Internal Vein Research Articles

Microsurgical anatomy of the great cerebral vein of Galen and its tributaries.

The deep cerebral veins may pose a major obstacle in operative approaches to deep-seated lesions, especially in the pineal region where multiple veins converge on the great cerebral vein of Galen. Because undesirable sequelae may occur from such surgery, the number of veins and branches to be sacrificed during these approaches should kept to a minimum. The purpose of this study was to examine venous drainage into the vein of Galen with a view to surgical approaches. If a vein hampering surgical access must be sacrificed, it can therefore be selected according to the smallest draining territory. The deep cerebral veins and their surrounding neural structures were examined in 50 cerebral hemispheres from 25 adult cadavers in which the arteries and veins had been perfused with red and blue silicone, respectively. Special consideration was given to the size and location of drainage of the vein of Galen and its tributaries. When a surgeon approaches the pineal region, several veins may hamper the access route. From posterior to anterior, these include the following: the superior vermian and the precentral or superior cerebellar veins, which drain into the posteroinferior aspect of the vein of Galen; and the tectal and pineal veins, which drain into its anterosuperior aspect. The internal occipital vein is the main vessel draining into the lateral aspect of the vein of Galen. It may be joined by the posterior pericallosal vein, and in that case has an extensive territory. To avoid intraoperative venous infarction, it is important to use angiography to determine the venous organization before surgery and to estimate the permeability and size of the branches of the deep venous system.

Antegrade sclerotherapy for varicocele testis--possible and avoidable complications

Antegrade sclerotherapy is an established procedure for the treatment of varicocele. To avoid complications during the dissection of the pampiniform plexus, detailed knowledge of the angioarchitecture of the spermatic cord is recommended. One group of plexus veins is situated ventrolaterally and is surrounded by a yellowish fat which serves as a landmark. This vein group should be chosen for preparation. Phlebography of the internal testicular vein is mandatory. If arteries or major pelvic veins become visible while applying contrast media, sclerotherapy should not be performed. Paravasation of sclerosing agent has to be recognized and treated immediately to prevent deleterious effects.

Priapism of the Glans and Corpus Spongiosum. Report of two cases with angiography

Priapism, whether of the arterial or veno-occlusive type, mainly affects the cavernous bodies, leaving the low-pressure system in glans and corpus spongiosum soft without urethral compression. In the present 2 case reports, the pathologically increased pressure primarily affected the corpus spongiosum. One had arterial priapism following penile revascularization and the other veno-occlusive priapism due to thrombosis of the internal pelvic veins. Both had ulcerations of the glans and urinary retention requiring suprapubic catheterization. Arteriography revealed the disease mechanism in both, and led to embolization in 1.

Aneurisma de la arteria poplítea como complicación del síndrome de atrapamiento de la arteria poplítea

Summary Introduction Popliteal artery entrapment syndrome is an infrequent entity. It chiefly affects young males who play sports, with an incidence of 0.3-3.5% according to different series, and is produced by the insertions of the internal gastrocnemius muscle into the condyle. Case report We report the case of a 54-year-old patient who was admitted to hospital because of acute ischemia of the lower right limb. Following physical and haemodynamic evaluation, arteriography was performed and an occlusion was observed in the second portion of the popliteal artery. Fibrinolysis was chosen as the initial treatment and the existence of a popliteal aneurysm was discovered. Once the acute phase had been overcome, the patient was submitted to a surgical intervention. Conclusion Poststenotic dilation (aneurysm) is infrequent as a complication of this syndrome and appears in the later stages of life. It can, however, be mistakenfor an arteriosclerotic popliteal aneurysm and pre-surgical diagnosis is difficult. Fibrinolysis is an option to be borne in mind as initial therapy during the acute phase, provided that the clinical situation of both the limb and the patient allow its use. Definitive therapy will involve surgical section of the muscle-fibre bands causing the problem; in the case reported here, we used aneurysmectomy and a popliteal-popliteal by-pass with the internal saphen vein.

