Download mrcs a essential revision notes book 2

M RC S A ESSENTIAL
R EVISIO N N OTES
BOO K 2
Edited by
Claire Ritchie Chalmers
BA PhD FRCS
Catherine Parchment Smith
BSc MBChB FRCS
Contents
Acknowledgements
v
Preface
v
Picture Permissions
vi
Contributors
vii
Introduction
ix
Chapter 1 – Abdominal Surgery
1
Catherine Parchment Smith, Arin K. Sara and Ravinder S. Vohra
Chapter 2 – Breast Surgery
337
Jenny McIlhenny and Ritchie Chalmers
Chapter 3 – Cardiothoracic Surgery
397
George Tse and Sai Prasad
Chapter 4 – Endocrine Surgery
465
Nicholas E Gibbins and Sylvia Brown
Chapter 5 – Head and Neck Surgery
521
Nicholas E Gibbins
Chapter 6 – Neurosurgery (Elective)
593
Paul Brennan
iii
Chapter 7 – Transplant Surgery
627
Karen S Stevenson
Chapter 8 – Urological Surgery
647
Mary M Brown
Chapter 9 – Vascular Surgery
729
Sam Andrews
Abbreviations
803
Bibliography
807
Index
809
iv
Abdominal Surgery
Catherine Parchment Smith,
Arin K. Saha and Ravinder S. Vohra
1.
2.
Abdominal wall and hernias
1.1 Anterior abdominal wall
1.2 Hernias
1.3 Complications of hernias
3
3
10
31
Oesophagus
2.1 Anatomy and physiology of the
oesophagus
2.2 Pain and difficulty swallowing
2.3 Gastro-oesophageal reflux
disease
2.4 Hiatus hernia
2.5 Motility disorders
2.6 Oesophageal perforation
2.7 Other benign oesophageal
disorders
2.8 Barrett’s oesophagus
2.9 Oesophageal carcinoma
37
3.9
Congenital abnormalities of
the duodenum
3.10 Other conditions of the
stomach and duodenum
4.
37
40
44
48
49
51
53
53
55
5.
3.
Stomach and duodenum
60
3.1 Anatomy of the stomach
60
3.2 Anatomy of the duodenum
64
3.3 Physiology of the upper GI tract 66
3.4 Peptic ulceration
77
3.5 Complications of peptic
ulceration
89
3.6 Gastric carcinoma
96
3.7 Gastritis
105
3.8 Congenital abnormalities of
the stomach
106
Liver and spleen
4.1 Anatomy of the liver
4.2 Physiology of the liver
4.3 Jaundice
4.4 Portal hypertension
4.5 Clinical evaluation of liver
disease
4.6 Cirrhosis
4.7 Liver masses
4.8 Liver infections
4.9 Liver cysts
4.10 The spleen
106
107
110
110
115
120
127
131
133
134
137
138
139
Biliary tree and pancreas
144
5.1 Anatomy of the biliary system 144
5.2 Physiology of the biliary tree 147
5.3 Gallstones
150
5.4 Other disorders of the biliary
tree
159
5.5 Anatomy of the pancreas
161
5.6 Physiology of the pancreas
162
5.7 Pancreatitis
164
5.8 Pancreatic carcinoma
168
5.9 Other pancreatic tumours
173
5.10 Other disorders of the pancreas 174
1
CHAPTER 1
C HA P TE R 1
6.
7.
2
Acute Abdomen
6.1 Acute abdominal pain
6.2 Common acute abdominal
emergencies
6.3 Intestinal obstruction
6.4 Peritonitis
6.5 Stomas
Small bowel
7.1 Anatomy and physiology of
the small bowel
7.2 Imaging and investigating the
small bowel
7.3 Intestinal fistulas
7.4 Tumours of the small bowel
7.5 Bleeding from the small bowel
7.6 Intestinal ischaemia
7.7 Diverticula of the small bowel
7.8 Infectious enteritis
7.9 Radiation small-bowel injury
7.10 Short-bowel syndrome
7.11 Short-bowel bypass
176
176
8.
Large bowel
242
8.1 Symptoms of non-acute
abdominal disorders
242
8.2 Anatomy and physiology of the
colon
259
8.3 Diagnosis of colorectal disease 263
8.4 Inflammatory bowel disease
269
8.5 Benign colorectal tumours
280
8.6 Colorectal cancer
289
8.7 Other colorectal conditions
307
9
Perianal conditions
9.1 Anatomy and physiology of
the rectum and anus
9.2 Haemmorhoids
9.3 Anal fissures
9.4 Anorectal abscesses
9.5 Anorectal fistulas
9.6 Pilonidal sinus
9.7 Pruritus ani
9.8 Rectal prolapsed
9.9 Proctalgia fugax
9.10 Faecal incontinence
9.11 Anal cancer
9.12 Sexually transmitted
anorectal infections
182
195
205
215
222
222
226
227
230
234
235
238
239
240
240
241
310
310
313
318
319
322
324
325
327
330
330
333
334
Abdominal wall
and hernias
1.1
Anterior abdominal wall
Layers of the abdominal wall
In a nutshell …
When you make an incision in the
anterior abdominal wall you will go
through several layers:
฀ Skin
฀ Subcutaneous fat
฀ Superficial fascia
฀ Deep fascia (vestigial)
฀ Muscles (depending on incision)
฀ Transversalis fascia
฀ Extraperitoneal fat
฀ Peritoneum
Skin
The skin has horizontal Langer’s lines over the
abdomen. Dermatomes are also arranged in
transverse bands.
