Abdominal Anomalies PDF

Anomalies of the Vitellointestinal Duct 1. Completely Patent Duct: o Forms an intestinal fistula. 2. Umbilical Sinus: o Only a small portion near the umbilicus remains patent, leading to a discharging umbilical sinus. o Mucosal lining may evert, forming...

Anomalies of the Vitellointestinal Duct 1. Completely Patent Duct: o Forms an intestinal fistula. 2. Umbilical Sinus: o Only a small portion near the umbilicus remains patent, leading to a discharging umbilical sinus. o Mucosal lining may evert, forming an umbilical adenoma. 3. Intra-Abdominal Cyst: o The duct is closed at both ends, but the intervening portion forms a intra-abdominal cyst. 4. Fibrous Band: o The obliterated duct persists as a fibrous band, potentially causing: ▪ Intestinal obstruction. Persistence of a vitelline duct remnant on ▪ Volvulus. the ileal border results in a Meckel ▪ Internal herniation. diverticulum. 5. Meckel’s Diverticulum: The intestinal end remains patent, Complete failure of the vitelline duct to forming a Meckel’s diverticulum. regress results in a vitelline duct fistula, o It may be attached to the umbilicus via a fibrous band. which is associated with drainage of small o Meckel’s diverticulum itself can cause: intestinal contents from the umbilicus. ▪ Diverticulitis and Obstruction. If both the intestinal and umbilical ends of the vitelline duct regress into fibrous Acquired Abnormalities of the Abdominal Wall cords, a central vitelline duct (omphalomesenteric) cyst may occur. Rectus Abdominis Diastasis (Divarication of Recti) When diagnosed, vitelline duct fistulas and cysts should be excised along with any 1. Definition: accompanying fibrous cord o Thinning of the linea alba in the midline of the epigatrium. 2. Clinical Features: o Midline abdominal wall protrusion with prominent divaricated edges of the both rectus muscles. o No hernia formation (transversalis fascia remains intact): ▪ No impulse on coughing. o Becomes prominent on lifting the head from the bed. 3. Differentiation: o CT scan can distinguish between rectus diastasis and a true ventral hernia. 4. Treatment: o No treatment required in most cases. o Surgical correction (anterior rectus sheath plication) may be performed for: ▪ Cosmetic reasons. ▪ Abdominal wall muscular dysfunction causing disability Continue Abdominal Wall: Acquired Abnormalities The terminal branches of the superior and inferior epigastric arteries course deep to the posterior Rectus Sheath Hematoma aspect of the left and right rectus pillars and penetrate the posterior rectus sheath. Definition: Bleeding into the rectus sheath due to injury to the superior or inferior epigastric arteries or their branches. Causes: 1. Trauma: o Significant blunt trauma to the abdominal wall. 2. Non-Traumatic Events: o Sudden contraction of rectus muscles (e.g., coughing, sneezing, vigorous activity). 3. Spontaneous: o Common in older adults or those on anticoagulation therapy. Clinical Features: Pain: o Sudden onset of unilateral abdominal pain, often mimicking localized peritoneal disorders (e.g., appendicitis). o If below the arcuate line, pain may be bilateral lower quadrant. Tender Mass: o Palpable abdominal mass that may worsen with rectus muscle contraction (Pain typically increases with contraction) Fothergill Sign: o Palpable mass unchanged with muscle contraction—classic for rectus sheath hematoma. Investigations: 1. Laboratory Tests: o Hemoglobin/Hematocrit: To assess blood loss. o Coagulation Studies: Especially in anticoagulated patients. 2. Imaging: o Ultrasound: ▪ May reveal a solid or cystic mass within the abdominal wall. o CT Scan: ▪ Most definitive for diagnosis and to exclude intra-abdominal pathology. Treatment: 1. Mild Cases (small, unilateral, contained): o Observation without hospitalization. 