Pablo Ajler

A New Classification of Complications in Neurosurgery

OBJECTIVE To define and grade neurosurgical and spinal postoperative complications based on their need for treatment. METHODS Complications were defined as any deviation from the normal postoperative course occurring within 30 days of surgery. A four-grade scale was proposed based on the therapy used to treat the complications: grade I, any non-life-threatening complications treated without invasive procedures; grade II, complications requiring invasive management such as surgical, endoscopic, and endovascular procedures; grade III, life-threatening adverse events requiring treatment in an intensive care unit (ICU); and grade IV, deaths as a result of complications. Each grade was classified as a surgical or medical complication. An observational test of this system was conducted between January 2008 and December 2009 in a cohort of 1190 patients at the Hospital Italiano de Buenos Aires. RESULTS Of 167 complications, 129 (10.84%) were classified as surgical, and 38 (3.19%) were classified as medical complications. Grade I (mild) complications accounted for 31.73%, grade II (moderate) complications accounted for 25.74%, and grade III (severe) complications accounted for 34.13%. The overall mortality rate was 1.17%; 0.84% of deaths were directly related to surgical procedures. CONCLUSIONS The authors present a simple, practical, and easy to reproduce way to report negative outcomes based on the therapy administered to treat a complication. The main advantages of this classification are the ability to compare surgical results among different centers and times, the ability to compare medical and surgical complications, and the ability to perform future meta-analyses.

Sternberg's canal as a cause of encephalocele within the lateral recess of the sphenoid sinus: A report of two cases

Background: Intrasphenoidal encephaloceles are extremely rare findings. Sternbergs canal is a lateral craniopharyngeal canal resulting from incomplete fusion of the greater wings of the sphenoid bone with the basisphenoid. It acts as a weak spot of the skull base, which may lead to develop a temporal lobe encephalocele protruding into the lateral recess of the sphenoid sinus (SS). Case Description: We present two cases of intrasphenoidal encephalocele due to persistence of the lateral craniopharyngeal canal. The first case presented with cerebrospinal fluid (CSF) rhinorrhea and the second one was referred to the neurosurgical department with CSF rhinorrhea and meningitis. Radiological investigations consisted of computed tomography (CT) scan, CT cisternography and magnetic resonance images in both cases. These imaging studies identified a herniated temporal lobe through a bony defect which communicates the middle cranial fossa with the lateral recess of the SS. Both patients underwent a transcranial repair of the encephalocele because of the previous failure of the endoscopic surgery. There was no complication related to the surgical procedure and no recurrence of CSF leakage occurred 2 and 3 years after surgery, respectively. Conclusion: Encephalocele within the lateral recess of the SS is a rare entity which must be suspected in patients who present with spontaneous CSF rhinorrhea. Congenital intrasphenoidal encephaloceles, which are located medial to the foramen rotundum, seem to be due to persistence of the Sternbergs canal. Transcranial approach is a good option when a transnasal approach had failed previously.

Histologically confirmed isolated IgG4-related hypophysitis: two case reports in young women

Summary IgG4-related hypophysitis is a recently described entity belonging to the group of IgG4-related diseases. Many other organs can also be affected, and it is more common in older men. To date, 32 cases of IgG4-related hypophysitis have been reported in the literature, 11 of which included confirmatory tissue biopsy and the majority affecting multiple organs. The aim of this report is to present two cases of biopsy-proven IgG4-related hypophysitis occurring in two young female patients with no evidence of involvement of other organs at the time of diagnosis. Learning points IgG4-related hypophysitis belongs to the group of IgG4-related diseases, and is a fibro-inflammatory condition characterized by dense lymphoplasmacytic infiltrates rich in IgG4-positive plasma cells and storiform fibrosis. It is more common in older men, but young women may also present this type of hypophysitis. Although involvement of other organs is frequent, isolated pituitary disease is possible. Frequent clinical manifestations include anterior hypopituitarism and/or diabetes insipidus. The diagnosis may be confirmed with any of the following criteria: a pituitary biopsy with lymphoplasmacytic infiltrates, with more than ten IgG4-positive cells; a sellar mass and/or thickened pituitary stalk and a biopsy-proven involvement of another organ; a sellar mass and/or thickened pituitary stalk and IgG4 serum levels >140 mg/dl and sellar mass reduction and symptom improvement after corticosteroid treatment. Glucocorticoids are recommended as first-line therapy.

