Quantitative imaging study of extent of surgical resection and prognosis of malignant astrocytomas.

OBJECTIVE: This study used quantitative radiological imaging to determine the effect of surgical resection on postoperative survival of patients with malignant astrocytomas. Previous studies relied on the surgeons' impressions of the amount of tumor removed, which is a less reliable measure of the extent of resection. METHODS: Information concerning possible prognostic factors was collected for 75 patients undergoing magnetic resonance imaging or computed tomography preoperatively and within 10 days postoperatively. Image analysis of the neuroradiological studies was conducted to quantify pre- and postoperative total tumor volumes and enhancing volumes. Univariate and multivariate proportional hazards models were used to analyze the regression of survival regarding 22 covariates that might affect survival. The covariates that were entered included age, gender, tumor grade, cumulative radiation dose, chemotherapy, seizures as a first symptom, Karnofsky performance status at presentation, pre- and postoperative total and enhancing tumor volumes, ratio of pre- to postoperative total and enhancing tumor volumes, tumor location, surgeon's impression of the degree of resection, and subsequent surgery. RESULTS: There were 23 patients with anaplastic astrocytomas and 52 with glioblastomas multiforme. The estimated mean survival time was 27 months for patients undergoing gross total resection, 33 months for subtotal resection, and 13 months for open or stereotactic biopsy. Five factors that were significant predictors of survival in multivariate analysis were tumor grade, age, Karnofsky performance status, radiation dose, and postoperative complications (P < 0.05). In univariate analysis, tumor grade, radiation dose, age, Karnofsky status, complications, presence of enhancing tumor in postoperative imaging, and postoperative volume of enhancing tumor were significantly associated with survival (P < 0.05). CONCLUSION: We conclude that the most important prognostic factors affecting survival of patients with anaplastic astrocytomas and glioblastomas multiforme are tumor grade, age, preoperative performance status, and radiation therapy. Postoperative complications adversely affect survival. Aggressive surgical resection did not impart a significant increase in survival time. Surgical resection may improve survival, but its importance is less than that of other factors and may be demonstrable only by larger studies.

The effect of mannitol on cerebral blood flow.

The objective of this study was to evaluate the effects of mannitol, given over different time periods, on regional cerebral blood flow (rCBF) in patients with intracranial aneurysms. Seven patients with unruptured aneurysms (Group I) and 16 patients with Grade I and II subarachnoid hemorrhage (SAH) (Group II) received 1.5 gm/kg/8 hrs of 20% mannitol intravenously over a 24-hour period. Seven other patients with unruptured aneurysms (Group III) received 1.5 gm/kg of mannitol over 8 hours only. The last seven patients with unruptured aneurysms (Group IV) received the same dose, but as an intravenous bolus. Over a period of 24 hours, the patients underwent serial measurements of rCBF, intracranial pressure (ICP), mean blood pressure (MBP), cardiac output, and cerebral metabolic rate of oxygen consumption (CMRO2). Mannitol, when given as a continuous intravenous infusion, increased rCBF significantly without increasing MBP or decreasing ICP. This increase was more pronounced in SAH patients. The effects of mannitol lasted for 18 hours when given over an 8-hour period only; however, when it was given as a bolus, the increase in rCBF lasted for 24 hours, cardiac output tended to increase, and the effect on CMRO2 was variable.

Causalgic pain relieved by prolonged procaine amide sympathetic blockade. Case report.

Reversible sympathetic blocks diagnostically relieve causalgic pain. At times, repeated blocks may be therapeutic. Causalgic pain of the left hand was successfully treated in a nonsurgical candidate by a continuous infusion of local anesthetic (procaine) into the region of the stellate ganglion. This technique was performed without significant complication and gave relief from the causalgia for extended periods of time. It may provide an effective alternative to surgical sympathectomy in high-risk patients.

Deflation of metrizamide-filled balloon used to occlude a carotid-cavernous fistula. Case report.

A carotid-cavernous fistula was occluded by a detachable latex balloon. Because of technical problems, the contrast-filled balloon was left in a precarious position in the ostium of the fistula. Premature deflation of the balloon would have resulted in intra-arterial migration of the device. Approximately 1 week is required for the balloon to become secured in place by fibrous attachment to the vascular wall. For success, if the ligature is adequate, a detachable Debrun balloon should remain inflated for this period of time. The deflation process was monitored radiographically in this patient. The balloon remained inflated for at least 2 weeks. A short summary of the experience with deflation of various contrast-containing balloon devices in the treatment of carotid-cavernous fistulas is given. Metrizamide may be the best contrast agent for use in these devices.

In vivo characterization of vasocontractile activities in erythrocytes.

Partially purified protein from washed and artificially hemolyzed erythrocytes, known to cause significant contractions of isolated canine cerebral vessels in vitro, was injected into the cisterna magna of intact anesthetized dogs. Cerebral blood flow, measured by the xenon-133 washout technique, decreased from a control value of 49.5 +/- 1.17 ml/100 gm/min to an experimental value of 34.1 +/- 1.65 ml/100 gm/min at 2 hours. Cerebral vascular resistance rose from a control value of 2.05 +/- 0.17 PRU (peripheral resistance units) to an experimental value of 2.91 +/- 0.25 PRU at 2 hours. Mean arterial blood pressure, heart rate, intracranial pressure, and cerebral perfusion pressure remained stable. Cardiac output also fell significantly (in 2-hour control animals it was 2.89 +/- 0.37 liter/min, and in 2-hour experimental animals 1.43 +/- 0.13 liter/min) and peripheral vascular resistance rose. These changes were evident by 10 minutes after the cisternal injection of the hemolysate protein, and remained for the duration of the 2-hour monitoring period. Serial vertebrobasilar angiograms demonstrated marked narrowing of the intracranial basilar artery when compared to control values. The narrowing persisted for several days in most animals, and tended to increase with time. Relaxation occurred by the 10th through the 14th day. The authors conclude that this experimental preparation may be a useful model for both in vitro and in vivo investigation of chronic cerebral vasospasm.