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Results for “MESENTERIC VESSELS”

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PubMed1979

Mesenteric occlusive lesion and ileal carcinoids.

Occlusion of mesenteric vessels due to fibrosis and adventitial elastosis complicated ileal carcinoids and resulted in infarction of bowel in two patients. Synovial sarcoma antedated the carcinoid syndrome in one patient who died; carcinoma of the breast was discovered one year after hemicolectomy in the other. This rare mesenteric occlusive lesion is associated exclusively with ileal carcinoids; it is poorly recognized and the mortality is high.

Aged↗

PubMed2005

Increased anandamide induced relaxation in mesenteric arteries of cirrhotic rats: role of cannabinoid and vanilloid receptors.

BACKGROUND AND AIMS: Anandamide is an endocannabinoid that evokes hypotension by interaction with peripheral cannabinoid CB1 receptors and with the perivascular transient receptor potential vanilloid type 1 protein (TRPV1). As anandamide has been implicated in the vasodilated state in advanced cirrhosis, the study investigated whether the mesenteric bed from cirrhotic rats has an altered and selective vasodilator response to anandamide. METHODS: We assessed vascular sensitivity to anandamide, mRNA and protein expression of cannabinoid CB1 receptor and TRPV1 receptor, and the topographical distribution of cannabinoid CB1 receptors in resistance mesenteric arteries of cirrhotic and control rats. RESULTS: Mesenteric vessels of cirrhotic animals displayed greater sensitivity to anandamide than control vessels. This vasodilator response was reverted by CB1 or TRPV1 receptor blockade, but not after endothelium denudation or nitric oxide inhibition. Anandamide had no effect on distal femoral arteries. CB1 and TRPV1 receptor protein was higher in cirrhotic than in control vessels. Neither CB1 mRNA nor protein was detected in femoral arteries. Immunochemistry showed that CB1 receptors were mainly in the adventitia and in the endothelial monolayer, with higher expression observed in vessels of cirrhotic rats than in controls. CONCLUSIONS: These results indicate that anandamide is a selective splanchnic vasodilator in cirrhosis which predominantly acts via interaction with two different types of receptors, CB1 and TRPV1 receptors, which are mainly located in perivascular sensory nerve terminals of the mesenteric resistance arteries of these animals.

Animals↗

PubMed1977

[Arteriomesenteric obstruction of the duodenum (author's transl)].

Survey of the clinical and diagnostic treatment of arteriomesenteric obstruction. Report on 4 cases of chronic obstruction and 2 cases of acute occlusion of the duodenum due to the root of mesenteric vessels. Indication of operation. Recommendation of retrocolic side-to-side duodenojejunostomy.

Adult↗

PubMed1996

Anatomic basis of mesenteric elongation for ileo-anal anastomosis with J-shaped reservoir: comparison of two techniques of vascular section.

Total proctocolectomy followed by ileo-anal anastomosis with a reservoir is the operation of choice for the treatment of familial adenomatous polyposis and of certain forms of hemorrhagic proctocolitis. Vascular section is sometimes necessary to enable the extremity of the reservoir to reach the anal sphincter without traction. The aim of this study was to compare the gain in length obtained by two different techniques of vascular section and to assess in terms of the vascular anatomy of the last small intestinal loop which technique best preserved the vascularisation of the reservoir as a whole. Twenty-two fresh cadavers had an ileal J-shaped reservoir of 18 cm fashioned from the last loop of small intestinal loop after section of the root of the mesentery. The gains in length so obtained were measured after section of the ileocolic a. at its origin (group A) or section between the two vascular arches of the last small intestinal loop (group B); the superior mesenteric vessels were then injected with colored resin. The gain in length obtained by these two methods was identical (2.3 +/- 1.1 cm for group A as against 2.18 +/- 0.9 cm for group B), but only if the section of the ileocolic a. was accompanied by section of the mesenteric peritoneum up to the vascular arch formed by the anastomosis between the terminal branch of the superior mesenteric a. and the ileocolic a. The constancy of this anastomosis always allowed section of the ileocolic a. while preserving good vascular distribution to the entirety of the reservoir. Section between the two arches was difficult when the distance separating them was small.

