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Folia Morphologica 2021The inferior mesenteric artery (IMA) is the third main branch of the abdominal aorta and arises at the level of L3, supplying the large intestine from the distal...
BACKGROUND
The inferior mesenteric artery (IMA) is the third main branch of the abdominal aorta and arises at the level of L3, supplying the large intestine from the distal transverse colon to the upper part of the anal canal. The aim of this study was to characterise the course and morphology of the terminal branches of the IMA, and also creating a new IMA classification, which seems to be necessary for clinicians performing surgery in this area.
MATERIALS AND METHODS
The anatomical variations in the branching patterns of the IMA were examined in 40 cadavers fixed in a 10% formalin solution. Morphometric measurements were then obtained twice by two researchers.
RESULTS
Due to the proposed classification system, type I characterised by a common trunk preceding bifurcation into sigmoidal branches and the superior rectal artery after giving left colic artery (LCA) occurred in 57.5% of cases, type II, trifurcation type, in 25%, type III with the superior rectal arteries originating firstly from the IMA in 5%, type IV with the ascending lumbar artery in 10% of cases and type V, a novelty, in 2.5%. The origin of IMA was observed at the level of L2/L3 in 22.5% of cases, at L3 in 25% of cases, at L3/L4 in 15% of cases, at L4 in 35% of cases and at the level of L5 in 2.5% of cases. More than one third (38.1%) of total cases with additional arteries and rapidly bifurcating branches occurred in types III, IV, and V. In women, only the IMA and LCA were significantly narrower than in men. Only the diameter of the IMA correlated with the diameter of the superior rectal artery.
CONCLUSIONS
The IMA is characterised by high morphological variability. The introduction of a new, structured, anatomical classification seems necessary for all clinicians.
Topics: Arteries; Female; Humans; Male; Mesenteric Artery, Inferior; Retrospective Studies
PubMed: 32964409
DOI: 10.5603/FM.a2020.0115 -
Radiologic Clinics of North America Jan 2016Multidetector computed tomography (MDCT) has largely supplanted other available radiologic modalities in the evaluation of a wide variety of different vascular and... (Review)
Review
Multidetector computed tomography (MDCT) has largely supplanted other available radiologic modalities in the evaluation of a wide variety of different vascular and inflammatory abnormalities of the small bowel, with computed tomography angiography (CTA) playing a major role in the diagnostic efficacy of MDCT for these diseases. Improvements in CTA imaging have proved particularly valuable in the evaluation of small bowel vascular and inflammatory disorders, diagnoses in which arterial phase images might be able to offer greater information than standard venous phase imaging. This article details the MDCT imaging findings of several small bowel vascular and inflammatory disorders.
Topics: Angiography; Humans; Intestine, Small; Mesenteric Arteries; Mesenteric Veins; Multidetector Computed Tomography
PubMed: 26654393
DOI: 10.1016/j.rcl.2015.08.002 -
BMC Anesthesiology Jun 2021Hypotension after neuraxial anaesthesia is one of the most common complications during caesarean section. Vasopressors are the most effective method to improve... (Comparative Study)
Comparative Study
BACKGROUND
Hypotension after neuraxial anaesthesia is one of the most common complications during caesarean section. Vasopressors are the most effective method to improve hypotension, but which of these drugs is best for caesarean section is not clear. We assessed the effects of vasopressors on the contractile response of uterine arteries and superior mesenteric arteries in pregnant rats to identify a drug that increases the blood pressure of the systemic circulation while minimally affecting the uterine and placental circulation.
METHODS
Isolated ring segments from the uterine and superior mesenteric arteries of pregnant rats were mounted in organ baths, and the contractile responses to several vasopressor agents were studied. Concentration-response curves for norepinephrine, phenylephrine, metaraminol and vasopressin were constructed.
RESULTS
The contractile response of the mesenteric artery to norepinephrine, as measured by the pEC50 of the drug, was stronger than the uterine artery (5.617 ± 0.11 vs. 4.493 ± 1.35, p = 0.009), and the contractile response of the uterine artery to metaraminol was stronger than the mesenteric artery (pEC50: 5.084 ± 0.17 vs. 4.92 ± 0.10, p = 0.007). There was no statistically significant difference in the pEC50 of phenylephrine or vasopressin between the two blood vessels.
