Biomedical subjects

Rod J Oskouian

Publications and source records attributed to Rod J Oskouian.

At least 19 recordsLinked to original sources

PubMed2006

Osteogenic differentiation of noncultured immunoisolated bone marrow-derived CD105+ cells.

The culture expansion of human mesenchymal stem cells (hMSCs) may alter their characteristics and is a costly and time-consuming stage. This study demonstrates for the first time that immunoisolated noncultured CD105-positive (CD105(+)) hMSCs are multipotent in vitro and exhibit the capacity to form bone in vivo. hMSCs are recognized as promising tools for bone regeneration. However, the culture stage is a limiting step in the clinical setting. To establish a simple, efficient, and fast method for applying these cells for bone formation, a distinct population of CD105(+) hMSCs was isolated from bone marrow (BM) by using positive selection based on the expression of CD105 (endoglin). The immunoisolated CD105(+) cell fraction represented 2.3% +/- 0.45% of the mononuclear cells (MNCs). Flow cytometry analysis of freshly immunoisolated CD105(+) cells revealed a purity of 79.7% +/- 3.2%. In vitro, the CD105(+) cell fraction displayed significantly more colony-forming units-fibroblasts (CFU-Fs; 6.3 +/- 1.4) than unseparated MNCs (1.1 +/- 0.3; p < .05). Culture-expanded CD105(+) cells expressed CD105, CD44, CD29, CD90, and CD106 but not CD14, CD34, CD45, or CD31 surface antigens, and these cells were able to differentiate into osteogenic, chondrogenic, and adipogenic lineages. In addition, freshly immunoisolated CD105(+) cells responded in vivo to recombinant bone morphogenetic protein-2 by differentiating into chondrocytes and osteoblasts. Genetic engineering of freshly immunoisolated CD105(+) cells was accomplished using either adenoviral or lentiviral vectors. Based on these findings, it is proposed that noncultured BM-derived CD105(+) hMSCs are osteogenic cells that can be genetically engineered to induce tissue generation in vivo.

Adolescent↗

PubMed2006

Degenerative lumbar scoliosis.

In adults, symptomatic scoliosis is usually a de novo primary degenerative deformity that develops in the fifth or sixth decade or an unrecognized or untreated idiopathic deformity with superimposed degeneration. The evaluation and treatment of adult scoliosis must focus on addressing patient symptoms while limiting the consequences of the treatment. The presence of neurological deficits, the flexibility of the deformity, the coronal and sagittal balance, and status of spinal segments outside of the main deformity are all important considerations when planning surgery. The complication rate of deformity surgery in adults is potentially high; but excellent functional outcome and patient satisfaction can occur with thorough preoperative patient education and meticulous surgical technique.

Adult↗

PubMed2006

The craniopharyngioma.

The craniopharyngioma is one of the most common destructive lesions of the hypothalamus and pituitary gland. It still remains one of the most difficult tumors to treat effectively since complete resection is often impossible and is associated with frequent recurrence. Current therapy is multimodal and focuses on a combination of surgical decompression, medical treatment, as well as stereotactic radiosurgery. This chapter reviews the embryology, neuroanatomy, current treatment strategies, clinical features and the several surgical approaches to its treatment.

Central Nervous System Cysts↗

PubMed2006

Vascular injury and transsphenoidal surgery.

Vascular complications can and do arise from transsphenoidal surgery and, when they occur, they have a high incidence of mortality and serious morbidity. The anatomic substrate for such complications is discussed, along with technical aspects of surgery and other methods for the avoidance of vascular complications.

Basilar Artery↗

PubMed2006

Peroneal neuropathy following successful bariatric surgery. Case report and review of the literature.

Peroneal neuropathy has been observed in starvation, anorexia, and other situations of extreme weight loss. The authors report a case in which sequential bilateral peroneal neuropathies developed after successful bariatric surgery resulting in a weight loss of 114 lbs over 12 months. The diagnosis was confirmed using nerve conduction studies and electromyography. Clinical improvement occurred with decompressive surgery at the level of the knee.

Decompression, Surgical↗

PubMed2006

Optimization of a mouse locomotor rating system to evaluate compression-induced spinal cord injury: correlation of locomotor and morphological injury indices.

