Search Results

You are looking at 1 - 10 of 17 items for

  • Author or Editor: Kevin Lillehei x
Clear All Modify Search
Full access

Kevin O. Lillehei

Restricted access

Todd S. Crawford, Bette K. Kleinschmidt-Demasters and Kevin O. Lillehei

✓ Primary intraosseous meningioma of the skull is an uncommon lesion often confused preoperatively with a primary bone tumor of the skull. The case of an intraosseous meningioma without dural connection or association with a cranial suture is reported that was radiographically diagnosed as Paget's disease and initially treated conservatively. Persistent headache prompted a biopsy, yielding a benign, heavily ossified, and psammomatous meningioma. The lesion was treated with wide surgical excision and acrylic cranioplasty. Subsequent review of the literature has revealed 35 additional cases of purely intraosseous meningioma. An analysis of these 36 cases demonstrates a mean patient age at diagnosis of 45 years and a 2:1 female preponderance, with the majority of lesions associated with cranial sutures. Sixty-four percent of the lesions were hyperostotic on plain skull x-ray films; the rest were osteolytic or a mixture of both. There was no relationship to prior trauma. The treatment of choice is wide surgical resection followed by cranial reconstruction.

Full access

Yang Liu, Ka-Yun Ng and Kevin O. Lillehei

Object

There have been numerous attempts to establish an effective immunotherapy for the treatment of brain tumors. To date, reliable methods to manipulate the immune system for promoting brain tumor regression have been disappointing. Generation of active immune responses in most of these studies was only possible in the absence of viable tumor cells, suggesting that immunotherapy can only be used as preventive therapy. In few studies the investigators have demonstrated success in using immunotherapy to treat a preestablished intracranial tumor. Using the 9L intracranial glioma model, the authors sought to delineate the underlying mechanisms for these observations.

Methods

In animals vaccinated with irradiated 9L glioma cells and interferon-gamma 14 and 7 days prior to intracranial tumor cell challenge, a significant increase in survival was shown. In contrast, vaccinations applied 3 days prior to, at the time of (Day 0) or 7 days after intracranial tumor cell challenge failed to influence survival. Histological examination of brain tissue specimens obtained in animals vaccinated before or after tumor cell challenge showed no difference in the degree of peritumoral mononuclear cell infiltration. When activated spleen cells obtained obtained from these animals were assayed for cytotoxicity and proliferative capacity, only those spleen cells derived from animals vaccinated prior to intracranial tumor cell challenge showed enhanced activity.

Conclusions

These data support the presence of a strong modulatory effect of tumor on local and systemic antitu-moral immune response. This immunosuppression appears to be secondary to a direct effect on T-cell function. Reversal of this immunosuppression may be a useful adjunct to tumor vaccine therapy.

Restricted access

Bette K. Kleinschmidt-DeMasters and Kevin O. Lillehei

✓ Meningiomas are known to be induced by low-, moderate-, and high-dose radiation therapy, with an average time interval to tumor appearance of 35, 26, and 19 to 24 years, respectively. An inverse relationship is suggested between the dose of radiation given and the time to tumor formation. The authors report a case of a 68-year-old woman who received orthovoltage radiotherapy at 5 years of age for a presumed (nonbiopsy confirmed) right cerebellar tumor and developed multiple meningiomas in the radiation portals 63 years later. Like many radiation-induced meningiomas, the tumor was histologically atypical and multiple in its presentation. This case suggests that previous radiotherapy may confer a low, but life-long, risk for meningioma occurrence.

Free access

D. Ryan Ormond, Joseph Kahamba, Kevin O. Lillehei and Nicephorus Rutabasibwa

Tanzania sits on the Indian Ocean in East Africa and has a population of over 53 million people. While the gross domestic product has been increasing in recent years, distribution of wealth remains a problem, and challenges in the distribution of health services abound. Neurosurgery is a unique case study of this problem. The challenges facing the development of neurosurgery in Tanzania are many and varied, built largely out of the special needs of modern neurosurgery. Task shifting (training nonphysician surgical providers) and 2-tiered systems (fast-track certification of general surgeons to perform basic neurosurgical procedures) may serve some of the immediate need, but these options will not sustain the development of a comprehensive neurosurgical footprint. Ultimately, long-term solutions to the need for neurosurgical care in Tanzania can only be fulfilled by local government investment in capacity building (infrastructure and neurosurgical training), and the commitment of Tanzanians trained in neurosurgery. With this task in mind, Tanzania developed an independent neurosurgery training program in Dar es Salaam. While significant progress has been made, a number of training deficiencies remain. To address these deficiencies, the Muhimbili Orthopedic Institute (MOI) Division of Neurosurgery and the University of Colorado School of Medicine Department of Neurosurgery set up a Memorandum of Understanding in 2016. This relationship was developed with the perspective of a “collaboration of equals.” Through this collaboration, faculty members and trainees from both institutions have the opportunity to participate in international exchange, join in collaborative research, experience the culture and friendship of a new country, and share scholarship through presentations and teaching. Ultimately, through this international partnership, mutual improvement in the care of the neurosurgical patient will develop, bringing programs like MOI out of isolation and obscurity. From Dar es Salaam, a center of excellence is developing to train neurosurgeons who can go well equipped throughout Tanzania to improve the care of the neurosurgical patient everywhere. The authors encourage further such exchanges to be developed between partnership training programs throughout the world, improving the scholarship, subspecialization, and teaching expertise of partner programs throughout the world.

