Faculty Bibliography

OBJECTIVE: Postoperative drawings of aneurysms serve as visual records and teaching tools for neurosurgeons and reinforce 3D vascular configurations that are specific for different cerebral aneurysms. This report brings this time-honored tradition back into focus in the digital era, and examines our experience with this technique, particularly in respect to the training of neurosurgical residents. METHODS: After craniotomy for aneurysm, a formal postoperative drawing was created and reviewed. Microsurgical issues graphically highlighted included the totality of aneurysmal dome anatomy, position of visible and hidden branch vessels, rupture points, clipping techniques, and location of adjacent cranial nerves. Drawings were cataloged and categorized according to location. RESULTS: Six hundred and nineteen drawings (ACA 221, MCA 154, ICA 214, Posterior Circulation 30) were created over a 28-year period, during a continuous series of 1,480 microsurgically treated aneurysms. Postoperative drawings in each location are presented and reviewed. Drawings demonstrated site-specific microsurgical approaches, morphologies, and points of obscuration and rupture. CONCLUSION: Creation and review of postoperative drawings are important adjuncts for the development of 3D understanding of aneurysmal anatomy. This classic art has impact in the digital age and allows patterns of morphology, projection and anatomy to be reinforced. Surgical atlases are created that function as reference and teaching tools. The creation of postoperative drawings should be a routine part of the training and methodology of vascular neurosurgeons.

Proximally located posterior communicating artery (PCoA) aneurysms, projecting postero-laterally in proximity to the tentorium, may pose a technical challenge for microsurgical clipping due to obscuration of the proximal aneurysmal neck by the anterior petroclinoid fold. We describe an efficacious technique utilizing fenestration of the anterior petroclinoid fold to facilitate visualization and clipping of PCoA aneurysms abutting this aspect of the tentorium. Of 86 cases of PCoA aneurysms treated between 2003 and 2013, the technique was used in nine (10.5 %) patients to allow for adequate clipping. A 3 mm fenestration in the anterior petroclinoid ligament is created adjacent and lateral to the anterior clinoid process. This fenestration is then widened into a small wedge corridor by bipolar coagulation. In all cases, the proximal aneurysm neck was visualized after the wedge fenestration. Additionally, an adequate corridor for placement of the proximal clip blade was uniformly established. All cases were adequately clipped, with complete occlusion of the aneurysm neck and fundus with preservation of the PCoA. There were two intraoperative ruptures not related to creation of the wedge fenestration. One patient experienced post-operative partial third nerve palsy, which resolved during follow-up. We describe a technique of fenestration of the anterior petroclinoid fold to establish a critical and safe corridor for both visualization and clipping of PCoA aneurysms.

BACKGROUND: Aneurysms located at the proximal posterior inferior cerebellar artery (PICA) may need to be addressed by trapping and concomitant bypass. An anastomosis of the Occipital Artery (OA) to PICA is one bypass option in these cases. This bypass is highly challenging and its technical description is seldom cited in the literature. METHODS: We describe the technical nuances of an OA-PICA end-to-side bypass in a 63-year-old man with a dissecting ruptured aneurysm of the third segment (tonsilomedullary) of the PICA. CONCLUSION: OA-PICA bypass option should remain as a treatment modality in the armamentarium of neurovascular surgeons.

BACKGROUND:: Internal maxillary artery (IMax) to middle cerebral artery (MCA) bypass has been recently described as an alternative to cervical EC-IC bypass. This technique utilizes a "key hole" craniectomy in the temporal fossa that requires a technically challenging end-to-side anastomosis. OBJECTIVE:: To describe a lateral subtemporal craniectomy of the middle cranial fossa floor to facilitate wide exposure of the IMax to facilitate bypass. METHODS:: Orbito-Zygomatic osteotomy is used followed by fronto-temporal craniotomy and subsequently lateral temporal fossa craniectomy, reaching its medial border at a virtual line connecting the foramen rotundum and foramen ovale. The IMax was identified by using established anatomical landmarks, neuronavigation and microdoppler. Additionally, we studied the approach in a cadaveric specimen in preparation for microsurgical bypass. RESULTS:: There were four cases in which the technique was utilized. One bypass was performed for flow augmentation in a hypo-perfused hemisphere. The other three were performed as part of treatment paradigms for giant MCA aneurysms. Vein grafts were used in all patients. The proximal anastomosis was performed in an end-to-side fashion in one patient, and end-to-end in three patients. Intraoperative graft flow measured with the Transonic flow probe ranged from 20-60 cc/min. Postoperative angiography demonstrated good filling of the graft with robust distal flow in all cases. All patients tolerated the procedure well. CONCLUSION:: IMax to MCA subcranial to intracranial (SC-IC) bypass is safe and efficacious. The lateral temporal fossa craniectomy technique resulted in reiable identification and wide exposure of the IMax, facilitating the proximal anastomosis.

