Essentials in intraoperative indocyanine green videoangiography assessment for intracranial aneurysm surgery: conclusions from 295 consecutively clipped aneurysms and review of the literature.

OBJECT: Indocyanine green (ICG) videoangiography (VA) in cerebral aneurysm surgery allows confirmation of blood flow in parent, branching, and perforating vessels as well as assessment of remnant aneurysm parts after clip application. A retrospective analysis and review of the literature were conducted to determine the current essential advantages of ICG-VA in aneurysm surgery. METHODS: The authors retrospectively evaluated all aneurysm cases treated with the aid of intraoperative ICG-VA at a single institution between 2007 and 2013. They also analyzed the literature published since the initial description of ICG-VA in 2003. RESULTS: Two hundred forty-six procedures were performed in 232 patients harboring 295 aneurysms. The patients, whose mean age was 54 years, consisted of 159 women and 73 men. One hundred twenty-four surgeries were performed after subarachnoid hemorrhage, and 122 were performed for incidental aneurysms. Single aneurysms were clipped in 185 patients, and multiple aneurysms were clipped in 47 (mean aneurysm diameter 6.9 mm, range 2-40 mm). No complications associated with ICG-VA occurred. Intraoperative microvascular Doppler ultrasonography was performed before ICG-VA in all patients, and postoperative digital subtraction angiography (DSA) studies were available in 121 patients (52.2%) for retrospective comparative analysis. In 22 (9%) of 246 procedures, the clip position was modified intraoperatively as a consequence of ICG-VA. Stenosis of the parent vessels (16 procedures) or occlusion of the perforators (6 procedures), not detected by micro-Doppler ultrasonography, were the most common problems demonstrated on ICG-VA. In another 11 procedures (4.5%), residual perfusion of the aneurysm was observed and one or more additional clips were applied. Vessel stenosis or a compromised perforating artery occurred independent of aneurysm location and was about equally common in middle cerebral artery and anterior communicating artery aneurysms. In 2 procedures (0.8%), aneurysm puncture revealed residual blood flow within the lesion, which had not been detected by the ICG-VA. In the postoperative DSA studies, unexpected small (< 2 mm) aneurysm neck remnants, which had not been detected on intraoperative ICG-VA, were found in 11 (9.1%) of 121 patients. However, these remnants remained without consequence except in 1 patient with a 6-mm residual aneurysm dome, which was subsequently embolized with coils. CONCLUSIONS: In a large cohort of consecutive patients, ICG-VA proved to be a helpful intraoperative tool and led to a significant intraoperative clip modification rate of 15%. However, small, < 2-mm-wide neck remnants and a 6-mm residual aneurysm were missed by intraoperative ICG-VA in up to 10% of patients. Results in this study confirm that DSA is indispensable for postoperative quality assessment in complex aneurysm surgery.

Computerized occlusion rating of embolized ruptured intracranial aneurysms: relation to intra- and postinterventional aneurysm rehemorrhage.

Endovascular coil occlusion of ruptured cerebral aneurysms has a higher rate of rebleeding compared to surgical clipping. Initial aneurysm coil occlusion rate (OR) is the strongest available predictor of aneurysm rebleeding. Standard clinical subjective occlusion rating (SOR) is limited by subjective bias. Therefore, computerized occlusion rating (COR) was introduced. Its superiority was established for experimental and human aneurysms. In the present clinical study, we aimed to evaluate COR as a risk factor for postprocedural reruptures (PPRs) and intraprocedural reruptures (IPRs). In our series of 249 consecutive patients treated in our institution, we observed 7 (2.8%) cases with IPR and 7 (2.8%) cases with PPR. These patients were analyzed in the present study. Mean COR value was 85% (range 71-96%). In 12 (85.7%) cases, COR was lower than SOR. In aneurysms with a COR of 95% or higher, no PPR occurred. All patients with IPR harbored multiple aneurysms. In -conclusion, our data showed a distinct tendency of potentially dangerous overestimations when using SOR compared to the objectively measured COR values. IPR was always associated with multiple aneurysms.

Clipping of unruptured cerebral aneurysms : Are older patients at higher risk?

