Allan Friedman

Overview:

At the present time, I am participating in collaborative research in the areas of primary malignant brain tumors, epilepsy and subarachnoid hemorrhage.

Primary malignant brain tumors are increasing in frequency. Patients harboring glioblastoma, the most malignant primary brain tumor, have a life expectancy of less than one year. In colloboration with the Division of Neurology and the Department of Pathology, clinical and laboratory trials have been initiated to identify better treatment for this condition. At present, trials of monoclonal antibodies and novel chemotherapeutic agents are being carried out.

Although physicians have been interested in seizures since the time of Hippocrates, the origin of seizures remains obscure. At Duke University we have treated approximately thirty seizure patients a year by removing abnormal portions of brain. Tissue from these resections is being analyzed for genetics and receptor abnormalities. Positron emission tomography and magnetic resonance imaging are being used to ferret out the origin of the patient's seizures.

Approximately 28,000 patients each year suffer a ruptured intracranial aneurysm. Approximately ten percent of these patients have a genetic predisposition to forming intracranial aneurysms. In conjunction with the Division of Neurology, we are screening candidate genes searching for the cause of intracranial aneurysms.

Positions:

Guy L. Odom Distinguished Professor of Neurosurgery, in the School of Medicine

Neurosurgery
School of Medicine

Professor of Neurosurgery

Neurosurgery
School of Medicine

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

M.D. 1974

University of Illinois

Grants:

Novel Targeted Therapeutics for CNS Malignancies

Awarded By
National Institutes of Health
Role
Collaborating Investigator
Start Date
End Date

IPA - Bharathi Hattiangady

Administered By
Neurosurgery
Awarded By
Durham Veterans Affairs Medical Center
Role
Principal Investigator
Start Date
End Date

IPA - Bing Shuai

Administered By
Neurosurgery
Awarded By
Durham Veterans Affairs Medical Center
Role
Principal Investigator
Start Date
End Date

A Wireless µECoG Prosthesis for Speech

Administered By
Biomedical Engineering
Awarded By
National Institutes of Health
Role
Co Investigator
Start Date
End Date

Publications:

Long-Term Outcomes for Patients With Atypical or Malignant Meningiomas Treated With or Without Radiation Therapy: A 25-Year Retrospective Analysis of a Single-Institution Experience.

Purpose: Atypical (World Health Organization [WHO] grade 2) and malignant (WHO grade 3) meningiomas have high rates of local recurrence, and questions remain about the role of adjuvant radiation therapy (RT) for patients with WHO grade 2 disease. These patients frequently require salvage therapy, and optimal management is uncertain given limited prospective data. We report on the long-term outcomes for patients with atypical and malignant meningiomas treated with surgery and/or RT at our institution. Methods and Materials: Data were collected through a retrospective chart review for all patients with WHO grade 2 or 3 meningiomas treated with surgery and/or RT at our institution between January 1992 and March 2017. Progression-free survival (PFS) and overall survival (OS) were described using the KaplanMeier estimator. The outcomes in the subgroups were compared with a log-rank test. A Cox proportional hazards model was used for the univariable and multivariable analyses of predictors of PFS. Results: A total of 66 patients were included in this analysis. The median follow-up was 12.4 years overall and 8.6 years among surviving patients. Fifty-two patients (78.8%) had WHO grade 2 meningiomas, and 14 patients (21.2%) had WHO grade 3 disease. Thirty-six patients (54.5%) were treated with surgery alone, 28 patients (42.4%) with surgery and adjuvant RT, and 2 patients (3%) with RT alone. Median PFS and OS were 3.2 years and 8.8 years, respectively. PFS was significantly improved with adjuvant RT compared with surgery alone (hazard ratio, 0.36; 95% confidence interval, 0.18-0.70). Patients with Ki-67 index >10% showed a trend toward worse PFS compared with patients with Ki-67 ≤10% (hazard ratio, 0.51; 95% confidence interval, 0.25-1.04). No significant differences in PFS or OS were observed with respect to Simpson or WHO grade. Conclusions: For patients with atypical or malignant meningiomas, adjuvant RT was associated with significantly improved PFS, and Ki-67 index >10% was associated with a trend toward worse PFS. Given the long-term survival, high recurrence rates, and efficacy of salvage therapy, patients with atypical and malignant meningiomas should be monitored systematically long after initial treatment.
Authors
Kent, CL; Mowery, YM; Babatunde, O; Wright, AO; Barak, I; McSherry, F; Herndon, JE; Friedman, AH; Zomorodi, A; Peters, K; Desjardins, A; Friedman, H; Sperduto, W; Kirkpatrick, JP
MLA Citation
Kent, Collin L., et al. “Long-Term Outcomes for Patients With Atypical or Malignant Meningiomas Treated With or Without Radiation Therapy: A 25-Year Retrospective Analysis of a Single-Institution Experience.Adv Radiat Oncol, vol. 7, no. 3, May 2022, p. 100878. Pubmed, doi:10.1016/j.adro.2021.100878.
URI
https://scholars.duke.edu/individual/pub1510656
PMID
35647401
Source
pubmed
Published In
Advances in Radiation Oncology
Volume
7
Published Date
Start Page
100878
DOI
10.1016/j.adro.2021.100878

