Microsurgical management of posterior circulation aneurysms

Objective To study the long⁃term effects of extracranial⁃intracranial (EC⁃IC) bypass and aneurysms trapping in patients with complex cerebral aneurysms. Methods Seventeen patients with complex aneurysms, who underwent EC ⁃ IC bypass and aneurysms trapping from 2008 to 2009, were followed up. Clinical records were reviewed, modified Rankin Scale (mRS) was recorded at admission, discharging, and follow⁃up point, and activities of daily living (ADL) scale (Barthel Index) at admission and follow⁃up point. Results Seventeen patients (11 males and 6 females) were followed up. At admission mRS scores were 1.06 ± 0.87, Barthel index 91.10 ± 10.30. Superficial temporal artery ⁃ middle cerebral artery (STA⁃MCA) was performed in 8 cases, extracarotid artery⁃great saphenous vein⁃middle cerebral artery (ECA⁃GSV⁃MCA) in 5 cases, extracarotid artery⁃radial artery⁃middle cerebral artery (ECA⁃RA⁃MCA) in 3 cases, occipital artery⁃posterior inferior cerebellar artery (OA⁃PICA) in 1 case. Patients were followed up for 19-39 months (mean 28.67 months). At follow⁃up point, 2 patients (11.76%) died, operation⁃related mortality was 5.88% (1/17), operation ⁃ related morbidity 5.88% (1/17), mRS scores 1.07 ± 1.16, Barthel index 96.40 ± 10.30. Conclusion Patients with complex aneurysms who were impossible to be treated with surgical clipping or endovascular intervention could be cured with extracranial⁃intracranial bypass and aneurysms trapping, and good follow⁃up results were acquired. DOI：10.3969/j.issn.1672⁃6731.2012.01.008

Objective The purpose of this study was to use graft bypass for giant serpentine aneurysms. Method 21 patients with giant serpentine aneurysms were treated with the use of graft bypass. Out of 14 patients with unruptured aneurysms, 4 patients presented with headache, 3 with reversible ischemic neurologic deficit( RIND), 5 patients had neck stiffness and features of lower cranial nerve palsy and out of the remaining two each had epilepsy and visual fields deficits respectively. 7 patients compromised ruptured aneurysms, inclusive of six patients with Hunt - Hess grade Ⅰ and Ⅱ1 , and one grade Ⅲ. Their suffering course ranged from 20 days to 3.5 years(mean, 7. 3 months). Cerebral angiography disclosed the M1 segment aneurysms of the middle cerebral artery in 6 patients and M2 segment in 4 patients, AI segment aneurysms of the anterior cerebral artery in 1 patients and A2 segment in 1 patient, P1 segment aneurysm of the posterior cerebral artery in 2 patients, basilar trunk in 2 patients, and the vertebral aneurysms in 5 patients. The aneurysm size in diameter from 0. 3 to 2. 5 cm(mean diameter, 1.2 cm), 13 aneurysms had length of more than 3. 0 cm and 8 patients with serpentine aneurysms had more than 5.0 cm. We used radial artery graft in 7 patients, superficial artery graft(STA) in 6 patients, occipital artery(OA) in 6 patients and greater saphenous vein ( GSV ) in remaining 2 patients. We underwent extra - intracranial bypass in 12 patients which includes external carotid artery to intracranial artery bypass in 5 cases, occipital artery to intracranial artery bypass in 4 cases and internal maxillary artery to intracranial artery bypass in 3 cases. The recipient intracranial vessel were anastomosed to the middle cerebral arteries in five patients, to the inferiopostrior cerebellar arteries in three patients, to P2 segment of the posterior cerebral arteries in three patients, and to anterioposterior cerebellar artery in one patient. The interposed grafts were performed between the arteries proximal and distal to the aneurysms in 9 patients, which includes interposition graft between M1 and M2 segment of the middle cerebral arteries(MCA) in three patients, M1 trunk of the MCA in two patients, the distal Al segment and proxmial A2 segment of the anterior cerebral arteries in two patients, and the extra - intracranial vertebral arteries in 2 patients. The aneurysms were trapped in 11 cases, the aneurysms were excised in 7 cases after isolating them, and the clip was places at the proximal end of the aneurysm in three cases with perforating arteries arising from the body of the aneurysm after performing the reverse flow bypass to the aneurysm sac securing the perforators. Results 20 patients returned to their normal life, they were free of headaches, seizure, visual acuity and visual field were improved and hemiparesis was recovered. One patient needed assist for his daily life. The postoperative angiographies demonstrated satisfactory patency of the bypass graft and elimination of the aneurysms in 19 patients though the patency of bypass graft in one patient was unidentifiable instead the patient was without neurological deficits clinically. One patient had developed postoperative hematoma in the ipsilateral sylvian fissure 2 days after the surgery. The hematoma was evacuated immediately but got neurological deficit on the contralateral lower limb with the power of grade Ⅳ. Conclusions Bypass graft should be an effective management for surgical treatment of giant serpentine aneurysms. Key words: Intracranial aneurysm; Cerebral revascularization; Vessel graft; Bypass