CONCLUSIONS
In vitro experiments showed that norepinephrine contracts peripheral blood vessels more strongly and had the least effect on uterine artery contraction. These findings support the use of norepinephrine in mothers between the time of neuraxial anaesthesia and the delivery of the foetus.
Topics: Anesthesia, Obstetrical; Animals; Blood Pressure; Cesarean Section; Dose-Response Relationship, Drug; Female; Hypotension; Mesenteric Artery, Superior; Placenta; Pregnancy; Rats; Rats, Sprague-Dawley; Uterine Artery; Vasoconstriction; Vasoconstrictor Agents
PubMed: 34193040
DOI: 10.1186/s12871-021-01395-6 -
Peptides Apr 2016The influence of intracellular angiotensin II on the regulation of potassium current and membrane potential of smooth muscle cells of mesenteric arteries and its... (Review)
Review
The influence of intracellular angiotensin II on the regulation of potassium current and membrane potential of smooth muscle cells of mesenteric arteries and its relevance for the regulation of vascular tone was reviewed. The presence of components of the renin angiotensin system (RAS) in different cells of the cardiovascular system, was discussed including their presence in the nuclei and mitochondria. Emphasis was given to the opposite effects of intracellular and extracellular angiotensin II (Ang II) on the regulation of potassium current, membrane potential and contractility of vascular resistance vessels and its implication to vascular physiology and pathology and the possible role of epigenetic factors on the expression of angiotensin II (Ang II) and renin in vascular resistance vessels as well as its possible pathophysiological role in hypertension and other cardiovascular diseases.
Topics: Angiotensin II; Cations, Monovalent; Epigenesis, Genetic; Humans; Hypertension; Ion Transport; Membrane Potentials; Mesenteric Arteries; Muscle Contraction; Muscle Tonus; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Potassium; Renin; Renin-Angiotensin System; Vascular Resistance
PubMed: 26944358
DOI: 10.1016/j.peptides.2016.02.006 -
European Journal of Vascular and... Dec 2022This study aimed to report outcomes of patients with symptomatic acute isolated mesenteric artery dissection (IMAD) treated within a French intestinal stroke centre...
OBJECTIVE
This study aimed to report outcomes of patients with symptomatic acute isolated mesenteric artery dissection (IMAD) treated within a French intestinal stroke centre (ISC).
METHODS
All patients with symptomatic IMAD referred to the ISC from January 2016 to January 2020 were included prospectively. Patients with aortic dissection and asymptomatic IMAD were not included. The standardised medical protocol included anticoagulation and antiplatelet therapy, gastrointestinal resting, and oral antibiotics. Operations were considered for acute mesenteric ischaemia (AMI).
RESULTS
Among the 453 patients admitted to an ISC during the study period, 34 (median age, 53 years [41 - 67]; 82% men) with acute symptomatic IMAD were included. According to the classification of Yun et al., IMADs were reported as follows: type I (n = 7, 20%), type IIa (n = 6, 18%), type IIb (n = 15, 44%), and type III (i.e., complete superior mesenteric artery [SMA] occlusion; n = 6, 18%). Overall, nine (26%) patients had AMI (type I/II, n = 3; type III, n = 6). On initial computerised tomography angiogram, nine (26%) patients had an associated visceral arterial dissection or pseudoaneurysm. All patients with types I/II (n = 28, 82%) followed a favourable clinical course with conservative therapy, with no need for any operation. All patients with type III (n = 6, 18%) underwent urgent laparotomy with SMA revascularisation (open, n = 4; stenting, n = 1) and or bowel resection (early, n = 3; late, n = 1). Rates of intestinal resection and short bowel syndrome were 12% and 8.8%, respectively. After a median follow up of 26 months [18 - 42], recurrence of symptoms occurred in four (12%) patients and aneurysmal change in 14 (41%), with no re-intervention.
CONCLUSION
Although IMAD was associated with a high frequency of AMI, a standardised protocol produced a low rate of intestinal resection. Conservative therapy seems appropriate in types I/II patients, whereas urgent SMA revascularisation should aim to avoid intestinal resection or death in type III patients.