Retrolabyrinthine transsigmoid approach to complex parabrainstem tumors in the posterior fossa.

OBJECTIVE: The surgical management of large and complex tumors of the posterior fossa poses a formidable challenge in neurosurgery. The standard retrosigmoid craniotomy approach has been performed at most neurosurgical centers; however, the retrosigmoid approach may not provide enough working space without significant retraction of the cerebellum. The transsigmoid approach provides wider and shallower surgical fields; however, there have been few clinical and no cadaveric studies on its usefulness. In the present study, the authors describe the transsigmoid approach in clinical cases and cadaveric specimens. METHODS: For the clinical study, the authors retrospectively reviewed the medical records and operative charts of patients who had been surgically treated for parabrainstem tumors using the transsigmoid approach between 1997 and 2019. They analyzed patient demographic and clinical data, as well as surgical and clinical outcomes. In the cadaveric study, they compared the surgical views obtained in different approaches (retrosigmoid, presigmoid, retrolabyrinthine, and transsigmoid) and measured the sigmoid sinus width at the level of the endolymphatic sac and the distance between the anterior edge of the sigmoid sinus and the endolymphatic sac on 35 sides in 19 cadaveric specimens. RESULTS: A total of 21 patients (6 males and 15 females) with a mean age of 42.2 (range 15-67) years were included in the clinical study. Eleven patients had meningioma, 7 had vestibular schwannoma, 2 had hemangioblastoma, and 1 had epidermoid cyst. Gross-total, near-total, and subtotal removal were achieved in 7 (33.3%), 3 (14.3%), and 11 (52.4%) patients, respectively. In the cadaveric study, 19 cadaveric specimens were used. The sigmoid sinus was cut in the middle, and the incision was extended from the retrosigmoid to the presigmoid dura. The dura was then retracted upward and downward like opening a door. The results indicated that this technique can widen the operative field anteriorly by approximately 2 cm as compared to the retrosigmoid approach and provides a better view anterior to the brainstem. CONCLUSIONS: The transsigmoid approach is useful for complex parabrainstem tumors in the posterior fossa because it provides a wider and shallower operative view with less retraction of the cerebellum. This enables safer tumor removal with less damage to important structures in the posterior fossa, resulting in better operative and clinical outcomes.
Authors
Kinoshita, Y; Zomorodi, AR; Friedman, AH; Sato, H; Carter, JH; Bawornvaraporn, U; Nakamura, H; Fukushima, T
MLA Citation
Kinoshita, Yusuke, et al. “Retrolabyrinthine transsigmoid approach to complex parabrainstem tumors in the posterior fossa.J Neurosurg, vol. 136, no. 4, Apr. 2022, pp. 1097–102. Pubmed, doi:10.3171/2021.5.JNS204130.
URI
https://scholars.duke.edu/individual/pub1498599
PMID
34624849
Source
pubmed
Published In
J Neurosurg
Volume
136
Published Date
Start Page
1097
End Page
1102
DOI
10.3171/2021.5.JNS204130

Neurosurgery residency and fellowship education in the United States: 2 decades of system development by the One Neurosurgery Summit organizations.