Superficial fascia
(Scarpa’s fascia)
฀ Absent above and laterally
฀ Fuses with deep fascia of leg inferior to
inguinal ligament
฀ Very prominent in children (can even be
mistaken for external oblique!)
฀ Continuous with Colles’ fascia over perineum
(forms tubular sheath for penis/clitoris and
sac-like covering for scrotum/labia)
Muscles
In a nutshell …
The muscles you’ll pass through depend
on the incision site:
฀ External oblique
฀ Internal oblique
฀ Rectus abdominis
฀ Transversus abdominis
฀ Pyramidalis
฀ Rectus sheath
Deep fascia
This is a vestigial thin layer of areolar tissue over
muscles.
3
CHAPTER 1
SEC TIO N 1
Abdominal Surgery
CHAPTER 1
฀ External oblique is a large sheet of muscle
fibres running downwards from lateral
to medial like a ‘hand in your pocket’.
Medially, the external oblique becomes
a fibrous aponeurosis which lies over the
rectus abdominis muscle (see below),
forming part of the anterior rectus sheath
฀ Internal oblique is a second large sheet
of muscle fibres lying deep to the external
oblique and at right angles to it. Medially,
it forms a fibrous aponeurosis which splits
to enclose the middle portion of rectus
abdominis as part of the anterior and
posterior rectus sheath
฀ Transversus abdominis is the third large
sheet of muscle lying deep to the internal
oblique and running transversely. Medially,
it forms a fibrous aponeurosis which
contributes to the posterior rectus sheath
lying behind rectus abdominis
฀ Rectus abdominis and its pair join at the
linea alba in the midline to form a wide
strap that runs longitudinally down the
anterior abdominal wall. It lies within the
rectus sheath formed by the aponeuroses
of the three muscles described above. It is
attached to the anterior rectus sheath, but
not to the posterior rectus sheath, by three
tendinous insertions. These insertions are
at the level of the xiphisternum, umbilicus
and halfway between (giving the ‘six-pack’
appearance in well-developed individuals!).
The blood supply of rectus abdominis is
through the superior epigastric artery (a
terminal branch of the internal thoracic
artery) and the inferior epigastric artery (a
branch of the external iliac artery) which
anastomose to form a connection between
the subclavian and external iliac systems
(Fig. 1.1). The superior epigastric artery is
the pedicle on which a TRAM flap is raised
for breast reconstruction. The nerve supply
to the recti is segmental from T6 to T12 and
4
the nerves enter the sheath laterally and
run towards the midline (so are disrupted in
Battle’s incision – see Figure 1.3)
฀ Linea alba is a fibrotendinous raphe running
vertically in the midline between the left
and right rectus abdominis muscles. It is
formed by the fusion of the external oblique,
internal oblique and transversus abdominis
aponeuroses. They fuse in an interlocking/
interdigitating structure through which
epigastric hernias may protrude. The linea
alba provides an avascular and relatively
bloodless plane through which midline
laparotomy incisions are made. It is easier
to begin a laparotomy incision above the
umbilicus, where the linea alba is wider,
thicker and better defined than below the
umbilicus
฀ Pyramidalis is a small (4 cm long)
unimportant muscle arising from the pubic
crest and inserting into the linea alba. It
lies behind the anterior rectus sheath in
front of rectus abdominis. This is the only
muscle you go through in your lower
midline laparotomy incision and it is not
as bloodless as the linea alba which it
underlies
Rectus sheath
In a nutshell …
Any incision over rectus abdominis will
go through the anterior rectus sheath.
Arrangement of the rectus sheath is best
considered in three sections:
฀ Above the level of the costal margin
฀ From the costal margin to just below
the umbilicus
฀ Below the line of Douglas
฀ Above the level of the costal margin: the
anterior rectus sheath is formed by the
external oblique aponeurosis only. There is
no internal oblique or transversus abdominis
aponeurosis at this level. Therefore there
is no posterior rectus sheath and rectus
abdominis lies directly on the fifth to
seventh costal cartilages
฀ From the costal margin to just below the
umbilicus: the anterior rectus sheath is formed
by the external oblique aponeurosis and
the anterior leaf of the split internal oblique
aponeurosis. It is attached to rectus abdominis
by tendinous intersections. The posterior
rectus sheath is formed by the posterior leaf
of the internal oblique aponeurosis and the
transversus abdominis aponeurosis
฀ Below the line of Douglas: about 2.5 cm
below the umbilicus lies a line called the
‘arcuate line of Douglas’ (Fig. 1.1). At
this level, the posterior rectus sheath (ie
the posterior leaf of the internal oblique
aponeurosis along with the transversus
abdominis aponeuroses) passes anterior
to rectus abdominis. Therefore, below the
arcuate line of Douglas there is no posterior
rectus sheath. Rectus abdominis lies directly
on transversalis fascia, which is thickened
here, and called the ‘iliopubic tract’. The
anterior rectus sheath is now formed by all
the combined aponeuroses of the external
oblique, internal oblique and transversus
abdominis muscles
Figure 1.1 Sagittal section of the abdominal wall
5
CHAPTER 1
Abdominal wall and hernias
Abdominal Surgery
CHAPTER 1
Figure 1.2 Surface
landmarks of the
anterior abdominal
wall
(A) Transpyloric line: halfway between jugular
notch and pubic symphysis at L1; this plane
passes through pylorus, pancreatic neck,
duodenojejunal flexure, fundus of gallbladder,
tip of ninth costal cartilage, hila of kidneys; also
it is the level of termination of the spinal cord.
(B) Subcostal line: under lowest rib (rib 10 at L3).
(C) Intertubercular/transtubercular line: between
two tubercles of iliac crest (L5); note that plane
of iliac crests (supracristal plane) is higher (at
L4).
