HERNIAS

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Inguinal HerniaClassified as congenital vs. acquired
commonly thought that repeated increases in intra-abdominal pressure contribute to hernia formation
collagen formation and structure deteriorates with age, and thus hernia formation is more common in the older individual.

Clinical Presentation
Groin bulge
Often asymptomatic
Dull feeling of discomfort or heaviness in the groin
Focal pain – raise suspicion for incarceration or strangulation
Symptoms of bowel obstruction

Direct Inguinal Hernia
Medial to the inferior epigastric artery and vein, and within Hesselbach's triangle
acquired weakness in the inguinal floor

Indirect Inguinal hernia
Abdominal contents protrude through internal inguinal ring
Accepted hypothesis: incomplete or defective obliteration of the processus vaginalis during the fetal period
Remnant layer of peritoneum forms a sac at the internal ring
more frequently on the right

Femoral Hernia
More common in females
Up to 40% present as emergencies with hernia incarceration or strangulation
Passes medial to the femoral vessels and nerve in the femoral canal through the empty space
Inguinal ligament forms the superior border

Non-Operative
Observation
Trusses can provide symptomatic relief    
 Hernia control in ~30% of patients

Operative
Bassini (early 20th Century)
Transversus abdominis to Thompson’s ligament and internal oblique musculoaponeurotic arches or conjoined tendon to the inguinal ligament
Shouldice (1930s)
Multilayer imbricated repair of the posterior wall of the inguinal canal
McVay (1948)
Edge of the transversus abdominis aponeurosis to Cooper’s ligament; incorporate Cooper’s ligament and the iliopubic tract (transition suture)
Lichtenstein -First pure prosthestic, tension-free repair to achieve low recurrence rates

Prosthetic Repair
Polypropylene mesh most common and preferred
allows for a fibrotic reaction to occur between the inguinal floor and the posterior surface of the mesh, thereby forming scar and strengthening the closure of the hernia defect
Polytetrafluoroethylene (PTFE) mesh
often used for repair of ventral or incision hernias in which the fibrotic reaction with the underlying serosal surface of the bowel is best avoided..

Anorectal Disease

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Anatomy
Wall consists of mucosa, submucosa, and two complete muscle layers, inner circular, outer longitudinal.
12-15cm in length, reflection is 6-8cm  above  anus.
Upper 1/3 ant/lat covered by peritoneum, middle 1/3 only anteriorly covered, lower 1/3  completely retroperitoneal.
The rectum starts where tenia coli coalesce to  form a complete layer of longitudinal muscle at level of sacral promontory.
Three distinct curves, proximal and distal curve to the right, middle curves to the left. These folds are called Valves of Huston. This area is great for biopsy purposes as  they do not contain all layers so risk of perforation is less.
Waldeyer’s fascia is a dense connection between sacrum and rectum at 4th sacral body goes anteriorly to rectum, covering sacrum and overlying vessels and nerves.
Dennonviller’s fascia is a retrovesical septum in men, rectovaginal in women.
Pelvic floor is musculotendinous sheet formed by the levator ani muscle  and is innervated by S4.
The pubococcygeus, iliococcygeus, and  puborectalis  make  the levator ani. These are paired  muscles that are intertwined and act as a unit.
The anal canal starts at pelvic diaphragm and ends at anal verge. Approximately 4cm long. The anatomic anal canal extends from anal verge to dentate line. Surgical anal canal is anal verge to anorectal ring, the circular upper border of puborectalis that is palpable by rectal exam. It is 1-1.5 cm from dentate line.
The anal verge is the junction between anoderm and perianal skin.
The dentate  line  is a true  mucocutaneous junction located 1-1.5 cm from anal verge. A 6-12mm transitional zone exists above the line where squamous becomes  cuboidal, then columnar.
Anal sphincter  mechanism  made by internal and external sphincters.
The internal sphincter is a specialized  continuation of the circular smooth muscle layer  of the rectum. It is involuntary, and contracted at rest.
The intersphincteric plane is a fibrous continuation of the longitudinal smooth muscle layer of the rectum..

Hemorrhoids
These cushions are thought to act as a plug to the anal canal, and contribute 15-20% to the resting pressure of the anal canal. There are three of these cushions 11,3,7 o'clock.
Abnormal swelling  of the cushions result in prolapse  of the upper anal/lower rectal tissue thru  the anal canal. This causes the symptoms of hemorrhoids: bleeding, discomfort, pruritis, prolapse, swelling, pain, discharge.
Bleeding  is the most common symptom, pain is not common, unless a associated fissure is present (20%), or it’s a thrombosed  external.
Classification of internal hemorrhoids.