Bypass to the intracranial internal carotid artery

Extracranial to intracranial internal carotid artery bypass surgery with vein is well described for a number of diverse conditions. They provide high blood flow with good initial patency. However, long term patencies for specific graft types remains unknown. This is an analysis of consecutive interposition saphenous vein bypass cases between the common carotid artery (CCA) and the intracranial internal carotid artery (ICA) where the distal anastomosis was placed end-to-end immediately proximal to the posterior communicating artery in 55 patients undergoing 57 bypass procedures (bilateral in 2 cases). Twenty-five patients underwent grafting for planned vessel obliteration where the pathology required vessel sacrifice. Twenty-eight patients had bypass grafting for stroke risk reduction in the setting of threatening stroke and 4 patients had bypass grafts for emergency revascularisation in the setting of stroke in evolution. Patients were assessed preoperatively and at follow-up with modified Rankin scores. Procedural related complications included a 7% mortality and 7% functional decline. Early graft occlusion occurred in 5% of grafts leading to death in each case. A further patient died of rupture at the distal anastomosis site. In surviving patients, patency was present in 100% at last follow-up (mean 5 years and maximum 11 years) with no patient sustaining new hemispheric ischemic events. One patient developed a delayed asymptomatic stenosis within the vein graft requiring stenting. Because of the high initial management risks this technique of common carotid to intracranial internal carotid artery saphenous vein bypass surgery should be reserved for patients at considerable risk by alternate management. However, once the acute postoperative period is past the bypass appears to be robust and capable of supplying the entire distribution of a normal internal carotid artery.

