Surgery of the Liver, Bile Ducts and Pancreas in Children

Mark Davenport, Nigel Heaton, Riccardo Superina

• Publisher: CRC Press
• Year: 2017
• ISBN:
  9781498716000
• Edition: 3
• Topic: Medicine
• Subtopic: Surgery & Surgical Medicine

Surgery of the Liver, Bile Ducts and Pancreas in Children, Third Edition describes the modern approach to the diagnosis, management and surgery of childhood conditions of the liver and associated structures. The first edition was recognized worldwide as a landmark publication and helped to establish pediatric hepatobiliary surgery as a discrete subspecialty; the second was expanded to include pancreatic diseases, transplantation and trauma. This third edition is overseen by a new editorial team from two world-leading centers for children's liver surgery: King's College Hospital in London, and Lurie Children's Hospital in Chicago. The book has been further expanded and updated by a team of international experts to take account of the very latest advances in research and practice.

PART I

Basic Science

1 Anatomy of the liver, bile ducts and pancreas

Mark Davenport

2 Development of the liver and pancreas

Mark Davenport and Philippa Francis-West

3 Liver physiology

Mark Davenport

1

Anatomy of the liver, bile ducts and pancreas

MARK DAVENPORT

1.1 Liver anatomy

1.2 Anatomy of the pancreas

1.3 Microscopic anatomy of liver and pancreas

1.4 Microscopic anatomy of the pancreas

Further reading

References

1.1 LIVER ANATOMY

1.1.1 Introduction

The liver is the largest solid organ in the body, normally weighing between 1.2 and 1.8 kg in adults (i.e. ~2% of body mass), but it is proportionally larger in neonates (about 200 g, i.e. ~10% of the body mass).

Various estimates have been given for measured liver volume in vivo (Table 1.1). It was assessed by ultrasonography in European adults as 18 ± 0.5 mL/kg body weight [1], and by computed tomography (CT) volumetric analysis in American adults as 1800 ± 350 mL [2] and 1518 ± 353 mL [3]. Liver volumes tend to be higher in Western than in Japanese subjects, by as much as 300 mL on average according to one source [3]. There is also a marked diurnal variation in liver volume, being maximal in the early morning and minimal towards the early afternoon [1]. The density of the liver is about that of water, which makes the conversion to liver mass relatively simple. (see Chapter 36).

The actual shape of the liver is determined by the cavity in which it develops. This is usually the dome of the right hemidiaphragm. There are some congenital anomalies where this changes, so in a right diaphragmatic hernia, for instance, the liver rotates around the axis of the hepatic vein/caval confluence into the hemithorax and can adopt an almost bilobed or dumb-bell appearance. Similarly, in a major exomphalos the whole organ prolapses into the sac and assumes a much more obviously symmetrically globular structure.

Some variations in shape and position have been recognised and still retain clinical significance; the most common is the elongated right lobe extending down towards the right iliac fossa, termed a Riedel’s^* lobe. Similarly, interposition of the transverse colon between the right hemidiaphragm and right lobe is known as Chilaiditi’s^† sign or syndrome.

1.1.2 Surface anatomy and peritoneal folds

The liver is protected largely by the lower rib cage, but it can be palpated in both children and adults up to 1 cm below this costal margin. The surface marking for the gallbladder is the tip of the ninth rib.

The liver is subdivided by a peritoneal reflection – the falciform ligament – from the anterior abdominal wall, into a larger anatomical right lobe and smaller anatomical left lobe (~16% of liver mass). The free edge contains the single, now obliterated umbilical vein, termed the ligamentum teres, running to the liver and creating a fissure on its undersurface. This joins the left portal vein in the portal recess (of Rex^‡) at the extreme left of the porta hepatis. Quite often, there is a band or tongue of liver tissue surrounding and obscuring this junction, which can be divided to show this relationship.

