment failure.
Results 81 patients underwent VSS with a mean follow-up of 10 months; 44 (54.3%) patients underwent LP after VSS due to persistent or recurrent symptoms at a mean of 12 months (median 7, range 2–43). There was a mean decrease in opening pressure (OP) on LP from pre- to post-VSS of 9.1 cm H2O (median 9.5). Overall, a total of 21 (25.9%) patients underwent further surgical intervention following VSS, including five who underwent repeat VSS (6.2% of total) and 18 who underwent cerebrospinal fluid shunting (22.2% of total). There was a non-significant (p=0.18) but overall increase in quality of life scores from pre-stenting (61.2) to last follow-up (71.2), and a significant decrease in Headache Impact Test-6 (HIT-6) scores (p=0.03) with mean pre-stenting and last follow-up scores of 62.7 and 55.8, respectively.
Conclusions VSS is an effective treatment for venous sinus stenosis in IIH; however, this study found higher rates of symptomatic recurrence and need for further surgical intervention (26%) than previously reported in the literature. Recurrence of symptoms occurred at a median of 7 months, even though OP remained lower at follow-up LP, suggestive of a re-equilibration phenomenon.
- intervention
- intracranial pressure
- stenosis
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Introduction
Idiopathic intracranial hypertension (IIH), formerly referred to as pseudotumor cerebri or benign intracranial hypertension, is a syndrome that is characterized by chronic headaches, tinnitus, ophthalmic manifestations including visual obscurations and papilledema which can lead to vision loss, and an elevated opening pressure (OP) on lumbar puncture (LP) in the absence of an intracranial mass. Most recently, intracranial venous hypertension has been proposed as the cause of the symptoms, with calls for changing the nomenclature to ‘chronic intracranial venous hypertension syndrome’ (CIVHS).1
In recent years, venous sinus stenting (VSS) has emerged as a safe and effective alternative treatment for medically refractory patients who are candidates.2 In a recent meta-analysis, Nicholson et al report high levels of symptomatic improvement following VSS, specifically, 79.6% of patients reporting an improvement in headache following stenting, 90.3% reporting an improvement in tinnitus, and 93.7% reporting an improvement in papilledema. This meta-analysis also reported a treatment failure rate of 12.4% (need for repeat endovascular procedure or a subsequent cerebrospinal fluid (CSF) diversion procedure).3 Another meta-analysis of VSS reported a 14% rate of adjacent stenosis.4 These studies represent a collection of small retrospective series and harbor significant limitations. To date, the largest published series on VSS includes 88 patients, of which 57 had follow-up.5 Quantitative symptomatic outcomes were not provided.
In our practice, we have noted failure rates of VSS that far exceed the published literature, with a clear incidence of symptom recurrence several months following stenting. We sought to examine these phenomena in a large prospectively-maintained series of VSS patients.
Methods
A prospective, single-center, single-operator database of patients with IIH undergoing venous sinus stenting was retrospectively queried after obtaining institutional review board approval. Dates of inclusion were August 2016 through January 2020. Criteria for inclusion in the study were presentation with clinical symptoms of IIH without evidence of an intracranial mass lesion on imaging, a lumbar puncture opening pressure >20 cm H2O in the lateral decubitus position, and either medically-refractory symptoms or medication intolerance. All included patients underwent diagnostic catheter angiography and retrograde venography with venous manometry prior to venous sinus stenting. Non-invasive venous imaging was not considered in determining candidacy for venography and manometry.
A chart review of each patient was performed to identify demographic features (age, gender, and body mass index (BMI)), OP on LP, and the presence of CSF shunt at the time of the procedure. In all cases, OP was recorded in cm H2O. In cases where multiple LPs had been performed, the most recent value prior to VSS was used. Patients who underwent repeat LP following the stenting procedure had the OP on LP recorded as well as the time to repeat LP. Patients requiring need for further intervention (venography, venous sinus stenting, and/or CSF shunting) were recorded as well as the details of the intervention. Time to follow-up (defined as time from stenting procedure to most recent visit) for all patients was recorded.