(D) Midclavicular line: through midinguinal point,
halfway between ASIS and symphysis pubis.
(1) Xiphoid process: xiphisternal junction is at T9.
(2) Costal margins: ribs 7–10 in front; ribs 11 and
12 behind; tenth costal cartilage is lowest at L3.
(3) Iliac crest: anterior superior iliac spine (ASIS)
to posterior superior iliac spine (PSIS); highest
point L4.
(4) ASIS.
6
(5)
(6)
Tubercle of iliac crest: 5 cm behind ASIS at L5.
Inguinal ligament: running from ASIS to pubic
tubercle.
(7) Pubic tubercle: tubercle on superior surface of
pubis; inguinal ligament attaches to it, as lateral
end of the superficial inguinal ring.
(8) Superficial inguinal ring: inguinal hernia comes
out above and medial to pubic tubercle at point
marked (I); femoral hernia below and lateral to
pubic tubercle at point marked (F).
(9) Symphysis pubis: midline cartilaginous joint
between pubic bones.
(10) Pubic crest: ridge on superior surface of pubic
bone medial to pubic tubercle.
(11) Linea alba: symphysis pubis to xiphoid process
midline.
(12) Linea semilunaris: lateral edge of rectus crosses
costal margin at ninth costal cartilage (tip of
gall bladder palpable here).
Abdominal wall and hernias
฀ Segmental vessels from T7 to T12
฀ Superior and inferior epigastric vessels (see
Figure 1.1)
CHAPTER 1
Contents of the rectus sheath
฀ Rectus abdominis
฀ Pyramidalis
฀ Segmental nerves
Layers of the abdominal wall divided in three common incisions
Midline laparotomy
Kocher’s incision
Gridiron appendicectomy
incision
Skin
Skin
Skin
Subcutaneous fat
Subcutaneous fat
Subcutaneous fat
Scarpa’s fascia
Scarpa’s fascia
Scarpa’s fascia
Linea alba
Medially:
Anterior rectus sheath
Rectus abdominis
Posterior rectus sheath
Laterally:
External oblique
Internal oblique
Transversus abdominis
External oblique
Internal oblique
Transversus abdominis
Fascia transversalis
Fascia transversalis
Fascia transversalis
Preperitoneal fat
Preperitoneal fat
Preperitoneal fat
Parietal peritoneum
Parietal peritoneum
Parietal peritoneum
Diseases of the umbilicus
Congenital
฀ Cord hernias
฀ Gastroschisis
฀ Exomphalos
Tumours
฀ Primary
฀ Benign (papilloma, lipoma)
฀ Malignant (squamous cell carcinoma
[SCC], melanoma)
฀ Secondary
฀ Breast
฀ Ovarian
฀ Colon (via lymphatic, transcoloemic and
direct spread along falciform ligament)
Endometriosis
Hernias
฀ Childhood (umbilical)
฀ Adult (paraumbilical)
Fistula
฀ Urinary tract (via urachal remnant)
฀ Gastrointestinal tract (via vitellointestinal duct)
Suppurations
฀ Primary
฀ Obesity
฀ Pilonidal
฀ Fungal infections
฀ Secondary
฀ From intra-abdominal abscess
7
Abdominal Surgery
CHAPTER 1
Surface markings of abdominal
organs and vessels
฀ Gallbladder: tip of right ninth costal
cartilage where linea semilunaris intersects
the costal margin (Figure 1.2)
฀ Spleen: under ribs 9, 10 and 11 on the
left; long axis lies along rib 10; palpable in
infants
฀ Pancreas: lies along the transpyloric plane
(L1)
฀ Kidney: from the level of T12 to L3; the
hilum lies on the transpyloric plane (L1);
right kidney is lower; kidneys move 2–5 cm
in respiration
฀ Appendix: McBurney’s point is the surface
marking of the base of the appendix one
third of the way up the line joining the
anterior superior iliac spine to the umbilicus
฀ Aortic bifurcation: at the level of L4
vertebra to left of midline
฀ External iliac artery: palpable at
midinguinal point halfway between ASIS
and symphysis pubis
Abdominal incisions
The ideal abdominal incision
฀ Allows easy and rapid access to
relevant structures
฀ Allows easy extension (if necessary)
฀ Favours secure healing in the short
term (no dehiscence) and in the long
term (no herniation)
฀ Leaves patients relatively pain-free
postoperatively
฀ Gives a satisfactory cosmetic
appearance
Figure 1.3
Abdominal
incisions
8
Abdominal wall and hernias
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
Midline incision through linea alba: provides
good access. Can be extended easily. Quick
to make and close. Relatively avascular. More
painful than transverse incisions. Incision
crosses Langer’s lines so it has poor cosmetic
appearance. Narrow linea alba below
umbilicus. Some vessels cross the midline. May
cause bladder damage.
Subumbilical incision: used for repair of
paraumbilical hernias and laparoscopic port.
Paramedian incision: 1.5 cm from midline
through rectus abdominis sheath. This was the
only effective vertical incision in the days when
catgut was the only available suture material.
Takes longer to make than midline incision.
Does not lend itself to closure by ‘Jenkins
rule’ (length of suture is 4 × length of wound).
Poor cosmetic result. Can lead to infection
in rectus sheath. Other hazards: tendinous
intersections must be dissected off; need to
divide falciform ligament above umbilicus on
the right; if rectus is split more than 1 cm from
medial border, intercostal nerves are disrupted
leading to denervation of medial rectus (avoid
by retracting rectus without splitting).
Pararectal ‘Battle’s’ incision: now not used
because of damage to nerves entering rectus
sheath and poor healing leading to postoperative incisional hernias.
