RESUMEN
Pneumatosis cystoides intestinalis (PCI) is characterized by gas-filled cystic lesions within the wall of the large intestine and presents along a spectrum of clinical severity ranging from benign to life threatening. Etiopathogenesis is multifactorial and postulated to result from either mechanical or bacterial causes. In this report, we present a patient with chronic abdominal pain evaluated with colonoscopy revealing segmental PCI isolated to the distal colon. Further investigation revealed an abdominal aortic aneurysm (AAA) compromising the inferior mesenteric artery takeoff. Endovascular repair of the AAA resulted in clinical resolution of abdominal pain and endoscopic resolution of PCI. To our knowledge, this is the first report to document endoscopic resolution of PCI with restoration of mesenteric arterial supply, highlighting vascular insufficiency as a predisposing and reversible pathogenic mechanism.
Asunto(s)
Aneurisma de la Aorta Abdominal/complicaciones , Aneurisma de la Aorta Abdominal/cirugía , Arteria Mesentérica Inferior/patología , Mesenterio/irrigación sanguínea , Neumatosis Cistoide Intestinal/etiología , Neumatosis Cistoide Intestinal/terapia , Dolor Abdominal/etiología , Dolor Abdominal/fisiopatología , Dolor Abdominal/terapia , Aneurisma de la Aorta Abdominal/patología , Dolor Crónico/etiología , Dolor Crónico/fisiopatología , Dolor Crónico/terapia , Colonoscopía , Constricción Patológica/etiología , Procedimientos Endovasculares , Femenino , Hepatitis C/complicaciones , Humanos , Cirrosis Hepática/complicaciones , Arteria Mesentérica Inferior/fisiología , Persona de Mediana Edad , Neumatosis Cistoide Intestinal/fisiopatología , StentsAsunto(s)
Colectomía/métodos , Arteria Mesentérica Inferior/diagnóstico por imagen , Imagen Óptica/métodos , Neoplasias del Recto/cirugía , Procedimientos Quirúrgicos Robotizados/métodos , Humanos , Rayos Infrarrojos , Arteria Mesentérica Inferior/fisiología , Cavidad Peritoneal/irrigación sanguínea , Cavidad Peritoneal/diagnóstico por imagen , Flujo Sanguíneo RegionalRESUMEN
BACKGROUND: Doppler studies of splanchnic vessels have demonstrated alteration in blood flow in bowel obstruction and strangulation. The aim of this study was to evaluate hemodynamic changes in celiac artery (CA), superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) using pulsed Doppler sonography (PDS) in Hirschsprung's disease. MATERIAL AND METHODS: Fasting splanchnic flowmetry of CA, SMA, and IMA arteries was performed using PDS preoperatively in 13 patients with Hirschsprung's disease and 13 healthy age- and sex-matched controls. Diagnostic workup for Hirschsprung's disease included a barium enema and a rectal biopsy. A primary transanal pull through was performed if the transition zone was at rectosigmoid or midsigmoid. Doppler studies were repeated on the 1st and 7th postoperative day under similar conditions. Mean flow velocity (V(mean)) and the pulsatility index (PI) of the three major vessels was measured. RESULTS: Patients with Hirschsprung's disease showed increased blood flow velocities in CA, SMA, and IMA (p < 0.001), an increased resistance to blood flow in IMA (p < 0.001) and a decreased resistance to blood flow in CA and SMA (p < 0.005 and p < 0.001, respectively). The blood flow velocity for IMA normalized after resection of the aganglionic segment (r = 0.41, p < 0.005, 95% CI: 45.4-52.7). CONCLUSIONS: Hirschsprung's diseaseis associated with alterations in splanchnic vessel hemodynamics which are reversible after corrective surgery. Doppler studies may play an important role in the assessment of bowel function after surgery.
