Marion Reddy

Defining the Role of Stereotactic Radiosurgery Versus Microsurgery in the Treatment of Single Brain Metastases

Summary Stereotactic radiosurgery (RS) and surgery have proved to be effective treatment modalities for brain metastasis. We followed 133 patients whose treatment for intracranial disease was either RS or a single surgical resection at the University of Vienna from August 1992 through October 1996. All patients who received additional Whole Brain Radiotherapy were included. This was a retrospective, case-control study comparing these treatment modalities. Sixty-seven patients were treated by RS and 66 patients were treated by microsurgery. The median size of the treated lesions for RS patients was 7800 mm3, and 12500 mm3 for microsurgery patients, respectively. The median dose delivered to the tumour margin for RS patients was 17 gray. The median survival for patients after RS was 12 months, and 9 months for patients after microsurgery. This difference was not statistically significant (p=0.19). Comparison of local tumour control, defined as absence of regrowth of a treated lesion, showed that tumours following RS had a preferred local control rate (p<0.05). Univariate and multivariate analysis showed that this fact was due to a greater response rate of “radioresistant” metastasis to RS (p<0.005). Postradiosurgical complications included the onset of peritumoural oedema (n=5) and radiation necrosis (n=1). Two patients after microsurgery experienced local wound infection. One postoperative death occurred due to pulmonary embolism in this group. On the basis of our data we conclude that RS and microsurgery combined with Whole Brain Radiotherapy are comparable modalities in treating single brain metastasis. Concerning morbidity and local tumour control, in particular in cases of “radioresistant” primary tumours, RS is superior. Therefore we advocate RS except for cases of large tumours (>3 cm in maximum diameter) and for those with mass effect.

A clinical study of a fibrinogen-based collagen fleece for dural repair in neurosurgery.

Summary.Summary. Background: There is frequently a need for dural grafts to cover defects resulting from retraction, shrinkage, or excision following neurosurgical procedures. Many substances have been tried as possible dural substitution, and different tissues and materials have been evaluated for use in dural repair. Method: The authors performed a retrospective review of 288 consecutive neurosurgical procedures using a fibrinogen based collagen fleece (TachoComb®), a resorbable mesh of collagen from horse tendons, coated with human fibrinogen, bovine thrombin, bovine aprotinin and riboflavin (for marking the coated side), for dural substitution. The fibrinogen and thrombin imitate the last step of the coagulation cascade. On contact with bleeding wounds or other body fluids the coagulation factors dissolve and a link is formed between the collagen carrier and the wound surface. Thrombin converts fibrinogen into fibrin by splitting off peptides. Aprotinin prevents premature lysis of the fibrin clot by plasmin. Findings: Neither superficial or deep wound infections nor aseptic meningitis were noted. We found good fibrous incorporation of TachoComb® into the surrounding normal dura. Postoperative cerebrospinal-fluid (CSF) leaks developed in only five cases, who had to be re-operated, upon as well as one patient with a rebleeding. In another four cases, there was notable subcutaneous cerebrospinal-fluid accumulation without CSF-leak. They required a lumbar cerebrospinal-fluid drainage. Interpretation: We conclude that TachoComb® is a valuable alternative to the patients fibrous tissues for dural repair in cases in which autogenous tissues are either unavailable or insufficient for proper reconstruction.

Prognostic factor analysis for multiple brain metastases after gamma knife radiosurgery: results in 97 patients.

