Arteriovenous malformations of the lateral ventricle

Nine cases with arteriovenous malformations (AVM's) predominantly involving the lateral ventricle are presented. All the AVM's were small, but caused intraventricular hemorrhage in eight cases. Only two patients had an intracerebral hemorrhage large enough to warrant evacuation. Eight patients were under the age of 40 years at the onset of their disease. Computerized tomography demonstrated intraventricular hemorrhage in eight patients, and after intravenous administration of contrast medium a small area of enhancement with dilated subependymal draining veins was seen in seven. The lateral ventricles were of normal size in seven cases, and only two patients required a shunting procedure. Angiography demonstrated that the lesion was an AVM in eight patients, and did not visualize the lesion in the ninth. One patient suffered a recurrent intraventricular hemorrhage when the AVM was demonstrated, although repeated angiography had failed to disclose a vascular lesion at his first intraventricular hemorrhage 14 months before. All nine lesions were resected by microsurgical techniques, and the results were excellent in eight patients. Of four caudate lesions, three were resected through a frontal transcortical approach and the other was operated on through an anterior transcallosal approach; the results were excellent in three of these patients. Only one (Case 4) was left with neurological deficits; he had confusion and disorientation following a right frontal transcortical approach. Even in the dominant hemisphere, lesions in the head of the caudate nucleus could be safely resected by an anterior transcallosal approach. Two choroidal lesions located in the temporal horn and trigone on the dominant side were resected through a middle temporal gyrus approach, and three thalamic lesions through a posterior transcallosal approach, all with excellent results. In all cases the brain opening required was about the width of the retractor (maximum 2.0 cm, average 1.5 cm).     

Computer-assisted stereotaxic laser resection of intra-axial brain neoplasms

Computer interpolation of stereotaxic computerized tomography (CT) scanning data allows the transposition of a tumor volume in stereotaxic space. A stereotaxically directed and computer-monitored CO2 laser is then utilized to vaporize that volume as the surgeon monitors the position of a cursor representing the laser beam against planar contours of the tumor displayed on an operating room computer monitor. Computer-assisted stereotaxic laser microsurgery provides precise three-dimensional control for aggressive resection of deep-seated tumors from neurologically important areas with acceptable postoperative results. Thus, a significant cytoreduction can be achieved in addition to providing a tissue diagnosis and internal decompression. The authors report 83 computer-assisted stereotaxic laser procedures for tumor excision in 78 patients. The tumors were located in the thalamus/basal ganglia in 15 patients, ventricular system in five, corpus callosum in four, brain stem in three, and deep and centrally in the hemispheres in 51. Histologically, there were 26 glioblastomas, seven grade III astrocytomas, 14 grade II astrocytomas, 14 metastatic tumors, nine vascular lesions, and eight miscellaneous lesions. Resection of these subcortical lesions was confirmed by postoperative contrast-enhanced CT scanning. Neurological examinations performed 1 week after the 83 procedures revealed that 48 patients had improved from their preoperative level and 23 were unchanged (12 were neurologically normal preoperatively). Twelve patients had an increase in a preoperative neurological deficit, three of whom died in the postoperative period: one from infection, one from pulmonary emboli, and one from brain-stem edema. The average survival period (37.6 weeks) of patients having glioblastomas treated by this technique and irradiation was no different from that of patients having glioblastomas in more favorable locations treated by conventional surgery and irradiation. Patients with circumscribed lower-grade astrocytomas did better in terms of morbidity and completeness of resection than those with infiltrative neoplasms. Other circumscribed lesions, such as metastatic tumors, vascular lesions, and intraventricular tumors, were easily resected by the technique described.     