Anal Canal↗

PubMedDate not supplied

Endovascular repair of an infrarenal abdominal aortic aneurysm with a dominant middle mesenteric artery: A case report.

The middle mesenteric artery is a rare anomalous mesenteric vessel that may supply variable segments of the colon. Occlusion of this artery during endovascular aortic aneurysm repair may bear a significant risk of bowel ischemia. We report the successful interventional treatment of a patient with a 5.3 cm infrarenal abdominal aortic aneurysm, sparing a dominant middle mesenteric artery.

Aged, 80 and over↗

PubMed2000

[Treatment of desmoid tumors of the mesenteric root].

OBJECTIVE: To elaborate a therapeutic scheme for desmoid tumors developing within the mesenteric root. These uncommon and often unrecognized tumors are difficult to treat as they lie very close to the superior mesenteric vessels. PATIENTS AND METHODS: Retrospective analysis of 14 cases treated in our center over the last 20 years and a review of the literature. RESULTS: The analysis led to the development of a therapeutic scheme. Patients are placed under regular surveillance to detect any progression of the mesenteric root desmoid tumor. In case of progression, surgery should be proposed as often as possible in spite of the real difficulty of this surgery. When the tumor is unresectable, hormone therapy, sulindac, chemotherapy and radiotherapy can be proposed as appropriate. CONCLUSION: Based on the available literature, the proposed decisional tree is a helpful management tool. This scheme should be validated with the help of a National Observatory focusing on this rare disease.

Adult↗

PubMed2005

Energy sources for laparoscopic colectomy: a prospective randomized comparison of conventional electrosurgery, bipolar computer-controlled electrosurgery and ultrasonic dissection. Operative outcome and costs analysis.

The development of operative laparoscopic surgery is linked to advances in ancillary surgical instrumentation. Ultrasonic energy devices avoid the use of electricity and provide effective control of small- to medium-sized vessels. Bipolar computer-controlled electrosurgical technology eliminates the disadvantages of electrical energy, and a mechanical blade adds a cutting action. This instrument can provide effective hemostasis of large vessels up to 7 mm. Such devices significantly increase the cost of laparoscopic procedures, however, and the amount of evidence-based information on this topic is surprisingly scarce. This study compared the effectiveness of three different energy sources on the laparoscopic performance of a left colectomy. The trial included 38 nonselected patients with a disease of the colon requiring an elective segmental left-sided colon resection. Patients were preoperatively randomized into three groups. Group I had electrosurgery; vascular dissection was performed entirely with an electrosurgery generator, and vessels were controlled with clips. Group II underwent computer-controlled bipolar electrosurgery; vascular and mesocolon section was completed by using the 10-mm Ligasure device alone. In group III, 5-mm ultrasonic shears (Harmonic Scalpel) were used for bowel dissection, vascular pedicle dissection, and mesocolon transection. The mesenteric vessel pedicle was controlled with an endostapler. Demographics (age, sex, body mass index, comorbidity, previous surgery and diagnoses requiring surgery) were recorded, as were surgical details (operative time, conversion, blood loss), additional disposable instruments (number of trocars, EndoGIA charges, and clip appliers), and clinical outcome. Intraoperative economic costs were also evaluated. End points of the trial were operative time and intraoperative blood loss, and an intention-to-treat principle was followed. The three groups were well matched for demographic and pathologic features. Surgical time was significantly longer in patients operated on with conventional electrosurgery vs the Harmonic Scalpel or computed-based bipolar energy devices. This finding correlated with a significant reduction in intraoperative blood loss. Conversion to other endoscopic techniques was more frequent in Group I; however, conversion to open surgery was similar in all three groups. No intraoperative accident related to the use of the specific device was observed in any group. Immediate outcome was similar in the three groups, without differences in morbidity, mortality, or hospital stay. Analysis of operative costs showed no significant differences between the three groups. High-energy power sources specifically adapted for endoscopic surgery reduce operative time and blood loss and may be considered cost-effective when left colectomy is used as a model.