Due to the diverse referral pattern at our institution, approximately two-thirds of patients received ophthalmologic care from unaffiliated community ophthalmologists, limiting access to the data. Where outside records were available for review, the presence of papilledema was recorded. In patients followed by neuro-ophthalmology at our institution, the Frisen scale was used to assess papilledema and was recorded.
Beginning in December 2017, questionnaires addressing symptom severity were administered to patients at all visits. These questionnaires included the Headache Impact Test-6 (HIT-6), the WHO Quality of Life-BREF (WHOQOL-BREF), and a four part questionnaire measuring pulsatile tinnitus which was designed by the authors (included in online supplementary materials).6 7 In brief, the pulsatile tinnitus score assesses the frequency and severity of tinnitus in both ears and represents a score from 0 (no tinnitus in either ear) to 16 (loud, constant tinnitus in both ears).
Supplemental material
Procedural details
Diagnostic cerebral arteriography, venography, and venous manometry were performed in all patients under mild conscious sedation using fentanyl only. In all patients, the femoral artery and vein were accessed and 5 French (5 F) sheaths were placed. A 5 F diagnostic catheter was used to perform a cerebral arteriogram to evaluate venous outflow pathways and rule out arteriovenous fistulae. Next, the 5 F diagnostic catheter was advanced into the dominant internal jugular vein. A Rebar-27 microcatheter (Medtronic; Minneapolis, MN) was then navigated over a 0.014 inch microwire into the superior sagittal sinus. A diagnostic cerebral venogram was then performed followed by serial venous manometry measurements in the superior sagittal sinus (SSS), torcula, transverse sinus (TS), transverse-sigmoid junction (TSJ), sigmoid sinus (SS), internal jugular vein (IJ), and central venous pressure (CVP) in the right atrium. In all cases, the venous manometry was performed in the dominant (or co-dominant) transverse-sigmoid-jugular pathway. In many cases, bilateral venous manometry was performed. All pressure measurements were obtained using standardized technique and standardized anatomical locations by a single operator; in all cases a single mean pressure was recorded in units of mmHg.
Venous sinus stenting was offered to patients with both the clinical diagnosis of IIH and a pathological trans-stenosis pressure gradient. Candidacy for stenting was determined based on the presence of a trans-stenosis pressure gradient of 8 mmHg, and in select cases stenting was offered to patients with pathological gradients of 4 to 7 mmHg in which stenting was felt to be of benefit.2 Prior to stent placement, all patients were started on 325 mg aspirin and 75 mg of clopidogrel daily for 1 week. Following general anesthesia with endotracheal intubation, femoral venous access was obtained. An 8 F sheath was placed in the femoral vein. Weight-based intravenous heparin was then administered. A 5 F Berenstein catheter was placed into a 0.070 inch Neuron catheter inside of a 0.088 inch Neuron Max guiding catheter (Penumbra; Alameda, CA) and navigated over a 0.038 inch wire into the IJ ipsilateral to the stenosis. Following this, pre-stenting diagnostic cerebral venography and manometry were performed from the SSS to the ipsilateral IJ with a Rebar-27 microcatheter, as described above. Then, venous stenting was performed using appropriate-sized open-cell Precise stents (Cordis; Milpitas, CA). Following stenting, the Rebar-27 microcatheter was advanced through the stents into the SSS and post-stenting venography and manometry was performed. For both pre- and post-stenting manometry, the guide catheters were positioned in the IJ to ensure there was no confounding from potential outflow obstruction from the guide catheters.
Practice management strategy
Care and treatment are provided by a care team led by a dual-trained neurosurgeon (KF) that performs venograms, venous sinus stenting procedures, lumbar punctures, and CSF shunt procedures. Following stenting, patients undergo a clinic evaluation at 2 weeks and 6 weeks. All patients maintain ongoing scheduled follow-up with their ophthalmologist.
