Median Caudal Artery Research Articles

Doppler ultrasound is more accurate than pulse oximeter plethysmography in the measurement of systolic arterial pressure from the median caudal artery in anesthetized dogs.

To compare the accuracy of doppler ultrasound (DOP) and pulse oximeter plethysmography (POP) in the measurement of systolic arterial pressure (SAP) to invasive blood pressure (IBP) in anesthetized dogs. 40 client-owned healthy dogs > 10 kg. Dogs were anesthetized for surgical procedures in dorsal recumbency. Invasive blood pressure was measured from a dorsal pedal artery. DOP and POP device probes were placed over the median caudal artery with a flow-occluding cuff for noninvasive blood pressure measurement. Systolic arterial pressure measured by DOP, loss of pulse oximeter plethysmograph (POPL), and return of pulse oximeter plethysmograph (POPR) were compared to SAP measured by IBP. A linear mixed model was used to determine correlation. Bland-Altman analyses were performed to determine bias, SD, and limits of agreement. The accuracy of DOP and POP was compared to IBP across different tensive states. Conditional R2 values for DOP, POPL, and POPR versus IBP were 0.92, 0.85, and 0.87, respectively (all P < .001). The biases for DOP, POPL, and POPR compared to IBP were +7.6 ± 13.1, +3.9 ± 14.4, and +8.6 ± 15.2 mm Hg (bias ± SD), respectively. Limits of agreement (lower, upper) were (-18.1, +33.3), (-24.3, +32.1), and (-21.2, +38.4) mm Hg for DOP, POPL, and POPR, respectively. DOP and POP overestimated SAP during hypotension (SAP < 90 mm Hg), DOP to a lesser magnitude. DOP measured from the median caudal artery may be acceptable for SAP measurement in dorsally recumbent, healthy anesthetized dogs > 10 kg. POP was determined an unacceptable method.

Validation of the oscillometric blood pressure monitor Vet20 SunTech in anesthetized healthy cats

ObjectiveTo evaluate a veterinary-specific oscillometric noninvasive blood pressure (NIBP) system according to the guidelines of the American College of Veterinary Internal Medicine (ACVIM) Consensus Statement. Study designProspective clinical study. AnimalsA total of 33 client-owned cats (20 females and 13 males). MethodsCats were premedicated with methadone (0.3 mg kg−1) and alfaxalone (2 mg kg−1) intramuscularly. After 15 minutes anesthesia was induced with isoflurane (3%) in 100% oxygen by facemask while breathing spontaneously. A 22 gauge catheter was placed in the median caudal artery and systolic (SAP), diastolic (DAP) and mean (MAP) arterial pressures were measured. NIBP measurements were collected by placing the cuff (40% of limb circumference) on the right or left antebrachium. The agreement between the two methods was evaluated with the Bland–Altman methods, and the oscillometric NIBP device was evaluated using the ACVIM guidelines for validation of devices. ResultsData from 30 of the 33 cats were analyzed. Five paired measurements were taken from each cat, totaling 150 paired measurements. Mean bias (limits of agreements) for SAP, DAP and MAP were 2.7 (−22.7 to 28.1), 0.9 (−22.3 to 24.2) and 1.3 (−20.4 to 23.0). The oscillometric NIBP passed all validation criteria, except correlation which was <0.9 for SAP, DAP and MAP. Conclusions and clinical relevanceThe Vet20 did not meet all validation criteria by the ACVIM. However, all criteria except correlation were met.

Assessment of a commercially available veterinary blood pressure device used on awake and anesthetized dogs.

To compare results of a commercially available device for oscillometrically measured blood pressure (OBP) with invasively measured blood pressure (IBP) in awake and anesthetized dogs. 19 adult dogs (mean ± SD body weight, 17.8 ± 7.5 kg). Blood pressures were measured in dogs while they were awake and anesthetized with isoflurane. The OBP was recorded on a thoracic limb, and IBP was simultaneously recorded from the median caudal artery. Agreement between OBP and IBP was evaluated with the Bland-Altman method. Guidelines of the American College of Veterinary Internal Medicine (ACVIM) were used for validation of the oscillometric device. In awake dogs, mean bias of the oscillometric device was -11.12 mm Hg (95% limits of agreement [LOA], -61.14 to 38.90 mm Hg) for systolic arterial blood pressure (SAP), 9.39 mm Hg (LOA, -28.26 to 47.04 mm Hg) for diastolic arterial blood pressure (DAP), and -0.85 mm Hg (LOA, -40.54 to 38.84 mm Hg) for mean arterial blood pressure (MAP). In anesthetized dogs, mean bias was -12.27 mm Hg (LOA, -47.36 to 22.82 mm Hg) for SAP, -3.92 mm Hg (LOA, -25.28 to 17.44 mm Hg) for DAP, and -7.89 mm Hg (LOA, -32.31 to 16.53 mm Hg) for MAP. The oscillometric device did not fulfill ACVIM guidelines for the validation of such devices. Agreement between OBP and IBP results for awake and anesthetized dogs was poor. The oscillometric blood pressure device did not fulfill ACVIM guidelines for validation. Therefore, clinical use of this device cannot be recommended.

