On the haemodynamics of arteriovenous fistulas in the rat

Treatment for intracranial dural arteriovenous malformations: a meta-analysis from the English language literature

OBJECTIVE

The treatment of intracranial dural arteriovenous malformations (DAVMs) remains problematic. Options include ligature of feeding vessels, endovascular procedures, surgical obliteration, or a combination of the latter two. We conducted a meta-analysis of the English language literature on DAVMs to determine the most effective treatment option related to location and angiographic characteristics.

METHODS

The criteria for inclusion were pre- and post-treatment angiography, a description of the type of treatment, and clinical outcome. The analysis included a total of 258 patients, 248 from a review of 223 published articles and 10 from the authors' series. DAVMs were divided into six categories by location, and the results of treatment were compared based on obliteration rates using chi 2 analysis.

RESULTS

In transverse-sigmoid sinus DAVMs (n = 64), combined therapy (endovascular plus surgical treatment) proved significantly more effective than either therapy alone (P < 0.01). For lesions of the tentorial incisura (n = 66), combined therapy and surgical obliteration alone proved superior to embolization (P < 0.001). For lesions of the cavernous sinus (n = 67), treatment was primarily endovascular, with success rates of 62 to 78% for transarterial and transvenous approaches, respectively. In the anterior fossa (n = 23), surgical obliteration was highly effective, with a success rate of 95%. The small number of cases in both the superior sagittal sinus (n = 28) and middle fossa (n = 10) regions, precluded any statistical analysis. Finally, simple ligature of feeding vessels produced success rates of only 0 to 8% and can no longer be recommended.

CONCLUSION

There is no single ideal treatment for the obliteration of DAVMs. The management of each case is best considered individually. The results of this review serve as a rational starting point for the selection of treatment options.

Carotid blood flow in anesthetized rats: effects of carotid ligation and anastomosis

An experimental model was developed for continuous measurement of the common carotid blood flow, in the anesthetized rat, with an electromagnetic flowmeter. The mean carotid blood flow for 41 rats averaged 3.2 +/- 0.2 ml/min at an average mean arterial pressure of 101 +/- 2.5 mm Hg and arterial pO2 of 106 +/- 3.4 mm Hg, pCO2 of 38 +/- 1.2 mm Hg, and pH of 7.36 +/- 0.02. This model allowed short- and long-term carotid hemodynamic changes to be recorded after contralateral carotid ligation or end-to-side carotid anastomosis. After ligation of the contralateral carotid, blood flow through the intact carotid increased 25% (at about 1 week) and 45% (at about 5-6 months), whereas, after anastomosis, carotid blood flow increased 76% and 89% at periods comparable to those after ligation. Arterial pressure and gases did not change throughout the experimental periods. Probable mechanisms involved in these carotid hemodynamic changes are discussed.