Adult↗

PubMed1991

Nonselective and semiselective catheters for renal artery evaluation: experimental study.

Abdominal aortography is widely used for evaluation of potential renal donors and for patients with renal failure or hypertension in whom a renal artery ostial or polar branch stenosis is suspected. It would be desirable to use a catheter that consistently enables good bilateral renal artery and polar branch visualization without opacification of overlying mesenteric vessels. Existing and newly designed catheters were compared to determine the optimal design necessary for these studies. An in vitro model of the abdominal aorta and its branches was made, and dye dilution densitometry was employed for quantitative evaluation. Semiselective catheters demonstrated significantly increased renal artery opacification with decreased mesenteric opacification in this in vitro model.

Aorta, Abdominal↗

PubMed2004

Impaired EDHF-mediated vasodilatation in adult offspring of rats exposed to a fat-rich diet in pregnancy.

We recently reported vascular dysfunction in adult offspring of rats fed a fat-rich (animal lard) diet in pregnancy. This study reports further characterization of constrictor and dilator function in mesenteric and caudal femoral arteries from 180-day-old offspring of dams fed the high fat diet (OHF). Endothelium-dependent relaxation in response to acetylcholine (10(-9)-10(-5)m) was impaired in mesenteric small arteries from male and female OHF compared with offspring of dams fed normal chow (males (maximum percentage relaxation): OHF 67.92 +/- 2.89, n= 8 versus control 92.08 +/- 2.19, n= 8, P < 0.01). Substantial relaxation in response to acetycholine in control mesenteric arteries remained after inhibition of nitric oxide synthase, soluble guanylate cyclase and cyclo-oxygenase but was blocked by 25 mm potassium. This component of relaxation, attributed to EDHF, was significantly reduced in OHF mesenteric arteries compared with controls. However, EDHF played a minor role in acetylcholine-induced relaxation in both control and OHF femoral caudal arteries (male and female). In these arteries, in contrast to mesenteric vessels, acetylcholine-induced relaxation was significantly enhanced in OHF but only in males (ACh (maximum percentage relaxation): OHF 58.40 +/- 4.39, n= 8 versus male controls 32.18 +/- 6.36, P < 0.05). This was attributable to enhanced nitric oxide-mediated relaxation. In conclusion, reduced endothelium-dependent relaxation in OHF mesenteric arteries is due to impaired EDHF-mediated relaxation. This defect was not apparent in femoral arteries in which EDHF has a less prominent role.

Acetylcholine↗

PubMed1992

Differences between vasorelaxant responses of the canine and human mesenteric arteries and veins to amrinone.

Amrinone induced similar degrees of relaxation in human mesenteric arteries and veins contracted with KCl, but exerted a more potent vasodilator effect in canine mesenteric veins than in arteries. Dibutyryl cAMP had a stronger effect on KCl-induced contraction in canine mesenteric veins than in arteries. These results suggest that amrinone promotes a different vasodilating action in human and canine mesenteric vessels, possibly via different sensitivity to cAMP in each vascular smooth muscle.

Amrinone↗

PubMed2003

Differential regulation of nitric oxide synthases and their allosteric regulators in heart and vessels of hypertensive rats.

