MSC - F. Surgery Answers 2025
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Intestinal:
o Strictures → obstruction
o Fistulas (e.g., entero-enteric, entero-vesical, entero-cutaneous)
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Perforation |
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Malabsorption (esp. B12, bile salts) |
oColorectal cancer (especially with colonic involvement)
Extraintestinal:
oJoint, skin, eye, and liver involvement
General:
oGrowth retardation (in children)
o Nutritional deficiencies
Diagnosis
1.Laboratory:
↑ CRP, ESR
Anemia (iron deficiency or chronic disease)
Hypoalbuminemia
Vitamin and mineral deficiencies
2.Stool studies:
Rule out infectious causes (e.g., C. difficile, parasites)
Fecal calprotectin: sensitive marker of intestinal inflammation
3.Imaging and endoscopy:
Colonoscopy with biopsy (gold standard): reveals skip lesions, cobblestone mucosa, aphthous ulcers
Histology: Transmural inflammation, granulomas (non-caseating)
MRI enterography/CT enterography: Useful for small bowel involvement, strictures, abscesses
Barium studies (e.g., small bowel follow-through): string sign, segmental narrowing
4.Other:
Capsule endoscopy (useful but avoid if strictures are suspected)
5.Crohn's disease: conservative treatment and surgical treatment.
Conservative (Medical) Treatment
A step-up approach is used based on severity.
1.Induction of Remission:
Mild-Moderate:
o Aminosalicylates (5-ASA): limited efficacy; not first-line
oBudesonide: for ileocecal disease
Moderate-Severe:
oSystemic corticosteroids: Prednisolone 40–60 mg/day
o Immunomodulators: Azathioprine, 6-mercaptopurine, methotrexate
oBiologics:
Anti-TNF: infliximab, adalimumab
Anti-integrin: vedolizumab
Anti-IL-12/23: ustekinumab
Antibiotics:
oMetronidazole, ciprofloxacin for perianal disease, abscesses, fistulas
Nutritional therapy:
oElemental diets, parenteral nutrition in severe cases
o Micronutrient supplementation: B12, folate, vitamin D, iron
Maintenance of Remission
Immunomodulators: azathioprine, methotrexate
Biologics (for those with moderate-severe disease or steroiddependent/refractory disease)
Smoking cessation is critical to reduce relapse
Surgical Treatment
Reserved for complications or medical failure. Not curative, unlike UC.
Absolute Indications:
1.Obstruction (due to strictures)
2.Fistulas, especially when complex and unresponsive to medical therapy
3.Perforation
4.Abscess formation
5.Refractory hemorrhage
6.Malignancy
Relative Indications:
Intractable symptoms despite optimal medical therapy
Growth failure in children
Severe perianal disease
Surgical Options:
Segmental bowel resection (avoid extensive resections; aim to preserve bowel length)
Strictureplasty (to relieve obstruction while preserving intestine)
Seton placement and drainage for perianal fistulas
Abscess drainage
Prognosis
Chronic disease with relapsing-remitting course
High recurrence rate after surgery (~30–50% at 5 years)
Higher morbidity than UC; mortality ~2× that of general population
Requires long-term multidisciplinary care
6.Differential diagnosis of ulcerative colitis and Crohn's disease.
Feature
Location
Ulcerative Colitis (UC) |
Crohn's Disease (CD) |
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Can affect any part of GI tract |
Limited to colon and always |
from mouth to anus; most |
involves the rectum |
commonly terminal ileum & |
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colon |
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Pattern of involvement
Depth of inflammation
Rectal involvement
Anal involvement
Granulomas (on histology)
Ulcers
Strictures
Continuous involvement (starting at rectum)
Mucosal and submucosal only
Always involved
Rare
Absent
Superficial, broad-based ulcers
Uncommon
Segmental/skip lesions — patchy areas with intervening normal mucosa
Transmural (entire wall thickness)
Often spared
Common — fissures, fistulas, skin tags, abscesses
Non-caseating granulomas present in ~50%
Deep, linear ulcers — may lead to “cobblestone” mucosa
Common, due to transmural fibrosis
Feature
Fistulas and abscesses
Toxic megacolon
Bleeding
Diarrhea
Abdominal pain
Malabsorption
Weight loss
Extraintestinal manifestations
Cancer risk
Smoking
Surgical treatment
Endoscopic findings
Radiology (Barium studies)
Ulcerative Colitis (UC)
Rare
More common
Frequent, often with bloody diarrhea
Bloody, frequent, urgent
Usually LLQ, cramping, relieved by defecation
Rare
Less common or mild
Common in both: arthritis, uveitis, erythema nodosum, PSC more common in UC
↑ Colorectal cancer risk with long-standing disease
Crohn's Disease (CD)
Common (e.g., enteroenteric, perianal)
Rare
Less common; if present, mild
Variable, often non-bloody, chronic
Often RLQ, cramping, chronic
Common, esp. if small intestine involved (e.g., B12, iron, fatsoluble vitamins)
Common and may be severe
Similar, but more nutrient- deficiency–related complications
↑ Colorectal cancer if colon is involved
Protective
Colectomy is curative
Continuous erythema, loss of vascular pattern, friability, pseudopolyps
Lead pipe colon (loss of haustra)
Risk factor — worsens disease
Not curative, disease often recurs at anastomosis site
Patchy inflammation, aphthous ulcers, cobblestoning, strictures
String sign of terminal ileum, fistulas, strictures
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Feature |
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Ulcerative Colitis (UC) |
Crohn's Disease (CD) |
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ASCA/ANCA |
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p-ANCA: Positive in ~70% |
ASCA: Positive in ~60% |
serology |
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Mnemonic Tip:
UC = ULCCCERS o Ulcers
o Large intestine o Continuous
o Colorectal carcinoma risk o Crypt abscesses
o Extraintestinal manifestations o Rectal involvement
o Sclerosing cholangitis
Crohn’s = FISTULAS
o Fistulas
o Ilial involvement
o Skip lesions
o Transmural
o Ulcers (deep, linear)
o Luminal narrowing
o Anal lesions
o Strictures
Thoracic surgery
1.Acute lung abscess. Etiology, clinic, diagnosis, treatment.
