Surgery Marrow Pg 467-476 (Vascular Surgery)

Mesenteric Cysts

• Mesenteric cysts are fluid-filled sacs in the mesentery, the tissue that holds the intestines in place
• Two main types: Chylolymphatic and Enterogenous
• Chylolymphatic cysts are more common and contain clear fluid, while Enterogenous cysts contain turbid fluid.

Clinical features

• Mesenteric cysts can attach to the mesentery, often near the junction of the duodenum and jejunum (DJ flexure)
• Tillaux triad:
  • Periumbilical swelling
  • Movement at right angle to attachment of mesentery (Tillaux sign)
  • Transverse band of resonance

Investigations

• Imaging studies like Computed Tomography (CT with contrast) are used for diagnosis

Management

• Chylolymphatic cysts are usually removed surgically (enucleation)
• Enterogenic cysts require resection (removal) and anastomosis (reconnection of the bowel)

Upper Limb Deep Vein Thrombosis (DVT)

• DVT in the upper limb can be primary or secondary.

Primary Upper Limb DVT

• Paget-Schroetter Disease:
  • Thrombosis in the axillary vein, often caused by repetitive arm movements
  • Diagnosed by Doppler ultrasound
  • Managed with anticoagulation

Secondary Upper Limb DVT

• Can be caused by thoracic outlet obstruction or cannula insertion

Superficial Thrombophlebitis

• Inflammation and thrombosis of superficial veins, often caused by IV line insertion.
• Symptoms include tenderness and cord-like swelling
• Treated with Thrombophlebitis gel

Lower Limb Deep Vein Thrombosis (DVT)

• Defined as semi-solid coagulum in the deep veins
• Major complications: Pulmonary embolism and post-thrombotic limb

Risk factors

• Virchow's Triad:
  • Stasis (blood flow slowing)
  • Hypercoagulability (increased clotting tendency)
  • Endothelial injury (damage to vessel lining)

Patient factors

• Patient factors that increase the risk of DVT:
  • Age, obesity, immobility, varicose veins, pregnancy, puerperium, high-dose estrogen therapy

Internal Hernias

• A type of hernia where a loop of intestine protrudes through a defect in the internal abdominal wall.
• Several types, including:
  • Stemmer's hernia, Left paraduodenal hernia, Petersen's hernia, Right duodeno-jejunal hernia

Management of Internal Hernias

• Mechanical ventilation (IPPV) is the preferred method
• Surgical intervention: Circumferential incision over the diaphragm followed by mesh placement to cover the defect

Venous Thrombosis

• Causes of venous thrombosis can be divided into two categories: Disease or surgical procedure and patient factors.

Disease or surgical procedure

• Trauma or surgery
• Malignancies
• Heart failure
• Myocardial infarction
• Paralysis
• Infection
• Homocystinemia
• May-Thurner syndrome: Right iliac artery compressing the left iliac vein

Patient factors

• Conditions that increase susceptibility to clots (e.g., inflammatory bowel disease, nephrotic syndrome, polycythemia, paraproteinemia, PNH antibody or lupus anticoagulant, Behcet's disease, Factor V Leiden mutation, Protein C & S deficiency)

Clinical features

• Often asymptomatic, especially in the early stages
• More common in one leg, but can affect both
• The most common vein affected: Calf/soleal veins

Pulmonary embolism

• Most common vein affected: Ilio-femoral veins
• Symptoms:
  • Chest pain
  • Dyspnea (shortness of breath)
  • Increased jugular venous pressure (↑ JVP)
  • Decreased systolic blood pressure (↓ SBP)

Signs

• Signs associated with DVT:
  • Limb edema (swelling)
  • Moses sign: Pain on squeezing the calf muscles
  • Homan's sign: Resistance in calf on dorsiflexion of the foot

Phlegmasia cerulea dolens

• Painful blue limbs, due to thrombosis of major axial veins and collaterals, leading to potential venous gangrene

Phlegmasia alba dolens (aka milk leg)

• Painful white limb, due to thrombosis of major axial veins without collateral involvement
• More common during pregnancy

Wells' Criteria for Predicting DVT

• A scoring system to predict the likelihood of DVT.
• Score is calculated based on clinical signs and risk factors.