Asunto(s)
Enfermedad de Hirschsprung/fisiopatología , Circulación Esplácnica/fisiología , Velocidad del Flujo Sanguíneo , Estudios de Casos y Controles , Arteria Celíaca/fisiología , Arteria Celíaca/fisiopatología , Femenino , Enfermedad de Hirschsprung/diagnóstico por imagen , Enfermedad de Hirschsprung/cirugía , Humanos , Lactante , Recién Nacido , Masculino , Arteria Mesentérica Inferior/fisiología , Arteria Mesentérica Inferior/fisiopatología , Arteria Mesentérica Superior/fisiología , Arteria Mesentérica Superior/fisiopatología , Flujo Pulsátil/fisiología , Valores de Referencia , Resultado del Tratamiento , Ultrasonografía Doppler de PulsoRESUMEN
Os dados da literatura especializada sobre a anatomia dos felinos são escassos e sempre relacionados aos cães. Este trabalho teve como finalidade estudar a origem e a distribuição da artéria mesentérica caudal em gatos, complementando a literatura e contribuindo para a cirurgia nessa espécie. Trabalhou-se com 31 gatos adultos, machos e fêmeas, sem raça definida, obtidos por meio de doações. No sistema arterial desses animais foi injetado Látex Altamira®, corado com pigmento específico, para análise da sistematização arterial da porção final do intestino. Notou-se que, em todos os casos, a artéria mesentérica caudal originou-se da aorta descendente abdominal e emitiu a artéria cólica esquerda e a artéria retal cranial. A artéria cólica esquerda irrigou a porção descendente do cólon, emitindo 2 ramos (3,22% dos casos), 3 (9,68%), 4 (22,58%), 5 (19,35%), 6 (19,35%), 7 (16,13%), 8 (6,45%) e 10 (3,22%). A artéria retal cranial apresentou ramos destinados ao cólon descendente em 90,32% das observações, enviando 1 ramo (32,26% dos animais), 2 (19,35%), 3 (9,64%), 4 (6,45%), 5 (12,90%), 6 (3,22%) e 8 (6,45%). Para o reto, a artéria retal cranial emitiu ramos em todos os gatos, que ocorreram em forma de 1 ramo em 3,22% das peças, 2 (9,68%), 3 (48,39%), 4 (12,90%), 5 (12,90%), 6 (6,45%) e 8 (6,45%)
Data from specialized literature on cat anatomy are scarce and they are always related to dogs. This paper studies the origin and distribution of the caudal mesenteric artery in cats, complementing the literature and contributing to surgery for such species. The project was carried out with 31 grown animals, male and female, without defined race, acquired by donations. Látex Altamira® was injected in the arterial system of these animals and colored with specific pigment for the analysis of the arterial systematization of the final portion of the intestine. It was noticed, in all cases, that the caudal mesenteric artery originated from the descending abdominal aorta and emitted the left colic artery and the cranial rectal artery. The left colic artery irrigated the descendent colon portion of all cats by emitting 2 branches (3.22% of cases), 3 (9.68%), 4 (22.58%), 5 (19.35%), 6 (19.35%), 7 (16.13%), 8 (6.45%), and 10 (3.22%). The cranial rectal artery presented branches towards the descendent colon in 90.32% of the observations, sending 1 branch (32.26% of animals), 2 (19.35%), 3 (9.64%), 4 (6.45%), 5 (12.90%), 6 (3.22%), and 8 (6.45%). Towards the rectum, the cranial rectal artery emitted branches in all cats, what occurred as 1 branch in 3.22% of the pieces, 2 (9.68%), 3 (48.39%), 4 (12.90%), 5 (12.90%), 6 (6.45%) and 8 (6.45%)
Los datos de la literatura especializada sobre la anatomía de los felinos son escasos y siempre relacionados a los perros. Esta investigación tuvo como objetivo estudiar el origen y la distribución de la arteria mesentérica caudal en gatos, complementando la literatura y contribuyendo para la cirugía en esa especie. Se trabajó con 31 gatos adultos, machos y hembras, sin raza definida, procedentes de donaciones. En los vasos arteriales de esos animales fue inyectado Látex Altamira®, teñido con coloraciones específicas, para análisis de la sistematización arterial de la porción final Del intestino. Fue observado que, en todos los casos, la arteria mesentérica caudal se originó de la aorta descendente abdominal y emitió a la arteria cólica izquierda y a la arteria rectal craneal. La arteria cólica izquierda irrigó la porción descendente del colon, emitiendo 2 ramales (3,22% de los casos), 3 (9,68%), 4 (22,58%), 5(19,35%), 6(19,35%), 7(16,13%), 8 (6,45%) y 10 (3,22%). La arteria rectal craneal presentó ramales destinados al colon descendente en 90,32% de las observaciones, emitiendo 1 (32,26% de los animales), 2 (19,35%), 3 (9,64%), 4 (6,45%), 5 (12,90%), 6 (3,22%) y 8 (6,45%). Para el recto, la arteria rectal craneal emitió ramales en todos los gatos, que ocurrieron en forma de 1 ramal en 3,22% de las piezas, 2 (9,68%), 3 (48,39%), 4 (12,90%), 5 (12,90%), 6 (6,45%) y 8 (6,45%)
