Minimally invasive resection of extradural dumbbell tumors of thoracic spine: surgical techniques and literature review

Purpose

Dumbbell-shaped thoracic tumors represent a distinct type of tumor and involve in both the spinal canal and the posterior thoracic cavity. Successful treatment for the tumors depends on gross total resection (GTR) via an open laminectomy and facetectomy or transthoracic transpleural approach. In this case series, we report our experiments with minimally invasive method for the removal of extradural dumbbell thoracic tumor and present related literature review.

Methods

We retrospectively reviewed two patients with dumbbell-shaped thoracic tumors who underwent minimally invasive resection and unilateral transforaminal thoracic intervertebral fusion (TTIF) through unilateral paraspinal muscle approachwith a spotlight expandable tubular retractor. Clinical data, tumor characteristics, and outcomes were analyzed.

Results

Two patients underwent successful minimally invasive treatment of their spinal neoplasms. There were no procedure-related complications. The efficacy in terms of neurological recovery, pain improvement and operative variables (length of incision, operative duration, blood loss, and hospital stay) was better when compared with prior published studies. Postoperative CT image demonstrated complete resection of dumbbell tumor in the patients. The solid fusion was obtained after 3 months follow-up and there was no failure of internal fixation.

Conclusion

If the medial border of intracanal component of extradural dumbbell tumor is near the midline of canal and the pedicles of adjacent vertebrae to tumor are intact, minimally invasive resection of tumor through unilateral paraspinal muscle approach combined with unilateral TTIF is good choice.

     

Surgical Treatment of Intraspinal Angiomatous Meningiomas from a Single Center

Intraspinal angiomatous meningiomas (AMs) are rare lesions, and no case series have been reported. We retrospectively reviewed the data of 12 patients with intraspinal AMs. All patients underwent magnetic resonance imaging (MRI) of the spine. Computed tomography angiography was performed for three cases with cervical lesion. The series included six females and six males with a mean age of 49.6 years. Five tumors were located in the cervical, one in the cervicothoracic, five in the thoracic, and one in the thoracolumbar spine. The most common symptom was motor deficits and the mean duration of symptoms was 18 months. All patients were treated surgically with gross total resection (GTR) (Simpson grade I and II resection). No patients underwent embolization. After surgery immediately, the neurological function was improved in five patients, remained stable in six patients, and was deteriorated in one patient. During an average follow up of 78.6 months, 11 patients experienced an improvement in the neurological function and one patient maintained preoperative status. No tumor recurrence was observed on MRI. Compared to conventional meningiomas, AMs have no special clinical and radiological features. The accurate diagnosis depends on pathology. Timely GTR (en bloc resection) is the best treatment and embolization is not necessary for most patients. Radiotherapy is not recommended after GTR (Simpson grade I and II resection), and the risk of tumor recurrence is low.     

Intramedullary hemangioblastomas: timing of surgery,microsurgical technique and follow-up in 23 patients

Hemangioblastomas are highly vascularised tumors of the central nervous system and account for 1.5–2.5% of all spinal cord tumors. Because of the rarity of these tumors, surgical experience is often limited and, therefore, treatment and indications for timing of surgery are discussed controversial. The authors reviewed their data of 23 consecutive patients with respect to timing of surgery, microsurgical technique, and follow-up. Clinical records of 23 consecutive patients with intramedullary hemangioblastomas who underwent first surgery in our department between 1990 and 2005 were reviewed. In three cases the tumors were localised at the craniocervical junction; four patients had a single tumor in the cervical spine, six patients multiple tumors in the cervical and thoracic spine, eight patients in the thoracic spine only, one patient in the conus region, and one patient had multiple tumors located in the thoracic and lumbar spine. In eight patients, a von-Hippel-Lindau disease (VHL) was associated. The neurological follow-up was evaluated according to the classification of McCormick. Operation was recommended to every symptomatic patient as early as possible. In asymptomatic patients with a sporadic tumor surgery was discussed for diagnostic purposes at any time. In VHL patients, surgery was recommended if tumor growth was observed on MRI in the next practicable time. All tumors were diagnosed by magnetic resonance imaging and in all cases but one a DSA was performed. All patients were treated microsurgically through a posterior approach. The tumors in the spinal cord were removed microsurgically through a partial hemilaminectomy (n = 1), a hemilaminectomy (n = 15), or laminectomy (n = 4) and at the craniocervical junction (n = 3) through a suboccipital craniotomy. During follow-up after 6 months, 18 patients remained neurologically stable (17 in McCormick grade I and 1 in McCormick grade II) and 5 patients recovered to a better status (3 from grade III to II, 2 from grade II to I). There was one complication with a CSF fistula and one recurrence/incomplete removal. Following the above-mentioned principles of microsurgical removal of intramedullary hemangioblastomas, operation is possible with a low procedure-related morbidity and can be recommended especially in VHL patients with progressive symptoms or tumor growth during follow-up. Patients without VHL most frequently require hemangioblastoma resection for diagnostic purposes and/or because symptoms prompted an imaging work-up that lead to the discovery of the tumor.     