Polyetheretherketone interbody cages versus autogenous iliac crest bone grafts with anterior fixation for cervical disc disease.

Objective: The aim of this study was to compare the fusion rate, operation time, recovery of disc space height, clinical duration and improvement, return to activities of daily living, and complication rate associated with anterior cervical discectomy with interbody fusion by using polyetheretherketone cages or autogenous iliac crest bone grafts as disc replacement in a series of 60 patients. Materials and Methods: Between November 2006 and February 2010 a retrospective analytical observational cohort study was carried out in 60 consecutive patients surgically treated with anterior cervical discectomy with interbody fusion for degenerative disc desease at the Neurosurgical Department of the Hospital Italiano de Buenos Aires. The patients were divided into 2 groups for the assessment of clinical characteristics, demographics, fusion rates, duration of surgical procedure, neurological and functional outcomes, imaging results, and complications. Group A included patients treated with autogenous iliac crest bone grafts, and group B included patients treated with polyetheretherketone cages. Results: The mean age of the patients was 50.8 years. Female patients comprised the majority in both groups (63.3%). Cervicobrachialgia was the most common presentation. Clinical improvement, fusion rates, and recovery of disc space height were similar in both groups. The operation time was significantly shorter in the polyetheretherketone group (P<0.001). Twenty percent (n=6) of the patients in group A suffered complications, >80% of which were associated with iliac crest bone graft harvesting. Patients in group B had no complications (P<0.05). Conclusions: Although outcomes were very successful in both groups in terms of fixation stability, recovery of disc space, return to activities of daily living and work, and remission of symptoms, operation time was considerably shorter for patients in the polyetheretherketone group, who had none of the complications associated with iliac crest bone graft harvesting, both differences being statistically significant.

A new model for dura mater healing: human dural fibroblast culture

Abstract Objective: Dura mater healing is crucial to prevent cerebrospinal fluid (CSF) leaks after neurosurgical procedures. Biological mechanisms leading to dural closure are only partially understood and have been studied in animals exclusively. We studied an in vitro model of dural closure which uses human cells. Materials and methods: We used human dura intended for disposal after surgery. Explant primary cultures were performed. Cells were characterized through common staining and immunohistochemistry. A cell growth curve was elaborated and the effect of dexamethasone on cell count was assessed. Spongostan®, oxidized regenerated cellulose and autologous plastic materials were also evaluated for their effect on cellular growth. Results: All specimens showed growth in fusiform cells, which project pseudopods and fuse into spindles. Cells showed desmin and vimentin positivity, and were negative for all the other stains, behaving phenotypically like fibroblasts. No collagen base was necessary for cell growth. Dexamethasone decreased cell count in the primary culture as well as in the explant, and reduced the cell proliferation marker Ki-67. Spongostan® was successfully used as a graft, and fibroblast cultures were additionally developed with muscle, pericranium, galea, and fascia. Oxidized cellulose induced cell death by lowering the pH of the solution. Discussion: According to the findings, unlike mini-pigs and rabbits, in humans, dural fibroblast sensitivity to collagen seems to be lower. Dexamethasone inhibits fibroblast invasion, which is the biological base of wound dehiscence in cranial surgery. Although Spongostan is useful, Surgicel® can lower the media pH, thereby inhibiting cellular growth.

Multicentric extramedullary myxopapillary ependymomas: Two case reports and literature review.

Background: Ependymoma has been described typically as an intramedullary tumor derived from ependymal cells. Intradural extramedullary presentation is rarely described and almost always as a unique lesion. Myxopapillary ependymoma is a histological variant that distinguishes from the ordinary type of ependymoma because of its generally better prognosis. We present two cases of multicentric extramedullary myxopapillary ependymomas. Case Description: Case 1 was a 30-year-old man with progressive paresthesia and paresis in the lower limbs, urinary sphincter disturbances, gait instability, ataxia, and chronic low back pain with multiple intradural extramedullary lesions at C2-C3, D2-D4-D5, and D12-L1. Case 2 was a 32-year-old man, presented with low back pain and mild paresthesia in the right lower limb. Magnetic resonance imaging (MRI) showed multiple intradural extramedullary lesions with homogeneous enhancement after gadolinium injection at C7, D2, D4, D5, D8, D10, D11, L1, L3, L5, S1, and S2. Complete tumor resection of the approached tumors was archived in both cases. Histological studies confirm myxopapillary ependymomas. Patients neurologic outcome was good and no residual tumor was present at MRI control at 10 years in case 1 and 12 months in case 2. Conclusions: We report the first two cases of multicentric extramedullary myxopapillary ependymomas, this etiology must be taken into account in the differential diagnosis of intradural extramedullary tumors.