Tratamiento quirúrgico del aneurisma poplíteo

The indication for surgery in an asymptomatic popliteal aneurysm is controversial, although ischemic complications are often associated with such aneurysms and there is a high risk of amputation of the limb. To compare the results of surgical treatment of symptomatic and asymptomatic popliteal aneurysms. We describe a retrospective study of 57 popliteal aneurysms in 45 patients seen between January 1991 and December 2000:20 asymptomatic (groupI) and 37 with acute ischaemia due to thrombosis or distal embolization (groupII). We used univariate analysis and Kaplan-Meier tables. The differences were taken as significant when p> 0.05. The number of permeable distal trunks showed differences between the two groups (p> 0.0001), greater in the asymptomatic group. The vascular procedure was exclusion of the aneurysm andpopliteal-popliteal by pass using the internal saphenous vein, except for four primary amputations in groupII. One month later the primary permeability was 95% in groupIand 72.7% in groupII (p = 0.04). After 39 ± 29 months of follow-up, the secondary permeabilitywas 92.8% and 55.8% respectively (p= 0.006). The rate of salvage of the limb was 100% and 80.8% (p= 0.04). Preoperative fibrinolysis (16 cases) in groupII did not lead to any difference in permeability or limb salvage. The best results of surgical treatment of poplitealaneurysms were seen in the asymptomatic group. This group showed a larger number of permeable distal trunks. Preoperative loco-regional fibrinolysis did not affect the permeability or salvage of the limb. La indicación de cirugía en elaneurisma poplíteo asintomático es controvertida, a pesar de que son frecuentes las complicaciones isquémicas asociadas al aneurismay delriesgo elevado de amputación de la extremidad. Comparar los resultados del tratamiento quirúrgico del aneurisma poplíteo sintomático y asintomático. Serie retrospectiva de 57 aneurismas poplíteos en 45 pacientes, desde enero de 1991 a diciembre de 2000: 20 asintomáticos (grupo I) y 37 con isquemia agudapor trombosis o embolización distal (grupo II). Se utilizó un análisis univariante y tablas de Kaplan-Meier. La diferencia se consideró significativa si p>0,05. Elnúmero de troncos distales permeables mostró diferencias entre ambos grupos (p> 0,0001), mayor en el grupo asintomático. El procedimiento vascu-larfue la exclusión del aneurisma y derivación poplítea-poplítea con vena safena interna, excepto cuatro amputaciones primarias en el grupo II. La permeabilidadprimaria al mes fue del 95% en el grupo Iy del 72,7% en el grupo II (p= 0,04). A 39 ± 29 meses de seguimiento, la permeabilidadsecundaria fue del92,8y del 55,8%, respectivamente (p=0,006). Latasade salvamento de extremidad fue del 100y del 80,8% (p= 0,04). Lafibrinólisis preoperatoria (16casos) en el grupoII no aportó diferencias en cuanto a lapermeabilidadni al salvamento de la extremidad. Los mejores resultados en el tratamiento quirúrgico del aneurismapoplíteo se obtienen en elgrupo asintomático. Este grupo presenta un mayor número de troncos distalespermeables. Lafibrinólisis locorregional preoperatoria no influye en lapermeabilidad ni en el salvamento de la extremidad. A indicação cirúrgica para o aneurisma popliteu assintomático é controversa, apesar de serem frequentes as complicações isquémicas associadas ao aneurisma e o risco elevado de amputação do membro. Comparar os resultados do tratamento cirúrgico do aneurisma popliteu sintomático e assintomático. Série retrospectiva de 57 aneurismas popliteus em 45 doentes, de Janeiro de 1991 a Dezembro de 2000:20 assintomáticos (grupo I) e 37 com isquemia agudapor trombose ou embolização distal (grupoII). Utilizou-se uma análise univariante e tabelas de Kaplan-Meier. A diferença foi considerada significativa para p> 0,05. O número de troncos distaispermeáveis mostrou diferenças entre ambos os grupos (p> 0,0001), maior no grupo assintomático. Oprocedimento vascular foi a exclusão do aneurisma e bypass popliteu-popliteu com a veia safena interna, excepto para quatro amputações primárias no grupo II. A permeabilidade primária ao mês foi de 95% no grupo I e de 72,7% no grupo II (p= 0,04). Aos 39 ± 29 meses de seguimento, a permeabilidade secundáriafoi de 92,8 e de 55,8%, respectivamente (p=0,006). A taxa de salvamento do membro foi de 100 e de 80,8% (p= 0,04). A fibrinólise pré-operatória (16 casos) no grupo II não comportou diferenças quanto á impermeabilidade nem ao salvamento do membro. Osmelhores resultados no tratamento cirúrgico do aneurismapopliteu obtiveram-se no grupo assintomático. Este grupo apresenta um maior número de troncos distais permeáveis. A fibrinólise loco-regionalpré-operatória não influência apermeabilidade nem o salvamento do membro.

Primary malignant lymphoma of the saphenous vein

We herein present a case of primary malignant lymphoma of the saphenous vein. A 72-year-old man suffered from tumor and pain of the anteromedial aspect of the left upper thigh. Local thigh ultrasound scanning and computed tomography revealed a mass within the superior third of the internal saphenous vein. The patient underwent surgical exploration and removal of the saphenous vein between the groin and the upper third of the leg. The resected vessel was surrounded and infiltrated by a whitish, rubbery tissue all along its course. The histologic findings were consistent with high-grade, diffuse, large-cell lymphoma of peripheral B lymphocyte origin, primarily arising in the saphenous vein. Antiactin monoclonal antibodies depicted the venous vascular wall infiltrated by tumor cells, confirming the lymphomatous localization within the saphenous vein. The patient is now alive and free of tumor 10 months after the operation. (J Vasc Surg 2002;35:168-71.)