Patients who have an improvement in symptoms at the 2 week visit are weaned off of medical therapies. Those who have a persistent improvement in symptoms at their 6 week visit are not scheduled for routine neuroendovascular follow-up, LP, or venography. This is done to avoid unnecessary procedures that will not change patient management. Clopidogrel is stopped after 12 weeks and aspirin 325 mg daily continued for 1 year.
Patients who have no improvement in symptoms at 6 weeks are continued on medical therapies and clopidogrel is stopped. An LP is then obtained after a week to evaluate both OP and clinical response to high volume CSF drainage. The decision to proceed with additional treatments, such as CSF shunting, is based on the degree of persistent OP elevation, the presence of temporary improvement in symptoms following CSF drainage, the presence of visual or ophthalmologic exam worsening, or the presence of severe symptoms (most commonly headache) that result in significant impairment of quality of life. The decision to proceed with repeat venography to evaluate for recurrent stenosis is based on the magnitude of the repeat OP (the presence of a gradient can be predicted based on OP),8 the mathematical possibility of the existence of a new pathologic gradient based on current OP in comparison to prior OP and SSS, CVP and trans-stenosis pressures, and patient preference in proceeding with recurrent endovascular treatment versus alternative medical or surgical options.
Patients with initial improvement following stenting but recurrent symptoms are encouraged to contact the clinic and scheduled for visits within a week. If symptoms are significant, an LP is obtained to measure OP and measure response to high volume CSF drainage. Given that most patients dislike LP and avoid these procedures unless necessary, the need for follow-up LP in our practice serves as a surrogate marker for treatment failure.
Patients with pre-stenting and 6 week post-stenting HIT-6, WHOQOL-BREF, and pulsatile tinnitus scores were contacted by telephone during March 2020. The HIT-6, WHOQOL-BREF and pulsatile tinnitus questionnaires were administered and scores recorded to obtain long-term follow-up data. Statistical comparison was performed with paired-sample two-tailed t-tests with a chosen α of 0.05.
Results
A total of 81 patients underwent venous sinus stenting for venous sinus stenosis with associated pressure gradient. The mean age (SEM) of these patients was 35.9 (1.3) years, and 90.1% were female. Mean BMI was 37.6 (0.9) kg/m2. Mean OP on LP was 33.6 (1.0) cm H2O. Of the 81 patients, 31 (38.3%) had ophthalmologic records of quantified papilledema prior to intervention. All patients underwent venous manometry while awake. All patients had a pathological pressure gradient across the transverse sinus with mean trans-stenosis pressure gradients of 18.1 mmHg (median 15, SEM 1.3, range 4–62 mmHg). Eleven patients (13.5%) with a gradient <8 mmHg underwent VSS. Of these 11 patients, eight had a gradient of 7 mmHg and three had a gradient <7 mmHg (4 mmHg in one patient, 5 mmHg in one patient, and 6 mmHg in one patient).
Based on the recent classification by Fargen for patients with IIH, 49.3% were type 1, 0% were type 2, 47.8% were type 3, and 2.9% were type 4.1 Categorization of 12 patients was not completed due to lack of recorded central venous pressure (CVP).
All procedures were performed successfully. The vast majority of patients (80; 98.8%) underwent stenting of the dominant TS. Two overlapping Cordis Precise stents were placed from immediately lateral to the torcula across the TS and into the sigmoid sinus in most patients (57; 70.4%). Only one stent was placed in a minority of patients (22; 27.2%). Three stents were placed in two patients (2.5%). The majority of patients (61; 75.3%) had size 8 mm stents placed, 14 (17.3%) had size 10 mm stents placed, and five (6.2%) had ≤6 mm diameter stents placed. Concomitant SSS stenting was performed in four patients (4.9%) due to additional stenosis and pressure gradients involving the S1 segment of the SSS (5, 6, 8, and 26 mmHg in the four cases, respectively).9
There were no instances (0%) of severe periprocedural complications (hemorrhage, stroke or permanent neurological disability). One patient (1.2%) developed intraprocedural thrombus formation on the stents necessitating the administration of local fibrinolytic with thrombus resolution and no further sequelae. No access site complications occurred necessitating transfusion or further treatment.