Breast carcinoma metastasis to meningioma in the thoracic spine: A case report and review of the literature

Abstract

Context

Systemic metastasis to a primary tumor of the central nervous system is uncommon. Breast carcinomas metastasizing to a possibly preexisting meningioma in the spine are reported very rarely.

Study design

Case report.

Findings

A 69-year-old female was referred to us with progressive gait disturbance. She had undergone a total mastectomy for carcinoma of the right breast 11 years previously. A magnetic resonance imaging of the thoracic spine showed an intra- and extradural spinal cord tumor. The patient underwent resection of the tumor via laminectomy from T2 to T4. After the operation, the patient's neurological status improved significantly, and she was able to walk without assistance. Histological examination showed the tumor to be a fibrous-type meningioma within a metastatic breast cancer tumor. The patient underwent 40 Gy radiation treatment for local control of the tumor. However, the tumor recurred locally 7 months after the surgery. The patient died of carcinomatous pleurisy 13 months after the surgery.

Conclusion

This case illustrates that a primary meningioma in the thoracic spine can be a recipient of breast cancer metastasis, which may alter the treatment strategy.     

Outcome of total en bloc spondylectomy for solitary metastasis of the thoracolumbar spine

BACKGROUND: Total en bloc spondylectomy (TES) was devised to minimize the incidence of local recurrence following resection of spinal tumor. Successful local control with TES has been reported for patients with primary malignant or aggressive benign spinal tumors. As for metastatic spinal tumors, however, only a few surgeons except for the inventor group have reported the outcome of TES. The purpose of this study was to investigate whether TES could provide radical resection of the tumor in patients with solitary spinal metastases. METHODS: Twelve patients underwent TES for a solitary metastatic tumor of the thoracolumbar spine. Primary malignancies included breast cancer in four patients, thyroid cancer in three, renal cell carcinoma in three, lung cancer in one, and unknown in one. All patients were regularly followed up with plain radiographs, computed tomography scans, and magnetic resonance imaging to detect local recurrence. RESULTS: In two of the four cases with paraspinal tumor extension, local recurrences developed at 25 months after surgery. Seven patients have survived for an average of 61 months, while the remaining five died of disseminated metastases with a mean survival of 23 months after surgery. Local recurrences were common in patients with paraspinal extensions. TES for lesions with paraspinal extensions failed to provide curative resection of the tumor. CONCLUSION: Given the great technical demands and potential risks of TES, the indication for TES with spinal metastases should be limited to cases with solitary lesions that do not extend to the paraspinal area.     

Functioning paraganglioma of the thoracic spine: case report

OBJECTIVE AND IMPORTANCE: Paragangliomas of the thoracic spine are rare. Previously described cases involved nonfunctioning tumors. This report documents the diagnosis and surgical treatment for a patient who presented with a functioning thoracic paraganglioma. CLINICAL PRESENTATION: A 53-year-old woman presented with a 10-month history of headaches, facial flushing, and palpitations associated with hypertension. Urinary catecholamine levels were markedly elevated. Magnetic resonance imaging and m-[(123)I]iodobenzylguanidine scans demonstrated an extradural tumor located within the T12 vertebra, with a significant paraspinal component. The neurological examination revealed mild hypesthesia in the right T12 dermatome. INTERVENTION: The patient underwent resection of the tumor after alpha-adrenergic receptor blockade. Grossly complete excision was achieved without neurological complications. Postoperatively, the patient was normotensive and exhibited catecholamine levels within the normal range. CONCLUSION: Functioning paragangliomas of the thoracic spine are rare lesions that are difficult to treat. Successful treatment requires careful surgical planning and expert pharmacological manipulation.     