外傷性両側舌下神経断裂の治療経験

Bilateral hypoglossal nerve transection is a rare complication of neck trauma because this injury generally results in death due to hemorrhage from a disrupted internal carotid artery or internal juglar vein. We report a case of bilateral hypoglossal nerve transection. The patient was 20-year-old man who suffered suprahyoid lacerations. He received emergency treatment, and two weeks after injury he underwent nerve grafting using the greaterauricular nerve on the right side and end to end anastomosis of the nerve on the left side. One and a half months after operation, weak tongue movement appeared. Two months after operation, he could move his tongue toward the right side. Three and a half months after operation, he could move his tongue toward the left side. One year after operation, he had good quality of life with out dysphagia or dysarthria.

Varicocele: Laparoscopic clipping and color Doppler follow-up

Purpose: The aim of this study was to evaluate the results of laparoscopic treatment of varicocele and findings of testicular volume and blood supply using color Doppler ultrasound scan on follow-up. Methods: Fourteen patients aged 7 to 15 years old (median, 12.3 years) with left varicocele (grade II, n = 4; grade III, n = 10) underwent laparoscopic clipping of internal testicular vein and artery. At follow-up, both testes were scanned by ultrasonography in axial and longitudinal planes, and at least 3 measurements—length, width, and thickness—were taken to calculate testicular volumes. Arterial perfusion of the testes also was assessed. Results: Operating time ranged from 25 to 80 minutes (mean, 60 minutes). There was no perioperative complication. At a mean follow-up of 14 months (range, 2 to 39 months) all children were asymptomatic with disappearance of varicocele. The volumes of bilateral testes were equal (difference in volumes less than 10%) in 9 children. Ipsilateral testicular hypertrophy was found in 3 children. There was no difference in arterial perfusion between the testes in each patient. Small transient ipsilateral hydrocele was observed in 2 patients. Conclusion: Laparoscopic clipping of testicular vein and artery was simple and effective for varicocele treatment and did not compromise testicular blood supply. J Pediatr Surg 36:1704-1707. Copyright © 2001 by W.B. Saunders Company.

Predictors of radial artery patency for coronary bypass operations

Background. Few data exist regarding angiographic predictors of radial artery patency for coronary bypass grafting, and the benefit of calcium antagonists is not clear. Methods. One hundred fifteen patients were studied who had myocardial revascularization with the radial artery plus internal mammary and vein grafts with 3.5 ± 1.1 grafts per patient. Sixty-three patients received diltiazem and 52 patients did not. Base line and follow-up angiographies were analyzed 1 year postoperatively in 50 of these patients with a quantitative computerized method. Results. One hundred fourteen patients survived and were followed for 30.1 ± 12.6 months. Patency for mammary grafts was 100%, for radial grafts it was 80%, and for saphenous vein grafts it was 68%. Patent radial artery grafts had significantly greater degree of stenosis in the native vessels than occluded grafts (73% ± 14% vs 40% ± 24%), ( p = 0.0007; confidence interval = 95%). Radial artery patency increased to 92% when arteries with 70% or more stenosis were considered. No differences were observed for clinical and angiographic end points in the patients that received diltiazem compared with the rest who had not. Conclusions. The degree of stenosis in the native coronary artery significantly influences the patency rate of radial artery grafts, independent of diltiazem.

Knotting of intracardiac flow-directed balloon catheter: A non-surgical technique for removal

A knot occurred in a flow-directed balloon tipped (Swan-Ganz) catheter inserted through the right internal jugulary vein. Knot was undone using right Judkins catheter introduced via left jugulary vein approach. By passing through the loop of knot, right Judkins catheter was used to stabilize the knotted segment and knot was unknotted by gently pulling the Swan-Ganz Catheter.

Knotting of intracardiac flow-directed balloon catheter: A non-surgical technique for removal

A knot occurred in a flow-directed balloon tipped (Swan-Ganz) catheter inserted through the right internal jugulary vein. Knot was undone using right Judkins catheter introduced via left jugulary vein approach. By passing through the loop of knot, right Judkins catheter was used to stabilize the knotted segment and knot was unknotted by gently pulling the Swan-Ganz Catheter.

