Sonographic Evaluation of the Liver in Pregnant Women
Chapter One
The Aim (General Objective)
The general objective of this study is to investigate on the ultrasonographic evaluation of the liver in pregnant women at the Agbor general Hospital.
The (Specific) Objectives
- To study, by means of conventional ultrasonography, kidneys, liver and the bile ducts in pregnant patients, establishing the morphological changes of the kidneys and liver in low-risk pregnant women.
- To establish, by means of pulsed color Doppler ultrasonography, velocity, RI and PI of the renal arteries.
- To establish, by means of pulsed color Doppler ultrasonography, RI and PI of intra-renal arteries (segmental, interlobar and arcuate) and the initial systolic acceleration of the segmental arteries.
- To establish the presence of renal lithiasis.
- To establish, by means of pulsed color Doppler ultrasonography, portal vein flow velocities.
- To establish, by means of pulsed color Doppler ultrasonography, the flow and wave pattern of the right hepatic vein.
- To establish the presence of cholelithiasis.
- To correlate the observed results with the physiological changes in pregnancy.
CHAPTER TWO
LITERATURE REVIEW
The liver
The liver has multiple functions. It is greatest metabolic organ, initially receiving all absorbed foodstuffs except fats. It is also our largest gland, functioning as an extrinsic intestinal gland in producing bile. The liver occupies essentially the entire right dome of the diaphragm and extends to the apex of the left dome (Moore and Dailey, 2006).
Embryology of the liver
The liver arises as a ventral outgrowth-hepatic diverticulum-from the caudal or distal part of the foregut early in the. fourth week (Tremblay and Zaret, 2005: Moore and Persuad, 2011).
The hepatic diverticulum develops from two cell populations in the embryonic endoderm. The diverticulum extends into the septum transversum, a mass of splanchnic mesoderm between the developing heart and midgut. The septum transversum forms the ventral msentery in this region. The hepatic diverticulum enlarges rapidly and divides into two parts as it grows between the layers of the ventral mesogastrium .The larger cranial part of the hepatic diverticulum is the primordium of the liver. The proliferating endodermal cells give rise to interlacing cords of hepatocytes and to the epithelial lining of the – intrahepatic part of the biliary apparatus. The hepatic cords anastomose around the primordia of the hepatic sinusoids. The fibrous and hematopoietic tissue and Kupffer cells of the liver are derived from mesenchyme in the septum transversum. The liver grows rapidly and, from the 5th to 10th weeks, fills a large part of the upper abdominal cavity .The quantity of oxygenated blood flowing from the umbilical vein into the liver determines the development and functional segmentation of the liver. Initially, the right and left lobes are approximately the same size, but the right lobe soon becomes larger.
Eematopoiesis begins during the sixth week, giving the liver a bright reddish appearance. By the ninth week, the liver accounts for approximately 10% of the total weight of the fetus. Bile formation by hepatic cells begins during the 12th week. (Moore and Persuad, 2010).
Gross anatomy of the liver
The liver is the largest internal organ and the largest gland of the human body, weighing about 1.3-1.5 kg (3.5—4.0 ibs) in an adult. It is positioned immediately beneath the diaphragm in the epigastric and right hypochondriac regions of the abdomen and it overlies the gall bladder. Its reddish brown color is due to its great vascularity (Standring, 2008).
Hepatic attachements
The liver is attached to the anterior abdominal wall, diaphragm and other viscera by several ligaments, which are formed from condensations of the peritoneum. A brief description of the ligaments is as follows: Falciform ligament: Anteriorly, the liver is attached to the anterior abdominal wall by the falciform ligament.
Coronary ligament: The coronary ligament is formed by the reflection of the peritoneum from the diaphragm onto the posterior surfaces of the right lobe of the liver.
Triangular ligaments: The triangular ligament is divided into two; the right and the left triangular ligament. The left triangular ligament is a double layer of peritoneum which extends to a variable length over the superior border of the left lobe of the liver. Medially the anterior leaf is continuous with the left layer of the falciform ligament. The posterior layer is continuous with the left layer of the lesser omentum.The left triangular ligament lies in front of the abdominal part of the esophagus, the upper end of the lesser omentum and part of the fundus of the stomach. Lsser omentum: The lesser omentum is a fold of peritoneum which extends from the lesser curvature of the stomach and proximal duodenum to the inferior surface of the liver (Moore and Dalley, 2006).