Primary thoracoscopic gross total resection of neuroblastoma

BACKGROUND: Thoracic neuroblastomas are generally less aggressive and have a better prognosis than those arising below the diaphragm. Our purpose was to study the safety and efficacy of thoracoscopic resection and to evaluate tumor data and patient outcomes. PATIENTS AND METHODS: We reviewed the records of patients who underwent primary thoracoscopic resection of neuroblastoma (NB) between 1998 and 2002. Data included demographics, symptoms, size, location, operative time, complications, hospital stay, histology, biologic markers, adjuvant therapy, and outcome. RESULTS: Five patients (age range, 9 to 44 months) underwent thoracoscopic resection of NB. Three of the patients had neurological symptoms. Tumor size ranged from 2.1 to 6.0 cm. Two tumors were apical, three supradiaphragmatic. Primary thoracoscopic gross total resection was achieved in all 5 cases, all of which were stage 1. Operative time ranged from 64 to 175 minutes. The only complications were two cases of small tumor spillage. Hospital stay was 1 to 4 days. Histology ranged from ganglioneuroma to differentiating NB, with a favorable classification in 4 of 5 cases. None of the tumors were N-Myc amplified. Chemotherapy or radiation therapy was not indicated for any patient. All are alive with no evidence of disease at 14 to 55 months' follow-up. CONCLUSION: Primary gross total resection of mediastinal NB can be achieved safely and effectively by a thoracoscopic approach. In our series, most tumors had favorable histology and biology, and all appear to be potentially treatable by primary thoracoscopic resection alone.     

Intramedullary spinal cord astrolipoma: case report

OBJECTIVE AND IMPORTANCE: Reported is a case of a thoracic intramedullary astrocytoma with a lipomatous component, a so-called astrolipoma. This is the only known case of a single intraspinal astrolipoma in an otherwise healthy patient. CLINICAL PRESENTATION: The patient was a 36-year-old woman with dorsal thoracic pain of more than 1 month's duration, mild lower extremity weakness, and incomplete sensory loss to the T10 level. INTERVENTION: Magnetic resonance imaging of the thoracolumbar spine revealed a fusiform mass at the T9-T11 level. The patient underwent T9-T11 laminectomies and complete resection of the tumor. In the initial postoperative period, the patient's symptoms worsened. However, 3 months after surgery, the patient was clinically improved and was able to walk without assistance. Twelve months after surgery, imaging revealed no evidence of tumor. CONCLUSION: The current treatment plan and recommendation, assuming this tumor will behave like a low-grade glioma or lipoma, is continued radiographic surveillance after gross total resection. Reresection is recommended for tumor recurrence or significant regrowth. The long-term prognosis for astrolipoma is unknown.     

The surgical approach to "dumbbell tumors" of the mediastinum

Background

Successful management of posterior mediastinal dumbbell tumors depends on complete resection with adequate exposure. Correct preoperative assessment of neuroforaminal extension is important to avoid spinal cord injury. The surgical approach remains controversial.

Methods

We report a retrospective analysis of posterior mediastinal dumbbell tumors over a 28-year period. All patients underwent one or more radiographic examinations available at the time of presentation and underwent a single-stage one-incision combined thoracic and neurosurgical procedure.

Results

Among 16 patients aged 5 to 76 years, neuroforaminal involvement was identified before operation in 14 (87.5%) and during the procedure in 2 patients (12.5%). Computed tomography scan missed neuroforaminal involvement in 3 patients. Magnetic resonance imaging in 9 patients correctly identified neuroforaminal extension of the tumor but before MRI, myelography missed this extension in 3 patients. All patients underwent thoracotomy and posterior laminectomy was required in 10 of them. In 6 patients (38%) without laminectomy, resection required widening of the neural foramen in 3 whereas tumor was removed in 3 others through an already widened foramen. Spinal stabilization was required in 2 patients. There were 14 benign and 2 malignant lesions. Complete resection was performed in all patients without spinal cord injury or other major complication. No recurrences have been observed in a follow-up period from 2 months to 28 years (mean, 7.5 years).