Endoscope-assisted microsurgical resection of epidermoid tumors of the cerebellopontine angle

OBJECT: Epidermoid tumors located in the cerebellopontine angle (CPA) are challenging lesions because they grow along the subarachnoid spaces around delicate neurovascular structures and often extend into the middle cranial fossa. The purpose of this study was to determine the value of endoscopic assistance in the microsurgical resection of these lesions, in which total removal is the therapy of choice. METHODS: Eight patients harboring an epidermoid tumor of the CPA were treated using an endoscope-assisted microsurgical technique. A retrosigmoid suboccipital approach was used in five patients and a pterional transsylvian approach was chosen in the other three. In four patients the lesion was resected microsurgically and the endoscope was used repeatedly to verify complete tumor removal, whereas most of the tumor mass was removed with the aid of an operating microscope in the other four. Tumor parts extending into other cranial compartments that were not visible through the microscope were removed under endoscopic view by using rigid rod-lens scopes with 30 and 70 degrees angles of view. All epidermoids were completely evacuated and the membranes were widely resected. Large tumors occupying both the middle and posterior cranial fossa were removed through a single small opening without enlarging the craniotomy. Permanent hearing loss and permanent hypacusis were observed in one patient each. One patient with facial and one with abducent nerve palsy recovered within 6 and 4 months, respectively. A transient weakness of the chewing muscles was encountered in one patient. Postoperative magnetic resonance imaging revealed no residual tumor in any patient. To date no recurrences have been-observed (follow up range 12-98 months). CONCLUSIONS: The endoscope-assisted microsurgical technique enables safe removal even when tumor parts are not visible in a straight line. Tumor extensions into adjacent cranial compartments can be removed with the same approach without retracting neurovascular structures or enlarging the craniotomy.     

CT-GUIDED STEREOTACTIC NEUROSURGERY USING THE BROWN-ROBERTSWELLS SYSTEM: EXPERIENCE WITH 125 PROCEDURES

Experience with a consecutive series of 125 computerized tomographic (CT) image guided stereotaxic neurosurgical procedures, performed using the Brown-Roberts-Wells (BRW) system is described. Operative objectives included tissue sampling for diagnostic purposes, intra-operative localization of craniotomy flaps and intracerebral lesions, cyst and abscess aspiration and lesion to modulate tremor. A neuropathological diagnosis was possible in 96% of the biopsies, and lesions were precisely localized in all patients undergoing microsurgical stereotaxic craniotomy. Two patients (2.2%) undergoing sterrotaxic biopsy died as a result of the procedure and one patient's hemiparesis was permanently worsened (0.8%). In only one of three patients undergoing stereotaxic thalamotomy was tremor abolished. This report confirms that (3 image guided stereotaxic neurosurgery is safe, accurate and versatile. There is, however, a moderate incidence (7.2%) of lesser complications that can occur with this type of surgery. These complications, which are emphasized in this paper, are related to both the site of surgery and the neuropathology.     

CT-guided stereotactic neurosurgery using the Brown-Roberts-Wells system: experience with 125 procedures.

Experience with a consecutive series of 125 computerized tomographic (CT) image guided stereotaxic neurosurgical procedures, performed using the Brown-Roberts-Wells (BRW) system is described. Operative objectives included tissue sampling for diagnostic purposes, intra-operative localization of craniotomy flaps and intracerebral lesions, cyst and abscess aspiration and lesion to modulate tremor. A neuropathological diagnosis was possible in 96% of the biopsies, and lesions were precisely localized in all patients undergoing microsurgical stereotaxic craniotomy. Two patients (2.2%) undergoing stereotaxic biopsy died as a result of the procedure and one patient's hemiparesis was permanently worsened (0.8%). In only one of three patients undergoing stereotaxic thalamotomy was tremor abolished. This report confirms that CT image guided stereotaxic neurosurgery is safe, accurate and versatile. There is, however, a moderate incidence (7.2%) of lesser complications that can occur with this type of surgery. These complications, which are emphasized in this paper, are related to both the site of surgery and the neuropathology.     

Stereotaxic suboccipital transcerebellar biopsy of pontine mass lesions

Twenty-six patients (16 male and 10 female) ranging in age from 5 to 68 years underwent suboccipital transcerebellar stereotaxic biopsy of mass lesions situated in the pons. Stereotaxic computerized tomography, magnetic resonance imaging, and angiographic data were obtained while the patient was positioned in an inverted custom stereotaxic head frame. The patients were then placed under general endotracheal anesthesia and positioned prone. Optimal trajectory planning utilized a transcerebellar route directed through the middle cerebellar peduncle, with target and entry points calculated to avoid vascular structures. No complications were encountered in the perioperative period when this technique was used. Histological diagnosis of the lesions revealed: astrocytomas in 14 patients, oligodendroglioma in one, ependymoma in one, arteriovenous malformations in two, radionecrosis in one, cryptococcal abscess in one, demyelinating disease in three, and infarctions in three. No consistent correlation could be made between radiographic characteristics and histological diagnoses. Empiric treatment of brain-stem lesions without tissue diagnosis based upon the radiological and clinical findings may result in inappropriate therapy administration. Alternatively, open operative procedures to obtain tissue require a visible surface abnormality to guide biopsy, and carry the risks of a major surgical procedure in already compromised patients. For these reasons the authors consider a suboccipital transcerebellar stereotaxic biopsy to be the diagnostic procedure of choice in the assessment of pontine mass lesions.     