CHAPTER THREE
RESEARACH METHODOLOGY
Research design
The study standardized the investigation protocol as well as of the performance of the scans and data acquisition. The present study evaluated a group of 25 low-risk pregnant women coming from the Nigerian Unified Health System, without any previous underlying disease and with prenatal follow-up results within normality parameters. The patients underwent ultrasonography scans at Agbor general Hospital.
Procedure
The patients were informed on the study project and agreed in participating by signing a term of free and informed consent.
The scans were performed by a single operator (performing investigator) in a Toshiba Aplio XG ultrasonography apparatus. The picture archiving and communication system (Philips Healthcare iSite Enterprise) was utilized for sonographic data filing and distribution.
CHAPTER FOUR
RESULTS AND DISCUSSION
Results
Renal volume
The renal volume presented changes as the pregnancies developed, with a progressive renal volume increase up to the third gestational trimester and volume decrease in the postpartum period. Such changes were statistically significant (Figure 1).
CHAPTER FIVE
CONCLUSION
This study was carried out on the Sonographic evaluation of the liver in pregnant women. The study correlated the observed alterations with the physiological changes of pregnancy. In the gestational period, increase in renal volume, pyelocaliceal dilatation (more frequent in the right kidney) and presence of renal lithiasis were significant. The renal indices presented higher values in pregnancy and also in the presence of pyelocaliceal dilatation, however such differences were not statistically significant.
Some of the patients did not present cholelithiasis at the first scan, but developed it during the gestational period, with cholelithiasis being significant in pregnancy. Portal vein flow velocities presented higher values in pregnancy, and the difference of mean value for portal vein maximum velocity in relation to the postpartum period was statistically significant. In the right hepatic vein, there was a predominance of the normal pattern in the first and second gestational trimesters. In the third gestational trimester, the damped pattern predominated. In the postpartum period, the incidence of the damped pattern was significant, persisting for several weeks after delivery.
It was possible to observe that even after several weeks after delivery, not all pregnancy physiological changes evolved back to the normality pattern, for example, the persistent changes in the right hepatic vein.
REFERENCES
- Abdalla, M.A and Abdalla, 0. (1979). Morphometric observations on the liver of the Camel, Camelus dromedarius. I Anat., 129: 45-50.
- Abd-Elgawwad, H.A. (1999). Comparative anatomical studies on some rodents and their correlation with ecosystem. M. Sc. Thesis, Al-Azhar University, Cairo for Girls.
- Adeyemo, 0 and Oke, B.O. (1990): Comparism of the testicular and epididymal proteins of the African giant rat (Cricetomysgambianus) I Vet. Anat. 6 3 Vol 3 No 2, (2010) 55-64
- Adler, R. (1970). Psychological factors in comparative biomedical research. N: Animal Models for Biomedical Research. Washington, D.C.: Nati. Acad. Sci., vol. 3, p. 91-102
- Ajayi, Itopa & Shawulu, James & Daniel, Nafarnda. (2009). Organ Body Weight Relationship of Some Organs in the Male African Grasscutter(Thryonomys swinderianus). Journal of Advanced Veterinary Research. 2. 86-90.
- Ali, N.H (1978): Comparative histological and histochemical studies on the kidney of vertebrates. M.Sc.. Thesis, Zool. Dep. Fac. Sci. Am Shams Univ. Cairo, Egypt.
- Ballard, D. and Reeder, s. (2003): Mammal Species of the World: A Taxonomic and Geographic Reference. The Smithsonian institution, Washington, D.C.
- Banhawy M.A; Demian, E.S, Shalaby, A.A and Roshdy, M.A (1972). Text Book of Zoology. Dar Al-Maaref, 1119 Cornishe Enile, Cairo, Egypt.
- Basuony M I; Salem M Mand Younis M I (2009): Habitat partitioning on anatomical basis among rodents of a desert ecosystem.Ph.D.Thesis,Al-Azhar University, Cairo. Berliner R W and Bennett C H (1967): Concentration of the urine in the mammalian kidney. Am. J. Med., 42: 777- 789.
- Bishop, S.P(1980). Cardiovascular Research. In: Baker, J.J., Lindsey, J.R. and Weisbroth, S.H. (eds.), The Laboratory Rat, Volume II, Research Applications. Academic press, NY,.
