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GYNAECOLOGY AND OBSTETRICS Table of Contents   
Year : 2006  |  Volume : 16  |  Issue : 4  |  Page : 785-787
Color duplex evaluation of flow pulsatility in portal vein in healthy adults


Department of Radiodiagnosis, R.N.T. Medical College and Associated Group of Hospitals, Udaipur 313004, Rajasthan, India

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Date of Submission24-Apr-2006
Date of Acceptance08-Aug-2006
 

   Abstract 

Material & Methods - 30 healthy volunteers (19 men; 11 women) with no cardiac; lung or liver disease were studied by Color Duplex Imaging (CDI) and portal vein (PV) was evaluated for flow pulsatility. Results - Inverse correlation was found between venous pulsatility index (VPI) and body mass index (BMI) of subjects. (R = -0.76; p<0.001). No correlation was found between VPI and age of the patients. Inverse correlation was also found between VPI and subjects position associated with increase in intra-abdominal pressure. Conclusion - PV flow pulsatility is probably due to several and often simultaneous factors; and therefore PV pulsatility should be interpreted in clinical context.

Keywords: Color Duplex Imaging (CDI); Portal Vein; Venous Pulsatility Index (VPI); Spectral Width Index (SWI).

How to cite this article:
Sharma N C. Color duplex evaluation of flow pulsatility in portal vein in healthy adults. Indian J Radiol Imaging 2006;16:785-7

How to cite this URL:
Sharma N C. Color duplex evaluation of flow pulsatility in portal vein in healthy adults. Indian J Radiol Imaging [serial online] 2006 [cited 2019 Dec 13];16:785-7. Available from: http://www.ijri.org/text.asp?2006/16/4/785/32348

   Introduction Top


CDI has been used to assess various portal vein hemodynamic parameters including flow direction; velocity and volume; in patients with portal hypertension and in association with certain situations particularly those related to cardiac diseases e.g. tricuspid regurgitation [1]; heart failure [2] and constrictive pericarditis. Precise description of PV waveforms in healthy individuals is lacking in literature and it is required to gather more information about normal PV waveform patterns especially in Indian population.

Physiological flow pattern in PV has been described as continuous hepatopetal with feeble pulsatility in rhythm with cardiac and respiratory variation [3]. Phasic PV blood flow generates a wind storm sound on audible Doppler signal. Marked pulsatility in the PV flow has been interpreted as a sign of congestive heart failure [2]. Marked modulation of portal blood flow was explained by exaggerated phasic pressure changes transmitted from the right atrium.

The aim of our study was to describe the degree of pulsatility identified in PV of healthy adults and to compare PV pulsatility with subjects BMI and position.


   Subjects and Methods Top


Subjects: Over a period of six month extending from Jan'2005 to June'2005; 30 healthy volunteers (19 men, 11 women) with no heart; lung or liver disease were studied. Their mean age was 34 ± 5.7 years old (range 15 to 60 years old); their mean height 1.66±0.08 meters (range 1.50 to 1.80 meters) and their mean BMI was 19.90 ± 2.5 (range 14 to 28 kg/m 2 ). We didn't specifically attempt to enroll thin, normal or obese subjects. All volunteers gave verbal consent to participate in the study.


   Equipment Top


All measurements were obtained using Toshiba Nemio 30 color duplex instrument with 4.2 MHz curvilinear array electronic probe. Wall filter setting was kept at its lowest available value (50 Hz) and pulse repetition frequency was adjusted manually to its lowest setting without aliasing. Axial size of the pulsed Doppler Sample volume was kept in the 3 to 5 mm range; and we always tried to use angle of incidence less than 60º. Doppler spectral tracing was recorded using computer software sonocapture programme.


   Study Protocol Top


All measurements were conducted early in the morning after subjects had fasted overnight. Real time spectrum analysis of the Doppler Signal was performed in the main portal vein as it crosses the hepatic artery using an epigastric approach. The examination was performed in supine position. We asked the subjects to stop breathing at mid expiration and recorded tracing from main PV. One additional recording of main PV was performed for all subjects; in the sitting position at mid expiration.


   Quantitative Analysis Top


Maximum Doppler frequency shift (Hz) of each positive and negative peak during one cardiac cycle was measured. We evaluated the venous pulsatility index (VPI) calculated as follows:

(Peak maximum velocity) - (Peak minimum velocity)

(Peak maximum velocity)

In addition to VPI; spectral width or the flow wave thickness representing the range of velocities across the vessel lumen was expressed as spectral width index (SWI) and calculated as

(Peak maximum velocity at the wave envelope) - (Minimum velocity at the wave length vertically below the point of peak maximum velocity)

(Peak maximum velocity)

As spectral width increases; window size (area below the waveform that is devoid of flow) decreases or even disappears. With maximum spectral broadening no window is seen and the SWI would be equal to 1.