OBJECTIVE: Nitric oxide synthase (NOS)-derived nitric oxide (NO) production is regulated posttranslationally through enzyme's inhibitory interaction with the caveolar coat protein, caveolin and stimulatory interaction with the chaperone heat shock protein, Hsp90. However, changes in the expression of these regulators with the development of hypertrophic cardiomyopathy are unknown. METHODS: Histochemical and immunoblotted signals for the NOS isoforms, caveolin and Hsp90 were compared in left ventricle (LV) and aortic or mesenteric vessels between spontaneously hypertensive rats (SHR; 18 and 63 weeks old) and age-matched normotensive Wistar-Kyoto (WKY) rats. To assess functional impacts on downstream NO signaling, superoxide anions (O(2)(-)) and cGMP contents were measured in the same tissues by oxidative fluorescent hydroethidine staining and enzyme immunoassay, respectively. RESULTS: Compared with levels in age-matched WKY rats, endothelial NOS (eNOS) proteins were increased in aorta of SHR at 18 weeks. Conversely, aortic caveolin-1 and -3 were decreased in SHR, whereas Hsp90 remained unchanged. In LV tissue of SHR at 18 weeks, caveolin-1 and -3 were similarly decreased, but Hsp90 upregulated, together with a downregulation of eNOS. However, at 63 weeks, both eNOS and neuronal NOS (nNOS) were markedly upregulated in the LV of SHR, together with an upregulation of Hsp90. No difference in cardiac and aortic cGMP contents was found between the two strains. In LV sections, O(2)(-) generation was higher in older compared with younger rats from both strains and highest in 63 weeks SHR. CONCLUSIONS: Changes in NOS protein abundance in SHR rats compared with WKY controls are differentially regulated according to the age of hypertension and the tissue examined and are not necessarily correlated with cGMP contents. The coordinate expressional changes in NOS isoforms and their allosteric regulators, such as caveolin and Hsp90, may act as a compensatory mechanism to maintain the production of bioactive NO in the face of increased oxidant stress.

Allosteric Regulation↗

PubMed2000

Simultaneous aortic surgery and malnutrition increase morbidity after revascularisation of the mesenteric arteries.

OBJECTIVE: To evaluate the early and late outcome of mesenteric revascularisation in patients who had had elective mesenteric revascularisation for chronic intestinal ischaemia. DESIGN: Retrospective review. SETTING: Academic clinic, United States. SUBJECT: 19 consecutive patients (7 men, 12 women; mean age 70 years, range 53-83). RESULTS: Angiography showed that 2 mesenteric vessels were affected in 7 patients and 3 in 12. Four patients had coexisting symptomatic aortoiliac occlusive disease and 1 patient had bilateral renal artery stenosis. A total of 36 visceral arteries were revascularised. One patient died postoperatively, and 8 developed serious complications. Morbidity and mortality were significantly higher in patients who had simultaneous infrarenal aortic or renal artery reconstructions (p = 0.01). Patients whose body weight before operation was less than 90% of ideal had more complications (8/11) than patients who were within 10% of their ideal body weight (1/8) (p = 0.02). Cumulative survival was 89% at 1 year, 72% at 3 years, and 57% at 5 years. The cumulative graft patency rate was 92% at 3 years and 66% at 5 years. CONCLUSIONS: Mesenteric bypass procedures for chronic mesenteric ischaemia are durable. Long-term survival and graft patency rates are excellent even in older patients. Simultaneous aortic surgery should be avoided because of the associated morbidity. More than 10% below ideal body weight was associated with higher morbidity. For these patients, early total parenteral nutrition postoperatively, or a period of total parenteral nutrition preoperatively may reduce postoperative morbidity and mortality.

Aged↗

PubMed1999

Inhibition of vascular K(ATP) channels by U-37883A: a comparison with cardiac and skeletal muscle.

1 The aim of this study was to investigate the selectivity of the ATP-sensitive potassium (K(ATP)) channel inhibitor U-37883A (4-morpholinecarboximidine-N-1-adamantyl-N'-1-cyclohexyl). Membrane currents through K(ATP) channels were recorded in single muscle cells enzymatically isolated from rat mesenteric artery, cardiac ventricle and skeletal muscle (flexor digitorum brevis). K(ATP) currents were induced either by cell dialysis with 0.1 mM ATP and 0.1 mM ADP, or by application of synthetic potassium channel openers (levcromakalim or pinacidil). 2 U-37883A inhibited K(ATP) currents in smooth muscle cells from rat mesenteric artery. Half inhibition of 10 microM levcromakalim-induced currents occurred at a concentration of 3.5 microM. 3 Relaxations of rat mesenteric vessels caused by levcromakalim were reversed by U-37883A. 1 microM levcromakalim-induced relaxations were inhibited at a similar concentration of U-37883A (half inhibition, 1.1 microM) to levcromakalim-induced KATP currents. 4 K(ATP) currents activated by 100 microM pinacidil were also studied in single myocytes from rat mesenteric artery, skeletal muscle and cardiac ventricle. 10 microM U-37883A substantially inhibited K(ATP) currents in vascular cells, but had little effect in skeletal or cardiac myocytes. Higher concentrations of U-37883A (100 microM) caused a modest decrease in K(ATP) currents in skeletal and cardiac muscle. The sulphonylurea K(ATP) channel antagonist glibenclamide (10 microM) abolished currents in all muscle types. 5 The effect of U-37883A on vascular inward rectifier (KIR) and voltage-dependent potassium (KV) currents was also examined. While 10 microM U-37883A had little effect on these currents, some inhibition was apparent at higher concentrations (100 microM) of the compound. 6 We conclude that U-37883A inhibits K(ATP) channels in arterial smooth muscle more effectively than in cardiac and skeletal muscle. Furthermore, this compound is selective for K(ATP) channels over KV and KIR channels in smooth muscle cells.