Kocher’s incision: 3 cm below and parallel to
costal margin from midline to rectus border.
Good incision for cholecystectomy on the
right and splenectomy on the left – but beware
superior epigastric vessels. If wound is extended
laterally too many intercostal nerves are
severed. Cannot be extended caudally.
Double Kocher’s (rooftop) incision: good
access to liver and spleen. Useful for
intrahepatic surgery. Used for radical pancreatic
and gastric surgery and bilateral adrenalectomy.
Transverse muscle-cutting incision: can be
across all muscles. Beware of intercostal nerves.
McBurney’s/gridiron incision: classic approach
to appendix through junction of the outer and
middle third of a line from the anterior superior
(8a)
(9)
(10)
(11)
(12)
iliac spine (ASIS) to the umbilicus at right angles
to that line. May be modified into a skin-crease
horizontal cut. External oblique aponeurosis
is cut in the line of the fibres. Internal oblique
and transversus abdominis are split transversely
in the line of the fibres. Beware: scarring if not
horizontal; iliohypogastric and ilioinguinal
nerves; deep circumflex artery.
Rutherford–Morrison incision: gridiron can
be extended cephalad and laterally, obliquely
splitting the external oblique to afford good
access to caecum, appendix and right colon.
Lanz incision: lower incision than McBurney’s
and closer to the ASIS. Better cosmetic result
(concealed by bikini). Tends to divide iliohypogastric and ilioinguinal nerves, leading to
denervation of inguinal canal mechanism (can
increase risk of inguinal hernia).
Pfannenstiel’s incision: most frequently used
transverse incision in adults. Excellent access
to female genitalia for caesarean section and
for bladder and prostate operations. Also used
for bilateral hernia repair. Skin incised in a
downward convex arc into suprapubic skin
crease 2 cm above the pubis. Upper flap is
raised and rectus sheath incised 1 cm cephalic
to the skin incision (not extending lateral to the
rectus). Rectus is then divided longitudinally in
the midline.
Transverse incision: particularly useful in
neonates and children (who do not have
the subdiaphragmatic and pelvic recesses
of adults). Heals securely and cosmetically.
Less pain and fewer respiratory problems
than with longitudinal midline incision but
division of red muscle involves more blood
loss than longitudinal incision. Not extended
easily. Takes longer to make and close. Limited
access in adults to pelvic or subdiaphragmatic
structures.
Thoracoabdominal incision: access to lower
thorax and upper abdomen. Used (rarely) for
liver and biliary surgery on the right. Used
(rarely) for oesophageal, gastric and aortic
surgery on the left.
9
CHAPTER 1
Figure 1.3 Abdominal incisions
Abdominal Surgery
1.2
Hernias
CHAPTER 1
In a nutshell …
A hernia is a protrusion of all or part of
a viscus through the wall of the cavity in
which it is normally contained.
Types of abdominal hernias:
Groin:
฀ Inguinal
฀ Femoral
Umbilical
Paraumbilical
Incisional
Epigastric
Spigelian
Lumbar
Gluteal
Sciatic
Groin hernias
Inguinal and femoral hernias are two of the most
common types of hernia. Their repairs make up
a large proportion of elective surgery.
All groin hernias
All hernias are more common on the right than
on the left (may be due to later descent of right
testis or previous appendicectomy)
10
Incidence of groin hernias
Male children
฀ 4% of male infants have indirect
inguinal hernia
฀ Risk of incarceration is high in babies
฀ Presents as lump in the groin when
child cries
฀ Indirect inguinal > direct inguinal >
femoral (very rare)
Female children
฀ All groin hernias rare in female
children
฀ Presence of bilateral hernias should
alert clinicians to possible testicular
feminisation syndrome
฀ Hernias in female children may
contain an ovary in the hernia sac
which must be reduced at surgery
฀ Indirect inguinal > direct inguinal >
femoral (very rare)
Male adults
฀ Direct inguinal > indirect inguinal >
femoral
Female adults
฀ Indirect inguinal > femoral > direct
(rare)
Inguinal hernias
Anatomy of the inguinal region
Inguinal canal
This is an oblique intermuscular slit, 6 cm long,
above the medial half of the inguinal ligament
between the deep and superficial rings. It
transmits the spermatic cord in the male and the
round ligament of the uterus in the female.
Deep inguinal ring
This is an oval opening in the transversalis fascia,
1.3 cm above the inguinal ligament, midway
between the ASIS and the pubic tubercle. This
is the midpoint of the inguinal ligament – just
lateral to the midinguinal point. The deep ring
is bounded laterally by the angle between the
transversus abdominis and the inguinal ligament.
It is bounded medially by the transversalis fascia
and the inferior epigastric vessels behind this.
Figure 1.4 Anatomy of the
inguinal region:
1.
2.
3.
4.
With skin and cutaneous
fat removed
With external oblique
removed
With internal oblique
removed
With transversus muscle
removed
11
CHAPTER 1
Abdominal wall and hernias
Abdominal Surgery
CHAPTER 1
Superficial inguinal ring
This is a triangular opening in the external
oblique aponeurosis. The lateral crus attaches to
the pubic tubercle. The medial crus attaches to
the pubic crest near the symphysis. The base of
the superficial ring is the pubic crest.
Floor of the inguinal canal
The inguinal ligament forms most of the floor of
the inguinal canal. The lacunar ligament forms
the medial part of the floor, filling in the angle
between the inguinal ligament and the pectineal
line.
Ceiling of the inguinal canal
Lateral to medial, this is formed by transversus
abdominis, internal oblique and the conjoint
tendon.