Conclusions

Posterior mediastinal tumors should be evaluated for neuroforaminal involvement. A single-stage combined thoracic and neurosurgical approach is safe and leads to good long-term results. Laminectomy may be avoided in some patients.     

Anatomic classification system for surgical management of paraspinal tumors

HYPOTHESIS: An anatomic classification system for paraspinal tumors that identifies complexity of regional anatomy, morbidity in complete or partial resection of anatomic structures, and potential complications may assist surgeons in preoperative planning. DESIGN: Application of a 6-level anatomic classification system for paraspinal tumors by retrospective medical record analysis. The classification system is defined by the following divisions of the vertebral column: I (C3-T3), II (T3-T10), III (T10-L2), IV (L1-L5, anterior to spine), V (L2-L5, lateral to spine), and VI (S1-S5). PATIENTS: All patients seen by us who underwent paraspinal tumor resection between 1997 and 2002. SETTING: Tertiary referral facility. MAIN OUTCOME MEASURES: Level-specific preoperative and surgical procedures and expected and unexpected vascular and neurologic morbidity caused by surgical intervention. RESULTS: Twenty-six patients met the inclusion criteria, and each of the levels (I through VI) of the classification system was represented by at least 2 patients. Expected morbidity that occurred because of surgical intervention included laryngeal paralysis in 1 patient with a level I tumor, femoral nerve palsy in 1 patient with a level V tumor, and neurogenic bladder and rectal dysfunction in 2 patients with level VI tumors. No unexpected neurologic deficit developed in any patient. Unanticipated intestinal ischemia and infarction occurred in 1 patient, who died after undergoing level IV surgery. Follow-up period ranged from 3 months to more than 5 years. CONCLUSION: Application of this 6-level anatomic classification system based on paraspinal tumor location may allow surgeons to anticipate specific surgical problems and to evaluate risks of resection and potential complications on the basis of regional anatomy.     

Removal of thoracic dumbbell tumors through a single-stage posterior approach: its usefulness and limitations

Background

The purpose of this study was to evaluate the surgical results of the single-stage surgery only from posterior approach for the management of thoracic dumbbell tumor and to discuss its usefulness and limitations.

Methods

Sixteen cases of large thoracic dumbbell tumor (11 men and 5 woman, mean age, 44 years) were analyzed retrospectively. Pathologic findings included schwannoma in 10 patients, neurofibroma in 2 patients (Recklinghausen in 1 patient), meningioma in 2 patients, myxolipoma in 1 and ganglioneuroma in 1. They underwent single-stage removal of dumbbell tumor using the posterior approach followed by laminectomy and often costotransversectomy combined with instrumentation. Clinical and radiologic outcomes are reviewed.

Results

The mean follow-up period for clinical and radiographic outcome variables was 66 months (range, 24–120 months). Operative time ranged from 185 to 420 min (mean, 320 min), with estimated blood loss ranging from 71 to 1830 ml (mean, 540 ml). Postoperative complications were pleural injury during the enucleation of paravertebral tumors, which could be repaired, and the chest tube was detained to prevent postoperative pneumothorax. Postoperative complications included atelectasis in one case. All patients had tumors successfully removed with no neurological deterioration. One patient underwent both posterior and anterior surgery because of attachment to and compression of an artery. We were not able to diagnose this case preoperatively, although a biopsy had been performed.

Conclusions

Single-stage surgery may be a useful method for removing thoracic dumbbell tumors without the combined anterior approach, unless they are attached to and compressing the artery and the diagnosis cannot be made preoperatively.     

Thoracoscopic removal of neurogenic mediastinal tumors: technical aspects

Background: Thoracoscopy is fast becoming the standard approach for the removal of neurogenic mediastinal tumors. However, there are risks for adjacent nervous structures (stellate ganglion, spinal cord). The aim of this study was to review the technical features of this approach.Methods: Between December 1999 and January 2003, nine patients underwent thoracoscopic resection of a mediastinal neurogenic tumor at our hospital. Five of these patients were asymptomatic with incidentally found tumor; the other four patients had compression-related syndromes. Two tumors had developed in the superior sulcus, and one had a spinal canal component (dumbell-type tumor).Results: Thoracoscopic dissection was possible in all cases. In one patient, resection of the tumor was performed via a combined neurosurgical and thoracoscopic approach. Seven tumors were benign nerve sheath tumors (schwannoma), and 2 were nerve cell tumors (ganglioneuroma). The postoperative course was uncomplicated in all patients.Conclusion: The thoracoscopic resection of mediastinal neurogenic tumors is technically easy, except for bulky tumors of the superior sulcus and dumbbell tumors, which require a combined thoracoscopic and neurosurgical approach.     

