Block 2 Anatomy Theory: Clinical Applications

Preperitoneal vs. Retroperitoneal

Preperitoneal fascia is toward the anterior side, while retroperitoneal fascia is toward the superior side

Central Craniocaudad Incision

The most commonly used large abdominal incision. From the xiphoid process to the pubic symphysis

Masses Around the Groin

Differentiating inguinal vs. femoral hernias based on location relative to the inguinal ligament and response to coughing.

Inguinal Hernias

Occur when the peritoneal sac enters the inguinal canal via deep (indirect) or posterior wall (direct). More common in men due to a larger inguinal canal.

Indirect Inguinal Hernias

Lateral to the inferior epigastric artery, commonly congenital due to a patent processus vaginalis.

Direct Inguinal Hernias

Medial to the inferior epigastric artery, typically acquired due to weakened abdominal musculature.

Femoral Hernias

Pass through the femoral canal into the medial anterior thigh. Common in women, with a high risk of bowel strangulation due to the narrow canal.

Hernia Complications

Herniated bowel or fat may become trapped, causing obstruction and ischemia, leading to potential bowel perforation.

Innervation of Peritoneum

Parietal peritoneum is pain-sensitive; visceral peritoneum leads to referred pain and reflex motor activity.

Peritoneal Spread of Disease

Infection or cancer can spread rapidly within the peritoneal cavity, worsening prognosis.

Greater Omentum

Protects inflamed organs by migrating and encapsulating the affected area. Also a site for metastatic cancer spread.

Annular Pancreas

Congenital condition where the pancreas encircles the duodenum, causing obstruction.

Gallstones & Cholecystitis

Can lodge in the neck of the gallbladder. The gallbladder cannot empty normally and contractions of the gallbladder wall produce severe pain. May require gallbladder removal.

Jaundice

Can be caused by bile duct obstruction or pancreatic tumors, leading to yellow discoloration of skin and eyes.

Hepatic Cirrhosis

Chronic liver damage causing fibrosis, portal hypertension, and possible life-threatening bleeding.

Epithelial Transition

The gastroesophageal junction is demarcated by a transition from one epithelial type (nonkeratinized stratified squamous epithelium) to another epithelial type (columnar epithelium).

In some people, the histological junction does not lie at the anatomical gastroesophageal junction but occurs more proximally in the lower one-third of the esophagus. This may predispose these people to esophageal ulceration and is also associated with an increased risk of adenocarcinoma

Duodenal Ulceration

Ulcers in the superior duodenum. Posterior ulcers can erode arteries causing hemorrhage; anterior ulcers cause peritonitis.

Appendicitis

Inflammation due to obstruction.

Initially, the pain begins as a central/ periumbilical, which tends to come and go (referred pain).

As the disease progresses, the pain shifts to the lower right groin and is focal (localized somatic pain).

Mechanical Bowel Obstruction

Caused by an intraluminal, mural, or extrinsic mass that can be secondary to a foreign body, obstructing tumor in the wall extrinsic compression from an adhesion, or an embryological band.

Functional Bowel Obstruction

Usually due to an inability of the bowel to peristalse.

Small bowel obstruction:

• caused by adhesions following previous surgery, hernias, or volvulus

Large Bowel obstruction:

• caused by a tumor, hernias, or inflammatory diverticular disease of the sigmoid colon

Diverticular Disease

Formation of multiple colonic diverticula, mainly in the sigmoid colon because of its small diameter (high intraluminal pressure).

Volvulus

Twisting of bowel on itself.

Colorectal Polyps

Growth of tissue into the lumen of the colon.

Vascular Supply to the GI system

As a result of Arteriosclerosis, the distal large bowel becomes supplied by this enlarged marginal artery (marginal artery of Drummond), which replaces the blood supply of the inferior mesenteric artery.

Esophageal Varices

Superiorly, dilated veins in the esophagus due to portal hypertension.

left gastric vv. >> esophageal vv. >> azygos system

Caput Medusae

Anteriorly, dilated umbilical veins due to portal hypertension.

veins near ligamentum teres hepatis >> paraumbilical vv. >> superior, inferior and superficial epigastric vv. >> superior vena cava, inferior vena cava

Hemorrhoids (in regards to portal anastomosis)

Inferiorly, dilated rectal veins due to portal hypertension.

superior rectal v. >> inferior rectal vv. >> internal iliac vv. >> inferior vena cava

Urinary Tract Stones

Polycrystalline aggregates of calcium, phosphate, oxalate, urate, and other salts; associated with sedentary lifestyles. Causes pain radiating from the infrascapular region to the groin and possible blood in urine.