Asunto(s)
Animales , Arteria Mesentérica Inferior/anatomía & histología , Arteria Mesentérica Inferior/fisiología , GatosRESUMEN
OBJECTIVE: Mesenteric blood flow measurement has been found to predict relapse after steroid-induced remission in patients with Crohn's disease (CD) and ulcerative colitis (UC). Therefore, we assessed prospectively the possible relationship between changes in mesenteric blood flow and prognosis in chronically active patients with need of immunosuppressive therapy with azathioprine (AZA) or 6-mercaptopurine (6-MP). METHODS: Doppler ultrasound (DUS) measurements of the pulsatility index (PI) of the superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) were performed in 52 patients with chronically active inflammatory bowel disease (CD 31 patients; UC 21 patients) before beginning therapy with AZA/6-MP (US1) and during clinical remission (CD activity index <150, Truelove index score I) (US2). Patients were weaned from concomitant therapy with corticosteroids as soon as possible and were followed up for 12 months. RESULTS: After 1 year, 16 patients with CD (51.6%) and 13 patients with UC (61.9%) were in remission, whereas 23 patients had recurrent disease or had undergone surgery. A decreased SMA PI at US2 predicted clinical relapse in all patients with CD [100%; P < 0.001; mean (+/-SD) 77 +/- 67 d after US1], but only 4 of 8 patients (50%; difference not significant; mean 84 +/- 75 d after US1) with UC. Conversely, an increase of SMA PI was associated with sustained remission in the majority of CD patients (12/16 patients; 75%; P < 0.002), but in only 7 of 13 patients (54%) with UC. Flow measurements in the IMA and postprandial values for both arteries were less reliable. CONCLUSION: Repeated DUS measurements of the SMA PI predict response to AZA/6-MP in patients with chronic active CD.
Asunto(s)
Azatioprina/uso terapéutico , Enfermedad de Crohn/tratamiento farmacológico , Inmunosupresores/uso terapéutico , Arteria Mesentérica Inferior/diagnóstico por imagen , Arteria Mesentérica Superior/diagnóstico por imagen , Adulto , Enfermedad de Crohn/patología , Femenino , Humanos , Masculino , Arteria Mesentérica Inferior/fisiología , Arteria Mesentérica Superior/fisiología , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Flujo Sanguíneo Regional , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Ultrasonografía DopplerAsunto(s)
Aneurisma de la Aorta Abdominal/terapia , Implantación de Prótesis Vascular/métodos , Circulación Colateral/fisiología , Aorta Abdominal/diagnóstico por imagen , Aorta Abdominal/patología , Embolización Terapéutica , Humanos , Vértebras Lumbares/irrigación sanguínea , Imagen por Resonancia Magnética/métodos , Arteria Mesentérica Inferior/fisiología , Arteria Mesentérica Inferior/cirugía , Stents , Técnicas de Sutura , Tomografía Computarizada por Rayos X/métodosRESUMEN
This study characterises the vasorelaxation and hyperpolarisation effects of the negatively charged quaternary compound tetraphenylboron (TPB) in the rat small mesenteric artery. Segments of rat small mesenteric artery were mounted in a myograph and vessel tone and membrane potential were measured simultaneously. In vessels pre-contracted with vasopressin (0.3-0.6 nM), U46619 (30-90 nM) or methoxamine (0.3-3 microM), TPB (0.1-100 microM) produced a marked endothelium-independent relaxation. However, vasorelaxation responses to TPB were abolished in tissues pre-contracted with K(+) (50 mM), and significantly inhibited by glibenclamide (glib, 10 microM). In the absence of tone, TPB (1-30 microM) caused a concentration-dependent membrane hyperpolarisation of rat mesenteric artery smooth muscle cells, which was not dependent on the endothelium, but sensitive to glibenclamide (10 microM). In methoxamine (0.3-3 microM) pre-contracted vessels, the relaxation response was associated with a marked hyperpolarisation, which was also sensitive to glibenclamide (10 microM), further inhibited by a combination of K(+) channel blockers (glib [10 microM], charybdotoxin [100 nM], apamin [100 nM], 4-aminopyridine [1 mM] and Ba(2+) [30 microM]) and abolished by 50 mM K(+). The results of this study show that TPB causes a vasorelaxation and hyperpolarisation response in the rat small mesenteric artery through a direct action on the vascular smooth muscle. TPB exerts its effects partially via the activation of K(ATP) channels, but also by another mechanism involving K(+)-dependent hyperpolarisation.