Validation of noninvasive blood pressure equipment: which peripheral artery is best for comparison studies in dogs?

Objectives1) To determine which peripheral artery commonly used for invasive arterial blood pressure (IBP) monitoring yields the least bias when compared with noninvasive blood pressure (NIBP) values obtained at the antebrachium of the dog, and 2) to identify and describe differences in systolic (SAP), mean (MAP) and diastolic arterial pressures (DAP) among different anatomical locations. Study designProspective experimental study. AnimalsTwenty adult hound dogs weighing 24.5 ± 1.1 kg (mean ± standard deviation). MethodsFour peripheral arteries—dorsal pedal, median caudal, intermediate auricular and superficial palmar arteries—were catheterized with 20 gauge, 3.8 cm catheters. One NIBP cuff was placed in the middle third of the antebrachium. Four sets of IBP and NIBP measurements were simultaneously collected every 2 minutes. A linear mixed model was performed to analyze the collected data. ResultsIBP values varied depending on the arterial catheterization site. The difference was greater for SAP. NIBP measured at the antebrachium had the best agreement with IBP measured at the median caudal artery. Conclusion and clinical relevanceIBP varies among anatomical locations. The smallest bias and narrowest limits of agreement were obtained at the median caudal artery, providing the best overall agreement with the equipment studied. The median caudal artery may be the preferable anatomical location for clinical comparison studies between IBP and NIBP in dogs when the cuff is on the antebrachium.

Rumen-protected arginine alters blood flow parameters and luteinizing hormone concentration in cyclic beef cows consuming toxic endophyte-infected tall fescue seed.

The objective of this study was to determine the effect of rumen-protected arginine on median caudal artery blood flow and LH dynamics in cows fed toxic endophyte-infected tall fescue seed. Four ruminally cannulated nonlactating beef cows (539 ± 30 kg) were used in a 2 × 2 factorial arrangement of treatments utilizing a 4 × 4 Latin square design with 4 periods of 31 d each. Each cow was assigned to individual pens and fed orchardgrass hay (10.3% CP and 85% NDF; OM basis) during a 10-d adaptation period, followed by a 21-d collection period in which each cow was assigned 1 of 4 treatments: 1) rumen-protected Arg (180 mg/kg of BW) and 1.0 kg/d of toxic endophyte-infected fescue seed (AE+), 2) rumen-protected Arg (180 mg/kg of BW) and 1.0 kg/d of endophyte-free fescue seed (AE-), 3) 1.0 kg/d of toxic endophyte-infected fescue seed (E+) alone, or 4) 1.0 kg/d of endophyte-free fescue seed (E-) alone. In each period, Doppler ultrasound measurements for blood flow parameters were quantified on d 1, 5, 10, 15, and 20. On d 20 of each period, blood samples were collected every 10 min for 6 h and then once every hour for 12 h for LH response following exogenous GnRH. There was an Arg × fescue seed type interaction ( = 0.05) for median caudal artery blood flow due to an increase in blood flow in cows fed rumen-protected Arg with endophyte-free fescue seed. In addition, mean blood flow velocity in the artery was greater ( = 0.01) with the inclusion of rumen-protected Arg in the diet. Median caudal artery area ( = 0.03) and diameter ( = 0.01) were decreased in cows consuming E+ compared to those consuming E- with no effect ( ≥ 0.38) by Arg inclusion. Circulating nitric oxide (NO) concentrations tended to be influenced ( = 0.09) by the interaction of Arg × fescue seed type with E+ alone decreasing NO concentrations. Circulating NO concentrations were unaffected by rumen-protected Arg ( = 0.48). Mean serum LH concentration exhibited ( = 0.02) an Arg × fescue seed type interaction. Cows consuming E+ had decreased ( < 0.05) LH concentrations compared to all other treatments. However, cows consuming AE+ had ( ≥ 0.67) LH concentrations similar to those of cows consuming AE- and E-. Thus, supplementing rumen-protected Arg to cows consuming toxic endophyte-infected fescue seed has the potential to increase reproductive performance and peripheral blood flow.

