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• The anterior abdominal wall forms the anterior limit of the abdominal viscera

  
• Anterior abdominal wall


  • Runs superiorly from the xiphoid process and costal cartilages of the 7th, 8th, 9th and 10th ribs to the iliac crest, anterior superior iliac spine, inguinal ligament, pubic tubercle, pubic crest and pubic symphysis inferiorly
  • Generally, from superficial to deep, it is comprised of the skin, superficial fascia (adipose and membranous tissues), deep fascia, layers of muscles, extraperitoneal tissue and the peritoneum
  • Most of these structures, especially the muscles, span the anterolateral abdominal wall and there is no definite boundary between the anterior and lateral abdominal walls, thus the anterior abdominal wall is sometimes referred to as the anterolateral abdominal wall

  
• Anterior abdominal wall


  • It is highly distensible and is involved in various functions ranging from support of movements of the abdominal viscera to protection of the abdominal cavity
  • It is more flexible than the posterior abdominal wall, and supports lateral bending, flexion, extension or protrusion and twisting
  • It plays a role in the maintenance of posture, and increases in intra abdominal pressure to support defecation, parturition and micturition

  
• Four region scheme


  The abdominal wall is divided into four quadrants by two imaginary lines; a midline (vertical) and a horizontal line which passes through the umbilicus

  
• Nine region scheme


  The anterior abdominal wall can also be divided into nine regions by two imaginary vertical lines called mid-clavicular lines or paramedian lines, and two imaginary horizontal lines

  
• The superior horizontal line is known as a transpyloric line (or transpyloric plane). This line is so named because of its relation to the pylorus of the stomach. It runs horizontally at the halfway point between the jugular notch and top of the pubic symphysis, passing through the pylorus of the stomach

  
• The lower horizontal line can be drawn to join the tubercles of the right and left iliac crests of the hip bones. It is called the transtubercular plane or intertubercular line (intertubercular plane)

  
• Regions of the anterior abdominal wall

  • Middle epigastric, umbilical, suprapubic or hypogastric, right hypochondrium, left hypochondrium, right flank (right lumbar), left flank (left lumbar), right groin (right iliac, inguinal) and left groin (left iliac, inguinal)

  
• Umbilicus


  Where the umbilical cord entered into the fetus and indicates the level of the T10 dermatome, typically at the level of the IV disc between the L3 and L4 vertebrae
• Epigastric Fossa


  Slight depression in the epigastric region, just inferior to the xiphoid process
• Linea alba


  A subcutaneous fibrous band extending from the xiphoid process to the pubic symphysis that is demarcated by a midline vertical skin groove as far inferiorly as the umbilicus

  
• Linea semilunaris


  Curved skin grooves that demarcate the lateral borders of the rectus abdominis muscle and rectus sheath

  
• Inguinal groove


  A skin crease, just inferior and parallel to the inguinal ligament, marking the division between the anterolateral abdominal wall and the thigh

  
• Pubic Crest and Symphysis

  The upper margins of the pubic bones and the cartilaginous joint that unite them can be felt at the inferior end of the linea alba

  
• Langer's lines


  Creases in the skin which represent the lines of orientation of collagen fibers in the dermis of the skin
• Stretch marks or striae distansae

  Dark elongate lines usually on the umbilical and hypogastric regions, seen in pregnant women, obese people and those with abdominal distention

  
• Camper's fascia


  A subcutaneous tissue containing variable amounts of fatty tissue
• Scarpa's fascia


  A membranous fatty layer containing fibrous tissue and very little fat, running inferiorly into the lower limbs where it changes its name to the fascia lata of the thigh

  
• Muscles of the anterior abdominal wall

  • External oblique
  • Internal oblique
  • Transverse abdominal
  • Rectus abdominis
  • Pyramidalis

  
• External oblique muscle


  • Origin: 5th to 12th ribs

  Insertion: Linea alba, pubic tubercle, and anterior half of iliac crest

  Innervation: Intercostal nerves (T7- T11), subcostal nerve (T12), iliohypogastric nerve (L1)

  Function: Flexion and rotation of the trunk, support and compression of the abdominal viscera

  
• Internal oblique muscle


  • Origin: Anterior two-thirds of iliac crest, Iliopectineal arch, thoracolumbar fascia

  Insertion: Inferior borders of ribs 10-12, linea alba, junction with cremaster muscle, pectinal line of pubis (via conjoint tendon)

  Innervation: Intercostal nerves (T7- T11), subcostal nerve (T12), iliohypogastric nerve (L1), ilioinguinal nerve (L1)

  Function: Flexion and rotation of the trunk, support and compression of the abdominal viscera

  
• Transversus abdominis


  • Origin: 7th to 12th costal cartilages, thoracolumbar fascia, iliac crest, connective tissue deep to lateral third of inguinal ligament

  Insertion: Linea alba, pubic crest, pectineal line of the pubis via the cojoint tendon

  Innervation: Anterior rami of T7 to T12 spinal nerves (a.k.a 7th- 11th intercostal nerves and subcostal nerve), Iliohypogastric nerve (L1), Ilioinguinal nerve (L1)