Atypical laparoscopic liver resection

The laparoscopic resection of small benign hepatic lesions located peripherally is described in three cases. The histology revealed adenomas in two patients and a focal nodular hyperplasia in a third patient. The area of resection measured between 9 and 15 cm2. Following laparoscopic endosonography with localisation of adjacent vascular structures to the tumor the lesion was resected by combined ultrasonographic dissection (endocusa) and clipligature. Bloodloss was limited to a maximum of 130 ml. The time of hospitalisation was 3 to 5 days.     

Transsulcal microsurgical approach for subcortical small brain lesions: technical note

We describe a transsulcal microsurgical approach for removal of small subcortical brain lesions, guided by frameless stereotaxy. This technique of simultaneous stereotactic localization of the subcortical lesion and its adjacent sulcus, before surgical approach, results in optimal surgical planning, leading to minimal brain tissue loss and excellent surgical outcome.     

Chondroid Syringoma: A Diagnosis More Frequent Than Expected

BACKGROUND: Chondroid syringoma or mixed tumor of the skin is a rare subcutaneous tumor that may be confused with various skin lesions. OBJECTIVE: To elucidate the incidence of condroid syringomas among skin lesions that were excised under local anesthesia. METHODS: The histopathologic diagnosis of 16,200 skin lesions that had been operated between 1986 and 2002 were retrospectively evaluated. The cases with condroid syringoma were histopathologically re-examined, and confirmed cases were further analyzed for preoperative diagnosis, age, gender, and lesion location. RESULTS: Sixteen patients were found to have histopathologic diagnosis of chondroid syringoma constituting 0.098% of the excised skin lesions in this series. All of these 16 cases were misdiagnosed preoperatively. The typical presentation was a solitary skin lesion located in the head and neck region in a middle-aged male patient. CONCLUSION: In the evaluation of a middle-aged male patient with a small subcutaneous nodule in the head and neck region, chondroid syringoma should be also taken into consideration for differential diagnosis. For such a lesion, excisional biopsy without destroying aesthetic and functional structures is the preferred diagnostic approach.     

Stereotactic guiding tube for open-system endoscopy: a new approach for the stereotactic endoscopic resection of intra-axial brain tumors

Stereotactic endoscopic resection of intra-axial brain tumors using a newly developed endoscopic system consisting of a stereotactic guiding tube and a fine endoscope is reported. The stereotactically inserted guiding tube acts in the place of brain retractors to expose deep-seated pathological lesions, which are then visualized by means of a fine endoscope. The lesions may then be treated by various microsurgical techniques such as laser vaporization. Fifteen intra-axial lesions were operated on by this method using a guiding tube of 8 mm in outer diameter without significant complications. Seven small lesions measuring 3 to 26 mm in maximal diameter were resected totally. Eight large lesions, including two highly vascularized tumors, were examined by biopsy and resected partially through a burr hole with complete hemostasis under direct vision. This system is particularly useful for removing small intra-axial tumors in deep or eloquent areas difficult to resect using ordinary surgical techniques. It will also be applicable for other stereotactic operations that require accuracy and minimum invasiveness with complete hemostasis under direct visualization.     