OBJECT: Due to the usefulness of mouse genetics, there is a need to improve procedures for producing and assessing spinal cord injury (SCI) in mice. The authors describe an improved locomotor scoring system for evaluating SCI. The modified Basso-Beattie-Bresnahan (mBBB) scoring system for mice is compared with existing procedures as well as histological SCI criteria. METHODS: Mice were subjected to SCI by placing a weight on the cord at T-12 for 5 to 15 minutes after laminectomy to produce spinal cord ischemia. Injury was assessed using mBBB scoring that incorporates elements of the rat BBB and the mouse motor function scoring systems that are best suited for precisely assessing mouse SCI. The mBBB score was found to be more discriminating than the inclined plane test, and in the authors' laboratory it had a significantly lower coefficient of variation than the Basso mouse scale score. The mBBB score is well correlated with sparing of white matter as assessed by eriochrome cyanine staining of myelin. CONCLUSIONS: Weight placement at T-12 in the mouse causes reproducible SCI. A new mBBB scoring system is useful for accurately assessing locomotor dysfunction following SCI in mice and is well correlated with histological assessment of spinal cord white matter.

Animals↗

PubMed2006

Anterior stabilization of three-column thoracolumbar spinal trauma.

OBJECT: The purpose of this study was to evaluate the results obtained in patients who underwent anterior stabilization for three-column thoracolumbar fractures. METHODS: The authors retrospectively reviewed available clinical and radiographic data (1997-2006) to classify three-column thoracolumbar fractures according to the Association for the Study of Internal Fixation (AO) system, neurological status, spinal canal compromise, pre- and postoperative segmental angulation, and arthrodesis rate. The mean computed tomography-measured preoperative spinal canal compromise was 48.3% (range 8-92%), and the mean vertebral body height loss was 39.4%. The mean preoperative kyphotic deformity of 14.9 degrees improved to 4.6 degrees at the final follow-up examination. Although this angulation had increased a mean of 1.8 degrees during the follow-up period, the extent of correction was still significant compared with the preoperative angulation (p < 0.01). There were no cases of vascular complication or neurological deterioration. CONCLUSIONS: Contemporary anterior spinal reconstruction techniques can allow certain types of unstable three-column thoracolumbar fractures to be treated via an anterior approach alone. Compared with traditional posterior approaches, the anterior route spares lumbar motion segments and obviates the need for harvesting of the iliac crest.

Adolescent↗

PubMed2005

Genetics of pituitary adenomas: current theories and future implications.

Pituitary tumors are often viewed as benign entities that are rarely associated with significant rates of mortality or morbidity. These tumors can still be extremely difficult to manage, however, and can cause significant morbidity to the patient, both from tumor mass effect and secondary to hormonal imbalances.

Adenoma↗

PubMed2005

Image-guided thoracoscopic spinal surgery: a merging of 2 technologies.

STUDY DESIGN: Retrospective clinical and intraoperative navigational data review. OBJECTIVE: To evaluate quantitatively the application of frameless stereotactic image guidance in thoracoscopic discectomy procedures. SUMMARY OF BACKGROUND DATA: Thoracoscopic spinal surgery has technical and anatomic challenges that result in difficult orientation with a 2-dimensional imaging procedure in a complex 3-dimensional structure. METHODS: There were 16 patients who underwent image-guided thoracoscopic discectomy procedures that combine these 2 technologies. Accuracy was determined by the registration (calculated) error and actual navigation (intraoperative) error. The clinical outcomes and complications were reviewed. RESULTS: Accuracy determined by registration (calculated) and navigation (intraoperative) was 1.7 and 1.2 mm, respectively. The additional time required for the image guidance portion of the procedure was countered by the efficiency of the remaining procedure. Clinical outcomes and complication were comparable with previous experience. CONCLUSIONS: Image-guided thoracoscopic spinal surgery can provide 3-dimensional orientation to a 2-dimensional imaging procedure that ultimately improves accuracy, efficiency, and safety. Future developments in combining guidance technology with standard surgical procedures will likely continue.

Adult↗

PubMed2005

Thoracolumbar vertebral reconstruction after surgery for metastatic spinal tumors: long-term outcomes.