Acute lung abscess is a localized suppurative (pus-forming) necrosis of lung parenchyma, characterized by one or more cavities filled with pus and gas, surrounded by inflammatory infiltration (perifocal inflammation).
Gangrenous abscess involves putrid suppurative decay with sequestra (dead lung tissue fragments) and significant perifocal inflammation.
Pulmonary gangrene is extensive putrid necrosis of a lung lobe or more, without demarcation, accompanied by severe systemic intoxication.
Etiology and Pathogenesis
The development of a lung abscess depends on several predisposing factors:
1. Presence of causative infectious agent:
oMainly Staphylococcus aureus and anaerobic bacteria play a major role.
2.Impaired bronchial drainage:
oObstruction leads to retention of secretions and predisposes to infection.
3.Impaired lung perfusion:
oVascular compromise promotes necrosis.
4.Reduced systemic and local immunity:
oConditions lowering host defenses, including malnutrition, immunosuppression, or chronic illness.
Common causes:
About 70% of acute lung abscesses develop as complications of acute pneumonia (commonly croupous or viral pneumonias).
Aspiration abscesses occur in patients with impaired consciousness or swallowing reflex, often localizing in posterior segments of the right lung.
Less common causes include septic emboli (from endocarditis, thrombophlebitis, osteomyelitis), chest trauma (penetrating or blunt), and rare lymphogenic spread.
Pathogenesis (example of postpneumonic abscess):
Infection activates inflammation, leading to bronchial edema, spasm, and obstruction → distal atelectasis → impaired circulation → necrosis → liquefaction and pus formation → abscess cavity formation.
Clinical Manifestations
Two clinical periods:
1. Closed period (before abscess rupture):
o Pleuritic chest pain localized to affected side, worsened by inspiration.
o Dry cough or scant sputum.
o High fever with hectic pattern, systemic intoxication.
o Dyspnea and decreased chest wall movement on affected side.
oPhysical exam: diminished breath sounds, dull percussion over inflamed area.
2.Open period (after abscess rupture into bronchus):
oExpectoration of large amounts of foul-smelling sputum (putrid or
“meat water” in gangrenous abscess).
o Decreased fever and systemic symptoms due to drainage.
o Possible hemoptysis.
oPhysical signs: tympanic percussion if near surface, bronchial breath sounds, rhonchi.
o If drainage is inadequate, fever and intoxication persist.
Pulmonary gangrene:
Severe systemic symptoms, cyanosis, marked dyspnea.
Large volumes of foamy, fetid sputum with blood.
Extensive dullness on percussion, diminished breath sounds, multiple moist crackles.
Diagnosis
Based on history (prior pneumonia, risk factors), clinical exam, and imaging.
Chest X-ray:
o Early stage: homogenous infiltrate without clear cavity.
o Later: cavitary lesion(s) with air-fluid levels.
oGangrene: large homogenous opacity expanding over a lobe or more, evolving into multiple cavitations.
Laboratory:
oLeukocytosis with neutrophilia, elevated ESR.
Differential diagnosis:
oSuppurated congenital cyst, tuberculous cavities, necrotic lung cancer.
Complications:
oPeripheral abscess → pneumothorax (11-39%).
o Central abscess → pulmonary hemorrhage (main cause of death).
Treatment
Conservative treatment is mainstay, consisting of:
1. Adequate drainage of pus:
oPromote bronchial drainage via postural drainage, inhalations, intratracheal administration of antiseptics, bronchodilators, antibiotics, and proteolytic enzymes.
oIn case of blocked drainage: thoracentesis and abscessoscopy to remove necrotic tissue.
2.Antibacterial therapy:
oEmpirical broad-spectrum antibiotics targeting anaerobes and staphylococci until culture results available.
oCommonly combinations of beta-lactams with metronidazole or clindamycin.
3.De-intoxication therapy:
oFluid resuscitation, plasma or plasma substitutes (albumin, amino acids).
oSupportive care to mitigate systemic effects of sepsis.
4.Immune correction:
oUse of bacteriophages (especially antistaphylococcal), immunoglobulins, and immunomodulators (gammaglobulin, decaris, T-activin).
Surgical treatment:
Reserved for complicated cases or non-responders to conservative therapy.
Indications include progressing gangrene, massive hemoptysis, or failure to resolve abscess.
Procedures include segmentectomy, lobectomy, or pneumonectomy depending on extent.
High mortality rate associated with surgery due to severity of disease.
In total lung gangrene with empyema, advanced techniques like splitsternum transpericardial bandaging of vessels and bronchus may be performed.
2.Complications of acute lung abscess. Causes of the transfer of acute lung abscess to chronic. Clinic, diagnosis, treatment of chronic lung abscess
Complications of Acute Lung Abscess
Empyema (pleural infection)
Pneumothorax and bronchopleural fistula
Sepsis and septicemia