Transversus abdominis arises lateral to the
deep ring from the lateral half of the inguinal
ligament. It arches over the roof of the inguinal
canal to become the conjoint tendon.
The internal oblique arises in front of the deep
ring from the lateral two-thirds of the inguinal
ligament and, lying superficial to transversus
abdominis, behaves in the same way.
The conjoint tendon is formed by the fusion
of the aponeurosis of the internal oblique and
transversus abdominis. It arches over the canal,
forming the medial roof, strengthening the
posterior wall. It inserts into the pubic crest and
the pectineal line at right angles to the lacunar
ligament, which forms the floor here.
12
Transversus abdominis, the internal oblique and
conjoint tendon can contract and lower the roof
of the inguinal canal, thereby strengthening it.
They are supplied by L1 from the iliohypogastric
and ilioinguinal nerves. These nerves are at risk
in the muscle-splitting incision for appendicectomy, which leads to increased risk of direct
hernia.
Anterior wall of the inguinal canal
The anterior wall is formed mostly by the
external oblique strengthened laterally by the
internal oblique. The superficial ring is a defect
in the anterior wall. The anterior wall is strongest
opposite the weakest point of the posterior
wall – the laterally placed deep ring. Here, the
anterior wall is strengthened by the internal
oblique fibres that originate anterior from the
lateral two-thirds of the inguinal ligament.
Posterior wall of the inguinal canal
The posterior wall is formed by the transversalis
fascia, strengthened medially by the conjoint
tendon. The deep ring is a defect in the posterior
wall. The posterior wall is strongest opposite the
weakest point of the anterior wall – the medially
placed superficial ring. Here, the posterior wall
is strengthened by the conjoint tendon fibres,
formed from the internal oblique and transversus
abdominis as they curve over to insert posteriorly
into the pubic crest and the pectineal line.
Abdominal wall and hernias
CHAPTER 1
Contents of the inguinal canal in the male
Vas
Arteries:
฀ Testicular
฀ Artery to vas
฀ Cremasteric
Veins: pampiniform plexus
Lymphatic vessels: the testis drains to the para-aortic lymph nodes; the coverings of the testis
drain to the external iliac nodes
Nerves:
฀ Genital branch of genitofemoral (supplies cremaster muscle)
฀ Sympathetic nerves accompanying arteries
฀ Ilioinguinal nerve (enters via anterior wall of canal, not via internal ring, and runs in front
of spermatic cord) supplies skin of inguinal region, upper part of thigh and anterior third
of scrotum or labia
Processus vaginalis: obliterated remains of peritoneal connection to tunica vaginalis
All of these are in the spermatic cord except the ilioinguinal nerve
Coverings of the spermatic cord
฀ Internal spermatic fascia (from
transversalis fascia)
฀ Cremasteric fascia (from internal
oblique and transversus abdominis)
฀ External spermatic fascia (from
external oblique)
The inguinal canal is a natural point of weakness
in the abdominal wall. There are several features
that normally reduce this weakness:
฀ The rings lie some distance apart (except in
infants)
฀ The anterior wall is reinforced by the
internal oblique in front of the deep ring
฀ The posterior wall is reinforced by the
conjoint tendon opposite the superficial ring
฀ When abdominal pressure increases, the
internal oblique and transversus abdominis
contract, lowering the roof
฀ When abdominal pressure increases, we
automatically squat so the anterior thigh
presses against the inguinal canal and
reinforces it
Indirect inguinal hernias
In a nutshell …
฀ 60% of adult male inguinal hernias are
indirect
฀ 4% of male infants have indirect
inguinal hernias
Indirect inguinal hernias are the most
common type of groin hernia in children.
They are thought to be caused by the
congenital failure of the processus
vaginalis to close (saccular theory of
Russell).
13
Abdominal Surgery
Direct inguinal hernias
CHAPTER 1
Predisposing factors for indirect
hernia
฀ Males: bigger processus vaginalis than
in women
฀ Premature twins or low birthweight:
processus vaginalis not closed
฀ Africans: the lower arch in the more
oblique African pelvis means the
internal oblique origin does not
protect the deep ring
฀ On the right side: right testis descends
later than the left
฀ Testicular feminisation syndrome:
genotypic male but androgeninsensitive so phenotypically female
฀ Young men: direct hernias become
more common with age
฀ Increased intraperitoneal fluid: from
whatever cause, eg cardiac, cirrhotic,
carcinomatosis, dialysis; tends to open
up the processus vaginalis
The indirect inguinal hernia sac is the remains
of the processus vaginalis. The sac extends
through the deep ring, inguinal canal and
superficial ring. The inferior epigastric artery
lies medial to the neck. In a complete sac the
testis is found in the fundus. In an incomplete
sac, the sac is limited to the canal or is
inguinoscrotal or inguinolabial. The indirect
hernia commonly descends into the scrotum.
In a nutshell …
฀ 35% of adult male inguinal hernias are
direct
฀ 5% of adult male inguinal hernias are
a combination of direct and indirect
The direct inguinal hernia is an acquired
weakness in the abdominal wall which
tends to develop in adulthood (unlike
indirect hernias which are common in
children) and are therefore the most
common groin hernias in old men.
The direct inguinal hernia sac lies behind the
cord. The inferior epigastric artery lies lateral to
the neck. The hernia passes directly forwards
through the defect in the posterior wall (fascia
transversalis) of the inguinal canal. This hernia
does not typically run down alongside the cord
to the scrotum, but may do so.