OBJECT: Metastatic spinal tumors continue to represent a major problem for patients and treating physicians. The purpose of this study was to assess quantitatively the functional outcome, quality of life, and survival rates of patients after major reconstructive spine surgery. METHODS: A prospective database was established and 58 patients were identified who had undergone thoracolumbar vertebral reconstruction for metastatic spinal tumors between March 1993 and October 1999. Surgical indications included disabling pain (92%) and/or progressive neurological dysfunction (60%). Forty-nine patients (85%) had clinical improvement in pain as determined based on the Oswestry pain scale (p < 0.05); 60% demonstrated improvement in their neurological status. The mean neurological improvement in Frankel grade was 1.2 (p < 0.05). The 12-month survival rate was 65%, and all patients who were ambulatory after surgery remained so until the time of death. Instrumentation failure requiring repeated operation occurred in two patients (3.5%), and in 12 patients (21%) local tumor recurrence necessitated repeated surgery. There were no cases of neurological deficit or death related to surgery. CONCLUSIONS: Major anterior thoracolumbar vertebral reconstruction is an effective treatment for local tumor control. More importantly, the authors have demonstrated that surgical treatment can significantly improve the quality of life by improvement of pain control and maintenance of ambulation during the patient's remaining life span.

Humans↗

PubMed2005

The transsphenoidal approach. A historical perspective.

Over the last century, the transsphenoidal approach has evolved into the first-line method of treatment for sellar as well as select groups of parasellar and suprasellar lesions. The journey to its current popularity has been marked by controversy and near abandonment in the late 1920s, followed by its renaissance in the late 1960s. Despite the profound skepticism with which this procedure was viewed, several visionary neurosurgeons persevered through its nadir in popularity, preserving this surgical corridor to the skull base. Advances in medical and surgical techniques, paralleling an improved understanding of pituitary pathophysiology, contributed to its resurgence. The transsphenoidal procedures now performed stem from an array of modifications and refinements accumulated through nearly 100 years of medical and surgical evolution. This era's critical innovations and neurosurgical personalities are the topic of this historical overview.

Brain Neoplasms↗

PubMed2005

Endoscopic thoracic microdiscectomy.

OBJECT: The purpose of this investigation was to evaluate surgical and neurological outcomes in thoracic disc surgery in a prospective fashion. METHODS: Quantifiable outcome data such as operating time, blood loss, duration of chest tube drainage, narcotic drug use, length of hospital stay (LOS), and long-term follow up of neurological function and pain-related symptoms were collected prospectively. In patients with myelopathy there was an improvement of two Frankel grades in the thoracoscopic discectomy group and one Frankel grade in the patients treated with thoracotomy; however, patients in the thoracotomy group were significantly worse preoperatively. None of the patients experienced worsened pain, and pain related to radiculopathy was improved by 75% in the thoracoscopic group. CONCLUSIONS: Thoracoscopic discectomy yields acceptable surgical results and has several distinct advantages, with reduced postoperative pain, morbidity, and LOS.

Adult↗

PubMed2005

Single-center experience with pediatric Cushing's disease.

OBJECT: Despite ongoing advances in surgical and radiotherapeutic techniques, pediatric Cushing's disease remains a diagnostic and therapeutic challenge. The authors report on the results of a single-center retrospective review of 33 pediatric patients with Cushing's disease, providing details with respect to clinical presentation, diagnostic evaluation, therapeutic course, complications, and outcomes. METHODS: There were 17 female and 16 male patients whose mean age was 13 years (range 5-19 years) in whom a diagnosis of Cushing's disease was based on clinical and biochemical criteria. Typical symptoms included weight gain (91%), prepubertal growth delay (83%), round facies (61%), hirsutism (58%), headache (45%), abdominal striae (42%), acne (33%), amenorrhea (24%), and hypertension (24%). In 67% of the cases, preoperative magnetic resonance images revealed a pituitary lesion and in 82% of the cases the imaging studies effectively predicted lateralization. Inferior petrosal sinus sampling was performed in seven patients (21%), and in all of these cases lateralization was 100% reliable. Fifty-five percent underwent selective adenomectomies and 45% underwent subtotal hypophysectomies. Complications included one case of diabetes insipidus, one of persistent hypocortisolemia necessitating prolonged glucocorticoid replacement therapy, and one minor vascular injury that did not necessitate postoperative management modification or cause sequelae. There were no surgery-related deaths and no cases of postoperative cerebrospinal fluid leakage or meningitis. During a mean follow-up period of 44 months, clinical remission was ultimately achieved in 91% of patients: 76% after transsphenoidal surgery alone and an additional 15% after adjuvant radiosurgery and/or adrenalectomy following surgical failure. Three patients (12%) experienced disease recurrence and underwent a second surgical procedure at 18, 81, and 92 months, respectively; based on clinical and biochemical criteria a second remission was achieved in all. Three patients (9%) remain with persistent disease. CONCLUSIONS: Pediatric Cushing's disease is a rare condition, often requiring a multidisciplinary diagnostic and a multimodal therapeutic approach for successful long-term remission.

