Effect of Ligation on Internal Carotid Artery Blood Pressure in Horses

Abstract

The effect of a single ligature on back pressure in the internal carotid artery was studied in nine horses. In six anesthetized horses, one internal carotid artery was catheterized 2 cm from its origin and blood pressure was recorded continuously. Then the artery was ligated, pressure was recorded again, and the horses were euthanatized. In another three anesthetized horses, indwelling catheters were placed in both internal carotid arteries and a loose ligature was placed proximal to one catheter. After horses recovered from anesthesia, the ligature was tied and blood pressure was recorded in both arteries on that day and 3 days later, then these horses were euthanatized. The anatomy of the cerebral arteries was examined in all nine horses. Blood pressure in the internal carotid arteries did not change after ligation. Subjectively, collateral channels considered most likely to maintain blood pressure in the ligated internal carotid artery were the caudal intercarotid artery and the cerebral arterial circle. We concluded that ligation of the internal carotid artery would not prevent severe hemorrhage from the internal carotid artery in horses with guttural pouch mycosis until the ligated artery thrombosed to the level of the lesion.

Occlusion of the Internal Carotid Artery by Means of Microcoils for Preventing Epistaxis Caused by Guttural Pouch Mycosis in Horses.

“…This implies that a portion of the obstructed blood flow is mainly being compensated through the vertebral artery. This finding suggests that occlusion of internal carotid artery does not affect the brain, and also confirms the observation of Freeman et al that the ligation of the internal carotid artery does not change the arterial pressure at distal sites [10].…”

“…Bleeding commonly occurs from the internal carotid artery and less commonly from the external carotid and maxillary arteries [2,4,5,9,11,21]. One surgical treatment is to ligate the internal carotid artery at its origin [4,11], however, fatal epistaxis may occur before adequate thrombus in the affected region [10,17,20]. Insertion of a balloon catheter can achieve effective occlusion of the arterial segment and prevent epistaxis [2,7,8], Although, problems associated with this technique include implantation of an indwelling catheter, increased potential for infection, failure of the balloon, and necessity of removing the catheter after healing [2,8,9].…”

Ingiliz atında arteria ophthalınica externa'nın çıkış, seyir ve dallanınası

“…Buna bağlı olarak gözün vaskularizasyonu hakkındaki bilgiler oldukça önemli hale gelmiştir (6)(7)(8)13).…”

Evaluation of a Technique to Occlude the Internal Carotid Artery of Horses

“…Consequently, horses treated with this technique continue to be at risk for hemorrhage until arterial thrombosis occurs beyond the level of the vascular lesion. Ligation of the internal carotid artery in horses does not decrease blood pressure distal to the ligature over a 3‐day period, 8 further emphasizing that horses treated by proximal ligation alone are at risk until adequate thrombus formation has occurred. Placement of an additional ligature distal to the mycotic lesion is usually not possible because the site is difficult to reach and is usually obscured by the mycotic lesion or a hematoma 9 …”