Kidney Transplant

Performed in the iliac fossa to avoid compromising other structures. In some cases, the renal artery and vein are anastomosed to the recipient's iliac vessels, and the ureter is tunneled into the bladder.

Imaging applications (Posterior Abd Wall)

IVU (Intravenous urogram): Allows visualization of the collecting system as well as the ureters and bladder

Ultrasound: Used to assess kidney size and the size of the calices, which may be dilated when obstructed

Computed tomography: Used to assess the kidneys, ureters, bladder, and adjacent structures

Nuclear medicine: Radioisotope compounds can be used to estimate renal cell mass and function, and assess the parenchyma for renal scarring

Abdominal Aortic Stent Graft

Used to treat abdominal aortic aneurysms, which commonly occur in the infrarenal region. A catheter delivers a compressed graft via the femoral artery to prevent rupture.

Inferior Vena Cava Filter

Inserted to prevent deep vein thrombosis by trapping any large clots.

Psoas Muscle Abscess

Infections can track along the psoas muscle. Intervertebral disc can be affected. Spreads inferiorly in the sheath and may appear below the inguinal ligament as a mass.

Diaphragmatic Hernias

Occurs when abdominal contents herniate into the thorax due to diaphragm defects.

Hiatal Hernia

Protrusion of the stomach through the esophageal hiatus. This typically causes symptoms of acid reflux. Ulceration may occur and may produce bleeding and anemia.

Nutcracker Syndrome

Blockage or pinching of the left renal vein where it passes between the superior mesenteric artery and the aorta. Or an obstruction of the left testicular vein.

Pelvic Fracture

Damage to the pelvic bones. If a fracture is demonstrated on one side, a second fracture should always be suspected

Defecation

Involves the pelvic diaphragm and anal sphincters in fecal retention and release.

Episiotomy

Surgical incision of the perineum during childbirth to prevent uncontrolled tearing. 2 types:

• median

• mediolateral

Bladder Cancer

Most common tumor of the urinary tract. May spread through the bladder wall and invade local structures.

Large tumors may produce complications, including invasion and obstruction of the ureters. Ureteric obstruction can then obstruct the kidneys and induce kidney failure.

Bladder Infection

Infection of the bladder, usually presents with inflammation of the bladder (cystitis). Women are more susceptible because of their relatively short urethra.

In children younger than 1 year of age, infection from the bladder may spread via the ureters to the kidneys, where it can produce renal damage and ultimately lead to renal failure

Urethral Catheterization

Performed to drain urine from a patient’s bladder when the patient is unable to urinate.

Undescended Testes

Testes fail to descend into the scrotum (normally in the 7th month of gestation), increasing infertility and cancer risk.

Hydrocele of the testis

Accumulation of fluid within the cavity of the tunica vaginalis

Ovarian Cancer

Malignancy in the ovaries, often spreading via the blood and lymphatics and frequently metastasizes directly into the peritoneal cavity.

Hysterectomy

The surgical removal of the uterus

Recto-Uterine Pouch

Region situated between the rectum and uterus, and is a site where infection and fluids typically collect.

Prostate problems

1. Prostate cancer: one of the most commonly diagnosed malignancies in men. Typically occurs in the peripheral regions of the prostate and is relatively asymptomatic

2. Benign prostatic hypertrophy (BPH): disease of the prostate that occurs with increasing age in most men. Generally involves the more central regions of the prostate, which enlarge

Prostatectomy and Impotence

Surgical removal of the prostate can damage nerves leading to erectile dysfunction.

Culdocentesis

Sampling of peritoneal fluid from the recto-uterine pouch via a needle that passes through the vaginal wall at the posterior fornix

Pudendal Nerve Block

Local anesthesia to the pudendal nerve for pain relief during childbirth.

It will NOT block the nociceptive signals for pain of uterine contraction because nociceptive innervation of the uterus follows the sympathetic pathway through the plexuses around the aorta to enter the spinal cord in upper lumbar levels.

Hemorrhoids types and symptoms

Internal: generally painless, but prolapse may cause strangulation

External: generally itchy or painful due to somatic innervation of tissue that is external to the pectinate line

May obscure the pectinate line

Urethral Rupture

Trauma leading to leakage of urine and blood into surrounding tissues.

Most common injury is a rupture of the proximal spongy urethra below the perineal membrane

Pudendal Nerve Irritation (Cyclist Syndrome)

The patient has pressed the pudendal n. between the bicycle saddle and the ischiopubic ramus. That interrupts the venous drainage (and maybe the arterial blood supply) at a microvascular level.