Classification of Internal Hemorrhoids
I- Bleed,  but do not prolapse.
II- Spontaneous prolapsing and reducing with or without bleeding.
III- Prolapsing,that require manual reduction.
IV- Prolapsed, cannot reduce...

Cardiogenic Shock
Inadequate tissue perfusion resulting from cardiac dysfunction
Clinical definition - decreased cardiac output and tissue hypoxia in the presence of adequate intravascular volume
Hemodynamic definition - sustained systolic BP <90 mm Hg, cardiac index<2.2 L/min/m2, PCWP >15 mm Hg

Causes of Cardiogenic Shock
Acute MI
Pump failure
Mechanical complications
Right ventricular infarction

Other conditions
End-stage cardiomyopathy
Myocarditis (fulminant myocarditis)
Myocardial contusion
Prolonged cardiopulmonary bypass
Septic shock with myocardial depression
Valvular disease

Initial Approach: Management
Assure oxygenation
Intubation and ventilation if needed
Venous access
Pain relief
Continuous EKG monitoring
Hemodynamic support
Fluid challenge if no pulmonary edema
Vasopressors for hypotension
- Dopamine
- Norepinephrine

Intra-aortic Balloon Counterpulsation
Reduces afterload and augments diastolic perfusion pressure
Beneficial effects occur without increase in oxygen demand
No improvement in blood flow distal to critical coronary stenosis
No improvement in survival when used alone
May be essential support mechanism to allow for definitive therapy

Pathophysiology of Cardiogenic Shock
Cardiogenic shock IS NOT simply the result of severe depression of LV function due to extensive myocardial ischemia/injury.

Depressed Myocardial Contractility combined with  Inadequate Systemic Vasoconstriction resulting from a systemic inflammatory response to extensive myocardial ischemia/injury results in cardiogenic shock .
The Overproduction of Nitric Oxide May Cause Both Myocardial Depression and Inappropriate Vasodilatation.
Thus, excess nitric oxide and peroxy nitrites may be a major contributor to cardiogenic shock complicating MI.

Acute Coronary Syndromes: Definitions
Acute coronary syndrome:
Constellation of clinical symptoms compatible with
acute myocardial ischemia
    ST-segment elevation MI (STEMI)
    Non-ST-segment elevation MI (NSTEMI)
    Unstable angina

Unstable angina:
    Angina at rest (usually >20 minutes)
    New-onset of class III or IV angina
    Increasing angina (from class I or II to III or IV)...

Burn Management

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Approx. one million burn patients/annually in the United States
3-5% cases are life-threatening
60,000 hospitalized / 5,000 die
Fires are the 5th most common cause of death from unintentional injury
Deaths are highest among children <5 yr. and adults >65 yr.

Skin is the largest organ of the body
Essential for:
   -  Thermoregulation
   -  Prevention of fluid loss by evaporation
   -  Barrier against infection
   -  Protection against environment provided by sensory information

Types of burn injuries
Thermal: direct contact with heat
    (flame, scald, contact)
 Electrical
    A.C. – alternating current (residential)
    D.C. – direct current (industrial/lightening)
 Chemical
 Frostbite

Burns are classified by depth, type and extent of injury
Every aspect of burn treatment depends on assessment of the depth and extent

First degree burn
Involves only the epidermis
Tissue will blanch with pressure
Tissue is erythematous and often painful
Involves minimal tissue damage
Sunburn

Second degree burn
Referred to as partial-thickness burns
Involve the epidermis and portions of the dermis
Often involve other structures such as sweat glands, hair follicles, etc.
Blisters and very painful
Edema and decreased blood flow in tissue can convert to a full-thickness burn

Third degree burn
Referred to as full-thickness burns
Charred skin or translucent white color
Coagulated vessels visible
Area insensate – patient still c/o pain from surrounding second degree burn area
Complete destruction of tissue and structures

Fourth degree burn
Involves subcutaneous tissue, tendons and bone

Criteria for burn center admission
Full-thickness  > 5% BSA
Partial-thickness > 10% BSA
Any full-thickness or partial-thickness burn involving critical areas (face, hands, feet, genitals, perineum, skin over major joint)
Children with severe burns
Circumferential burns of thorax or extremities
Significant chemical injury, electrical burns, lightening injury, co-existing major trauma or significant pre-existing medical conditions
Presence of inhalation injury

Assess underlying need for airway control
Duration of intubation
 Nasal intubation less advantageous for potentially prolonged ventilator requirements
Permanent support
 Underlying advanced intrinsic lung or neuromuscular disease
Temporary support
 Anesthesia
 Presence of reversible intrinsic lung or neuromuscular disease
 Protection of the airway due to depressed mental status
 Presence of reversible upper airway pathology
 Patient care needs (e.g., transport, CT scan, etc.)
 Significant comorbidities
  Aspiration potential or increased respiratory secretions
  Hemodynamic issues such as cardiac disease or sepsis
  Renal or liver failure

Pathophysiology of the respiratory failure
Hypoxic respiratory failure
-    In case of hypoxic respiratory failure, different noninvasive oxygen delivery devices can be used.
-    The severity of hypoxia and presence or absence of underlying disease (such as COPD) will dictate the device of choice.
Hypercapnic respiratory failure
-    The noninvasive device of choice for hypercapnic respiratory failure is BIPAP.

