Reduction of cerebrospinal fluid rhinorrhea after vestibular schwannoma surgery by reconstruction of the drilled porus acusticus with hydroxyapatite bone cement.

OBJECT: Cerebrospinal fluid (CSF) rhinorrhea remains a significant cause of morbidity after resection of vestibular schwannomas (VSs), with rates of rhinorrhea after this procedure reported to range between 0 and 27%. The authors investigated whether reconstruction of the drilled posterior wall of the porus acusticus with hydroxyapatite cement (HAC) would decrease the incidence of postoperative CSF rhinorrhea. METHODS: A prospective observational study of 130 consecutive patients who underwent surgery for reconstruction of the posterior wall of the drilled porus acusticus with HAC was conducted between October 2002 and September 2005. All patients underwent a retrosigmoid transmeatal approach for VS resection and were followed up to document cases of CSF rhinorrhea, incisional CSF leak, meningitis, or rhinorrhea-associated meningitis. A cohort of 150 patients with VSs who were treated with the same surgical approach but without HAC reconstruction served as a control group. RESULTS: The authors found that HAC reconstruction of the porus acusticus wall significantly reduced the rate of postoperative CSF rhinorrhea in their patients. In the patients treated with HAC, rhinorrhea developed in only three patients (2.3%) compared with 18 patients (12%) in the control group. This was a statistically significant finding (p = 0.002, odds ratio = 5.8). CONCLUSIONS: The use of HAC in the reconstruction of the drilled posterior wall of the porus acusticus, occluding exposed air cells, greatly reduces the risk of CSF rhinorrhea.

A Pivotal Randomized Clinical Trial Evaluating the Safety and Effectiveness of a Novel Hydrogel Dural Sealant as an Adjunct to Dural Repair.

BACKGROUND: A watertight dural repair is critical to minimizing the risk of postoperative complications secondary to cerebrospinal fluid (CSF) leaks. OBJECTIVE: To evaluate the safety and efficacy of a novel hydrogel, Adherus Dural Sealant, when compared with control, DuraSeal Dural Sealant System, as an adjunct to standard methods of dural repair. METHODS: In this 17-center, prospective, randomized clinical trial designed as a noninferiority, single-blinded study, 124 patients received Adherus Dural Sealant (test sealant) and 126 received DuraSeal (control). The primary composite endpoint was the proportion of patients who were free of any intraoperative CSF leakage during Valsalva maneuver after dural repair, CSF leak/pseudomeningocele, and unplanned retreatment of the surgical site. Each component was then analyzed individually as a secondary endpoint. Patients were followed for 4 mo after surgery. RESULTS: The primary composite endpoint at the 120-d follow-up was achieved in 91.2% of the test sealant group compared with 90.6% of the control, thus showing that the test sealant was statistically significantly noninferior to DuraSeal ( P = .0049). Post hoc analysis of the primary composite endpoint at 14 d demonstrated superiority of the test sealant over the control ( P = .030). Primary endpoint failures in the control group tended to occur early in follow-up period, while a majority of test dural sealant failures were identified through protocol-required radiographic imaging at the 120-d follow-up visit. CONCLUSION: The test sealant, Adherus Dural Sealant, is a practical, safe, and effective adjunct to achieving a watertight dural closure after primary dural closure in cranial procedures.

Radiographic and anatomic basis of endoscopic anterior craniocervical decompression: a comparison of endonasal, transoral, and transcervical approaches.