Background: Distal posterior inferior cerebellar artery (PICA) aneurysms are uncommon intracranial vascular lesions. The coincidence of these aneurysms and Arteriovenous malformation (AVM) is even more rare. Since 1956, a total of 57 cases of distal PICA aneurysms associated with AVM have been reported with clear and adequate description. None of these reports describe a giant prenidal aneurysm at this particular location. The paucity of natural history data as well as lack of consensus about treatment strategies in such cases present a significant challenge that requires an individualized management approach.Case Description: A 68-year-old male presented with recurrent episodes of nausea and vomiting precipitated by physical exertion and change of head position. An MRI of the brain demonstrated a giant partially thrombosed right posterior inferior cerebellar artery (PICA) aneurysm with mass effect on the floor of the fourth ventricle. A conventional cerebral angiogram revealed a giant (3.1 x 3.1 x 2.8cm) distal right PICA pre-nidal aneurysm with two smaller distal PICA aneurysms. An AVM (Spetzler-Martin Grade 1) supplied by the right PICA as well as the right superior cerebellar artery (SCA) was also identified on cerebral angiography (not seen on an MRI). Endovascular coil embolization with parent vessel sacrifice was performed to occlude the giant aneurysm. Due to the asymptomatic nature, low risk of rupture, and the patient's age, AVM treatment was deferred.Conclusion: This paper presents the first case of a giant PICA aneurysm associated with cerebellar AVM. For PICA aneurysm-AVM complexes, meticulous evaluation of the morphology, associated anatomy, and comparative risk analysis for both lesions are key for treatment planning. Distal PICA aneurysms can be treated safely with parent vessel occlusion, particularly in the case of prenidal aneurysms.

Objective To investigate the correlation between the location of ruptured intracranial vertebral artery dissecting aneurysm (VADA) and the outcome after endovascular treatment. Methods Thirty-six patients with ruptured intracranial VADA undergoing endovascular treatment were enrolled retrospectively. According to the relationship between VADA and the location of the opening of posterior inferior cerebellar artery (PICA), they were divided into 3 groups: proximal to PICA group (n=13), distal to PICA group (n=13), and PICA involvement group (n=10). The demographic data, vascular risk factors, clinical features, imaging features, endovascular treatment mode, postoperative complications, and differece of the good outcome rate (defined as the modified Rankin scale 0-2) after 6 months of treatment were compared. Results Seven patients in the proximal to PICA group received reconstructive endovascular treatment (RET), and 6 received endovascular internal trapping (EIT); the good outcome rate was 100%(13/13). Seven patients in the distal to PICA group received RET, 6 were treated with EIT; the good outcome rate was 84.6%(11/13). Four patients in the PICA involvement group received RET, and 6 received EIT, and 2 of them received contralateral vertebral artery retrograde PICA stenting combined with VADA segment and proximal vertebral artery coil embolization; the good outcome rate was 60.0%(6/10). There were significant differences in the overall outcome good rate among the 3 groups (P<0.05). The good outcome rate in the PICA involvement group was significant lower than that in the proximal to PICA group, and significantly lower than that in the proximal to PICA combined with distal to PICA group (P<0.05). Multivariate logistic regression analysis showed that only Fisher grade 3-4 was the independent risk factor for poor outcome (odds ratio 28.0, 95% confidence interval 1.71-458.82; P=0.020). Conclusions The surgical options of endovascular treatment for ruptured intracranial VADA needs to evaluate the relationship between the location of dissecting aneurysms and the PICA origin. The risk of endovascular treatment in patients with intracranial VADA involving the origin of PICA is higher and it may affect the outcome. Key words: Intracranial Aneurysm; Aneurysm, Dissecting; Vertebral Artery Dissection; Subarachnoid Hemorrhage; Endovascular Procedures; Embolization, Therapeutic; Stents; Treatment Outcome