The purpose of this report is to chronicle a 2-decade period of educational innovation and improvement, as well as governance reform, across the specialty of neurological surgery. Neurological surgery educational and professional governance systems have evolved substantially over the past 2 decades with the goal of improving training outcomes, patient safety, and the quality of US neurosurgical care. Innovations during this period have included the following: creating a consensus national curriculum; standardizing the length and structure of neurosurgical training; introducing educational outcomes milestones and required case minimums; establishing national skills, safety, and professionalism courses; systematically accrediting subspecialty fellowships; expanding professional development for educators; promoting training in research; and coordinating policy and strategy through the cooperation of national stakeholder organizations. A series of education summits held between 2007 and 2009 restructured some aspects of neurosurgical residency training. Since 2010, ongoing meetings of the One Neurosurgery Summit have provided strategic coordination for specialty definition, neurosurgical education, public policy, and governance. The Summit now includes leadership representatives from the Society of Neurological Surgeons, the American Association of Neurological Surgeons, the Congress of Neurological Surgeons, the American Board of Neurological Surgery, the Review Committee for Neurological Surgery of the Accreditation Council for Graduate Medical Education, the American Academy of Neurological Surgery, and the AANS/CNS Joint Washington Committee. Together, these organizations have increased the effectiveness and efficiency of the specialty of neurosurgery in advancing educational best practices, aligning policymaking, and coordinating strategic planning in order to meet the highest standards of professionalism and promote public health.
Authors
Selden, NR; Barbaro, NM; Barrow, DL; Batjer, HH; Branch, CL; Burchiel, KJ; Byrne, RW; Dacey, RG; Day, AL; Dempsey, RJ; Derstine, P; Friedman, AH; Giannotta, SL; Grady, MS; Harsh, GR; Harbaugh, RE; Mapstone, TB; Muraszko, KM; Origitano, TC; Orrico, KO; Popp, AJ; Sagher, O; Selman, WR; Zipfel, GJ
MLA Citation
Selden, Nathan R., et al. “Neurosurgery residency and fellowship education in the United States: 2 decades of system development by the One Neurosurgery Summit organizations.J Neurosurg, vol. 136, no. 2, Feb. 2022, pp. 565–74. Pubmed, doi:10.3171/2020.10.JNS203125.
URI
https://scholars.duke.edu/individual/pub1493264
PMID
34359022
Source
pubmed
Published In
J Neurosurg
Volume
136
Published Date
Start Page
565
End Page
574
DOI
10.3171/2020.10.JNS203125

Neurosurgical management of petrous bone lesions: classification system and selection of surgical approaches.