OBJECTIVE: To evaluate surgical access to the craniocervical junction using 3 endoscopic approaches: endonasal, transoral, and transcervical. METHODS: Nine cadaveric specimens were used. Image guidance was used in 1 specimen for each approach; fluoroscopy was used in every case. The Vitrea imaging station (Vital Images Inc., Minnetonka, MN) was used to evaluate the angles and distances to the target of the approach, centered on the tip of the odontoid. The entry site was defined as: 1) the endonasal approach (inferior midline of the nasal bone), 2) the transoral approach (the tip of the upper incisor), and 3) the transcervical approach (the skin at the C4-C5 level). RESULTS: Adequate lower clivus and craniocervical decompression was achieved using the endonasal and transoral approaches. Lower clivus decompression was not achieved with the transcervical approach. The average distance to the surgical target was as follows: endonasal (94 mm), transoral (102 mm), and transcervical (100 mm). The angle of attack was as follows: endonasal (28 degrees), transoral (30 degrees), and transcervical (15 degrees). The working area at the base of the field was as follows: endonasal (1305 mm2), transoral (1406 mm2), and transcervical (743 mm2). CONCLUSION: The endonasal and transoral approaches allow wide exposure with large working angles to the craniocervical junction. The transcervical approach accesses the odontoid for resection from the body of C2 to the lip of the basion. The angles of attack in the transcervical approach when centered on the surgical target are limited, but this approach offers a clean, sterile operative field. Clinical investigation will be required to determine the optimal indications for each approach.

Inaccuracy of the administrative database: comparative analysis of two databases for the diagnosis and treatment of intracranial aneurysms.

OBJECTIVE: Administrative databases of hospital admissions are increasingly being used, mostly without validation, for epidemiological and clinical outcomes studies. Although it has been difficult to assess the true accuracy of administrative databases, we have identified an opportunity to directly compare the State of Maryland administrative database against a prospectively maintained departmental database at The Johns Hopkins Hospital. METHODS: Data for patients with the diagnosis of an intracranial aneurysm treated at The Johns Hopkins Hospital over a 17-year period were compared in the State of Maryland administrative database and the neurosurgery departmental database. Discrepancies were clarified by review of the original medical records. The sensitivity, specificity, and positive predictive value of each database were calculated. RESULTS: The administrative database missed 16% of all cases and was significantly inaccurate in 10 of 12 categories. It had particularly low values in the specificity regarding surgical treatment (67%), the sensitivity regarding endovascular treatment (48%), and the positive predictive value regarding endovascular treatment (30%). By contrast, the lowest score of the departmental database in any category was 97%. CONCLUSION: We show that this representative administrative database is significantly flawed. Given the exponentially increasing number of research studies based on administrative databases, the pitfalls of research based solely on these need to be recognized. Strong criteria requiring accurate data validation are critical to justify the conclusions of these studies, regardless of their large numbers and complex statistics.

Polyethylene glycol hydrogel dural sealant may reduce incisional cerebrospinal fluid leak after posterior fossa surgery.

OBJECTIVE: Incisional cerebrospinal fluid (CSF) leak remains a significant cause of morbidity, particularly after posterior fossa surgery, with ranges between 4 and 17% in most series. We aimed to determine whether the use of a new polyethylene glycol (PEG) dural sealant product (DuraSeal; Confluent Surgical, Waltham, MA) is effective at preventing incisional CSF leak after posterior fossa surgery. METHODS: One hundred cases of posterior fossa surgery with the PEG dural sealant applied at the time of dural closure were prospectively observed from May 2005 to April 2006. All patients underwent posterior fossa craniotomy or craniectomy. Clinical histories were followed to document cases of incisional CSF leak, pseudomeningocele, meningitis, wound infection, and interventions required to treat a CSF leak or pseudomeningocele. A retrospective cohort of 100 patients treated in a similar fashion but with fibrin glue augmented dural closure served as controls. RESULTS: In the PEG group, two of 100 (2%) patients developed an incisional CSF leak postoperatively. By comparison, 10 of 100 (10%) patients in whom fibrin glue was used developed an incisional CSF leak. This difference was statistically significant, with a P value of 0.03. There were no significant differences in the rates of pseudomeningocele, meningitis, or other postoperative interventions. CONCLUSION: The application of PEG dural sealant to the closed dural edges may be effective at reducing incisional CSF leak after posterior fossa surgery.