Surgical treatment of posterior inferior cerebellar artery (PICA) aneurysms is challenging due to limited surgical accessibility. Endovascular approach has a benefit of avoiding direct injury to the brainstem or lower cranial nerves. Therefore, it has recently been considered an alternative or primary modality for PICA aneurysms. We retrospectively assessed outcomes following detachable coil embolization of saccular PICA aneurysms. From February 1997 to December 2007, we performed endovascular procedures to treat 15 patients with 15 PICA aneurysms. Fourteen patients with 14 PICA aneurysms morphology of which was saccular were reviewed retrospectively. Twelve patients had ruptured aneurysms. The aneurysms arose from the PICA origin site (n = 12), the PICA lateral medullary segment (n = 1), or the PICA tonsilomedullary segment (n = 1). Complete aneurysm occlusion was achieved in 10 patients, residual neck in 3, and residual sac in one. Radiological follow-up was performed in 7 patients with mean duration of 34.7 months (range, 1-97 months) and showed stable or complete occlusion in 6 patients. There were no rebleeding or retreatment after endovascular treatment. Thromboembolism was the only procedure-related complication (n = 4 ; 28.6%). Asymptomatic PICA infarction occurred in two patients and symptomatic PICA infarction in two elderly patients with poor clinical grade. Of these procedural PICA infarction cases, 1 symptomatic PICA infarction patient developed ventriculitis and septic shock leading to death. The clinical outcome was good in 10 patients (71.4%). In the present study, detachable coil embolization has shown as an efficient modality for PICA saccular aneurysms challenging indications of microsurgery. However, thromboembolic complications should be considered, especially in poor clinical elderly patients with ruptured aneurysms.

OBJECT Intracranial-to-intracranial (IC-IC) bypasses are alternatives to traditional extracranial-to-intracranial (EC-IC) bypasses to reanastomose parent arteries, reimplant efferent branches, revascularize branches with in situ donor arteries, and reconstruct bifurcations with interposition grafts that are entirely intracranial. These bypasses represent an evolution in bypass surgery from using scalp arteries and remote donor sites toward a more local and reconstructive approach. IC-IC bypass can be utilized preferentially when revascularization is needed in the management of complex aneurysms. Experiences using IC-IC bypass, as applied to posterior inferior cerebellar artery (PICA) aneurysms in 35 patients, were reviewed. METHODS Patients with PICA aneurysms and vertebral artery (VA) aneurysms involving the PICA's origin were identified from a prospectively maintained database of the Vascular Neurosurgery Service, and patients who underwent bypass procedures for PICA revascularization were included. RESULTS During a 17-year period in which 129 PICA aneurysms in 125 patients were treated microsurgically, 35 IC-IC bypasses were performed as part of PICA aneurysm management, including in situ p3-p3 PICA-PICA bypass in 11 patients (31%), PICA reimplantation in 9 patients (26%), reanastomosis in 14 patients (40%), and 1 V3 VA-to-PICA bypass with an interposition graft (3%). All aneurysms were completely or nearly completely obliterated, 94% of bypasses were patent, 77% of patients were improved or unchanged after treatment, and good outcomes (modified Rankin Scale ≤ 2) were observed in 76% of patients. Two patients died expectantly. Ischemic complications were limited to 2 patients in whom the bypasses occluded, and permanent lower cranial nerve morbidity was limited to 3 patients and did not compromise independent function in any of the patients. CONCLUSIONS PICA aneurysms receive the application of IC-IC bypass better than any other aneurysm, with nearly one-quarter of all PICA aneurysms treated microsurgically at our center requiring bypass without a single EC-IC bypass. The selection of PICA bypass is almost algorithmic: trapped aneurysms at the PICA origin or p1 segment are revascularized with a PICA-PICA bypass, with PICA reimplantation as an alternative; trapped p2 segment aneurysms are reanastomosed, bypassed in situ, or reimplanted; distal p3 segment aneurysms are reanastomosed or revascularized with a PICA-PICA bypass; and aneurysms of the p4 segment that are too distal for PICA-PICA bypass are reanastomosed. Interposition grafts are reserved for when these 3 primary options are unsuitable. A constructive approach that preserves the PICA with direct clipping or replaces flow with a bypass when sacrificed should remain an alternative to deconstructive PICA occlusion and endovascular coiling when complete aneurysm occlusion is unlikely.

