Pawel G. Ochalski

Bio: Pawel G. Ochalski is an academic researcher from University of Pittsburgh. The author has contributed to research in topics: Clivus & Diastasis. The author has an hindex of 8, co-authored 12 publications receiving 202 citations.

Stereotactically guided endoscopic port surgery for intraventricular tumor and colloid cyst resection.

Abstract: BACKGROUND: Intraventricular lesions are challenging entities that may be difficult to resect completely and safely, especially larger lesions with high vascularity or firm consistency. OBJECTIVE: To assess the results of stereotactically guided endoscopic port (SEP) surgery for resection of colloid cysts and intraventricular tumors. METHODS: The authors developed a minimally invasive microsurgical technique for intraventricular surgery using parallel endoscopy to visualize the lesion. Surgical resection was performed via an 11.5-mm transparent conduit (Neuroendoport) deployed under stereotactic guidance. Forty-seven consecutive cases were performed, and all had a minimum 1-year follow-up to assess the efficacy of the technique. RESULTS: For colloid cysts, gross total resection was achieved in 31 (96.9%) of the 32 cases. The transient neurologic morbidity rate was 9.4%; no permanent neurologic morbidity occurred. For intraventricular tumors, gross or near total resection was achieved in 80% of cases. The transient neurological morbidity rate was 6.7%, and no permanent neurological morbidity occurred. CONCLUSION: SEP surgery for colloid cysts and intraventricular tumors proved to be a safe and effective alternative to conventional microsurgical resection. This technique was not limited by the vascularity, friability, or size of any of the lesions.

Intracranial angiomatoid fibrous histiocytoma presenting as recurrent multifocal intraparenchymal hemorrhage.

Abstract: Angiomatoid fibrous histiocytoma (AFH) is a rare soft-tissue neoplasm that most commonly appears in the limbs, typically affecting children and young adults. The tumor has a propensity for local recurrence and recurrent hemorrhage but rarely for remote metastasis. To date, only 2 reports have documented an intracranial occurrence of the tumor (1 of which was believed to be metastatic disease). This is the second report of primary intracranial AFH. Additionally, hemorrhage from an intracranial AFH lesion has yet to be reported, and little is known about the radiographic characteristics and biological behavior of these lesions. In this report, the authors describe the case of a patient with recurrent hemorrhage due to primary multifocal intracranial AFH. Initially misdiagnosed as a cavernous malformation and then an unusual meningioma, the tumor was finally correctly identified when there was a large enough intact resection specimen to reveal the characteristic histological pattern. The diagnosis was confirmed using immunohistochemical and molecular studies.

Fractures of the clivus: a contemporary series in the computed tomography era.

Abstract: OBJECTIVE: We report the morbidity and mortality associated with fractures of the clivus and discuss management approaches specific to this unique diagnostic entity. METHODS: We performed a boolean search of our electronic medical record database to identify patients with fractures of the clivus that were diagnosed using computed tomography of the head. A retrospective imaging and chart analysis was completed to further characterize the fractures and to analyze outcomes. RESULTS: Between January 1999 and December 2007, 41 patients were identified with fractures of the clivus. We found a 0.21 % overall incidence among all head-injured patients presenting to our institution and a 2.3% incidence among those patients with a cranial fracture. Ten of 41 patients (24.4%) died, and neurological and vascular complications associated with central cranial base fractures were observed in 19 of 41 patients (46%). Furthermore, associated cranial fractures remote from the central cranial base and associated intracranial hemorrhages were observed in 40 of 41 (97.6%) and 33 of 41 (80.5%) patients, respectively. In terms of outcomes, 26 of 41 patients (63.5%) had a Glasgow Coma Scale score of 12 or greater at the time of discharge from the hospital. CONCLUSION: We demonstrate a lower than previously reported mortality rate in patients with clival fractures. Nevertheless, as a result of location, fractures of the clivus were frequently associated with a high rate of complications and neurological sequelae.

Fractures of the clivus and traumatic diastasis of the central skull base in the pediatric population.

Abstract: Object Fractures of the clivus and traumatic diastases of the clival synchondroses are rare in the pediatric population. The incidence, outcome, and biomechanics associated with these fractures have been difficult to ascertain secondary to the lack of literature pertaining to their occurrence. Methods A Boolean search of the electronic medical record database at the Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, was performed to identify patients with fractures of the clivus that were diagnosed using CT of the head. A retrospective review of the chart and radiographic imaging was then performed to assess data regarding patient demographics, mechanism of injury, and skull and brain parenchymal injuries, as well as outcomes. Results Between May 2002 and November 2007, 16 patients with fractures of the clivus were identified. The mean age of these patients was 9 years (range 1–16 years). Eleven (68.8%) of the 16 patients had an associated traumatic diastasis of the central skull ...

Outcomes after endoscopic port surgery for spontaneous intracerebral hematomas.