Knotting of intracardiac flow-directed balloon catheter: A non-surgical technique for removal

A knot occurred in a flow-directed balloon tipped (Swan-Ganz) catheter inserted through the right internal jugulary vein. Knot was undone using right Judkins catheter introduced via left jugulary vein approach. By passing through the loop of knot, right Judkins catheter was used to stabilize the knotted segment and knot was unknotted by gently pulling the Swan-Ganz Catheter.

Removal of the thrombosed prosthetic axillofemoral graft

Late thrombosis of prosthetic graft material is rarely managed successfully by simple thrombectomy or thrombolytic therapy. Replacement with a new graft may be necessary. Although several techniques have been described, mobilizing and removing an old thrombosed prosthetic graft is usually extremely difficult because of a firm attachment to its tunnel. This attempt is more difficult especially for ringed grafts. We describe a simple technique of using an internal varicose vein stripper for the removal of such a late thrombosed axillofemoral spiral polytetrafluoroethylene graft and positioning a new graft into the old tunnel.

Managing the therapeutic dilemma: patients with spontaneous intracerebral hemorrhage and urgent need for anticoagulation.

Physicians face a therapeutic dilemma in patients with acute hemorrhagic stroke requiring long-term, high-intensity anticoagulants because this treatment increases the risk of intracranial hemorrhage (ICH) 8- to 11-fold. We retrospectively studied 15 patients with ICH which occurred under anticoagulation with phenprocoumon, with an international norrmalized ratio (INR) of 2.5-6.5 on admission. Hemispheric, thalamic, cerebellar, intraventricular, or subarachnoid hemorrhage without aneurysm occurred. Absolute indications for anticoagulation were double, mitral, or aortic valve replacement, combined mitral valve failure with atrial fibrillation and atrial enlargement, internal carotid artery-jugular vein graft, frequently recurring deep vein thrombosis with risk of pulmonary embolism, and severe nontreatable ischemic heart disease. As soon as the diagnosis of ICH was established, INR normalization was attempted in all patients by administration of prothrombin complex, fresh frozen plasma, or vitamin K. After giving phenprocoumon antagonists (and neurosurgical therapy in four patients) heparin administration was started. Nine patients received full-dose intravenous and six low-dose subcutaneous heparin. The following observations were made: (a) All patients with effective, full-dose heparin treatment with a 1.5- to 2-fold elevation in partial thromboplastin time after normalization of the INR were discharged without complication. (b) Three of four of the patients with only incomplete correction of the INR (> 1.35) experienced relevant rebleeding within 3 days (all patients with an INR higher than 1.5), two of whom were on full-dose heparin. (c) Three of seven of the patients with normalized INR and without significant PTT elevation developed severe cerebral embolism. Although our data are based on a retrospective analysis, they support treatment with intravenous heparin (partial thromboplastin time 1.5-2 times baseline value) after normalization of the INR in patients with an ICH and an urgent need for anticoagulation.

Three-dimensional phase contrast MR cerebral venography with zero filling interpolation in the slice encoding direction

The purpose of this study was to evaluate the magnetic resonance (MR) cerebral venography findings of a three-dimensional phase contrast MR sequence with zero filling interpolation of the data in the slice encoding direction. Fifty volunteers were enrolled in the study. Images were obtained on a 1.5 MR imaging system with acquisition time of 12 min. MIP images were reconstructed throughout the entire imaging volume. A grading scale system was used to assess dural venous sinuses, major deep veins, cortical, and cortical eponymic veins. Inferior group of dural venous sinuses, inferior sagittal sinus, and cortical eponymic veins were poorly demonstrated. Score of the superior sagittal sinus, the straight sinus, the confluence of the superior sinus group, the right transverse and sigmoid sinuses, the internal veins, and the vein of Galen was excellent. The score of the left transverse and sigmoid sinuses was good. In conclusion, when using zero filling interpolation of the data in a three-dimensional phase contrast MR cerebral venography sequence, the superior group of dural venous sinuses and main major deep veins are demonstrated with good conspicuity.