Objective To evaluate the use of this stent for treatment of fusiform and broad-necked intracranial aneurysms. Method Seventeen fusiform and broad-necked intracranial aneurysms in 15 patients were treated electively. They were located at the internal carotid artery (8), vertebral artery (5), basilar tip(1), middle cerebral artery (1), posterior cerebellar artery (1) and posterior inferior cerebellar artery(1). In all cases,previous attempts with the remodeling technique were technically judged difficult and combined stent placement across the aneurysm neck and subsequent coiling of the sac. Aneurysms diameter size varied from 4 to 30 mm. Results A total of 16 aneurysms in 15 patients were treated with this procedure. In no cases, stent deployment failed. All aneurysms were initially stented, followed by coil placement. Complere or subtotal (>95%) occlusion was achieved in 6 patients, and partial occlusion (<95%) was achieved in 9 patients. The periprocedural rate of any stroke or death was 0%. Angiographic follow-up was obtained in 10 patients. Neurological status remained well in all patients at a mean clinical follow-up of (6.2±3.2)months. Conclusions Primary and recurrence treatment of fusiforra and wide-necked intracranial aneurysms using the Neurofonn stent is feasible and effective. No permanent neurological deficits were associated with stent deployment. Short-term follow-up identified intact parent arteries and stable occlusion rates in the majority of cases. Key words: Intracranial aneurysm; Neuroform stent; Coil

Cerebral arteriovenous malformations (AVMs) are congenital lesions which rarely recur after complete microsurgical excision. This case report presents a 35-year-old woman who had been referred with a hemorrhagic AVM five years ago. This patient has recently undergone microsurgical excision for her left parieto-occipital Grade II AVM and surgical clipping of the left posterior inferior cerebellar artery (PICA) aneurysm which was concomitantly detected. She is the oldest case reported whose AVM recurred as Grade III, which is bigger than her first AVM associated with an aneurysm. Although some authors do not propose routine additional follow-up in adults after the initial negative postoperative angiogram, we believe that such patients should be followed clinically and radiologically.

Given advances in endovascular technique, the indications for revascularization in aneurysm surgery have declined. We sought to define indications, outline technical strategies, and evaluate the outcomes of patients treated with bypass in the endovascular era. We retrospectively reviewed all aneurysms treated between September 2006 and February 2013. We identified 54 consecutive patients (16 males and 39 females) with 56 aneurysms. Aneurysms were located along the cervical internal carotid artery (ICA) (n = 1), petrous/cavernous ICA (n = 1), cavernous ICA (n = 16), supraclinoid ICA (n = 7), posterior communicating artery (n = 2), anterior cerebral artery (n = 4), middle cerebral artery (MCA) (n = 13), posterior cerebral artery (PCA) (n = 3), posterior inferior cerebellar artery (n = 4), and vertebrobasilar arteries (n = 5). Revascularization was performed with superficial temporal artery (STA) to MCA bypass (n = 25), STA to superior cerebellar artery (SCA) (n = 3), STA to PCA (n = 1), STA-SCA/STA-PCA (n = 1), occipital artery (OA) to PCA (n = 2), external carotid artery/ICA to MCA (n = 15), OA to MCA (n = 1), OA to posterior inferior cerebellar artery (n = 1), and in situ bypasses (n = 8). At a mean clinical follow-up of 18.5 months, 45 patients (81.8%) had a good outcome (Glasgow Outcome Scale 4 or 5). There were 7 cases of mortality (12.7%) and an additional 9 cases of morbidity (15.8%). At a mean angiographic follow-up of 17.8 months, 14 bypasses were occluded. Excluding the 7 cases of mortality, the majority of aneurysms (n = 42) were obliterated. We identified 7 cases of residual aneurysm and recurrence in 6 patients at follow-up. Given current limitations with existing treatments, cerebral revascularization remains an essential technique for aneurysm surgery.