Restricted access

Stephen E. Doran, Stephen M. Papadopoulos, Thomas B. Ducker and Kevin O. Lillehei

✓ The coexistence of traumatic locked facets of the cervical spine and a herniated disc is not well described. The authors present a series of patients with traumatic locked facets who demonstrated a high incidence of associated disc herniation documented on magnetic resonance (MR) imaging. Thirteen patients with either unilateral (four cases) or bilateral (nine cases) locked facets of the cervical spine were analyzed retrospectively. Immediate closed reduction using traction and/or manipulation was attempted in the first nine cases treated and was successful in only three; however, the procedure was abandoned in three cases due to deterioration in the patient's clinical status. In the subsequent four patients, an MR image was obtained prior to attempts at closed reduction. All patients underwent MR imaging of the cervical spine. Of eight consecutive cases treated at the University of Michigan, frank disc herniation with fragmented disc in the canal was found in five while pathological disc bulging was found in the other three. All five cases contributed by other institutions had concurrent disc herniation.

This series illustrates the importance of using MR imaging to document the presence of a herniated disc during the initial evaluation of a patient with traumatic locked facets of the cervical spine and prior to attempted reduction of the locked facets. Experience indicates that closed reduction of facet dislocation associated with disc rupture may result in increased spinal cord compression and neurological deficit. If a herniated disc is discovered. anterior discectomy and fusion would be favored as the initial therapy over attempts at closed reduction or operative posterior reduction.

Full access

Joshua Seinfeld, Bette K. Kleinschmidt-Demasters, Shalini Tayal and Kevin O. Lillehei

✓Desmoid-type fibromatosis involving the brachial plexus is a rare and challenging disease. Due to involvement of crucial neurovascular structures, wide local excision of the associated fibromas is rarely feasible and recurrence is common. The authors describe their experience in four surgically treated patients with desmoid-type fibromatosis involving the brachial plexus and review the relevant neurosurgical literature.

All tumors were assessed for c-KIT oncogene mutations in hopes of establishing a biological basis for using the tyrosine kinase inhibitor imatimib mesylate as an adjuvant therapy. Three patients experienced tumor recurrence requiring reoperation. Fractionated radiotherapy achieved local control in three patients, and the disease in one patient progressed beyond the treatment field. Single base pair changes at exon 10 of the c-KIT oncogene were identified in three tumors. One tumor with this mutation did not respond to treatment with imatimib mesylate. A review of the literature revealed 17 additional patients in two different case series. Analysis of these cases emphasizes the need for careful resection in patients with desmoid-type fibromatosis and supports the conclusion that without adjuvant radiotherapy a high local recurrence rate can be anticipated. For optimal local disease control, the authors recommend post-surgical radiation therapy regardless of the extent of resection achieved. The mutational status of the c-KIT oncogene remains an intriguing biological marker that in the future may predict which lesions will be responsive to imatimib mesylate; larger series will be necessary to test this hypothesis.

Restricted access

William F. Chandler, James E. Knake, John E. McGillicuddy, Kevin O. Lillehei and Terry M. Silver

✓ The authors' experience with the intraoperative use of real-time ultrasonography during 21 neurosurgical procedures is reported. These procedures include neoplasm surgery in 18 cases, treatment of an arteriovenous malformation in one case, and ventricular catheter placement for hydrocephalus in two cases. In each of the neoplasm cases, the tumors were imaged just as well through the intact dura as on the brain surface itself. There were no cases in which the pathology could not easily be identified. The use of portable intraoperative ultrasonography in sterile coverings has proven to be extremely useful in localizing small subcortical neoplasms, as well as locating the solid and cystic portions of deep lesions. It has assisted in guiding needles for both biopsy and aspiration. It has also accurately identified and guided Silastic catheters during their placement in the ventricular system in cases of hydrocephalus. The authors have found real-time ultrasonography to be an important new tool in the operating room and will continue to rely on its imaging ability during selected procedures in the future.

Restricted access

Joshua Seinfeld, Bette K. Kleinschmidt-Demasters, Shalini Tayal and Kevin O. Lillehei

Object

Desmoid-type fibromatoses are a locally invasive soft-tissue lesion that is most commonly encountered in abdominal sites. The tumor also affects head and neck areas, particularly the supraclavicular region, where it may encase and distort the brachial plexus and compromise neurovascular structures. Neurosurgeons may be called on to treat desmoid-type fibromatoses in these sites. The authors describe their experience in treating four patients with desmoid-type fibromatoses involving the brachial plexus and report the results of immunohistochemical analysis of the tumors.

Methods

Gross-total excision with nerve sparing was the first-line therapy of choice, although the surgery was challenging. Intraoperative identification of the site of tumor origin from musculoaponeurotic tissues by the neurosurgeon was necessary in two of the four cases to achieve a correct frozen section or final pathological diagnosis. Immunostaining for c-KIT (CD117) was undertaken in all cases in light of a previous report of positive CD117 immunoreactivity in abdominal desmoid-type fibromatoses.

All four tumors manifested weak focal immunostaining for c-KIT. One of the patients was given adjuvant imatinib mesylate therapy, with limited success. Subsequent polymerase chain reaction testing revealed that three of the four tumors manifested a single base pair change in exon 10 of the c-KIT gene (A to C in two cases and A to G in one case). There was local recurrence in three patients, despite gross-total excision. With the combination of surgery and radiation therapy, local disease control was achieved in three of the four patients.

Conclusions

This represents the first report of c-KIT sequencing in desmoid-type fibromatoses and suggests a possible biological basis for continuing to explore the use of adjuvant imatinib mesylate therapy.

Restricted access