BACKGROUND: Surgery of petrous bone lesions (PBLs) is challenging for neurosurgeons. Selection of the surgical approach is an important key for success. In this study, the authors present an anatomical classification for PBLs that has been used by our group for over the past 26 years. The objective of this study is to investigate the benefits and applicability of this classification. METHODS: Between 1994 and 2019, 117 patients treated for PBLs were retrospectively reviewed. Using the V3 and arcuate eminence as reference points, the petrous bone is segmented into 3 parts: petrous apex, rhomboid, and posterior. The pathological diagnoses, selection of the operative approach, and the extent of resection (EOR) were analyzed and correlated using this classification. RESULTS: This series included 22 facial nerve schwannomas (18.8%), 22 cholesterol granulomas (18.8%), 39 chordomas/chondrosarcomas (33.3%), 6 trigeminal schwannomas (5.1%), 13 epidermoids/dermoids (11.1%), and 15 other pathologies (12.8%). PBLs were most often involved with the petrous apex and rhomboid areas (46.2%). The extradural subtemporal approach (ESTA) was most frequently used (57.3%). Gross total resection was achieved in 58.4%. Symptomatic improvement occurred in 92 patients (78.6%). Our results demonstrated a correlation between this classification with each type of pathology (p < .001), selection of surgical approaches (p < 0.001), and EOR (p = 0.008). Chordoma/chondrosarcoma, redo operations, and lesions located medially were less likely to have total resection. Temporary complications occurred in 8 cases (6.8%), persistent morbidity in 5 cases (4.3%), and mortality in 1 case. CONCLUSION: In this study, we proposed a simple classification of PBLs. Using landmarks on the superior petrosal surface, the petrous bone is divided into 3 parts, apex, rhomboid, and posterior. Our results demonstrated that chordoma/chondrosarcoma, redo operations, and lesions involving the tip of the petrous apex or far medial locations were more difficult to achieve total resection. This classification could help surgeons understand surgical anatomy framework, predict possible structures at risk, and select the most appropriate approach for each patient.
Authors
Bawornvaraporn, U; Zomorodi, AR; Friedman, AH; Fukushima, T
MLA Citation
Bawornvaraporn, Udom, et al. “Neurosurgical management of petrous bone lesions: classification system and selection of surgical approaches.Acta Neurochir (Wien), vol. 163, no. 10, Oct. 2021, pp. 2895–907. Pubmed, doi:10.1007/s00701-021-04934-9.
URI
https://scholars.duke.edu/individual/pub1489785
PMID
34313854
Source
pubmed
Published In
Acta Neurochir (Wien)
Volume
163
Published Date
Start Page
2895
End Page
2907
DOI
10.1007/s00701-021-04934-9

Petrous bone lesions: surgical implementation and outcomes of extradural subtemporal approach.

BACKGROUND: Petrous bone lesions (PBLs) are rare with few reports in the neurosurgical literature. In this study, the authors describe our current technique of extradural subtemporal approach (ESTA). The objective of this study was to evaluate the role and efficacy of ESTA for treatment of the PBLs. To our knowledge, this is the largest reported clinical series of using an ESTA-treated PBLs in which the clinical outcomes were evaluated. METHODS: Between 1994 and 2019, 67 patients with PBLs treated by ESTA were retrospectively reviewed. Extent of resection, neurological outcomes, recurrence rate, and surgical complications were evaluated and compared with previous studies. The indications, advantages, limitations, and outcomes of ESTA were analyzed according to pathology. RESULTS: This series included 7 facial nerve schwannomas (10.4%), 16 cholesterol granulomas (23.9%), 16 chordomas (23.9%), 6 chondrosarcomas (9%), 5 trigeminal schwannomas (7.5%), 9 epidermoids/dermoids (13.4%), and 8 other pathologies (11.9%). The most common location of PBLs operated with ESTA was at the petrous apex and rhomboid areas (68.7%). Gross total resection was achieved in 35 (55.6%). Symptomatic improvement occurred in 56 patients (83.6%). Complications occurred in 7 (10.4%) of cases including one mortality. Nine patients (17%) had recurrence within the mean follow-up 71 months. Compared to previous literature, our results demonstrated comparable outcomes but with higher rates of hearing and facial nerve preservation as well as minimal morbidity. From our results, ESTA is an effective therapeutic option for lesions located at the rhomboid and petrous apex, particularly when patients presented with intact facial and hearing function. CONCLUSION: Our series demonstrated that ESTA provided satisfactory outcomes with excellent benefits of hearing and facial function preservation for patients with petrous bone lesions. ESTA should be considered as a safe and effective therapeutic option for selected patients with PBLs.
Authors
Bawornvaraporn, U; Zomorodi, AR; Friedman, AH; Fukushima, T
MLA Citation
Bawornvaraporn, Udom, et al. “Petrous bone lesions: surgical implementation and outcomes of extradural subtemporal approach.Acta Neurochir (Wien), vol. 163, no. 10, Oct. 2021, pp. 2881–94. Pubmed, doi:10.1007/s00701-021-04962-5.
URI
https://scholars.duke.edu/individual/pub1494544
PMID
34420107
Source
pubmed
Published In
Acta Neurochir (Wien)
Volume
163
Published Date
Start Page
2881
End Page
2894
DOI
10.1007/s00701-021-04962-5