Mesozoic mesothermal quartz‐gold‐scheelite lodes, Wakamarina, Marlborough, New Zealand

In the Wakamarina valley, Marlborough, ribbon‐banded quartz lodes fill tensional faults in Caples Terrane‐derived, Marlborough Schist and Wakamarina Quartzite. The largest of the lodes, the Golden Bar, has a strike length of at least 1.8 km and an average width of 2 m. It fills a steeply dipping normal fault which separates pumpellyite‐actinolite fades psammitic schists on the footwall from stilpnomelane‐pumpellyite‐spessartine quartzite (Wakamarina Quartzite) and metabasites on the hanging wall. The lode consists of bands of buck quartz separated by thin chlorite‐sericite‐rich laminae that have been split off the wall‐rock schist. Five deformation events are recognised. The first two are linked with early Jurassic metamorphism, the younger event producing the earliest scheelite, whereas in early Mid Jurassic (illite/sericite K‐Ar age of c. 175 Ma), the third event produced late metamorphic transtensional mylonites with minor quartz‐scheelite veining. As uplift of the schist belt continued through the brittle‐ductile transition zone, the fourth deformation created tensional faults across the mylonites which localised deposition of the quartz‐scheelite ± gold lodes (Golden Bar and Alfords). Internal lode structures indicate that internal pulsed fluid inflow and ductile vein deformation continued during this deformation. The fifth deformation, again with minor quartz‐scheelite veining, created late brittle fracturing and compressional deformation of the lodes and country rocks. Fluid P‐T conditions are probably comparable to those in similar mesothermal quartz‐scheelite lodes at Glenorchy in Otago (1.5–3.5 kbar and 275–330°C), but co‐existing albite and calcic plagioclase in Alfords lode implies that fluid temperatures at Wakamarina may have been locally higher. An extensive zone of sericitic hydrothermal alteration characterised by sericite and K‐feldspar (sericite K‐Ar age of c. 140 Ma — earliest Cretaceous) and loss of pumpellyite, stilpnomelane, and actinolitic amphibole surrounds the Golden Bar lode. The potassic enrichment, the stability of albite and chlorite in both wall rocks and the lodes, and a low sulphide content indicate that the fluids at Wakamarina had a higher aK+/aH+ than in the Otago lodes, and a more neutral pH with a low capacity to carry gold in solution.

New Buccinator Myomucosal Island Flap: Anatomic Study and Clinical Application

The authors studied the vascular anatomy of the buccinator muscle by dissecting fresh cadavers. The anatomy of the buccal branches of the facial artery consistently confirmed the existence of a posterior buccal branch, a few inferior buccal branches, and anterior buccal branches to the posterior, inferior, and anterior portions of the buccinator. The buccal artery and posterior buccal branch anastomose to each other and ramify over the muscle. Several veins originate from the lateral aspect of the muscle, converge into the buccal venous plexus, and drain into the facial vein (from two to four tributaries) or into the pterygoid plexus and the internal maxillary vein (from the buccal vein). These vessels and nerves enter the posterior half of the buccinator posterolaterally. The facial artery and vein are located at variable distances from each other around the oral commissure and the nasal base. Two patterns of buccinator musculomucosal island flaps supplied by these buccal arterial branches are proposed in this article. The buccal musculomucosal neurovascular island flap (posteriorly based), supplied by the buccal artery, its posterior buccal branch, and the long buccal nerve, can be passed through a tunnel under the pterygomandibular ligament for closure of mucosal defects in the palate, pharyngeal sites, the alveolus, and the floor of the mouth. The buccal musculomucosal reversed-flow arterial island flap (superiorly based), supplied by the distal portion of the facial artery through the anterior buccal branches, can be used to close mucosal defects in the anterior hard palate, alveolus, maxillary antrum, nasal floor and septum, lip, and orbit. The authors have used the flaps in 12 patients. There has been no flap necrosis, and results have been satisfactory, both aesthetically and functionally.