The mean time from stenting to final follow-up for all patients in the study was 10 months (median 6, SEM 1.0, range 0.5–38 months).
Recurrence or persistence of symptoms necessitating repeat LP
Of the 81 patients, 44 (54.3%) underwent LP following the initial stenting procedure due to persistent severe symptoms or delayed symptom recurrence (figure 1). An additional two (2.5%) patients returned to clinic with reported significant return of symptoms but refused to undergo repeat LP, for a total of 46 patients (56.9%) with symptom recurrence or persistence of symptoms considered of significant enough severity to warrant consideration of further treatment.
Of the 44 patients who had a post-stenting LP performed, 11 (25.0%; 13.5% of total) had no significant subjective improvement of symptoms following the VSS procedure, 24 (54.5%; 29.6% of total) reported initial improvement after VSS but delayed recurrence of symptoms, and nine (20.5%; 11.1% of total) patients reported mild improvement but still persistent symptoms. The mean time to follow-up LP was 12.4 months (median 7.2, range 2.2–43 months).
Table 1 shows the comparison of OP on LP pre- and post-stenting for the 44 patients with relapse or persistence of symptoms. Four patients did not have a recorded initial OP on LP and thus were excluded. Of the 40 patients who had both pre- and post-stenting follow-up LP performed, six (15.0%) had no significant change in OP on LP, and two (5.0%) had higher OP on LP. A total of 32 (80.0%) patients had a lower OP on LP, with the majority (27; 67.5%) having an OP decrease of at least 5 cm H2O after stenting. The mean difference in OP on LP was −9.1 cm H2O (median −9.5, range −36 to +4.5 cm H2O).
Post-stenting ophthalmologic data
Of the 28 patients with available pre- and post-intervention ophthalmology records for review, 17 had improvement in papilledema (61%), nine had no change in papilledema (32%), and two had worsened papilledema (7%). Twenty-two patients had both pre- and post-stenting Frisen grades available for review, all of which demonstrated stable or decreased Frisen grades. The average change in Frisen grade was a decrease of 1.2. The two patients with noted worsening papilledema did not have Frisen grades available for review.
Post-stenting venography
Of the 81 total patients, 18 (22.2%) had a second awake diagnostic venogram following the initial stenting procedure. Repeat venography was performed in these patients due to suspicion of recurrent stenosis based on repeat LP. Of the patients who underwent repeat venography, the mean difference in OP on LP was a decrease of 6.4 cm H2O (median 7.5, SEM 1.8, range −18 to +4.5 cm H2O). The mean (median) time to follow-up venogram was 7 months (5.4). Table 1 shows the comparison of SSS pressures pre- and post-stenting for the 18 patients who underwent repeat venography. The mean difference in SSS pressures between the initial venogram and the venogram post-stenting was 11.2 mmHg lower. Of the patients undergoing repeat venography, five (27.8%) were found to have de novo stenosis in the SSS rostral to the torcula (S1 segment), distant to the terminal ends of the stents in the transverse sinuses. The mean gradient across the new stenoses was 16.8 mmHg (range 8–24 mmHg).
Surgical intervention after stenting
Overall, a total of 21 (25.9%) patients underwent further surgical intervention following stenting. The mean time to further surgical intervention (including either second stent placement or CSF shunting) was 7.4 months (median 6.2, range 1.2–16.8 months). Only one of the 81 patients underwent surgical treatment for IIH by a different treating physician during the follow-up period.