Computer assisted brain surgery for small lesions in the central sensorimotor region

Summary The capacity of a new optical navigation device is demonstrated by six microsurgical procedures for small subcortical lesions within the central sensorimotor strip. This small series is aimed at less invasive resection in this functionally critical region, independently of primary diagnosis and outcome.Guided by high resolution CT imaging data five brain tumours and one cavernous angioma was selectively located and most sparingly removed without additional sensorimotor deficit. In two cases improvement of a pre-operative paresis was observed immediately after surgery. Thanks to light-weight freehand pointing instruments and a ranging accuracy of +/- 1 mm, damage to functionally important brain areas and vessels was avoided by using uncommonlyoblique, e.g., transsulcal ways of access which would hardly have been possible even with guidance by conventional stereotaxy.The demanding systematic cortical stimulation of the precentral gyrus applied in three cases was only sensitive in infiltrating tumours — e.g., low grade astrocytomas — where for want of adjuvant therapy it was essential to proceed to the extreme limits of resection. In general, precise anatomical localisation by computer aided surgery (CAS) is sufficient in small central lesions which guarantees minimally invasive surgery. The potential of this new, soon commercially available optical navigation system in (neuro)surgery, quality control and teaching is discussed.     

Benign gastric tumors

Background: Historically, major subsets of benign gastric tumors requiring surgical excision have required open laparotomy. Methods: We have used laparoscopy to resect lesions in eight such patients. Lesion locations were gastroesophageal junction (one), gastric body (three), and pylorus (four). Four lesions were successfully located by instrument palpation. Six lesions were excised using gastrotomy, eversion of tumor, and resection, followed by stapled gastrotomy closure. The lesion at the posterior GE junction was evaluated through a gastrotomy and resected transgastrically. The two pyloric lesions were removed by laparoscopic distal gastrectomy and gastrojejunostomy. Results: Procedure times were 55–210 min; oral feeding was instituted on postoperative day 1–5; patients were discharged 1–6 days postoperatively. Conclusions: Benign tumors of the stomach may be approached and resected laparoscopically; a transgastric, intra-organ approach is safe and efficient; laparoscopic distal gastrectomy is safe and technically feasible; patients have a shorter recovery interval and shorter postoperative hospital stay. Cautious progress in this field is recommended.Presented at the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), Orlando, Florida, USA, 11–14 March 1995     

Trigeminal neuralgia caused by microarteriovenous malformations of the trigeminal nerve root entry zone: symptomatic relief following complete excision of the lesion with nerve root preservation

OBJECT: Within a series of 341 consecutive patients who underwent posterior fossa surgery for trigeminal neuralgia (TN), in five the cause was found to be a microarteriovenous malformation (micro-AVM) located in the region of the trigeminal nerve root entry zone (REZ). The surgical management and clinical outcomes of these cases are presented. METHODS: Patients were identified from a prospectively collected database of all cases of TN treated at one institution between 1980 and 2000. Presentation was clinically indistinguishable from TN caused by vascular compression. Preoperative imaging, including computerized tomography scanning (two cases) and magnetic resonance (MR) imaging and MR angiography (three cases), failed to demonstrate an AVM except for one case in which multiple abnormal vessels were identified in the trigeminal REZ on an MR image obtained using a 1.5-tesla magnet. All patients underwent a standard retromastoid craniotomy. In all cases a small AVM embedded in the trigeminal REZ was identified and completely excised, with preservation of the trigeminal nerve. All patients experienced immediate relief of pain following surgery. Postoperatively, in one patient a small pontine hematoma developed, resulting in permanent trigeminal nerve anesthesia in the V2 and V3 divisions. All patients were free from pain at a mean follow-up period of 30 months. CONCLUSIONS: These rare lesions are usually angiographically occult, but may sometimes be identifiable on high-resolution MR images. Total microsurgical resection with nerve preservation is possible, although operative complications are relatively common, reflecting the intimate association between these lesions and the pons. Complete resection is advised not only for symptom relief, but also to eliminate the theoretical risk of pontine hemorrhage.     

Treatment of colloid cysts of the third ventricle by stereotaxic microsurgical laser craniotomy

The therapeutic strategies employed in the management of anterior third-ventricular mass lesions remain controversial. Resection by conventional craniotomy, whether via a transcallosal or transcortical approach, carries well-known risks and limitations. Alternatively, in this region traditional stereotaxy has been relegated to use with biopsy only or cyst aspiration procedures. Combining aspects of both conventional and stereotaxic techniques has allowed total removal of 12 colloid cysts in six women and six men ranging in age from 25 to 71 years. No mortality and minimal morbidity have been associated with the procedures. There has been no evidence of recurrence in an average follow-up period of 19 months. By coupling the benefits of stereotaxic precision and localization to the microsurgical management of colloid cysts, several rewards have been realized: 1) only a limited cortical dissection is needed; 2) the hazards of callosal or forniceal injury can be avoided; 3) the lesion is easily localized regardless of ventricular size; 4) hemostasis can be readily achieved with bipolar cautery or defocused laser power; and 5) most importantly, a total resection is possible with little risk to the patient. Stereotaxic microsurgical laser craniotomy provides a new option for the management of colloid cysts and other anterior third-ventricular lesions.     