Intraocular and Intraorbital Compartment Pressure Changes following Orbital Bone Grafting: A Clinical and Laboratory Study

Visual loss is an uncommon but catastrophic complication after intraorbital bone grafting for the reconstruction of acute traumatic defects or long-standing enophthalmos. Increased intraocular or intraorbital compartment pressure may be pathogenic in this setting. A two-part study was designed to test the null hypothesis that intraocular and intraorbital compartment pressure values remain constant despite orbital volume reduction with graft material. Laboratory study: Intraocular and intraorbital compartment pressures were measured during sequential orbital volume reduction in New Zealand White rabbits that had been randomized to one of three groups: intact orbits (n = 10), acute orbital wall defects (n = 8), and chronic (3 months) orbital wall defects (n = 11). Intraocular pressure was significantly (p<0.05) elevated in all three groups of orbits undergoing orbital volume reduction compared with control, nonoperated orbits. Intraorbital compartment pressure values did not change significantly from control levels throughout the grafting sequence. Although no significant differences existed between groups in the maximum levels of intraocular pressure attained, the chronic group demonstrated a greater rate of rise and slower rate of decline. Clinical study: Using applanation tonometry, intraocular pressure was measured before and serially after orbital floor exploration and intraorbital placement of split calvarial bone grafts in 19 patients who presented with orbital-zygomatic complex fractures that required surgery. A separate group of 16 patients with orbital-zygomatic complex fractures that required exploration of the orbital floor but not bone grafting was used for comparison. A significant (p<0.05) elevation of intraocular pressure was observed immediately after bone grafting compared with nongrafted orbits, but values returned to normal within 30 minutes and remained stable through the third postoperative day. There were no cases of visual impairment in any patients in either group as the result of surgical treatment. These data indicate that orbital volume reduction with graft material results in significant, temporary elevation of intraocular pressure. No significant elevations of intraorbital compartment pressure were detected in the rabbit orbits. Data from this study may have direct relevance in defining guidelines for "tolerable" changes in orbital tissue and globe pressures after surgery.

Comparative Doppler imaging of the ophthalmic vasculature in normal Beagles and Beagles with inherited primary open-angle glaucoma.

The objective of this study was to compare orbital and ocular vasculature velocity, measured by Doppler imaging, in normal Beagles and Beagles with inherited primary open-angle glaucoma. Eight normal Beagles and 13 Beagles with different stages of primary open-angle glaucoma were evaluated twice with a 2-4-week period between measurements. Doppler imaging was performed with the dogs anesthetized, and the Doppler transducer applied directly on the corneal surface. The majority of the orbital vasculature (external ethmoidal artery; internal ophthalmic artery and vein; and external ophthalmic artery and vein) and ocular blood vessels (anterior ciliary artery and veins; long posterior ciliary arteries; short posterior ciliary arteries; primary retinal arteries; and the vortex veins) were identified and Doppler blood velocity parameters were determined. The glaucomatous dogs demonstrated significant differences in the Doppler velocity parameters of several orbital vessels (external ethmoidal, external ophthalmic, and internal ophthalmic arteries), and several ocular vessels (anterior ciliary, short posterior ciliary, and long posterior ciliary arteries). These differences included decreased blood velocities, and increased pulsatility and resistive indexes. The Doppler blood flow velocities of the primary retinal arteries were unchanged between the normal and glaucomatous dogs. In the glaucomatous dogs, the Doppler imaging suggests increased vascular resistance downstream in both the orbital and ocular vasculature. These blood velocity parameter changes may be primary or secondary, and may offer therapeutic opportunities to increase perfusion, prolong the retina and optic nerve head function, and maintain vision in the canine glaucomas.