2. Severe Cases (large, bilateral, or expanding hematomas): o Hospitalization with resuscitation as needed. o Transfusion: Red blood cells or coagulation factors if necessary. o Anticoagulation Reversal: In patients on Coumadin (warfarin). 3. Intervention for Uncontrolled Hemorrhage:  o Operative Management: Evacuate hematoma and ligate bleeding vessels. o Angiographic Embolization: For uncontrolled bleeding. Details number 3 (Emergent operative intervention or angiographic embolization may be necessary if hematoma enlargement, free bleeding, or clinical deterioration occurs) Prognosis: Mortality: o Rare but reported in older adults and patients requiring surgical intervention. Hernias of the Anterior Abdominal Wall (Ventral Hernias) Definition Defects in the abdominal wall fascia and muscle through which intra-abdominal or preperitoneal contents protrude. Types 1. Congenital: Present at birth. 2. Acquired: ▪ May develop via slow architectural deterioration of muscular aponeuroses. o Primary (True) Ventral Hernias: ▪ Non-incisional. ▪ Named based on anatomical location. o Incisional Hernias: ▪ Result from failed healing of an anterior abdominal wall incision. Primary (True) Ventral Hernias 1. Epigastric Hernias: o Location: Midline between the xiphoid process and the umbilicus. o Contents: Usually omentum or falciform ligament. o Characteristics: Generally small. 2. Umbilical Hernias: o Location: Umbilical ring. o Onset: ▪ Present at birth or develops gradually. ▪ Small and asymptomatic cases can be followed clinically. o Indications for Surgery: ▪ Enlargement. ▪ Associated symptoms. ▪ Incarceration.  ▪ Spigelian Hernias Location: o Along the Spigelian line (aponeurotic band at the lateral border of the rectus abdominis). o Most common at or slightly above the arcuate line. Characteristics: o Rare. o Often not clinically evident as a bulge. o Common presentations: Pain or incarceration. Incisional Hernias Cause: o Failure of healing after a prior abdominal wall surgical closure. o Occurs in 10–15% of laparotomy incisions. Clinical Features: o Asymptomatic or symptomatic (pain, incarceration, strangulation). Risk Factors: o Postoperative wound infection. o Malnutrition. o Obesity. o Immunosuppression. Clinical Presentation of ventral hernias Most Common Finding: o Mass or bulge on the anterior abdominal wall. o Enlarges with Valsalva maneuver (e.g., coughing, straining). Symptomatology: o May be asymptomatic. o Can cause discomfort and generally enlarge over time. Physical Examination Findings 1. Reducible Hernia: o Spontaneously reduces with recumbency or manual pressure. 2. Incarcerated Hernia: o Cannot be reduced. o Symptoms: Nausea, vomiting, and significant pain. 3. Strangulated Hernia: o Compromised blood supply to the incarcerated bowel. o Risks: Localized ischemia, infarction, and perforation. Management of Ventral Hernias Repair Techniques 1. Primary Repair: The hernia defect is closed using sutures to approximate the edges of the abdominal wall without reinforcement. o Suitable for small defects (10 cm. o 20% present with metastases. 3. Diagnostic Investigations Imaging: o CT Scan: Primary diagnostic tool. o MRI: Highly accurate for staging and extent. o CT Chest & Abdomen: To check for metastases. o Renal Scintigraphy or IVU: Evaluate contralateral kidney function. Biopsy: o CT-guided core biopsy (posterior approach): Preferred for inconclusive imaging or when lymphoma/germ cell tumors are suspected. o Open biopsy: Avoided due to risks of peritoneal contamination; used only if core biopsy is inconclusive. o FNAC: Not useful. PET Scan: Limited role; used for therapy response assessment. 