Asunto(s)
Arteria Mesentérica Inferior/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Tetrafenilborato/farmacología , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Animales , Membrana Celular/fisiología , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Masculino , Potenciales de la Membrana , Arteria Mesentérica Inferior/fisiología , Músculo Liso Vascular/citología , Músculo Liso Vascular/fisiología , Potasio/fisiología , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio/fisiología , Ratas , Ratas Sprague-Dawley , Tetrafenilborato/administración & dosificaciónRESUMEN
We previously reported that acute incubation with tetrahydrobiopterin (BH4) or sepiapterin, a cofactor for endothelial nitric oxide synthase and a stable precursor of BH4, respectively, enhanced the acetylcholine (Ach)-induced relaxation of isolated small mesenteric arteries (SMA) from diabetic (db/db) mice. In this study, we investigated the effect of chronic oral supplementation of sepiapterin (10 mg x kg-1 x day-1) to db/db mice on endothelium function, biopterin levels and lipid peroxidation in SMA. Oral dietary supplementation with sepiapterin had no effect on glucose, triglyceride, cholesterol levels and body weight. SMA from db/db mice showed enhanced vascular reactivity to phenylephrine, which was corrected with sepiapterin supplementation. Furthermore, Ach, but not sodium nitroprusside-induced relaxation, was improved with sepiapterin supplementation in db/db mice. BH4 levels and guanosine triphosphate cyclohydrolase I activity in SMA were similar in db/+ and db/db mice. Sepiapterin treatment had no effects on BH4 or guanosine triphosphate cyclohydrolase I activity. However, the level of dihydrobiopterin+biopterin was higher in SMA from db/db mice, which was corrected following sepiapterin treatment. Thiobarbituric acid reactive substance, malondialdehyde, a marker of lipid peroxidation, was higher in SMA from db/db mice, and was normalized by sepiapterin treatment. These results indicate that sepiapterin improves endothelial dysfunction in SMA from db/db mice by reducing oxidative stress. Furthermore, these results suggest that decreased biosynthesis of BH4 may not be the basis for endothelial dysfunction in SMA from db/db mice.
Asunto(s)
Administración Oral , Biopterinas/análogos & derivados , Diabetes Mellitus/tratamiento farmacológico , Endotelio Vascular/efectos de los fármacos , Arteria Mesentérica Inferior/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Pterinas/administración & dosificación , Acetilcolina/farmacología , Animales , Biopterinas/efectos adversos , Biopterinas/biosíntesis , Biopterinas/química , Diabetes Mellitus/fisiopatología , Modelos Animales de Enfermedad , Esquema de Medicación , Quimioterapia Combinada , Endotelio Vascular/química , Endotelio Vascular/fisiología , GTP Ciclohidrolasa/química , GTP Ciclohidrolasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Peroxidación de Lípido/fisiología , Masculino , Malondialdehído/sangre , Arteria Mesentérica Inferior/química , Arteria Mesentérica Inferior/fisiología , Ratones , Ratones Endogámicos C57BL/metabolismo , Neopterin/química , Neopterin/metabolismo , Estrés Oxidativo/fisiología , Fenilefrina/farmacología , Pterinas/farmacocinética , Pterinas/uso terapéutico , Vasoconstricción/efectos de los fármacos , Vasoconstricción/fisiología , Vasodilatación/efectos de los fármacos , Vasodilatación/fisiologíaRESUMEN
In the present study, a numerical calculation procedure based on a finite volume method was developed to simulate steady flow fields in a model of abdominal aorta with its peripheral branches. The study focused on the steady baseline flow fields and the wall shear stress (WSS) distribution as well as the localization of the reversed flow regions and results were compared to those obtained by other investigators. In the case of resting conditions, the existence of a region of reversed flow of about one to two diameters in size and next to the renal arteries and along the posterior wall as observed by other researchers was confirmed. However, under the exercise conditions this region could be wiped out. The flow reversal along the lateral walls proximal to the bifurcation persisted in both rest and exercise conditions. The WSS distribution and the wall shear stress gradient distribution were obtained. The lowest WSS occurred near the ostia of the renal arteries and the lateral walls of the iliac arteries. And the highest is always at the turn to the branch. The results were generally consistent with those obtained experimentally and numerically by other investigators. It was also shown that the steady flow might be used to depict the averaged behavior of pulsatile flow. The present computer code provides a platform for the future more realistic simulations.