Agreement between two oscillometric blood pressure technologies and invasively measured arterial pressure in the dog

ObjectivesTo compare two commonly used oscillometric technologies for obtaining noninvasive blood pressure (NIBP) measurements and to determine if there is a difference in agreement between these systems and invasive blood pressure (IBP) measurements. Study designProspective, experimental study. AnimalsTwenty adult laboratory dogs. MethodsEach dog was anesthetized and its median caudal artery catheterized for IBP monitoring. An NIBP cuff was placed in the middle third of the antebrachium and attached to either monitor-1 or monitor-2. Four pairs of concurrent NIBP and IBP measurements were recorded with each monitor. Agreement between IBP and NIBP measurements was explored using Bland–Altman analysis, as well as the American College of Veterinary Internal Medicine (ACVIM) and Association for the Advancement of Medical Instrumentation (AAMI) guidelines for the validation of NIBP devices. ResultsBoth NIBP technologies produced results that met the ACVIM and AAMI guidelines for the validation of NIBP devices. For monitor-1, analyses of agreement showed biases of 0.2 mmHg [95% limits of agreement (LoA) -11.8 to 12.3 mmHg] in systolic arterial pressure (SAP) values, -2.6 mmHg (95% LoA -14.4 to 9.1 mmHg) in diastolic arterial pressure (DAP) values, and -2.5 mmHg (95% LoA -12.7 to 7.3 mmHg) in mean arterial pressure (MAP) values. For monitor-2, analyses of agreement showed biases of 3.4 mmHg (95% LoA -8.7 to 15.5 mmHg) in SAP values, 2.2 mmHg (95% LoA -6.6 to 10.9 mmHg) in DAP values, and 1.6 mmHg (95% LoA -5.9 to 8.9 mmHg) in MAP values. Conclusions and clinical relevanceMulti-function monitors can contain components from various manufacturers. Clinicians should consider whether these have been validated in the species to be monitored. Both of the technologies studied here seem appropriate for use in dogs.

Macroscopic Features of the Arterial Supply to the Reproductive System of the Male Ostrich (Struthio camelus)

The macroscopic features of the arterial supply to the reproductive system of the male ostrich was studied in 16 pre-pubertal and eight sexually mature and active birds. The left and right cranial renal arteries arise from the aorta, between the cranial divisions of the kidneys. These vessels supply the cranial divisions of the kidneys, the testes, the epididymides and the cranial segments of the ducti deferentia. Accessory testicular arteries which arise directly from the aorta are present in 45.8% of the specimens. They supply the testes and cranial parts of the ducti deferentia. They are variable in number and origin, and four variants are identified. A cranial ureterodeferential branch originates from the cranial renal artery, supplies the cranial portion of the ductus deferens and ureter, and runs caudally to anastomose with the middle renal artery. The sciatic artery arises laterally from the aorta, just caudal to the acetabulum, and gives rise, ventrally, to a common trunk, the common renal artery, which divides into the middle and caudal renal arteries. The middle renal artery gives rise to the middle ureterodeferential branch which supplies the middle part of the ductus deferens and ureter. A few centimetres caudal to the kidney, the aorta terminates in three branches, namely, the left and right internal iliac arteries and the median caudal artery. The internal iliac artery divides into the lateral caudal artery and the pudendal artery; the latter gives off caudal ureterodeferential branches that supply the caudal segments of the ductus deferens and ureter. In addition, the pudendal artery gives off vessels that supply the cloaca, some of which continue to the base of the phallus, where they form an arterial network. In conclusion, the pattern of the blood supply to the reproductive organs of the male ostrich is, in general, similar to that of the domestic fowl and pigeon, although there are a few highlighted distinctive features.

The influence of temperature variation upon vascular dynamics in cattle as measured by Doppler-image ultrasonography

Two studies were performed to determine if Doppler ultrasound can detect vascular changes in cattle exposed to hot and cold conditions. Three calves per study (320±38 kg) were acclimated to 17.5oC, and then exposed to 32oC and 8oC. Animals were maintained under these conditions for 24 h and then returned to the original thermoneutral level. Three replicated ultrasound measurements of the median caudal artery were performed. Scans were repeated at -2, 5, 23, 24 and 28 h. Blood flow rates of 32oC cattle ranged from 27.84 (-2 h) to 43.42 ml/min at 23 h (P

Arterial vascularization of the uropygial glands (Gl. uropygialis) in the rock partridge (Alectoris graeca) living in Turkey.