4. Treatment Modalities A. Surgery  Monobloc complete surgical resection: o Dissection outside the pseudocapsule with adequate margins. o Possible in ~50% of cases. o May involve removal of adjacent structures: ▪ Kidney and adrenals (45%). ▪ Colon (25%), small bowel, pancreas (15%), spleen (10%). Palliative Debulking: For unresectable cases. Enucleation: High recurrence; rarely used. B. Radiotherapy (RT) Indications: Prevent local recurrence. Types: o Preoperative RT: ▪ Advantages: Tumor displacement, absence of abdominal contamination, better oxygenation. o Intraoperative RT (IORT): Single high dose (~20 Gy). o Postoperative RT: Higher toxicity; selective cases. o Intensity-Modulated RT (IMRT): Precision targeting; doses up to 65 Gy. C. Chemotherapy (CT) Adjuvant CT: May benefit synovial or myxoid liposarcomas. Palliative CT: o For unresectable or metastatic cases. o Regimens: MAID (Mesna, Adriamycin, Ifosfamide, Dacarbazine) and AIM (Adriamycin, Ifosfamide, Mesna). Targeted Therapy: o Angiogenesis inhibitors. o Tyrosine kinase inhibitors. o mTOR inhibitors. o Trabectedin: Effective for synovial, myxoid sarcomas, and leiomyosarcoma. 5. Prognostic Factors Key Factors: o Tumor grade. o Complete surgical resection. Local Recurrence: o Common in 50% of cases, especially in high-grade liposarcomas. o Leiomyosarcomas often show distant spread alongside local recurrence. Retroperitoneal Infections 1. Causes  Primary Source: Often from an organ in or near the retroperitoneum. o Common Causes: ▪ Retrocecal appendicitis. ▪ Perforated duodenal ulcers. ▪ Pancreatitis. ▪ Diverticulitis. Infection can progress to form abscesses due to the large space and indistinct boundaries of the retroperitoneum. 2. Clinical Features Symptoms: o Pain: Can be variable (back, pelvis, or thighs). o Fever. o Malaise. Signs: o Tachypnea. o Tachycardia. o Palpable flank or abdominal mass (in some cases). 3. Diagnosis Laboratory Findings: o Leukocytosis. Imaging: o Abdominal CT: Diagnostic modality of choice. ▪ Findings: ▪ Stranding of retroperitoneal soft tissues. ▪ Unilocular or multilocular collections. 4. Management Initial Steps: o Treat underlying condition. o Intravenous antibiotics. Drainage: o Unilocular Abscesses: ▪ Percutaneous drainage under CT guidance. o Multilocular Collections: ▪ Require operative intervention for effective drainage. 5. Prognosis Challenges in Diagnosis:  o Retroperitoneal abscesses often become large before diagnosis due to the expansive retroperitoneal space. Mortality: o Despite drainage, mortality rates can be as high as 25%, emphasizing the need for early diagnosis and treatment. Psoas Abscess 1. Etiology Common Causes: o Tuberculosis of the spine (Pott’s disease, commonly T10). o Involvement of retroperitoneal structures or lymph nodes. o Pyogenic infections. 2. Clinical Features General Symptoms: o Back pain. o Fever. o Spinal tenderness. o Paraspinal spasm. o Restricted spinal movement. Local Signs: o Swelling in the iliac fossa: ▪ Smooth, non-tender, non-mobile. ▪ Does not move with respiration. ▪ Can extend across the groin and below the inguinal ligament, presenting as cross fluctuant. Psoas Muscle Spasm: o Patient can flex the hip but has difficulty with hip extension. 3. Differential Diagnosis of Iliac Fossa Swelling Psoas Abscess. Iliac artery aneurysm. Ovarian cyst (in females). Soft tissue tumors or cysts. Hernia. 4. Diagnostic Investigations  Imaging: o X-ray (spine and chest). o Ultrasound abdomen. o CT scan. Laboratory Tests: o Mantoux test. o ESR. o Peripheral smear. 5. Treatment a. Medical Management Antituberculous Therapy (ATT): o Drugs: ▪ Isoniazid (INH). ▪ Rifampicin. ▪ Ethambutol. ▪ Pyrazinamide. b. Surgical Management Procedure: o Approach: Lateral loin incision (extraperitoneal). o Steps: ▪ Drain pus. ▪ Collect pus for investigations: ▪ Culture & sensitivity. ▪ Acid-fast bacilli (AFB) culture. ▪ Remove caseating material and diseased vertebra. Thoracic Involvement: o Anterolateral decompression with costotransversectomy and bone grafting. Avoid: o Posterior approach (e.g., laminectomy) is contraindicated. Additional Notes Swellings that show cross fluctuation across regions include: o Psoas abscess. o Ranula. o Compound palmar ganglion. o Bilocular hydrocele.