Extensive posterolateral exposure and total removal of the giant extraforaminal dumbbell tumors of cervical spine: surgical technique in a series of 16 patients

Background contextRemoval of cervical dumbbell tumors can be particularly challenging because of unique exposure requirements and proximity of the vertebral artery (VA). There are no reports describing the treatment of giant cervical spine dumbbell tumors (CSDTs).PurposeTo introduce an extensive posterolateral approach to CSDTs involving total lateral mass resection and laminectomy.Study designProspective study of all the patients with multilevel CSDTs treated by this new procedure between December 2002 and March 2006.Patient sampleSixteen patients (3 men and 13 women) with CSDTs underwent the procedure we describe. The follow-up periods ranged from 9 to 51 months (average 9 months). Average age at surgery was 45 years (range 23–68 years).Outcome measuresAxial symptoms and Japanese Orthopedic Association scores were recorded. Pre- and postoperative ranges of neck motion were measured on lateral flexion and extension radiographs.MethodsAfter making a midline incision, we preferred exposing the extraforaminal component of the tumor before performing a semilaminectomy and lateral mass resection. Any lateral extension of a tumor can be attained by detachment of the adjacent three or more segments of the lateral mass muscle insertion. The most lateral portion can be separated beneath the tumor's superficial muscle flap, and then when the tumor is retracted medially, the whole portion of the lateral component can be totally exposed. We then performed total lateral mass resection and laminectomy to expose the tumor at the foramina and cervical canal.ResultsWe were able to completely resect the tumors in every patient. The average duration of surgery was 150 minutes. Blood loss was minimal (average 400 mL). All patients were monitored for a minimum of 9 months (range 9–51 months; mean 28 months). The follow-up period was uneventful, and no patients developed spinal instability.ConclusionsExtensive posterolateral exposure enables surgeons to reach the lateralmost portion of CSDTs and also facilitates septation of the VA and resection of vertebral body encroachment of the tumor.     

后路椎板切除入路手术治疗椎管内神经鞘瘤的疗效

目的:探讨后路椎板切除入路手术治疗椎管内神经鞘瘤的临床疗效。方法:我院2005年1月~2011年1月收治71例椎管内神经鞘瘤,男39例,女32例,年龄25~99岁,平均51.6岁;颈段22例,胸段24例,腰、骶段25例,3例肿瘤位于髓内,66例位于髓外硬膜下,2例位于硬膜外。均行后路椎板切除入路手术治疗,术中57例采用半椎板切除,6例行全椎板切除,2例行多节段半椎板切除,6例行半椎板联合患侧关节突关节切除以完全暴露肿瘤组织,切除肿瘤;其中载瘤神经根与肿瘤无法分离而一并切除者9例;14例行全椎板切除或多节段半椎板切除或半椎板联合患侧关节突切除者采用脊柱内固定及植骨融合术。术后随访8~70个月,观察临床疗效,复查X线片观察脊柱稳定性及植骨融合情况,复查MRI观察肿瘤有无复发。结果:手术时间2~6h,平均3.5h;术中出血量300~800ml,平均450ml。71例患者肿瘤均获完全切除,术后均经病理检查证实为神经鞘瘤。术中无脊髓神经损伤。术后12例患者出现不同程度脑脊液漏,4例患者出现脊髓缺血再灌注损伤,给予对症治疗后康复。随访期内(8~70个月)全部患者临床症状及神经功能均有明显改善,复查MRI未见肿瘤残留或复发。14例采用脊柱内固定及植骨融合术患者植骨融合,内固定稳定。随访期间所有患者未见椎体滑脱、失稳现象。结论:后路椎板切除入路能充分暴露肿瘤,有利于完全切除肿瘤,采用此入路手术治疗椎管内神经鞘瘤临床疗效满意。     

Epithelioid hemangioendotheliomas of the spine: clinical characters with middle and long-term follow-up under surgical treatments