Seven of the 21 patients (33.3%) had deterioration in vision or worsening papilledema that led to the second surgical intervention. The reason for further surgical intervention in the remaining 14 patients was headache with impairment of quality of life.
Of the 81 patients, five (6.2%) underwent a second stenting procedure with mean time to second stent procedure of 8.4 months (median 9.3, range 1.2–16.8 months). The second stents were all placed in the proximal SSS. Of the five patients, three (60%) had initial size 8 mm stents implanted and two (40%) had initial size 10 mm stents placed. Eighteen of 81 (22.2%) went on to have a CSF shunt placed, with mean time to shunt implantation of 7.1 months (median 5.7, range 1.2–16.4 months). Two patients required both a second stent and a CSF shunt following initial intervention. In both patients, repeat venography showed de novo SSS stenosis leading to placement of the second stent which eventually failed to adequately alleviate symptoms and thus a CSF shunt was placed.
Table 2 shows the comparison of patients who had recurrence or persistence of symptoms and those who required a surgical intervention post-stenting stratified by BMI, initial OP on LP, CVP, trans-stenosis pressure gradient, and number of implanted stents.
Quality of life and symptom severity questionnaires
Quality of life and symptom severity questionnaires were initiated in December 2017, providing data for the latter half of the cohort (46 patients). Mean length of follow-up was 26.6 weeks (6.1 months) with a median of 15 weeks (3.5 months) and range of 4–104 weeks.
Mean (SD) WHOQOL-BREF baseline (pre-stenting) domain scores were as follows: physical 11.6 (3.9), psychological 13.3 (3.5), social relationships 14.9 (3.5), and environment 15.2 (2.6). Figure 2 demonstrates changes in quality of life and HIT-6 headache scores from pre-stenting to last clinical follow-up. At initial consultation pre-stenting, 47% and 13% of patients had composite WHOQOL-BREF scores less than 60 and 40, respectively. At last follow-up, 25% and 0% of patients had WHOQOL-BREF composite scores less than 60 and 40, respectively. At initial consultation, 30% and 70% of patients had HIT-6 composite scores greater than 70 and 60, respectively. At last follow-up, 6% and 50% of patients had composite HIT-6 scores greater than 70 and 60, respectively. Figure 3 demonstrates descriptive analysis of composite pulsatile tinnitus scores.
Paired sample t-test demonstrated a significant decrease in HIT-6 scores from baseline to last follow-up (p=0.03). There was no significant difference between WHOQOL-BREF scores from baseline to last follow-up (p=0.18) or in pulsatile tinnitus scores from baseline to last follow-up (p=0.11).
Discussion
The present study was designed to report on long-term outcomes following VSS for IIH and is one of the largest series to date with 81 patients. Among this patient population, rates of recurrence or persistence of symptoms and need for retreatment following VSS were higher than that which has previously been reported. Over half of the patients underwent a repeat LP due to persistence or recurrence of symptoms severe enough to warrant evaluation for additional surgical intervention, and over one-quarter (26%) of patients underwent an additional treatment, including second stent placement or CSF shunting. Nearly 30% of patients had initial symptomatic improvement but then relapsed at a median of 7 months after VSS. Interestingly, in patients with recurrence or persistence of symptoms after VSS, measured OP and SSS pressures remained lower in the majority of patients with concomitant improvement in subjective quality of life and headache scores.
