Abdominal Wall, Surface Markings, and Peritoneal Cavity PDF

Abdominal Wall, Surface Markings and Peritoneal Cavity Prof. Isabel Stabile LRCP., MRCS., FRCOG., Ph.D. Ideas do not have to be correct in order to be good; it's only necessary that, if they fail, they do so in an interesting way Robert Rosen Rectus Sheath: No Post...

Abdominal Wall, Surface Markings and Peritoneal Cavity Prof. Isabel Stabile LRCP., MRCS., FRCOG., Ph.D. Ideas do not have to be correct in order to be good; it's only necessary that, if they fail, they do so in an interesting way Robert Rosen Rectus Sheath: No Posterior Layer below Arcuate Line  Protrusion of What is a Hernia? parietal peritoneum and viscera Inguinal: Direct & indirect Femoral Most hernias are reducible i.e. they can be returned to the peritoneal cavity by digital pressure Congenital Indirect Inguinal Hernia Most common of all abdominal hernias (75%) Passes through internal ring, along canal, and if large enough descends into scrotum Reducible by digital pressure over deep ring, which lies approx. 1 cm above the femoral pulse – Mid-inguinal point, half- way between anterior superior iliac spine and symphysis pubis Large Indirect Inguinal Hernia Indirect Inguinal Hernia in Females Can occur in women, but are 20 times more common in men Persistent processus vaginalis forms a small peritoneal pouch in the inguinal canal that may enter labium majora Part of small intestine may herniate into this pouch and through the inguinal canal, forming an indirect inguinal hernia  Inguinal (Hesselbach) Triangle Inferior epigastric vessels form medial edge of deep internal ring Indirect hernial sac will pass lateral and a direct hernia medial to these vessels Both hernias may co-exist bulging on either side of vessels Direct Inguinal Hernia Protrudes directly forwards through inguinal (Hesselbach) triangle Medial to deep ring Cannot be reduced by digital pressure on femoral pulse Hernial sac formed by transversalis fascia Does not traverse the entire inguinal canal  Umbilical Hernias Common in newborns because anterior abdominal wall is relatively weak Usually small Herniation occurs through the umbilical ring: opening in linea alba Acquired umbilical hernias occur most commonly in women and obese Contain extraperitoneal fat and/or peritoneum Incisional Hernia  Mesentery Double fold of peritoneum that connects an intra-peritoneal organ to the abdominal wall –Transmit blood vessels and nerves Examples: – The mesentery = mesentery of small intestine – Transverse and sigmoid mesocolon  Mesenteries Small intestine: Mesentery proper = The mesentery Transverse Colon: Transverse meso-colon Sigmoid colon: Sigmoid meso-colon Appendix: Meso-appendix Stomach: Greater and Lesser omentum  “Ligaments” Double fold of peritoneum between two organs or between an organ and the abdominal wall E.g., Falciform ligament Falciform Ligament  Omentum Double layered fold of peritoneum from stomach and proximal duodenum to adjacent organs –Greater and Lesser  Lesser Omentum From lesser curve of stomach to inferior surface of liver Lies in the coronal plane Behind it and the stomach is the lesser sac The two layers surround the stomach and leave the greater curvature as the greater omentum  Greater Omentum From greater curve of stomach Double layer of fatty mesentery ie 4 layers Becomes adherent to the mesentery of the transverse colon so that the transverse colon is attached to the undersurface of the greater omentum Liver and Greater Omentum  Greater Omentum Clinical Correlates First structure seen at laparotomy Fatty, double layered apron, vascular Policeman, walls off inflammation Metastatic spread esp. from ovary  Peritoneal Sacs Greater sac: Most of the peritoneal cavity, from diaphragm to pelvis Lesser sac: Posterior to stomach and liver – Communicates with greater sac through epiploic foramen (of Winslow) – Aka omental bursa = omental foramen Lesser Sac Remember that your left is the cross section's right since you are looking upwards towards the body  Retro-Peritoneal Structures Pancreas Most of the duodenum Ascending and Descending colon NOT the appendix in most patients  Surface Anatomy Vitally Important in clinical practice Consider the clinical relevance of each surface marking Where possible find it on yourself or a colleague Vertebral Levels Vertebral Levels versus Dermatomes  Important Landmarks Sub-costal plane: Lower border of 10th costal cartilage Trans-tubercular plane: L5, 5cm posterior to Ant. Sup. Iliac Spine Nine Quadrants Epigastric Umbilical Pubic R and L hypochondrium R and L flank R and L groin  Confused? Lumbar Lateral Flank Loin Inguinal Groin Iliac fossa  Epigastrium Pain from foregut structures ie as far as duodenal papilla is referred here Stomach tumours may be palpable here Pulsating aorta palpable slightly to the left of the midline  Umbilical Region Pain from mid-gut structures ie from duodenal papilla to splenic flexure of colon is referred here Pulsating aorta palpable above umbilicus  Suprapubic = Hypogastrium Pain from hind-gut structures ie from descending colon to anal canal is referred here Enlarged pelvic organs (bladder, uterus) palpable here  Right Hypochondrium Liver and gallbladder may be palpable GB Fundus: Tip of 9th costal cartilage = Mc Murphy’s Point Lumbar Region  Iliac Fossa = Inguinal Region Appendix = Mc Burney’s Point Palpable mass = cancer of caecum, ascending or descending colon (left) or more commonly especially in a thin individual – FAECES Four Quadrants Horizontal Trans- umbilical plane: L3/4 vertebra Vertical median plane Used clinically  L lobe of liver Contents R lobe of liver Spleen Gallbladder Stomach Stomach pylorus Jejunum & prox. Duodenum: parts 1-3 Ileum Pancreas head Pancreas: body & R. Adrenal tail R kidney L adrenal R colic flexure L colic flexure Ascending colon Descending Colon Transverse colon Transverse colon Caecum & Appendix Sigmoid colon Ileum Descending colon Ascending colon L ovary & tube R ovary & tube L ureter R ureter L spermatic cord R spermatic cord Uterus and bladder if Uterus and bladder if enlarged enlarged  Surface Anatomy of Stomach Supine: R and L upper quadrants or epigastric, umbilical and R hypochondiac regions Lower when erect  Surface Anatomy of Spleen Left hypochondrium, 9-11 ribs Long axis parallel to long axis of 10th rib in supine position Does not normally extend below costal margin Palpating the Spleen Percussion  Surface Anatomy of Liver Right upper quadrant, protected by ribs & diaphragm Fills most of R. hypochondrium and upper epigastrium Extends into left hypochondrium Moves down with respiration Normal liver may be palpable in thin person Surface Anatomy of Colon & Small Intestine Palpable Abdominal Organs  If you want others to be happy, practice compassion. If you want to be happy, practice compassion Dalai Lama