Autocrine IL-6 mediates pituitary tumor senescence

Cellular senescence is a stable proliferative arrest state. Pituitary adenomas are frequent and mostly benign, but the mechanism for this remains unknown. IL-6 is involved in pituitary tumor progression and is produced by the tumoral cells. In a cell autonomous fashion, IL-6 participates in oncogene-induced senescence in transduced human melanocytes. Here we prove that autocrine IL-6 participates in pituitary tumor senescence. Endogenous IL-6 inhibition in somatotroph MtT/S shRNA stable clones results in decreased SA-β-gal activity and p16INK4a but increased pRb, proliferation and invasion. Nude mice injected with IL-6 silenced clones develop tumors contrary to MtT/S wild type that do not, demonstrating that clones that escape senescence are capable of becoming tumorigenic. When endogenous IL-6 is silenced, cell cultures derived from positive SA-β-gal human tumor samples decrease the expression of the senescence marker. Our results establish that IL-6 contributes to maintain senescence by its autocrine action, providing a natural model of IL-6 mediated benign adenoma senescence.

Three-step anterolateral approaches to the skull base.

Adequate intraoperative exposure of the brain is paramount to prevent unnecessary retraction of the brain parenchyma. Lesions in the anterior skull base, the middle fossa and even the upper part of the posterior fossa can be managed anterolaterally through the pterional approach, the orbitozygomatic approach and the transzygomatic approach. Although commonly discussed on a separate basis, these three procedures are here considered to belong in the same spectrum, which includes one, two or three step procedures depending on the case and the level of exposure required. Ten hemispheres were used to describe the surgical technique applied in a three-step anterolateral approach. The pterional approach provides adequate access to the frontal base and the Sylvian fissure, the circle of Willis and the optic nerves. Where access to the temporal base is needed, improved exposure can be afforded by sectioning the zygomatic arch and lowering the masseter muscle. The lateral orbital wall is sectioned to improve the vertical angle of approach and facilitate access to hypothalamic and posterior fossa lesions. The combination of three approaches into one procedure introduces a new perspective on this technique, one which makes them easier to understand and shows how craniotomy may be modified for optimal exposure, even while conducting the surgery.

Brain sulci and gyri: A practical anatomical review

Despite technological advances, such as intraoperative MRI, intraoperative sensory and motor monitoring, and awake brain surgery, brain anatomy and its relationship with cranial landmarks still remains the basis of neurosurgery. Our objective is to describe the utility of anatomical knowledge of brain sulci and gyri in neurosurgery. This study was performed on 10 human adult cadaveric heads fixed in formalin and injected with colored silicone rubber. Additionally, using procedures done by the authors between June 2006 and June 2011, we describe anatomical knowledge of brain sulci and gyri used to manage brain lesions. Knowledge of the brain sulci and gyri can be used (a) to localize the craniotomy procedure, (b) to recognize eloquent areas of the brain, and (c) to identify any given sulcus for access to deep areas of the brain. Despite technological advances, anatomical knowledge of brain sulci and gyri remains essential to perform brain surgery safely and effectively.

Ectopic prolactinoma within the sphenoidal sinus associated with empty sella

Background: Pituitary adenomas are a common cause of endocrinal dysfunction, which comprise 10–20% of all intracranial tumors. Although almost all of them arise within the sella turcica, there are some rare cases in which a pituitary adenoma is located outside the intrasellar region, so it is defined as an ectopic pituitary adenoma (EPA). Case Description: We described a case of a 31-year-old male with a serum prolactin (PRL) value of 240 ng/ml Magnetic resonance imaging (MRI) showed a space-occupying mass within the sphenoid sinus (SS) which partially enhanced by gadolinium. MRI did not reveal any sellar floor defect and an empty sella was detected. As dopamine agonist treatment had failed in lowering the serum PRL level, he underwent surgical treatment. A transsphenoidal approach without opening the sellar floor was performed using an operating microscope and the lesion within the SS was completely removed. Conclusion: Although intrasphenoidal EPAs are rare findings, the presence of an endocrine disorder related to pituitary hormones, and a space-occupying mass within the SS associated with either a normal sellar pituitary gland or an empty sella must lead us to suspect this diagnosis.