Asunto(s)
Aorta Abdominal/fisiología , Simulación por Computador , Hemodinámica , Modelos Cardiovasculares , Velocidad del Flujo Sanguíneo/fisiología , Arteria Celíaca/fisiología , Elasticidad , Análisis de Elementos Finitos , Humanos , Arteria Ilíaca/fisiología , Arteria Mesentérica Inferior/fisiología , Arteria Mesentérica Superior/fisiología , Arteria Renal/fisiología , Sensibilidad y Especificidad , Estrés MecánicoRESUMEN
Vasoconstrictor responses to exogenous adenine and pyrimidine nucleotides were measured in endothelium-denuded segments of guinea pig mesenteric vein and compared with responses in mesenteric artery. The rank order of potency for nucleotides in veins was: 2-MeSADP = 2-MeSATP > UTP > ATPgammaS = alpha,betaMeATP > UDP = ATP > ADP >> beta,gamma-D-MeATP = beta,gamma-L-MeATP. In contrast 2-MeSADP, UTP, and UDP were inactive in arteries, and the rank order of potency of other nucleotides differed; that is, alpha,betaMeATP > beta, gamma-D-MeATP > beta,gamma-L-MeATP = ATPgammaS = 2-MeSATP > ATP > ADP. In veins, UTP, ATP, and 2-MeSATP were more efficacious contractile agents than alpha,beta MeATP. In addition, the ability to desensitize responses to these nucleotides and inhibit them with various blockers differed. The response to alpha,betaMeATP in veins exhibited rapid desensitization and was inhibited by pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid tetrasodium (PPADS) and suramin. The response to 2-MeSATP in veins did not desensitize; nor was it inhibited by prior alpha,betaMeATP desensitization, but it was inhibited by PPADS, suramin, and the selective P2Y(1) receptor antagonist adenosine 3',5'-bisphosphate (ABP, 10-100 microM). Responses to ATP and UTP in veins did not desensitize and were not inhibited by PPADS, suramin, ABP, or alpha, betaMeATP desensitization. In conclusion, our results suggest that venous contraction to a variety of nucleotides is mediated in large part by P2Y receptors including P2Y(1) receptors and an UTP-preferring P2Y receptor. A small component of contraction also appears to be mediated by P2X(1) receptors. This receptor profile differs markedly from that of mesenteric arteries in which P2X(1) receptors predominate.