The falciform ligament can be traced backwards over the dome of the liver, and as it nears the confluence of the hepatic veins and inferior vena cava, its layers separate. On the left side, it has a long, thin peritoneal reflection – the left triangular ligament, which extends onto the left hemi-diaphragm lying anterior to the aortic and oesophageal hiatus and almost onto the upper pole of the spleen. The posterior aspect of the anatomical left lobe has a distinct fissure (containing the ligamentum venosum) separating it from the caudate lobe and serving as an attachment for the lesser omentum. On the right side, the upper coronary ligament swings in a posterolateral direction over the diaphragm before turning sharply back as the short right triangular ligament and lower coronary ligament towards the cava as it emerges from the liver. The ‘bare area’ of the liver is the nonperitonealised surface of the right lobe adjacent to the intrahepatic course of the vena cava. The right adrenal gland and its short adrenal vein draining into the cava are consistently identified here.

Table 1.1 Estimates of liver volume in adults

Segment	Section	Volume (mL)		Volume (%)^a
1				2^c
2 3	Left lateral	500^b–800^c	240^b	16 ± 4
4	Left medial		250^b	17 ± 4
5 8	Right anterior	~1000^b,^c		65 ± 7
6 7	Right posterior

Note: Both studies are on American subjects.

^a Mean ± standard deviation.

^b From Abdalla EK, et al., Surgery 2004, 135: 404–410.

^c From Kamel IR, et al., American Journal of Roentgenology 2001, 176: 483–487.

The vascular pedicle of the liver, containing the portal vein posteriorly and the hepatic artery and bile duct anteriorly, lies in the free edge of the lesser omentum (or hepatoduodenal ligament). One can encircle this pedicle and, by breaking through the lesser omentum, achieve complete control of the blood supply to the liver, a technique now associated with the name of James Hogarth Pringle^* [4]. The portal vein is separated from the inferior vena cava by the epiploic foramen (of Winslow^†) and the entrance to the lesser sac lying behind the stomach on the left side. The subhepatic pouch (of Rutherford Morison^‡) is just to the right of the foramen and is the most dependent part of the recumbent peritoneal cavity, and hence a common site for collections and abscess.

The gallbladder lies on the undersurface of the right lobe, usually within a distinct fossa. It is at least partially peritonealised, with its fundus extending almost to the liver edge. The minor anatomical lobe between this fossa and the falciform ligament is termed the quadrate lobe because of its shape.

1.1.3 Lobes and segments of the liver

Although, as described above, there are obvious anatomical right and left lobes, this has no real functional relevance. The division into two equal hemilivers is based upon the portal venous blood supply. The right and left portal veins are roughly equal in size, and ligation of one or the other will demonstrate an ischaemic hemiliver with a line of demarcation running over the anterior surface of the liver from a point just to the left of the hepatic venous confluence through to the gallbladder fossa. This is termed the principal plane or Rex–Cantlie^§ line (after the first two people to show this in 1888 and 1897, respectively) and is the basic plane of transection for hemihepatectomy. Thus, the quadrate lobe, anatomically a right lobe structure, in fact, belongs to the left hemiliver.

The French anatomist Claude Couinaud^¶ was not the first to recognise that the liver could be divided into smaller units or ‘segments’; Healey and Schroy’s system was based on bile duct distribution and, published in 1953, just predated this work, using the equivalent term area instead [5]. Nevertheless, the former’s work has become the better known and is based upon the interdigitation of the hepatic veins and the intrahepatic portal veins [6]. Thus, the current ubiquitous nomenclature of eight segments (initially I–VIII, now 1–8) was first published in French, in 1954, and formalises the concept of independent segments with their own vascular inflow, outflow and biliary drainage [7] (Box 1.1). Most segments are therefore bounded by named hepatic veins (lying in so-called scissurae) with an axial pedicle of the portal vein, hepatic artery and biliary duct (Figure 1.1).

The principal plane runs a...

Table of contents

• Cover
• Title Page
• Copyright Page
• Table of Contents
• Preface to third edition
• Preface to second edition
• Acknowledgements
• Contributors
• PART I BASIC SCIENCE
• PART II INVESTIGATIONS
• PART III INFECTION
• PART IV LIVER AND BILE DUCT DISEASE
• PART V PANCREAS DISEASE
• PART VI NEOPLASIA
• PART VII VASCULAR ANOMALIES AND PORTAL HYPERTENSION
• PART VIII TRAUMA
• PART IX LIVER TRANSPLANTATION
• PART X TRANSITION TO ADULTHOOD
• Index