Objective – according to the separate clinical observation to evaluate the strategy and tactics of an individualized treatment planning after the rupture of posterior inferior cerebellar artery (PICA) aneurysm in acute period of hemorrhagic stroke. Materials and methods. A retrospective analysis of the case of microsurgical treatment of PICA aneurysm in the acute period after hemorrhage was performed. The patient’s diagnosis and treatment was held at the State Institution «Romodanov Neurosurgery Institute, NAMS of Ukraine» in 2019. The patients age at the time of diagnosis was 50 years. The complex of diagnostic workout included clinical neurological examination, instrumental (neuroimaging and functional tests) and laboratory investigation. Results. According to the results of comprehensive clinical and instrumental examination, patient underwent emergency combined one-stage surgical procedure that include aneurysms clipping with external ventriculostomy of the posterior horn of the right lateral ventricle for surgical correction of the consequences after aneurysms rupture (expansion of the blood into the ventricular system, with hemotamponade of III and IV ventricle, internal obstructive hydrocephalus), which caused the emergency of surgical procedure. The intervention (external drainage of the posterior horn of the right lateral ventricle, clipping of left PICA aneurysm) was performed on the 5th day after rapture. Operation and postoperative period have passed without complications with positive neurological and neuroimaging follow-up. Conclusions. The applied diagnostic and therapeutic options can be utilized as a method of choice for individualized surgical planning after rapture of PICA aneurysm.

Respiratory and Swallowing Outcomes Based on Aneurysm Location in 360 Patients with Subarachnoid Hemorrhage

Background:The choice of surgical approaches and options for the microsurgical vertebral artery (VA) and posterior inferior cerebellar artery (PICA) aneurysms repair remains controversial.Methods:A retrospective analysis of the clinical, surgical, and angiographic data of 80 patients with VA and PICA aneurysms treated from 2012 to 2018 was performed.Results:The aneurysms were saccular in 50 cases (62.5%) and fusiform in 30 cases (37.5%). The median suboccipital craniotomy was the most common approach (73.8%). Retrosigmoid craniotomy was performed in 25% of patients. There were the following types of microsurgical operations: neck clipping (61.25%), clipping with the artery lumen formation (13.75%), trapping (10%), proximal clipping (5%), and deconstruction with anastomosis (10%). Fifty-seven (71.3%) patients were discharged without worsening of the clinical signs after surgery. The most common postoperative neurological disorder was palsy of IX and X cranial nerve revealed in 14 (17.5%) patients. No fatal outcomes or patients in vegetative state were identified. The complete occlusion of PICA and VA aneurysms according angiography was in 77 (96.3%) cases.Conclusion:Microsurgical treatment is an effective method for VA and PICA aneurysms. The majority of VA and PICA aneurysms do not require complex basal approaches. A thorough preoperative planning, reconstructive clipping techniques, and anastomoses creation, as well as patient selection based on the established algorithms and consultations with endovascular surgeons, may reduce the number of complications and increase the rate of complete microsurgical occlusion in VA and PICA aneurysms.