Adamantane↗

PubMed2006

Anandamide mediates hyperdynamic circulation in cirrhotic rats via CB(1) and VR(1) receptors.

BACKGROUND AND PURPOSE: Hyperdynamic circulation and mesenteric hyperaemia are found in cirrhosis. To delineate the role of endocannabinoids in these changes, we examined the cardiovascular effects of anandamide, AM251 (CB(1) antagonist), AM630 (CB(2) antagonist) and capsazepine (VR1 antagonist), in a rat model of cirrhosis. EXPERIMENTAL APPROACH: Cirrhosis was induced by bile duct ligation. Controls underwent sham operation. Four weeks later, diameters of mesenteric arteriole and venule (intravital microscopy), arterial pressure, cardiac output, systemic vascular resistance and superior mesenteric artery (SMA) flow were measured after anandamide, AM251 (with or without anandamide), AM630 and capsazepine administration. CB(1), CB(2) and VR1 receptor expression in SMA was assessed by western blot and RT-PCR. KEY RESULTS: Anandamide increased mesenteric vessel diameter and flow, and cardiac output in cirrhotic rats, but did not affect controls. Anandamide induced a triphasic arterial pressure response in controls, but this pattern differed markedly in cirrhotic rats. Pre-administration of AM251 blocked the effects of anandamide. AM251 (without anandamide) increased arterial pressure and systemic vascular resistance, constricted mesenteric arterioles, decreased SMA flow and changed cardiac output in a time-dependent fashion in cirrhotic rats. Capsazepine decreased cardiac output and mesenteric arteriolar diameter and flow, and increased systemic vascular resistance in cirrhotic rats, but lacked effect in controls. Expression of CB(1) and VR1 receptor proteins were increased in cirrhotic rats. AM630 did not affect any cardiovascular parameter in either group. CONCLUSIONS AND IMPLICATIONS: These data suggest that endocannabinoids contribute to hyperdynamic circulation and mesenteric hyperaemia in cirrhosis, via CB(1)- and VR1-mediated mechanisms.

Animals↗

PubMed1975

Histopathologic changes induced in rats by localized x-irradiation of an exteriorized segment of the small intestine.

The sequence of histopathological changes was described after X-irradiation of the exteriorized segment (3 cm) of the rat ileum with a single dose of 2200 R. A one-year follow-up was provided in rats whose exteriorized intestinal segments were irradiated. Comparisons were made between one group of animals in which the superior mesentric artery and vein were clamped during irradiation and a second group in which these vessels were not clamped. A third group of sham-irradiated controls was used for comparisons. There was a delay in the onset and progression of the radiation damage to the mucosa of the hypoxic animals in the acute post-irradiation phase. In addition, prolongation of survival in the rats with the superior mesenteric vessels clamped was observed. Mucosal regeneration was noted, occurring at 52 days post-exposure. No adenocarcinomas were found up to 354 days after irradiation. An angiofibroma and a highly differentiated osteoid lesion were described.

Adenocarcinoma↗

PubMed1989

[Preoperative angiography of colorectal cancer].