Use of stimulation mapping and corticography in the excision of arteriovenous malformations in sensorimotor and language-related neocortex

The excision of an arteriovenous malformation (AVM) located within eloquent neocortex presents a formidable neurosurgical challenge. Compromise of the vascular supply to normal surrounding brain or surgical trauma to essential neighboring neocortex may result in unacceptable postoperative neurological morbidity. In addition, successful removal of these lesions without the benefit of intraoperative corticography may leave in situ areas of highly epileptogenic brain, resulting in continued epilepsy. In this report, we describe eight patients who underwent craniotomy and excision of AVMs at our institutions. Six of these lesions were located in the dominant (left) hemisphere, and two were on the right. All patients underwent preoperative testing with Amytal administered via the carotid artery (Wada test). Subsequently, the patient was placed under local anesthesia, and we performed a craniotomy. Electrocorticography was used to identify epileptogenic brain in the region of the AVM and to establish after-discharge thresholds to electrical stimulation. Stimulation-mapping techniques were then used to delineate critical motor, sensory, and language areas. Trial occlusion of feeding vessels was also carried out to document postocclusion neurological deterioration, if any. At a later time, a second procedure was performed under general anesthesia to excise the lesion and any epileptogenic foci, using the cortical maps derived earlier. Using these techniques, it was possible to effect complete excision of these lesions in seven of eight patients without causing additional neurological deficits.     

CT-guided computer-assisted stereotactic resection of brain tumours

Summary A computer-assisted technique was developed for CT-guided stereotactic microsurgical resection of small intracerebral lesions. An original stereotactic retractor was developed to work with the Riechert-Mundinger's equipment for precise localisation, safe exposure and microsurgical removal of these tumours. A software-program was developed to work on an ordinary IBM-compatible PC/AT. It assisted the procedure from treatment planning till the end, including tumour excision, and provided computerized support for the removal of pathological tissues within the CT-defined boundaries of the lesion.6 patients, harbouring supratentorial intracerebral lesions underwent surgery using this technique. 2 of them suffered from brain metastases, in 1 patient a cavernous angioma was removed, 2 patients had glial tumours, and in the last patient only radiation necrotic tissue was found to be the cause of ring-enhanced lesion, which had been suspected to be a recurrent glioma. Their largest dimensions varied between 18 and 30 mm and the age of the patients ranged from 15 to 52 years. In 2 cases the lesions were localised deeply in the region of basal ganglia and thalamus. In the remaining patients the tumours were rather superficial, infiltrating subcortical white-matter close to the central sulci. There was no mortality nor significant morbidity following the procedure, the Karnofsky Performance Status (KPS) cumulative scores being either unchanged (in 3), or improved (in 3 patients).Current state and modern concepts in image-guided open stereotactic methodology is discussed.     

Stereotaxic technics with an open skull in the treatment of space-occupying brain lesions

When intra-cerebral space-occupying lesions are small or when they are deeply located in the brain parenchyma, it is sometimes difficult to localize them at surgery or to design the most direct and least hazardous surgical approach. Therefore we have developed a method which combines conventional neurosurgical techniques with craniotomy using stereotaxic guidance. We have used the Brown-Roberts-Wells (B.R.W.) stereotaxic system which allows for CT scan or MRI guidance and does not interfere with the absolute sterility mandatory every time a flap is created. Eleven patients were operated on using this method. The deep tumors were approached through a linear incision of the cerebral cortex; then a needle fixed in the right position on the arc system of the B.R.W. was inserted toward the surface of the lesion; the exposure was finally widened by the inflation of a rubber balloon set on the stereotaxic needle. The post-operative course was very uncomplicated in all these patients. No permanent post-operative neurological worsening was observed, even after the removal of an intra-thalamic tumor.     