This work records an investigation of the anatomy of the cranial blood supply in various species of mammal. The findings were based on a study of radiographs of specimens injected with a radioopaque mass and of casts of the vessels made by injection of neoprene latex, and on dissections of injected preparations. A well-developed carotid rete was found to be present in the cat, sheep, goat, ox and pig, and a rudimentary form of this structure was found in the dog. In the cat the rete is situated extracranially, but in the other species it lies within the cranium in the cavernous sinus. There is no carotid rete in the rabbit or the rat. The carotid rete consists of a compact network of intertwined, freely anastomosing arteries, and is related to the branches of the trigeminal nerve. When the rete is situated intracranially there is a variable degree of communication across the mid-line with the rete of the opposite side. W hether situated intracranially or extracranially the rete lies within a venous lake. The presence of a well-developed carotid rete was associated with the non-persistence of, or a degenerating internal carotid artery. A thin fibrous cord was the only rem nant of this artery found in the cat. In the goat, sheep and pig the internal carotid artery was absent proximal to the rete, but the large trunk which connected the rete with the circle of Willis was identified as representing the still persisting distal segment of this artery. In the ox (a young animal) a similar trunk connecting the rete with the circle of Willis formed the continuation of a still persisting but relatively narrow proximal segment of the internal carotid artery. The main vessels which may supply the carotid rete are the internal maxillary artery (usually via the ramus anastomoticus and the arteria anastomotica), the ascending pharyngeal artery, and the occipital artery. In the cat, sheep, goat and ox the chief vessel of supply is the internal maxillary artery, but in the pig it is the ascending pharyngeal artery. In the ox a substantial contribution is provided by the occipital artery. Both the ramus anastomoticus and the arteria anastomotica form connexions between the external and internal carotid systems and they join one another within the cavernous sinus. It is at his site that the intracranial carotid rete is developed, but the extracranial carotid rete, seen in the cat, is situated around the internal maxillary artery at the site of origin of the arteria anastomotica of the artiodactyls. The variations in the situation of the carotid rete in different species is along the line of the arteria anastomotica. It is suggested that the arteria anastomotica and the ramus anastomoticus respectively are homologous with the recurrent meningeal and the middle meningeal arteries of the rabbit and man. The arteries which supply the orbital and the ethmoidal regions are described and the homologies of the external ophthalmic artery are discussed. The great variability in the supply of these territories which was seen in the cat is thought to be associated with the presence of an extracranial carotid rete. In spite of variations in different species of animal a basic pattern can be discerned in the major arteries supplying the head. It is suggested that this basic pattern is related to a primitive stapedial artery, and that the variations seen are due to modifications of the branches of this earlier vessel. The circle of Willis was found to derive its blood supply from one or more of five sources: the internal carotid artery, the external carotid arterial system, the ascending pharyngeal artery, the vertebral artery (via the basilar artery) and the occipital artery. In the absence of an internal carotid artery the greatest contribution of blood passes to the circle of Willis through the carotid rete. An occipito-vertebral anastomosis seems to be of some importance in supplying the circle of Willis in the cat, pig, dog and rabbit. In the sheep, goat and ox the direction of the flow of blood in the basilar artery would appear to be away from and not towards the circle of Willis. In the pig the two anterior cerebral arteries anastomose in the mid-line and continue forward as a single vessel. The peculiar structure of the vessels which compose the carotid rete suggests that this compact network has a haemodynamic significance, and since the rete lies in the pathway of the major artery or arteries which supply the brain, its existence and possible influence should be borne in mind when problems of the cerebral circulation are considered in species in which this structure is present.

Advances in diagnosis of posterior inferior cerebellar artery (PICA) aneurysms have revealed the high frequency of distal and/or dissecting PICA aneurysms. Surgical treatment of such aneurysms often requires revascularization of the PICA including but not limited to its caudal loop. To examine the microsurgical anatomy involved in occipital artery (OA)-PICA anastomosis at various anatomic segments of the PICA. Twenty-eight PICAs in 15 cadaveric heads were examined with the operating microscope to take morphometric measurements and explore the specific anatomy of bypass procedures. OA bypass to the p2, p3, p4, or p5 segment was feasible with a recipient vessel of sufficient diameter. The loop wandering near the jugular foramen in the p2 segment provided sufficient length without requiring cauterization of any perforating arteries to the brainstem. Wide dissection of the cerebellomedullary fissure provided sufficient exposure for the examination of some p3 segments and all p4 segments hidden by the tonsil. OA-p5 bypass was placed at the main trunk before the bifurcation in 5 hemispheres and at the larger hemispheric trunk in others. Understanding the possible variations of OA-PICA bypass may enable revascularization of the appropriate portion of the PICA when the parent artery must be occluded. A detailed anatomic understanding of each segment clarifies important technical nuances for the bypass on each segment. Dissection of the cerebellomedullary fissure helps to achieve sufficient exposure for the bypass procedures on most of the segments.

Balloon-tipped catheters were used to occlude the external carotid artery and its branches in nine horses with hemorrhage caused by guttural pouch mycosis. The internal carotid artery on the affected side was occluded simultaneously in four horses and had been occluded previously in two others. In three horses, a single balloon-tipped catheter was inserted in the external carotid artery beneath the floor of the guttural pouch and its tip was advanced blindly into distal branches. In one horse, the superficial temporal artery was occluded briefly during surgery by a balloon-tipped catheter so a catheter inserted into the external carotid artery could be diverted into the maxillary artery. In the other five horses, the external carotid artery was occluded proximally and the maxillary artery was occluded immediately caudal to the alar canal by a balloon-tipped catheter inserted into the major palatine artery. Serious postoperative hemorrhage did not occur in eight horses, but one horse that had a single balloon-tipped catheter inserted into the external carotid artery had profuse hemorrhage 11 days after surgery and was euthanatized. One horse was euthanatized because of persistent dysphagia. The only complication related to use of balloon catheters was a mild incisional infection in one horse. It was concluded that the external carotid and maxillary arteries must be occluded on both sides of the eroded segment to prevent hemorrhage from normograde and retrograde flow.