Stereotactic radiosurgery (SR) is being used with increasing frequency in the treatment of brain metastases. This study provides data from a clinical experience with radiosurgery in the treatment of cases with multiple metastases and identifies parameters that may be useful in the proper selection and therapy of these patients. From January 1993 to April 1997, 97 patients (43 women and 54 men; median age 58 years) suffering from multiple brain metastases (median 3; range 2–4) in MRI scans, received SR with the Gamma Knife. The median dose at the tumor margin was 20 Gy (range 17–30 Gy). Median tumor volume was 3900 cmm (range 100–10 000). Different forms of hemiparesis, focal and generalized seizures, cognitive deficit, headache, dizziness and ataxia had been the predominant neurological symptoms. Major histologies included lung carcinoma (44%), breast cancer (21%), renal cell carcinoma (10%), colorectal cancer (8%), and melanoma (7%).The median survival time was 6 months after SR. The actual one-year survival rate was 26%. In univariate and multivariate analysis, a higher Karnofsky performance rating and absence of extracranial metastases had a significantly positive effect on survival. Local tumor control was achieved in 94% of the patients. Complications included the onset of peritumoral edema (n=5) and necrosis (n=1).SR induces a significant tumor remission accompanied by neurological improvement and, therefore, provides the opportunity for prolonged high quality survival. We conclude that radiosurgical treatment of multiple brain metastases leads to an equivalent rate of survival when compared to the historic experience of patients treated with whole brain radiotherapy. Patients presenting initially with a higher Karnofsky performance rating and without extracranial metastases had a median survival time of nine months. Each such case should therefore be evaluated based on these factors to determine an optimal treatment regimen.

Microsurgical anterior cervical foraminotomy (uncoforaminotomy) for unilateral radiculopathy: clinical results of a new technique.

Summary.Summary. Background: The authors report the clinical application of a new microsurgical technique. The cervical anterior foraminotomy (uncoforaminotomy), which is used for the surgical treatment of unilateral cervical radiculopathy secondary to posterolateral disc herniations or spondylotic foraminal stenoses. Method: Between June 2000 and May 2001, 34 patients (16 men and 18 women with a mean age of 43.8 years, range 29 to 80 years) underwent anterior cervical foraminotomy (uncoforaminotomy) for the treatment of cervical radiculopathy at one or two adjacent levels in the Neurosurgical Department of the University of Vienna. This surgical technique was devised to accomplish direct anterior decompression of the affected nerve root by removing an offending posterolateral sponylotic spur or disc fragment. The nerve root is decompressed from its origin in the spinal cord to the point were it passes behind the vertebral artery laterally. The intervertebral disc of the affected level is maintained in its form and function. Thus, the functioning motion segment is preserved and fusion related sequelae, including graft related complications, graft site complications and the adjacent level disease, are avoided. Prior to its clinical application, anatomical features of the anterior cervical spine were reviewed, and an anatomical morphometric analysis and work-up of the technique was performed in 4 cervical specimens. Findings: The follow-up period varied from two to 17 months with a mean of 8.2 months. The large majority (97%) of patients were pleased with the results of their operation. The relief of neck pain and redicular pain in the affected dermatome was immediate in all patients. Motor-weakness and sensory deficit improved dramatically immediately postoperatively, and improved to normalisation in the majority of patients within 3 to 6 months. Two of the patients sustained an incomplete transient recurrent laryngeal nerve palsy, which fully resolved within two to 4 weeks. One of the patients had a repeat herniation on the second postoperative day, but recovered completely after re-operation and continued to do well at the 6-month follow-up. No permanent surgery related morbidity or associated complications were encountered. Interpretation: The results indicate that this new microsurgical technique is an attractive treatment option for adequate anterior decompression of the cervical nerve root via a minimized approach. It was associated with excellent clinical outcome and a less painful postoperative course, allowing patients an almost immediate return to unrestricted full activity.

Intraoperative Computed Tomography Guided Neuronavigation: Concepts, Efficiency, and Work Flow