Femoral hernias
Anatomy of the femoral region
Femoral sheath
The femoral sheath is a downward protrusion
into the thigh of the fascial envelope lining
the abdominal walls. It surrounds the femoral
vessels and lymphatics for about 2.5 cm below
the inguinal ligament. The sheath ends by fusing
with the tunica adventitia of the femoral vessels.
This occurs close to the saphenous opening in
the deep fascia of thigh.
The anterior wall is continuous above with fascia
transversalis and the posterior wall is continuous
above with fascia iliacus/psoas fascia. It does
14
not protrude below the inguinal ligament in the
fetal position.
The femoral sheath exists to provide freedom for
vessel movement beneath the inguinal ligament
during movement of the hip.
Contents of the femoral sheath
฀ Femoral artery: in lateral compartment
฀ Femoral veins: in intermediate
compartment
฀ Lymphatics: in medial compartment or
femoral canal
฀ Femoral branch (L1) of genitofemoral
nerve: pierces the anterior wall of the
femoral sheath running on the anterior
surface of the external iliac artery
Note that the femoral nerve lies in the
iliac fossa between the psoas and the
iliacus behind the fascia, so it enters the
thigh outside the femoral sheath.
about 1.3 cm long with an upper opening called
the ‘femoral ring’.
The femoral canal allows lymph vessels to be
transmitted from the lower limbs to the abdomen
and is also a dead space into which the femoral
vein can expand when venous return increases.
The femoral canal is the path taken by femoral
hernias.
Contents of the femoral canal
฀ Fatty connective tissue
฀ Efferent lymph vessels from deep
inguinal nodes
฀ Deep inguinal node of Cloquet (drains
penis/clitoris)
Femoral ring
The top of the femoral canal is called the femoral
ring. It is covered by the femoral septum – a
condensation of extraperitoneal tissue. This is
pushed downwards into the canal in a hernia.
Femoral canal
The femoral canal is the medial compartment of
the femoral sheath containing lymphatics. It is
Figure 1.5 The
femoral region
15
CHAPTER 1
Abdominal wall and hernias
Abdominal Surgery
CHAPTER 1
Boundaries of the femoral ring
฀ Anteriorly: inguinal ligament
฀ Posteriorly: superior ramus of pubis
and pectineal ligament
฀ Medially: lacunar ligament or
iliopubic tract
฀ Laterally: femoral vein
These are also the margins of the neck of
a femoral hernia. Note that three of the
four boundaries are rigid, so a femoral
hernia is prone to strangulation.
The lacunar ligament may have to be incised to
release a strangulated hernia, risking bleeding
from the accessory (abnormal) obturator artery.
Epidemiology of femoral hernia
In females, indirect inguinal hernias are still
more common than femoral hernias. However,
they are found 2.5 times more commonly in
females because:
฀ The inguinal ligament makes a wider angle
with the pubis in the female
฀ Enlargement of the fat in the femoral canal
of fat middle-aged women stretches the
femoral canal; this fat disappears in old
age, leaving a bigger canal
฀ Pregnancy increases intra-abdominal
pressure and stretches the fascia
transversalis
Mechanics of femoral hernia
The femoral hernia enters the femoral canal
through the femoral ring. The hernia arrives in
the thigh next to the saphenous opening of the
16
femoral sheath. The cribriform fascia over the
saphenous opening becomes stretched over
the hernia. The hernia enlarges upwards and
medially into the superficial fascia of the inguinal
ligament. Typically it lies between the superficial
external pudendal and superficial epigastric
veins, compressing the saphenous vein as it
emerges through the saphenous opening.
Characteristics of a typical femoral
hernia
฀ Small (hard to find in an obese patient)
฀ Not reducible
฀ No cough impulse
฀ Often contains only omentum
฀ May contain a knuckle of bowel (most
common site for Richter’s hernia)
฀ More common on the right
฀ 35–50% of all strangulated groin
hernias in adults are femoral hernias
Differential diagnosis of femoral
hernia
Inguinal hernia:
฀ Femoral hernia emerges below and
lateral to pubic tubercle
฀ Inguinal hernia emerges above and
medial to pubic tubercle
Saphena varix
Enlarged lymph node
Lipoma
Femoral artery aneurysm
Sarcoma
Ectopic testis
Obturator hernia
Psoas bursa
Psoas abscess
Abdominal wall and hernias
Diagnosis of a groin hernia is usually clinical.
However, various imaging methods are available
to confirm the diagnosis and assess anatomy
in cases that are not straightforward (ultrasonography, contrast herniogram, computed
tomography [CT] / magnetic resonance imaging
[MRI]). In a contrast herniogram, water-soluble
contrast media is injected into the peritoneal
cavity through the anterior abdominal wall.
The patient is positioned prone and pooling of
contrast into the hernia sac is looked for on a
radiograph. This is now rarely performed.
European Hernia Society Guidelines
for the Treatment of Inguinal Hernia
in Adult Patients (2009)
Primary unilateral: mesh repair
(Lichtenstein’s or endoscopic repair if
expertise is available)
Primary bilateral: mesh repair
(Lichtenstein’s or endoscopic)
Recurrent inguinal hernia: modify
technique in relation:
฀ If previously anterior – open
preperitoneal mesh or endoscopic
approach
฀ If previously posterior – Lichtenstein’s
totally extraperitoneal (TEP) is
preferred to transabdominal preperitoneal (TAPP) repair in the case of
endoscopic surgery
Prophylactic antibiotics are not
recommended in low-risk patients or in
endoscopic surgery
Anaesthesia:
ASA 1/2: always consider day surgery
ASA 3/4: consider local anaesthesia or
day surgery
Indications for groin hernia repair
Elective
(to be
prioritised
by job)
Indirect
Symptomatic
direct
Rate of strangulation of inguinal
hernia is 0.3–2.9%
per year; increased
risk if irreducible
or indirect
Prompt
Irreducible
inguinal hernia
History of less
than 4 weeks
Greater risk of
strangulation in
first 3 months after
appearance
Urgent
All femoral
hernias
50% strangulate
within 1 month
Emergency
Painful
irreducible
hernias
Repair of inguinal hernia
In a nutshell …
Main aims of inguinal hernia repair:
฀ Reduce hernia contents
฀ Remove hernia sac
฀ Repair defect
Main approaches
For primary uncomplicated inguinal
hernias:
฀ Lichtenstein’s mesh repair
฀ Laparoscopic repair
Other recognised techniques:
฀ Shouldice technique
฀ McVay–Cooper ligament operation
Herniotomy for children is a different
operation from herniorraphy for adults as
there is no need to repair the posterior
wall of the inguinal canal in children
because there is no defect there.