  Function: Support and compression of the abdominal viscera

  
• Rectus abdominis


  • Origin: Pubic crest and symphysis

  Insertion: Xiphoid process and 5th to 7th costal cartilages

  Innervation: Intercostal nerves (T6- T11), Subcostal nerve (T12)

  Function: Trunk flexion, compression of abdominal viscera, stability of the pelvis

  
• Pyramidalis


  • Origin: Pubis and pubic symphysis

  Insertion: Linea alba

  Innervation: Subcostal nerve (T12)

  Function: Tension of linea alba

  
• Blood supply to the anterior abdominal wall

  • Superior epigastric vessels and branches of the musculophrenic vessels from internal thoracic vessels
  • Inferior epigastric and deep circumflex iliac vessels from external iliac vessels
  • Superficial circumflex and superficial epigastric vessels from femoral and saphenous vessels
• Common abdominal incisions


  • Midline incision
  • Paramedian incision
  • Pararectal incision
  • Gridiron incision
  • Lanz incision
  • Transverse incision
  • Kocher incision
• Structures within the transpyloric plane

  • L1 vertebral body
  • Tip of 9th costal cartilage
  • Fundus of the gallbladder
  • Duodeno-jejunal flexure
  • Pylorus of the stomach
  • The neck of the pancreas
  • Renal hila
  • Conus of the spinal cord

  
• Visceral referred pain


  Foregut Pain – Epigastric region

  Midgut pain – Periumbilical region

  Hindgut Pain – Suprapubic region

  Visceral pain is caused by ischaemia, abnormally strong muscle contraction, inflammation and stretch

  Touch, burning, cutting and crushing does not cause visceral pain

  
• In acute appendicitis, in early appendicitis the pain begins at the umbilicus, later, as the appendix becomes more inflamed it irritates the surrounding bowel wall, localising the pain to the right lower quadrant (irritation to somatic nerve)
• Small bowel colic centered in periumbilical (midgut)
• Large bowel colic centered in suprapubic (hindgut)
• Git is an open-source distributed version control system
• Distributed means that every developer has their own copy of the repository, which can be pushed to other repositories.
• The aims of this session are: to give an impression of the relative incidence of gastrointestinal tumors and their age and sex distribution, to demonstrate some of the ways in which a gastrointestinal tumour may draw attention to itself and thus how the patient may present, describe common GI cancers and their clinical presentations, describe how G.I. derived infection or cancers may spread within the body, describe the incidence of various common cancers of the G.I. tract, describe the histological appearance of common gastro-intestinal cancers

  
• Common GI malignancies


  • Cancers of the Oesophagus
  • Stomach
  • Large Intestine
  • Pancreas
  • Liver
• Oesophageal Carcinoma


  Epidemiology: Wide geographical variation, 2% of malignancies in the UK, Males > Females

  Clinical Features: Dysphagia, weight loss, anorexia, lymphadenopathy, odynophagia

  Investigation: Endoscopy, Biopsy, Barium study

  Pathological Features: Squamous cell carcinoma (commonest, upper 2/3, link to HPV, Vitamin A deficiency, low fibre diet, smoking and drinking), Adenocarcinoma (uncommon, lower third, association with Barrett's oesophagus)

  Prognosis: Advances disease at presentation, only 40% resectable, 5% five year survival
• Gastric Cancer


  Epidemiology: 4th most common cancer worldwide, 15% of cancer deaths worldwide, Men > Women, common in Japan, Columbia, Finland, associated with Gastritis, common in Blood Group A, link to dietary factors, smoking, genetic/familial

  Clinical Features: Vague symptoms, epigastric pain, vomiting, weight loss

  Investigations: Endoscopy, Biopsy, Barium study

  Macroscopic Features: Fungating, Ulcerating, Infiltrative, Linitis plastica

  Microscopic Features: Intestinal type (variable gland formation, ulcerating, associated with H. Pylori), Diffuse type (single cells, signet ring, infiltrative, worse prognosis)

  Early Gastric Cancer: Confined to mucosa/submucosa, good prognosis

  Advanced Gastric Cancer: Further spread, polypoid, ulcerative, infiltrative, common in UK, ~10% 5 year survival

  Spread: Direct, Lymph nodes, Liver, Trans-coelomic to peritoneum and ovaries

  Staging: Stage 0 to Stage 4

  H. Pylori and Gastric Cancer: Chronic inflammation link, common in high H. Pylori prevalence countries
• Gastric Lymphoma


  Commonest GI lymphoma, starts as low-grade, strong association with H. Pylori, eradication may lead to regression, better prognosis than gastric cancer

  
• Gastrointestinal Stromal Tumours


  Uncommon, derived from interstitial cells of Cajal, causative mutation C-kit (CD117) makes it vulnerable to targeted treatment, unpredictable behaviour, pleomorphism, mitoses, necrosis

  
• Tumours of the Large Intestine


  • Adenomas (benign, neoplastic lesions with dysplasia, Familial Adenomatous Polyposis, Gardner's Syndrome)

  Adenocarcinomas

  Polyps

  Anal Carcinoma