Primary cardiac neoplasms. Early and late results of surgical treatment in 42 patients

Forty-two patients underwent resection of primary cardiac neoplasms at Stanford University Medical Center and the Palo Alto Veterans Administration Medical Center between 1961 and 1986. A total of 27 atrial myxomas, seven benign nonmyxomatous tumors, and eight malignant tumors were resected. The mean age was 47 years (range 8 to 79) in 27 female and 15 male patients. The clinical presentations included congestive heart failure in 24 patients, palpitations in nine, neurologic symptoms in six, recurrent cardiac tamponade in three, vasculitis in two, and chest pain in two. Thirty-one of 34 benign lesions were completely resected, although one patient required cardiac transplantation to resect completely an "inoperable" benign tumor. All gross tumor was resected in four of eight patients with malignant lesions. All patients survived operation, but three with malignant disease died within 30 days. Late outcome was known for 41 of 42 (98%) patients. Total follow-up for the series was 200.1 patient-years, for an average of 4.7 years (range 1 month to 18 years). Excellent early and late results were obtained in patients with benign lesions, as there was no known tumor recurrence even if resection was incomplete. Effective palliation and local control of disease is possible with extensive resection of malignant primary tumors, but more effective adjuvant therapy will be necessary to improve long-term prognosis.     

A clinicopathological study of resected pulmonary nodules with focal pure ground-glass opacity.

OBJECTIVE: Pulmonary lesions with focal ground-glass opacity (GGO) have been detected increasingly by low-dose helical computed tomography (CT). However, the strategy of treatment for focal pure GGO lesions is still undecided. This study evaluates clinicopathological characteristics of resected pulmonary nodules with focal pure ground-glass opacity. METHODS: Between January 1997 and December 2005, 26 patients (35 lesions) with pure GGO lesions underwent pulmonary resection. The data on patient age, lesion size, pathology, carcinoembryonic antigen (CEA) level and palpability of the tumor in the resected specimen were evaluated. RESULTS: The histological diagnosis was bronchioloalveolar carcinoma (BAC) in 10 patients (12 lesions), atypical adenomatous hyperplasia (AAH) in 15 patients (22 lesions), and focal scar in 1 patient (1 lesion). There were no significant differences in age, sex, tumor size, and CEA level between the patients with BAC, AAH, and focal scar. However, the lesions >10mm in size were all BAC. Palpability of the tumor in the resected specimen was significantly more frequent in BAC cases than in AAH cases (p<0.01). For BAC, lobectomy was performed for four lesions, and limited resection for eight. None of the BACs showed lymphatic or vascular invasion upon pathological examination. At the median follow-up point of 44 months (range: 4-84 months), no recurrences were observed. CONCLUSIONS: BAC and AAH cannot be discriminated by their size. In the resected specimen, BAC lesions are more frequently palpable than AAH lesions. Thoracoscopic surgery is recommended for focal pure GGO after repeated CT even if the GGO lesion is small. Partial resection is a sufficient treatment for pure GGO.     

经胼胝体-穹窿间入路显微手术切除第三脑室肿瘤

目的探讨经胼胝体-穹窿间入路显微手术切除第三脑室肿瘤的方法，并对相应的显微解剖学基础加以讨论。方法经胼胝体-穹窿间入路显微手术切除第三脑室肿瘤12例，其中突入第三脑室颅咽管瘤8例，丘脑内侧型胶质瘤2型，室管膜瘤1例，畸胎瘤1例。结论10例在手术显微镜下肿瘤全切，2例次全切除，全切除率83．3％，其中8例颅咽管瘤中7例全切，术后复查头颅MR未见肿瘤残留及复发。无死亡病例，近期并发症主要为多饮、多尿、电解质紊乱。经处理后1-2周消失。远期并发症为2例脑积水，其中1例半年后行脑室腹腔分流，2例硬膜下积液，3月后自行吸收。全组病例随访最短2个月，最长2年半，1例颅咽管瘤大部切除8月后复发，1例丘脑胶质瘤术后1年复发，其余10例中9例生活正常，1例生活自理。结论经胼胝体-穹窿间入路显微手术切除第三脑室肿瘤系通过胚胎组织残留的组织间隙进入第三脑室，几乎不损伤正常脑组织，手术视野大，直视下操作，可切除第三脑室前、中、后各部位肿瘤，肿瘤全切除率高，并发症少。