Assessment of above mentioned patient characteristics in conjunction with the mechanism of respiratory distress leads the clinician to proper choice and duration of  invasive or noninvasive options for airway management.

Code status should be clarified prior to proceeding.

Oxygenation
Respiratory rate and use of accessory muscles
-    Is the patient in respiratory distress?
Amount of supplemental oxygen
-    What is the patient’s oxygen demand?
Pulse oximeter or arterial blood gas
-    Is the patient physiologically capable of providing appropriate supply?

Airway
Anatomy
-    Will this patient be difficult to intubate?
Patency
-    Is there a reversible anatomical cause of  respiratory failure as opposed to intrinsic lung dysfunction?
Airway device in place
-    Is there a nasopharyngeal airway or combitube in place?

Oxygen Delivery Devices
Nasal Cannula
4% increase in FiO2 for each 1 L of flow (e.g., 4 L flow = 37% or 6 L flow = 45%)

Face tent
At most delivers 40% at 10-15 L flow

Ventimask
Small amount of rebreathing
8 L flow = 40%, 15 L flow = 60%

Nonrebreather mask
Attached reservoir bag allows 100% oxygen to enter mask with inlet/outlet ports to allow exhalation to escape - does not guarantee 100% delivery.

CPAP is a continuous positive pressure
Indicated in hypoxic respiratory failure and obstructive sleep apnea

BiPAP allows for an inspiratory and expiratory pressure to support and improve spontaneous ventilation
Mainly indicated in hypercapnic respiratory failure and obstructive sleep apnea

If use of noninvasive modes of ventilation does not result in improved ventilation or oxygenation in two to three hours, intubation should be considered

These devices can be used if following conditions are met:
Patient is cooperative with appropriate level of consciousness
Patient does not have increased respiratory secretions or aspiration potential
Concurrent enteral feeding is contraindicated.

Facilitates early extubation, especially in COPD patients
Some devices allow respiratory rate to be set.
Up to 10 L of oxygen can be delivered into the mask for 100% oxygen delivery.
Nasal or oral (full face) mask can be used; less aspiration potential with nasal....

Adrenal Glands

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Adrenal Glands Anatomy
Composed of a cortex and medulla, which have separate embryology.
The adrenal cortex arises fro m the coelomic mesoderm between the fourth and sixth weeks of gestation.
 The adrenal medulla is derived from cells of the neural crest that also form the sympathetic nervous system and the sympathetic ganglia.Some of these neural crest cells migrate into the adrenal cortex to form the adrenal medulla, but chromaffin tissue may also develop in extraadrenal sites.
The most common site of extraadrenal chromaffin tissue is the organ of Zuckerkandl, located adjacent to the aorta near IMA.
The glands weigh about 4g each, located in the retroperitoneum along the superior-medial aspect of the kidneys.
Yellow appearance because of their high lipid content.
3-5 cm in length, 4-6mm in thickness
Left>right
Receive arterial blood from branches of the inferior phrenic artery, aorta, and renal arteries.
The right adrenal vein is short and exits the gland medially to enter the vena cava. The left adrenal vein exits anteriorly and usually drains into the left renal vein. As a result, adrenal venous catheterization is accomplished more easily on the left than the right.

The adrenal cortex is composed of three zones histologically.
Outer zona glomerulosa, site for aldosterone synthesis.
Central zona fasciculata and inner zona reticularis produce both cortisol and androgens.

Most of the blood supply to the medulla comes from venous blood draining through the cortex. This provides the adrenal chromaffin cells with high concentration of the enzyme phenyethanolamine N- methyltransferase (PNMT) required for conversion of norepinephrine to epinephrine.

The Cortex
Zona glomerulosa is the exclusive site of production of aldosterone because it lacks the enzyme 17 alpha hydroxylase necessary for production of 17 a- progesterone and 17 a-pregnalone, which are the precursors to cortisol and androgens.
Zona fasciculata and reticularis function as a unit to produce cortisol, androgens, and small amounts of estrogen, but it lacks the enzymes necessary to convert 18-hydroxycorticosterone to aldosterone.
Cholesterol is the precursor from which all adrenal steroids are synthesized.
Conversion of cholesterol to pregnenolone is the rate limiting step in adrenal steroidogenesis and is the major site of action of ACTH..