This study aims to observe the morphological characteristics of the uropygial gland (Glandula uropygialis), specifically the arterial vascularization, in rock partridges (Alectoris graeca) living in Turkey. Coloured-latex-injected animals were dissected and the gland and related arteries were observed. Mostly, the fourth paired caudal segmental arteries (Aa. segmentales caudales) arising from the median caudal artery (A. mediana caudae) were specified as the uropygial gland arteries. These arteries, in turn, gave the following rami: the muscular ramus (Ramus muscularis) to the levator coccygeus and lateral caudal muscles, the lateral ramus (Ramus lateralis) to the lateral coccygeus muscle and a small ventro-lateral division of the caudal component of the gland, and the medial rami (Ramus medialis) to the dorsal surface of the gland.

Irrigação da bolsa cloacal em Gallus gallus domesticus (Matrizes de corte Hubbard)

The Cloacal Bursa's arteries of 30 females Hubbard were injected with 50% Neoprene Latex 450 solution, and submited to dissection. The ages of the birds was to 10 to 12 weeks. The vessel's origin, number and sequence were studied The results showed the participation of the left and right internal pudendal artery in all cases, witch the association of the cranial mesenteric artery (333,33%), to median caudal artery (3,33%), and to left internal iliac artery (3,33%). The total branches number, without considering its origin, varied in 2 to 9, being 4 branches the major frequency. The vessels distribuition was the same in each bird.

Irrigação da bolsa cloacal em Gallus gallus domesticus (matrizes de corte Hubbard)

The Cloacal Bursa's arteries of 30 females Hubbard were injected with 50% Neoprene Latex 450 solution, and submited to dissection. The ages of the birds was to 10 to 12 weeks. The vessel's origin, number and sequence were studied The results showed the participation of the left and right internal pudendal artery in all cases, witch the association of the cranial mesenteric artery (333,33%), to median caudal artery (3,33%), and to left internal iliac artery (3,33%). The total branches number, without considering its origin, varied in 2 to 9, being 4 branches the major frequency. The vessels distribuition was the same in each bird.

Irrigação da bolsa cloacal, em aves reprodutoras, da linhagem Peterson (Gallus gallus domesticus)

Estudaram-se em 30 exemplares de matrizes pesadas de corte machos da linhagem Peterson (Gallus gallus domesticus), com idade variando de 10 a 12 semanas, a origem, o numero e a ordenacao dos vasos arteriais da bolsa cloacal, um dos orgaos responsaveis pela producao de respostas humorais nas aves. Mediante injecao dos contingentes arteriais com solucao aquosa de Artecola® a 50%, via arteria isquiatica direita, a dissecacao evidenciou que em 100% dos casos a bolsa cloacal era irrigada por 1 ou 2 arterias bursocloacais; em 16,66% dos casos por 1 ramo direto oriundo das arterias cloacais; em 6,66% dos casos por 2 ramos diretos da arteria caudal mediana e em 3,33% dos casos por 1 ramo bursal da arteria mesenterica caudal. O numero de vasos, independentemente da sua origem, variou de 2 a 5 com maior frequencia de 2 vasos. A distribuicao dos vasos se fez de maneira propria para cada peca.

Pharmacological characterization of α-adrenoceptors in the bovine median caudal artery

This study was initiated to characterize α-adrenoceptors in the isolated bovine median caudal (tail) artery preparation for use as a model of blood vessels in the extremities of cattle. Prazosin shifted the concentration–response relationship for noradrenaline and phenylephrine to the right with pA 2 values of 8.74 and 9.04, respectively. Against noradrenaline, phentolamine yielded a pA 2 of 7.36. The concentration–response relationship for medetomidine was not inhibited by rauwolscine or idazoxan. The noradrenaline K A was 3.11 μM. These results suggest that catecholamines elicit α-adrenoceptor-mediated contractions primarily through α 1-adrenoceptors and not α 2-adrenoceptors.

Vascularized autogenous canine coccygeal bone transfer

Based on cadaver studies in dogs, the 8th, 9th, or 10th canine coccygeal vertebra with overlying skin was designed for free vascularized bone transfer. In six dogs the coccygeal osteocutaneous flap was transferred to fill a defect of the tibia, anastomosing the median caudal artery and one of the two caudal veins to the tibial vessels. The overlying skin provided a reliable monitoring system for the transferred tissue. The behavior of the vascularized coccygeal vertebrae was then evaluated with radiographic and histologic examination and compared with control vertebrae transferred without reconnection of the blood vessels. The results revealed that the canine coccygeal bone graft is a reliable vascularized osteocutaneous flap, which can be applied either in clinical veterinary surgery or in orthopedic microsurgical research.