Adolescent↗

PubMed2005

Endoscopic thoracic microdiscectomy.

OBJECT: The purpose of this clinical study was to evaluate prospectively surgical and neurological outcomes after endoscopic thoracic disc surgery. METHODS: The authors assessed the following quantifiable outcome data in 46 patients: operative time, blood loss, duration of chest tube insertion, narcotic use, hospital length of stay (LOS), and long-term follow-up neurological function and pain-related symptoms. In patients who presented with myelopathy there was a postoperative improvement of two Frankel grades. Pain related to radiculopathy was improved by 75% and in one patient it worsened postoperatively. The authors also present operative data, surgical outcomes, and complications. CONCLUSIONS: Thoracoscopic discectomy can be used to achieve acceptable results. It has several distinct advantages such as reduced postoperative pain, morbidity, and LOS compared with traditional open procedures.

Adult↗

PubMed2004

The future of spinal arthroplasty: a biomaterial perspective.

Both total hip and knee arthroplasty have demonstrated outstanding clinical results. The functional spinal unit composed of the intervertebral disc and facet joints is at least as complex. The intricacies of the coupled motions of the functional spinal unit have made development of an artificial disc a challenge. There have been several failed attempts to create a disc replacement that recapitulates normal motion while providing significant longevity and a low incidence of complications. Better understanding of the biomechanics of the intervertebral disc complex and improvements in implant material have made successful intervertebral disc replacement a likely reality, now that several artificial discs have completed Food and Drug Administration clinical trials. In this manuscript the authors detail the biomaterials used in disc arthroplasty and discuss joint wear and the host response to wear debris.

Arthroplasty↗

PubMed2002

Surgical management of unruptured basilar artery bifurcation aneurysms. Technical note.

The basilar artery (BA) bifurcation is the most common site for aneurysms arising from the posterior circulation. Their inhospitable location, nested within the narrow confines of the interpeduncular fossa anterior to the brainstem, coupled with the rich network of adjacent critical thalamoperforating arteries irrigating the midbrain and thalamus, pose difficult anatomical obstacles for the surgeon. The age old adage that the only cure for intracranial aneurysms remains exclusion from circulation before rupture still holds true. Although management of unruptured aneurysms in general is still controversial, unruptured aneurysms of the BA bifurcation can be treated surgically with acceptable rates of morbidity. The clinician must gather and weigh all clinical, pathological, and radiological data when formulating recommendations for the individual patient. In the present report the authors describe their current technique for the surgical management of unruptured BA bifurcation aneurysms; this represents the culmination of the senior author's (N.K.) experience in the management of both ruptured and unruptured BA bifurcation aneurysms. A modified, right-sided subtemporal transtentorial approach has been adopted in all cases of isolated unruptured BA bifurcation aneurysms. Technical nuances are described.

Disease Management↗

PubMed2002

Esthesioneuroblastoma: clinical presentation, radiological, and pathological features, treatment, review of the literature, and the University of Virginia experience.

Esthesioneuroblastoma is a rare and malignant upper nasal cavity neoplasm involving the anterior skull base. Treatment includes surgery, radiotherapy, chemotherapy, or a combination. The ideal treatment modality has yet to be determined. Esthesioneuroblastoma often lies in proximity to the optic nerves, optic chiasm, and the orbit. Resection risks damaging these critical structures, and radiotherapeutic techniques, similar to those applied for paranasal sinus tumors, may damage these vital structures and result in late sequelae such as blindness and cortical necrosis. Management strategies for this neoplasm lack uniformity, and there is no universally accepted staging system. In this paper the authors discuss the clinical presentation, radiological and pathological features, and treatment of this rare, malignant skull base neoplasm, as well as review the literature. They also present their results and treatment regimen, which includes preoperative radio- and chemotherapy or 1) craniofacial resection if the lesion has a significant intracerebral component, or 2) frontal sinus resection if little intracranial extension exists.

Adolescent↗

PubMed2002

Thoracoscopic microdiscectomy.

The thorascopic approach for the microsurgical removal of herniated thoracic discs is described, and perioperative management is also discussed. The microsurgical techniques used for decompression of the spinal canal in the thoracic spine are presented in detail. The diagnostic imaging, surgical positioning, approach, port placement, localization of the thoracic level, exposure of the surgical field, excision of the rib head, exposure with removal of the herniated disc, and postoperative management are outlined. Surgical and operative "pearls" in thoracoscopic spinal surgery for removing herniated thoracic discs when possible are described and illustrated.

Diskectomy↗