Abstract: Background Spontaneous intracerebral hemorrhages (ICHs) cause significant morbidity and mortality. Traditional open surgical management strategies offer limited benefit except for the most superficial hemorrhages in select patients. Recent reports suggest that endoscopic approaches may improve outcomes, particularly for deep subcortical hemorrhages. However, the management of these patients remains controversial. We reviewed our experience using endoscopic port surgery to identify characteristics that may predict acceptable outcomes. Materials and Methods We completed a retrospective chart and imaging review of patients who underwent endoscopic port surgery for evacuation of spontaneous ICH at a single center. Data were gathered regarding patient demographics, hemorrhage locations, operative findings, and clinical outcomes. Results From 2007 to 2011, 18 patients underwent evacuation of spontaneous intracerebral hematomas using an endoscopic port. The mean age in years was 62 years (range, 43–84 years). Six of 18 patients (33%) died before discharge, and 2 others (11%) died after at least 1 month of survival. Of 12 initial survivors, all were discharged to a rehabilitation or nursing facility. Complete hematoma evacuation was achieved in 7 of 18 patients, with the remaining 11 having a partial evacuation. The patients who died ( n = 6) before discharge were statistically more likely to have a left-sided hemorrhage, partial evacuation, or older age than the survivors; death at least 1 month after evacuation was additionally associated with greater preoperative hematoma volumes. Conclusions Our series demonstrates that endoscopic port surgery for acute intracerebral hematoma evacuation has the ability to achieve significant decompression of large and deep-seated hematomas. Patient age, extent of evacuation, laterality, and preoperative hematoma volume appear to influence patient outcome. Most overall outcomes remain poor. Future studies are necessary to determine if surgical evacuation is in fact superior to best medical treatment and if so, to validate, refute, or further identify characteristics that define surgical candidates.

Tumors With EWSR1-CREB1 and EWSR1-ATF1 Fusions: The Current Status

Abstract: EWSR1-CREB1 and EWSR1-ATF1 are gene fusions of which one or both have now been consistently described in 5 histopathologically and behaviorally diverse neoplasms: angiomatoid fibrous histiocytoma, conventional clear cell sarcoma (of tendons and aponeuroses), clear cell sarcoma-like tumor of the gastrointestinal tract, hyalinizing clear cell carcinoma of the salivary gland, and primary pulmonary myxoid sarcoma. Some of the tumors in this group have been described only recently, and others have been the subject of recent genetic insights contributing to their characterization. These neoplasms are all rare; yet, the increasing frequency with which EWSR1-CREB1 and EWSR1-ATF1 fusions are being described in separate entities is noteworthy. The additional molecular mechanisms by which tumors with such variable morphologic, immunohistochemical, and clinical phenotypes are generated are yet to be understood. We review the clinicopathologic and molecular features of this group of neoplasms unified by the presence of EWSR1-CREB1 and EWSR1-ATF1 genetic fusions.

The diversity of soft tissue tumours with EWSR1 gene rearrangements: a review

Abstract: Many soft tissue sarcomas have chromosomal translocations with resultant formation of new fusion genes. Among the genes that can be rearranged, the EWSR1 gene has been identified as a partner in a wide variety of clinically and pathologically diverse sarcomas as well as some non-mesenchymal tumours. The former include Ewing sarcoma and similar (Ewing-like) small round cell sarcomas, desmoplastic small round cell tumour, myxoid liposarcoma, extraskeletal myxoid chondrosarcoma, angiomatoid fibrous histiocytoma, clear cell sarcoma of soft tissue and clear cell sarcoma-like tumours of the gastrointestinal tract, primary pulmonary myxoid sarcoma, extrasalivary myoepithelial tumours and sporadic examples of low-grade fibromyxoid sarcoma, sclerosing epithelioid fibrosarcoma and mesothelioma. EWSR1 is a 'promiscuous' gene that can fuse with many different partner genes, but sometimes this results in phenotypically identical tumours. EWSR1 can, conversely, partner with the same genes in morphologically and behaviourally different neoplasms. This paper reviews the diversity of the several soft tissue tumour types that are associated with rearrangement of the EWSR1 gene.

Benzodiazepine dependence and its treatment with low dose flumazenil

Abstract: Globally benzodiazepines remain one of the most prescribed medication groups, especially in the primary care setting. With such high levels of prescribing it is not surprising that benzodiazepine dependence is common, cutting across all socioeconomic levels. Despite recognition of the potential for the development of iatrogenic dependence and the lack of any effective treatment, benzodiazepines continue to be widely prescribed in general practice. Conventional dependence management, benzodiazepine tapering, is commonly a protracted process over several weeks or months. It is often associated with significant withdrawal symptoms and craving leading to patient drop out and return to use. Accordingly, there is a worldwide need to find effective pharmacotherapeutic interventions for benzodiazepine dependence. One drug of increasing interest is the GABAA benzodiazepine receptor antagonist/partial agonist, flumazenil. Multiple bolus intravenous infusions of low dose flumazenil used either with or without benzodiazepine tapering can reduce withdrawal sequelae, and/or longer term symptoms in the months following withdrawal. Preliminary data suggest that continuous intravenous or subcutaneous flumazenil infusion for 4 days significantly reduces acute benzodiazepine withdrawal sequelae. The subcutaneous infusion was shown to be tissue compatible so the development of a longer acting (i.e. several weeks) depot flumazenil formulation has been explored. This could be capable of managing both acute and longer term benzodiazepine withdrawal sequelae. Preliminary in vitro water bath and in vivo biocompatibility data in sheep show that such an implant is feasible and so is likely to be used in clinical trials in the near future.