17
CHAPTER 1
Management of groin hernias
Abdominal Surgery
CHAPTER 1
Op Box: Open repair of inguinal hernia (mesh or Shouldice)
Mesh repair
This is the method of choice for nearly all elective open inguinal hernia repairs in the UK and
is also used in incarcerated or even strangulated emergency hernia repairs where there is no
gross contamination by pus or bowel contents.
฀ Reinforce posterior wall of inguinal canal with Prolene mesh
฀ Apply mesh on transversalis fascia and internal oblique muscle
฀ Slit lateral end to accommodate spermatic cord
฀ Suture inferior margin of mesh to inner surface of inguinal ligament using continuous
Prolene or nylon suture
฀ Fix medial and superior margins to internal oblique muscle using interrupted sutures
฀ Medial end should reach pubic tubercle
฀ Suture lateral tail ends to one another around the cord, ensuring that the gap left in the
mesh for the cord is enough to admit the little fingertip (therefore no cord damage) but
will not admit a whole finger (therefore no hernia recurrence)
Shouldice repair
This is a recognised method for open inguinal hernia repair and is useful when a mesh is
contraindicated (eg in a strangulated hernia with pus or bowel contents contaminating the
inguinal canal).
฀ Cremaster muscle should always be divided to give good access to the deep ring
฀ Margins of the deep ring are dissected from the cord
฀ Fascia transversalis is opened from the deep ring medially down to the pubic tubercle
฀ Fascia transversalis is cleaned of extraperitoneal fat to expose: the deep surface of the
conjoint tendon above and medially; and the fascia transversalis as it plunges into the
thigh below and laterally to become the anterior layer of femoral sheath
฀ Lower lateral fascia transversalis flap is sutured to the undersurface of the conjoint tendon
฀ Upper flap is overlapped and sutured to anterior surface of lower lateral flap of the fascia
transversalis (this reconstructs the posterior wall of the inguinal canal)
฀ Suturing is taken laterally to make a new deep ring flush with the emergent cord
฀ Repair is reinforced medially by suturing the conjoint tendon to the aponeurosis of
external oblique
Closure of Shouldice and mesh repairs
฀ Same for both methods
฀ Inspect for potential femoral hernia before closure
฀ Close external oblique aponeurosis with continuous absorbable suture (eg PDS) over the cord
฀ Close Scarpa’s fascia with interrupted Vicryl
฀ Close skin with undyed subcuticular Monocryl
฀ Draw down ipsilateral testicle to the bottom of the scrotum
18
Postoperative advice after open repair of
inguinal hernia
฀
฀
฀
฀
Often home the same day
Eat, drink and mobilise on waking
Back to sedentary job within 2 weeks
Back to heavy lifting, strenuous sports and
manual labour in 6 weeks
฀ Safe to drive when performing an
emergency stop does not cause any
discomfort (advise them to check with their
insurance company if they are in doubt)
฀ Oral analgesia may be needed for a few
days
฀ Follow-up is usually by GP only unless there
is an ongoing audit
Complications of open repair of inguinal
hernia
฀ Haematoma
฀ Wound infection and mesh infection
฀ Recurrence
฀ Testicular atrophy or ischaemic orchitis due
to cord damage in males
฀ Temporary postoperative urinary retention
due to pain in elderly people or men with
pre-existing prostatic symptoms
Intraoperative hazards of open repair of inguinal hernia
Damage to the ilioinguinal nerve
This may be cut when the canal is entered
(causing sensory loss in the lower groin or
scrotum) or sutured into the mesh, causing
chronic pain if care is not taken.
In large or emergency hernias where
damage or entrapment of the nerve is
unavoidable, the nerve should be cut as
proximally as possible because numbness is
preferable to pain.
Damage to the cord structures in the
male
฀ Vas
฀ Testicular artery
฀ Pampiniform plexus of veins
This may lead to reduced fertility, ischaemic
orchitis or varicocele respectively.
Orchidectomy
Very occasionally in an emergency
situation with a large incarcerated or
strangulated inguinoscrotal hernia, or in
the elective patient with enormous chronic
inguinoscrotal hernias or recurrent open
hernias, it may impossible to preserve the
cord and it might be necessary to remove
the cord and testicle to achieve safe closure
of the posterior wall. These patients should
have the risk explained in the consent.