Asunto(s)
Adenosina Trifosfato/análogos & derivados , Venas Mesentéricas/fisiología , Contracción Muscular/fisiología , Músculo Liso Vascular/fisiología , Fosfato de Piridoxal/análogos & derivados , Receptores Purinérgicos P2/fisiología , Nucleótidos de Adenina/farmacología , Adenosina Difosfato/farmacología , Adenosina Trifosfato/farmacología , Animales , Cobayas , Técnicas In Vitro , Masculino , Arteria Mesentérica Inferior/efectos de los fármacos , Arteria Mesentérica Inferior/fisiología , Venas Mesentéricas/efectos de los fármacos , Contracción Muscular/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Cloruro de Potasio/farmacología , Antagonistas del Receptor Purinérgico P2 , Fosfato de Piridoxal/farmacología , Nucleótidos de Pirimidina/farmacología , Receptores Purinérgicos P2/clasificación , Receptores Purinérgicos P2X , Suramina/farmacología , Uridina Trifosfato/farmacologíaRESUMEN
El conocimiento de la circulación colateral abdominal es importante en las cirugías de la región. Con la finalidad de esclarecer la capacidad de flujos de la anastomosis recto-sigmoídea, su localización y las eventuales variaciones anatómicas, estudiamos las arterias componentes de ella en 43 cadáveres de individuos adultos, brasileños, a los que se inyectó una mezcla de alginato con agua y teñida de tal manera de visualizar su recorrido. Los resultados obtenidos mostraron que la anastomosis recto-sigmoídea está presente en 86.1 por ciento del total de casos; se observó permeable en 70,3 por ciento y se presentó sin permeabilidad en 29,7 por ciento. Estos datos permiten asegurar que esta anastomosis está presente y es funcional en más de la mitad de los casos
Asunto(s)
Humanos , Adulto , Abdomen/irrigación sanguínea , Anastomosis Arteriovenosa/anatomía & histología , Arteria Mesentérica Inferior/fisiología , Colon Sigmoide/irrigación sanguínea , Recto/irrigación sanguíneaRESUMEN
BACKGROUND: We wanted to evaluate prospectively the feasibility of sonographic and Doppler assessment of the inferior mesenteric artery (IMA) and to provide data on its normal morphological and hemodynamic characteristics. METHODS: Sonography and Doppler study of the IMA were performed on 116 patients without splanchnic vessel pathology. Vessel diameter, systolic, diastolic, and time-averaged mean flow velocities, pulsatility index values, and flow volumes were correlated with patient age (< 50 years vs. > or = 50 years) using the Wilcoxon rank-sum test. Findings were verified by splanchnic angiography in 11 cases. RESULTS: Technically valid studies were obtained in 103/116 cases (88.8%). Flowmetric data showed high peripheral resistance (mean +/- SD: systolic flow velocity, 1.41 m/s +/- 0.48; minimal diastolic flow velocity, 0.10 m/s +/- 0.16; pulsatility index, 3.49 +/- 0.49). Mean flow volume calculated in 80 cases was 0.13 L/min +/- 0.06. Older subjects presented significantly higher time-averaged mean flow velocities and lower resistance than those younger than 50 years. CONCLUSIONS: The success rate for sonographic and Doppler study of the IMA is similar to that observed with larger splanchnic vessels. Knowledge of its normal characteristics is necessary for recognition of pathological conditions and for studies of its physiological behavior.
Asunto(s)
Arteria Mesentérica Inferior/diagnóstico por imagen , Arteria Mesentérica Inferior/fisiología , Ultrasonografía Doppler , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/fisiología , Angiografía , Velocidad del Flujo Sanguíneo , Niño , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Circulación Esplácnica , Resistencia VascularRESUMEN
When operating on abdominal aortic aneurysms associated with stenoses or occlusions of iliac vessels, surgeons may face the problem of reestablishing circulation to pelvic or gluteal territories. A new technique consists of anastomosing a posterior opening in the body or one of the branches of a bifurcated graft, distally sutured to the femoral artery, to the distal aortic stump, which contains all the patent vessels arising from the end of the aorta, such as inferior mesenteric and lumbar arteries. This technique, successfully performed in two cases, has the advantages of avoiding closure of the distal aortic stump and a possible backflow leak and of ensuring adequate pelvic circulation.