Complete tumor resection with preservation or improvement of visual function is the goal of tuberculum sellae meningioma (TSM) treatment. The authors retrospectively reviewed 51 patients treated surgically for TSM between 2003 and 2010, with special attention to surgical technique, visual outcomes, and prognostic factors for treatment outcome. All patients were operated via the lateral subfrontal approach. The cohort mean age and Karnofsky performance status (KPS) on admission was 57.1 ± 13.6 and 84.3 ± 11.7, respectively. The most common presenting sign was visual impairment. The mean tumor size was 29.4 ± 10.7 mm. In 45 of the patients (88.2%), gross total resection was achieved. Improvement and/or preservation of visual acuity and visual field were achieved in 95.9% and 85.3%, respectively. Visual functions on admission were found to be the strongest predictors for postoperative improvement in visual outcome, followed by better KPS on admission, smaller tumor size, and young age. Postoperative neurological complications included cerebrospinal fluid (CSF) leak, meningitis, and postoperative seizures. TSM can be safely operated on through the lateral subfrontal approach. A high percentage of complete tumor resection and excellent visual outcomes are achieved using this technique. Surgical treatment in the early stage of the disease may result in a better visual outcome.

BACKGROUND: Awake craniotomy (AC) for removal of intra-axial brain tumors is a well-established procedure. However, the occurrence and consequences of intraoperative seizures during AC have not been well characterized. OBJECTIVE: To analyze the incidence, risk factors, and consequences of seizures during AC. METHODS: The database of AC at Tel Aviv Medical Center between 2003 to 2011 was reviewed. Occurrences of intraoperative seizures were analyzed with respect to medical history, medications, tumor characteristics, and postoperative outcome. RESULTS: Of the 549 ACs performed during the index period, 477 with complete records were identified. Sixty patients (12.6%) experienced intraoperative seizures. The AC procedure failed in 11 patients (2.3%) due to seizures. Patients with intraoperative seizures were significantly younger than nonseizing patients (45 +/- 14 years vs 52 +/- 16 years, P = .003), had a higher incidence of frontal lobe involvement (86% vs % 57%, P < .0001), and had higher prevalence of a history of seizures (P = .008). Short-term motor deterioration developed postoperatively in a higher percentage of patients with intraoperative seizures (20% vs 10.1%, P = .02) with a longer hospitalization period (4.0 +/- 3.0 days vs 3.0 +/- 3.0 days, P = .045). CONCLUSION: Although in most cases intraoperative seizures will not result in AC failure, the surgical team should be prepared to treat them promptly to avoid intractable seizures. Intraoperative seizures are more common in younger patients with a tumor in the frontal lobe and those with a history of seizures. Moreover, they are associated with a higher incidence of transient postoperative motor deterioration and protracted length of hospital stay.

BACKGROUND: Awake-craniotomy allows maximal tumor resection, which has been associated with extended survival. The feasibility and safety of awake-craniotomy and the effect of extent of resection on survival in the elderly population has not been established. The aim of this study was to compare surgical outcome of elderly patients undergoing awake-craniotomy to that of younger patients. METHODS: Outcomes of consecutive patients younger and older than 65 years who underwent awake-craniotomy at a single institution between 2003 and 2010 were retrospectively reviewed. The groups were compared for clinical variables and surgical outcome parameters, as well as overall survival. RESULTS: A total of 334 young (45.4 +/- 13.2 years, mean +/- SD) and 90 elderly (71.7 +/- 5.1 years) patients were studied. Distribution of gender, mannitol treatment, hemodynamic stability, and extent of tumor resection were similar. Significantly more younger patients had a better preoperative Karnofsky Performance Scale score (>70) than elderly patients (P = 0.0012). Older patients harbored significantly more high-grade gliomas (HGG) and brain metastases, and fewer low-grade gliomas (P < 0.0001). No significantly higher rate of mortality, or complications were observed in the elderly group. Age was associated with increased length of stay (4.9 +/- 6.3 vs. 6.6 +/- 7.5 days, P = 0.01). Maximal extent of tumor resection in patients with HGG was associated with prolonged survival in the elderly patients. CONCLUSIONS: Awake-craniotomy is a well-tolerated and safe procedure, even in elderly patients. Gross total tumor resection in elderly patients with HGG was associated with prolonged survival. The data suggest that favorable prognostic factors for patients with malignant brain tumors are also valid in elderly patients.