Image-guided surgery is currently considered to be of undisputed value in microsurgical and endoscopical neurosurgery, but one of its major drawbacks is the degradation of accuracy during frameless stereotactic neuronavigation due to brain and/or lesion shift. A computed tomography (CT) scanner system (Philips Tomoscan M) developed for the operating room was connected to a pointer device navigation system for image-guided surgery (Philips EasyGuide system) in order to provide an integrated solution to this problem, and the advantages of this combination were evaluated in 20 cases (15 microsurgical and 5 endoscopic). The integration of the scanner into the operating room setup was successful in all procedures. The patients were positioned on a specially developed scanner table, which permitted movement to a scanning position then back to the operating position at any time during surgery. Contrast-enhanced preoperative CCTs performed following positioning and draping were of high quality in all cases, because a radiolucent head fixation technique was used. The accuracy achieved with this combination was significantly better (1.6:1.22.2). The overall concept is one of working in a closed system where everything is done in the same room, and the efficiency of this is clearly proven in different ways. The most important fact is the time saved in the overall treatment process (about 55 h for one operating room over a 6-month period). The combination of an intraoperative CCT scanner with the pointer device neuronavigation system permits not only the intraoperative control of resection of brain tumors, but also (in about 20% of cases) the identification of otherwise invisible residual tumor tissue by intraoperative update of the neuronavigation data set. Additionally, an image update solves the problem of intraoperative brain and/or tumor shifts during image-guided resection. Having the option of making an intraoperative quality check at any time leads to significantly increased efficiency, improves the operating work flow because of the closed-system concept, and offers an integrated solution for improved patient work flow and clinical outcome.

Watertightness and Effectiveness of a Fibrinogen-Based Collagen Fleece (TachoComb®) in Neurosurgery

SummaryBACKGROUND: Meningitis or cerebrospinal fluid rhinorrhoea can occur years or even decades after trauma or operation and can be the first indication of a previously unidentified dural lesion. Preventing cerebrospinal fluid (CSF) leakage with a fibrinogen-based collagen fleece (TachoComb®) was the interest of our clinical study. METHODS: In the present study, we examined the watertightness and effectiveness of TachoComb® following supratentorial/infratentorial as well as skull-base operations. The dura was closed primarily by sutures and covered with a fibrinogen-based collagen fleece to prevent CSF leakage. RESULTS: Twelve patients developed a subcutaneous CSF collection requiring no further treatment, seven patients were managed by lumbar CSF drainages, and three patients had to be reoperated. CONCLUSIONS: Based on these results, we proved the watertightness and effectiveness of this fibrinogen-based collagen fleece.ZusammenfassungGRUNDLAGEN: Eine Meningitis oder eine Liquorfistel kann Jahre bis Jahrzehnte nach einem Trauma oder einer neurochirurgischen Operation erstmalig auftreten. Als Prophylaxe gegen eine Liquorfistel haben wir ein resorbierbares Kollagenvlies, das mit Bestandteilen eines Fibrinklebers beschichtet ist (TachoComb®), klinisch getestet. METHODIK: In unserer vorliegenden Studie haben wir die Wasserdichtheit von TachoComb® in 421 Fällen getestet. Die primär vernähte Dura mater wurde mit einem beschichteten Kollagenvlies bedeckt, ebenso die Schädelbasis nach Schädelbasisoperationen. ERGEBNISSE: 12 Patienten entwickelten ein subcutanes Liquorkissen, welches keiner weiteren Therapie bedurfte. In 7 Fällen wurden die Patienten mit einer Lumbaldrainage behandelt und in 3 Fällen mußte reoperiert werden, um den Defekt zu decken. SCHLUSSFOLGERUNGEN: Basierend auf diesen Ergebnissen können wir die Verwendung von TachoComb® zum Erreichen eines wasserdichten Duraverschlusses empfehlen.

A lateral mass fracture of C1 associated with left vertebral artery and mid-basilar artery occlusion.

Extreme acceleration and deceleration forces as well as axial loading are exerted at the occipito-cervical junction of drivers involved in high-velocity motor vehicle accidents, especially with fastened seatbelts. Injury at this level, usually lethal, can go unrecognized despite modern emergency management of the unconscious patient. A precise neurologic and radiographic workup of damage to this area is often not possible or overlooked in the initial phase of such severe trauma. We describe a patient with multiple injuries who sustained a left vertebral artery occlusion associated with a left-sided lateral mass fracture of C1 and a basilar artery occlusion resulting in a locked-in syndrome after an automobile accident.