Diseases of peritoneum & retroperitoneal space M K Alam

ILOs At the end of this presentation students will be able to:   Describe types and causes peritonitis. Recognize features of localized & generalized peritonitis. Enumerate sites & features of intra-abdominal collection. Describe management of local& general peritonitis. Describe types & management of peritoneal tumours. Describe retroperitoneal diseases.

Anatomy Lined by single layer mesothelial cells on thin layer of fibroepithelial tissue Few ml of pale yellow fluid lubricates peritoneal surface Greater and lessor sac Peritoneal membrane: Visceral & Parietal Visceral peritoneum: Poor nerve supply by autonomic, its irritation/ inflammation- poorly pain localized, dull and felt in midline Parietal: Rich somatic nerve, when irritated- severe & accurately localized pain to affected area

Peritoneal Inflammation Acute or chronic Secondary, primary (uncommon) Causes of peritonitis: Bacterial infection: perforated bowel- appendicitis (acute) Tuberculosis (chronic) Chemical peritonitis: Bile peritonitis, Acute pancreatitis Ischemic injury: Bowel strangulation, vascular occlusion Trauma: Surgery Allergic: Starch peritonitis from gloves

Bacterial peritonitis Usually polymicrobial Common organisms: E coli, Streptococci, Bacteroides, Klebsiela, staphylococcus Uncommon organisms: Chlamydia, pneumococcus, mycobacterium tuberculosis

Routes of infection GI perforation: Most common Exogenous: Drains, trauma Transmural: Ischemic bowel, fallopian tubes (PID) Haematogenous: Rare ? Primary peritonitis

Clinical types of peritonitis Localized peritonitis Factors for localization: Anatomical divisions: Subphrenic, peritoneal cavity proper (supracolic, infracolic), pelvic Pathological factors: Inflammatory adhesions, slow progress.

Clinical features- Localized peritonitis Fever, tachycardia Abdominal pain located in the area of the involved organ. Guarding, rigidity and rebound tenderness overlying the involved area. Rest of the abdomen non-tender. Special features: Shoulder tip pain (subphrenic), Suprapubic/both iliac fossa tenderness, DRE: Anterior pelvic tenderness and fullness (pelvic collection)

Management Investigations: CBC, u/e, AXR, Ultrasound, CT scan (most helpful) Treatment: NPO, IV fluid, Antibiotics (polymicrobial cover) can help resolve localized peritonitis. Percutaneous/ open surgical drainage if no resolution or abscess formation

Subdiaphragmatic collection

Generalized peritonitis Free bowel perforation Peristalsis Virulent infecting organisms Improper handling of inflammatory mass Young children (small omentum)

Clinical features of generalized peritonitis Abdominal pain: spreading to whole abdomen, aggravated with movement Fever, tachycardia Restricted abdominal wall movement, Generalized tenderness, guarding, rigidity Absent bowel sounds Late cases: Septic shock, silent abdomen, increasing distension, anxious face

Management of generalized peritonitis Investigations: CBC, u/e, amylase, upright CXR, AXR, U/S , CT scan, peritoneal aspiration (sometimes under imaging) Treatment: NPO, IV fluid (correct fluid & electrolyte imbalance) NG tube: Aspiration & drainage Broad spectrum antibiotic therapy Analgesia Operative management: Excision, repair, lavage & drainage

Complications of peritonitis Systemic: Septic shock, pneumonia, respiratory failure, multi-system failure Local: Adhesions, paralytic ileus, abscess formation (residual or recurrent), portal pyaemia, liver abscess

Tuberculous peritonitis Uncommon but still seen where tuberculosis still occurs. Infection originates from lymph nodes, ileo-caecal, pyosalpinx, haematogenous Abdominal pain (90%), fever & loss of wt. (60%), ascites (60%), night sweats, abdominal mass Diagnosis: Positive tuberculin test, mycobacterium in ascitic fluid, biopsy of tubercle or caseating area (laparoscopy) Treatment: Antituberculous therapy. Surgery: Diagnosis/ complications

Tuberculous Peritonitis

Tuberculous Peritonitis

Spontaneous Bacterial Peritonitis (Primary peritonitis) Acute bacterial infection of ascitic fluid No source of infection is easily identifiable Affects children & adults Risk group: Cirrhosis (70% child class C), CCF, Budd-Chiari syndrome Organism: Monomicrobial- 92%, E coli (50%), Streptococci (19%) Diagnosis by paracentesis of ascitic fluid: Polymorphonuclear > 250 per mm3 or a positive ascites culture, Total protein > 1gm/dl, LDH > serum LDH, Glucose < 50 mg/dl- all suggest 2° peritonitis Treatment: 5- to 10-day of cefotaxime or a combination of amoxicillin and clavulanic acid.

Spontaneous Bacterial Peritonitis

Neoplasms of peritoneum Carcinomatosis peritonei: Terminal event, studded with secondary growth, ascites (straw, blood stained). Pseudomyxoma peritonei: Rare, frequently female due to ruptured mucinous cystadenocarcinoma (appendiceal origin in most cases). Abdominal distended due to yellow jelly like fluid. U/S, CT scan help diagnosis. Treatment: Excision of primary, debulking, chemotherapy. Recur over months to years Mesothelioma

Peritoneal secondaries (carcinomatosis)

Pseudomyxoma peritonei Scalloped indentation of the surface of the liver and spleen.

Mesothelioma

Retroperitoneal space

Retroperitoneal Infections Aetiology: Extension of intraperitoneal infections- appendicitis, perforated DU, diverticulitis. Presentation: Tachycardia, pain , fever, malaise, Palpable mass (sometime) CT scan – modality of choice Management: Antibiotics, treatment of primary infection, CT guided drainage for unilocular abscess, Surgical drainage for multilocular abscesses.

Retroperitoneal Fibrosis Proliferation of fibrosis in retroperitoneum. Aetiology: Idiopathic (Ormond’s disease) ? autoimmune Secondary to malignancy- Hodgkin’s, carcinoid, medication- methysergide. More common in men, 4-6th decade. Fibrosis gradually involves ureter, IVC, aorta, mesenteric vessels.

Retroperitoneal Fibrosis Presenting symptoms depends upon organ/ organs involved. Poorly localized abdominal pain, sudden sever pain (MVO), unilateral leg swelling, oliguria, dysuria, haematuria. CT scan, MRI- fibrotic process Management: Exclude drug or malignancy. For idiopathic type: Steroid therapy, Surgical debulking, ureterolyis, ureteric stent.

Retroperitoneal Malignancies Primary malignancy Retroperitoneal Sarcoma- the most common 15% of all soft tissue sarcomas occur in the retroperitoneum Asymptomatic abdominal mass, often tumor has reached a considerable size. Abdominal pain(50%), Less common symptoms- GI hemorrhage, early satiety, nausea and vomiting, weight loss, and lower extremity swelling. CT and MRI Treatment: Complete en bloc resection of the tumor and any involved adjacent organs. Lymph node metastases are rare

Retroperitoneal Mass- CT scan

Retroperitoneal Malignancies Retroperitoneal malignancies from other organs: Kidney, Adrenal, Colon, Pancreas, lymphoma, Metastases from a remote primary malignancy

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