OBJECT: Awake craniotomy for removal of intraaxial tumors within or adjacent to eloquent brain regions is a well-established procedure. However, awake craniotomy failures have not been well characterized. In the present study, the authors aimed to analyze and assess the incidence and causes for failed awake craniotomy. METHODS: The database of awake craniotomies performed at Tel Aviv Medical Center between 2003 and 2010 was reviewed. Awake craniotomy was considered a failure if conversion to general anesthesia was required, or if adequate mapping or monitoring could not have been achieved. RESULTS: Of 488 patients undergoing awake craniotomy, 424 were identified as having complete medical, operative, and anesthesiology records. The awake craniotomies performed in 27 (6.4%) of these 424 patients were considered failures. The main causes of failure were lack of intraoperative communication with the patient (n = 18 [4.2%]) and/or intraoperative seizures (n = 9 [2.1%]). Preoperative mixed dysphasia (p < 0.001) and treatment with phenytoin (p = 0.0019) were related to failure due to lack of communication. History of seizures (p = 0.03) and treatment with multiple antiepileptic drugs (p = 0.0012) were found to be related to failure due to intraoperative seizures. Compared with the successful awake craniotomy group, a significantly lower rate of gross-total resection was achieved (83% vs 54%, p = 0.008), there was a higher incidence of short-term speech deterioration postoperatively (6.1% vs 23.5%, p = 0.0017) as well as at 3 months postoperatively (2.3% vs 15.4%, p = 0.0002), and the hospitalization period was longer (4.9 +/- 6.2 days vs 8.0 +/- 10.1 days, p < 0.001). Significantly more major complications occurred in the failure group (4 [14.8%] of 27) than in the successful group (16 [4%] of 397) (p = 0.037). CONCLUSIONS: Failures of awake craniotomy were associated with a lower incidence of gross-total resection and increased postoperative morbidity. The majority of awake craniotomy failures were preventable by adequate patient selection and avoiding side effects of drugs administered during surgery.

The impact of enrollment in a clinical study on the survival of patients with glioblastoma has not been established. We retrospectively analyzed 564 patients with newly diagnosed glioblastoma treated between 1995 and 2008. They were divided into those enrolled in a clinical trial and randomized to a treatment or control arm, and those not enrolled and who received best standard of care (BSC). The three groups were matched for age and Karnofsky performance scale (KPS) score at presentation, and included only patients who underwent at least one tumor resection. Survival analysis was performed and multivariate Cox proportional hazards model and recursive partitioning analysis (RPA) identified predictors of survival. Following the matching process, 261 patients remained to form the final cohort. Of the 124 patients enrolled in a study, 81 (31.0%) were randomized to the treatment and 43 (16.5%) to the control arms. The overall median survival for the BSC (n=137), control, and treatment groups was 11.57 months (95% confidence interval [CI], 10.41-12.73), 16.27 months (95% CI, 14.10-18.43) and 16.10 months (95% CI, 14.34-17.86), respectively (p=0.002). Participation in a clinical trial, regardless of the arm, was a significant predictor of survival, as were age and KPS at diagnosis. The RPA also demonstrated a favorable impact of participation in a clinical trial. Additional tumor resections and various treatment modalities were administered with significantly higher frequency among patients enrolled in clinical studies. Thus, enrollment in a clinical study carried a significant survival advantage for patients with glioblastoma, raising practical and ethical issues regarding the quality of care of patients who receive "standard" therapy.

BACKGROUND: Freezing of gait (FOG) is defined as an episodic inability to generate effective stepping in the absence of any known cause other than parkinsonism or high-level gait disorders. METHODS: We present a 59-year-old male with acute, progressive episodes of FOG. Imaging studies revealed a dural arteriovenous fistula (DAVF) associated with edema of the globus pallidus interna (GPi). Cerebral angiography confirmed the diagnosis of DAVF and demonstrated an occluded straight sinus and a retrograde blood flow of deep cerebral veins. RESULTS: After endovascular closure of the DAVF, a major improvement of FOG was observed concomitant with striking near resolution of GPi congestion. CONCLUSIONS: This reversal of the clinical course, correlated with changes in imaging studies, suggests a major role of the GPi in the pathology of FOG.