Preoperative pharmaco-angiography using prostaglandin E1 was performed in 62 patients with colorectal cancer. The diagnostic significance of angiography for the prospect of invasion was evaluated comparing with operative and histological findings. The relationships between the histological incidence of extramural venous invasion, the incidence of liver metastasis and the angiographic extent of invasion were analyzed. Mesenteric vessels were classified into the following 3 groups for the angiographic evaluation. Group A: proximal to marginal vessels, marginal vessels and the proximal portion of the vasa recta Group B: the mid portion of the vasa recta Group C: the terminal portion of the vasa recta Angiographic abnormalities in Group A vessels were considered to correspond to a histological depth of serosa or more, abnormalities in Group B vessels to serosa or subserosa, abnormalities in Group C vessels to muscularis propria, and no abnormalities to submucosa or mucosa. According to these criteria, the evidence of extramural invasion could be diagnosed exactly on the basis of angiographic abnormalities in Group A or B vessels. Extramural venous invasion was histologically detected in 18 cases and 13 of them showed angiographic abnormalities in Group A vessels among 60 patients. Including cases found in post operative periods, 14 cases of liver metastasis were presented among 62 patients. Angiographic abnormalities were found in 11 of them in Group A vessels. Therefore it is thought that there is a high risk of liver metastasis in cases with angiographic abnormalities in Group A vessels. Preoperative angiography is useful in prospecting the invasive depth and in assessing the risk of liver metastasis of colorectal cancer.

Adult↗

PubMedDate not supplied

Adjuvant therapy following pancreatic resection for pancreatic duct carcinoma: a prospective randomized study.

BACKGROUND/AIMS: This study was made to determine the efficacy of locoregional immunochemotherapy in the treatment of pancreatic ductal carcinoma. MATERIAL AND METHODS: From November 1991 to June 1996, eighty patients with a diagnosis of pancreatic duct carcinoma underwent pancreatic resection. Patients were divided into two groups, Group A and Group B. Both groups received a standard operative procedure of extended subtotal pancreatectomy with regional lymphadenectomy of the celiac axis, the hepatoduodenal ligament and the superior mesenteric vessels. However, Group B patients had two arterial catheters implanted at the end of the operative procedure: one via the splenic artery, after its ligation near the origin at the celiac axis and directed towards the spleen; the second catheter was implanted into a side arterial branch of the middle colic artery into the superior mesenteric artery. RESULTS: Group B patients have a significantly greater survival (30 months) compared to Group A patients (16.8 months). The proportion of alive patients between both Groups is much higher for Group's B patients (92% versus 55%). Grading of the tumor, size of the tumor, and presence of positive lymph nodes were seen to be very important factors affecting overall survival in Group A patients, but not in Group B patients. It is impressive that from 25 Group A patients with lymph node involvement, only 8 are presently alive versus 25 alive of 28 total Group B patients with positive lymph nodes. CONCLUSION: Locoregional immunochemotherapy as an adjuvant modality following pancreatic resection offers impressive advantages in terms of survival regardless of stage, lymph involvement, and tumor size. This therapy deserves further attention and consideration in the treatment of Pancreatic Duct Carcinoma.

Adenocarcinoma↗

PubMedDate not supplied

Multi-detector row CT of mesenteric ischemia: can it be done?

Mesenteric ischemia is a complicated disorder whose prevalence in the United States is increasing as the population ages. It is often difficult to diagnose, both clinically and radiologically. In the past, computed tomography (CT) has allowed only limited success in the early detection of ischemia. However, with the introduction of multi-detector row CT and three-dimensional (3D) imaging, it is now possible to perform a detailed CT examination of the small bowel and mesenteric vessels. Multi-detector row CT allows routine studies to be performed much faster than with single-detector CT scanners and makes available new applications, especially in the field of CT angiography. Its increased speed and narrower collimation, coupled with the use of water as an oral contrast agent, improve visualization of the bowel wall and mesenteric vasculature. Multi-detector row CT with 3D reformatting may improve the ability to make an early diagnosis and identify the cause of disease in patients with suspected acute or chronic mesenteric ischemia. In many cases, this examination has eliminated the need for additional imaging studies such as Doppler ultrasonography or angiography. Further investigation will be needed to determine the scope of the utility of multi-detector row CT in this clinical setting.

Acute Disease↗