   Statistical Analysis Top


Results obtained were expressed as mean±SD. Differences in the distribution of marked spectral broadening and VPI were analyzed with 2 test. Probability values <0.05 were considered significant.


   Results Top


In healthy subjects; inspection of the PV wave envelope has shown slight fluctuations measured between the maximum and minimum velocities [Figure - 1]. Maximum velocity range was 13-30 cm/sec (20.5±4.21) whereas the minimum velocity range was 6-20 cm/sec (12.5±3.6).

VPI varied between 0.21 and 0.48 (0.39 ± 0.1) SWI was 0.60 ± 0.12; range 0.35-1. SWI was equal to 1 in only one (1/30 - 3.33%) healthy subject; which means that the spectrum of velocities covered the whole area from the wave envelope to the baseline (broad spectrum) in only one healthy volunteer. However, in this one individual the waveform was still pulsatile.

We found an inverse correlation between VPI and BMI of the subjects. (R = -0.76; p<0.001) (Graph No. 1). Largest indexes were seen in thin subjects. No correlation was found between the VPI and age (r = 0.26; p=0.36) of the subjects (Graph No. 2).

VPI was significantly lower in the sitting position than in the supine position. (p<0.05) (Graph No. 1). However in inverse correlation between pulsatility and body mass index was still present in the sitting position (r = -0.76, p<0.001).


   Discussion Top


Our study shows that in normal Indian population; portal V flow shows feeble pulsatility as originally described [4],[5]. The results of our study are in contradiction to studies conducted by Wachberg et al [6] and Gallia et al [7] who found PV flow to be pulsatile in normal subjects; with VPI more than 5 in more than 50% of normal subjects they studied. Discovery of a pulsatile PV during an abdominal sonographic examination should not automatically be considered as a sign of cardiac abnormality especially if Doppler tracing show no reversal of portal venous flow.

The reason why PV flow is more pulsatile in some subjects than in others seems to be related to their body weight. Study conducted by us shows that subjects with low BMI have more pulsatile PV flow than obese subjects.

We conclude that PV pulsatility is commonly seen in normal subjects and is particularly obvious in thin patients. PV pulsatility is probably due to several and often simultaneous factors. The finding of pulsatile PV needs to be interpreted in clinical context and doesn't necessarily imply right atrial dysfunction.[8]

 
   References Top

1.Abu-Yousef MM, Milam SG, Farner RM; Pulsatile portal vein flow: a sign of tricuspid regurgitation on duplex Doppler sonography; AJR 1990; 155: 785-8.  Back to cited text no. 1    
2.Duerineckx AJ, Grant EG, Perrella RR, Tessler FN; The pulsatile portal vein in cases of CHF: correlation of duplex Doppler finding with right atrial pressure; Radiology 1990; 176: 655-8.  Back to cited text no. 2    
3.Zwiebel WJ et al; Semin Ultrasound CT MR 1992; 13: 3-21.  Back to cited text no. 3    
4.Patriquin H, Lafortune M, Burns P, Dauzat M; Duplex Doppler examination in portal hypertension: technique and anatomy; AJR 1987; 149: 71-76.  Back to cited text no. 4    
5.Koslin B, Muligan SA, Berland LL; Duplex Assessment of portal venous system; Semin Ultrasound CT MR; 1992; 13: 22-33.  Back to cited text no. 5    
6.Wachberg RH, Needleman L, Wilson DJ; Portal vein pulsatility in normal and cirrhotic adults without cardiac disease. J Chin Ultrasound 1995; 23: 3-15.  Back to cited text no. 6    
7.Gallix BP, Taourel P, Dauzat M, Bruel JM, Lafortune M; Flow pulsatility in the portal venous system: A study of Doppler sonography in healthy adults; AJR 1997; 169: 141-4.  Back to cited text no. 7    
8.Sakai K, Nakamura K, Satomi G; Evaluation of tricuspid regurgitation by blood flow pattern in the hepatic vein pulsed Doppler technique; Am Heart J 1984; 108: 516-523.  Back to cited text no. 8    

Top
Correspondence Address:
N C Sharma
D-12, M.B. Government Hospital Camp, Udaipur (Raj).
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0971-3026.32348

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    Figures

  [Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4]



 

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    Abstract
    Introduction
    Subjects and Methods
    Equipment
    Study Protocol
    Quantitative Ana...
    Statistical Analysis
    Results
    Discussion
    References
    Article Figures

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