Doppler Sonography Assessment Of Hemodynamic Changes Of The Inferior Mesenteric Artery In Old Patients

BackgroundAs the increasing causes of the diseases lead to arterioclerosis, chronic mesenteric ischemiaes (CMI) increase gradually. Ischaemic colitis belongs to intestinal blood vessel diseases, because the flow disorder of the celiac artery, the superior mesenteric artery(SMA), the inferior mesenteric artery(IMA) and their branches lead to acute or chronic intestinal ischemia. Arteriosclerosis is the most common reason. Ischaemic colitis often occurs in the old female more than 65 years, usually with some basal diseases. Abdominal pain is the prominent symptom, although most patients present with non-specific symptoms. The most commonly part include the left colon, mostly in descending colon and sigmoid flexure, secondly in splenic flexure of colon and transverse colon, only a minority in ascending colon or hepatic flexure of colon, seldom in rectum. There are several ways of examination, such as seroligical excamination, Doppler ultrasonography, conventional angiography, computer tomographic angiography, endoscopy. The conventional angiography, computer tomographic angiography, endoscopy belong to invasive imaging. Andhigh-resolution Doppler ultrasonography has many advantages such as non-invasiveness, simpleness and good repetality, so it gets more and more recognition.In the past several years, many scholars have done a lot of associated researches in different sides about ultrasonic image of ischemic colitis and the artery supplying the intestine, because many factors such as age, gender, basical disease influence the hemodynamic changes of the artery. The SMA gets more attention because of it shallow position, wide supplying area, clear sonographic visualization, including the normal hemodynamic parameter, the fasting and postprandial hemodynamic changes, the SMA hemodynamic changes in patients with hepatic cirrhos or crohn's disease, the changes of plagues and so on. Because of its small caliber and its position behind loops of the small intestine, sonographic visualization of the IMA has usually been considered difficult and gotten less attention. But in the past years the studies of IMA were developed, mainly in the following aspects. 1^st, normal ranges of hemodynamic parameters of IMA in adults and the fasting and postprandial hemodynamic changes. 2^nd, the influence of inflammatory bowel disease to IMA hemodynamic parameters. 3^rd, analyze Doppler waveform changes and the caliber of the inferior mesenteric artery as a collateral vessel in occlusive disease of the abdominal aorta or its main branches. And some scholars tried to make use of both grey and colour Doppler ultrasound to provide useful information for evaluating and differentiating bowel wall thickening in ischaemia colitis.The assured reason of arteriosclerosis is not clear, but plentiful statistical data indicated that some factors have obvious statistical relation with arteriosclerosis, such as age, hyperlipidemia, hepertension, diabetes, and smoking. All the above factors have influences to intestines flow supply and function. Because the time, course and extent of the Ischaemic colitis can not be predicted, it is very important to defend against the disease. For discuss the intestine hemodynamic changes, we analyzed objectively the changes of the IMA hemodynamic parameters of the old man below 65 years old under the influence of the dangerous above factors, providing the normal ranges and some useful information to the clinic.Materials and methodsParticipants (subjects) were recruited from outpatients and inpatients in Hangzhou Traditional Chinese Medicine (TCM) hospital, after exclusion of those with suspected intestinal disease, blood disease, malignancy and so on. 134 patients were studied, divided into 4 groups: Group 1, 34 patients (20 men and 14 women), were all health for physical excamination, age 67-83years (mean 72.0years), without hypertension and diabete. Group 2, 30 diabetics (18 men and 16 women), age 67-83 years (mean 72.6 years), average history 6.3 years and without hypertension. Group 3, 36 hypertensives (26 men and 10 women), age 65-90years (mean 74.4 years), average history 8.4 years, without diabete. Group 4, 34 patients with hypertension and diabete (20 men and 14 women), age 69-90 years (mean 75.5 years), diabete average history 8.2 years, hypertension average history 10.5 years.All the patients were performed after an overnight fast, examination of IMA were operated by the same doctor, using Siemens Sequoia 512 with a curved linear probe 4C1-S. During the study, the patient remained in the supine position, and the IMA origination was identified by B-mode sonography, with recording the diameter. Doppler scans were made in the longitudinal plane, velocity waveforms were obtained by sampling 0.5～1.0cm distal to the origin of the IMA from the aorta, with an angle of insonation less than 60° . Maximal systolic velocity (PSV), minimal diastolic velocity (EDV), pulsatility index (PI), resistance index (RI) were recorded .All the data were input into the computer, processed with SPSS 13.0 for windows, and analyzed with t test. P value ≤ 0.05 was considered statistically significant.RESULITS:1. Imaging. The vasal walls of the IMA in group 1 were smooth, without incrassation, and the Doppler waveform were characterized by a high systolic peak and a high resistance, the minority has transient retrograde flow during protodiastole. The vasal walls of the IMA in group 2, 3, 4 were not smooth, and the Doppler waveform were characterized by a high systolic peak, a high resistance and little or no diastolic flow, all transient retrograde flow during protodiastole disappear.2. Separately comparing group 2, 3, 4 with group 1, there were significantdifference among hemodynamic parameters. The enlarged vasal inside diameter, increase PSV, decrease EDV, increased RI and PI.3. PSV of group 3 and 4 were found greater than that of group 2, And the EDV of group 2 and 3 were higher than that of group IV. At the mean time, the RI in group 4 was higher than that of group 2.CONCLUSION:1. The diameter of the IMA of the old patients with hypertension or diabete was wilder than the control group, the arterioclerosis degree of the vasal walls with hypertension or diabete was more obviously than the control group.2. Normal ranges of blood flow parameters of IMA in the control group were provided in this paper, The PSV, PI, RI of the IMA of the old patients with hypertension or diabete were increased, and the EDV of that was decreased.3. The PSV, RI of the IMA of the hypertension were higher than that of the normal. The PSV, RI of IMA of the old patients with hypertension and diabete were higher than that of that with diabete. These suggest that hypertension had obvious influence to the hemodynamic parameters of IMA, hpertension can strengthen the IMA arterioclerosis degree of the old patients with diabete.