Topics: Male; Humans; Middle Aged; Female; Endovascular Procedures; Treatment Outcome; Aortic Dissection; Mesenteric Artery, Superior; Mesenteric Ischemia; Mesenteric Arteries; Stroke; Retrospective Studies
PubMed: 36075544
DOI: 10.1016/j.ejvs.2022.08.032 -
Anticancer Research Aug 2020We studied the role of high or low inferior mesenteric artery (IMA) tie on defecatory, sexual and urinary dysfunctions in patients who underwent laparoscopic TME for...
BACKGROUND/AIM
We studied the role of high or low inferior mesenteric artery (IMA) tie on defecatory, sexual and urinary dysfunctions in patients who underwent laparoscopic TME for early rectal cancer.
PATIENTS AND METHODS
Forty-six consecutive patients undergoing curative laparoscopic resection for pT2N0M0, rectal adenocarcinoma from February 2013 to March 2019 were enrolled into this prospective randomized open label parallel trial to have a laparoscopic TME with a high (Group 1) or low IMA ligation (Group 2). Demographic data and information on symptoms and comorbidity, intra- and post-operative outcomes and defecatory, sexual and urinary functions before and after surgery according to the validated International quality of life questionnaires.
RESULTS
A significant difference in postoperative total score of FIQL scale, Jorge-Wexner incontinence score and Agachan-Wexner constipation score were observed between the high and low tie groups at 1, 6, and 12 months after surgery. ICIQ-UI short form, FSFI, and IIEF demonstrated at 1, 6 and 12 months, the scores were significantly higher for patients of Group 1 as compared to those of Group 2.
CONCLUSION
A low IMA ligation permits a better fecal continence, less abdominal pain, and less genito-urinary and sexual dysfunctions in patients submitted to TME for rectal cancer.
Topics: Female; Humans; Laparoscopy; Male; Mesenteric Arteries; Middle Aged; Postoperative Complications; Rectal Neoplasms; Sexual Dysfunction, Physiological; Survival Rate; Urinary Incontinence
PubMed: 32727748
DOI: 10.21873/anticanres.14423 -
Vascular Apr 2020
Observational Study
Topics: Adult; Aged; Aortic Dissection; Computed Tomography Angiography; Conservative Treatment; Diagnostic Errors; Endovascular Procedures; Female; Fibrinolytic Agents; Humans; Male; Mesenteric Arteries; Middle Aged; Predictive Value of Tests; Retrospective Studies; Risk Factors; Treatment Outcome; Vascular Surgical Procedures
PubMed: 31600123
DOI: 10.1177/1708538119882280 -
Life Sciences Jul 2016The purpose of the present study was to explore anti-hypertensive effect of chronic intermittent hypobaric hypoxia (CIHH) in renovascular hypertension (RVH) rats, as... (Review)
Review
AIM
The purpose of the present study was to explore anti-hypertensive effect of chronic intermittent hypobaric hypoxia (CIHH) in renovascular hypertension (RVH) rats, as well as the role of large-conductance calcium-activated potassium channel (BKCa) in anti-hypertensive effect of CIHH.
MAIN METHODS
Male adult age- and body weight-matched Sprague-Dawley rats were divided into SHAM, CIHH, RVH and RVH+CIHH groups. Hypertension was induced by two-kidney-1-clip method (2K1C) in RVH rats. CIHH rats were exposed to 28-days hypobaric hypoxia simulating 5000m altitude, 6h daily. SHAM rats got an operation without 2K1C, and RVH+CIHH rats received CIHH treatment after 2K1C. The endothelium-dependent vasorelaxation induced by acetylcholine (ACh), BKCa currents in smooth muscle cells (VSMCs) of mesenteric arteries and the protein expression of BKCa in mesenteric arteries was examined.
KEY FINDINGS
The systolic arterial blood pressure (SAP) in RVH rats was higher than that in SHAM rats and CIHH treatment significantly decreased SAP in RVH rats. The enhanced vasorelaxation of mesenteric artery in CIHH-treated RVH rats was cancelled by BKCa blocker IBTX. The vasorelaxation induced by BKCa activator was reduced in RVH rats and the decreased vasorelaxation was improved by CIHH treatment. The β1 subunit of BKCa in mesenteric artery was upregulated and BKCa current in VSMCs was increased in CIHH-treated RVH rats compared with RVH rats.
