Diseases of the Peritoneum and

RetroperitoneumCody Stares, M.D.

Basics●Visceral Peritoneum – mesothelial lining around viscera●Parietal Peritoneum – the rest●Total surface area ~ TBSA●Exchanges about 500mL of fluid per hour●However, only about 50mL of peritoneal fluid in cavity at any given time●Most fluid clearance occurs at the lymphatics along the undersurface of the diaphragms.

Natural Therapy●Omentum – double-layered peritoneal flap of vascularized fat and lymphatics.●The “duct-tape” of the peritoneal cavity●It seals perforations – sometimes●Provides vascular pedicled flaps to ischemic tissue●Provides macrophages for bacterial clearance

Frank Netter, M.D.

PeritonitisThe etiologies are numerous and too exhaustive to discuss here.The tell-tell sign of peritoneal inflammation results in an acute abdominal exam usually.Remember that a benign exam does not exclude an abdominal septic source.Age and immunosuppression can modify the labs and exam (i.e. the body’s response)

SBP●Seen in cirrhotics●Diagnose with paracentesis●Fluid PMNs >250/mm3 (>25% PMNs)●Often monomicrobial (75% grow nothing)●pH <7.31●Low protein in peritoneal fluid – also seen in nephrotic syndrome●No obvious visceral or malignant source

SBPTreat with antibioticsNo surgeryCirrhotic admitted with variceal bleed gets prophylactic norfloxacinOther indications for prophylaxis exist but are not uniformly agreed upon.

Familial Mediterranean

Fever Very rare Seen in families with the MEFV gene

mutation that leads to production of pyrin

95% of patient with MFM will present with sterile diffuse peritonitis

The pleura of the chest and scrotum can also be involved, as well as joints

Acute attacks are treated with NSAIDs

Chronic colchicine is used for disease suppression

NO SURGERY – this is where a thorough H&P comes in to play.

LaparotomyMost causes of peritonitis that we encountered are treated with laparotomy or laparoscopy.For focal peritonitis – suction debris at sourceFor diffuse peritonitis – with diffuse gross contamination, the solution to pollution then becomes dilutionBe sure to suction every last drop possible so as not to dilute innate opsonin and phagocyte concentrations.

MPI vs. APACHE IIVery similar in prognostic value.

Peritoneal Tuberculosis

Hematogenous seeding commonPresent in about 0.5% of TB cases50% have pulmonary effusionAscitic protein >3g/dLLymphocyte predominate cells“Doughy Abdomen”

Peritoneal Tuberculosis

Julie A. Taub

Peritoneal Tuberculosis

Often chronic in natureSometimes see an elevated CA-125Treatment is same as for pulmonary TBIf you perform SBR or stricturoplasty for sequela of nodules, continue Isoniazid and Rifampin x 18 mos.

Granulomatous Peritonitis

Catchall phrase for anything that causes granuloma formation, for which TB is one.Other causes include fungi, parasites, and surgical sponges, gloves, talc, etc.Treatment almost never requires surgery.Should see prompt response with steroids and NSAIDs.

Chylous and Malignant Ascites

Chylous if not cause by malignancy often resolves with non-surgical management.Malignant ascites is often seen in advanced cases where palliation, periodic paracentesis, or peritoneovenous shunting are options.

Denver ShuntMedically refractory malignant ascites with estimated survival greater than 2 months.Rife with complications.

AdhesionsLaparoscopy has been shown to result in less adhesions than laparotomy.Adhesions develop as fibrin deposition goes unopposed from inactivated plasminogen activators.Seprafilm has questionable utility in select cases.

MesotheliomaPleural to peritoneal

prevalence 3:1B-symptoms,

distention, and ascitesHistory of asbestos

exposure.Treat with surgical

debulking, intra-peritoneal cisplatin-doxorubicin, and whole-abdomen irradiation.

World J Gastrointest Surg. 2009 November 30; 1(1): 38-48.

Figure 18c.  Pseudomyxoma peritonei.

Woodward P J et al. Radiographics 2004;24:225-246

Pseudomyxoma Peritonei

Gelatinous mucus with epithelial cellsCommonly seen in low-grade mucinous cystadenocarcinoma of the appendix and ovaries.Surgery is aimed at removing the primary tumor.If one cannot be found, consider right hemicolectomy and BSO.Adjuvant intra-peritoneal 5-FU can be used.

Mesenteric Panniculitis

●Often seen in those over 50yo.●Lipid-laden macrophages invade the root of the mesentery – most often of jejunum.●Most cases resolve spontaneously and are asymptomatic●However, chronic cases can develop fibrosis with lymphatic and venous obstruction becoming retractile mesenteritis, which becomes fatal.●Treatment involves surgery for obstructions; yet steroids, cyclophosphamide, and azathioprine are the mainstay.

Mesenteric Panniculitis

Zones of Retroperitoneum

Mattox ManeuverCattell-Brasch Maneuver

Anterior Retroperitoneum

Posterior Retroperitoneum

Retroperitoneal Fibrosis

●Several causes – autoimmune, drugs (methysergide, hydralazine, and beta-blockers), aortic aneurysms w/ inflammation, infections, and cancers.●Circulating antibodies to ceroid, a lipoproteinaceous by-product of vascular atheromatous plaque oxidation, are present in >90% of patients with retroperitoneal fibrosis.●You will most commonly see its effect on the ureters●Hydroureter with hydronephrosis●Medialization of the ureters●Extrinsic ureter compression at L4-5●Treat with stents, surgical freeing of ureters followed with an omental wrap, and possibly steroids and tamoxifen.

Retroperitoneal Fibrosis

Tumors of the Retroperitoneum

●These encompass all of the organs contained within●Duodenum (D2-D3)●Pancreas●Kidneys and ureters●Adrenals●Ascending and descending colons●These will be covered later with each system.

Retroperitoneal Contamination

●Sources●Retrocecal appendicitis●Perforated diverticulum (posterior ascending/descending colon●Perforated duodenal ulcers●Pancreatitis●Trauma

Space of Retzius