A recent meta-analysis by Nicholson and colleagues reported high levels of symptomatic improvement following VSS with 79.6% of patients reporting improvement in headache, 90.3% improvement in tinnitus, and 93.7% improvement in papilledema. The authors also reported a rate of recurrence of symptoms following VSS that required further intervention at 12.4%.3 Other meta-analyses or systematic reviews have reported similar retreatment rates with excellent symptomatic control. For instance, Satti et al reported a 10.3% repeat procedure rate, Starke et al reported a 6% repeat VSS rate, and Nicholson et al reported a 9.3% repeat procedure rate (table 3).3 10 11 Saber et al reported a 14% rate of recurrent stenosis and Starke et al reported an 11.4% rate of recurrent stenosis with 6% of patients undergoing repeat stenting procedures.10 11 The largest series thus far by Liu et al did not report on whether any of the 88 patients required further treatment.5 In comparison, our study found a much higher rate of need for repeat procedure at 26%. Interestingly, a small series by El Mekabaty et al reported a very similar rate of 26% symptomatic recurrence requiring revision.12
Unfortunately, the published literature on outcomes following VSS is probably inaccurate. Nearly all published series forming the substrate for these meta-analyses are small retrospective series with variable follow-up and the symptomatic improvement rates may overestimate durable cure. IIH patients are a notoriously challenging patient population due to associated morbid obesity, chronic pain medication use, associated depression or fibromyalgia, and need for frequent surgical retreatments. The average 10% retreatment rate reported in the literature should be cautiously interpreted. As seen in this series, recurrent symptoms may occur in a delayed fashion, around 7–12 months, whereas most published series have relatively short follow-up. Also, patients often seek second opinions or treatment elsewhere. If VSS is performed by neurointerventionalists who do not perform CSF shunting for IIH, these patients may be unknowingly referred elsewhere for ongoing or recurrent symptoms. As the senior author performs both VSS and CSF shunting with close patient-centric follow-up, this series has a low attrition rate. This is further evidenced by the fact that only one of the 81 patients (1%) underwent surgical treatment by a different physician after VSS. The present series therefore probably represents a more realistic symptomatic improvement rate and need for surgical retreatment after VSS.
Initial, immediate symptomatic improvement after VSS with progressive symptom recurrence approximately 6 months after stenting is commonly identified anecdotally in clinical practice but has never been reported in the published literature. In this series, 30% of patients reported immediate symptomatic improvement but subsequently developed recurrent, severe headaches that led to a repeat LP at a median of 7 months after VSS. In a minority of cases, patients with relapse are found to have OP similar to pre-stenting, indicating that VSS has had a negligible effect on intracranial pressures. Interestingly, the majority of patients who relapsed and underwent LP had lower OP compared with pre-stenting (on average 8 cm H20 lower), despite increasing symptom severity as measured by increasing HIT-6 scores from 6 weeks to last follow-up. We hypothesize that this observation may be explained by a “re-equilibration” phenomenon in which patients initially report marked symptomatic improvement following stenting due to an immediate reduction in intracranial pressures, though this lower value may still be abnormally high. Over the ensuing months, patients may “re-equilibrate” to the new pressure, followed by development of recurrent, progressive symptoms of intracranial hypertension. Eventually, patients again report severe symptoms but OP on LP is usually less than pre-stenting. Interestingly, this phenomenon has been noted by the senior author anecdotally after CSF shunting as well, but similarly has not been reported in the published literature.
This is the first study to use validated quality of life and headache scores in patients undergoing VSS. There are several important observations. In this sample, mean and median HIT-6 scores prior to stenting are higher than those reported for patients with chronic migraine, episodic migraine, or other headache conditions.13 14 As would be expected of IIH patients with medically refractory symptoms, these patients also have higher HIT-6 baseline scores than medically untreated patients in the IIH Treatment Trial, (62.7 compared with 59.7).15 16 In addition, baseline pre-stenting WHOQOL-BREF physical domain scores for IIH patients are lower than those for the general population (15.5 vs 11.6), and in patients with chronic medical conditions, such as multiple sclerosis (13.2) and sickle cell disease (14.0).17–19 These findings formally document the suffering of medically-refractory IIH patients and support the use of surgical therapies in this patient population, especially when the risk of bleeding or symptomatic neurological complication with VSS is rare (0% in this series). Second, changes in HIT-6 and WHOQOL-BREF scores after stenting probably represent real and significant symptomatic improvement. HIT-6 improved significantly from baseline by almost seven points on average at last follow-up; similarly, WHOQOL-BREF scores were 10 points higher at last follow-up. One study demonstrated that significant headache improvement was represented by a change of only 2.5 points on the HIT-6 score.20 Similarly, only minor changes in WHOQOL-BREF scores may represent significant improvement in quality of life.21 The improvements seen in subjective symptoms as noted by these questionnaires indicate that VSS is efficacious in reducing headache symptoms and improving overall life quality. Third, while the pulsatile tinnitus grading scale used in this sample has not been validated, observed reductions in the severity of pulsatile tinnitus mimicked that of headache in this patient population. Other series have reported resolution of tinnitus in an overwhelming majority of patients after VSS.22 Differences in tinnitus resolution may be secondary to variability in follow-up as well as the way tinnitus is categorized, scored and reported. The current study suggests that VSS may still be effective in reducing the severity of tinnitus in IIH patients with associated venous sinus stenosis, but clearly demonstrates that in the overwhelming majority pulsatile tinnitus is not cured by stenting.