Epithelioid hemangioendothelioma, an aggressive vascular tumor has the rarity of morbidity that arises in the spine. There were few cases reported in literatures in recent years, and little was known about this disease. A review study of the patient files in our constitutions between 1996 and 2006 showed that five patients were treated for spinal epithelioid hemangioendothelioma. Although only five patients, this study attempts to bring more informations about this rare lesion. This patient group included two males and three females. The lesions located in the cervical (case 1) or thoracic (case 2–4) or lumbar spine (case 5). Treatments included: laminectomy and cytoreductive surgery followed by external beam irradiation (one patient), expanded resection in piece meal with postoperative external beam irradiation (three patients), and total en bloc resection alone (one patient). Reconstruction of the spinal stability was performed in four patients. Follow-up period ranged from 25 to 72 months, averaged 47.4 months. The neurologic function of patients got a satisfactory progress except the paraplegic patient at diagnosis. The patient who received laminectomy and cytoreductive surgery followed by external beam irradiation still presented with tumor local progress, metastasis, and she died at 34 months after operation. No local recurrence or distant metastasis was detected in the other four patients. Epithelioid hemangioendothelioma of the spine is so rare in clinic as a primary aggressive vascular tumor. Based on our experience, a valid expanded resection of the tumor with adjunct radiation therapy or total en bloc excision may present with acceptable results.     

Breast carcinoma metastasis to meningioma in the thoracic spine: A case report and review of the literature

Context

Systemic metastasis to a primary tumor of the central nervous system is uncommon. Breast carcinomas metastasizing to a possibly preexisting meningioma in the spine are reported very rarely.

Study design

Case report.

Findings

A 69-year-old female was referred to us with progressive gait disturbance. She had undergone a total mastectomy for carcinoma of the right breast 11 years previously. A magnetic resonance imaging of the thoracic spine showed an intra- and extradural spinal cord tumor. The patient underwent resection of the tumor via laminectomy from T2 to T4. After the operation, the patient''s neurological status improved significantly, and she was able to walk without assistance. Histological examination showed the tumor to be a fibrous-type meningioma within a metastatic breast cancer tumor. The patient underwent 40 Gy radiation treatment for local control of the tumor. However, the tumor recurred locally 7 months after the surgery. The patient died of carcinomatous pleurisy 13 months after the surgery.

Conclusion

This case illustrates that a primary meningioma in the thoracic spine can be a recipient of breast cancer metastasis, which may alter the treatment strategy.     

Osteoid osteoma and osteoblastoma of the spine: experiences with 22 patients

Osteoblastomas and osteoid osteomas of the spine are relatively rare bone-forming tumors. Between 1980 and 1999, nine patients with osteoid osteoma and 13 patients with osteoblastoma had surgery for their tumors. Four tumors were in the cervical spine, six tumors were in thoracic spine, 10 tumors were in the lumbar spine, and two tumors were in the sacrum. The average duration between onset of pain and surgery was 16.6 months in 12 patients treated in the 1980s and 8.6 months in 10 patients treated in the 1990s. Seventeen patients had scoliosis. In nine of 10 patients with magnetic resonance imaging scans, high signal intensity areas in the muscles and bone around the lesion were seen. Two of nine patients with osteoid osteoma and nine of 13 patients with osteoblastoma had neurologic disorders before treatment. All patients had open resection of the lesions. Two patients with osteoid osteoma had relapse because of incomplete resection, necessitating a second excision. In 16 of 17 patients with preoperative spinal deformity, the deformity improved during followup. With development of modern imaging techniques, exact surgical planning may become possible; however, in some cases, intraoperative complete resection of the lesion still is difficult.     

Thoracoscopic removal of intrathoracic neurogenic tumors: a combined Chinese experience