Probability based on Score

• Low probability: Score -2 to 0
• Moderate probability: Score 1-2
• High probability: Score >2

Investigations

• Doppler/Duplex scan (color Doppler and B-mode ultrasound) is the initial investigation
• Magnetic Resonance Imaging (MRI) if Doppler inconclusive
• Pulmonary embolism:
  • Gold standard: Pulmonary angiography (invasive)
  • Initial investigation: CT angiography
  • D-dimer: High negative predictive value

Management

• Anticoagulants:
  • Mainstay treatment to prevent clot propagation
  • Low-molecular-weight heparin (LMWH) and warfarin are commonly used
  • Warfarin therapy monitoring is essential (INR)
  • Target INR: 2-3
  • INR target before surgery: 1.4-1.5

Post thrombotic limb

• Affects 2/3rd of patients with DVT

Features

• Varicose veins, pigmentation, lipodermatosclerosis (inverted champagne bottle appearance)

Risk factors

• Proximal DVT, subtherapeutic anticoagulation, recurrent DVT

DVT risk groups and Prophylaxis

• High-risk groups: Major orthopaedic surgery, major abdominal/pelvic surgery, major surgery in patients with previous DVT, PE or thrombophilia, lower limb paralysis, major lower limb amputation.

Prophylaxis: Types

• Pharmacological:
  • LMWH (low-molecular-weight heparin) is preferred, last dose given 6 hours before surgery
• Mechanical:
  • Early ambulation
  • Pneumatic compression stockings.

Congenital Diaphragmatic Hernia (CDH)

• A birth defect where organs from the abdomen protrude into the chest.
• Two main types: Bochdalek and Morgagni hernia.

Bochdalek vs Morgagni hernia

Complications

• Pulmonary hypoplasia (underdevelopment of the lungs): Most common cause of death
• Pulmonary hypertension (high blood pressure in the lungs): Second most common cause of death

Features

• Mother: Polyhydramnios (excess amniotic fluid) during pregnancy
• Newborn child:
  • Scaphoid abdomen (abnormal shape)
  • Respiratory distress

Investigations

• Chest X-ray

Auscultation

• Bowel sounds can be heard in the chest cavity

Venous Thrombosis

• In-depth information on anticoagulants, direct thrombolysis, IVC filters.

Anticoagulants

• Sensitive to heparin:
  • Fondaparinux: Factor Xa inhibitor
  • Bivalirudin: Direct thrombin inhibitor
• Novel anticoagulants (NOAC):
  • Rivaroxaban
  • Apixaban

Direct thrombolysis

• Used to dissolve clots
• Agents: Streptokinase, urokinase
• Catheter-induced
• Reduces the risk of post-thrombotic limb
• Beneficial for early presentation
• Suitable for proximal DVT with moderate to severe symptoms

IVC filter/Greenfield filter

• Insertion into the inferior vena cava (IVC)
• Prevents clot embolisms to the lungs

Indications for IVC filter

• Recurrent thromboembolism despite anticoagulation
• DVT with contraindication to anticoagulation
• Chronic pulmonary embolism with pulmonary hypertension
• Complications of anticoagulation

Indications for retrievable IVC filters

• Prophylactic placement in high-risk trauma patients
• Short-term contraindication to anticoagulation
• Protection during venous thrombolytic therapy
• Extensive iliocaval thrombosis

Complications of anticoagulation

• Migration
• Bleeding
• IVC blockage by clot

Obturator hernia

• A type of hernia that occurs in the obturator canal, located in the pelvis near the hip.
• The hernia occurs because the tissues that hold the canal closed have a defect, and a part of the intestine might slip through.

Types

• Classified as:
  • Children: Small defect
  • Adults: Large defect
  • Complications: Strangulation

Characteristics

• Known as Little Old Lady's hernia
• Most common in elderly, multiparous women
• Can be categorized by the size of the defect (narrow or large)

Complications

• Strangulation: Blood supply to the herniated intestine is cut off
• Richter's hernia: Very narrow defect

Clinical features

• Bowel obstruction
• Pain

Signs

• Howship-Romberg sign: Shooting pain along the obturator nerve during abduction and medial rotation of the hip
• Hannington-Kiff sign: Diminished or absent adductor reflex and normal patellar reflex.
• Compression: Often caused by obturator nerve compression.

Management

• Hernioplasty: Surgical hernia repair

Richter's hernia

• Very narrow defect
• Associated with paraumbilical, femoral, and obturator hernias
• Signs: Gastroenteritis, possible strangulation, or progression to peritonitis
• Rapid transit through the proximal part of the hernia, which contracts vigorously, leading to obstructed bowel and strangulation/peritonitis.

Maydl's hernia

• Large defect
• W-shaped hernia
• Located in the connecting portion within the intraperitoneal cavity

Diagrams

• Anatomical depictions of the hip region showing the obturator canal, surrounding ligaments, and the location of different structures
• Diagram depicting the progress of Richter's hernia and the progression of Maydl's hernia.
• The diagrams include labels for different anatomical features and indicate the location of the herniated intestine.