Many practitioners primarily use objective outcomes, such as visual deterioration or papilledema, as the primary indication for surgical IIH treatment or as criteria for defining treatment failure. This may underestimate the importance of the full spectrum of IIH symptoms, such as headache, on quality of life. In this series, only seven of the 81 patients (9%) underwent repeat VSS or CSF shunting due to worsening visual impairment or worsening ophthalmologic exam after stenting. This fact may explain the discrepancy between the 26% retreatment rate in this series compared with 6–12% in the previously cited meta-analyses. We argue that a more patient-centric approach that takes not only objective visual criteria into consideration but also subjective quality of life measures (which impact the ability to maintain employment, complete schooling, and/or sustain relationships) may be the most humane and appropriate way to make important treatment decisions in this population. Routine use of validated headache and quality of life scores in the future may provide a quantifiable method of determining candidacy for further treatment.
This study has some important limitations. The patients represent a single-center, single provider practice and therefore patients and referral patterns may not be generalizable to centers elsewhere. Indications for CSF shunting may differ at other centers. Concurrent use of acetazolamide, topiramate, furosemide or other medications in this patient population are routine, especially when symptoms worsen, but due to variations in doses and starting or cessation of treatment, the role of these agents in symptom recurrence could not be considered. In treating patients based on subjective symptomatic worsening, there is the possibility that persistent or refractory headaches may be secondary to concomitant, alternative headache conditions. Early in the study, questionnaires regarding symptoms and quality of life were not administered. The method of evaluating pulsatile tinnitus was an unvalidated measurement tool and thus is not easily comparable to results from other studies. Patients were not scheduled for follow-up after the 6 week postoperative visit and thus all follow-up visits after that time were initiated by the patient; therefore, long-term data were not available in a small number of patients who could not be contacted by phone. Additionally, objective ophthalmologic data were not available for most patients and thus an important parameter in surgical decision-making was unable to be included in this manuscript. Finally, while this study is one of the largest series to date, the sample size precludes adequate statistical regression analysis of risk factors for treatment failure given the large number of potentially important interacting or confounding variables.
Conclusions
VSS stenting is an effective treatment for venous sinus stenosis in IIH; however, this study found higher rates of symptomatic recurrence and need for further surgical intervention than has previously been reported in the literature. Recurrence of symptoms occurred in roughly one-third of patients at a median of 7 months, even though OP remained lower at follow-up LP, suggestive of a re-equilibration phenomenon. More comprehensive quality of life measures and long-term follow-up are needed to better assess the full burden of disease and treatment success for IIH.
References
Footnotes
Contributors Concept design: KMF. Data collection: RMG, JBA. Data review: RMG, KMF. Manuscript composition: RMG, KMF, SQW. Final approval of article: All authors.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval This study involved human participants and was approved by the Wake Forest University Institutional Review Boards, IRB00061472.
Provenance and peer review Not commissioned; externally peer reviewed.