OBJECTIVE: To review the surgical and clinical results of minimally invasive resection of intrathoracic neurogenic tumors using a video-assisted thoracoscopic technique. SUMMARY BACKGROUND DATA: Thoracoscopy has emerged as a possible means for diagnosing and managing various intrathoracic disorders. Benign intrathoracic tumors often are ideal lesions for resection using a video-assisted technique. The authors report on their combined experience with the thoracoscopic resection of 143 intrathoracic neurogenic tumors. METHODS: Between March 1992 and February 1999, 143 patients with intrathoracic neurogenic tumors were diagnosed and underwent resection using video-assisted thoracoscopic techniques in three teaching centers. Case selection, surgical technique, and clinical results were reviewed. RESULTS: The average age of the patients was 40.8 years; 57.3% were male. Thirty-eight patients (27%) had symptoms attributable to the masses. Seventy-two masses were neurofibromas, 33 were neurilemmomas, 7 were paragangliomas, and 31 were ganglioneuromas. All but seven tumors were located in the posterior mediastinum. The masses were on average 3.5 cm in greatest diameter. The mean surgical time was 40 minutes, and the average hospital stay was 4.1 days. There were no major postoperative complications or recurrences to date. Nine patients reported paresthesias over the chest wall during a mean follow-up of 29 months. CONCLUSIONS: Resection of intrathoracic neurogenic tumors using a thoracoscopic technique based on standard surgical indications would seem to be appropriate. Most of these masses are benign and readily removed. For dumbbell tumors, a combined thoracic and neurosurgical approach is mandatory.     

Intraoperative magnetic resonance imaging to determine the extent of resection of pituitary macroadenomas during transsphenoidal microsurgery

OBJECTIVE: Well-established surgical goals for pituitary macroadenomas include gross total resection for noninvasive tumors and debulking with optic chiasm decompression for invasive tumors. In this report, we examine the safety, reliability, and outcome of intraoperative magnetic resonance imaging (iMRI) used to assess the extent of resection, and thus the achievement of preoperative surgical goals, during transsphenoidal microneurosurgery. METHODS: Our magnetic resonance operating room contains a Hitachi AIRIS II 0.3-T, vertical-field open magnet (Hitachi Medical Systems America, Inc., Twinsburg, OH). A motorized scanner tabletop moves the patient between the imaging and operative positions. For transsphenoidal surgery, the patient is positioned directly on the scanner tabletop so that the surgical field is located between 1.2 and 1.6 m from the magnet isocenter. At this location, the magnetic field strength is low (<20 G), thus permitting the use of many conventional surgical instruments. Thirty consecutive patients with pituitary macroadenomas underwent tumor resection in our magnetic resonance operating room by use of a standard transsphenoidal approach. After initial resection, the patient was advanced into the scanner for imaging. If residual tumor was demonstrated and deemed surgically accessible, the patient underwent immediate re-exploration. RESULTS: iMRI was performed successfully in all 30 patients. In one patient, iMRI was used to clarify the significance of hemorrhage from the sellar region and resulted in immediate conversion of the procedure to a craniotomy. In the remaining 29 patients, initial iMRI demonstrated that the endpoint for extent of resection had been achieved in only 10 patients (34%) after an initial resection attempt, whereas 19 patients (66%) still had unacceptable residual tumor. All 19 of these latter patients underwent re-exploration. Ultimately, re-exploration resulted in the achievement of the planned endpoint for extent of resection in all of the 29 completed transsphenoidal explorations. Operative time was extended in all cases by at least 20 minutes. CONCLUSION: iMRI can be used to safely, reliably, and objectively assess the extent of resection of pituitary macroadenomas during the transsphenoidal approach. The surgeon is frequently surprised by the extent of residual tumor after an initial resection attempt and finds the intraoperative images useful for guiding further resection.     

Diagnostic imaging and surgical treatment of dumbbell tumors of the mediastinum

We describe the diagnostic procedures and surgical approaches employed in 5 patients with dumbbell tumors of the mediastinum. Magnetic resonance imaging accurately described the existence and longitudinal extension of the intraspinal component of the tumor and assisted in choosing the appropriate surgical approach. Both the intrathoracic and intraspinal components of the tumor were resected at one time by a thoracic and neurosurgical team. We employed the Grillo technique three times and a separate laminectomy and thoracotomy approach. Magnetic resonance imaging proved the most useful diagnostic technique for suspected dumbbell mediastinal tumors. In our experience, the extended thoracotomy proposed by Grillo and co-workers worked well for small tumors involving only one foramen in which the intraspinal extension was limited to 2 to 3 cm, and when no more than two laminectomies were required. On the other hand, thoracotomy and a longitudinal paravertebral incision are preferable for larger tumors (more than 4 cm) involving more than one foramen in which the intraspinal extension exceeds 2 to 3 cm, for tumors requiring multiple laminectomy, and when bony infiltration is present.