SIGNIFICANCE
In conclusion, CIHH treatment enhances the relaxation of mesenteric artery through activation of BKCavia up-regulating β1 subunit of BKCa, which might be one of mechanisms for anti-hypertensive effect of CIHH in RVH rats.
Topics: Animals; Hypertension, Renovascular; Hypoxia; Kidney; Large-Conductance Calcium-Activated Potassium Channels; Male; Mesenteric Arteries; Rats; Rats, Sprague-Dawley; Vasodilation
PubMed: 27216772
DOI: 10.1016/j.lfs.2016.05.028 -
European Journal of Radiology Jun 2022The physiological increase of mesenteric blood flow after a meal is impaired in patients with occlusive chronic mesenteric ischemia (CMI). This principle could be used...
PURPOSE
The physiological increase of mesenteric blood flow after a meal is impaired in patients with occlusive chronic mesenteric ischemia (CMI). This principle could be used to develop a highly desired diagnostic test assessing the sufficiency of the collateral mesenteric circulation. This study assesses the potential to identify CMI patients using two-dimensional time-resolved phase-contrast magnetic resonance imaging (2D PC-MRI) flow measurements.
METHOD
This prospective cohort study included patients with suspected CMI, based on: typical history, imaging, and functional testing. Cardiac gated 2D PC-MRI flow measurements (expressed as ml/min/kg) were performed in mesenteric arteries and veins during inspiration and expiration, after six hours of fasting and 20, 30, and 40 min after a meal challenge with a high caloric drink.
RESULTS
Flow measurements were obtained in 19 patients: 8 CMI and 11 non-CMI. CMI patients showed a significantly smaller increase in postprandial blood flow in the superior mesenteric artery (SMA) at 30 and 40 min (30 min CMI 1.27(0.12-2.44) vs. non-CMI 7.82(6.28-10.90); 40 min CMI 0.30(-0.26-3.16) vs. non-CMI 7.94(6.32-10.90)) and a lower total arterial flow at 40 min (CMI 3.21(-0.72-5.05) vs. non-CMI 9.31(5.58-13.83)). Repeated flow measurements showed normalization of impaired postprandial venous flow after mesenteric artery stenting in one patient.
CONCLUSIONS
The significantly lower increase in postprandial mesenteric blood flow in CMI patients confirms the promise of mesenteric blood flow measurements, before and 30-40 min after a meal, as a future diagnostic test to identify CMI patients among patients with a high clinical suspicion of CMI and mesenteric artery stenosis.
Topics: Chronic Disease; Humans; Ischemia; Magnetic Resonance Imaging; Mesenteric Artery, Superior; Mesenteric Ischemia; Mesenteric Vascular Occlusion; Postprandial Period; Prospective Studies
PubMed: 35436758
DOI: 10.1016/j.ejrad.2022.110316 -
Die Pharmazie Jan 2022The relationship between large conductance calcium activated potassium channel (BK) and vascular lesions in type 2 diabetes mellitus (T2DM) was investigated by observing...
The relationship between large conductance calcium activated potassium channel (BK) and vascular lesions in type 2 diabetes mellitus (T2DM) was investigated by observing vascular reactivity of thoracic aorta and mesenteric artery and the current changes of BK in vascular smooth muscle cells (VSMCs). The thoracic aorta and mesenteric artery of T2DM rats were isolated, the whole cell perforated patch clamp experiment and single channel patch clamp experiment of acute enzyme separation of thoracic aorta and mesenteric artery smooth muscle cells were performed to measure the membrane capacitance and the amplitude of macro current. And the vascular ring experiment was performed to observe the change of relaxation percentage. The results showed that the amplitude of BK current in vascular smooth muscle cells of diabetic rats was higher than that of the control group. The channel current had outward rectifying characteristics. BK is related to vascular reactivity and smooth muscle relaxation in T2DM rats. The opening probability of BK in VSMCs of diabetic rats was significantly increased. This study suggests that BK may be a new target for diabetic vascular disease.
Topics: Animals; Aorta, Thoracic; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Mesenteric Arteries; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Rats
PubMed: 35045921
DOI: 10.1691/ph.2022.1740