19
CHAPTER 1
Abdominal wall and hernias
Abdominal Surgery
CHAPTER 1
Advantages and disadvantages of mesh repair
Advantages
Disadvantages
Easier to learn and perform for trainees
Risk of infection (avoid haematomas and use
prophylactic antibiotics)
Lower recurrence rate (1 in 1000)
Tension-free repair
Reduced analgesic requirement
Advantages and disadvantages of Shouldice repair
Advantages
Disadvantages
Low risk of infection
Indicated in presence of
strangulated bowel where mesh is not
recommended
Technically more difficult than mesh repair
Low recurrence rate in the right hands
Surgical time longer than with mesh repair
High standard of training needed
Tension-free repair difficult to perform
Postop analgesic requirement higher than with
mesh repair
This technique was perfected by the Shouldice Clinic. Recurrence rate is <1% there, but approaches
3.5% elsewhere. Trainee surgeons at the Shouldice Clinic must assist in 50 hernia repairs then perform
100 hernia repairs under supervision before being allowed to repair inguinal hernias independently.
Other types of inguinal hernia repair
Laparoscopic repair is a popular and recognised
form of hernia repair. There are two types:
transabdominal preperitoneal (TAPP) or totally
extraperitoneal (TEP) repair. Laparoscopic
inguinal hernia surgery should be performed
only by appropriately trained surgeons.
Laparoscopic repair is associated with an
increase in operation time; however, there is a
shorter recovery time when compared with open
hernia repair. Both TAPP and TEP procedures are
associated with a reduction in wound-related
infections, haematoma, persistent numbness
and pain compared with open repair. The rates
of recurrence is similar for laparoscopic and
open repair.
20
In the McVay–Cooper ligament operation the
fascia transversalis is opened and the upper
medial flap is sutured to the iliopectineal
ligament (Cooper’s ligament).
The Bassini (darn) repair is no longer
recommended due to high recurrence rates.
Inguinal hernia repair in children
In the repair of inguinal hernias in children:
฀ Herniotomy alone is sufficient
฀ The hernia is reduced, the sac divided and
ligated but there is no need to repair the
posterior wall of the canal as there is no
weakness there
฀ Mesh or darn herniorrhaphy is not indicated
Ovaries should be looked for in females and
reduced at the time of surgery. The possibility
of testicular feminisation syndrome should be
considered in female children with bilateral
hernias.
Repair of femoral hernias
In a nutshell …
Main aims
฀ Reduce hernia contents
฀ Remove peritoneal sac
฀ Repair defect
Three main approaches
฀ Low crural (Lockwood)
฀ High inguinal (Lotheissen)
฀ High extraperitoneal (McEvedy)
Laparoscopic repair can also be
performed.
RCS guidelines on repair of femoral
hernias
฀ Recommends high inguinal approach
except in thin females, where a low crural
approach is acceptable
฀ Advises high extraperitoneal approach in
complex, recurrent or obstructed hernias
Groin hernia repair under local
anaesthetic
The advantages of any surgery under local
anaesthetic (LA) are discussed fully in Book 1.
They include removing the risk of general
anaesthesia, as well as decreased cost and
shorter patient stay. Groin hernia repair is an
ideal operation to be performed under local
or regional anaesthesia, especially when
combined with day-case surgery. This is likely
to become more popular with the increasing use
of preoperative ultrasound-guided transversus
abdominis plane (TAP) block. The anaesthetic
agents, precautions and complications are
discussed in Book 1. LA is not suitable for
obese, anxious or uncooperative patients, or in
complex or recurrent hernias.
Method of administering LA in groin
hernia repair
฀ Subcutaneous weal in line of incision
฀ Deep injection at ilioinguinal and
iliohypogastric nerves (one fingerbreadth medial to ASIS)
฀ Further injection deep to proposed
incision
฀ Deep infiltration as needed
฀ Bupivacaine block before closure in
both GA and LA
21
CHAPTER 1
Abdominal wall and hernias
Abdominal Surgery
CHAPTER 1
Op box: Femoral hernia repair 1: crural (low) approach
(Lockwood’s approach)
Indications
All femoral hernias should be repaired within a month of diagnosis if the patient is fit, due to
the high risk of strangulation.
The low approach is the simplest approach and the most often used for elective repair. It is
a controversial approach for an incarcerated or strangulated hernia because it is difficult to
resect compromised bowel through this incision (if compromised bowel slips through the
canal back into the abdomen, laparotomy is needed to retrieve it).
Preop preparation: similar to inguinal hernias.
฀ Suitable for day case?
฀ Local, spinal or general anaesthetic? Urgent or emergency repair?
฀ Open or laparoscopic? Crural, inguinal or extraperitoneal approach?
฀ Social circumstances for discharge?
฀ Patient must be consented (mention relevant hazards and complications; see below)
฀ The correct side should be marked and shaved
฀ GA cases with comorbidity may need appropriate work-up and anaesthetic review
Position: supine.
Incision: oblique incision 1 cm below and parallel to the medial inguinal ligament.
Procedure
฀ Expose and open the femoral sac in the subcutaneous tissue
฀ Examine contents and reduce into the abdomen
฀ In an elective repair usually only omentum is present
฀ Compromised bowel should never be returned to the abdomen
฀ Once contents are reduced into the abdomen, transfix the sac neck using Vicryl and excise
it 1 cm distal to the ligation
฀ Suture the inguinal to the pectineal ligaments for 1 cm laterally with interrupted nylon
sutures on a J-shaped needle, tying the sutures only once they have all been placed
฀ Take care to protect the laterally located femoral vein and avoid constricting it
Intraoperative hazards
฀ Damage to the femoral vein, bladder or hernial sac contents
฀ Failure to identify Richter’s hernia
฀ Bleeding from an abnormal obturator artery
Closure: close subcutaneous tissue using Vicryl; close skin with subcuticular Monocryl
Postop: as for inguinal hernia repair although recovery from this approach is usually faster.
Complications
฀ Wound infection
฀ Haematoma
฀ Missed Richter’s hernia
฀ Recurrence is rare
22