Asunto(s)
Aorta Abdominal/cirugía , Aneurisma de la Aorta Abdominal/cirugía , Implantación de Prótesis Vascular/métodos , Arteria Femoral/cirugía , Pelvis/irrigación sanguínea , Anciano , Anastomosis Quirúrgica/métodos , Arteriopatías Oclusivas/cirugía , Arterias/fisiología , Prótesis Vascular , Nalgas/irrigación sanguínea , Estudios de Seguimiento , Humanos , Arteria Ilíaca/cirugía , Claudicación Intermitente/cirugía , Vértebras Lumbares/irrigación sanguínea , Masculino , Arteria Mesentérica Inferior/fisiología , Persona de Mediana Edad , Diseño de Prótesis , Flujo Sanguíneo Regional/fisiologíaRESUMEN
Previous studies have shown that the guinea pig inferior mesenteric artery receives spinal sensory vasodilatory innervation, which can be activated by colon distention and electrical nerve stimulation. In the present study, we investigated the hypotheses that nitric oxide synthase (NOS) is present in guinea pig primary sensory neurons in the dorsal root ganglion (DRG) and in nerve fibers surrounding the mesenteric arteries, and that nitric oxide (NO) is a sensory neurotransmitter in the inferior mesenteric artery in vitro. Double-labeling immunohistochemistry showed that neuronal NOS-IR was found in 12% of cells of guinea pig thoracic and lumbar DRGs; in 95.1% of these cells it was colocalized with substance P (SP), and SP immunoreactivity (SP-IR) was present in 23% of cells of the same DRGs. Neuronal NOS-like immunoreactivity was localized in nerve fibers surrounding guinea pig mesenteric artery and 25% of them were double stained with SP-IR. Endothelium-denuded inferior mesenteric artery preparations in vitro were incubated with guanethidine (30 microns, 30 min) and pre-contracted with methoxamine (30 microns). The NO donors, sodium nitroprusside (1 micron) and L-nitrosocysteine (300 microns), produced 91.0 +/- 5.5 and 90.4 +/- 9.6% vasodilatation of total vasodilatation in the vessel segments, respectively, which was capsaicin- or tetrodotoxin-insensitive. Repetitive electrical field stimulation of the preparations produced a frequency-dependent vasodilatation which was reduced by pretreatment with capsaicin or by tetrodotoxin (10 microns). The NOS inhibitor N omega-nitro-L-arginine (L-NNA) (100 microns, 30 min) diminished the nerve-evoked vasodilatation from 41.8 +/- 8.4 to 21.4 +/- 9.7% at 2 Hz and from 50.8 +/- 5.6 to 19.0 +/- 7.3% at 15 Hz (P < 0.05), whereas NG-nitro-L-arginine methyl ester (L-NAME, 100 microns-1 mM) did not significantly inhibit the relaxation. The stereo isomer nitro-D-arginine (D-NNA, 100 microns, 30 min) was ineffective. These findings suggest that NO is a neurotransmitter released from primary sensory nerves which mediates vasodilation in vitro.
Asunto(s)
Arteria Mesentérica Inferior/fisiología , Neuronas Aferentes/fisiología , Neurotransmisores/fisiología , Óxido Nítrico/fisiología , Animales , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/enzimología , Endotelio Vascular/fisiología , Cobayas , Arteria Mesentérica Inferior/efectos de los fármacos , Arteria Mesentérica Inferior/enzimología , Neuronas Aferentes/enzimología , Óxido Nítrico Sintasa/metabolismo , Vasodilatación/efectos de los fármacos , Vasodilatación/fisiologíaRESUMEN
BACKGROUND: The value of the sigmoid tonometer in predicting sigmoid ischaemia and postoperative enteric organism infection has been reported but the value of tonometric measurement has been challenged. The purpose of this study was to examine the use of tonometric measurements in a series of patients undergoing infrarenal aortic aneurysm repair. METHODS: We assessed the results obtained when sigmoid (n=11) and gastric (n=8) tonometry were performed in patients undergoing infrarenal aortic aneurysm repair (n=11). We measured blood flow ultrasonically (n=6) in the inferior mesenteric artery(IMA) and IMA stump pressures. Sigmoid and gastric tonometry were measured prior to clamping of the infrarenal aorta, during cross clamping and after clamp release at 1, 4, 16 and 20h. Ultrasonic flow was measured before clamping. Stump pressures in the IMA were measured before, during and after clamping. RESULTS: The IMA was chronically occluded in five patients. The IMA flow was 37.5 +/- 8.7 mL/min (mean +/- s.e.). The mean IMA stump pressures before, during and after clamping were 64 +/- 13, 48 +/- 8 and 69 +/- 10 mmHg, respectively, and did not differ significantly. Mean systematic arterial pressures at these times were 89 +/- 7, 95 +/- 5 and 86 +/- 8 mmHg. These did not differ significantly or when compared with IMA stump pressure. The gradient between systemic arterial pressure and IMA stump pressure did not vary significantly at any of these times. Sigmoid and gastric intramucosal pH (pHi) did not differ significantly at any of the above times. Both sigmoid gastric pHi dropped on clamp application but 4 h afterwards had returned to baseline levels. Systemic arterial pH reflected significant ischaemia during clamping and shortly after release of the clamp(P=0.008). CONCLUSIONS: Tonometry may reflect systemic events as much as regional ischaemia. Useful tonometry results may depend on the development of a trend rather that individual measurements. The routine use of tonometry to detect intestinal ischaemia may not be cost-effective in aortic surgery.