Bariatric surgery (weight-loss surgery)

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Bariatric surgery (weight-loss surgery) includes a variety of procedures performed on people who are obese. Weight loss is achieved by reducing the size of the stomach with an implanted medical device (gastric banding) or through removal of a portion of the stomach (sleeve gastrectomy or biliopancreatic diversion with duodenal switch) or by resecting and re-routing the small intestines to a small stomach pouch (gastric bypass surgery).
Surgery should be considered as a treatment option for patients with a BMI of 40 kg/m2 or greater who instituted but failed an adequate exercise and diet program (with or without adjunctive drug therapy) and who present with obesity-related comorbid conditions, such as hypertension, impaired glucose tolerance, diabetes mellitus, hyperlipidemia, and obstructive sleep apnea. A doctor–patient discussion of surgical options should include the long-term side effects, such as possible need for reoperation, gallbladder disease, and malabsorption.
Classification of surgical procedures
Procedures that are solely restrictive, act to reduce oral intake by limiting gastric volume, produces early satiety, and leave the alimentary canal in continuity, minimizing the risks of metabolic complications. Some of these procedures are Vertical banded gastroplasty,Adjustable gastric band,Sleeve gastrectomy,Intragastric balloon (Gastric balloon),Gastric Plication ect
Predominantly malabsorptive procedures, although they also reduce stomach size, these operations are based mainly on creating malabsorption.
Biliopancreatic diversion
This complex operation is termed biliopancreatic diversion (BPD) or the Scopinaro procedure. The original form of this procedure is now rarely performed because of problems with malnourishment. It has been replaced with a modification known as duodenal switch (BPD/DS). Part of the stomach is resected, creating a smaller stomach (however the patient can eat a free diet as there is no restrictive component). The distal part of the small intestine is then connected to the pouch, bypassing the duodenum and jejunum.
Endoluminal sleeve
A trial study performed on rats involved placing a 10 cm long impermeable sleeve into the rat's intestine to block absorption of food in the duodenum and upper jejunum.
Complications from weight loss surgery are frequent.Common problems were gastric dumping syndrome in about 20% (bloatedness and diarrhoea after eating, necessitating small meals or medication), leaks at the surgical site (12%), incisional hernia (7%), infections (6%) and pneumonia (4%). Mortality was 0.2%.As the rate of complications appears to be reduced when the procedure is performed by an experienced surgeon, guidelines recommend that surgery is performed in dedicated or experienced units.

Benign Breast Disease

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Majority of surgical consultation for Breast complaints ultimately prove to have a benign origin.
Surgeon’s role in management of Benign Breast Disease includes:
 Assessment of Breast Cancer Risk
 Breast Cancer Screening
 Providing Specific Diagnosis
 Treatment/Management

ANATOMY
Develops from Ectoderm Milk Streak
Lobules and Ducts
The breast glandular tissue consists of 15 to 20 lobules (clusters of milk forming glands, or acini) that enter into branching and interconnected ducts. The ducts widen beneath the nipple as lactiferous sinuses and then empty via nipple openings.

Blood Supply
Branches of Internal Mammary Artery, Intercostal arteries, Axillary Artery
Venous drainage via Internal Mammary, Intercostal, Axillary Veins

Lymphatic Drainage
97% to Axillary Nodes
Internal Mammary and Supraclavicular nodes
Three Lymph Node Levels:
Level I – Lateral to Pectoralis Minor
Level II – Deep to Pectoralis Minor
Level III – Medial to Pectoralis Minor
Rotter’s – Between Pectoralis Minor & Major

Nerves
Long Thoracic Nerve
Serratus Anterior m.
Winged Scapula
Thoracodorsal Nerve
Latissimus Dorsi
Intercostobrachial Nerve

Breast Pain (Mastodynia)
More common during reproductive years (premenopausal)
Association with cancer is uncommon
Cyclic pain associated with Fibrocystic changes
Noncyclic pain associated with infection or cancer if associated with mass or bloody nipple discharge.
Tx: NSAIDs, Eve primrose oil, OCP, avoid caffeine

Parenchymal
Cysts
Simple cyst may be observed or aspirated
Bloody aspirate – send for cytology
Fibrocystic Changes
Not considered “disease”
No increase risk of cancer
Common finding >50%
           
Fibroadenoma
Most common mass in <30 y/o
Smooth, firm, rounded, mobile
Definitive dx by core or excisional bx.
Change size with menses, pregnancy
Excise if growing or >30 y/o
Long-term risk = 2.17 for cancer (IDC)

Cystosarcoma Phyllodes
10% malignant
Resembles Fibroadenoma
Tx is WLE
Gynecomastia
Associated with THC, spironolactone
Liver Failure
Idiopathic

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