BACKGROUND: The incidence of aneurysms is steadily increasing in older patients due to the aging population. This study compared radiological parameters as well as clinical outcomes between patients younger than 65 years and those over 65 years of age, with special respect to individual treatment options. METHODS: Retrospective data were obtained for patients with cerebral aneurysms at a single academic institution within a 7-year period. Data reviewed included admission protocols, patient charts, operating reports as well as outpatient clinic charts. Aneurysmal characteristics as well as surgical outcome were compared between older patients, defined as patients older than 65 years of age, and a control group of patients younger than 65 years of age. To evaluate and compare individual clinical characteristics various scores including the Hunt and Hess score, the Fisher score, and the Glasgow outcome scale were used. RESULTS: A total of 347 patients were included in the final analysis. The control group included 290 patients, while 57 patients were in the older patient group. Neither the Hunt and Hess scores nor Fisher scores were significantly correlated to patient age. The Glasgow outcome scale was significantly lower in the older group after clipping of ruptured aneurysms (p < 0.000) but not significantly different after clipping of unruptured aneurysms (p = 0.793). CONCLUSION: Postoperative Glasgow outcome scale scores were not significantly different after clipping of unruptured cerebral aneurysms approximately 1 cm in diameter in older patients compared to the younger age group. Therefore, clipping of unruptured cerebral aneurysms may also be a valuable treatment option for older patients.

Risk Factors for Dropping Out of Neurosurgical Residency Programs-A Survey Study.

BACKGROUND: Resident education has to adapt to a changing health care environment. Although aspects such as working hours and attrition rates have been studied in detail, data about the residents' perspective, especially in European countries, are underrepresented in the scientific literature. The aim of this study was to assess and report aspects of neurosurgical education in German-speaking countries and to identify risk factors for quitting or changing the neurosurgical residency program. METHODS: We conducted a nonanonymous online survey among neurosurgical residents in Germany, Austria, and Switzerland. Log-binomial regression models were calculated to further assess risk factors. RESULTS: Of 201 residents who responded to the survey, 37.3% (n = 75) dropped out of neurosurgical training programs, including 20 residents (10%) who ultimately quit neurosurgery and changed to another specialty. Only female gender (relative risk, 2.97; 95% confidence interval, 1.3-6.78) and starting residency in a city one studied or grew up in (2.38; 1.01-5.62) were significant risk factors. Residents who had close supervision at work (0.39; 0.17-0.89), who observed the residency program for >3 days before applying (0.54; 0.31-0.95), who had well-defined guidelines within the program (0.57; 0.35-0.92), and who were working in a university hospital (0.41; 0.26-0.64) were significantly less likely to quit or change their program. CONCLUSIONS: The high attrition rate, especially among female residents, in Germany, Austria, and Switzerland should encourage program directors to specifically address the issues reported by this survey during interviews and to further improve their residency program accordingly.

Improved Postoperative Facial Nerve and Hearing Function in Retrosigmoid Vestibular Schwannoma Surgery Significantly Associated with Semisitting Position.

OBJECTIVE: The pros and cons of semisitting positioning (SSP) versus lateral, horizontal positioning (LP) during retrosigmoid vestibular schwannoma (VS) surgery, especially concerning postoperative cranial nerve and brain stem preservation, are under continuous discussion. METHODS: In a single-center retrospective cohort study, 30 VSs operated on in SSP compared with 30 operated on in LP with comparable demography were analyzed. During SSP surgery, transesophageal echocardiographic monitoring for venous air embolism was used continuously. Electrophysiologic cranial nerve monitoring was used in both groups. RESULTS: Length of surgery was significantly different between both groups: 183 minutes mean in SSP surgery versus 365 minutes mean in LP surgery (P = 0.0001). Postoperative rates of facial palsy and hearing loss were also significantly different. Six months postoperatively, 63% had normal facial nerve function after SSP surgery, whereas in LP surgery, 40% had no facial palsy (P = 0.02). Hearing preservation rate was also significantly different: 44% in SSP surgery compared with 14% in LP surgery who had preserved hearing (P = 0.006). Because of cerebrospinal fluid leaks, there were 3 operative revisions in the LP group (10%) and 1 (3.3%) in the SSP group. A clinically insignificant venous air embolism rate was found in 3.3% of patients (1/30) during SSP surgery. The neurologic outcome after 6 months was 1.2 on the Rankin Scale in the LP group and 1.0 in the SSP group, with zero mortality. CONCLUSIONS: SSP compared with LP surgery was associated with significantly shorter operation time and better facial and cochlear nerve function in VS surgery postoperatively, without differences in complication rates.