Asunto(s)
Aneurisma de la Aorta Abdominal/cirugía , Colon Sigmoide/irrigación sanguínea , Isquemia/diagnóstico , Estómago/irrigación sanguínea , Velocidad del Flujo Sanguíneo , Presión Sanguínea , Humanos , Concentración de Iones de Hidrógeno , Manometría , Arteria Mesentérica Inferior/fisiología , Monitoreo Fisiológico , Factores de Tiempo , UltrasonografíaAsunto(s)
Arteria Mesentérica Inferior/diagnóstico por imagen , Ultrasonografía Doppler , Factores de Edad , Velocidad del Flujo Sanguíneo , Volumen Sanguíneo , Ayuno , Estudios de Factibilidad , Humanos , Arteria Mesentérica Inferior/fisiología , Persona de Mediana Edad , Flujo Pulsátil , Resistencia VascularRESUMEN
The purposes of this study were to look for the inferior mesenteric artery in patients undergoing abdominal sonography, to determine in what percentage of patients it is visible, and to characterize Doppler flow patterns of the inferior mesenteric artery in fasting patients without intestinal vascular disease. The inferior mesenteric artery was sought in 100 consecutive fasting adults (mean age, 54 years; 63 women, 37 men), as follows: the infrarenal aorta was scanned in a transverse plane; the origin of the inferior mesenteric artery was identified on the left anterolateral surface of the aorta; the inferior mesenteric artery was then traced caudally along the left side of the aorta. The inferior mesenteric artery and the superior mesenteric artery were studied with Doppler sonography in 50 different subjects without clinical or Doppler sonographic evidence of abdominal vascular disease (mean age, 44.9 years; 17 men, 33 women). Pulsed Doppler samples were taken within the inferior mesenteric artery in sagittal planes. The resistive index was calculated from the superior mesenteric artery and the inferior mesenteric artery. The inferior mesenteric artery was detected in all but eight patients (92%). In seven patients obesity prevented visualization. The eighth patient had undergone abdominal surgery on the previous day, limiting the sonographic examination. The diastolic flow in the inferior mesenteric artery was less than that in the superior mesenteric artery in all patients. The resistive index was 0.959 +/- 0.045 in the inferior mesenteric artery and 0.856 +/- 0.046 in the superior mesenteric artery (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Arteria Mesentérica Inferior/diagnóstico por imagen , Ultrasonografía Doppler , Adulto , Velocidad del Flujo Sanguíneo/fisiología , Femenino , Humanos , Masculino , Arteria Mesentérica Inferior/fisiología , Arteria Mesentérica Superior/diagnóstico por imagen , Arteria Mesentérica Superior/fisiología , Persona de Mediana Edad , Estudios Prospectivos , Flujo Sanguíneo RegionalRESUMEN
The flow velocity and volume of the superior and inferior mesenteric arteries (SMA, IMA) were measured with cine phase contrast magnetic resonance (MR) imaging in five healthy volunteers. Each volunteer was first measured in a fasting state, and then one, two, and three hours after a meal. The average SMA flow volume of the volunteers was 230.3 +/- 46.8 ml/min (mean +/- standard error) during the fasting state, and 714.7 +/- 207.7 ml/min, 339.2 +/- 85.7 ml/min, and 263.8 +/- 21.0 ml/min, respectively, at one, two, and three hours postmeal. The increase at one hour postmeal was statistically significant (p < 0.05). The corresponding flow measurements in the IMA were 63.1 +/- 11.2 ml/min, 67.6 +/- 11.2 ml/min, 57.9 +/- 8.6 ml/min, and 53.2 +/- 6.8 ml/min. These values do not represent a statistically significant flow volume change in the IMA. In all volunteers, the SMA volumetric flow increased the most one hour after the food challenge (72-400% relative to baseline). Diastolic velocity in the SMA increased significantly one hour postmeal, but systolic velocity did not change significantly. The IMA did not demonstrate a significant change in either systolic or diastolic velocity. The difference between the SMA and IMA in the way of reacting against the food challenge is thought to represent the difference between the requirements of small and large intestine for blood supply after the food challenge. These data demonstrate the possibility of this modality for the assessment of conditions such as chronic mesenteric ischemia.